SemaOverload.cpp revision eadb1e8ff5a7d778576df4c4d7ce0eadc3fd867e
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInherit.h" 16#include "clang/Basic/Diagnostic.h" 17#include "clang/Lex/Preprocessor.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/TypeOrdering.h" 22#include "clang/Basic/PartialDiagnostic.h" 23#include "llvm/ADT/SmallPtrSet.h" 24#include "llvm/ADT/STLExtras.h" 25#include "llvm/Support/Compiler.h" 26#include <algorithm> 27#include <cstdio> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Qualification_Adjustment, 42 ICC_Promotion, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Conversion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion 55 }; 56 return Category[(int)Kind]; 57} 58 59/// GetConversionRank - Retrieve the implicit conversion rank 60/// corresponding to the given implicit conversion kind. 61ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 62 static const ImplicitConversionRank 63 Rank[(int)ICK_Num_Conversion_Kinds] = { 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Promotion, 70 ICR_Promotion, 71 ICR_Promotion, 72 ICR_Conversion, 73 ICR_Conversion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion 82 }; 83 return Rank[(int)Kind]; 84} 85 86/// GetImplicitConversionName - Return the name of this kind of 87/// implicit conversion. 88const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 89 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 90 "No conversion", 91 "Lvalue-to-rvalue", 92 "Array-to-pointer", 93 "Function-to-pointer", 94 "Qualification", 95 "Integral promotion", 96 "Floating point promotion", 97 "Complex promotion", 98 "Integral conversion", 99 "Floating conversion", 100 "Complex conversion", 101 "Floating-integral conversion", 102 "Complex-real conversion", 103 "Pointer conversion", 104 "Pointer-to-member conversion", 105 "Boolean conversion", 106 "Compatible-types conversion", 107 "Derived-to-base conversion" 108 }; 109 return Name[Kind]; 110} 111 112/// StandardConversionSequence - Set the standard conversion 113/// sequence to the identity conversion. 114void StandardConversionSequence::setAsIdentityConversion() { 115 First = ICK_Identity; 116 Second = ICK_Identity; 117 Third = ICK_Identity; 118 Deprecated = false; 119 ReferenceBinding = false; 120 DirectBinding = false; 121 RRefBinding = false; 122 CopyConstructor = 0; 123} 124 125/// getRank - Retrieve the rank of this standard conversion sequence 126/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 127/// implicit conversions. 128ImplicitConversionRank StandardConversionSequence::getRank() const { 129 ImplicitConversionRank Rank = ICR_Exact_Match; 130 if (GetConversionRank(First) > Rank) 131 Rank = GetConversionRank(First); 132 if (GetConversionRank(Second) > Rank) 133 Rank = GetConversionRank(Second); 134 if (GetConversionRank(Third) > Rank) 135 Rank = GetConversionRank(Third); 136 return Rank; 137} 138 139/// isPointerConversionToBool - Determines whether this conversion is 140/// a conversion of a pointer or pointer-to-member to bool. This is 141/// used as part of the ranking of standard conversion sequences 142/// (C++ 13.3.3.2p4). 143bool StandardConversionSequence::isPointerConversionToBool() const { 144 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 145 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 146 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (ToType->isBooleanType() && 152 (FromType->isPointerType() || FromType->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 167 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 bool PrintedSomething = false; 186 if (First != ICK_Identity) { 187 fprintf(stderr, "%s", GetImplicitConversionName(First)); 188 PrintedSomething = true; 189 } 190 191 if (Second != ICK_Identity) { 192 if (PrintedSomething) { 193 fprintf(stderr, " -> "); 194 } 195 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 196 197 if (CopyConstructor) { 198 fprintf(stderr, " (by copy constructor)"); 199 } else if (DirectBinding) { 200 fprintf(stderr, " (direct reference binding)"); 201 } else if (ReferenceBinding) { 202 fprintf(stderr, " (reference binding)"); 203 } 204 PrintedSomething = true; 205 } 206 207 if (Third != ICK_Identity) { 208 if (PrintedSomething) { 209 fprintf(stderr, " -> "); 210 } 211 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 212 PrintedSomething = true; 213 } 214 215 if (!PrintedSomething) { 216 fprintf(stderr, "No conversions required"); 217 } 218} 219 220/// DebugPrint - Print this user-defined conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void UserDefinedConversionSequence::DebugPrint() const { 223 if (Before.First || Before.Second || Before.Third) { 224 Before.DebugPrint(); 225 fprintf(stderr, " -> "); 226 } 227 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 228 if (After.First || After.Second || After.Third) { 229 fprintf(stderr, " -> "); 230 After.DebugPrint(); 231 } 232} 233 234/// DebugPrint - Print this implicit conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void ImplicitConversionSequence::DebugPrint() const { 237 switch (ConversionKind) { 238 case StandardConversion: 239 fprintf(stderr, "Standard conversion: "); 240 Standard.DebugPrint(); 241 break; 242 case UserDefinedConversion: 243 fprintf(stderr, "User-defined conversion: "); 244 UserDefined.DebugPrint(); 245 break; 246 case EllipsisConversion: 247 fprintf(stderr, "Ellipsis conversion"); 248 break; 249 case BadConversion: 250 fprintf(stderr, "Bad conversion"); 251 break; 252 } 253 254 fprintf(stderr, "\n"); 255} 256 257// IsOverload - Determine whether the given New declaration is an 258// overload of the Old declaration. This routine returns false if New 259// and Old cannot be overloaded, e.g., if they are functions with the 260// same signature (C++ 1.3.10) or if the Old declaration isn't a 261// function (or overload set). When it does return false and Old is an 262// OverloadedFunctionDecl, MatchedDecl will be set to point to the 263// FunctionDecl that New cannot be overloaded with. 264// 265// Example: Given the following input: 266// 267// void f(int, float); // #1 268// void f(int, int); // #2 269// int f(int, int); // #3 270// 271// When we process #1, there is no previous declaration of "f", 272// so IsOverload will not be used. 273// 274// When we process #2, Old is a FunctionDecl for #1. By comparing the 275// parameter types, we see that #1 and #2 are overloaded (since they 276// have different signatures), so this routine returns false; 277// MatchedDecl is unchanged. 278// 279// When we process #3, Old is an OverloadedFunctionDecl containing #1 280// and #2. We compare the signatures of #3 to #1 (they're overloaded, 281// so we do nothing) and then #3 to #2. Since the signatures of #3 and 282// #2 are identical (return types of functions are not part of the 283// signature), IsOverload returns false and MatchedDecl will be set to 284// point to the FunctionDecl for #2. 285bool 286Sema::IsOverload(FunctionDecl *New, Decl* OldD, 287 OverloadedFunctionDecl::function_iterator& MatchedDecl) { 288 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 289 // Is this new function an overload of every function in the 290 // overload set? 291 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 292 FuncEnd = Ovl->function_end(); 293 for (; Func != FuncEnd; ++Func) { 294 if (!IsOverload(New, *Func, MatchedDecl)) { 295 MatchedDecl = Func; 296 return false; 297 } 298 } 299 300 // This function overloads every function in the overload set. 301 return true; 302 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 303 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 304 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 305 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 306 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 307 308 // C++ [temp.fct]p2: 309 // A function template can be overloaded with other function templates 310 // and with normal (non-template) functions. 311 if ((OldTemplate == 0) != (NewTemplate == 0)) 312 return true; 313 314 // Is the function New an overload of the function Old? 315 QualType OldQType = Context.getCanonicalType(Old->getType()); 316 QualType NewQType = Context.getCanonicalType(New->getType()); 317 318 // Compare the signatures (C++ 1.3.10) of the two functions to 319 // determine whether they are overloads. If we find any mismatch 320 // in the signature, they are overloads. 321 322 // If either of these functions is a K&R-style function (no 323 // prototype), then we consider them to have matching signatures. 324 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 325 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 326 return false; 327 328 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 329 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 330 331 // The signature of a function includes the types of its 332 // parameters (C++ 1.3.10), which includes the presence or absence 333 // of the ellipsis; see C++ DR 357). 334 if (OldQType != NewQType && 335 (OldType->getNumArgs() != NewType->getNumArgs() || 336 OldType->isVariadic() != NewType->isVariadic() || 337 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 338 NewType->arg_type_begin()))) 339 return true; 340 341 // C++ [temp.over.link]p4: 342 // The signature of a function template consists of its function 343 // signature, its return type and its template parameter list. The names 344 // of the template parameters are significant only for establishing the 345 // relationship between the template parameters and the rest of the 346 // signature. 347 // 348 // We check the return type and template parameter lists for function 349 // templates first; the remaining checks follow. 350 if (NewTemplate && 351 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 352 OldTemplate->getTemplateParameters(), 353 false, false, SourceLocation()) || 354 OldType->getResultType() != NewType->getResultType())) 355 return true; 356 357 // If the function is a class member, its signature includes the 358 // cv-qualifiers (if any) on the function itself. 359 // 360 // As part of this, also check whether one of the member functions 361 // is static, in which case they are not overloads (C++ 362 // 13.1p2). While not part of the definition of the signature, 363 // this check is important to determine whether these functions 364 // can be overloaded. 365 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 366 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 367 if (OldMethod && NewMethod && 368 !OldMethod->isStatic() && !NewMethod->isStatic() && 369 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 370 return true; 371 372 // The signatures match; this is not an overload. 373 return false; 374 } else { 375 // (C++ 13p1): 376 // Only function declarations can be overloaded; object and type 377 // declarations cannot be overloaded. 378 return false; 379 } 380} 381 382/// TryImplicitConversion - Attempt to perform an implicit conversion 383/// from the given expression (Expr) to the given type (ToType). This 384/// function returns an implicit conversion sequence that can be used 385/// to perform the initialization. Given 386/// 387/// void f(float f); 388/// void g(int i) { f(i); } 389/// 390/// this routine would produce an implicit conversion sequence to 391/// describe the initialization of f from i, which will be a standard 392/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 393/// 4.1) followed by a floating-integral conversion (C++ 4.9). 394// 395/// Note that this routine only determines how the conversion can be 396/// performed; it does not actually perform the conversion. As such, 397/// it will not produce any diagnostics if no conversion is available, 398/// but will instead return an implicit conversion sequence of kind 399/// "BadConversion". 400/// 401/// If @p SuppressUserConversions, then user-defined conversions are 402/// not permitted. 403/// If @p AllowExplicit, then explicit user-defined conversions are 404/// permitted. 405/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 406/// no matter its actual lvalueness. 407ImplicitConversionSequence 408Sema::TryImplicitConversion(Expr* From, QualType ToType, 409 bool SuppressUserConversions, 410 bool AllowExplicit, bool ForceRValue, 411 bool InOverloadResolution) { 412 ImplicitConversionSequence ICS; 413 OverloadCandidateSet Conversions; 414 OverloadingResult UserDefResult = OR_Success; 415 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 416 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 417 else if (getLangOptions().CPlusPlus && 418 (UserDefResult = IsUserDefinedConversion(From, ToType, 419 ICS.UserDefined, 420 Conversions, 421 !SuppressUserConversions, AllowExplicit, 422 ForceRValue)) == OR_Success) { 423 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 424 // C++ [over.ics.user]p4: 425 // A conversion of an expression of class type to the same class 426 // type is given Exact Match rank, and a conversion of an 427 // expression of class type to a base class of that type is 428 // given Conversion rank, in spite of the fact that a copy 429 // constructor (i.e., a user-defined conversion function) is 430 // called for those cases. 431 if (CXXConstructorDecl *Constructor 432 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 433 QualType FromCanon 434 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 435 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 436 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 437 // Turn this into a "standard" conversion sequence, so that it 438 // gets ranked with standard conversion sequences. 439 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 440 ICS.Standard.setAsIdentityConversion(); 441 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 442 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 443 ICS.Standard.CopyConstructor = Constructor; 444 if (ToCanon != FromCanon) 445 ICS.Standard.Second = ICK_Derived_To_Base; 446 } 447 } 448 449 // C++ [over.best.ics]p4: 450 // However, when considering the argument of a user-defined 451 // conversion function that is a candidate by 13.3.1.3 when 452 // invoked for the copying of the temporary in the second step 453 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 454 // 13.3.1.6 in all cases, only standard conversion sequences and 455 // ellipsis conversion sequences are allowed. 456 if (SuppressUserConversions && 457 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 458 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 459 } else { 460 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 461 if (UserDefResult == OR_Ambiguous) { 462 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 463 Cand != Conversions.end(); ++Cand) 464 ICS.ConversionFunctionSet.push_back(Cand->Function); 465 } 466 } 467 468 return ICS; 469} 470 471/// IsStandardConversion - Determines whether there is a standard 472/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 473/// expression From to the type ToType. Standard conversion sequences 474/// only consider non-class types; for conversions that involve class 475/// types, use TryImplicitConversion. If a conversion exists, SCS will 476/// contain the standard conversion sequence required to perform this 477/// conversion and this routine will return true. Otherwise, this 478/// routine will return false and the value of SCS is unspecified. 479bool 480Sema::IsStandardConversion(Expr* From, QualType ToType, 481 bool InOverloadResolution, 482 StandardConversionSequence &SCS) { 483 QualType FromType = From->getType(); 484 485 // Standard conversions (C++ [conv]) 486 SCS.setAsIdentityConversion(); 487 SCS.Deprecated = false; 488 SCS.IncompatibleObjC = false; 489 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 490 SCS.CopyConstructor = 0; 491 492 // There are no standard conversions for class types in C++, so 493 // abort early. When overloading in C, however, we do permit 494 if (FromType->isRecordType() || ToType->isRecordType()) { 495 if (getLangOptions().CPlusPlus) 496 return false; 497 498 // When we're overloading in C, we allow, as standard conversions, 499 } 500 501 // The first conversion can be an lvalue-to-rvalue conversion, 502 // array-to-pointer conversion, or function-to-pointer conversion 503 // (C++ 4p1). 504 505 // Lvalue-to-rvalue conversion (C++ 4.1): 506 // An lvalue (3.10) of a non-function, non-array type T can be 507 // converted to an rvalue. 508 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 509 if (argIsLvalue == Expr::LV_Valid && 510 !FromType->isFunctionType() && !FromType->isArrayType() && 511 Context.getCanonicalType(FromType) != Context.OverloadTy) { 512 SCS.First = ICK_Lvalue_To_Rvalue; 513 514 // If T is a non-class type, the type of the rvalue is the 515 // cv-unqualified version of T. Otherwise, the type of the rvalue 516 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 517 // just strip the qualifiers because they don't matter. 518 519 // FIXME: Doesn't see through to qualifiers behind a typedef! 520 FromType = FromType.getUnqualifiedType(); 521 } else if (FromType->isArrayType()) { 522 // Array-to-pointer conversion (C++ 4.2) 523 SCS.First = ICK_Array_To_Pointer; 524 525 // An lvalue or rvalue of type "array of N T" or "array of unknown 526 // bound of T" can be converted to an rvalue of type "pointer to 527 // T" (C++ 4.2p1). 528 FromType = Context.getArrayDecayedType(FromType); 529 530 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 531 // This conversion is deprecated. (C++ D.4). 532 SCS.Deprecated = true; 533 534 // For the purpose of ranking in overload resolution 535 // (13.3.3.1.1), this conversion is considered an 536 // array-to-pointer conversion followed by a qualification 537 // conversion (4.4). (C++ 4.2p2) 538 SCS.Second = ICK_Identity; 539 SCS.Third = ICK_Qualification; 540 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 541 return true; 542 } 543 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 544 // Function-to-pointer conversion (C++ 4.3). 545 SCS.First = ICK_Function_To_Pointer; 546 547 // An lvalue of function type T can be converted to an rvalue of 548 // type "pointer to T." The result is a pointer to the 549 // function. (C++ 4.3p1). 550 FromType = Context.getPointerType(FromType); 551 } else if (FunctionDecl *Fn 552 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 553 // Address of overloaded function (C++ [over.over]). 554 SCS.First = ICK_Function_To_Pointer; 555 556 // We were able to resolve the address of the overloaded function, 557 // so we can convert to the type of that function. 558 FromType = Fn->getType(); 559 if (ToType->isLValueReferenceType()) 560 FromType = Context.getLValueReferenceType(FromType); 561 else if (ToType->isRValueReferenceType()) 562 FromType = Context.getRValueReferenceType(FromType); 563 else if (ToType->isMemberPointerType()) { 564 // Resolve address only succeeds if both sides are member pointers, 565 // but it doesn't have to be the same class. See DR 247. 566 // Note that this means that the type of &Derived::fn can be 567 // Ret (Base::*)(Args) if the fn overload actually found is from the 568 // base class, even if it was brought into the derived class via a 569 // using declaration. The standard isn't clear on this issue at all. 570 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 571 FromType = Context.getMemberPointerType(FromType, 572 Context.getTypeDeclType(M->getParent()).getTypePtr()); 573 } else 574 FromType = Context.getPointerType(FromType); 575 } else { 576 // We don't require any conversions for the first step. 577 SCS.First = ICK_Identity; 578 } 579 580 // The second conversion can be an integral promotion, floating 581 // point promotion, integral conversion, floating point conversion, 582 // floating-integral conversion, pointer conversion, 583 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 584 // For overloading in C, this can also be a "compatible-type" 585 // conversion. 586 bool IncompatibleObjC = false; 587 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 588 // The unqualified versions of the types are the same: there's no 589 // conversion to do. 590 SCS.Second = ICK_Identity; 591 } else if (IsIntegralPromotion(From, FromType, ToType)) { 592 // Integral promotion (C++ 4.5). 593 SCS.Second = ICK_Integral_Promotion; 594 FromType = ToType.getUnqualifiedType(); 595 } else if (IsFloatingPointPromotion(FromType, ToType)) { 596 // Floating point promotion (C++ 4.6). 597 SCS.Second = ICK_Floating_Promotion; 598 FromType = ToType.getUnqualifiedType(); 599 } else if (IsComplexPromotion(FromType, ToType)) { 600 // Complex promotion (Clang extension) 601 SCS.Second = ICK_Complex_Promotion; 602 FromType = ToType.getUnqualifiedType(); 603 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 604 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 605 // Integral conversions (C++ 4.7). 606 // FIXME: isIntegralType shouldn't be true for enums in C++. 607 SCS.Second = ICK_Integral_Conversion; 608 FromType = ToType.getUnqualifiedType(); 609 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 610 // Floating point conversions (C++ 4.8). 611 SCS.Second = ICK_Floating_Conversion; 612 FromType = ToType.getUnqualifiedType(); 613 } else if (FromType->isComplexType() && ToType->isComplexType()) { 614 // Complex conversions (C99 6.3.1.6) 615 SCS.Second = ICK_Complex_Conversion; 616 FromType = ToType.getUnqualifiedType(); 617 } else if ((FromType->isFloatingType() && 618 ToType->isIntegralType() && (!ToType->isBooleanType() && 619 !ToType->isEnumeralType())) || 620 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 621 ToType->isFloatingType())) { 622 // Floating-integral conversions (C++ 4.9). 623 // FIXME: isIntegralType shouldn't be true for enums in C++. 624 SCS.Second = ICK_Floating_Integral; 625 FromType = ToType.getUnqualifiedType(); 626 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 627 (ToType->isComplexType() && FromType->isArithmeticType())) { 628 // Complex-real conversions (C99 6.3.1.7) 629 SCS.Second = ICK_Complex_Real; 630 FromType = ToType.getUnqualifiedType(); 631 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 632 FromType, IncompatibleObjC)) { 633 // Pointer conversions (C++ 4.10). 634 SCS.Second = ICK_Pointer_Conversion; 635 SCS.IncompatibleObjC = IncompatibleObjC; 636 } else if (IsMemberPointerConversion(From, FromType, ToType, 637 InOverloadResolution, FromType)) { 638 // Pointer to member conversions (4.11). 639 SCS.Second = ICK_Pointer_Member; 640 } else if (ToType->isBooleanType() && 641 (FromType->isArithmeticType() || 642 FromType->isEnumeralType() || 643 FromType->isPointerType() || 644 FromType->isBlockPointerType() || 645 FromType->isMemberPointerType() || 646 FromType->isNullPtrType())) { 647 // Boolean conversions (C++ 4.12). 648 SCS.Second = ICK_Boolean_Conversion; 649 FromType = Context.BoolTy; 650 } else if (!getLangOptions().CPlusPlus && 651 Context.typesAreCompatible(ToType, FromType)) { 652 // Compatible conversions (Clang extension for C function overloading) 653 SCS.Second = ICK_Compatible_Conversion; 654 } else { 655 // No second conversion required. 656 SCS.Second = ICK_Identity; 657 } 658 659 QualType CanonFrom; 660 QualType CanonTo; 661 // The third conversion can be a qualification conversion (C++ 4p1). 662 if (IsQualificationConversion(FromType, ToType)) { 663 SCS.Third = ICK_Qualification; 664 FromType = ToType; 665 CanonFrom = Context.getCanonicalType(FromType); 666 CanonTo = Context.getCanonicalType(ToType); 667 } else { 668 // No conversion required 669 SCS.Third = ICK_Identity; 670 671 // C++ [over.best.ics]p6: 672 // [...] Any difference in top-level cv-qualification is 673 // subsumed by the initialization itself and does not constitute 674 // a conversion. [...] 675 CanonFrom = Context.getCanonicalType(FromType); 676 CanonTo = Context.getCanonicalType(ToType); 677 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 678 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 679 FromType = ToType; 680 CanonFrom = CanonTo; 681 } 682 } 683 684 // If we have not converted the argument type to the parameter type, 685 // this is a bad conversion sequence. 686 if (CanonFrom != CanonTo) 687 return false; 688 689 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 690 return true; 691} 692 693/// IsIntegralPromotion - Determines whether the conversion from the 694/// expression From (whose potentially-adjusted type is FromType) to 695/// ToType is an integral promotion (C++ 4.5). If so, returns true and 696/// sets PromotedType to the promoted type. 697bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 698 const BuiltinType *To = ToType->getAs<BuiltinType>(); 699 // All integers are built-in. 700 if (!To) { 701 return false; 702 } 703 704 // An rvalue of type char, signed char, unsigned char, short int, or 705 // unsigned short int can be converted to an rvalue of type int if 706 // int can represent all the values of the source type; otherwise, 707 // the source rvalue can be converted to an rvalue of type unsigned 708 // int (C++ 4.5p1). 709 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 710 if (// We can promote any signed, promotable integer type to an int 711 (FromType->isSignedIntegerType() || 712 // We can promote any unsigned integer type whose size is 713 // less than int to an int. 714 (!FromType->isSignedIntegerType() && 715 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 716 return To->getKind() == BuiltinType::Int; 717 } 718 719 return To->getKind() == BuiltinType::UInt; 720 } 721 722 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 723 // can be converted to an rvalue of the first of the following types 724 // that can represent all the values of its underlying type: int, 725 // unsigned int, long, or unsigned long (C++ 4.5p2). 726 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 727 && ToType->isIntegerType()) { 728 // Determine whether the type we're converting from is signed or 729 // unsigned. 730 bool FromIsSigned; 731 uint64_t FromSize = Context.getTypeSize(FromType); 732 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 733 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 734 FromIsSigned = UnderlyingType->isSignedIntegerType(); 735 } else { 736 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 737 FromIsSigned = true; 738 } 739 740 // The types we'll try to promote to, in the appropriate 741 // order. Try each of these types. 742 QualType PromoteTypes[6] = { 743 Context.IntTy, Context.UnsignedIntTy, 744 Context.LongTy, Context.UnsignedLongTy , 745 Context.LongLongTy, Context.UnsignedLongLongTy 746 }; 747 for (int Idx = 0; Idx < 6; ++Idx) { 748 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 749 if (FromSize < ToSize || 750 (FromSize == ToSize && 751 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 752 // We found the type that we can promote to. If this is the 753 // type we wanted, we have a promotion. Otherwise, no 754 // promotion. 755 return Context.getCanonicalType(ToType).getUnqualifiedType() 756 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 757 } 758 } 759 } 760 761 // An rvalue for an integral bit-field (9.6) can be converted to an 762 // rvalue of type int if int can represent all the values of the 763 // bit-field; otherwise, it can be converted to unsigned int if 764 // unsigned int can represent all the values of the bit-field. If 765 // the bit-field is larger yet, no integral promotion applies to 766 // it. If the bit-field has an enumerated type, it is treated as any 767 // other value of that type for promotion purposes (C++ 4.5p3). 768 // FIXME: We should delay checking of bit-fields until we actually perform the 769 // conversion. 770 using llvm::APSInt; 771 if (From) 772 if (FieldDecl *MemberDecl = From->getBitField()) { 773 APSInt BitWidth; 774 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 775 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 776 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 777 ToSize = Context.getTypeSize(ToType); 778 779 // Are we promoting to an int from a bitfield that fits in an int? 780 if (BitWidth < ToSize || 781 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 782 return To->getKind() == BuiltinType::Int; 783 } 784 785 // Are we promoting to an unsigned int from an unsigned bitfield 786 // that fits into an unsigned int? 787 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 788 return To->getKind() == BuiltinType::UInt; 789 } 790 791 return false; 792 } 793 } 794 795 // An rvalue of type bool can be converted to an rvalue of type int, 796 // with false becoming zero and true becoming one (C++ 4.5p4). 797 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 798 return true; 799 } 800 801 return false; 802} 803 804/// IsFloatingPointPromotion - Determines whether the conversion from 805/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 806/// returns true and sets PromotedType to the promoted type. 807bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 808 /// An rvalue of type float can be converted to an rvalue of type 809 /// double. (C++ 4.6p1). 810 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 811 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 812 if (FromBuiltin->getKind() == BuiltinType::Float && 813 ToBuiltin->getKind() == BuiltinType::Double) 814 return true; 815 816 // C99 6.3.1.5p1: 817 // When a float is promoted to double or long double, or a 818 // double is promoted to long double [...]. 819 if (!getLangOptions().CPlusPlus && 820 (FromBuiltin->getKind() == BuiltinType::Float || 821 FromBuiltin->getKind() == BuiltinType::Double) && 822 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 823 return true; 824 } 825 826 return false; 827} 828 829/// \brief Determine if a conversion is a complex promotion. 830/// 831/// A complex promotion is defined as a complex -> complex conversion 832/// where the conversion between the underlying real types is a 833/// floating-point or integral promotion. 834bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 835 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 836 if (!FromComplex) 837 return false; 838 839 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 840 if (!ToComplex) 841 return false; 842 843 return IsFloatingPointPromotion(FromComplex->getElementType(), 844 ToComplex->getElementType()) || 845 IsIntegralPromotion(0, FromComplex->getElementType(), 846 ToComplex->getElementType()); 847} 848 849/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 850/// the pointer type FromPtr to a pointer to type ToPointee, with the 851/// same type qualifiers as FromPtr has on its pointee type. ToType, 852/// if non-empty, will be a pointer to ToType that may or may not have 853/// the right set of qualifiers on its pointee. 854static QualType 855BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 856 QualType ToPointee, QualType ToType, 857 ASTContext &Context) { 858 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 859 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 860 Qualifiers Quals = CanonFromPointee.getQualifiers(); 861 862 // Exact qualifier match -> return the pointer type we're converting to. 863 if (CanonToPointee.getQualifiers() == Quals) { 864 // ToType is exactly what we need. Return it. 865 if (!ToType.isNull()) 866 return ToType; 867 868 // Build a pointer to ToPointee. It has the right qualifiers 869 // already. 870 return Context.getPointerType(ToPointee); 871 } 872 873 // Just build a canonical type that has the right qualifiers. 874 return Context.getPointerType( 875 Context.getQualifiedType(CanonToPointee.getUnqualifiedType(), Quals)); 876} 877 878static bool isNullPointerConstantForConversion(Expr *Expr, 879 bool InOverloadResolution, 880 ASTContext &Context) { 881 // Handle value-dependent integral null pointer constants correctly. 882 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 883 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 884 Expr->getType()->isIntegralType()) 885 return !InOverloadResolution; 886 887 return Expr->isNullPointerConstant(Context, 888 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 889 : Expr::NPC_ValueDependentIsNull); 890} 891 892/// IsPointerConversion - Determines whether the conversion of the 893/// expression From, which has the (possibly adjusted) type FromType, 894/// can be converted to the type ToType via a pointer conversion (C++ 895/// 4.10). If so, returns true and places the converted type (that 896/// might differ from ToType in its cv-qualifiers at some level) into 897/// ConvertedType. 898/// 899/// This routine also supports conversions to and from block pointers 900/// and conversions with Objective-C's 'id', 'id<protocols...>', and 901/// pointers to interfaces. FIXME: Once we've determined the 902/// appropriate overloading rules for Objective-C, we may want to 903/// split the Objective-C checks into a different routine; however, 904/// GCC seems to consider all of these conversions to be pointer 905/// conversions, so for now they live here. IncompatibleObjC will be 906/// set if the conversion is an allowed Objective-C conversion that 907/// should result in a warning. 908bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 909 bool InOverloadResolution, 910 QualType& ConvertedType, 911 bool &IncompatibleObjC) { 912 IncompatibleObjC = false; 913 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 914 return true; 915 916 // Conversion from a null pointer constant to any Objective-C pointer type. 917 if (ToType->isObjCObjectPointerType() && 918 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 919 ConvertedType = ToType; 920 return true; 921 } 922 923 // Blocks: Block pointers can be converted to void*. 924 if (FromType->isBlockPointerType() && ToType->isPointerType() && 925 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 926 ConvertedType = ToType; 927 return true; 928 } 929 // Blocks: A null pointer constant can be converted to a block 930 // pointer type. 931 if (ToType->isBlockPointerType() && 932 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 933 ConvertedType = ToType; 934 return true; 935 } 936 937 // If the left-hand-side is nullptr_t, the right side can be a null 938 // pointer constant. 939 if (ToType->isNullPtrType() && 940 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 941 ConvertedType = ToType; 942 return true; 943 } 944 945 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 946 if (!ToTypePtr) 947 return false; 948 949 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 950 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 951 ConvertedType = ToType; 952 return true; 953 } 954 955 // Beyond this point, both types need to be pointers. 956 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 957 if (!FromTypePtr) 958 return false; 959 960 QualType FromPointeeType = FromTypePtr->getPointeeType(); 961 QualType ToPointeeType = ToTypePtr->getPointeeType(); 962 963 // An rvalue of type "pointer to cv T," where T is an object type, 964 // can be converted to an rvalue of type "pointer to cv void" (C++ 965 // 4.10p2). 966 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 967 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 968 ToPointeeType, 969 ToType, Context); 970 return true; 971 } 972 973 // When we're overloading in C, we allow a special kind of pointer 974 // conversion for compatible-but-not-identical pointee types. 975 if (!getLangOptions().CPlusPlus && 976 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 977 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 978 ToPointeeType, 979 ToType, Context); 980 return true; 981 } 982 983 // C++ [conv.ptr]p3: 984 // 985 // An rvalue of type "pointer to cv D," where D is a class type, 986 // can be converted to an rvalue of type "pointer to cv B," where 987 // B is a base class (clause 10) of D. If B is an inaccessible 988 // (clause 11) or ambiguous (10.2) base class of D, a program that 989 // necessitates this conversion is ill-formed. The result of the 990 // conversion is a pointer to the base class sub-object of the 991 // derived class object. The null pointer value is converted to 992 // the null pointer value of the destination type. 993 // 994 // Note that we do not check for ambiguity or inaccessibility 995 // here. That is handled by CheckPointerConversion. 996 if (getLangOptions().CPlusPlus && 997 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 998 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 999 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1000 ToPointeeType, 1001 ToType, Context); 1002 return true; 1003 } 1004 1005 return false; 1006} 1007 1008/// isObjCPointerConversion - Determines whether this is an 1009/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1010/// with the same arguments and return values. 1011bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1012 QualType& ConvertedType, 1013 bool &IncompatibleObjC) { 1014 if (!getLangOptions().ObjC1) 1015 return false; 1016 1017 // First, we handle all conversions on ObjC object pointer types. 1018 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1019 const ObjCObjectPointerType *FromObjCPtr = 1020 FromType->getAs<ObjCObjectPointerType>(); 1021 1022 if (ToObjCPtr && FromObjCPtr) { 1023 // Objective C++: We're able to convert between "id" or "Class" and a 1024 // pointer to any interface (in both directions). 1025 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1026 ConvertedType = ToType; 1027 return true; 1028 } 1029 // Conversions with Objective-C's id<...>. 1030 if ((FromObjCPtr->isObjCQualifiedIdType() || 1031 ToObjCPtr->isObjCQualifiedIdType()) && 1032 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1033 /*compare=*/false)) { 1034 ConvertedType = ToType; 1035 return true; 1036 } 1037 // Objective C++: We're able to convert from a pointer to an 1038 // interface to a pointer to a different interface. 1039 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1040 ConvertedType = ToType; 1041 return true; 1042 } 1043 1044 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1045 // Okay: this is some kind of implicit downcast of Objective-C 1046 // interfaces, which is permitted. However, we're going to 1047 // complain about it. 1048 IncompatibleObjC = true; 1049 ConvertedType = FromType; 1050 return true; 1051 } 1052 } 1053 // Beyond this point, both types need to be C pointers or block pointers. 1054 QualType ToPointeeType; 1055 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1056 ToPointeeType = ToCPtr->getPointeeType(); 1057 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1058 ToPointeeType = ToBlockPtr->getPointeeType(); 1059 else 1060 return false; 1061 1062 QualType FromPointeeType; 1063 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1064 FromPointeeType = FromCPtr->getPointeeType(); 1065 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1066 FromPointeeType = FromBlockPtr->getPointeeType(); 1067 else 1068 return false; 1069 1070 // If we have pointers to pointers, recursively check whether this 1071 // is an Objective-C conversion. 1072 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1073 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1074 IncompatibleObjC)) { 1075 // We always complain about this conversion. 1076 IncompatibleObjC = true; 1077 ConvertedType = ToType; 1078 return true; 1079 } 1080 // If we have pointers to functions or blocks, check whether the only 1081 // differences in the argument and result types are in Objective-C 1082 // pointer conversions. If so, we permit the conversion (but 1083 // complain about it). 1084 const FunctionProtoType *FromFunctionType 1085 = FromPointeeType->getAs<FunctionProtoType>(); 1086 const FunctionProtoType *ToFunctionType 1087 = ToPointeeType->getAs<FunctionProtoType>(); 1088 if (FromFunctionType && ToFunctionType) { 1089 // If the function types are exactly the same, this isn't an 1090 // Objective-C pointer conversion. 1091 if (Context.getCanonicalType(FromPointeeType) 1092 == Context.getCanonicalType(ToPointeeType)) 1093 return false; 1094 1095 // Perform the quick checks that will tell us whether these 1096 // function types are obviously different. 1097 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1098 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1099 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1100 return false; 1101 1102 bool HasObjCConversion = false; 1103 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1104 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1105 // Okay, the types match exactly. Nothing to do. 1106 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1107 ToFunctionType->getResultType(), 1108 ConvertedType, IncompatibleObjC)) { 1109 // Okay, we have an Objective-C pointer conversion. 1110 HasObjCConversion = true; 1111 } else { 1112 // Function types are too different. Abort. 1113 return false; 1114 } 1115 1116 // Check argument types. 1117 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1118 ArgIdx != NumArgs; ++ArgIdx) { 1119 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1120 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1121 if (Context.getCanonicalType(FromArgType) 1122 == Context.getCanonicalType(ToArgType)) { 1123 // Okay, the types match exactly. Nothing to do. 1124 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1125 ConvertedType, IncompatibleObjC)) { 1126 // Okay, we have an Objective-C pointer conversion. 1127 HasObjCConversion = true; 1128 } else { 1129 // Argument types are too different. Abort. 1130 return false; 1131 } 1132 } 1133 1134 if (HasObjCConversion) { 1135 // We had an Objective-C conversion. Allow this pointer 1136 // conversion, but complain about it. 1137 ConvertedType = ToType; 1138 IncompatibleObjC = true; 1139 return true; 1140 } 1141 } 1142 1143 return false; 1144} 1145 1146/// CheckPointerConversion - Check the pointer conversion from the 1147/// expression From to the type ToType. This routine checks for 1148/// ambiguous or inaccessible derived-to-base pointer 1149/// conversions for which IsPointerConversion has already returned 1150/// true. It returns true and produces a diagnostic if there was an 1151/// error, or returns false otherwise. 1152bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1153 CastExpr::CastKind &Kind) { 1154 QualType FromType = From->getType(); 1155 1156 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1157 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1158 QualType FromPointeeType = FromPtrType->getPointeeType(), 1159 ToPointeeType = ToPtrType->getPointeeType(); 1160 1161 if (FromPointeeType->isRecordType() && 1162 ToPointeeType->isRecordType()) { 1163 // We must have a derived-to-base conversion. Check an 1164 // ambiguous or inaccessible conversion. 1165 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1166 From->getExprLoc(), 1167 From->getSourceRange())) 1168 return true; 1169 1170 // The conversion was successful. 1171 Kind = CastExpr::CK_DerivedToBase; 1172 } 1173 } 1174 if (const ObjCObjectPointerType *FromPtrType = 1175 FromType->getAs<ObjCObjectPointerType>()) 1176 if (const ObjCObjectPointerType *ToPtrType = 1177 ToType->getAs<ObjCObjectPointerType>()) { 1178 // Objective-C++ conversions are always okay. 1179 // FIXME: We should have a different class of conversions for the 1180 // Objective-C++ implicit conversions. 1181 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1182 return false; 1183 1184 } 1185 return false; 1186} 1187 1188/// IsMemberPointerConversion - Determines whether the conversion of the 1189/// expression From, which has the (possibly adjusted) type FromType, can be 1190/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1191/// If so, returns true and places the converted type (that might differ from 1192/// ToType in its cv-qualifiers at some level) into ConvertedType. 1193bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1194 QualType ToType, 1195 bool InOverloadResolution, 1196 QualType &ConvertedType) { 1197 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1198 if (!ToTypePtr) 1199 return false; 1200 1201 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1202 if (From->isNullPointerConstant(Context, 1203 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1204 : Expr::NPC_ValueDependentIsNull)) { 1205 ConvertedType = ToType; 1206 return true; 1207 } 1208 1209 // Otherwise, both types have to be member pointers. 1210 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1211 if (!FromTypePtr) 1212 return false; 1213 1214 // A pointer to member of B can be converted to a pointer to member of D, 1215 // where D is derived from B (C++ 4.11p2). 1216 QualType FromClass(FromTypePtr->getClass(), 0); 1217 QualType ToClass(ToTypePtr->getClass(), 0); 1218 // FIXME: What happens when these are dependent? Is this function even called? 1219 1220 if (IsDerivedFrom(ToClass, FromClass)) { 1221 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1222 ToClass.getTypePtr()); 1223 return true; 1224 } 1225 1226 return false; 1227} 1228 1229/// CheckMemberPointerConversion - Check the member pointer conversion from the 1230/// expression From to the type ToType. This routine checks for ambiguous or 1231/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1232/// for which IsMemberPointerConversion has already returned true. It returns 1233/// true and produces a diagnostic if there was an error, or returns false 1234/// otherwise. 1235bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1236 CastExpr::CastKind &Kind) { 1237 QualType FromType = From->getType(); 1238 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1239 if (!FromPtrType) { 1240 // This must be a null pointer to member pointer conversion 1241 assert(From->isNullPointerConstant(Context, 1242 Expr::NPC_ValueDependentIsNull) && 1243 "Expr must be null pointer constant!"); 1244 Kind = CastExpr::CK_NullToMemberPointer; 1245 return false; 1246 } 1247 1248 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1249 assert(ToPtrType && "No member pointer cast has a target type " 1250 "that is not a member pointer."); 1251 1252 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1253 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1254 1255 // FIXME: What about dependent types? 1256 assert(FromClass->isRecordType() && "Pointer into non-class."); 1257 assert(ToClass->isRecordType() && "Pointer into non-class."); 1258 1259 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1260 /*DetectVirtual=*/true); 1261 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1262 assert(DerivationOkay && 1263 "Should not have been called if derivation isn't OK."); 1264 (void)DerivationOkay; 1265 1266 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1267 getUnqualifiedType())) { 1268 // Derivation is ambiguous. Redo the check to find the exact paths. 1269 Paths.clear(); 1270 Paths.setRecordingPaths(true); 1271 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1272 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1273 (void)StillOkay; 1274 1275 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1276 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1277 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1278 return true; 1279 } 1280 1281 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1282 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1283 << FromClass << ToClass << QualType(VBase, 0) 1284 << From->getSourceRange(); 1285 return true; 1286 } 1287 1288 // Must be a base to derived member conversion. 1289 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1290 return false; 1291} 1292 1293/// IsQualificationConversion - Determines whether the conversion from 1294/// an rvalue of type FromType to ToType is a qualification conversion 1295/// (C++ 4.4). 1296bool 1297Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1298 FromType = Context.getCanonicalType(FromType); 1299 ToType = Context.getCanonicalType(ToType); 1300 1301 // If FromType and ToType are the same type, this is not a 1302 // qualification conversion. 1303 if (FromType == ToType) 1304 return false; 1305 1306 // (C++ 4.4p4): 1307 // A conversion can add cv-qualifiers at levels other than the first 1308 // in multi-level pointers, subject to the following rules: [...] 1309 bool PreviousToQualsIncludeConst = true; 1310 bool UnwrappedAnyPointer = false; 1311 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1312 // Within each iteration of the loop, we check the qualifiers to 1313 // determine if this still looks like a qualification 1314 // conversion. Then, if all is well, we unwrap one more level of 1315 // pointers or pointers-to-members and do it all again 1316 // until there are no more pointers or pointers-to-members left to 1317 // unwrap. 1318 UnwrappedAnyPointer = true; 1319 1320 // -- for every j > 0, if const is in cv 1,j then const is in cv 1321 // 2,j, and similarly for volatile. 1322 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1323 return false; 1324 1325 // -- if the cv 1,j and cv 2,j are different, then const is in 1326 // every cv for 0 < k < j. 1327 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1328 && !PreviousToQualsIncludeConst) 1329 return false; 1330 1331 // Keep track of whether all prior cv-qualifiers in the "to" type 1332 // include const. 1333 PreviousToQualsIncludeConst 1334 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1335 } 1336 1337 // We are left with FromType and ToType being the pointee types 1338 // after unwrapping the original FromType and ToType the same number 1339 // of types. If we unwrapped any pointers, and if FromType and 1340 // ToType have the same unqualified type (since we checked 1341 // qualifiers above), then this is a qualification conversion. 1342 return UnwrappedAnyPointer && 1343 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1344} 1345 1346/// \brief Given a function template or function, extract the function template 1347/// declaration (if any) and the underlying function declaration. 1348template<typename T> 1349static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1350 FunctionTemplateDecl *&FunctionTemplate) { 1351 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1352 if (FunctionTemplate) 1353 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1354 else 1355 Function = cast<T>(Orig); 1356} 1357 1358/// Determines whether there is a user-defined conversion sequence 1359/// (C++ [over.ics.user]) that converts expression From to the type 1360/// ToType. If such a conversion exists, User will contain the 1361/// user-defined conversion sequence that performs such a conversion 1362/// and this routine will return true. Otherwise, this routine returns 1363/// false and User is unspecified. 1364/// 1365/// \param AllowConversionFunctions true if the conversion should 1366/// consider conversion functions at all. If false, only constructors 1367/// will be considered. 1368/// 1369/// \param AllowExplicit true if the conversion should consider C++0x 1370/// "explicit" conversion functions as well as non-explicit conversion 1371/// functions (C++0x [class.conv.fct]p2). 1372/// 1373/// \param ForceRValue true if the expression should be treated as an rvalue 1374/// for overload resolution. 1375Sema::OverloadingResult Sema::IsUserDefinedConversion( 1376 Expr *From, QualType ToType, 1377 UserDefinedConversionSequence& User, 1378 OverloadCandidateSet& CandidateSet, 1379 bool AllowConversionFunctions, 1380 bool AllowExplicit, bool ForceRValue) { 1381 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1382 if (CXXRecordDecl *ToRecordDecl 1383 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1384 // C++ [over.match.ctor]p1: 1385 // When objects of class type are direct-initialized (8.5), or 1386 // copy-initialized from an expression of the same or a 1387 // derived class type (8.5), overload resolution selects the 1388 // constructor. [...] For copy-initialization, the candidate 1389 // functions are all the converting constructors (12.3.1) of 1390 // that class. The argument list is the expression-list within 1391 // the parentheses of the initializer. 1392 DeclarationName ConstructorName 1393 = Context.DeclarationNames.getCXXConstructorName( 1394 Context.getCanonicalType(ToType).getUnqualifiedType()); 1395 DeclContext::lookup_iterator Con, ConEnd; 1396 for (llvm::tie(Con, ConEnd) 1397 = ToRecordDecl->lookup(ConstructorName); 1398 Con != ConEnd; ++Con) { 1399 // Find the constructor (which may be a template). 1400 CXXConstructorDecl *Constructor = 0; 1401 FunctionTemplateDecl *ConstructorTmpl 1402 = dyn_cast<FunctionTemplateDecl>(*Con); 1403 if (ConstructorTmpl) 1404 Constructor 1405 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1406 else 1407 Constructor = cast<CXXConstructorDecl>(*Con); 1408 1409 if (!Constructor->isInvalidDecl() && 1410 Constructor->isConvertingConstructor(AllowExplicit)) { 1411 if (ConstructorTmpl) 1412 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1413 1, CandidateSet, 1414 /*SuppressUserConversions=*/true, 1415 ForceRValue); 1416 else 1417 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1418 /*SuppressUserConversions=*/true, ForceRValue); 1419 } 1420 } 1421 } 1422 } 1423 1424 if (!AllowConversionFunctions) { 1425 // Don't allow any conversion functions to enter the overload set. 1426 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1427 PDiag(0) 1428 << From->getSourceRange())) { 1429 // No conversion functions from incomplete types. 1430 } else if (const RecordType *FromRecordType 1431 = From->getType()->getAs<RecordType>()) { 1432 if (CXXRecordDecl *FromRecordDecl 1433 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1434 // Add all of the conversion functions as candidates. 1435 OverloadedFunctionDecl *Conversions 1436 = FromRecordDecl->getVisibleConversionFunctions(); 1437 for (OverloadedFunctionDecl::function_iterator Func 1438 = Conversions->function_begin(); 1439 Func != Conversions->function_end(); ++Func) { 1440 CXXConversionDecl *Conv; 1441 FunctionTemplateDecl *ConvTemplate; 1442 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1443 if (ConvTemplate) 1444 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1445 else 1446 Conv = dyn_cast<CXXConversionDecl>(*Func); 1447 1448 if (AllowExplicit || !Conv->isExplicit()) { 1449 if (ConvTemplate) 1450 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1451 CandidateSet); 1452 else 1453 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1454 } 1455 } 1456 } 1457 } 1458 1459 OverloadCandidateSet::iterator Best; 1460 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1461 case OR_Success: 1462 // Record the standard conversion we used and the conversion function. 1463 if (CXXConstructorDecl *Constructor 1464 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1465 // C++ [over.ics.user]p1: 1466 // If the user-defined conversion is specified by a 1467 // constructor (12.3.1), the initial standard conversion 1468 // sequence converts the source type to the type required by 1469 // the argument of the constructor. 1470 // 1471 // FIXME: What about ellipsis conversions? 1472 QualType ThisType = Constructor->getThisType(Context); 1473 User.Before = Best->Conversions[0].Standard; 1474 User.ConversionFunction = Constructor; 1475 User.After.setAsIdentityConversion(); 1476 User.After.FromTypePtr 1477 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1478 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1479 return OR_Success; 1480 } else if (CXXConversionDecl *Conversion 1481 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1482 // C++ [over.ics.user]p1: 1483 // 1484 // [...] If the user-defined conversion is specified by a 1485 // conversion function (12.3.2), the initial standard 1486 // conversion sequence converts the source type to the 1487 // implicit object parameter of the conversion function. 1488 User.Before = Best->Conversions[0].Standard; 1489 User.ConversionFunction = Conversion; 1490 1491 // C++ [over.ics.user]p2: 1492 // The second standard conversion sequence converts the 1493 // result of the user-defined conversion to the target type 1494 // for the sequence. Since an implicit conversion sequence 1495 // is an initialization, the special rules for 1496 // initialization by user-defined conversion apply when 1497 // selecting the best user-defined conversion for a 1498 // user-defined conversion sequence (see 13.3.3 and 1499 // 13.3.3.1). 1500 User.After = Best->FinalConversion; 1501 return OR_Success; 1502 } else { 1503 assert(false && "Not a constructor or conversion function?"); 1504 return OR_No_Viable_Function; 1505 } 1506 1507 case OR_No_Viable_Function: 1508 return OR_No_Viable_Function; 1509 case OR_Deleted: 1510 // No conversion here! We're done. 1511 return OR_Deleted; 1512 1513 case OR_Ambiguous: 1514 // FIXME: See C++ [over.best.ics]p10 for the handling of 1515 // ambiguous conversion sequences. 1516 return OR_Ambiguous; 1517 } 1518 1519 return OR_No_Viable_Function; 1520} 1521 1522bool 1523Sema::DiagnoseAmbiguousUserDefinedConversion(Expr *From, QualType ToType) { 1524 ImplicitConversionSequence ICS; 1525 OverloadCandidateSet CandidateSet; 1526 OverloadingResult OvResult = 1527 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1528 CandidateSet, true, false, false); 1529 if (OvResult != OR_Ambiguous) 1530 return false; 1531 Diag(From->getSourceRange().getBegin(), 1532 diag::err_typecheck_ambiguous_condition) 1533 << From->getType() << ToType << From->getSourceRange(); 1534 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1535 return true; 1536} 1537 1538/// CompareImplicitConversionSequences - Compare two implicit 1539/// conversion sequences to determine whether one is better than the 1540/// other or if they are indistinguishable (C++ 13.3.3.2). 1541ImplicitConversionSequence::CompareKind 1542Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1543 const ImplicitConversionSequence& ICS2) 1544{ 1545 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1546 // conversion sequences (as defined in 13.3.3.1) 1547 // -- a standard conversion sequence (13.3.3.1.1) is a better 1548 // conversion sequence than a user-defined conversion sequence or 1549 // an ellipsis conversion sequence, and 1550 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1551 // conversion sequence than an ellipsis conversion sequence 1552 // (13.3.3.1.3). 1553 // 1554 if (ICS1.ConversionKind < ICS2.ConversionKind) 1555 return ImplicitConversionSequence::Better; 1556 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1557 return ImplicitConversionSequence::Worse; 1558 1559 // Two implicit conversion sequences of the same form are 1560 // indistinguishable conversion sequences unless one of the 1561 // following rules apply: (C++ 13.3.3.2p3): 1562 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1563 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1564 else if (ICS1.ConversionKind == 1565 ImplicitConversionSequence::UserDefinedConversion) { 1566 // User-defined conversion sequence U1 is a better conversion 1567 // sequence than another user-defined conversion sequence U2 if 1568 // they contain the same user-defined conversion function or 1569 // constructor and if the second standard conversion sequence of 1570 // U1 is better than the second standard conversion sequence of 1571 // U2 (C++ 13.3.3.2p3). 1572 if (ICS1.UserDefined.ConversionFunction == 1573 ICS2.UserDefined.ConversionFunction) 1574 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1575 ICS2.UserDefined.After); 1576 } 1577 1578 return ImplicitConversionSequence::Indistinguishable; 1579} 1580 1581/// CompareStandardConversionSequences - Compare two standard 1582/// conversion sequences to determine whether one is better than the 1583/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1584ImplicitConversionSequence::CompareKind 1585Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1586 const StandardConversionSequence& SCS2) 1587{ 1588 // Standard conversion sequence S1 is a better conversion sequence 1589 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1590 1591 // -- S1 is a proper subsequence of S2 (comparing the conversion 1592 // sequences in the canonical form defined by 13.3.3.1.1, 1593 // excluding any Lvalue Transformation; the identity conversion 1594 // sequence is considered to be a subsequence of any 1595 // non-identity conversion sequence) or, if not that, 1596 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1597 // Neither is a proper subsequence of the other. Do nothing. 1598 ; 1599 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1600 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1601 (SCS1.Second == ICK_Identity && 1602 SCS1.Third == ICK_Identity)) 1603 // SCS1 is a proper subsequence of SCS2. 1604 return ImplicitConversionSequence::Better; 1605 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1606 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1607 (SCS2.Second == ICK_Identity && 1608 SCS2.Third == ICK_Identity)) 1609 // SCS2 is a proper subsequence of SCS1. 1610 return ImplicitConversionSequence::Worse; 1611 1612 // -- the rank of S1 is better than the rank of S2 (by the rules 1613 // defined below), or, if not that, 1614 ImplicitConversionRank Rank1 = SCS1.getRank(); 1615 ImplicitConversionRank Rank2 = SCS2.getRank(); 1616 if (Rank1 < Rank2) 1617 return ImplicitConversionSequence::Better; 1618 else if (Rank2 < Rank1) 1619 return ImplicitConversionSequence::Worse; 1620 1621 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1622 // are indistinguishable unless one of the following rules 1623 // applies: 1624 1625 // A conversion that is not a conversion of a pointer, or 1626 // pointer to member, to bool is better than another conversion 1627 // that is such a conversion. 1628 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1629 return SCS2.isPointerConversionToBool() 1630 ? ImplicitConversionSequence::Better 1631 : ImplicitConversionSequence::Worse; 1632 1633 // C++ [over.ics.rank]p4b2: 1634 // 1635 // If class B is derived directly or indirectly from class A, 1636 // conversion of B* to A* is better than conversion of B* to 1637 // void*, and conversion of A* to void* is better than conversion 1638 // of B* to void*. 1639 bool SCS1ConvertsToVoid 1640 = SCS1.isPointerConversionToVoidPointer(Context); 1641 bool SCS2ConvertsToVoid 1642 = SCS2.isPointerConversionToVoidPointer(Context); 1643 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1644 // Exactly one of the conversion sequences is a conversion to 1645 // a void pointer; it's the worse conversion. 1646 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1647 : ImplicitConversionSequence::Worse; 1648 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1649 // Neither conversion sequence converts to a void pointer; compare 1650 // their derived-to-base conversions. 1651 if (ImplicitConversionSequence::CompareKind DerivedCK 1652 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1653 return DerivedCK; 1654 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1655 // Both conversion sequences are conversions to void 1656 // pointers. Compare the source types to determine if there's an 1657 // inheritance relationship in their sources. 1658 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1659 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1660 1661 // Adjust the types we're converting from via the array-to-pointer 1662 // conversion, if we need to. 1663 if (SCS1.First == ICK_Array_To_Pointer) 1664 FromType1 = Context.getArrayDecayedType(FromType1); 1665 if (SCS2.First == ICK_Array_To_Pointer) 1666 FromType2 = Context.getArrayDecayedType(FromType2); 1667 1668 QualType FromPointee1 1669 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1670 QualType FromPointee2 1671 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1672 1673 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1674 return ImplicitConversionSequence::Better; 1675 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1676 return ImplicitConversionSequence::Worse; 1677 1678 // Objective-C++: If one interface is more specific than the 1679 // other, it is the better one. 1680 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1681 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1682 if (FromIface1 && FromIface1) { 1683 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1684 return ImplicitConversionSequence::Better; 1685 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1686 return ImplicitConversionSequence::Worse; 1687 } 1688 } 1689 1690 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1691 // bullet 3). 1692 if (ImplicitConversionSequence::CompareKind QualCK 1693 = CompareQualificationConversions(SCS1, SCS2)) 1694 return QualCK; 1695 1696 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1697 // C++0x [over.ics.rank]p3b4: 1698 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1699 // implicit object parameter of a non-static member function declared 1700 // without a ref-qualifier, and S1 binds an rvalue reference to an 1701 // rvalue and S2 binds an lvalue reference. 1702 // FIXME: We don't know if we're dealing with the implicit object parameter, 1703 // or if the member function in this case has a ref qualifier. 1704 // (Of course, we don't have ref qualifiers yet.) 1705 if (SCS1.RRefBinding != SCS2.RRefBinding) 1706 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1707 : ImplicitConversionSequence::Worse; 1708 1709 // C++ [over.ics.rank]p3b4: 1710 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1711 // which the references refer are the same type except for 1712 // top-level cv-qualifiers, and the type to which the reference 1713 // initialized by S2 refers is more cv-qualified than the type 1714 // to which the reference initialized by S1 refers. 1715 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1716 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1717 T1 = Context.getCanonicalType(T1); 1718 T2 = Context.getCanonicalType(T2); 1719 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1720 if (T2.isMoreQualifiedThan(T1)) 1721 return ImplicitConversionSequence::Better; 1722 else if (T1.isMoreQualifiedThan(T2)) 1723 return ImplicitConversionSequence::Worse; 1724 } 1725 } 1726 1727 return ImplicitConversionSequence::Indistinguishable; 1728} 1729 1730/// CompareQualificationConversions - Compares two standard conversion 1731/// sequences to determine whether they can be ranked based on their 1732/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1733ImplicitConversionSequence::CompareKind 1734Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1735 const StandardConversionSequence& SCS2) { 1736 // C++ 13.3.3.2p3: 1737 // -- S1 and S2 differ only in their qualification conversion and 1738 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1739 // cv-qualification signature of type T1 is a proper subset of 1740 // the cv-qualification signature of type T2, and S1 is not the 1741 // deprecated string literal array-to-pointer conversion (4.2). 1742 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1743 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1744 return ImplicitConversionSequence::Indistinguishable; 1745 1746 // FIXME: the example in the standard doesn't use a qualification 1747 // conversion (!) 1748 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1749 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1750 T1 = Context.getCanonicalType(T1); 1751 T2 = Context.getCanonicalType(T2); 1752 1753 // If the types are the same, we won't learn anything by unwrapped 1754 // them. 1755 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1756 return ImplicitConversionSequence::Indistinguishable; 1757 1758 ImplicitConversionSequence::CompareKind Result 1759 = ImplicitConversionSequence::Indistinguishable; 1760 while (UnwrapSimilarPointerTypes(T1, T2)) { 1761 // Within each iteration of the loop, we check the qualifiers to 1762 // determine if this still looks like a qualification 1763 // conversion. Then, if all is well, we unwrap one more level of 1764 // pointers or pointers-to-members and do it all again 1765 // until there are no more pointers or pointers-to-members left 1766 // to unwrap. This essentially mimics what 1767 // IsQualificationConversion does, but here we're checking for a 1768 // strict subset of qualifiers. 1769 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1770 // The qualifiers are the same, so this doesn't tell us anything 1771 // about how the sequences rank. 1772 ; 1773 else if (T2.isMoreQualifiedThan(T1)) { 1774 // T1 has fewer qualifiers, so it could be the better sequence. 1775 if (Result == ImplicitConversionSequence::Worse) 1776 // Neither has qualifiers that are a subset of the other's 1777 // qualifiers. 1778 return ImplicitConversionSequence::Indistinguishable; 1779 1780 Result = ImplicitConversionSequence::Better; 1781 } else if (T1.isMoreQualifiedThan(T2)) { 1782 // T2 has fewer qualifiers, so it could be the better sequence. 1783 if (Result == ImplicitConversionSequence::Better) 1784 // Neither has qualifiers that are a subset of the other's 1785 // qualifiers. 1786 return ImplicitConversionSequence::Indistinguishable; 1787 1788 Result = ImplicitConversionSequence::Worse; 1789 } else { 1790 // Qualifiers are disjoint. 1791 return ImplicitConversionSequence::Indistinguishable; 1792 } 1793 1794 // If the types after this point are equivalent, we're done. 1795 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1796 break; 1797 } 1798 1799 // Check that the winning standard conversion sequence isn't using 1800 // the deprecated string literal array to pointer conversion. 1801 switch (Result) { 1802 case ImplicitConversionSequence::Better: 1803 if (SCS1.Deprecated) 1804 Result = ImplicitConversionSequence::Indistinguishable; 1805 break; 1806 1807 case ImplicitConversionSequence::Indistinguishable: 1808 break; 1809 1810 case ImplicitConversionSequence::Worse: 1811 if (SCS2.Deprecated) 1812 Result = ImplicitConversionSequence::Indistinguishable; 1813 break; 1814 } 1815 1816 return Result; 1817} 1818 1819/// CompareDerivedToBaseConversions - Compares two standard conversion 1820/// sequences to determine whether they can be ranked based on their 1821/// various kinds of derived-to-base conversions (C++ 1822/// [over.ics.rank]p4b3). As part of these checks, we also look at 1823/// conversions between Objective-C interface types. 1824ImplicitConversionSequence::CompareKind 1825Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1826 const StandardConversionSequence& SCS2) { 1827 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1828 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1829 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1830 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1831 1832 // Adjust the types we're converting from via the array-to-pointer 1833 // conversion, if we need to. 1834 if (SCS1.First == ICK_Array_To_Pointer) 1835 FromType1 = Context.getArrayDecayedType(FromType1); 1836 if (SCS2.First == ICK_Array_To_Pointer) 1837 FromType2 = Context.getArrayDecayedType(FromType2); 1838 1839 // Canonicalize all of the types. 1840 FromType1 = Context.getCanonicalType(FromType1); 1841 ToType1 = Context.getCanonicalType(ToType1); 1842 FromType2 = Context.getCanonicalType(FromType2); 1843 ToType2 = Context.getCanonicalType(ToType2); 1844 1845 // C++ [over.ics.rank]p4b3: 1846 // 1847 // If class B is derived directly or indirectly from class A and 1848 // class C is derived directly or indirectly from B, 1849 // 1850 // For Objective-C, we let A, B, and C also be Objective-C 1851 // interfaces. 1852 1853 // Compare based on pointer conversions. 1854 if (SCS1.Second == ICK_Pointer_Conversion && 1855 SCS2.Second == ICK_Pointer_Conversion && 1856 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1857 FromType1->isPointerType() && FromType2->isPointerType() && 1858 ToType1->isPointerType() && ToType2->isPointerType()) { 1859 QualType FromPointee1 1860 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1861 QualType ToPointee1 1862 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1863 QualType FromPointee2 1864 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1865 QualType ToPointee2 1866 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1867 1868 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1869 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1870 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1871 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1872 1873 // -- conversion of C* to B* is better than conversion of C* to A*, 1874 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1875 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1876 return ImplicitConversionSequence::Better; 1877 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1878 return ImplicitConversionSequence::Worse; 1879 1880 if (ToIface1 && ToIface2) { 1881 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1882 return ImplicitConversionSequence::Better; 1883 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1884 return ImplicitConversionSequence::Worse; 1885 } 1886 } 1887 1888 // -- conversion of B* to A* is better than conversion of C* to A*, 1889 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1890 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1891 return ImplicitConversionSequence::Better; 1892 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1893 return ImplicitConversionSequence::Worse; 1894 1895 if (FromIface1 && FromIface2) { 1896 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1897 return ImplicitConversionSequence::Better; 1898 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1899 return ImplicitConversionSequence::Worse; 1900 } 1901 } 1902 } 1903 1904 // Compare based on reference bindings. 1905 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1906 SCS1.Second == ICK_Derived_To_Base) { 1907 // -- binding of an expression of type C to a reference of type 1908 // B& is better than binding an expression of type C to a 1909 // reference of type A&, 1910 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1911 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1912 if (IsDerivedFrom(ToType1, ToType2)) 1913 return ImplicitConversionSequence::Better; 1914 else if (IsDerivedFrom(ToType2, ToType1)) 1915 return ImplicitConversionSequence::Worse; 1916 } 1917 1918 // -- binding of an expression of type B to a reference of type 1919 // A& is better than binding an expression of type C to a 1920 // reference of type A&, 1921 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1922 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1923 if (IsDerivedFrom(FromType2, FromType1)) 1924 return ImplicitConversionSequence::Better; 1925 else if (IsDerivedFrom(FromType1, FromType2)) 1926 return ImplicitConversionSequence::Worse; 1927 } 1928 } 1929 1930 1931 // FIXME: conversion of A::* to B::* is better than conversion of 1932 // A::* to C::*, 1933 1934 // FIXME: conversion of B::* to C::* is better than conversion of 1935 // A::* to C::*, and 1936 1937 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1938 SCS1.Second == ICK_Derived_To_Base) { 1939 // -- conversion of C to B is better than conversion of C to A, 1940 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1941 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1942 if (IsDerivedFrom(ToType1, ToType2)) 1943 return ImplicitConversionSequence::Better; 1944 else if (IsDerivedFrom(ToType2, ToType1)) 1945 return ImplicitConversionSequence::Worse; 1946 } 1947 1948 // -- conversion of B to A is better than conversion of C to A. 1949 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1950 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1951 if (IsDerivedFrom(FromType2, FromType1)) 1952 return ImplicitConversionSequence::Better; 1953 else if (IsDerivedFrom(FromType1, FromType2)) 1954 return ImplicitConversionSequence::Worse; 1955 } 1956 } 1957 1958 return ImplicitConversionSequence::Indistinguishable; 1959} 1960 1961/// TryCopyInitialization - Try to copy-initialize a value of type 1962/// ToType from the expression From. Return the implicit conversion 1963/// sequence required to pass this argument, which may be a bad 1964/// conversion sequence (meaning that the argument cannot be passed to 1965/// a parameter of this type). If @p SuppressUserConversions, then we 1966/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1967/// then we treat @p From as an rvalue, even if it is an lvalue. 1968ImplicitConversionSequence 1969Sema::TryCopyInitialization(Expr *From, QualType ToType, 1970 bool SuppressUserConversions, bool ForceRValue, 1971 bool InOverloadResolution) { 1972 if (ToType->isReferenceType()) { 1973 ImplicitConversionSequence ICS; 1974 CheckReferenceInit(From, ToType, 1975 /*FIXME:*/From->getLocStart(), 1976 SuppressUserConversions, 1977 /*AllowExplicit=*/false, 1978 ForceRValue, 1979 &ICS); 1980 return ICS; 1981 } else { 1982 return TryImplicitConversion(From, ToType, 1983 SuppressUserConversions, 1984 /*AllowExplicit=*/false, 1985 ForceRValue, 1986 InOverloadResolution); 1987 } 1988} 1989 1990/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1991/// the expression @p From. Returns true (and emits a diagnostic) if there was 1992/// an error, returns false if the initialization succeeded. Elidable should 1993/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1994/// differently in C++0x for this case. 1995bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1996 const char* Flavor, bool Elidable) { 1997 if (!getLangOptions().CPlusPlus) { 1998 // In C, argument passing is the same as performing an assignment. 1999 QualType FromType = From->getType(); 2000 2001 AssignConvertType ConvTy = 2002 CheckSingleAssignmentConstraints(ToType, From); 2003 if (ConvTy != Compatible && 2004 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2005 ConvTy = Compatible; 2006 2007 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2008 FromType, From, Flavor); 2009 } 2010 2011 if (ToType->isReferenceType()) 2012 return CheckReferenceInit(From, ToType, 2013 /*FIXME:*/From->getLocStart(), 2014 /*SuppressUserConversions=*/false, 2015 /*AllowExplicit=*/false, 2016 /*ForceRValue=*/false); 2017 2018 if (!PerformImplicitConversion(From, ToType, Flavor, 2019 /*AllowExplicit=*/false, Elidable)) 2020 return false; 2021 if (!DiagnoseAmbiguousUserDefinedConversion(From, ToType)) 2022 return Diag(From->getSourceRange().getBegin(), 2023 diag::err_typecheck_convert_incompatible) 2024 << ToType << From->getType() << Flavor << From->getSourceRange(); 2025 return true; 2026} 2027 2028/// TryObjectArgumentInitialization - Try to initialize the object 2029/// parameter of the given member function (@c Method) from the 2030/// expression @p From. 2031ImplicitConversionSequence 2032Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2033 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2034 QualType ImplicitParamType 2035 = Context.getCVRQualifiedType(ClassType, Method->getTypeQualifiers()); 2036 2037 // Set up the conversion sequence as a "bad" conversion, to allow us 2038 // to exit early. 2039 ImplicitConversionSequence ICS; 2040 ICS.Standard.setAsIdentityConversion(); 2041 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2042 2043 // We need to have an object of class type. 2044 QualType FromType = From->getType(); 2045 if (const PointerType *PT = FromType->getAs<PointerType>()) 2046 FromType = PT->getPointeeType(); 2047 2048 assert(FromType->isRecordType()); 2049 2050 // The implicit object parmeter is has the type "reference to cv X", 2051 // where X is the class of which the function is a member 2052 // (C++ [over.match.funcs]p4). However, when finding an implicit 2053 // conversion sequence for the argument, we are not allowed to 2054 // create temporaries or perform user-defined conversions 2055 // (C++ [over.match.funcs]p5). We perform a simplified version of 2056 // reference binding here, that allows class rvalues to bind to 2057 // non-constant references. 2058 2059 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2060 // with the implicit object parameter (C++ [over.match.funcs]p5). 2061 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2062 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 2063 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 2064 return ICS; 2065 2066 // Check that we have either the same type or a derived type. It 2067 // affects the conversion rank. 2068 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2069 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2070 ICS.Standard.Second = ICK_Identity; 2071 else if (IsDerivedFrom(FromType, ClassType)) 2072 ICS.Standard.Second = ICK_Derived_To_Base; 2073 else 2074 return ICS; 2075 2076 // Success. Mark this as a reference binding. 2077 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2078 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2079 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2080 ICS.Standard.ReferenceBinding = true; 2081 ICS.Standard.DirectBinding = true; 2082 ICS.Standard.RRefBinding = false; 2083 return ICS; 2084} 2085 2086/// PerformObjectArgumentInitialization - Perform initialization of 2087/// the implicit object parameter for the given Method with the given 2088/// expression. 2089bool 2090Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2091 QualType FromRecordType, DestType; 2092 QualType ImplicitParamRecordType = 2093 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2094 2095 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2096 FromRecordType = PT->getPointeeType(); 2097 DestType = Method->getThisType(Context); 2098 } else { 2099 FromRecordType = From->getType(); 2100 DestType = ImplicitParamRecordType; 2101 } 2102 2103 ImplicitConversionSequence ICS 2104 = TryObjectArgumentInitialization(From, Method); 2105 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2106 return Diag(From->getSourceRange().getBegin(), 2107 diag::err_implicit_object_parameter_init) 2108 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2109 2110 if (ICS.Standard.Second == ICK_Derived_To_Base && 2111 CheckDerivedToBaseConversion(FromRecordType, 2112 ImplicitParamRecordType, 2113 From->getSourceRange().getBegin(), 2114 From->getSourceRange())) 2115 return true; 2116 2117 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2118 /*isLvalue=*/true); 2119 return false; 2120} 2121 2122/// TryContextuallyConvertToBool - Attempt to contextually convert the 2123/// expression From to bool (C++0x [conv]p3). 2124ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2125 return TryImplicitConversion(From, Context.BoolTy, 2126 // FIXME: Are these flags correct? 2127 /*SuppressUserConversions=*/false, 2128 /*AllowExplicit=*/true, 2129 /*ForceRValue=*/false, 2130 /*InOverloadResolution=*/false); 2131} 2132 2133/// PerformContextuallyConvertToBool - Perform a contextual conversion 2134/// of the expression From to bool (C++0x [conv]p3). 2135bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2136 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2137 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2138 return false; 2139 2140 if (!DiagnoseAmbiguousUserDefinedConversion(From, Context.BoolTy)) 2141 return Diag(From->getSourceRange().getBegin(), 2142 diag::err_typecheck_bool_condition) 2143 << From->getType() << From->getSourceRange(); 2144 return true; 2145} 2146 2147/// AddOverloadCandidate - Adds the given function to the set of 2148/// candidate functions, using the given function call arguments. If 2149/// @p SuppressUserConversions, then don't allow user-defined 2150/// conversions via constructors or conversion operators. 2151/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2152/// hacky way to implement the overloading rules for elidable copy 2153/// initialization in C++0x (C++0x 12.8p15). 2154/// 2155/// \para PartialOverloading true if we are performing "partial" overloading 2156/// based on an incomplete set of function arguments. This feature is used by 2157/// code completion. 2158void 2159Sema::AddOverloadCandidate(FunctionDecl *Function, 2160 Expr **Args, unsigned NumArgs, 2161 OverloadCandidateSet& CandidateSet, 2162 bool SuppressUserConversions, 2163 bool ForceRValue, 2164 bool PartialOverloading) { 2165 const FunctionProtoType* Proto 2166 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2167 assert(Proto && "Functions without a prototype cannot be overloaded"); 2168 assert(!isa<CXXConversionDecl>(Function) && 2169 "Use AddConversionCandidate for conversion functions"); 2170 assert(!Function->getDescribedFunctionTemplate() && 2171 "Use AddTemplateOverloadCandidate for function templates"); 2172 2173 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2174 if (!isa<CXXConstructorDecl>(Method)) { 2175 // If we get here, it's because we're calling a member function 2176 // that is named without a member access expression (e.g., 2177 // "this->f") that was either written explicitly or created 2178 // implicitly. This can happen with a qualified call to a member 2179 // function, e.g., X::f(). We use a NULL object as the implied 2180 // object argument (C++ [over.call.func]p3). 2181 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2182 SuppressUserConversions, ForceRValue); 2183 return; 2184 } 2185 // We treat a constructor like a non-member function, since its object 2186 // argument doesn't participate in overload resolution. 2187 } 2188 2189 2190 // Add this candidate 2191 CandidateSet.push_back(OverloadCandidate()); 2192 OverloadCandidate& Candidate = CandidateSet.back(); 2193 Candidate.Function = Function; 2194 Candidate.Viable = true; 2195 Candidate.IsSurrogate = false; 2196 Candidate.IgnoreObjectArgument = false; 2197 2198 unsigned NumArgsInProto = Proto->getNumArgs(); 2199 2200 // (C++ 13.3.2p2): A candidate function having fewer than m 2201 // parameters is viable only if it has an ellipsis in its parameter 2202 // list (8.3.5). 2203 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2204 !Proto->isVariadic()) { 2205 Candidate.Viable = false; 2206 return; 2207 } 2208 2209 // (C++ 13.3.2p2): A candidate function having more than m parameters 2210 // is viable only if the (m+1)st parameter has a default argument 2211 // (8.3.6). For the purposes of overload resolution, the 2212 // parameter list is truncated on the right, so that there are 2213 // exactly m parameters. 2214 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2215 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2216 // Not enough arguments. 2217 Candidate.Viable = false; 2218 return; 2219 } 2220 2221 // Determine the implicit conversion sequences for each of the 2222 // arguments. 2223 Candidate.Conversions.resize(NumArgs); 2224 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2225 if (ArgIdx < NumArgsInProto) { 2226 // (C++ 13.3.2p3): for F to be a viable function, there shall 2227 // exist for each argument an implicit conversion sequence 2228 // (13.3.3.1) that converts that argument to the corresponding 2229 // parameter of F. 2230 QualType ParamType = Proto->getArgType(ArgIdx); 2231 Candidate.Conversions[ArgIdx] 2232 = TryCopyInitialization(Args[ArgIdx], ParamType, 2233 SuppressUserConversions, ForceRValue, 2234 /*InOverloadResolution=*/true); 2235 if (Candidate.Conversions[ArgIdx].ConversionKind 2236 == ImplicitConversionSequence::BadConversion) { 2237 Candidate.Viable = false; 2238 break; 2239 } 2240 } else { 2241 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2242 // argument for which there is no corresponding parameter is 2243 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2244 Candidate.Conversions[ArgIdx].ConversionKind 2245 = ImplicitConversionSequence::EllipsisConversion; 2246 } 2247 } 2248} 2249 2250/// \brief Add all of the function declarations in the given function set to 2251/// the overload canddiate set. 2252void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2253 Expr **Args, unsigned NumArgs, 2254 OverloadCandidateSet& CandidateSet, 2255 bool SuppressUserConversions) { 2256 for (FunctionSet::const_iterator F = Functions.begin(), 2257 FEnd = Functions.end(); 2258 F != FEnd; ++F) { 2259 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) 2260 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2261 SuppressUserConversions); 2262 else 2263 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*F), 2264 /*FIXME: explicit args */false, 0, 0, 2265 Args, NumArgs, CandidateSet, 2266 SuppressUserConversions); 2267 } 2268} 2269 2270/// AddMethodCandidate - Adds the given C++ member function to the set 2271/// of candidate functions, using the given function call arguments 2272/// and the object argument (@c Object). For example, in a call 2273/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2274/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2275/// allow user-defined conversions via constructors or conversion 2276/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2277/// a slightly hacky way to implement the overloading rules for elidable copy 2278/// initialization in C++0x (C++0x 12.8p15). 2279void 2280Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2281 Expr **Args, unsigned NumArgs, 2282 OverloadCandidateSet& CandidateSet, 2283 bool SuppressUserConversions, bool ForceRValue) { 2284 const FunctionProtoType* Proto 2285 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2286 assert(Proto && "Methods without a prototype cannot be overloaded"); 2287 assert(!isa<CXXConversionDecl>(Method) && 2288 "Use AddConversionCandidate for conversion functions"); 2289 assert(!isa<CXXConstructorDecl>(Method) && 2290 "Use AddOverloadCandidate for constructors"); 2291 2292 // Add this candidate 2293 CandidateSet.push_back(OverloadCandidate()); 2294 OverloadCandidate& Candidate = CandidateSet.back(); 2295 Candidate.Function = Method; 2296 Candidate.IsSurrogate = false; 2297 Candidate.IgnoreObjectArgument = false; 2298 2299 unsigned NumArgsInProto = Proto->getNumArgs(); 2300 2301 // (C++ 13.3.2p2): A candidate function having fewer than m 2302 // parameters is viable only if it has an ellipsis in its parameter 2303 // list (8.3.5). 2304 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2305 Candidate.Viable = false; 2306 return; 2307 } 2308 2309 // (C++ 13.3.2p2): A candidate function having more than m parameters 2310 // is viable only if the (m+1)st parameter has a default argument 2311 // (8.3.6). For the purposes of overload resolution, the 2312 // parameter list is truncated on the right, so that there are 2313 // exactly m parameters. 2314 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2315 if (NumArgs < MinRequiredArgs) { 2316 // Not enough arguments. 2317 Candidate.Viable = false; 2318 return; 2319 } 2320 2321 Candidate.Viable = true; 2322 Candidate.Conversions.resize(NumArgs + 1); 2323 2324 if (Method->isStatic() || !Object) 2325 // The implicit object argument is ignored. 2326 Candidate.IgnoreObjectArgument = true; 2327 else { 2328 // Determine the implicit conversion sequence for the object 2329 // parameter. 2330 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2331 if (Candidate.Conversions[0].ConversionKind 2332 == ImplicitConversionSequence::BadConversion) { 2333 Candidate.Viable = false; 2334 return; 2335 } 2336 } 2337 2338 // Determine the implicit conversion sequences for each of the 2339 // arguments. 2340 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2341 if (ArgIdx < NumArgsInProto) { 2342 // (C++ 13.3.2p3): for F to be a viable function, there shall 2343 // exist for each argument an implicit conversion sequence 2344 // (13.3.3.1) that converts that argument to the corresponding 2345 // parameter of F. 2346 QualType ParamType = Proto->getArgType(ArgIdx); 2347 Candidate.Conversions[ArgIdx + 1] 2348 = TryCopyInitialization(Args[ArgIdx], ParamType, 2349 SuppressUserConversions, ForceRValue, 2350 /*InOverloadResolution=*/true); 2351 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2352 == ImplicitConversionSequence::BadConversion) { 2353 Candidate.Viable = false; 2354 break; 2355 } 2356 } else { 2357 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2358 // argument for which there is no corresponding parameter is 2359 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2360 Candidate.Conversions[ArgIdx + 1].ConversionKind 2361 = ImplicitConversionSequence::EllipsisConversion; 2362 } 2363 } 2364} 2365 2366/// \brief Add a C++ member function template as a candidate to the candidate 2367/// set, using template argument deduction to produce an appropriate member 2368/// function template specialization. 2369void 2370Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2371 bool HasExplicitTemplateArgs, 2372 const TemplateArgument *ExplicitTemplateArgs, 2373 unsigned NumExplicitTemplateArgs, 2374 Expr *Object, Expr **Args, unsigned NumArgs, 2375 OverloadCandidateSet& CandidateSet, 2376 bool SuppressUserConversions, 2377 bool ForceRValue) { 2378 // C++ [over.match.funcs]p7: 2379 // In each case where a candidate is a function template, candidate 2380 // function template specializations are generated using template argument 2381 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2382 // candidate functions in the usual way.113) A given name can refer to one 2383 // or more function templates and also to a set of overloaded non-template 2384 // functions. In such a case, the candidate functions generated from each 2385 // function template are combined with the set of non-template candidate 2386 // functions. 2387 TemplateDeductionInfo Info(Context); 2388 FunctionDecl *Specialization = 0; 2389 if (TemplateDeductionResult Result 2390 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2391 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2392 Args, NumArgs, Specialization, Info)) { 2393 // FIXME: Record what happened with template argument deduction, so 2394 // that we can give the user a beautiful diagnostic. 2395 (void)Result; 2396 return; 2397 } 2398 2399 // Add the function template specialization produced by template argument 2400 // deduction as a candidate. 2401 assert(Specialization && "Missing member function template specialization?"); 2402 assert(isa<CXXMethodDecl>(Specialization) && 2403 "Specialization is not a member function?"); 2404 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2405 CandidateSet, SuppressUserConversions, ForceRValue); 2406} 2407 2408/// \brief Add a C++ function template specialization as a candidate 2409/// in the candidate set, using template argument deduction to produce 2410/// an appropriate function template specialization. 2411void 2412Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2413 bool HasExplicitTemplateArgs, 2414 const TemplateArgument *ExplicitTemplateArgs, 2415 unsigned NumExplicitTemplateArgs, 2416 Expr **Args, unsigned NumArgs, 2417 OverloadCandidateSet& CandidateSet, 2418 bool SuppressUserConversions, 2419 bool ForceRValue) { 2420 // C++ [over.match.funcs]p7: 2421 // In each case where a candidate is a function template, candidate 2422 // function template specializations are generated using template argument 2423 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2424 // candidate functions in the usual way.113) A given name can refer to one 2425 // or more function templates and also to a set of overloaded non-template 2426 // functions. In such a case, the candidate functions generated from each 2427 // function template are combined with the set of non-template candidate 2428 // functions. 2429 TemplateDeductionInfo Info(Context); 2430 FunctionDecl *Specialization = 0; 2431 if (TemplateDeductionResult Result 2432 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2433 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2434 Args, NumArgs, Specialization, Info)) { 2435 // FIXME: Record what happened with template argument deduction, so 2436 // that we can give the user a beautiful diagnostic. 2437 (void)Result; 2438 return; 2439 } 2440 2441 // Add the function template specialization produced by template argument 2442 // deduction as a candidate. 2443 assert(Specialization && "Missing function template specialization?"); 2444 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2445 SuppressUserConversions, ForceRValue); 2446} 2447 2448/// AddConversionCandidate - Add a C++ conversion function as a 2449/// candidate in the candidate set (C++ [over.match.conv], 2450/// C++ [over.match.copy]). From is the expression we're converting from, 2451/// and ToType is the type that we're eventually trying to convert to 2452/// (which may or may not be the same type as the type that the 2453/// conversion function produces). 2454void 2455Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2456 Expr *From, QualType ToType, 2457 OverloadCandidateSet& CandidateSet) { 2458 assert(!Conversion->getDescribedFunctionTemplate() && 2459 "Conversion function templates use AddTemplateConversionCandidate"); 2460 2461 // Add this candidate 2462 CandidateSet.push_back(OverloadCandidate()); 2463 OverloadCandidate& Candidate = CandidateSet.back(); 2464 Candidate.Function = Conversion; 2465 Candidate.IsSurrogate = false; 2466 Candidate.IgnoreObjectArgument = false; 2467 Candidate.FinalConversion.setAsIdentityConversion(); 2468 Candidate.FinalConversion.FromTypePtr 2469 = Conversion->getConversionType().getAsOpaquePtr(); 2470 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2471 2472 // Determine the implicit conversion sequence for the implicit 2473 // object parameter. 2474 Candidate.Viable = true; 2475 Candidate.Conversions.resize(1); 2476 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2477 // Conversion functions to a different type in the base class is visible in 2478 // the derived class. So, a derived to base conversion should not participate 2479 // in overload resolution. 2480 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2481 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2482 if (Candidate.Conversions[0].ConversionKind 2483 == ImplicitConversionSequence::BadConversion) { 2484 Candidate.Viable = false; 2485 return; 2486 } 2487 2488 // To determine what the conversion from the result of calling the 2489 // conversion function to the type we're eventually trying to 2490 // convert to (ToType), we need to synthesize a call to the 2491 // conversion function and attempt copy initialization from it. This 2492 // makes sure that we get the right semantics with respect to 2493 // lvalues/rvalues and the type. Fortunately, we can allocate this 2494 // call on the stack and we don't need its arguments to be 2495 // well-formed. 2496 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2497 SourceLocation()); 2498 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2499 CastExpr::CK_Unknown, 2500 &ConversionRef, false); 2501 2502 // Note that it is safe to allocate CallExpr on the stack here because 2503 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2504 // allocator). 2505 CallExpr Call(Context, &ConversionFn, 0, 0, 2506 Conversion->getConversionType().getNonReferenceType(), 2507 SourceLocation()); 2508 ImplicitConversionSequence ICS = 2509 TryCopyInitialization(&Call, ToType, 2510 /*SuppressUserConversions=*/true, 2511 /*ForceRValue=*/false, 2512 /*InOverloadResolution=*/false); 2513 2514 switch (ICS.ConversionKind) { 2515 case ImplicitConversionSequence::StandardConversion: 2516 Candidate.FinalConversion = ICS.Standard; 2517 break; 2518 2519 case ImplicitConversionSequence::BadConversion: 2520 Candidate.Viable = false; 2521 break; 2522 2523 default: 2524 assert(false && 2525 "Can only end up with a standard conversion sequence or failure"); 2526 } 2527} 2528 2529/// \brief Adds a conversion function template specialization 2530/// candidate to the overload set, using template argument deduction 2531/// to deduce the template arguments of the conversion function 2532/// template from the type that we are converting to (C++ 2533/// [temp.deduct.conv]). 2534void 2535Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2536 Expr *From, QualType ToType, 2537 OverloadCandidateSet &CandidateSet) { 2538 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2539 "Only conversion function templates permitted here"); 2540 2541 TemplateDeductionInfo Info(Context); 2542 CXXConversionDecl *Specialization = 0; 2543 if (TemplateDeductionResult Result 2544 = DeduceTemplateArguments(FunctionTemplate, ToType, 2545 Specialization, Info)) { 2546 // FIXME: Record what happened with template argument deduction, so 2547 // that we can give the user a beautiful diagnostic. 2548 (void)Result; 2549 return; 2550 } 2551 2552 // Add the conversion function template specialization produced by 2553 // template argument deduction as a candidate. 2554 assert(Specialization && "Missing function template specialization?"); 2555 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2556} 2557 2558/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2559/// converts the given @c Object to a function pointer via the 2560/// conversion function @c Conversion, and then attempts to call it 2561/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2562/// the type of function that we'll eventually be calling. 2563void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2564 const FunctionProtoType *Proto, 2565 Expr *Object, Expr **Args, unsigned NumArgs, 2566 OverloadCandidateSet& CandidateSet) { 2567 CandidateSet.push_back(OverloadCandidate()); 2568 OverloadCandidate& Candidate = CandidateSet.back(); 2569 Candidate.Function = 0; 2570 Candidate.Surrogate = Conversion; 2571 Candidate.Viable = true; 2572 Candidate.IsSurrogate = true; 2573 Candidate.IgnoreObjectArgument = false; 2574 Candidate.Conversions.resize(NumArgs + 1); 2575 2576 // Determine the implicit conversion sequence for the implicit 2577 // object parameter. 2578 ImplicitConversionSequence ObjectInit 2579 = TryObjectArgumentInitialization(Object, Conversion); 2580 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2581 Candidate.Viable = false; 2582 return; 2583 } 2584 2585 // The first conversion is actually a user-defined conversion whose 2586 // first conversion is ObjectInit's standard conversion (which is 2587 // effectively a reference binding). Record it as such. 2588 Candidate.Conversions[0].ConversionKind 2589 = ImplicitConversionSequence::UserDefinedConversion; 2590 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2591 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2592 Candidate.Conversions[0].UserDefined.After 2593 = Candidate.Conversions[0].UserDefined.Before; 2594 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2595 2596 // Find the 2597 unsigned NumArgsInProto = Proto->getNumArgs(); 2598 2599 // (C++ 13.3.2p2): A candidate function having fewer than m 2600 // parameters is viable only if it has an ellipsis in its parameter 2601 // list (8.3.5). 2602 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2603 Candidate.Viable = false; 2604 return; 2605 } 2606 2607 // Function types don't have any default arguments, so just check if 2608 // we have enough arguments. 2609 if (NumArgs < NumArgsInProto) { 2610 // Not enough arguments. 2611 Candidate.Viable = false; 2612 return; 2613 } 2614 2615 // Determine the implicit conversion sequences for each of the 2616 // arguments. 2617 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2618 if (ArgIdx < NumArgsInProto) { 2619 // (C++ 13.3.2p3): for F to be a viable function, there shall 2620 // exist for each argument an implicit conversion sequence 2621 // (13.3.3.1) that converts that argument to the corresponding 2622 // parameter of F. 2623 QualType ParamType = Proto->getArgType(ArgIdx); 2624 Candidate.Conversions[ArgIdx + 1] 2625 = TryCopyInitialization(Args[ArgIdx], ParamType, 2626 /*SuppressUserConversions=*/false, 2627 /*ForceRValue=*/false, 2628 /*InOverloadResolution=*/false); 2629 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2630 == ImplicitConversionSequence::BadConversion) { 2631 Candidate.Viable = false; 2632 break; 2633 } 2634 } else { 2635 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2636 // argument for which there is no corresponding parameter is 2637 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2638 Candidate.Conversions[ArgIdx + 1].ConversionKind 2639 = ImplicitConversionSequence::EllipsisConversion; 2640 } 2641 } 2642} 2643 2644// FIXME: This will eventually be removed, once we've migrated all of the 2645// operator overloading logic over to the scheme used by binary operators, which 2646// works for template instantiation. 2647void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2648 SourceLocation OpLoc, 2649 Expr **Args, unsigned NumArgs, 2650 OverloadCandidateSet& CandidateSet, 2651 SourceRange OpRange) { 2652 2653 FunctionSet Functions; 2654 2655 QualType T1 = Args[0]->getType(); 2656 QualType T2; 2657 if (NumArgs > 1) 2658 T2 = Args[1]->getType(); 2659 2660 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2661 if (S) 2662 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2663 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2664 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2665 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2666 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2667} 2668 2669/// \brief Add overload candidates for overloaded operators that are 2670/// member functions. 2671/// 2672/// Add the overloaded operator candidates that are member functions 2673/// for the operator Op that was used in an operator expression such 2674/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2675/// CandidateSet will store the added overload candidates. (C++ 2676/// [over.match.oper]). 2677void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2678 SourceLocation OpLoc, 2679 Expr **Args, unsigned NumArgs, 2680 OverloadCandidateSet& CandidateSet, 2681 SourceRange OpRange) { 2682 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2683 2684 // C++ [over.match.oper]p3: 2685 // For a unary operator @ with an operand of a type whose 2686 // cv-unqualified version is T1, and for a binary operator @ with 2687 // a left operand of a type whose cv-unqualified version is T1 and 2688 // a right operand of a type whose cv-unqualified version is T2, 2689 // three sets of candidate functions, designated member 2690 // candidates, non-member candidates and built-in candidates, are 2691 // constructed as follows: 2692 QualType T1 = Args[0]->getType(); 2693 QualType T2; 2694 if (NumArgs > 1) 2695 T2 = Args[1]->getType(); 2696 2697 // -- If T1 is a class type, the set of member candidates is the 2698 // result of the qualified lookup of T1::operator@ 2699 // (13.3.1.1.1); otherwise, the set of member candidates is 2700 // empty. 2701 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2702 // Complete the type if it can be completed. Otherwise, we're done. 2703 if (RequireCompleteType(OpLoc, T1, PartialDiagnostic(0))) 2704 return; 2705 2706 LookupResult Operators = LookupQualifiedName(T1Rec->getDecl(), OpName, 2707 LookupOrdinaryName, false); 2708 for (LookupResult::iterator Oper = Operators.begin(), 2709 OperEnd = Operators.end(); 2710 Oper != OperEnd; 2711 ++Oper) 2712 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2713 Args+1, NumArgs - 1, CandidateSet, 2714 /*SuppressUserConversions=*/false); 2715 } 2716} 2717 2718/// AddBuiltinCandidate - Add a candidate for a built-in 2719/// operator. ResultTy and ParamTys are the result and parameter types 2720/// of the built-in candidate, respectively. Args and NumArgs are the 2721/// arguments being passed to the candidate. IsAssignmentOperator 2722/// should be true when this built-in candidate is an assignment 2723/// operator. NumContextualBoolArguments is the number of arguments 2724/// (at the beginning of the argument list) that will be contextually 2725/// converted to bool. 2726void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2727 Expr **Args, unsigned NumArgs, 2728 OverloadCandidateSet& CandidateSet, 2729 bool IsAssignmentOperator, 2730 unsigned NumContextualBoolArguments) { 2731 // Add this candidate 2732 CandidateSet.push_back(OverloadCandidate()); 2733 OverloadCandidate& Candidate = CandidateSet.back(); 2734 Candidate.Function = 0; 2735 Candidate.IsSurrogate = false; 2736 Candidate.IgnoreObjectArgument = false; 2737 Candidate.BuiltinTypes.ResultTy = ResultTy; 2738 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2739 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2740 2741 // Determine the implicit conversion sequences for each of the 2742 // arguments. 2743 Candidate.Viable = true; 2744 Candidate.Conversions.resize(NumArgs); 2745 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2746 // C++ [over.match.oper]p4: 2747 // For the built-in assignment operators, conversions of the 2748 // left operand are restricted as follows: 2749 // -- no temporaries are introduced to hold the left operand, and 2750 // -- no user-defined conversions are applied to the left 2751 // operand to achieve a type match with the left-most 2752 // parameter of a built-in candidate. 2753 // 2754 // We block these conversions by turning off user-defined 2755 // conversions, since that is the only way that initialization of 2756 // a reference to a non-class type can occur from something that 2757 // is not of the same type. 2758 if (ArgIdx < NumContextualBoolArguments) { 2759 assert(ParamTys[ArgIdx] == Context.BoolTy && 2760 "Contextual conversion to bool requires bool type"); 2761 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2762 } else { 2763 Candidate.Conversions[ArgIdx] 2764 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2765 ArgIdx == 0 && IsAssignmentOperator, 2766 /*ForceRValue=*/false, 2767 /*InOverloadResolution=*/false); 2768 } 2769 if (Candidate.Conversions[ArgIdx].ConversionKind 2770 == ImplicitConversionSequence::BadConversion) { 2771 Candidate.Viable = false; 2772 break; 2773 } 2774 } 2775} 2776 2777/// BuiltinCandidateTypeSet - A set of types that will be used for the 2778/// candidate operator functions for built-in operators (C++ 2779/// [over.built]). The types are separated into pointer types and 2780/// enumeration types. 2781class BuiltinCandidateTypeSet { 2782 /// TypeSet - A set of types. 2783 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2784 2785 /// PointerTypes - The set of pointer types that will be used in the 2786 /// built-in candidates. 2787 TypeSet PointerTypes; 2788 2789 /// MemberPointerTypes - The set of member pointer types that will be 2790 /// used in the built-in candidates. 2791 TypeSet MemberPointerTypes; 2792 2793 /// EnumerationTypes - The set of enumeration types that will be 2794 /// used in the built-in candidates. 2795 TypeSet EnumerationTypes; 2796 2797 /// Sema - The semantic analysis instance where we are building the 2798 /// candidate type set. 2799 Sema &SemaRef; 2800 2801 /// Context - The AST context in which we will build the type sets. 2802 ASTContext &Context; 2803 2804 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2805 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2806 2807public: 2808 /// iterator - Iterates through the types that are part of the set. 2809 typedef TypeSet::iterator iterator; 2810 2811 BuiltinCandidateTypeSet(Sema &SemaRef) 2812 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2813 2814 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2815 bool AllowExplicitConversions); 2816 2817 /// pointer_begin - First pointer type found; 2818 iterator pointer_begin() { return PointerTypes.begin(); } 2819 2820 /// pointer_end - Past the last pointer type found; 2821 iterator pointer_end() { return PointerTypes.end(); } 2822 2823 /// member_pointer_begin - First member pointer type found; 2824 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2825 2826 /// member_pointer_end - Past the last member pointer type found; 2827 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2828 2829 /// enumeration_begin - First enumeration type found; 2830 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2831 2832 /// enumeration_end - Past the last enumeration type found; 2833 iterator enumeration_end() { return EnumerationTypes.end(); } 2834}; 2835 2836/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2837/// the set of pointer types along with any more-qualified variants of 2838/// that type. For example, if @p Ty is "int const *", this routine 2839/// will add "int const *", "int const volatile *", "int const 2840/// restrict *", and "int const volatile restrict *" to the set of 2841/// pointer types. Returns true if the add of @p Ty itself succeeded, 2842/// false otherwise. 2843/// 2844/// FIXME: what to do about extended qualifiers? 2845bool 2846BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2847 2848 // Insert this type. 2849 if (!PointerTypes.insert(Ty)) 2850 return false; 2851 2852 const PointerType *PointerTy = Ty->getAs<PointerType>(); 2853 assert(PointerTy && "type was not a pointer type!"); 2854 2855 QualType PointeeTy = PointerTy->getPointeeType(); 2856 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2857 2858 // Iterate through all strict supersets of BaseCVR. 2859 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2860 if ((CVR | BaseCVR) != CVR) continue; 2861 2862 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2863 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 2864 } 2865 2866 return true; 2867} 2868 2869/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2870/// to the set of pointer types along with any more-qualified variants of 2871/// that type. For example, if @p Ty is "int const *", this routine 2872/// will add "int const *", "int const volatile *", "int const 2873/// restrict *", and "int const volatile restrict *" to the set of 2874/// pointer types. Returns true if the add of @p Ty itself succeeded, 2875/// false otherwise. 2876/// 2877/// FIXME: what to do about extended qualifiers? 2878bool 2879BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2880 QualType Ty) { 2881 // Insert this type. 2882 if (!MemberPointerTypes.insert(Ty)) 2883 return false; 2884 2885 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 2886 assert(PointerTy && "type was not a member pointer type!"); 2887 2888 QualType PointeeTy = PointerTy->getPointeeType(); 2889 const Type *ClassTy = PointerTy->getClass(); 2890 2891 // Iterate through all strict supersets of the pointee type's CVR 2892 // qualifiers. 2893 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2894 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2895 if ((CVR | BaseCVR) != CVR) continue; 2896 2897 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2898 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 2899 } 2900 2901 return true; 2902} 2903 2904/// AddTypesConvertedFrom - Add each of the types to which the type @p 2905/// Ty can be implicit converted to the given set of @p Types. We're 2906/// primarily interested in pointer types and enumeration types. We also 2907/// take member pointer types, for the conditional operator. 2908/// AllowUserConversions is true if we should look at the conversion 2909/// functions of a class type, and AllowExplicitConversions if we 2910/// should also include the explicit conversion functions of a class 2911/// type. 2912void 2913BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2914 bool AllowUserConversions, 2915 bool AllowExplicitConversions) { 2916 // Only deal with canonical types. 2917 Ty = Context.getCanonicalType(Ty); 2918 2919 // Look through reference types; they aren't part of the type of an 2920 // expression for the purposes of conversions. 2921 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 2922 Ty = RefTy->getPointeeType(); 2923 2924 // We don't care about qualifiers on the type. 2925 Ty = Ty.getUnqualifiedType(); 2926 2927 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2928 QualType PointeeTy = PointerTy->getPointeeType(); 2929 2930 // Insert our type, and its more-qualified variants, into the set 2931 // of types. 2932 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2933 return; 2934 2935 // Add 'cv void*' to our set of types. 2936 if (!Ty->isVoidType()) { 2937 QualType QualVoid 2938 = Context.getCVRQualifiedType(Context.VoidTy, 2939 PointeeTy.getCVRQualifiers()); 2940 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2941 } 2942 2943 // If this is a pointer to a class type, add pointers to its bases 2944 // (with the same level of cv-qualification as the original 2945 // derived class, of course). 2946 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 2947 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2948 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2949 Base != ClassDecl->bases_end(); ++Base) { 2950 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2951 BaseTy = Context.getCVRQualifiedType(BaseTy.getUnqualifiedType(), 2952 PointeeTy.getCVRQualifiers()); 2953 2954 // Add the pointer type, recursively, so that we get all of 2955 // the indirect base classes, too. 2956 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2957 } 2958 } 2959 } else if (Ty->isMemberPointerType()) { 2960 // Member pointers are far easier, since the pointee can't be converted. 2961 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2962 return; 2963 } else if (Ty->isEnumeralType()) { 2964 EnumerationTypes.insert(Ty); 2965 } else if (AllowUserConversions) { 2966 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 2967 if (SemaRef.RequireCompleteType(SourceLocation(), Ty, 0)) { 2968 // No conversion functions in incomplete types. 2969 return; 2970 } 2971 2972 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2973 // FIXME: Visit conversion functions in the base classes, too. 2974 OverloadedFunctionDecl *Conversions 2975 = ClassDecl->getConversionFunctions(); 2976 for (OverloadedFunctionDecl::function_iterator Func 2977 = Conversions->function_begin(); 2978 Func != Conversions->function_end(); ++Func) { 2979 CXXConversionDecl *Conv; 2980 FunctionTemplateDecl *ConvTemplate; 2981 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 2982 2983 // Skip conversion function templates; they don't tell us anything 2984 // about which builtin types we can convert to. 2985 if (ConvTemplate) 2986 continue; 2987 2988 if (AllowExplicitConversions || !Conv->isExplicit()) 2989 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2990 } 2991 } 2992 } 2993} 2994 2995/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 2996/// the volatile- and non-volatile-qualified assignment operators for the 2997/// given type to the candidate set. 2998static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 2999 QualType T, 3000 Expr **Args, 3001 unsigned NumArgs, 3002 OverloadCandidateSet &CandidateSet) { 3003 QualType ParamTypes[2]; 3004 3005 // T& operator=(T&, T) 3006 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3007 ParamTypes[1] = T; 3008 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3009 /*IsAssignmentOperator=*/true); 3010 3011 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3012 // volatile T& operator=(volatile T&, T) 3013 ParamTypes[0] 3014 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3015 ParamTypes[1] = T; 3016 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3017 /*IsAssignmentOperator=*/true); 3018 } 3019} 3020 3021/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3022/// operator overloads to the candidate set (C++ [over.built]), based 3023/// on the operator @p Op and the arguments given. For example, if the 3024/// operator is a binary '+', this routine might add "int 3025/// operator+(int, int)" to cover integer addition. 3026void 3027Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3028 Expr **Args, unsigned NumArgs, 3029 OverloadCandidateSet& CandidateSet) { 3030 // The set of "promoted arithmetic types", which are the arithmetic 3031 // types are that preserved by promotion (C++ [over.built]p2). Note 3032 // that the first few of these types are the promoted integral 3033 // types; these types need to be first. 3034 // FIXME: What about complex? 3035 const unsigned FirstIntegralType = 0; 3036 const unsigned LastIntegralType = 13; 3037 const unsigned FirstPromotedIntegralType = 7, 3038 LastPromotedIntegralType = 13; 3039 const unsigned FirstPromotedArithmeticType = 7, 3040 LastPromotedArithmeticType = 16; 3041 const unsigned NumArithmeticTypes = 16; 3042 QualType ArithmeticTypes[NumArithmeticTypes] = { 3043 Context.BoolTy, Context.CharTy, Context.WCharTy, 3044// FIXME: Context.Char16Ty, Context.Char32Ty, 3045 Context.SignedCharTy, Context.ShortTy, 3046 Context.UnsignedCharTy, Context.UnsignedShortTy, 3047 Context.IntTy, Context.LongTy, Context.LongLongTy, 3048 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3049 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3050 }; 3051 3052 // Find all of the types that the arguments can convert to, but only 3053 // if the operator we're looking at has built-in operator candidates 3054 // that make use of these types. 3055 BuiltinCandidateTypeSet CandidateTypes(*this); 3056 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3057 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3058 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3059 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3060 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3061 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3062 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3063 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3064 true, 3065 (Op == OO_Exclaim || 3066 Op == OO_AmpAmp || 3067 Op == OO_PipePipe)); 3068 } 3069 3070 bool isComparison = false; 3071 switch (Op) { 3072 case OO_None: 3073 case NUM_OVERLOADED_OPERATORS: 3074 assert(false && "Expected an overloaded operator"); 3075 break; 3076 3077 case OO_Star: // '*' is either unary or binary 3078 if (NumArgs == 1) 3079 goto UnaryStar; 3080 else 3081 goto BinaryStar; 3082 break; 3083 3084 case OO_Plus: // '+' is either unary or binary 3085 if (NumArgs == 1) 3086 goto UnaryPlus; 3087 else 3088 goto BinaryPlus; 3089 break; 3090 3091 case OO_Minus: // '-' is either unary or binary 3092 if (NumArgs == 1) 3093 goto UnaryMinus; 3094 else 3095 goto BinaryMinus; 3096 break; 3097 3098 case OO_Amp: // '&' is either unary or binary 3099 if (NumArgs == 1) 3100 goto UnaryAmp; 3101 else 3102 goto BinaryAmp; 3103 3104 case OO_PlusPlus: 3105 case OO_MinusMinus: 3106 // C++ [over.built]p3: 3107 // 3108 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3109 // is either volatile or empty, there exist candidate operator 3110 // functions of the form 3111 // 3112 // VQ T& operator++(VQ T&); 3113 // T operator++(VQ T&, int); 3114 // 3115 // C++ [over.built]p4: 3116 // 3117 // For every pair (T, VQ), where T is an arithmetic type other 3118 // than bool, and VQ is either volatile or empty, there exist 3119 // candidate operator functions of the form 3120 // 3121 // VQ T& operator--(VQ T&); 3122 // T operator--(VQ T&, int); 3123 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3124 Arith < NumArithmeticTypes; ++Arith) { 3125 QualType ArithTy = ArithmeticTypes[Arith]; 3126 QualType ParamTypes[2] 3127 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3128 3129 // Non-volatile version. 3130 if (NumArgs == 1) 3131 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3132 else 3133 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3134 3135 // Volatile version 3136 ParamTypes[0] 3137 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3138 if (NumArgs == 1) 3139 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3140 else 3141 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3142 } 3143 3144 // C++ [over.built]p5: 3145 // 3146 // For every pair (T, VQ), where T is a cv-qualified or 3147 // cv-unqualified object type, and VQ is either volatile or 3148 // empty, there exist candidate operator functions of the form 3149 // 3150 // T*VQ& operator++(T*VQ&); 3151 // T*VQ& operator--(T*VQ&); 3152 // T* operator++(T*VQ&, int); 3153 // T* operator--(T*VQ&, int); 3154 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3155 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3156 // Skip pointer types that aren't pointers to object types. 3157 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3158 continue; 3159 3160 QualType ParamTypes[2] = { 3161 Context.getLValueReferenceType(*Ptr), Context.IntTy 3162 }; 3163 3164 // Without volatile 3165 if (NumArgs == 1) 3166 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3167 else 3168 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3169 3170 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3171 // With volatile 3172 ParamTypes[0] 3173 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3174 if (NumArgs == 1) 3175 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3176 else 3177 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3178 } 3179 } 3180 break; 3181 3182 UnaryStar: 3183 // C++ [over.built]p6: 3184 // For every cv-qualified or cv-unqualified object type T, there 3185 // exist candidate operator functions of the form 3186 // 3187 // T& operator*(T*); 3188 // 3189 // C++ [over.built]p7: 3190 // For every function type T, there exist candidate operator 3191 // functions of the form 3192 // T& operator*(T*); 3193 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3194 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3195 QualType ParamTy = *Ptr; 3196 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3197 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3198 &ParamTy, Args, 1, CandidateSet); 3199 } 3200 break; 3201 3202 UnaryPlus: 3203 // C++ [over.built]p8: 3204 // For every type T, there exist candidate operator functions of 3205 // the form 3206 // 3207 // T* operator+(T*); 3208 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3209 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3210 QualType ParamTy = *Ptr; 3211 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3212 } 3213 3214 // Fall through 3215 3216 UnaryMinus: 3217 // C++ [over.built]p9: 3218 // For every promoted arithmetic type T, there exist candidate 3219 // operator functions of the form 3220 // 3221 // T operator+(T); 3222 // T operator-(T); 3223 for (unsigned Arith = FirstPromotedArithmeticType; 3224 Arith < LastPromotedArithmeticType; ++Arith) { 3225 QualType ArithTy = ArithmeticTypes[Arith]; 3226 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3227 } 3228 break; 3229 3230 case OO_Tilde: 3231 // C++ [over.built]p10: 3232 // For every promoted integral type T, there exist candidate 3233 // operator functions of the form 3234 // 3235 // T operator~(T); 3236 for (unsigned Int = FirstPromotedIntegralType; 3237 Int < LastPromotedIntegralType; ++Int) { 3238 QualType IntTy = ArithmeticTypes[Int]; 3239 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3240 } 3241 break; 3242 3243 case OO_New: 3244 case OO_Delete: 3245 case OO_Array_New: 3246 case OO_Array_Delete: 3247 case OO_Call: 3248 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3249 break; 3250 3251 case OO_Comma: 3252 UnaryAmp: 3253 case OO_Arrow: 3254 // C++ [over.match.oper]p3: 3255 // -- For the operator ',', the unary operator '&', or the 3256 // operator '->', the built-in candidates set is empty. 3257 break; 3258 3259 case OO_EqualEqual: 3260 case OO_ExclaimEqual: 3261 // C++ [over.match.oper]p16: 3262 // For every pointer to member type T, there exist candidate operator 3263 // functions of the form 3264 // 3265 // bool operator==(T,T); 3266 // bool operator!=(T,T); 3267 for (BuiltinCandidateTypeSet::iterator 3268 MemPtr = CandidateTypes.member_pointer_begin(), 3269 MemPtrEnd = CandidateTypes.member_pointer_end(); 3270 MemPtr != MemPtrEnd; 3271 ++MemPtr) { 3272 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3273 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3274 } 3275 3276 // Fall through 3277 3278 case OO_Less: 3279 case OO_Greater: 3280 case OO_LessEqual: 3281 case OO_GreaterEqual: 3282 // C++ [over.built]p15: 3283 // 3284 // For every pointer or enumeration type T, there exist 3285 // candidate operator functions of the form 3286 // 3287 // bool operator<(T, T); 3288 // bool operator>(T, T); 3289 // bool operator<=(T, T); 3290 // bool operator>=(T, T); 3291 // bool operator==(T, T); 3292 // bool operator!=(T, T); 3293 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3294 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3295 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3296 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3297 } 3298 for (BuiltinCandidateTypeSet::iterator Enum 3299 = CandidateTypes.enumeration_begin(); 3300 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3301 QualType ParamTypes[2] = { *Enum, *Enum }; 3302 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3303 } 3304 3305 // Fall through. 3306 isComparison = true; 3307 3308 BinaryPlus: 3309 BinaryMinus: 3310 if (!isComparison) { 3311 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3312 3313 // C++ [over.built]p13: 3314 // 3315 // For every cv-qualified or cv-unqualified object type T 3316 // there exist candidate operator functions of the form 3317 // 3318 // T* operator+(T*, ptrdiff_t); 3319 // T& operator[](T*, ptrdiff_t); [BELOW] 3320 // T* operator-(T*, ptrdiff_t); 3321 // T* operator+(ptrdiff_t, T*); 3322 // T& operator[](ptrdiff_t, T*); [BELOW] 3323 // 3324 // C++ [over.built]p14: 3325 // 3326 // For every T, where T is a pointer to object type, there 3327 // exist candidate operator functions of the form 3328 // 3329 // ptrdiff_t operator-(T, T); 3330 for (BuiltinCandidateTypeSet::iterator Ptr 3331 = CandidateTypes.pointer_begin(); 3332 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3333 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3334 3335 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3336 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3337 3338 if (Op == OO_Plus) { 3339 // T* operator+(ptrdiff_t, T*); 3340 ParamTypes[0] = ParamTypes[1]; 3341 ParamTypes[1] = *Ptr; 3342 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3343 } else { 3344 // ptrdiff_t operator-(T, T); 3345 ParamTypes[1] = *Ptr; 3346 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3347 Args, 2, CandidateSet); 3348 } 3349 } 3350 } 3351 // Fall through 3352 3353 case OO_Slash: 3354 BinaryStar: 3355 Conditional: 3356 // C++ [over.built]p12: 3357 // 3358 // For every pair of promoted arithmetic types L and R, there 3359 // exist candidate operator functions of the form 3360 // 3361 // LR operator*(L, R); 3362 // LR operator/(L, R); 3363 // LR operator+(L, R); 3364 // LR operator-(L, R); 3365 // bool operator<(L, R); 3366 // bool operator>(L, R); 3367 // bool operator<=(L, R); 3368 // bool operator>=(L, R); 3369 // bool operator==(L, R); 3370 // bool operator!=(L, R); 3371 // 3372 // where LR is the result of the usual arithmetic conversions 3373 // between types L and R. 3374 // 3375 // C++ [over.built]p24: 3376 // 3377 // For every pair of promoted arithmetic types L and R, there exist 3378 // candidate operator functions of the form 3379 // 3380 // LR operator?(bool, L, R); 3381 // 3382 // where LR is the result of the usual arithmetic conversions 3383 // between types L and R. 3384 // Our candidates ignore the first parameter. 3385 for (unsigned Left = FirstPromotedArithmeticType; 3386 Left < LastPromotedArithmeticType; ++Left) { 3387 for (unsigned Right = FirstPromotedArithmeticType; 3388 Right < LastPromotedArithmeticType; ++Right) { 3389 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3390 QualType Result 3391 = isComparison 3392 ? Context.BoolTy 3393 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3394 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3395 } 3396 } 3397 break; 3398 3399 case OO_Percent: 3400 BinaryAmp: 3401 case OO_Caret: 3402 case OO_Pipe: 3403 case OO_LessLess: 3404 case OO_GreaterGreater: 3405 // C++ [over.built]p17: 3406 // 3407 // For every pair of promoted integral types L and R, there 3408 // exist candidate operator functions of the form 3409 // 3410 // LR operator%(L, R); 3411 // LR operator&(L, R); 3412 // LR operator^(L, R); 3413 // LR operator|(L, R); 3414 // L operator<<(L, R); 3415 // L operator>>(L, R); 3416 // 3417 // where LR is the result of the usual arithmetic conversions 3418 // between types L and R. 3419 for (unsigned Left = FirstPromotedIntegralType; 3420 Left < LastPromotedIntegralType; ++Left) { 3421 for (unsigned Right = FirstPromotedIntegralType; 3422 Right < LastPromotedIntegralType; ++Right) { 3423 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3424 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3425 ? LandR[0] 3426 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3427 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3428 } 3429 } 3430 break; 3431 3432 case OO_Equal: 3433 // C++ [over.built]p20: 3434 // 3435 // For every pair (T, VQ), where T is an enumeration or 3436 // pointer to member type and VQ is either volatile or 3437 // empty, there exist candidate operator functions of the form 3438 // 3439 // VQ T& operator=(VQ T&, T); 3440 for (BuiltinCandidateTypeSet::iterator 3441 Enum = CandidateTypes.enumeration_begin(), 3442 EnumEnd = CandidateTypes.enumeration_end(); 3443 Enum != EnumEnd; ++Enum) 3444 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3445 CandidateSet); 3446 for (BuiltinCandidateTypeSet::iterator 3447 MemPtr = CandidateTypes.member_pointer_begin(), 3448 MemPtrEnd = CandidateTypes.member_pointer_end(); 3449 MemPtr != MemPtrEnd; ++MemPtr) 3450 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3451 CandidateSet); 3452 // Fall through. 3453 3454 case OO_PlusEqual: 3455 case OO_MinusEqual: 3456 // C++ [over.built]p19: 3457 // 3458 // For every pair (T, VQ), where T is any type and VQ is either 3459 // volatile or empty, there exist candidate operator functions 3460 // of the form 3461 // 3462 // T*VQ& operator=(T*VQ&, T*); 3463 // 3464 // C++ [over.built]p21: 3465 // 3466 // For every pair (T, VQ), where T is a cv-qualified or 3467 // cv-unqualified object type and VQ is either volatile or 3468 // empty, there exist candidate operator functions of the form 3469 // 3470 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3471 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3472 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3473 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3474 QualType ParamTypes[2]; 3475 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3476 3477 // non-volatile version 3478 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3479 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3480 /*IsAssigmentOperator=*/Op == OO_Equal); 3481 3482 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3483 // volatile version 3484 ParamTypes[0] 3485 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3486 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3487 /*IsAssigmentOperator=*/Op == OO_Equal); 3488 } 3489 } 3490 // Fall through. 3491 3492 case OO_StarEqual: 3493 case OO_SlashEqual: 3494 // C++ [over.built]p18: 3495 // 3496 // For every triple (L, VQ, R), where L is an arithmetic type, 3497 // VQ is either volatile or empty, and R is a promoted 3498 // arithmetic type, there exist candidate operator functions of 3499 // the form 3500 // 3501 // VQ L& operator=(VQ L&, R); 3502 // VQ L& operator*=(VQ L&, R); 3503 // VQ L& operator/=(VQ L&, R); 3504 // VQ L& operator+=(VQ L&, R); 3505 // VQ L& operator-=(VQ L&, R); 3506 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3507 for (unsigned Right = FirstPromotedArithmeticType; 3508 Right < LastPromotedArithmeticType; ++Right) { 3509 QualType ParamTypes[2]; 3510 ParamTypes[1] = ArithmeticTypes[Right]; 3511 3512 // Add this built-in operator as a candidate (VQ is empty). 3513 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3514 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3515 /*IsAssigmentOperator=*/Op == OO_Equal); 3516 3517 // Add this built-in operator as a candidate (VQ is 'volatile'). 3518 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3519 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3520 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3521 /*IsAssigmentOperator=*/Op == OO_Equal); 3522 } 3523 } 3524 break; 3525 3526 case OO_PercentEqual: 3527 case OO_LessLessEqual: 3528 case OO_GreaterGreaterEqual: 3529 case OO_AmpEqual: 3530 case OO_CaretEqual: 3531 case OO_PipeEqual: 3532 // C++ [over.built]p22: 3533 // 3534 // For every triple (L, VQ, R), where L is an integral type, VQ 3535 // is either volatile or empty, and R is a promoted integral 3536 // type, there exist candidate operator functions of the form 3537 // 3538 // VQ L& operator%=(VQ L&, R); 3539 // VQ L& operator<<=(VQ L&, R); 3540 // VQ L& operator>>=(VQ L&, R); 3541 // VQ L& operator&=(VQ L&, R); 3542 // VQ L& operator^=(VQ L&, R); 3543 // VQ L& operator|=(VQ L&, R); 3544 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3545 for (unsigned Right = FirstPromotedIntegralType; 3546 Right < LastPromotedIntegralType; ++Right) { 3547 QualType ParamTypes[2]; 3548 ParamTypes[1] = ArithmeticTypes[Right]; 3549 3550 // Add this built-in operator as a candidate (VQ is empty). 3551 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3552 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3553 3554 // Add this built-in operator as a candidate (VQ is 'volatile'). 3555 ParamTypes[0] = ArithmeticTypes[Left]; 3556 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3557 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3558 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3559 } 3560 } 3561 break; 3562 3563 case OO_Exclaim: { 3564 // C++ [over.operator]p23: 3565 // 3566 // There also exist candidate operator functions of the form 3567 // 3568 // bool operator!(bool); 3569 // bool operator&&(bool, bool); [BELOW] 3570 // bool operator||(bool, bool); [BELOW] 3571 QualType ParamTy = Context.BoolTy; 3572 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3573 /*IsAssignmentOperator=*/false, 3574 /*NumContextualBoolArguments=*/1); 3575 break; 3576 } 3577 3578 case OO_AmpAmp: 3579 case OO_PipePipe: { 3580 // C++ [over.operator]p23: 3581 // 3582 // There also exist candidate operator functions of the form 3583 // 3584 // bool operator!(bool); [ABOVE] 3585 // bool operator&&(bool, bool); 3586 // bool operator||(bool, bool); 3587 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3588 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3589 /*IsAssignmentOperator=*/false, 3590 /*NumContextualBoolArguments=*/2); 3591 break; 3592 } 3593 3594 case OO_Subscript: 3595 // C++ [over.built]p13: 3596 // 3597 // For every cv-qualified or cv-unqualified object type T there 3598 // exist candidate operator functions of the form 3599 // 3600 // T* operator+(T*, ptrdiff_t); [ABOVE] 3601 // T& operator[](T*, ptrdiff_t); 3602 // T* operator-(T*, ptrdiff_t); [ABOVE] 3603 // T* operator+(ptrdiff_t, T*); [ABOVE] 3604 // T& operator[](ptrdiff_t, T*); 3605 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3606 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3607 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3608 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3609 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3610 3611 // T& operator[](T*, ptrdiff_t) 3612 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3613 3614 // T& operator[](ptrdiff_t, T*); 3615 ParamTypes[0] = ParamTypes[1]; 3616 ParamTypes[1] = *Ptr; 3617 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3618 } 3619 break; 3620 3621 case OO_ArrowStar: 3622 // FIXME: No support for pointer-to-members yet. 3623 break; 3624 3625 case OO_Conditional: 3626 // Note that we don't consider the first argument, since it has been 3627 // contextually converted to bool long ago. The candidates below are 3628 // therefore added as binary. 3629 // 3630 // C++ [over.built]p24: 3631 // For every type T, where T is a pointer or pointer-to-member type, 3632 // there exist candidate operator functions of the form 3633 // 3634 // T operator?(bool, T, T); 3635 // 3636 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3637 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3638 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3639 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3640 } 3641 for (BuiltinCandidateTypeSet::iterator Ptr = 3642 CandidateTypes.member_pointer_begin(), 3643 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3644 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3645 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3646 } 3647 goto Conditional; 3648 } 3649} 3650 3651/// \brief Add function candidates found via argument-dependent lookup 3652/// to the set of overloading candidates. 3653/// 3654/// This routine performs argument-dependent name lookup based on the 3655/// given function name (which may also be an operator name) and adds 3656/// all of the overload candidates found by ADL to the overload 3657/// candidate set (C++ [basic.lookup.argdep]). 3658void 3659Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3660 Expr **Args, unsigned NumArgs, 3661 bool HasExplicitTemplateArgs, 3662 const TemplateArgument *ExplicitTemplateArgs, 3663 unsigned NumExplicitTemplateArgs, 3664 OverloadCandidateSet& CandidateSet, 3665 bool PartialOverloading) { 3666 FunctionSet Functions; 3667 3668 // FIXME: Should we be trafficking in canonical function decls throughout? 3669 3670 // Record all of the function candidates that we've already 3671 // added to the overload set, so that we don't add those same 3672 // candidates a second time. 3673 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3674 CandEnd = CandidateSet.end(); 3675 Cand != CandEnd; ++Cand) 3676 if (Cand->Function) { 3677 Functions.insert(Cand->Function); 3678 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3679 Functions.insert(FunTmpl); 3680 } 3681 3682 // FIXME: Pass in the explicit template arguments? 3683 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3684 3685 // Erase all of the candidates we already knew about. 3686 // FIXME: This is suboptimal. Is there a better way? 3687 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3688 CandEnd = CandidateSet.end(); 3689 Cand != CandEnd; ++Cand) 3690 if (Cand->Function) { 3691 Functions.erase(Cand->Function); 3692 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3693 Functions.erase(FunTmpl); 3694 } 3695 3696 // For each of the ADL candidates we found, add it to the overload 3697 // set. 3698 for (FunctionSet::iterator Func = Functions.begin(), 3699 FuncEnd = Functions.end(); 3700 Func != FuncEnd; ++Func) { 3701 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3702 if (HasExplicitTemplateArgs) 3703 continue; 3704 3705 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3706 false, false, PartialOverloading); 3707 } else 3708 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3709 HasExplicitTemplateArgs, 3710 ExplicitTemplateArgs, 3711 NumExplicitTemplateArgs, 3712 Args, NumArgs, CandidateSet); 3713 } 3714} 3715 3716/// isBetterOverloadCandidate - Determines whether the first overload 3717/// candidate is a better candidate than the second (C++ 13.3.3p1). 3718bool 3719Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3720 const OverloadCandidate& Cand2) { 3721 // Define viable functions to be better candidates than non-viable 3722 // functions. 3723 if (!Cand2.Viable) 3724 return Cand1.Viable; 3725 else if (!Cand1.Viable) 3726 return false; 3727 3728 // C++ [over.match.best]p1: 3729 // 3730 // -- if F is a static member function, ICS1(F) is defined such 3731 // that ICS1(F) is neither better nor worse than ICS1(G) for 3732 // any function G, and, symmetrically, ICS1(G) is neither 3733 // better nor worse than ICS1(F). 3734 unsigned StartArg = 0; 3735 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3736 StartArg = 1; 3737 3738 // C++ [over.match.best]p1: 3739 // A viable function F1 is defined to be a better function than another 3740 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3741 // conversion sequence than ICSi(F2), and then... 3742 unsigned NumArgs = Cand1.Conversions.size(); 3743 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3744 bool HasBetterConversion = false; 3745 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3746 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3747 Cand2.Conversions[ArgIdx])) { 3748 case ImplicitConversionSequence::Better: 3749 // Cand1 has a better conversion sequence. 3750 HasBetterConversion = true; 3751 break; 3752 3753 case ImplicitConversionSequence::Worse: 3754 // Cand1 can't be better than Cand2. 3755 return false; 3756 3757 case ImplicitConversionSequence::Indistinguishable: 3758 // Do nothing. 3759 break; 3760 } 3761 } 3762 3763 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3764 // ICSj(F2), or, if not that, 3765 if (HasBetterConversion) 3766 return true; 3767 3768 // - F1 is a non-template function and F2 is a function template 3769 // specialization, or, if not that, 3770 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3771 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3772 return true; 3773 3774 // -- F1 and F2 are function template specializations, and the function 3775 // template for F1 is more specialized than the template for F2 3776 // according to the partial ordering rules described in 14.5.5.2, or, 3777 // if not that, 3778 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3779 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3780 if (FunctionTemplateDecl *BetterTemplate 3781 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 3782 Cand2.Function->getPrimaryTemplate(), 3783 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 3784 : TPOC_Call)) 3785 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 3786 3787 // -- the context is an initialization by user-defined conversion 3788 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3789 // from the return type of F1 to the destination type (i.e., 3790 // the type of the entity being initialized) is a better 3791 // conversion sequence than the standard conversion sequence 3792 // from the return type of F2 to the destination type. 3793 if (Cand1.Function && Cand2.Function && 3794 isa<CXXConversionDecl>(Cand1.Function) && 3795 isa<CXXConversionDecl>(Cand2.Function)) { 3796 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3797 Cand2.FinalConversion)) { 3798 case ImplicitConversionSequence::Better: 3799 // Cand1 has a better conversion sequence. 3800 return true; 3801 3802 case ImplicitConversionSequence::Worse: 3803 // Cand1 can't be better than Cand2. 3804 return false; 3805 3806 case ImplicitConversionSequence::Indistinguishable: 3807 // Do nothing 3808 break; 3809 } 3810 } 3811 3812 return false; 3813} 3814 3815/// \brief Computes the best viable function (C++ 13.3.3) 3816/// within an overload candidate set. 3817/// 3818/// \param CandidateSet the set of candidate functions. 3819/// 3820/// \param Loc the location of the function name (or operator symbol) for 3821/// which overload resolution occurs. 3822/// 3823/// \param Best f overload resolution was successful or found a deleted 3824/// function, Best points to the candidate function found. 3825/// 3826/// \returns The result of overload resolution. 3827Sema::OverloadingResult 3828Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3829 SourceLocation Loc, 3830 OverloadCandidateSet::iterator& Best) { 3831 // Find the best viable function. 3832 Best = CandidateSet.end(); 3833 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3834 Cand != CandidateSet.end(); ++Cand) { 3835 if (Cand->Viable) { 3836 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3837 Best = Cand; 3838 } 3839 } 3840 3841 // If we didn't find any viable functions, abort. 3842 if (Best == CandidateSet.end()) 3843 return OR_No_Viable_Function; 3844 3845 // Make sure that this function is better than every other viable 3846 // function. If not, we have an ambiguity. 3847 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3848 Cand != CandidateSet.end(); ++Cand) { 3849 if (Cand->Viable && 3850 Cand != Best && 3851 !isBetterOverloadCandidate(*Best, *Cand)) { 3852 Best = CandidateSet.end(); 3853 return OR_Ambiguous; 3854 } 3855 } 3856 3857 // Best is the best viable function. 3858 if (Best->Function && 3859 (Best->Function->isDeleted() || 3860 Best->Function->getAttr<UnavailableAttr>())) 3861 return OR_Deleted; 3862 3863 // C++ [basic.def.odr]p2: 3864 // An overloaded function is used if it is selected by overload resolution 3865 // when referred to from a potentially-evaluated expression. [Note: this 3866 // covers calls to named functions (5.2.2), operator overloading 3867 // (clause 13), user-defined conversions (12.3.2), allocation function for 3868 // placement new (5.3.4), as well as non-default initialization (8.5). 3869 if (Best->Function) 3870 MarkDeclarationReferenced(Loc, Best->Function); 3871 return OR_Success; 3872} 3873 3874/// PrintOverloadCandidates - When overload resolution fails, prints 3875/// diagnostic messages containing the candidates in the candidate 3876/// set. If OnlyViable is true, only viable candidates will be printed. 3877void 3878Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3879 bool OnlyViable) { 3880 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3881 LastCand = CandidateSet.end(); 3882 for (; Cand != LastCand; ++Cand) { 3883 if (Cand->Viable || !OnlyViable) { 3884 if (Cand->Function) { 3885 if (Cand->Function->isDeleted() || 3886 Cand->Function->getAttr<UnavailableAttr>()) { 3887 // Deleted or "unavailable" function. 3888 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3889 << Cand->Function->isDeleted(); 3890 } else if (FunctionTemplateDecl *FunTmpl 3891 = Cand->Function->getPrimaryTemplate()) { 3892 // Function template specialization 3893 // FIXME: Give a better reason! 3894 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 3895 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 3896 *Cand->Function->getTemplateSpecializationArgs()); 3897 } else { 3898 // Normal function 3899 bool errReported = false; 3900 if (!Cand->Viable && Cand->Conversions.size() > 0) { 3901 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 3902 const ImplicitConversionSequence &Conversion = 3903 Cand->Conversions[i]; 3904 if ((Conversion.ConversionKind != 3905 ImplicitConversionSequence::BadConversion) || 3906 Conversion.ConversionFunctionSet.size() == 0) 3907 continue; 3908 Diag(Cand->Function->getLocation(), 3909 diag::err_ovl_candidate_not_viable) << (i+1); 3910 errReported = true; 3911 for (int j = Conversion.ConversionFunctionSet.size()-1; 3912 j >= 0; j--) { 3913 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 3914 Diag(Func->getLocation(), diag::err_ovl_candidate); 3915 } 3916 } 3917 } 3918 if (!errReported) 3919 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3920 } 3921 } else if (Cand->IsSurrogate) { 3922 // Desugar the type of the surrogate down to a function type, 3923 // retaining as many typedefs as possible while still showing 3924 // the function type (and, therefore, its parameter types). 3925 QualType FnType = Cand->Surrogate->getConversionType(); 3926 bool isLValueReference = false; 3927 bool isRValueReference = false; 3928 bool isPointer = false; 3929 if (const LValueReferenceType *FnTypeRef = 3930 FnType->getAs<LValueReferenceType>()) { 3931 FnType = FnTypeRef->getPointeeType(); 3932 isLValueReference = true; 3933 } else if (const RValueReferenceType *FnTypeRef = 3934 FnType->getAs<RValueReferenceType>()) { 3935 FnType = FnTypeRef->getPointeeType(); 3936 isRValueReference = true; 3937 } 3938 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 3939 FnType = FnTypePtr->getPointeeType(); 3940 isPointer = true; 3941 } 3942 // Desugar down to a function type. 3943 FnType = QualType(FnType->getAs<FunctionType>(), 0); 3944 // Reconstruct the pointer/reference as appropriate. 3945 if (isPointer) FnType = Context.getPointerType(FnType); 3946 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3947 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3948 3949 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3950 << FnType; 3951 } else { 3952 // FIXME: We need to get the identifier in here 3953 // FIXME: Do we want the error message to point at the operator? 3954 // (built-ins won't have a location) 3955 QualType FnType 3956 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3957 Cand->BuiltinTypes.ParamTypes, 3958 Cand->Conversions.size(), 3959 false, 0); 3960 3961 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3962 } 3963 } 3964 } 3965} 3966 3967/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3968/// an overloaded function (C++ [over.over]), where @p From is an 3969/// expression with overloaded function type and @p ToType is the type 3970/// we're trying to resolve to. For example: 3971/// 3972/// @code 3973/// int f(double); 3974/// int f(int); 3975/// 3976/// int (*pfd)(double) = f; // selects f(double) 3977/// @endcode 3978/// 3979/// This routine returns the resulting FunctionDecl if it could be 3980/// resolved, and NULL otherwise. When @p Complain is true, this 3981/// routine will emit diagnostics if there is an error. 3982FunctionDecl * 3983Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3984 bool Complain) { 3985 QualType FunctionType = ToType; 3986 bool IsMember = false; 3987 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 3988 FunctionType = ToTypePtr->getPointeeType(); 3989 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 3990 FunctionType = ToTypeRef->getPointeeType(); 3991 else if (const MemberPointerType *MemTypePtr = 3992 ToType->getAs<MemberPointerType>()) { 3993 FunctionType = MemTypePtr->getPointeeType(); 3994 IsMember = true; 3995 } 3996 3997 // We only look at pointers or references to functions. 3998 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 3999 if (!FunctionType->isFunctionType()) 4000 return 0; 4001 4002 // Find the actual overloaded function declaration. 4003 OverloadedFunctionDecl *Ovl = 0; 4004 4005 // C++ [over.over]p1: 4006 // [...] [Note: any redundant set of parentheses surrounding the 4007 // overloaded function name is ignored (5.1). ] 4008 Expr *OvlExpr = From->IgnoreParens(); 4009 4010 // C++ [over.over]p1: 4011 // [...] The overloaded function name can be preceded by the & 4012 // operator. 4013 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4014 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4015 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4016 } 4017 4018 // Try to dig out the overloaded function. 4019 FunctionTemplateDecl *FunctionTemplate = 0; 4020 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4021 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4022 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4023 } 4024 4025 // If there's no overloaded function declaration or function template, 4026 // we're done. 4027 if (!Ovl && !FunctionTemplate) 4028 return 0; 4029 4030 OverloadIterator Fun; 4031 if (Ovl) 4032 Fun = Ovl; 4033 else 4034 Fun = FunctionTemplate; 4035 4036 // Look through all of the overloaded functions, searching for one 4037 // whose type matches exactly. 4038 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4039 4040 bool FoundNonTemplateFunction = false; 4041 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4042 // C++ [over.over]p3: 4043 // Non-member functions and static member functions match 4044 // targets of type "pointer-to-function" or "reference-to-function." 4045 // Nonstatic member functions match targets of 4046 // type "pointer-to-member-function." 4047 // Note that according to DR 247, the containing class does not matter. 4048 4049 if (FunctionTemplateDecl *FunctionTemplate 4050 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4051 if (CXXMethodDecl *Method 4052 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4053 // Skip non-static function templates when converting to pointer, and 4054 // static when converting to member pointer. 4055 if (Method->isStatic() == IsMember) 4056 continue; 4057 } else if (IsMember) 4058 continue; 4059 4060 // C++ [over.over]p2: 4061 // If the name is a function template, template argument deduction is 4062 // done (14.8.2.2), and if the argument deduction succeeds, the 4063 // resulting template argument list is used to generate a single 4064 // function template specialization, which is added to the set of 4065 // overloaded functions considered. 4066 // FIXME: We don't really want to build the specialization here, do we? 4067 FunctionDecl *Specialization = 0; 4068 TemplateDeductionInfo Info(Context); 4069 if (TemplateDeductionResult Result 4070 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 4071 /*FIXME:*/0, /*FIXME:*/0, 4072 FunctionType, Specialization, Info)) { 4073 // FIXME: make a note of the failed deduction for diagnostics. 4074 (void)Result; 4075 } else { 4076 // FIXME: If the match isn't exact, shouldn't we just drop this as 4077 // a candidate? Find a testcase before changing the code. 4078 assert(FunctionType 4079 == Context.getCanonicalType(Specialization->getType())); 4080 Matches.insert( 4081 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4082 } 4083 } 4084 4085 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4086 // Skip non-static functions when converting to pointer, and static 4087 // when converting to member pointer. 4088 if (Method->isStatic() == IsMember) 4089 continue; 4090 } else if (IsMember) 4091 continue; 4092 4093 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4094 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4095 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4096 FoundNonTemplateFunction = true; 4097 } 4098 } 4099 } 4100 4101 // If there were 0 or 1 matches, we're done. 4102 if (Matches.empty()) 4103 return 0; 4104 else if (Matches.size() == 1) 4105 return *Matches.begin(); 4106 4107 // C++ [over.over]p4: 4108 // If more than one function is selected, [...] 4109 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4110 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4111 if (FoundNonTemplateFunction) { 4112 // [...] any function template specializations in the set are 4113 // eliminated if the set also contains a non-template function, [...] 4114 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4115 if ((*M)->getPrimaryTemplate() == 0) 4116 RemainingMatches.push_back(*M); 4117 } else { 4118 // [...] and any given function template specialization F1 is 4119 // eliminated if the set contains a second function template 4120 // specialization whose function template is more specialized 4121 // than the function template of F1 according to the partial 4122 // ordering rules of 14.5.5.2. 4123 4124 // The algorithm specified above is quadratic. We instead use a 4125 // two-pass algorithm (similar to the one used to identify the 4126 // best viable function in an overload set) that identifies the 4127 // best function template (if it exists). 4128 MatchIter Best = Matches.begin(); 4129 MatchIter M = Best, MEnd = Matches.end(); 4130 // Find the most specialized function. 4131 for (++M; M != MEnd; ++M) 4132 if (getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4133 (*Best)->getPrimaryTemplate(), 4134 TPOC_Other) 4135 == (*M)->getPrimaryTemplate()) 4136 Best = M; 4137 4138 // Determine whether this function template is more specialized 4139 // that all of the others. 4140 bool Ambiguous = false; 4141 for (M = Matches.begin(); M != MEnd; ++M) { 4142 if (M != Best && 4143 getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4144 (*Best)->getPrimaryTemplate(), 4145 TPOC_Other) 4146 != (*Best)->getPrimaryTemplate()) { 4147 Ambiguous = true; 4148 break; 4149 } 4150 } 4151 4152 // If one function template was more specialized than all of the 4153 // others, return it. 4154 if (!Ambiguous) 4155 return *Best; 4156 4157 // We could not find a most-specialized function template, which 4158 // is equivalent to having a set of function templates with more 4159 // than one such template. So, we place all of the function 4160 // templates into the set of remaining matches and produce a 4161 // diagnostic below. FIXME: we could perform the quadratic 4162 // algorithm here, pruning the result set to limit the number of 4163 // candidates output later. 4164 RemainingMatches.append(Matches.begin(), Matches.end()); 4165 } 4166 4167 // [...] After such eliminations, if any, there shall remain exactly one 4168 // selected function. 4169 if (RemainingMatches.size() == 1) 4170 return RemainingMatches.front(); 4171 4172 // FIXME: We should probably return the same thing that BestViableFunction 4173 // returns (even if we issue the diagnostics here). 4174 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4175 << RemainingMatches[0]->getDeclName(); 4176 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4177 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4178 return 0; 4179} 4180 4181/// \brief Add a single candidate to the overload set. 4182static void AddOverloadedCallCandidate(Sema &S, 4183 AnyFunctionDecl Callee, 4184 bool &ArgumentDependentLookup, 4185 bool HasExplicitTemplateArgs, 4186 const TemplateArgument *ExplicitTemplateArgs, 4187 unsigned NumExplicitTemplateArgs, 4188 Expr **Args, unsigned NumArgs, 4189 OverloadCandidateSet &CandidateSet, 4190 bool PartialOverloading) { 4191 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4192 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4193 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4194 PartialOverloading); 4195 4196 if (Func->getDeclContext()->isRecord() || 4197 Func->getDeclContext()->isFunctionOrMethod()) 4198 ArgumentDependentLookup = false; 4199 return; 4200 } 4201 4202 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4203 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4204 ExplicitTemplateArgs, 4205 NumExplicitTemplateArgs, 4206 Args, NumArgs, CandidateSet); 4207 4208 if (FuncTemplate->getDeclContext()->isRecord()) 4209 ArgumentDependentLookup = false; 4210} 4211 4212/// \brief Add the overload candidates named by callee and/or found by argument 4213/// dependent lookup to the given overload set. 4214void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4215 DeclarationName &UnqualifiedName, 4216 bool &ArgumentDependentLookup, 4217 bool HasExplicitTemplateArgs, 4218 const TemplateArgument *ExplicitTemplateArgs, 4219 unsigned NumExplicitTemplateArgs, 4220 Expr **Args, unsigned NumArgs, 4221 OverloadCandidateSet &CandidateSet, 4222 bool PartialOverloading) { 4223 // Add the functions denoted by Callee to the set of candidate 4224 // functions. While we're doing so, track whether argument-dependent 4225 // lookup still applies, per: 4226 // 4227 // C++0x [basic.lookup.argdep]p3: 4228 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4229 // and let Y be the lookup set produced by argument dependent 4230 // lookup (defined as follows). If X contains 4231 // 4232 // -- a declaration of a class member, or 4233 // 4234 // -- a block-scope function declaration that is not a 4235 // using-declaration (FIXME: check for using declaration), or 4236 // 4237 // -- a declaration that is neither a function or a function 4238 // template 4239 // 4240 // then Y is empty. 4241 if (!Callee) { 4242 // Nothing to do. 4243 } else if (OverloadedFunctionDecl *Ovl 4244 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4245 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4246 FuncEnd = Ovl->function_end(); 4247 Func != FuncEnd; ++Func) 4248 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4249 HasExplicitTemplateArgs, 4250 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4251 Args, NumArgs, CandidateSet, 4252 PartialOverloading); 4253 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4254 AddOverloadedCallCandidate(*this, 4255 AnyFunctionDecl::getFromNamedDecl(Callee), 4256 ArgumentDependentLookup, 4257 HasExplicitTemplateArgs, 4258 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4259 Args, NumArgs, CandidateSet, 4260 PartialOverloading); 4261 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4262 // checking dynamically. 4263 4264 if (Callee) 4265 UnqualifiedName = Callee->getDeclName(); 4266 4267 if (ArgumentDependentLookup) 4268 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4269 HasExplicitTemplateArgs, 4270 ExplicitTemplateArgs, 4271 NumExplicitTemplateArgs, 4272 CandidateSet, 4273 PartialOverloading); 4274} 4275 4276/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4277/// (which eventually refers to the declaration Func) and the call 4278/// arguments Args/NumArgs, attempt to resolve the function call down 4279/// to a specific function. If overload resolution succeeds, returns 4280/// the function declaration produced by overload 4281/// resolution. Otherwise, emits diagnostics, deletes all of the 4282/// arguments and Fn, and returns NULL. 4283FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4284 DeclarationName UnqualifiedName, 4285 bool HasExplicitTemplateArgs, 4286 const TemplateArgument *ExplicitTemplateArgs, 4287 unsigned NumExplicitTemplateArgs, 4288 SourceLocation LParenLoc, 4289 Expr **Args, unsigned NumArgs, 4290 SourceLocation *CommaLocs, 4291 SourceLocation RParenLoc, 4292 bool &ArgumentDependentLookup) { 4293 OverloadCandidateSet CandidateSet; 4294 4295 // Add the functions denoted by Callee to the set of candidate 4296 // functions. 4297 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4298 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4299 NumExplicitTemplateArgs, Args, NumArgs, 4300 CandidateSet); 4301 OverloadCandidateSet::iterator Best; 4302 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4303 case OR_Success: 4304 return Best->Function; 4305 4306 case OR_No_Viable_Function: 4307 Diag(Fn->getSourceRange().getBegin(), 4308 diag::err_ovl_no_viable_function_in_call) 4309 << UnqualifiedName << Fn->getSourceRange(); 4310 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4311 break; 4312 4313 case OR_Ambiguous: 4314 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4315 << UnqualifiedName << Fn->getSourceRange(); 4316 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4317 break; 4318 4319 case OR_Deleted: 4320 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4321 << Best->Function->isDeleted() 4322 << UnqualifiedName 4323 << Fn->getSourceRange(); 4324 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4325 break; 4326 } 4327 4328 // Overload resolution failed. Destroy all of the subexpressions and 4329 // return NULL. 4330 Fn->Destroy(Context); 4331 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4332 Args[Arg]->Destroy(Context); 4333 return 0; 4334} 4335 4336/// \brief Create a unary operation that may resolve to an overloaded 4337/// operator. 4338/// 4339/// \param OpLoc The location of the operator itself (e.g., '*'). 4340/// 4341/// \param OpcIn The UnaryOperator::Opcode that describes this 4342/// operator. 4343/// 4344/// \param Functions The set of non-member functions that will be 4345/// considered by overload resolution. The caller needs to build this 4346/// set based on the context using, e.g., 4347/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4348/// set should not contain any member functions; those will be added 4349/// by CreateOverloadedUnaryOp(). 4350/// 4351/// \param input The input argument. 4352Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4353 unsigned OpcIn, 4354 FunctionSet &Functions, 4355 ExprArg input) { 4356 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4357 Expr *Input = (Expr *)input.get(); 4358 4359 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4360 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4361 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4362 4363 Expr *Args[2] = { Input, 0 }; 4364 unsigned NumArgs = 1; 4365 4366 // For post-increment and post-decrement, add the implicit '0' as 4367 // the second argument, so that we know this is a post-increment or 4368 // post-decrement. 4369 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4370 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4371 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4372 SourceLocation()); 4373 NumArgs = 2; 4374 } 4375 4376 if (Input->isTypeDependent()) { 4377 OverloadedFunctionDecl *Overloads 4378 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4379 for (FunctionSet::iterator Func = Functions.begin(), 4380 FuncEnd = Functions.end(); 4381 Func != FuncEnd; ++Func) 4382 Overloads->addOverload(*Func); 4383 4384 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4385 OpLoc, false, false); 4386 4387 input.release(); 4388 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4389 &Args[0], NumArgs, 4390 Context.DependentTy, 4391 OpLoc)); 4392 } 4393 4394 // Build an empty overload set. 4395 OverloadCandidateSet CandidateSet; 4396 4397 // Add the candidates from the given function set. 4398 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4399 4400 // Add operator candidates that are member functions. 4401 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4402 4403 // Add builtin operator candidates. 4404 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4405 4406 // Perform overload resolution. 4407 OverloadCandidateSet::iterator Best; 4408 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4409 case OR_Success: { 4410 // We found a built-in operator or an overloaded operator. 4411 FunctionDecl *FnDecl = Best->Function; 4412 4413 if (FnDecl) { 4414 // We matched an overloaded operator. Build a call to that 4415 // operator. 4416 4417 // Convert the arguments. 4418 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4419 if (PerformObjectArgumentInitialization(Input, Method)) 4420 return ExprError(); 4421 } else { 4422 // Convert the arguments. 4423 if (PerformCopyInitialization(Input, 4424 FnDecl->getParamDecl(0)->getType(), 4425 "passing")) 4426 return ExprError(); 4427 } 4428 4429 // Determine the result type 4430 QualType ResultTy 4431 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4432 ResultTy = ResultTy.getNonReferenceType(); 4433 4434 // Build the actual expression node. 4435 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4436 SourceLocation()); 4437 UsualUnaryConversions(FnExpr); 4438 4439 input.release(); 4440 4441 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4442 &Input, 1, ResultTy, OpLoc); 4443 return MaybeBindToTemporary(CE); 4444 } else { 4445 // We matched a built-in operator. Convert the arguments, then 4446 // break out so that we will build the appropriate built-in 4447 // operator node. 4448 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4449 Best->Conversions[0], "passing")) 4450 return ExprError(); 4451 4452 break; 4453 } 4454 } 4455 4456 case OR_No_Viable_Function: 4457 // No viable function; fall through to handling this as a 4458 // built-in operator, which will produce an error message for us. 4459 break; 4460 4461 case OR_Ambiguous: 4462 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4463 << UnaryOperator::getOpcodeStr(Opc) 4464 << Input->getSourceRange(); 4465 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4466 return ExprError(); 4467 4468 case OR_Deleted: 4469 Diag(OpLoc, diag::err_ovl_deleted_oper) 4470 << Best->Function->isDeleted() 4471 << UnaryOperator::getOpcodeStr(Opc) 4472 << Input->getSourceRange(); 4473 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4474 return ExprError(); 4475 } 4476 4477 // Either we found no viable overloaded operator or we matched a 4478 // built-in operator. In either case, fall through to trying to 4479 // build a built-in operation. 4480 input.release(); 4481 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4482} 4483 4484/// \brief Create a binary operation that may resolve to an overloaded 4485/// operator. 4486/// 4487/// \param OpLoc The location of the operator itself (e.g., '+'). 4488/// 4489/// \param OpcIn The BinaryOperator::Opcode that describes this 4490/// operator. 4491/// 4492/// \param Functions The set of non-member functions that will be 4493/// considered by overload resolution. The caller needs to build this 4494/// set based on the context using, e.g., 4495/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4496/// set should not contain any member functions; those will be added 4497/// by CreateOverloadedBinOp(). 4498/// 4499/// \param LHS Left-hand argument. 4500/// \param RHS Right-hand argument. 4501Sema::OwningExprResult 4502Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4503 unsigned OpcIn, 4504 FunctionSet &Functions, 4505 Expr *LHS, Expr *RHS) { 4506 Expr *Args[2] = { LHS, RHS }; 4507 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4508 4509 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4510 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4511 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4512 4513 // If either side is type-dependent, create an appropriate dependent 4514 // expression. 4515 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4516 // .* cannot be overloaded. 4517 if (Opc == BinaryOperator::PtrMemD) 4518 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4519 Context.DependentTy, OpLoc)); 4520 4521 OverloadedFunctionDecl *Overloads 4522 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4523 for (FunctionSet::iterator Func = Functions.begin(), 4524 FuncEnd = Functions.end(); 4525 Func != FuncEnd; ++Func) 4526 Overloads->addOverload(*Func); 4527 4528 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4529 OpLoc, false, false); 4530 4531 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4532 Args, 2, 4533 Context.DependentTy, 4534 OpLoc)); 4535 } 4536 4537 // If this is the .* operator, which is not overloadable, just 4538 // create a built-in binary operator. 4539 if (Opc == BinaryOperator::PtrMemD) 4540 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4541 4542 // If this is one of the assignment operators, we only perform 4543 // overload resolution if the left-hand side is a class or 4544 // enumeration type (C++ [expr.ass]p3). 4545 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4546 !Args[0]->getType()->isOverloadableType()) 4547 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4548 4549 // Build an empty overload set. 4550 OverloadCandidateSet CandidateSet; 4551 4552 // Add the candidates from the given function set. 4553 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4554 4555 // Add operator candidates that are member functions. 4556 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4557 4558 // Add builtin operator candidates. 4559 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4560 4561 // Perform overload resolution. 4562 OverloadCandidateSet::iterator Best; 4563 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4564 case OR_Success: { 4565 // We found a built-in operator or an overloaded operator. 4566 FunctionDecl *FnDecl = Best->Function; 4567 4568 if (FnDecl) { 4569 // We matched an overloaded operator. Build a call to that 4570 // operator. 4571 4572 // Convert the arguments. 4573 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4574 if (PerformObjectArgumentInitialization(Args[0], Method) || 4575 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4576 "passing")) 4577 return ExprError(); 4578 } else { 4579 // Convert the arguments. 4580 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4581 "passing") || 4582 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4583 "passing")) 4584 return ExprError(); 4585 } 4586 4587 // Determine the result type 4588 QualType ResultTy 4589 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4590 ResultTy = ResultTy.getNonReferenceType(); 4591 4592 // Build the actual expression node. 4593 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4594 OpLoc); 4595 UsualUnaryConversions(FnExpr); 4596 4597 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4598 Args, 2, ResultTy, OpLoc); 4599 return MaybeBindToTemporary(CE); 4600 } else { 4601 // We matched a built-in operator. Convert the arguments, then 4602 // break out so that we will build the appropriate built-in 4603 // operator node. 4604 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4605 Best->Conversions[0], "passing") || 4606 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4607 Best->Conversions[1], "passing")) 4608 return ExprError(); 4609 4610 break; 4611 } 4612 } 4613 4614 case OR_No_Viable_Function: 4615 // For class as left operand for assignment or compound assigment operator 4616 // do not fall through to handling in built-in, but report that no overloaded 4617 // assignment operator found 4618 if (Args[0]->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4619 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4620 << BinaryOperator::getOpcodeStr(Opc) 4621 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4622 return ExprError(); 4623 } 4624 // No viable function; fall through to handling this as a 4625 // built-in operator, which will produce an error message for us. 4626 break; 4627 4628 case OR_Ambiguous: 4629 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4630 << BinaryOperator::getOpcodeStr(Opc) 4631 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4632 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4633 return ExprError(); 4634 4635 case OR_Deleted: 4636 Diag(OpLoc, diag::err_ovl_deleted_oper) 4637 << Best->Function->isDeleted() 4638 << BinaryOperator::getOpcodeStr(Opc) 4639 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4640 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4641 return ExprError(); 4642 } 4643 4644 // Either we found no viable overloaded operator or we matched a 4645 // built-in operator. In either case, try to build a built-in 4646 // operation. 4647 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4648} 4649 4650/// BuildCallToMemberFunction - Build a call to a member 4651/// function. MemExpr is the expression that refers to the member 4652/// function (and includes the object parameter), Args/NumArgs are the 4653/// arguments to the function call (not including the object 4654/// parameter). The caller needs to validate that the member 4655/// expression refers to a member function or an overloaded member 4656/// function. 4657Sema::ExprResult 4658Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4659 SourceLocation LParenLoc, Expr **Args, 4660 unsigned NumArgs, SourceLocation *CommaLocs, 4661 SourceLocation RParenLoc) { 4662 // Dig out the member expression. This holds both the object 4663 // argument and the member function we're referring to. 4664 MemberExpr *MemExpr = 0; 4665 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4666 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4667 else 4668 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4669 assert(MemExpr && "Building member call without member expression"); 4670 4671 // Extract the object argument. 4672 Expr *ObjectArg = MemExpr->getBase(); 4673 4674 CXXMethodDecl *Method = 0; 4675 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 4676 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 4677 // Add overload candidates 4678 OverloadCandidateSet CandidateSet; 4679 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 4680 4681 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 4682 Func != FuncEnd; ++Func) { 4683 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) 4684 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4685 /*SuppressUserConversions=*/false); 4686 else 4687 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 4688 MemExpr->hasExplicitTemplateArgumentList(), 4689 MemExpr->getTemplateArgs(), 4690 MemExpr->getNumTemplateArgs(), 4691 ObjectArg, Args, NumArgs, 4692 CandidateSet, 4693 /*SuppressUsedConversions=*/false); 4694 } 4695 4696 OverloadCandidateSet::iterator Best; 4697 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4698 case OR_Success: 4699 Method = cast<CXXMethodDecl>(Best->Function); 4700 break; 4701 4702 case OR_No_Viable_Function: 4703 Diag(MemExpr->getSourceRange().getBegin(), 4704 diag::err_ovl_no_viable_member_function_in_call) 4705 << DeclName << MemExprE->getSourceRange(); 4706 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4707 // FIXME: Leaking incoming expressions! 4708 return true; 4709 4710 case OR_Ambiguous: 4711 Diag(MemExpr->getSourceRange().getBegin(), 4712 diag::err_ovl_ambiguous_member_call) 4713 << DeclName << MemExprE->getSourceRange(); 4714 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4715 // FIXME: Leaking incoming expressions! 4716 return true; 4717 4718 case OR_Deleted: 4719 Diag(MemExpr->getSourceRange().getBegin(), 4720 diag::err_ovl_deleted_member_call) 4721 << Best->Function->isDeleted() 4722 << DeclName << MemExprE->getSourceRange(); 4723 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4724 // FIXME: Leaking incoming expressions! 4725 return true; 4726 } 4727 4728 FixOverloadedFunctionReference(MemExpr, Method); 4729 } else { 4730 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4731 } 4732 4733 assert(Method && "Member call to something that isn't a method?"); 4734 ExprOwningPtr<CXXMemberCallExpr> 4735 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4736 NumArgs, 4737 Method->getResultType().getNonReferenceType(), 4738 RParenLoc)); 4739 4740 // Convert the object argument (for a non-static member function call). 4741 if (!Method->isStatic() && 4742 PerformObjectArgumentInitialization(ObjectArg, Method)) 4743 return true; 4744 MemExpr->setBase(ObjectArg); 4745 4746 // Convert the rest of the arguments 4747 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4748 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4749 RParenLoc)) 4750 return true; 4751 4752 if (CheckFunctionCall(Method, TheCall.get())) 4753 return true; 4754 4755 return MaybeBindToTemporary(TheCall.release()).release(); 4756} 4757 4758/// BuildCallToObjectOfClassType - Build a call to an object of class 4759/// type (C++ [over.call.object]), which can end up invoking an 4760/// overloaded function call operator (@c operator()) or performing a 4761/// user-defined conversion on the object argument. 4762Sema::ExprResult 4763Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4764 SourceLocation LParenLoc, 4765 Expr **Args, unsigned NumArgs, 4766 SourceLocation *CommaLocs, 4767 SourceLocation RParenLoc) { 4768 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4769 const RecordType *Record = Object->getType()->getAs<RecordType>(); 4770 4771 // C++ [over.call.object]p1: 4772 // If the primary-expression E in the function call syntax 4773 // evaluates to a class object of type "cv T", then the set of 4774 // candidate functions includes at least the function call 4775 // operators of T. The function call operators of T are obtained by 4776 // ordinary lookup of the name operator() in the context of 4777 // (E).operator(). 4778 OverloadCandidateSet CandidateSet; 4779 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4780 DeclContext::lookup_const_iterator Oper, OperEnd; 4781 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4782 Oper != OperEnd; ++Oper) 4783 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4784 CandidateSet, /*SuppressUserConversions=*/false); 4785 4786 // C++ [over.call.object]p2: 4787 // In addition, for each conversion function declared in T of the 4788 // form 4789 // 4790 // operator conversion-type-id () cv-qualifier; 4791 // 4792 // where cv-qualifier is the same cv-qualification as, or a 4793 // greater cv-qualification than, cv, and where conversion-type-id 4794 // denotes the type "pointer to function of (P1,...,Pn) returning 4795 // R", or the type "reference to pointer to function of 4796 // (P1,...,Pn) returning R", or the type "reference to function 4797 // of (P1,...,Pn) returning R", a surrogate call function [...] 4798 // is also considered as a candidate function. Similarly, 4799 // surrogate call functions are added to the set of candidate 4800 // functions for each conversion function declared in an 4801 // accessible base class provided the function is not hidden 4802 // within T by another intervening declaration. 4803 4804 if (!RequireCompleteType(SourceLocation(), Object->getType(), 0)) { 4805 // FIXME: Look in base classes for more conversion operators! 4806 OverloadedFunctionDecl *Conversions 4807 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4808 for (OverloadedFunctionDecl::function_iterator 4809 Func = Conversions->function_begin(), 4810 FuncEnd = Conversions->function_end(); 4811 Func != FuncEnd; ++Func) { 4812 CXXConversionDecl *Conv; 4813 FunctionTemplateDecl *ConvTemplate; 4814 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 4815 4816 // Skip over templated conversion functions; they aren't 4817 // surrogates. 4818 if (ConvTemplate) 4819 continue; 4820 4821 // Strip the reference type (if any) and then the pointer type (if 4822 // any) to get down to what might be a function type. 4823 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4824 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4825 ConvType = ConvPtrType->getPointeeType(); 4826 4827 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 4828 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4829 } 4830 } 4831 4832 // Perform overload resolution. 4833 OverloadCandidateSet::iterator Best; 4834 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4835 case OR_Success: 4836 // Overload resolution succeeded; we'll build the appropriate call 4837 // below. 4838 break; 4839 4840 case OR_No_Viable_Function: 4841 Diag(Object->getSourceRange().getBegin(), 4842 diag::err_ovl_no_viable_object_call) 4843 << Object->getType() << Object->getSourceRange(); 4844 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4845 break; 4846 4847 case OR_Ambiguous: 4848 Diag(Object->getSourceRange().getBegin(), 4849 diag::err_ovl_ambiguous_object_call) 4850 << Object->getType() << Object->getSourceRange(); 4851 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4852 break; 4853 4854 case OR_Deleted: 4855 Diag(Object->getSourceRange().getBegin(), 4856 diag::err_ovl_deleted_object_call) 4857 << Best->Function->isDeleted() 4858 << Object->getType() << Object->getSourceRange(); 4859 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4860 break; 4861 } 4862 4863 if (Best == CandidateSet.end()) { 4864 // We had an error; delete all of the subexpressions and return 4865 // the error. 4866 Object->Destroy(Context); 4867 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4868 Args[ArgIdx]->Destroy(Context); 4869 return true; 4870 } 4871 4872 if (Best->Function == 0) { 4873 // Since there is no function declaration, this is one of the 4874 // surrogate candidates. Dig out the conversion function. 4875 CXXConversionDecl *Conv 4876 = cast<CXXConversionDecl>( 4877 Best->Conversions[0].UserDefined.ConversionFunction); 4878 4879 // We selected one of the surrogate functions that converts the 4880 // object parameter to a function pointer. Perform the conversion 4881 // on the object argument, then let ActOnCallExpr finish the job. 4882 // FIXME: Represent the user-defined conversion in the AST! 4883 ImpCastExprToType(Object, 4884 Conv->getConversionType().getNonReferenceType(), 4885 CastExpr::CK_Unknown, 4886 Conv->getConversionType()->isLValueReferenceType()); 4887 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4888 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4889 CommaLocs, RParenLoc).release(); 4890 } 4891 4892 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4893 // that calls this method, using Object for the implicit object 4894 // parameter and passing along the remaining arguments. 4895 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4896 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 4897 4898 unsigned NumArgsInProto = Proto->getNumArgs(); 4899 unsigned NumArgsToCheck = NumArgs; 4900 4901 // Build the full argument list for the method call (the 4902 // implicit object parameter is placed at the beginning of the 4903 // list). 4904 Expr **MethodArgs; 4905 if (NumArgs < NumArgsInProto) { 4906 NumArgsToCheck = NumArgsInProto; 4907 MethodArgs = new Expr*[NumArgsInProto + 1]; 4908 } else { 4909 MethodArgs = new Expr*[NumArgs + 1]; 4910 } 4911 MethodArgs[0] = Object; 4912 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4913 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4914 4915 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4916 SourceLocation()); 4917 UsualUnaryConversions(NewFn); 4918 4919 // Once we've built TheCall, all of the expressions are properly 4920 // owned. 4921 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4922 ExprOwningPtr<CXXOperatorCallExpr> 4923 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4924 MethodArgs, NumArgs + 1, 4925 ResultTy, RParenLoc)); 4926 delete [] MethodArgs; 4927 4928 // We may have default arguments. If so, we need to allocate more 4929 // slots in the call for them. 4930 if (NumArgs < NumArgsInProto) 4931 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4932 else if (NumArgs > NumArgsInProto) 4933 NumArgsToCheck = NumArgsInProto; 4934 4935 bool IsError = false; 4936 4937 // Initialize the implicit object parameter. 4938 IsError |= PerformObjectArgumentInitialization(Object, Method); 4939 TheCall->setArg(0, Object); 4940 4941 4942 // Check the argument types. 4943 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4944 Expr *Arg; 4945 if (i < NumArgs) { 4946 Arg = Args[i]; 4947 4948 // Pass the argument. 4949 QualType ProtoArgType = Proto->getArgType(i); 4950 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4951 } else { 4952 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 4953 } 4954 4955 TheCall->setArg(i + 1, Arg); 4956 } 4957 4958 // If this is a variadic call, handle args passed through "...". 4959 if (Proto->isVariadic()) { 4960 // Promote the arguments (C99 6.5.2.2p7). 4961 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4962 Expr *Arg = Args[i]; 4963 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4964 TheCall->setArg(i + 1, Arg); 4965 } 4966 } 4967 4968 if (IsError) return true; 4969 4970 if (CheckFunctionCall(Method, TheCall.get())) 4971 return true; 4972 4973 return MaybeBindToTemporary(TheCall.release()).release(); 4974} 4975 4976/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4977/// (if one exists), where @c Base is an expression of class type and 4978/// @c Member is the name of the member we're trying to find. 4979Sema::OwningExprResult 4980Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 4981 Expr *Base = static_cast<Expr *>(BaseIn.get()); 4982 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4983 4984 // C++ [over.ref]p1: 4985 // 4986 // [...] An expression x->m is interpreted as (x.operator->())->m 4987 // for a class object x of type T if T::operator->() exists and if 4988 // the operator is selected as the best match function by the 4989 // overload resolution mechanism (13.3). 4990 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4991 OverloadCandidateSet CandidateSet; 4992 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 4993 4994 LookupResult R = LookupQualifiedName(BaseRecord->getDecl(), OpName, 4995 LookupOrdinaryName); 4996 4997 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 4998 Oper != OperEnd; ++Oper) 4999 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 5000 /*SuppressUserConversions=*/false); 5001 5002 // Perform overload resolution. 5003 OverloadCandidateSet::iterator Best; 5004 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5005 case OR_Success: 5006 // Overload resolution succeeded; we'll build the call below. 5007 break; 5008 5009 case OR_No_Viable_Function: 5010 if (CandidateSet.empty()) 5011 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5012 << Base->getType() << Base->getSourceRange(); 5013 else 5014 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5015 << "operator->" << Base->getSourceRange(); 5016 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5017 return ExprError(); 5018 5019 case OR_Ambiguous: 5020 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5021 << "->" << Base->getSourceRange(); 5022 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5023 return ExprError(); 5024 5025 case OR_Deleted: 5026 Diag(OpLoc, diag::err_ovl_deleted_oper) 5027 << Best->Function->isDeleted() 5028 << "->" << Base->getSourceRange(); 5029 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5030 return ExprError(); 5031 } 5032 5033 // Convert the object parameter. 5034 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5035 if (PerformObjectArgumentInitialization(Base, Method)) 5036 return ExprError(); 5037 5038 // No concerns about early exits now. 5039 BaseIn.release(); 5040 5041 // Build the operator call. 5042 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5043 SourceLocation()); 5044 UsualUnaryConversions(FnExpr); 5045 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 5046 Method->getResultType().getNonReferenceType(), 5047 OpLoc); 5048 return Owned(Base); 5049} 5050 5051/// FixOverloadedFunctionReference - E is an expression that refers to 5052/// a C++ overloaded function (possibly with some parentheses and 5053/// perhaps a '&' around it). We have resolved the overloaded function 5054/// to the function declaration Fn, so patch up the expression E to 5055/// refer (possibly indirectly) to Fn. 5056void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5057 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5058 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5059 E->setType(PE->getSubExpr()->getType()); 5060 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5061 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5062 "Can only take the address of an overloaded function"); 5063 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5064 if (Method->isStatic()) { 5065 // Do nothing: static member functions aren't any different 5066 // from non-member functions. 5067 } else if (QualifiedDeclRefExpr *DRE 5068 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 5069 // We have taken the address of a pointer to member 5070 // function. Perform the computation here so that we get the 5071 // appropriate pointer to member type. 5072 DRE->setDecl(Fn); 5073 DRE->setType(Fn->getType()); 5074 QualType ClassType 5075 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5076 E->setType(Context.getMemberPointerType(Fn->getType(), 5077 ClassType.getTypePtr())); 5078 return; 5079 } 5080 } 5081 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5082 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 5083 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5084 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5085 isa<FunctionTemplateDecl>(DR->getDecl())) && 5086 "Expected overloaded function or function template"); 5087 DR->setDecl(Fn); 5088 E->setType(Fn->getType()); 5089 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5090 MemExpr->setMemberDecl(Fn); 5091 E->setType(Fn->getType()); 5092 } else { 5093 assert(false && "Invalid reference to overloaded function"); 5094 } 5095} 5096 5097} // end namespace clang 5098