SemaOverload.cpp revision b9aa6b214c8fbc3e081dde575eef1f0913d48bdc
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 Qualifiers Quals = CanonFromPointee.getQualifiers(); 860 861 // Exact qualifier match -> return the pointer type we're converting to. 862 if (CanonToPointee.getQualifiers() == Quals) { 863 // ToType is exactly what we need. Return it. 864 if (!ToType.isNull()) 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( 874 Context.getQualifiedType(CanonToPointee.getUnqualifiedType(), Quals)); 875} 876 877static bool isNullPointerConstantForConversion(Expr *Expr, 878 bool InOverloadResolution, 879 ASTContext &Context) { 880 // Handle value-dependent integral null pointer constants correctly. 881 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 882 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 883 Expr->getType()->isIntegralType()) 884 return !InOverloadResolution; 885 886 return Expr->isNullPointerConstant(Context); 887} 888 889/// IsPointerConversion - Determines whether the conversion of the 890/// expression From, which has the (possibly adjusted) type FromType, 891/// can be converted to the type ToType via a pointer conversion (C++ 892/// 4.10). If so, returns true and places the converted type (that 893/// might differ from ToType in its cv-qualifiers at some level) into 894/// ConvertedType. 895/// 896/// This routine also supports conversions to and from block pointers 897/// and conversions with Objective-C's 'id', 'id<protocols...>', and 898/// pointers to interfaces. FIXME: Once we've determined the 899/// appropriate overloading rules for Objective-C, we may want to 900/// split the Objective-C checks into a different routine; however, 901/// GCC seems to consider all of these conversions to be pointer 902/// conversions, so for now they live here. IncompatibleObjC will be 903/// set if the conversion is an allowed Objective-C conversion that 904/// should result in a warning. 905bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 906 bool InOverloadResolution, 907 QualType& ConvertedType, 908 bool &IncompatibleObjC) { 909 IncompatibleObjC = false; 910 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 911 return true; 912 913 // Conversion from a null pointer constant to any Objective-C pointer type. 914 if (ToType->isObjCObjectPointerType() && 915 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 916 ConvertedType = ToType; 917 return true; 918 } 919 920 // Blocks: Block pointers can be converted to void*. 921 if (FromType->isBlockPointerType() && ToType->isPointerType() && 922 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 923 ConvertedType = ToType; 924 return true; 925 } 926 // Blocks: A null pointer constant can be converted to a block 927 // pointer type. 928 if (ToType->isBlockPointerType() && 929 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 930 ConvertedType = ToType; 931 return true; 932 } 933 934 // If the left-hand-side is nullptr_t, the right side can be a null 935 // pointer constant. 936 if (ToType->isNullPtrType() && 937 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 938 ConvertedType = ToType; 939 return true; 940 } 941 942 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 943 if (!ToTypePtr) 944 return false; 945 946 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 947 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 948 ConvertedType = ToType; 949 return true; 950 } 951 952 // Beyond this point, both types need to be pointers. 953 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 954 if (!FromTypePtr) 955 return false; 956 957 QualType FromPointeeType = FromTypePtr->getPointeeType(); 958 QualType ToPointeeType = ToTypePtr->getPointeeType(); 959 960 // An rvalue of type "pointer to cv T," where T is an object type, 961 // can be converted to an rvalue of type "pointer to cv void" (C++ 962 // 4.10p2). 963 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 964 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 965 ToPointeeType, 966 ToType, Context); 967 return true; 968 } 969 970 // When we're overloading in C, we allow a special kind of pointer 971 // conversion for compatible-but-not-identical pointee types. 972 if (!getLangOptions().CPlusPlus && 973 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 974 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 975 ToPointeeType, 976 ToType, Context); 977 return true; 978 } 979 980 // C++ [conv.ptr]p3: 981 // 982 // An rvalue of type "pointer to cv D," where D is a class type, 983 // can be converted to an rvalue of type "pointer to cv B," where 984 // B is a base class (clause 10) of D. If B is an inaccessible 985 // (clause 11) or ambiguous (10.2) base class of D, a program that 986 // necessitates this conversion is ill-formed. The result of the 987 // conversion is a pointer to the base class sub-object of the 988 // derived class object. The null pointer value is converted to 989 // the null pointer value of the destination type. 990 // 991 // Note that we do not check for ambiguity or inaccessibility 992 // here. That is handled by CheckPointerConversion. 993 if (getLangOptions().CPlusPlus && 994 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 995 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 996 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 997 ToPointeeType, 998 ToType, Context); 999 return true; 1000 } 1001 1002 return false; 1003} 1004 1005/// isObjCPointerConversion - Determines whether this is an 1006/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1007/// with the same arguments and return values. 1008bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1009 QualType& ConvertedType, 1010 bool &IncompatibleObjC) { 1011 if (!getLangOptions().ObjC1) 1012 return false; 1013 1014 // First, we handle all conversions on ObjC object pointer types. 1015 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1016 const ObjCObjectPointerType *FromObjCPtr = 1017 FromType->getAs<ObjCObjectPointerType>(); 1018 1019 if (ToObjCPtr && FromObjCPtr) { 1020 // Objective C++: We're able to convert between "id" or "Class" and a 1021 // pointer to any interface (in both directions). 1022 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1023 ConvertedType = ToType; 1024 return true; 1025 } 1026 // Conversions with Objective-C's id<...>. 1027 if ((FromObjCPtr->isObjCQualifiedIdType() || 1028 ToObjCPtr->isObjCQualifiedIdType()) && 1029 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1030 /*compare=*/false)) { 1031 ConvertedType = ToType; 1032 return true; 1033 } 1034 // Objective C++: We're able to convert from a pointer to an 1035 // interface to a pointer to a different interface. 1036 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1037 ConvertedType = ToType; 1038 return true; 1039 } 1040 1041 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1042 // Okay: this is some kind of implicit downcast of Objective-C 1043 // interfaces, which is permitted. However, we're going to 1044 // complain about it. 1045 IncompatibleObjC = true; 1046 ConvertedType = FromType; 1047 return true; 1048 } 1049 } 1050 // Beyond this point, both types need to be C pointers or block pointers. 1051 QualType ToPointeeType; 1052 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1053 ToPointeeType = ToCPtr->getPointeeType(); 1054 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1055 ToPointeeType = ToBlockPtr->getPointeeType(); 1056 else 1057 return false; 1058 1059 QualType FromPointeeType; 1060 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1061 FromPointeeType = FromCPtr->getPointeeType(); 1062 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1063 FromPointeeType = FromBlockPtr->getPointeeType(); 1064 else 1065 return false; 1066 1067 // If we have pointers to pointers, recursively check whether this 1068 // is an Objective-C conversion. 1069 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1070 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1071 IncompatibleObjC)) { 1072 // We always complain about this conversion. 1073 IncompatibleObjC = true; 1074 ConvertedType = ToType; 1075 return true; 1076 } 1077 // If we have pointers to functions or blocks, check whether the only 1078 // differences in the argument and result types are in Objective-C 1079 // pointer conversions. If so, we permit the conversion (but 1080 // complain about it). 1081 const FunctionProtoType *FromFunctionType 1082 = FromPointeeType->getAs<FunctionProtoType>(); 1083 const FunctionProtoType *ToFunctionType 1084 = ToPointeeType->getAs<FunctionProtoType>(); 1085 if (FromFunctionType && ToFunctionType) { 1086 // If the function types are exactly the same, this isn't an 1087 // Objective-C pointer conversion. 1088 if (Context.getCanonicalType(FromPointeeType) 1089 == Context.getCanonicalType(ToPointeeType)) 1090 return false; 1091 1092 // Perform the quick checks that will tell us whether these 1093 // function types are obviously different. 1094 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1095 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1096 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1097 return false; 1098 1099 bool HasObjCConversion = false; 1100 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1101 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1102 // Okay, the types match exactly. Nothing to do. 1103 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1104 ToFunctionType->getResultType(), 1105 ConvertedType, IncompatibleObjC)) { 1106 // Okay, we have an Objective-C pointer conversion. 1107 HasObjCConversion = true; 1108 } else { 1109 // Function types are too different. Abort. 1110 return false; 1111 } 1112 1113 // Check argument types. 1114 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1115 ArgIdx != NumArgs; ++ArgIdx) { 1116 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1117 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1118 if (Context.getCanonicalType(FromArgType) 1119 == Context.getCanonicalType(ToArgType)) { 1120 // Okay, the types match exactly. Nothing to do. 1121 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1122 ConvertedType, IncompatibleObjC)) { 1123 // Okay, we have an Objective-C pointer conversion. 1124 HasObjCConversion = true; 1125 } else { 1126 // Argument types are too different. Abort. 1127 return false; 1128 } 1129 } 1130 1131 if (HasObjCConversion) { 1132 // We had an Objective-C conversion. Allow this pointer 1133 // conversion, but complain about it. 1134 ConvertedType = ToType; 1135 IncompatibleObjC = true; 1136 return true; 1137 } 1138 } 1139 1140 return false; 1141} 1142 1143/// CheckPointerConversion - Check the pointer conversion from the 1144/// expression From to the type ToType. This routine checks for 1145/// ambiguous or inaccessible derived-to-base pointer 1146/// conversions for which IsPointerConversion has already returned 1147/// true. It returns true and produces a diagnostic if there was an 1148/// error, or returns false otherwise. 1149bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1150 CastExpr::CastKind &Kind) { 1151 QualType FromType = From->getType(); 1152 1153 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1154 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1155 QualType FromPointeeType = FromPtrType->getPointeeType(), 1156 ToPointeeType = ToPtrType->getPointeeType(); 1157 1158 if (FromPointeeType->isRecordType() && 1159 ToPointeeType->isRecordType()) { 1160 // We must have a derived-to-base conversion. Check an 1161 // ambiguous or inaccessible conversion. 1162 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1163 From->getExprLoc(), 1164 From->getSourceRange())) 1165 return true; 1166 1167 // The conversion was successful. 1168 Kind = CastExpr::CK_DerivedToBase; 1169 } 1170 } 1171 if (const ObjCObjectPointerType *FromPtrType = 1172 FromType->getAs<ObjCObjectPointerType>()) 1173 if (const ObjCObjectPointerType *ToPtrType = 1174 ToType->getAs<ObjCObjectPointerType>()) { 1175 // Objective-C++ conversions are always okay. 1176 // FIXME: We should have a different class of conversions for the 1177 // Objective-C++ implicit conversions. 1178 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1179 return false; 1180 1181 } 1182 return false; 1183} 1184 1185/// IsMemberPointerConversion - Determines whether the conversion of the 1186/// expression From, which has the (possibly adjusted) type FromType, can be 1187/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1188/// If so, returns true and places the converted type (that might differ from 1189/// ToType in its cv-qualifiers at some level) into ConvertedType. 1190bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1191 QualType ToType, QualType &ConvertedType) { 1192 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1193 if (!ToTypePtr) 1194 return false; 1195 1196 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1197 if (From->isNullPointerConstant(Context)) { 1198 ConvertedType = ToType; 1199 return true; 1200 } 1201 1202 // Otherwise, both types have to be member pointers. 1203 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1204 if (!FromTypePtr) 1205 return false; 1206 1207 // A pointer to member of B can be converted to a pointer to member of D, 1208 // where D is derived from B (C++ 4.11p2). 1209 QualType FromClass(FromTypePtr->getClass(), 0); 1210 QualType ToClass(ToTypePtr->getClass(), 0); 1211 // FIXME: What happens when these are dependent? Is this function even called? 1212 1213 if (IsDerivedFrom(ToClass, FromClass)) { 1214 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1215 ToClass.getTypePtr()); 1216 return true; 1217 } 1218 1219 return false; 1220} 1221 1222/// CheckMemberPointerConversion - Check the member pointer conversion from the 1223/// expression From to the type ToType. This routine checks for ambiguous or 1224/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1225/// for which IsMemberPointerConversion has already returned true. It returns 1226/// true and produces a diagnostic if there was an error, or returns false 1227/// otherwise. 1228bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1229 CastExpr::CastKind &Kind) { 1230 QualType FromType = From->getType(); 1231 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1232 if (!FromPtrType) { 1233 // This must be a null pointer to member pointer conversion 1234 assert(From->isNullPointerConstant(Context) && 1235 "Expr must be null pointer constant!"); 1236 Kind = CastExpr::CK_NullToMemberPointer; 1237 return false; 1238 } 1239 1240 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1241 assert(ToPtrType && "No member pointer cast has a target type " 1242 "that is not a member pointer."); 1243 1244 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1245 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1246 1247 // FIXME: What about dependent types? 1248 assert(FromClass->isRecordType() && "Pointer into non-class."); 1249 assert(ToClass->isRecordType() && "Pointer into non-class."); 1250 1251 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1252 /*DetectVirtual=*/true); 1253 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1254 assert(DerivationOkay && 1255 "Should not have been called if derivation isn't OK."); 1256 (void)DerivationOkay; 1257 1258 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1259 getUnqualifiedType())) { 1260 // Derivation is ambiguous. Redo the check to find the exact paths. 1261 Paths.clear(); 1262 Paths.setRecordingPaths(true); 1263 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1264 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1265 (void)StillOkay; 1266 1267 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1268 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1269 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1270 return true; 1271 } 1272 1273 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1274 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1275 << FromClass << ToClass << QualType(VBase, 0) 1276 << From->getSourceRange(); 1277 return true; 1278 } 1279 1280 // Must be a base to derived member conversion. 1281 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1282 return false; 1283} 1284 1285/// IsQualificationConversion - Determines whether the conversion from 1286/// an rvalue of type FromType to ToType is a qualification conversion 1287/// (C++ 4.4). 1288bool 1289Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1290 FromType = Context.getCanonicalType(FromType); 1291 ToType = Context.getCanonicalType(ToType); 1292 1293 // If FromType and ToType are the same type, this is not a 1294 // qualification conversion. 1295 if (FromType == ToType) 1296 return false; 1297 1298 // (C++ 4.4p4): 1299 // A conversion can add cv-qualifiers at levels other than the first 1300 // in multi-level pointers, subject to the following rules: [...] 1301 bool PreviousToQualsIncludeConst = true; 1302 bool UnwrappedAnyPointer = false; 1303 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1304 // Within each iteration of the loop, we check the qualifiers to 1305 // determine if this still looks like a qualification 1306 // conversion. Then, if all is well, we unwrap one more level of 1307 // pointers or pointers-to-members and do it all again 1308 // until there are no more pointers or pointers-to-members left to 1309 // unwrap. 1310 UnwrappedAnyPointer = true; 1311 1312 // -- for every j > 0, if const is in cv 1,j then const is in cv 1313 // 2,j, and similarly for volatile. 1314 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1315 return false; 1316 1317 // -- if the cv 1,j and cv 2,j are different, then const is in 1318 // every cv for 0 < k < j. 1319 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1320 && !PreviousToQualsIncludeConst) 1321 return false; 1322 1323 // Keep track of whether all prior cv-qualifiers in the "to" type 1324 // include const. 1325 PreviousToQualsIncludeConst 1326 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1327 } 1328 1329 // We are left with FromType and ToType being the pointee types 1330 // after unwrapping the original FromType and ToType the same number 1331 // of types. If we unwrapped any pointers, and if FromType and 1332 // ToType have the same unqualified type (since we checked 1333 // qualifiers above), then this is a qualification conversion. 1334 return UnwrappedAnyPointer && 1335 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1336} 1337 1338/// \brief Given a function template or function, extract the function template 1339/// declaration (if any) and the underlying function declaration. 1340template<typename T> 1341static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1342 FunctionTemplateDecl *&FunctionTemplate) { 1343 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1344 if (FunctionTemplate) 1345 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1346 else 1347 Function = cast<T>(Orig); 1348} 1349 1350/// Determines whether there is a user-defined conversion sequence 1351/// (C++ [over.ics.user]) that converts expression From to the type 1352/// ToType. If such a conversion exists, User will contain the 1353/// user-defined conversion sequence that performs such a conversion 1354/// and this routine will return true. Otherwise, this routine returns 1355/// false and User is unspecified. 1356/// 1357/// \param AllowConversionFunctions true if the conversion should 1358/// consider conversion functions at all. If false, only constructors 1359/// will be considered. 1360/// 1361/// \param AllowExplicit true if the conversion should consider C++0x 1362/// "explicit" conversion functions as well as non-explicit conversion 1363/// functions (C++0x [class.conv.fct]p2). 1364/// 1365/// \param ForceRValue true if the expression should be treated as an rvalue 1366/// for overload resolution. 1367Sema::OverloadingResult Sema::IsUserDefinedConversion( 1368 Expr *From, QualType ToType, 1369 UserDefinedConversionSequence& User, 1370 OverloadCandidateSet& CandidateSet, 1371 bool AllowConversionFunctions, 1372 bool AllowExplicit, bool ForceRValue) { 1373 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1374 if (CXXRecordDecl *ToRecordDecl 1375 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1376 // C++ [over.match.ctor]p1: 1377 // When objects of class type are direct-initialized (8.5), or 1378 // copy-initialized from an expression of the same or a 1379 // derived class type (8.5), overload resolution selects the 1380 // constructor. [...] For copy-initialization, the candidate 1381 // functions are all the converting constructors (12.3.1) of 1382 // that class. The argument list is the expression-list within 1383 // the parentheses of the initializer. 1384 DeclarationName ConstructorName 1385 = Context.DeclarationNames.getCXXConstructorName( 1386 Context.getCanonicalType(ToType).getUnqualifiedType()); 1387 DeclContext::lookup_iterator Con, ConEnd; 1388 for (llvm::tie(Con, ConEnd) 1389 = ToRecordDecl->lookup(ConstructorName); 1390 Con != ConEnd; ++Con) { 1391 // Find the constructor (which may be a template). 1392 CXXConstructorDecl *Constructor = 0; 1393 FunctionTemplateDecl *ConstructorTmpl 1394 = dyn_cast<FunctionTemplateDecl>(*Con); 1395 if (ConstructorTmpl) 1396 Constructor 1397 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1398 else 1399 Constructor = cast<CXXConstructorDecl>(*Con); 1400 1401 if (!Constructor->isInvalidDecl() && 1402 Constructor->isConvertingConstructor(AllowExplicit)) { 1403 if (ConstructorTmpl) 1404 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1405 1, CandidateSet, 1406 /*SuppressUserConversions=*/true, 1407 ForceRValue); 1408 else 1409 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1410 /*SuppressUserConversions=*/true, ForceRValue); 1411 } 1412 } 1413 } 1414 } 1415 1416 if (!AllowConversionFunctions) { 1417 // Don't allow any conversion functions to enter the overload set. 1418 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1419 PDiag(0) 1420 << From->getSourceRange())) { 1421 // No conversion functions from incomplete types. 1422 } else if (const RecordType *FromRecordType 1423 = From->getType()->getAs<RecordType>()) { 1424 if (CXXRecordDecl *FromRecordDecl 1425 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1426 // Add all of the conversion functions as candidates. 1427 OverloadedFunctionDecl *Conversions 1428 = FromRecordDecl->getVisibleConversionFunctions(); 1429 for (OverloadedFunctionDecl::function_iterator Func 1430 = Conversions->function_begin(); 1431 Func != Conversions->function_end(); ++Func) { 1432 CXXConversionDecl *Conv; 1433 FunctionTemplateDecl *ConvTemplate; 1434 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1435 if (ConvTemplate) 1436 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1437 else 1438 Conv = dyn_cast<CXXConversionDecl>(*Func); 1439 1440 if (AllowExplicit || !Conv->isExplicit()) { 1441 if (ConvTemplate) 1442 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1443 CandidateSet); 1444 else 1445 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1446 } 1447 } 1448 } 1449 } 1450 1451 OverloadCandidateSet::iterator Best; 1452 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1453 case OR_Success: 1454 // Record the standard conversion we used and the conversion function. 1455 if (CXXConstructorDecl *Constructor 1456 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1457 // C++ [over.ics.user]p1: 1458 // If the user-defined conversion is specified by a 1459 // constructor (12.3.1), the initial standard conversion 1460 // sequence converts the source type to the type required by 1461 // the argument of the constructor. 1462 // 1463 // FIXME: What about ellipsis conversions? 1464 QualType ThisType = Constructor->getThisType(Context); 1465 User.Before = Best->Conversions[0].Standard; 1466 User.ConversionFunction = Constructor; 1467 User.After.setAsIdentityConversion(); 1468 User.After.FromTypePtr 1469 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1470 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1471 return OR_Success; 1472 } else if (CXXConversionDecl *Conversion 1473 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1474 // C++ [over.ics.user]p1: 1475 // 1476 // [...] If the user-defined conversion is specified by a 1477 // conversion function (12.3.2), the initial standard 1478 // conversion sequence converts the source type to the 1479 // implicit object parameter of the conversion function. 1480 User.Before = Best->Conversions[0].Standard; 1481 User.ConversionFunction = Conversion; 1482 1483 // C++ [over.ics.user]p2: 1484 // The second standard conversion sequence converts the 1485 // result of the user-defined conversion to the target type 1486 // for the sequence. Since an implicit conversion sequence 1487 // is an initialization, the special rules for 1488 // initialization by user-defined conversion apply when 1489 // selecting the best user-defined conversion for a 1490 // user-defined conversion sequence (see 13.3.3 and 1491 // 13.3.3.1). 1492 User.After = Best->FinalConversion; 1493 return OR_Success; 1494 } else { 1495 assert(false && "Not a constructor or conversion function?"); 1496 return OR_No_Viable_Function; 1497 } 1498 1499 case OR_No_Viable_Function: 1500 return OR_No_Viable_Function; 1501 case OR_Deleted: 1502 // No conversion here! We're done. 1503 return OR_Deleted; 1504 1505 case OR_Ambiguous: 1506 // FIXME: See C++ [over.best.ics]p10 for the handling of 1507 // ambiguous conversion sequences. 1508 return OR_Ambiguous; 1509 } 1510 1511 return OR_No_Viable_Function; 1512} 1513 1514bool 1515Sema::DiagnoseAmbiguousUserDefinedConversion(Expr *From, QualType ToType) { 1516 ImplicitConversionSequence ICS; 1517 OverloadCandidateSet CandidateSet; 1518 OverloadingResult OvResult = 1519 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1520 CandidateSet, true, false, false); 1521 if (OvResult != OR_Ambiguous) 1522 return false; 1523 Diag(From->getSourceRange().getBegin(), 1524 diag::err_typecheck_ambiguous_condition) 1525 << From->getType() << ToType << From->getSourceRange(); 1526 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1527 return true; 1528} 1529 1530/// CompareImplicitConversionSequences - Compare two implicit 1531/// conversion sequences to determine whether one is better than the 1532/// other or if they are indistinguishable (C++ 13.3.3.2). 1533ImplicitConversionSequence::CompareKind 1534Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1535 const ImplicitConversionSequence& ICS2) 1536{ 1537 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1538 // conversion sequences (as defined in 13.3.3.1) 1539 // -- a standard conversion sequence (13.3.3.1.1) is a better 1540 // conversion sequence than a user-defined conversion sequence or 1541 // an ellipsis conversion sequence, and 1542 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1543 // conversion sequence than an ellipsis conversion sequence 1544 // (13.3.3.1.3). 1545 // 1546 if (ICS1.ConversionKind < ICS2.ConversionKind) 1547 return ImplicitConversionSequence::Better; 1548 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1549 return ImplicitConversionSequence::Worse; 1550 1551 // Two implicit conversion sequences of the same form are 1552 // indistinguishable conversion sequences unless one of the 1553 // following rules apply: (C++ 13.3.3.2p3): 1554 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1555 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1556 else if (ICS1.ConversionKind == 1557 ImplicitConversionSequence::UserDefinedConversion) { 1558 // User-defined conversion sequence U1 is a better conversion 1559 // sequence than another user-defined conversion sequence U2 if 1560 // they contain the same user-defined conversion function or 1561 // constructor and if the second standard conversion sequence of 1562 // U1 is better than the second standard conversion sequence of 1563 // U2 (C++ 13.3.3.2p3). 1564 if (ICS1.UserDefined.ConversionFunction == 1565 ICS2.UserDefined.ConversionFunction) 1566 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1567 ICS2.UserDefined.After); 1568 } 1569 1570 return ImplicitConversionSequence::Indistinguishable; 1571} 1572 1573/// CompareStandardConversionSequences - Compare two standard 1574/// conversion sequences to determine whether one is better than the 1575/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1576ImplicitConversionSequence::CompareKind 1577Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1578 const StandardConversionSequence& SCS2) 1579{ 1580 // Standard conversion sequence S1 is a better conversion sequence 1581 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1582 1583 // -- S1 is a proper subsequence of S2 (comparing the conversion 1584 // sequences in the canonical form defined by 13.3.3.1.1, 1585 // excluding any Lvalue Transformation; the identity conversion 1586 // sequence is considered to be a subsequence of any 1587 // non-identity conversion sequence) or, if not that, 1588 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1589 // Neither is a proper subsequence of the other. Do nothing. 1590 ; 1591 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1592 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1593 (SCS1.Second == ICK_Identity && 1594 SCS1.Third == ICK_Identity)) 1595 // SCS1 is a proper subsequence of SCS2. 1596 return ImplicitConversionSequence::Better; 1597 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1598 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1599 (SCS2.Second == ICK_Identity && 1600 SCS2.Third == ICK_Identity)) 1601 // SCS2 is a proper subsequence of SCS1. 1602 return ImplicitConversionSequence::Worse; 1603 1604 // -- the rank of S1 is better than the rank of S2 (by the rules 1605 // defined below), or, if not that, 1606 ImplicitConversionRank Rank1 = SCS1.getRank(); 1607 ImplicitConversionRank Rank2 = SCS2.getRank(); 1608 if (Rank1 < Rank2) 1609 return ImplicitConversionSequence::Better; 1610 else if (Rank2 < Rank1) 1611 return ImplicitConversionSequence::Worse; 1612 1613 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1614 // are indistinguishable unless one of the following rules 1615 // applies: 1616 1617 // A conversion that is not a conversion of a pointer, or 1618 // pointer to member, to bool is better than another conversion 1619 // that is such a conversion. 1620 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1621 return SCS2.isPointerConversionToBool() 1622 ? ImplicitConversionSequence::Better 1623 : ImplicitConversionSequence::Worse; 1624 1625 // C++ [over.ics.rank]p4b2: 1626 // 1627 // If class B is derived directly or indirectly from class A, 1628 // conversion of B* to A* is better than conversion of B* to 1629 // void*, and conversion of A* to void* is better than conversion 1630 // of B* to void*. 1631 bool SCS1ConvertsToVoid 1632 = SCS1.isPointerConversionToVoidPointer(Context); 1633 bool SCS2ConvertsToVoid 1634 = SCS2.isPointerConversionToVoidPointer(Context); 1635 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1636 // Exactly one of the conversion sequences is a conversion to 1637 // a void pointer; it's the worse conversion. 1638 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1639 : ImplicitConversionSequence::Worse; 1640 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1641 // Neither conversion sequence converts to a void pointer; compare 1642 // their derived-to-base conversions. 1643 if (ImplicitConversionSequence::CompareKind DerivedCK 1644 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1645 return DerivedCK; 1646 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1647 // Both conversion sequences are conversions to void 1648 // pointers. Compare the source types to determine if there's an 1649 // inheritance relationship in their sources. 1650 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1651 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1652 1653 // Adjust the types we're converting from via the array-to-pointer 1654 // conversion, if we need to. 1655 if (SCS1.First == ICK_Array_To_Pointer) 1656 FromType1 = Context.getArrayDecayedType(FromType1); 1657 if (SCS2.First == ICK_Array_To_Pointer) 1658 FromType2 = Context.getArrayDecayedType(FromType2); 1659 1660 QualType FromPointee1 1661 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1662 QualType FromPointee2 1663 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1664 1665 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1666 return ImplicitConversionSequence::Better; 1667 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1668 return ImplicitConversionSequence::Worse; 1669 1670 // Objective-C++: If one interface is more specific than the 1671 // other, it is the better one. 1672 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1673 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1674 if (FromIface1 && FromIface1) { 1675 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1676 return ImplicitConversionSequence::Better; 1677 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1678 return ImplicitConversionSequence::Worse; 1679 } 1680 } 1681 1682 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1683 // bullet 3). 1684 if (ImplicitConversionSequence::CompareKind QualCK 1685 = CompareQualificationConversions(SCS1, SCS2)) 1686 return QualCK; 1687 1688 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1689 // C++0x [over.ics.rank]p3b4: 1690 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1691 // implicit object parameter of a non-static member function declared 1692 // without a ref-qualifier, and S1 binds an rvalue reference to an 1693 // rvalue and S2 binds an lvalue reference. 1694 // FIXME: We don't know if we're dealing with the implicit object parameter, 1695 // or if the member function in this case has a ref qualifier. 1696 // (Of course, we don't have ref qualifiers yet.) 1697 if (SCS1.RRefBinding != SCS2.RRefBinding) 1698 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1699 : ImplicitConversionSequence::Worse; 1700 1701 // C++ [over.ics.rank]p3b4: 1702 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1703 // which the references refer are the same type except for 1704 // top-level cv-qualifiers, and the type to which the reference 1705 // initialized by S2 refers is more cv-qualified than the type 1706 // to which the reference initialized by S1 refers. 1707 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1708 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1709 T1 = Context.getCanonicalType(T1); 1710 T2 = Context.getCanonicalType(T2); 1711 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1712 if (T2.isMoreQualifiedThan(T1)) 1713 return ImplicitConversionSequence::Better; 1714 else if (T1.isMoreQualifiedThan(T2)) 1715 return ImplicitConversionSequence::Worse; 1716 } 1717 } 1718 1719 return ImplicitConversionSequence::Indistinguishable; 1720} 1721 1722/// CompareQualificationConversions - Compares two standard conversion 1723/// sequences to determine whether they can be ranked based on their 1724/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1725ImplicitConversionSequence::CompareKind 1726Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1727 const StandardConversionSequence& SCS2) { 1728 // C++ 13.3.3.2p3: 1729 // -- S1 and S2 differ only in their qualification conversion and 1730 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1731 // cv-qualification signature of type T1 is a proper subset of 1732 // the cv-qualification signature of type T2, and S1 is not the 1733 // deprecated string literal array-to-pointer conversion (4.2). 1734 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1735 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1736 return ImplicitConversionSequence::Indistinguishable; 1737 1738 // FIXME: the example in the standard doesn't use a qualification 1739 // conversion (!) 1740 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1741 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1742 T1 = Context.getCanonicalType(T1); 1743 T2 = Context.getCanonicalType(T2); 1744 1745 // If the types are the same, we won't learn anything by unwrapped 1746 // them. 1747 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1748 return ImplicitConversionSequence::Indistinguishable; 1749 1750 ImplicitConversionSequence::CompareKind Result 1751 = ImplicitConversionSequence::Indistinguishable; 1752 while (UnwrapSimilarPointerTypes(T1, T2)) { 1753 // Within each iteration of the loop, we check the qualifiers to 1754 // determine if this still looks like a qualification 1755 // conversion. Then, if all is well, we unwrap one more level of 1756 // pointers or pointers-to-members and do it all again 1757 // until there are no more pointers or pointers-to-members left 1758 // to unwrap. This essentially mimics what 1759 // IsQualificationConversion does, but here we're checking for a 1760 // strict subset of qualifiers. 1761 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1762 // The qualifiers are the same, so this doesn't tell us anything 1763 // about how the sequences rank. 1764 ; 1765 else if (T2.isMoreQualifiedThan(T1)) { 1766 // T1 has fewer qualifiers, so it could be the better sequence. 1767 if (Result == ImplicitConversionSequence::Worse) 1768 // Neither has qualifiers that are a subset of the other's 1769 // qualifiers. 1770 return ImplicitConversionSequence::Indistinguishable; 1771 1772 Result = ImplicitConversionSequence::Better; 1773 } else if (T1.isMoreQualifiedThan(T2)) { 1774 // T2 has fewer qualifiers, so it could be the better sequence. 1775 if (Result == ImplicitConversionSequence::Better) 1776 // Neither has qualifiers that are a subset of the other's 1777 // qualifiers. 1778 return ImplicitConversionSequence::Indistinguishable; 1779 1780 Result = ImplicitConversionSequence::Worse; 1781 } else { 1782 // Qualifiers are disjoint. 1783 return ImplicitConversionSequence::Indistinguishable; 1784 } 1785 1786 // If the types after this point are equivalent, we're done. 1787 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1788 break; 1789 } 1790 1791 // Check that the winning standard conversion sequence isn't using 1792 // the deprecated string literal array to pointer conversion. 1793 switch (Result) { 1794 case ImplicitConversionSequence::Better: 1795 if (SCS1.Deprecated) 1796 Result = ImplicitConversionSequence::Indistinguishable; 1797 break; 1798 1799 case ImplicitConversionSequence::Indistinguishable: 1800 break; 1801 1802 case ImplicitConversionSequence::Worse: 1803 if (SCS2.Deprecated) 1804 Result = ImplicitConversionSequence::Indistinguishable; 1805 break; 1806 } 1807 1808 return Result; 1809} 1810 1811/// CompareDerivedToBaseConversions - Compares two standard conversion 1812/// sequences to determine whether they can be ranked based on their 1813/// various kinds of derived-to-base conversions (C++ 1814/// [over.ics.rank]p4b3). As part of these checks, we also look at 1815/// conversions between Objective-C interface types. 1816ImplicitConversionSequence::CompareKind 1817Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1818 const StandardConversionSequence& SCS2) { 1819 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1820 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1821 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1822 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1823 1824 // Adjust the types we're converting from via the array-to-pointer 1825 // conversion, if we need to. 1826 if (SCS1.First == ICK_Array_To_Pointer) 1827 FromType1 = Context.getArrayDecayedType(FromType1); 1828 if (SCS2.First == ICK_Array_To_Pointer) 1829 FromType2 = Context.getArrayDecayedType(FromType2); 1830 1831 // Canonicalize all of the types. 1832 FromType1 = Context.getCanonicalType(FromType1); 1833 ToType1 = Context.getCanonicalType(ToType1); 1834 FromType2 = Context.getCanonicalType(FromType2); 1835 ToType2 = Context.getCanonicalType(ToType2); 1836 1837 // C++ [over.ics.rank]p4b3: 1838 // 1839 // If class B is derived directly or indirectly from class A and 1840 // class C is derived directly or indirectly from B, 1841 // 1842 // For Objective-C, we let A, B, and C also be Objective-C 1843 // interfaces. 1844 1845 // Compare based on pointer conversions. 1846 if (SCS1.Second == ICK_Pointer_Conversion && 1847 SCS2.Second == ICK_Pointer_Conversion && 1848 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1849 FromType1->isPointerType() && FromType2->isPointerType() && 1850 ToType1->isPointerType() && ToType2->isPointerType()) { 1851 QualType FromPointee1 1852 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1853 QualType ToPointee1 1854 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1855 QualType FromPointee2 1856 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1857 QualType ToPointee2 1858 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1859 1860 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1861 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1862 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1863 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1864 1865 // -- conversion of C* to B* is better than conversion of C* to A*, 1866 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1867 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1868 return ImplicitConversionSequence::Better; 1869 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1870 return ImplicitConversionSequence::Worse; 1871 1872 if (ToIface1 && ToIface2) { 1873 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1874 return ImplicitConversionSequence::Better; 1875 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1876 return ImplicitConversionSequence::Worse; 1877 } 1878 } 1879 1880 // -- conversion of B* to A* is better than conversion of C* to A*, 1881 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1882 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1883 return ImplicitConversionSequence::Better; 1884 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1885 return ImplicitConversionSequence::Worse; 1886 1887 if (FromIface1 && FromIface2) { 1888 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1889 return ImplicitConversionSequence::Better; 1890 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1891 return ImplicitConversionSequence::Worse; 1892 } 1893 } 1894 } 1895 1896 // Compare based on reference bindings. 1897 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1898 SCS1.Second == ICK_Derived_To_Base) { 1899 // -- binding of an expression of type C to a reference of type 1900 // B& is better than binding an expression of type C to a 1901 // reference of type A&, 1902 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1903 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1904 if (IsDerivedFrom(ToType1, ToType2)) 1905 return ImplicitConversionSequence::Better; 1906 else if (IsDerivedFrom(ToType2, ToType1)) 1907 return ImplicitConversionSequence::Worse; 1908 } 1909 1910 // -- binding of an expression of type B to a reference of type 1911 // A& is better than binding an expression of type C to a 1912 // reference of type A&, 1913 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1914 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1915 if (IsDerivedFrom(FromType2, FromType1)) 1916 return ImplicitConversionSequence::Better; 1917 else if (IsDerivedFrom(FromType1, FromType2)) 1918 return ImplicitConversionSequence::Worse; 1919 } 1920 } 1921 1922 1923 // FIXME: conversion of A::* to B::* is better than conversion of 1924 // A::* to C::*, 1925 1926 // FIXME: conversion of B::* to C::* is better than conversion of 1927 // A::* to C::*, and 1928 1929 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1930 SCS1.Second == ICK_Derived_To_Base) { 1931 // -- conversion of C to B is better than conversion of C to A, 1932 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1933 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1934 if (IsDerivedFrom(ToType1, ToType2)) 1935 return ImplicitConversionSequence::Better; 1936 else if (IsDerivedFrom(ToType2, ToType1)) 1937 return ImplicitConversionSequence::Worse; 1938 } 1939 1940 // -- conversion of B to A is better than conversion of C to A. 1941 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1942 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1943 if (IsDerivedFrom(FromType2, FromType1)) 1944 return ImplicitConversionSequence::Better; 1945 else if (IsDerivedFrom(FromType1, FromType2)) 1946 return ImplicitConversionSequence::Worse; 1947 } 1948 } 1949 1950 return ImplicitConversionSequence::Indistinguishable; 1951} 1952 1953/// TryCopyInitialization - Try to copy-initialize a value of type 1954/// ToType from the expression From. Return the implicit conversion 1955/// sequence required to pass this argument, which may be a bad 1956/// conversion sequence (meaning that the argument cannot be passed to 1957/// a parameter of this type). If @p SuppressUserConversions, then we 1958/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1959/// then we treat @p From as an rvalue, even if it is an lvalue. 1960ImplicitConversionSequence 1961Sema::TryCopyInitialization(Expr *From, QualType ToType, 1962 bool SuppressUserConversions, bool ForceRValue, 1963 bool InOverloadResolution) { 1964 if (ToType->isReferenceType()) { 1965 ImplicitConversionSequence ICS; 1966 CheckReferenceInit(From, ToType, 1967 /*FIXME:*/From->getLocStart(), 1968 SuppressUserConversions, 1969 /*AllowExplicit=*/false, 1970 ForceRValue, 1971 &ICS); 1972 return ICS; 1973 } else { 1974 return TryImplicitConversion(From, ToType, 1975 SuppressUserConversions, 1976 /*AllowExplicit=*/false, 1977 ForceRValue, 1978 InOverloadResolution); 1979 } 1980} 1981 1982/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1983/// the expression @p From. Returns true (and emits a diagnostic) if there was 1984/// an error, returns false if the initialization succeeded. Elidable should 1985/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1986/// differently in C++0x for this case. 1987bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1988 const char* Flavor, bool Elidable) { 1989 if (!getLangOptions().CPlusPlus) { 1990 // In C, argument passing is the same as performing an assignment. 1991 QualType FromType = From->getType(); 1992 1993 AssignConvertType ConvTy = 1994 CheckSingleAssignmentConstraints(ToType, From); 1995 if (ConvTy != Compatible && 1996 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1997 ConvTy = Compatible; 1998 1999 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2000 FromType, From, Flavor); 2001 } 2002 2003 if (ToType->isReferenceType()) 2004 return CheckReferenceInit(From, ToType, 2005 /*FIXME:*/From->getLocStart(), 2006 /*SuppressUserConversions=*/false, 2007 /*AllowExplicit=*/false, 2008 /*ForceRValue=*/false); 2009 2010 if (!PerformImplicitConversion(From, ToType, Flavor, 2011 /*AllowExplicit=*/false, Elidable)) 2012 return false; 2013 if (!DiagnoseAmbiguousUserDefinedConversion(From, ToType)) 2014 return Diag(From->getSourceRange().getBegin(), 2015 diag::err_typecheck_convert_incompatible) 2016 << ToType << From->getType() << Flavor << From->getSourceRange(); 2017 return true; 2018} 2019 2020/// TryObjectArgumentInitialization - Try to initialize the object 2021/// parameter of the given member function (@c Method) from the 2022/// expression @p From. 2023ImplicitConversionSequence 2024Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2025 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2026 QualType ImplicitParamType 2027 = Context.getCVRQualifiedType(ClassType, Method->getTypeQualifiers()); 2028 2029 // Set up the conversion sequence as a "bad" conversion, to allow us 2030 // to exit early. 2031 ImplicitConversionSequence ICS; 2032 ICS.Standard.setAsIdentityConversion(); 2033 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2034 2035 // We need to have an object of class type. 2036 QualType FromType = From->getType(); 2037 if (const PointerType *PT = FromType->getAs<PointerType>()) 2038 FromType = PT->getPointeeType(); 2039 2040 assert(FromType->isRecordType()); 2041 2042 // The implicit object parmeter is has the type "reference to cv X", 2043 // where X is the class of which the function is a member 2044 // (C++ [over.match.funcs]p4). However, when finding an implicit 2045 // conversion sequence for the argument, we are not allowed to 2046 // create temporaries or perform user-defined conversions 2047 // (C++ [over.match.funcs]p5). We perform a simplified version of 2048 // reference binding here, that allows class rvalues to bind to 2049 // non-constant references. 2050 2051 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2052 // with the implicit object parameter (C++ [over.match.funcs]p5). 2053 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2054 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 2055 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 2056 return ICS; 2057 2058 // Check that we have either the same type or a derived type. It 2059 // affects the conversion rank. 2060 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2061 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2062 ICS.Standard.Second = ICK_Identity; 2063 else if (IsDerivedFrom(FromType, ClassType)) 2064 ICS.Standard.Second = ICK_Derived_To_Base; 2065 else 2066 return ICS; 2067 2068 // Success. Mark this as a reference binding. 2069 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2070 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2071 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2072 ICS.Standard.ReferenceBinding = true; 2073 ICS.Standard.DirectBinding = true; 2074 ICS.Standard.RRefBinding = false; 2075 return ICS; 2076} 2077 2078/// PerformObjectArgumentInitialization - Perform initialization of 2079/// the implicit object parameter for the given Method with the given 2080/// expression. 2081bool 2082Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2083 QualType FromRecordType, DestType; 2084 QualType ImplicitParamRecordType = 2085 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2086 2087 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2088 FromRecordType = PT->getPointeeType(); 2089 DestType = Method->getThisType(Context); 2090 } else { 2091 FromRecordType = From->getType(); 2092 DestType = ImplicitParamRecordType; 2093 } 2094 2095 ImplicitConversionSequence ICS 2096 = TryObjectArgumentInitialization(From, Method); 2097 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2098 return Diag(From->getSourceRange().getBegin(), 2099 diag::err_implicit_object_parameter_init) 2100 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2101 2102 if (ICS.Standard.Second == ICK_Derived_To_Base && 2103 CheckDerivedToBaseConversion(FromRecordType, 2104 ImplicitParamRecordType, 2105 From->getSourceRange().getBegin(), 2106 From->getSourceRange())) 2107 return true; 2108 2109 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2110 /*isLvalue=*/true); 2111 return false; 2112} 2113 2114/// TryContextuallyConvertToBool - Attempt to contextually convert the 2115/// expression From to bool (C++0x [conv]p3). 2116ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2117 return TryImplicitConversion(From, Context.BoolTy, 2118 // FIXME: Are these flags correct? 2119 /*SuppressUserConversions=*/false, 2120 /*AllowExplicit=*/true, 2121 /*ForceRValue=*/false, 2122 /*InOverloadResolution=*/false); 2123} 2124 2125/// PerformContextuallyConvertToBool - Perform a contextual conversion 2126/// of the expression From to bool (C++0x [conv]p3). 2127bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2128 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2129 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2130 return false; 2131 2132 if (!DiagnoseAmbiguousUserDefinedConversion(From, Context.BoolTy)) 2133 return Diag(From->getSourceRange().getBegin(), 2134 diag::err_typecheck_bool_condition) 2135 << From->getType() << From->getSourceRange(); 2136 return true; 2137} 2138 2139/// AddOverloadCandidate - Adds the given function to the set of 2140/// candidate functions, using the given function call arguments. If 2141/// @p SuppressUserConversions, then don't allow user-defined 2142/// conversions via constructors or conversion operators. 2143/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2144/// hacky way to implement the overloading rules for elidable copy 2145/// initialization in C++0x (C++0x 12.8p15). 2146/// 2147/// \para PartialOverloading true if we are performing "partial" overloading 2148/// based on an incomplete set of function arguments. This feature is used by 2149/// code completion. 2150void 2151Sema::AddOverloadCandidate(FunctionDecl *Function, 2152 Expr **Args, unsigned NumArgs, 2153 OverloadCandidateSet& CandidateSet, 2154 bool SuppressUserConversions, 2155 bool ForceRValue, 2156 bool PartialOverloading) { 2157 const FunctionProtoType* Proto 2158 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2159 assert(Proto && "Functions without a prototype cannot be overloaded"); 2160 assert(!isa<CXXConversionDecl>(Function) && 2161 "Use AddConversionCandidate for conversion functions"); 2162 assert(!Function->getDescribedFunctionTemplate() && 2163 "Use AddTemplateOverloadCandidate for function templates"); 2164 2165 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2166 if (!isa<CXXConstructorDecl>(Method)) { 2167 // If we get here, it's because we're calling a member function 2168 // that is named without a member access expression (e.g., 2169 // "this->f") that was either written explicitly or created 2170 // implicitly. This can happen with a qualified call to a member 2171 // function, e.g., X::f(). We use a NULL object as the implied 2172 // object argument (C++ [over.call.func]p3). 2173 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2174 SuppressUserConversions, ForceRValue); 2175 return; 2176 } 2177 // We treat a constructor like a non-member function, since its object 2178 // argument doesn't participate in overload resolution. 2179 } 2180 2181 2182 // Add this candidate 2183 CandidateSet.push_back(OverloadCandidate()); 2184 OverloadCandidate& Candidate = CandidateSet.back(); 2185 Candidate.Function = Function; 2186 Candidate.Viable = true; 2187 Candidate.IsSurrogate = false; 2188 Candidate.IgnoreObjectArgument = false; 2189 2190 unsigned NumArgsInProto = Proto->getNumArgs(); 2191 2192 // (C++ 13.3.2p2): A candidate function having fewer than m 2193 // parameters is viable only if it has an ellipsis in its parameter 2194 // list (8.3.5). 2195 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2196 !Proto->isVariadic()) { 2197 Candidate.Viable = false; 2198 return; 2199 } 2200 2201 // (C++ 13.3.2p2): A candidate function having more than m parameters 2202 // is viable only if the (m+1)st parameter has a default argument 2203 // (8.3.6). For the purposes of overload resolution, the 2204 // parameter list is truncated on the right, so that there are 2205 // exactly m parameters. 2206 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2207 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2208 // Not enough arguments. 2209 Candidate.Viable = false; 2210 return; 2211 } 2212 2213 // Determine the implicit conversion sequences for each of the 2214 // arguments. 2215 Candidate.Conversions.resize(NumArgs); 2216 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2217 if (ArgIdx < NumArgsInProto) { 2218 // (C++ 13.3.2p3): for F to be a viable function, there shall 2219 // exist for each argument an implicit conversion sequence 2220 // (13.3.3.1) that converts that argument to the corresponding 2221 // parameter of F. 2222 QualType ParamType = Proto->getArgType(ArgIdx); 2223 Candidate.Conversions[ArgIdx] 2224 = TryCopyInitialization(Args[ArgIdx], ParamType, 2225 SuppressUserConversions, ForceRValue, 2226 /*InOverloadResolution=*/true); 2227 if (Candidate.Conversions[ArgIdx].ConversionKind 2228 == ImplicitConversionSequence::BadConversion) { 2229 Candidate.Viable = false; 2230 break; 2231 } 2232 } else { 2233 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2234 // argument for which there is no corresponding parameter is 2235 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2236 Candidate.Conversions[ArgIdx].ConversionKind 2237 = ImplicitConversionSequence::EllipsisConversion; 2238 } 2239 } 2240} 2241 2242/// \brief Add all of the function declarations in the given function set to 2243/// the overload canddiate set. 2244void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2245 Expr **Args, unsigned NumArgs, 2246 OverloadCandidateSet& CandidateSet, 2247 bool SuppressUserConversions) { 2248 for (FunctionSet::const_iterator F = Functions.begin(), 2249 FEnd = Functions.end(); 2250 F != FEnd; ++F) { 2251 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) 2252 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2253 SuppressUserConversions); 2254 else 2255 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*F), 2256 /*FIXME: explicit args */false, 0, 0, 2257 Args, NumArgs, CandidateSet, 2258 SuppressUserConversions); 2259 } 2260} 2261 2262/// AddMethodCandidate - Adds the given C++ member function to the set 2263/// of candidate functions, using the given function call arguments 2264/// and the object argument (@c Object). For example, in a call 2265/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2266/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2267/// allow user-defined conversions via constructors or conversion 2268/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2269/// a slightly hacky way to implement the overloading rules for elidable copy 2270/// initialization in C++0x (C++0x 12.8p15). 2271void 2272Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2273 Expr **Args, unsigned NumArgs, 2274 OverloadCandidateSet& CandidateSet, 2275 bool SuppressUserConversions, bool ForceRValue) { 2276 const FunctionProtoType* Proto 2277 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2278 assert(Proto && "Methods without a prototype cannot be overloaded"); 2279 assert(!isa<CXXConversionDecl>(Method) && 2280 "Use AddConversionCandidate for conversion functions"); 2281 assert(!isa<CXXConstructorDecl>(Method) && 2282 "Use AddOverloadCandidate for constructors"); 2283 2284 // Add this candidate 2285 CandidateSet.push_back(OverloadCandidate()); 2286 OverloadCandidate& Candidate = CandidateSet.back(); 2287 Candidate.Function = Method; 2288 Candidate.IsSurrogate = false; 2289 Candidate.IgnoreObjectArgument = false; 2290 2291 unsigned NumArgsInProto = Proto->getNumArgs(); 2292 2293 // (C++ 13.3.2p2): A candidate function having fewer than m 2294 // parameters is viable only if it has an ellipsis in its parameter 2295 // list (8.3.5). 2296 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2297 Candidate.Viable = false; 2298 return; 2299 } 2300 2301 // (C++ 13.3.2p2): A candidate function having more than m parameters 2302 // is viable only if the (m+1)st parameter has a default argument 2303 // (8.3.6). For the purposes of overload resolution, the 2304 // parameter list is truncated on the right, so that there are 2305 // exactly m parameters. 2306 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2307 if (NumArgs < MinRequiredArgs) { 2308 // Not enough arguments. 2309 Candidate.Viable = false; 2310 return; 2311 } 2312 2313 Candidate.Viable = true; 2314 Candidate.Conversions.resize(NumArgs + 1); 2315 2316 if (Method->isStatic() || !Object) 2317 // The implicit object argument is ignored. 2318 Candidate.IgnoreObjectArgument = true; 2319 else { 2320 // Determine the implicit conversion sequence for the object 2321 // parameter. 2322 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2323 if (Candidate.Conversions[0].ConversionKind 2324 == ImplicitConversionSequence::BadConversion) { 2325 Candidate.Viable = false; 2326 return; 2327 } 2328 } 2329 2330 // Determine the implicit conversion sequences for each of the 2331 // arguments. 2332 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2333 if (ArgIdx < NumArgsInProto) { 2334 // (C++ 13.3.2p3): for F to be a viable function, there shall 2335 // exist for each argument an implicit conversion sequence 2336 // (13.3.3.1) that converts that argument to the corresponding 2337 // parameter of F. 2338 QualType ParamType = Proto->getArgType(ArgIdx); 2339 Candidate.Conversions[ArgIdx + 1] 2340 = TryCopyInitialization(Args[ArgIdx], ParamType, 2341 SuppressUserConversions, ForceRValue, 2342 /*InOverloadResolution=*/true); 2343 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2344 == ImplicitConversionSequence::BadConversion) { 2345 Candidate.Viable = false; 2346 break; 2347 } 2348 } else { 2349 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2350 // argument for which there is no corresponding parameter is 2351 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2352 Candidate.Conversions[ArgIdx + 1].ConversionKind 2353 = ImplicitConversionSequence::EllipsisConversion; 2354 } 2355 } 2356} 2357 2358/// \brief Add a C++ member function template as a candidate to the candidate 2359/// set, using template argument deduction to produce an appropriate member 2360/// function template specialization. 2361void 2362Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2363 bool HasExplicitTemplateArgs, 2364 const TemplateArgument *ExplicitTemplateArgs, 2365 unsigned NumExplicitTemplateArgs, 2366 Expr *Object, Expr **Args, unsigned NumArgs, 2367 OverloadCandidateSet& CandidateSet, 2368 bool SuppressUserConversions, 2369 bool ForceRValue) { 2370 // C++ [over.match.funcs]p7: 2371 // In each case where a candidate is a function template, candidate 2372 // function template specializations are generated using template argument 2373 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2374 // candidate functions in the usual way.113) A given name can refer to one 2375 // or more function templates and also to a set of overloaded non-template 2376 // functions. In such a case, the candidate functions generated from each 2377 // function template are combined with the set of non-template candidate 2378 // functions. 2379 TemplateDeductionInfo Info(Context); 2380 FunctionDecl *Specialization = 0; 2381 if (TemplateDeductionResult Result 2382 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2383 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2384 Args, NumArgs, Specialization, Info)) { 2385 // FIXME: Record what happened with template argument deduction, so 2386 // that we can give the user a beautiful diagnostic. 2387 (void)Result; 2388 return; 2389 } 2390 2391 // Add the function template specialization produced by template argument 2392 // deduction as a candidate. 2393 assert(Specialization && "Missing member function template specialization?"); 2394 assert(isa<CXXMethodDecl>(Specialization) && 2395 "Specialization is not a member function?"); 2396 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2397 CandidateSet, SuppressUserConversions, ForceRValue); 2398} 2399 2400/// \brief Add a C++ function template specialization as a candidate 2401/// in the candidate set, using template argument deduction to produce 2402/// an appropriate function template specialization. 2403void 2404Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2405 bool HasExplicitTemplateArgs, 2406 const TemplateArgument *ExplicitTemplateArgs, 2407 unsigned NumExplicitTemplateArgs, 2408 Expr **Args, unsigned NumArgs, 2409 OverloadCandidateSet& CandidateSet, 2410 bool SuppressUserConversions, 2411 bool ForceRValue) { 2412 // C++ [over.match.funcs]p7: 2413 // In each case where a candidate is a function template, candidate 2414 // function template specializations are generated using template argument 2415 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2416 // candidate functions in the usual way.113) A given name can refer to one 2417 // or more function templates and also to a set of overloaded non-template 2418 // functions. In such a case, the candidate functions generated from each 2419 // function template are combined with the set of non-template candidate 2420 // functions. 2421 TemplateDeductionInfo Info(Context); 2422 FunctionDecl *Specialization = 0; 2423 if (TemplateDeductionResult Result 2424 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2425 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2426 Args, NumArgs, Specialization, Info)) { 2427 // FIXME: Record what happened with template argument deduction, so 2428 // that we can give the user a beautiful diagnostic. 2429 (void)Result; 2430 return; 2431 } 2432 2433 // Add the function template specialization produced by template argument 2434 // deduction as a candidate. 2435 assert(Specialization && "Missing function template specialization?"); 2436 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2437 SuppressUserConversions, ForceRValue); 2438} 2439 2440/// AddConversionCandidate - Add a C++ conversion function as a 2441/// candidate in the candidate set (C++ [over.match.conv], 2442/// C++ [over.match.copy]). From is the expression we're converting from, 2443/// and ToType is the type that we're eventually trying to convert to 2444/// (which may or may not be the same type as the type that the 2445/// conversion function produces). 2446void 2447Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2448 Expr *From, QualType ToType, 2449 OverloadCandidateSet& CandidateSet) { 2450 assert(!Conversion->getDescribedFunctionTemplate() && 2451 "Conversion function templates use AddTemplateConversionCandidate"); 2452 2453 // Add this candidate 2454 CandidateSet.push_back(OverloadCandidate()); 2455 OverloadCandidate& Candidate = CandidateSet.back(); 2456 Candidate.Function = Conversion; 2457 Candidate.IsSurrogate = false; 2458 Candidate.IgnoreObjectArgument = false; 2459 Candidate.FinalConversion.setAsIdentityConversion(); 2460 Candidate.FinalConversion.FromTypePtr 2461 = Conversion->getConversionType().getAsOpaquePtr(); 2462 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2463 2464 // Determine the implicit conversion sequence for the implicit 2465 // object parameter. 2466 Candidate.Viable = true; 2467 Candidate.Conversions.resize(1); 2468 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2469 // Conversion functions to a different type in the base class is visible in 2470 // the derived class. So, a derived to base conversion should not participate 2471 // in overload resolution. 2472 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2473 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2474 if (Candidate.Conversions[0].ConversionKind 2475 == ImplicitConversionSequence::BadConversion) { 2476 Candidate.Viable = false; 2477 return; 2478 } 2479 2480 // To determine what the conversion from the result of calling the 2481 // conversion function to the type we're eventually trying to 2482 // convert to (ToType), we need to synthesize a call to the 2483 // conversion function and attempt copy initialization from it. This 2484 // makes sure that we get the right semantics with respect to 2485 // lvalues/rvalues and the type. Fortunately, we can allocate this 2486 // call on the stack and we don't need its arguments to be 2487 // well-formed. 2488 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2489 SourceLocation()); 2490 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2491 CastExpr::CK_Unknown, 2492 &ConversionRef, false); 2493 2494 // Note that it is safe to allocate CallExpr on the stack here because 2495 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2496 // allocator). 2497 CallExpr Call(Context, &ConversionFn, 0, 0, 2498 Conversion->getConversionType().getNonReferenceType(), 2499 SourceLocation()); 2500 ImplicitConversionSequence ICS = 2501 TryCopyInitialization(&Call, ToType, 2502 /*SuppressUserConversions=*/true, 2503 /*ForceRValue=*/false, 2504 /*InOverloadResolution=*/false); 2505 2506 switch (ICS.ConversionKind) { 2507 case ImplicitConversionSequence::StandardConversion: 2508 Candidate.FinalConversion = ICS.Standard; 2509 break; 2510 2511 case ImplicitConversionSequence::BadConversion: 2512 Candidate.Viable = false; 2513 break; 2514 2515 default: 2516 assert(false && 2517 "Can only end up with a standard conversion sequence or failure"); 2518 } 2519} 2520 2521/// \brief Adds a conversion function template specialization 2522/// candidate to the overload set, using template argument deduction 2523/// to deduce the template arguments of the conversion function 2524/// template from the type that we are converting to (C++ 2525/// [temp.deduct.conv]). 2526void 2527Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2528 Expr *From, QualType ToType, 2529 OverloadCandidateSet &CandidateSet) { 2530 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2531 "Only conversion function templates permitted here"); 2532 2533 TemplateDeductionInfo Info(Context); 2534 CXXConversionDecl *Specialization = 0; 2535 if (TemplateDeductionResult Result 2536 = DeduceTemplateArguments(FunctionTemplate, ToType, 2537 Specialization, Info)) { 2538 // FIXME: Record what happened with template argument deduction, so 2539 // that we can give the user a beautiful diagnostic. 2540 (void)Result; 2541 return; 2542 } 2543 2544 // Add the conversion function template specialization produced by 2545 // template argument deduction as a candidate. 2546 assert(Specialization && "Missing function template specialization?"); 2547 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2548} 2549 2550/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2551/// converts the given @c Object to a function pointer via the 2552/// conversion function @c Conversion, and then attempts to call it 2553/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2554/// the type of function that we'll eventually be calling. 2555void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2556 const FunctionProtoType *Proto, 2557 Expr *Object, Expr **Args, unsigned NumArgs, 2558 OverloadCandidateSet& CandidateSet) { 2559 CandidateSet.push_back(OverloadCandidate()); 2560 OverloadCandidate& Candidate = CandidateSet.back(); 2561 Candidate.Function = 0; 2562 Candidate.Surrogate = Conversion; 2563 Candidate.Viable = true; 2564 Candidate.IsSurrogate = true; 2565 Candidate.IgnoreObjectArgument = false; 2566 Candidate.Conversions.resize(NumArgs + 1); 2567 2568 // Determine the implicit conversion sequence for the implicit 2569 // object parameter. 2570 ImplicitConversionSequence ObjectInit 2571 = TryObjectArgumentInitialization(Object, Conversion); 2572 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2573 Candidate.Viable = false; 2574 return; 2575 } 2576 2577 // The first conversion is actually a user-defined conversion whose 2578 // first conversion is ObjectInit's standard conversion (which is 2579 // effectively a reference binding). Record it as such. 2580 Candidate.Conversions[0].ConversionKind 2581 = ImplicitConversionSequence::UserDefinedConversion; 2582 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2583 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2584 Candidate.Conversions[0].UserDefined.After 2585 = Candidate.Conversions[0].UserDefined.Before; 2586 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2587 2588 // Find the 2589 unsigned NumArgsInProto = Proto->getNumArgs(); 2590 2591 // (C++ 13.3.2p2): A candidate function having fewer than m 2592 // parameters is viable only if it has an ellipsis in its parameter 2593 // list (8.3.5). 2594 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2595 Candidate.Viable = false; 2596 return; 2597 } 2598 2599 // Function types don't have any default arguments, so just check if 2600 // we have enough arguments. 2601 if (NumArgs < NumArgsInProto) { 2602 // Not enough arguments. 2603 Candidate.Viable = false; 2604 return; 2605 } 2606 2607 // Determine the implicit conversion sequences for each of the 2608 // arguments. 2609 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2610 if (ArgIdx < NumArgsInProto) { 2611 // (C++ 13.3.2p3): for F to be a viable function, there shall 2612 // exist for each argument an implicit conversion sequence 2613 // (13.3.3.1) that converts that argument to the corresponding 2614 // parameter of F. 2615 QualType ParamType = Proto->getArgType(ArgIdx); 2616 Candidate.Conversions[ArgIdx + 1] 2617 = TryCopyInitialization(Args[ArgIdx], ParamType, 2618 /*SuppressUserConversions=*/false, 2619 /*ForceRValue=*/false, 2620 /*InOverloadResolution=*/false); 2621 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2622 == ImplicitConversionSequence::BadConversion) { 2623 Candidate.Viable = false; 2624 break; 2625 } 2626 } else { 2627 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2628 // argument for which there is no corresponding parameter is 2629 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2630 Candidate.Conversions[ArgIdx + 1].ConversionKind 2631 = ImplicitConversionSequence::EllipsisConversion; 2632 } 2633 } 2634} 2635 2636// FIXME: This will eventually be removed, once we've migrated all of the 2637// operator overloading logic over to the scheme used by binary operators, which 2638// works for template instantiation. 2639void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2640 SourceLocation OpLoc, 2641 Expr **Args, unsigned NumArgs, 2642 OverloadCandidateSet& CandidateSet, 2643 SourceRange OpRange) { 2644 2645 FunctionSet Functions; 2646 2647 QualType T1 = Args[0]->getType(); 2648 QualType T2; 2649 if (NumArgs > 1) 2650 T2 = Args[1]->getType(); 2651 2652 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2653 if (S) 2654 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2655 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2656 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2657 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2658 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2659} 2660 2661/// \brief Add overload candidates for overloaded operators that are 2662/// member functions. 2663/// 2664/// Add the overloaded operator candidates that are member functions 2665/// for the operator Op that was used in an operator expression such 2666/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2667/// CandidateSet will store the added overload candidates. (C++ 2668/// [over.match.oper]). 2669void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2670 SourceLocation OpLoc, 2671 Expr **Args, unsigned NumArgs, 2672 OverloadCandidateSet& CandidateSet, 2673 SourceRange OpRange) { 2674 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2675 2676 // C++ [over.match.oper]p3: 2677 // For a unary operator @ with an operand of a type whose 2678 // cv-unqualified version is T1, and for a binary operator @ with 2679 // a left operand of a type whose cv-unqualified version is T1 and 2680 // a right operand of a type whose cv-unqualified version is T2, 2681 // three sets of candidate functions, designated member 2682 // candidates, non-member candidates and built-in candidates, are 2683 // constructed as follows: 2684 QualType T1 = Args[0]->getType(); 2685 QualType T2; 2686 if (NumArgs > 1) 2687 T2 = Args[1]->getType(); 2688 2689 // -- If T1 is a class type, the set of member candidates is the 2690 // result of the qualified lookup of T1::operator@ 2691 // (13.3.1.1.1); otherwise, the set of member candidates is 2692 // empty. 2693 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2694 // Complete the type if it can be completed. Otherwise, we're done. 2695 if (RequireCompleteType(OpLoc, T1, PartialDiagnostic(0))) 2696 return; 2697 2698 LookupResult Operators = LookupQualifiedName(T1Rec->getDecl(), OpName, 2699 LookupOrdinaryName, false); 2700 for (LookupResult::iterator Oper = Operators.begin(), 2701 OperEnd = Operators.end(); 2702 Oper != OperEnd; 2703 ++Oper) 2704 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2705 Args+1, NumArgs - 1, CandidateSet, 2706 /*SuppressUserConversions=*/false); 2707 } 2708} 2709 2710/// AddBuiltinCandidate - Add a candidate for a built-in 2711/// operator. ResultTy and ParamTys are the result and parameter types 2712/// of the built-in candidate, respectively. Args and NumArgs are the 2713/// arguments being passed to the candidate. IsAssignmentOperator 2714/// should be true when this built-in candidate is an assignment 2715/// operator. NumContextualBoolArguments is the number of arguments 2716/// (at the beginning of the argument list) that will be contextually 2717/// converted to bool. 2718void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2719 Expr **Args, unsigned NumArgs, 2720 OverloadCandidateSet& CandidateSet, 2721 bool IsAssignmentOperator, 2722 unsigned NumContextualBoolArguments) { 2723 // Add this candidate 2724 CandidateSet.push_back(OverloadCandidate()); 2725 OverloadCandidate& Candidate = CandidateSet.back(); 2726 Candidate.Function = 0; 2727 Candidate.IsSurrogate = false; 2728 Candidate.IgnoreObjectArgument = false; 2729 Candidate.BuiltinTypes.ResultTy = ResultTy; 2730 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2731 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2732 2733 // Determine the implicit conversion sequences for each of the 2734 // arguments. 2735 Candidate.Viable = true; 2736 Candidate.Conversions.resize(NumArgs); 2737 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2738 // C++ [over.match.oper]p4: 2739 // For the built-in assignment operators, conversions of the 2740 // left operand are restricted as follows: 2741 // -- no temporaries are introduced to hold the left operand, and 2742 // -- no user-defined conversions are applied to the left 2743 // operand to achieve a type match with the left-most 2744 // parameter of a built-in candidate. 2745 // 2746 // We block these conversions by turning off user-defined 2747 // conversions, since that is the only way that initialization of 2748 // a reference to a non-class type can occur from something that 2749 // is not of the same type. 2750 if (ArgIdx < NumContextualBoolArguments) { 2751 assert(ParamTys[ArgIdx] == Context.BoolTy && 2752 "Contextual conversion to bool requires bool type"); 2753 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2754 } else { 2755 Candidate.Conversions[ArgIdx] 2756 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2757 ArgIdx == 0 && IsAssignmentOperator, 2758 /*ForceRValue=*/false, 2759 /*InOverloadResolution=*/false); 2760 } 2761 if (Candidate.Conversions[ArgIdx].ConversionKind 2762 == ImplicitConversionSequence::BadConversion) { 2763 Candidate.Viable = false; 2764 break; 2765 } 2766 } 2767} 2768 2769/// BuiltinCandidateTypeSet - A set of types that will be used for the 2770/// candidate operator functions for built-in operators (C++ 2771/// [over.built]). The types are separated into pointer types and 2772/// enumeration types. 2773class BuiltinCandidateTypeSet { 2774 /// TypeSet - A set of types. 2775 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2776 2777 /// PointerTypes - The set of pointer types that will be used in the 2778 /// built-in candidates. 2779 TypeSet PointerTypes; 2780 2781 /// MemberPointerTypes - The set of member pointer types that will be 2782 /// used in the built-in candidates. 2783 TypeSet MemberPointerTypes; 2784 2785 /// EnumerationTypes - The set of enumeration types that will be 2786 /// used in the built-in candidates. 2787 TypeSet EnumerationTypes; 2788 2789 /// Sema - The semantic analysis instance where we are building the 2790 /// candidate type set. 2791 Sema &SemaRef; 2792 2793 /// Context - The AST context in which we will build the type sets. 2794 ASTContext &Context; 2795 2796 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2797 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2798 2799public: 2800 /// iterator - Iterates through the types that are part of the set. 2801 typedef TypeSet::iterator iterator; 2802 2803 BuiltinCandidateTypeSet(Sema &SemaRef) 2804 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2805 2806 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2807 bool AllowExplicitConversions); 2808 2809 /// pointer_begin - First pointer type found; 2810 iterator pointer_begin() { return PointerTypes.begin(); } 2811 2812 /// pointer_end - Past the last pointer type found; 2813 iterator pointer_end() { return PointerTypes.end(); } 2814 2815 /// member_pointer_begin - First member pointer type found; 2816 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2817 2818 /// member_pointer_end - Past the last member pointer type found; 2819 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2820 2821 /// enumeration_begin - First enumeration type found; 2822 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2823 2824 /// enumeration_end - Past the last enumeration type found; 2825 iterator enumeration_end() { return EnumerationTypes.end(); } 2826}; 2827 2828/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2829/// the set of pointer types along with any more-qualified variants of 2830/// that type. For example, if @p Ty is "int const *", this routine 2831/// will add "int const *", "int const volatile *", "int const 2832/// restrict *", and "int const volatile restrict *" to the set of 2833/// pointer types. Returns true if the add of @p Ty itself succeeded, 2834/// false otherwise. 2835/// 2836/// FIXME: what to do about extended qualifiers? 2837bool 2838BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2839 2840 // Insert this type. 2841 if (!PointerTypes.insert(Ty)) 2842 return false; 2843 2844 const PointerType *PointerTy = Ty->getAs<PointerType>(); 2845 assert(PointerTy && "type was not a pointer type!"); 2846 2847 QualType PointeeTy = PointerTy->getPointeeType(); 2848 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2849 2850 // Iterate through all strict supersets of BaseCVR. 2851 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2852 if ((CVR | BaseCVR) != CVR) continue; 2853 2854 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2855 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 2856 } 2857 2858 return true; 2859} 2860 2861/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2862/// to the set of pointer types along with any more-qualified variants of 2863/// that type. For example, if @p Ty is "int const *", this routine 2864/// will add "int const *", "int const volatile *", "int const 2865/// restrict *", and "int const volatile restrict *" to the set of 2866/// pointer types. Returns true if the add of @p Ty itself succeeded, 2867/// false otherwise. 2868/// 2869/// FIXME: what to do about extended qualifiers? 2870bool 2871BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2872 QualType Ty) { 2873 // Insert this type. 2874 if (!MemberPointerTypes.insert(Ty)) 2875 return false; 2876 2877 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 2878 assert(PointerTy && "type was not a member pointer type!"); 2879 2880 QualType PointeeTy = PointerTy->getPointeeType(); 2881 const Type *ClassTy = PointerTy->getClass(); 2882 2883 // Iterate through all strict supersets of the pointee type's CVR 2884 // qualifiers. 2885 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2886 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2887 if ((CVR | BaseCVR) != CVR) continue; 2888 2889 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2890 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 2891 } 2892 2893 return true; 2894} 2895 2896/// AddTypesConvertedFrom - Add each of the types to which the type @p 2897/// Ty can be implicit converted to the given set of @p Types. We're 2898/// primarily interested in pointer types and enumeration types. We also 2899/// take member pointer types, for the conditional operator. 2900/// AllowUserConversions is true if we should look at the conversion 2901/// functions of a class type, and AllowExplicitConversions if we 2902/// should also include the explicit conversion functions of a class 2903/// type. 2904void 2905BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2906 bool AllowUserConversions, 2907 bool AllowExplicitConversions) { 2908 // Only deal with canonical types. 2909 Ty = Context.getCanonicalType(Ty); 2910 2911 // Look through reference types; they aren't part of the type of an 2912 // expression for the purposes of conversions. 2913 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 2914 Ty = RefTy->getPointeeType(); 2915 2916 // We don't care about qualifiers on the type. 2917 Ty = Ty.getUnqualifiedType(); 2918 2919 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2920 QualType PointeeTy = PointerTy->getPointeeType(); 2921 2922 // Insert our type, and its more-qualified variants, into the set 2923 // of types. 2924 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2925 return; 2926 2927 // Add 'cv void*' to our set of types. 2928 if (!Ty->isVoidType()) { 2929 QualType QualVoid 2930 = Context.getCVRQualifiedType(Context.VoidTy, 2931 PointeeTy.getCVRQualifiers()); 2932 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2933 } 2934 2935 // If this is a pointer to a class type, add pointers to its bases 2936 // (with the same level of cv-qualification as the original 2937 // derived class, of course). 2938 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 2939 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2940 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2941 Base != ClassDecl->bases_end(); ++Base) { 2942 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2943 BaseTy = Context.getCVRQualifiedType(BaseTy.getUnqualifiedType(), 2944 PointeeTy.getCVRQualifiers()); 2945 2946 // Add the pointer type, recursively, so that we get all of 2947 // the indirect base classes, too. 2948 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2949 } 2950 } 2951 } else if (Ty->isMemberPointerType()) { 2952 // Member pointers are far easier, since the pointee can't be converted. 2953 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2954 return; 2955 } else if (Ty->isEnumeralType()) { 2956 EnumerationTypes.insert(Ty); 2957 } else if (AllowUserConversions) { 2958 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 2959 if (SemaRef.RequireCompleteType(SourceLocation(), Ty, 0)) { 2960 // No conversion functions in incomplete types. 2961 return; 2962 } 2963 2964 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2965 // FIXME: Visit conversion functions in the base classes, too. 2966 OverloadedFunctionDecl *Conversions 2967 = ClassDecl->getConversionFunctions(); 2968 for (OverloadedFunctionDecl::function_iterator Func 2969 = Conversions->function_begin(); 2970 Func != Conversions->function_end(); ++Func) { 2971 CXXConversionDecl *Conv; 2972 FunctionTemplateDecl *ConvTemplate; 2973 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 2974 2975 // Skip conversion function templates; they don't tell us anything 2976 // about which builtin types we can convert to. 2977 if (ConvTemplate) 2978 continue; 2979 2980 if (AllowExplicitConversions || !Conv->isExplicit()) 2981 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2982 } 2983 } 2984 } 2985} 2986 2987/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 2988/// the volatile- and non-volatile-qualified assignment operators for the 2989/// given type to the candidate set. 2990static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 2991 QualType T, 2992 Expr **Args, 2993 unsigned NumArgs, 2994 OverloadCandidateSet &CandidateSet) { 2995 QualType ParamTypes[2]; 2996 2997 // T& operator=(T&, T) 2998 ParamTypes[0] = S.Context.getLValueReferenceType(T); 2999 ParamTypes[1] = T; 3000 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3001 /*IsAssignmentOperator=*/true); 3002 3003 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3004 // volatile T& operator=(volatile T&, T) 3005 ParamTypes[0] 3006 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3007 ParamTypes[1] = T; 3008 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3009 /*IsAssignmentOperator=*/true); 3010 } 3011} 3012 3013/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3014/// operator overloads to the candidate set (C++ [over.built]), based 3015/// on the operator @p Op and the arguments given. For example, if the 3016/// operator is a binary '+', this routine might add "int 3017/// operator+(int, int)" to cover integer addition. 3018void 3019Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3020 Expr **Args, unsigned NumArgs, 3021 OverloadCandidateSet& CandidateSet) { 3022 // The set of "promoted arithmetic types", which are the arithmetic 3023 // types are that preserved by promotion (C++ [over.built]p2). Note 3024 // that the first few of these types are the promoted integral 3025 // types; these types need to be first. 3026 // FIXME: What about complex? 3027 const unsigned FirstIntegralType = 0; 3028 const unsigned LastIntegralType = 13; 3029 const unsigned FirstPromotedIntegralType = 7, 3030 LastPromotedIntegralType = 13; 3031 const unsigned FirstPromotedArithmeticType = 7, 3032 LastPromotedArithmeticType = 16; 3033 const unsigned NumArithmeticTypes = 16; 3034 QualType ArithmeticTypes[NumArithmeticTypes] = { 3035 Context.BoolTy, Context.CharTy, Context.WCharTy, 3036// FIXME: Context.Char16Ty, Context.Char32Ty, 3037 Context.SignedCharTy, Context.ShortTy, 3038 Context.UnsignedCharTy, Context.UnsignedShortTy, 3039 Context.IntTy, Context.LongTy, Context.LongLongTy, 3040 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3041 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3042 }; 3043 3044 // Find all of the types that the arguments can convert to, but only 3045 // if the operator we're looking at has built-in operator candidates 3046 // that make use of these types. 3047 BuiltinCandidateTypeSet CandidateTypes(*this); 3048 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3049 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3050 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3051 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3052 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3053 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3054 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3055 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3056 true, 3057 (Op == OO_Exclaim || 3058 Op == OO_AmpAmp || 3059 Op == OO_PipePipe)); 3060 } 3061 3062 bool isComparison = false; 3063 switch (Op) { 3064 case OO_None: 3065 case NUM_OVERLOADED_OPERATORS: 3066 assert(false && "Expected an overloaded operator"); 3067 break; 3068 3069 case OO_Star: // '*' is either unary or binary 3070 if (NumArgs == 1) 3071 goto UnaryStar; 3072 else 3073 goto BinaryStar; 3074 break; 3075 3076 case OO_Plus: // '+' is either unary or binary 3077 if (NumArgs == 1) 3078 goto UnaryPlus; 3079 else 3080 goto BinaryPlus; 3081 break; 3082 3083 case OO_Minus: // '-' is either unary or binary 3084 if (NumArgs == 1) 3085 goto UnaryMinus; 3086 else 3087 goto BinaryMinus; 3088 break; 3089 3090 case OO_Amp: // '&' is either unary or binary 3091 if (NumArgs == 1) 3092 goto UnaryAmp; 3093 else 3094 goto BinaryAmp; 3095 3096 case OO_PlusPlus: 3097 case OO_MinusMinus: 3098 // C++ [over.built]p3: 3099 // 3100 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3101 // is either volatile or empty, there exist candidate operator 3102 // functions of the form 3103 // 3104 // VQ T& operator++(VQ T&); 3105 // T operator++(VQ T&, int); 3106 // 3107 // C++ [over.built]p4: 3108 // 3109 // For every pair (T, VQ), where T is an arithmetic type other 3110 // than bool, and VQ is either volatile or empty, there exist 3111 // candidate operator functions of the form 3112 // 3113 // VQ T& operator--(VQ T&); 3114 // T operator--(VQ T&, int); 3115 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3116 Arith < NumArithmeticTypes; ++Arith) { 3117 QualType ArithTy = ArithmeticTypes[Arith]; 3118 QualType ParamTypes[2] 3119 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3120 3121 // Non-volatile version. 3122 if (NumArgs == 1) 3123 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3124 else 3125 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3126 3127 // Volatile version 3128 ParamTypes[0] 3129 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3130 if (NumArgs == 1) 3131 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3132 else 3133 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3134 } 3135 3136 // C++ [over.built]p5: 3137 // 3138 // For every pair (T, VQ), where T is a cv-qualified or 3139 // cv-unqualified object type, and VQ is either volatile or 3140 // empty, there exist candidate operator functions of the form 3141 // 3142 // T*VQ& operator++(T*VQ&); 3143 // T*VQ& operator--(T*VQ&); 3144 // T* operator++(T*VQ&, int); 3145 // T* operator--(T*VQ&, int); 3146 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3147 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3148 // Skip pointer types that aren't pointers to object types. 3149 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3150 continue; 3151 3152 QualType ParamTypes[2] = { 3153 Context.getLValueReferenceType(*Ptr), Context.IntTy 3154 }; 3155 3156 // Without volatile 3157 if (NumArgs == 1) 3158 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3159 else 3160 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3161 3162 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3163 // With volatile 3164 ParamTypes[0] 3165 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3166 if (NumArgs == 1) 3167 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3168 else 3169 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3170 } 3171 } 3172 break; 3173 3174 UnaryStar: 3175 // C++ [over.built]p6: 3176 // For every cv-qualified or cv-unqualified object type T, there 3177 // exist candidate operator functions of the form 3178 // 3179 // T& operator*(T*); 3180 // 3181 // C++ [over.built]p7: 3182 // For every function type T, there exist candidate operator 3183 // functions of the form 3184 // T& operator*(T*); 3185 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3186 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3187 QualType ParamTy = *Ptr; 3188 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3189 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3190 &ParamTy, Args, 1, CandidateSet); 3191 } 3192 break; 3193 3194 UnaryPlus: 3195 // C++ [over.built]p8: 3196 // For every type T, there exist candidate operator functions of 3197 // the form 3198 // 3199 // T* operator+(T*); 3200 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3201 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3202 QualType ParamTy = *Ptr; 3203 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3204 } 3205 3206 // Fall through 3207 3208 UnaryMinus: 3209 // C++ [over.built]p9: 3210 // For every promoted arithmetic type T, there exist candidate 3211 // operator functions of the form 3212 // 3213 // T operator+(T); 3214 // T operator-(T); 3215 for (unsigned Arith = FirstPromotedArithmeticType; 3216 Arith < LastPromotedArithmeticType; ++Arith) { 3217 QualType ArithTy = ArithmeticTypes[Arith]; 3218 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3219 } 3220 break; 3221 3222 case OO_Tilde: 3223 // C++ [over.built]p10: 3224 // For every promoted integral type T, there exist candidate 3225 // operator functions of the form 3226 // 3227 // T operator~(T); 3228 for (unsigned Int = FirstPromotedIntegralType; 3229 Int < LastPromotedIntegralType; ++Int) { 3230 QualType IntTy = ArithmeticTypes[Int]; 3231 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3232 } 3233 break; 3234 3235 case OO_New: 3236 case OO_Delete: 3237 case OO_Array_New: 3238 case OO_Array_Delete: 3239 case OO_Call: 3240 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3241 break; 3242 3243 case OO_Comma: 3244 UnaryAmp: 3245 case OO_Arrow: 3246 // C++ [over.match.oper]p3: 3247 // -- For the operator ',', the unary operator '&', or the 3248 // operator '->', the built-in candidates set is empty. 3249 break; 3250 3251 case OO_EqualEqual: 3252 case OO_ExclaimEqual: 3253 // C++ [over.match.oper]p16: 3254 // For every pointer to member type T, there exist candidate operator 3255 // functions of the form 3256 // 3257 // bool operator==(T,T); 3258 // bool operator!=(T,T); 3259 for (BuiltinCandidateTypeSet::iterator 3260 MemPtr = CandidateTypes.member_pointer_begin(), 3261 MemPtrEnd = CandidateTypes.member_pointer_end(); 3262 MemPtr != MemPtrEnd; 3263 ++MemPtr) { 3264 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3265 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3266 } 3267 3268 // Fall through 3269 3270 case OO_Less: 3271 case OO_Greater: 3272 case OO_LessEqual: 3273 case OO_GreaterEqual: 3274 // C++ [over.built]p15: 3275 // 3276 // For every pointer or enumeration type T, there exist 3277 // candidate operator functions of the form 3278 // 3279 // bool operator<(T, T); 3280 // bool operator>(T, T); 3281 // bool operator<=(T, T); 3282 // bool operator>=(T, T); 3283 // bool operator==(T, T); 3284 // bool operator!=(T, T); 3285 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3286 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3287 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3288 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3289 } 3290 for (BuiltinCandidateTypeSet::iterator Enum 3291 = CandidateTypes.enumeration_begin(); 3292 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3293 QualType ParamTypes[2] = { *Enum, *Enum }; 3294 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3295 } 3296 3297 // Fall through. 3298 isComparison = true; 3299 3300 BinaryPlus: 3301 BinaryMinus: 3302 if (!isComparison) { 3303 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3304 3305 // C++ [over.built]p13: 3306 // 3307 // For every cv-qualified or cv-unqualified object type T 3308 // there exist candidate operator functions of the form 3309 // 3310 // T* operator+(T*, ptrdiff_t); 3311 // T& operator[](T*, ptrdiff_t); [BELOW] 3312 // T* operator-(T*, ptrdiff_t); 3313 // T* operator+(ptrdiff_t, T*); 3314 // T& operator[](ptrdiff_t, T*); [BELOW] 3315 // 3316 // C++ [over.built]p14: 3317 // 3318 // For every T, where T is a pointer to object type, there 3319 // exist candidate operator functions of the form 3320 // 3321 // ptrdiff_t operator-(T, T); 3322 for (BuiltinCandidateTypeSet::iterator Ptr 3323 = CandidateTypes.pointer_begin(); 3324 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3325 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3326 3327 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3328 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3329 3330 if (Op == OO_Plus) { 3331 // T* operator+(ptrdiff_t, T*); 3332 ParamTypes[0] = ParamTypes[1]; 3333 ParamTypes[1] = *Ptr; 3334 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3335 } else { 3336 // ptrdiff_t operator-(T, T); 3337 ParamTypes[1] = *Ptr; 3338 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3339 Args, 2, CandidateSet); 3340 } 3341 } 3342 } 3343 // Fall through 3344 3345 case OO_Slash: 3346 BinaryStar: 3347 Conditional: 3348 // C++ [over.built]p12: 3349 // 3350 // For every pair of promoted arithmetic types L and R, there 3351 // exist candidate operator functions of the form 3352 // 3353 // LR operator*(L, R); 3354 // LR operator/(L, R); 3355 // LR operator+(L, R); 3356 // LR operator-(L, R); 3357 // bool operator<(L, R); 3358 // bool operator>(L, R); 3359 // bool operator<=(L, R); 3360 // bool operator>=(L, R); 3361 // bool operator==(L, R); 3362 // bool operator!=(L, R); 3363 // 3364 // where LR is the result of the usual arithmetic conversions 3365 // between types L and R. 3366 // 3367 // C++ [over.built]p24: 3368 // 3369 // For every pair of promoted arithmetic types L and R, there exist 3370 // candidate operator functions of the form 3371 // 3372 // LR operator?(bool, L, R); 3373 // 3374 // where LR is the result of the usual arithmetic conversions 3375 // between types L and R. 3376 // Our candidates ignore the first parameter. 3377 for (unsigned Left = FirstPromotedArithmeticType; 3378 Left < LastPromotedArithmeticType; ++Left) { 3379 for (unsigned Right = FirstPromotedArithmeticType; 3380 Right < LastPromotedArithmeticType; ++Right) { 3381 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3382 QualType Result 3383 = isComparison 3384 ? Context.BoolTy 3385 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3386 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3387 } 3388 } 3389 break; 3390 3391 case OO_Percent: 3392 BinaryAmp: 3393 case OO_Caret: 3394 case OO_Pipe: 3395 case OO_LessLess: 3396 case OO_GreaterGreater: 3397 // C++ [over.built]p17: 3398 // 3399 // For every pair of promoted integral types L and R, there 3400 // exist candidate operator functions of the form 3401 // 3402 // LR operator%(L, R); 3403 // LR operator&(L, R); 3404 // LR operator^(L, R); 3405 // LR operator|(L, R); 3406 // L operator<<(L, R); 3407 // L operator>>(L, R); 3408 // 3409 // where LR is the result of the usual arithmetic conversions 3410 // between types L and R. 3411 for (unsigned Left = FirstPromotedIntegralType; 3412 Left < LastPromotedIntegralType; ++Left) { 3413 for (unsigned Right = FirstPromotedIntegralType; 3414 Right < LastPromotedIntegralType; ++Right) { 3415 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3416 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3417 ? LandR[0] 3418 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3419 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3420 } 3421 } 3422 break; 3423 3424 case OO_Equal: 3425 // C++ [over.built]p20: 3426 // 3427 // For every pair (T, VQ), where T is an enumeration or 3428 // pointer to member type and VQ is either volatile or 3429 // empty, there exist candidate operator functions of the form 3430 // 3431 // VQ T& operator=(VQ T&, T); 3432 for (BuiltinCandidateTypeSet::iterator 3433 Enum = CandidateTypes.enumeration_begin(), 3434 EnumEnd = CandidateTypes.enumeration_end(); 3435 Enum != EnumEnd; ++Enum) 3436 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3437 CandidateSet); 3438 for (BuiltinCandidateTypeSet::iterator 3439 MemPtr = CandidateTypes.member_pointer_begin(), 3440 MemPtrEnd = CandidateTypes.member_pointer_end(); 3441 MemPtr != MemPtrEnd; ++MemPtr) 3442 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3443 CandidateSet); 3444 // Fall through. 3445 3446 case OO_PlusEqual: 3447 case OO_MinusEqual: 3448 // C++ [over.built]p19: 3449 // 3450 // For every pair (T, VQ), where T is any type and VQ is either 3451 // volatile or empty, there exist candidate operator functions 3452 // of the form 3453 // 3454 // T*VQ& operator=(T*VQ&, T*); 3455 // 3456 // C++ [over.built]p21: 3457 // 3458 // For every pair (T, VQ), where T is a cv-qualified or 3459 // cv-unqualified object type and VQ is either volatile or 3460 // empty, there exist candidate operator functions of the form 3461 // 3462 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3463 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3464 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3465 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3466 QualType ParamTypes[2]; 3467 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3468 3469 // non-volatile version 3470 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3471 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3472 /*IsAssigmentOperator=*/Op == OO_Equal); 3473 3474 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3475 // volatile version 3476 ParamTypes[0] 3477 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3478 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3479 /*IsAssigmentOperator=*/Op == OO_Equal); 3480 } 3481 } 3482 // Fall through. 3483 3484 case OO_StarEqual: 3485 case OO_SlashEqual: 3486 // C++ [over.built]p18: 3487 // 3488 // For every triple (L, VQ, R), where L is an arithmetic type, 3489 // VQ is either volatile or empty, and R is a promoted 3490 // arithmetic type, there exist candidate operator functions of 3491 // the form 3492 // 3493 // VQ L& operator=(VQ L&, R); 3494 // VQ L& operator*=(VQ L&, R); 3495 // VQ L& operator/=(VQ L&, R); 3496 // VQ L& operator+=(VQ L&, R); 3497 // VQ L& operator-=(VQ L&, R); 3498 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3499 for (unsigned Right = FirstPromotedArithmeticType; 3500 Right < LastPromotedArithmeticType; ++Right) { 3501 QualType ParamTypes[2]; 3502 ParamTypes[1] = ArithmeticTypes[Right]; 3503 3504 // Add this built-in operator as a candidate (VQ is empty). 3505 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3506 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3507 /*IsAssigmentOperator=*/Op == OO_Equal); 3508 3509 // Add this built-in operator as a candidate (VQ is 'volatile'). 3510 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3511 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3512 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3513 /*IsAssigmentOperator=*/Op == OO_Equal); 3514 } 3515 } 3516 break; 3517 3518 case OO_PercentEqual: 3519 case OO_LessLessEqual: 3520 case OO_GreaterGreaterEqual: 3521 case OO_AmpEqual: 3522 case OO_CaretEqual: 3523 case OO_PipeEqual: 3524 // C++ [over.built]p22: 3525 // 3526 // For every triple (L, VQ, R), where L is an integral type, VQ 3527 // is either volatile or empty, and R is a promoted integral 3528 // type, there exist candidate operator functions of the form 3529 // 3530 // VQ L& operator%=(VQ L&, R); 3531 // VQ L& operator<<=(VQ L&, R); 3532 // VQ L& operator>>=(VQ L&, R); 3533 // VQ L& operator&=(VQ L&, R); 3534 // VQ L& operator^=(VQ L&, R); 3535 // VQ L& operator|=(VQ L&, R); 3536 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3537 for (unsigned Right = FirstPromotedIntegralType; 3538 Right < LastPromotedIntegralType; ++Right) { 3539 QualType ParamTypes[2]; 3540 ParamTypes[1] = ArithmeticTypes[Right]; 3541 3542 // Add this built-in operator as a candidate (VQ is empty). 3543 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3544 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3545 3546 // Add this built-in operator as a candidate (VQ is 'volatile'). 3547 ParamTypes[0] = ArithmeticTypes[Left]; 3548 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3549 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3550 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3551 } 3552 } 3553 break; 3554 3555 case OO_Exclaim: { 3556 // C++ [over.operator]p23: 3557 // 3558 // There also exist candidate operator functions of the form 3559 // 3560 // bool operator!(bool); 3561 // bool operator&&(bool, bool); [BELOW] 3562 // bool operator||(bool, bool); [BELOW] 3563 QualType ParamTy = Context.BoolTy; 3564 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3565 /*IsAssignmentOperator=*/false, 3566 /*NumContextualBoolArguments=*/1); 3567 break; 3568 } 3569 3570 case OO_AmpAmp: 3571 case OO_PipePipe: { 3572 // C++ [over.operator]p23: 3573 // 3574 // There also exist candidate operator functions of the form 3575 // 3576 // bool operator!(bool); [ABOVE] 3577 // bool operator&&(bool, bool); 3578 // bool operator||(bool, bool); 3579 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3580 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3581 /*IsAssignmentOperator=*/false, 3582 /*NumContextualBoolArguments=*/2); 3583 break; 3584 } 3585 3586 case OO_Subscript: 3587 // C++ [over.built]p13: 3588 // 3589 // For every cv-qualified or cv-unqualified object type T there 3590 // exist candidate operator functions of the form 3591 // 3592 // T* operator+(T*, ptrdiff_t); [ABOVE] 3593 // T& operator[](T*, ptrdiff_t); 3594 // T* operator-(T*, ptrdiff_t); [ABOVE] 3595 // T* operator+(ptrdiff_t, T*); [ABOVE] 3596 // T& operator[](ptrdiff_t, T*); 3597 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3598 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3599 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3600 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3601 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3602 3603 // T& operator[](T*, ptrdiff_t) 3604 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3605 3606 // T& operator[](ptrdiff_t, T*); 3607 ParamTypes[0] = ParamTypes[1]; 3608 ParamTypes[1] = *Ptr; 3609 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3610 } 3611 break; 3612 3613 case OO_ArrowStar: 3614 // FIXME: No support for pointer-to-members yet. 3615 break; 3616 3617 case OO_Conditional: 3618 // Note that we don't consider the first argument, since it has been 3619 // contextually converted to bool long ago. The candidates below are 3620 // therefore added as binary. 3621 // 3622 // C++ [over.built]p24: 3623 // For every type T, where T is a pointer or pointer-to-member type, 3624 // there exist candidate operator functions of the form 3625 // 3626 // T operator?(bool, T, T); 3627 // 3628 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3629 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3630 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3631 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3632 } 3633 for (BuiltinCandidateTypeSet::iterator Ptr = 3634 CandidateTypes.member_pointer_begin(), 3635 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3636 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3637 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3638 } 3639 goto Conditional; 3640 } 3641} 3642 3643/// \brief Add function candidates found via argument-dependent lookup 3644/// to the set of overloading candidates. 3645/// 3646/// This routine performs argument-dependent name lookup based on the 3647/// given function name (which may also be an operator name) and adds 3648/// all of the overload candidates found by ADL to the overload 3649/// candidate set (C++ [basic.lookup.argdep]). 3650void 3651Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3652 Expr **Args, unsigned NumArgs, 3653 bool HasExplicitTemplateArgs, 3654 const TemplateArgument *ExplicitTemplateArgs, 3655 unsigned NumExplicitTemplateArgs, 3656 OverloadCandidateSet& CandidateSet, 3657 bool PartialOverloading) { 3658 FunctionSet Functions; 3659 3660 // FIXME: Should we be trafficking in canonical function decls throughout? 3661 3662 // Record all of the function candidates that we've already 3663 // added to the overload set, so that we don't add those same 3664 // candidates a second time. 3665 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3666 CandEnd = CandidateSet.end(); 3667 Cand != CandEnd; ++Cand) 3668 if (Cand->Function) { 3669 Functions.insert(Cand->Function); 3670 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3671 Functions.insert(FunTmpl); 3672 } 3673 3674 // FIXME: Pass in the explicit template arguments? 3675 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3676 3677 // Erase all of the candidates we already knew about. 3678 // FIXME: This is suboptimal. Is there a better way? 3679 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3680 CandEnd = CandidateSet.end(); 3681 Cand != CandEnd; ++Cand) 3682 if (Cand->Function) { 3683 Functions.erase(Cand->Function); 3684 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3685 Functions.erase(FunTmpl); 3686 } 3687 3688 // For each of the ADL candidates we found, add it to the overload 3689 // set. 3690 for (FunctionSet::iterator Func = Functions.begin(), 3691 FuncEnd = Functions.end(); 3692 Func != FuncEnd; ++Func) { 3693 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3694 if (HasExplicitTemplateArgs) 3695 continue; 3696 3697 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3698 false, false, PartialOverloading); 3699 } else 3700 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3701 HasExplicitTemplateArgs, 3702 ExplicitTemplateArgs, 3703 NumExplicitTemplateArgs, 3704 Args, NumArgs, CandidateSet); 3705 } 3706} 3707 3708/// isBetterOverloadCandidate - Determines whether the first overload 3709/// candidate is a better candidate than the second (C++ 13.3.3p1). 3710bool 3711Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3712 const OverloadCandidate& Cand2) { 3713 // Define viable functions to be better candidates than non-viable 3714 // functions. 3715 if (!Cand2.Viable) 3716 return Cand1.Viable; 3717 else if (!Cand1.Viable) 3718 return false; 3719 3720 // C++ [over.match.best]p1: 3721 // 3722 // -- if F is a static member function, ICS1(F) is defined such 3723 // that ICS1(F) is neither better nor worse than ICS1(G) for 3724 // any function G, and, symmetrically, ICS1(G) is neither 3725 // better nor worse than ICS1(F). 3726 unsigned StartArg = 0; 3727 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3728 StartArg = 1; 3729 3730 // C++ [over.match.best]p1: 3731 // A viable function F1 is defined to be a better function than another 3732 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3733 // conversion sequence than ICSi(F2), and then... 3734 unsigned NumArgs = Cand1.Conversions.size(); 3735 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3736 bool HasBetterConversion = false; 3737 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3738 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3739 Cand2.Conversions[ArgIdx])) { 3740 case ImplicitConversionSequence::Better: 3741 // Cand1 has a better conversion sequence. 3742 HasBetterConversion = true; 3743 break; 3744 3745 case ImplicitConversionSequence::Worse: 3746 // Cand1 can't be better than Cand2. 3747 return false; 3748 3749 case ImplicitConversionSequence::Indistinguishable: 3750 // Do nothing. 3751 break; 3752 } 3753 } 3754 3755 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3756 // ICSj(F2), or, if not that, 3757 if (HasBetterConversion) 3758 return true; 3759 3760 // - F1 is a non-template function and F2 is a function template 3761 // specialization, or, if not that, 3762 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3763 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3764 return true; 3765 3766 // -- F1 and F2 are function template specializations, and the function 3767 // template for F1 is more specialized than the template for F2 3768 // according to the partial ordering rules described in 14.5.5.2, or, 3769 // if not that, 3770 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3771 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3772 if (FunctionTemplateDecl *BetterTemplate 3773 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 3774 Cand2.Function->getPrimaryTemplate(), 3775 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 3776 : TPOC_Call)) 3777 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 3778 3779 // -- the context is an initialization by user-defined conversion 3780 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3781 // from the return type of F1 to the destination type (i.e., 3782 // the type of the entity being initialized) is a better 3783 // conversion sequence than the standard conversion sequence 3784 // from the return type of F2 to the destination type. 3785 if (Cand1.Function && Cand2.Function && 3786 isa<CXXConversionDecl>(Cand1.Function) && 3787 isa<CXXConversionDecl>(Cand2.Function)) { 3788 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3789 Cand2.FinalConversion)) { 3790 case ImplicitConversionSequence::Better: 3791 // Cand1 has a better conversion sequence. 3792 return true; 3793 3794 case ImplicitConversionSequence::Worse: 3795 // Cand1 can't be better than Cand2. 3796 return false; 3797 3798 case ImplicitConversionSequence::Indistinguishable: 3799 // Do nothing 3800 break; 3801 } 3802 } 3803 3804 return false; 3805} 3806 3807/// \brief Computes the best viable function (C++ 13.3.3) 3808/// within an overload candidate set. 3809/// 3810/// \param CandidateSet the set of candidate functions. 3811/// 3812/// \param Loc the location of the function name (or operator symbol) for 3813/// which overload resolution occurs. 3814/// 3815/// \param Best f overload resolution was successful or found a deleted 3816/// function, Best points to the candidate function found. 3817/// 3818/// \returns The result of overload resolution. 3819Sema::OverloadingResult 3820Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3821 SourceLocation Loc, 3822 OverloadCandidateSet::iterator& Best) { 3823 // Find the best viable function. 3824 Best = CandidateSet.end(); 3825 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3826 Cand != CandidateSet.end(); ++Cand) { 3827 if (Cand->Viable) { 3828 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3829 Best = Cand; 3830 } 3831 } 3832 3833 // If we didn't find any viable functions, abort. 3834 if (Best == CandidateSet.end()) 3835 return OR_No_Viable_Function; 3836 3837 // Make sure that this function is better than every other viable 3838 // function. If not, we have an ambiguity. 3839 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3840 Cand != CandidateSet.end(); ++Cand) { 3841 if (Cand->Viable && 3842 Cand != Best && 3843 !isBetterOverloadCandidate(*Best, *Cand)) { 3844 Best = CandidateSet.end(); 3845 return OR_Ambiguous; 3846 } 3847 } 3848 3849 // Best is the best viable function. 3850 if (Best->Function && 3851 (Best->Function->isDeleted() || 3852 Best->Function->getAttr<UnavailableAttr>())) 3853 return OR_Deleted; 3854 3855 // C++ [basic.def.odr]p2: 3856 // An overloaded function is used if it is selected by overload resolution 3857 // when referred to from a potentially-evaluated expression. [Note: this 3858 // covers calls to named functions (5.2.2), operator overloading 3859 // (clause 13), user-defined conversions (12.3.2), allocation function for 3860 // placement new (5.3.4), as well as non-default initialization (8.5). 3861 if (Best->Function) 3862 MarkDeclarationReferenced(Loc, Best->Function); 3863 return OR_Success; 3864} 3865 3866/// PrintOverloadCandidates - When overload resolution fails, prints 3867/// diagnostic messages containing the candidates in the candidate 3868/// set. If OnlyViable is true, only viable candidates will be printed. 3869void 3870Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3871 bool OnlyViable) { 3872 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3873 LastCand = CandidateSet.end(); 3874 for (; Cand != LastCand; ++Cand) { 3875 if (Cand->Viable || !OnlyViable) { 3876 if (Cand->Function) { 3877 if (Cand->Function->isDeleted() || 3878 Cand->Function->getAttr<UnavailableAttr>()) { 3879 // Deleted or "unavailable" function. 3880 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3881 << Cand->Function->isDeleted(); 3882 } else if (FunctionTemplateDecl *FunTmpl 3883 = Cand->Function->getPrimaryTemplate()) { 3884 // Function template specialization 3885 // FIXME: Give a better reason! 3886 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 3887 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 3888 *Cand->Function->getTemplateSpecializationArgs()); 3889 } else { 3890 // Normal function 3891 bool errReported = false; 3892 if (!Cand->Viable && Cand->Conversions.size() > 0) { 3893 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 3894 const ImplicitConversionSequence &Conversion = 3895 Cand->Conversions[i]; 3896 if ((Conversion.ConversionKind != 3897 ImplicitConversionSequence::BadConversion) || 3898 Conversion.ConversionFunctionSet.size() == 0) 3899 continue; 3900 Diag(Cand->Function->getLocation(), 3901 diag::err_ovl_candidate_not_viable) << (i+1); 3902 errReported = true; 3903 for (int j = Conversion.ConversionFunctionSet.size()-1; 3904 j >= 0; j--) { 3905 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 3906 Diag(Func->getLocation(), diag::err_ovl_candidate); 3907 } 3908 } 3909 } 3910 if (!errReported) 3911 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3912 } 3913 } else if (Cand->IsSurrogate) { 3914 // Desugar the type of the surrogate down to a function type, 3915 // retaining as many typedefs as possible while still showing 3916 // the function type (and, therefore, its parameter types). 3917 QualType FnType = Cand->Surrogate->getConversionType(); 3918 bool isLValueReference = false; 3919 bool isRValueReference = false; 3920 bool isPointer = false; 3921 if (const LValueReferenceType *FnTypeRef = 3922 FnType->getAs<LValueReferenceType>()) { 3923 FnType = FnTypeRef->getPointeeType(); 3924 isLValueReference = true; 3925 } else if (const RValueReferenceType *FnTypeRef = 3926 FnType->getAs<RValueReferenceType>()) { 3927 FnType = FnTypeRef->getPointeeType(); 3928 isRValueReference = true; 3929 } 3930 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 3931 FnType = FnTypePtr->getPointeeType(); 3932 isPointer = true; 3933 } 3934 // Desugar down to a function type. 3935 FnType = QualType(FnType->getAs<FunctionType>(), 0); 3936 // Reconstruct the pointer/reference as appropriate. 3937 if (isPointer) FnType = Context.getPointerType(FnType); 3938 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3939 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3940 3941 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3942 << FnType; 3943 } else { 3944 // FIXME: We need to get the identifier in here 3945 // FIXME: Do we want the error message to point at the operator? 3946 // (built-ins won't have a location) 3947 QualType FnType 3948 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3949 Cand->BuiltinTypes.ParamTypes, 3950 Cand->Conversions.size(), 3951 false, 0); 3952 3953 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3954 } 3955 } 3956 } 3957} 3958 3959/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3960/// an overloaded function (C++ [over.over]), where @p From is an 3961/// expression with overloaded function type and @p ToType is the type 3962/// we're trying to resolve to. For example: 3963/// 3964/// @code 3965/// int f(double); 3966/// int f(int); 3967/// 3968/// int (*pfd)(double) = f; // selects f(double) 3969/// @endcode 3970/// 3971/// This routine returns the resulting FunctionDecl if it could be 3972/// resolved, and NULL otherwise. When @p Complain is true, this 3973/// routine will emit diagnostics if there is an error. 3974FunctionDecl * 3975Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3976 bool Complain) { 3977 QualType FunctionType = ToType; 3978 bool IsMember = false; 3979 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 3980 FunctionType = ToTypePtr->getPointeeType(); 3981 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 3982 FunctionType = ToTypeRef->getPointeeType(); 3983 else if (const MemberPointerType *MemTypePtr = 3984 ToType->getAs<MemberPointerType>()) { 3985 FunctionType = MemTypePtr->getPointeeType(); 3986 IsMember = true; 3987 } 3988 3989 // We only look at pointers or references to functions. 3990 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 3991 if (!FunctionType->isFunctionType()) 3992 return 0; 3993 3994 // Find the actual overloaded function declaration. 3995 OverloadedFunctionDecl *Ovl = 0; 3996 3997 // C++ [over.over]p1: 3998 // [...] [Note: any redundant set of parentheses surrounding the 3999 // overloaded function name is ignored (5.1). ] 4000 Expr *OvlExpr = From->IgnoreParens(); 4001 4002 // C++ [over.over]p1: 4003 // [...] The overloaded function name can be preceded by the & 4004 // operator. 4005 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4006 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4007 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4008 } 4009 4010 // Try to dig out the overloaded function. 4011 FunctionTemplateDecl *FunctionTemplate = 0; 4012 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4013 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4014 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4015 } 4016 4017 // If there's no overloaded function declaration or function template, 4018 // we're done. 4019 if (!Ovl && !FunctionTemplate) 4020 return 0; 4021 4022 OverloadIterator Fun; 4023 if (Ovl) 4024 Fun = Ovl; 4025 else 4026 Fun = FunctionTemplate; 4027 4028 // Look through all of the overloaded functions, searching for one 4029 // whose type matches exactly. 4030 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4031 4032 bool FoundNonTemplateFunction = false; 4033 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4034 // C++ [over.over]p3: 4035 // Non-member functions and static member functions match 4036 // targets of type "pointer-to-function" or "reference-to-function." 4037 // Nonstatic member functions match targets of 4038 // type "pointer-to-member-function." 4039 // Note that according to DR 247, the containing class does not matter. 4040 4041 if (FunctionTemplateDecl *FunctionTemplate 4042 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4043 if (CXXMethodDecl *Method 4044 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4045 // Skip non-static function templates when converting to pointer, and 4046 // static when converting to member pointer. 4047 if (Method->isStatic() == IsMember) 4048 continue; 4049 } else if (IsMember) 4050 continue; 4051 4052 // C++ [over.over]p2: 4053 // If the name is a function template, template argument deduction is 4054 // done (14.8.2.2), and if the argument deduction succeeds, the 4055 // resulting template argument list is used to generate a single 4056 // function template specialization, which is added to the set of 4057 // overloaded functions considered. 4058 // FIXME: We don't really want to build the specialization here, do we? 4059 FunctionDecl *Specialization = 0; 4060 TemplateDeductionInfo Info(Context); 4061 if (TemplateDeductionResult Result 4062 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 4063 /*FIXME:*/0, /*FIXME:*/0, 4064 FunctionType, Specialization, Info)) { 4065 // FIXME: make a note of the failed deduction for diagnostics. 4066 (void)Result; 4067 } else { 4068 // FIXME: If the match isn't exact, shouldn't we just drop this as 4069 // a candidate? Find a testcase before changing the code. 4070 assert(FunctionType 4071 == Context.getCanonicalType(Specialization->getType())); 4072 Matches.insert( 4073 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4074 } 4075 } 4076 4077 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4078 // Skip non-static functions when converting to pointer, and static 4079 // when converting to member pointer. 4080 if (Method->isStatic() == IsMember) 4081 continue; 4082 } else if (IsMember) 4083 continue; 4084 4085 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4086 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4087 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4088 FoundNonTemplateFunction = true; 4089 } 4090 } 4091 } 4092 4093 // If there were 0 or 1 matches, we're done. 4094 if (Matches.empty()) 4095 return 0; 4096 else if (Matches.size() == 1) 4097 return *Matches.begin(); 4098 4099 // C++ [over.over]p4: 4100 // If more than one function is selected, [...] 4101 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4102 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4103 if (FoundNonTemplateFunction) { 4104 // [...] any function template specializations in the set are 4105 // eliminated if the set also contains a non-template function, [...] 4106 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4107 if ((*M)->getPrimaryTemplate() == 0) 4108 RemainingMatches.push_back(*M); 4109 } else { 4110 // [...] and any given function template specialization F1 is 4111 // eliminated if the set contains a second function template 4112 // specialization whose function template is more specialized 4113 // than the function template of F1 according to the partial 4114 // ordering rules of 14.5.5.2. 4115 4116 // The algorithm specified above is quadratic. We instead use a 4117 // two-pass algorithm (similar to the one used to identify the 4118 // best viable function in an overload set) that identifies the 4119 // best function template (if it exists). 4120 MatchIter Best = Matches.begin(); 4121 MatchIter M = Best, MEnd = Matches.end(); 4122 // Find the most specialized function. 4123 for (++M; M != MEnd; ++M) 4124 if (getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4125 (*Best)->getPrimaryTemplate(), 4126 TPOC_Other) 4127 == (*M)->getPrimaryTemplate()) 4128 Best = M; 4129 4130 // Determine whether this function template is more specialized 4131 // that all of the others. 4132 bool Ambiguous = false; 4133 for (M = Matches.begin(); M != MEnd; ++M) { 4134 if (M != Best && 4135 getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4136 (*Best)->getPrimaryTemplate(), 4137 TPOC_Other) 4138 != (*Best)->getPrimaryTemplate()) { 4139 Ambiguous = true; 4140 break; 4141 } 4142 } 4143 4144 // If one function template was more specialized than all of the 4145 // others, return it. 4146 if (!Ambiguous) 4147 return *Best; 4148 4149 // We could not find a most-specialized function template, which 4150 // is equivalent to having a set of function templates with more 4151 // than one such template. So, we place all of the function 4152 // templates into the set of remaining matches and produce a 4153 // diagnostic below. FIXME: we could perform the quadratic 4154 // algorithm here, pruning the result set to limit the number of 4155 // candidates output later. 4156 RemainingMatches.append(Matches.begin(), Matches.end()); 4157 } 4158 4159 // [...] After such eliminations, if any, there shall remain exactly one 4160 // selected function. 4161 if (RemainingMatches.size() == 1) 4162 return RemainingMatches.front(); 4163 4164 // FIXME: We should probably return the same thing that BestViableFunction 4165 // returns (even if we issue the diagnostics here). 4166 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4167 << RemainingMatches[0]->getDeclName(); 4168 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4169 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4170 return 0; 4171} 4172 4173/// \brief Add a single candidate to the overload set. 4174static void AddOverloadedCallCandidate(Sema &S, 4175 AnyFunctionDecl Callee, 4176 bool &ArgumentDependentLookup, 4177 bool HasExplicitTemplateArgs, 4178 const TemplateArgument *ExplicitTemplateArgs, 4179 unsigned NumExplicitTemplateArgs, 4180 Expr **Args, unsigned NumArgs, 4181 OverloadCandidateSet &CandidateSet, 4182 bool PartialOverloading) { 4183 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4184 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4185 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4186 PartialOverloading); 4187 4188 if (Func->getDeclContext()->isRecord() || 4189 Func->getDeclContext()->isFunctionOrMethod()) 4190 ArgumentDependentLookup = false; 4191 return; 4192 } 4193 4194 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4195 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4196 ExplicitTemplateArgs, 4197 NumExplicitTemplateArgs, 4198 Args, NumArgs, CandidateSet); 4199 4200 if (FuncTemplate->getDeclContext()->isRecord()) 4201 ArgumentDependentLookup = false; 4202} 4203 4204/// \brief Add the overload candidates named by callee and/or found by argument 4205/// dependent lookup to the given overload set. 4206void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4207 DeclarationName &UnqualifiedName, 4208 bool &ArgumentDependentLookup, 4209 bool HasExplicitTemplateArgs, 4210 const TemplateArgument *ExplicitTemplateArgs, 4211 unsigned NumExplicitTemplateArgs, 4212 Expr **Args, unsigned NumArgs, 4213 OverloadCandidateSet &CandidateSet, 4214 bool PartialOverloading) { 4215 // Add the functions denoted by Callee to the set of candidate 4216 // functions. While we're doing so, track whether argument-dependent 4217 // lookup still applies, per: 4218 // 4219 // C++0x [basic.lookup.argdep]p3: 4220 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4221 // and let Y be the lookup set produced by argument dependent 4222 // lookup (defined as follows). If X contains 4223 // 4224 // -- a declaration of a class member, or 4225 // 4226 // -- a block-scope function declaration that is not a 4227 // using-declaration (FIXME: check for using declaration), or 4228 // 4229 // -- a declaration that is neither a function or a function 4230 // template 4231 // 4232 // then Y is empty. 4233 if (!Callee) { 4234 // Nothing to do. 4235 } else if (OverloadedFunctionDecl *Ovl 4236 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4237 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4238 FuncEnd = Ovl->function_end(); 4239 Func != FuncEnd; ++Func) 4240 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4241 HasExplicitTemplateArgs, 4242 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4243 Args, NumArgs, CandidateSet, 4244 PartialOverloading); 4245 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4246 AddOverloadedCallCandidate(*this, 4247 AnyFunctionDecl::getFromNamedDecl(Callee), 4248 ArgumentDependentLookup, 4249 HasExplicitTemplateArgs, 4250 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4251 Args, NumArgs, CandidateSet, 4252 PartialOverloading); 4253 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4254 // checking dynamically. 4255 4256 if (Callee) 4257 UnqualifiedName = Callee->getDeclName(); 4258 4259 if (ArgumentDependentLookup) 4260 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4261 HasExplicitTemplateArgs, 4262 ExplicitTemplateArgs, 4263 NumExplicitTemplateArgs, 4264 CandidateSet, 4265 PartialOverloading); 4266} 4267 4268/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4269/// (which eventually refers to the declaration Func) and the call 4270/// arguments Args/NumArgs, attempt to resolve the function call down 4271/// to a specific function. If overload resolution succeeds, returns 4272/// the function declaration produced by overload 4273/// resolution. Otherwise, emits diagnostics, deletes all of the 4274/// arguments and Fn, and returns NULL. 4275FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4276 DeclarationName UnqualifiedName, 4277 bool HasExplicitTemplateArgs, 4278 const TemplateArgument *ExplicitTemplateArgs, 4279 unsigned NumExplicitTemplateArgs, 4280 SourceLocation LParenLoc, 4281 Expr **Args, unsigned NumArgs, 4282 SourceLocation *CommaLocs, 4283 SourceLocation RParenLoc, 4284 bool &ArgumentDependentLookup) { 4285 OverloadCandidateSet CandidateSet; 4286 4287 // Add the functions denoted by Callee to the set of candidate 4288 // functions. 4289 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4290 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4291 NumExplicitTemplateArgs, Args, NumArgs, 4292 CandidateSet); 4293 OverloadCandidateSet::iterator Best; 4294 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4295 case OR_Success: 4296 return Best->Function; 4297 4298 case OR_No_Viable_Function: 4299 Diag(Fn->getSourceRange().getBegin(), 4300 diag::err_ovl_no_viable_function_in_call) 4301 << UnqualifiedName << Fn->getSourceRange(); 4302 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4303 break; 4304 4305 case OR_Ambiguous: 4306 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4307 << UnqualifiedName << Fn->getSourceRange(); 4308 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4309 break; 4310 4311 case OR_Deleted: 4312 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4313 << Best->Function->isDeleted() 4314 << UnqualifiedName 4315 << Fn->getSourceRange(); 4316 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4317 break; 4318 } 4319 4320 // Overload resolution failed. Destroy all of the subexpressions and 4321 // return NULL. 4322 Fn->Destroy(Context); 4323 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4324 Args[Arg]->Destroy(Context); 4325 return 0; 4326} 4327 4328/// \brief Create a unary operation that may resolve to an overloaded 4329/// operator. 4330/// 4331/// \param OpLoc The location of the operator itself (e.g., '*'). 4332/// 4333/// \param OpcIn The UnaryOperator::Opcode that describes this 4334/// operator. 4335/// 4336/// \param Functions The set of non-member functions that will be 4337/// considered by overload resolution. The caller needs to build this 4338/// set based on the context using, e.g., 4339/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4340/// set should not contain any member functions; those will be added 4341/// by CreateOverloadedUnaryOp(). 4342/// 4343/// \param input The input argument. 4344Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4345 unsigned OpcIn, 4346 FunctionSet &Functions, 4347 ExprArg input) { 4348 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4349 Expr *Input = (Expr *)input.get(); 4350 4351 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4352 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4353 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4354 4355 Expr *Args[2] = { Input, 0 }; 4356 unsigned NumArgs = 1; 4357 4358 // For post-increment and post-decrement, add the implicit '0' as 4359 // the second argument, so that we know this is a post-increment or 4360 // post-decrement. 4361 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4362 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4363 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4364 SourceLocation()); 4365 NumArgs = 2; 4366 } 4367 4368 if (Input->isTypeDependent()) { 4369 OverloadedFunctionDecl *Overloads 4370 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4371 for (FunctionSet::iterator Func = Functions.begin(), 4372 FuncEnd = Functions.end(); 4373 Func != FuncEnd; ++Func) 4374 Overloads->addOverload(*Func); 4375 4376 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4377 OpLoc, false, false); 4378 4379 input.release(); 4380 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4381 &Args[0], NumArgs, 4382 Context.DependentTy, 4383 OpLoc)); 4384 } 4385 4386 // Build an empty overload set. 4387 OverloadCandidateSet CandidateSet; 4388 4389 // Add the candidates from the given function set. 4390 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4391 4392 // Add operator candidates that are member functions. 4393 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4394 4395 // Add builtin operator candidates. 4396 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4397 4398 // Perform overload resolution. 4399 OverloadCandidateSet::iterator Best; 4400 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4401 case OR_Success: { 4402 // We found a built-in operator or an overloaded operator. 4403 FunctionDecl *FnDecl = Best->Function; 4404 4405 if (FnDecl) { 4406 // We matched an overloaded operator. Build a call to that 4407 // operator. 4408 4409 // Convert the arguments. 4410 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4411 if (PerformObjectArgumentInitialization(Input, Method)) 4412 return ExprError(); 4413 } else { 4414 // Convert the arguments. 4415 if (PerformCopyInitialization(Input, 4416 FnDecl->getParamDecl(0)->getType(), 4417 "passing")) 4418 return ExprError(); 4419 } 4420 4421 // Determine the result type 4422 QualType ResultTy 4423 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4424 ResultTy = ResultTy.getNonReferenceType(); 4425 4426 // Build the actual expression node. 4427 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4428 SourceLocation()); 4429 UsualUnaryConversions(FnExpr); 4430 4431 input.release(); 4432 4433 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4434 &Input, 1, ResultTy, OpLoc); 4435 return MaybeBindToTemporary(CE); 4436 } else { 4437 // We matched a built-in operator. Convert the arguments, then 4438 // break out so that we will build the appropriate built-in 4439 // operator node. 4440 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4441 Best->Conversions[0], "passing")) 4442 return ExprError(); 4443 4444 break; 4445 } 4446 } 4447 4448 case OR_No_Viable_Function: 4449 // No viable function; fall through to handling this as a 4450 // built-in operator, which will produce an error message for us. 4451 break; 4452 4453 case OR_Ambiguous: 4454 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4455 << UnaryOperator::getOpcodeStr(Opc) 4456 << Input->getSourceRange(); 4457 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4458 return ExprError(); 4459 4460 case OR_Deleted: 4461 Diag(OpLoc, diag::err_ovl_deleted_oper) 4462 << Best->Function->isDeleted() 4463 << UnaryOperator::getOpcodeStr(Opc) 4464 << Input->getSourceRange(); 4465 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4466 return ExprError(); 4467 } 4468 4469 // Either we found no viable overloaded operator or we matched a 4470 // built-in operator. In either case, fall through to trying to 4471 // build a built-in operation. 4472 input.release(); 4473 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4474} 4475 4476/// \brief Create a binary operation that may resolve to an overloaded 4477/// operator. 4478/// 4479/// \param OpLoc The location of the operator itself (e.g., '+'). 4480/// 4481/// \param OpcIn The BinaryOperator::Opcode that describes this 4482/// operator. 4483/// 4484/// \param Functions The set of non-member functions that will be 4485/// considered by overload resolution. The caller needs to build this 4486/// set based on the context using, e.g., 4487/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4488/// set should not contain any member functions; those will be added 4489/// by CreateOverloadedBinOp(). 4490/// 4491/// \param LHS Left-hand argument. 4492/// \param RHS Right-hand argument. 4493Sema::OwningExprResult 4494Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4495 unsigned OpcIn, 4496 FunctionSet &Functions, 4497 Expr *LHS, Expr *RHS) { 4498 Expr *Args[2] = { LHS, RHS }; 4499 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4500 4501 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4502 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4503 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4504 4505 // If either side is type-dependent, create an appropriate dependent 4506 // expression. 4507 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4508 // .* cannot be overloaded. 4509 if (Opc == BinaryOperator::PtrMemD) 4510 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4511 Context.DependentTy, OpLoc)); 4512 4513 OverloadedFunctionDecl *Overloads 4514 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4515 for (FunctionSet::iterator Func = Functions.begin(), 4516 FuncEnd = Functions.end(); 4517 Func != FuncEnd; ++Func) 4518 Overloads->addOverload(*Func); 4519 4520 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4521 OpLoc, false, false); 4522 4523 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4524 Args, 2, 4525 Context.DependentTy, 4526 OpLoc)); 4527 } 4528 4529 // If this is the .* operator, which is not overloadable, just 4530 // create a built-in binary operator. 4531 if (Opc == BinaryOperator::PtrMemD) 4532 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4533 4534 // If this is one of the assignment operators, we only perform 4535 // overload resolution if the left-hand side is a class or 4536 // enumeration type (C++ [expr.ass]p3). 4537 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4538 !Args[0]->getType()->isOverloadableType()) 4539 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4540 4541 // Build an empty overload set. 4542 OverloadCandidateSet CandidateSet; 4543 4544 // Add the candidates from the given function set. 4545 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4546 4547 // Add operator candidates that are member functions. 4548 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4549 4550 // Add builtin operator candidates. 4551 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4552 4553 // Perform overload resolution. 4554 OverloadCandidateSet::iterator Best; 4555 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4556 case OR_Success: { 4557 // We found a built-in operator or an overloaded operator. 4558 FunctionDecl *FnDecl = Best->Function; 4559 4560 if (FnDecl) { 4561 // We matched an overloaded operator. Build a call to that 4562 // operator. 4563 4564 // Convert the arguments. 4565 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4566 if (PerformObjectArgumentInitialization(Args[0], Method) || 4567 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4568 "passing")) 4569 return ExprError(); 4570 } else { 4571 // Convert the arguments. 4572 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4573 "passing") || 4574 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4575 "passing")) 4576 return ExprError(); 4577 } 4578 4579 // Determine the result type 4580 QualType ResultTy 4581 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4582 ResultTy = ResultTy.getNonReferenceType(); 4583 4584 // Build the actual expression node. 4585 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4586 OpLoc); 4587 UsualUnaryConversions(FnExpr); 4588 4589 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4590 Args, 2, ResultTy, OpLoc); 4591 return MaybeBindToTemporary(CE); 4592 } else { 4593 // We matched a built-in operator. Convert the arguments, then 4594 // break out so that we will build the appropriate built-in 4595 // operator node. 4596 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4597 Best->Conversions[0], "passing") || 4598 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4599 Best->Conversions[1], "passing")) 4600 return ExprError(); 4601 4602 break; 4603 } 4604 } 4605 4606 case OR_No_Viable_Function: 4607 // For class as left operand for assignment or compound assigment operator 4608 // do not fall through to handling in built-in, but report that no overloaded 4609 // assignment operator found 4610 if (Args[0]->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4611 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4612 << BinaryOperator::getOpcodeStr(Opc) 4613 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4614 return ExprError(); 4615 } 4616 // No viable function; fall through to handling this as a 4617 // built-in operator, which will produce an error message for us. 4618 break; 4619 4620 case OR_Ambiguous: 4621 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4622 << BinaryOperator::getOpcodeStr(Opc) 4623 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4624 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4625 return ExprError(); 4626 4627 case OR_Deleted: 4628 Diag(OpLoc, diag::err_ovl_deleted_oper) 4629 << Best->Function->isDeleted() 4630 << BinaryOperator::getOpcodeStr(Opc) 4631 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4632 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4633 return ExprError(); 4634 } 4635 4636 // Either we found no viable overloaded operator or we matched a 4637 // built-in operator. In either case, try to build a built-in 4638 // operation. 4639 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4640} 4641 4642/// BuildCallToMemberFunction - Build a call to a member 4643/// function. MemExpr is the expression that refers to the member 4644/// function (and includes the object parameter), Args/NumArgs are the 4645/// arguments to the function call (not including the object 4646/// parameter). The caller needs to validate that the member 4647/// expression refers to a member function or an overloaded member 4648/// function. 4649Sema::ExprResult 4650Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4651 SourceLocation LParenLoc, Expr **Args, 4652 unsigned NumArgs, SourceLocation *CommaLocs, 4653 SourceLocation RParenLoc) { 4654 // Dig out the member expression. This holds both the object 4655 // argument and the member function we're referring to. 4656 MemberExpr *MemExpr = 0; 4657 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4658 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4659 else 4660 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4661 assert(MemExpr && "Building member call without member expression"); 4662 4663 // Extract the object argument. 4664 Expr *ObjectArg = MemExpr->getBase(); 4665 4666 CXXMethodDecl *Method = 0; 4667 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 4668 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 4669 // Add overload candidates 4670 OverloadCandidateSet CandidateSet; 4671 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 4672 4673 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 4674 Func != FuncEnd; ++Func) { 4675 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) 4676 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4677 /*SuppressUserConversions=*/false); 4678 else 4679 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 4680 MemExpr->hasExplicitTemplateArgumentList(), 4681 MemExpr->getTemplateArgs(), 4682 MemExpr->getNumTemplateArgs(), 4683 ObjectArg, Args, NumArgs, 4684 CandidateSet, 4685 /*SuppressUsedConversions=*/false); 4686 } 4687 4688 OverloadCandidateSet::iterator Best; 4689 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4690 case OR_Success: 4691 Method = cast<CXXMethodDecl>(Best->Function); 4692 break; 4693 4694 case OR_No_Viable_Function: 4695 Diag(MemExpr->getSourceRange().getBegin(), 4696 diag::err_ovl_no_viable_member_function_in_call) 4697 << DeclName << MemExprE->getSourceRange(); 4698 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4699 // FIXME: Leaking incoming expressions! 4700 return true; 4701 4702 case OR_Ambiguous: 4703 Diag(MemExpr->getSourceRange().getBegin(), 4704 diag::err_ovl_ambiguous_member_call) 4705 << DeclName << MemExprE->getSourceRange(); 4706 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4707 // FIXME: Leaking incoming expressions! 4708 return true; 4709 4710 case OR_Deleted: 4711 Diag(MemExpr->getSourceRange().getBegin(), 4712 diag::err_ovl_deleted_member_call) 4713 << Best->Function->isDeleted() 4714 << DeclName << MemExprE->getSourceRange(); 4715 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4716 // FIXME: Leaking incoming expressions! 4717 return true; 4718 } 4719 4720 FixOverloadedFunctionReference(MemExpr, Method); 4721 } else { 4722 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4723 } 4724 4725 assert(Method && "Member call to something that isn't a method?"); 4726 ExprOwningPtr<CXXMemberCallExpr> 4727 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4728 NumArgs, 4729 Method->getResultType().getNonReferenceType(), 4730 RParenLoc)); 4731 4732 // Convert the object argument (for a non-static member function call). 4733 if (!Method->isStatic() && 4734 PerformObjectArgumentInitialization(ObjectArg, Method)) 4735 return true; 4736 MemExpr->setBase(ObjectArg); 4737 4738 // Convert the rest of the arguments 4739 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4740 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4741 RParenLoc)) 4742 return true; 4743 4744 if (CheckFunctionCall(Method, TheCall.get())) 4745 return true; 4746 4747 return MaybeBindToTemporary(TheCall.release()).release(); 4748} 4749 4750/// BuildCallToObjectOfClassType - Build a call to an object of class 4751/// type (C++ [over.call.object]), which can end up invoking an 4752/// overloaded function call operator (@c operator()) or performing a 4753/// user-defined conversion on the object argument. 4754Sema::ExprResult 4755Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4756 SourceLocation LParenLoc, 4757 Expr **Args, unsigned NumArgs, 4758 SourceLocation *CommaLocs, 4759 SourceLocation RParenLoc) { 4760 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4761 const RecordType *Record = Object->getType()->getAs<RecordType>(); 4762 4763 // C++ [over.call.object]p1: 4764 // If the primary-expression E in the function call syntax 4765 // evaluates to a class object of type "cv T", then the set of 4766 // candidate functions includes at least the function call 4767 // operators of T. The function call operators of T are obtained by 4768 // ordinary lookup of the name operator() in the context of 4769 // (E).operator(). 4770 OverloadCandidateSet CandidateSet; 4771 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4772 DeclContext::lookup_const_iterator Oper, OperEnd; 4773 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4774 Oper != OperEnd; ++Oper) 4775 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4776 CandidateSet, /*SuppressUserConversions=*/false); 4777 4778 // C++ [over.call.object]p2: 4779 // In addition, for each conversion function declared in T of the 4780 // form 4781 // 4782 // operator conversion-type-id () cv-qualifier; 4783 // 4784 // where cv-qualifier is the same cv-qualification as, or a 4785 // greater cv-qualification than, cv, and where conversion-type-id 4786 // denotes the type "pointer to function of (P1,...,Pn) returning 4787 // R", or the type "reference to pointer to function of 4788 // (P1,...,Pn) returning R", or the type "reference to function 4789 // of (P1,...,Pn) returning R", a surrogate call function [...] 4790 // is also considered as a candidate function. Similarly, 4791 // surrogate call functions are added to the set of candidate 4792 // functions for each conversion function declared in an 4793 // accessible base class provided the function is not hidden 4794 // within T by another intervening declaration. 4795 4796 if (!RequireCompleteType(SourceLocation(), Object->getType(), 0)) { 4797 // FIXME: Look in base classes for more conversion operators! 4798 OverloadedFunctionDecl *Conversions 4799 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4800 for (OverloadedFunctionDecl::function_iterator 4801 Func = Conversions->function_begin(), 4802 FuncEnd = Conversions->function_end(); 4803 Func != FuncEnd; ++Func) { 4804 CXXConversionDecl *Conv; 4805 FunctionTemplateDecl *ConvTemplate; 4806 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 4807 4808 // Skip over templated conversion functions; they aren't 4809 // surrogates. 4810 if (ConvTemplate) 4811 continue; 4812 4813 // Strip the reference type (if any) and then the pointer type (if 4814 // any) to get down to what might be a function type. 4815 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4816 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4817 ConvType = ConvPtrType->getPointeeType(); 4818 4819 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 4820 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4821 } 4822 } 4823 4824 // Perform overload resolution. 4825 OverloadCandidateSet::iterator Best; 4826 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4827 case OR_Success: 4828 // Overload resolution succeeded; we'll build the appropriate call 4829 // below. 4830 break; 4831 4832 case OR_No_Viable_Function: 4833 Diag(Object->getSourceRange().getBegin(), 4834 diag::err_ovl_no_viable_object_call) 4835 << Object->getType() << Object->getSourceRange(); 4836 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4837 break; 4838 4839 case OR_Ambiguous: 4840 Diag(Object->getSourceRange().getBegin(), 4841 diag::err_ovl_ambiguous_object_call) 4842 << Object->getType() << Object->getSourceRange(); 4843 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4844 break; 4845 4846 case OR_Deleted: 4847 Diag(Object->getSourceRange().getBegin(), 4848 diag::err_ovl_deleted_object_call) 4849 << Best->Function->isDeleted() 4850 << Object->getType() << Object->getSourceRange(); 4851 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4852 break; 4853 } 4854 4855 if (Best == CandidateSet.end()) { 4856 // We had an error; delete all of the subexpressions and return 4857 // the error. 4858 Object->Destroy(Context); 4859 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4860 Args[ArgIdx]->Destroy(Context); 4861 return true; 4862 } 4863 4864 if (Best->Function == 0) { 4865 // Since there is no function declaration, this is one of the 4866 // surrogate candidates. Dig out the conversion function. 4867 CXXConversionDecl *Conv 4868 = cast<CXXConversionDecl>( 4869 Best->Conversions[0].UserDefined.ConversionFunction); 4870 4871 // We selected one of the surrogate functions that converts the 4872 // object parameter to a function pointer. Perform the conversion 4873 // on the object argument, then let ActOnCallExpr finish the job. 4874 // FIXME: Represent the user-defined conversion in the AST! 4875 ImpCastExprToType(Object, 4876 Conv->getConversionType().getNonReferenceType(), 4877 CastExpr::CK_Unknown, 4878 Conv->getConversionType()->isLValueReferenceType()); 4879 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4880 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4881 CommaLocs, RParenLoc).release(); 4882 } 4883 4884 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4885 // that calls this method, using Object for the implicit object 4886 // parameter and passing along the remaining arguments. 4887 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4888 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 4889 4890 unsigned NumArgsInProto = Proto->getNumArgs(); 4891 unsigned NumArgsToCheck = NumArgs; 4892 4893 // Build the full argument list for the method call (the 4894 // implicit object parameter is placed at the beginning of the 4895 // list). 4896 Expr **MethodArgs; 4897 if (NumArgs < NumArgsInProto) { 4898 NumArgsToCheck = NumArgsInProto; 4899 MethodArgs = new Expr*[NumArgsInProto + 1]; 4900 } else { 4901 MethodArgs = new Expr*[NumArgs + 1]; 4902 } 4903 MethodArgs[0] = Object; 4904 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4905 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4906 4907 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4908 SourceLocation()); 4909 UsualUnaryConversions(NewFn); 4910 4911 // Once we've built TheCall, all of the expressions are properly 4912 // owned. 4913 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4914 ExprOwningPtr<CXXOperatorCallExpr> 4915 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4916 MethodArgs, NumArgs + 1, 4917 ResultTy, RParenLoc)); 4918 delete [] MethodArgs; 4919 4920 // We may have default arguments. If so, we need to allocate more 4921 // slots in the call for them. 4922 if (NumArgs < NumArgsInProto) 4923 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4924 else if (NumArgs > NumArgsInProto) 4925 NumArgsToCheck = NumArgsInProto; 4926 4927 bool IsError = false; 4928 4929 // Initialize the implicit object parameter. 4930 IsError |= PerformObjectArgumentInitialization(Object, Method); 4931 TheCall->setArg(0, Object); 4932 4933 4934 // Check the argument types. 4935 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4936 Expr *Arg; 4937 if (i < NumArgs) { 4938 Arg = Args[i]; 4939 4940 // Pass the argument. 4941 QualType ProtoArgType = Proto->getArgType(i); 4942 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4943 } else { 4944 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 4945 } 4946 4947 TheCall->setArg(i + 1, Arg); 4948 } 4949 4950 // If this is a variadic call, handle args passed through "...". 4951 if (Proto->isVariadic()) { 4952 // Promote the arguments (C99 6.5.2.2p7). 4953 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4954 Expr *Arg = Args[i]; 4955 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4956 TheCall->setArg(i + 1, Arg); 4957 } 4958 } 4959 4960 if (IsError) return true; 4961 4962 if (CheckFunctionCall(Method, TheCall.get())) 4963 return true; 4964 4965 return MaybeBindToTemporary(TheCall.release()).release(); 4966} 4967 4968/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4969/// (if one exists), where @c Base is an expression of class type and 4970/// @c Member is the name of the member we're trying to find. 4971Sema::OwningExprResult 4972Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 4973 Expr *Base = static_cast<Expr *>(BaseIn.get()); 4974 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4975 4976 // C++ [over.ref]p1: 4977 // 4978 // [...] An expression x->m is interpreted as (x.operator->())->m 4979 // for a class object x of type T if T::operator->() exists and if 4980 // the operator is selected as the best match function by the 4981 // overload resolution mechanism (13.3). 4982 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4983 OverloadCandidateSet CandidateSet; 4984 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 4985 4986 LookupResult R = LookupQualifiedName(BaseRecord->getDecl(), OpName, 4987 LookupOrdinaryName); 4988 4989 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 4990 Oper != OperEnd; ++Oper) 4991 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4992 /*SuppressUserConversions=*/false); 4993 4994 // Perform overload resolution. 4995 OverloadCandidateSet::iterator Best; 4996 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4997 case OR_Success: 4998 // Overload resolution succeeded; we'll build the call below. 4999 break; 5000 5001 case OR_No_Viable_Function: 5002 if (CandidateSet.empty()) 5003 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5004 << Base->getType() << Base->getSourceRange(); 5005 else 5006 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5007 << "operator->" << Base->getSourceRange(); 5008 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5009 return ExprError(); 5010 5011 case OR_Ambiguous: 5012 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5013 << "->" << Base->getSourceRange(); 5014 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5015 return ExprError(); 5016 5017 case OR_Deleted: 5018 Diag(OpLoc, diag::err_ovl_deleted_oper) 5019 << Best->Function->isDeleted() 5020 << "->" << Base->getSourceRange(); 5021 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5022 return ExprError(); 5023 } 5024 5025 // Convert the object parameter. 5026 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5027 if (PerformObjectArgumentInitialization(Base, Method)) 5028 return ExprError(); 5029 5030 // No concerns about early exits now. 5031 BaseIn.release(); 5032 5033 // Build the operator call. 5034 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5035 SourceLocation()); 5036 UsualUnaryConversions(FnExpr); 5037 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 5038 Method->getResultType().getNonReferenceType(), 5039 OpLoc); 5040 return Owned(Base); 5041} 5042 5043/// FixOverloadedFunctionReference - E is an expression that refers to 5044/// a C++ overloaded function (possibly with some parentheses and 5045/// perhaps a '&' around it). We have resolved the overloaded function 5046/// to the function declaration Fn, so patch up the expression E to 5047/// refer (possibly indirectly) to Fn. 5048void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5049 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5050 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5051 E->setType(PE->getSubExpr()->getType()); 5052 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5053 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5054 "Can only take the address of an overloaded function"); 5055 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5056 if (Method->isStatic()) { 5057 // Do nothing: static member functions aren't any different 5058 // from non-member functions. 5059 } else if (QualifiedDeclRefExpr *DRE 5060 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 5061 // We have taken the address of a pointer to member 5062 // function. Perform the computation here so that we get the 5063 // appropriate pointer to member type. 5064 DRE->setDecl(Fn); 5065 DRE->setType(Fn->getType()); 5066 QualType ClassType 5067 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5068 E->setType(Context.getMemberPointerType(Fn->getType(), 5069 ClassType.getTypePtr())); 5070 return; 5071 } 5072 } 5073 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5074 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 5075 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5076 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5077 isa<FunctionTemplateDecl>(DR->getDecl())) && 5078 "Expected overloaded function or function template"); 5079 DR->setDecl(Fn); 5080 E->setType(Fn->getType()); 5081 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5082 MemExpr->setMemberDecl(Fn); 5083 E->setType(Fn->getType()); 5084 } else { 5085 assert(false && "Invalid reference to overloaded function"); 5086 } 5087} 5088 5089} // end namespace clang 5090