SemaOverload.cpp revision 66724ea67d7d598b937d86fa66f03f09a1c758f3
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "clang/Basic/Diagnostic.h" 16#include "clang/Lex/Preprocessor.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/CXXInheritance.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/TypeOrdering.h" 22#include "clang/Basic/PartialDiagnostic.h" 23#include "llvm/ADT/SmallPtrSet.h" 24#include "llvm/ADT/STLExtras.h" 25#include "llvm/Support/Compiler.h" 26#include <algorithm> 27#include <cstdio> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Qualification_Adjustment, 42 ICC_Promotion, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Conversion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion 55 }; 56 return Category[(int)Kind]; 57} 58 59/// GetConversionRank - Retrieve the implicit conversion rank 60/// corresponding to the given implicit conversion kind. 61ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 62 static const ImplicitConversionRank 63 Rank[(int)ICK_Num_Conversion_Kinds] = { 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Promotion, 70 ICR_Promotion, 71 ICR_Promotion, 72 ICR_Conversion, 73 ICR_Conversion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion 82 }; 83 return Rank[(int)Kind]; 84} 85 86/// GetImplicitConversionName - Return the name of this kind of 87/// implicit conversion. 88const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 89 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 90 "No conversion", 91 "Lvalue-to-rvalue", 92 "Array-to-pointer", 93 "Function-to-pointer", 94 "Qualification", 95 "Integral promotion", 96 "Floating point promotion", 97 "Complex promotion", 98 "Integral conversion", 99 "Floating conversion", 100 "Complex conversion", 101 "Floating-integral conversion", 102 "Complex-real conversion", 103 "Pointer conversion", 104 "Pointer-to-member conversion", 105 "Boolean conversion", 106 "Compatible-types conversion", 107 "Derived-to-base conversion" 108 }; 109 return Name[Kind]; 110} 111 112/// StandardConversionSequence - Set the standard conversion 113/// sequence to the identity conversion. 114void StandardConversionSequence::setAsIdentityConversion() { 115 First = ICK_Identity; 116 Second = ICK_Identity; 117 Third = ICK_Identity; 118 Deprecated = false; 119 ReferenceBinding = false; 120 DirectBinding = false; 121 RRefBinding = false; 122 CopyConstructor = 0; 123} 124 125/// getRank - Retrieve the rank of this standard conversion sequence 126/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 127/// implicit conversions. 128ImplicitConversionRank StandardConversionSequence::getRank() const { 129 ImplicitConversionRank Rank = ICR_Exact_Match; 130 if (GetConversionRank(First) > Rank) 131 Rank = GetConversionRank(First); 132 if (GetConversionRank(Second) > Rank) 133 Rank = GetConversionRank(Second); 134 if (GetConversionRank(Third) > Rank) 135 Rank = GetConversionRank(Third); 136 return Rank; 137} 138 139/// isPointerConversionToBool - Determines whether this conversion is 140/// a conversion of a pointer or pointer-to-member to bool. This is 141/// used as part of the ranking of standard conversion sequences 142/// (C++ 13.3.3.2p4). 143bool StandardConversionSequence::isPointerConversionToBool() const { 144 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 145 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 146 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (ToType->isBooleanType() && 152 (FromType->isPointerType() || FromType->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 167 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 bool PrintedSomething = false; 186 if (First != ICK_Identity) { 187 fprintf(stderr, "%s", GetImplicitConversionName(First)); 188 PrintedSomething = true; 189 } 190 191 if (Second != ICK_Identity) { 192 if (PrintedSomething) { 193 fprintf(stderr, " -> "); 194 } 195 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 196 197 if (CopyConstructor) { 198 fprintf(stderr, " (by copy constructor)"); 199 } else if (DirectBinding) { 200 fprintf(stderr, " (direct reference binding)"); 201 } else if (ReferenceBinding) { 202 fprintf(stderr, " (reference binding)"); 203 } 204 PrintedSomething = true; 205 } 206 207 if (Third != ICK_Identity) { 208 if (PrintedSomething) { 209 fprintf(stderr, " -> "); 210 } 211 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 212 PrintedSomething = true; 213 } 214 215 if (!PrintedSomething) { 216 fprintf(stderr, "No conversions required"); 217 } 218} 219 220/// DebugPrint - Print this user-defined conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void UserDefinedConversionSequence::DebugPrint() const { 223 if (Before.First || Before.Second || Before.Third) { 224 Before.DebugPrint(); 225 fprintf(stderr, " -> "); 226 } 227 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 228 if (After.First || After.Second || After.Third) { 229 fprintf(stderr, " -> "); 230 After.DebugPrint(); 231 } 232} 233 234/// DebugPrint - Print this implicit conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void ImplicitConversionSequence::DebugPrint() const { 237 switch (ConversionKind) { 238 case StandardConversion: 239 fprintf(stderr, "Standard conversion: "); 240 Standard.DebugPrint(); 241 break; 242 case UserDefinedConversion: 243 fprintf(stderr, "User-defined conversion: "); 244 UserDefined.DebugPrint(); 245 break; 246 case EllipsisConversion: 247 fprintf(stderr, "Ellipsis conversion"); 248 break; 249 case BadConversion: 250 fprintf(stderr, "Bad conversion"); 251 break; 252 } 253 254 fprintf(stderr, "\n"); 255} 256 257// IsOverload - Determine whether the given New declaration is an 258// overload of the Old declaration. This routine returns false if New 259// and Old cannot be overloaded, e.g., if they are functions with the 260// same signature (C++ 1.3.10) or if the Old declaration isn't a 261// function (or overload set). When it does return false and Old is an 262// OverloadedFunctionDecl, MatchedDecl will be set to point to the 263// FunctionDecl that New cannot be overloaded with. 264// 265// Example: Given the following input: 266// 267// void f(int, float); // #1 268// void f(int, int); // #2 269// int f(int, int); // #3 270// 271// When we process #1, there is no previous declaration of "f", 272// so IsOverload will not be used. 273// 274// When we process #2, Old is a FunctionDecl for #1. By comparing the 275// parameter types, we see that #1 and #2 are overloaded (since they 276// have different signatures), so this routine returns false; 277// MatchedDecl is unchanged. 278// 279// When we process #3, Old is an OverloadedFunctionDecl containing #1 280// and #2. We compare the signatures of #3 to #1 (they're overloaded, 281// so we do nothing) and then #3 to #2. Since the signatures of #3 and 282// #2 are identical (return types of functions are not part of the 283// signature), IsOverload returns false and MatchedDecl will be set to 284// point to the FunctionDecl for #2. 285bool 286Sema::IsOverload(FunctionDecl *New, Decl* OldD, 287 OverloadedFunctionDecl::function_iterator& MatchedDecl) { 288 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 289 // Is this new function an overload of every function in the 290 // overload set? 291 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 292 FuncEnd = Ovl->function_end(); 293 for (; Func != FuncEnd; ++Func) { 294 if (!IsOverload(New, *Func, MatchedDecl)) { 295 MatchedDecl = Func; 296 return false; 297 } 298 } 299 300 // This function overloads every function in the overload set. 301 return true; 302 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 303 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 304 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 305 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 306 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 307 308 // C++ [temp.fct]p2: 309 // A function template can be overloaded with other function templates 310 // and with normal (non-template) functions. 311 if ((OldTemplate == 0) != (NewTemplate == 0)) 312 return true; 313 314 // Is the function New an overload of the function Old? 315 QualType OldQType = Context.getCanonicalType(Old->getType()); 316 QualType NewQType = Context.getCanonicalType(New->getType()); 317 318 // Compare the signatures (C++ 1.3.10) of the two functions to 319 // determine whether they are overloads. If we find any mismatch 320 // in the signature, they are overloads. 321 322 // If either of these functions is a K&R-style function (no 323 // prototype), then we consider them to have matching signatures. 324 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 325 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 326 return false; 327 328 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 329 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 330 331 // The signature of a function includes the types of its 332 // parameters (C++ 1.3.10), which includes the presence or absence 333 // of the ellipsis; see C++ DR 357). 334 if (OldQType != NewQType && 335 (OldType->getNumArgs() != NewType->getNumArgs() || 336 OldType->isVariadic() != NewType->isVariadic() || 337 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 338 NewType->arg_type_begin()))) 339 return true; 340 341 // C++ [temp.over.link]p4: 342 // The signature of a function template consists of its function 343 // signature, its return type and its template parameter list. The names 344 // of the template parameters are significant only for establishing the 345 // relationship between the template parameters and the rest of the 346 // signature. 347 // 348 // We check the return type and template parameter lists for function 349 // templates first; the remaining checks follow. 350 if (NewTemplate && 351 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 352 OldTemplate->getTemplateParameters(), 353 false, TPL_TemplateMatch) || 354 OldType->getResultType() != NewType->getResultType())) 355 return true; 356 357 // If the function is a class member, its signature includes the 358 // cv-qualifiers (if any) on the function itself. 359 // 360 // As part of this, also check whether one of the member functions 361 // is static, in which case they are not overloads (C++ 362 // 13.1p2). While not part of the definition of the signature, 363 // this check is important to determine whether these functions 364 // can be overloaded. 365 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 366 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 367 if (OldMethod && NewMethod && 368 !OldMethod->isStatic() && !NewMethod->isStatic() && 369 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 370 return true; 371 372 // The signatures match; this is not an overload. 373 return false; 374 } else { 375 // (C++ 13p1): 376 // Only function declarations can be overloaded; object and type 377 // declarations cannot be overloaded. 378 return false; 379 } 380} 381 382/// TryImplicitConversion - Attempt to perform an implicit conversion 383/// from the given expression (Expr) to the given type (ToType). This 384/// function returns an implicit conversion sequence that can be used 385/// to perform the initialization. Given 386/// 387/// void f(float f); 388/// void g(int i) { f(i); } 389/// 390/// this routine would produce an implicit conversion sequence to 391/// describe the initialization of f from i, which will be a standard 392/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 393/// 4.1) followed by a floating-integral conversion (C++ 4.9). 394// 395/// Note that this routine only determines how the conversion can be 396/// performed; it does not actually perform the conversion. As such, 397/// it will not produce any diagnostics if no conversion is available, 398/// but will instead return an implicit conversion sequence of kind 399/// "BadConversion". 400/// 401/// If @p SuppressUserConversions, then user-defined conversions are 402/// not permitted. 403/// If @p AllowExplicit, then explicit user-defined conversions are 404/// permitted. 405/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 406/// no matter its actual lvalueness. 407/// If @p UserCast, the implicit conversion is being done for a user-specified 408/// cast. 409ImplicitConversionSequence 410Sema::TryImplicitConversion(Expr* From, QualType ToType, 411 bool SuppressUserConversions, 412 bool AllowExplicit, bool ForceRValue, 413 bool InOverloadResolution, 414 bool UserCast) { 415 ImplicitConversionSequence ICS; 416 OverloadCandidateSet Conversions; 417 OverloadingResult UserDefResult = OR_Success; 418 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 419 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 420 else if (getLangOptions().CPlusPlus && 421 (UserDefResult = IsUserDefinedConversion(From, ToType, 422 ICS.UserDefined, 423 Conversions, 424 !SuppressUserConversions, AllowExplicit, 425 ForceRValue, UserCast)) == OR_Success) { 426 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 427 // C++ [over.ics.user]p4: 428 // A conversion of an expression of class type to the same class 429 // type is given Exact Match rank, and a conversion of an 430 // expression of class type to a base class of that type is 431 // given Conversion rank, in spite of the fact that a copy 432 // constructor (i.e., a user-defined conversion function) is 433 // called for those cases. 434 if (CXXConstructorDecl *Constructor 435 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 436 QualType FromCanon 437 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 438 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 439 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 440 // Turn this into a "standard" conversion sequence, so that it 441 // gets ranked with standard conversion sequences. 442 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 443 ICS.Standard.setAsIdentityConversion(); 444 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 445 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 446 ICS.Standard.CopyConstructor = Constructor; 447 if (ToCanon != FromCanon) 448 ICS.Standard.Second = ICK_Derived_To_Base; 449 } 450 } 451 452 // C++ [over.best.ics]p4: 453 // However, when considering the argument of a user-defined 454 // conversion function that is a candidate by 13.3.1.3 when 455 // invoked for the copying of the temporary in the second step 456 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 457 // 13.3.1.6 in all cases, only standard conversion sequences and 458 // ellipsis conversion sequences are allowed. 459 if (SuppressUserConversions && 460 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 461 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 462 } else { 463 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 464 if (UserDefResult == OR_Ambiguous) { 465 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 466 Cand != Conversions.end(); ++Cand) 467 if (Cand->Viable) 468 ICS.ConversionFunctionSet.push_back(Cand->Function); 469 } 470 } 471 472 return ICS; 473} 474 475/// IsStandardConversion - Determines whether there is a standard 476/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 477/// expression From to the type ToType. Standard conversion sequences 478/// only consider non-class types; for conversions that involve class 479/// types, use TryImplicitConversion. If a conversion exists, SCS will 480/// contain the standard conversion sequence required to perform this 481/// conversion and this routine will return true. Otherwise, this 482/// routine will return false and the value of SCS is unspecified. 483bool 484Sema::IsStandardConversion(Expr* From, QualType ToType, 485 bool InOverloadResolution, 486 StandardConversionSequence &SCS) { 487 QualType FromType = From->getType(); 488 489 // Standard conversions (C++ [conv]) 490 SCS.setAsIdentityConversion(); 491 SCS.Deprecated = false; 492 SCS.IncompatibleObjC = false; 493 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 494 SCS.CopyConstructor = 0; 495 496 // There are no standard conversions for class types in C++, so 497 // abort early. When overloading in C, however, we do permit 498 if (FromType->isRecordType() || ToType->isRecordType()) { 499 if (getLangOptions().CPlusPlus) 500 return false; 501 502 // When we're overloading in C, we allow, as standard conversions, 503 } 504 505 // The first conversion can be an lvalue-to-rvalue conversion, 506 // array-to-pointer conversion, or function-to-pointer conversion 507 // (C++ 4p1). 508 509 // Lvalue-to-rvalue conversion (C++ 4.1): 510 // An lvalue (3.10) of a non-function, non-array type T can be 511 // converted to an rvalue. 512 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 513 if (argIsLvalue == Expr::LV_Valid && 514 !FromType->isFunctionType() && !FromType->isArrayType() && 515 Context.getCanonicalType(FromType) != Context.OverloadTy) { 516 SCS.First = ICK_Lvalue_To_Rvalue; 517 518 // If T is a non-class type, the type of the rvalue is the 519 // cv-unqualified version of T. Otherwise, the type of the rvalue 520 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 521 // just strip the qualifiers because they don't matter. 522 523 // FIXME: Doesn't see through to qualifiers behind a typedef! 524 FromType = FromType.getUnqualifiedType(); 525 } else if (FromType->isArrayType()) { 526 // Array-to-pointer conversion (C++ 4.2) 527 SCS.First = ICK_Array_To_Pointer; 528 529 // An lvalue or rvalue of type "array of N T" or "array of unknown 530 // bound of T" can be converted to an rvalue of type "pointer to 531 // T" (C++ 4.2p1). 532 FromType = Context.getArrayDecayedType(FromType); 533 534 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 535 // This conversion is deprecated. (C++ D.4). 536 SCS.Deprecated = true; 537 538 // For the purpose of ranking in overload resolution 539 // (13.3.3.1.1), this conversion is considered an 540 // array-to-pointer conversion followed by a qualification 541 // conversion (4.4). (C++ 4.2p2) 542 SCS.Second = ICK_Identity; 543 SCS.Third = ICK_Qualification; 544 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 545 return true; 546 } 547 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 548 // Function-to-pointer conversion (C++ 4.3). 549 SCS.First = ICK_Function_To_Pointer; 550 551 // An lvalue of function type T can be converted to an rvalue of 552 // type "pointer to T." The result is a pointer to the 553 // function. (C++ 4.3p1). 554 FromType = Context.getPointerType(FromType); 555 } else if (FunctionDecl *Fn 556 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 557 // Address of overloaded function (C++ [over.over]). 558 SCS.First = ICK_Function_To_Pointer; 559 560 // We were able to resolve the address of the overloaded function, 561 // so we can convert to the type of that function. 562 FromType = Fn->getType(); 563 if (ToType->isLValueReferenceType()) 564 FromType = Context.getLValueReferenceType(FromType); 565 else if (ToType->isRValueReferenceType()) 566 FromType = Context.getRValueReferenceType(FromType); 567 else if (ToType->isMemberPointerType()) { 568 // Resolve address only succeeds if both sides are member pointers, 569 // but it doesn't have to be the same class. See DR 247. 570 // Note that this means that the type of &Derived::fn can be 571 // Ret (Base::*)(Args) if the fn overload actually found is from the 572 // base class, even if it was brought into the derived class via a 573 // using declaration. The standard isn't clear on this issue at all. 574 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 575 FromType = Context.getMemberPointerType(FromType, 576 Context.getTypeDeclType(M->getParent()).getTypePtr()); 577 } else 578 FromType = Context.getPointerType(FromType); 579 } else { 580 // We don't require any conversions for the first step. 581 SCS.First = ICK_Identity; 582 } 583 584 // The second conversion can be an integral promotion, floating 585 // point promotion, integral conversion, floating point conversion, 586 // floating-integral conversion, pointer conversion, 587 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 588 // For overloading in C, this can also be a "compatible-type" 589 // conversion. 590 bool IncompatibleObjC = false; 591 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 592 // The unqualified versions of the types are the same: there's no 593 // conversion to do. 594 SCS.Second = ICK_Identity; 595 } else if (IsIntegralPromotion(From, FromType, ToType)) { 596 // Integral promotion (C++ 4.5). 597 SCS.Second = ICK_Integral_Promotion; 598 FromType = ToType.getUnqualifiedType(); 599 } else if (IsFloatingPointPromotion(FromType, ToType)) { 600 // Floating point promotion (C++ 4.6). 601 SCS.Second = ICK_Floating_Promotion; 602 FromType = ToType.getUnqualifiedType(); 603 } else if (IsComplexPromotion(FromType, ToType)) { 604 // Complex promotion (Clang extension) 605 SCS.Second = ICK_Complex_Promotion; 606 FromType = ToType.getUnqualifiedType(); 607 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 608 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 609 // Integral conversions (C++ 4.7). 610 // FIXME: isIntegralType shouldn't be true for enums in C++. 611 SCS.Second = ICK_Integral_Conversion; 612 FromType = ToType.getUnqualifiedType(); 613 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 614 // Floating point conversions (C++ 4.8). 615 SCS.Second = ICK_Floating_Conversion; 616 FromType = ToType.getUnqualifiedType(); 617 } else if (FromType->isComplexType() && ToType->isComplexType()) { 618 // Complex conversions (C99 6.3.1.6) 619 SCS.Second = ICK_Complex_Conversion; 620 FromType = ToType.getUnqualifiedType(); 621 } else if ((FromType->isFloatingType() && 622 ToType->isIntegralType() && (!ToType->isBooleanType() && 623 !ToType->isEnumeralType())) || 624 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 625 ToType->isFloatingType())) { 626 // Floating-integral conversions (C++ 4.9). 627 // FIXME: isIntegralType shouldn't be true for enums in C++. 628 SCS.Second = ICK_Floating_Integral; 629 FromType = ToType.getUnqualifiedType(); 630 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 631 (ToType->isComplexType() && FromType->isArithmeticType())) { 632 // Complex-real conversions (C99 6.3.1.7) 633 SCS.Second = ICK_Complex_Real; 634 FromType = ToType.getUnqualifiedType(); 635 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 636 FromType, IncompatibleObjC)) { 637 // Pointer conversions (C++ 4.10). 638 SCS.Second = ICK_Pointer_Conversion; 639 SCS.IncompatibleObjC = IncompatibleObjC; 640 } else if (IsMemberPointerConversion(From, FromType, ToType, 641 InOverloadResolution, FromType)) { 642 // Pointer to member conversions (4.11). 643 SCS.Second = ICK_Pointer_Member; 644 } else if (ToType->isBooleanType() && 645 (FromType->isArithmeticType() || 646 FromType->isEnumeralType() || 647 FromType->isPointerType() || 648 FromType->isBlockPointerType() || 649 FromType->isMemberPointerType() || 650 FromType->isNullPtrType())) { 651 // Boolean conversions (C++ 4.12). 652 SCS.Second = ICK_Boolean_Conversion; 653 FromType = Context.BoolTy; 654 } else if (!getLangOptions().CPlusPlus && 655 Context.typesAreCompatible(ToType, FromType)) { 656 // Compatible conversions (Clang extension for C function overloading) 657 SCS.Second = ICK_Compatible_Conversion; 658 } else { 659 // No second conversion required. 660 SCS.Second = ICK_Identity; 661 } 662 663 QualType CanonFrom; 664 QualType CanonTo; 665 // The third conversion can be a qualification conversion (C++ 4p1). 666 if (IsQualificationConversion(FromType, ToType)) { 667 SCS.Third = ICK_Qualification; 668 FromType = ToType; 669 CanonFrom = Context.getCanonicalType(FromType); 670 CanonTo = Context.getCanonicalType(ToType); 671 } else { 672 // No conversion required 673 SCS.Third = ICK_Identity; 674 675 // C++ [over.best.ics]p6: 676 // [...] Any difference in top-level cv-qualification is 677 // subsumed by the initialization itself and does not constitute 678 // a conversion. [...] 679 CanonFrom = Context.getCanonicalType(FromType); 680 CanonTo = Context.getCanonicalType(ToType); 681 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 682 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 683 FromType = ToType; 684 CanonFrom = CanonTo; 685 } 686 } 687 688 // If we have not converted the argument type to the parameter type, 689 // this is a bad conversion sequence. 690 if (CanonFrom != CanonTo) 691 return false; 692 693 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 694 return true; 695} 696 697/// IsIntegralPromotion - Determines whether the conversion from the 698/// expression From (whose potentially-adjusted type is FromType) to 699/// ToType is an integral promotion (C++ 4.5). If so, returns true and 700/// sets PromotedType to the promoted type. 701bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 702 const BuiltinType *To = ToType->getAs<BuiltinType>(); 703 // All integers are built-in. 704 if (!To) { 705 return false; 706 } 707 708 // An rvalue of type char, signed char, unsigned char, short int, or 709 // unsigned short int can be converted to an rvalue of type int if 710 // int can represent all the values of the source type; otherwise, 711 // the source rvalue can be converted to an rvalue of type unsigned 712 // int (C++ 4.5p1). 713 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 714 if (// We can promote any signed, promotable integer type to an int 715 (FromType->isSignedIntegerType() || 716 // We can promote any unsigned integer type whose size is 717 // less than int to an int. 718 (!FromType->isSignedIntegerType() && 719 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 720 return To->getKind() == BuiltinType::Int; 721 } 722 723 return To->getKind() == BuiltinType::UInt; 724 } 725 726 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 727 // can be converted to an rvalue of the first of the following types 728 // that can represent all the values of its underlying type: int, 729 // unsigned int, long, or unsigned long (C++ 4.5p2). 730 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 731 && ToType->isIntegerType()) { 732 // Determine whether the type we're converting from is signed or 733 // unsigned. 734 bool FromIsSigned; 735 uint64_t FromSize = Context.getTypeSize(FromType); 736 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 737 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 738 FromIsSigned = UnderlyingType->isSignedIntegerType(); 739 } else { 740 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 741 FromIsSigned = true; 742 } 743 744 // The types we'll try to promote to, in the appropriate 745 // order. Try each of these types. 746 QualType PromoteTypes[6] = { 747 Context.IntTy, Context.UnsignedIntTy, 748 Context.LongTy, Context.UnsignedLongTy , 749 Context.LongLongTy, Context.UnsignedLongLongTy 750 }; 751 for (int Idx = 0; Idx < 6; ++Idx) { 752 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 753 if (FromSize < ToSize || 754 (FromSize == ToSize && 755 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 756 // We found the type that we can promote to. If this is the 757 // type we wanted, we have a promotion. Otherwise, no 758 // promotion. 759 return Context.getCanonicalType(ToType).getUnqualifiedType() 760 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 761 } 762 } 763 } 764 765 // An rvalue for an integral bit-field (9.6) can be converted to an 766 // rvalue of type int if int can represent all the values of the 767 // bit-field; otherwise, it can be converted to unsigned int if 768 // unsigned int can represent all the values of the bit-field. If 769 // the bit-field is larger yet, no integral promotion applies to 770 // it. If the bit-field has an enumerated type, it is treated as any 771 // other value of that type for promotion purposes (C++ 4.5p3). 772 // FIXME: We should delay checking of bit-fields until we actually perform the 773 // conversion. 774 using llvm::APSInt; 775 if (From) 776 if (FieldDecl *MemberDecl = From->getBitField()) { 777 APSInt BitWidth; 778 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 779 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 780 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 781 ToSize = Context.getTypeSize(ToType); 782 783 // Are we promoting to an int from a bitfield that fits in an int? 784 if (BitWidth < ToSize || 785 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 786 return To->getKind() == BuiltinType::Int; 787 } 788 789 // Are we promoting to an unsigned int from an unsigned bitfield 790 // that fits into an unsigned int? 791 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 792 return To->getKind() == BuiltinType::UInt; 793 } 794 795 return false; 796 } 797 } 798 799 // An rvalue of type bool can be converted to an rvalue of type int, 800 // with false becoming zero and true becoming one (C++ 4.5p4). 801 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 802 return true; 803 } 804 805 return false; 806} 807 808/// IsFloatingPointPromotion - Determines whether the conversion from 809/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 810/// returns true and sets PromotedType to the promoted type. 811bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 812 /// An rvalue of type float can be converted to an rvalue of type 813 /// double. (C++ 4.6p1). 814 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 815 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 816 if (FromBuiltin->getKind() == BuiltinType::Float && 817 ToBuiltin->getKind() == BuiltinType::Double) 818 return true; 819 820 // C99 6.3.1.5p1: 821 // When a float is promoted to double or long double, or a 822 // double is promoted to long double [...]. 823 if (!getLangOptions().CPlusPlus && 824 (FromBuiltin->getKind() == BuiltinType::Float || 825 FromBuiltin->getKind() == BuiltinType::Double) && 826 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 827 return true; 828 } 829 830 return false; 831} 832 833/// \brief Determine if a conversion is a complex promotion. 834/// 835/// A complex promotion is defined as a complex -> complex conversion 836/// where the conversion between the underlying real types is a 837/// floating-point or integral promotion. 838bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 839 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 840 if (!FromComplex) 841 return false; 842 843 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 844 if (!ToComplex) 845 return false; 846 847 return IsFloatingPointPromotion(FromComplex->getElementType(), 848 ToComplex->getElementType()) || 849 IsIntegralPromotion(0, FromComplex->getElementType(), 850 ToComplex->getElementType()); 851} 852 853/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 854/// the pointer type FromPtr to a pointer to type ToPointee, with the 855/// same type qualifiers as FromPtr has on its pointee type. ToType, 856/// if non-empty, will be a pointer to ToType that may or may not have 857/// the right set of qualifiers on its pointee. 858static QualType 859BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 860 QualType ToPointee, QualType ToType, 861 ASTContext &Context) { 862 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 863 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 864 Qualifiers Quals = CanonFromPointee.getQualifiers(); 865 866 // Exact qualifier match -> return the pointer type we're converting to. 867 if (CanonToPointee.getQualifiers() == Quals) { 868 // ToType is exactly what we need. Return it. 869 if (!ToType.isNull()) 870 return ToType; 871 872 // Build a pointer to ToPointee. It has the right qualifiers 873 // already. 874 return Context.getPointerType(ToPointee); 875 } 876 877 // Just build a canonical type that has the right qualifiers. 878 return Context.getPointerType( 879 Context.getQualifiedType(CanonToPointee.getUnqualifiedType(), Quals)); 880} 881 882static bool isNullPointerConstantForConversion(Expr *Expr, 883 bool InOverloadResolution, 884 ASTContext &Context) { 885 // Handle value-dependent integral null pointer constants correctly. 886 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 887 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 888 Expr->getType()->isIntegralType()) 889 return !InOverloadResolution; 890 891 return Expr->isNullPointerConstant(Context, 892 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 893 : Expr::NPC_ValueDependentIsNull); 894} 895 896/// IsPointerConversion - Determines whether the conversion of the 897/// expression From, which has the (possibly adjusted) type FromType, 898/// can be converted to the type ToType via a pointer conversion (C++ 899/// 4.10). If so, returns true and places the converted type (that 900/// might differ from ToType in its cv-qualifiers at some level) into 901/// ConvertedType. 902/// 903/// This routine also supports conversions to and from block pointers 904/// and conversions with Objective-C's 'id', 'id<protocols...>', and 905/// pointers to interfaces. FIXME: Once we've determined the 906/// appropriate overloading rules for Objective-C, we may want to 907/// split the Objective-C checks into a different routine; however, 908/// GCC seems to consider all of these conversions to be pointer 909/// conversions, so for now they live here. IncompatibleObjC will be 910/// set if the conversion is an allowed Objective-C conversion that 911/// should result in a warning. 912bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 913 bool InOverloadResolution, 914 QualType& ConvertedType, 915 bool &IncompatibleObjC) { 916 IncompatibleObjC = false; 917 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 918 return true; 919 920 // Conversion from a null pointer constant to any Objective-C pointer type. 921 if (ToType->isObjCObjectPointerType() && 922 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 923 ConvertedType = ToType; 924 return true; 925 } 926 927 // Blocks: Block pointers can be converted to void*. 928 if (FromType->isBlockPointerType() && ToType->isPointerType() && 929 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 930 ConvertedType = ToType; 931 return true; 932 } 933 // Blocks: A null pointer constant can be converted to a block 934 // pointer type. 935 if (ToType->isBlockPointerType() && 936 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 937 ConvertedType = ToType; 938 return true; 939 } 940 941 // If the left-hand-side is nullptr_t, the right side can be a null 942 // pointer constant. 943 if (ToType->isNullPtrType() && 944 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 945 ConvertedType = ToType; 946 return true; 947 } 948 949 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 950 if (!ToTypePtr) 951 return false; 952 953 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 954 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 955 ConvertedType = ToType; 956 return true; 957 } 958 959 // Beyond this point, both types need to be pointers. 960 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 961 if (!FromTypePtr) 962 return false; 963 964 QualType FromPointeeType = FromTypePtr->getPointeeType(); 965 QualType ToPointeeType = ToTypePtr->getPointeeType(); 966 967 // An rvalue of type "pointer to cv T," where T is an object type, 968 // can be converted to an rvalue of type "pointer to cv void" (C++ 969 // 4.10p2). 970 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 971 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 972 ToPointeeType, 973 ToType, Context); 974 return true; 975 } 976 977 // When we're overloading in C, we allow a special kind of pointer 978 // conversion for compatible-but-not-identical pointee types. 979 if (!getLangOptions().CPlusPlus && 980 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 981 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 982 ToPointeeType, 983 ToType, Context); 984 return true; 985 } 986 987 // C++ [conv.ptr]p3: 988 // 989 // An rvalue of type "pointer to cv D," where D is a class type, 990 // can be converted to an rvalue of type "pointer to cv B," where 991 // B is a base class (clause 10) of D. If B is an inaccessible 992 // (clause 11) or ambiguous (10.2) base class of D, a program that 993 // necessitates this conversion is ill-formed. The result of the 994 // conversion is a pointer to the base class sub-object of the 995 // derived class object. The null pointer value is converted to 996 // the null pointer value of the destination type. 997 // 998 // Note that we do not check for ambiguity or inaccessibility 999 // here. That is handled by CheckPointerConversion. 1000 if (getLangOptions().CPlusPlus && 1001 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1002 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1003 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1004 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1005 ToPointeeType, 1006 ToType, Context); 1007 return true; 1008 } 1009 1010 return false; 1011} 1012 1013/// isObjCPointerConversion - Determines whether this is an 1014/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1015/// with the same arguments and return values. 1016bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1017 QualType& ConvertedType, 1018 bool &IncompatibleObjC) { 1019 if (!getLangOptions().ObjC1) 1020 return false; 1021 1022 // First, we handle all conversions on ObjC object pointer types. 1023 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1024 const ObjCObjectPointerType *FromObjCPtr = 1025 FromType->getAs<ObjCObjectPointerType>(); 1026 1027 if (ToObjCPtr && FromObjCPtr) { 1028 // Objective C++: We're able to convert between "id" or "Class" and a 1029 // pointer to any interface (in both directions). 1030 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1031 ConvertedType = ToType; 1032 return true; 1033 } 1034 // Conversions with Objective-C's id<...>. 1035 if ((FromObjCPtr->isObjCQualifiedIdType() || 1036 ToObjCPtr->isObjCQualifiedIdType()) && 1037 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1038 /*compare=*/false)) { 1039 ConvertedType = ToType; 1040 return true; 1041 } 1042 // Objective C++: We're able to convert from a pointer to an 1043 // interface to a pointer to a different interface. 1044 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1045 ConvertedType = ToType; 1046 return true; 1047 } 1048 1049 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1050 // Okay: this is some kind of implicit downcast of Objective-C 1051 // interfaces, which is permitted. However, we're going to 1052 // complain about it. 1053 IncompatibleObjC = true; 1054 ConvertedType = FromType; 1055 return true; 1056 } 1057 } 1058 // Beyond this point, both types need to be C pointers or block pointers. 1059 QualType ToPointeeType; 1060 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1061 ToPointeeType = ToCPtr->getPointeeType(); 1062 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1063 ToPointeeType = ToBlockPtr->getPointeeType(); 1064 else 1065 return false; 1066 1067 QualType FromPointeeType; 1068 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1069 FromPointeeType = FromCPtr->getPointeeType(); 1070 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1071 FromPointeeType = FromBlockPtr->getPointeeType(); 1072 else 1073 return false; 1074 1075 // If we have pointers to pointers, recursively check whether this 1076 // is an Objective-C conversion. 1077 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1078 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1079 IncompatibleObjC)) { 1080 // We always complain about this conversion. 1081 IncompatibleObjC = true; 1082 ConvertedType = ToType; 1083 return true; 1084 } 1085 // If we have pointers to functions or blocks, check whether the only 1086 // differences in the argument and result types are in Objective-C 1087 // pointer conversions. If so, we permit the conversion (but 1088 // complain about it). 1089 const FunctionProtoType *FromFunctionType 1090 = FromPointeeType->getAs<FunctionProtoType>(); 1091 const FunctionProtoType *ToFunctionType 1092 = ToPointeeType->getAs<FunctionProtoType>(); 1093 if (FromFunctionType && ToFunctionType) { 1094 // If the function types are exactly the same, this isn't an 1095 // Objective-C pointer conversion. 1096 if (Context.getCanonicalType(FromPointeeType) 1097 == Context.getCanonicalType(ToPointeeType)) 1098 return false; 1099 1100 // Perform the quick checks that will tell us whether these 1101 // function types are obviously different. 1102 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1103 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1104 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1105 return false; 1106 1107 bool HasObjCConversion = false; 1108 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1109 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1110 // Okay, the types match exactly. Nothing to do. 1111 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1112 ToFunctionType->getResultType(), 1113 ConvertedType, IncompatibleObjC)) { 1114 // Okay, we have an Objective-C pointer conversion. 1115 HasObjCConversion = true; 1116 } else { 1117 // Function types are too different. Abort. 1118 return false; 1119 } 1120 1121 // Check argument types. 1122 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1123 ArgIdx != NumArgs; ++ArgIdx) { 1124 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1125 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1126 if (Context.getCanonicalType(FromArgType) 1127 == Context.getCanonicalType(ToArgType)) { 1128 // Okay, the types match exactly. Nothing to do. 1129 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1130 ConvertedType, IncompatibleObjC)) { 1131 // Okay, we have an Objective-C pointer conversion. 1132 HasObjCConversion = true; 1133 } else { 1134 // Argument types are too different. Abort. 1135 return false; 1136 } 1137 } 1138 1139 if (HasObjCConversion) { 1140 // We had an Objective-C conversion. Allow this pointer 1141 // conversion, but complain about it. 1142 ConvertedType = ToType; 1143 IncompatibleObjC = true; 1144 return true; 1145 } 1146 } 1147 1148 return false; 1149} 1150 1151/// CheckPointerConversion - Check the pointer conversion from the 1152/// expression From to the type ToType. This routine checks for 1153/// ambiguous or inaccessible derived-to-base pointer 1154/// conversions for which IsPointerConversion has already returned 1155/// true. It returns true and produces a diagnostic if there was an 1156/// error, or returns false otherwise. 1157bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1158 CastExpr::CastKind &Kind) { 1159 QualType FromType = From->getType(); 1160 1161 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1162 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1163 QualType FromPointeeType = FromPtrType->getPointeeType(), 1164 ToPointeeType = ToPtrType->getPointeeType(); 1165 1166 if (FromPointeeType->isRecordType() && 1167 ToPointeeType->isRecordType()) { 1168 // We must have a derived-to-base conversion. Check an 1169 // ambiguous or inaccessible conversion. 1170 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1171 From->getExprLoc(), 1172 From->getSourceRange())) 1173 return true; 1174 1175 // The conversion was successful. 1176 Kind = CastExpr::CK_DerivedToBase; 1177 } 1178 } 1179 if (const ObjCObjectPointerType *FromPtrType = 1180 FromType->getAs<ObjCObjectPointerType>()) 1181 if (const ObjCObjectPointerType *ToPtrType = 1182 ToType->getAs<ObjCObjectPointerType>()) { 1183 // Objective-C++ conversions are always okay. 1184 // FIXME: We should have a different class of conversions for the 1185 // Objective-C++ implicit conversions. 1186 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1187 return false; 1188 1189 } 1190 return false; 1191} 1192 1193/// IsMemberPointerConversion - Determines whether the conversion of the 1194/// expression From, which has the (possibly adjusted) type FromType, can be 1195/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1196/// If so, returns true and places the converted type (that might differ from 1197/// ToType in its cv-qualifiers at some level) into ConvertedType. 1198bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1199 QualType ToType, 1200 bool InOverloadResolution, 1201 QualType &ConvertedType) { 1202 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1203 if (!ToTypePtr) 1204 return false; 1205 1206 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1207 if (From->isNullPointerConstant(Context, 1208 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1209 : Expr::NPC_ValueDependentIsNull)) { 1210 ConvertedType = ToType; 1211 return true; 1212 } 1213 1214 // Otherwise, both types have to be member pointers. 1215 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1216 if (!FromTypePtr) 1217 return false; 1218 1219 // A pointer to member of B can be converted to a pointer to member of D, 1220 // where D is derived from B (C++ 4.11p2). 1221 QualType FromClass(FromTypePtr->getClass(), 0); 1222 QualType ToClass(ToTypePtr->getClass(), 0); 1223 // FIXME: What happens when these are dependent? Is this function even called? 1224 1225 if (IsDerivedFrom(ToClass, FromClass)) { 1226 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1227 ToClass.getTypePtr()); 1228 return true; 1229 } 1230 1231 return false; 1232} 1233 1234/// CheckMemberPointerConversion - Check the member pointer conversion from the 1235/// expression From to the type ToType. This routine checks for ambiguous or 1236/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1237/// for which IsMemberPointerConversion has already returned true. It returns 1238/// true and produces a diagnostic if there was an error, or returns false 1239/// otherwise. 1240bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1241 CastExpr::CastKind &Kind) { 1242 QualType FromType = From->getType(); 1243 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1244 if (!FromPtrType) { 1245 // This must be a null pointer to member pointer conversion 1246 assert(From->isNullPointerConstant(Context, 1247 Expr::NPC_ValueDependentIsNull) && 1248 "Expr must be null pointer constant!"); 1249 Kind = CastExpr::CK_NullToMemberPointer; 1250 return false; 1251 } 1252 1253 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1254 assert(ToPtrType && "No member pointer cast has a target type " 1255 "that is not a member pointer."); 1256 1257 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1258 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1259 1260 // FIXME: What about dependent types? 1261 assert(FromClass->isRecordType() && "Pointer into non-class."); 1262 assert(ToClass->isRecordType() && "Pointer into non-class."); 1263 1264 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1265 /*DetectVirtual=*/true); 1266 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1267 assert(DerivationOkay && 1268 "Should not have been called if derivation isn't OK."); 1269 (void)DerivationOkay; 1270 1271 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1272 getUnqualifiedType())) { 1273 // Derivation is ambiguous. Redo the check to find the exact paths. 1274 Paths.clear(); 1275 Paths.setRecordingPaths(true); 1276 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1277 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1278 (void)StillOkay; 1279 1280 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1281 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1282 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1283 return true; 1284 } 1285 1286 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1287 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1288 << FromClass << ToClass << QualType(VBase, 0) 1289 << From->getSourceRange(); 1290 return true; 1291 } 1292 1293 // Must be a base to derived member conversion. 1294 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1295 return false; 1296} 1297 1298/// IsQualificationConversion - Determines whether the conversion from 1299/// an rvalue of type FromType to ToType is a qualification conversion 1300/// (C++ 4.4). 1301bool 1302Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1303 FromType = Context.getCanonicalType(FromType); 1304 ToType = Context.getCanonicalType(ToType); 1305 1306 // If FromType and ToType are the same type, this is not a 1307 // qualification conversion. 1308 if (FromType == ToType) 1309 return false; 1310 1311 // (C++ 4.4p4): 1312 // A conversion can add cv-qualifiers at levels other than the first 1313 // in multi-level pointers, subject to the following rules: [...] 1314 bool PreviousToQualsIncludeConst = true; 1315 bool UnwrappedAnyPointer = false; 1316 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1317 // Within each iteration of the loop, we check the qualifiers to 1318 // determine if this still looks like a qualification 1319 // conversion. Then, if all is well, we unwrap one more level of 1320 // pointers or pointers-to-members and do it all again 1321 // until there are no more pointers or pointers-to-members left to 1322 // unwrap. 1323 UnwrappedAnyPointer = true; 1324 1325 // -- for every j > 0, if const is in cv 1,j then const is in cv 1326 // 2,j, and similarly for volatile. 1327 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1328 return false; 1329 1330 // -- if the cv 1,j and cv 2,j are different, then const is in 1331 // every cv for 0 < k < j. 1332 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1333 && !PreviousToQualsIncludeConst) 1334 return false; 1335 1336 // Keep track of whether all prior cv-qualifiers in the "to" type 1337 // include const. 1338 PreviousToQualsIncludeConst 1339 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1340 } 1341 1342 // We are left with FromType and ToType being the pointee types 1343 // after unwrapping the original FromType and ToType the same number 1344 // of types. If we unwrapped any pointers, and if FromType and 1345 // ToType have the same unqualified type (since we checked 1346 // qualifiers above), then this is a qualification conversion. 1347 return UnwrappedAnyPointer && 1348 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1349} 1350 1351/// \brief Given a function template or function, extract the function template 1352/// declaration (if any) and the underlying function declaration. 1353template<typename T> 1354static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1355 FunctionTemplateDecl *&FunctionTemplate) { 1356 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1357 if (FunctionTemplate) 1358 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1359 else 1360 Function = cast<T>(Orig); 1361} 1362 1363/// Determines whether there is a user-defined conversion sequence 1364/// (C++ [over.ics.user]) that converts expression From to the type 1365/// ToType. If such a conversion exists, User will contain the 1366/// user-defined conversion sequence that performs such a conversion 1367/// and this routine will return true. Otherwise, this routine returns 1368/// false and User is unspecified. 1369/// 1370/// \param AllowConversionFunctions true if the conversion should 1371/// consider conversion functions at all. If false, only constructors 1372/// will be considered. 1373/// 1374/// \param AllowExplicit true if the conversion should consider C++0x 1375/// "explicit" conversion functions as well as non-explicit conversion 1376/// functions (C++0x [class.conv.fct]p2). 1377/// 1378/// \param ForceRValue true if the expression should be treated as an rvalue 1379/// for overload resolution. 1380/// \param UserCast true if looking for user defined conversion for a static 1381/// cast. 1382Sema::OverloadingResult Sema::IsUserDefinedConversion( 1383 Expr *From, QualType ToType, 1384 UserDefinedConversionSequence& User, 1385 OverloadCandidateSet& CandidateSet, 1386 bool AllowConversionFunctions, 1387 bool AllowExplicit, bool ForceRValue, 1388 bool UserCast) { 1389 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1390 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1391 // We're not going to find any constructors. 1392 } else if (CXXRecordDecl *ToRecordDecl 1393 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1394 // C++ [over.match.ctor]p1: 1395 // When objects of class type are direct-initialized (8.5), or 1396 // copy-initialized from an expression of the same or a 1397 // derived class type (8.5), overload resolution selects the 1398 // constructor. [...] For copy-initialization, the candidate 1399 // functions are all the converting constructors (12.3.1) of 1400 // that class. The argument list is the expression-list within 1401 // the parentheses of the initializer. 1402 bool SuppressUserConversions = !UserCast; 1403 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1404 IsDerivedFrom(From->getType(), ToType)) { 1405 SuppressUserConversions = false; 1406 AllowConversionFunctions = false; 1407 } 1408 1409 DeclarationName ConstructorName 1410 = Context.DeclarationNames.getCXXConstructorName( 1411 Context.getCanonicalType(ToType).getUnqualifiedType()); 1412 DeclContext::lookup_iterator Con, ConEnd; 1413 for (llvm::tie(Con, ConEnd) 1414 = ToRecordDecl->lookup(ConstructorName); 1415 Con != ConEnd; ++Con) { 1416 // Find the constructor (which may be a template). 1417 CXXConstructorDecl *Constructor = 0; 1418 FunctionTemplateDecl *ConstructorTmpl 1419 = dyn_cast<FunctionTemplateDecl>(*Con); 1420 if (ConstructorTmpl) 1421 Constructor 1422 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1423 else 1424 Constructor = cast<CXXConstructorDecl>(*Con); 1425 1426 if (!Constructor->isInvalidDecl() && 1427 Constructor->isConvertingConstructor(AllowExplicit)) { 1428 if (ConstructorTmpl) 1429 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1430 1, CandidateSet, 1431 SuppressUserConversions, ForceRValue); 1432 else 1433 // Allow one user-defined conversion when user specifies a 1434 // From->ToType conversion via an static cast (c-style, etc). 1435 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1436 SuppressUserConversions, ForceRValue); 1437 } 1438 } 1439 } 1440 } 1441 1442 if (!AllowConversionFunctions) { 1443 // Don't allow any conversion functions to enter the overload set. 1444 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1445 PDiag(0) 1446 << From->getSourceRange())) { 1447 // No conversion functions from incomplete types. 1448 } else if (const RecordType *FromRecordType 1449 = From->getType()->getAs<RecordType>()) { 1450 if (CXXRecordDecl *FromRecordDecl 1451 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1452 // Add all of the conversion functions as candidates. 1453 OverloadedFunctionDecl *Conversions 1454 = FromRecordDecl->getVisibleConversionFunctions(); 1455 for (OverloadedFunctionDecl::function_iterator Func 1456 = Conversions->function_begin(); 1457 Func != Conversions->function_end(); ++Func) { 1458 CXXConversionDecl *Conv; 1459 FunctionTemplateDecl *ConvTemplate; 1460 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1461 if (ConvTemplate) 1462 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1463 else 1464 Conv = dyn_cast<CXXConversionDecl>(*Func); 1465 1466 if (AllowExplicit || !Conv->isExplicit()) { 1467 if (ConvTemplate) 1468 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1469 CandidateSet); 1470 else 1471 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1472 } 1473 } 1474 } 1475 } 1476 1477 OverloadCandidateSet::iterator Best; 1478 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1479 case OR_Success: 1480 // Record the standard conversion we used and the conversion function. 1481 if (CXXConstructorDecl *Constructor 1482 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1483 // C++ [over.ics.user]p1: 1484 // If the user-defined conversion is specified by a 1485 // constructor (12.3.1), the initial standard conversion 1486 // sequence converts the source type to the type required by 1487 // the argument of the constructor. 1488 // 1489 QualType ThisType = Constructor->getThisType(Context); 1490 if (Best->Conversions[0].ConversionKind == 1491 ImplicitConversionSequence::EllipsisConversion) 1492 User.EllipsisConversion = true; 1493 else { 1494 User.Before = Best->Conversions[0].Standard; 1495 User.EllipsisConversion = false; 1496 } 1497 User.ConversionFunction = Constructor; 1498 User.After.setAsIdentityConversion(); 1499 User.After.FromTypePtr 1500 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1501 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1502 return OR_Success; 1503 } else if (CXXConversionDecl *Conversion 1504 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1505 // C++ [over.ics.user]p1: 1506 // 1507 // [...] If the user-defined conversion is specified by a 1508 // conversion function (12.3.2), the initial standard 1509 // conversion sequence converts the source type to the 1510 // implicit object parameter of the conversion function. 1511 User.Before = Best->Conversions[0].Standard; 1512 User.ConversionFunction = Conversion; 1513 User.EllipsisConversion = false; 1514 1515 // C++ [over.ics.user]p2: 1516 // The second standard conversion sequence converts the 1517 // result of the user-defined conversion to the target type 1518 // for the sequence. Since an implicit conversion sequence 1519 // is an initialization, the special rules for 1520 // initialization by user-defined conversion apply when 1521 // selecting the best user-defined conversion for a 1522 // user-defined conversion sequence (see 13.3.3 and 1523 // 13.3.3.1). 1524 User.After = Best->FinalConversion; 1525 return OR_Success; 1526 } else { 1527 assert(false && "Not a constructor or conversion function?"); 1528 return OR_No_Viable_Function; 1529 } 1530 1531 case OR_No_Viable_Function: 1532 return OR_No_Viable_Function; 1533 case OR_Deleted: 1534 // No conversion here! We're done. 1535 return OR_Deleted; 1536 1537 case OR_Ambiguous: 1538 return OR_Ambiguous; 1539 } 1540 1541 return OR_No_Viable_Function; 1542} 1543 1544bool 1545Sema::DiagnoseAmbiguousUserDefinedConversion(Expr *From, QualType ToType) { 1546 ImplicitConversionSequence ICS; 1547 OverloadCandidateSet CandidateSet; 1548 OverloadingResult OvResult = 1549 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1550 CandidateSet, true, false, false); 1551 if (OvResult != OR_Ambiguous) 1552 return false; 1553 Diag(From->getSourceRange().getBegin(), 1554 diag::err_typecheck_ambiguous_condition) 1555 << From->getType() << ToType << From->getSourceRange(); 1556 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1557 return true; 1558} 1559 1560/// CompareImplicitConversionSequences - Compare two implicit 1561/// conversion sequences to determine whether one is better than the 1562/// other or if they are indistinguishable (C++ 13.3.3.2). 1563ImplicitConversionSequence::CompareKind 1564Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1565 const ImplicitConversionSequence& ICS2) 1566{ 1567 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1568 // conversion sequences (as defined in 13.3.3.1) 1569 // -- a standard conversion sequence (13.3.3.1.1) is a better 1570 // conversion sequence than a user-defined conversion sequence or 1571 // an ellipsis conversion sequence, and 1572 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1573 // conversion sequence than an ellipsis conversion sequence 1574 // (13.3.3.1.3). 1575 // 1576 if (ICS1.ConversionKind < ICS2.ConversionKind) 1577 return ImplicitConversionSequence::Better; 1578 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1579 return ImplicitConversionSequence::Worse; 1580 1581 // Two implicit conversion sequences of the same form are 1582 // indistinguishable conversion sequences unless one of the 1583 // following rules apply: (C++ 13.3.3.2p3): 1584 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1585 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1586 else if (ICS1.ConversionKind == 1587 ImplicitConversionSequence::UserDefinedConversion) { 1588 // User-defined conversion sequence U1 is a better conversion 1589 // sequence than another user-defined conversion sequence U2 if 1590 // they contain the same user-defined conversion function or 1591 // constructor and if the second standard conversion sequence of 1592 // U1 is better than the second standard conversion sequence of 1593 // U2 (C++ 13.3.3.2p3). 1594 if (ICS1.UserDefined.ConversionFunction == 1595 ICS2.UserDefined.ConversionFunction) 1596 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1597 ICS2.UserDefined.After); 1598 } 1599 1600 return ImplicitConversionSequence::Indistinguishable; 1601} 1602 1603/// CompareStandardConversionSequences - Compare two standard 1604/// conversion sequences to determine whether one is better than the 1605/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1606ImplicitConversionSequence::CompareKind 1607Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1608 const StandardConversionSequence& SCS2) 1609{ 1610 // Standard conversion sequence S1 is a better conversion sequence 1611 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1612 1613 // -- S1 is a proper subsequence of S2 (comparing the conversion 1614 // sequences in the canonical form defined by 13.3.3.1.1, 1615 // excluding any Lvalue Transformation; the identity conversion 1616 // sequence is considered to be a subsequence of any 1617 // non-identity conversion sequence) or, if not that, 1618 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1619 // Neither is a proper subsequence of the other. Do nothing. 1620 ; 1621 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1622 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1623 (SCS1.Second == ICK_Identity && 1624 SCS1.Third == ICK_Identity)) 1625 // SCS1 is a proper subsequence of SCS2. 1626 return ImplicitConversionSequence::Better; 1627 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1628 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1629 (SCS2.Second == ICK_Identity && 1630 SCS2.Third == ICK_Identity)) 1631 // SCS2 is a proper subsequence of SCS1. 1632 return ImplicitConversionSequence::Worse; 1633 1634 // -- the rank of S1 is better than the rank of S2 (by the rules 1635 // defined below), or, if not that, 1636 ImplicitConversionRank Rank1 = SCS1.getRank(); 1637 ImplicitConversionRank Rank2 = SCS2.getRank(); 1638 if (Rank1 < Rank2) 1639 return ImplicitConversionSequence::Better; 1640 else if (Rank2 < Rank1) 1641 return ImplicitConversionSequence::Worse; 1642 1643 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1644 // are indistinguishable unless one of the following rules 1645 // applies: 1646 1647 // A conversion that is not a conversion of a pointer, or 1648 // pointer to member, to bool is better than another conversion 1649 // that is such a conversion. 1650 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1651 return SCS2.isPointerConversionToBool() 1652 ? ImplicitConversionSequence::Better 1653 : ImplicitConversionSequence::Worse; 1654 1655 // C++ [over.ics.rank]p4b2: 1656 // 1657 // If class B is derived directly or indirectly from class A, 1658 // conversion of B* to A* is better than conversion of B* to 1659 // void*, and conversion of A* to void* is better than conversion 1660 // of B* to void*. 1661 bool SCS1ConvertsToVoid 1662 = SCS1.isPointerConversionToVoidPointer(Context); 1663 bool SCS2ConvertsToVoid 1664 = SCS2.isPointerConversionToVoidPointer(Context); 1665 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1666 // Exactly one of the conversion sequences is a conversion to 1667 // a void pointer; it's the worse conversion. 1668 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1669 : ImplicitConversionSequence::Worse; 1670 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1671 // Neither conversion sequence converts to a void pointer; compare 1672 // their derived-to-base conversions. 1673 if (ImplicitConversionSequence::CompareKind DerivedCK 1674 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1675 return DerivedCK; 1676 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1677 // Both conversion sequences are conversions to void 1678 // pointers. Compare the source types to determine if there's an 1679 // inheritance relationship in their sources. 1680 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1681 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1682 1683 // Adjust the types we're converting from via the array-to-pointer 1684 // conversion, if we need to. 1685 if (SCS1.First == ICK_Array_To_Pointer) 1686 FromType1 = Context.getArrayDecayedType(FromType1); 1687 if (SCS2.First == ICK_Array_To_Pointer) 1688 FromType2 = Context.getArrayDecayedType(FromType2); 1689 1690 QualType FromPointee1 1691 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1692 QualType FromPointee2 1693 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1694 1695 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1696 return ImplicitConversionSequence::Better; 1697 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1698 return ImplicitConversionSequence::Worse; 1699 1700 // Objective-C++: If one interface is more specific than the 1701 // other, it is the better one. 1702 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1703 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1704 if (FromIface1 && FromIface1) { 1705 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1706 return ImplicitConversionSequence::Better; 1707 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1708 return ImplicitConversionSequence::Worse; 1709 } 1710 } 1711 1712 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1713 // bullet 3). 1714 if (ImplicitConversionSequence::CompareKind QualCK 1715 = CompareQualificationConversions(SCS1, SCS2)) 1716 return QualCK; 1717 1718 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1719 // C++0x [over.ics.rank]p3b4: 1720 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1721 // implicit object parameter of a non-static member function declared 1722 // without a ref-qualifier, and S1 binds an rvalue reference to an 1723 // rvalue and S2 binds an lvalue reference. 1724 // FIXME: We don't know if we're dealing with the implicit object parameter, 1725 // or if the member function in this case has a ref qualifier. 1726 // (Of course, we don't have ref qualifiers yet.) 1727 if (SCS1.RRefBinding != SCS2.RRefBinding) 1728 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1729 : ImplicitConversionSequence::Worse; 1730 1731 // C++ [over.ics.rank]p3b4: 1732 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1733 // which the references refer are the same type except for 1734 // top-level cv-qualifiers, and the type to which the reference 1735 // initialized by S2 refers is more cv-qualified than the type 1736 // to which the reference initialized by S1 refers. 1737 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1738 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1739 T1 = Context.getCanonicalType(T1); 1740 T2 = Context.getCanonicalType(T2); 1741 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1742 if (T2.isMoreQualifiedThan(T1)) 1743 return ImplicitConversionSequence::Better; 1744 else if (T1.isMoreQualifiedThan(T2)) 1745 return ImplicitConversionSequence::Worse; 1746 } 1747 } 1748 1749 return ImplicitConversionSequence::Indistinguishable; 1750} 1751 1752/// CompareQualificationConversions - Compares two standard conversion 1753/// sequences to determine whether they can be ranked based on their 1754/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1755ImplicitConversionSequence::CompareKind 1756Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1757 const StandardConversionSequence& SCS2) { 1758 // C++ 13.3.3.2p3: 1759 // -- S1 and S2 differ only in their qualification conversion and 1760 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1761 // cv-qualification signature of type T1 is a proper subset of 1762 // the cv-qualification signature of type T2, and S1 is not the 1763 // deprecated string literal array-to-pointer conversion (4.2). 1764 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1765 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1766 return ImplicitConversionSequence::Indistinguishable; 1767 1768 // FIXME: the example in the standard doesn't use a qualification 1769 // conversion (!) 1770 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1771 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1772 T1 = Context.getCanonicalType(T1); 1773 T2 = Context.getCanonicalType(T2); 1774 1775 // If the types are the same, we won't learn anything by unwrapped 1776 // them. 1777 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1778 return ImplicitConversionSequence::Indistinguishable; 1779 1780 ImplicitConversionSequence::CompareKind Result 1781 = ImplicitConversionSequence::Indistinguishable; 1782 while (UnwrapSimilarPointerTypes(T1, T2)) { 1783 // Within each iteration of the loop, we check the qualifiers to 1784 // determine if this still looks like a qualification 1785 // conversion. Then, if all is well, we unwrap one more level of 1786 // pointers or pointers-to-members and do it all again 1787 // until there are no more pointers or pointers-to-members left 1788 // to unwrap. This essentially mimics what 1789 // IsQualificationConversion does, but here we're checking for a 1790 // strict subset of qualifiers. 1791 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1792 // The qualifiers are the same, so this doesn't tell us anything 1793 // about how the sequences rank. 1794 ; 1795 else if (T2.isMoreQualifiedThan(T1)) { 1796 // T1 has fewer qualifiers, so it could be the better sequence. 1797 if (Result == ImplicitConversionSequence::Worse) 1798 // Neither has qualifiers that are a subset of the other's 1799 // qualifiers. 1800 return ImplicitConversionSequence::Indistinguishable; 1801 1802 Result = ImplicitConversionSequence::Better; 1803 } else if (T1.isMoreQualifiedThan(T2)) { 1804 // T2 has fewer qualifiers, so it could be the better sequence. 1805 if (Result == ImplicitConversionSequence::Better) 1806 // Neither has qualifiers that are a subset of the other's 1807 // qualifiers. 1808 return ImplicitConversionSequence::Indistinguishable; 1809 1810 Result = ImplicitConversionSequence::Worse; 1811 } else { 1812 // Qualifiers are disjoint. 1813 return ImplicitConversionSequence::Indistinguishable; 1814 } 1815 1816 // If the types after this point are equivalent, we're done. 1817 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1818 break; 1819 } 1820 1821 // Check that the winning standard conversion sequence isn't using 1822 // the deprecated string literal array to pointer conversion. 1823 switch (Result) { 1824 case ImplicitConversionSequence::Better: 1825 if (SCS1.Deprecated) 1826 Result = ImplicitConversionSequence::Indistinguishable; 1827 break; 1828 1829 case ImplicitConversionSequence::Indistinguishable: 1830 break; 1831 1832 case ImplicitConversionSequence::Worse: 1833 if (SCS2.Deprecated) 1834 Result = ImplicitConversionSequence::Indistinguishable; 1835 break; 1836 } 1837 1838 return Result; 1839} 1840 1841/// CompareDerivedToBaseConversions - Compares two standard conversion 1842/// sequences to determine whether they can be ranked based on their 1843/// various kinds of derived-to-base conversions (C++ 1844/// [over.ics.rank]p4b3). As part of these checks, we also look at 1845/// conversions between Objective-C interface types. 1846ImplicitConversionSequence::CompareKind 1847Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1848 const StandardConversionSequence& SCS2) { 1849 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1850 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1851 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1852 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1853 1854 // Adjust the types we're converting from via the array-to-pointer 1855 // conversion, if we need to. 1856 if (SCS1.First == ICK_Array_To_Pointer) 1857 FromType1 = Context.getArrayDecayedType(FromType1); 1858 if (SCS2.First == ICK_Array_To_Pointer) 1859 FromType2 = Context.getArrayDecayedType(FromType2); 1860 1861 // Canonicalize all of the types. 1862 FromType1 = Context.getCanonicalType(FromType1); 1863 ToType1 = Context.getCanonicalType(ToType1); 1864 FromType2 = Context.getCanonicalType(FromType2); 1865 ToType2 = Context.getCanonicalType(ToType2); 1866 1867 // C++ [over.ics.rank]p4b3: 1868 // 1869 // If class B is derived directly or indirectly from class A and 1870 // class C is derived directly or indirectly from B, 1871 // 1872 // For Objective-C, we let A, B, and C also be Objective-C 1873 // interfaces. 1874 1875 // Compare based on pointer conversions. 1876 if (SCS1.Second == ICK_Pointer_Conversion && 1877 SCS2.Second == ICK_Pointer_Conversion && 1878 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1879 FromType1->isPointerType() && FromType2->isPointerType() && 1880 ToType1->isPointerType() && ToType2->isPointerType()) { 1881 QualType FromPointee1 1882 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1883 QualType ToPointee1 1884 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1885 QualType FromPointee2 1886 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1887 QualType ToPointee2 1888 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1889 1890 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1891 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1892 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1893 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1894 1895 // -- conversion of C* to B* is better than conversion of C* to A*, 1896 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1897 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1898 return ImplicitConversionSequence::Better; 1899 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1900 return ImplicitConversionSequence::Worse; 1901 1902 if (ToIface1 && ToIface2) { 1903 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1904 return ImplicitConversionSequence::Better; 1905 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1906 return ImplicitConversionSequence::Worse; 1907 } 1908 } 1909 1910 // -- conversion of B* to A* is better than conversion of C* to A*, 1911 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1912 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1913 return ImplicitConversionSequence::Better; 1914 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1915 return ImplicitConversionSequence::Worse; 1916 1917 if (FromIface1 && FromIface2) { 1918 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1919 return ImplicitConversionSequence::Better; 1920 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1921 return ImplicitConversionSequence::Worse; 1922 } 1923 } 1924 } 1925 1926 // Compare based on reference bindings. 1927 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1928 SCS1.Second == ICK_Derived_To_Base) { 1929 // -- binding of an expression of type C to a reference of type 1930 // B& is better than binding an expression of type C to a 1931 // reference of type 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 // -- binding of an expression of type B to a reference of type 1941 // A& is better than binding an expression of type C to a 1942 // reference of type A&, 1943 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1944 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1945 if (IsDerivedFrom(FromType2, FromType1)) 1946 return ImplicitConversionSequence::Better; 1947 else if (IsDerivedFrom(FromType1, FromType2)) 1948 return ImplicitConversionSequence::Worse; 1949 } 1950 } 1951 1952 // Ranking of member-pointer types. 1953 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 1954 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 1955 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 1956 const MemberPointerType * FromMemPointer1 = 1957 FromType1->getAs<MemberPointerType>(); 1958 const MemberPointerType * ToMemPointer1 = 1959 ToType1->getAs<MemberPointerType>(); 1960 const MemberPointerType * FromMemPointer2 = 1961 FromType2->getAs<MemberPointerType>(); 1962 const MemberPointerType * ToMemPointer2 = 1963 ToType2->getAs<MemberPointerType>(); 1964 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 1965 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 1966 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 1967 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 1968 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 1969 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 1970 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 1971 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 1972 // conversion of A::* to B::* is better than conversion of A::* to C::*, 1973 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1974 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1975 return ImplicitConversionSequence::Worse; 1976 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1977 return ImplicitConversionSequence::Better; 1978 } 1979 // conversion of B::* to C::* is better than conversion of A::* to C::* 1980 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 1981 if (IsDerivedFrom(FromPointee1, FromPointee2)) 1982 return ImplicitConversionSequence::Better; 1983 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 1984 return ImplicitConversionSequence::Worse; 1985 } 1986 } 1987 1988 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1989 SCS1.Second == ICK_Derived_To_Base) { 1990 // -- conversion of C to B is better than conversion of C to A, 1991 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1992 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1993 if (IsDerivedFrom(ToType1, ToType2)) 1994 return ImplicitConversionSequence::Better; 1995 else if (IsDerivedFrom(ToType2, ToType1)) 1996 return ImplicitConversionSequence::Worse; 1997 } 1998 1999 // -- conversion of B to A is better than conversion of C to A. 2000 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 2001 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 2002 if (IsDerivedFrom(FromType2, FromType1)) 2003 return ImplicitConversionSequence::Better; 2004 else if (IsDerivedFrom(FromType1, FromType2)) 2005 return ImplicitConversionSequence::Worse; 2006 } 2007 } 2008 2009 return ImplicitConversionSequence::Indistinguishable; 2010} 2011 2012/// TryCopyInitialization - Try to copy-initialize a value of type 2013/// ToType from the expression From. Return the implicit conversion 2014/// sequence required to pass this argument, which may be a bad 2015/// conversion sequence (meaning that the argument cannot be passed to 2016/// a parameter of this type). If @p SuppressUserConversions, then we 2017/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2018/// then we treat @p From as an rvalue, even if it is an lvalue. 2019ImplicitConversionSequence 2020Sema::TryCopyInitialization(Expr *From, QualType ToType, 2021 bool SuppressUserConversions, bool ForceRValue, 2022 bool InOverloadResolution) { 2023 if (ToType->isReferenceType()) { 2024 ImplicitConversionSequence ICS; 2025 CheckReferenceInit(From, ToType, 2026 /*FIXME:*/From->getLocStart(), 2027 SuppressUserConversions, 2028 /*AllowExplicit=*/false, 2029 ForceRValue, 2030 &ICS); 2031 return ICS; 2032 } else { 2033 return TryImplicitConversion(From, ToType, 2034 SuppressUserConversions, 2035 /*AllowExplicit=*/false, 2036 ForceRValue, 2037 InOverloadResolution); 2038 } 2039} 2040 2041/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 2042/// the expression @p From. Returns true (and emits a diagnostic) if there was 2043/// an error, returns false if the initialization succeeded. Elidable should 2044/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2045/// differently in C++0x for this case. 2046bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2047 const char* Flavor, bool Elidable) { 2048 if (!getLangOptions().CPlusPlus) { 2049 // In C, argument passing is the same as performing an assignment. 2050 QualType FromType = From->getType(); 2051 2052 AssignConvertType ConvTy = 2053 CheckSingleAssignmentConstraints(ToType, From); 2054 if (ConvTy != Compatible && 2055 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2056 ConvTy = Compatible; 2057 2058 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2059 FromType, From, Flavor); 2060 } 2061 2062 if (ToType->isReferenceType()) 2063 return CheckReferenceInit(From, ToType, 2064 /*FIXME:*/From->getLocStart(), 2065 /*SuppressUserConversions=*/false, 2066 /*AllowExplicit=*/false, 2067 /*ForceRValue=*/false); 2068 2069 if (!PerformImplicitConversion(From, ToType, Flavor, 2070 /*AllowExplicit=*/false, Elidable)) 2071 return false; 2072 if (!DiagnoseAmbiguousUserDefinedConversion(From, ToType)) 2073 return Diag(From->getSourceRange().getBegin(), 2074 diag::err_typecheck_convert_incompatible) 2075 << ToType << From->getType() << Flavor << From->getSourceRange(); 2076 return true; 2077} 2078 2079/// TryObjectArgumentInitialization - Try to initialize the object 2080/// parameter of the given member function (@c Method) from the 2081/// expression @p From. 2082ImplicitConversionSequence 2083Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2084 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2085 QualType ImplicitParamType 2086 = Context.getCVRQualifiedType(ClassType, Method->getTypeQualifiers()); 2087 2088 // Set up the conversion sequence as a "bad" conversion, to allow us 2089 // to exit early. 2090 ImplicitConversionSequence ICS; 2091 ICS.Standard.setAsIdentityConversion(); 2092 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2093 2094 // We need to have an object of class type. 2095 QualType FromType = From->getType(); 2096 if (const PointerType *PT = FromType->getAs<PointerType>()) 2097 FromType = PT->getPointeeType(); 2098 2099 assert(FromType->isRecordType()); 2100 2101 // The implicit object parmeter is has the type "reference to cv X", 2102 // where X is the class of which the function is a member 2103 // (C++ [over.match.funcs]p4). However, when finding an implicit 2104 // conversion sequence for the argument, we are not allowed to 2105 // create temporaries or perform user-defined conversions 2106 // (C++ [over.match.funcs]p5). We perform a simplified version of 2107 // reference binding here, that allows class rvalues to bind to 2108 // non-constant references. 2109 2110 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2111 // with the implicit object parameter (C++ [over.match.funcs]p5). 2112 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2113 if (ImplicitParamType.getCVRQualifiers() != FromTypeCanon.getCVRQualifiers() && 2114 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) 2115 return ICS; 2116 2117 // Check that we have either the same type or a derived type. It 2118 // affects the conversion rank. 2119 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2120 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2121 ICS.Standard.Second = ICK_Identity; 2122 else if (IsDerivedFrom(FromType, ClassType)) 2123 ICS.Standard.Second = ICK_Derived_To_Base; 2124 else 2125 return ICS; 2126 2127 // Success. Mark this as a reference binding. 2128 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2129 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2130 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2131 ICS.Standard.ReferenceBinding = true; 2132 ICS.Standard.DirectBinding = true; 2133 ICS.Standard.RRefBinding = false; 2134 return ICS; 2135} 2136 2137/// PerformObjectArgumentInitialization - Perform initialization of 2138/// the implicit object parameter for the given Method with the given 2139/// expression. 2140bool 2141Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2142 QualType FromRecordType, DestType; 2143 QualType ImplicitParamRecordType = 2144 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2145 2146 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2147 FromRecordType = PT->getPointeeType(); 2148 DestType = Method->getThisType(Context); 2149 } else { 2150 FromRecordType = From->getType(); 2151 DestType = ImplicitParamRecordType; 2152 } 2153 2154 ImplicitConversionSequence ICS 2155 = TryObjectArgumentInitialization(From, Method); 2156 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2157 return Diag(From->getSourceRange().getBegin(), 2158 diag::err_implicit_object_parameter_init) 2159 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2160 2161 if (ICS.Standard.Second == ICK_Derived_To_Base && 2162 CheckDerivedToBaseConversion(FromRecordType, 2163 ImplicitParamRecordType, 2164 From->getSourceRange().getBegin(), 2165 From->getSourceRange())) 2166 return true; 2167 2168 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2169 /*isLvalue=*/true); 2170 return false; 2171} 2172 2173/// TryContextuallyConvertToBool - Attempt to contextually convert the 2174/// expression From to bool (C++0x [conv]p3). 2175ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2176 return TryImplicitConversion(From, Context.BoolTy, 2177 // FIXME: Are these flags correct? 2178 /*SuppressUserConversions=*/false, 2179 /*AllowExplicit=*/true, 2180 /*ForceRValue=*/false, 2181 /*InOverloadResolution=*/false); 2182} 2183 2184/// PerformContextuallyConvertToBool - Perform a contextual conversion 2185/// of the expression From to bool (C++0x [conv]p3). 2186bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2187 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2188 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2189 return false; 2190 2191 if (!DiagnoseAmbiguousUserDefinedConversion(From, Context.BoolTy)) 2192 return Diag(From->getSourceRange().getBegin(), 2193 diag::err_typecheck_bool_condition) 2194 << From->getType() << From->getSourceRange(); 2195 return true; 2196} 2197 2198/// AddOverloadCandidate - Adds the given function to the set of 2199/// candidate functions, using the given function call arguments. If 2200/// @p SuppressUserConversions, then don't allow user-defined 2201/// conversions via constructors or conversion operators. 2202/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2203/// hacky way to implement the overloading rules for elidable copy 2204/// initialization in C++0x (C++0x 12.8p15). 2205/// 2206/// \para PartialOverloading true if we are performing "partial" overloading 2207/// based on an incomplete set of function arguments. This feature is used by 2208/// code completion. 2209void 2210Sema::AddOverloadCandidate(FunctionDecl *Function, 2211 Expr **Args, unsigned NumArgs, 2212 OverloadCandidateSet& CandidateSet, 2213 bool SuppressUserConversions, 2214 bool ForceRValue, 2215 bool PartialOverloading) { 2216 const FunctionProtoType* Proto 2217 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2218 assert(Proto && "Functions without a prototype cannot be overloaded"); 2219 assert(!isa<CXXConversionDecl>(Function) && 2220 "Use AddConversionCandidate for conversion functions"); 2221 assert(!Function->getDescribedFunctionTemplate() && 2222 "Use AddTemplateOverloadCandidate for function templates"); 2223 2224 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2225 if (!isa<CXXConstructorDecl>(Method)) { 2226 // If we get here, it's because we're calling a member function 2227 // that is named without a member access expression (e.g., 2228 // "this->f") that was either written explicitly or created 2229 // implicitly. This can happen with a qualified call to a member 2230 // function, e.g., X::f(). We use a NULL object as the implied 2231 // object argument (C++ [over.call.func]p3). 2232 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2233 SuppressUserConversions, ForceRValue); 2234 return; 2235 } 2236 // We treat a constructor like a non-member function, since its object 2237 // argument doesn't participate in overload resolution. 2238 } 2239 2240 if (!CandidateSet.isNewCandidate(Function)) 2241 return; 2242 2243 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2244 // C++ [class.copy]p3: 2245 // A member function template is never instantiated to perform the copy 2246 // of a class object to an object of its class type. 2247 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2248 if (NumArgs == 1 && 2249 Constructor->isCopyConstructorLikeSpecialization() && 2250 Context.hasSameUnqualifiedType(ClassType, Args[0]->getType())) 2251 return; 2252 } 2253 2254 // Add this candidate 2255 CandidateSet.push_back(OverloadCandidate()); 2256 OverloadCandidate& Candidate = CandidateSet.back(); 2257 Candidate.Function = Function; 2258 Candidate.Viable = true; 2259 Candidate.IsSurrogate = false; 2260 Candidate.IgnoreObjectArgument = false; 2261 2262 unsigned NumArgsInProto = Proto->getNumArgs(); 2263 2264 // (C++ 13.3.2p2): A candidate function having fewer than m 2265 // parameters is viable only if it has an ellipsis in its parameter 2266 // list (8.3.5). 2267 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2268 !Proto->isVariadic()) { 2269 Candidate.Viable = false; 2270 return; 2271 } 2272 2273 // (C++ 13.3.2p2): A candidate function having more than m parameters 2274 // is viable only if the (m+1)st parameter has a default argument 2275 // (8.3.6). For the purposes of overload resolution, the 2276 // parameter list is truncated on the right, so that there are 2277 // exactly m parameters. 2278 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2279 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2280 // Not enough arguments. 2281 Candidate.Viable = false; 2282 return; 2283 } 2284 2285 // Determine the implicit conversion sequences for each of the 2286 // arguments. 2287 Candidate.Conversions.resize(NumArgs); 2288 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2289 if (ArgIdx < NumArgsInProto) { 2290 // (C++ 13.3.2p3): for F to be a viable function, there shall 2291 // exist for each argument an implicit conversion sequence 2292 // (13.3.3.1) that converts that argument to the corresponding 2293 // parameter of F. 2294 QualType ParamType = Proto->getArgType(ArgIdx); 2295 Candidate.Conversions[ArgIdx] 2296 = TryCopyInitialization(Args[ArgIdx], ParamType, 2297 SuppressUserConversions, ForceRValue, 2298 /*InOverloadResolution=*/true); 2299 if (Candidate.Conversions[ArgIdx].ConversionKind 2300 == ImplicitConversionSequence::BadConversion) { 2301 // 13.3.3.1-p10 If several different sequences of conversions exist that 2302 // each convert the argument to the parameter type, the implicit conversion 2303 // sequence associated with the parameter is defined to be the unique conversion 2304 // sequence designated the ambiguous conversion sequence. For the purpose of 2305 // ranking implicit conversion sequences as described in 13.3.3.2, the ambiguous 2306 // conversion sequence is treated as a user-defined sequence that is 2307 // indistinguishable from any other user-defined conversion sequence 2308 if (!Candidate.Conversions[ArgIdx].ConversionFunctionSet.empty()) { 2309 Candidate.Conversions[ArgIdx].ConversionKind = 2310 ImplicitConversionSequence::UserDefinedConversion; 2311 // Set the conversion function to one of them. As due to ambiguity, 2312 // they carry the same weight and is needed for overload resolution 2313 // later. 2314 Candidate.Conversions[ArgIdx].UserDefined.ConversionFunction = 2315 Candidate.Conversions[ArgIdx].ConversionFunctionSet[0]; 2316 } 2317 else { 2318 Candidate.Viable = false; 2319 break; 2320 } 2321 } 2322 } else { 2323 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2324 // argument for which there is no corresponding parameter is 2325 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2326 Candidate.Conversions[ArgIdx].ConversionKind 2327 = ImplicitConversionSequence::EllipsisConversion; 2328 } 2329 } 2330} 2331 2332/// \brief Add all of the function declarations in the given function set to 2333/// the overload canddiate set. 2334void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2335 Expr **Args, unsigned NumArgs, 2336 OverloadCandidateSet& CandidateSet, 2337 bool SuppressUserConversions) { 2338 for (FunctionSet::const_iterator F = Functions.begin(), 2339 FEnd = Functions.end(); 2340 F != FEnd; ++F) { 2341 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2342 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2343 AddMethodCandidate(cast<CXXMethodDecl>(FD), 2344 Args[0], Args + 1, NumArgs - 1, 2345 CandidateSet, SuppressUserConversions); 2346 else 2347 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2348 SuppressUserConversions); 2349 } else { 2350 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2351 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2352 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2353 AddMethodTemplateCandidate(FunTmpl, 2354 /*FIXME: explicit args */false, 0, 0, 2355 Args[0], Args + 1, NumArgs - 1, 2356 CandidateSet, 2357 SuppressUserConversions); 2358 else 2359 AddTemplateOverloadCandidate(FunTmpl, 2360 /*FIXME: explicit args */false, 0, 0, 2361 Args, NumArgs, CandidateSet, 2362 SuppressUserConversions); 2363 } 2364 } 2365} 2366 2367/// AddMethodCandidate - Adds the given C++ member function to the set 2368/// of candidate functions, using the given function call arguments 2369/// and the object argument (@c Object). For example, in a call 2370/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2371/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2372/// allow user-defined conversions via constructors or conversion 2373/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2374/// a slightly hacky way to implement the overloading rules for elidable copy 2375/// initialization in C++0x (C++0x 12.8p15). 2376void 2377Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2378 Expr **Args, unsigned NumArgs, 2379 OverloadCandidateSet& CandidateSet, 2380 bool SuppressUserConversions, bool ForceRValue) { 2381 const FunctionProtoType* Proto 2382 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2383 assert(Proto && "Methods without a prototype cannot be overloaded"); 2384 assert(!isa<CXXConversionDecl>(Method) && 2385 "Use AddConversionCandidate for conversion functions"); 2386 assert(!isa<CXXConstructorDecl>(Method) && 2387 "Use AddOverloadCandidate for constructors"); 2388 2389 if (!CandidateSet.isNewCandidate(Method)) 2390 return; 2391 2392 // Add this candidate 2393 CandidateSet.push_back(OverloadCandidate()); 2394 OverloadCandidate& Candidate = CandidateSet.back(); 2395 Candidate.Function = Method; 2396 Candidate.IsSurrogate = false; 2397 Candidate.IgnoreObjectArgument = false; 2398 2399 unsigned NumArgsInProto = Proto->getNumArgs(); 2400 2401 // (C++ 13.3.2p2): A candidate function having fewer than m 2402 // parameters is viable only if it has an ellipsis in its parameter 2403 // list (8.3.5). 2404 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2405 Candidate.Viable = false; 2406 return; 2407 } 2408 2409 // (C++ 13.3.2p2): A candidate function having more than m parameters 2410 // is viable only if the (m+1)st parameter has a default argument 2411 // (8.3.6). For the purposes of overload resolution, the 2412 // parameter list is truncated on the right, so that there are 2413 // exactly m parameters. 2414 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2415 if (NumArgs < MinRequiredArgs) { 2416 // Not enough arguments. 2417 Candidate.Viable = false; 2418 return; 2419 } 2420 2421 Candidate.Viable = true; 2422 Candidate.Conversions.resize(NumArgs + 1); 2423 2424 if (Method->isStatic() || !Object) 2425 // The implicit object argument is ignored. 2426 Candidate.IgnoreObjectArgument = true; 2427 else { 2428 // Determine the implicit conversion sequence for the object 2429 // parameter. 2430 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2431 if (Candidate.Conversions[0].ConversionKind 2432 == ImplicitConversionSequence::BadConversion) { 2433 Candidate.Viable = false; 2434 return; 2435 } 2436 } 2437 2438 // Determine the implicit conversion sequences for each of the 2439 // arguments. 2440 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2441 if (ArgIdx < NumArgsInProto) { 2442 // (C++ 13.3.2p3): for F to be a viable function, there shall 2443 // exist for each argument an implicit conversion sequence 2444 // (13.3.3.1) that converts that argument to the corresponding 2445 // parameter of F. 2446 QualType ParamType = Proto->getArgType(ArgIdx); 2447 Candidate.Conversions[ArgIdx + 1] 2448 = TryCopyInitialization(Args[ArgIdx], ParamType, 2449 SuppressUserConversions, ForceRValue, 2450 /*InOverloadResolution=*/true); 2451 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2452 == ImplicitConversionSequence::BadConversion) { 2453 Candidate.Viable = false; 2454 break; 2455 } 2456 } else { 2457 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2458 // argument for which there is no corresponding parameter is 2459 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2460 Candidate.Conversions[ArgIdx + 1].ConversionKind 2461 = ImplicitConversionSequence::EllipsisConversion; 2462 } 2463 } 2464} 2465 2466/// \brief Add a C++ member function template as a candidate to the candidate 2467/// set, using template argument deduction to produce an appropriate member 2468/// function template specialization. 2469void 2470Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2471 bool HasExplicitTemplateArgs, 2472 const TemplateArgumentLoc *ExplicitTemplateArgs, 2473 unsigned NumExplicitTemplateArgs, 2474 Expr *Object, Expr **Args, unsigned NumArgs, 2475 OverloadCandidateSet& CandidateSet, 2476 bool SuppressUserConversions, 2477 bool ForceRValue) { 2478 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2479 return; 2480 2481 // C++ [over.match.funcs]p7: 2482 // In each case where a candidate is a function template, candidate 2483 // function template specializations are generated using template argument 2484 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2485 // candidate functions in the usual way.113) A given name can refer to one 2486 // or more function templates and also to a set of overloaded non-template 2487 // functions. In such a case, the candidate functions generated from each 2488 // function template are combined with the set of non-template candidate 2489 // functions. 2490 TemplateDeductionInfo Info(Context); 2491 FunctionDecl *Specialization = 0; 2492 if (TemplateDeductionResult Result 2493 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2494 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2495 Args, NumArgs, Specialization, Info)) { 2496 // FIXME: Record what happened with template argument deduction, so 2497 // that we can give the user a beautiful diagnostic. 2498 (void)Result; 2499 return; 2500 } 2501 2502 // Add the function template specialization produced by template argument 2503 // deduction as a candidate. 2504 assert(Specialization && "Missing member function template specialization?"); 2505 assert(isa<CXXMethodDecl>(Specialization) && 2506 "Specialization is not a member function?"); 2507 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2508 CandidateSet, SuppressUserConversions, ForceRValue); 2509} 2510 2511/// \brief Add a C++ function template specialization as a candidate 2512/// in the candidate set, using template argument deduction to produce 2513/// an appropriate function template specialization. 2514void 2515Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2516 bool HasExplicitTemplateArgs, 2517 const TemplateArgumentLoc *ExplicitTemplateArgs, 2518 unsigned NumExplicitTemplateArgs, 2519 Expr **Args, unsigned NumArgs, 2520 OverloadCandidateSet& CandidateSet, 2521 bool SuppressUserConversions, 2522 bool ForceRValue) { 2523 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2524 return; 2525 2526 // C++ [over.match.funcs]p7: 2527 // In each case where a candidate is a function template, candidate 2528 // function template specializations are generated using template argument 2529 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2530 // candidate functions in the usual way.113) A given name can refer to one 2531 // or more function templates and also to a set of overloaded non-template 2532 // functions. In such a case, the candidate functions generated from each 2533 // function template are combined with the set of non-template candidate 2534 // functions. 2535 TemplateDeductionInfo Info(Context); 2536 FunctionDecl *Specialization = 0; 2537 if (TemplateDeductionResult Result 2538 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2539 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2540 Args, NumArgs, Specialization, Info)) { 2541 // FIXME: Record what happened with template argument deduction, so 2542 // that we can give the user a beautiful diagnostic. 2543 (void)Result; 2544 return; 2545 } 2546 2547 // Add the function template specialization produced by template argument 2548 // deduction as a candidate. 2549 assert(Specialization && "Missing function template specialization?"); 2550 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2551 SuppressUserConversions, ForceRValue); 2552} 2553 2554/// AddConversionCandidate - Add a C++ conversion function as a 2555/// candidate in the candidate set (C++ [over.match.conv], 2556/// C++ [over.match.copy]). From is the expression we're converting from, 2557/// and ToType is the type that we're eventually trying to convert to 2558/// (which may or may not be the same type as the type that the 2559/// conversion function produces). 2560void 2561Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2562 Expr *From, QualType ToType, 2563 OverloadCandidateSet& CandidateSet) { 2564 assert(!Conversion->getDescribedFunctionTemplate() && 2565 "Conversion function templates use AddTemplateConversionCandidate"); 2566 2567 if (!CandidateSet.isNewCandidate(Conversion)) 2568 return; 2569 2570 // Add this candidate 2571 CandidateSet.push_back(OverloadCandidate()); 2572 OverloadCandidate& Candidate = CandidateSet.back(); 2573 Candidate.Function = Conversion; 2574 Candidate.IsSurrogate = false; 2575 Candidate.IgnoreObjectArgument = false; 2576 Candidate.FinalConversion.setAsIdentityConversion(); 2577 Candidate.FinalConversion.FromTypePtr 2578 = Conversion->getConversionType().getAsOpaquePtr(); 2579 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2580 2581 // Determine the implicit conversion sequence for the implicit 2582 // object parameter. 2583 Candidate.Viable = true; 2584 Candidate.Conversions.resize(1); 2585 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2586 // Conversion functions to a different type in the base class is visible in 2587 // the derived class. So, a derived to base conversion should not participate 2588 // in overload resolution. 2589 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2590 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2591 if (Candidate.Conversions[0].ConversionKind 2592 == ImplicitConversionSequence::BadConversion) { 2593 Candidate.Viable = false; 2594 return; 2595 } 2596 2597 // We won't go through a user-define type conversion function to convert a 2598 // derived to base as such conversions are given Conversion Rank. They only 2599 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2600 QualType FromCanon 2601 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2602 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2603 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2604 Candidate.Viable = false; 2605 return; 2606 } 2607 2608 2609 // To determine what the conversion from the result of calling the 2610 // conversion function to the type we're eventually trying to 2611 // convert to (ToType), we need to synthesize a call to the 2612 // conversion function and attempt copy initialization from it. This 2613 // makes sure that we get the right semantics with respect to 2614 // lvalues/rvalues and the type. Fortunately, we can allocate this 2615 // call on the stack and we don't need its arguments to be 2616 // well-formed. 2617 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2618 SourceLocation()); 2619 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2620 CastExpr::CK_FunctionToPointerDecay, 2621 &ConversionRef, false); 2622 2623 // Note that it is safe to allocate CallExpr on the stack here because 2624 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2625 // allocator). 2626 CallExpr Call(Context, &ConversionFn, 0, 0, 2627 Conversion->getConversionType().getNonReferenceType(), 2628 SourceLocation()); 2629 ImplicitConversionSequence ICS = 2630 TryCopyInitialization(&Call, ToType, 2631 /*SuppressUserConversions=*/true, 2632 /*ForceRValue=*/false, 2633 /*InOverloadResolution=*/false); 2634 2635 switch (ICS.ConversionKind) { 2636 case ImplicitConversionSequence::StandardConversion: 2637 Candidate.FinalConversion = ICS.Standard; 2638 break; 2639 2640 case ImplicitConversionSequence::BadConversion: 2641 Candidate.Viable = false; 2642 break; 2643 2644 default: 2645 assert(false && 2646 "Can only end up with a standard conversion sequence or failure"); 2647 } 2648} 2649 2650/// \brief Adds a conversion function template specialization 2651/// candidate to the overload set, using template argument deduction 2652/// to deduce the template arguments of the conversion function 2653/// template from the type that we are converting to (C++ 2654/// [temp.deduct.conv]). 2655void 2656Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2657 Expr *From, QualType ToType, 2658 OverloadCandidateSet &CandidateSet) { 2659 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2660 "Only conversion function templates permitted here"); 2661 2662 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2663 return; 2664 2665 TemplateDeductionInfo Info(Context); 2666 CXXConversionDecl *Specialization = 0; 2667 if (TemplateDeductionResult Result 2668 = DeduceTemplateArguments(FunctionTemplate, ToType, 2669 Specialization, Info)) { 2670 // FIXME: Record what happened with template argument deduction, so 2671 // that we can give the user a beautiful diagnostic. 2672 (void)Result; 2673 return; 2674 } 2675 2676 // Add the conversion function template specialization produced by 2677 // template argument deduction as a candidate. 2678 assert(Specialization && "Missing function template specialization?"); 2679 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2680} 2681 2682/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2683/// converts the given @c Object to a function pointer via the 2684/// conversion function @c Conversion, and then attempts to call it 2685/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2686/// the type of function that we'll eventually be calling. 2687void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2688 const FunctionProtoType *Proto, 2689 Expr *Object, Expr **Args, unsigned NumArgs, 2690 OverloadCandidateSet& CandidateSet) { 2691 if (!CandidateSet.isNewCandidate(Conversion)) 2692 return; 2693 2694 CandidateSet.push_back(OverloadCandidate()); 2695 OverloadCandidate& Candidate = CandidateSet.back(); 2696 Candidate.Function = 0; 2697 Candidate.Surrogate = Conversion; 2698 Candidate.Viable = true; 2699 Candidate.IsSurrogate = true; 2700 Candidate.IgnoreObjectArgument = false; 2701 Candidate.Conversions.resize(NumArgs + 1); 2702 2703 // Determine the implicit conversion sequence for the implicit 2704 // object parameter. 2705 ImplicitConversionSequence ObjectInit 2706 = TryObjectArgumentInitialization(Object, Conversion); 2707 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2708 Candidate.Viable = false; 2709 return; 2710 } 2711 2712 // The first conversion is actually a user-defined conversion whose 2713 // first conversion is ObjectInit's standard conversion (which is 2714 // effectively a reference binding). Record it as such. 2715 Candidate.Conversions[0].ConversionKind 2716 = ImplicitConversionSequence::UserDefinedConversion; 2717 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2718 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2719 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2720 Candidate.Conversions[0].UserDefined.After 2721 = Candidate.Conversions[0].UserDefined.Before; 2722 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2723 2724 // Find the 2725 unsigned NumArgsInProto = Proto->getNumArgs(); 2726 2727 // (C++ 13.3.2p2): A candidate function having fewer than m 2728 // parameters is viable only if it has an ellipsis in its parameter 2729 // list (8.3.5). 2730 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2731 Candidate.Viable = false; 2732 return; 2733 } 2734 2735 // Function types don't have any default arguments, so just check if 2736 // we have enough arguments. 2737 if (NumArgs < NumArgsInProto) { 2738 // Not enough arguments. 2739 Candidate.Viable = false; 2740 return; 2741 } 2742 2743 // Determine the implicit conversion sequences for each of the 2744 // arguments. 2745 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2746 if (ArgIdx < NumArgsInProto) { 2747 // (C++ 13.3.2p3): for F to be a viable function, there shall 2748 // exist for each argument an implicit conversion sequence 2749 // (13.3.3.1) that converts that argument to the corresponding 2750 // parameter of F. 2751 QualType ParamType = Proto->getArgType(ArgIdx); 2752 Candidate.Conversions[ArgIdx + 1] 2753 = TryCopyInitialization(Args[ArgIdx], ParamType, 2754 /*SuppressUserConversions=*/false, 2755 /*ForceRValue=*/false, 2756 /*InOverloadResolution=*/false); 2757 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2758 == ImplicitConversionSequence::BadConversion) { 2759 Candidate.Viable = false; 2760 break; 2761 } 2762 } else { 2763 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2764 // argument for which there is no corresponding parameter is 2765 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2766 Candidate.Conversions[ArgIdx + 1].ConversionKind 2767 = ImplicitConversionSequence::EllipsisConversion; 2768 } 2769 } 2770} 2771 2772// FIXME: This will eventually be removed, once we've migrated all of the 2773// operator overloading logic over to the scheme used by binary operators, which 2774// works for template instantiation. 2775void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2776 SourceLocation OpLoc, 2777 Expr **Args, unsigned NumArgs, 2778 OverloadCandidateSet& CandidateSet, 2779 SourceRange OpRange) { 2780 FunctionSet Functions; 2781 2782 QualType T1 = Args[0]->getType(); 2783 QualType T2; 2784 if (NumArgs > 1) 2785 T2 = Args[1]->getType(); 2786 2787 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2788 if (S) 2789 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2790 ArgumentDependentLookup(OpName, /*Operator*/true, Args, NumArgs, Functions); 2791 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2792 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2793 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 2794} 2795 2796/// \brief Add overload candidates for overloaded operators that are 2797/// member functions. 2798/// 2799/// Add the overloaded operator candidates that are member functions 2800/// for the operator Op that was used in an operator expression such 2801/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2802/// CandidateSet will store the added overload candidates. (C++ 2803/// [over.match.oper]). 2804void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2805 SourceLocation OpLoc, 2806 Expr **Args, unsigned NumArgs, 2807 OverloadCandidateSet& CandidateSet, 2808 SourceRange OpRange) { 2809 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2810 2811 // C++ [over.match.oper]p3: 2812 // For a unary operator @ with an operand of a type whose 2813 // cv-unqualified version is T1, and for a binary operator @ with 2814 // a left operand of a type whose cv-unqualified version is T1 and 2815 // a right operand of a type whose cv-unqualified version is T2, 2816 // three sets of candidate functions, designated member 2817 // candidates, non-member candidates and built-in candidates, are 2818 // constructed as follows: 2819 QualType T1 = Args[0]->getType(); 2820 QualType T2; 2821 if (NumArgs > 1) 2822 T2 = Args[1]->getType(); 2823 2824 // -- If T1 is a class type, the set of member candidates is the 2825 // result of the qualified lookup of T1::operator@ 2826 // (13.3.1.1.1); otherwise, the set of member candidates is 2827 // empty. 2828 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2829 // Complete the type if it can be completed. Otherwise, we're done. 2830 if (RequireCompleteType(OpLoc, T1, PDiag())) 2831 return; 2832 2833 LookupResult Operators; 2834 LookupQualifiedName(Operators, T1Rec->getDecl(), OpName, 2835 LookupOrdinaryName, false); 2836 for (LookupResult::iterator Oper = Operators.begin(), 2837 OperEnd = Operators.end(); 2838 Oper != OperEnd; 2839 ++Oper) { 2840 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Oper)) { 2841 AddMethodCandidate(Method, Args[0], Args+1, NumArgs - 1, CandidateSet, 2842 /*SuppressUserConversions=*/false); 2843 continue; 2844 } 2845 2846 assert(isa<FunctionTemplateDecl>(*Oper) && 2847 isa<CXXMethodDecl>(cast<FunctionTemplateDecl>(*Oper) 2848 ->getTemplatedDecl()) && 2849 "Expected a member function template"); 2850 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Oper), false, 0, 0, 2851 Args[0], Args+1, NumArgs - 1, CandidateSet, 2852 /*SuppressUserConversions=*/false); 2853 } 2854 } 2855} 2856 2857/// AddBuiltinCandidate - Add a candidate for a built-in 2858/// operator. ResultTy and ParamTys are the result and parameter types 2859/// of the built-in candidate, respectively. Args and NumArgs are the 2860/// arguments being passed to the candidate. IsAssignmentOperator 2861/// should be true when this built-in candidate is an assignment 2862/// operator. NumContextualBoolArguments is the number of arguments 2863/// (at the beginning of the argument list) that will be contextually 2864/// converted to bool. 2865void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2866 Expr **Args, unsigned NumArgs, 2867 OverloadCandidateSet& CandidateSet, 2868 bool IsAssignmentOperator, 2869 unsigned NumContextualBoolArguments) { 2870 // Add this candidate 2871 CandidateSet.push_back(OverloadCandidate()); 2872 OverloadCandidate& Candidate = CandidateSet.back(); 2873 Candidate.Function = 0; 2874 Candidate.IsSurrogate = false; 2875 Candidate.IgnoreObjectArgument = false; 2876 Candidate.BuiltinTypes.ResultTy = ResultTy; 2877 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2878 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2879 2880 // Determine the implicit conversion sequences for each of the 2881 // arguments. 2882 Candidate.Viable = true; 2883 Candidate.Conversions.resize(NumArgs); 2884 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2885 // C++ [over.match.oper]p4: 2886 // For the built-in assignment operators, conversions of the 2887 // left operand are restricted as follows: 2888 // -- no temporaries are introduced to hold the left operand, and 2889 // -- no user-defined conversions are applied to the left 2890 // operand to achieve a type match with the left-most 2891 // parameter of a built-in candidate. 2892 // 2893 // We block these conversions by turning off user-defined 2894 // conversions, since that is the only way that initialization of 2895 // a reference to a non-class type can occur from something that 2896 // is not of the same type. 2897 if (ArgIdx < NumContextualBoolArguments) { 2898 assert(ParamTys[ArgIdx] == Context.BoolTy && 2899 "Contextual conversion to bool requires bool type"); 2900 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2901 } else { 2902 Candidate.Conversions[ArgIdx] 2903 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2904 ArgIdx == 0 && IsAssignmentOperator, 2905 /*ForceRValue=*/false, 2906 /*InOverloadResolution=*/false); 2907 } 2908 if (Candidate.Conversions[ArgIdx].ConversionKind 2909 == ImplicitConversionSequence::BadConversion) { 2910 Candidate.Viable = false; 2911 break; 2912 } 2913 } 2914} 2915 2916/// BuiltinCandidateTypeSet - A set of types that will be used for the 2917/// candidate operator functions for built-in operators (C++ 2918/// [over.built]). The types are separated into pointer types and 2919/// enumeration types. 2920class BuiltinCandidateTypeSet { 2921 /// TypeSet - A set of types. 2922 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2923 2924 /// PointerTypes - The set of pointer types that will be used in the 2925 /// built-in candidates. 2926 TypeSet PointerTypes; 2927 2928 /// MemberPointerTypes - The set of member pointer types that will be 2929 /// used in the built-in candidates. 2930 TypeSet MemberPointerTypes; 2931 2932 /// EnumerationTypes - The set of enumeration types that will be 2933 /// used in the built-in candidates. 2934 TypeSet EnumerationTypes; 2935 2936 /// Sema - The semantic analysis instance where we are building the 2937 /// candidate type set. 2938 Sema &SemaRef; 2939 2940 /// Context - The AST context in which we will build the type sets. 2941 ASTContext &Context; 2942 2943 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 2944 const Qualifiers &VisibleQuals); 2945 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2946 2947public: 2948 /// iterator - Iterates through the types that are part of the set. 2949 typedef TypeSet::iterator iterator; 2950 2951 BuiltinCandidateTypeSet(Sema &SemaRef) 2952 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2953 2954 void AddTypesConvertedFrom(QualType Ty, 2955 SourceLocation Loc, 2956 bool AllowUserConversions, 2957 bool AllowExplicitConversions, 2958 const Qualifiers &VisibleTypeConversionsQuals); 2959 2960 /// pointer_begin - First pointer type found; 2961 iterator pointer_begin() { return PointerTypes.begin(); } 2962 2963 /// pointer_end - Past the last pointer type found; 2964 iterator pointer_end() { return PointerTypes.end(); } 2965 2966 /// member_pointer_begin - First member pointer type found; 2967 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2968 2969 /// member_pointer_end - Past the last member pointer type found; 2970 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2971 2972 /// enumeration_begin - First enumeration type found; 2973 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2974 2975 /// enumeration_end - Past the last enumeration type found; 2976 iterator enumeration_end() { return EnumerationTypes.end(); } 2977}; 2978 2979/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2980/// the set of pointer types along with any more-qualified variants of 2981/// that type. For example, if @p Ty is "int const *", this routine 2982/// will add "int const *", "int const volatile *", "int const 2983/// restrict *", and "int const volatile restrict *" to the set of 2984/// pointer types. Returns true if the add of @p Ty itself succeeded, 2985/// false otherwise. 2986/// 2987/// FIXME: what to do about extended qualifiers? 2988bool 2989BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 2990 const Qualifiers &VisibleQuals) { 2991 2992 // Insert this type. 2993 if (!PointerTypes.insert(Ty)) 2994 return false; 2995 2996 const PointerType *PointerTy = Ty->getAs<PointerType>(); 2997 assert(PointerTy && "type was not a pointer type!"); 2998 2999 QualType PointeeTy = PointerTy->getPointeeType(); 3000 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3001 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3002 BaseCVR = Array->getElementType().getCVRQualifiers(); 3003 bool hasVolatile = VisibleQuals.hasVolatile(); 3004 bool hasRestrict = VisibleQuals.hasRestrict(); 3005 3006 // Iterate through all strict supersets of BaseCVR. 3007 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3008 if ((CVR | BaseCVR) != CVR) continue; 3009 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3010 // in the types. 3011 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3012 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3013 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3014 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3015 } 3016 3017 return true; 3018} 3019 3020/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3021/// to the set of pointer types along with any more-qualified variants of 3022/// that type. For example, if @p Ty is "int const *", this routine 3023/// will add "int const *", "int const volatile *", "int const 3024/// restrict *", and "int const volatile restrict *" to the set of 3025/// pointer types. Returns true if the add of @p Ty itself succeeded, 3026/// false otherwise. 3027/// 3028/// FIXME: what to do about extended qualifiers? 3029bool 3030BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3031 QualType Ty) { 3032 // Insert this type. 3033 if (!MemberPointerTypes.insert(Ty)) 3034 return false; 3035 3036 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3037 assert(PointerTy && "type was not a member pointer type!"); 3038 3039 QualType PointeeTy = PointerTy->getPointeeType(); 3040 const Type *ClassTy = PointerTy->getClass(); 3041 3042 // Iterate through all strict supersets of the pointee type's CVR 3043 // qualifiers. 3044 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3045 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3046 if ((CVR | BaseCVR) != CVR) continue; 3047 3048 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3049 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3050 } 3051 3052 return true; 3053} 3054 3055/// AddTypesConvertedFrom - Add each of the types to which the type @p 3056/// Ty can be implicit converted to the given set of @p Types. We're 3057/// primarily interested in pointer types and enumeration types. We also 3058/// take member pointer types, for the conditional operator. 3059/// AllowUserConversions is true if we should look at the conversion 3060/// functions of a class type, and AllowExplicitConversions if we 3061/// should also include the explicit conversion functions of a class 3062/// type. 3063void 3064BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3065 SourceLocation Loc, 3066 bool AllowUserConversions, 3067 bool AllowExplicitConversions, 3068 const Qualifiers &VisibleQuals) { 3069 // Only deal with canonical types. 3070 Ty = Context.getCanonicalType(Ty); 3071 3072 // Look through reference types; they aren't part of the type of an 3073 // expression for the purposes of conversions. 3074 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3075 Ty = RefTy->getPointeeType(); 3076 3077 // We don't care about qualifiers on the type. 3078 Ty = Ty.getUnqualifiedType(); 3079 3080 // If we're dealing with an array type, decay to the pointer. 3081 if (Ty->isArrayType()) 3082 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3083 3084 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3085 QualType PointeeTy = PointerTy->getPointeeType(); 3086 3087 // Insert our type, and its more-qualified variants, into the set 3088 // of types. 3089 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3090 return; 3091 } else if (Ty->isMemberPointerType()) { 3092 // Member pointers are far easier, since the pointee can't be converted. 3093 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3094 return; 3095 } else if (Ty->isEnumeralType()) { 3096 EnumerationTypes.insert(Ty); 3097 } else if (AllowUserConversions) { 3098 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3099 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3100 // No conversion functions in incomplete types. 3101 return; 3102 } 3103 3104 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3105 OverloadedFunctionDecl *Conversions 3106 = ClassDecl->getVisibleConversionFunctions(); 3107 for (OverloadedFunctionDecl::function_iterator Func 3108 = Conversions->function_begin(); 3109 Func != Conversions->function_end(); ++Func) { 3110 CXXConversionDecl *Conv; 3111 FunctionTemplateDecl *ConvTemplate; 3112 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 3113 3114 // Skip conversion function templates; they don't tell us anything 3115 // about which builtin types we can convert to. 3116 if (ConvTemplate) 3117 continue; 3118 3119 if (AllowExplicitConversions || !Conv->isExplicit()) { 3120 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3121 VisibleQuals); 3122 } 3123 } 3124 } 3125 } 3126} 3127 3128/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3129/// the volatile- and non-volatile-qualified assignment operators for the 3130/// given type to the candidate set. 3131static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3132 QualType T, 3133 Expr **Args, 3134 unsigned NumArgs, 3135 OverloadCandidateSet &CandidateSet) { 3136 QualType ParamTypes[2]; 3137 3138 // T& operator=(T&, T) 3139 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3140 ParamTypes[1] = T; 3141 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3142 /*IsAssignmentOperator=*/true); 3143 3144 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3145 // volatile T& operator=(volatile T&, T) 3146 ParamTypes[0] 3147 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3148 ParamTypes[1] = T; 3149 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3150 /*IsAssignmentOperator=*/true); 3151 } 3152} 3153 3154/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3155/// if any, found in visible type conversion functions found in ArgExpr's type. 3156static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3157 Qualifiers VRQuals; 3158 const RecordType *TyRec; 3159 if (const MemberPointerType *RHSMPType = 3160 ArgExpr->getType()->getAs<MemberPointerType>()) 3161 TyRec = cast<RecordType>(RHSMPType->getClass()); 3162 else 3163 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3164 if (!TyRec) { 3165 // Just to be safe, assume the worst case. 3166 VRQuals.addVolatile(); 3167 VRQuals.addRestrict(); 3168 return VRQuals; 3169 } 3170 3171 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3172 OverloadedFunctionDecl *Conversions = 3173 ClassDecl->getVisibleConversionFunctions(); 3174 3175 for (OverloadedFunctionDecl::function_iterator Func 3176 = Conversions->function_begin(); 3177 Func != Conversions->function_end(); ++Func) { 3178 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*Func)) { 3179 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3180 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3181 CanTy = ResTypeRef->getPointeeType(); 3182 // Need to go down the pointer/mempointer chain and add qualifiers 3183 // as see them. 3184 bool done = false; 3185 while (!done) { 3186 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3187 CanTy = ResTypePtr->getPointeeType(); 3188 else if (const MemberPointerType *ResTypeMPtr = 3189 CanTy->getAs<MemberPointerType>()) 3190 CanTy = ResTypeMPtr->getPointeeType(); 3191 else 3192 done = true; 3193 if (CanTy.isVolatileQualified()) 3194 VRQuals.addVolatile(); 3195 if (CanTy.isRestrictQualified()) 3196 VRQuals.addRestrict(); 3197 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3198 return VRQuals; 3199 } 3200 } 3201 } 3202 return VRQuals; 3203} 3204 3205/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3206/// operator overloads to the candidate set (C++ [over.built]), based 3207/// on the operator @p Op and the arguments given. For example, if the 3208/// operator is a binary '+', this routine might add "int 3209/// operator+(int, int)" to cover integer addition. 3210void 3211Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3212 SourceLocation OpLoc, 3213 Expr **Args, unsigned NumArgs, 3214 OverloadCandidateSet& CandidateSet) { 3215 // The set of "promoted arithmetic types", which are the arithmetic 3216 // types are that preserved by promotion (C++ [over.built]p2). Note 3217 // that the first few of these types are the promoted integral 3218 // types; these types need to be first. 3219 // FIXME: What about complex? 3220 const unsigned FirstIntegralType = 0; 3221 const unsigned LastIntegralType = 13; 3222 const unsigned FirstPromotedIntegralType = 7, 3223 LastPromotedIntegralType = 13; 3224 const unsigned FirstPromotedArithmeticType = 7, 3225 LastPromotedArithmeticType = 16; 3226 const unsigned NumArithmeticTypes = 16; 3227 QualType ArithmeticTypes[NumArithmeticTypes] = { 3228 Context.BoolTy, Context.CharTy, Context.WCharTy, 3229// FIXME: Context.Char16Ty, Context.Char32Ty, 3230 Context.SignedCharTy, Context.ShortTy, 3231 Context.UnsignedCharTy, Context.UnsignedShortTy, 3232 Context.IntTy, Context.LongTy, Context.LongLongTy, 3233 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3234 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3235 }; 3236 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3237 "Invalid first promoted integral type"); 3238 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3239 == Context.UnsignedLongLongTy && 3240 "Invalid last promoted integral type"); 3241 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3242 "Invalid first promoted arithmetic type"); 3243 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3244 == Context.LongDoubleTy && 3245 "Invalid last promoted arithmetic type"); 3246 3247 // Find all of the types that the arguments can convert to, but only 3248 // if the operator we're looking at has built-in operator candidates 3249 // that make use of these types. 3250 Qualifiers VisibleTypeConversionsQuals; 3251 VisibleTypeConversionsQuals.addConst(); 3252 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3253 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3254 3255 BuiltinCandidateTypeSet CandidateTypes(*this); 3256 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3257 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3258 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3259 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3260 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3261 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3262 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3263 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3264 OpLoc, 3265 true, 3266 (Op == OO_Exclaim || 3267 Op == OO_AmpAmp || 3268 Op == OO_PipePipe), 3269 VisibleTypeConversionsQuals); 3270 } 3271 3272 bool isComparison = false; 3273 switch (Op) { 3274 case OO_None: 3275 case NUM_OVERLOADED_OPERATORS: 3276 assert(false && "Expected an overloaded operator"); 3277 break; 3278 3279 case OO_Star: // '*' is either unary or binary 3280 if (NumArgs == 1) 3281 goto UnaryStar; 3282 else 3283 goto BinaryStar; 3284 break; 3285 3286 case OO_Plus: // '+' is either unary or binary 3287 if (NumArgs == 1) 3288 goto UnaryPlus; 3289 else 3290 goto BinaryPlus; 3291 break; 3292 3293 case OO_Minus: // '-' is either unary or binary 3294 if (NumArgs == 1) 3295 goto UnaryMinus; 3296 else 3297 goto BinaryMinus; 3298 break; 3299 3300 case OO_Amp: // '&' is either unary or binary 3301 if (NumArgs == 1) 3302 goto UnaryAmp; 3303 else 3304 goto BinaryAmp; 3305 3306 case OO_PlusPlus: 3307 case OO_MinusMinus: 3308 // C++ [over.built]p3: 3309 // 3310 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3311 // is either volatile or empty, there exist candidate operator 3312 // functions of the form 3313 // 3314 // VQ T& operator++(VQ T&); 3315 // T operator++(VQ T&, int); 3316 // 3317 // C++ [over.built]p4: 3318 // 3319 // For every pair (T, VQ), where T is an arithmetic type other 3320 // than bool, and VQ is either volatile or empty, there exist 3321 // candidate operator functions of the form 3322 // 3323 // VQ T& operator--(VQ T&); 3324 // T operator--(VQ T&, int); 3325 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3326 Arith < NumArithmeticTypes; ++Arith) { 3327 QualType ArithTy = ArithmeticTypes[Arith]; 3328 QualType ParamTypes[2] 3329 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3330 3331 // Non-volatile version. 3332 if (NumArgs == 1) 3333 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3334 else 3335 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3336 // heuristic to reduce number of builtin candidates in the set. 3337 // Add volatile version only if there are conversions to a volatile type. 3338 if (VisibleTypeConversionsQuals.hasVolatile()) { 3339 // Volatile version 3340 ParamTypes[0] 3341 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3342 if (NumArgs == 1) 3343 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3344 else 3345 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3346 } 3347 } 3348 3349 // C++ [over.built]p5: 3350 // 3351 // For every pair (T, VQ), where T is a cv-qualified or 3352 // cv-unqualified object type, and VQ is either volatile or 3353 // empty, there exist candidate operator functions of the form 3354 // 3355 // T*VQ& operator++(T*VQ&); 3356 // T*VQ& operator--(T*VQ&); 3357 // T* operator++(T*VQ&, int); 3358 // T* operator--(T*VQ&, int); 3359 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3360 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3361 // Skip pointer types that aren't pointers to object types. 3362 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3363 continue; 3364 3365 QualType ParamTypes[2] = { 3366 Context.getLValueReferenceType(*Ptr), Context.IntTy 3367 }; 3368 3369 // Without volatile 3370 if (NumArgs == 1) 3371 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3372 else 3373 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3374 3375 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3376 VisibleTypeConversionsQuals.hasVolatile()) { 3377 // With volatile 3378 ParamTypes[0] 3379 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3380 if (NumArgs == 1) 3381 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3382 else 3383 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3384 } 3385 } 3386 break; 3387 3388 UnaryStar: 3389 // C++ [over.built]p6: 3390 // For every cv-qualified or cv-unqualified object type T, there 3391 // exist candidate operator functions of the form 3392 // 3393 // T& operator*(T*); 3394 // 3395 // C++ [over.built]p7: 3396 // For every function type T, there exist candidate operator 3397 // functions of the form 3398 // T& operator*(T*); 3399 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3400 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3401 QualType ParamTy = *Ptr; 3402 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3403 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3404 &ParamTy, Args, 1, CandidateSet); 3405 } 3406 break; 3407 3408 UnaryPlus: 3409 // C++ [over.built]p8: 3410 // For every type T, there exist candidate operator functions of 3411 // the form 3412 // 3413 // T* operator+(T*); 3414 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3415 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3416 QualType ParamTy = *Ptr; 3417 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3418 } 3419 3420 // Fall through 3421 3422 UnaryMinus: 3423 // C++ [over.built]p9: 3424 // For every promoted arithmetic type T, there exist candidate 3425 // operator functions of the form 3426 // 3427 // T operator+(T); 3428 // T operator-(T); 3429 for (unsigned Arith = FirstPromotedArithmeticType; 3430 Arith < LastPromotedArithmeticType; ++Arith) { 3431 QualType ArithTy = ArithmeticTypes[Arith]; 3432 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3433 } 3434 break; 3435 3436 case OO_Tilde: 3437 // C++ [over.built]p10: 3438 // For every promoted integral type T, there exist candidate 3439 // operator functions of the form 3440 // 3441 // T operator~(T); 3442 for (unsigned Int = FirstPromotedIntegralType; 3443 Int < LastPromotedIntegralType; ++Int) { 3444 QualType IntTy = ArithmeticTypes[Int]; 3445 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3446 } 3447 break; 3448 3449 case OO_New: 3450 case OO_Delete: 3451 case OO_Array_New: 3452 case OO_Array_Delete: 3453 case OO_Call: 3454 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3455 break; 3456 3457 case OO_Comma: 3458 UnaryAmp: 3459 case OO_Arrow: 3460 // C++ [over.match.oper]p3: 3461 // -- For the operator ',', the unary operator '&', or the 3462 // operator '->', the built-in candidates set is empty. 3463 break; 3464 3465 case OO_EqualEqual: 3466 case OO_ExclaimEqual: 3467 // C++ [over.match.oper]p16: 3468 // For every pointer to member type T, there exist candidate operator 3469 // functions of the form 3470 // 3471 // bool operator==(T,T); 3472 // bool operator!=(T,T); 3473 for (BuiltinCandidateTypeSet::iterator 3474 MemPtr = CandidateTypes.member_pointer_begin(), 3475 MemPtrEnd = CandidateTypes.member_pointer_end(); 3476 MemPtr != MemPtrEnd; 3477 ++MemPtr) { 3478 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3479 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3480 } 3481 3482 // Fall through 3483 3484 case OO_Less: 3485 case OO_Greater: 3486 case OO_LessEqual: 3487 case OO_GreaterEqual: 3488 // C++ [over.built]p15: 3489 // 3490 // For every pointer or enumeration type T, there exist 3491 // candidate operator functions of the form 3492 // 3493 // bool operator<(T, T); 3494 // bool operator>(T, T); 3495 // bool operator<=(T, T); 3496 // bool operator>=(T, T); 3497 // bool operator==(T, T); 3498 // bool operator!=(T, T); 3499 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3500 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3501 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3502 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3503 } 3504 for (BuiltinCandidateTypeSet::iterator Enum 3505 = CandidateTypes.enumeration_begin(); 3506 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3507 QualType ParamTypes[2] = { *Enum, *Enum }; 3508 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3509 } 3510 3511 // Fall through. 3512 isComparison = true; 3513 3514 BinaryPlus: 3515 BinaryMinus: 3516 if (!isComparison) { 3517 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3518 3519 // C++ [over.built]p13: 3520 // 3521 // For every cv-qualified or cv-unqualified object type T 3522 // there exist candidate operator functions of the form 3523 // 3524 // T* operator+(T*, ptrdiff_t); 3525 // T& operator[](T*, ptrdiff_t); [BELOW] 3526 // T* operator-(T*, ptrdiff_t); 3527 // T* operator+(ptrdiff_t, T*); 3528 // T& operator[](ptrdiff_t, T*); [BELOW] 3529 // 3530 // C++ [over.built]p14: 3531 // 3532 // For every T, where T is a pointer to object type, there 3533 // exist candidate operator functions of the form 3534 // 3535 // ptrdiff_t operator-(T, T); 3536 for (BuiltinCandidateTypeSet::iterator Ptr 3537 = CandidateTypes.pointer_begin(); 3538 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3539 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3540 3541 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3542 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3543 3544 if (Op == OO_Plus) { 3545 // T* operator+(ptrdiff_t, T*); 3546 ParamTypes[0] = ParamTypes[1]; 3547 ParamTypes[1] = *Ptr; 3548 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3549 } else { 3550 // ptrdiff_t operator-(T, T); 3551 ParamTypes[1] = *Ptr; 3552 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3553 Args, 2, CandidateSet); 3554 } 3555 } 3556 } 3557 // Fall through 3558 3559 case OO_Slash: 3560 BinaryStar: 3561 Conditional: 3562 // C++ [over.built]p12: 3563 // 3564 // For every pair of promoted arithmetic types L and R, there 3565 // exist candidate operator functions of the form 3566 // 3567 // LR operator*(L, R); 3568 // LR operator/(L, R); 3569 // LR operator+(L, R); 3570 // LR operator-(L, R); 3571 // bool operator<(L, R); 3572 // bool operator>(L, R); 3573 // bool operator<=(L, R); 3574 // bool operator>=(L, R); 3575 // bool operator==(L, R); 3576 // bool operator!=(L, R); 3577 // 3578 // where LR is the result of the usual arithmetic conversions 3579 // between types L and R. 3580 // 3581 // C++ [over.built]p24: 3582 // 3583 // For every pair of promoted arithmetic types L and R, there exist 3584 // candidate operator functions of the form 3585 // 3586 // LR operator?(bool, L, R); 3587 // 3588 // where LR is the result of the usual arithmetic conversions 3589 // between types L and R. 3590 // Our candidates ignore the first parameter. 3591 for (unsigned Left = FirstPromotedArithmeticType; 3592 Left < LastPromotedArithmeticType; ++Left) { 3593 for (unsigned Right = FirstPromotedArithmeticType; 3594 Right < LastPromotedArithmeticType; ++Right) { 3595 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3596 QualType Result 3597 = isComparison 3598 ? Context.BoolTy 3599 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3600 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3601 } 3602 } 3603 break; 3604 3605 case OO_Percent: 3606 BinaryAmp: 3607 case OO_Caret: 3608 case OO_Pipe: 3609 case OO_LessLess: 3610 case OO_GreaterGreater: 3611 // C++ [over.built]p17: 3612 // 3613 // For every pair of promoted integral types L and R, there 3614 // exist candidate operator functions of the form 3615 // 3616 // LR operator%(L, R); 3617 // LR operator&(L, R); 3618 // LR operator^(L, R); 3619 // LR operator|(L, R); 3620 // L operator<<(L, R); 3621 // L operator>>(L, R); 3622 // 3623 // where LR is the result of the usual arithmetic conversions 3624 // between types L and R. 3625 for (unsigned Left = FirstPromotedIntegralType; 3626 Left < LastPromotedIntegralType; ++Left) { 3627 for (unsigned Right = FirstPromotedIntegralType; 3628 Right < LastPromotedIntegralType; ++Right) { 3629 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3630 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3631 ? LandR[0] 3632 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3633 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3634 } 3635 } 3636 break; 3637 3638 case OO_Equal: 3639 // C++ [over.built]p20: 3640 // 3641 // For every pair (T, VQ), where T is an enumeration or 3642 // pointer to member type and VQ is either volatile or 3643 // empty, there exist candidate operator functions of the form 3644 // 3645 // VQ T& operator=(VQ T&, T); 3646 for (BuiltinCandidateTypeSet::iterator 3647 Enum = CandidateTypes.enumeration_begin(), 3648 EnumEnd = CandidateTypes.enumeration_end(); 3649 Enum != EnumEnd; ++Enum) 3650 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3651 CandidateSet); 3652 for (BuiltinCandidateTypeSet::iterator 3653 MemPtr = CandidateTypes.member_pointer_begin(), 3654 MemPtrEnd = CandidateTypes.member_pointer_end(); 3655 MemPtr != MemPtrEnd; ++MemPtr) 3656 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3657 CandidateSet); 3658 // Fall through. 3659 3660 case OO_PlusEqual: 3661 case OO_MinusEqual: 3662 // C++ [over.built]p19: 3663 // 3664 // For every pair (T, VQ), where T is any type and VQ is either 3665 // volatile or empty, there exist candidate operator functions 3666 // of the form 3667 // 3668 // T*VQ& operator=(T*VQ&, T*); 3669 // 3670 // C++ [over.built]p21: 3671 // 3672 // For every pair (T, VQ), where T is a cv-qualified or 3673 // cv-unqualified object type and VQ is either volatile or 3674 // empty, there exist candidate operator functions of the form 3675 // 3676 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3677 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3678 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3679 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3680 QualType ParamTypes[2]; 3681 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3682 3683 // non-volatile version 3684 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3685 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3686 /*IsAssigmentOperator=*/Op == OO_Equal); 3687 3688 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3689 VisibleTypeConversionsQuals.hasVolatile()) { 3690 // volatile version 3691 ParamTypes[0] 3692 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3693 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3694 /*IsAssigmentOperator=*/Op == OO_Equal); 3695 } 3696 } 3697 // Fall through. 3698 3699 case OO_StarEqual: 3700 case OO_SlashEqual: 3701 // C++ [over.built]p18: 3702 // 3703 // For every triple (L, VQ, R), where L is an arithmetic type, 3704 // VQ is either volatile or empty, and R is a promoted 3705 // arithmetic type, there exist candidate operator functions of 3706 // the form 3707 // 3708 // VQ L& operator=(VQ L&, R); 3709 // VQ L& operator*=(VQ L&, R); 3710 // VQ L& operator/=(VQ L&, R); 3711 // VQ L& operator+=(VQ L&, R); 3712 // VQ L& operator-=(VQ L&, R); 3713 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3714 for (unsigned Right = FirstPromotedArithmeticType; 3715 Right < LastPromotedArithmeticType; ++Right) { 3716 QualType ParamTypes[2]; 3717 ParamTypes[1] = ArithmeticTypes[Right]; 3718 3719 // Add this built-in operator as a candidate (VQ is empty). 3720 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3721 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3722 /*IsAssigmentOperator=*/Op == OO_Equal); 3723 3724 // Add this built-in operator as a candidate (VQ is 'volatile'). 3725 if (VisibleTypeConversionsQuals.hasVolatile()) { 3726 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3727 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3728 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3729 /*IsAssigmentOperator=*/Op == OO_Equal); 3730 } 3731 } 3732 } 3733 break; 3734 3735 case OO_PercentEqual: 3736 case OO_LessLessEqual: 3737 case OO_GreaterGreaterEqual: 3738 case OO_AmpEqual: 3739 case OO_CaretEqual: 3740 case OO_PipeEqual: 3741 // C++ [over.built]p22: 3742 // 3743 // For every triple (L, VQ, R), where L is an integral type, VQ 3744 // is either volatile or empty, and R is a promoted integral 3745 // type, there exist candidate operator functions of the form 3746 // 3747 // VQ L& operator%=(VQ L&, R); 3748 // VQ L& operator<<=(VQ L&, R); 3749 // VQ L& operator>>=(VQ L&, R); 3750 // VQ L& operator&=(VQ L&, R); 3751 // VQ L& operator^=(VQ L&, R); 3752 // VQ L& operator|=(VQ L&, R); 3753 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3754 for (unsigned Right = FirstPromotedIntegralType; 3755 Right < LastPromotedIntegralType; ++Right) { 3756 QualType ParamTypes[2]; 3757 ParamTypes[1] = ArithmeticTypes[Right]; 3758 3759 // Add this built-in operator as a candidate (VQ is empty). 3760 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3761 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3762 if (VisibleTypeConversionsQuals.hasVolatile()) { 3763 // Add this built-in operator as a candidate (VQ is 'volatile'). 3764 ParamTypes[0] = ArithmeticTypes[Left]; 3765 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3766 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3767 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3768 } 3769 } 3770 } 3771 break; 3772 3773 case OO_Exclaim: { 3774 // C++ [over.operator]p23: 3775 // 3776 // There also exist candidate operator functions of the form 3777 // 3778 // bool operator!(bool); 3779 // bool operator&&(bool, bool); [BELOW] 3780 // bool operator||(bool, bool); [BELOW] 3781 QualType ParamTy = Context.BoolTy; 3782 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3783 /*IsAssignmentOperator=*/false, 3784 /*NumContextualBoolArguments=*/1); 3785 break; 3786 } 3787 3788 case OO_AmpAmp: 3789 case OO_PipePipe: { 3790 // C++ [over.operator]p23: 3791 // 3792 // There also exist candidate operator functions of the form 3793 // 3794 // bool operator!(bool); [ABOVE] 3795 // bool operator&&(bool, bool); 3796 // bool operator||(bool, bool); 3797 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3798 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3799 /*IsAssignmentOperator=*/false, 3800 /*NumContextualBoolArguments=*/2); 3801 break; 3802 } 3803 3804 case OO_Subscript: 3805 // C++ [over.built]p13: 3806 // 3807 // For every cv-qualified or cv-unqualified object type T there 3808 // exist candidate operator functions of the form 3809 // 3810 // T* operator+(T*, ptrdiff_t); [ABOVE] 3811 // T& operator[](T*, ptrdiff_t); 3812 // T* operator-(T*, ptrdiff_t); [ABOVE] 3813 // T* operator+(ptrdiff_t, T*); [ABOVE] 3814 // T& operator[](ptrdiff_t, T*); 3815 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3816 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3817 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3818 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3819 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3820 3821 // T& operator[](T*, ptrdiff_t) 3822 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3823 3824 // T& operator[](ptrdiff_t, T*); 3825 ParamTypes[0] = ParamTypes[1]; 3826 ParamTypes[1] = *Ptr; 3827 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3828 } 3829 break; 3830 3831 case OO_ArrowStar: 3832 // C++ [over.built]p11: 3833 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 3834 // C1 is the same type as C2 or is a derived class of C2, T is an object 3835 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 3836 // there exist candidate operator functions of the form 3837 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 3838 // where CV12 is the union of CV1 and CV2. 3839 { 3840 for (BuiltinCandidateTypeSet::iterator Ptr = 3841 CandidateTypes.pointer_begin(); 3842 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3843 QualType C1Ty = (*Ptr); 3844 QualType C1; 3845 QualifierCollector Q1; 3846 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 3847 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 3848 if (!isa<RecordType>(C1)) 3849 continue; 3850 // heuristic to reduce number of builtin candidates in the set. 3851 // Add volatile/restrict version only if there are conversions to a 3852 // volatile/restrict type. 3853 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 3854 continue; 3855 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 3856 continue; 3857 } 3858 for (BuiltinCandidateTypeSet::iterator 3859 MemPtr = CandidateTypes.member_pointer_begin(), 3860 MemPtrEnd = CandidateTypes.member_pointer_end(); 3861 MemPtr != MemPtrEnd; ++MemPtr) { 3862 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 3863 QualType C2 = QualType(mptr->getClass(), 0); 3864 C2 = C2.getUnqualifiedType(); 3865 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 3866 break; 3867 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 3868 // build CV12 T& 3869 QualType T = mptr->getPointeeType(); 3870 if (!VisibleTypeConversionsQuals.hasVolatile() && 3871 T.isVolatileQualified()) 3872 continue; 3873 if (!VisibleTypeConversionsQuals.hasRestrict() && 3874 T.isRestrictQualified()) 3875 continue; 3876 T = Q1.apply(T); 3877 QualType ResultTy = Context.getLValueReferenceType(T); 3878 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3879 } 3880 } 3881 } 3882 break; 3883 3884 case OO_Conditional: 3885 // Note that we don't consider the first argument, since it has been 3886 // contextually converted to bool long ago. The candidates below are 3887 // therefore added as binary. 3888 // 3889 // C++ [over.built]p24: 3890 // For every type T, where T is a pointer or pointer-to-member type, 3891 // there exist candidate operator functions of the form 3892 // 3893 // T operator?(bool, T, T); 3894 // 3895 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3896 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3897 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3898 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3899 } 3900 for (BuiltinCandidateTypeSet::iterator Ptr = 3901 CandidateTypes.member_pointer_begin(), 3902 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3903 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3904 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3905 } 3906 goto Conditional; 3907 } 3908} 3909 3910/// \brief Add function candidates found via argument-dependent lookup 3911/// to the set of overloading candidates. 3912/// 3913/// This routine performs argument-dependent name lookup based on the 3914/// given function name (which may also be an operator name) and adds 3915/// all of the overload candidates found by ADL to the overload 3916/// candidate set (C++ [basic.lookup.argdep]). 3917void 3918Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3919 Expr **Args, unsigned NumArgs, 3920 bool HasExplicitTemplateArgs, 3921 const TemplateArgumentLoc *ExplicitTemplateArgs, 3922 unsigned NumExplicitTemplateArgs, 3923 OverloadCandidateSet& CandidateSet, 3924 bool PartialOverloading) { 3925 FunctionSet Functions; 3926 3927 // FIXME: Should we be trafficking in canonical function decls throughout? 3928 3929 // Record all of the function candidates that we've already 3930 // added to the overload set, so that we don't add those same 3931 // candidates a second time. 3932 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3933 CandEnd = CandidateSet.end(); 3934 Cand != CandEnd; ++Cand) 3935 if (Cand->Function) { 3936 Functions.insert(Cand->Function); 3937 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3938 Functions.insert(FunTmpl); 3939 } 3940 3941 // FIXME: Pass in the explicit template arguments? 3942 ArgumentDependentLookup(Name, /*Operator*/false, Args, NumArgs, Functions); 3943 3944 // Erase all of the candidates we already knew about. 3945 // FIXME: This is suboptimal. Is there a better way? 3946 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3947 CandEnd = CandidateSet.end(); 3948 Cand != CandEnd; ++Cand) 3949 if (Cand->Function) { 3950 Functions.erase(Cand->Function); 3951 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3952 Functions.erase(FunTmpl); 3953 } 3954 3955 // For each of the ADL candidates we found, add it to the overload 3956 // set. 3957 for (FunctionSet::iterator Func = Functions.begin(), 3958 FuncEnd = Functions.end(); 3959 Func != FuncEnd; ++Func) { 3960 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3961 if (HasExplicitTemplateArgs) 3962 continue; 3963 3964 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3965 false, false, PartialOverloading); 3966 } else 3967 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3968 HasExplicitTemplateArgs, 3969 ExplicitTemplateArgs, 3970 NumExplicitTemplateArgs, 3971 Args, NumArgs, CandidateSet); 3972 } 3973} 3974 3975/// isBetterOverloadCandidate - Determines whether the first overload 3976/// candidate is a better candidate than the second (C++ 13.3.3p1). 3977bool 3978Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3979 const OverloadCandidate& Cand2) { 3980 // Define viable functions to be better candidates than non-viable 3981 // functions. 3982 if (!Cand2.Viable) 3983 return Cand1.Viable; 3984 else if (!Cand1.Viable) 3985 return false; 3986 3987 // C++ [over.match.best]p1: 3988 // 3989 // -- if F is a static member function, ICS1(F) is defined such 3990 // that ICS1(F) is neither better nor worse than ICS1(G) for 3991 // any function G, and, symmetrically, ICS1(G) is neither 3992 // better nor worse than ICS1(F). 3993 unsigned StartArg = 0; 3994 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3995 StartArg = 1; 3996 3997 // C++ [over.match.best]p1: 3998 // A viable function F1 is defined to be a better function than another 3999 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4000 // conversion sequence than ICSi(F2), and then... 4001 unsigned NumArgs = Cand1.Conversions.size(); 4002 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4003 bool HasBetterConversion = false; 4004 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4005 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4006 Cand2.Conversions[ArgIdx])) { 4007 case ImplicitConversionSequence::Better: 4008 // Cand1 has a better conversion sequence. 4009 HasBetterConversion = true; 4010 break; 4011 4012 case ImplicitConversionSequence::Worse: 4013 // Cand1 can't be better than Cand2. 4014 return false; 4015 4016 case ImplicitConversionSequence::Indistinguishable: 4017 // Do nothing. 4018 break; 4019 } 4020 } 4021 4022 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4023 // ICSj(F2), or, if not that, 4024 if (HasBetterConversion) 4025 return true; 4026 4027 // - F1 is a non-template function and F2 is a function template 4028 // specialization, or, if not that, 4029 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4030 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4031 return true; 4032 4033 // -- F1 and F2 are function template specializations, and the function 4034 // template for F1 is more specialized than the template for F2 4035 // according to the partial ordering rules described in 14.5.5.2, or, 4036 // if not that, 4037 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4038 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4039 if (FunctionTemplateDecl *BetterTemplate 4040 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4041 Cand2.Function->getPrimaryTemplate(), 4042 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4043 : TPOC_Call)) 4044 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4045 4046 // -- the context is an initialization by user-defined conversion 4047 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4048 // from the return type of F1 to the destination type (i.e., 4049 // the type of the entity being initialized) is a better 4050 // conversion sequence than the standard conversion sequence 4051 // from the return type of F2 to the destination type. 4052 if (Cand1.Function && Cand2.Function && 4053 isa<CXXConversionDecl>(Cand1.Function) && 4054 isa<CXXConversionDecl>(Cand2.Function)) { 4055 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4056 Cand2.FinalConversion)) { 4057 case ImplicitConversionSequence::Better: 4058 // Cand1 has a better conversion sequence. 4059 return true; 4060 4061 case ImplicitConversionSequence::Worse: 4062 // Cand1 can't be better than Cand2. 4063 return false; 4064 4065 case ImplicitConversionSequence::Indistinguishable: 4066 // Do nothing 4067 break; 4068 } 4069 } 4070 4071 return false; 4072} 4073 4074/// \brief Computes the best viable function (C++ 13.3.3) 4075/// within an overload candidate set. 4076/// 4077/// \param CandidateSet the set of candidate functions. 4078/// 4079/// \param Loc the location of the function name (or operator symbol) for 4080/// which overload resolution occurs. 4081/// 4082/// \param Best f overload resolution was successful or found a deleted 4083/// function, Best points to the candidate function found. 4084/// 4085/// \returns The result of overload resolution. 4086Sema::OverloadingResult 4087Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4088 SourceLocation Loc, 4089 OverloadCandidateSet::iterator& Best) { 4090 // Find the best viable function. 4091 Best = CandidateSet.end(); 4092 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4093 Cand != CandidateSet.end(); ++Cand) { 4094 if (Cand->Viable) { 4095 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 4096 Best = Cand; 4097 } 4098 } 4099 4100 // If we didn't find any viable functions, abort. 4101 if (Best == CandidateSet.end()) 4102 return OR_No_Viable_Function; 4103 4104 // Make sure that this function is better than every other viable 4105 // function. If not, we have an ambiguity. 4106 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4107 Cand != CandidateSet.end(); ++Cand) { 4108 if (Cand->Viable && 4109 Cand != Best && 4110 !isBetterOverloadCandidate(*Best, *Cand)) { 4111 Best = CandidateSet.end(); 4112 return OR_Ambiguous; 4113 } 4114 } 4115 4116 // Best is the best viable function. 4117 if (Best->Function && 4118 (Best->Function->isDeleted() || 4119 Best->Function->getAttr<UnavailableAttr>())) 4120 return OR_Deleted; 4121 4122 // C++ [basic.def.odr]p2: 4123 // An overloaded function is used if it is selected by overload resolution 4124 // when referred to from a potentially-evaluated expression. [Note: this 4125 // covers calls to named functions (5.2.2), operator overloading 4126 // (clause 13), user-defined conversions (12.3.2), allocation function for 4127 // placement new (5.3.4), as well as non-default initialization (8.5). 4128 if (Best->Function) 4129 MarkDeclarationReferenced(Loc, Best->Function); 4130 return OR_Success; 4131} 4132 4133/// PrintOverloadCandidates - When overload resolution fails, prints 4134/// diagnostic messages containing the candidates in the candidate 4135/// set. If OnlyViable is true, only viable candidates will be printed. 4136void 4137Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4138 bool OnlyViable, 4139 const char *Opc, 4140 SourceLocation OpLoc) { 4141 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4142 LastCand = CandidateSet.end(); 4143 bool Reported = false; 4144 for (; Cand != LastCand; ++Cand) { 4145 if (Cand->Viable || !OnlyViable) { 4146 if (Cand->Function) { 4147 if (Cand->Function->isDeleted() || 4148 Cand->Function->getAttr<UnavailableAttr>()) { 4149 // Deleted or "unavailable" function. 4150 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 4151 << Cand->Function->isDeleted(); 4152 } else if (FunctionTemplateDecl *FunTmpl 4153 = Cand->Function->getPrimaryTemplate()) { 4154 // Function template specialization 4155 // FIXME: Give a better reason! 4156 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 4157 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 4158 *Cand->Function->getTemplateSpecializationArgs()); 4159 } else { 4160 // Normal function 4161 bool errReported = false; 4162 if (!Cand->Viable && Cand->Conversions.size() > 0) { 4163 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 4164 const ImplicitConversionSequence &Conversion = 4165 Cand->Conversions[i]; 4166 if ((Conversion.ConversionKind != 4167 ImplicitConversionSequence::BadConversion) || 4168 Conversion.ConversionFunctionSet.size() == 0) 4169 continue; 4170 Diag(Cand->Function->getLocation(), 4171 diag::err_ovl_candidate_not_viable) << (i+1); 4172 errReported = true; 4173 for (int j = Conversion.ConversionFunctionSet.size()-1; 4174 j >= 0; j--) { 4175 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 4176 Diag(Func->getLocation(), diag::err_ovl_candidate); 4177 } 4178 } 4179 } 4180 if (!errReported) 4181 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 4182 } 4183 } else if (Cand->IsSurrogate) { 4184 // Desugar the type of the surrogate down to a function type, 4185 // retaining as many typedefs as possible while still showing 4186 // the function type (and, therefore, its parameter types). 4187 QualType FnType = Cand->Surrogate->getConversionType(); 4188 bool isLValueReference = false; 4189 bool isRValueReference = false; 4190 bool isPointer = false; 4191 if (const LValueReferenceType *FnTypeRef = 4192 FnType->getAs<LValueReferenceType>()) { 4193 FnType = FnTypeRef->getPointeeType(); 4194 isLValueReference = true; 4195 } else if (const RValueReferenceType *FnTypeRef = 4196 FnType->getAs<RValueReferenceType>()) { 4197 FnType = FnTypeRef->getPointeeType(); 4198 isRValueReference = true; 4199 } 4200 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4201 FnType = FnTypePtr->getPointeeType(); 4202 isPointer = true; 4203 } 4204 // Desugar down to a function type. 4205 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4206 // Reconstruct the pointer/reference as appropriate. 4207 if (isPointer) FnType = Context.getPointerType(FnType); 4208 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 4209 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 4210 4211 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 4212 << FnType; 4213 } else if (OnlyViable) { 4214 assert(Cand->Conversions.size() <= 2 && 4215 "builtin-binary-operator-not-binary"); 4216 std::string TypeStr("operator"); 4217 TypeStr += Opc; 4218 TypeStr += "("; 4219 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4220 if (Cand->Conversions.size() == 1) { 4221 TypeStr += ")"; 4222 Diag(OpLoc, diag::err_ovl_builtin_unary_candidate) << TypeStr; 4223 } 4224 else { 4225 TypeStr += ", "; 4226 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4227 TypeStr += ")"; 4228 Diag(OpLoc, diag::err_ovl_builtin_binary_candidate) << TypeStr; 4229 } 4230 } 4231 else if (!Cand->Viable && !Reported) { 4232 // Non-viability might be due to ambiguous user-defined conversions, 4233 // needed for built-in operators. Report them as well, but only once 4234 // as we have typically many built-in candidates. 4235 unsigned NoOperands = Cand->Conversions.size(); 4236 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4237 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4238 if (ICS.ConversionKind != ImplicitConversionSequence::BadConversion || 4239 ICS.ConversionFunctionSet.empty()) 4240 continue; 4241 if (CXXConversionDecl *Func = dyn_cast<CXXConversionDecl>( 4242 Cand->Conversions[ArgIdx].ConversionFunctionSet[0])) { 4243 QualType FromTy = 4244 QualType( 4245 static_cast<Type*>(ICS.UserDefined.Before.FromTypePtr),0); 4246 Diag(OpLoc,diag::note_ambiguous_type_conversion) 4247 << FromTy << Func->getConversionType(); 4248 } 4249 for (unsigned j = 0; j < ICS.ConversionFunctionSet.size(); j++) { 4250 FunctionDecl *Func = 4251 Cand->Conversions[ArgIdx].ConversionFunctionSet[j]; 4252 Diag(Func->getLocation(),diag::err_ovl_candidate); 4253 } 4254 } 4255 Reported = true; 4256 } 4257 } 4258 } 4259} 4260 4261/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4262/// an overloaded function (C++ [over.over]), where @p From is an 4263/// expression with overloaded function type and @p ToType is the type 4264/// we're trying to resolve to. For example: 4265/// 4266/// @code 4267/// int f(double); 4268/// int f(int); 4269/// 4270/// int (*pfd)(double) = f; // selects f(double) 4271/// @endcode 4272/// 4273/// This routine returns the resulting FunctionDecl if it could be 4274/// resolved, and NULL otherwise. When @p Complain is true, this 4275/// routine will emit diagnostics if there is an error. 4276FunctionDecl * 4277Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4278 bool Complain) { 4279 QualType FunctionType = ToType; 4280 bool IsMember = false; 4281 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4282 FunctionType = ToTypePtr->getPointeeType(); 4283 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4284 FunctionType = ToTypeRef->getPointeeType(); 4285 else if (const MemberPointerType *MemTypePtr = 4286 ToType->getAs<MemberPointerType>()) { 4287 FunctionType = MemTypePtr->getPointeeType(); 4288 IsMember = true; 4289 } 4290 4291 // We only look at pointers or references to functions. 4292 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4293 if (!FunctionType->isFunctionType()) 4294 return 0; 4295 4296 // Find the actual overloaded function declaration. 4297 OverloadedFunctionDecl *Ovl = 0; 4298 4299 // C++ [over.over]p1: 4300 // [...] [Note: any redundant set of parentheses surrounding the 4301 // overloaded function name is ignored (5.1). ] 4302 Expr *OvlExpr = From->IgnoreParens(); 4303 4304 // C++ [over.over]p1: 4305 // [...] The overloaded function name can be preceded by the & 4306 // operator. 4307 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4308 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4309 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4310 } 4311 4312 bool HasExplicitTemplateArgs = false; 4313 const TemplateArgumentLoc *ExplicitTemplateArgs = 0; 4314 unsigned NumExplicitTemplateArgs = 0; 4315 4316 // Try to dig out the overloaded function. 4317 FunctionTemplateDecl *FunctionTemplate = 0; 4318 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4319 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4320 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4321 HasExplicitTemplateArgs = DR->hasExplicitTemplateArgumentList(); 4322 ExplicitTemplateArgs = DR->getTemplateArgs(); 4323 NumExplicitTemplateArgs = DR->getNumTemplateArgs(); 4324 } else if (MemberExpr *ME = dyn_cast<MemberExpr>(OvlExpr)) { 4325 Ovl = dyn_cast<OverloadedFunctionDecl>(ME->getMemberDecl()); 4326 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(ME->getMemberDecl()); 4327 HasExplicitTemplateArgs = ME->hasExplicitTemplateArgumentList(); 4328 ExplicitTemplateArgs = ME->getTemplateArgs(); 4329 NumExplicitTemplateArgs = ME->getNumTemplateArgs(); 4330 } else if (TemplateIdRefExpr *TIRE = dyn_cast<TemplateIdRefExpr>(OvlExpr)) { 4331 TemplateName Name = TIRE->getTemplateName(); 4332 Ovl = Name.getAsOverloadedFunctionDecl(); 4333 FunctionTemplate = 4334 dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl()); 4335 4336 HasExplicitTemplateArgs = true; 4337 ExplicitTemplateArgs = TIRE->getTemplateArgs(); 4338 NumExplicitTemplateArgs = TIRE->getNumTemplateArgs(); 4339 } 4340 4341 // If there's no overloaded function declaration or function template, 4342 // we're done. 4343 if (!Ovl && !FunctionTemplate) 4344 return 0; 4345 4346 OverloadIterator Fun; 4347 if (Ovl) 4348 Fun = Ovl; 4349 else 4350 Fun = FunctionTemplate; 4351 4352 // Look through all of the overloaded functions, searching for one 4353 // whose type matches exactly. 4354 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4355 bool FoundNonTemplateFunction = false; 4356 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4357 // C++ [over.over]p3: 4358 // Non-member functions and static member functions match 4359 // targets of type "pointer-to-function" or "reference-to-function." 4360 // Nonstatic member functions match targets of 4361 // type "pointer-to-member-function." 4362 // Note that according to DR 247, the containing class does not matter. 4363 4364 if (FunctionTemplateDecl *FunctionTemplate 4365 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4366 if (CXXMethodDecl *Method 4367 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4368 // Skip non-static function templates when converting to pointer, and 4369 // static when converting to member pointer. 4370 if (Method->isStatic() == IsMember) 4371 continue; 4372 } else if (IsMember) 4373 continue; 4374 4375 // C++ [over.over]p2: 4376 // If the name is a function template, template argument deduction is 4377 // done (14.8.2.2), and if the argument deduction succeeds, the 4378 // resulting template argument list is used to generate a single 4379 // function template specialization, which is added to the set of 4380 // overloaded functions considered. 4381 // FIXME: We don't really want to build the specialization here, do we? 4382 FunctionDecl *Specialization = 0; 4383 TemplateDeductionInfo Info(Context); 4384 if (TemplateDeductionResult Result 4385 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 4386 ExplicitTemplateArgs, 4387 NumExplicitTemplateArgs, 4388 FunctionType, Specialization, Info)) { 4389 // FIXME: make a note of the failed deduction for diagnostics. 4390 (void)Result; 4391 } else { 4392 // FIXME: If the match isn't exact, shouldn't we just drop this as 4393 // a candidate? Find a testcase before changing the code. 4394 assert(FunctionType 4395 == Context.getCanonicalType(Specialization->getType())); 4396 Matches.insert( 4397 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4398 } 4399 } 4400 4401 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4402 // Skip non-static functions when converting to pointer, and static 4403 // when converting to member pointer. 4404 if (Method->isStatic() == IsMember) 4405 continue; 4406 4407 // If we have explicit template arguments, skip non-templates. 4408 if (HasExplicitTemplateArgs) 4409 continue; 4410 } else if (IsMember) 4411 continue; 4412 4413 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4414 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4415 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4416 FoundNonTemplateFunction = true; 4417 } 4418 } 4419 } 4420 4421 // If there were 0 or 1 matches, we're done. 4422 if (Matches.empty()) 4423 return 0; 4424 else if (Matches.size() == 1) { 4425 FunctionDecl *Result = *Matches.begin(); 4426 MarkDeclarationReferenced(From->getLocStart(), Result); 4427 return Result; 4428 } 4429 4430 // C++ [over.over]p4: 4431 // If more than one function is selected, [...] 4432 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4433 if (!FoundNonTemplateFunction) { 4434 // [...] and any given function template specialization F1 is 4435 // eliminated if the set contains a second function template 4436 // specialization whose function template is more specialized 4437 // than the function template of F1 according to the partial 4438 // ordering rules of 14.5.5.2. 4439 4440 // The algorithm specified above is quadratic. We instead use a 4441 // two-pass algorithm (similar to the one used to identify the 4442 // best viable function in an overload set) that identifies the 4443 // best function template (if it exists). 4444 llvm::SmallVector<FunctionDecl *, 8> TemplateMatches(Matches.begin(), 4445 Matches.end()); 4446 FunctionDecl *Result = 4447 getMostSpecialized(TemplateMatches.data(), TemplateMatches.size(), 4448 TPOC_Other, From->getLocStart(), 4449 PDiag(), 4450 PDiag(diag::err_addr_ovl_ambiguous) 4451 << TemplateMatches[0]->getDeclName(), 4452 PDiag(diag::err_ovl_template_candidate)); 4453 MarkDeclarationReferenced(From->getLocStart(), Result); 4454 return Result; 4455 } 4456 4457 // [...] any function template specializations in the set are 4458 // eliminated if the set also contains a non-template function, [...] 4459 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4460 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4461 if ((*M)->getPrimaryTemplate() == 0) 4462 RemainingMatches.push_back(*M); 4463 4464 // [...] After such eliminations, if any, there shall remain exactly one 4465 // selected function. 4466 if (RemainingMatches.size() == 1) { 4467 FunctionDecl *Result = RemainingMatches.front(); 4468 MarkDeclarationReferenced(From->getLocStart(), Result); 4469 return Result; 4470 } 4471 4472 // FIXME: We should probably return the same thing that BestViableFunction 4473 // returns (even if we issue the diagnostics here). 4474 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4475 << RemainingMatches[0]->getDeclName(); 4476 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4477 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4478 return 0; 4479} 4480 4481/// \brief Add a single candidate to the overload set. 4482static void AddOverloadedCallCandidate(Sema &S, 4483 AnyFunctionDecl Callee, 4484 bool &ArgumentDependentLookup, 4485 bool HasExplicitTemplateArgs, 4486 const TemplateArgumentLoc *ExplicitTemplateArgs, 4487 unsigned NumExplicitTemplateArgs, 4488 Expr **Args, unsigned NumArgs, 4489 OverloadCandidateSet &CandidateSet, 4490 bool PartialOverloading) { 4491 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4492 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4493 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4494 PartialOverloading); 4495 4496 if (Func->getDeclContext()->isRecord() || 4497 Func->getDeclContext()->isFunctionOrMethod()) 4498 ArgumentDependentLookup = false; 4499 return; 4500 } 4501 4502 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4503 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4504 ExplicitTemplateArgs, 4505 NumExplicitTemplateArgs, 4506 Args, NumArgs, CandidateSet); 4507 4508 if (FuncTemplate->getDeclContext()->isRecord()) 4509 ArgumentDependentLookup = false; 4510} 4511 4512/// \brief Add the overload candidates named by callee and/or found by argument 4513/// dependent lookup to the given overload set. 4514void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4515 DeclarationName &UnqualifiedName, 4516 bool &ArgumentDependentLookup, 4517 bool HasExplicitTemplateArgs, 4518 const TemplateArgumentLoc *ExplicitTemplateArgs, 4519 unsigned NumExplicitTemplateArgs, 4520 Expr **Args, unsigned NumArgs, 4521 OverloadCandidateSet &CandidateSet, 4522 bool PartialOverloading) { 4523 // Add the functions denoted by Callee to the set of candidate 4524 // functions. While we're doing so, track whether argument-dependent 4525 // lookup still applies, per: 4526 // 4527 // C++0x [basic.lookup.argdep]p3: 4528 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4529 // and let Y be the lookup set produced by argument dependent 4530 // lookup (defined as follows). If X contains 4531 // 4532 // -- a declaration of a class member, or 4533 // 4534 // -- a block-scope function declaration that is not a 4535 // using-declaration (FIXME: check for using declaration), or 4536 // 4537 // -- a declaration that is neither a function or a function 4538 // template 4539 // 4540 // then Y is empty. 4541 if (!Callee) { 4542 // Nothing to do. 4543 } else if (OverloadedFunctionDecl *Ovl 4544 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4545 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4546 FuncEnd = Ovl->function_end(); 4547 Func != FuncEnd; ++Func) 4548 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4549 HasExplicitTemplateArgs, 4550 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4551 Args, NumArgs, CandidateSet, 4552 PartialOverloading); 4553 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4554 AddOverloadedCallCandidate(*this, 4555 AnyFunctionDecl::getFromNamedDecl(Callee), 4556 ArgumentDependentLookup, 4557 HasExplicitTemplateArgs, 4558 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4559 Args, NumArgs, CandidateSet, 4560 PartialOverloading); 4561 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4562 // checking dynamically. 4563 4564 if (Callee) 4565 UnqualifiedName = Callee->getDeclName(); 4566 4567 if (ArgumentDependentLookup) 4568 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4569 HasExplicitTemplateArgs, 4570 ExplicitTemplateArgs, 4571 NumExplicitTemplateArgs, 4572 CandidateSet, 4573 PartialOverloading); 4574} 4575 4576/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4577/// (which eventually refers to the declaration Func) and the call 4578/// arguments Args/NumArgs, attempt to resolve the function call down 4579/// to a specific function. If overload resolution succeeds, returns 4580/// the function declaration produced by overload 4581/// resolution. Otherwise, emits diagnostics, deletes all of the 4582/// arguments and Fn, and returns NULL. 4583FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4584 DeclarationName UnqualifiedName, 4585 bool HasExplicitTemplateArgs, 4586 const TemplateArgumentLoc *ExplicitTemplateArgs, 4587 unsigned NumExplicitTemplateArgs, 4588 SourceLocation LParenLoc, 4589 Expr **Args, unsigned NumArgs, 4590 SourceLocation *CommaLocs, 4591 SourceLocation RParenLoc, 4592 bool &ArgumentDependentLookup) { 4593 OverloadCandidateSet CandidateSet; 4594 4595 // Add the functions denoted by Callee to the set of candidate 4596 // functions. 4597 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4598 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4599 NumExplicitTemplateArgs, Args, NumArgs, 4600 CandidateSet); 4601 OverloadCandidateSet::iterator Best; 4602 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4603 case OR_Success: 4604 return Best->Function; 4605 4606 case OR_No_Viable_Function: 4607 Diag(Fn->getSourceRange().getBegin(), 4608 diag::err_ovl_no_viable_function_in_call) 4609 << UnqualifiedName << Fn->getSourceRange(); 4610 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4611 break; 4612 4613 case OR_Ambiguous: 4614 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4615 << UnqualifiedName << Fn->getSourceRange(); 4616 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4617 break; 4618 4619 case OR_Deleted: 4620 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4621 << Best->Function->isDeleted() 4622 << UnqualifiedName 4623 << Fn->getSourceRange(); 4624 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4625 break; 4626 } 4627 4628 // Overload resolution failed. Destroy all of the subexpressions and 4629 // return NULL. 4630 Fn->Destroy(Context); 4631 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4632 Args[Arg]->Destroy(Context); 4633 return 0; 4634} 4635 4636/// \brief Create a unary operation that may resolve to an overloaded 4637/// operator. 4638/// 4639/// \param OpLoc The location of the operator itself (e.g., '*'). 4640/// 4641/// \param OpcIn The UnaryOperator::Opcode that describes this 4642/// operator. 4643/// 4644/// \param Functions The set of non-member functions that will be 4645/// considered by overload resolution. The caller needs to build this 4646/// set based on the context using, e.g., 4647/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4648/// set should not contain any member functions; those will be added 4649/// by CreateOverloadedUnaryOp(). 4650/// 4651/// \param input The input argument. 4652Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4653 unsigned OpcIn, 4654 FunctionSet &Functions, 4655 ExprArg input) { 4656 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4657 Expr *Input = (Expr *)input.get(); 4658 4659 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4660 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4661 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4662 4663 Expr *Args[2] = { Input, 0 }; 4664 unsigned NumArgs = 1; 4665 4666 // For post-increment and post-decrement, add the implicit '0' as 4667 // the second argument, so that we know this is a post-increment or 4668 // post-decrement. 4669 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4670 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4671 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4672 SourceLocation()); 4673 NumArgs = 2; 4674 } 4675 4676 if (Input->isTypeDependent()) { 4677 OverloadedFunctionDecl *Overloads 4678 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4679 for (FunctionSet::iterator Func = Functions.begin(), 4680 FuncEnd = Functions.end(); 4681 Func != FuncEnd; ++Func) 4682 Overloads->addOverload(*Func); 4683 4684 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4685 OpLoc, false, false); 4686 4687 input.release(); 4688 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4689 &Args[0], NumArgs, 4690 Context.DependentTy, 4691 OpLoc)); 4692 } 4693 4694 // Build an empty overload set. 4695 OverloadCandidateSet CandidateSet; 4696 4697 // Add the candidates from the given function set. 4698 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4699 4700 // Add operator candidates that are member functions. 4701 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4702 4703 // Add builtin operator candidates. 4704 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4705 4706 // Perform overload resolution. 4707 OverloadCandidateSet::iterator Best; 4708 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4709 case OR_Success: { 4710 // We found a built-in operator or an overloaded operator. 4711 FunctionDecl *FnDecl = Best->Function; 4712 4713 if (FnDecl) { 4714 // We matched an overloaded operator. Build a call to that 4715 // operator. 4716 4717 // Convert the arguments. 4718 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4719 if (PerformObjectArgumentInitialization(Input, Method)) 4720 return ExprError(); 4721 } else { 4722 // Convert the arguments. 4723 if (PerformCopyInitialization(Input, 4724 FnDecl->getParamDecl(0)->getType(), 4725 "passing")) 4726 return ExprError(); 4727 } 4728 4729 // Determine the result type 4730 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 4731 4732 // Build the actual expression node. 4733 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4734 SourceLocation()); 4735 UsualUnaryConversions(FnExpr); 4736 4737 input.release(); 4738 4739 ExprOwningPtr<CallExpr> TheCall(this, 4740 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4741 &Input, 1, ResultTy, OpLoc)); 4742 4743 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4744 FnDecl)) 4745 return ExprError(); 4746 4747 return MaybeBindToTemporary(TheCall.release()); 4748 } else { 4749 // We matched a built-in operator. Convert the arguments, then 4750 // break out so that we will build the appropriate built-in 4751 // operator node. 4752 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4753 Best->Conversions[0], "passing")) 4754 return ExprError(); 4755 4756 break; 4757 } 4758 } 4759 4760 case OR_No_Viable_Function: 4761 // No viable function; fall through to handling this as a 4762 // built-in operator, which will produce an error message for us. 4763 break; 4764 4765 case OR_Ambiguous: 4766 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4767 << UnaryOperator::getOpcodeStr(Opc) 4768 << Input->getSourceRange(); 4769 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4770 UnaryOperator::getOpcodeStr(Opc), OpLoc); 4771 return ExprError(); 4772 4773 case OR_Deleted: 4774 Diag(OpLoc, diag::err_ovl_deleted_oper) 4775 << Best->Function->isDeleted() 4776 << UnaryOperator::getOpcodeStr(Opc) 4777 << Input->getSourceRange(); 4778 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4779 return ExprError(); 4780 } 4781 4782 // Either we found no viable overloaded operator or we matched a 4783 // built-in operator. In either case, fall through to trying to 4784 // build a built-in operation. 4785 input.release(); 4786 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4787} 4788 4789/// \brief Create a binary operation that may resolve to an overloaded 4790/// operator. 4791/// 4792/// \param OpLoc The location of the operator itself (e.g., '+'). 4793/// 4794/// \param OpcIn The BinaryOperator::Opcode that describes this 4795/// operator. 4796/// 4797/// \param Functions The set of non-member functions that will be 4798/// considered by overload resolution. The caller needs to build this 4799/// set based on the context using, e.g., 4800/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4801/// set should not contain any member functions; those will be added 4802/// by CreateOverloadedBinOp(). 4803/// 4804/// \param LHS Left-hand argument. 4805/// \param RHS Right-hand argument. 4806Sema::OwningExprResult 4807Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4808 unsigned OpcIn, 4809 FunctionSet &Functions, 4810 Expr *LHS, Expr *RHS) { 4811 Expr *Args[2] = { LHS, RHS }; 4812 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4813 4814 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4815 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4816 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4817 4818 // If either side is type-dependent, create an appropriate dependent 4819 // expression. 4820 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4821 if (Functions.empty()) { 4822 // If there are no functions to store, just build a dependent 4823 // BinaryOperator or CompoundAssignment. 4824 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 4825 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4826 Context.DependentTy, OpLoc)); 4827 4828 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 4829 Context.DependentTy, 4830 Context.DependentTy, 4831 Context.DependentTy, 4832 OpLoc)); 4833 } 4834 4835 OverloadedFunctionDecl *Overloads 4836 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4837 for (FunctionSet::iterator Func = Functions.begin(), 4838 FuncEnd = Functions.end(); 4839 Func != FuncEnd; ++Func) 4840 Overloads->addOverload(*Func); 4841 4842 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4843 OpLoc, false, false); 4844 4845 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4846 Args, 2, 4847 Context.DependentTy, 4848 OpLoc)); 4849 } 4850 4851 // If this is the .* operator, which is not overloadable, just 4852 // create a built-in binary operator. 4853 if (Opc == BinaryOperator::PtrMemD) 4854 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4855 4856 // If this is one of the assignment operators, we only perform 4857 // overload resolution if the left-hand side is a class or 4858 // enumeration type (C++ [expr.ass]p3). 4859 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4860 !Args[0]->getType()->isOverloadableType()) 4861 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4862 4863 // Build an empty overload set. 4864 OverloadCandidateSet CandidateSet; 4865 4866 // Add the candidates from the given function set. 4867 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4868 4869 // Add operator candidates that are member functions. 4870 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4871 4872 // Add builtin operator candidates. 4873 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4874 4875 // Perform overload resolution. 4876 OverloadCandidateSet::iterator Best; 4877 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4878 case OR_Success: { 4879 // We found a built-in operator or an overloaded operator. 4880 FunctionDecl *FnDecl = Best->Function; 4881 4882 if (FnDecl) { 4883 // We matched an overloaded operator. Build a call to that 4884 // operator. 4885 4886 // Convert the arguments. 4887 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4888 if (PerformObjectArgumentInitialization(Args[0], Method) || 4889 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4890 "passing")) 4891 return ExprError(); 4892 } else { 4893 // Convert the arguments. 4894 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4895 "passing") || 4896 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4897 "passing")) 4898 return ExprError(); 4899 } 4900 4901 // Determine the result type 4902 QualType ResultTy 4903 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4904 ResultTy = ResultTy.getNonReferenceType(); 4905 4906 // Build the actual expression node. 4907 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4908 OpLoc); 4909 UsualUnaryConversions(FnExpr); 4910 4911 ExprOwningPtr<CXXOperatorCallExpr> 4912 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4913 Args, 2, ResultTy, 4914 OpLoc)); 4915 4916 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4917 FnDecl)) 4918 return ExprError(); 4919 4920 return MaybeBindToTemporary(TheCall.release()); 4921 } else { 4922 // We matched a built-in operator. Convert the arguments, then 4923 // break out so that we will build the appropriate built-in 4924 // operator node. 4925 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4926 Best->Conversions[0], "passing") || 4927 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4928 Best->Conversions[1], "passing")) 4929 return ExprError(); 4930 4931 break; 4932 } 4933 } 4934 4935 case OR_No_Viable_Function: { 4936 // C++ [over.match.oper]p9: 4937 // If the operator is the operator , [...] and there are no 4938 // viable functions, then the operator is assumed to be the 4939 // built-in operator and interpreted according to clause 5. 4940 if (Opc == BinaryOperator::Comma) 4941 break; 4942 4943 // For class as left operand for assignment or compound assigment operator 4944 // do not fall through to handling in built-in, but report that no overloaded 4945 // assignment operator found 4946 OwningExprResult Result = ExprError(); 4947 if (Args[0]->getType()->isRecordType() && 4948 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4949 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4950 << BinaryOperator::getOpcodeStr(Opc) 4951 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4952 } else { 4953 // No viable function; try to create a built-in operation, which will 4954 // produce an error. Then, show the non-viable candidates. 4955 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4956 } 4957 assert(Result.isInvalid() && 4958 "C++ binary operator overloading is missing candidates!"); 4959 if (Result.isInvalid()) 4960 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 4961 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4962 return move(Result); 4963 } 4964 4965 case OR_Ambiguous: 4966 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4967 << BinaryOperator::getOpcodeStr(Opc) 4968 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4969 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4970 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4971 return ExprError(); 4972 4973 case OR_Deleted: 4974 Diag(OpLoc, diag::err_ovl_deleted_oper) 4975 << Best->Function->isDeleted() 4976 << BinaryOperator::getOpcodeStr(Opc) 4977 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4978 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4979 return ExprError(); 4980 } 4981 4982 // We matched a built-in operator; build it. 4983 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4984} 4985 4986Action::OwningExprResult 4987Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 4988 SourceLocation RLoc, 4989 ExprArg Base, ExprArg Idx) { 4990 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 4991 static_cast<Expr*>(Idx.get()) }; 4992 DeclarationName OpName = 4993 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 4994 4995 // If either side is type-dependent, create an appropriate dependent 4996 // expression. 4997 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4998 4999 OverloadedFunctionDecl *Overloads 5000 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 5001 5002 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 5003 LLoc, false, false); 5004 5005 Base.release(); 5006 Idx.release(); 5007 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5008 Args, 2, 5009 Context.DependentTy, 5010 RLoc)); 5011 } 5012 5013 // Build an empty overload set. 5014 OverloadCandidateSet CandidateSet; 5015 5016 // Subscript can only be overloaded as a member function. 5017 5018 // Add operator candidates that are member functions. 5019 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5020 5021 // Add builtin operator candidates. 5022 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5023 5024 // Perform overload resolution. 5025 OverloadCandidateSet::iterator Best; 5026 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5027 case OR_Success: { 5028 // We found a built-in operator or an overloaded operator. 5029 FunctionDecl *FnDecl = Best->Function; 5030 5031 if (FnDecl) { 5032 // We matched an overloaded operator. Build a call to that 5033 // operator. 5034 5035 // Convert the arguments. 5036 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5037 if (PerformObjectArgumentInitialization(Args[0], Method) || 5038 PerformCopyInitialization(Args[1], 5039 FnDecl->getParamDecl(0)->getType(), 5040 "passing")) 5041 return ExprError(); 5042 5043 // Determine the result type 5044 QualType ResultTy 5045 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5046 ResultTy = ResultTy.getNonReferenceType(); 5047 5048 // Build the actual expression node. 5049 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5050 LLoc); 5051 UsualUnaryConversions(FnExpr); 5052 5053 Base.release(); 5054 Idx.release(); 5055 ExprOwningPtr<CXXOperatorCallExpr> 5056 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5057 FnExpr, Args, 2, 5058 ResultTy, RLoc)); 5059 5060 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5061 FnDecl)) 5062 return ExprError(); 5063 5064 return MaybeBindToTemporary(TheCall.release()); 5065 } else { 5066 // We matched a built-in operator. Convert the arguments, then 5067 // break out so that we will build the appropriate built-in 5068 // operator node. 5069 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5070 Best->Conversions[0], "passing") || 5071 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5072 Best->Conversions[1], "passing")) 5073 return ExprError(); 5074 5075 break; 5076 } 5077 } 5078 5079 case OR_No_Viable_Function: { 5080 // No viable function; try to create a built-in operation, which will 5081 // produce an error. Then, show the non-viable candidates. 5082 OwningExprResult Result = 5083 CreateBuiltinArraySubscriptExpr(move(Base), LLoc, move(Idx), RLoc); 5084 assert(Result.isInvalid() && 5085 "C++ subscript operator overloading is missing candidates!"); 5086 if (Result.isInvalid()) 5087 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 5088 "[]", LLoc); 5089 return move(Result); 5090 } 5091 5092 case OR_Ambiguous: 5093 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5094 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5095 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 5096 "[]", LLoc); 5097 return ExprError(); 5098 5099 case OR_Deleted: 5100 Diag(LLoc, diag::err_ovl_deleted_oper) 5101 << Best->Function->isDeleted() << "[]" 5102 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5103 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5104 return ExprError(); 5105 } 5106 5107 // We matched a built-in operator; build it. 5108 Base.release(); 5109 Idx.release(); 5110 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 5111 Owned(Args[1]), RLoc); 5112} 5113 5114/// BuildCallToMemberFunction - Build a call to a member 5115/// function. MemExpr is the expression that refers to the member 5116/// function (and includes the object parameter), Args/NumArgs are the 5117/// arguments to the function call (not including the object 5118/// parameter). The caller needs to validate that the member 5119/// expression refers to a member function or an overloaded member 5120/// function. 5121Sema::ExprResult 5122Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 5123 SourceLocation LParenLoc, Expr **Args, 5124 unsigned NumArgs, SourceLocation *CommaLocs, 5125 SourceLocation RParenLoc) { 5126 // Dig out the member expression. This holds both the object 5127 // argument and the member function we're referring to. 5128 MemberExpr *MemExpr = 0; 5129 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 5130 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 5131 else 5132 MemExpr = dyn_cast<MemberExpr>(MemExprE); 5133 assert(MemExpr && "Building member call without member expression"); 5134 5135 // Extract the object argument. 5136 Expr *ObjectArg = MemExpr->getBase(); 5137 5138 CXXMethodDecl *Method = 0; 5139 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 5140 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 5141 // Add overload candidates 5142 OverloadCandidateSet CandidateSet; 5143 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 5144 5145 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 5146 Func != FuncEnd; ++Func) { 5147 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) { 5148 // If explicit template arguments were provided, we can't call a 5149 // non-template member function. 5150 if (MemExpr->hasExplicitTemplateArgumentList()) 5151 continue; 5152 5153 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 5154 /*SuppressUserConversions=*/false); 5155 } else 5156 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 5157 MemExpr->hasExplicitTemplateArgumentList(), 5158 MemExpr->getTemplateArgs(), 5159 MemExpr->getNumTemplateArgs(), 5160 ObjectArg, Args, NumArgs, 5161 CandidateSet, 5162 /*SuppressUsedConversions=*/false); 5163 } 5164 5165 OverloadCandidateSet::iterator Best; 5166 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 5167 case OR_Success: 5168 Method = cast<CXXMethodDecl>(Best->Function); 5169 break; 5170 5171 case OR_No_Viable_Function: 5172 Diag(MemExpr->getSourceRange().getBegin(), 5173 diag::err_ovl_no_viable_member_function_in_call) 5174 << DeclName << MemExprE->getSourceRange(); 5175 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5176 // FIXME: Leaking incoming expressions! 5177 return true; 5178 5179 case OR_Ambiguous: 5180 Diag(MemExpr->getSourceRange().getBegin(), 5181 diag::err_ovl_ambiguous_member_call) 5182 << DeclName << MemExprE->getSourceRange(); 5183 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5184 // FIXME: Leaking incoming expressions! 5185 return true; 5186 5187 case OR_Deleted: 5188 Diag(MemExpr->getSourceRange().getBegin(), 5189 diag::err_ovl_deleted_member_call) 5190 << Best->Function->isDeleted() 5191 << DeclName << MemExprE->getSourceRange(); 5192 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5193 // FIXME: Leaking incoming expressions! 5194 return true; 5195 } 5196 5197 FixOverloadedFunctionReference(MemExpr, Method); 5198 } else { 5199 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 5200 } 5201 5202 assert(Method && "Member call to something that isn't a method?"); 5203 ExprOwningPtr<CXXMemberCallExpr> 5204 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 5205 NumArgs, 5206 Method->getResultType().getNonReferenceType(), 5207 RParenLoc)); 5208 5209 // Check for a valid return type. 5210 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 5211 TheCall.get(), Method)) 5212 return true; 5213 5214 // Convert the object argument (for a non-static member function call). 5215 if (!Method->isStatic() && 5216 PerformObjectArgumentInitialization(ObjectArg, Method)) 5217 return true; 5218 MemExpr->setBase(ObjectArg); 5219 5220 // Convert the rest of the arguments 5221 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 5222 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 5223 RParenLoc)) 5224 return true; 5225 5226 if (CheckFunctionCall(Method, TheCall.get())) 5227 return true; 5228 5229 return MaybeBindToTemporary(TheCall.release()).release(); 5230} 5231 5232/// BuildCallToObjectOfClassType - Build a call to an object of class 5233/// type (C++ [over.call.object]), which can end up invoking an 5234/// overloaded function call operator (@c operator()) or performing a 5235/// user-defined conversion on the object argument. 5236Sema::ExprResult 5237Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 5238 SourceLocation LParenLoc, 5239 Expr **Args, unsigned NumArgs, 5240 SourceLocation *CommaLocs, 5241 SourceLocation RParenLoc) { 5242 assert(Object->getType()->isRecordType() && "Requires object type argument"); 5243 const RecordType *Record = Object->getType()->getAs<RecordType>(); 5244 5245 // C++ [over.call.object]p1: 5246 // If the primary-expression E in the function call syntax 5247 // evaluates to a class object of type "cv T", then the set of 5248 // candidate functions includes at least the function call 5249 // operators of T. The function call operators of T are obtained by 5250 // ordinary lookup of the name operator() in the context of 5251 // (E).operator(). 5252 OverloadCandidateSet CandidateSet; 5253 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 5254 DeclContext::lookup_const_iterator Oper, OperEnd; 5255 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 5256 Oper != OperEnd; ++Oper) { 5257 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(*Oper)) { 5258 AddMethodTemplateCandidate(FunTmpl, false, 0, 0, Object, Args, NumArgs, 5259 CandidateSet, 5260 /*SuppressUserConversions=*/false); 5261 continue; 5262 } 5263 5264 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 5265 CandidateSet, /*SuppressUserConversions=*/false); 5266 } 5267 5268 if (RequireCompleteType(LParenLoc, Object->getType(), 5269 PartialDiagnostic(diag::err_incomplete_object_call) 5270 << Object->getSourceRange())) 5271 return true; 5272 5273 // C++ [over.call.object]p2: 5274 // In addition, for each conversion function declared in T of the 5275 // form 5276 // 5277 // operator conversion-type-id () cv-qualifier; 5278 // 5279 // where cv-qualifier is the same cv-qualification as, or a 5280 // greater cv-qualification than, cv, and where conversion-type-id 5281 // denotes the type "pointer to function of (P1,...,Pn) returning 5282 // R", or the type "reference to pointer to function of 5283 // (P1,...,Pn) returning R", or the type "reference to function 5284 // of (P1,...,Pn) returning R", a surrogate call function [...] 5285 // is also considered as a candidate function. Similarly, 5286 // surrogate call functions are added to the set of candidate 5287 // functions for each conversion function declared in an 5288 // accessible base class provided the function is not hidden 5289 // within T by another intervening declaration. 5290 // FIXME: Look in base classes for more conversion operators! 5291 OverloadedFunctionDecl *Conversions 5292 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 5293 for (OverloadedFunctionDecl::function_iterator 5294 Func = Conversions->function_begin(), 5295 FuncEnd = Conversions->function_end(); 5296 Func != FuncEnd; ++Func) { 5297 CXXConversionDecl *Conv; 5298 FunctionTemplateDecl *ConvTemplate; 5299 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 5300 5301 // Skip over templated conversion functions; they aren't 5302 // surrogates. 5303 if (ConvTemplate) 5304 continue; 5305 5306 // Strip the reference type (if any) and then the pointer type (if 5307 // any) to get down to what might be a function type. 5308 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 5309 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5310 ConvType = ConvPtrType->getPointeeType(); 5311 5312 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 5313 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 5314 } 5315 5316 // Perform overload resolution. 5317 OverloadCandidateSet::iterator Best; 5318 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 5319 case OR_Success: 5320 // Overload resolution succeeded; we'll build the appropriate call 5321 // below. 5322 break; 5323 5324 case OR_No_Viable_Function: 5325 Diag(Object->getSourceRange().getBegin(), 5326 diag::err_ovl_no_viable_object_call) 5327 << Object->getType() << Object->getSourceRange(); 5328 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5329 break; 5330 5331 case OR_Ambiguous: 5332 Diag(Object->getSourceRange().getBegin(), 5333 diag::err_ovl_ambiguous_object_call) 5334 << Object->getType() << Object->getSourceRange(); 5335 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5336 break; 5337 5338 case OR_Deleted: 5339 Diag(Object->getSourceRange().getBegin(), 5340 diag::err_ovl_deleted_object_call) 5341 << Best->Function->isDeleted() 5342 << Object->getType() << Object->getSourceRange(); 5343 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5344 break; 5345 } 5346 5347 if (Best == CandidateSet.end()) { 5348 // We had an error; delete all of the subexpressions and return 5349 // the error. 5350 Object->Destroy(Context); 5351 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5352 Args[ArgIdx]->Destroy(Context); 5353 return true; 5354 } 5355 5356 if (Best->Function == 0) { 5357 // Since there is no function declaration, this is one of the 5358 // surrogate candidates. Dig out the conversion function. 5359 CXXConversionDecl *Conv 5360 = cast<CXXConversionDecl>( 5361 Best->Conversions[0].UserDefined.ConversionFunction); 5362 5363 // We selected one of the surrogate functions that converts the 5364 // object parameter to a function pointer. Perform the conversion 5365 // on the object argument, then let ActOnCallExpr finish the job. 5366 5367 // Create an implicit member expr to refer to the conversion operator. 5368 // and then call it. 5369 CXXMemberCallExpr *CE = 5370 BuildCXXMemberCallExpr(Object, Conv); 5371 5372 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 5373 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 5374 CommaLocs, RParenLoc).release(); 5375 } 5376 5377 // We found an overloaded operator(). Build a CXXOperatorCallExpr 5378 // that calls this method, using Object for the implicit object 5379 // parameter and passing along the remaining arguments. 5380 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5381 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 5382 5383 unsigned NumArgsInProto = Proto->getNumArgs(); 5384 unsigned NumArgsToCheck = NumArgs; 5385 5386 // Build the full argument list for the method call (the 5387 // implicit object parameter is placed at the beginning of the 5388 // list). 5389 Expr **MethodArgs; 5390 if (NumArgs < NumArgsInProto) { 5391 NumArgsToCheck = NumArgsInProto; 5392 MethodArgs = new Expr*[NumArgsInProto + 1]; 5393 } else { 5394 MethodArgs = new Expr*[NumArgs + 1]; 5395 } 5396 MethodArgs[0] = Object; 5397 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5398 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 5399 5400 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 5401 SourceLocation()); 5402 UsualUnaryConversions(NewFn); 5403 5404 // Once we've built TheCall, all of the expressions are properly 5405 // owned. 5406 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5407 ExprOwningPtr<CXXOperatorCallExpr> 5408 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 5409 MethodArgs, NumArgs + 1, 5410 ResultTy, RParenLoc)); 5411 delete [] MethodArgs; 5412 5413 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 5414 Method)) 5415 return true; 5416 5417 // We may have default arguments. If so, we need to allocate more 5418 // slots in the call for them. 5419 if (NumArgs < NumArgsInProto) 5420 TheCall->setNumArgs(Context, NumArgsInProto + 1); 5421 else if (NumArgs > NumArgsInProto) 5422 NumArgsToCheck = NumArgsInProto; 5423 5424 bool IsError = false; 5425 5426 // Initialize the implicit object parameter. 5427 IsError |= PerformObjectArgumentInitialization(Object, Method); 5428 TheCall->setArg(0, Object); 5429 5430 5431 // Check the argument types. 5432 for (unsigned i = 0; i != NumArgsToCheck; i++) { 5433 Expr *Arg; 5434 if (i < NumArgs) { 5435 Arg = Args[i]; 5436 5437 // Pass the argument. 5438 QualType ProtoArgType = Proto->getArgType(i); 5439 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 5440 } else { 5441 OwningExprResult DefArg 5442 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 5443 if (DefArg.isInvalid()) { 5444 IsError = true; 5445 break; 5446 } 5447 5448 Arg = DefArg.takeAs<Expr>(); 5449 } 5450 5451 TheCall->setArg(i + 1, Arg); 5452 } 5453 5454 // If this is a variadic call, handle args passed through "...". 5455 if (Proto->isVariadic()) { 5456 // Promote the arguments (C99 6.5.2.2p7). 5457 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 5458 Expr *Arg = Args[i]; 5459 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 5460 TheCall->setArg(i + 1, Arg); 5461 } 5462 } 5463 5464 if (IsError) return true; 5465 5466 if (CheckFunctionCall(Method, TheCall.get())) 5467 return true; 5468 5469 return MaybeBindToTemporary(TheCall.release()).release(); 5470} 5471 5472/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 5473/// (if one exists), where @c Base is an expression of class type and 5474/// @c Member is the name of the member we're trying to find. 5475Sema::OwningExprResult 5476Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 5477 Expr *Base = static_cast<Expr *>(BaseIn.get()); 5478 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 5479 5480 // C++ [over.ref]p1: 5481 // 5482 // [...] An expression x->m is interpreted as (x.operator->())->m 5483 // for a class object x of type T if T::operator->() exists and if 5484 // the operator is selected as the best match function by the 5485 // overload resolution mechanism (13.3). 5486 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 5487 OverloadCandidateSet CandidateSet; 5488 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 5489 5490 LookupResult R; 5491 LookupQualifiedName(R, BaseRecord->getDecl(), OpName, LookupOrdinaryName); 5492 5493 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5494 Oper != OperEnd; ++Oper) 5495 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 5496 /*SuppressUserConversions=*/false); 5497 5498 // Perform overload resolution. 5499 OverloadCandidateSet::iterator Best; 5500 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5501 case OR_Success: 5502 // Overload resolution succeeded; we'll build the call below. 5503 break; 5504 5505 case OR_No_Viable_Function: 5506 if (CandidateSet.empty()) 5507 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5508 << Base->getType() << Base->getSourceRange(); 5509 else 5510 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5511 << "operator->" << Base->getSourceRange(); 5512 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5513 return ExprError(); 5514 5515 case OR_Ambiguous: 5516 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5517 << "->" << Base->getSourceRange(); 5518 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5519 return ExprError(); 5520 5521 case OR_Deleted: 5522 Diag(OpLoc, diag::err_ovl_deleted_oper) 5523 << Best->Function->isDeleted() 5524 << "->" << Base->getSourceRange(); 5525 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5526 return ExprError(); 5527 } 5528 5529 // Convert the object parameter. 5530 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5531 if (PerformObjectArgumentInitialization(Base, Method)) 5532 return ExprError(); 5533 5534 // No concerns about early exits now. 5535 BaseIn.release(); 5536 5537 // Build the operator call. 5538 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5539 SourceLocation()); 5540 UsualUnaryConversions(FnExpr); 5541 5542 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5543 ExprOwningPtr<CXXOperatorCallExpr> 5544 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 5545 &Base, 1, ResultTy, OpLoc)); 5546 5547 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 5548 Method)) 5549 return ExprError(); 5550 return move(TheCall); 5551} 5552 5553/// FixOverloadedFunctionReference - E is an expression that refers to 5554/// a C++ overloaded function (possibly with some parentheses and 5555/// perhaps a '&' around it). We have resolved the overloaded function 5556/// to the function declaration Fn, so patch up the expression E to 5557/// refer (possibly indirectly) to Fn. Returns the new expr. 5558Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5559 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5560 Expr *NewExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5561 PE->setSubExpr(NewExpr); 5562 PE->setType(NewExpr->getType()); 5563 } else if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 5564 Expr *NewExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 5565 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 5566 NewExpr->getType()) && 5567 "Implicit cast type cannot be determined from overload"); 5568 ICE->setSubExpr(NewExpr); 5569 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5570 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5571 "Can only take the address of an overloaded function"); 5572 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5573 if (Method->isStatic()) { 5574 // Do nothing: static member functions aren't any different 5575 // from non-member functions. 5576 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr())) { 5577 if (DRE->getQualifier()) { 5578 // We have taken the address of a pointer to member 5579 // function. Perform the computation here so that we get the 5580 // appropriate pointer to member type. 5581 DRE->setDecl(Fn); 5582 DRE->setType(Fn->getType()); 5583 QualType ClassType 5584 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5585 E->setType(Context.getMemberPointerType(Fn->getType(), 5586 ClassType.getTypePtr())); 5587 return E; 5588 } 5589 } 5590 // FIXME: TemplateIdRefExpr referring to a member function template 5591 // specialization! 5592 } 5593 Expr *NewExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5594 UnOp->setSubExpr(NewExpr); 5595 UnOp->setType(Context.getPointerType(NewExpr->getType())); 5596 5597 return UnOp; 5598 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5599 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5600 isa<FunctionTemplateDecl>(DR->getDecl()) || 5601 isa<FunctionDecl>(DR->getDecl())) && 5602 "Expected function or function template"); 5603 DR->setDecl(Fn); 5604 E->setType(Fn->getType()); 5605 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5606 MemExpr->setMemberDecl(Fn); 5607 E->setType(Fn->getType()); 5608 } else if (TemplateIdRefExpr *TID = dyn_cast<TemplateIdRefExpr>(E)) { 5609 E = DeclRefExpr::Create(Context, 5610 TID->getQualifier(), TID->getQualifierRange(), 5611 Fn, TID->getTemplateNameLoc(), 5612 true, 5613 TID->getLAngleLoc(), 5614 TID->getTemplateArgs(), 5615 TID->getNumTemplateArgs(), 5616 TID->getRAngleLoc(), 5617 Fn->getType(), 5618 /*FIXME?*/false, /*FIXME?*/false); 5619 5620 // FIXME: Don't destroy TID here, since we need its template arguments 5621 // to survive. 5622 // TID->Destroy(Context); 5623 } else if (isa<UnresolvedFunctionNameExpr>(E)) { 5624 return DeclRefExpr::Create(Context, 5625 /*Qualifier=*/0, 5626 /*QualifierRange=*/SourceRange(), 5627 Fn, E->getLocStart(), 5628 Fn->getType(), false, false); 5629 } else { 5630 assert(false && "Invalid reference to overloaded function"); 5631 } 5632 5633 return E; 5634} 5635 5636} // end namespace clang 5637