SemaOverload.cpp revision f42e4a6e089e8413247400fe58ad299193371f9c
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 "llvm/ADT/SmallPtrSet.h" 23#include "llvm/ADT/STLExtras.h" 24#include "llvm/Support/Compiler.h" 25#include <algorithm> 26#include <cstdio> 27 28namespace clang { 29 30/// GetConversionCategory - Retrieve the implicit conversion 31/// category corresponding to the given implicit conversion kind. 32ImplicitConversionCategory 33GetConversionCategory(ImplicitConversionKind Kind) { 34 static const ImplicitConversionCategory 35 Category[(int)ICK_Num_Conversion_Kinds] = { 36 ICC_Identity, 37 ICC_Lvalue_Transformation, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Qualification_Adjustment, 41 ICC_Promotion, 42 ICC_Promotion, 43 ICC_Promotion, 44 ICC_Conversion, 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 }; 55 return Category[(int)Kind]; 56} 57 58/// GetConversionRank - Retrieve the implicit conversion rank 59/// corresponding to the given implicit conversion kind. 60ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 61 static const ImplicitConversionRank 62 Rank[(int)ICK_Num_Conversion_Kinds] = { 63 ICR_Exact_Match, 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Promotion, 69 ICR_Promotion, 70 ICR_Promotion, 71 ICR_Conversion, 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 }; 82 return Rank[(int)Kind]; 83} 84 85/// GetImplicitConversionName - Return the name of this kind of 86/// implicit conversion. 87const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 88 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 89 "No conversion", 90 "Lvalue-to-rvalue", 91 "Array-to-pointer", 92 "Function-to-pointer", 93 "Qualification", 94 "Integral promotion", 95 "Floating point promotion", 96 "Complex promotion", 97 "Integral conversion", 98 "Floating conversion", 99 "Complex conversion", 100 "Floating-integral conversion", 101 "Complex-real conversion", 102 "Pointer conversion", 103 "Pointer-to-member conversion", 104 "Boolean conversion", 105 "Compatible-types conversion", 106 "Derived-to-base conversion" 107 }; 108 return Name[Kind]; 109} 110 111/// StandardConversionSequence - Set the standard conversion 112/// sequence to the identity conversion. 113void StandardConversionSequence::setAsIdentityConversion() { 114 First = ICK_Identity; 115 Second = ICK_Identity; 116 Third = ICK_Identity; 117 Deprecated = false; 118 ReferenceBinding = false; 119 DirectBinding = false; 120 RRefBinding = false; 121 CopyConstructor = 0; 122} 123 124/// getRank - Retrieve the rank of this standard conversion sequence 125/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 126/// implicit conversions. 127ImplicitConversionRank StandardConversionSequence::getRank() const { 128 ImplicitConversionRank Rank = ICR_Exact_Match; 129 if (GetConversionRank(First) > Rank) 130 Rank = GetConversionRank(First); 131 if (GetConversionRank(Second) > Rank) 132 Rank = GetConversionRank(Second); 133 if (GetConversionRank(Third) > Rank) 134 Rank = GetConversionRank(Third); 135 return Rank; 136} 137 138/// isPointerConversionToBool - Determines whether this conversion is 139/// a conversion of a pointer or pointer-to-member to bool. This is 140/// used as part of the ranking of standard conversion sequences 141/// (C++ 13.3.3.2p4). 142bool StandardConversionSequence::isPointerConversionToBool() const 143{ 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{ 167 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 168 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 169 170 // Note that FromType has not necessarily been transformed by the 171 // array-to-pointer implicit conversion, so check for its presence 172 // and redo the conversion to get a pointer. 173 if (First == ICK_Array_To_Pointer) 174 FromType = Context.getArrayDecayedType(FromType); 175 176 if (Second == ICK_Pointer_Conversion) 177 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 178 return ToPtrType->getPointeeType()->isVoidType(); 179 180 return false; 181} 182 183/// DebugPrint - Print this standard conversion sequence to standard 184/// error. Useful for debugging overloading issues. 185void StandardConversionSequence::DebugPrint() const { 186 bool PrintedSomething = false; 187 if (First != ICK_Identity) { 188 fprintf(stderr, "%s", GetImplicitConversionName(First)); 189 PrintedSomething = true; 190 } 191 192 if (Second != ICK_Identity) { 193 if (PrintedSomething) { 194 fprintf(stderr, " -> "); 195 } 196 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 197 198 if (CopyConstructor) { 199 fprintf(stderr, " (by copy constructor)"); 200 } else if (DirectBinding) { 201 fprintf(stderr, " (direct reference binding)"); 202 } else if (ReferenceBinding) { 203 fprintf(stderr, " (reference binding)"); 204 } 205 PrintedSomething = true; 206 } 207 208 if (Third != ICK_Identity) { 209 if (PrintedSomething) { 210 fprintf(stderr, " -> "); 211 } 212 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 213 PrintedSomething = true; 214 } 215 216 if (!PrintedSomething) { 217 fprintf(stderr, "No conversions required"); 218 } 219} 220 221/// DebugPrint - Print this user-defined conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void UserDefinedConversionSequence::DebugPrint() const { 224 if (Before.First || Before.Second || Before.Third) { 225 Before.DebugPrint(); 226 fprintf(stderr, " -> "); 227 } 228 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 229 if (After.First || After.Second || After.Third) { 230 fprintf(stderr, " -> "); 231 After.DebugPrint(); 232 } 233} 234 235/// DebugPrint - Print this implicit conversion sequence to standard 236/// error. Useful for debugging overloading issues. 237void ImplicitConversionSequence::DebugPrint() const { 238 switch (ConversionKind) { 239 case StandardConversion: 240 fprintf(stderr, "Standard conversion: "); 241 Standard.DebugPrint(); 242 break; 243 case UserDefinedConversion: 244 fprintf(stderr, "User-defined conversion: "); 245 UserDefined.DebugPrint(); 246 break; 247 case EllipsisConversion: 248 fprintf(stderr, "Ellipsis conversion"); 249 break; 250 case BadConversion: 251 fprintf(stderr, "Bad conversion"); 252 break; 253 } 254 255 fprintf(stderr, "\n"); 256} 257 258// IsOverload - Determine whether the given New declaration is an 259// overload of the Old declaration. This routine returns false if New 260// and Old cannot be overloaded, e.g., if they are functions with the 261// same signature (C++ 1.3.10) or if the Old declaration isn't a 262// function (or overload set). When it does return false and Old is an 263// OverloadedFunctionDecl, MatchedDecl will be set to point to the 264// FunctionDecl that New cannot be overloaded with. 265// 266// Example: Given the following input: 267// 268// void f(int, float); // #1 269// void f(int, int); // #2 270// int f(int, int); // #3 271// 272// When we process #1, there is no previous declaration of "f", 273// so IsOverload will not be used. 274// 275// When we process #2, Old is a FunctionDecl for #1. By comparing the 276// parameter types, we see that #1 and #2 are overloaded (since they 277// have different signatures), so this routine returns false; 278// MatchedDecl is unchanged. 279// 280// When we process #3, Old is an OverloadedFunctionDecl containing #1 281// and #2. We compare the signatures of #3 to #1 (they're overloaded, 282// so we do nothing) and then #3 to #2. Since the signatures of #3 and 283// #2 are identical (return types of functions are not part of the 284// signature), IsOverload returns false and MatchedDecl will be set to 285// point to the FunctionDecl for #2. 286bool 287Sema::IsOverload(FunctionDecl *New, Decl* OldD, 288 OverloadedFunctionDecl::function_iterator& MatchedDecl) 289{ 290 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 291 // Is this new function an overload of every function in the 292 // overload set? 293 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 294 FuncEnd = Ovl->function_end(); 295 for (; Func != FuncEnd; ++Func) { 296 if (!IsOverload(New, *Func, MatchedDecl)) { 297 MatchedDecl = Func; 298 return false; 299 } 300 } 301 302 // This function overloads every function in the overload set. 303 return true; 304 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 305 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 306 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 307 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 308 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 309 310 // C++ [temp.fct]p2: 311 // A function template can be overloaded with other function templates 312 // and with normal (non-template) functions. 313 if ((OldTemplate == 0) != (NewTemplate == 0)) 314 return true; 315 316 // Is the function New an overload of the function Old? 317 QualType OldQType = Context.getCanonicalType(Old->getType()); 318 QualType NewQType = Context.getCanonicalType(New->getType()); 319 320 // Compare the signatures (C++ 1.3.10) of the two functions to 321 // determine whether they are overloads. If we find any mismatch 322 // in the signature, they are overloads. 323 324 // If either of these functions is a K&R-style function (no 325 // prototype), then we consider them to have matching signatures. 326 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 327 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 328 return false; 329 330 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 331 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 332 333 // The signature of a function includes the types of its 334 // parameters (C++ 1.3.10), which includes the presence or absence 335 // of the ellipsis; see C++ DR 357). 336 if (OldQType != NewQType && 337 (OldType->getNumArgs() != NewType->getNumArgs() || 338 OldType->isVariadic() != NewType->isVariadic() || 339 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 340 NewType->arg_type_begin()))) 341 return true; 342 343 // C++ [temp.over.link]p4: 344 // The signature of a function template consists of its function 345 // signature, its return type and its template parameter list. The names 346 // of the template parameters are significant only for establishing the 347 // relationship between the template parameters and the rest of the 348 // signature. 349 // 350 // We check the return type and template parameter lists for function 351 // templates first; the remaining checks follow. 352 if (NewTemplate && 353 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 354 OldTemplate->getTemplateParameters(), 355 false, false, SourceLocation()) || 356 OldType->getResultType() != NewType->getResultType())) 357 return true; 358 359 // If the function is a class member, its signature includes the 360 // cv-qualifiers (if any) on the function itself. 361 // 362 // As part of this, also check whether one of the member functions 363 // is static, in which case they are not overloads (C++ 364 // 13.1p2). While not part of the definition of the signature, 365 // this check is important to determine whether these functions 366 // can be overloaded. 367 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 368 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 369 if (OldMethod && NewMethod && 370 !OldMethod->isStatic() && !NewMethod->isStatic() && 371 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 372 return true; 373 374 // The signatures match; this is not an overload. 375 return false; 376 } else { 377 // (C++ 13p1): 378 // Only function declarations can be overloaded; object and type 379 // declarations cannot be overloaded. 380 return false; 381 } 382} 383 384/// TryImplicitConversion - Attempt to perform an implicit conversion 385/// from the given expression (Expr) to the given type (ToType). This 386/// function returns an implicit conversion sequence that can be used 387/// to perform the initialization. Given 388/// 389/// void f(float f); 390/// void g(int i) { f(i); } 391/// 392/// this routine would produce an implicit conversion sequence to 393/// describe the initialization of f from i, which will be a standard 394/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 395/// 4.1) followed by a floating-integral conversion (C++ 4.9). 396// 397/// Note that this routine only determines how the conversion can be 398/// performed; it does not actually perform the conversion. As such, 399/// it will not produce any diagnostics if no conversion is available, 400/// but will instead return an implicit conversion sequence of kind 401/// "BadConversion". 402/// 403/// If @p SuppressUserConversions, then user-defined conversions are 404/// not permitted. 405/// If @p AllowExplicit, then explicit user-defined conversions are 406/// permitted. 407/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 408/// no matter its actual lvalueness. 409ImplicitConversionSequence 410Sema::TryImplicitConversion(Expr* From, QualType ToType, 411 bool SuppressUserConversions, 412 bool AllowExplicit, bool ForceRValue) 413{ 414 ImplicitConversionSequence ICS; 415 if (IsStandardConversion(From, ToType, ICS.Standard)) 416 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 417 else if (getLangOptions().CPlusPlus && 418 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 419 !SuppressUserConversions, AllowExplicit, 420 ForceRValue)) { 421 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 422 // C++ [over.ics.user]p4: 423 // A conversion of an expression of class type to the same class 424 // type is given Exact Match rank, and a conversion of an 425 // expression of class type to a base class of that type is 426 // given Conversion rank, in spite of the fact that a copy 427 // constructor (i.e., a user-defined conversion function) is 428 // called for those cases. 429 if (CXXConstructorDecl *Constructor 430 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 431 QualType FromCanon 432 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 433 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 434 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 435 // Turn this into a "standard" conversion sequence, so that it 436 // gets ranked with standard conversion sequences. 437 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 438 ICS.Standard.setAsIdentityConversion(); 439 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 440 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 441 ICS.Standard.CopyConstructor = Constructor; 442 if (ToCanon != FromCanon) 443 ICS.Standard.Second = ICK_Derived_To_Base; 444 } 445 } 446 447 // C++ [over.best.ics]p4: 448 // However, when considering the argument of a user-defined 449 // conversion function that is a candidate by 13.3.1.3 when 450 // invoked for the copying of the temporary in the second step 451 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 452 // 13.3.1.6 in all cases, only standard conversion sequences and 453 // ellipsis conversion sequences are allowed. 454 if (SuppressUserConversions && 455 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 456 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 457 } else 458 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 459 460 return ICS; 461} 462 463/// IsStandardConversion - Determines whether there is a standard 464/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 465/// expression From to the type ToType. Standard conversion sequences 466/// only consider non-class types; for conversions that involve class 467/// types, use TryImplicitConversion. If a conversion exists, SCS will 468/// contain the standard conversion sequence required to perform this 469/// conversion and this routine will return true. Otherwise, this 470/// routine will return false and the value of SCS is unspecified. 471bool 472Sema::IsStandardConversion(Expr* From, QualType ToType, 473 StandardConversionSequence &SCS) 474{ 475 QualType FromType = From->getType(); 476 477 // Standard conversions (C++ [conv]) 478 SCS.setAsIdentityConversion(); 479 SCS.Deprecated = false; 480 SCS.IncompatibleObjC = false; 481 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 482 SCS.CopyConstructor = 0; 483 484 // There are no standard conversions for class types in C++, so 485 // abort early. When overloading in C, however, we do permit 486 if (FromType->isRecordType() || ToType->isRecordType()) { 487 if (getLangOptions().CPlusPlus) 488 return false; 489 490 // When we're overloading in C, we allow, as standard conversions, 491 } 492 493 // The first conversion can be an lvalue-to-rvalue conversion, 494 // array-to-pointer conversion, or function-to-pointer conversion 495 // (C++ 4p1). 496 497 // Lvalue-to-rvalue conversion (C++ 4.1): 498 // An lvalue (3.10) of a non-function, non-array type T can be 499 // converted to an rvalue. 500 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 501 if (argIsLvalue == Expr::LV_Valid && 502 !FromType->isFunctionType() && !FromType->isArrayType() && 503 Context.getCanonicalType(FromType) != Context.OverloadTy) { 504 SCS.First = ICK_Lvalue_To_Rvalue; 505 506 // If T is a non-class type, the type of the rvalue is the 507 // cv-unqualified version of T. Otherwise, the type of the rvalue 508 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 509 // just strip the qualifiers because they don't matter. 510 511 // FIXME: Doesn't see through to qualifiers behind a typedef! 512 FromType = FromType.getUnqualifiedType(); 513 } else if (FromType->isArrayType()) { 514 // Array-to-pointer conversion (C++ 4.2) 515 SCS.First = ICK_Array_To_Pointer; 516 517 // An lvalue or rvalue of type "array of N T" or "array of unknown 518 // bound of T" can be converted to an rvalue of type "pointer to 519 // T" (C++ 4.2p1). 520 FromType = Context.getArrayDecayedType(FromType); 521 522 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 523 // This conversion is deprecated. (C++ D.4). 524 SCS.Deprecated = true; 525 526 // For the purpose of ranking in overload resolution 527 // (13.3.3.1.1), this conversion is considered an 528 // array-to-pointer conversion followed by a qualification 529 // conversion (4.4). (C++ 4.2p2) 530 SCS.Second = ICK_Identity; 531 SCS.Third = ICK_Qualification; 532 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 533 return true; 534 } 535 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 536 // Function-to-pointer conversion (C++ 4.3). 537 SCS.First = ICK_Function_To_Pointer; 538 539 // An lvalue of function type T can be converted to an rvalue of 540 // type "pointer to T." The result is a pointer to the 541 // function. (C++ 4.3p1). 542 FromType = Context.getPointerType(FromType); 543 } else if (FunctionDecl *Fn 544 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 545 // Address of overloaded function (C++ [over.over]). 546 SCS.First = ICK_Function_To_Pointer; 547 548 // We were able to resolve the address of the overloaded function, 549 // so we can convert to the type of that function. 550 FromType = Fn->getType(); 551 if (ToType->isLValueReferenceType()) 552 FromType = Context.getLValueReferenceType(FromType); 553 else if (ToType->isRValueReferenceType()) 554 FromType = Context.getRValueReferenceType(FromType); 555 else if (ToType->isMemberPointerType()) { 556 // Resolve address only succeeds if both sides are member pointers, 557 // but it doesn't have to be the same class. See DR 247. 558 // Note that this means that the type of &Derived::fn can be 559 // Ret (Base::*)(Args) if the fn overload actually found is from the 560 // base class, even if it was brought into the derived class via a 561 // using declaration. The standard isn't clear on this issue at all. 562 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 563 FromType = Context.getMemberPointerType(FromType, 564 Context.getTypeDeclType(M->getParent()).getTypePtr()); 565 } else 566 FromType = Context.getPointerType(FromType); 567 } else { 568 // We don't require any conversions for the first step. 569 SCS.First = ICK_Identity; 570 } 571 572 // The second conversion can be an integral promotion, floating 573 // point promotion, integral conversion, floating point conversion, 574 // floating-integral conversion, pointer conversion, 575 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 576 // For overloading in C, this can also be a "compatible-type" 577 // conversion. 578 bool IncompatibleObjC = false; 579 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 580 // The unqualified versions of the types are the same: there's no 581 // conversion to do. 582 SCS.Second = ICK_Identity; 583 } else if (IsIntegralPromotion(From, FromType, ToType)) { 584 // Integral promotion (C++ 4.5). 585 SCS.Second = ICK_Integral_Promotion; 586 FromType = ToType.getUnqualifiedType(); 587 } else if (IsFloatingPointPromotion(FromType, ToType)) { 588 // Floating point promotion (C++ 4.6). 589 SCS.Second = ICK_Floating_Promotion; 590 FromType = ToType.getUnqualifiedType(); 591 } else if (IsComplexPromotion(FromType, ToType)) { 592 // Complex promotion (Clang extension) 593 SCS.Second = ICK_Complex_Promotion; 594 FromType = ToType.getUnqualifiedType(); 595 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 596 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 597 // Integral conversions (C++ 4.7). 598 // FIXME: isIntegralType shouldn't be true for enums in C++. 599 SCS.Second = ICK_Integral_Conversion; 600 FromType = ToType.getUnqualifiedType(); 601 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 602 // Floating point conversions (C++ 4.8). 603 SCS.Second = ICK_Floating_Conversion; 604 FromType = ToType.getUnqualifiedType(); 605 } else if (FromType->isComplexType() && ToType->isComplexType()) { 606 // Complex conversions (C99 6.3.1.6) 607 SCS.Second = ICK_Complex_Conversion; 608 FromType = ToType.getUnqualifiedType(); 609 } else if ((FromType->isFloatingType() && 610 ToType->isIntegralType() && (!ToType->isBooleanType() && 611 !ToType->isEnumeralType())) || 612 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 613 ToType->isFloatingType())) { 614 // Floating-integral conversions (C++ 4.9). 615 // FIXME: isIntegralType shouldn't be true for enums in C++. 616 SCS.Second = ICK_Floating_Integral; 617 FromType = ToType.getUnqualifiedType(); 618 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 619 (ToType->isComplexType() && FromType->isArithmeticType())) { 620 // Complex-real conversions (C99 6.3.1.7) 621 SCS.Second = ICK_Complex_Real; 622 FromType = ToType.getUnqualifiedType(); 623 } else if (IsPointerConversion(From, FromType, ToType, FromType, 624 IncompatibleObjC)) { 625 // Pointer conversions (C++ 4.10). 626 SCS.Second = ICK_Pointer_Conversion; 627 SCS.IncompatibleObjC = IncompatibleObjC; 628 } else if (IsMemberPointerConversion(From, FromType, ToType, FromType)) { 629 // Pointer to member conversions (4.11). 630 SCS.Second = ICK_Pointer_Member; 631 } else if (ToType->isBooleanType() && 632 (FromType->isArithmeticType() || 633 FromType->isEnumeralType() || 634 FromType->isPointerType() || 635 FromType->isBlockPointerType() || 636 FromType->isMemberPointerType() || 637 FromType->isNullPtrType())) { 638 // Boolean conversions (C++ 4.12). 639 SCS.Second = ICK_Boolean_Conversion; 640 FromType = Context.BoolTy; 641 } else if (!getLangOptions().CPlusPlus && 642 Context.typesAreCompatible(ToType, FromType)) { 643 // Compatible conversions (Clang extension for C function overloading) 644 SCS.Second = ICK_Compatible_Conversion; 645 } else { 646 // No second conversion required. 647 SCS.Second = ICK_Identity; 648 } 649 650 QualType CanonFrom; 651 QualType CanonTo; 652 // The third conversion can be a qualification conversion (C++ 4p1). 653 if (IsQualificationConversion(FromType, ToType)) { 654 SCS.Third = ICK_Qualification; 655 FromType = ToType; 656 CanonFrom = Context.getCanonicalType(FromType); 657 CanonTo = Context.getCanonicalType(ToType); 658 } else { 659 // No conversion required 660 SCS.Third = ICK_Identity; 661 662 // C++ [over.best.ics]p6: 663 // [...] Any difference in top-level cv-qualification is 664 // subsumed by the initialization itself and does not constitute 665 // a conversion. [...] 666 CanonFrom = Context.getCanonicalType(FromType); 667 CanonTo = Context.getCanonicalType(ToType); 668 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 669 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 670 FromType = ToType; 671 CanonFrom = CanonTo; 672 } 673 } 674 675 // If we have not converted the argument type to the parameter type, 676 // this is a bad conversion sequence. 677 if (CanonFrom != CanonTo) 678 return false; 679 680 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 681 return true; 682} 683 684/// IsIntegralPromotion - Determines whether the conversion from the 685/// expression From (whose potentially-adjusted type is FromType) to 686/// ToType is an integral promotion (C++ 4.5). If so, returns true and 687/// sets PromotedType to the promoted type. 688bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) 689{ 690 const BuiltinType *To = ToType->getAsBuiltinType(); 691 // All integers are built-in. 692 if (!To) { 693 return false; 694 } 695 696 // An rvalue of type char, signed char, unsigned char, short int, or 697 // unsigned short int can be converted to an rvalue of type int if 698 // int can represent all the values of the source type; otherwise, 699 // the source rvalue can be converted to an rvalue of type unsigned 700 // int (C++ 4.5p1). 701 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 702 if (// We can promote any signed, promotable integer type to an int 703 (FromType->isSignedIntegerType() || 704 // We can promote any unsigned integer type whose size is 705 // less than int to an int. 706 (!FromType->isSignedIntegerType() && 707 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 708 return To->getKind() == BuiltinType::Int; 709 } 710 711 return To->getKind() == BuiltinType::UInt; 712 } 713 714 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 715 // can be converted to an rvalue of the first of the following types 716 // that can represent all the values of its underlying type: int, 717 // unsigned int, long, or unsigned long (C++ 4.5p2). 718 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 719 && ToType->isIntegerType()) { 720 // Determine whether the type we're converting from is signed or 721 // unsigned. 722 bool FromIsSigned; 723 uint64_t FromSize = Context.getTypeSize(FromType); 724 if (const EnumType *FromEnumType = FromType->getAsEnumType()) { 725 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 726 FromIsSigned = UnderlyingType->isSignedIntegerType(); 727 } else { 728 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 729 FromIsSigned = true; 730 } 731 732 // The types we'll try to promote to, in the appropriate 733 // order. Try each of these types. 734 QualType PromoteTypes[6] = { 735 Context.IntTy, Context.UnsignedIntTy, 736 Context.LongTy, Context.UnsignedLongTy , 737 Context.LongLongTy, Context.UnsignedLongLongTy 738 }; 739 for (int Idx = 0; Idx < 6; ++Idx) { 740 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 741 if (FromSize < ToSize || 742 (FromSize == ToSize && 743 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 744 // We found the type that we can promote to. If this is the 745 // type we wanted, we have a promotion. Otherwise, no 746 // promotion. 747 return Context.getCanonicalType(ToType).getUnqualifiedType() 748 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 749 } 750 } 751 } 752 753 // An rvalue for an integral bit-field (9.6) can be converted to an 754 // rvalue of type int if int can represent all the values of the 755 // bit-field; otherwise, it can be converted to unsigned int if 756 // unsigned int can represent all the values of the bit-field. If 757 // the bit-field is larger yet, no integral promotion applies to 758 // it. If the bit-field has an enumerated type, it is treated as any 759 // other value of that type for promotion purposes (C++ 4.5p3). 760 // FIXME: We should delay checking of bit-fields until we actually perform the 761 // conversion. 762 using llvm::APSInt; 763 if (From) 764 if (FieldDecl *MemberDecl = From->getBitField()) { 765 APSInt BitWidth; 766 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 767 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 768 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 769 ToSize = Context.getTypeSize(ToType); 770 771 // Are we promoting to an int from a bitfield that fits in an int? 772 if (BitWidth < ToSize || 773 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 774 return To->getKind() == BuiltinType::Int; 775 } 776 777 // Are we promoting to an unsigned int from an unsigned bitfield 778 // that fits into an unsigned int? 779 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 780 return To->getKind() == BuiltinType::UInt; 781 } 782 783 return false; 784 } 785 } 786 787 // An rvalue of type bool can be converted to an rvalue of type int, 788 // with false becoming zero and true becoming one (C++ 4.5p4). 789 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 790 return true; 791 } 792 793 return false; 794} 795 796/// IsFloatingPointPromotion - Determines whether the conversion from 797/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 798/// returns true and sets PromotedType to the promoted type. 799bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) 800{ 801 /// An rvalue of type float can be converted to an rvalue of type 802 /// double. (C++ 4.6p1). 803 if (const BuiltinType *FromBuiltin = FromType->getAsBuiltinType()) 804 if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType()) { 805 if (FromBuiltin->getKind() == BuiltinType::Float && 806 ToBuiltin->getKind() == BuiltinType::Double) 807 return true; 808 809 // C99 6.3.1.5p1: 810 // When a float is promoted to double or long double, or a 811 // double is promoted to long double [...]. 812 if (!getLangOptions().CPlusPlus && 813 (FromBuiltin->getKind() == BuiltinType::Float || 814 FromBuiltin->getKind() == BuiltinType::Double) && 815 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 816 return true; 817 } 818 819 return false; 820} 821 822/// \brief Determine if a conversion is a complex promotion. 823/// 824/// A complex promotion is defined as a complex -> complex conversion 825/// where the conversion between the underlying real types is a 826/// floating-point or integral promotion. 827bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 828 const ComplexType *FromComplex = FromType->getAsComplexType(); 829 if (!FromComplex) 830 return false; 831 832 const ComplexType *ToComplex = ToType->getAsComplexType(); 833 if (!ToComplex) 834 return false; 835 836 return IsFloatingPointPromotion(FromComplex->getElementType(), 837 ToComplex->getElementType()) || 838 IsIntegralPromotion(0, FromComplex->getElementType(), 839 ToComplex->getElementType()); 840} 841 842/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 843/// the pointer type FromPtr to a pointer to type ToPointee, with the 844/// same type qualifiers as FromPtr has on its pointee type. ToType, 845/// if non-empty, will be a pointer to ToType that may or may not have 846/// the right set of qualifiers on its pointee. 847static QualType 848BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 849 QualType ToPointee, QualType ToType, 850 ASTContext &Context) { 851 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 852 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 853 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 854 855 // Exact qualifier match -> return the pointer type we're converting to. 856 if (CanonToPointee.getCVRQualifiers() == Quals) { 857 // ToType is exactly what we need. Return it. 858 if (ToType.getTypePtr()) 859 return ToType; 860 861 // Build a pointer to ToPointee. It has the right qualifiers 862 // already. 863 return Context.getPointerType(ToPointee); 864 } 865 866 // Just build a canonical type that has the right qualifiers. 867 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 868} 869 870/// IsPointerConversion - Determines whether the conversion of the 871/// expression From, which has the (possibly adjusted) type FromType, 872/// can be converted to the type ToType via a pointer conversion (C++ 873/// 4.10). If so, returns true and places the converted type (that 874/// might differ from ToType in its cv-qualifiers at some level) into 875/// ConvertedType. 876/// 877/// This routine also supports conversions to and from block pointers 878/// and conversions with Objective-C's 'id', 'id<protocols...>', and 879/// pointers to interfaces. FIXME: Once we've determined the 880/// appropriate overloading rules for Objective-C, we may want to 881/// split the Objective-C checks into a different routine; however, 882/// GCC seems to consider all of these conversions to be pointer 883/// conversions, so for now they live here. IncompatibleObjC will be 884/// set if the conversion is an allowed Objective-C conversion that 885/// should result in a warning. 886bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 887 QualType& ConvertedType, 888 bool &IncompatibleObjC) 889{ 890 IncompatibleObjC = false; 891 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 892 return true; 893 894 // Conversion from a null pointer constant to any Objective-C pointer type. 895 if (ToType->isObjCObjectPointerType() && 896 From->isNullPointerConstant(Context)) { 897 ConvertedType = ToType; 898 return true; 899 } 900 901 // Blocks: Block pointers can be converted to void*. 902 if (FromType->isBlockPointerType() && ToType->isPointerType() && 903 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 904 ConvertedType = ToType; 905 return true; 906 } 907 // Blocks: A null pointer constant can be converted to a block 908 // pointer type. 909 if (ToType->isBlockPointerType() && From->isNullPointerConstant(Context)) { 910 ConvertedType = ToType; 911 return true; 912 } 913 914 // If the left-hand-side is nullptr_t, the right side can be a null 915 // pointer constant. 916 if (ToType->isNullPtrType() && From->isNullPointerConstant(Context)) { 917 ConvertedType = ToType; 918 return true; 919 } 920 921 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 922 if (!ToTypePtr) 923 return false; 924 925 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 926 if (From->isNullPointerConstant(Context)) { 927 ConvertedType = ToType; 928 return true; 929 } 930 931 // Beyond this point, both types need to be pointers. 932 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 933 if (!FromTypePtr) 934 return false; 935 936 QualType FromPointeeType = FromTypePtr->getPointeeType(); 937 QualType ToPointeeType = ToTypePtr->getPointeeType(); 938 939 // An rvalue of type "pointer to cv T," where T is an object type, 940 // can be converted to an rvalue of type "pointer to cv void" (C++ 941 // 4.10p2). 942 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 943 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 944 ToPointeeType, 945 ToType, Context); 946 return true; 947 } 948 949 // When we're overloading in C, we allow a special kind of pointer 950 // conversion for compatible-but-not-identical pointee types. 951 if (!getLangOptions().CPlusPlus && 952 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 953 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 954 ToPointeeType, 955 ToType, Context); 956 return true; 957 } 958 959 // C++ [conv.ptr]p3: 960 // 961 // An rvalue of type "pointer to cv D," where D is a class type, 962 // can be converted to an rvalue of type "pointer to cv B," where 963 // B is a base class (clause 10) of D. If B is an inaccessible 964 // (clause 11) or ambiguous (10.2) base class of D, a program that 965 // necessitates this conversion is ill-formed. The result of the 966 // conversion is a pointer to the base class sub-object of the 967 // derived class object. The null pointer value is converted to 968 // the null pointer value of the destination type. 969 // 970 // Note that we do not check for ambiguity or inaccessibility 971 // here. That is handled by CheckPointerConversion. 972 if (getLangOptions().CPlusPlus && 973 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 974 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 975 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 976 ToPointeeType, 977 ToType, Context); 978 return true; 979 } 980 981 return false; 982} 983 984/// isObjCPointerConversion - Determines whether this is an 985/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 986/// with the same arguments and return values. 987bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 988 QualType& ConvertedType, 989 bool &IncompatibleObjC) { 990 if (!getLangOptions().ObjC1) 991 return false; 992 993 // First, we handle all conversions on ObjC object pointer types. 994 const ObjCObjectPointerType* ToObjCPtr = ToType->getAsObjCObjectPointerType(); 995 const ObjCObjectPointerType *FromObjCPtr = 996 FromType->getAsObjCObjectPointerType(); 997 998 if (ToObjCPtr && FromObjCPtr) { 999 // Objective C++: We're able to convert between "id" or "Class" and a 1000 // pointer to any interface (in both directions). 1001 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1002 ConvertedType = ToType; 1003 return true; 1004 } 1005 // Conversions with Objective-C's id<...>. 1006 if ((FromObjCPtr->isObjCQualifiedIdType() || 1007 ToObjCPtr->isObjCQualifiedIdType()) && 1008 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1009 /*compare=*/false)) { 1010 ConvertedType = ToType; 1011 return true; 1012 } 1013 // Objective C++: We're able to convert from a pointer to an 1014 // interface to a pointer to a different interface. 1015 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1016 ConvertedType = ToType; 1017 return true; 1018 } 1019 1020 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1021 // Okay: this is some kind of implicit downcast of Objective-C 1022 // interfaces, which is permitted. However, we're going to 1023 // complain about it. 1024 IncompatibleObjC = true; 1025 ConvertedType = FromType; 1026 return true; 1027 } 1028 } 1029 // Beyond this point, both types need to be C pointers or block pointers. 1030 QualType ToPointeeType; 1031 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1032 ToPointeeType = ToCPtr->getPointeeType(); 1033 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1034 ToPointeeType = ToBlockPtr->getPointeeType(); 1035 else 1036 return false; 1037 1038 QualType FromPointeeType; 1039 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1040 FromPointeeType = FromCPtr->getPointeeType(); 1041 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1042 FromPointeeType = FromBlockPtr->getPointeeType(); 1043 else 1044 return false; 1045 1046 // If we have pointers to pointers, recursively check whether this 1047 // is an Objective-C conversion. 1048 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1049 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1050 IncompatibleObjC)) { 1051 // We always complain about this conversion. 1052 IncompatibleObjC = true; 1053 ConvertedType = ToType; 1054 return true; 1055 } 1056 // If we have pointers to functions or blocks, check whether the only 1057 // differences in the argument and result types are in Objective-C 1058 // pointer conversions. If so, we permit the conversion (but 1059 // complain about it). 1060 const FunctionProtoType *FromFunctionType 1061 = FromPointeeType->getAsFunctionProtoType(); 1062 const FunctionProtoType *ToFunctionType 1063 = ToPointeeType->getAsFunctionProtoType(); 1064 if (FromFunctionType && ToFunctionType) { 1065 // If the function types are exactly the same, this isn't an 1066 // Objective-C pointer conversion. 1067 if (Context.getCanonicalType(FromPointeeType) 1068 == Context.getCanonicalType(ToPointeeType)) 1069 return false; 1070 1071 // Perform the quick checks that will tell us whether these 1072 // function types are obviously different. 1073 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1074 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1075 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1076 return false; 1077 1078 bool HasObjCConversion = false; 1079 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1080 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1081 // Okay, the types match exactly. Nothing to do. 1082 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1083 ToFunctionType->getResultType(), 1084 ConvertedType, IncompatibleObjC)) { 1085 // Okay, we have an Objective-C pointer conversion. 1086 HasObjCConversion = true; 1087 } else { 1088 // Function types are too different. Abort. 1089 return false; 1090 } 1091 1092 // Check argument types. 1093 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1094 ArgIdx != NumArgs; ++ArgIdx) { 1095 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1096 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1097 if (Context.getCanonicalType(FromArgType) 1098 == Context.getCanonicalType(ToArgType)) { 1099 // Okay, the types match exactly. Nothing to do. 1100 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1101 ConvertedType, IncompatibleObjC)) { 1102 // Okay, we have an Objective-C pointer conversion. 1103 HasObjCConversion = true; 1104 } else { 1105 // Argument types are too different. Abort. 1106 return false; 1107 } 1108 } 1109 1110 if (HasObjCConversion) { 1111 // We had an Objective-C conversion. Allow this pointer 1112 // conversion, but complain about it. 1113 ConvertedType = ToType; 1114 IncompatibleObjC = true; 1115 return true; 1116 } 1117 } 1118 1119 return false; 1120} 1121 1122/// CheckPointerConversion - Check the pointer conversion from the 1123/// expression From to the type ToType. This routine checks for 1124/// ambiguous or inaccessible derived-to-base pointer 1125/// conversions for which IsPointerConversion has already returned 1126/// true. It returns true and produces a diagnostic if there was an 1127/// error, or returns false otherwise. 1128bool Sema::CheckPointerConversion(Expr *From, QualType ToType) { 1129 QualType FromType = From->getType(); 1130 1131 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1132 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1133 QualType FromPointeeType = FromPtrType->getPointeeType(), 1134 ToPointeeType = ToPtrType->getPointeeType(); 1135 1136 if (FromPointeeType->isRecordType() && 1137 ToPointeeType->isRecordType()) { 1138 // We must have a derived-to-base conversion. Check an 1139 // ambiguous or inaccessible conversion. 1140 return CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1141 From->getExprLoc(), 1142 From->getSourceRange()); 1143 } 1144 } 1145 if (const ObjCObjectPointerType *FromPtrType = 1146 FromType->getAsObjCObjectPointerType()) 1147 if (const ObjCObjectPointerType *ToPtrType = 1148 ToType->getAsObjCObjectPointerType()) { 1149 // Objective-C++ conversions are always okay. 1150 // FIXME: We should have a different class of conversions for the 1151 // Objective-C++ implicit conversions. 1152 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1153 return false; 1154 1155 } 1156 return false; 1157} 1158 1159/// IsMemberPointerConversion - Determines whether the conversion of the 1160/// expression From, which has the (possibly adjusted) type FromType, can be 1161/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1162/// If so, returns true and places the converted type (that might differ from 1163/// ToType in its cv-qualifiers at some level) into ConvertedType. 1164bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1165 QualType ToType, QualType &ConvertedType) 1166{ 1167 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1168 if (!ToTypePtr) 1169 return false; 1170 1171 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1172 if (From->isNullPointerConstant(Context)) { 1173 ConvertedType = ToType; 1174 return true; 1175 } 1176 1177 // Otherwise, both types have to be member pointers. 1178 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1179 if (!FromTypePtr) 1180 return false; 1181 1182 // A pointer to member of B can be converted to a pointer to member of D, 1183 // where D is derived from B (C++ 4.11p2). 1184 QualType FromClass(FromTypePtr->getClass(), 0); 1185 QualType ToClass(ToTypePtr->getClass(), 0); 1186 // FIXME: What happens when these are dependent? Is this function even called? 1187 1188 if (IsDerivedFrom(ToClass, FromClass)) { 1189 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1190 ToClass.getTypePtr()); 1191 return true; 1192 } 1193 1194 return false; 1195} 1196 1197/// CheckMemberPointerConversion - Check the member pointer conversion from the 1198/// expression From to the type ToType. This routine checks for ambiguous or 1199/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1200/// for which IsMemberPointerConversion has already returned true. It returns 1201/// true and produces a diagnostic if there was an error, or returns false 1202/// otherwise. 1203bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1204 CastExpr::CastKind &Kind) { 1205 QualType FromType = From->getType(); 1206 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1207 if (!FromPtrType) { 1208 // This must be a null pointer to member pointer conversion 1209 assert(From->isNullPointerConstant(Context) && 1210 "Expr must be null pointer constant!"); 1211 Kind = CastExpr::CK_NullToMemberPointer; 1212 return false; 1213 } 1214 1215 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1216 assert(ToPtrType && "No member pointer cast has a target type " 1217 "that is not a member pointer."); 1218 1219 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1220 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1221 1222 // FIXME: What about dependent types? 1223 assert(FromClass->isRecordType() && "Pointer into non-class."); 1224 assert(ToClass->isRecordType() && "Pointer into non-class."); 1225 1226 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1227 /*DetectVirtual=*/true); 1228 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1229 assert(DerivationOkay && 1230 "Should not have been called if derivation isn't OK."); 1231 (void)DerivationOkay; 1232 1233 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1234 getUnqualifiedType())) { 1235 // Derivation is ambiguous. Redo the check to find the exact paths. 1236 Paths.clear(); 1237 Paths.setRecordingPaths(true); 1238 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1239 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1240 (void)StillOkay; 1241 1242 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1243 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1244 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1245 return true; 1246 } 1247 1248 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1249 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1250 << FromClass << ToClass << QualType(VBase, 0) 1251 << From->getSourceRange(); 1252 return true; 1253 } 1254 1255 // Must be a base to derived member conversion. 1256 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1257 return false; 1258} 1259 1260/// IsQualificationConversion - Determines whether the conversion from 1261/// an rvalue of type FromType to ToType is a qualification conversion 1262/// (C++ 4.4). 1263bool 1264Sema::IsQualificationConversion(QualType FromType, QualType ToType) 1265{ 1266 FromType = Context.getCanonicalType(FromType); 1267 ToType = Context.getCanonicalType(ToType); 1268 1269 // If FromType and ToType are the same type, this is not a 1270 // qualification conversion. 1271 if (FromType == ToType) 1272 return false; 1273 1274 // (C++ 4.4p4): 1275 // A conversion can add cv-qualifiers at levels other than the first 1276 // in multi-level pointers, subject to the following rules: [...] 1277 bool PreviousToQualsIncludeConst = true; 1278 bool UnwrappedAnyPointer = false; 1279 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1280 // Within each iteration of the loop, we check the qualifiers to 1281 // determine if this still looks like a qualification 1282 // conversion. Then, if all is well, we unwrap one more level of 1283 // pointers or pointers-to-members and do it all again 1284 // until there are no more pointers or pointers-to-members left to 1285 // unwrap. 1286 UnwrappedAnyPointer = true; 1287 1288 // -- for every j > 0, if const is in cv 1,j then const is in cv 1289 // 2,j, and similarly for volatile. 1290 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1291 return false; 1292 1293 // -- if the cv 1,j and cv 2,j are different, then const is in 1294 // every cv for 0 < k < j. 1295 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1296 && !PreviousToQualsIncludeConst) 1297 return false; 1298 1299 // Keep track of whether all prior cv-qualifiers in the "to" type 1300 // include const. 1301 PreviousToQualsIncludeConst 1302 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1303 } 1304 1305 // We are left with FromType and ToType being the pointee types 1306 // after unwrapping the original FromType and ToType the same number 1307 // of types. If we unwrapped any pointers, and if FromType and 1308 // ToType have the same unqualified type (since we checked 1309 // qualifiers above), then this is a qualification conversion. 1310 return UnwrappedAnyPointer && 1311 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1312} 1313 1314/// \brief Given a function template or function, extract the function template 1315/// declaration (if any) and the underlying function declaration. 1316template<typename T> 1317static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1318 FunctionTemplateDecl *&FunctionTemplate) { 1319 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1320 if (FunctionTemplate) 1321 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1322 else 1323 Function = cast<T>(Orig); 1324} 1325 1326 1327/// Determines whether there is a user-defined conversion sequence 1328/// (C++ [over.ics.user]) that converts expression From to the type 1329/// ToType. If such a conversion exists, User will contain the 1330/// user-defined conversion sequence that performs such a conversion 1331/// and this routine will return true. Otherwise, this routine returns 1332/// false and User is unspecified. 1333/// 1334/// \param AllowConversionFunctions true if the conversion should 1335/// consider conversion functions at all. If false, only constructors 1336/// will be considered. 1337/// 1338/// \param AllowExplicit true if the conversion should consider C++0x 1339/// "explicit" conversion functions as well as non-explicit conversion 1340/// functions (C++0x [class.conv.fct]p2). 1341/// 1342/// \param ForceRValue true if the expression should be treated as an rvalue 1343/// for overload resolution. 1344bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1345 UserDefinedConversionSequence& User, 1346 bool AllowConversionFunctions, 1347 bool AllowExplicit, bool ForceRValue) 1348{ 1349 OverloadCandidateSet CandidateSet; 1350 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1351 if (CXXRecordDecl *ToRecordDecl 1352 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1353 // C++ [over.match.ctor]p1: 1354 // When objects of class type are direct-initialized (8.5), or 1355 // copy-initialized from an expression of the same or a 1356 // derived class type (8.5), overload resolution selects the 1357 // constructor. [...] For copy-initialization, the candidate 1358 // functions are all the converting constructors (12.3.1) of 1359 // that class. The argument list is the expression-list within 1360 // the parentheses of the initializer. 1361 DeclarationName ConstructorName 1362 = Context.DeclarationNames.getCXXConstructorName( 1363 Context.getCanonicalType(ToType).getUnqualifiedType()); 1364 DeclContext::lookup_iterator Con, ConEnd; 1365 for (llvm::tie(Con, ConEnd) 1366 = ToRecordDecl->lookup(ConstructorName); 1367 Con != ConEnd; ++Con) { 1368 // Find the constructor (which may be a template). 1369 CXXConstructorDecl *Constructor = 0; 1370 FunctionTemplateDecl *ConstructorTmpl 1371 = dyn_cast<FunctionTemplateDecl>(*Con); 1372 if (ConstructorTmpl) 1373 Constructor 1374 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1375 else 1376 Constructor = cast<CXXConstructorDecl>(*Con); 1377 1378 if (!Constructor->isInvalidDecl() && 1379 Constructor->isConvertingConstructor()) { 1380 if (ConstructorTmpl) 1381 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1382 1, CandidateSet, 1383 /*SuppressUserConversions=*/true, 1384 ForceRValue); 1385 else 1386 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1387 /*SuppressUserConversions=*/true, ForceRValue); 1388 } 1389 } 1390 } 1391 } 1392 1393 if (!AllowConversionFunctions) { 1394 // Don't allow any conversion functions to enter the overload set. 1395 } else if (const RecordType *FromRecordType 1396 = From->getType()->getAs<RecordType>()) { 1397 if (CXXRecordDecl *FromRecordDecl 1398 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1399 // Add all of the conversion functions as candidates. 1400 // FIXME: Look for conversions in base classes! 1401 OverloadedFunctionDecl *Conversions 1402 = FromRecordDecl->getConversionFunctions(); 1403 for (OverloadedFunctionDecl::function_iterator Func 1404 = Conversions->function_begin(); 1405 Func != Conversions->function_end(); ++Func) { 1406 CXXConversionDecl *Conv; 1407 FunctionTemplateDecl *ConvTemplate; 1408 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1409 if (ConvTemplate) 1410 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1411 else 1412 Conv = dyn_cast<CXXConversionDecl>(*Func); 1413 1414 if (AllowExplicit || !Conv->isExplicit()) { 1415 if (ConvTemplate) 1416 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1417 CandidateSet); 1418 else 1419 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1420 } 1421 } 1422 } 1423 } 1424 1425 OverloadCandidateSet::iterator Best; 1426 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1427 case OR_Success: 1428 // Record the standard conversion we used and the conversion function. 1429 if (CXXConstructorDecl *Constructor 1430 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1431 // C++ [over.ics.user]p1: 1432 // If the user-defined conversion is specified by a 1433 // constructor (12.3.1), the initial standard conversion 1434 // sequence converts the source type to the type required by 1435 // the argument of the constructor. 1436 // 1437 // FIXME: What about ellipsis conversions? 1438 QualType ThisType = Constructor->getThisType(Context); 1439 User.Before = Best->Conversions[0].Standard; 1440 User.ConversionFunction = Constructor; 1441 User.After.setAsIdentityConversion(); 1442 User.After.FromTypePtr 1443 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1444 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1445 return true; 1446 } else if (CXXConversionDecl *Conversion 1447 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1448 // C++ [over.ics.user]p1: 1449 // 1450 // [...] If the user-defined conversion is specified by a 1451 // conversion function (12.3.2), the initial standard 1452 // conversion sequence converts the source type to the 1453 // implicit object parameter of the conversion function. 1454 User.Before = Best->Conversions[0].Standard; 1455 User.ConversionFunction = Conversion; 1456 1457 // C++ [over.ics.user]p2: 1458 // The second standard conversion sequence converts the 1459 // result of the user-defined conversion to the target type 1460 // for the sequence. Since an implicit conversion sequence 1461 // is an initialization, the special rules for 1462 // initialization by user-defined conversion apply when 1463 // selecting the best user-defined conversion for a 1464 // user-defined conversion sequence (see 13.3.3 and 1465 // 13.3.3.1). 1466 User.After = Best->FinalConversion; 1467 return true; 1468 } else { 1469 assert(false && "Not a constructor or conversion function?"); 1470 return false; 1471 } 1472 1473 case OR_No_Viable_Function: 1474 case OR_Deleted: 1475 // No conversion here! We're done. 1476 return false; 1477 1478 case OR_Ambiguous: 1479 // FIXME: See C++ [over.best.ics]p10 for the handling of 1480 // ambiguous conversion sequences. 1481 return false; 1482 } 1483 1484 return false; 1485} 1486 1487/// CompareImplicitConversionSequences - Compare two implicit 1488/// conversion sequences to determine whether one is better than the 1489/// other or if they are indistinguishable (C++ 13.3.3.2). 1490ImplicitConversionSequence::CompareKind 1491Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1492 const ImplicitConversionSequence& ICS2) 1493{ 1494 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1495 // conversion sequences (as defined in 13.3.3.1) 1496 // -- a standard conversion sequence (13.3.3.1.1) is a better 1497 // conversion sequence than a user-defined conversion sequence or 1498 // an ellipsis conversion sequence, and 1499 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1500 // conversion sequence than an ellipsis conversion sequence 1501 // (13.3.3.1.3). 1502 // 1503 if (ICS1.ConversionKind < ICS2.ConversionKind) 1504 return ImplicitConversionSequence::Better; 1505 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1506 return ImplicitConversionSequence::Worse; 1507 1508 // Two implicit conversion sequences of the same form are 1509 // indistinguishable conversion sequences unless one of the 1510 // following rules apply: (C++ 13.3.3.2p3): 1511 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1512 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1513 else if (ICS1.ConversionKind == 1514 ImplicitConversionSequence::UserDefinedConversion) { 1515 // User-defined conversion sequence U1 is a better conversion 1516 // sequence than another user-defined conversion sequence U2 if 1517 // they contain the same user-defined conversion function or 1518 // constructor and if the second standard conversion sequence of 1519 // U1 is better than the second standard conversion sequence of 1520 // U2 (C++ 13.3.3.2p3). 1521 if (ICS1.UserDefined.ConversionFunction == 1522 ICS2.UserDefined.ConversionFunction) 1523 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1524 ICS2.UserDefined.After); 1525 } 1526 1527 return ImplicitConversionSequence::Indistinguishable; 1528} 1529 1530/// CompareStandardConversionSequences - Compare two standard 1531/// conversion sequences to determine whether one is better than the 1532/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1533ImplicitConversionSequence::CompareKind 1534Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1535 const StandardConversionSequence& SCS2) 1536{ 1537 // Standard conversion sequence S1 is a better conversion sequence 1538 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1539 1540 // -- S1 is a proper subsequence of S2 (comparing the conversion 1541 // sequences in the canonical form defined by 13.3.3.1.1, 1542 // excluding any Lvalue Transformation; the identity conversion 1543 // sequence is considered to be a subsequence of any 1544 // non-identity conversion sequence) or, if not that, 1545 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1546 // Neither is a proper subsequence of the other. Do nothing. 1547 ; 1548 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1549 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1550 (SCS1.Second == ICK_Identity && 1551 SCS1.Third == ICK_Identity)) 1552 // SCS1 is a proper subsequence of SCS2. 1553 return ImplicitConversionSequence::Better; 1554 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1555 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1556 (SCS2.Second == ICK_Identity && 1557 SCS2.Third == ICK_Identity)) 1558 // SCS2 is a proper subsequence of SCS1. 1559 return ImplicitConversionSequence::Worse; 1560 1561 // -- the rank of S1 is better than the rank of S2 (by the rules 1562 // defined below), or, if not that, 1563 ImplicitConversionRank Rank1 = SCS1.getRank(); 1564 ImplicitConversionRank Rank2 = SCS2.getRank(); 1565 if (Rank1 < Rank2) 1566 return ImplicitConversionSequence::Better; 1567 else if (Rank2 < Rank1) 1568 return ImplicitConversionSequence::Worse; 1569 1570 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1571 // are indistinguishable unless one of the following rules 1572 // applies: 1573 1574 // A conversion that is not a conversion of a pointer, or 1575 // pointer to member, to bool is better than another conversion 1576 // that is such a conversion. 1577 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1578 return SCS2.isPointerConversionToBool() 1579 ? ImplicitConversionSequence::Better 1580 : ImplicitConversionSequence::Worse; 1581 1582 // C++ [over.ics.rank]p4b2: 1583 // 1584 // If class B is derived directly or indirectly from class A, 1585 // conversion of B* to A* is better than conversion of B* to 1586 // void*, and conversion of A* to void* is better than conversion 1587 // of B* to void*. 1588 bool SCS1ConvertsToVoid 1589 = SCS1.isPointerConversionToVoidPointer(Context); 1590 bool SCS2ConvertsToVoid 1591 = SCS2.isPointerConversionToVoidPointer(Context); 1592 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1593 // Exactly one of the conversion sequences is a conversion to 1594 // a void pointer; it's the worse conversion. 1595 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1596 : ImplicitConversionSequence::Worse; 1597 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1598 // Neither conversion sequence converts to a void pointer; compare 1599 // their derived-to-base conversions. 1600 if (ImplicitConversionSequence::CompareKind DerivedCK 1601 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1602 return DerivedCK; 1603 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1604 // Both conversion sequences are conversions to void 1605 // pointers. Compare the source types to determine if there's an 1606 // inheritance relationship in their sources. 1607 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1608 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1609 1610 // Adjust the types we're converting from via the array-to-pointer 1611 // conversion, if we need to. 1612 if (SCS1.First == ICK_Array_To_Pointer) 1613 FromType1 = Context.getArrayDecayedType(FromType1); 1614 if (SCS2.First == ICK_Array_To_Pointer) 1615 FromType2 = Context.getArrayDecayedType(FromType2); 1616 1617 QualType FromPointee1 1618 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1619 QualType FromPointee2 1620 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1621 1622 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1623 return ImplicitConversionSequence::Better; 1624 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1625 return ImplicitConversionSequence::Worse; 1626 1627 // Objective-C++: If one interface is more specific than the 1628 // other, it is the better one. 1629 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1630 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1631 if (FromIface1 && FromIface1) { 1632 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1633 return ImplicitConversionSequence::Better; 1634 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1635 return ImplicitConversionSequence::Worse; 1636 } 1637 } 1638 1639 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1640 // bullet 3). 1641 if (ImplicitConversionSequence::CompareKind QualCK 1642 = CompareQualificationConversions(SCS1, SCS2)) 1643 return QualCK; 1644 1645 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1646 // C++0x [over.ics.rank]p3b4: 1647 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1648 // implicit object parameter of a non-static member function declared 1649 // without a ref-qualifier, and S1 binds an rvalue reference to an 1650 // rvalue and S2 binds an lvalue reference. 1651 // FIXME: We don't know if we're dealing with the implicit object parameter, 1652 // or if the member function in this case has a ref qualifier. 1653 // (Of course, we don't have ref qualifiers yet.) 1654 if (SCS1.RRefBinding != SCS2.RRefBinding) 1655 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1656 : ImplicitConversionSequence::Worse; 1657 1658 // C++ [over.ics.rank]p3b4: 1659 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1660 // which the references refer are the same type except for 1661 // top-level cv-qualifiers, and the type to which the reference 1662 // initialized by S2 refers is more cv-qualified than the type 1663 // to which the reference initialized by S1 refers. 1664 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1665 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1666 T1 = Context.getCanonicalType(T1); 1667 T2 = Context.getCanonicalType(T2); 1668 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1669 if (T2.isMoreQualifiedThan(T1)) 1670 return ImplicitConversionSequence::Better; 1671 else if (T1.isMoreQualifiedThan(T2)) 1672 return ImplicitConversionSequence::Worse; 1673 } 1674 } 1675 1676 return ImplicitConversionSequence::Indistinguishable; 1677} 1678 1679/// CompareQualificationConversions - Compares two standard conversion 1680/// sequences to determine whether they can be ranked based on their 1681/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1682ImplicitConversionSequence::CompareKind 1683Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1684 const StandardConversionSequence& SCS2) 1685{ 1686 // C++ 13.3.3.2p3: 1687 // -- S1 and S2 differ only in their qualification conversion and 1688 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1689 // cv-qualification signature of type T1 is a proper subset of 1690 // the cv-qualification signature of type T2, and S1 is not the 1691 // deprecated string literal array-to-pointer conversion (4.2). 1692 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1693 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1694 return ImplicitConversionSequence::Indistinguishable; 1695 1696 // FIXME: the example in the standard doesn't use a qualification 1697 // conversion (!) 1698 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1699 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1700 T1 = Context.getCanonicalType(T1); 1701 T2 = Context.getCanonicalType(T2); 1702 1703 // If the types are the same, we won't learn anything by unwrapped 1704 // them. 1705 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1706 return ImplicitConversionSequence::Indistinguishable; 1707 1708 ImplicitConversionSequence::CompareKind Result 1709 = ImplicitConversionSequence::Indistinguishable; 1710 while (UnwrapSimilarPointerTypes(T1, T2)) { 1711 // Within each iteration of the loop, we check the qualifiers to 1712 // determine if this still looks like a qualification 1713 // conversion. Then, if all is well, we unwrap one more level of 1714 // pointers or pointers-to-members and do it all again 1715 // until there are no more pointers or pointers-to-members left 1716 // to unwrap. This essentially mimics what 1717 // IsQualificationConversion does, but here we're checking for a 1718 // strict subset of qualifiers. 1719 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1720 // The qualifiers are the same, so this doesn't tell us anything 1721 // about how the sequences rank. 1722 ; 1723 else if (T2.isMoreQualifiedThan(T1)) { 1724 // T1 has fewer qualifiers, so it could be the better sequence. 1725 if (Result == ImplicitConversionSequence::Worse) 1726 // Neither has qualifiers that are a subset of the other's 1727 // qualifiers. 1728 return ImplicitConversionSequence::Indistinguishable; 1729 1730 Result = ImplicitConversionSequence::Better; 1731 } else if (T1.isMoreQualifiedThan(T2)) { 1732 // T2 has fewer qualifiers, so it could be the better sequence. 1733 if (Result == ImplicitConversionSequence::Better) 1734 // Neither has qualifiers that are a subset of the other's 1735 // qualifiers. 1736 return ImplicitConversionSequence::Indistinguishable; 1737 1738 Result = ImplicitConversionSequence::Worse; 1739 } else { 1740 // Qualifiers are disjoint. 1741 return ImplicitConversionSequence::Indistinguishable; 1742 } 1743 1744 // If the types after this point are equivalent, we're done. 1745 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1746 break; 1747 } 1748 1749 // Check that the winning standard conversion sequence isn't using 1750 // the deprecated string literal array to pointer conversion. 1751 switch (Result) { 1752 case ImplicitConversionSequence::Better: 1753 if (SCS1.Deprecated) 1754 Result = ImplicitConversionSequence::Indistinguishable; 1755 break; 1756 1757 case ImplicitConversionSequence::Indistinguishable: 1758 break; 1759 1760 case ImplicitConversionSequence::Worse: 1761 if (SCS2.Deprecated) 1762 Result = ImplicitConversionSequence::Indistinguishable; 1763 break; 1764 } 1765 1766 return Result; 1767} 1768 1769/// CompareDerivedToBaseConversions - Compares two standard conversion 1770/// sequences to determine whether they can be ranked based on their 1771/// various kinds of derived-to-base conversions (C++ 1772/// [over.ics.rank]p4b3). As part of these checks, we also look at 1773/// conversions between Objective-C interface types. 1774ImplicitConversionSequence::CompareKind 1775Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1776 const StandardConversionSequence& SCS2) { 1777 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1778 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1779 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1780 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1781 1782 // Adjust the types we're converting from via the array-to-pointer 1783 // conversion, if we need to. 1784 if (SCS1.First == ICK_Array_To_Pointer) 1785 FromType1 = Context.getArrayDecayedType(FromType1); 1786 if (SCS2.First == ICK_Array_To_Pointer) 1787 FromType2 = Context.getArrayDecayedType(FromType2); 1788 1789 // Canonicalize all of the types. 1790 FromType1 = Context.getCanonicalType(FromType1); 1791 ToType1 = Context.getCanonicalType(ToType1); 1792 FromType2 = Context.getCanonicalType(FromType2); 1793 ToType2 = Context.getCanonicalType(ToType2); 1794 1795 // C++ [over.ics.rank]p4b3: 1796 // 1797 // If class B is derived directly or indirectly from class A and 1798 // class C is derived directly or indirectly from B, 1799 // 1800 // For Objective-C, we let A, B, and C also be Objective-C 1801 // interfaces. 1802 1803 // Compare based on pointer conversions. 1804 if (SCS1.Second == ICK_Pointer_Conversion && 1805 SCS2.Second == ICK_Pointer_Conversion && 1806 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1807 FromType1->isPointerType() && FromType2->isPointerType() && 1808 ToType1->isPointerType() && ToType2->isPointerType()) { 1809 QualType FromPointee1 1810 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1811 QualType ToPointee1 1812 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1813 QualType FromPointee2 1814 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1815 QualType ToPointee2 1816 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1817 1818 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1819 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1820 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1821 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1822 1823 // -- conversion of C* to B* is better than conversion of C* to A*, 1824 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1825 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1826 return ImplicitConversionSequence::Better; 1827 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1828 return ImplicitConversionSequence::Worse; 1829 1830 if (ToIface1 && ToIface2) { 1831 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1832 return ImplicitConversionSequence::Better; 1833 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1834 return ImplicitConversionSequence::Worse; 1835 } 1836 } 1837 1838 // -- conversion of B* to A* is better than conversion of C* to A*, 1839 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1840 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1841 return ImplicitConversionSequence::Better; 1842 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1843 return ImplicitConversionSequence::Worse; 1844 1845 if (FromIface1 && FromIface2) { 1846 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1847 return ImplicitConversionSequence::Better; 1848 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1849 return ImplicitConversionSequence::Worse; 1850 } 1851 } 1852 } 1853 1854 // Compare based on reference bindings. 1855 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1856 SCS1.Second == ICK_Derived_To_Base) { 1857 // -- binding of an expression of type C to a reference of type 1858 // B& is better than binding an expression of type C to a 1859 // reference of type A&, 1860 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1861 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1862 if (IsDerivedFrom(ToType1, ToType2)) 1863 return ImplicitConversionSequence::Better; 1864 else if (IsDerivedFrom(ToType2, ToType1)) 1865 return ImplicitConversionSequence::Worse; 1866 } 1867 1868 // -- binding of an expression of type B to a reference of type 1869 // A& is better than binding an expression of type C to a 1870 // reference of type A&, 1871 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1872 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1873 if (IsDerivedFrom(FromType2, FromType1)) 1874 return ImplicitConversionSequence::Better; 1875 else if (IsDerivedFrom(FromType1, FromType2)) 1876 return ImplicitConversionSequence::Worse; 1877 } 1878 } 1879 1880 1881 // FIXME: conversion of A::* to B::* is better than conversion of 1882 // A::* to C::*, 1883 1884 // FIXME: conversion of B::* to C::* is better than conversion of 1885 // A::* to C::*, and 1886 1887 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1888 SCS1.Second == ICK_Derived_To_Base) { 1889 // -- conversion of C to B is better than conversion of C to A, 1890 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1891 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1892 if (IsDerivedFrom(ToType1, ToType2)) 1893 return ImplicitConversionSequence::Better; 1894 else if (IsDerivedFrom(ToType2, ToType1)) 1895 return ImplicitConversionSequence::Worse; 1896 } 1897 1898 // -- conversion of B to A is better than conversion of C to A. 1899 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1900 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1901 if (IsDerivedFrom(FromType2, FromType1)) 1902 return ImplicitConversionSequence::Better; 1903 else if (IsDerivedFrom(FromType1, FromType2)) 1904 return ImplicitConversionSequence::Worse; 1905 } 1906 } 1907 1908 return ImplicitConversionSequence::Indistinguishable; 1909} 1910 1911/// TryCopyInitialization - Try to copy-initialize a value of type 1912/// ToType from the expression From. Return the implicit conversion 1913/// sequence required to pass this argument, which may be a bad 1914/// conversion sequence (meaning that the argument cannot be passed to 1915/// a parameter of this type). If @p SuppressUserConversions, then we 1916/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1917/// then we treat @p From as an rvalue, even if it is an lvalue. 1918ImplicitConversionSequence 1919Sema::TryCopyInitialization(Expr *From, QualType ToType, 1920 bool SuppressUserConversions, bool ForceRValue) { 1921 if (ToType->isReferenceType()) { 1922 ImplicitConversionSequence ICS; 1923 CheckReferenceInit(From, ToType, &ICS, SuppressUserConversions, 1924 /*AllowExplicit=*/false, ForceRValue); 1925 return ICS; 1926 } else { 1927 return TryImplicitConversion(From, ToType, SuppressUserConversions, 1928 ForceRValue); 1929 } 1930} 1931 1932/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1933/// the expression @p From. Returns true (and emits a diagnostic) if there was 1934/// an error, returns false if the initialization succeeded. Elidable should 1935/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1936/// differently in C++0x for this case. 1937bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1938 const char* Flavor, bool Elidable) { 1939 if (!getLangOptions().CPlusPlus) { 1940 // In C, argument passing is the same as performing an assignment. 1941 QualType FromType = From->getType(); 1942 1943 AssignConvertType ConvTy = 1944 CheckSingleAssignmentConstraints(ToType, From); 1945 if (ConvTy != Compatible && 1946 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1947 ConvTy = Compatible; 1948 1949 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1950 FromType, From, Flavor); 1951 } 1952 1953 if (ToType->isReferenceType()) 1954 return CheckReferenceInit(From, ToType); 1955 1956 if (!PerformImplicitConversion(From, ToType, Flavor, 1957 /*AllowExplicit=*/false, Elidable)) 1958 return false; 1959 1960 return Diag(From->getSourceRange().getBegin(), 1961 diag::err_typecheck_convert_incompatible) 1962 << ToType << From->getType() << Flavor << From->getSourceRange(); 1963} 1964 1965/// TryObjectArgumentInitialization - Try to initialize the object 1966/// parameter of the given member function (@c Method) from the 1967/// expression @p From. 1968ImplicitConversionSequence 1969Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1970 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1971 unsigned MethodQuals = Method->getTypeQualifiers(); 1972 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 1973 1974 // Set up the conversion sequence as a "bad" conversion, to allow us 1975 // to exit early. 1976 ImplicitConversionSequence ICS; 1977 ICS.Standard.setAsIdentityConversion(); 1978 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1979 1980 // We need to have an object of class type. 1981 QualType FromType = From->getType(); 1982 if (const PointerType *PT = FromType->getAs<PointerType>()) 1983 FromType = PT->getPointeeType(); 1984 1985 assert(FromType->isRecordType()); 1986 1987 // The implicit object parmeter is has the type "reference to cv X", 1988 // where X is the class of which the function is a member 1989 // (C++ [over.match.funcs]p4). However, when finding an implicit 1990 // conversion sequence for the argument, we are not allowed to 1991 // create temporaries or perform user-defined conversions 1992 // (C++ [over.match.funcs]p5). We perform a simplified version of 1993 // reference binding here, that allows class rvalues to bind to 1994 // non-constant references. 1995 1996 // First check the qualifiers. We don't care about lvalue-vs-rvalue 1997 // with the implicit object parameter (C++ [over.match.funcs]p5). 1998 QualType FromTypeCanon = Context.getCanonicalType(FromType); 1999 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 2000 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 2001 return ICS; 2002 2003 // Check that we have either the same type or a derived type. It 2004 // affects the conversion rank. 2005 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2006 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2007 ICS.Standard.Second = ICK_Identity; 2008 else if (IsDerivedFrom(FromType, ClassType)) 2009 ICS.Standard.Second = ICK_Derived_To_Base; 2010 else 2011 return ICS; 2012 2013 // Success. Mark this as a reference binding. 2014 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2015 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2016 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2017 ICS.Standard.ReferenceBinding = true; 2018 ICS.Standard.DirectBinding = true; 2019 ICS.Standard.RRefBinding = false; 2020 return ICS; 2021} 2022 2023/// PerformObjectArgumentInitialization - Perform initialization of 2024/// the implicit object parameter for the given Method with the given 2025/// expression. 2026bool 2027Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2028 QualType FromRecordType, DestType; 2029 QualType ImplicitParamRecordType = 2030 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2031 2032 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2033 FromRecordType = PT->getPointeeType(); 2034 DestType = Method->getThisType(Context); 2035 } else { 2036 FromRecordType = From->getType(); 2037 DestType = ImplicitParamRecordType; 2038 } 2039 2040 ImplicitConversionSequence ICS 2041 = TryObjectArgumentInitialization(From, Method); 2042 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2043 return Diag(From->getSourceRange().getBegin(), 2044 diag::err_implicit_object_parameter_init) 2045 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2046 2047 if (ICS.Standard.Second == ICK_Derived_To_Base && 2048 CheckDerivedToBaseConversion(FromRecordType, 2049 ImplicitParamRecordType, 2050 From->getSourceRange().getBegin(), 2051 From->getSourceRange())) 2052 return true; 2053 2054 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2055 /*isLvalue=*/true); 2056 return false; 2057} 2058 2059/// TryContextuallyConvertToBool - Attempt to contextually convert the 2060/// expression From to bool (C++0x [conv]p3). 2061ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2062 return TryImplicitConversion(From, Context.BoolTy, false, true); 2063} 2064 2065/// PerformContextuallyConvertToBool - Perform a contextual conversion 2066/// of the expression From to bool (C++0x [conv]p3). 2067bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2068 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2069 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2070 return false; 2071 2072 return Diag(From->getSourceRange().getBegin(), 2073 diag::err_typecheck_bool_condition) 2074 << From->getType() << From->getSourceRange(); 2075} 2076 2077/// AddOverloadCandidate - Adds the given function to the set of 2078/// candidate functions, using the given function call arguments. If 2079/// @p SuppressUserConversions, then don't allow user-defined 2080/// conversions via constructors or conversion operators. 2081/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2082/// hacky way to implement the overloading rules for elidable copy 2083/// initialization in C++0x (C++0x 12.8p15). 2084void 2085Sema::AddOverloadCandidate(FunctionDecl *Function, 2086 Expr **Args, unsigned NumArgs, 2087 OverloadCandidateSet& CandidateSet, 2088 bool SuppressUserConversions, 2089 bool ForceRValue) 2090{ 2091 const FunctionProtoType* Proto 2092 = dyn_cast<FunctionProtoType>(Function->getType()->getAsFunctionType()); 2093 assert(Proto && "Functions without a prototype cannot be overloaded"); 2094 assert(!isa<CXXConversionDecl>(Function) && 2095 "Use AddConversionCandidate for conversion functions"); 2096 assert(!Function->getDescribedFunctionTemplate() && 2097 "Use AddTemplateOverloadCandidate for function templates"); 2098 2099 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2100 if (!isa<CXXConstructorDecl>(Method)) { 2101 // If we get here, it's because we're calling a member function 2102 // that is named without a member access expression (e.g., 2103 // "this->f") that was either written explicitly or created 2104 // implicitly. This can happen with a qualified call to a member 2105 // function, e.g., X::f(). We use a NULL object as the implied 2106 // object argument (C++ [over.call.func]p3). 2107 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2108 SuppressUserConversions, ForceRValue); 2109 return; 2110 } 2111 // We treat a constructor like a non-member function, since its object 2112 // argument doesn't participate in overload resolution. 2113 } 2114 2115 2116 // Add this candidate 2117 CandidateSet.push_back(OverloadCandidate()); 2118 OverloadCandidate& Candidate = CandidateSet.back(); 2119 Candidate.Function = Function; 2120 Candidate.Viable = true; 2121 Candidate.IsSurrogate = false; 2122 Candidate.IgnoreObjectArgument = false; 2123 2124 unsigned NumArgsInProto = Proto->getNumArgs(); 2125 2126 // (C++ 13.3.2p2): A candidate function having fewer than m 2127 // parameters is viable only if it has an ellipsis in its parameter 2128 // list (8.3.5). 2129 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2130 Candidate.Viable = false; 2131 return; 2132 } 2133 2134 // (C++ 13.3.2p2): A candidate function having more than m parameters 2135 // is viable only if the (m+1)st parameter has a default argument 2136 // (8.3.6). For the purposes of overload resolution, the 2137 // parameter list is truncated on the right, so that there are 2138 // exactly m parameters. 2139 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2140 if (NumArgs < MinRequiredArgs) { 2141 // Not enough arguments. 2142 Candidate.Viable = false; 2143 return; 2144 } 2145 2146 // Determine the implicit conversion sequences for each of the 2147 // arguments. 2148 Candidate.Conversions.resize(NumArgs); 2149 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2150 if (ArgIdx < NumArgsInProto) { 2151 // (C++ 13.3.2p3): for F to be a viable function, there shall 2152 // exist for each argument an implicit conversion sequence 2153 // (13.3.3.1) that converts that argument to the corresponding 2154 // parameter of F. 2155 QualType ParamType = Proto->getArgType(ArgIdx); 2156 Candidate.Conversions[ArgIdx] 2157 = TryCopyInitialization(Args[ArgIdx], ParamType, 2158 SuppressUserConversions, ForceRValue); 2159 if (Candidate.Conversions[ArgIdx].ConversionKind 2160 == ImplicitConversionSequence::BadConversion) { 2161 Candidate.Viable = false; 2162 break; 2163 } 2164 } else { 2165 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2166 // argument for which there is no corresponding parameter is 2167 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2168 Candidate.Conversions[ArgIdx].ConversionKind 2169 = ImplicitConversionSequence::EllipsisConversion; 2170 } 2171 } 2172} 2173 2174/// \brief Add all of the function declarations in the given function set to 2175/// the overload canddiate set. 2176void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2177 Expr **Args, unsigned NumArgs, 2178 OverloadCandidateSet& CandidateSet, 2179 bool SuppressUserConversions) { 2180 for (FunctionSet::const_iterator F = Functions.begin(), 2181 FEnd = Functions.end(); 2182 F != FEnd; ++F) { 2183 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) 2184 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2185 SuppressUserConversions); 2186 else 2187 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*F), 2188 /*FIXME: explicit args */false, 0, 0, 2189 Args, NumArgs, CandidateSet, 2190 SuppressUserConversions); 2191 } 2192} 2193 2194/// AddMethodCandidate - Adds the given C++ member function to the set 2195/// of candidate functions, using the given function call arguments 2196/// and the object argument (@c Object). For example, in a call 2197/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2198/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2199/// allow user-defined conversions via constructors or conversion 2200/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2201/// a slightly hacky way to implement the overloading rules for elidable copy 2202/// initialization in C++0x (C++0x 12.8p15). 2203void 2204Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2205 Expr **Args, unsigned NumArgs, 2206 OverloadCandidateSet& CandidateSet, 2207 bool SuppressUserConversions, bool ForceRValue) 2208{ 2209 const FunctionProtoType* Proto 2210 = dyn_cast<FunctionProtoType>(Method->getType()->getAsFunctionType()); 2211 assert(Proto && "Methods without a prototype cannot be overloaded"); 2212 assert(!isa<CXXConversionDecl>(Method) && 2213 "Use AddConversionCandidate for conversion functions"); 2214 assert(!isa<CXXConstructorDecl>(Method) && 2215 "Use AddOverloadCandidate for constructors"); 2216 2217 // Add this candidate 2218 CandidateSet.push_back(OverloadCandidate()); 2219 OverloadCandidate& Candidate = CandidateSet.back(); 2220 Candidate.Function = Method; 2221 Candidate.IsSurrogate = false; 2222 Candidate.IgnoreObjectArgument = false; 2223 2224 unsigned NumArgsInProto = Proto->getNumArgs(); 2225 2226 // (C++ 13.3.2p2): A candidate function having fewer than m 2227 // parameters is viable only if it has an ellipsis in its parameter 2228 // list (8.3.5). 2229 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2230 Candidate.Viable = false; 2231 return; 2232 } 2233 2234 // (C++ 13.3.2p2): A candidate function having more than m parameters 2235 // is viable only if the (m+1)st parameter has a default argument 2236 // (8.3.6). For the purposes of overload resolution, the 2237 // parameter list is truncated on the right, so that there are 2238 // exactly m parameters. 2239 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2240 if (NumArgs < MinRequiredArgs) { 2241 // Not enough arguments. 2242 Candidate.Viable = false; 2243 return; 2244 } 2245 2246 Candidate.Viable = true; 2247 Candidate.Conversions.resize(NumArgs + 1); 2248 2249 if (Method->isStatic() || !Object) 2250 // The implicit object argument is ignored. 2251 Candidate.IgnoreObjectArgument = true; 2252 else { 2253 // Determine the implicit conversion sequence for the object 2254 // parameter. 2255 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2256 if (Candidate.Conversions[0].ConversionKind 2257 == ImplicitConversionSequence::BadConversion) { 2258 Candidate.Viable = false; 2259 return; 2260 } 2261 } 2262 2263 // Determine the implicit conversion sequences for each of the 2264 // arguments. 2265 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2266 if (ArgIdx < NumArgsInProto) { 2267 // (C++ 13.3.2p3): for F to be a viable function, there shall 2268 // exist for each argument an implicit conversion sequence 2269 // (13.3.3.1) that converts that argument to the corresponding 2270 // parameter of F. 2271 QualType ParamType = Proto->getArgType(ArgIdx); 2272 Candidate.Conversions[ArgIdx + 1] 2273 = TryCopyInitialization(Args[ArgIdx], ParamType, 2274 SuppressUserConversions, ForceRValue); 2275 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2276 == ImplicitConversionSequence::BadConversion) { 2277 Candidate.Viable = false; 2278 break; 2279 } 2280 } else { 2281 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2282 // argument for which there is no corresponding parameter is 2283 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2284 Candidate.Conversions[ArgIdx + 1].ConversionKind 2285 = ImplicitConversionSequence::EllipsisConversion; 2286 } 2287 } 2288} 2289 2290/// \brief Add a C++ member function template as a candidate to the candidate 2291/// set, using template argument deduction to produce an appropriate member 2292/// function template specialization. 2293void 2294Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2295 bool HasExplicitTemplateArgs, 2296 const TemplateArgument *ExplicitTemplateArgs, 2297 unsigned NumExplicitTemplateArgs, 2298 Expr *Object, Expr **Args, unsigned NumArgs, 2299 OverloadCandidateSet& CandidateSet, 2300 bool SuppressUserConversions, 2301 bool ForceRValue) { 2302 // C++ [over.match.funcs]p7: 2303 // In each case where a candidate is a function template, candidate 2304 // function template specializations are generated using template argument 2305 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2306 // candidate functions in the usual way.113) A given name can refer to one 2307 // or more function templates and also to a set of overloaded non-template 2308 // functions. In such a case, the candidate functions generated from each 2309 // function template are combined with the set of non-template candidate 2310 // functions. 2311 TemplateDeductionInfo Info(Context); 2312 FunctionDecl *Specialization = 0; 2313 if (TemplateDeductionResult Result 2314 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2315 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2316 Args, NumArgs, Specialization, Info)) { 2317 // FIXME: Record what happened with template argument deduction, so 2318 // that we can give the user a beautiful diagnostic. 2319 (void)Result; 2320 return; 2321 } 2322 2323 // Add the function template specialization produced by template argument 2324 // deduction as a candidate. 2325 assert(Specialization && "Missing member function template specialization?"); 2326 assert(isa<CXXMethodDecl>(Specialization) && 2327 "Specialization is not a member function?"); 2328 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2329 CandidateSet, SuppressUserConversions, ForceRValue); 2330} 2331 2332/// \brief Add a C++ function template specialization as a candidate 2333/// in the candidate set, using template argument deduction to produce 2334/// an appropriate function template specialization. 2335void 2336Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2337 bool HasExplicitTemplateArgs, 2338 const TemplateArgument *ExplicitTemplateArgs, 2339 unsigned NumExplicitTemplateArgs, 2340 Expr **Args, unsigned NumArgs, 2341 OverloadCandidateSet& CandidateSet, 2342 bool SuppressUserConversions, 2343 bool ForceRValue) { 2344 // C++ [over.match.funcs]p7: 2345 // In each case where a candidate is a function template, candidate 2346 // function template specializations are generated using template argument 2347 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2348 // candidate functions in the usual way.113) A given name can refer to one 2349 // or more function templates and also to a set of overloaded non-template 2350 // functions. In such a case, the candidate functions generated from each 2351 // function template are combined with the set of non-template candidate 2352 // functions. 2353 TemplateDeductionInfo Info(Context); 2354 FunctionDecl *Specialization = 0; 2355 if (TemplateDeductionResult Result 2356 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2357 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2358 Args, NumArgs, Specialization, Info)) { 2359 // FIXME: Record what happened with template argument deduction, so 2360 // that we can give the user a beautiful diagnostic. 2361 (void)Result; 2362 return; 2363 } 2364 2365 // Add the function template specialization produced by template argument 2366 // deduction as a candidate. 2367 assert(Specialization && "Missing function template specialization?"); 2368 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2369 SuppressUserConversions, ForceRValue); 2370} 2371 2372/// AddConversionCandidate - Add a C++ conversion function as a 2373/// candidate in the candidate set (C++ [over.match.conv], 2374/// C++ [over.match.copy]). From is the expression we're converting from, 2375/// and ToType is the type that we're eventually trying to convert to 2376/// (which may or may not be the same type as the type that the 2377/// conversion function produces). 2378void 2379Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2380 Expr *From, QualType ToType, 2381 OverloadCandidateSet& CandidateSet) { 2382 assert(!Conversion->getDescribedFunctionTemplate() && 2383 "Conversion function templates use AddTemplateConversionCandidate"); 2384 2385 // Add this candidate 2386 CandidateSet.push_back(OverloadCandidate()); 2387 OverloadCandidate& Candidate = CandidateSet.back(); 2388 Candidate.Function = Conversion; 2389 Candidate.IsSurrogate = false; 2390 Candidate.IgnoreObjectArgument = false; 2391 Candidate.FinalConversion.setAsIdentityConversion(); 2392 Candidate.FinalConversion.FromTypePtr 2393 = Conversion->getConversionType().getAsOpaquePtr(); 2394 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2395 2396 // Determine the implicit conversion sequence for the implicit 2397 // object parameter. 2398 Candidate.Viable = true; 2399 Candidate.Conversions.resize(1); 2400 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2401 2402 if (Candidate.Conversions[0].ConversionKind 2403 == ImplicitConversionSequence::BadConversion) { 2404 Candidate.Viable = false; 2405 return; 2406 } 2407 2408 // To determine what the conversion from the result of calling the 2409 // conversion function to the type we're eventually trying to 2410 // convert to (ToType), we need to synthesize a call to the 2411 // conversion function and attempt copy initialization from it. This 2412 // makes sure that we get the right semantics with respect to 2413 // lvalues/rvalues and the type. Fortunately, we can allocate this 2414 // call on the stack and we don't need its arguments to be 2415 // well-formed. 2416 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2417 SourceLocation()); 2418 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2419 CastExpr::CK_Unknown, 2420 &ConversionRef, false); 2421 2422 // Note that it is safe to allocate CallExpr on the stack here because 2423 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2424 // allocator). 2425 CallExpr Call(Context, &ConversionFn, 0, 0, 2426 Conversion->getConversionType().getNonReferenceType(), 2427 SourceLocation()); 2428 ImplicitConversionSequence ICS = TryCopyInitialization(&Call, ToType, true); 2429 switch (ICS.ConversionKind) { 2430 case ImplicitConversionSequence::StandardConversion: 2431 Candidate.FinalConversion = ICS.Standard; 2432 break; 2433 2434 case ImplicitConversionSequence::BadConversion: 2435 Candidate.Viable = false; 2436 break; 2437 2438 default: 2439 assert(false && 2440 "Can only end up with a standard conversion sequence or failure"); 2441 } 2442} 2443 2444/// \brief Adds a conversion function template specialization 2445/// candidate to the overload set, using template argument deduction 2446/// to deduce the template arguments of the conversion function 2447/// template from the type that we are converting to (C++ 2448/// [temp.deduct.conv]). 2449void 2450Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2451 Expr *From, QualType ToType, 2452 OverloadCandidateSet &CandidateSet) { 2453 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2454 "Only conversion function templates permitted here"); 2455 2456 TemplateDeductionInfo Info(Context); 2457 CXXConversionDecl *Specialization = 0; 2458 if (TemplateDeductionResult Result 2459 = DeduceTemplateArguments(FunctionTemplate, ToType, 2460 Specialization, Info)) { 2461 // FIXME: Record what happened with template argument deduction, so 2462 // that we can give the user a beautiful diagnostic. 2463 (void)Result; 2464 return; 2465 } 2466 2467 // Add the conversion function template specialization produced by 2468 // template argument deduction as a candidate. 2469 assert(Specialization && "Missing function template specialization?"); 2470 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2471} 2472 2473/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2474/// converts the given @c Object to a function pointer via the 2475/// conversion function @c Conversion, and then attempts to call it 2476/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2477/// the type of function that we'll eventually be calling. 2478void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2479 const FunctionProtoType *Proto, 2480 Expr *Object, Expr **Args, unsigned NumArgs, 2481 OverloadCandidateSet& CandidateSet) { 2482 CandidateSet.push_back(OverloadCandidate()); 2483 OverloadCandidate& Candidate = CandidateSet.back(); 2484 Candidate.Function = 0; 2485 Candidate.Surrogate = Conversion; 2486 Candidate.Viable = true; 2487 Candidate.IsSurrogate = true; 2488 Candidate.IgnoreObjectArgument = false; 2489 Candidate.Conversions.resize(NumArgs + 1); 2490 2491 // Determine the implicit conversion sequence for the implicit 2492 // object parameter. 2493 ImplicitConversionSequence ObjectInit 2494 = TryObjectArgumentInitialization(Object, Conversion); 2495 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2496 Candidate.Viable = false; 2497 return; 2498 } 2499 2500 // The first conversion is actually a user-defined conversion whose 2501 // first conversion is ObjectInit's standard conversion (which is 2502 // effectively a reference binding). Record it as such. 2503 Candidate.Conversions[0].ConversionKind 2504 = ImplicitConversionSequence::UserDefinedConversion; 2505 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2506 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2507 Candidate.Conversions[0].UserDefined.After 2508 = Candidate.Conversions[0].UserDefined.Before; 2509 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2510 2511 // Find the 2512 unsigned NumArgsInProto = Proto->getNumArgs(); 2513 2514 // (C++ 13.3.2p2): A candidate function having fewer than m 2515 // parameters is viable only if it has an ellipsis in its parameter 2516 // list (8.3.5). 2517 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2518 Candidate.Viable = false; 2519 return; 2520 } 2521 2522 // Function types don't have any default arguments, so just check if 2523 // we have enough arguments. 2524 if (NumArgs < NumArgsInProto) { 2525 // Not enough arguments. 2526 Candidate.Viable = false; 2527 return; 2528 } 2529 2530 // Determine the implicit conversion sequences for each of the 2531 // arguments. 2532 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2533 if (ArgIdx < NumArgsInProto) { 2534 // (C++ 13.3.2p3): for F to be a viable function, there shall 2535 // exist for each argument an implicit conversion sequence 2536 // (13.3.3.1) that converts that argument to the corresponding 2537 // parameter of F. 2538 QualType ParamType = Proto->getArgType(ArgIdx); 2539 Candidate.Conversions[ArgIdx + 1] 2540 = TryCopyInitialization(Args[ArgIdx], ParamType, 2541 /*SuppressUserConversions=*/false); 2542 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2543 == ImplicitConversionSequence::BadConversion) { 2544 Candidate.Viable = false; 2545 break; 2546 } 2547 } else { 2548 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2549 // argument for which there is no corresponding parameter is 2550 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2551 Candidate.Conversions[ArgIdx + 1].ConversionKind 2552 = ImplicitConversionSequence::EllipsisConversion; 2553 } 2554 } 2555} 2556 2557// FIXME: This will eventually be removed, once we've migrated all of the 2558// operator overloading logic over to the scheme used by binary operators, which 2559// works for template instantiation. 2560void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2561 SourceLocation OpLoc, 2562 Expr **Args, unsigned NumArgs, 2563 OverloadCandidateSet& CandidateSet, 2564 SourceRange OpRange) { 2565 2566 FunctionSet Functions; 2567 2568 QualType T1 = Args[0]->getType(); 2569 QualType T2; 2570 if (NumArgs > 1) 2571 T2 = Args[1]->getType(); 2572 2573 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2574 if (S) 2575 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2576 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2577 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2578 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2579 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2580} 2581 2582/// \brief Add overload candidates for overloaded operators that are 2583/// member functions. 2584/// 2585/// Add the overloaded operator candidates that are member functions 2586/// for the operator Op that was used in an operator expression such 2587/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2588/// CandidateSet will store the added overload candidates. (C++ 2589/// [over.match.oper]). 2590void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2591 SourceLocation OpLoc, 2592 Expr **Args, unsigned NumArgs, 2593 OverloadCandidateSet& CandidateSet, 2594 SourceRange OpRange) { 2595 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2596 2597 // C++ [over.match.oper]p3: 2598 // For a unary operator @ with an operand of a type whose 2599 // cv-unqualified version is T1, and for a binary operator @ with 2600 // a left operand of a type whose cv-unqualified version is T1 and 2601 // a right operand of a type whose cv-unqualified version is T2, 2602 // three sets of candidate functions, designated member 2603 // candidates, non-member candidates and built-in candidates, are 2604 // constructed as follows: 2605 QualType T1 = Args[0]->getType(); 2606 QualType T2; 2607 if (NumArgs > 1) 2608 T2 = Args[1]->getType(); 2609 2610 // -- If T1 is a class type, the set of member candidates is the 2611 // result of the qualified lookup of T1::operator@ 2612 // (13.3.1.1.1); otherwise, the set of member candidates is 2613 // empty. 2614 // FIXME: Lookup in base classes, too! 2615 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2616 DeclContext::lookup_const_iterator Oper, OperEnd; 2617 for (llvm::tie(Oper, OperEnd) = T1Rec->getDecl()->lookup(OpName); 2618 Oper != OperEnd; ++Oper) 2619 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2620 Args+1, NumArgs - 1, CandidateSet, 2621 /*SuppressUserConversions=*/false); 2622 } 2623} 2624 2625/// AddBuiltinCandidate - Add a candidate for a built-in 2626/// operator. ResultTy and ParamTys are the result and parameter types 2627/// of the built-in candidate, respectively. Args and NumArgs are the 2628/// arguments being passed to the candidate. IsAssignmentOperator 2629/// should be true when this built-in candidate is an assignment 2630/// operator. NumContextualBoolArguments is the number of arguments 2631/// (at the beginning of the argument list) that will be contextually 2632/// converted to bool. 2633void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2634 Expr **Args, unsigned NumArgs, 2635 OverloadCandidateSet& CandidateSet, 2636 bool IsAssignmentOperator, 2637 unsigned NumContextualBoolArguments) { 2638 // Add this candidate 2639 CandidateSet.push_back(OverloadCandidate()); 2640 OverloadCandidate& Candidate = CandidateSet.back(); 2641 Candidate.Function = 0; 2642 Candidate.IsSurrogate = false; 2643 Candidate.IgnoreObjectArgument = false; 2644 Candidate.BuiltinTypes.ResultTy = ResultTy; 2645 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2646 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2647 2648 // Determine the implicit conversion sequences for each of the 2649 // arguments. 2650 Candidate.Viable = true; 2651 Candidate.Conversions.resize(NumArgs); 2652 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2653 // C++ [over.match.oper]p4: 2654 // For the built-in assignment operators, conversions of the 2655 // left operand are restricted as follows: 2656 // -- no temporaries are introduced to hold the left operand, and 2657 // -- no user-defined conversions are applied to the left 2658 // operand to achieve a type match with the left-most 2659 // parameter of a built-in candidate. 2660 // 2661 // We block these conversions by turning off user-defined 2662 // conversions, since that is the only way that initialization of 2663 // a reference to a non-class type can occur from something that 2664 // is not of the same type. 2665 if (ArgIdx < NumContextualBoolArguments) { 2666 assert(ParamTys[ArgIdx] == Context.BoolTy && 2667 "Contextual conversion to bool requires bool type"); 2668 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2669 } else { 2670 Candidate.Conversions[ArgIdx] 2671 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2672 ArgIdx == 0 && IsAssignmentOperator); 2673 } 2674 if (Candidate.Conversions[ArgIdx].ConversionKind 2675 == ImplicitConversionSequence::BadConversion) { 2676 Candidate.Viable = false; 2677 break; 2678 } 2679 } 2680} 2681 2682/// BuiltinCandidateTypeSet - A set of types that will be used for the 2683/// candidate operator functions for built-in operators (C++ 2684/// [over.built]). The types are separated into pointer types and 2685/// enumeration types. 2686class BuiltinCandidateTypeSet { 2687 /// TypeSet - A set of types. 2688 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2689 2690 /// PointerTypes - The set of pointer types that will be used in the 2691 /// built-in candidates. 2692 TypeSet PointerTypes; 2693 2694 /// MemberPointerTypes - The set of member pointer types that will be 2695 /// used in the built-in candidates. 2696 TypeSet MemberPointerTypes; 2697 2698 /// EnumerationTypes - The set of enumeration types that will be 2699 /// used in the built-in candidates. 2700 TypeSet EnumerationTypes; 2701 2702 /// Context - The AST context in which we will build the type sets. 2703 ASTContext &Context; 2704 2705 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2706 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2707 2708public: 2709 /// iterator - Iterates through the types that are part of the set. 2710 typedef TypeSet::iterator iterator; 2711 2712 BuiltinCandidateTypeSet(ASTContext &Context) : Context(Context) { } 2713 2714 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2715 bool AllowExplicitConversions); 2716 2717 /// pointer_begin - First pointer type found; 2718 iterator pointer_begin() { return PointerTypes.begin(); } 2719 2720 /// pointer_end - Past the last pointer type found; 2721 iterator pointer_end() { return PointerTypes.end(); } 2722 2723 /// member_pointer_begin - First member pointer type found; 2724 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2725 2726 /// member_pointer_end - Past the last member pointer type found; 2727 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2728 2729 /// enumeration_begin - First enumeration type found; 2730 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2731 2732 /// enumeration_end - Past the last enumeration type found; 2733 iterator enumeration_end() { return EnumerationTypes.end(); } 2734}; 2735 2736/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2737/// the set of pointer types along with any more-qualified variants of 2738/// that type. For example, if @p Ty is "int const *", this routine 2739/// will add "int const *", "int const volatile *", "int const 2740/// restrict *", and "int const volatile restrict *" to the set of 2741/// pointer types. Returns true if the add of @p Ty itself succeeded, 2742/// false otherwise. 2743bool 2744BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2745 // Insert this type. 2746 if (!PointerTypes.insert(Ty)) 2747 return false; 2748 2749 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2750 QualType PointeeTy = PointerTy->getPointeeType(); 2751 // FIXME: Optimize this so that we don't keep trying to add the same types. 2752 2753 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal with all 2754 // pointer conversions that don't cast away constness? 2755 if (!PointeeTy.isConstQualified()) 2756 AddPointerWithMoreQualifiedTypeVariants 2757 (Context.getPointerType(PointeeTy.withConst())); 2758 if (!PointeeTy.isVolatileQualified()) 2759 AddPointerWithMoreQualifiedTypeVariants 2760 (Context.getPointerType(PointeeTy.withVolatile())); 2761 if (!PointeeTy.isRestrictQualified()) 2762 AddPointerWithMoreQualifiedTypeVariants 2763 (Context.getPointerType(PointeeTy.withRestrict())); 2764 } 2765 2766 return true; 2767} 2768 2769/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2770/// to the set of pointer types along with any more-qualified variants of 2771/// that type. For example, if @p Ty is "int const *", this routine 2772/// will add "int const *", "int const volatile *", "int const 2773/// restrict *", and "int const volatile restrict *" to the set of 2774/// pointer types. Returns true if the add of @p Ty itself succeeded, 2775/// false otherwise. 2776bool 2777BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2778 QualType Ty) { 2779 // Insert this type. 2780 if (!MemberPointerTypes.insert(Ty)) 2781 return false; 2782 2783 if (const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>()) { 2784 QualType PointeeTy = PointerTy->getPointeeType(); 2785 const Type *ClassTy = PointerTy->getClass(); 2786 // FIXME: Optimize this so that we don't keep trying to add the same types. 2787 2788 if (!PointeeTy.isConstQualified()) 2789 AddMemberPointerWithMoreQualifiedTypeVariants 2790 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2791 if (!PointeeTy.isVolatileQualified()) 2792 AddMemberPointerWithMoreQualifiedTypeVariants 2793 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2794 if (!PointeeTy.isRestrictQualified()) 2795 AddMemberPointerWithMoreQualifiedTypeVariants 2796 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2797 } 2798 2799 return true; 2800} 2801 2802/// AddTypesConvertedFrom - Add each of the types to which the type @p 2803/// Ty can be implicit converted to the given set of @p Types. We're 2804/// primarily interested in pointer types and enumeration types. We also 2805/// take member pointer types, for the conditional operator. 2806/// AllowUserConversions is true if we should look at the conversion 2807/// functions of a class type, and AllowExplicitConversions if we 2808/// should also include the explicit conversion functions of a class 2809/// type. 2810void 2811BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2812 bool AllowUserConversions, 2813 bool AllowExplicitConversions) { 2814 // Only deal with canonical types. 2815 Ty = Context.getCanonicalType(Ty); 2816 2817 // Look through reference types; they aren't part of the type of an 2818 // expression for the purposes of conversions. 2819 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 2820 Ty = RefTy->getPointeeType(); 2821 2822 // We don't care about qualifiers on the type. 2823 Ty = Ty.getUnqualifiedType(); 2824 2825 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2826 QualType PointeeTy = PointerTy->getPointeeType(); 2827 2828 // Insert our type, and its more-qualified variants, into the set 2829 // of types. 2830 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2831 return; 2832 2833 // Add 'cv void*' to our set of types. 2834 if (!Ty->isVoidType()) { 2835 QualType QualVoid 2836 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2837 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2838 } 2839 2840 // If this is a pointer to a class type, add pointers to its bases 2841 // (with the same level of cv-qualification as the original 2842 // derived class, of course). 2843 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 2844 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2845 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2846 Base != ClassDecl->bases_end(); ++Base) { 2847 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2848 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2849 2850 // Add the pointer type, recursively, so that we get all of 2851 // the indirect base classes, too. 2852 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2853 } 2854 } 2855 } else if (Ty->isMemberPointerType()) { 2856 // Member pointers are far easier, since the pointee can't be converted. 2857 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2858 return; 2859 } else if (Ty->isEnumeralType()) { 2860 EnumerationTypes.insert(Ty); 2861 } else if (AllowUserConversions) { 2862 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 2863 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2864 // FIXME: Visit conversion functions in the base classes, too. 2865 OverloadedFunctionDecl *Conversions 2866 = ClassDecl->getConversionFunctions(); 2867 for (OverloadedFunctionDecl::function_iterator Func 2868 = Conversions->function_begin(); 2869 Func != Conversions->function_end(); ++Func) { 2870 CXXConversionDecl *Conv; 2871 FunctionTemplateDecl *ConvTemplate; 2872 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 2873 2874 // Skip conversion function templates; they don't tell us anything 2875 // about which builtin types we can convert to. 2876 if (ConvTemplate) 2877 continue; 2878 2879 if (AllowExplicitConversions || !Conv->isExplicit()) 2880 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2881 } 2882 } 2883 } 2884} 2885 2886/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2887/// operator overloads to the candidate set (C++ [over.built]), based 2888/// on the operator @p Op and the arguments given. For example, if the 2889/// operator is a binary '+', this routine might add "int 2890/// operator+(int, int)" to cover integer addition. 2891void 2892Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2893 Expr **Args, unsigned NumArgs, 2894 OverloadCandidateSet& CandidateSet) { 2895 // The set of "promoted arithmetic types", which are the arithmetic 2896 // types are that preserved by promotion (C++ [over.built]p2). Note 2897 // that the first few of these types are the promoted integral 2898 // types; these types need to be first. 2899 // FIXME: What about complex? 2900 const unsigned FirstIntegralType = 0; 2901 const unsigned LastIntegralType = 13; 2902 const unsigned FirstPromotedIntegralType = 7, 2903 LastPromotedIntegralType = 13; 2904 const unsigned FirstPromotedArithmeticType = 7, 2905 LastPromotedArithmeticType = 16; 2906 const unsigned NumArithmeticTypes = 16; 2907 QualType ArithmeticTypes[NumArithmeticTypes] = { 2908 Context.BoolTy, Context.CharTy, Context.WCharTy, 2909// Context.Char16Ty, Context.Char32Ty, 2910 Context.SignedCharTy, Context.ShortTy, 2911 Context.UnsignedCharTy, Context.UnsignedShortTy, 2912 Context.IntTy, Context.LongTy, Context.LongLongTy, 2913 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 2914 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 2915 }; 2916 2917 // Find all of the types that the arguments can convert to, but only 2918 // if the operator we're looking at has built-in operator candidates 2919 // that make use of these types. 2920 BuiltinCandidateTypeSet CandidateTypes(Context); 2921 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 2922 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 2923 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 2924 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 2925 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 2926 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 2927 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2928 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 2929 true, 2930 (Op == OO_Exclaim || 2931 Op == OO_AmpAmp || 2932 Op == OO_PipePipe)); 2933 } 2934 2935 bool isComparison = false; 2936 switch (Op) { 2937 case OO_None: 2938 case NUM_OVERLOADED_OPERATORS: 2939 assert(false && "Expected an overloaded operator"); 2940 break; 2941 2942 case OO_Star: // '*' is either unary or binary 2943 if (NumArgs == 1) 2944 goto UnaryStar; 2945 else 2946 goto BinaryStar; 2947 break; 2948 2949 case OO_Plus: // '+' is either unary or binary 2950 if (NumArgs == 1) 2951 goto UnaryPlus; 2952 else 2953 goto BinaryPlus; 2954 break; 2955 2956 case OO_Minus: // '-' is either unary or binary 2957 if (NumArgs == 1) 2958 goto UnaryMinus; 2959 else 2960 goto BinaryMinus; 2961 break; 2962 2963 case OO_Amp: // '&' is either unary or binary 2964 if (NumArgs == 1) 2965 goto UnaryAmp; 2966 else 2967 goto BinaryAmp; 2968 2969 case OO_PlusPlus: 2970 case OO_MinusMinus: 2971 // C++ [over.built]p3: 2972 // 2973 // For every pair (T, VQ), where T is an arithmetic type, and VQ 2974 // is either volatile or empty, there exist candidate operator 2975 // functions of the form 2976 // 2977 // VQ T& operator++(VQ T&); 2978 // T operator++(VQ T&, int); 2979 // 2980 // C++ [over.built]p4: 2981 // 2982 // For every pair (T, VQ), where T is an arithmetic type other 2983 // than bool, and VQ is either volatile or empty, there exist 2984 // candidate operator functions of the form 2985 // 2986 // VQ T& operator--(VQ T&); 2987 // T operator--(VQ T&, int); 2988 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 2989 Arith < NumArithmeticTypes; ++Arith) { 2990 QualType ArithTy = ArithmeticTypes[Arith]; 2991 QualType ParamTypes[2] 2992 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 2993 2994 // Non-volatile version. 2995 if (NumArgs == 1) 2996 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2997 else 2998 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2999 3000 // Volatile version 3001 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 3002 if (NumArgs == 1) 3003 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3004 else 3005 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3006 } 3007 3008 // C++ [over.built]p5: 3009 // 3010 // For every pair (T, VQ), where T is a cv-qualified or 3011 // cv-unqualified object type, and VQ is either volatile or 3012 // empty, there exist candidate operator functions of the form 3013 // 3014 // T*VQ& operator++(T*VQ&); 3015 // T*VQ& operator--(T*VQ&); 3016 // T* operator++(T*VQ&, int); 3017 // T* operator--(T*VQ&, int); 3018 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3019 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3020 // Skip pointer types that aren't pointers to object types. 3021 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3022 continue; 3023 3024 QualType ParamTypes[2] = { 3025 Context.getLValueReferenceType(*Ptr), Context.IntTy 3026 }; 3027 3028 // Without volatile 3029 if (NumArgs == 1) 3030 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3031 else 3032 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3033 3034 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3035 // With volatile 3036 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3037 if (NumArgs == 1) 3038 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3039 else 3040 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3041 } 3042 } 3043 break; 3044 3045 UnaryStar: 3046 // C++ [over.built]p6: 3047 // For every cv-qualified or cv-unqualified object type T, there 3048 // exist candidate operator functions of the form 3049 // 3050 // T& operator*(T*); 3051 // 3052 // C++ [over.built]p7: 3053 // For every function type T, there exist candidate operator 3054 // functions of the form 3055 // T& operator*(T*); 3056 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3057 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3058 QualType ParamTy = *Ptr; 3059 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3060 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3061 &ParamTy, Args, 1, CandidateSet); 3062 } 3063 break; 3064 3065 UnaryPlus: 3066 // C++ [over.built]p8: 3067 // For every type T, there exist candidate operator functions of 3068 // the form 3069 // 3070 // T* operator+(T*); 3071 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3072 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3073 QualType ParamTy = *Ptr; 3074 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3075 } 3076 3077 // Fall through 3078 3079 UnaryMinus: 3080 // C++ [over.built]p9: 3081 // For every promoted arithmetic type T, there exist candidate 3082 // operator functions of the form 3083 // 3084 // T operator+(T); 3085 // T operator-(T); 3086 for (unsigned Arith = FirstPromotedArithmeticType; 3087 Arith < LastPromotedArithmeticType; ++Arith) { 3088 QualType ArithTy = ArithmeticTypes[Arith]; 3089 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3090 } 3091 break; 3092 3093 case OO_Tilde: 3094 // C++ [over.built]p10: 3095 // For every promoted integral type T, there exist candidate 3096 // operator functions of the form 3097 // 3098 // T operator~(T); 3099 for (unsigned Int = FirstPromotedIntegralType; 3100 Int < LastPromotedIntegralType; ++Int) { 3101 QualType IntTy = ArithmeticTypes[Int]; 3102 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3103 } 3104 break; 3105 3106 case OO_New: 3107 case OO_Delete: 3108 case OO_Array_New: 3109 case OO_Array_Delete: 3110 case OO_Call: 3111 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3112 break; 3113 3114 case OO_Comma: 3115 UnaryAmp: 3116 case OO_Arrow: 3117 // C++ [over.match.oper]p3: 3118 // -- For the operator ',', the unary operator '&', or the 3119 // operator '->', the built-in candidates set is empty. 3120 break; 3121 3122 case OO_Less: 3123 case OO_Greater: 3124 case OO_LessEqual: 3125 case OO_GreaterEqual: 3126 case OO_EqualEqual: 3127 case OO_ExclaimEqual: 3128 // C++ [over.built]p15: 3129 // 3130 // For every pointer or enumeration type T, there exist 3131 // candidate operator functions of the form 3132 // 3133 // bool operator<(T, T); 3134 // bool operator>(T, T); 3135 // bool operator<=(T, T); 3136 // bool operator>=(T, T); 3137 // bool operator==(T, T); 3138 // bool operator!=(T, T); 3139 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3140 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3141 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3142 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3143 } 3144 for (BuiltinCandidateTypeSet::iterator Enum 3145 = CandidateTypes.enumeration_begin(); 3146 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3147 QualType ParamTypes[2] = { *Enum, *Enum }; 3148 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3149 } 3150 3151 // Fall through. 3152 isComparison = true; 3153 3154 BinaryPlus: 3155 BinaryMinus: 3156 if (!isComparison) { 3157 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3158 3159 // C++ [over.built]p13: 3160 // 3161 // For every cv-qualified or cv-unqualified object type T 3162 // there exist candidate operator functions of the form 3163 // 3164 // T* operator+(T*, ptrdiff_t); 3165 // T& operator[](T*, ptrdiff_t); [BELOW] 3166 // T* operator-(T*, ptrdiff_t); 3167 // T* operator+(ptrdiff_t, T*); 3168 // T& operator[](ptrdiff_t, T*); [BELOW] 3169 // 3170 // C++ [over.built]p14: 3171 // 3172 // For every T, where T is a pointer to object type, there 3173 // exist candidate operator functions of the form 3174 // 3175 // ptrdiff_t operator-(T, T); 3176 for (BuiltinCandidateTypeSet::iterator Ptr 3177 = CandidateTypes.pointer_begin(); 3178 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3179 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3180 3181 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3182 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3183 3184 if (Op == OO_Plus) { 3185 // T* operator+(ptrdiff_t, T*); 3186 ParamTypes[0] = ParamTypes[1]; 3187 ParamTypes[1] = *Ptr; 3188 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3189 } else { 3190 // ptrdiff_t operator-(T, T); 3191 ParamTypes[1] = *Ptr; 3192 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3193 Args, 2, CandidateSet); 3194 } 3195 } 3196 } 3197 // Fall through 3198 3199 case OO_Slash: 3200 BinaryStar: 3201 Conditional: 3202 // C++ [over.built]p12: 3203 // 3204 // For every pair of promoted arithmetic types L and R, there 3205 // exist candidate operator functions of the form 3206 // 3207 // LR operator*(L, R); 3208 // LR operator/(L, R); 3209 // LR operator+(L, R); 3210 // LR operator-(L, R); 3211 // bool operator<(L, R); 3212 // bool operator>(L, R); 3213 // bool operator<=(L, R); 3214 // bool operator>=(L, R); 3215 // bool operator==(L, R); 3216 // bool operator!=(L, R); 3217 // 3218 // where LR is the result of the usual arithmetic conversions 3219 // between types L and R. 3220 // 3221 // C++ [over.built]p24: 3222 // 3223 // For every pair of promoted arithmetic types L and R, there exist 3224 // candidate operator functions of the form 3225 // 3226 // LR operator?(bool, L, R); 3227 // 3228 // where LR is the result of the usual arithmetic conversions 3229 // between types L and R. 3230 // Our candidates ignore the first parameter. 3231 for (unsigned Left = FirstPromotedArithmeticType; 3232 Left < LastPromotedArithmeticType; ++Left) { 3233 for (unsigned Right = FirstPromotedArithmeticType; 3234 Right < LastPromotedArithmeticType; ++Right) { 3235 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3236 QualType Result 3237 = isComparison 3238 ? Context.BoolTy 3239 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3240 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3241 } 3242 } 3243 break; 3244 3245 case OO_Percent: 3246 BinaryAmp: 3247 case OO_Caret: 3248 case OO_Pipe: 3249 case OO_LessLess: 3250 case OO_GreaterGreater: 3251 // C++ [over.built]p17: 3252 // 3253 // For every pair of promoted integral types L and R, there 3254 // exist candidate operator functions of the form 3255 // 3256 // LR operator%(L, R); 3257 // LR operator&(L, R); 3258 // LR operator^(L, R); 3259 // LR operator|(L, R); 3260 // L operator<<(L, R); 3261 // L operator>>(L, R); 3262 // 3263 // where LR is the result of the usual arithmetic conversions 3264 // between types L and R. 3265 for (unsigned Left = FirstPromotedIntegralType; 3266 Left < LastPromotedIntegralType; ++Left) { 3267 for (unsigned Right = FirstPromotedIntegralType; 3268 Right < LastPromotedIntegralType; ++Right) { 3269 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3270 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3271 ? LandR[0] 3272 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3273 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3274 } 3275 } 3276 break; 3277 3278 case OO_Equal: 3279 // C++ [over.built]p20: 3280 // 3281 // For every pair (T, VQ), where T is an enumeration or 3282 // (FIXME:) pointer to member type and VQ is either volatile or 3283 // empty, there exist candidate operator functions of the form 3284 // 3285 // VQ T& operator=(VQ T&, T); 3286 for (BuiltinCandidateTypeSet::iterator Enum 3287 = CandidateTypes.enumeration_begin(); 3288 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3289 QualType ParamTypes[2]; 3290 3291 // T& operator=(T&, T) 3292 ParamTypes[0] = Context.getLValueReferenceType(*Enum); 3293 ParamTypes[1] = *Enum; 3294 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3295 /*IsAssignmentOperator=*/false); 3296 3297 if (!Context.getCanonicalType(*Enum).isVolatileQualified()) { 3298 // volatile T& operator=(volatile T&, T) 3299 ParamTypes[0] = Context.getLValueReferenceType((*Enum).withVolatile()); 3300 ParamTypes[1] = *Enum; 3301 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3302 /*IsAssignmentOperator=*/false); 3303 } 3304 } 3305 // Fall through. 3306 3307 case OO_PlusEqual: 3308 case OO_MinusEqual: 3309 // C++ [over.built]p19: 3310 // 3311 // For every pair (T, VQ), where T is any type and VQ is either 3312 // volatile or empty, there exist candidate operator functions 3313 // of the form 3314 // 3315 // T*VQ& operator=(T*VQ&, T*); 3316 // 3317 // C++ [over.built]p21: 3318 // 3319 // For every pair (T, VQ), where T is a cv-qualified or 3320 // cv-unqualified object type and VQ is either volatile or 3321 // empty, there exist candidate operator functions of the form 3322 // 3323 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3324 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3325 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3326 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3327 QualType ParamTypes[2]; 3328 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3329 3330 // non-volatile version 3331 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3332 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3333 /*IsAssigmentOperator=*/Op == OO_Equal); 3334 3335 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3336 // volatile version 3337 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3338 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3339 /*IsAssigmentOperator=*/Op == OO_Equal); 3340 } 3341 } 3342 // Fall through. 3343 3344 case OO_StarEqual: 3345 case OO_SlashEqual: 3346 // C++ [over.built]p18: 3347 // 3348 // For every triple (L, VQ, R), where L is an arithmetic type, 3349 // VQ is either volatile or empty, and R is a promoted 3350 // arithmetic type, there exist candidate operator functions of 3351 // the form 3352 // 3353 // VQ L& operator=(VQ L&, R); 3354 // VQ L& operator*=(VQ L&, R); 3355 // VQ L& operator/=(VQ L&, R); 3356 // VQ L& operator+=(VQ L&, R); 3357 // VQ L& operator-=(VQ L&, R); 3358 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3359 for (unsigned Right = FirstPromotedArithmeticType; 3360 Right < LastPromotedArithmeticType; ++Right) { 3361 QualType ParamTypes[2]; 3362 ParamTypes[1] = ArithmeticTypes[Right]; 3363 3364 // Add this built-in operator as a candidate (VQ is empty). 3365 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3366 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3367 /*IsAssigmentOperator=*/Op == OO_Equal); 3368 3369 // Add this built-in operator as a candidate (VQ is 'volatile'). 3370 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3371 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3372 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3373 /*IsAssigmentOperator=*/Op == OO_Equal); 3374 } 3375 } 3376 break; 3377 3378 case OO_PercentEqual: 3379 case OO_LessLessEqual: 3380 case OO_GreaterGreaterEqual: 3381 case OO_AmpEqual: 3382 case OO_CaretEqual: 3383 case OO_PipeEqual: 3384 // C++ [over.built]p22: 3385 // 3386 // For every triple (L, VQ, R), where L is an integral type, VQ 3387 // is either volatile or empty, and R is a promoted integral 3388 // type, there exist candidate operator functions of the form 3389 // 3390 // VQ L& operator%=(VQ L&, R); 3391 // VQ L& operator<<=(VQ L&, R); 3392 // VQ L& operator>>=(VQ L&, R); 3393 // VQ L& operator&=(VQ L&, R); 3394 // VQ L& operator^=(VQ L&, R); 3395 // VQ L& operator|=(VQ L&, R); 3396 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3397 for (unsigned Right = FirstPromotedIntegralType; 3398 Right < LastPromotedIntegralType; ++Right) { 3399 QualType ParamTypes[2]; 3400 ParamTypes[1] = ArithmeticTypes[Right]; 3401 3402 // Add this built-in operator as a candidate (VQ is empty). 3403 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3404 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3405 3406 // Add this built-in operator as a candidate (VQ is 'volatile'). 3407 ParamTypes[0] = ArithmeticTypes[Left]; 3408 ParamTypes[0].addVolatile(); 3409 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3410 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3411 } 3412 } 3413 break; 3414 3415 case OO_Exclaim: { 3416 // C++ [over.operator]p23: 3417 // 3418 // There also exist candidate operator functions of the form 3419 // 3420 // bool operator!(bool); 3421 // bool operator&&(bool, bool); [BELOW] 3422 // bool operator||(bool, bool); [BELOW] 3423 QualType ParamTy = Context.BoolTy; 3424 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3425 /*IsAssignmentOperator=*/false, 3426 /*NumContextualBoolArguments=*/1); 3427 break; 3428 } 3429 3430 case OO_AmpAmp: 3431 case OO_PipePipe: { 3432 // C++ [over.operator]p23: 3433 // 3434 // There also exist candidate operator functions of the form 3435 // 3436 // bool operator!(bool); [ABOVE] 3437 // bool operator&&(bool, bool); 3438 // bool operator||(bool, bool); 3439 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3440 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3441 /*IsAssignmentOperator=*/false, 3442 /*NumContextualBoolArguments=*/2); 3443 break; 3444 } 3445 3446 case OO_Subscript: 3447 // C++ [over.built]p13: 3448 // 3449 // For every cv-qualified or cv-unqualified object type T there 3450 // exist candidate operator functions of the form 3451 // 3452 // T* operator+(T*, ptrdiff_t); [ABOVE] 3453 // T& operator[](T*, ptrdiff_t); 3454 // T* operator-(T*, ptrdiff_t); [ABOVE] 3455 // T* operator+(ptrdiff_t, T*); [ABOVE] 3456 // T& operator[](ptrdiff_t, T*); 3457 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3458 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3459 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3460 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3461 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3462 3463 // T& operator[](T*, ptrdiff_t) 3464 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3465 3466 // T& operator[](ptrdiff_t, T*); 3467 ParamTypes[0] = ParamTypes[1]; 3468 ParamTypes[1] = *Ptr; 3469 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3470 } 3471 break; 3472 3473 case OO_ArrowStar: 3474 // FIXME: No support for pointer-to-members yet. 3475 break; 3476 3477 case OO_Conditional: 3478 // Note that we don't consider the first argument, since it has been 3479 // contextually converted to bool long ago. The candidates below are 3480 // therefore added as binary. 3481 // 3482 // C++ [over.built]p24: 3483 // For every type T, where T is a pointer or pointer-to-member type, 3484 // there exist candidate operator functions of the form 3485 // 3486 // T operator?(bool, T, T); 3487 // 3488 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3489 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3490 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3491 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3492 } 3493 for (BuiltinCandidateTypeSet::iterator Ptr = 3494 CandidateTypes.member_pointer_begin(), 3495 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3496 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3497 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3498 } 3499 goto Conditional; 3500 } 3501} 3502 3503/// \brief Add function candidates found via argument-dependent lookup 3504/// to the set of overloading candidates. 3505/// 3506/// This routine performs argument-dependent name lookup based on the 3507/// given function name (which may also be an operator name) and adds 3508/// all of the overload candidates found by ADL to the overload 3509/// candidate set (C++ [basic.lookup.argdep]). 3510void 3511Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3512 Expr **Args, unsigned NumArgs, 3513 OverloadCandidateSet& CandidateSet) { 3514 FunctionSet Functions; 3515 3516 // Record all of the function candidates that we've already 3517 // added to the overload set, so that we don't add those same 3518 // candidates a second time. 3519 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3520 CandEnd = CandidateSet.end(); 3521 Cand != CandEnd; ++Cand) 3522 if (Cand->Function) { 3523 Functions.insert(Cand->Function); 3524 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3525 Functions.insert(FunTmpl); 3526 } 3527 3528 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3529 3530 // Erase all of the candidates we already knew about. 3531 // FIXME: This is suboptimal. Is there a better way? 3532 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3533 CandEnd = CandidateSet.end(); 3534 Cand != CandEnd; ++Cand) 3535 if (Cand->Function) { 3536 Functions.erase(Cand->Function); 3537 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3538 Functions.erase(FunTmpl); 3539 } 3540 3541 // For each of the ADL candidates we found, add it to the overload 3542 // set. 3543 for (FunctionSet::iterator Func = Functions.begin(), 3544 FuncEnd = Functions.end(); 3545 Func != FuncEnd; ++Func) { 3546 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) 3547 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet); 3548 else 3549 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3550 /*FIXME: explicit args */false, 0, 0, 3551 Args, NumArgs, CandidateSet); 3552 } 3553} 3554 3555/// isBetterOverloadCandidate - Determines whether the first overload 3556/// candidate is a better candidate than the second (C++ 13.3.3p1). 3557bool 3558Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3559 const OverloadCandidate& Cand2) 3560{ 3561 // Define viable functions to be better candidates than non-viable 3562 // functions. 3563 if (!Cand2.Viable) 3564 return Cand1.Viable; 3565 else if (!Cand1.Viable) 3566 return false; 3567 3568 // C++ [over.match.best]p1: 3569 // 3570 // -- if F is a static member function, ICS1(F) is defined such 3571 // that ICS1(F) is neither better nor worse than ICS1(G) for 3572 // any function G, and, symmetrically, ICS1(G) is neither 3573 // better nor worse than ICS1(F). 3574 unsigned StartArg = 0; 3575 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3576 StartArg = 1; 3577 3578 // C++ [over.match.best]p1: 3579 // A viable function F1 is defined to be a better function than another 3580 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3581 // conversion sequence than ICSi(F2), and then... 3582 unsigned NumArgs = Cand1.Conversions.size(); 3583 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3584 bool HasBetterConversion = false; 3585 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3586 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3587 Cand2.Conversions[ArgIdx])) { 3588 case ImplicitConversionSequence::Better: 3589 // Cand1 has a better conversion sequence. 3590 HasBetterConversion = true; 3591 break; 3592 3593 case ImplicitConversionSequence::Worse: 3594 // Cand1 can't be better than Cand2. 3595 return false; 3596 3597 case ImplicitConversionSequence::Indistinguishable: 3598 // Do nothing. 3599 break; 3600 } 3601 } 3602 3603 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3604 // ICSj(F2), or, if not that, 3605 if (HasBetterConversion) 3606 return true; 3607 3608 // - F1 is a non-template function and F2 is a function template 3609 // specialization, or, if not that, 3610 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3611 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3612 return true; 3613 3614 // -- F1 and F2 are function template specializations, and the function 3615 // template for F1 is more specialized than the template for F2 3616 // according to the partial ordering rules described in 14.5.5.2, or, 3617 // if not that, 3618 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3619 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3620 if (FunctionTemplateDecl *BetterTemplate 3621 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 3622 Cand2.Function->getPrimaryTemplate(), 3623 true)) 3624 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 3625 3626 // -- the context is an initialization by user-defined conversion 3627 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3628 // from the return type of F1 to the destination type (i.e., 3629 // the type of the entity being initialized) is a better 3630 // conversion sequence than the standard conversion sequence 3631 // from the return type of F2 to the destination type. 3632 if (Cand1.Function && Cand2.Function && 3633 isa<CXXConversionDecl>(Cand1.Function) && 3634 isa<CXXConversionDecl>(Cand2.Function)) { 3635 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3636 Cand2.FinalConversion)) { 3637 case ImplicitConversionSequence::Better: 3638 // Cand1 has a better conversion sequence. 3639 return true; 3640 3641 case ImplicitConversionSequence::Worse: 3642 // Cand1 can't be better than Cand2. 3643 return false; 3644 3645 case ImplicitConversionSequence::Indistinguishable: 3646 // Do nothing 3647 break; 3648 } 3649 } 3650 3651 return false; 3652} 3653 3654/// \brief Computes the best viable function (C++ 13.3.3) 3655/// within an overload candidate set. 3656/// 3657/// \param CandidateSet the set of candidate functions. 3658/// 3659/// \param Loc the location of the function name (or operator symbol) for 3660/// which overload resolution occurs. 3661/// 3662/// \param Best f overload resolution was successful or found a deleted 3663/// function, Best points to the candidate function found. 3664/// 3665/// \returns The result of overload resolution. 3666Sema::OverloadingResult 3667Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3668 SourceLocation Loc, 3669 OverloadCandidateSet::iterator& Best) 3670{ 3671 // Find the best viable function. 3672 Best = CandidateSet.end(); 3673 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3674 Cand != CandidateSet.end(); ++Cand) { 3675 if (Cand->Viable) { 3676 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3677 Best = Cand; 3678 } 3679 } 3680 3681 // If we didn't find any viable functions, abort. 3682 if (Best == CandidateSet.end()) 3683 return OR_No_Viable_Function; 3684 3685 // Make sure that this function is better than every other viable 3686 // function. If not, we have an ambiguity. 3687 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3688 Cand != CandidateSet.end(); ++Cand) { 3689 if (Cand->Viable && 3690 Cand != Best && 3691 !isBetterOverloadCandidate(*Best, *Cand)) { 3692 Best = CandidateSet.end(); 3693 return OR_Ambiguous; 3694 } 3695 } 3696 3697 // Best is the best viable function. 3698 if (Best->Function && 3699 (Best->Function->isDeleted() || 3700 Best->Function->getAttr<UnavailableAttr>())) 3701 return OR_Deleted; 3702 3703 // C++ [basic.def.odr]p2: 3704 // An overloaded function is used if it is selected by overload resolution 3705 // when referred to from a potentially-evaluated expression. [Note: this 3706 // covers calls to named functions (5.2.2), operator overloading 3707 // (clause 13), user-defined conversions (12.3.2), allocation function for 3708 // placement new (5.3.4), as well as non-default initialization (8.5). 3709 if (Best->Function) 3710 MarkDeclarationReferenced(Loc, Best->Function); 3711 return OR_Success; 3712} 3713 3714/// PrintOverloadCandidates - When overload resolution fails, prints 3715/// diagnostic messages containing the candidates in the candidate 3716/// set. If OnlyViable is true, only viable candidates will be printed. 3717void 3718Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3719 bool OnlyViable) 3720{ 3721 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3722 LastCand = CandidateSet.end(); 3723 for (; Cand != LastCand; ++Cand) { 3724 if (Cand->Viable || !OnlyViable) { 3725 if (Cand->Function) { 3726 if (Cand->Function->isDeleted() || 3727 Cand->Function->getAttr<UnavailableAttr>()) { 3728 // Deleted or "unavailable" function. 3729 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3730 << Cand->Function->isDeleted(); 3731 } else { 3732 // Normal function 3733 // FIXME: Give a better reason! 3734 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3735 } 3736 } else if (Cand->IsSurrogate) { 3737 // Desugar the type of the surrogate down to a function type, 3738 // retaining as many typedefs as possible while still showing 3739 // the function type (and, therefore, its parameter types). 3740 QualType FnType = Cand->Surrogate->getConversionType(); 3741 bool isLValueReference = false; 3742 bool isRValueReference = false; 3743 bool isPointer = false; 3744 if (const LValueReferenceType *FnTypeRef = 3745 FnType->getAs<LValueReferenceType>()) { 3746 FnType = FnTypeRef->getPointeeType(); 3747 isLValueReference = true; 3748 } else if (const RValueReferenceType *FnTypeRef = 3749 FnType->getAs<RValueReferenceType>()) { 3750 FnType = FnTypeRef->getPointeeType(); 3751 isRValueReference = true; 3752 } 3753 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 3754 FnType = FnTypePtr->getPointeeType(); 3755 isPointer = true; 3756 } 3757 // Desugar down to a function type. 3758 FnType = QualType(FnType->getAsFunctionType(), 0); 3759 // Reconstruct the pointer/reference as appropriate. 3760 if (isPointer) FnType = Context.getPointerType(FnType); 3761 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3762 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3763 3764 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3765 << FnType; 3766 } else { 3767 // FIXME: We need to get the identifier in here 3768 // FIXME: Do we want the error message to point at the operator? 3769 // (built-ins won't have a location) 3770 QualType FnType 3771 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3772 Cand->BuiltinTypes.ParamTypes, 3773 Cand->Conversions.size(), 3774 false, 0); 3775 3776 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3777 } 3778 } 3779 } 3780} 3781 3782/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3783/// an overloaded function (C++ [over.over]), where @p From is an 3784/// expression with overloaded function type and @p ToType is the type 3785/// we're trying to resolve to. For example: 3786/// 3787/// @code 3788/// int f(double); 3789/// int f(int); 3790/// 3791/// int (*pfd)(double) = f; // selects f(double) 3792/// @endcode 3793/// 3794/// This routine returns the resulting FunctionDecl if it could be 3795/// resolved, and NULL otherwise. When @p Complain is true, this 3796/// routine will emit diagnostics if there is an error. 3797FunctionDecl * 3798Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3799 bool Complain) { 3800 QualType FunctionType = ToType; 3801 bool IsMember = false; 3802 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 3803 FunctionType = ToTypePtr->getPointeeType(); 3804 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 3805 FunctionType = ToTypeRef->getPointeeType(); 3806 else if (const MemberPointerType *MemTypePtr = 3807 ToType->getAs<MemberPointerType>()) { 3808 FunctionType = MemTypePtr->getPointeeType(); 3809 IsMember = true; 3810 } 3811 3812 // We only look at pointers or references to functions. 3813 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 3814 if (!FunctionType->isFunctionType()) 3815 return 0; 3816 3817 // Find the actual overloaded function declaration. 3818 OverloadedFunctionDecl *Ovl = 0; 3819 3820 // C++ [over.over]p1: 3821 // [...] [Note: any redundant set of parentheses surrounding the 3822 // overloaded function name is ignored (5.1). ] 3823 Expr *OvlExpr = From->IgnoreParens(); 3824 3825 // C++ [over.over]p1: 3826 // [...] The overloaded function name can be preceded by the & 3827 // operator. 3828 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3829 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3830 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3831 } 3832 3833 // Try to dig out the overloaded function. 3834 FunctionTemplateDecl *FunctionTemplate = 0; 3835 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 3836 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3837 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 3838 } 3839 3840 // If there's no overloaded function declaration or function template, 3841 // we're done. 3842 if (!Ovl && !FunctionTemplate) 3843 return 0; 3844 3845 OverloadIterator Fun; 3846 if (Ovl) 3847 Fun = Ovl; 3848 else 3849 Fun = FunctionTemplate; 3850 3851 // Look through all of the overloaded functions, searching for one 3852 // whose type matches exactly. 3853 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 3854 3855 bool FoundNonTemplateFunction = false; 3856 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 3857 // C++ [over.over]p3: 3858 // Non-member functions and static member functions match 3859 // targets of type "pointer-to-function" or "reference-to-function." 3860 // Nonstatic member functions match targets of 3861 // type "pointer-to-member-function." 3862 // Note that according to DR 247, the containing class does not matter. 3863 3864 if (FunctionTemplateDecl *FunctionTemplate 3865 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 3866 if (CXXMethodDecl *Method 3867 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 3868 // Skip non-static function templates when converting to pointer, and 3869 // static when converting to member pointer. 3870 if (Method->isStatic() == IsMember) 3871 continue; 3872 } else if (IsMember) 3873 continue; 3874 3875 // C++ [over.over]p2: 3876 // If the name is a function template, template argument deduction is 3877 // done (14.8.2.2), and if the argument deduction succeeds, the 3878 // resulting template argument list is used to generate a single 3879 // function template specialization, which is added to the set of 3880 // overloaded functions considered. 3881 FunctionDecl *Specialization = 0; 3882 TemplateDeductionInfo Info(Context); 3883 if (TemplateDeductionResult Result 3884 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 3885 /*FIXME:*/0, /*FIXME:*/0, 3886 FunctionType, Specialization, Info)) { 3887 // FIXME: make a note of the failed deduction for diagnostics. 3888 (void)Result; 3889 } else { 3890 assert(FunctionType 3891 == Context.getCanonicalType(Specialization->getType())); 3892 Matches.insert( 3893 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 3894 } 3895 } 3896 3897 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 3898 // Skip non-static functions when converting to pointer, and static 3899 // when converting to member pointer. 3900 if (Method->isStatic() == IsMember) 3901 continue; 3902 } else if (IsMember) 3903 continue; 3904 3905 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 3906 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 3907 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 3908 FoundNonTemplateFunction = true; 3909 } 3910 } 3911 } 3912 3913 // If there were 0 or 1 matches, we're done. 3914 if (Matches.empty()) 3915 return 0; 3916 else if (Matches.size() == 1) 3917 return *Matches.begin(); 3918 3919 // C++ [over.over]p4: 3920 // If more than one function is selected, [...] 3921 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 3922 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 3923 if (FoundNonTemplateFunction) { 3924 // [...] any function template specializations in the set are 3925 // eliminated if the set also contains a non-template function, [...] 3926 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 3927 if ((*M)->getPrimaryTemplate() == 0) 3928 RemainingMatches.push_back(*M); 3929 } else { 3930 // [...] and any given function template specialization F1 is 3931 // eliminated if the set contains a second function template 3932 // specialization whose function template is more specialized 3933 // than the function template of F1 according to the partial 3934 // ordering rules of 14.5.5.2. 3935 3936 // The algorithm specified above is quadratic. We instead use a 3937 // two-pass algorithm (similar to the one used to identify the 3938 // best viable function in an overload set) that identifies the 3939 // best function template (if it exists). 3940 MatchIter Best = Matches.begin(); 3941 MatchIter M = Best, MEnd = Matches.end(); 3942 // Find the most specialized function. 3943 for (++M; M != MEnd; ++M) 3944 if (getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 3945 (*Best)->getPrimaryTemplate(), 3946 false) 3947 == (*M)->getPrimaryTemplate()) 3948 Best = M; 3949 3950 // Determine whether this function template is more specialized 3951 // that all of the others. 3952 bool Ambiguous = false; 3953 for (M = Matches.begin(); M != MEnd; ++M) { 3954 if (M != Best && 3955 getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 3956 (*Best)->getPrimaryTemplate(), 3957 false) 3958 != (*Best)->getPrimaryTemplate()) { 3959 Ambiguous = true; 3960 break; 3961 } 3962 } 3963 3964 // If one function template was more specialized than all of the 3965 // others, return it. 3966 if (!Ambiguous) 3967 return *Best; 3968 3969 // We could not find a most-specialized function template, which 3970 // is equivalent to having a set of function templates with more 3971 // than one such template. So, we place all of the function 3972 // templates into the set of remaining matches and produce a 3973 // diagnostic below. FIXME: we could perform the quadratic 3974 // algorithm here, pruning the result set to limit the number of 3975 // candidates output later. 3976 RemainingMatches.append(Matches.begin(), Matches.end()); 3977 } 3978 3979 // [...] After such eliminations, if any, there shall remain exactly one 3980 // selected function. 3981 if (RemainingMatches.size() == 1) 3982 return RemainingMatches.front(); 3983 3984 // FIXME: We should probably return the same thing that BestViableFunction 3985 // returns (even if we issue the diagnostics here). 3986 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 3987 << RemainingMatches[0]->getDeclName(); 3988 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 3989 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 3990 return 0; 3991} 3992 3993/// ResolveOverloadedCallFn - Given the call expression that calls Fn 3994/// (which eventually refers to the declaration Func) and the call 3995/// arguments Args/NumArgs, attempt to resolve the function call down 3996/// to a specific function. If overload resolution succeeds, returns 3997/// the function declaration produced by overload 3998/// resolution. Otherwise, emits diagnostics, deletes all of the 3999/// arguments and Fn, and returns NULL. 4000FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4001 DeclarationName UnqualifiedName, 4002 bool HasExplicitTemplateArgs, 4003 const TemplateArgument *ExplicitTemplateArgs, 4004 unsigned NumExplicitTemplateArgs, 4005 SourceLocation LParenLoc, 4006 Expr **Args, unsigned NumArgs, 4007 SourceLocation *CommaLocs, 4008 SourceLocation RParenLoc, 4009 bool &ArgumentDependentLookup) { 4010 OverloadCandidateSet CandidateSet; 4011 4012 // Add the functions denoted by Callee to the set of candidate 4013 // functions. While we're doing so, track whether argument-dependent 4014 // lookup still applies, per: 4015 // 4016 // C++0x [basic.lookup.argdep]p3: 4017 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4018 // and let Y be the lookup set produced by argument dependent 4019 // lookup (defined as follows). If X contains 4020 // 4021 // -- a declaration of a class member, or 4022 // 4023 // -- a block-scope function declaration that is not a 4024 // using-declaration, or 4025 // 4026 // -- a declaration that is neither a function or a function 4027 // template 4028 // 4029 // then Y is empty. 4030 if (OverloadedFunctionDecl *Ovl 4031 = dyn_cast_or_null<OverloadedFunctionDecl>(Callee)) { 4032 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4033 FuncEnd = Ovl->function_end(); 4034 Func != FuncEnd; ++Func) { 4035 DeclContext *Ctx = 0; 4036 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Func)) { 4037 if (HasExplicitTemplateArgs) 4038 continue; 4039 4040 AddOverloadCandidate(FunDecl, Args, NumArgs, CandidateSet); 4041 Ctx = FunDecl->getDeclContext(); 4042 } else { 4043 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*Func); 4044 AddTemplateOverloadCandidate(FunTmpl, HasExplicitTemplateArgs, 4045 ExplicitTemplateArgs, 4046 NumExplicitTemplateArgs, 4047 Args, NumArgs, CandidateSet); 4048 Ctx = FunTmpl->getDeclContext(); 4049 } 4050 4051 4052 if (Ctx->isRecord() || Ctx->isFunctionOrMethod()) 4053 ArgumentDependentLookup = false; 4054 } 4055 } else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee)) { 4056 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4057 AddOverloadCandidate(Func, Args, NumArgs, CandidateSet); 4058 4059 if (Func->getDeclContext()->isRecord() || 4060 Func->getDeclContext()->isFunctionOrMethod()) 4061 ArgumentDependentLookup = false; 4062 } else if (FunctionTemplateDecl *FuncTemplate 4063 = dyn_cast_or_null<FunctionTemplateDecl>(Callee)) { 4064 AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4065 ExplicitTemplateArgs, 4066 NumExplicitTemplateArgs, 4067 Args, NumArgs, CandidateSet); 4068 4069 if (FuncTemplate->getDeclContext()->isRecord()) 4070 ArgumentDependentLookup = false; 4071 } 4072 4073 if (Callee) 4074 UnqualifiedName = Callee->getDeclName(); 4075 4076 // FIXME: Pass explicit template arguments through for ADL 4077 if (ArgumentDependentLookup) 4078 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4079 CandidateSet); 4080 4081 OverloadCandidateSet::iterator Best; 4082 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4083 case OR_Success: 4084 return Best->Function; 4085 4086 case OR_No_Viable_Function: 4087 Diag(Fn->getSourceRange().getBegin(), 4088 diag::err_ovl_no_viable_function_in_call) 4089 << UnqualifiedName << Fn->getSourceRange(); 4090 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4091 break; 4092 4093 case OR_Ambiguous: 4094 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4095 << UnqualifiedName << Fn->getSourceRange(); 4096 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4097 break; 4098 4099 case OR_Deleted: 4100 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4101 << Best->Function->isDeleted() 4102 << UnqualifiedName 4103 << Fn->getSourceRange(); 4104 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4105 break; 4106 } 4107 4108 // Overload resolution failed. Destroy all of the subexpressions and 4109 // return NULL. 4110 Fn->Destroy(Context); 4111 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4112 Args[Arg]->Destroy(Context); 4113 return 0; 4114} 4115 4116/// \brief Create a unary operation that may resolve to an overloaded 4117/// operator. 4118/// 4119/// \param OpLoc The location of the operator itself (e.g., '*'). 4120/// 4121/// \param OpcIn The UnaryOperator::Opcode that describes this 4122/// operator. 4123/// 4124/// \param Functions The set of non-member functions that will be 4125/// considered by overload resolution. The caller needs to build this 4126/// set based on the context using, e.g., 4127/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4128/// set should not contain any member functions; those will be added 4129/// by CreateOverloadedUnaryOp(). 4130/// 4131/// \param input The input argument. 4132Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4133 unsigned OpcIn, 4134 FunctionSet &Functions, 4135 ExprArg input) { 4136 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4137 Expr *Input = (Expr *)input.get(); 4138 4139 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4140 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4141 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4142 4143 Expr *Args[2] = { Input, 0 }; 4144 unsigned NumArgs = 1; 4145 4146 // For post-increment and post-decrement, add the implicit '0' as 4147 // the second argument, so that we know this is a post-increment or 4148 // post-decrement. 4149 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4150 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4151 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4152 SourceLocation()); 4153 NumArgs = 2; 4154 } 4155 4156 if (Input->isTypeDependent()) { 4157 OverloadedFunctionDecl *Overloads 4158 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4159 for (FunctionSet::iterator Func = Functions.begin(), 4160 FuncEnd = Functions.end(); 4161 Func != FuncEnd; ++Func) 4162 Overloads->addOverload(*Func); 4163 4164 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4165 OpLoc, false, false); 4166 4167 input.release(); 4168 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4169 &Args[0], NumArgs, 4170 Context.DependentTy, 4171 OpLoc)); 4172 } 4173 4174 // Build an empty overload set. 4175 OverloadCandidateSet CandidateSet; 4176 4177 // Add the candidates from the given function set. 4178 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4179 4180 // Add operator candidates that are member functions. 4181 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4182 4183 // Add builtin operator candidates. 4184 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4185 4186 // Perform overload resolution. 4187 OverloadCandidateSet::iterator Best; 4188 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4189 case OR_Success: { 4190 // We found a built-in operator or an overloaded operator. 4191 FunctionDecl *FnDecl = Best->Function; 4192 4193 if (FnDecl) { 4194 // We matched an overloaded operator. Build a call to that 4195 // operator. 4196 4197 // Convert the arguments. 4198 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4199 if (PerformObjectArgumentInitialization(Input, Method)) 4200 return ExprError(); 4201 } else { 4202 // Convert the arguments. 4203 if (PerformCopyInitialization(Input, 4204 FnDecl->getParamDecl(0)->getType(), 4205 "passing")) 4206 return ExprError(); 4207 } 4208 4209 // Determine the result type 4210 QualType ResultTy 4211 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4212 ResultTy = ResultTy.getNonReferenceType(); 4213 4214 // Build the actual expression node. 4215 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4216 SourceLocation()); 4217 UsualUnaryConversions(FnExpr); 4218 4219 input.release(); 4220 4221 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4222 &Input, 1, ResultTy, OpLoc); 4223 return MaybeBindToTemporary(CE); 4224 } else { 4225 // We matched a built-in operator. Convert the arguments, then 4226 // break out so that we will build the appropriate built-in 4227 // operator node. 4228 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4229 Best->Conversions[0], "passing")) 4230 return ExprError(); 4231 4232 break; 4233 } 4234 } 4235 4236 case OR_No_Viable_Function: 4237 // No viable function; fall through to handling this as a 4238 // built-in operator, which will produce an error message for us. 4239 break; 4240 4241 case OR_Ambiguous: 4242 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4243 << UnaryOperator::getOpcodeStr(Opc) 4244 << Input->getSourceRange(); 4245 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4246 return ExprError(); 4247 4248 case OR_Deleted: 4249 Diag(OpLoc, diag::err_ovl_deleted_oper) 4250 << Best->Function->isDeleted() 4251 << UnaryOperator::getOpcodeStr(Opc) 4252 << Input->getSourceRange(); 4253 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4254 return ExprError(); 4255 } 4256 4257 // Either we found no viable overloaded operator or we matched a 4258 // built-in operator. In either case, fall through to trying to 4259 // build a built-in operation. 4260 input.release(); 4261 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4262} 4263 4264/// \brief Create a binary operation that may resolve to an overloaded 4265/// operator. 4266/// 4267/// \param OpLoc The location of the operator itself (e.g., '+'). 4268/// 4269/// \param OpcIn The BinaryOperator::Opcode that describes this 4270/// operator. 4271/// 4272/// \param Functions The set of non-member functions that will be 4273/// considered by overload resolution. The caller needs to build this 4274/// set based on the context using, e.g., 4275/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4276/// set should not contain any member functions; those will be added 4277/// by CreateOverloadedBinOp(). 4278/// 4279/// \param LHS Left-hand argument. 4280/// \param RHS Right-hand argument. 4281Sema::OwningExprResult 4282Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4283 unsigned OpcIn, 4284 FunctionSet &Functions, 4285 Expr *LHS, Expr *RHS) { 4286 Expr *Args[2] = { LHS, RHS }; 4287 4288 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4289 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4290 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4291 4292 // If either side is type-dependent, create an appropriate dependent 4293 // expression. 4294 if (LHS->isTypeDependent() || RHS->isTypeDependent()) { 4295 // .* cannot be overloaded. 4296 if (Opc == BinaryOperator::PtrMemD) 4297 return Owned(new (Context) BinaryOperator(LHS, RHS, Opc, 4298 Context.DependentTy, OpLoc)); 4299 4300 OverloadedFunctionDecl *Overloads 4301 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4302 for (FunctionSet::iterator Func = Functions.begin(), 4303 FuncEnd = Functions.end(); 4304 Func != FuncEnd; ++Func) 4305 Overloads->addOverload(*Func); 4306 4307 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4308 OpLoc, false, false); 4309 4310 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4311 Args, 2, 4312 Context.DependentTy, 4313 OpLoc)); 4314 } 4315 4316 // If this is the .* operator, which is not overloadable, just 4317 // create a built-in binary operator. 4318 if (Opc == BinaryOperator::PtrMemD) 4319 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4320 4321 // If this is one of the assignment operators, we only perform 4322 // overload resolution if the left-hand side is a class or 4323 // enumeration type (C++ [expr.ass]p3). 4324 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4325 !LHS->getType()->isOverloadableType()) 4326 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4327 4328 // Build an empty overload set. 4329 OverloadCandidateSet CandidateSet; 4330 4331 // Add the candidates from the given function set. 4332 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4333 4334 // Add operator candidates that are member functions. 4335 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4336 4337 // Add builtin operator candidates. 4338 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4339 4340 // Perform overload resolution. 4341 OverloadCandidateSet::iterator Best; 4342 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4343 case OR_Success: { 4344 // We found a built-in operator or an overloaded operator. 4345 FunctionDecl *FnDecl = Best->Function; 4346 4347 if (FnDecl) { 4348 // We matched an overloaded operator. Build a call to that 4349 // operator. 4350 4351 // Convert the arguments. 4352 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4353 if (PerformObjectArgumentInitialization(LHS, Method) || 4354 PerformCopyInitialization(RHS, FnDecl->getParamDecl(0)->getType(), 4355 "passing")) 4356 return ExprError(); 4357 } else { 4358 // Convert the arguments. 4359 if (PerformCopyInitialization(LHS, FnDecl->getParamDecl(0)->getType(), 4360 "passing") || 4361 PerformCopyInitialization(RHS, FnDecl->getParamDecl(1)->getType(), 4362 "passing")) 4363 return ExprError(); 4364 } 4365 4366 // Determine the result type 4367 QualType ResultTy 4368 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4369 ResultTy = ResultTy.getNonReferenceType(); 4370 4371 // Build the actual expression node. 4372 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4373 OpLoc); 4374 UsualUnaryConversions(FnExpr); 4375 4376 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4377 Args, 2, ResultTy, OpLoc); 4378 return MaybeBindToTemporary(CE); 4379 } else { 4380 // We matched a built-in operator. Convert the arguments, then 4381 // break out so that we will build the appropriate built-in 4382 // operator node. 4383 if (PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0], 4384 Best->Conversions[0], "passing") || 4385 PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1], 4386 Best->Conversions[1], "passing")) 4387 return ExprError(); 4388 4389 break; 4390 } 4391 } 4392 4393 case OR_No_Viable_Function: 4394 // For class as left operand for assignment or compound assigment operator 4395 // do not fall through to handling in built-in, but report that no overloaded 4396 // assignment operator found 4397 if (LHS->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4398 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4399 << BinaryOperator::getOpcodeStr(Opc) 4400 << LHS->getSourceRange() << RHS->getSourceRange(); 4401 return ExprError(); 4402 } 4403 // No viable function; fall through to handling this as a 4404 // built-in operator, which will produce an error message for us. 4405 break; 4406 4407 case OR_Ambiguous: 4408 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4409 << BinaryOperator::getOpcodeStr(Opc) 4410 << LHS->getSourceRange() << RHS->getSourceRange(); 4411 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4412 return ExprError(); 4413 4414 case OR_Deleted: 4415 Diag(OpLoc, diag::err_ovl_deleted_oper) 4416 << Best->Function->isDeleted() 4417 << BinaryOperator::getOpcodeStr(Opc) 4418 << LHS->getSourceRange() << RHS->getSourceRange(); 4419 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4420 return ExprError(); 4421 } 4422 4423 // Either we found no viable overloaded operator or we matched a 4424 // built-in operator. In either case, try to build a built-in 4425 // operation. 4426 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4427} 4428 4429/// BuildCallToMemberFunction - Build a call to a member 4430/// function. MemExpr is the expression that refers to the member 4431/// function (and includes the object parameter), Args/NumArgs are the 4432/// arguments to the function call (not including the object 4433/// parameter). The caller needs to validate that the member 4434/// expression refers to a member function or an overloaded member 4435/// function. 4436Sema::ExprResult 4437Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4438 SourceLocation LParenLoc, Expr **Args, 4439 unsigned NumArgs, SourceLocation *CommaLocs, 4440 SourceLocation RParenLoc) { 4441 // Dig out the member expression. This holds both the object 4442 // argument and the member function we're referring to. 4443 MemberExpr *MemExpr = 0; 4444 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4445 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4446 else 4447 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4448 assert(MemExpr && "Building member call without member expression"); 4449 4450 // Extract the object argument. 4451 Expr *ObjectArg = MemExpr->getBase(); 4452 4453 CXXMethodDecl *Method = 0; 4454 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 4455 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 4456 // Add overload candidates 4457 OverloadCandidateSet CandidateSet; 4458 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 4459 4460 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 4461 Func != FuncEnd; ++Func) { 4462 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) 4463 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4464 /*SuppressUserConversions=*/false); 4465 else 4466 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 4467 /*FIXME:*/false, /*FIXME:*/0, 4468 /*FIXME:*/0, ObjectArg, Args, NumArgs, 4469 CandidateSet, 4470 /*SuppressUsedConversions=*/false); 4471 } 4472 4473 OverloadCandidateSet::iterator Best; 4474 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4475 case OR_Success: 4476 Method = cast<CXXMethodDecl>(Best->Function); 4477 break; 4478 4479 case OR_No_Viable_Function: 4480 Diag(MemExpr->getSourceRange().getBegin(), 4481 diag::err_ovl_no_viable_member_function_in_call) 4482 << DeclName << MemExprE->getSourceRange(); 4483 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4484 // FIXME: Leaking incoming expressions! 4485 return true; 4486 4487 case OR_Ambiguous: 4488 Diag(MemExpr->getSourceRange().getBegin(), 4489 diag::err_ovl_ambiguous_member_call) 4490 << DeclName << MemExprE->getSourceRange(); 4491 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4492 // FIXME: Leaking incoming expressions! 4493 return true; 4494 4495 case OR_Deleted: 4496 Diag(MemExpr->getSourceRange().getBegin(), 4497 diag::err_ovl_deleted_member_call) 4498 << Best->Function->isDeleted() 4499 << DeclName << MemExprE->getSourceRange(); 4500 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4501 // FIXME: Leaking incoming expressions! 4502 return true; 4503 } 4504 4505 FixOverloadedFunctionReference(MemExpr, Method); 4506 } else { 4507 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4508 } 4509 4510 assert(Method && "Member call to something that isn't a method?"); 4511 ExprOwningPtr<CXXMemberCallExpr> 4512 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4513 NumArgs, 4514 Method->getResultType().getNonReferenceType(), 4515 RParenLoc)); 4516 4517 // Convert the object argument (for a non-static member function call). 4518 if (!Method->isStatic() && 4519 PerformObjectArgumentInitialization(ObjectArg, Method)) 4520 return true; 4521 MemExpr->setBase(ObjectArg); 4522 4523 // Convert the rest of the arguments 4524 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4525 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4526 RParenLoc)) 4527 return true; 4528 4529 if (CheckFunctionCall(Method, TheCall.get())) 4530 return true; 4531 4532 return MaybeBindToTemporary(TheCall.release()).release(); 4533} 4534 4535/// BuildCallToObjectOfClassType - Build a call to an object of class 4536/// type (C++ [over.call.object]), which can end up invoking an 4537/// overloaded function call operator (@c operator()) or performing a 4538/// user-defined conversion on the object argument. 4539Sema::ExprResult 4540Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4541 SourceLocation LParenLoc, 4542 Expr **Args, unsigned NumArgs, 4543 SourceLocation *CommaLocs, 4544 SourceLocation RParenLoc) { 4545 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4546 const RecordType *Record = Object->getType()->getAs<RecordType>(); 4547 4548 // C++ [over.call.object]p1: 4549 // If the primary-expression E in the function call syntax 4550 // evaluates to a class object of type "cv T", then the set of 4551 // candidate functions includes at least the function call 4552 // operators of T. The function call operators of T are obtained by 4553 // ordinary lookup of the name operator() in the context of 4554 // (E).operator(). 4555 OverloadCandidateSet CandidateSet; 4556 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4557 DeclContext::lookup_const_iterator Oper, OperEnd; 4558 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4559 Oper != OperEnd; ++Oper) 4560 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4561 CandidateSet, /*SuppressUserConversions=*/false); 4562 4563 // C++ [over.call.object]p2: 4564 // In addition, for each conversion function declared in T of the 4565 // form 4566 // 4567 // operator conversion-type-id () cv-qualifier; 4568 // 4569 // where cv-qualifier is the same cv-qualification as, or a 4570 // greater cv-qualification than, cv, and where conversion-type-id 4571 // denotes the type "pointer to function of (P1,...,Pn) returning 4572 // R", or the type "reference to pointer to function of 4573 // (P1,...,Pn) returning R", or the type "reference to function 4574 // of (P1,...,Pn) returning R", a surrogate call function [...] 4575 // is also considered as a candidate function. Similarly, 4576 // surrogate call functions are added to the set of candidate 4577 // functions for each conversion function declared in an 4578 // accessible base class provided the function is not hidden 4579 // within T by another intervening declaration. 4580 // 4581 // FIXME: Look in base classes for more conversion operators! 4582 OverloadedFunctionDecl *Conversions 4583 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4584 for (OverloadedFunctionDecl::function_iterator 4585 Func = Conversions->function_begin(), 4586 FuncEnd = Conversions->function_end(); 4587 Func != FuncEnd; ++Func) { 4588 CXXConversionDecl *Conv; 4589 FunctionTemplateDecl *ConvTemplate; 4590 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 4591 4592 // Skip over templated conversion functions; they aren't 4593 // surrogates. 4594 if (ConvTemplate) 4595 continue; 4596 4597 // Strip the reference type (if any) and then the pointer type (if 4598 // any) to get down to what might be a function type. 4599 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4600 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4601 ConvType = ConvPtrType->getPointeeType(); 4602 4603 if (const FunctionProtoType *Proto = ConvType->getAsFunctionProtoType()) 4604 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4605 } 4606 4607 // Perform overload resolution. 4608 OverloadCandidateSet::iterator Best; 4609 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4610 case OR_Success: 4611 // Overload resolution succeeded; we'll build the appropriate call 4612 // below. 4613 break; 4614 4615 case OR_No_Viable_Function: 4616 Diag(Object->getSourceRange().getBegin(), 4617 diag::err_ovl_no_viable_object_call) 4618 << Object->getType() << Object->getSourceRange(); 4619 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4620 break; 4621 4622 case OR_Ambiguous: 4623 Diag(Object->getSourceRange().getBegin(), 4624 diag::err_ovl_ambiguous_object_call) 4625 << Object->getType() << Object->getSourceRange(); 4626 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4627 break; 4628 4629 case OR_Deleted: 4630 Diag(Object->getSourceRange().getBegin(), 4631 diag::err_ovl_deleted_object_call) 4632 << Best->Function->isDeleted() 4633 << Object->getType() << Object->getSourceRange(); 4634 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4635 break; 4636 } 4637 4638 if (Best == CandidateSet.end()) { 4639 // We had an error; delete all of the subexpressions and return 4640 // the error. 4641 Object->Destroy(Context); 4642 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4643 Args[ArgIdx]->Destroy(Context); 4644 return true; 4645 } 4646 4647 if (Best->Function == 0) { 4648 // Since there is no function declaration, this is one of the 4649 // surrogate candidates. Dig out the conversion function. 4650 CXXConversionDecl *Conv 4651 = cast<CXXConversionDecl>( 4652 Best->Conversions[0].UserDefined.ConversionFunction); 4653 4654 // We selected one of the surrogate functions that converts the 4655 // object parameter to a function pointer. Perform the conversion 4656 // on the object argument, then let ActOnCallExpr finish the job. 4657 // FIXME: Represent the user-defined conversion in the AST! 4658 ImpCastExprToType(Object, 4659 Conv->getConversionType().getNonReferenceType(), 4660 CastExpr::CK_Unknown, 4661 Conv->getConversionType()->isLValueReferenceType()); 4662 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4663 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4664 CommaLocs, RParenLoc).release(); 4665 } 4666 4667 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4668 // that calls this method, using Object for the implicit object 4669 // parameter and passing along the remaining arguments. 4670 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4671 const FunctionProtoType *Proto = Method->getType()->getAsFunctionProtoType(); 4672 4673 unsigned NumArgsInProto = Proto->getNumArgs(); 4674 unsigned NumArgsToCheck = NumArgs; 4675 4676 // Build the full argument list for the method call (the 4677 // implicit object parameter is placed at the beginning of the 4678 // list). 4679 Expr **MethodArgs; 4680 if (NumArgs < NumArgsInProto) { 4681 NumArgsToCheck = NumArgsInProto; 4682 MethodArgs = new Expr*[NumArgsInProto + 1]; 4683 } else { 4684 MethodArgs = new Expr*[NumArgs + 1]; 4685 } 4686 MethodArgs[0] = Object; 4687 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4688 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4689 4690 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4691 SourceLocation()); 4692 UsualUnaryConversions(NewFn); 4693 4694 // Once we've built TheCall, all of the expressions are properly 4695 // owned. 4696 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4697 ExprOwningPtr<CXXOperatorCallExpr> 4698 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4699 MethodArgs, NumArgs + 1, 4700 ResultTy, RParenLoc)); 4701 delete [] MethodArgs; 4702 4703 // We may have default arguments. If so, we need to allocate more 4704 // slots in the call for them. 4705 if (NumArgs < NumArgsInProto) 4706 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4707 else if (NumArgs > NumArgsInProto) 4708 NumArgsToCheck = NumArgsInProto; 4709 4710 bool IsError = false; 4711 4712 // Initialize the implicit object parameter. 4713 IsError |= PerformObjectArgumentInitialization(Object, Method); 4714 TheCall->setArg(0, Object); 4715 4716 4717 // Check the argument types. 4718 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4719 Expr *Arg; 4720 if (i < NumArgs) { 4721 Arg = Args[i]; 4722 4723 // Pass the argument. 4724 QualType ProtoArgType = Proto->getArgType(i); 4725 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4726 } else { 4727 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 4728 } 4729 4730 TheCall->setArg(i + 1, Arg); 4731 } 4732 4733 // If this is a variadic call, handle args passed through "...". 4734 if (Proto->isVariadic()) { 4735 // Promote the arguments (C99 6.5.2.2p7). 4736 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4737 Expr *Arg = Args[i]; 4738 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4739 TheCall->setArg(i + 1, Arg); 4740 } 4741 } 4742 4743 if (IsError) return true; 4744 4745 if (CheckFunctionCall(Method, TheCall.get())) 4746 return true; 4747 4748 return MaybeBindToTemporary(TheCall.release()).release(); 4749} 4750 4751/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4752/// (if one exists), where @c Base is an expression of class type and 4753/// @c Member is the name of the member we're trying to find. 4754Sema::OwningExprResult 4755Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 4756 Expr *Base = static_cast<Expr *>(BaseIn.get()); 4757 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4758 4759 // C++ [over.ref]p1: 4760 // 4761 // [...] An expression x->m is interpreted as (x.operator->())->m 4762 // for a class object x of type T if T::operator->() exists and if 4763 // the operator is selected as the best match function by the 4764 // overload resolution mechanism (13.3). 4765 // FIXME: look in base classes. 4766 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4767 OverloadCandidateSet CandidateSet; 4768 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 4769 4770 DeclContext::lookup_const_iterator Oper, OperEnd; 4771 for (llvm::tie(Oper, OperEnd) 4772 = BaseRecord->getDecl()->lookup(OpName); Oper != OperEnd; ++Oper) 4773 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4774 /*SuppressUserConversions=*/false); 4775 4776 // Perform overload resolution. 4777 OverloadCandidateSet::iterator Best; 4778 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4779 case OR_Success: 4780 // Overload resolution succeeded; we'll build the call below. 4781 break; 4782 4783 case OR_No_Viable_Function: 4784 if (CandidateSet.empty()) 4785 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4786 << Base->getType() << Base->getSourceRange(); 4787 else 4788 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4789 << "operator->" << Base->getSourceRange(); 4790 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4791 return ExprError(); 4792 4793 case OR_Ambiguous: 4794 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4795 << "operator->" << Base->getSourceRange(); 4796 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4797 return ExprError(); 4798 4799 case OR_Deleted: 4800 Diag(OpLoc, diag::err_ovl_deleted_oper) 4801 << Best->Function->isDeleted() 4802 << "operator->" << Base->getSourceRange(); 4803 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4804 return ExprError(); 4805 } 4806 4807 // Convert the object parameter. 4808 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4809 if (PerformObjectArgumentInitialization(Base, Method)) 4810 return ExprError(); 4811 4812 // No concerns about early exits now. 4813 BaseIn.release(); 4814 4815 // Build the operator call. 4816 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 4817 SourceLocation()); 4818 UsualUnaryConversions(FnExpr); 4819 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 4820 Method->getResultType().getNonReferenceType(), 4821 OpLoc); 4822 return Owned(Base); 4823} 4824 4825/// FixOverloadedFunctionReference - E is an expression that refers to 4826/// a C++ overloaded function (possibly with some parentheses and 4827/// perhaps a '&' around it). We have resolved the overloaded function 4828/// to the function declaration Fn, so patch up the expression E to 4829/// refer (possibly indirectly) to Fn. 4830void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 4831 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4832 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 4833 E->setType(PE->getSubExpr()->getType()); 4834 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 4835 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 4836 "Can only take the address of an overloaded function"); 4837 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4838 if (Method->isStatic()) { 4839 // Do nothing: static member functions aren't any different 4840 // from non-member functions. 4841 } else if (QualifiedDeclRefExpr *DRE 4842 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 4843 // We have taken the address of a pointer to member 4844 // function. Perform the computation here so that we get the 4845 // appropriate pointer to member type. 4846 DRE->setDecl(Fn); 4847 DRE->setType(Fn->getType()); 4848 QualType ClassType 4849 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 4850 E->setType(Context.getMemberPointerType(Fn->getType(), 4851 ClassType.getTypePtr())); 4852 return; 4853 } 4854 } 4855 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 4856 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 4857 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 4858 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 4859 isa<FunctionTemplateDecl>(DR->getDecl())) && 4860 "Expected overloaded function or function template"); 4861 DR->setDecl(Fn); 4862 E->setType(Fn->getType()); 4863 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 4864 MemExpr->setMemberDecl(Fn); 4865 E->setType(Fn->getType()); 4866 } else { 4867 assert(false && "Invalid reference to overloaded function"); 4868 } 4869} 4870 4871} // end namespace clang 4872