SemaOverload.cpp revision b1663d050744ab3a4987df2d3a394f3ae0468435
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInherit.h" 16#include "clang/Basic/Diagnostic.h" 17#include "clang/Lex/Preprocessor.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/TypeOrdering.h" 22#include "clang/Basic/PartialDiagnostic.h" 23#include "llvm/ADT/SmallPtrSet.h" 24#include "llvm/ADT/STLExtras.h" 25#include "llvm/Support/Compiler.h" 26#include <algorithm> 27#include <cstdio> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Qualification_Adjustment, 42 ICC_Promotion, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Conversion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion 55 }; 56 return Category[(int)Kind]; 57} 58 59/// GetConversionRank - Retrieve the implicit conversion rank 60/// corresponding to the given implicit conversion kind. 61ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 62 static const ImplicitConversionRank 63 Rank[(int)ICK_Num_Conversion_Kinds] = { 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Promotion, 70 ICR_Promotion, 71 ICR_Promotion, 72 ICR_Conversion, 73 ICR_Conversion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion 82 }; 83 return Rank[(int)Kind]; 84} 85 86/// GetImplicitConversionName - Return the name of this kind of 87/// implicit conversion. 88const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 89 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 90 "No conversion", 91 "Lvalue-to-rvalue", 92 "Array-to-pointer", 93 "Function-to-pointer", 94 "Qualification", 95 "Integral promotion", 96 "Floating point promotion", 97 "Complex promotion", 98 "Integral conversion", 99 "Floating conversion", 100 "Complex conversion", 101 "Floating-integral conversion", 102 "Complex-real conversion", 103 "Pointer conversion", 104 "Pointer-to-member conversion", 105 "Boolean conversion", 106 "Compatible-types conversion", 107 "Derived-to-base conversion" 108 }; 109 return Name[Kind]; 110} 111 112/// StandardConversionSequence - Set the standard conversion 113/// sequence to the identity conversion. 114void StandardConversionSequence::setAsIdentityConversion() { 115 First = ICK_Identity; 116 Second = ICK_Identity; 117 Third = ICK_Identity; 118 Deprecated = false; 119 ReferenceBinding = false; 120 DirectBinding = false; 121 RRefBinding = false; 122 CopyConstructor = 0; 123} 124 125/// getRank - Retrieve the rank of this standard conversion sequence 126/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 127/// implicit conversions. 128ImplicitConversionRank StandardConversionSequence::getRank() const { 129 ImplicitConversionRank Rank = ICR_Exact_Match; 130 if (GetConversionRank(First) > Rank) 131 Rank = GetConversionRank(First); 132 if (GetConversionRank(Second) > Rank) 133 Rank = GetConversionRank(Second); 134 if (GetConversionRank(Third) > Rank) 135 Rank = GetConversionRank(Third); 136 return Rank; 137} 138 139/// isPointerConversionToBool - Determines whether this conversion is 140/// a conversion of a pointer or pointer-to-member to bool. This is 141/// used as part of the ranking of standard conversion sequences 142/// (C++ 13.3.3.2p4). 143bool StandardConversionSequence::isPointerConversionToBool() const { 144 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 145 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 146 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (ToType->isBooleanType() && 152 (FromType->isPointerType() || FromType->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 167 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 bool PrintedSomething = false; 186 if (First != ICK_Identity) { 187 fprintf(stderr, "%s", GetImplicitConversionName(First)); 188 PrintedSomething = true; 189 } 190 191 if (Second != ICK_Identity) { 192 if (PrintedSomething) { 193 fprintf(stderr, " -> "); 194 } 195 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 196 197 if (CopyConstructor) { 198 fprintf(stderr, " (by copy constructor)"); 199 } else if (DirectBinding) { 200 fprintf(stderr, " (direct reference binding)"); 201 } else if (ReferenceBinding) { 202 fprintf(stderr, " (reference binding)"); 203 } 204 PrintedSomething = true; 205 } 206 207 if (Third != ICK_Identity) { 208 if (PrintedSomething) { 209 fprintf(stderr, " -> "); 210 } 211 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 212 PrintedSomething = true; 213 } 214 215 if (!PrintedSomething) { 216 fprintf(stderr, "No conversions required"); 217 } 218} 219 220/// DebugPrint - Print this user-defined conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void UserDefinedConversionSequence::DebugPrint() const { 223 if (Before.First || Before.Second || Before.Third) { 224 Before.DebugPrint(); 225 fprintf(stderr, " -> "); 226 } 227 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 228 if (After.First || After.Second || After.Third) { 229 fprintf(stderr, " -> "); 230 After.DebugPrint(); 231 } 232} 233 234/// DebugPrint - Print this implicit conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void ImplicitConversionSequence::DebugPrint() const { 237 switch (ConversionKind) { 238 case StandardConversion: 239 fprintf(stderr, "Standard conversion: "); 240 Standard.DebugPrint(); 241 break; 242 case UserDefinedConversion: 243 fprintf(stderr, "User-defined conversion: "); 244 UserDefined.DebugPrint(); 245 break; 246 case EllipsisConversion: 247 fprintf(stderr, "Ellipsis conversion"); 248 break; 249 case BadConversion: 250 fprintf(stderr, "Bad conversion"); 251 break; 252 } 253 254 fprintf(stderr, "\n"); 255} 256 257// IsOverload - Determine whether the given New declaration is an 258// overload of the Old declaration. This routine returns false if New 259// and Old cannot be overloaded, e.g., if they are functions with the 260// same signature (C++ 1.3.10) or if the Old declaration isn't a 261// function (or overload set). When it does return false and Old is an 262// OverloadedFunctionDecl, MatchedDecl will be set to point to the 263// FunctionDecl that New cannot be overloaded with. 264// 265// Example: Given the following input: 266// 267// void f(int, float); // #1 268// void f(int, int); // #2 269// int f(int, int); // #3 270// 271// When we process #1, there is no previous declaration of "f", 272// so IsOverload will not be used. 273// 274// When we process #2, Old is a FunctionDecl for #1. By comparing the 275// parameter types, we see that #1 and #2 are overloaded (since they 276// have different signatures), so this routine returns false; 277// MatchedDecl is unchanged. 278// 279// When we process #3, Old is an OverloadedFunctionDecl containing #1 280// and #2. We compare the signatures of #3 to #1 (they're overloaded, 281// so we do nothing) and then #3 to #2. Since the signatures of #3 and 282// #2 are identical (return types of functions are not part of the 283// signature), IsOverload returns false and MatchedDecl will be set to 284// point to the FunctionDecl for #2. 285bool 286Sema::IsOverload(FunctionDecl *New, Decl* OldD, 287 OverloadedFunctionDecl::function_iterator& MatchedDecl) { 288 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 289 // Is this new function an overload of every function in the 290 // overload set? 291 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 292 FuncEnd = Ovl->function_end(); 293 for (; Func != FuncEnd; ++Func) { 294 if (!IsOverload(New, *Func, MatchedDecl)) { 295 MatchedDecl = Func; 296 return false; 297 } 298 } 299 300 // This function overloads every function in the overload set. 301 return true; 302 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 303 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 304 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 305 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 306 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 307 308 // C++ [temp.fct]p2: 309 // A function template can be overloaded with other function templates 310 // and with normal (non-template) functions. 311 if ((OldTemplate == 0) != (NewTemplate == 0)) 312 return true; 313 314 // Is the function New an overload of the function Old? 315 QualType OldQType = Context.getCanonicalType(Old->getType()); 316 QualType NewQType = Context.getCanonicalType(New->getType()); 317 318 // Compare the signatures (C++ 1.3.10) of the two functions to 319 // determine whether they are overloads. If we find any mismatch 320 // in the signature, they are overloads. 321 322 // If either of these functions is a K&R-style function (no 323 // prototype), then we consider them to have matching signatures. 324 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 325 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 326 return false; 327 328 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 329 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 330 331 // The signature of a function includes the types of its 332 // parameters (C++ 1.3.10), which includes the presence or absence 333 // of the ellipsis; see C++ DR 357). 334 if (OldQType != NewQType && 335 (OldType->getNumArgs() != NewType->getNumArgs() || 336 OldType->isVariadic() != NewType->isVariadic() || 337 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 338 NewType->arg_type_begin()))) 339 return true; 340 341 // C++ [temp.over.link]p4: 342 // The signature of a function template consists of its function 343 // signature, its return type and its template parameter list. The names 344 // of the template parameters are significant only for establishing the 345 // relationship between the template parameters and the rest of the 346 // signature. 347 // 348 // We check the return type and template parameter lists for function 349 // templates first; the remaining checks follow. 350 if (NewTemplate && 351 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 352 OldTemplate->getTemplateParameters(), 353 false, false, SourceLocation()) || 354 OldType->getResultType() != NewType->getResultType())) 355 return true; 356 357 // If the function is a class member, its signature includes the 358 // cv-qualifiers (if any) on the function itself. 359 // 360 // As part of this, also check whether one of the member functions 361 // is static, in which case they are not overloads (C++ 362 // 13.1p2). While not part of the definition of the signature, 363 // this check is important to determine whether these functions 364 // can be overloaded. 365 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 366 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 367 if (OldMethod && NewMethod && 368 !OldMethod->isStatic() && !NewMethod->isStatic() && 369 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 370 return true; 371 372 // The signatures match; this is not an overload. 373 return false; 374 } else { 375 // (C++ 13p1): 376 // Only function declarations can be overloaded; object and type 377 // declarations cannot be overloaded. 378 return false; 379 } 380} 381 382/// TryImplicitConversion - Attempt to perform an implicit conversion 383/// from the given expression (Expr) to the given type (ToType). This 384/// function returns an implicit conversion sequence that can be used 385/// to perform the initialization. Given 386/// 387/// void f(float f); 388/// void g(int i) { f(i); } 389/// 390/// this routine would produce an implicit conversion sequence to 391/// describe the initialization of f from i, which will be a standard 392/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 393/// 4.1) followed by a floating-integral conversion (C++ 4.9). 394// 395/// Note that this routine only determines how the conversion can be 396/// performed; it does not actually perform the conversion. As such, 397/// it will not produce any diagnostics if no conversion is available, 398/// but will instead return an implicit conversion sequence of kind 399/// "BadConversion". 400/// 401/// If @p SuppressUserConversions, then user-defined conversions are 402/// not permitted. 403/// If @p AllowExplicit, then explicit user-defined conversions are 404/// permitted. 405/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 406/// no matter its actual lvalueness. 407ImplicitConversionSequence 408Sema::TryImplicitConversion(Expr* From, QualType ToType, 409 bool SuppressUserConversions, 410 bool AllowExplicit, bool ForceRValue, 411 bool InOverloadResolution) { 412 ImplicitConversionSequence ICS; 413 OverloadCandidateSet Conversions; 414 OverloadingResult UserDefResult = OR_Success; 415 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 416 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 417 else if (getLangOptions().CPlusPlus && 418 (UserDefResult = IsUserDefinedConversion(From, ToType, 419 ICS.UserDefined, 420 Conversions, 421 !SuppressUserConversions, AllowExplicit, 422 ForceRValue)) == OR_Success) { 423 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 424 // C++ [over.ics.user]p4: 425 // A conversion of an expression of class type to the same class 426 // type is given Exact Match rank, and a conversion of an 427 // expression of class type to a base class of that type is 428 // given Conversion rank, in spite of the fact that a copy 429 // constructor (i.e., a user-defined conversion function) is 430 // called for those cases. 431 if (CXXConstructorDecl *Constructor 432 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 433 QualType FromCanon 434 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 435 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 436 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 437 // Turn this into a "standard" conversion sequence, so that it 438 // gets ranked with standard conversion sequences. 439 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 440 ICS.Standard.setAsIdentityConversion(); 441 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 442 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 443 ICS.Standard.CopyConstructor = Constructor; 444 if (ToCanon != FromCanon) 445 ICS.Standard.Second = ICK_Derived_To_Base; 446 } 447 } 448 449 // C++ [over.best.ics]p4: 450 // However, when considering the argument of a user-defined 451 // conversion function that is a candidate by 13.3.1.3 when 452 // invoked for the copying of the temporary in the second step 453 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 454 // 13.3.1.6 in all cases, only standard conversion sequences and 455 // ellipsis conversion sequences are allowed. 456 if (SuppressUserConversions && 457 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 458 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 459 } else { 460 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 461 if (UserDefResult == OR_Ambiguous) { 462 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 463 Cand != Conversions.end(); ++Cand) 464 ICS.ConversionFunctionSet.push_back(Cand->Function); 465 } 466 } 467 468 return ICS; 469} 470 471/// IsStandardConversion - Determines whether there is a standard 472/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 473/// expression From to the type ToType. Standard conversion sequences 474/// only consider non-class types; for conversions that involve class 475/// types, use TryImplicitConversion. If a conversion exists, SCS will 476/// contain the standard conversion sequence required to perform this 477/// conversion and this routine will return true. Otherwise, this 478/// routine will return false and the value of SCS is unspecified. 479bool 480Sema::IsStandardConversion(Expr* From, QualType ToType, 481 bool InOverloadResolution, 482 StandardConversionSequence &SCS) { 483 QualType FromType = From->getType(); 484 485 // Standard conversions (C++ [conv]) 486 SCS.setAsIdentityConversion(); 487 SCS.Deprecated = false; 488 SCS.IncompatibleObjC = false; 489 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 490 SCS.CopyConstructor = 0; 491 492 // There are no standard conversions for class types in C++, so 493 // abort early. When overloading in C, however, we do permit 494 if (FromType->isRecordType() || ToType->isRecordType()) { 495 if (getLangOptions().CPlusPlus) 496 return false; 497 498 // When we're overloading in C, we allow, as standard conversions, 499 } 500 501 // The first conversion can be an lvalue-to-rvalue conversion, 502 // array-to-pointer conversion, or function-to-pointer conversion 503 // (C++ 4p1). 504 505 // Lvalue-to-rvalue conversion (C++ 4.1): 506 // An lvalue (3.10) of a non-function, non-array type T can be 507 // converted to an rvalue. 508 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 509 if (argIsLvalue == Expr::LV_Valid && 510 !FromType->isFunctionType() && !FromType->isArrayType() && 511 Context.getCanonicalType(FromType) != Context.OverloadTy) { 512 SCS.First = ICK_Lvalue_To_Rvalue; 513 514 // If T is a non-class type, the type of the rvalue is the 515 // cv-unqualified version of T. Otherwise, the type of the rvalue 516 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 517 // just strip the qualifiers because they don't matter. 518 519 // FIXME: Doesn't see through to qualifiers behind a typedef! 520 FromType = FromType.getUnqualifiedType(); 521 } else if (FromType->isArrayType()) { 522 // Array-to-pointer conversion (C++ 4.2) 523 SCS.First = ICK_Array_To_Pointer; 524 525 // An lvalue or rvalue of type "array of N T" or "array of unknown 526 // bound of T" can be converted to an rvalue of type "pointer to 527 // T" (C++ 4.2p1). 528 FromType = Context.getArrayDecayedType(FromType); 529 530 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 531 // This conversion is deprecated. (C++ D.4). 532 SCS.Deprecated = true; 533 534 // For the purpose of ranking in overload resolution 535 // (13.3.3.1.1), this conversion is considered an 536 // array-to-pointer conversion followed by a qualification 537 // conversion (4.4). (C++ 4.2p2) 538 SCS.Second = ICK_Identity; 539 SCS.Third = ICK_Qualification; 540 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 541 return true; 542 } 543 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 544 // Function-to-pointer conversion (C++ 4.3). 545 SCS.First = ICK_Function_To_Pointer; 546 547 // An lvalue of function type T can be converted to an rvalue of 548 // type "pointer to T." The result is a pointer to the 549 // function. (C++ 4.3p1). 550 FromType = Context.getPointerType(FromType); 551 } else if (FunctionDecl *Fn 552 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 553 // Address of overloaded function (C++ [over.over]). 554 SCS.First = ICK_Function_To_Pointer; 555 556 // We were able to resolve the address of the overloaded function, 557 // so we can convert to the type of that function. 558 FromType = Fn->getType(); 559 if (ToType->isLValueReferenceType()) 560 FromType = Context.getLValueReferenceType(FromType); 561 else if (ToType->isRValueReferenceType()) 562 FromType = Context.getRValueReferenceType(FromType); 563 else if (ToType->isMemberPointerType()) { 564 // Resolve address only succeeds if both sides are member pointers, 565 // but it doesn't have to be the same class. See DR 247. 566 // Note that this means that the type of &Derived::fn can be 567 // Ret (Base::*)(Args) if the fn overload actually found is from the 568 // base class, even if it was brought into the derived class via a 569 // using declaration. The standard isn't clear on this issue at all. 570 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 571 FromType = Context.getMemberPointerType(FromType, 572 Context.getTypeDeclType(M->getParent()).getTypePtr()); 573 } else 574 FromType = Context.getPointerType(FromType); 575 } else { 576 // We don't require any conversions for the first step. 577 SCS.First = ICK_Identity; 578 } 579 580 // The second conversion can be an integral promotion, floating 581 // point promotion, integral conversion, floating point conversion, 582 // floating-integral conversion, pointer conversion, 583 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 584 // For overloading in C, this can also be a "compatible-type" 585 // conversion. 586 bool IncompatibleObjC = false; 587 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 588 // The unqualified versions of the types are the same: there's no 589 // conversion to do. 590 SCS.Second = ICK_Identity; 591 } else if (IsIntegralPromotion(From, FromType, ToType)) { 592 // Integral promotion (C++ 4.5). 593 SCS.Second = ICK_Integral_Promotion; 594 FromType = ToType.getUnqualifiedType(); 595 } else if (IsFloatingPointPromotion(FromType, ToType)) { 596 // Floating point promotion (C++ 4.6). 597 SCS.Second = ICK_Floating_Promotion; 598 FromType = ToType.getUnqualifiedType(); 599 } else if (IsComplexPromotion(FromType, ToType)) { 600 // Complex promotion (Clang extension) 601 SCS.Second = ICK_Complex_Promotion; 602 FromType = ToType.getUnqualifiedType(); 603 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 604 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 605 // Integral conversions (C++ 4.7). 606 // FIXME: isIntegralType shouldn't be true for enums in C++. 607 SCS.Second = ICK_Integral_Conversion; 608 FromType = ToType.getUnqualifiedType(); 609 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 610 // Floating point conversions (C++ 4.8). 611 SCS.Second = ICK_Floating_Conversion; 612 FromType = ToType.getUnqualifiedType(); 613 } else if (FromType->isComplexType() && ToType->isComplexType()) { 614 // Complex conversions (C99 6.3.1.6) 615 SCS.Second = ICK_Complex_Conversion; 616 FromType = ToType.getUnqualifiedType(); 617 } else if ((FromType->isFloatingType() && 618 ToType->isIntegralType() && (!ToType->isBooleanType() && 619 !ToType->isEnumeralType())) || 620 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 621 ToType->isFloatingType())) { 622 // Floating-integral conversions (C++ 4.9). 623 // FIXME: isIntegralType shouldn't be true for enums in C++. 624 SCS.Second = ICK_Floating_Integral; 625 FromType = ToType.getUnqualifiedType(); 626 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 627 (ToType->isComplexType() && FromType->isArithmeticType())) { 628 // Complex-real conversions (C99 6.3.1.7) 629 SCS.Second = ICK_Complex_Real; 630 FromType = ToType.getUnqualifiedType(); 631 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 632 FromType, IncompatibleObjC)) { 633 // Pointer conversions (C++ 4.10). 634 SCS.Second = ICK_Pointer_Conversion; 635 SCS.IncompatibleObjC = IncompatibleObjC; 636 } else if (IsMemberPointerConversion(From, FromType, ToType, FromType)) { 637 // Pointer to member conversions (4.11). 638 SCS.Second = ICK_Pointer_Member; 639 } else if (ToType->isBooleanType() && 640 (FromType->isArithmeticType() || 641 FromType->isEnumeralType() || 642 FromType->isPointerType() || 643 FromType->isBlockPointerType() || 644 FromType->isMemberPointerType() || 645 FromType->isNullPtrType())) { 646 // Boolean conversions (C++ 4.12). 647 SCS.Second = ICK_Boolean_Conversion; 648 FromType = Context.BoolTy; 649 } else if (!getLangOptions().CPlusPlus && 650 Context.typesAreCompatible(ToType, FromType)) { 651 // Compatible conversions (Clang extension for C function overloading) 652 SCS.Second = ICK_Compatible_Conversion; 653 } else { 654 // No second conversion required. 655 SCS.Second = ICK_Identity; 656 } 657 658 QualType CanonFrom; 659 QualType CanonTo; 660 // The third conversion can be a qualification conversion (C++ 4p1). 661 if (IsQualificationConversion(FromType, ToType)) { 662 SCS.Third = ICK_Qualification; 663 FromType = ToType; 664 CanonFrom = Context.getCanonicalType(FromType); 665 CanonTo = Context.getCanonicalType(ToType); 666 } else { 667 // No conversion required 668 SCS.Third = ICK_Identity; 669 670 // C++ [over.best.ics]p6: 671 // [...] Any difference in top-level cv-qualification is 672 // subsumed by the initialization itself and does not constitute 673 // a conversion. [...] 674 CanonFrom = Context.getCanonicalType(FromType); 675 CanonTo = Context.getCanonicalType(ToType); 676 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 677 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 678 FromType = ToType; 679 CanonFrom = CanonTo; 680 } 681 } 682 683 // If we have not converted the argument type to the parameter type, 684 // this is a bad conversion sequence. 685 if (CanonFrom != CanonTo) 686 return false; 687 688 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 689 return true; 690} 691 692/// IsIntegralPromotion - Determines whether the conversion from the 693/// expression From (whose potentially-adjusted type is FromType) to 694/// ToType is an integral promotion (C++ 4.5). If so, returns true and 695/// sets PromotedType to the promoted type. 696bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 697 const BuiltinType *To = ToType->getAs<BuiltinType>(); 698 // All integers are built-in. 699 if (!To) { 700 return false; 701 } 702 703 // An rvalue of type char, signed char, unsigned char, short int, or 704 // unsigned short int can be converted to an rvalue of type int if 705 // int can represent all the values of the source type; otherwise, 706 // the source rvalue can be converted to an rvalue of type unsigned 707 // int (C++ 4.5p1). 708 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 709 if (// We can promote any signed, promotable integer type to an int 710 (FromType->isSignedIntegerType() || 711 // We can promote any unsigned integer type whose size is 712 // less than int to an int. 713 (!FromType->isSignedIntegerType() && 714 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 715 return To->getKind() == BuiltinType::Int; 716 } 717 718 return To->getKind() == BuiltinType::UInt; 719 } 720 721 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 722 // can be converted to an rvalue of the first of the following types 723 // that can represent all the values of its underlying type: int, 724 // unsigned int, long, or unsigned long (C++ 4.5p2). 725 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 726 && ToType->isIntegerType()) { 727 // Determine whether the type we're converting from is signed or 728 // unsigned. 729 bool FromIsSigned; 730 uint64_t FromSize = Context.getTypeSize(FromType); 731 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 732 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 733 FromIsSigned = UnderlyingType->isSignedIntegerType(); 734 } else { 735 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 736 FromIsSigned = true; 737 } 738 739 // The types we'll try to promote to, in the appropriate 740 // order. Try each of these types. 741 QualType PromoteTypes[6] = { 742 Context.IntTy, Context.UnsignedIntTy, 743 Context.LongTy, Context.UnsignedLongTy , 744 Context.LongLongTy, Context.UnsignedLongLongTy 745 }; 746 for (int Idx = 0; Idx < 6; ++Idx) { 747 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 748 if (FromSize < ToSize || 749 (FromSize == ToSize && 750 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 751 // We found the type that we can promote to. If this is the 752 // type we wanted, we have a promotion. Otherwise, no 753 // promotion. 754 return Context.getCanonicalType(ToType).getUnqualifiedType() 755 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 756 } 757 } 758 } 759 760 // An rvalue for an integral bit-field (9.6) can be converted to an 761 // rvalue of type int if int can represent all the values of the 762 // bit-field; otherwise, it can be converted to unsigned int if 763 // unsigned int can represent all the values of the bit-field. If 764 // the bit-field is larger yet, no integral promotion applies to 765 // it. If the bit-field has an enumerated type, it is treated as any 766 // other value of that type for promotion purposes (C++ 4.5p3). 767 // FIXME: We should delay checking of bit-fields until we actually perform the 768 // conversion. 769 using llvm::APSInt; 770 if (From) 771 if (FieldDecl *MemberDecl = From->getBitField()) { 772 APSInt BitWidth; 773 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 774 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 775 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 776 ToSize = Context.getTypeSize(ToType); 777 778 // Are we promoting to an int from a bitfield that fits in an int? 779 if (BitWidth < ToSize || 780 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 781 return To->getKind() == BuiltinType::Int; 782 } 783 784 // Are we promoting to an unsigned int from an unsigned bitfield 785 // that fits into an unsigned int? 786 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 787 return To->getKind() == BuiltinType::UInt; 788 } 789 790 return false; 791 } 792 } 793 794 // An rvalue of type bool can be converted to an rvalue of type int, 795 // with false becoming zero and true becoming one (C++ 4.5p4). 796 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 797 return true; 798 } 799 800 return false; 801} 802 803/// IsFloatingPointPromotion - Determines whether the conversion from 804/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 805/// returns true and sets PromotedType to the promoted type. 806bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 807 /// An rvalue of type float can be converted to an rvalue of type 808 /// double. (C++ 4.6p1). 809 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 810 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 811 if (FromBuiltin->getKind() == BuiltinType::Float && 812 ToBuiltin->getKind() == BuiltinType::Double) 813 return true; 814 815 // C99 6.3.1.5p1: 816 // When a float is promoted to double or long double, or a 817 // double is promoted to long double [...]. 818 if (!getLangOptions().CPlusPlus && 819 (FromBuiltin->getKind() == BuiltinType::Float || 820 FromBuiltin->getKind() == BuiltinType::Double) && 821 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 822 return true; 823 } 824 825 return false; 826} 827 828/// \brief Determine if a conversion is a complex promotion. 829/// 830/// A complex promotion is defined as a complex -> complex conversion 831/// where the conversion between the underlying real types is a 832/// floating-point or integral promotion. 833bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 834 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 835 if (!FromComplex) 836 return false; 837 838 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 839 if (!ToComplex) 840 return false; 841 842 return IsFloatingPointPromotion(FromComplex->getElementType(), 843 ToComplex->getElementType()) || 844 IsIntegralPromotion(0, FromComplex->getElementType(), 845 ToComplex->getElementType()); 846} 847 848/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 849/// the pointer type FromPtr to a pointer to type ToPointee, with the 850/// same type qualifiers as FromPtr has on its pointee type. ToType, 851/// if non-empty, will be a pointer to ToType that may or may not have 852/// the right set of qualifiers on its pointee. 853static QualType 854BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 855 QualType ToPointee, QualType ToType, 856 ASTContext &Context) { 857 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 858 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 859 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 860 861 // Exact qualifier match -> return the pointer type we're converting to. 862 if (CanonToPointee.getCVRQualifiers() == Quals) { 863 // ToType is exactly what we need. Return it. 864 if (ToType.getTypePtr()) 865 return ToType; 866 867 // Build a pointer to ToPointee. It has the right qualifiers 868 // already. 869 return Context.getPointerType(ToPointee); 870 } 871 872 // Just build a canonical type that has the right qualifiers. 873 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 874} 875 876static bool isNullPointerConstantForConversion(Expr *Expr, 877 bool InOverloadResolution, 878 ASTContext &Context) { 879 // Handle value-dependent integral null pointer constants correctly. 880 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 881 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 882 Expr->getType()->isIntegralType()) 883 return !InOverloadResolution; 884 885 return Expr->isNullPointerConstant(Context); 886} 887 888/// IsPointerConversion - Determines whether the conversion of the 889/// expression From, which has the (possibly adjusted) type FromType, 890/// can be converted to the type ToType via a pointer conversion (C++ 891/// 4.10). If so, returns true and places the converted type (that 892/// might differ from ToType in its cv-qualifiers at some level) into 893/// ConvertedType. 894/// 895/// This routine also supports conversions to and from block pointers 896/// and conversions with Objective-C's 'id', 'id<protocols...>', and 897/// pointers to interfaces. FIXME: Once we've determined the 898/// appropriate overloading rules for Objective-C, we may want to 899/// split the Objective-C checks into a different routine; however, 900/// GCC seems to consider all of these conversions to be pointer 901/// conversions, so for now they live here. IncompatibleObjC will be 902/// set if the conversion is an allowed Objective-C conversion that 903/// should result in a warning. 904bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 905 bool InOverloadResolution, 906 QualType& ConvertedType, 907 bool &IncompatibleObjC) { 908 IncompatibleObjC = false; 909 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 910 return true; 911 912 // Conversion from a null pointer constant to any Objective-C pointer type. 913 if (ToType->isObjCObjectPointerType() && 914 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 915 ConvertedType = ToType; 916 return true; 917 } 918 919 // Blocks: Block pointers can be converted to void*. 920 if (FromType->isBlockPointerType() && ToType->isPointerType() && 921 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 922 ConvertedType = ToType; 923 return true; 924 } 925 // Blocks: A null pointer constant can be converted to a block 926 // pointer type. 927 if (ToType->isBlockPointerType() && 928 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 929 ConvertedType = ToType; 930 return true; 931 } 932 933 // If the left-hand-side is nullptr_t, the right side can be a null 934 // pointer constant. 935 if (ToType->isNullPtrType() && 936 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 937 ConvertedType = ToType; 938 return true; 939 } 940 941 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 942 if (!ToTypePtr) 943 return false; 944 945 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 946 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 947 ConvertedType = ToType; 948 return true; 949 } 950 951 // Beyond this point, both types need to be pointers. 952 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 953 if (!FromTypePtr) 954 return false; 955 956 QualType FromPointeeType = FromTypePtr->getPointeeType(); 957 QualType ToPointeeType = ToTypePtr->getPointeeType(); 958 959 // An rvalue of type "pointer to cv T," where T is an object type, 960 // can be converted to an rvalue of type "pointer to cv void" (C++ 961 // 4.10p2). 962 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 963 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 964 ToPointeeType, 965 ToType, Context); 966 return true; 967 } 968 969 // When we're overloading in C, we allow a special kind of pointer 970 // conversion for compatible-but-not-identical pointee types. 971 if (!getLangOptions().CPlusPlus && 972 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 973 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 974 ToPointeeType, 975 ToType, Context); 976 return true; 977 } 978 979 // C++ [conv.ptr]p3: 980 // 981 // An rvalue of type "pointer to cv D," where D is a class type, 982 // can be converted to an rvalue of type "pointer to cv B," where 983 // B is a base class (clause 10) of D. If B is an inaccessible 984 // (clause 11) or ambiguous (10.2) base class of D, a program that 985 // necessitates this conversion is ill-formed. The result of the 986 // conversion is a pointer to the base class sub-object of the 987 // derived class object. The null pointer value is converted to 988 // the null pointer value of the destination type. 989 // 990 // Note that we do not check for ambiguity or inaccessibility 991 // here. That is handled by CheckPointerConversion. 992 if (getLangOptions().CPlusPlus && 993 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 994 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 995 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 996 ToPointeeType, 997 ToType, Context); 998 return true; 999 } 1000 1001 return false; 1002} 1003 1004/// isObjCPointerConversion - Determines whether this is an 1005/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1006/// with the same arguments and return values. 1007bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1008 QualType& ConvertedType, 1009 bool &IncompatibleObjC) { 1010 if (!getLangOptions().ObjC1) 1011 return false; 1012 1013 // First, we handle all conversions on ObjC object pointer types. 1014 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1015 const ObjCObjectPointerType *FromObjCPtr = 1016 FromType->getAs<ObjCObjectPointerType>(); 1017 1018 if (ToObjCPtr && FromObjCPtr) { 1019 // Objective C++: We're able to convert between "id" or "Class" and a 1020 // pointer to any interface (in both directions). 1021 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1022 ConvertedType = ToType; 1023 return true; 1024 } 1025 // Conversions with Objective-C's id<...>. 1026 if ((FromObjCPtr->isObjCQualifiedIdType() || 1027 ToObjCPtr->isObjCQualifiedIdType()) && 1028 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1029 /*compare=*/false)) { 1030 ConvertedType = ToType; 1031 return true; 1032 } 1033 // Objective C++: We're able to convert from a pointer to an 1034 // interface to a pointer to a different interface. 1035 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1036 ConvertedType = ToType; 1037 return true; 1038 } 1039 1040 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1041 // Okay: this is some kind of implicit downcast of Objective-C 1042 // interfaces, which is permitted. However, we're going to 1043 // complain about it. 1044 IncompatibleObjC = true; 1045 ConvertedType = FromType; 1046 return true; 1047 } 1048 } 1049 // Beyond this point, both types need to be C pointers or block pointers. 1050 QualType ToPointeeType; 1051 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1052 ToPointeeType = ToCPtr->getPointeeType(); 1053 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1054 ToPointeeType = ToBlockPtr->getPointeeType(); 1055 else 1056 return false; 1057 1058 QualType FromPointeeType; 1059 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1060 FromPointeeType = FromCPtr->getPointeeType(); 1061 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1062 FromPointeeType = FromBlockPtr->getPointeeType(); 1063 else 1064 return false; 1065 1066 // If we have pointers to pointers, recursively check whether this 1067 // is an Objective-C conversion. 1068 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1069 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1070 IncompatibleObjC)) { 1071 // We always complain about this conversion. 1072 IncompatibleObjC = true; 1073 ConvertedType = ToType; 1074 return true; 1075 } 1076 // If we have pointers to functions or blocks, check whether the only 1077 // differences in the argument and result types are in Objective-C 1078 // pointer conversions. If so, we permit the conversion (but 1079 // complain about it). 1080 const FunctionProtoType *FromFunctionType 1081 = FromPointeeType->getAs<FunctionProtoType>(); 1082 const FunctionProtoType *ToFunctionType 1083 = ToPointeeType->getAs<FunctionProtoType>(); 1084 if (FromFunctionType && ToFunctionType) { 1085 // If the function types are exactly the same, this isn't an 1086 // Objective-C pointer conversion. 1087 if (Context.getCanonicalType(FromPointeeType) 1088 == Context.getCanonicalType(ToPointeeType)) 1089 return false; 1090 1091 // Perform the quick checks that will tell us whether these 1092 // function types are obviously different. 1093 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1094 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1095 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1096 return false; 1097 1098 bool HasObjCConversion = false; 1099 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1100 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1101 // Okay, the types match exactly. Nothing to do. 1102 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1103 ToFunctionType->getResultType(), 1104 ConvertedType, IncompatibleObjC)) { 1105 // Okay, we have an Objective-C pointer conversion. 1106 HasObjCConversion = true; 1107 } else { 1108 // Function types are too different. Abort. 1109 return false; 1110 } 1111 1112 // Check argument types. 1113 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1114 ArgIdx != NumArgs; ++ArgIdx) { 1115 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1116 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1117 if (Context.getCanonicalType(FromArgType) 1118 == Context.getCanonicalType(ToArgType)) { 1119 // Okay, the types match exactly. Nothing to do. 1120 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1121 ConvertedType, IncompatibleObjC)) { 1122 // Okay, we have an Objective-C pointer conversion. 1123 HasObjCConversion = true; 1124 } else { 1125 // Argument types are too different. Abort. 1126 return false; 1127 } 1128 } 1129 1130 if (HasObjCConversion) { 1131 // We had an Objective-C conversion. Allow this pointer 1132 // conversion, but complain about it. 1133 ConvertedType = ToType; 1134 IncompatibleObjC = true; 1135 return true; 1136 } 1137 } 1138 1139 return false; 1140} 1141 1142/// CheckPointerConversion - Check the pointer conversion from the 1143/// expression From to the type ToType. This routine checks for 1144/// ambiguous or inaccessible derived-to-base pointer 1145/// conversions for which IsPointerConversion has already returned 1146/// true. It returns true and produces a diagnostic if there was an 1147/// error, or returns false otherwise. 1148bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1149 CastExpr::CastKind &Kind) { 1150 QualType FromType = From->getType(); 1151 1152 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1153 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1154 QualType FromPointeeType = FromPtrType->getPointeeType(), 1155 ToPointeeType = ToPtrType->getPointeeType(); 1156 1157 if (FromPointeeType->isRecordType() && 1158 ToPointeeType->isRecordType()) { 1159 // We must have a derived-to-base conversion. Check an 1160 // ambiguous or inaccessible conversion. 1161 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1162 From->getExprLoc(), 1163 From->getSourceRange())) 1164 return true; 1165 1166 // The conversion was successful. 1167 Kind = CastExpr::CK_DerivedToBase; 1168 } 1169 } 1170 if (const ObjCObjectPointerType *FromPtrType = 1171 FromType->getAs<ObjCObjectPointerType>()) 1172 if (const ObjCObjectPointerType *ToPtrType = 1173 ToType->getAs<ObjCObjectPointerType>()) { 1174 // Objective-C++ conversions are always okay. 1175 // FIXME: We should have a different class of conversions for the 1176 // Objective-C++ implicit conversions. 1177 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1178 return false; 1179 1180 } 1181 return false; 1182} 1183 1184/// IsMemberPointerConversion - Determines whether the conversion of the 1185/// expression From, which has the (possibly adjusted) type FromType, can be 1186/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1187/// If so, returns true and places the converted type (that might differ from 1188/// ToType in its cv-qualifiers at some level) into ConvertedType. 1189bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1190 QualType ToType, QualType &ConvertedType) { 1191 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1192 if (!ToTypePtr) 1193 return false; 1194 1195 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1196 if (From->isNullPointerConstant(Context)) { 1197 ConvertedType = ToType; 1198 return true; 1199 } 1200 1201 // Otherwise, both types have to be member pointers. 1202 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1203 if (!FromTypePtr) 1204 return false; 1205 1206 // A pointer to member of B can be converted to a pointer to member of D, 1207 // where D is derived from B (C++ 4.11p2). 1208 QualType FromClass(FromTypePtr->getClass(), 0); 1209 QualType ToClass(ToTypePtr->getClass(), 0); 1210 // FIXME: What happens when these are dependent? Is this function even called? 1211 1212 if (IsDerivedFrom(ToClass, FromClass)) { 1213 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1214 ToClass.getTypePtr()); 1215 return true; 1216 } 1217 1218 return false; 1219} 1220 1221/// CheckMemberPointerConversion - Check the member pointer conversion from the 1222/// expression From to the type ToType. This routine checks for ambiguous or 1223/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1224/// for which IsMemberPointerConversion has already returned true. It returns 1225/// true and produces a diagnostic if there was an error, or returns false 1226/// otherwise. 1227bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1228 CastExpr::CastKind &Kind) { 1229 QualType FromType = From->getType(); 1230 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1231 if (!FromPtrType) { 1232 // This must be a null pointer to member pointer conversion 1233 assert(From->isNullPointerConstant(Context) && 1234 "Expr must be null pointer constant!"); 1235 Kind = CastExpr::CK_NullToMemberPointer; 1236 return false; 1237 } 1238 1239 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1240 assert(ToPtrType && "No member pointer cast has a target type " 1241 "that is not a member pointer."); 1242 1243 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1244 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1245 1246 // FIXME: What about dependent types? 1247 assert(FromClass->isRecordType() && "Pointer into non-class."); 1248 assert(ToClass->isRecordType() && "Pointer into non-class."); 1249 1250 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1251 /*DetectVirtual=*/true); 1252 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1253 assert(DerivationOkay && 1254 "Should not have been called if derivation isn't OK."); 1255 (void)DerivationOkay; 1256 1257 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1258 getUnqualifiedType())) { 1259 // Derivation is ambiguous. Redo the check to find the exact paths. 1260 Paths.clear(); 1261 Paths.setRecordingPaths(true); 1262 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1263 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1264 (void)StillOkay; 1265 1266 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1267 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1268 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1269 return true; 1270 } 1271 1272 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1273 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1274 << FromClass << ToClass << QualType(VBase, 0) 1275 << From->getSourceRange(); 1276 return true; 1277 } 1278 1279 // Must be a base to derived member conversion. 1280 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1281 return false; 1282} 1283 1284/// IsQualificationConversion - Determines whether the conversion from 1285/// an rvalue of type FromType to ToType is a qualification conversion 1286/// (C++ 4.4). 1287bool 1288Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1289 FromType = Context.getCanonicalType(FromType); 1290 ToType = Context.getCanonicalType(ToType); 1291 1292 // If FromType and ToType are the same type, this is not a 1293 // qualification conversion. 1294 if (FromType == ToType) 1295 return false; 1296 1297 // (C++ 4.4p4): 1298 // A conversion can add cv-qualifiers at levels other than the first 1299 // in multi-level pointers, subject to the following rules: [...] 1300 bool PreviousToQualsIncludeConst = true; 1301 bool UnwrappedAnyPointer = false; 1302 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1303 // Within each iteration of the loop, we check the qualifiers to 1304 // determine if this still looks like a qualification 1305 // conversion. Then, if all is well, we unwrap one more level of 1306 // pointers or pointers-to-members and do it all again 1307 // until there are no more pointers or pointers-to-members left to 1308 // unwrap. 1309 UnwrappedAnyPointer = true; 1310 1311 // -- for every j > 0, if const is in cv 1,j then const is in cv 1312 // 2,j, and similarly for volatile. 1313 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1314 return false; 1315 1316 // -- if the cv 1,j and cv 2,j are different, then const is in 1317 // every cv for 0 < k < j. 1318 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1319 && !PreviousToQualsIncludeConst) 1320 return false; 1321 1322 // Keep track of whether all prior cv-qualifiers in the "to" type 1323 // include const. 1324 PreviousToQualsIncludeConst 1325 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1326 } 1327 1328 // We are left with FromType and ToType being the pointee types 1329 // after unwrapping the original FromType and ToType the same number 1330 // of types. If we unwrapped any pointers, and if FromType and 1331 // ToType have the same unqualified type (since we checked 1332 // qualifiers above), then this is a qualification conversion. 1333 return UnwrappedAnyPointer && 1334 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1335} 1336 1337/// \brief Given a function template or function, extract the function template 1338/// declaration (if any) and the underlying function declaration. 1339template<typename T> 1340static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1341 FunctionTemplateDecl *&FunctionTemplate) { 1342 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1343 if (FunctionTemplate) 1344 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1345 else 1346 Function = cast<T>(Orig); 1347} 1348 1349/// Determines whether there is a user-defined conversion sequence 1350/// (C++ [over.ics.user]) that converts expression From to the type 1351/// ToType. If such a conversion exists, User will contain the 1352/// user-defined conversion sequence that performs such a conversion 1353/// and this routine will return true. Otherwise, this routine returns 1354/// false and User is unspecified. 1355/// 1356/// \param AllowConversionFunctions true if the conversion should 1357/// consider conversion functions at all. If false, only constructors 1358/// will be considered. 1359/// 1360/// \param AllowExplicit true if the conversion should consider C++0x 1361/// "explicit" conversion functions as well as non-explicit conversion 1362/// functions (C++0x [class.conv.fct]p2). 1363/// 1364/// \param ForceRValue true if the expression should be treated as an rvalue 1365/// for overload resolution. 1366Sema::OverloadingResult Sema::IsUserDefinedConversion( 1367 Expr *From, QualType ToType, 1368 UserDefinedConversionSequence& User, 1369 OverloadCandidateSet& CandidateSet, 1370 bool AllowConversionFunctions, 1371 bool AllowExplicit, bool ForceRValue) { 1372 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1373 if (CXXRecordDecl *ToRecordDecl 1374 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1375 // C++ [over.match.ctor]p1: 1376 // When objects of class type are direct-initialized (8.5), or 1377 // copy-initialized from an expression of the same or a 1378 // derived class type (8.5), overload resolution selects the 1379 // constructor. [...] For copy-initialization, the candidate 1380 // functions are all the converting constructors (12.3.1) of 1381 // that class. The argument list is the expression-list within 1382 // the parentheses of the initializer. 1383 DeclarationName ConstructorName 1384 = Context.DeclarationNames.getCXXConstructorName( 1385 Context.getCanonicalType(ToType).getUnqualifiedType()); 1386 DeclContext::lookup_iterator Con, ConEnd; 1387 for (llvm::tie(Con, ConEnd) 1388 = ToRecordDecl->lookup(ConstructorName); 1389 Con != ConEnd; ++Con) { 1390 // Find the constructor (which may be a template). 1391 CXXConstructorDecl *Constructor = 0; 1392 FunctionTemplateDecl *ConstructorTmpl 1393 = dyn_cast<FunctionTemplateDecl>(*Con); 1394 if (ConstructorTmpl) 1395 Constructor 1396 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1397 else 1398 Constructor = cast<CXXConstructorDecl>(*Con); 1399 1400 if (!Constructor->isInvalidDecl() && 1401 Constructor->isConvertingConstructor(AllowExplicit)) { 1402 if (ConstructorTmpl) 1403 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1404 1, CandidateSet, 1405 /*SuppressUserConversions=*/true, 1406 ForceRValue); 1407 else 1408 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1409 /*SuppressUserConversions=*/true, ForceRValue); 1410 } 1411 } 1412 } 1413 } 1414 1415 if (!AllowConversionFunctions) { 1416 // Don't allow any conversion functions to enter the overload set. 1417 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1418 PDiag(0) 1419 << From->getSourceRange())) { 1420 // No conversion functions from incomplete types. 1421 } else if (const RecordType *FromRecordType 1422 = From->getType()->getAs<RecordType>()) { 1423 if (CXXRecordDecl *FromRecordDecl 1424 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1425 // Add all of the conversion functions as candidates. 1426 OverloadedFunctionDecl *Conversions 1427 = FromRecordDecl->getVisibleConversionFunctions(); 1428 for (OverloadedFunctionDecl::function_iterator Func 1429 = Conversions->function_begin(); 1430 Func != Conversions->function_end(); ++Func) { 1431 CXXConversionDecl *Conv; 1432 FunctionTemplateDecl *ConvTemplate; 1433 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1434 if (ConvTemplate) 1435 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1436 else 1437 Conv = dyn_cast<CXXConversionDecl>(*Func); 1438 1439 if (AllowExplicit || !Conv->isExplicit()) { 1440 if (ConvTemplate) 1441 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1442 CandidateSet); 1443 else 1444 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1445 } 1446 } 1447 } 1448 } 1449 1450 OverloadCandidateSet::iterator Best; 1451 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1452 case OR_Success: 1453 // Record the standard conversion we used and the conversion function. 1454 if (CXXConstructorDecl *Constructor 1455 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1456 // C++ [over.ics.user]p1: 1457 // If the user-defined conversion is specified by a 1458 // constructor (12.3.1), the initial standard conversion 1459 // sequence converts the source type to the type required by 1460 // the argument of the constructor. 1461 // 1462 // FIXME: What about ellipsis conversions? 1463 QualType ThisType = Constructor->getThisType(Context); 1464 User.Before = Best->Conversions[0].Standard; 1465 User.ConversionFunction = Constructor; 1466 User.After.setAsIdentityConversion(); 1467 User.After.FromTypePtr 1468 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1469 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1470 return OR_Success; 1471 } else if (CXXConversionDecl *Conversion 1472 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1473 // C++ [over.ics.user]p1: 1474 // 1475 // [...] If the user-defined conversion is specified by a 1476 // conversion function (12.3.2), the initial standard 1477 // conversion sequence converts the source type to the 1478 // implicit object parameter of the conversion function. 1479 User.Before = Best->Conversions[0].Standard; 1480 User.ConversionFunction = Conversion; 1481 1482 // C++ [over.ics.user]p2: 1483 // The second standard conversion sequence converts the 1484 // result of the user-defined conversion to the target type 1485 // for the sequence. Since an implicit conversion sequence 1486 // is an initialization, the special rules for 1487 // initialization by user-defined conversion apply when 1488 // selecting the best user-defined conversion for a 1489 // user-defined conversion sequence (see 13.3.3 and 1490 // 13.3.3.1). 1491 User.After = Best->FinalConversion; 1492 return OR_Success; 1493 } else { 1494 assert(false && "Not a constructor or conversion function?"); 1495 return OR_No_Viable_Function; 1496 } 1497 1498 case OR_No_Viable_Function: 1499 return OR_No_Viable_Function; 1500 case OR_Deleted: 1501 // No conversion here! We're done. 1502 return OR_Deleted; 1503 1504 case OR_Ambiguous: 1505 // FIXME: See C++ [over.best.ics]p10 for the handling of 1506 // ambiguous conversion sequences. 1507 return OR_Ambiguous; 1508 } 1509 1510 return OR_No_Viable_Function; 1511} 1512 1513bool 1514Sema::DiagnoseAmbiguousUserDefinedConversion(Expr *From, QualType ToType) { 1515 ImplicitConversionSequence ICS; 1516 OverloadCandidateSet CandidateSet; 1517 OverloadingResult OvResult = 1518 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1519 CandidateSet, true, false, false); 1520 if (OvResult != OR_Ambiguous) 1521 return false; 1522 Diag(From->getSourceRange().getBegin(), 1523 diag::err_typecheck_ambiguous_condition) 1524 << From->getType() << ToType << From->getSourceRange(); 1525 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1526 return true; 1527} 1528 1529/// CompareImplicitConversionSequences - Compare two implicit 1530/// conversion sequences to determine whether one is better than the 1531/// other or if they are indistinguishable (C++ 13.3.3.2). 1532ImplicitConversionSequence::CompareKind 1533Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1534 const ImplicitConversionSequence& ICS2) 1535{ 1536 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1537 // conversion sequences (as defined in 13.3.3.1) 1538 // -- a standard conversion sequence (13.3.3.1.1) is a better 1539 // conversion sequence than a user-defined conversion sequence or 1540 // an ellipsis conversion sequence, and 1541 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1542 // conversion sequence than an ellipsis conversion sequence 1543 // (13.3.3.1.3). 1544 // 1545 if (ICS1.ConversionKind < ICS2.ConversionKind) 1546 return ImplicitConversionSequence::Better; 1547 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1548 return ImplicitConversionSequence::Worse; 1549 1550 // Two implicit conversion sequences of the same form are 1551 // indistinguishable conversion sequences unless one of the 1552 // following rules apply: (C++ 13.3.3.2p3): 1553 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1554 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1555 else if (ICS1.ConversionKind == 1556 ImplicitConversionSequence::UserDefinedConversion) { 1557 // User-defined conversion sequence U1 is a better conversion 1558 // sequence than another user-defined conversion sequence U2 if 1559 // they contain the same user-defined conversion function or 1560 // constructor and if the second standard conversion sequence of 1561 // U1 is better than the second standard conversion sequence of 1562 // U2 (C++ 13.3.3.2p3). 1563 if (ICS1.UserDefined.ConversionFunction == 1564 ICS2.UserDefined.ConversionFunction) 1565 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1566 ICS2.UserDefined.After); 1567 } 1568 1569 return ImplicitConversionSequence::Indistinguishable; 1570} 1571 1572/// CompareStandardConversionSequences - Compare two standard 1573/// conversion sequences to determine whether one is better than the 1574/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1575ImplicitConversionSequence::CompareKind 1576Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1577 const StandardConversionSequence& SCS2) 1578{ 1579 // Standard conversion sequence S1 is a better conversion sequence 1580 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1581 1582 // -- S1 is a proper subsequence of S2 (comparing the conversion 1583 // sequences in the canonical form defined by 13.3.3.1.1, 1584 // excluding any Lvalue Transformation; the identity conversion 1585 // sequence is considered to be a subsequence of any 1586 // non-identity conversion sequence) or, if not that, 1587 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1588 // Neither is a proper subsequence of the other. Do nothing. 1589 ; 1590 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1591 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1592 (SCS1.Second == ICK_Identity && 1593 SCS1.Third == ICK_Identity)) 1594 // SCS1 is a proper subsequence of SCS2. 1595 return ImplicitConversionSequence::Better; 1596 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1597 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1598 (SCS2.Second == ICK_Identity && 1599 SCS2.Third == ICK_Identity)) 1600 // SCS2 is a proper subsequence of SCS1. 1601 return ImplicitConversionSequence::Worse; 1602 1603 // -- the rank of S1 is better than the rank of S2 (by the rules 1604 // defined below), or, if not that, 1605 ImplicitConversionRank Rank1 = SCS1.getRank(); 1606 ImplicitConversionRank Rank2 = SCS2.getRank(); 1607 if (Rank1 < Rank2) 1608 return ImplicitConversionSequence::Better; 1609 else if (Rank2 < Rank1) 1610 return ImplicitConversionSequence::Worse; 1611 1612 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1613 // are indistinguishable unless one of the following rules 1614 // applies: 1615 1616 // A conversion that is not a conversion of a pointer, or 1617 // pointer to member, to bool is better than another conversion 1618 // that is such a conversion. 1619 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1620 return SCS2.isPointerConversionToBool() 1621 ? ImplicitConversionSequence::Better 1622 : ImplicitConversionSequence::Worse; 1623 1624 // C++ [over.ics.rank]p4b2: 1625 // 1626 // If class B is derived directly or indirectly from class A, 1627 // conversion of B* to A* is better than conversion of B* to 1628 // void*, and conversion of A* to void* is better than conversion 1629 // of B* to void*. 1630 bool SCS1ConvertsToVoid 1631 = SCS1.isPointerConversionToVoidPointer(Context); 1632 bool SCS2ConvertsToVoid 1633 = SCS2.isPointerConversionToVoidPointer(Context); 1634 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1635 // Exactly one of the conversion sequences is a conversion to 1636 // a void pointer; it's the worse conversion. 1637 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1638 : ImplicitConversionSequence::Worse; 1639 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1640 // Neither conversion sequence converts to a void pointer; compare 1641 // their derived-to-base conversions. 1642 if (ImplicitConversionSequence::CompareKind DerivedCK 1643 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1644 return DerivedCK; 1645 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1646 // Both conversion sequences are conversions to void 1647 // pointers. Compare the source types to determine if there's an 1648 // inheritance relationship in their sources. 1649 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1650 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1651 1652 // Adjust the types we're converting from via the array-to-pointer 1653 // conversion, if we need to. 1654 if (SCS1.First == ICK_Array_To_Pointer) 1655 FromType1 = Context.getArrayDecayedType(FromType1); 1656 if (SCS2.First == ICK_Array_To_Pointer) 1657 FromType2 = Context.getArrayDecayedType(FromType2); 1658 1659 QualType FromPointee1 1660 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1661 QualType FromPointee2 1662 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1663 1664 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1665 return ImplicitConversionSequence::Better; 1666 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1667 return ImplicitConversionSequence::Worse; 1668 1669 // Objective-C++: If one interface is more specific than the 1670 // other, it is the better one. 1671 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1672 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1673 if (FromIface1 && FromIface1) { 1674 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1675 return ImplicitConversionSequence::Better; 1676 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1677 return ImplicitConversionSequence::Worse; 1678 } 1679 } 1680 1681 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1682 // bullet 3). 1683 if (ImplicitConversionSequence::CompareKind QualCK 1684 = CompareQualificationConversions(SCS1, SCS2)) 1685 return QualCK; 1686 1687 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1688 // C++0x [over.ics.rank]p3b4: 1689 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1690 // implicit object parameter of a non-static member function declared 1691 // without a ref-qualifier, and S1 binds an rvalue reference to an 1692 // rvalue and S2 binds an lvalue reference. 1693 // FIXME: We don't know if we're dealing with the implicit object parameter, 1694 // or if the member function in this case has a ref qualifier. 1695 // (Of course, we don't have ref qualifiers yet.) 1696 if (SCS1.RRefBinding != SCS2.RRefBinding) 1697 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1698 : ImplicitConversionSequence::Worse; 1699 1700 // C++ [over.ics.rank]p3b4: 1701 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1702 // which the references refer are the same type except for 1703 // top-level cv-qualifiers, and the type to which the reference 1704 // initialized by S2 refers is more cv-qualified than the type 1705 // to which the reference initialized by S1 refers. 1706 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1707 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1708 T1 = Context.getCanonicalType(T1); 1709 T2 = Context.getCanonicalType(T2); 1710 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1711 if (T2.isMoreQualifiedThan(T1)) 1712 return ImplicitConversionSequence::Better; 1713 else if (T1.isMoreQualifiedThan(T2)) 1714 return ImplicitConversionSequence::Worse; 1715 } 1716 } 1717 1718 return ImplicitConversionSequence::Indistinguishable; 1719} 1720 1721/// CompareQualificationConversions - Compares two standard conversion 1722/// sequences to determine whether they can be ranked based on their 1723/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1724ImplicitConversionSequence::CompareKind 1725Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1726 const StandardConversionSequence& SCS2) { 1727 // C++ 13.3.3.2p3: 1728 // -- S1 and S2 differ only in their qualification conversion and 1729 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1730 // cv-qualification signature of type T1 is a proper subset of 1731 // the cv-qualification signature of type T2, and S1 is not the 1732 // deprecated string literal array-to-pointer conversion (4.2). 1733 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1734 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1735 return ImplicitConversionSequence::Indistinguishable; 1736 1737 // FIXME: the example in the standard doesn't use a qualification 1738 // conversion (!) 1739 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1740 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1741 T1 = Context.getCanonicalType(T1); 1742 T2 = Context.getCanonicalType(T2); 1743 1744 // If the types are the same, we won't learn anything by unwrapped 1745 // them. 1746 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1747 return ImplicitConversionSequence::Indistinguishable; 1748 1749 ImplicitConversionSequence::CompareKind Result 1750 = ImplicitConversionSequence::Indistinguishable; 1751 while (UnwrapSimilarPointerTypes(T1, T2)) { 1752 // Within each iteration of the loop, we check the qualifiers to 1753 // determine if this still looks like a qualification 1754 // conversion. Then, if all is well, we unwrap one more level of 1755 // pointers or pointers-to-members and do it all again 1756 // until there are no more pointers or pointers-to-members left 1757 // to unwrap. This essentially mimics what 1758 // IsQualificationConversion does, but here we're checking for a 1759 // strict subset of qualifiers. 1760 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1761 // The qualifiers are the same, so this doesn't tell us anything 1762 // about how the sequences rank. 1763 ; 1764 else if (T2.isMoreQualifiedThan(T1)) { 1765 // T1 has fewer qualifiers, so it could be the better sequence. 1766 if (Result == ImplicitConversionSequence::Worse) 1767 // Neither has qualifiers that are a subset of the other's 1768 // qualifiers. 1769 return ImplicitConversionSequence::Indistinguishable; 1770 1771 Result = ImplicitConversionSequence::Better; 1772 } else if (T1.isMoreQualifiedThan(T2)) { 1773 // T2 has fewer qualifiers, so it could be the better sequence. 1774 if (Result == ImplicitConversionSequence::Better) 1775 // Neither has qualifiers that are a subset of the other's 1776 // qualifiers. 1777 return ImplicitConversionSequence::Indistinguishable; 1778 1779 Result = ImplicitConversionSequence::Worse; 1780 } else { 1781 // Qualifiers are disjoint. 1782 return ImplicitConversionSequence::Indistinguishable; 1783 } 1784 1785 // If the types after this point are equivalent, we're done. 1786 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1787 break; 1788 } 1789 1790 // Check that the winning standard conversion sequence isn't using 1791 // the deprecated string literal array to pointer conversion. 1792 switch (Result) { 1793 case ImplicitConversionSequence::Better: 1794 if (SCS1.Deprecated) 1795 Result = ImplicitConversionSequence::Indistinguishable; 1796 break; 1797 1798 case ImplicitConversionSequence::Indistinguishable: 1799 break; 1800 1801 case ImplicitConversionSequence::Worse: 1802 if (SCS2.Deprecated) 1803 Result = ImplicitConversionSequence::Indistinguishable; 1804 break; 1805 } 1806 1807 return Result; 1808} 1809 1810/// CompareDerivedToBaseConversions - Compares two standard conversion 1811/// sequences to determine whether they can be ranked based on their 1812/// various kinds of derived-to-base conversions (C++ 1813/// [over.ics.rank]p4b3). As part of these checks, we also look at 1814/// conversions between Objective-C interface types. 1815ImplicitConversionSequence::CompareKind 1816Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1817 const StandardConversionSequence& SCS2) { 1818 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1819 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1820 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1821 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1822 1823 // Adjust the types we're converting from via the array-to-pointer 1824 // conversion, if we need to. 1825 if (SCS1.First == ICK_Array_To_Pointer) 1826 FromType1 = Context.getArrayDecayedType(FromType1); 1827 if (SCS2.First == ICK_Array_To_Pointer) 1828 FromType2 = Context.getArrayDecayedType(FromType2); 1829 1830 // Canonicalize all of the types. 1831 FromType1 = Context.getCanonicalType(FromType1); 1832 ToType1 = Context.getCanonicalType(ToType1); 1833 FromType2 = Context.getCanonicalType(FromType2); 1834 ToType2 = Context.getCanonicalType(ToType2); 1835 1836 // C++ [over.ics.rank]p4b3: 1837 // 1838 // If class B is derived directly or indirectly from class A and 1839 // class C is derived directly or indirectly from B, 1840 // 1841 // For Objective-C, we let A, B, and C also be Objective-C 1842 // interfaces. 1843 1844 // Compare based on pointer conversions. 1845 if (SCS1.Second == ICK_Pointer_Conversion && 1846 SCS2.Second == ICK_Pointer_Conversion && 1847 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1848 FromType1->isPointerType() && FromType2->isPointerType() && 1849 ToType1->isPointerType() && ToType2->isPointerType()) { 1850 QualType FromPointee1 1851 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1852 QualType ToPointee1 1853 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1854 QualType FromPointee2 1855 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1856 QualType ToPointee2 1857 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1858 1859 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1860 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1861 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1862 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1863 1864 // -- conversion of C* to B* is better than conversion of C* to A*, 1865 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1866 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1867 return ImplicitConversionSequence::Better; 1868 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1869 return ImplicitConversionSequence::Worse; 1870 1871 if (ToIface1 && ToIface2) { 1872 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1873 return ImplicitConversionSequence::Better; 1874 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1875 return ImplicitConversionSequence::Worse; 1876 } 1877 } 1878 1879 // -- conversion of B* to A* is better than conversion of C* to A*, 1880 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1881 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1882 return ImplicitConversionSequence::Better; 1883 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1884 return ImplicitConversionSequence::Worse; 1885 1886 if (FromIface1 && FromIface2) { 1887 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1888 return ImplicitConversionSequence::Better; 1889 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1890 return ImplicitConversionSequence::Worse; 1891 } 1892 } 1893 } 1894 1895 // Compare based on reference bindings. 1896 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1897 SCS1.Second == ICK_Derived_To_Base) { 1898 // -- binding of an expression of type C to a reference of type 1899 // B& is better than binding an expression of type C to a 1900 // reference of type A&, 1901 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1902 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1903 if (IsDerivedFrom(ToType1, ToType2)) 1904 return ImplicitConversionSequence::Better; 1905 else if (IsDerivedFrom(ToType2, ToType1)) 1906 return ImplicitConversionSequence::Worse; 1907 } 1908 1909 // -- binding of an expression of type B to a reference of type 1910 // A& is better than binding an expression of type C to a 1911 // reference of type A&, 1912 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1913 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1914 if (IsDerivedFrom(FromType2, FromType1)) 1915 return ImplicitConversionSequence::Better; 1916 else if (IsDerivedFrom(FromType1, FromType2)) 1917 return ImplicitConversionSequence::Worse; 1918 } 1919 } 1920 1921 1922 // FIXME: conversion of A::* to B::* is better than conversion of 1923 // A::* to C::*, 1924 1925 // FIXME: conversion of B::* to C::* is better than conversion of 1926 // A::* to C::*, and 1927 1928 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1929 SCS1.Second == ICK_Derived_To_Base) { 1930 // -- conversion of C to B is better than conversion of C to A, 1931 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1932 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1933 if (IsDerivedFrom(ToType1, ToType2)) 1934 return ImplicitConversionSequence::Better; 1935 else if (IsDerivedFrom(ToType2, ToType1)) 1936 return ImplicitConversionSequence::Worse; 1937 } 1938 1939 // -- conversion of B to A is better than conversion of C to A. 1940 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1941 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1942 if (IsDerivedFrom(FromType2, FromType1)) 1943 return ImplicitConversionSequence::Better; 1944 else if (IsDerivedFrom(FromType1, FromType2)) 1945 return ImplicitConversionSequence::Worse; 1946 } 1947 } 1948 1949 return ImplicitConversionSequence::Indistinguishable; 1950} 1951 1952/// TryCopyInitialization - Try to copy-initialize a value of type 1953/// ToType from the expression From. Return the implicit conversion 1954/// sequence required to pass this argument, which may be a bad 1955/// conversion sequence (meaning that the argument cannot be passed to 1956/// a parameter of this type). If @p SuppressUserConversions, then we 1957/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1958/// then we treat @p From as an rvalue, even if it is an lvalue. 1959ImplicitConversionSequence 1960Sema::TryCopyInitialization(Expr *From, QualType ToType, 1961 bool SuppressUserConversions, bool ForceRValue, 1962 bool InOverloadResolution) { 1963 if (ToType->isReferenceType()) { 1964 ImplicitConversionSequence ICS; 1965 CheckReferenceInit(From, ToType, 1966 SuppressUserConversions, 1967 /*AllowExplicit=*/false, 1968 ForceRValue, 1969 &ICS); 1970 return ICS; 1971 } else { 1972 return TryImplicitConversion(From, ToType, 1973 SuppressUserConversions, 1974 /*AllowExplicit=*/false, 1975 ForceRValue, 1976 InOverloadResolution); 1977 } 1978} 1979 1980/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1981/// the expression @p From. Returns true (and emits a diagnostic) if there was 1982/// an error, returns false if the initialization succeeded. Elidable should 1983/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1984/// differently in C++0x for this case. 1985bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1986 const char* Flavor, bool Elidable) { 1987 if (!getLangOptions().CPlusPlus) { 1988 // In C, argument passing is the same as performing an assignment. 1989 QualType FromType = From->getType(); 1990 1991 AssignConvertType ConvTy = 1992 CheckSingleAssignmentConstraints(ToType, From); 1993 if (ConvTy != Compatible && 1994 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1995 ConvTy = Compatible; 1996 1997 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1998 FromType, From, Flavor); 1999 } 2000 2001 if (ToType->isReferenceType()) 2002 return CheckReferenceInit(From, ToType, 2003 /*SuppressUserConversions=*/false, 2004 /*AllowExplicit=*/false, 2005 /*ForceRValue=*/false); 2006 2007 if (!PerformImplicitConversion(From, ToType, Flavor, 2008 /*AllowExplicit=*/false, Elidable)) 2009 return false; 2010 if (!DiagnoseAmbiguousUserDefinedConversion(From, ToType)) 2011 return Diag(From->getSourceRange().getBegin(), 2012 diag::err_typecheck_convert_incompatible) 2013 << ToType << From->getType() << Flavor << From->getSourceRange(); 2014 return true; 2015} 2016 2017/// TryObjectArgumentInitialization - Try to initialize the object 2018/// parameter of the given member function (@c Method) from the 2019/// expression @p From. 2020ImplicitConversionSequence 2021Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2022 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2023 unsigned MethodQuals = Method->getTypeQualifiers(); 2024 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 2025 2026 // Set up the conversion sequence as a "bad" conversion, to allow us 2027 // to exit early. 2028 ImplicitConversionSequence ICS; 2029 ICS.Standard.setAsIdentityConversion(); 2030 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2031 2032 // We need to have an object of class type. 2033 QualType FromType = From->getType(); 2034 if (const PointerType *PT = FromType->getAs<PointerType>()) 2035 FromType = PT->getPointeeType(); 2036 2037 assert(FromType->isRecordType()); 2038 2039 // The implicit object parmeter is has the type "reference to cv X", 2040 // where X is the class of which the function is a member 2041 // (C++ [over.match.funcs]p4). However, when finding an implicit 2042 // conversion sequence for the argument, we are not allowed to 2043 // create temporaries or perform user-defined conversions 2044 // (C++ [over.match.funcs]p5). We perform a simplified version of 2045 // reference binding here, that allows class rvalues to bind to 2046 // non-constant references. 2047 2048 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2049 // with the implicit object parameter (C++ [over.match.funcs]p5). 2050 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2051 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 2052 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 2053 return ICS; 2054 2055 // Check that we have either the same type or a derived type. It 2056 // affects the conversion rank. 2057 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2058 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2059 ICS.Standard.Second = ICK_Identity; 2060 else if (IsDerivedFrom(FromType, ClassType)) 2061 ICS.Standard.Second = ICK_Derived_To_Base; 2062 else 2063 return ICS; 2064 2065 // Success. Mark this as a reference binding. 2066 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2067 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2068 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2069 ICS.Standard.ReferenceBinding = true; 2070 ICS.Standard.DirectBinding = true; 2071 ICS.Standard.RRefBinding = false; 2072 return ICS; 2073} 2074 2075/// PerformObjectArgumentInitialization - Perform initialization of 2076/// the implicit object parameter for the given Method with the given 2077/// expression. 2078bool 2079Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2080 QualType FromRecordType, DestType; 2081 QualType ImplicitParamRecordType = 2082 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2083 2084 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2085 FromRecordType = PT->getPointeeType(); 2086 DestType = Method->getThisType(Context); 2087 } else { 2088 FromRecordType = From->getType(); 2089 DestType = ImplicitParamRecordType; 2090 } 2091 2092 ImplicitConversionSequence ICS 2093 = TryObjectArgumentInitialization(From, Method); 2094 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2095 return Diag(From->getSourceRange().getBegin(), 2096 diag::err_implicit_object_parameter_init) 2097 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2098 2099 if (ICS.Standard.Second == ICK_Derived_To_Base && 2100 CheckDerivedToBaseConversion(FromRecordType, 2101 ImplicitParamRecordType, 2102 From->getSourceRange().getBegin(), 2103 From->getSourceRange())) 2104 return true; 2105 2106 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2107 /*isLvalue=*/true); 2108 return false; 2109} 2110 2111/// TryContextuallyConvertToBool - Attempt to contextually convert the 2112/// expression From to bool (C++0x [conv]p3). 2113ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2114 return TryImplicitConversion(From, Context.BoolTy, 2115 // FIXME: Are these flags correct? 2116 /*SuppressUserConversions=*/false, 2117 /*AllowExplicit=*/true, 2118 /*ForceRValue=*/false, 2119 /*InOverloadResolution=*/false); 2120} 2121 2122/// PerformContextuallyConvertToBool - Perform a contextual conversion 2123/// of the expression From to bool (C++0x [conv]p3). 2124bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2125 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2126 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2127 return false; 2128 2129 if (!DiagnoseAmbiguousUserDefinedConversion(From, Context.BoolTy)) 2130 return Diag(From->getSourceRange().getBegin(), 2131 diag::err_typecheck_bool_condition) 2132 << From->getType() << From->getSourceRange(); 2133 return true; 2134} 2135 2136/// AddOverloadCandidate - Adds the given function to the set of 2137/// candidate functions, using the given function call arguments. If 2138/// @p SuppressUserConversions, then don't allow user-defined 2139/// conversions via constructors or conversion operators. 2140/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2141/// hacky way to implement the overloading rules for elidable copy 2142/// initialization in C++0x (C++0x 12.8p15). 2143/// 2144/// \para PartialOverloading true if we are performing "partial" overloading 2145/// based on an incomplete set of function arguments. This feature is used by 2146/// code completion. 2147void 2148Sema::AddOverloadCandidate(FunctionDecl *Function, 2149 Expr **Args, unsigned NumArgs, 2150 OverloadCandidateSet& CandidateSet, 2151 bool SuppressUserConversions, 2152 bool ForceRValue, 2153 bool PartialOverloading) { 2154 const FunctionProtoType* Proto 2155 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2156 assert(Proto && "Functions without a prototype cannot be overloaded"); 2157 assert(!isa<CXXConversionDecl>(Function) && 2158 "Use AddConversionCandidate for conversion functions"); 2159 assert(!Function->getDescribedFunctionTemplate() && 2160 "Use AddTemplateOverloadCandidate for function templates"); 2161 2162 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2163 if (!isa<CXXConstructorDecl>(Method)) { 2164 // If we get here, it's because we're calling a member function 2165 // that is named without a member access expression (e.g., 2166 // "this->f") that was either written explicitly or created 2167 // implicitly. This can happen with a qualified call to a member 2168 // function, e.g., X::f(). We use a NULL object as the implied 2169 // object argument (C++ [over.call.func]p3). 2170 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2171 SuppressUserConversions, ForceRValue); 2172 return; 2173 } 2174 // We treat a constructor like a non-member function, since its object 2175 // argument doesn't participate in overload resolution. 2176 } 2177 2178 2179 // Add this candidate 2180 CandidateSet.push_back(OverloadCandidate()); 2181 OverloadCandidate& Candidate = CandidateSet.back(); 2182 Candidate.Function = Function; 2183 Candidate.Viable = true; 2184 Candidate.IsSurrogate = false; 2185 Candidate.IgnoreObjectArgument = false; 2186 2187 unsigned NumArgsInProto = Proto->getNumArgs(); 2188 2189 // (C++ 13.3.2p2): A candidate function having fewer than m 2190 // parameters is viable only if it has an ellipsis in its parameter 2191 // list (8.3.5). 2192 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2193 Candidate.Viable = false; 2194 return; 2195 } 2196 2197 // (C++ 13.3.2p2): A candidate function having more than m parameters 2198 // is viable only if the (m+1)st parameter has a default argument 2199 // (8.3.6). For the purposes of overload resolution, the 2200 // parameter list is truncated on the right, so that there are 2201 // exactly m parameters. 2202 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2203 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2204 // Not enough arguments. 2205 Candidate.Viable = false; 2206 return; 2207 } 2208 2209 // Determine the implicit conversion sequences for each of the 2210 // arguments. 2211 Candidate.Conversions.resize(NumArgs); 2212 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2213 if (ArgIdx < NumArgsInProto) { 2214 // (C++ 13.3.2p3): for F to be a viable function, there shall 2215 // exist for each argument an implicit conversion sequence 2216 // (13.3.3.1) that converts that argument to the corresponding 2217 // parameter of F. 2218 QualType ParamType = Proto->getArgType(ArgIdx); 2219 Candidate.Conversions[ArgIdx] 2220 = TryCopyInitialization(Args[ArgIdx], ParamType, 2221 SuppressUserConversions, ForceRValue, 2222 /*InOverloadResolution=*/true); 2223 if (Candidate.Conversions[ArgIdx].ConversionKind 2224 == ImplicitConversionSequence::BadConversion) { 2225 Candidate.Viable = false; 2226 break; 2227 } 2228 } else { 2229 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2230 // argument for which there is no corresponding parameter is 2231 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2232 Candidate.Conversions[ArgIdx].ConversionKind 2233 = ImplicitConversionSequence::EllipsisConversion; 2234 } 2235 } 2236} 2237 2238/// \brief Add all of the function declarations in the given function set to 2239/// the overload canddiate set. 2240void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2241 Expr **Args, unsigned NumArgs, 2242 OverloadCandidateSet& CandidateSet, 2243 bool SuppressUserConversions) { 2244 for (FunctionSet::const_iterator F = Functions.begin(), 2245 FEnd = Functions.end(); 2246 F != FEnd; ++F) { 2247 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) 2248 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2249 SuppressUserConversions); 2250 else 2251 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*F), 2252 /*FIXME: explicit args */false, 0, 0, 2253 Args, NumArgs, CandidateSet, 2254 SuppressUserConversions); 2255 } 2256} 2257 2258/// AddMethodCandidate - Adds the given C++ member function to the set 2259/// of candidate functions, using the given function call arguments 2260/// and the object argument (@c Object). For example, in a call 2261/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2262/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2263/// allow user-defined conversions via constructors or conversion 2264/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2265/// a slightly hacky way to implement the overloading rules for elidable copy 2266/// initialization in C++0x (C++0x 12.8p15). 2267void 2268Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2269 Expr **Args, unsigned NumArgs, 2270 OverloadCandidateSet& CandidateSet, 2271 bool SuppressUserConversions, bool ForceRValue) { 2272 const FunctionProtoType* Proto 2273 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2274 assert(Proto && "Methods without a prototype cannot be overloaded"); 2275 assert(!isa<CXXConversionDecl>(Method) && 2276 "Use AddConversionCandidate for conversion functions"); 2277 assert(!isa<CXXConstructorDecl>(Method) && 2278 "Use AddOverloadCandidate for constructors"); 2279 2280 // Add this candidate 2281 CandidateSet.push_back(OverloadCandidate()); 2282 OverloadCandidate& Candidate = CandidateSet.back(); 2283 Candidate.Function = Method; 2284 Candidate.IsSurrogate = false; 2285 Candidate.IgnoreObjectArgument = false; 2286 2287 unsigned NumArgsInProto = Proto->getNumArgs(); 2288 2289 // (C++ 13.3.2p2): A candidate function having fewer than m 2290 // parameters is viable only if it has an ellipsis in its parameter 2291 // list (8.3.5). 2292 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2293 Candidate.Viable = false; 2294 return; 2295 } 2296 2297 // (C++ 13.3.2p2): A candidate function having more than m parameters 2298 // is viable only if the (m+1)st parameter has a default argument 2299 // (8.3.6). For the purposes of overload resolution, the 2300 // parameter list is truncated on the right, so that there are 2301 // exactly m parameters. 2302 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2303 if (NumArgs < MinRequiredArgs) { 2304 // Not enough arguments. 2305 Candidate.Viable = false; 2306 return; 2307 } 2308 2309 Candidate.Viable = true; 2310 Candidate.Conversions.resize(NumArgs + 1); 2311 2312 if (Method->isStatic() || !Object) 2313 // The implicit object argument is ignored. 2314 Candidate.IgnoreObjectArgument = true; 2315 else { 2316 // Determine the implicit conversion sequence for the object 2317 // parameter. 2318 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2319 if (Candidate.Conversions[0].ConversionKind 2320 == ImplicitConversionSequence::BadConversion) { 2321 Candidate.Viable = false; 2322 return; 2323 } 2324 } 2325 2326 // Determine the implicit conversion sequences for each of the 2327 // arguments. 2328 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2329 if (ArgIdx < NumArgsInProto) { 2330 // (C++ 13.3.2p3): for F to be a viable function, there shall 2331 // exist for each argument an implicit conversion sequence 2332 // (13.3.3.1) that converts that argument to the corresponding 2333 // parameter of F. 2334 QualType ParamType = Proto->getArgType(ArgIdx); 2335 Candidate.Conversions[ArgIdx + 1] 2336 = TryCopyInitialization(Args[ArgIdx], ParamType, 2337 SuppressUserConversions, ForceRValue, 2338 /*InOverloadResolution=*/true); 2339 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2340 == ImplicitConversionSequence::BadConversion) { 2341 Candidate.Viable = false; 2342 break; 2343 } 2344 } else { 2345 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2346 // argument for which there is no corresponding parameter is 2347 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2348 Candidate.Conversions[ArgIdx + 1].ConversionKind 2349 = ImplicitConversionSequence::EllipsisConversion; 2350 } 2351 } 2352} 2353 2354/// \brief Add a C++ member function template as a candidate to the candidate 2355/// set, using template argument deduction to produce an appropriate member 2356/// function template specialization. 2357void 2358Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2359 bool HasExplicitTemplateArgs, 2360 const TemplateArgument *ExplicitTemplateArgs, 2361 unsigned NumExplicitTemplateArgs, 2362 Expr *Object, Expr **Args, unsigned NumArgs, 2363 OverloadCandidateSet& CandidateSet, 2364 bool SuppressUserConversions, 2365 bool ForceRValue) { 2366 // C++ [over.match.funcs]p7: 2367 // In each case where a candidate is a function template, candidate 2368 // function template specializations are generated using template argument 2369 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2370 // candidate functions in the usual way.113) A given name can refer to one 2371 // or more function templates and also to a set of overloaded non-template 2372 // functions. In such a case, the candidate functions generated from each 2373 // function template are combined with the set of non-template candidate 2374 // functions. 2375 TemplateDeductionInfo Info(Context); 2376 FunctionDecl *Specialization = 0; 2377 if (TemplateDeductionResult Result 2378 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2379 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2380 Args, NumArgs, Specialization, Info)) { 2381 // FIXME: Record what happened with template argument deduction, so 2382 // that we can give the user a beautiful diagnostic. 2383 (void)Result; 2384 return; 2385 } 2386 2387 // Add the function template specialization produced by template argument 2388 // deduction as a candidate. 2389 assert(Specialization && "Missing member function template specialization?"); 2390 assert(isa<CXXMethodDecl>(Specialization) && 2391 "Specialization is not a member function?"); 2392 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2393 CandidateSet, SuppressUserConversions, ForceRValue); 2394} 2395 2396/// \brief Add a C++ function template specialization as a candidate 2397/// in the candidate set, using template argument deduction to produce 2398/// an appropriate function template specialization. 2399void 2400Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2401 bool HasExplicitTemplateArgs, 2402 const TemplateArgument *ExplicitTemplateArgs, 2403 unsigned NumExplicitTemplateArgs, 2404 Expr **Args, unsigned NumArgs, 2405 OverloadCandidateSet& CandidateSet, 2406 bool SuppressUserConversions, 2407 bool ForceRValue) { 2408 // C++ [over.match.funcs]p7: 2409 // In each case where a candidate is a function template, candidate 2410 // function template specializations are generated using template argument 2411 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2412 // candidate functions in the usual way.113) A given name can refer to one 2413 // or more function templates and also to a set of overloaded non-template 2414 // functions. In such a case, the candidate functions generated from each 2415 // function template are combined with the set of non-template candidate 2416 // functions. 2417 TemplateDeductionInfo Info(Context); 2418 FunctionDecl *Specialization = 0; 2419 if (TemplateDeductionResult Result 2420 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2421 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2422 Args, NumArgs, Specialization, Info)) { 2423 // FIXME: Record what happened with template argument deduction, so 2424 // that we can give the user a beautiful diagnostic. 2425 (void)Result; 2426 return; 2427 } 2428 2429 // Add the function template specialization produced by template argument 2430 // deduction as a candidate. 2431 assert(Specialization && "Missing function template specialization?"); 2432 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2433 SuppressUserConversions, ForceRValue); 2434} 2435 2436/// AddConversionCandidate - Add a C++ conversion function as a 2437/// candidate in the candidate set (C++ [over.match.conv], 2438/// C++ [over.match.copy]). From is the expression we're converting from, 2439/// and ToType is the type that we're eventually trying to convert to 2440/// (which may or may not be the same type as the type that the 2441/// conversion function produces). 2442void 2443Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2444 Expr *From, QualType ToType, 2445 OverloadCandidateSet& CandidateSet) { 2446 assert(!Conversion->getDescribedFunctionTemplate() && 2447 "Conversion function templates use AddTemplateConversionCandidate"); 2448 2449 // Add this candidate 2450 CandidateSet.push_back(OverloadCandidate()); 2451 OverloadCandidate& Candidate = CandidateSet.back(); 2452 Candidate.Function = Conversion; 2453 Candidate.IsSurrogate = false; 2454 Candidate.IgnoreObjectArgument = false; 2455 Candidate.FinalConversion.setAsIdentityConversion(); 2456 Candidate.FinalConversion.FromTypePtr 2457 = Conversion->getConversionType().getAsOpaquePtr(); 2458 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2459 2460 // Determine the implicit conversion sequence for the implicit 2461 // object parameter. 2462 Candidate.Viable = true; 2463 Candidate.Conversions.resize(1); 2464 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2465 // Conversion functions to a different type in the base class is visible in 2466 // the derived class. So, a derived to base conversion should not participate 2467 // in overload resolution. 2468 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2469 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2470 if (Candidate.Conversions[0].ConversionKind 2471 == ImplicitConversionSequence::BadConversion) { 2472 Candidate.Viable = false; 2473 return; 2474 } 2475 2476 // To determine what the conversion from the result of calling the 2477 // conversion function to the type we're eventually trying to 2478 // convert to (ToType), we need to synthesize a call to the 2479 // conversion function and attempt copy initialization from it. This 2480 // makes sure that we get the right semantics with respect to 2481 // lvalues/rvalues and the type. Fortunately, we can allocate this 2482 // call on the stack and we don't need its arguments to be 2483 // well-formed. 2484 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2485 SourceLocation()); 2486 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2487 CastExpr::CK_Unknown, 2488 &ConversionRef, false); 2489 2490 // Note that it is safe to allocate CallExpr on the stack here because 2491 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2492 // allocator). 2493 CallExpr Call(Context, &ConversionFn, 0, 0, 2494 Conversion->getConversionType().getNonReferenceType(), 2495 SourceLocation()); 2496 ImplicitConversionSequence ICS = 2497 TryCopyInitialization(&Call, ToType, 2498 /*SuppressUserConversions=*/true, 2499 /*ForceRValue=*/false, 2500 /*InOverloadResolution=*/false); 2501 2502 switch (ICS.ConversionKind) { 2503 case ImplicitConversionSequence::StandardConversion: 2504 Candidate.FinalConversion = ICS.Standard; 2505 break; 2506 2507 case ImplicitConversionSequence::BadConversion: 2508 Candidate.Viable = false; 2509 break; 2510 2511 default: 2512 assert(false && 2513 "Can only end up with a standard conversion sequence or failure"); 2514 } 2515} 2516 2517/// \brief Adds a conversion function template specialization 2518/// candidate to the overload set, using template argument deduction 2519/// to deduce the template arguments of the conversion function 2520/// template from the type that we are converting to (C++ 2521/// [temp.deduct.conv]). 2522void 2523Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2524 Expr *From, QualType ToType, 2525 OverloadCandidateSet &CandidateSet) { 2526 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2527 "Only conversion function templates permitted here"); 2528 2529 TemplateDeductionInfo Info(Context); 2530 CXXConversionDecl *Specialization = 0; 2531 if (TemplateDeductionResult Result 2532 = DeduceTemplateArguments(FunctionTemplate, ToType, 2533 Specialization, Info)) { 2534 // FIXME: Record what happened with template argument deduction, so 2535 // that we can give the user a beautiful diagnostic. 2536 (void)Result; 2537 return; 2538 } 2539 2540 // Add the conversion function template specialization produced by 2541 // template argument deduction as a candidate. 2542 assert(Specialization && "Missing function template specialization?"); 2543 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2544} 2545 2546/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2547/// converts the given @c Object to a function pointer via the 2548/// conversion function @c Conversion, and then attempts to call it 2549/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2550/// the type of function that we'll eventually be calling. 2551void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2552 const FunctionProtoType *Proto, 2553 Expr *Object, Expr **Args, unsigned NumArgs, 2554 OverloadCandidateSet& CandidateSet) { 2555 CandidateSet.push_back(OverloadCandidate()); 2556 OverloadCandidate& Candidate = CandidateSet.back(); 2557 Candidate.Function = 0; 2558 Candidate.Surrogate = Conversion; 2559 Candidate.Viable = true; 2560 Candidate.IsSurrogate = true; 2561 Candidate.IgnoreObjectArgument = false; 2562 Candidate.Conversions.resize(NumArgs + 1); 2563 2564 // Determine the implicit conversion sequence for the implicit 2565 // object parameter. 2566 ImplicitConversionSequence ObjectInit 2567 = TryObjectArgumentInitialization(Object, Conversion); 2568 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2569 Candidate.Viable = false; 2570 return; 2571 } 2572 2573 // The first conversion is actually a user-defined conversion whose 2574 // first conversion is ObjectInit's standard conversion (which is 2575 // effectively a reference binding). Record it as such. 2576 Candidate.Conversions[0].ConversionKind 2577 = ImplicitConversionSequence::UserDefinedConversion; 2578 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2579 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2580 Candidate.Conversions[0].UserDefined.After 2581 = Candidate.Conversions[0].UserDefined.Before; 2582 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2583 2584 // Find the 2585 unsigned NumArgsInProto = Proto->getNumArgs(); 2586 2587 // (C++ 13.3.2p2): A candidate function having fewer than m 2588 // parameters is viable only if it has an ellipsis in its parameter 2589 // list (8.3.5). 2590 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2591 Candidate.Viable = false; 2592 return; 2593 } 2594 2595 // Function types don't have any default arguments, so just check if 2596 // we have enough arguments. 2597 if (NumArgs < NumArgsInProto) { 2598 // Not enough arguments. 2599 Candidate.Viable = false; 2600 return; 2601 } 2602 2603 // Determine the implicit conversion sequences for each of the 2604 // arguments. 2605 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2606 if (ArgIdx < NumArgsInProto) { 2607 // (C++ 13.3.2p3): for F to be a viable function, there shall 2608 // exist for each argument an implicit conversion sequence 2609 // (13.3.3.1) that converts that argument to the corresponding 2610 // parameter of F. 2611 QualType ParamType = Proto->getArgType(ArgIdx); 2612 Candidate.Conversions[ArgIdx + 1] 2613 = TryCopyInitialization(Args[ArgIdx], ParamType, 2614 /*SuppressUserConversions=*/false, 2615 /*ForceRValue=*/false, 2616 /*InOverloadResolution=*/false); 2617 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2618 == ImplicitConversionSequence::BadConversion) { 2619 Candidate.Viable = false; 2620 break; 2621 } 2622 } else { 2623 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2624 // argument for which there is no corresponding parameter is 2625 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2626 Candidate.Conversions[ArgIdx + 1].ConversionKind 2627 = ImplicitConversionSequence::EllipsisConversion; 2628 } 2629 } 2630} 2631 2632// FIXME: This will eventually be removed, once we've migrated all of the 2633// operator overloading logic over to the scheme used by binary operators, which 2634// works for template instantiation. 2635void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2636 SourceLocation OpLoc, 2637 Expr **Args, unsigned NumArgs, 2638 OverloadCandidateSet& CandidateSet, 2639 SourceRange OpRange) { 2640 2641 FunctionSet Functions; 2642 2643 QualType T1 = Args[0]->getType(); 2644 QualType T2; 2645 if (NumArgs > 1) 2646 T2 = Args[1]->getType(); 2647 2648 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2649 if (S) 2650 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2651 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2652 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2653 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2654 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2655} 2656 2657/// \brief Add overload candidates for overloaded operators that are 2658/// member functions. 2659/// 2660/// Add the overloaded operator candidates that are member functions 2661/// for the operator Op that was used in an operator expression such 2662/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2663/// CandidateSet will store the added overload candidates. (C++ 2664/// [over.match.oper]). 2665void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2666 SourceLocation OpLoc, 2667 Expr **Args, unsigned NumArgs, 2668 OverloadCandidateSet& CandidateSet, 2669 SourceRange OpRange) { 2670 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2671 2672 // C++ [over.match.oper]p3: 2673 // For a unary operator @ with an operand of a type whose 2674 // cv-unqualified version is T1, and for a binary operator @ with 2675 // a left operand of a type whose cv-unqualified version is T1 and 2676 // a right operand of a type whose cv-unqualified version is T2, 2677 // three sets of candidate functions, designated member 2678 // candidates, non-member candidates and built-in candidates, are 2679 // constructed as follows: 2680 QualType T1 = Args[0]->getType(); 2681 QualType T2; 2682 if (NumArgs > 1) 2683 T2 = Args[1]->getType(); 2684 2685 // -- If T1 is a class type, the set of member candidates is the 2686 // result of the qualified lookup of T1::operator@ 2687 // (13.3.1.1.1); otherwise, the set of member candidates is 2688 // empty. 2689 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2690 // Complete the type if it can be completed. Otherwise, we're done. 2691 if (RequireCompleteType(OpLoc, T1, PartialDiagnostic(0))) 2692 return; 2693 2694 LookupResult Operators = LookupQualifiedName(T1Rec->getDecl(), OpName, 2695 LookupOrdinaryName, false); 2696 for (LookupResult::iterator Oper = Operators.begin(), 2697 OperEnd = Operators.end(); 2698 Oper != OperEnd; 2699 ++Oper) 2700 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2701 Args+1, NumArgs - 1, CandidateSet, 2702 /*SuppressUserConversions=*/false); 2703 } 2704} 2705 2706/// AddBuiltinCandidate - Add a candidate for a built-in 2707/// operator. ResultTy and ParamTys are the result and parameter types 2708/// of the built-in candidate, respectively. Args and NumArgs are the 2709/// arguments being passed to the candidate. IsAssignmentOperator 2710/// should be true when this built-in candidate is an assignment 2711/// operator. NumContextualBoolArguments is the number of arguments 2712/// (at the beginning of the argument list) that will be contextually 2713/// converted to bool. 2714void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2715 Expr **Args, unsigned NumArgs, 2716 OverloadCandidateSet& CandidateSet, 2717 bool IsAssignmentOperator, 2718 unsigned NumContextualBoolArguments) { 2719 // Add this candidate 2720 CandidateSet.push_back(OverloadCandidate()); 2721 OverloadCandidate& Candidate = CandidateSet.back(); 2722 Candidate.Function = 0; 2723 Candidate.IsSurrogate = false; 2724 Candidate.IgnoreObjectArgument = false; 2725 Candidate.BuiltinTypes.ResultTy = ResultTy; 2726 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2727 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2728 2729 // Determine the implicit conversion sequences for each of the 2730 // arguments. 2731 Candidate.Viable = true; 2732 Candidate.Conversions.resize(NumArgs); 2733 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2734 // C++ [over.match.oper]p4: 2735 // For the built-in assignment operators, conversions of the 2736 // left operand are restricted as follows: 2737 // -- no temporaries are introduced to hold the left operand, and 2738 // -- no user-defined conversions are applied to the left 2739 // operand to achieve a type match with the left-most 2740 // parameter of a built-in candidate. 2741 // 2742 // We block these conversions by turning off user-defined 2743 // conversions, since that is the only way that initialization of 2744 // a reference to a non-class type can occur from something that 2745 // is not of the same type. 2746 if (ArgIdx < NumContextualBoolArguments) { 2747 assert(ParamTys[ArgIdx] == Context.BoolTy && 2748 "Contextual conversion to bool requires bool type"); 2749 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2750 } else { 2751 Candidate.Conversions[ArgIdx] 2752 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2753 ArgIdx == 0 && IsAssignmentOperator, 2754 /*ForceRValue=*/false, 2755 /*InOverloadResolution=*/false); 2756 } 2757 if (Candidate.Conversions[ArgIdx].ConversionKind 2758 == ImplicitConversionSequence::BadConversion) { 2759 Candidate.Viable = false; 2760 break; 2761 } 2762 } 2763} 2764 2765/// BuiltinCandidateTypeSet - A set of types that will be used for the 2766/// candidate operator functions for built-in operators (C++ 2767/// [over.built]). The types are separated into pointer types and 2768/// enumeration types. 2769class BuiltinCandidateTypeSet { 2770 /// TypeSet - A set of types. 2771 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2772 2773 /// PointerTypes - The set of pointer types that will be used in the 2774 /// built-in candidates. 2775 TypeSet PointerTypes; 2776 2777 /// MemberPointerTypes - The set of member pointer types that will be 2778 /// used in the built-in candidates. 2779 TypeSet MemberPointerTypes; 2780 2781 /// EnumerationTypes - The set of enumeration types that will be 2782 /// used in the built-in candidates. 2783 TypeSet EnumerationTypes; 2784 2785 /// Sema - The semantic analysis instance where we are building the 2786 /// candidate type set. 2787 Sema &SemaRef; 2788 2789 /// Context - The AST context in which we will build the type sets. 2790 ASTContext &Context; 2791 2792 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2793 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2794 2795public: 2796 /// iterator - Iterates through the types that are part of the set. 2797 typedef TypeSet::iterator iterator; 2798 2799 BuiltinCandidateTypeSet(Sema &SemaRef) 2800 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2801 2802 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2803 bool AllowExplicitConversions); 2804 2805 /// pointer_begin - First pointer type found; 2806 iterator pointer_begin() { return PointerTypes.begin(); } 2807 2808 /// pointer_end - Past the last pointer type found; 2809 iterator pointer_end() { return PointerTypes.end(); } 2810 2811 /// member_pointer_begin - First member pointer type found; 2812 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2813 2814 /// member_pointer_end - Past the last member pointer type found; 2815 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2816 2817 /// enumeration_begin - First enumeration type found; 2818 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2819 2820 /// enumeration_end - Past the last enumeration type found; 2821 iterator enumeration_end() { return EnumerationTypes.end(); } 2822}; 2823 2824/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2825/// the set of pointer types along with any more-qualified variants of 2826/// that type. For example, if @p Ty is "int const *", this routine 2827/// will add "int const *", "int const volatile *", "int const 2828/// restrict *", and "int const volatile restrict *" to the set of 2829/// pointer types. Returns true if the add of @p Ty itself succeeded, 2830/// false otherwise. 2831bool 2832BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2833 // Insert this type. 2834 if (!PointerTypes.insert(Ty)) 2835 return false; 2836 2837 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2838 QualType PointeeTy = PointerTy->getPointeeType(); 2839 // FIXME: Optimize this so that we don't keep trying to add the same types. 2840 2841 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal with all 2842 // pointer conversions that don't cast away constness? 2843 if (!PointeeTy.isConstQualified()) 2844 AddPointerWithMoreQualifiedTypeVariants 2845 (Context.getPointerType(PointeeTy.withConst())); 2846 if (!PointeeTy.isVolatileQualified()) 2847 AddPointerWithMoreQualifiedTypeVariants 2848 (Context.getPointerType(PointeeTy.withVolatile())); 2849 if (!PointeeTy.isRestrictQualified()) 2850 AddPointerWithMoreQualifiedTypeVariants 2851 (Context.getPointerType(PointeeTy.withRestrict())); 2852 } 2853 2854 return true; 2855} 2856 2857/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2858/// to the set of pointer types along with any more-qualified variants of 2859/// that type. For example, if @p Ty is "int const *", this routine 2860/// will add "int const *", "int const volatile *", "int const 2861/// restrict *", and "int const volatile restrict *" to the set of 2862/// pointer types. Returns true if the add of @p Ty itself succeeded, 2863/// false otherwise. 2864bool 2865BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2866 QualType Ty) { 2867 // Insert this type. 2868 if (!MemberPointerTypes.insert(Ty)) 2869 return false; 2870 2871 if (const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>()) { 2872 QualType PointeeTy = PointerTy->getPointeeType(); 2873 const Type *ClassTy = PointerTy->getClass(); 2874 // FIXME: Optimize this so that we don't keep trying to add the same types. 2875 2876 if (!PointeeTy.isConstQualified()) 2877 AddMemberPointerWithMoreQualifiedTypeVariants 2878 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2879 if (!PointeeTy.isVolatileQualified()) 2880 AddMemberPointerWithMoreQualifiedTypeVariants 2881 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2882 if (!PointeeTy.isRestrictQualified()) 2883 AddMemberPointerWithMoreQualifiedTypeVariants 2884 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2885 } 2886 2887 return true; 2888} 2889 2890/// AddTypesConvertedFrom - Add each of the types to which the type @p 2891/// Ty can be implicit converted to the given set of @p Types. We're 2892/// primarily interested in pointer types and enumeration types. We also 2893/// take member pointer types, for the conditional operator. 2894/// AllowUserConversions is true if we should look at the conversion 2895/// functions of a class type, and AllowExplicitConversions if we 2896/// should also include the explicit conversion functions of a class 2897/// type. 2898void 2899BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2900 bool AllowUserConversions, 2901 bool AllowExplicitConversions) { 2902 // Only deal with canonical types. 2903 Ty = Context.getCanonicalType(Ty); 2904 2905 // Look through reference types; they aren't part of the type of an 2906 // expression for the purposes of conversions. 2907 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 2908 Ty = RefTy->getPointeeType(); 2909 2910 // We don't care about qualifiers on the type. 2911 Ty = Ty.getUnqualifiedType(); 2912 2913 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2914 QualType PointeeTy = PointerTy->getPointeeType(); 2915 2916 // Insert our type, and its more-qualified variants, into the set 2917 // of types. 2918 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2919 return; 2920 2921 // Add 'cv void*' to our set of types. 2922 if (!Ty->isVoidType()) { 2923 QualType QualVoid 2924 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2925 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2926 } 2927 2928 // If this is a pointer to a class type, add pointers to its bases 2929 // (with the same level of cv-qualification as the original 2930 // derived class, of course). 2931 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 2932 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2933 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2934 Base != ClassDecl->bases_end(); ++Base) { 2935 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2936 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2937 2938 // Add the pointer type, recursively, so that we get all of 2939 // the indirect base classes, too. 2940 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2941 } 2942 } 2943 } else if (Ty->isMemberPointerType()) { 2944 // Member pointers are far easier, since the pointee can't be converted. 2945 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2946 return; 2947 } else if (Ty->isEnumeralType()) { 2948 EnumerationTypes.insert(Ty); 2949 } else if (AllowUserConversions) { 2950 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 2951 if (SemaRef.RequireCompleteType(SourceLocation(), Ty, 0)) { 2952 // No conversion functions in incomplete types. 2953 return; 2954 } 2955 2956 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2957 // FIXME: Visit conversion functions in the base classes, too. 2958 OverloadedFunctionDecl *Conversions 2959 = ClassDecl->getConversionFunctions(); 2960 for (OverloadedFunctionDecl::function_iterator Func 2961 = Conversions->function_begin(); 2962 Func != Conversions->function_end(); ++Func) { 2963 CXXConversionDecl *Conv; 2964 FunctionTemplateDecl *ConvTemplate; 2965 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 2966 2967 // Skip conversion function templates; they don't tell us anything 2968 // about which builtin types we can convert to. 2969 if (ConvTemplate) 2970 continue; 2971 2972 if (AllowExplicitConversions || !Conv->isExplicit()) 2973 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2974 } 2975 } 2976 } 2977} 2978 2979/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 2980/// the volatile- and non-volatile-qualified assignment operators for the 2981/// given type to the candidate set. 2982static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 2983 QualType T, 2984 Expr **Args, 2985 unsigned NumArgs, 2986 OverloadCandidateSet &CandidateSet) { 2987 QualType ParamTypes[2]; 2988 2989 // T& operator=(T&, T) 2990 ParamTypes[0] = S.Context.getLValueReferenceType(T); 2991 ParamTypes[1] = T; 2992 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 2993 /*IsAssignmentOperator=*/true); 2994 2995 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 2996 // volatile T& operator=(volatile T&, T) 2997 ParamTypes[0] = S.Context.getLValueReferenceType(T.withVolatile()); 2998 ParamTypes[1] = T; 2999 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3000 /*IsAssignmentOperator=*/true); 3001 } 3002} 3003 3004/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3005/// operator overloads to the candidate set (C++ [over.built]), based 3006/// on the operator @p Op and the arguments given. For example, if the 3007/// operator is a binary '+', this routine might add "int 3008/// operator+(int, int)" to cover integer addition. 3009void 3010Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3011 Expr **Args, unsigned NumArgs, 3012 OverloadCandidateSet& CandidateSet) { 3013 // The set of "promoted arithmetic types", which are the arithmetic 3014 // types are that preserved by promotion (C++ [over.built]p2). Note 3015 // that the first few of these types are the promoted integral 3016 // types; these types need to be first. 3017 // FIXME: What about complex? 3018 const unsigned FirstIntegralType = 0; 3019 const unsigned LastIntegralType = 13; 3020 const unsigned FirstPromotedIntegralType = 7, 3021 LastPromotedIntegralType = 13; 3022 const unsigned FirstPromotedArithmeticType = 7, 3023 LastPromotedArithmeticType = 16; 3024 const unsigned NumArithmeticTypes = 16; 3025 QualType ArithmeticTypes[NumArithmeticTypes] = { 3026 Context.BoolTy, Context.CharTy, Context.WCharTy, 3027// FIXME: Context.Char16Ty, Context.Char32Ty, 3028 Context.SignedCharTy, Context.ShortTy, 3029 Context.UnsignedCharTy, Context.UnsignedShortTy, 3030 Context.IntTy, Context.LongTy, Context.LongLongTy, 3031 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3032 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3033 }; 3034 3035 // Find all of the types that the arguments can convert to, but only 3036 // if the operator we're looking at has built-in operator candidates 3037 // that make use of these types. 3038 BuiltinCandidateTypeSet CandidateTypes(*this); 3039 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3040 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3041 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3042 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3043 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3044 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3045 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3046 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3047 true, 3048 (Op == OO_Exclaim || 3049 Op == OO_AmpAmp || 3050 Op == OO_PipePipe)); 3051 } 3052 3053 bool isComparison = false; 3054 switch (Op) { 3055 case OO_None: 3056 case NUM_OVERLOADED_OPERATORS: 3057 assert(false && "Expected an overloaded operator"); 3058 break; 3059 3060 case OO_Star: // '*' is either unary or binary 3061 if (NumArgs == 1) 3062 goto UnaryStar; 3063 else 3064 goto BinaryStar; 3065 break; 3066 3067 case OO_Plus: // '+' is either unary or binary 3068 if (NumArgs == 1) 3069 goto UnaryPlus; 3070 else 3071 goto BinaryPlus; 3072 break; 3073 3074 case OO_Minus: // '-' is either unary or binary 3075 if (NumArgs == 1) 3076 goto UnaryMinus; 3077 else 3078 goto BinaryMinus; 3079 break; 3080 3081 case OO_Amp: // '&' is either unary or binary 3082 if (NumArgs == 1) 3083 goto UnaryAmp; 3084 else 3085 goto BinaryAmp; 3086 3087 case OO_PlusPlus: 3088 case OO_MinusMinus: 3089 // C++ [over.built]p3: 3090 // 3091 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3092 // is either volatile or empty, there exist candidate operator 3093 // functions of the form 3094 // 3095 // VQ T& operator++(VQ T&); 3096 // T operator++(VQ T&, int); 3097 // 3098 // C++ [over.built]p4: 3099 // 3100 // For every pair (T, VQ), where T is an arithmetic type other 3101 // than bool, and VQ is either volatile or empty, there exist 3102 // candidate operator functions of the form 3103 // 3104 // VQ T& operator--(VQ T&); 3105 // T operator--(VQ T&, int); 3106 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3107 Arith < NumArithmeticTypes; ++Arith) { 3108 QualType ArithTy = ArithmeticTypes[Arith]; 3109 QualType ParamTypes[2] 3110 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3111 3112 // Non-volatile version. 3113 if (NumArgs == 1) 3114 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3115 else 3116 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3117 3118 // Volatile version 3119 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 3120 if (NumArgs == 1) 3121 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3122 else 3123 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3124 } 3125 3126 // C++ [over.built]p5: 3127 // 3128 // For every pair (T, VQ), where T is a cv-qualified or 3129 // cv-unqualified object type, and VQ is either volatile or 3130 // empty, there exist candidate operator functions of the form 3131 // 3132 // T*VQ& operator++(T*VQ&); 3133 // T*VQ& operator--(T*VQ&); 3134 // T* operator++(T*VQ&, int); 3135 // T* operator--(T*VQ&, int); 3136 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3137 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3138 // Skip pointer types that aren't pointers to object types. 3139 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3140 continue; 3141 3142 QualType ParamTypes[2] = { 3143 Context.getLValueReferenceType(*Ptr), Context.IntTy 3144 }; 3145 3146 // Without volatile 3147 if (NumArgs == 1) 3148 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3149 else 3150 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3151 3152 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3153 // With volatile 3154 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3155 if (NumArgs == 1) 3156 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3157 else 3158 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3159 } 3160 } 3161 break; 3162 3163 UnaryStar: 3164 // C++ [over.built]p6: 3165 // For every cv-qualified or cv-unqualified object type T, there 3166 // exist candidate operator functions of the form 3167 // 3168 // T& operator*(T*); 3169 // 3170 // C++ [over.built]p7: 3171 // For every function type T, there exist candidate operator 3172 // functions of the form 3173 // T& operator*(T*); 3174 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3175 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3176 QualType ParamTy = *Ptr; 3177 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3178 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3179 &ParamTy, Args, 1, CandidateSet); 3180 } 3181 break; 3182 3183 UnaryPlus: 3184 // C++ [over.built]p8: 3185 // For every type T, there exist candidate operator functions of 3186 // the form 3187 // 3188 // T* operator+(T*); 3189 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3190 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3191 QualType ParamTy = *Ptr; 3192 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3193 } 3194 3195 // Fall through 3196 3197 UnaryMinus: 3198 // C++ [over.built]p9: 3199 // For every promoted arithmetic type T, there exist candidate 3200 // operator functions of the form 3201 // 3202 // T operator+(T); 3203 // T operator-(T); 3204 for (unsigned Arith = FirstPromotedArithmeticType; 3205 Arith < LastPromotedArithmeticType; ++Arith) { 3206 QualType ArithTy = ArithmeticTypes[Arith]; 3207 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3208 } 3209 break; 3210 3211 case OO_Tilde: 3212 // C++ [over.built]p10: 3213 // For every promoted integral type T, there exist candidate 3214 // operator functions of the form 3215 // 3216 // T operator~(T); 3217 for (unsigned Int = FirstPromotedIntegralType; 3218 Int < LastPromotedIntegralType; ++Int) { 3219 QualType IntTy = ArithmeticTypes[Int]; 3220 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3221 } 3222 break; 3223 3224 case OO_New: 3225 case OO_Delete: 3226 case OO_Array_New: 3227 case OO_Array_Delete: 3228 case OO_Call: 3229 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3230 break; 3231 3232 case OO_Comma: 3233 UnaryAmp: 3234 case OO_Arrow: 3235 // C++ [over.match.oper]p3: 3236 // -- For the operator ',', the unary operator '&', or the 3237 // operator '->', the built-in candidates set is empty. 3238 break; 3239 3240 case OO_EqualEqual: 3241 case OO_ExclaimEqual: 3242 // C++ [over.match.oper]p16: 3243 // For every pointer to member type T, there exist candidate operator 3244 // functions of the form 3245 // 3246 // bool operator==(T,T); 3247 // bool operator!=(T,T); 3248 for (BuiltinCandidateTypeSet::iterator 3249 MemPtr = CandidateTypes.member_pointer_begin(), 3250 MemPtrEnd = CandidateTypes.member_pointer_end(); 3251 MemPtr != MemPtrEnd; 3252 ++MemPtr) { 3253 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3254 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3255 } 3256 3257 // Fall through 3258 3259 case OO_Less: 3260 case OO_Greater: 3261 case OO_LessEqual: 3262 case OO_GreaterEqual: 3263 // C++ [over.built]p15: 3264 // 3265 // For every pointer or enumeration type T, there exist 3266 // candidate operator functions of the form 3267 // 3268 // bool operator<(T, T); 3269 // bool operator>(T, T); 3270 // bool operator<=(T, T); 3271 // bool operator>=(T, T); 3272 // bool operator==(T, T); 3273 // bool operator!=(T, T); 3274 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3275 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3276 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3277 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3278 } 3279 for (BuiltinCandidateTypeSet::iterator Enum 3280 = CandidateTypes.enumeration_begin(); 3281 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3282 QualType ParamTypes[2] = { *Enum, *Enum }; 3283 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3284 } 3285 3286 // Fall through. 3287 isComparison = true; 3288 3289 BinaryPlus: 3290 BinaryMinus: 3291 if (!isComparison) { 3292 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3293 3294 // C++ [over.built]p13: 3295 // 3296 // For every cv-qualified or cv-unqualified object type T 3297 // there exist candidate operator functions of the form 3298 // 3299 // T* operator+(T*, ptrdiff_t); 3300 // T& operator[](T*, ptrdiff_t); [BELOW] 3301 // T* operator-(T*, ptrdiff_t); 3302 // T* operator+(ptrdiff_t, T*); 3303 // T& operator[](ptrdiff_t, T*); [BELOW] 3304 // 3305 // C++ [over.built]p14: 3306 // 3307 // For every T, where T is a pointer to object type, there 3308 // exist candidate operator functions of the form 3309 // 3310 // ptrdiff_t operator-(T, T); 3311 for (BuiltinCandidateTypeSet::iterator Ptr 3312 = CandidateTypes.pointer_begin(); 3313 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3314 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3315 3316 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3317 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3318 3319 if (Op == OO_Plus) { 3320 // T* operator+(ptrdiff_t, T*); 3321 ParamTypes[0] = ParamTypes[1]; 3322 ParamTypes[1] = *Ptr; 3323 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3324 } else { 3325 // ptrdiff_t operator-(T, T); 3326 ParamTypes[1] = *Ptr; 3327 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3328 Args, 2, CandidateSet); 3329 } 3330 } 3331 } 3332 // Fall through 3333 3334 case OO_Slash: 3335 BinaryStar: 3336 Conditional: 3337 // C++ [over.built]p12: 3338 // 3339 // For every pair of promoted arithmetic types L and R, there 3340 // exist candidate operator functions of the form 3341 // 3342 // LR operator*(L, R); 3343 // LR operator/(L, R); 3344 // LR operator+(L, R); 3345 // LR operator-(L, R); 3346 // bool operator<(L, R); 3347 // bool operator>(L, R); 3348 // bool operator<=(L, R); 3349 // bool operator>=(L, R); 3350 // bool operator==(L, R); 3351 // bool operator!=(L, R); 3352 // 3353 // where LR is the result of the usual arithmetic conversions 3354 // between types L and R. 3355 // 3356 // C++ [over.built]p24: 3357 // 3358 // For every pair of promoted arithmetic types L and R, there exist 3359 // candidate operator functions of the form 3360 // 3361 // LR operator?(bool, L, R); 3362 // 3363 // where LR is the result of the usual arithmetic conversions 3364 // between types L and R. 3365 // Our candidates ignore the first parameter. 3366 for (unsigned Left = FirstPromotedArithmeticType; 3367 Left < LastPromotedArithmeticType; ++Left) { 3368 for (unsigned Right = FirstPromotedArithmeticType; 3369 Right < LastPromotedArithmeticType; ++Right) { 3370 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3371 QualType Result 3372 = isComparison 3373 ? Context.BoolTy 3374 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3375 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3376 } 3377 } 3378 break; 3379 3380 case OO_Percent: 3381 BinaryAmp: 3382 case OO_Caret: 3383 case OO_Pipe: 3384 case OO_LessLess: 3385 case OO_GreaterGreater: 3386 // C++ [over.built]p17: 3387 // 3388 // For every pair of promoted integral types L and R, there 3389 // exist candidate operator functions of the form 3390 // 3391 // LR operator%(L, R); 3392 // LR operator&(L, R); 3393 // LR operator^(L, R); 3394 // LR operator|(L, R); 3395 // L operator<<(L, R); 3396 // L operator>>(L, R); 3397 // 3398 // where LR is the result of the usual arithmetic conversions 3399 // between types L and R. 3400 for (unsigned Left = FirstPromotedIntegralType; 3401 Left < LastPromotedIntegralType; ++Left) { 3402 for (unsigned Right = FirstPromotedIntegralType; 3403 Right < LastPromotedIntegralType; ++Right) { 3404 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3405 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3406 ? LandR[0] 3407 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3408 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3409 } 3410 } 3411 break; 3412 3413 case OO_Equal: 3414 // C++ [over.built]p20: 3415 // 3416 // For every pair (T, VQ), where T is an enumeration or 3417 // pointer to member type and VQ is either volatile or 3418 // empty, there exist candidate operator functions of the form 3419 // 3420 // VQ T& operator=(VQ T&, T); 3421 for (BuiltinCandidateTypeSet::iterator 3422 Enum = CandidateTypes.enumeration_begin(), 3423 EnumEnd = CandidateTypes.enumeration_end(); 3424 Enum != EnumEnd; ++Enum) 3425 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3426 CandidateSet); 3427 for (BuiltinCandidateTypeSet::iterator 3428 MemPtr = CandidateTypes.member_pointer_begin(), 3429 MemPtrEnd = CandidateTypes.member_pointer_end(); 3430 MemPtr != MemPtrEnd; ++MemPtr) 3431 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3432 CandidateSet); 3433 // Fall through. 3434 3435 case OO_PlusEqual: 3436 case OO_MinusEqual: 3437 // C++ [over.built]p19: 3438 // 3439 // For every pair (T, VQ), where T is any type and VQ is either 3440 // volatile or empty, there exist candidate operator functions 3441 // of the form 3442 // 3443 // T*VQ& operator=(T*VQ&, T*); 3444 // 3445 // C++ [over.built]p21: 3446 // 3447 // For every pair (T, VQ), where T is a cv-qualified or 3448 // cv-unqualified object type and VQ is either volatile or 3449 // empty, there exist candidate operator functions of the form 3450 // 3451 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3452 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3453 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3454 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3455 QualType ParamTypes[2]; 3456 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3457 3458 // non-volatile version 3459 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3460 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3461 /*IsAssigmentOperator=*/Op == OO_Equal); 3462 3463 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3464 // volatile version 3465 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3466 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3467 /*IsAssigmentOperator=*/Op == OO_Equal); 3468 } 3469 } 3470 // Fall through. 3471 3472 case OO_StarEqual: 3473 case OO_SlashEqual: 3474 // C++ [over.built]p18: 3475 // 3476 // For every triple (L, VQ, R), where L is an arithmetic type, 3477 // VQ is either volatile or empty, and R is a promoted 3478 // arithmetic type, there exist candidate operator functions of 3479 // the form 3480 // 3481 // VQ L& operator=(VQ L&, R); 3482 // VQ L& operator*=(VQ L&, R); 3483 // VQ L& operator/=(VQ L&, R); 3484 // VQ L& operator+=(VQ L&, R); 3485 // VQ L& operator-=(VQ L&, R); 3486 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3487 for (unsigned Right = FirstPromotedArithmeticType; 3488 Right < LastPromotedArithmeticType; ++Right) { 3489 QualType ParamTypes[2]; 3490 ParamTypes[1] = ArithmeticTypes[Right]; 3491 3492 // Add this built-in operator as a candidate (VQ is empty). 3493 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3494 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3495 /*IsAssigmentOperator=*/Op == OO_Equal); 3496 3497 // Add this built-in operator as a candidate (VQ is 'volatile'). 3498 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3499 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3500 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3501 /*IsAssigmentOperator=*/Op == OO_Equal); 3502 } 3503 } 3504 break; 3505 3506 case OO_PercentEqual: 3507 case OO_LessLessEqual: 3508 case OO_GreaterGreaterEqual: 3509 case OO_AmpEqual: 3510 case OO_CaretEqual: 3511 case OO_PipeEqual: 3512 // C++ [over.built]p22: 3513 // 3514 // For every triple (L, VQ, R), where L is an integral type, VQ 3515 // is either volatile or empty, and R is a promoted integral 3516 // type, there exist candidate operator functions of the form 3517 // 3518 // VQ L& operator%=(VQ L&, R); 3519 // VQ L& operator<<=(VQ L&, R); 3520 // VQ L& operator>>=(VQ L&, R); 3521 // VQ L& operator&=(VQ L&, R); 3522 // VQ L& operator^=(VQ L&, R); 3523 // VQ L& operator|=(VQ L&, R); 3524 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3525 for (unsigned Right = FirstPromotedIntegralType; 3526 Right < LastPromotedIntegralType; ++Right) { 3527 QualType ParamTypes[2]; 3528 ParamTypes[1] = ArithmeticTypes[Right]; 3529 3530 // Add this built-in operator as a candidate (VQ is empty). 3531 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3532 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3533 3534 // Add this built-in operator as a candidate (VQ is 'volatile'). 3535 ParamTypes[0] = ArithmeticTypes[Left]; 3536 ParamTypes[0].addVolatile(); 3537 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3538 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3539 } 3540 } 3541 break; 3542 3543 case OO_Exclaim: { 3544 // C++ [over.operator]p23: 3545 // 3546 // There also exist candidate operator functions of the form 3547 // 3548 // bool operator!(bool); 3549 // bool operator&&(bool, bool); [BELOW] 3550 // bool operator||(bool, bool); [BELOW] 3551 QualType ParamTy = Context.BoolTy; 3552 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3553 /*IsAssignmentOperator=*/false, 3554 /*NumContextualBoolArguments=*/1); 3555 break; 3556 } 3557 3558 case OO_AmpAmp: 3559 case OO_PipePipe: { 3560 // C++ [over.operator]p23: 3561 // 3562 // There also exist candidate operator functions of the form 3563 // 3564 // bool operator!(bool); [ABOVE] 3565 // bool operator&&(bool, bool); 3566 // bool operator||(bool, bool); 3567 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3568 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3569 /*IsAssignmentOperator=*/false, 3570 /*NumContextualBoolArguments=*/2); 3571 break; 3572 } 3573 3574 case OO_Subscript: 3575 // C++ [over.built]p13: 3576 // 3577 // For every cv-qualified or cv-unqualified object type T there 3578 // exist candidate operator functions of the form 3579 // 3580 // T* operator+(T*, ptrdiff_t); [ABOVE] 3581 // T& operator[](T*, ptrdiff_t); 3582 // T* operator-(T*, ptrdiff_t); [ABOVE] 3583 // T* operator+(ptrdiff_t, T*); [ABOVE] 3584 // T& operator[](ptrdiff_t, T*); 3585 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3586 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3587 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3588 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3589 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3590 3591 // T& operator[](T*, ptrdiff_t) 3592 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3593 3594 // T& operator[](ptrdiff_t, T*); 3595 ParamTypes[0] = ParamTypes[1]; 3596 ParamTypes[1] = *Ptr; 3597 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3598 } 3599 break; 3600 3601 case OO_ArrowStar: 3602 // FIXME: No support for pointer-to-members yet. 3603 break; 3604 3605 case OO_Conditional: 3606 // Note that we don't consider the first argument, since it has been 3607 // contextually converted to bool long ago. The candidates below are 3608 // therefore added as binary. 3609 // 3610 // C++ [over.built]p24: 3611 // For every type T, where T is a pointer or pointer-to-member type, 3612 // there exist candidate operator functions of the form 3613 // 3614 // T operator?(bool, T, T); 3615 // 3616 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3617 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3618 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3619 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3620 } 3621 for (BuiltinCandidateTypeSet::iterator Ptr = 3622 CandidateTypes.member_pointer_begin(), 3623 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3624 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3625 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3626 } 3627 goto Conditional; 3628 } 3629} 3630 3631/// \brief Add function candidates found via argument-dependent lookup 3632/// to the set of overloading candidates. 3633/// 3634/// This routine performs argument-dependent name lookup based on the 3635/// given function name (which may also be an operator name) and adds 3636/// all of the overload candidates found by ADL to the overload 3637/// candidate set (C++ [basic.lookup.argdep]). 3638void 3639Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3640 Expr **Args, unsigned NumArgs, 3641 bool HasExplicitTemplateArgs, 3642 const TemplateArgument *ExplicitTemplateArgs, 3643 unsigned NumExplicitTemplateArgs, 3644 OverloadCandidateSet& CandidateSet, 3645 bool PartialOverloading) { 3646 FunctionSet Functions; 3647 3648 // FIXME: Should we be trafficking in canonical function decls throughout? 3649 3650 // Record all of the function candidates that we've already 3651 // added to the overload set, so that we don't add those same 3652 // candidates a second time. 3653 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3654 CandEnd = CandidateSet.end(); 3655 Cand != CandEnd; ++Cand) 3656 if (Cand->Function) { 3657 Functions.insert(Cand->Function); 3658 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3659 Functions.insert(FunTmpl); 3660 } 3661 3662 // FIXME: Pass in the explicit template arguments? 3663 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3664 3665 // Erase all of the candidates we already knew about. 3666 // FIXME: This is suboptimal. Is there a better way? 3667 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3668 CandEnd = CandidateSet.end(); 3669 Cand != CandEnd; ++Cand) 3670 if (Cand->Function) { 3671 Functions.erase(Cand->Function); 3672 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3673 Functions.erase(FunTmpl); 3674 } 3675 3676 // For each of the ADL candidates we found, add it to the overload 3677 // set. 3678 for (FunctionSet::iterator Func = Functions.begin(), 3679 FuncEnd = Functions.end(); 3680 Func != FuncEnd; ++Func) { 3681 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3682 if (HasExplicitTemplateArgs) 3683 continue; 3684 3685 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3686 false, false, PartialOverloading); 3687 } else 3688 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3689 HasExplicitTemplateArgs, 3690 ExplicitTemplateArgs, 3691 NumExplicitTemplateArgs, 3692 Args, NumArgs, CandidateSet); 3693 } 3694} 3695 3696/// isBetterOverloadCandidate - Determines whether the first overload 3697/// candidate is a better candidate than the second (C++ 13.3.3p1). 3698bool 3699Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3700 const OverloadCandidate& Cand2) { 3701 // Define viable functions to be better candidates than non-viable 3702 // functions. 3703 if (!Cand2.Viable) 3704 return Cand1.Viable; 3705 else if (!Cand1.Viable) 3706 return false; 3707 3708 // C++ [over.match.best]p1: 3709 // 3710 // -- if F is a static member function, ICS1(F) is defined such 3711 // that ICS1(F) is neither better nor worse than ICS1(G) for 3712 // any function G, and, symmetrically, ICS1(G) is neither 3713 // better nor worse than ICS1(F). 3714 unsigned StartArg = 0; 3715 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3716 StartArg = 1; 3717 3718 // C++ [over.match.best]p1: 3719 // A viable function F1 is defined to be a better function than another 3720 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3721 // conversion sequence than ICSi(F2), and then... 3722 unsigned NumArgs = Cand1.Conversions.size(); 3723 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3724 bool HasBetterConversion = false; 3725 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3726 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3727 Cand2.Conversions[ArgIdx])) { 3728 case ImplicitConversionSequence::Better: 3729 // Cand1 has a better conversion sequence. 3730 HasBetterConversion = true; 3731 break; 3732 3733 case ImplicitConversionSequence::Worse: 3734 // Cand1 can't be better than Cand2. 3735 return false; 3736 3737 case ImplicitConversionSequence::Indistinguishable: 3738 // Do nothing. 3739 break; 3740 } 3741 } 3742 3743 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3744 // ICSj(F2), or, if not that, 3745 if (HasBetterConversion) 3746 return true; 3747 3748 // - F1 is a non-template function and F2 is a function template 3749 // specialization, or, if not that, 3750 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3751 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3752 return true; 3753 3754 // -- F1 and F2 are function template specializations, and the function 3755 // template for F1 is more specialized than the template for F2 3756 // according to the partial ordering rules described in 14.5.5.2, or, 3757 // if not that, 3758 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3759 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3760 if (FunctionTemplateDecl *BetterTemplate 3761 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 3762 Cand2.Function->getPrimaryTemplate(), 3763 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 3764 : TPOC_Call)) 3765 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 3766 3767 // -- the context is an initialization by user-defined conversion 3768 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3769 // from the return type of F1 to the destination type (i.e., 3770 // the type of the entity being initialized) is a better 3771 // conversion sequence than the standard conversion sequence 3772 // from the return type of F2 to the destination type. 3773 if (Cand1.Function && Cand2.Function && 3774 isa<CXXConversionDecl>(Cand1.Function) && 3775 isa<CXXConversionDecl>(Cand2.Function)) { 3776 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3777 Cand2.FinalConversion)) { 3778 case ImplicitConversionSequence::Better: 3779 // Cand1 has a better conversion sequence. 3780 return true; 3781 3782 case ImplicitConversionSequence::Worse: 3783 // Cand1 can't be better than Cand2. 3784 return false; 3785 3786 case ImplicitConversionSequence::Indistinguishable: 3787 // Do nothing 3788 break; 3789 } 3790 } 3791 3792 return false; 3793} 3794 3795/// \brief Computes the best viable function (C++ 13.3.3) 3796/// within an overload candidate set. 3797/// 3798/// \param CandidateSet the set of candidate functions. 3799/// 3800/// \param Loc the location of the function name (or operator symbol) for 3801/// which overload resolution occurs. 3802/// 3803/// \param Best f overload resolution was successful or found a deleted 3804/// function, Best points to the candidate function found. 3805/// 3806/// \returns The result of overload resolution. 3807Sema::OverloadingResult 3808Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3809 SourceLocation Loc, 3810 OverloadCandidateSet::iterator& Best) { 3811 // Find the best viable function. 3812 Best = CandidateSet.end(); 3813 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3814 Cand != CandidateSet.end(); ++Cand) { 3815 if (Cand->Viable) { 3816 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3817 Best = Cand; 3818 } 3819 } 3820 3821 // If we didn't find any viable functions, abort. 3822 if (Best == CandidateSet.end()) 3823 return OR_No_Viable_Function; 3824 3825 // Make sure that this function is better than every other viable 3826 // function. If not, we have an ambiguity. 3827 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3828 Cand != CandidateSet.end(); ++Cand) { 3829 if (Cand->Viable && 3830 Cand != Best && 3831 !isBetterOverloadCandidate(*Best, *Cand)) { 3832 Best = CandidateSet.end(); 3833 return OR_Ambiguous; 3834 } 3835 } 3836 3837 // Best is the best viable function. 3838 if (Best->Function && 3839 (Best->Function->isDeleted() || 3840 Best->Function->getAttr<UnavailableAttr>())) 3841 return OR_Deleted; 3842 3843 // C++ [basic.def.odr]p2: 3844 // An overloaded function is used if it is selected by overload resolution 3845 // when referred to from a potentially-evaluated expression. [Note: this 3846 // covers calls to named functions (5.2.2), operator overloading 3847 // (clause 13), user-defined conversions (12.3.2), allocation function for 3848 // placement new (5.3.4), as well as non-default initialization (8.5). 3849 if (Best->Function) 3850 MarkDeclarationReferenced(Loc, Best->Function); 3851 return OR_Success; 3852} 3853 3854/// PrintOverloadCandidates - When overload resolution fails, prints 3855/// diagnostic messages containing the candidates in the candidate 3856/// set. If OnlyViable is true, only viable candidates will be printed. 3857void 3858Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3859 bool OnlyViable) { 3860 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3861 LastCand = CandidateSet.end(); 3862 for (; Cand != LastCand; ++Cand) { 3863 if (Cand->Viable || !OnlyViable) { 3864 if (Cand->Function) { 3865 if (Cand->Function->isDeleted() || 3866 Cand->Function->getAttr<UnavailableAttr>()) { 3867 // Deleted or "unavailable" function. 3868 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3869 << Cand->Function->isDeleted(); 3870 } else if (FunctionTemplateDecl *FunTmpl 3871 = Cand->Function->getPrimaryTemplate()) { 3872 // Function template specialization 3873 // FIXME: Give a better reason! 3874 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 3875 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 3876 *Cand->Function->getTemplateSpecializationArgs()); 3877 } else { 3878 // Normal function 3879 bool errReported = false; 3880 if (!Cand->Viable && Cand->Conversions.size() > 0) { 3881 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 3882 const ImplicitConversionSequence &Conversion = 3883 Cand->Conversions[i]; 3884 if ((Conversion.ConversionKind != 3885 ImplicitConversionSequence::BadConversion) || 3886 Conversion.ConversionFunctionSet.size() == 0) 3887 continue; 3888 Diag(Cand->Function->getLocation(), 3889 diag::err_ovl_candidate_not_viable) << (i+1); 3890 errReported = true; 3891 for (int j = Conversion.ConversionFunctionSet.size()-1; 3892 j >= 0; j--) { 3893 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 3894 Diag(Func->getLocation(), diag::err_ovl_candidate); 3895 } 3896 } 3897 } 3898 if (!errReported) 3899 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3900 } 3901 } else if (Cand->IsSurrogate) { 3902 // Desugar the type of the surrogate down to a function type, 3903 // retaining as many typedefs as possible while still showing 3904 // the function type (and, therefore, its parameter types). 3905 QualType FnType = Cand->Surrogate->getConversionType(); 3906 bool isLValueReference = false; 3907 bool isRValueReference = false; 3908 bool isPointer = false; 3909 if (const LValueReferenceType *FnTypeRef = 3910 FnType->getAs<LValueReferenceType>()) { 3911 FnType = FnTypeRef->getPointeeType(); 3912 isLValueReference = true; 3913 } else if (const RValueReferenceType *FnTypeRef = 3914 FnType->getAs<RValueReferenceType>()) { 3915 FnType = FnTypeRef->getPointeeType(); 3916 isRValueReference = true; 3917 } 3918 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 3919 FnType = FnTypePtr->getPointeeType(); 3920 isPointer = true; 3921 } 3922 // Desugar down to a function type. 3923 FnType = QualType(FnType->getAs<FunctionType>(), 0); 3924 // Reconstruct the pointer/reference as appropriate. 3925 if (isPointer) FnType = Context.getPointerType(FnType); 3926 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3927 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3928 3929 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3930 << FnType; 3931 } else { 3932 // FIXME: We need to get the identifier in here 3933 // FIXME: Do we want the error message to point at the operator? 3934 // (built-ins won't have a location) 3935 QualType FnType 3936 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3937 Cand->BuiltinTypes.ParamTypes, 3938 Cand->Conversions.size(), 3939 false, 0); 3940 3941 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3942 } 3943 } 3944 } 3945} 3946 3947/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3948/// an overloaded function (C++ [over.over]), where @p From is an 3949/// expression with overloaded function type and @p ToType is the type 3950/// we're trying to resolve to. For example: 3951/// 3952/// @code 3953/// int f(double); 3954/// int f(int); 3955/// 3956/// int (*pfd)(double) = f; // selects f(double) 3957/// @endcode 3958/// 3959/// This routine returns the resulting FunctionDecl if it could be 3960/// resolved, and NULL otherwise. When @p Complain is true, this 3961/// routine will emit diagnostics if there is an error. 3962FunctionDecl * 3963Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3964 bool Complain) { 3965 QualType FunctionType = ToType; 3966 bool IsMember = false; 3967 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 3968 FunctionType = ToTypePtr->getPointeeType(); 3969 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 3970 FunctionType = ToTypeRef->getPointeeType(); 3971 else if (const MemberPointerType *MemTypePtr = 3972 ToType->getAs<MemberPointerType>()) { 3973 FunctionType = MemTypePtr->getPointeeType(); 3974 IsMember = true; 3975 } 3976 3977 // We only look at pointers or references to functions. 3978 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 3979 if (!FunctionType->isFunctionType()) 3980 return 0; 3981 3982 // Find the actual overloaded function declaration. 3983 OverloadedFunctionDecl *Ovl = 0; 3984 3985 // C++ [over.over]p1: 3986 // [...] [Note: any redundant set of parentheses surrounding the 3987 // overloaded function name is ignored (5.1). ] 3988 Expr *OvlExpr = From->IgnoreParens(); 3989 3990 // C++ [over.over]p1: 3991 // [...] The overloaded function name can be preceded by the & 3992 // operator. 3993 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3994 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3995 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3996 } 3997 3998 // Try to dig out the overloaded function. 3999 FunctionTemplateDecl *FunctionTemplate = 0; 4000 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4001 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4002 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4003 } 4004 4005 // If there's no overloaded function declaration or function template, 4006 // we're done. 4007 if (!Ovl && !FunctionTemplate) 4008 return 0; 4009 4010 OverloadIterator Fun; 4011 if (Ovl) 4012 Fun = Ovl; 4013 else 4014 Fun = FunctionTemplate; 4015 4016 // Look through all of the overloaded functions, searching for one 4017 // whose type matches exactly. 4018 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4019 4020 bool FoundNonTemplateFunction = false; 4021 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4022 // C++ [over.over]p3: 4023 // Non-member functions and static member functions match 4024 // targets of type "pointer-to-function" or "reference-to-function." 4025 // Nonstatic member functions match targets of 4026 // type "pointer-to-member-function." 4027 // Note that according to DR 247, the containing class does not matter. 4028 4029 if (FunctionTemplateDecl *FunctionTemplate 4030 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4031 if (CXXMethodDecl *Method 4032 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4033 // Skip non-static function templates when converting to pointer, and 4034 // static when converting to member pointer. 4035 if (Method->isStatic() == IsMember) 4036 continue; 4037 } else if (IsMember) 4038 continue; 4039 4040 // C++ [over.over]p2: 4041 // If the name is a function template, template argument deduction is 4042 // done (14.8.2.2), and if the argument deduction succeeds, the 4043 // resulting template argument list is used to generate a single 4044 // function template specialization, which is added to the set of 4045 // overloaded functions considered. 4046 FunctionDecl *Specialization = 0; 4047 TemplateDeductionInfo Info(Context); 4048 if (TemplateDeductionResult Result 4049 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 4050 /*FIXME:*/0, /*FIXME:*/0, 4051 FunctionType, Specialization, Info)) { 4052 // FIXME: make a note of the failed deduction for diagnostics. 4053 (void)Result; 4054 } else { 4055 assert(FunctionType 4056 == Context.getCanonicalType(Specialization->getType())); 4057 Matches.insert( 4058 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4059 } 4060 } 4061 4062 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4063 // Skip non-static functions when converting to pointer, and static 4064 // when converting to member pointer. 4065 if (Method->isStatic() == IsMember) 4066 continue; 4067 } else if (IsMember) 4068 continue; 4069 4070 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4071 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4072 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4073 FoundNonTemplateFunction = true; 4074 } 4075 } 4076 } 4077 4078 // If there were 0 or 1 matches, we're done. 4079 if (Matches.empty()) 4080 return 0; 4081 else if (Matches.size() == 1) 4082 return *Matches.begin(); 4083 4084 // C++ [over.over]p4: 4085 // If more than one function is selected, [...] 4086 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4087 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4088 if (FoundNonTemplateFunction) { 4089 // [...] any function template specializations in the set are 4090 // eliminated if the set also contains a non-template function, [...] 4091 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4092 if ((*M)->getPrimaryTemplate() == 0) 4093 RemainingMatches.push_back(*M); 4094 } else { 4095 // [...] and any given function template specialization F1 is 4096 // eliminated if the set contains a second function template 4097 // specialization whose function template is more specialized 4098 // than the function template of F1 according to the partial 4099 // ordering rules of 14.5.5.2. 4100 4101 // The algorithm specified above is quadratic. We instead use a 4102 // two-pass algorithm (similar to the one used to identify the 4103 // best viable function in an overload set) that identifies the 4104 // best function template (if it exists). 4105 MatchIter Best = Matches.begin(); 4106 MatchIter M = Best, MEnd = Matches.end(); 4107 // Find the most specialized function. 4108 for (++M; M != MEnd; ++M) 4109 if (getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4110 (*Best)->getPrimaryTemplate(), 4111 TPOC_Other) 4112 == (*M)->getPrimaryTemplate()) 4113 Best = M; 4114 4115 // Determine whether this function template is more specialized 4116 // that all of the others. 4117 bool Ambiguous = false; 4118 for (M = Matches.begin(); M != MEnd; ++M) { 4119 if (M != Best && 4120 getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4121 (*Best)->getPrimaryTemplate(), 4122 TPOC_Other) 4123 != (*Best)->getPrimaryTemplate()) { 4124 Ambiguous = true; 4125 break; 4126 } 4127 } 4128 4129 // If one function template was more specialized than all of the 4130 // others, return it. 4131 if (!Ambiguous) 4132 return *Best; 4133 4134 // We could not find a most-specialized function template, which 4135 // is equivalent to having a set of function templates with more 4136 // than one such template. So, we place all of the function 4137 // templates into the set of remaining matches and produce a 4138 // diagnostic below. FIXME: we could perform the quadratic 4139 // algorithm here, pruning the result set to limit the number of 4140 // candidates output later. 4141 RemainingMatches.append(Matches.begin(), Matches.end()); 4142 } 4143 4144 // [...] After such eliminations, if any, there shall remain exactly one 4145 // selected function. 4146 if (RemainingMatches.size() == 1) 4147 return RemainingMatches.front(); 4148 4149 // FIXME: We should probably return the same thing that BestViableFunction 4150 // returns (even if we issue the diagnostics here). 4151 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4152 << RemainingMatches[0]->getDeclName(); 4153 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4154 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4155 return 0; 4156} 4157 4158/// \brief Add a single candidate to the overload set. 4159static void AddOverloadedCallCandidate(Sema &S, 4160 AnyFunctionDecl Callee, 4161 bool &ArgumentDependentLookup, 4162 bool HasExplicitTemplateArgs, 4163 const TemplateArgument *ExplicitTemplateArgs, 4164 unsigned NumExplicitTemplateArgs, 4165 Expr **Args, unsigned NumArgs, 4166 OverloadCandidateSet &CandidateSet, 4167 bool PartialOverloading) { 4168 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4169 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4170 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4171 PartialOverloading); 4172 4173 if (Func->getDeclContext()->isRecord() || 4174 Func->getDeclContext()->isFunctionOrMethod()) 4175 ArgumentDependentLookup = false; 4176 return; 4177 } 4178 4179 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4180 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4181 ExplicitTemplateArgs, 4182 NumExplicitTemplateArgs, 4183 Args, NumArgs, CandidateSet); 4184 4185 if (FuncTemplate->getDeclContext()->isRecord()) 4186 ArgumentDependentLookup = false; 4187} 4188 4189/// \brief Add the overload candidates named by callee and/or found by argument 4190/// dependent lookup to the given overload set. 4191void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4192 DeclarationName &UnqualifiedName, 4193 bool &ArgumentDependentLookup, 4194 bool HasExplicitTemplateArgs, 4195 const TemplateArgument *ExplicitTemplateArgs, 4196 unsigned NumExplicitTemplateArgs, 4197 Expr **Args, unsigned NumArgs, 4198 OverloadCandidateSet &CandidateSet, 4199 bool PartialOverloading) { 4200 // Add the functions denoted by Callee to the set of candidate 4201 // functions. While we're doing so, track whether argument-dependent 4202 // lookup still applies, per: 4203 // 4204 // C++0x [basic.lookup.argdep]p3: 4205 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4206 // and let Y be the lookup set produced by argument dependent 4207 // lookup (defined as follows). If X contains 4208 // 4209 // -- a declaration of a class member, or 4210 // 4211 // -- a block-scope function declaration that is not a 4212 // using-declaration (FIXME: check for using declaration), or 4213 // 4214 // -- a declaration that is neither a function or a function 4215 // template 4216 // 4217 // then Y is empty. 4218 if (!Callee) { 4219 // Nothing to do. 4220 } else if (OverloadedFunctionDecl *Ovl 4221 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4222 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4223 FuncEnd = Ovl->function_end(); 4224 Func != FuncEnd; ++Func) 4225 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4226 HasExplicitTemplateArgs, 4227 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4228 Args, NumArgs, CandidateSet, 4229 PartialOverloading); 4230 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4231 AddOverloadedCallCandidate(*this, 4232 AnyFunctionDecl::getFromNamedDecl(Callee), 4233 ArgumentDependentLookup, 4234 HasExplicitTemplateArgs, 4235 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4236 Args, NumArgs, CandidateSet, 4237 PartialOverloading); 4238 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4239 // checking dynamically. 4240 4241 if (Callee) 4242 UnqualifiedName = Callee->getDeclName(); 4243 4244 if (ArgumentDependentLookup) 4245 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4246 HasExplicitTemplateArgs, 4247 ExplicitTemplateArgs, 4248 NumExplicitTemplateArgs, 4249 CandidateSet, 4250 PartialOverloading); 4251} 4252 4253/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4254/// (which eventually refers to the declaration Func) and the call 4255/// arguments Args/NumArgs, attempt to resolve the function call down 4256/// to a specific function. If overload resolution succeeds, returns 4257/// the function declaration produced by overload 4258/// resolution. Otherwise, emits diagnostics, deletes all of the 4259/// arguments and Fn, and returns NULL. 4260FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4261 DeclarationName UnqualifiedName, 4262 bool HasExplicitTemplateArgs, 4263 const TemplateArgument *ExplicitTemplateArgs, 4264 unsigned NumExplicitTemplateArgs, 4265 SourceLocation LParenLoc, 4266 Expr **Args, unsigned NumArgs, 4267 SourceLocation *CommaLocs, 4268 SourceLocation RParenLoc, 4269 bool &ArgumentDependentLookup) { 4270 OverloadCandidateSet CandidateSet; 4271 4272 // Add the functions denoted by Callee to the set of candidate 4273 // functions. 4274 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4275 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4276 NumExplicitTemplateArgs, Args, NumArgs, 4277 CandidateSet); 4278 OverloadCandidateSet::iterator Best; 4279 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4280 case OR_Success: 4281 return Best->Function; 4282 4283 case OR_No_Viable_Function: 4284 Diag(Fn->getSourceRange().getBegin(), 4285 diag::err_ovl_no_viable_function_in_call) 4286 << UnqualifiedName << Fn->getSourceRange(); 4287 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4288 break; 4289 4290 case OR_Ambiguous: 4291 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4292 << UnqualifiedName << Fn->getSourceRange(); 4293 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4294 break; 4295 4296 case OR_Deleted: 4297 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4298 << Best->Function->isDeleted() 4299 << UnqualifiedName 4300 << Fn->getSourceRange(); 4301 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4302 break; 4303 } 4304 4305 // Overload resolution failed. Destroy all of the subexpressions and 4306 // return NULL. 4307 Fn->Destroy(Context); 4308 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4309 Args[Arg]->Destroy(Context); 4310 return 0; 4311} 4312 4313/// \brief Create a unary operation that may resolve to an overloaded 4314/// operator. 4315/// 4316/// \param OpLoc The location of the operator itself (e.g., '*'). 4317/// 4318/// \param OpcIn The UnaryOperator::Opcode that describes this 4319/// operator. 4320/// 4321/// \param Functions The set of non-member functions that will be 4322/// considered by overload resolution. The caller needs to build this 4323/// set based on the context using, e.g., 4324/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4325/// set should not contain any member functions; those will be added 4326/// by CreateOverloadedUnaryOp(). 4327/// 4328/// \param input The input argument. 4329Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4330 unsigned OpcIn, 4331 FunctionSet &Functions, 4332 ExprArg input) { 4333 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4334 Expr *Input = (Expr *)input.get(); 4335 4336 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4337 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4338 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4339 4340 Expr *Args[2] = { Input, 0 }; 4341 unsigned NumArgs = 1; 4342 4343 // For post-increment and post-decrement, add the implicit '0' as 4344 // the second argument, so that we know this is a post-increment or 4345 // post-decrement. 4346 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4347 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4348 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4349 SourceLocation()); 4350 NumArgs = 2; 4351 } 4352 4353 if (Input->isTypeDependent()) { 4354 OverloadedFunctionDecl *Overloads 4355 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4356 for (FunctionSet::iterator Func = Functions.begin(), 4357 FuncEnd = Functions.end(); 4358 Func != FuncEnd; ++Func) 4359 Overloads->addOverload(*Func); 4360 4361 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4362 OpLoc, false, false); 4363 4364 input.release(); 4365 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4366 &Args[0], NumArgs, 4367 Context.DependentTy, 4368 OpLoc)); 4369 } 4370 4371 // Build an empty overload set. 4372 OverloadCandidateSet CandidateSet; 4373 4374 // Add the candidates from the given function set. 4375 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4376 4377 // Add operator candidates that are member functions. 4378 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4379 4380 // Add builtin operator candidates. 4381 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4382 4383 // Perform overload resolution. 4384 OverloadCandidateSet::iterator Best; 4385 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4386 case OR_Success: { 4387 // We found a built-in operator or an overloaded operator. 4388 FunctionDecl *FnDecl = Best->Function; 4389 4390 if (FnDecl) { 4391 // We matched an overloaded operator. Build a call to that 4392 // operator. 4393 4394 // Convert the arguments. 4395 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4396 if (PerformObjectArgumentInitialization(Input, Method)) 4397 return ExprError(); 4398 } else { 4399 // Convert the arguments. 4400 if (PerformCopyInitialization(Input, 4401 FnDecl->getParamDecl(0)->getType(), 4402 "passing")) 4403 return ExprError(); 4404 } 4405 4406 // Determine the result type 4407 QualType ResultTy 4408 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4409 ResultTy = ResultTy.getNonReferenceType(); 4410 4411 // Build the actual expression node. 4412 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4413 SourceLocation()); 4414 UsualUnaryConversions(FnExpr); 4415 4416 input.release(); 4417 4418 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4419 &Input, 1, ResultTy, OpLoc); 4420 return MaybeBindToTemporary(CE); 4421 } else { 4422 // We matched a built-in operator. Convert the arguments, then 4423 // break out so that we will build the appropriate built-in 4424 // operator node. 4425 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4426 Best->Conversions[0], "passing")) 4427 return ExprError(); 4428 4429 break; 4430 } 4431 } 4432 4433 case OR_No_Viable_Function: 4434 // No viable function; fall through to handling this as a 4435 // built-in operator, which will produce an error message for us. 4436 break; 4437 4438 case OR_Ambiguous: 4439 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4440 << UnaryOperator::getOpcodeStr(Opc) 4441 << Input->getSourceRange(); 4442 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4443 return ExprError(); 4444 4445 case OR_Deleted: 4446 Diag(OpLoc, diag::err_ovl_deleted_oper) 4447 << Best->Function->isDeleted() 4448 << UnaryOperator::getOpcodeStr(Opc) 4449 << Input->getSourceRange(); 4450 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4451 return ExprError(); 4452 } 4453 4454 // Either we found no viable overloaded operator or we matched a 4455 // built-in operator. In either case, fall through to trying to 4456 // build a built-in operation. 4457 input.release(); 4458 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4459} 4460 4461/// \brief Create a binary operation that may resolve to an overloaded 4462/// operator. 4463/// 4464/// \param OpLoc The location of the operator itself (e.g., '+'). 4465/// 4466/// \param OpcIn The BinaryOperator::Opcode that describes this 4467/// operator. 4468/// 4469/// \param Functions The set of non-member functions that will be 4470/// considered by overload resolution. The caller needs to build this 4471/// set based on the context using, e.g., 4472/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4473/// set should not contain any member functions; those will be added 4474/// by CreateOverloadedBinOp(). 4475/// 4476/// \param LHS Left-hand argument. 4477/// \param RHS Right-hand argument. 4478Sema::OwningExprResult 4479Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4480 unsigned OpcIn, 4481 FunctionSet &Functions, 4482 Expr *LHS, Expr *RHS) { 4483 Expr *Args[2] = { LHS, RHS }; 4484 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4485 4486 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4487 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4488 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4489 4490 // If either side is type-dependent, create an appropriate dependent 4491 // expression. 4492 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4493 // .* cannot be overloaded. 4494 if (Opc == BinaryOperator::PtrMemD) 4495 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4496 Context.DependentTy, OpLoc)); 4497 4498 OverloadedFunctionDecl *Overloads 4499 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4500 for (FunctionSet::iterator Func = Functions.begin(), 4501 FuncEnd = Functions.end(); 4502 Func != FuncEnd; ++Func) 4503 Overloads->addOverload(*Func); 4504 4505 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4506 OpLoc, false, false); 4507 4508 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4509 Args, 2, 4510 Context.DependentTy, 4511 OpLoc)); 4512 } 4513 4514 // If this is the .* operator, which is not overloadable, just 4515 // create a built-in binary operator. 4516 if (Opc == BinaryOperator::PtrMemD) 4517 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4518 4519 // If this is one of the assignment operators, we only perform 4520 // overload resolution if the left-hand side is a class or 4521 // enumeration type (C++ [expr.ass]p3). 4522 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4523 !Args[0]->getType()->isOverloadableType()) 4524 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4525 4526 // Build an empty overload set. 4527 OverloadCandidateSet CandidateSet; 4528 4529 // Add the candidates from the given function set. 4530 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4531 4532 // Add operator candidates that are member functions. 4533 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4534 4535 // Add builtin operator candidates. 4536 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4537 4538 // Perform overload resolution. 4539 OverloadCandidateSet::iterator Best; 4540 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4541 case OR_Success: { 4542 // We found a built-in operator or an overloaded operator. 4543 FunctionDecl *FnDecl = Best->Function; 4544 4545 if (FnDecl) { 4546 // We matched an overloaded operator. Build a call to that 4547 // operator. 4548 4549 // Convert the arguments. 4550 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4551 if (PerformObjectArgumentInitialization(Args[0], Method) || 4552 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4553 "passing")) 4554 return ExprError(); 4555 } else { 4556 // Convert the arguments. 4557 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4558 "passing") || 4559 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4560 "passing")) 4561 return ExprError(); 4562 } 4563 4564 // Determine the result type 4565 QualType ResultTy 4566 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4567 ResultTy = ResultTy.getNonReferenceType(); 4568 4569 // Build the actual expression node. 4570 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4571 OpLoc); 4572 UsualUnaryConversions(FnExpr); 4573 4574 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4575 Args, 2, ResultTy, OpLoc); 4576 return MaybeBindToTemporary(CE); 4577 } else { 4578 // We matched a built-in operator. Convert the arguments, then 4579 // break out so that we will build the appropriate built-in 4580 // operator node. 4581 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4582 Best->Conversions[0], "passing") || 4583 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4584 Best->Conversions[1], "passing")) 4585 return ExprError(); 4586 4587 break; 4588 } 4589 } 4590 4591 case OR_No_Viable_Function: 4592 // For class as left operand for assignment or compound assigment operator 4593 // do not fall through to handling in built-in, but report that no overloaded 4594 // assignment operator found 4595 if (Args[0]->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4596 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4597 << BinaryOperator::getOpcodeStr(Opc) 4598 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4599 return ExprError(); 4600 } 4601 // No viable function; fall through to handling this as a 4602 // built-in operator, which will produce an error message for us. 4603 break; 4604 4605 case OR_Ambiguous: 4606 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4607 << BinaryOperator::getOpcodeStr(Opc) 4608 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4609 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4610 return ExprError(); 4611 4612 case OR_Deleted: 4613 Diag(OpLoc, diag::err_ovl_deleted_oper) 4614 << Best->Function->isDeleted() 4615 << BinaryOperator::getOpcodeStr(Opc) 4616 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4617 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4618 return ExprError(); 4619 } 4620 4621 // Either we found no viable overloaded operator or we matched a 4622 // built-in operator. In either case, try to build a built-in 4623 // operation. 4624 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4625} 4626 4627/// BuildCallToMemberFunction - Build a call to a member 4628/// function. MemExpr is the expression that refers to the member 4629/// function (and includes the object parameter), Args/NumArgs are the 4630/// arguments to the function call (not including the object 4631/// parameter). The caller needs to validate that the member 4632/// expression refers to a member function or an overloaded member 4633/// function. 4634Sema::ExprResult 4635Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4636 SourceLocation LParenLoc, Expr **Args, 4637 unsigned NumArgs, SourceLocation *CommaLocs, 4638 SourceLocation RParenLoc) { 4639 // Dig out the member expression. This holds both the object 4640 // argument and the member function we're referring to. 4641 MemberExpr *MemExpr = 0; 4642 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4643 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4644 else 4645 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4646 assert(MemExpr && "Building member call without member expression"); 4647 4648 // Extract the object argument. 4649 Expr *ObjectArg = MemExpr->getBase(); 4650 4651 CXXMethodDecl *Method = 0; 4652 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 4653 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 4654 // Add overload candidates 4655 OverloadCandidateSet CandidateSet; 4656 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 4657 4658 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 4659 Func != FuncEnd; ++Func) { 4660 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) 4661 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4662 /*SuppressUserConversions=*/false); 4663 else 4664 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 4665 MemExpr->hasExplicitTemplateArgumentList(), 4666 MemExpr->getTemplateArgs(), 4667 MemExpr->getNumTemplateArgs(), 4668 ObjectArg, Args, NumArgs, 4669 CandidateSet, 4670 /*SuppressUsedConversions=*/false); 4671 } 4672 4673 OverloadCandidateSet::iterator Best; 4674 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4675 case OR_Success: 4676 Method = cast<CXXMethodDecl>(Best->Function); 4677 break; 4678 4679 case OR_No_Viable_Function: 4680 Diag(MemExpr->getSourceRange().getBegin(), 4681 diag::err_ovl_no_viable_member_function_in_call) 4682 << DeclName << MemExprE->getSourceRange(); 4683 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4684 // FIXME: Leaking incoming expressions! 4685 return true; 4686 4687 case OR_Ambiguous: 4688 Diag(MemExpr->getSourceRange().getBegin(), 4689 diag::err_ovl_ambiguous_member_call) 4690 << DeclName << MemExprE->getSourceRange(); 4691 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4692 // FIXME: Leaking incoming expressions! 4693 return true; 4694 4695 case OR_Deleted: 4696 Diag(MemExpr->getSourceRange().getBegin(), 4697 diag::err_ovl_deleted_member_call) 4698 << Best->Function->isDeleted() 4699 << DeclName << MemExprE->getSourceRange(); 4700 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4701 // FIXME: Leaking incoming expressions! 4702 return true; 4703 } 4704 4705 FixOverloadedFunctionReference(MemExpr, Method); 4706 } else { 4707 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4708 } 4709 4710 assert(Method && "Member call to something that isn't a method?"); 4711 ExprOwningPtr<CXXMemberCallExpr> 4712 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4713 NumArgs, 4714 Method->getResultType().getNonReferenceType(), 4715 RParenLoc)); 4716 4717 // Convert the object argument (for a non-static member function call). 4718 if (!Method->isStatic() && 4719 PerformObjectArgumentInitialization(ObjectArg, Method)) 4720 return true; 4721 MemExpr->setBase(ObjectArg); 4722 4723 // Convert the rest of the arguments 4724 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4725 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4726 RParenLoc)) 4727 return true; 4728 4729 if (CheckFunctionCall(Method, TheCall.get())) 4730 return true; 4731 4732 return MaybeBindToTemporary(TheCall.release()).release(); 4733} 4734 4735/// BuildCallToObjectOfClassType - Build a call to an object of class 4736/// type (C++ [over.call.object]), which can end up invoking an 4737/// overloaded function call operator (@c operator()) or performing a 4738/// user-defined conversion on the object argument. 4739Sema::ExprResult 4740Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4741 SourceLocation LParenLoc, 4742 Expr **Args, unsigned NumArgs, 4743 SourceLocation *CommaLocs, 4744 SourceLocation RParenLoc) { 4745 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4746 const RecordType *Record = Object->getType()->getAs<RecordType>(); 4747 4748 // C++ [over.call.object]p1: 4749 // If the primary-expression E in the function call syntax 4750 // evaluates to a class object of type "cv T", then the set of 4751 // candidate functions includes at least the function call 4752 // operators of T. The function call operators of T are obtained by 4753 // ordinary lookup of the name operator() in the context of 4754 // (E).operator(). 4755 OverloadCandidateSet CandidateSet; 4756 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4757 DeclContext::lookup_const_iterator Oper, OperEnd; 4758 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4759 Oper != OperEnd; ++Oper) 4760 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4761 CandidateSet, /*SuppressUserConversions=*/false); 4762 4763 // C++ [over.call.object]p2: 4764 // In addition, for each conversion function declared in T of the 4765 // form 4766 // 4767 // operator conversion-type-id () cv-qualifier; 4768 // 4769 // where cv-qualifier is the same cv-qualification as, or a 4770 // greater cv-qualification than, cv, and where conversion-type-id 4771 // denotes the type "pointer to function of (P1,...,Pn) returning 4772 // R", or the type "reference to pointer to function of 4773 // (P1,...,Pn) returning R", or the type "reference to function 4774 // of (P1,...,Pn) returning R", a surrogate call function [...] 4775 // is also considered as a candidate function. Similarly, 4776 // surrogate call functions are added to the set of candidate 4777 // functions for each conversion function declared in an 4778 // accessible base class provided the function is not hidden 4779 // within T by another intervening declaration. 4780 4781 if (!RequireCompleteType(SourceLocation(), Object->getType(), 0)) { 4782 // FIXME: Look in base classes for more conversion operators! 4783 OverloadedFunctionDecl *Conversions 4784 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4785 for (OverloadedFunctionDecl::function_iterator 4786 Func = Conversions->function_begin(), 4787 FuncEnd = Conversions->function_end(); 4788 Func != FuncEnd; ++Func) { 4789 CXXConversionDecl *Conv; 4790 FunctionTemplateDecl *ConvTemplate; 4791 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 4792 4793 // Skip over templated conversion functions; they aren't 4794 // surrogates. 4795 if (ConvTemplate) 4796 continue; 4797 4798 // Strip the reference type (if any) and then the pointer type (if 4799 // any) to get down to what might be a function type. 4800 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4801 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4802 ConvType = ConvPtrType->getPointeeType(); 4803 4804 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 4805 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4806 } 4807 } 4808 4809 // Perform overload resolution. 4810 OverloadCandidateSet::iterator Best; 4811 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4812 case OR_Success: 4813 // Overload resolution succeeded; we'll build the appropriate call 4814 // below. 4815 break; 4816 4817 case OR_No_Viable_Function: 4818 Diag(Object->getSourceRange().getBegin(), 4819 diag::err_ovl_no_viable_object_call) 4820 << Object->getType() << Object->getSourceRange(); 4821 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4822 break; 4823 4824 case OR_Ambiguous: 4825 Diag(Object->getSourceRange().getBegin(), 4826 diag::err_ovl_ambiguous_object_call) 4827 << Object->getType() << Object->getSourceRange(); 4828 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4829 break; 4830 4831 case OR_Deleted: 4832 Diag(Object->getSourceRange().getBegin(), 4833 diag::err_ovl_deleted_object_call) 4834 << Best->Function->isDeleted() 4835 << Object->getType() << Object->getSourceRange(); 4836 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4837 break; 4838 } 4839 4840 if (Best == CandidateSet.end()) { 4841 // We had an error; delete all of the subexpressions and return 4842 // the error. 4843 Object->Destroy(Context); 4844 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4845 Args[ArgIdx]->Destroy(Context); 4846 return true; 4847 } 4848 4849 if (Best->Function == 0) { 4850 // Since there is no function declaration, this is one of the 4851 // surrogate candidates. Dig out the conversion function. 4852 CXXConversionDecl *Conv 4853 = cast<CXXConversionDecl>( 4854 Best->Conversions[0].UserDefined.ConversionFunction); 4855 4856 // We selected one of the surrogate functions that converts the 4857 // object parameter to a function pointer. Perform the conversion 4858 // on the object argument, then let ActOnCallExpr finish the job. 4859 // FIXME: Represent the user-defined conversion in the AST! 4860 ImpCastExprToType(Object, 4861 Conv->getConversionType().getNonReferenceType(), 4862 CastExpr::CK_Unknown, 4863 Conv->getConversionType()->isLValueReferenceType()); 4864 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4865 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4866 CommaLocs, RParenLoc).release(); 4867 } 4868 4869 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4870 // that calls this method, using Object for the implicit object 4871 // parameter and passing along the remaining arguments. 4872 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4873 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 4874 4875 unsigned NumArgsInProto = Proto->getNumArgs(); 4876 unsigned NumArgsToCheck = NumArgs; 4877 4878 // Build the full argument list for the method call (the 4879 // implicit object parameter is placed at the beginning of the 4880 // list). 4881 Expr **MethodArgs; 4882 if (NumArgs < NumArgsInProto) { 4883 NumArgsToCheck = NumArgsInProto; 4884 MethodArgs = new Expr*[NumArgsInProto + 1]; 4885 } else { 4886 MethodArgs = new Expr*[NumArgs + 1]; 4887 } 4888 MethodArgs[0] = Object; 4889 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4890 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4891 4892 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4893 SourceLocation()); 4894 UsualUnaryConversions(NewFn); 4895 4896 // Once we've built TheCall, all of the expressions are properly 4897 // owned. 4898 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4899 ExprOwningPtr<CXXOperatorCallExpr> 4900 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4901 MethodArgs, NumArgs + 1, 4902 ResultTy, RParenLoc)); 4903 delete [] MethodArgs; 4904 4905 // We may have default arguments. If so, we need to allocate more 4906 // slots in the call for them. 4907 if (NumArgs < NumArgsInProto) 4908 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4909 else if (NumArgs > NumArgsInProto) 4910 NumArgsToCheck = NumArgsInProto; 4911 4912 bool IsError = false; 4913 4914 // Initialize the implicit object parameter. 4915 IsError |= PerformObjectArgumentInitialization(Object, Method); 4916 TheCall->setArg(0, Object); 4917 4918 4919 // Check the argument types. 4920 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4921 Expr *Arg; 4922 if (i < NumArgs) { 4923 Arg = Args[i]; 4924 4925 // Pass the argument. 4926 QualType ProtoArgType = Proto->getArgType(i); 4927 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4928 } else { 4929 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 4930 } 4931 4932 TheCall->setArg(i + 1, Arg); 4933 } 4934 4935 // If this is a variadic call, handle args passed through "...". 4936 if (Proto->isVariadic()) { 4937 // Promote the arguments (C99 6.5.2.2p7). 4938 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4939 Expr *Arg = Args[i]; 4940 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4941 TheCall->setArg(i + 1, Arg); 4942 } 4943 } 4944 4945 if (IsError) return true; 4946 4947 if (CheckFunctionCall(Method, TheCall.get())) 4948 return true; 4949 4950 return MaybeBindToTemporary(TheCall.release()).release(); 4951} 4952 4953/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4954/// (if one exists), where @c Base is an expression of class type and 4955/// @c Member is the name of the member we're trying to find. 4956Sema::OwningExprResult 4957Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 4958 Expr *Base = static_cast<Expr *>(BaseIn.get()); 4959 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4960 4961 // C++ [over.ref]p1: 4962 // 4963 // [...] An expression x->m is interpreted as (x.operator->())->m 4964 // for a class object x of type T if T::operator->() exists and if 4965 // the operator is selected as the best match function by the 4966 // overload resolution mechanism (13.3). 4967 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4968 OverloadCandidateSet CandidateSet; 4969 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 4970 4971 LookupResult R = LookupQualifiedName(BaseRecord->getDecl(), OpName, 4972 LookupOrdinaryName); 4973 4974 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 4975 Oper != OperEnd; ++Oper) 4976 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4977 /*SuppressUserConversions=*/false); 4978 4979 // Perform overload resolution. 4980 OverloadCandidateSet::iterator Best; 4981 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4982 case OR_Success: 4983 // Overload resolution succeeded; we'll build the call below. 4984 break; 4985 4986 case OR_No_Viable_Function: 4987 if (CandidateSet.empty()) 4988 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4989 << Base->getType() << Base->getSourceRange(); 4990 else 4991 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4992 << "operator->" << Base->getSourceRange(); 4993 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4994 return ExprError(); 4995 4996 case OR_Ambiguous: 4997 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4998 << "->" << Base->getSourceRange(); 4999 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5000 return ExprError(); 5001 5002 case OR_Deleted: 5003 Diag(OpLoc, diag::err_ovl_deleted_oper) 5004 << Best->Function->isDeleted() 5005 << "->" << Base->getSourceRange(); 5006 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5007 return ExprError(); 5008 } 5009 5010 // Convert the object parameter. 5011 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5012 if (PerformObjectArgumentInitialization(Base, Method)) 5013 return ExprError(); 5014 5015 // No concerns about early exits now. 5016 BaseIn.release(); 5017 5018 // Build the operator call. 5019 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5020 SourceLocation()); 5021 UsualUnaryConversions(FnExpr); 5022 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 5023 Method->getResultType().getNonReferenceType(), 5024 OpLoc); 5025 return Owned(Base); 5026} 5027 5028/// FixOverloadedFunctionReference - E is an expression that refers to 5029/// a C++ overloaded function (possibly with some parentheses and 5030/// perhaps a '&' around it). We have resolved the overloaded function 5031/// to the function declaration Fn, so patch up the expression E to 5032/// refer (possibly indirectly) to Fn. 5033void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5034 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5035 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5036 E->setType(PE->getSubExpr()->getType()); 5037 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5038 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5039 "Can only take the address of an overloaded function"); 5040 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5041 if (Method->isStatic()) { 5042 // Do nothing: static member functions aren't any different 5043 // from non-member functions. 5044 } else if (QualifiedDeclRefExpr *DRE 5045 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 5046 // We have taken the address of a pointer to member 5047 // function. Perform the computation here so that we get the 5048 // appropriate pointer to member type. 5049 DRE->setDecl(Fn); 5050 DRE->setType(Fn->getType()); 5051 QualType ClassType 5052 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5053 E->setType(Context.getMemberPointerType(Fn->getType(), 5054 ClassType.getTypePtr())); 5055 return; 5056 } 5057 } 5058 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5059 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 5060 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5061 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5062 isa<FunctionTemplateDecl>(DR->getDecl())) && 5063 "Expected overloaded function or function template"); 5064 DR->setDecl(Fn); 5065 E->setType(Fn->getType()); 5066 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5067 MemExpr->setMemberDecl(Fn); 5068 E->setType(Fn->getType()); 5069 } else { 5070 assert(false && "Invalid reference to overloaded function"); 5071 } 5072} 5073 5074} // end namespace clang 5075