SemaOverload.cpp revision cad84b7c12564ff37feb66d6d004bb609bea8788
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 // FIXME: It would be nice if it were safe to keep invalid methods in the 2241 // overload set (but it isn't due to broken copy constructors). 2242 if (!CandidateSet.isNewCandidate(Function) || Function->isInvalidDecl()) 2243 return; 2244 2245 // Add this candidate 2246 CandidateSet.push_back(OverloadCandidate()); 2247 OverloadCandidate& Candidate = CandidateSet.back(); 2248 Candidate.Function = Function; 2249 Candidate.Viable = true; 2250 Candidate.IsSurrogate = false; 2251 Candidate.IgnoreObjectArgument = false; 2252 2253 unsigned NumArgsInProto = Proto->getNumArgs(); 2254 2255 // (C++ 13.3.2p2): A candidate function having fewer than m 2256 // parameters is viable only if it has an ellipsis in its parameter 2257 // list (8.3.5). 2258 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2259 !Proto->isVariadic()) { 2260 Candidate.Viable = false; 2261 return; 2262 } 2263 2264 // (C++ 13.3.2p2): A candidate function having more than m parameters 2265 // is viable only if the (m+1)st parameter has a default argument 2266 // (8.3.6). For the purposes of overload resolution, the 2267 // parameter list is truncated on the right, so that there are 2268 // exactly m parameters. 2269 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2270 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2271 // Not enough arguments. 2272 Candidate.Viable = false; 2273 return; 2274 } 2275 2276 // Determine the implicit conversion sequences for each of the 2277 // arguments. 2278 Candidate.Conversions.resize(NumArgs); 2279 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2280 if (ArgIdx < NumArgsInProto) { 2281 // (C++ 13.3.2p3): for F to be a viable function, there shall 2282 // exist for each argument an implicit conversion sequence 2283 // (13.3.3.1) that converts that argument to the corresponding 2284 // parameter of F. 2285 QualType ParamType = Proto->getArgType(ArgIdx); 2286 Candidate.Conversions[ArgIdx] 2287 = TryCopyInitialization(Args[ArgIdx], ParamType, 2288 SuppressUserConversions, ForceRValue, 2289 /*InOverloadResolution=*/true); 2290 if (Candidate.Conversions[ArgIdx].ConversionKind 2291 == ImplicitConversionSequence::BadConversion) { 2292 // 13.3.3.1-p10 If several different sequences of conversions exist that 2293 // each convert the argument to the parameter type, the implicit conversion 2294 // sequence associated with the parameter is defined to be the unique conversion 2295 // sequence designated the ambiguous conversion sequence. For the purpose of 2296 // ranking implicit conversion sequences as described in 13.3.3.2, the ambiguous 2297 // conversion sequence is treated as a user-defined sequence that is 2298 // indistinguishable from any other user-defined conversion sequence 2299 if (!Candidate.Conversions[ArgIdx].ConversionFunctionSet.empty()) { 2300 Candidate.Conversions[ArgIdx].ConversionKind = 2301 ImplicitConversionSequence::UserDefinedConversion; 2302 // Set the conversion function to one of them. As due to ambiguity, 2303 // they carry the same weight and is needed for overload resolution 2304 // later. 2305 Candidate.Conversions[ArgIdx].UserDefined.ConversionFunction = 2306 Candidate.Conversions[ArgIdx].ConversionFunctionSet[0]; 2307 } 2308 else { 2309 Candidate.Viable = false; 2310 break; 2311 } 2312 } 2313 } else { 2314 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2315 // argument for which there is no corresponding parameter is 2316 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2317 Candidate.Conversions[ArgIdx].ConversionKind 2318 = ImplicitConversionSequence::EllipsisConversion; 2319 } 2320 } 2321} 2322 2323/// \brief Add all of the function declarations in the given function set to 2324/// the overload canddiate set. 2325void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2326 Expr **Args, unsigned NumArgs, 2327 OverloadCandidateSet& CandidateSet, 2328 bool SuppressUserConversions) { 2329 for (FunctionSet::const_iterator F = Functions.begin(), 2330 FEnd = Functions.end(); 2331 F != FEnd; ++F) { 2332 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2333 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2334 AddMethodCandidate(cast<CXXMethodDecl>(FD), 2335 Args[0], Args + 1, NumArgs - 1, 2336 CandidateSet, SuppressUserConversions); 2337 else 2338 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2339 SuppressUserConversions); 2340 } else { 2341 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2342 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2343 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2344 AddMethodTemplateCandidate(FunTmpl, 2345 /*FIXME: explicit args */false, 0, 0, 2346 Args[0], Args + 1, NumArgs - 1, 2347 CandidateSet, 2348 SuppressUserConversions); 2349 else 2350 AddTemplateOverloadCandidate(FunTmpl, 2351 /*FIXME: explicit args */false, 0, 0, 2352 Args, NumArgs, CandidateSet, 2353 SuppressUserConversions); 2354 } 2355 } 2356} 2357 2358/// AddMethodCandidate - Adds the given C++ member function to the set 2359/// of candidate functions, using the given function call arguments 2360/// and the object argument (@c Object). For example, in a call 2361/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2362/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2363/// allow user-defined conversions via constructors or conversion 2364/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2365/// a slightly hacky way to implement the overloading rules for elidable copy 2366/// initialization in C++0x (C++0x 12.8p15). 2367void 2368Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2369 Expr **Args, unsigned NumArgs, 2370 OverloadCandidateSet& CandidateSet, 2371 bool SuppressUserConversions, bool ForceRValue) { 2372 const FunctionProtoType* Proto 2373 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2374 assert(Proto && "Methods without a prototype cannot be overloaded"); 2375 assert(!isa<CXXConversionDecl>(Method) && 2376 "Use AddConversionCandidate for conversion functions"); 2377 assert(!isa<CXXConstructorDecl>(Method) && 2378 "Use AddOverloadCandidate for constructors"); 2379 2380 if (!CandidateSet.isNewCandidate(Method)) 2381 return; 2382 2383 // Add this candidate 2384 CandidateSet.push_back(OverloadCandidate()); 2385 OverloadCandidate& Candidate = CandidateSet.back(); 2386 Candidate.Function = Method; 2387 Candidate.IsSurrogate = false; 2388 Candidate.IgnoreObjectArgument = false; 2389 2390 unsigned NumArgsInProto = Proto->getNumArgs(); 2391 2392 // (C++ 13.3.2p2): A candidate function having fewer than m 2393 // parameters is viable only if it has an ellipsis in its parameter 2394 // list (8.3.5). 2395 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2396 Candidate.Viable = false; 2397 return; 2398 } 2399 2400 // (C++ 13.3.2p2): A candidate function having more than m parameters 2401 // is viable only if the (m+1)st parameter has a default argument 2402 // (8.3.6). For the purposes of overload resolution, the 2403 // parameter list is truncated on the right, so that there are 2404 // exactly m parameters. 2405 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2406 if (NumArgs < MinRequiredArgs) { 2407 // Not enough arguments. 2408 Candidate.Viable = false; 2409 return; 2410 } 2411 2412 Candidate.Viable = true; 2413 Candidate.Conversions.resize(NumArgs + 1); 2414 2415 if (Method->isStatic() || !Object) 2416 // The implicit object argument is ignored. 2417 Candidate.IgnoreObjectArgument = true; 2418 else { 2419 // Determine the implicit conversion sequence for the object 2420 // parameter. 2421 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2422 if (Candidate.Conversions[0].ConversionKind 2423 == ImplicitConversionSequence::BadConversion) { 2424 Candidate.Viable = false; 2425 return; 2426 } 2427 } 2428 2429 // Determine the implicit conversion sequences for each of the 2430 // arguments. 2431 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2432 if (ArgIdx < NumArgsInProto) { 2433 // (C++ 13.3.2p3): for F to be a viable function, there shall 2434 // exist for each argument an implicit conversion sequence 2435 // (13.3.3.1) that converts that argument to the corresponding 2436 // parameter of F. 2437 QualType ParamType = Proto->getArgType(ArgIdx); 2438 Candidate.Conversions[ArgIdx + 1] 2439 = TryCopyInitialization(Args[ArgIdx], ParamType, 2440 SuppressUserConversions, ForceRValue, 2441 /*InOverloadResolution=*/true); 2442 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2443 == ImplicitConversionSequence::BadConversion) { 2444 Candidate.Viable = false; 2445 break; 2446 } 2447 } else { 2448 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2449 // argument for which there is no corresponding parameter is 2450 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2451 Candidate.Conversions[ArgIdx + 1].ConversionKind 2452 = ImplicitConversionSequence::EllipsisConversion; 2453 } 2454 } 2455} 2456 2457/// \brief Add a C++ member function template as a candidate to the candidate 2458/// set, using template argument deduction to produce an appropriate member 2459/// function template specialization. 2460void 2461Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2462 bool HasExplicitTemplateArgs, 2463 const TemplateArgumentLoc *ExplicitTemplateArgs, 2464 unsigned NumExplicitTemplateArgs, 2465 Expr *Object, Expr **Args, unsigned NumArgs, 2466 OverloadCandidateSet& CandidateSet, 2467 bool SuppressUserConversions, 2468 bool ForceRValue) { 2469 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2470 return; 2471 2472 // C++ [over.match.funcs]p7: 2473 // In each case where a candidate is a function template, candidate 2474 // function template specializations are generated using template argument 2475 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2476 // candidate functions in the usual way.113) A given name can refer to one 2477 // or more function templates and also to a set of overloaded non-template 2478 // functions. In such a case, the candidate functions generated from each 2479 // function template are combined with the set of non-template candidate 2480 // functions. 2481 TemplateDeductionInfo Info(Context); 2482 FunctionDecl *Specialization = 0; 2483 if (TemplateDeductionResult Result 2484 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2485 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2486 Args, NumArgs, Specialization, Info)) { 2487 // FIXME: Record what happened with template argument deduction, so 2488 // that we can give the user a beautiful diagnostic. 2489 (void)Result; 2490 return; 2491 } 2492 2493 // Add the function template specialization produced by template argument 2494 // deduction as a candidate. 2495 assert(Specialization && "Missing member function template specialization?"); 2496 assert(isa<CXXMethodDecl>(Specialization) && 2497 "Specialization is not a member function?"); 2498 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2499 CandidateSet, SuppressUserConversions, ForceRValue); 2500} 2501 2502/// \brief Add a C++ function template specialization as a candidate 2503/// in the candidate set, using template argument deduction to produce 2504/// an appropriate function template specialization. 2505void 2506Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2507 bool HasExplicitTemplateArgs, 2508 const TemplateArgumentLoc *ExplicitTemplateArgs, 2509 unsigned NumExplicitTemplateArgs, 2510 Expr **Args, unsigned NumArgs, 2511 OverloadCandidateSet& CandidateSet, 2512 bool SuppressUserConversions, 2513 bool ForceRValue) { 2514 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2515 return; 2516 2517 // C++ [over.match.funcs]p7: 2518 // In each case where a candidate is a function template, candidate 2519 // function template specializations are generated using template argument 2520 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2521 // candidate functions in the usual way.113) A given name can refer to one 2522 // or more function templates and also to a set of overloaded non-template 2523 // functions. In such a case, the candidate functions generated from each 2524 // function template are combined with the set of non-template candidate 2525 // functions. 2526 TemplateDeductionInfo Info(Context); 2527 FunctionDecl *Specialization = 0; 2528 if (TemplateDeductionResult Result 2529 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2530 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2531 Args, NumArgs, Specialization, Info)) { 2532 // FIXME: Record what happened with template argument deduction, so 2533 // that we can give the user a beautiful diagnostic. 2534 (void)Result; 2535 return; 2536 } 2537 2538 // Add the function template specialization produced by template argument 2539 // deduction as a candidate. 2540 assert(Specialization && "Missing function template specialization?"); 2541 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2542 SuppressUserConversions, ForceRValue); 2543} 2544 2545/// AddConversionCandidate - Add a C++ conversion function as a 2546/// candidate in the candidate set (C++ [over.match.conv], 2547/// C++ [over.match.copy]). From is the expression we're converting from, 2548/// and ToType is the type that we're eventually trying to convert to 2549/// (which may or may not be the same type as the type that the 2550/// conversion function produces). 2551void 2552Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2553 Expr *From, QualType ToType, 2554 OverloadCandidateSet& CandidateSet) { 2555 assert(!Conversion->getDescribedFunctionTemplate() && 2556 "Conversion function templates use AddTemplateConversionCandidate"); 2557 2558 if (!CandidateSet.isNewCandidate(Conversion)) 2559 return; 2560 2561 // Add this candidate 2562 CandidateSet.push_back(OverloadCandidate()); 2563 OverloadCandidate& Candidate = CandidateSet.back(); 2564 Candidate.Function = Conversion; 2565 Candidate.IsSurrogate = false; 2566 Candidate.IgnoreObjectArgument = false; 2567 Candidate.FinalConversion.setAsIdentityConversion(); 2568 Candidate.FinalConversion.FromTypePtr 2569 = Conversion->getConversionType().getAsOpaquePtr(); 2570 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2571 2572 // Determine the implicit conversion sequence for the implicit 2573 // object parameter. 2574 Candidate.Viable = true; 2575 Candidate.Conversions.resize(1); 2576 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2577 // Conversion functions to a different type in the base class is visible in 2578 // the derived class. So, a derived to base conversion should not participate 2579 // in overload resolution. 2580 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2581 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2582 if (Candidate.Conversions[0].ConversionKind 2583 == ImplicitConversionSequence::BadConversion) { 2584 Candidate.Viable = false; 2585 return; 2586 } 2587 2588 // We won't go through a user-define type conversion function to convert a 2589 // derived to base as such conversions are given Conversion Rank. They only 2590 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2591 QualType FromCanon 2592 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2593 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2594 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2595 Candidate.Viable = false; 2596 return; 2597 } 2598 2599 2600 // To determine what the conversion from the result of calling the 2601 // conversion function to the type we're eventually trying to 2602 // convert to (ToType), we need to synthesize a call to the 2603 // conversion function and attempt copy initialization from it. This 2604 // makes sure that we get the right semantics with respect to 2605 // lvalues/rvalues and the type. Fortunately, we can allocate this 2606 // call on the stack and we don't need its arguments to be 2607 // well-formed. 2608 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2609 SourceLocation()); 2610 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2611 CastExpr::CK_FunctionToPointerDecay, 2612 &ConversionRef, false); 2613 2614 // Note that it is safe to allocate CallExpr on the stack here because 2615 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2616 // allocator). 2617 CallExpr Call(Context, &ConversionFn, 0, 0, 2618 Conversion->getConversionType().getNonReferenceType(), 2619 SourceLocation()); 2620 ImplicitConversionSequence ICS = 2621 TryCopyInitialization(&Call, ToType, 2622 /*SuppressUserConversions=*/true, 2623 /*ForceRValue=*/false, 2624 /*InOverloadResolution=*/false); 2625 2626 switch (ICS.ConversionKind) { 2627 case ImplicitConversionSequence::StandardConversion: 2628 Candidate.FinalConversion = ICS.Standard; 2629 break; 2630 2631 case ImplicitConversionSequence::BadConversion: 2632 Candidate.Viable = false; 2633 break; 2634 2635 default: 2636 assert(false && 2637 "Can only end up with a standard conversion sequence or failure"); 2638 } 2639} 2640 2641/// \brief Adds a conversion function template specialization 2642/// candidate to the overload set, using template argument deduction 2643/// to deduce the template arguments of the conversion function 2644/// template from the type that we are converting to (C++ 2645/// [temp.deduct.conv]). 2646void 2647Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2648 Expr *From, QualType ToType, 2649 OverloadCandidateSet &CandidateSet) { 2650 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2651 "Only conversion function templates permitted here"); 2652 2653 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2654 return; 2655 2656 TemplateDeductionInfo Info(Context); 2657 CXXConversionDecl *Specialization = 0; 2658 if (TemplateDeductionResult Result 2659 = DeduceTemplateArguments(FunctionTemplate, ToType, 2660 Specialization, Info)) { 2661 // FIXME: Record what happened with template argument deduction, so 2662 // that we can give the user a beautiful diagnostic. 2663 (void)Result; 2664 return; 2665 } 2666 2667 // Add the conversion function template specialization produced by 2668 // template argument deduction as a candidate. 2669 assert(Specialization && "Missing function template specialization?"); 2670 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2671} 2672 2673/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2674/// converts the given @c Object to a function pointer via the 2675/// conversion function @c Conversion, and then attempts to call it 2676/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2677/// the type of function that we'll eventually be calling. 2678void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2679 const FunctionProtoType *Proto, 2680 Expr *Object, Expr **Args, unsigned NumArgs, 2681 OverloadCandidateSet& CandidateSet) { 2682 if (!CandidateSet.isNewCandidate(Conversion)) 2683 return; 2684 2685 CandidateSet.push_back(OverloadCandidate()); 2686 OverloadCandidate& Candidate = CandidateSet.back(); 2687 Candidate.Function = 0; 2688 Candidate.Surrogate = Conversion; 2689 Candidate.Viable = true; 2690 Candidate.IsSurrogate = true; 2691 Candidate.IgnoreObjectArgument = false; 2692 Candidate.Conversions.resize(NumArgs + 1); 2693 2694 // Determine the implicit conversion sequence for the implicit 2695 // object parameter. 2696 ImplicitConversionSequence ObjectInit 2697 = TryObjectArgumentInitialization(Object, Conversion); 2698 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2699 Candidate.Viable = false; 2700 return; 2701 } 2702 2703 // The first conversion is actually a user-defined conversion whose 2704 // first conversion is ObjectInit's standard conversion (which is 2705 // effectively a reference binding). Record it as such. 2706 Candidate.Conversions[0].ConversionKind 2707 = ImplicitConversionSequence::UserDefinedConversion; 2708 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2709 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2710 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2711 Candidate.Conversions[0].UserDefined.After 2712 = Candidate.Conversions[0].UserDefined.Before; 2713 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2714 2715 // Find the 2716 unsigned NumArgsInProto = Proto->getNumArgs(); 2717 2718 // (C++ 13.3.2p2): A candidate function having fewer than m 2719 // parameters is viable only if it has an ellipsis in its parameter 2720 // list (8.3.5). 2721 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2722 Candidate.Viable = false; 2723 return; 2724 } 2725 2726 // Function types don't have any default arguments, so just check if 2727 // we have enough arguments. 2728 if (NumArgs < NumArgsInProto) { 2729 // Not enough arguments. 2730 Candidate.Viable = false; 2731 return; 2732 } 2733 2734 // Determine the implicit conversion sequences for each of the 2735 // arguments. 2736 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2737 if (ArgIdx < NumArgsInProto) { 2738 // (C++ 13.3.2p3): for F to be a viable function, there shall 2739 // exist for each argument an implicit conversion sequence 2740 // (13.3.3.1) that converts that argument to the corresponding 2741 // parameter of F. 2742 QualType ParamType = Proto->getArgType(ArgIdx); 2743 Candidate.Conversions[ArgIdx + 1] 2744 = TryCopyInitialization(Args[ArgIdx], ParamType, 2745 /*SuppressUserConversions=*/false, 2746 /*ForceRValue=*/false, 2747 /*InOverloadResolution=*/false); 2748 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2749 == ImplicitConversionSequence::BadConversion) { 2750 Candidate.Viable = false; 2751 break; 2752 } 2753 } else { 2754 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2755 // argument for which there is no corresponding parameter is 2756 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2757 Candidate.Conversions[ArgIdx + 1].ConversionKind 2758 = ImplicitConversionSequence::EllipsisConversion; 2759 } 2760 } 2761} 2762 2763// FIXME: This will eventually be removed, once we've migrated all of the 2764// operator overloading logic over to the scheme used by binary operators, which 2765// works for template instantiation. 2766void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2767 SourceLocation OpLoc, 2768 Expr **Args, unsigned NumArgs, 2769 OverloadCandidateSet& CandidateSet, 2770 SourceRange OpRange) { 2771 FunctionSet Functions; 2772 2773 QualType T1 = Args[0]->getType(); 2774 QualType T2; 2775 if (NumArgs > 1) 2776 T2 = Args[1]->getType(); 2777 2778 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2779 if (S) 2780 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2781 ArgumentDependentLookup(OpName, /*Operator*/true, Args, NumArgs, Functions); 2782 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2783 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2784 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 2785} 2786 2787/// \brief Add overload candidates for overloaded operators that are 2788/// member functions. 2789/// 2790/// Add the overloaded operator candidates that are member functions 2791/// for the operator Op that was used in an operator expression such 2792/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2793/// CandidateSet will store the added overload candidates. (C++ 2794/// [over.match.oper]). 2795void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2796 SourceLocation OpLoc, 2797 Expr **Args, unsigned NumArgs, 2798 OverloadCandidateSet& CandidateSet, 2799 SourceRange OpRange) { 2800 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2801 2802 // C++ [over.match.oper]p3: 2803 // For a unary operator @ with an operand of a type whose 2804 // cv-unqualified version is T1, and for a binary operator @ with 2805 // a left operand of a type whose cv-unqualified version is T1 and 2806 // a right operand of a type whose cv-unqualified version is T2, 2807 // three sets of candidate functions, designated member 2808 // candidates, non-member candidates and built-in candidates, are 2809 // constructed as follows: 2810 QualType T1 = Args[0]->getType(); 2811 QualType T2; 2812 if (NumArgs > 1) 2813 T2 = Args[1]->getType(); 2814 2815 // -- If T1 is a class type, the set of member candidates is the 2816 // result of the qualified lookup of T1::operator@ 2817 // (13.3.1.1.1); otherwise, the set of member candidates is 2818 // empty. 2819 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2820 // Complete the type if it can be completed. Otherwise, we're done. 2821 if (RequireCompleteType(OpLoc, T1, PDiag())) 2822 return; 2823 2824 LookupResult Operators; 2825 LookupQualifiedName(Operators, T1Rec->getDecl(), OpName, 2826 LookupOrdinaryName, false); 2827 for (LookupResult::iterator Oper = Operators.begin(), 2828 OperEnd = Operators.end(); 2829 Oper != OperEnd; 2830 ++Oper) { 2831 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Oper)) { 2832 AddMethodCandidate(Method, Args[0], Args+1, NumArgs - 1, CandidateSet, 2833 /*SuppressUserConversions=*/false); 2834 continue; 2835 } 2836 2837 assert(isa<FunctionTemplateDecl>(*Oper) && 2838 isa<CXXMethodDecl>(cast<FunctionTemplateDecl>(*Oper) 2839 ->getTemplatedDecl()) && 2840 "Expected a member function template"); 2841 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Oper), false, 0, 0, 2842 Args[0], Args+1, NumArgs - 1, CandidateSet, 2843 /*SuppressUserConversions=*/false); 2844 } 2845 } 2846} 2847 2848/// AddBuiltinCandidate - Add a candidate for a built-in 2849/// operator. ResultTy and ParamTys are the result and parameter types 2850/// of the built-in candidate, respectively. Args and NumArgs are the 2851/// arguments being passed to the candidate. IsAssignmentOperator 2852/// should be true when this built-in candidate is an assignment 2853/// operator. NumContextualBoolArguments is the number of arguments 2854/// (at the beginning of the argument list) that will be contextually 2855/// converted to bool. 2856void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2857 Expr **Args, unsigned NumArgs, 2858 OverloadCandidateSet& CandidateSet, 2859 bool IsAssignmentOperator, 2860 unsigned NumContextualBoolArguments) { 2861 // Add this candidate 2862 CandidateSet.push_back(OverloadCandidate()); 2863 OverloadCandidate& Candidate = CandidateSet.back(); 2864 Candidate.Function = 0; 2865 Candidate.IsSurrogate = false; 2866 Candidate.IgnoreObjectArgument = false; 2867 Candidate.BuiltinTypes.ResultTy = ResultTy; 2868 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2869 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2870 2871 // Determine the implicit conversion sequences for each of the 2872 // arguments. 2873 Candidate.Viable = true; 2874 Candidate.Conversions.resize(NumArgs); 2875 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2876 // C++ [over.match.oper]p4: 2877 // For the built-in assignment operators, conversions of the 2878 // left operand are restricted as follows: 2879 // -- no temporaries are introduced to hold the left operand, and 2880 // -- no user-defined conversions are applied to the left 2881 // operand to achieve a type match with the left-most 2882 // parameter of a built-in candidate. 2883 // 2884 // We block these conversions by turning off user-defined 2885 // conversions, since that is the only way that initialization of 2886 // a reference to a non-class type can occur from something that 2887 // is not of the same type. 2888 if (ArgIdx < NumContextualBoolArguments) { 2889 assert(ParamTys[ArgIdx] == Context.BoolTy && 2890 "Contextual conversion to bool requires bool type"); 2891 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2892 } else { 2893 Candidate.Conversions[ArgIdx] 2894 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2895 ArgIdx == 0 && IsAssignmentOperator, 2896 /*ForceRValue=*/false, 2897 /*InOverloadResolution=*/false); 2898 } 2899 if (Candidate.Conversions[ArgIdx].ConversionKind 2900 == ImplicitConversionSequence::BadConversion) { 2901 Candidate.Viable = false; 2902 break; 2903 } 2904 } 2905} 2906 2907/// BuiltinCandidateTypeSet - A set of types that will be used for the 2908/// candidate operator functions for built-in operators (C++ 2909/// [over.built]). The types are separated into pointer types and 2910/// enumeration types. 2911class BuiltinCandidateTypeSet { 2912 /// TypeSet - A set of types. 2913 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2914 2915 /// PointerTypes - The set of pointer types that will be used in the 2916 /// built-in candidates. 2917 TypeSet PointerTypes; 2918 2919 /// MemberPointerTypes - The set of member pointer types that will be 2920 /// used in the built-in candidates. 2921 TypeSet MemberPointerTypes; 2922 2923 /// EnumerationTypes - The set of enumeration types that will be 2924 /// used in the built-in candidates. 2925 TypeSet EnumerationTypes; 2926 2927 /// Sema - The semantic analysis instance where we are building the 2928 /// candidate type set. 2929 Sema &SemaRef; 2930 2931 /// Context - The AST context in which we will build the type sets. 2932 ASTContext &Context; 2933 2934 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 2935 const Qualifiers &VisibleQuals); 2936 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2937 2938public: 2939 /// iterator - Iterates through the types that are part of the set. 2940 typedef TypeSet::iterator iterator; 2941 2942 BuiltinCandidateTypeSet(Sema &SemaRef) 2943 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2944 2945 void AddTypesConvertedFrom(QualType Ty, 2946 SourceLocation Loc, 2947 bool AllowUserConversions, 2948 bool AllowExplicitConversions, 2949 const Qualifiers &VisibleTypeConversionsQuals); 2950 2951 /// pointer_begin - First pointer type found; 2952 iterator pointer_begin() { return PointerTypes.begin(); } 2953 2954 /// pointer_end - Past the last pointer type found; 2955 iterator pointer_end() { return PointerTypes.end(); } 2956 2957 /// member_pointer_begin - First member pointer type found; 2958 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2959 2960 /// member_pointer_end - Past the last member pointer type found; 2961 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2962 2963 /// enumeration_begin - First enumeration type found; 2964 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2965 2966 /// enumeration_end - Past the last enumeration type found; 2967 iterator enumeration_end() { return EnumerationTypes.end(); } 2968}; 2969 2970/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2971/// the set of pointer types along with any more-qualified variants of 2972/// that type. For example, if @p Ty is "int const *", this routine 2973/// will add "int const *", "int const volatile *", "int const 2974/// restrict *", and "int const volatile restrict *" to the set of 2975/// pointer types. Returns true if the add of @p Ty itself succeeded, 2976/// false otherwise. 2977/// 2978/// FIXME: what to do about extended qualifiers? 2979bool 2980BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 2981 const Qualifiers &VisibleQuals) { 2982 2983 // Insert this type. 2984 if (!PointerTypes.insert(Ty)) 2985 return false; 2986 2987 const PointerType *PointerTy = Ty->getAs<PointerType>(); 2988 assert(PointerTy && "type was not a pointer type!"); 2989 2990 QualType PointeeTy = PointerTy->getPointeeType(); 2991 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2992 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 2993 BaseCVR = Array->getElementType().getCVRQualifiers(); 2994 bool hasVolatile = VisibleQuals.hasVolatile(); 2995 bool hasRestrict = VisibleQuals.hasRestrict(); 2996 2997 // Iterate through all strict supersets of BaseCVR. 2998 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2999 if ((CVR | BaseCVR) != CVR) continue; 3000 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3001 // in the types. 3002 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3003 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3004 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3005 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3006 } 3007 3008 return true; 3009} 3010 3011/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3012/// to the set of pointer types along with any more-qualified variants of 3013/// that type. For example, if @p Ty is "int const *", this routine 3014/// will add "int const *", "int const volatile *", "int const 3015/// restrict *", and "int const volatile restrict *" to the set of 3016/// pointer types. Returns true if the add of @p Ty itself succeeded, 3017/// false otherwise. 3018/// 3019/// FIXME: what to do about extended qualifiers? 3020bool 3021BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3022 QualType Ty) { 3023 // Insert this type. 3024 if (!MemberPointerTypes.insert(Ty)) 3025 return false; 3026 3027 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3028 assert(PointerTy && "type was not a member pointer type!"); 3029 3030 QualType PointeeTy = PointerTy->getPointeeType(); 3031 const Type *ClassTy = PointerTy->getClass(); 3032 3033 // Iterate through all strict supersets of the pointee type's CVR 3034 // qualifiers. 3035 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3036 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3037 if ((CVR | BaseCVR) != CVR) continue; 3038 3039 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3040 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3041 } 3042 3043 return true; 3044} 3045 3046/// AddTypesConvertedFrom - Add each of the types to which the type @p 3047/// Ty can be implicit converted to the given set of @p Types. We're 3048/// primarily interested in pointer types and enumeration types. We also 3049/// take member pointer types, for the conditional operator. 3050/// AllowUserConversions is true if we should look at the conversion 3051/// functions of a class type, and AllowExplicitConversions if we 3052/// should also include the explicit conversion functions of a class 3053/// type. 3054void 3055BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3056 SourceLocation Loc, 3057 bool AllowUserConversions, 3058 bool AllowExplicitConversions, 3059 const Qualifiers &VisibleQuals) { 3060 // Only deal with canonical types. 3061 Ty = Context.getCanonicalType(Ty); 3062 3063 // Look through reference types; they aren't part of the type of an 3064 // expression for the purposes of conversions. 3065 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3066 Ty = RefTy->getPointeeType(); 3067 3068 // We don't care about qualifiers on the type. 3069 Ty = Ty.getUnqualifiedType(); 3070 3071 // If we're dealing with an array type, decay to the pointer. 3072 if (Ty->isArrayType()) 3073 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3074 3075 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3076 QualType PointeeTy = PointerTy->getPointeeType(); 3077 3078 // Insert our type, and its more-qualified variants, into the set 3079 // of types. 3080 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3081 return; 3082 } else if (Ty->isMemberPointerType()) { 3083 // Member pointers are far easier, since the pointee can't be converted. 3084 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3085 return; 3086 } else if (Ty->isEnumeralType()) { 3087 EnumerationTypes.insert(Ty); 3088 } else if (AllowUserConversions) { 3089 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3090 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3091 // No conversion functions in incomplete types. 3092 return; 3093 } 3094 3095 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3096 OverloadedFunctionDecl *Conversions 3097 = ClassDecl->getVisibleConversionFunctions(); 3098 for (OverloadedFunctionDecl::function_iterator Func 3099 = Conversions->function_begin(); 3100 Func != Conversions->function_end(); ++Func) { 3101 CXXConversionDecl *Conv; 3102 FunctionTemplateDecl *ConvTemplate; 3103 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 3104 3105 // Skip conversion function templates; they don't tell us anything 3106 // about which builtin types we can convert to. 3107 if (ConvTemplate) 3108 continue; 3109 3110 if (AllowExplicitConversions || !Conv->isExplicit()) { 3111 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3112 VisibleQuals); 3113 } 3114 } 3115 } 3116 } 3117} 3118 3119/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3120/// the volatile- and non-volatile-qualified assignment operators for the 3121/// given type to the candidate set. 3122static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3123 QualType T, 3124 Expr **Args, 3125 unsigned NumArgs, 3126 OverloadCandidateSet &CandidateSet) { 3127 QualType ParamTypes[2]; 3128 3129 // T& operator=(T&, T) 3130 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3131 ParamTypes[1] = T; 3132 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3133 /*IsAssignmentOperator=*/true); 3134 3135 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3136 // volatile T& operator=(volatile T&, T) 3137 ParamTypes[0] 3138 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3139 ParamTypes[1] = T; 3140 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3141 /*IsAssignmentOperator=*/true); 3142 } 3143} 3144 3145/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3146/// if any, found in visible type conversion functions found in ArgExpr's type. 3147static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3148 Qualifiers VRQuals; 3149 const RecordType *TyRec; 3150 if (const MemberPointerType *RHSMPType = 3151 ArgExpr->getType()->getAs<MemberPointerType>()) 3152 TyRec = cast<RecordType>(RHSMPType->getClass()); 3153 else 3154 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3155 if (!TyRec) { 3156 // Just to be safe, assume the worst case. 3157 VRQuals.addVolatile(); 3158 VRQuals.addRestrict(); 3159 return VRQuals; 3160 } 3161 3162 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3163 OverloadedFunctionDecl *Conversions = 3164 ClassDecl->getVisibleConversionFunctions(); 3165 3166 for (OverloadedFunctionDecl::function_iterator Func 3167 = Conversions->function_begin(); 3168 Func != Conversions->function_end(); ++Func) { 3169 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*Func)) { 3170 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3171 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3172 CanTy = ResTypeRef->getPointeeType(); 3173 // Need to go down the pointer/mempointer chain and add qualifiers 3174 // as see them. 3175 bool done = false; 3176 while (!done) { 3177 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3178 CanTy = ResTypePtr->getPointeeType(); 3179 else if (const MemberPointerType *ResTypeMPtr = 3180 CanTy->getAs<MemberPointerType>()) 3181 CanTy = ResTypeMPtr->getPointeeType(); 3182 else 3183 done = true; 3184 if (CanTy.isVolatileQualified()) 3185 VRQuals.addVolatile(); 3186 if (CanTy.isRestrictQualified()) 3187 VRQuals.addRestrict(); 3188 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3189 return VRQuals; 3190 } 3191 } 3192 } 3193 return VRQuals; 3194} 3195 3196/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3197/// operator overloads to the candidate set (C++ [over.built]), based 3198/// on the operator @p Op and the arguments given. For example, if the 3199/// operator is a binary '+', this routine might add "int 3200/// operator+(int, int)" to cover integer addition. 3201void 3202Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3203 SourceLocation OpLoc, 3204 Expr **Args, unsigned NumArgs, 3205 OverloadCandidateSet& CandidateSet) { 3206 // The set of "promoted arithmetic types", which are the arithmetic 3207 // types are that preserved by promotion (C++ [over.built]p2). Note 3208 // that the first few of these types are the promoted integral 3209 // types; these types need to be first. 3210 // FIXME: What about complex? 3211 const unsigned FirstIntegralType = 0; 3212 const unsigned LastIntegralType = 13; 3213 const unsigned FirstPromotedIntegralType = 7, 3214 LastPromotedIntegralType = 13; 3215 const unsigned FirstPromotedArithmeticType = 7, 3216 LastPromotedArithmeticType = 16; 3217 const unsigned NumArithmeticTypes = 16; 3218 QualType ArithmeticTypes[NumArithmeticTypes] = { 3219 Context.BoolTy, Context.CharTy, Context.WCharTy, 3220// FIXME: Context.Char16Ty, Context.Char32Ty, 3221 Context.SignedCharTy, Context.ShortTy, 3222 Context.UnsignedCharTy, Context.UnsignedShortTy, 3223 Context.IntTy, Context.LongTy, Context.LongLongTy, 3224 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3225 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3226 }; 3227 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3228 "Invalid first promoted integral type"); 3229 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3230 == Context.UnsignedLongLongTy && 3231 "Invalid last promoted integral type"); 3232 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3233 "Invalid first promoted arithmetic type"); 3234 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3235 == Context.LongDoubleTy && 3236 "Invalid last promoted arithmetic type"); 3237 3238 // Find all of the types that the arguments can convert to, but only 3239 // if the operator we're looking at has built-in operator candidates 3240 // that make use of these types. 3241 Qualifiers VisibleTypeConversionsQuals; 3242 VisibleTypeConversionsQuals.addConst(); 3243 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3244 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3245 3246 BuiltinCandidateTypeSet CandidateTypes(*this); 3247 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3248 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3249 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3250 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3251 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3252 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3253 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3254 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3255 OpLoc, 3256 true, 3257 (Op == OO_Exclaim || 3258 Op == OO_AmpAmp || 3259 Op == OO_PipePipe), 3260 VisibleTypeConversionsQuals); 3261 } 3262 3263 bool isComparison = false; 3264 switch (Op) { 3265 case OO_None: 3266 case NUM_OVERLOADED_OPERATORS: 3267 assert(false && "Expected an overloaded operator"); 3268 break; 3269 3270 case OO_Star: // '*' is either unary or binary 3271 if (NumArgs == 1) 3272 goto UnaryStar; 3273 else 3274 goto BinaryStar; 3275 break; 3276 3277 case OO_Plus: // '+' is either unary or binary 3278 if (NumArgs == 1) 3279 goto UnaryPlus; 3280 else 3281 goto BinaryPlus; 3282 break; 3283 3284 case OO_Minus: // '-' is either unary or binary 3285 if (NumArgs == 1) 3286 goto UnaryMinus; 3287 else 3288 goto BinaryMinus; 3289 break; 3290 3291 case OO_Amp: // '&' is either unary or binary 3292 if (NumArgs == 1) 3293 goto UnaryAmp; 3294 else 3295 goto BinaryAmp; 3296 3297 case OO_PlusPlus: 3298 case OO_MinusMinus: 3299 // C++ [over.built]p3: 3300 // 3301 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3302 // is either volatile or empty, there exist candidate operator 3303 // functions of the form 3304 // 3305 // VQ T& operator++(VQ T&); 3306 // T operator++(VQ T&, int); 3307 // 3308 // C++ [over.built]p4: 3309 // 3310 // For every pair (T, VQ), where T is an arithmetic type other 3311 // than bool, and VQ is either volatile or empty, there exist 3312 // candidate operator functions of the form 3313 // 3314 // VQ T& operator--(VQ T&); 3315 // T operator--(VQ T&, int); 3316 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3317 Arith < NumArithmeticTypes; ++Arith) { 3318 QualType ArithTy = ArithmeticTypes[Arith]; 3319 QualType ParamTypes[2] 3320 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3321 3322 // Non-volatile version. 3323 if (NumArgs == 1) 3324 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3325 else 3326 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3327 // heuristic to reduce number of builtin candidates in the set. 3328 // Add volatile version only if there are conversions to a volatile type. 3329 if (VisibleTypeConversionsQuals.hasVolatile()) { 3330 // Volatile version 3331 ParamTypes[0] 3332 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3333 if (NumArgs == 1) 3334 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3335 else 3336 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3337 } 3338 } 3339 3340 // C++ [over.built]p5: 3341 // 3342 // For every pair (T, VQ), where T is a cv-qualified or 3343 // cv-unqualified object type, and VQ is either volatile or 3344 // empty, there exist candidate operator functions of the form 3345 // 3346 // T*VQ& operator++(T*VQ&); 3347 // T*VQ& operator--(T*VQ&); 3348 // T* operator++(T*VQ&, int); 3349 // T* operator--(T*VQ&, int); 3350 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3351 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3352 // Skip pointer types that aren't pointers to object types. 3353 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3354 continue; 3355 3356 QualType ParamTypes[2] = { 3357 Context.getLValueReferenceType(*Ptr), Context.IntTy 3358 }; 3359 3360 // Without volatile 3361 if (NumArgs == 1) 3362 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3363 else 3364 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3365 3366 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3367 VisibleTypeConversionsQuals.hasVolatile()) { 3368 // With volatile 3369 ParamTypes[0] 3370 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3371 if (NumArgs == 1) 3372 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3373 else 3374 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3375 } 3376 } 3377 break; 3378 3379 UnaryStar: 3380 // C++ [over.built]p6: 3381 // For every cv-qualified or cv-unqualified object type T, there 3382 // exist candidate operator functions of the form 3383 // 3384 // T& operator*(T*); 3385 // 3386 // C++ [over.built]p7: 3387 // For every function type T, there exist candidate operator 3388 // functions of the form 3389 // T& operator*(T*); 3390 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3391 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3392 QualType ParamTy = *Ptr; 3393 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3394 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3395 &ParamTy, Args, 1, CandidateSet); 3396 } 3397 break; 3398 3399 UnaryPlus: 3400 // C++ [over.built]p8: 3401 // For every type T, there exist candidate operator functions of 3402 // the form 3403 // 3404 // T* operator+(T*); 3405 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3406 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3407 QualType ParamTy = *Ptr; 3408 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3409 } 3410 3411 // Fall through 3412 3413 UnaryMinus: 3414 // C++ [over.built]p9: 3415 // For every promoted arithmetic type T, there exist candidate 3416 // operator functions of the form 3417 // 3418 // T operator+(T); 3419 // T operator-(T); 3420 for (unsigned Arith = FirstPromotedArithmeticType; 3421 Arith < LastPromotedArithmeticType; ++Arith) { 3422 QualType ArithTy = ArithmeticTypes[Arith]; 3423 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3424 } 3425 break; 3426 3427 case OO_Tilde: 3428 // C++ [over.built]p10: 3429 // For every promoted integral type T, there exist candidate 3430 // operator functions of the form 3431 // 3432 // T operator~(T); 3433 for (unsigned Int = FirstPromotedIntegralType; 3434 Int < LastPromotedIntegralType; ++Int) { 3435 QualType IntTy = ArithmeticTypes[Int]; 3436 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3437 } 3438 break; 3439 3440 case OO_New: 3441 case OO_Delete: 3442 case OO_Array_New: 3443 case OO_Array_Delete: 3444 case OO_Call: 3445 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3446 break; 3447 3448 case OO_Comma: 3449 UnaryAmp: 3450 case OO_Arrow: 3451 // C++ [over.match.oper]p3: 3452 // -- For the operator ',', the unary operator '&', or the 3453 // operator '->', the built-in candidates set is empty. 3454 break; 3455 3456 case OO_EqualEqual: 3457 case OO_ExclaimEqual: 3458 // C++ [over.match.oper]p16: 3459 // For every pointer to member type T, there exist candidate operator 3460 // functions of the form 3461 // 3462 // bool operator==(T,T); 3463 // bool operator!=(T,T); 3464 for (BuiltinCandidateTypeSet::iterator 3465 MemPtr = CandidateTypes.member_pointer_begin(), 3466 MemPtrEnd = CandidateTypes.member_pointer_end(); 3467 MemPtr != MemPtrEnd; 3468 ++MemPtr) { 3469 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3470 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3471 } 3472 3473 // Fall through 3474 3475 case OO_Less: 3476 case OO_Greater: 3477 case OO_LessEqual: 3478 case OO_GreaterEqual: 3479 // C++ [over.built]p15: 3480 // 3481 // For every pointer or enumeration type T, there exist 3482 // candidate operator functions of the form 3483 // 3484 // bool operator<(T, T); 3485 // bool operator>(T, T); 3486 // bool operator<=(T, T); 3487 // bool operator>=(T, T); 3488 // bool operator==(T, T); 3489 // bool operator!=(T, T); 3490 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3491 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3492 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3493 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3494 } 3495 for (BuiltinCandidateTypeSet::iterator Enum 3496 = CandidateTypes.enumeration_begin(); 3497 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3498 QualType ParamTypes[2] = { *Enum, *Enum }; 3499 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3500 } 3501 3502 // Fall through. 3503 isComparison = true; 3504 3505 BinaryPlus: 3506 BinaryMinus: 3507 if (!isComparison) { 3508 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3509 3510 // C++ [over.built]p13: 3511 // 3512 // For every cv-qualified or cv-unqualified object type T 3513 // there exist candidate operator functions of the form 3514 // 3515 // T* operator+(T*, ptrdiff_t); 3516 // T& operator[](T*, ptrdiff_t); [BELOW] 3517 // T* operator-(T*, ptrdiff_t); 3518 // T* operator+(ptrdiff_t, T*); 3519 // T& operator[](ptrdiff_t, T*); [BELOW] 3520 // 3521 // C++ [over.built]p14: 3522 // 3523 // For every T, where T is a pointer to object type, there 3524 // exist candidate operator functions of the form 3525 // 3526 // ptrdiff_t operator-(T, T); 3527 for (BuiltinCandidateTypeSet::iterator Ptr 3528 = CandidateTypes.pointer_begin(); 3529 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3530 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3531 3532 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3533 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3534 3535 if (Op == OO_Plus) { 3536 // T* operator+(ptrdiff_t, T*); 3537 ParamTypes[0] = ParamTypes[1]; 3538 ParamTypes[1] = *Ptr; 3539 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3540 } else { 3541 // ptrdiff_t operator-(T, T); 3542 ParamTypes[1] = *Ptr; 3543 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3544 Args, 2, CandidateSet); 3545 } 3546 } 3547 } 3548 // Fall through 3549 3550 case OO_Slash: 3551 BinaryStar: 3552 Conditional: 3553 // C++ [over.built]p12: 3554 // 3555 // For every pair of promoted arithmetic types L and R, there 3556 // exist candidate operator functions of the form 3557 // 3558 // LR operator*(L, R); 3559 // LR operator/(L, R); 3560 // LR operator+(L, R); 3561 // LR operator-(L, R); 3562 // bool operator<(L, R); 3563 // bool operator>(L, R); 3564 // bool operator<=(L, R); 3565 // bool operator>=(L, R); 3566 // bool operator==(L, R); 3567 // bool operator!=(L, R); 3568 // 3569 // where LR is the result of the usual arithmetic conversions 3570 // between types L and R. 3571 // 3572 // C++ [over.built]p24: 3573 // 3574 // For every pair of promoted arithmetic types L and R, there exist 3575 // candidate operator functions of the form 3576 // 3577 // LR operator?(bool, L, R); 3578 // 3579 // where LR is the result of the usual arithmetic conversions 3580 // between types L and R. 3581 // Our candidates ignore the first parameter. 3582 for (unsigned Left = FirstPromotedArithmeticType; 3583 Left < LastPromotedArithmeticType; ++Left) { 3584 for (unsigned Right = FirstPromotedArithmeticType; 3585 Right < LastPromotedArithmeticType; ++Right) { 3586 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3587 QualType Result 3588 = isComparison 3589 ? Context.BoolTy 3590 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3591 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3592 } 3593 } 3594 break; 3595 3596 case OO_Percent: 3597 BinaryAmp: 3598 case OO_Caret: 3599 case OO_Pipe: 3600 case OO_LessLess: 3601 case OO_GreaterGreater: 3602 // C++ [over.built]p17: 3603 // 3604 // For every pair of promoted integral types L and R, there 3605 // exist candidate operator functions of the form 3606 // 3607 // LR operator%(L, R); 3608 // LR operator&(L, R); 3609 // LR operator^(L, R); 3610 // LR operator|(L, R); 3611 // L operator<<(L, R); 3612 // L operator>>(L, R); 3613 // 3614 // where LR is the result of the usual arithmetic conversions 3615 // between types L and R. 3616 for (unsigned Left = FirstPromotedIntegralType; 3617 Left < LastPromotedIntegralType; ++Left) { 3618 for (unsigned Right = FirstPromotedIntegralType; 3619 Right < LastPromotedIntegralType; ++Right) { 3620 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3621 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3622 ? LandR[0] 3623 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3624 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3625 } 3626 } 3627 break; 3628 3629 case OO_Equal: 3630 // C++ [over.built]p20: 3631 // 3632 // For every pair (T, VQ), where T is an enumeration or 3633 // pointer to member type and VQ is either volatile or 3634 // empty, there exist candidate operator functions of the form 3635 // 3636 // VQ T& operator=(VQ T&, T); 3637 for (BuiltinCandidateTypeSet::iterator 3638 Enum = CandidateTypes.enumeration_begin(), 3639 EnumEnd = CandidateTypes.enumeration_end(); 3640 Enum != EnumEnd; ++Enum) 3641 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3642 CandidateSet); 3643 for (BuiltinCandidateTypeSet::iterator 3644 MemPtr = CandidateTypes.member_pointer_begin(), 3645 MemPtrEnd = CandidateTypes.member_pointer_end(); 3646 MemPtr != MemPtrEnd; ++MemPtr) 3647 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3648 CandidateSet); 3649 // Fall through. 3650 3651 case OO_PlusEqual: 3652 case OO_MinusEqual: 3653 // C++ [over.built]p19: 3654 // 3655 // For every pair (T, VQ), where T is any type and VQ is either 3656 // volatile or empty, there exist candidate operator functions 3657 // of the form 3658 // 3659 // T*VQ& operator=(T*VQ&, T*); 3660 // 3661 // C++ [over.built]p21: 3662 // 3663 // For every pair (T, VQ), where T is a cv-qualified or 3664 // cv-unqualified object type and VQ is either volatile or 3665 // empty, there exist candidate operator functions of the form 3666 // 3667 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3668 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3669 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3670 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3671 QualType ParamTypes[2]; 3672 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3673 3674 // non-volatile version 3675 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3676 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3677 /*IsAssigmentOperator=*/Op == OO_Equal); 3678 3679 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3680 VisibleTypeConversionsQuals.hasVolatile()) { 3681 // volatile version 3682 ParamTypes[0] 3683 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3684 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3685 /*IsAssigmentOperator=*/Op == OO_Equal); 3686 } 3687 } 3688 // Fall through. 3689 3690 case OO_StarEqual: 3691 case OO_SlashEqual: 3692 // C++ [over.built]p18: 3693 // 3694 // For every triple (L, VQ, R), where L is an arithmetic type, 3695 // VQ is either volatile or empty, and R is a promoted 3696 // arithmetic type, there exist candidate operator functions of 3697 // the form 3698 // 3699 // VQ L& operator=(VQ L&, R); 3700 // VQ L& operator*=(VQ L&, R); 3701 // VQ L& operator/=(VQ L&, R); 3702 // VQ L& operator+=(VQ L&, R); 3703 // VQ L& operator-=(VQ L&, R); 3704 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3705 for (unsigned Right = FirstPromotedArithmeticType; 3706 Right < LastPromotedArithmeticType; ++Right) { 3707 QualType ParamTypes[2]; 3708 ParamTypes[1] = ArithmeticTypes[Right]; 3709 3710 // Add this built-in operator as a candidate (VQ is empty). 3711 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3712 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3713 /*IsAssigmentOperator=*/Op == OO_Equal); 3714 3715 // Add this built-in operator as a candidate (VQ is 'volatile'). 3716 if (VisibleTypeConversionsQuals.hasVolatile()) { 3717 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3718 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3719 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3720 /*IsAssigmentOperator=*/Op == OO_Equal); 3721 } 3722 } 3723 } 3724 break; 3725 3726 case OO_PercentEqual: 3727 case OO_LessLessEqual: 3728 case OO_GreaterGreaterEqual: 3729 case OO_AmpEqual: 3730 case OO_CaretEqual: 3731 case OO_PipeEqual: 3732 // C++ [over.built]p22: 3733 // 3734 // For every triple (L, VQ, R), where L is an integral type, VQ 3735 // is either volatile or empty, and R is a promoted integral 3736 // type, there exist candidate operator functions of the form 3737 // 3738 // VQ L& operator%=(VQ L&, R); 3739 // VQ L& operator<<=(VQ L&, R); 3740 // VQ L& operator>>=(VQ L&, R); 3741 // VQ L& operator&=(VQ L&, R); 3742 // VQ L& operator^=(VQ L&, R); 3743 // VQ L& operator|=(VQ L&, R); 3744 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3745 for (unsigned Right = FirstPromotedIntegralType; 3746 Right < LastPromotedIntegralType; ++Right) { 3747 QualType ParamTypes[2]; 3748 ParamTypes[1] = ArithmeticTypes[Right]; 3749 3750 // Add this built-in operator as a candidate (VQ is empty). 3751 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3752 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3753 if (VisibleTypeConversionsQuals.hasVolatile()) { 3754 // Add this built-in operator as a candidate (VQ is 'volatile'). 3755 ParamTypes[0] = ArithmeticTypes[Left]; 3756 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3757 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3758 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3759 } 3760 } 3761 } 3762 break; 3763 3764 case OO_Exclaim: { 3765 // C++ [over.operator]p23: 3766 // 3767 // There also exist candidate operator functions of the form 3768 // 3769 // bool operator!(bool); 3770 // bool operator&&(bool, bool); [BELOW] 3771 // bool operator||(bool, bool); [BELOW] 3772 QualType ParamTy = Context.BoolTy; 3773 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3774 /*IsAssignmentOperator=*/false, 3775 /*NumContextualBoolArguments=*/1); 3776 break; 3777 } 3778 3779 case OO_AmpAmp: 3780 case OO_PipePipe: { 3781 // C++ [over.operator]p23: 3782 // 3783 // There also exist candidate operator functions of the form 3784 // 3785 // bool operator!(bool); [ABOVE] 3786 // bool operator&&(bool, bool); 3787 // bool operator||(bool, bool); 3788 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3789 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3790 /*IsAssignmentOperator=*/false, 3791 /*NumContextualBoolArguments=*/2); 3792 break; 3793 } 3794 3795 case OO_Subscript: 3796 // C++ [over.built]p13: 3797 // 3798 // For every cv-qualified or cv-unqualified object type T there 3799 // exist candidate operator functions of the form 3800 // 3801 // T* operator+(T*, ptrdiff_t); [ABOVE] 3802 // T& operator[](T*, ptrdiff_t); 3803 // T* operator-(T*, ptrdiff_t); [ABOVE] 3804 // T* operator+(ptrdiff_t, T*); [ABOVE] 3805 // T& operator[](ptrdiff_t, T*); 3806 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3807 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3808 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3809 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3810 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3811 3812 // T& operator[](T*, ptrdiff_t) 3813 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3814 3815 // T& operator[](ptrdiff_t, T*); 3816 ParamTypes[0] = ParamTypes[1]; 3817 ParamTypes[1] = *Ptr; 3818 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3819 } 3820 break; 3821 3822 case OO_ArrowStar: 3823 // C++ [over.built]p11: 3824 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 3825 // C1 is the same type as C2 or is a derived class of C2, T is an object 3826 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 3827 // there exist candidate operator functions of the form 3828 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 3829 // where CV12 is the union of CV1 and CV2. 3830 { 3831 for (BuiltinCandidateTypeSet::iterator Ptr = 3832 CandidateTypes.pointer_begin(); 3833 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3834 QualType C1Ty = (*Ptr); 3835 QualType C1; 3836 QualifierCollector Q1; 3837 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 3838 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 3839 if (!isa<RecordType>(C1)) 3840 continue; 3841 // heuristic to reduce number of builtin candidates in the set. 3842 // Add volatile/restrict version only if there are conversions to a 3843 // volatile/restrict type. 3844 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 3845 continue; 3846 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 3847 continue; 3848 } 3849 for (BuiltinCandidateTypeSet::iterator 3850 MemPtr = CandidateTypes.member_pointer_begin(), 3851 MemPtrEnd = CandidateTypes.member_pointer_end(); 3852 MemPtr != MemPtrEnd; ++MemPtr) { 3853 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 3854 QualType C2 = QualType(mptr->getClass(), 0); 3855 C2 = C2.getUnqualifiedType(); 3856 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 3857 break; 3858 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 3859 // build CV12 T& 3860 QualType T = mptr->getPointeeType(); 3861 if (!VisibleTypeConversionsQuals.hasVolatile() && 3862 T.isVolatileQualified()) 3863 continue; 3864 if (!VisibleTypeConversionsQuals.hasRestrict() && 3865 T.isRestrictQualified()) 3866 continue; 3867 T = Q1.apply(T); 3868 QualType ResultTy = Context.getLValueReferenceType(T); 3869 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3870 } 3871 } 3872 } 3873 break; 3874 3875 case OO_Conditional: 3876 // Note that we don't consider the first argument, since it has been 3877 // contextually converted to bool long ago. The candidates below are 3878 // therefore added as binary. 3879 // 3880 // C++ [over.built]p24: 3881 // For every type T, where T is a pointer or pointer-to-member type, 3882 // there exist candidate operator functions of the form 3883 // 3884 // T operator?(bool, T, T); 3885 // 3886 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3887 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3888 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3889 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3890 } 3891 for (BuiltinCandidateTypeSet::iterator Ptr = 3892 CandidateTypes.member_pointer_begin(), 3893 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3894 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3895 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3896 } 3897 goto Conditional; 3898 } 3899} 3900 3901/// \brief Add function candidates found via argument-dependent lookup 3902/// to the set of overloading candidates. 3903/// 3904/// This routine performs argument-dependent name lookup based on the 3905/// given function name (which may also be an operator name) and adds 3906/// all of the overload candidates found by ADL to the overload 3907/// candidate set (C++ [basic.lookup.argdep]). 3908void 3909Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3910 Expr **Args, unsigned NumArgs, 3911 bool HasExplicitTemplateArgs, 3912 const TemplateArgumentLoc *ExplicitTemplateArgs, 3913 unsigned NumExplicitTemplateArgs, 3914 OverloadCandidateSet& CandidateSet, 3915 bool PartialOverloading) { 3916 FunctionSet Functions; 3917 3918 // FIXME: Should we be trafficking in canonical function decls throughout? 3919 3920 // Record all of the function candidates that we've already 3921 // added to the overload set, so that we don't add those same 3922 // candidates a second time. 3923 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3924 CandEnd = CandidateSet.end(); 3925 Cand != CandEnd; ++Cand) 3926 if (Cand->Function) { 3927 Functions.insert(Cand->Function); 3928 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3929 Functions.insert(FunTmpl); 3930 } 3931 3932 // FIXME: Pass in the explicit template arguments? 3933 ArgumentDependentLookup(Name, /*Operator*/false, Args, NumArgs, Functions); 3934 3935 // Erase all of the candidates we already knew about. 3936 // FIXME: This is suboptimal. Is there a better way? 3937 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3938 CandEnd = CandidateSet.end(); 3939 Cand != CandEnd; ++Cand) 3940 if (Cand->Function) { 3941 Functions.erase(Cand->Function); 3942 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3943 Functions.erase(FunTmpl); 3944 } 3945 3946 // For each of the ADL candidates we found, add it to the overload 3947 // set. 3948 for (FunctionSet::iterator Func = Functions.begin(), 3949 FuncEnd = Functions.end(); 3950 Func != FuncEnd; ++Func) { 3951 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3952 if (HasExplicitTemplateArgs) 3953 continue; 3954 3955 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3956 false, false, PartialOverloading); 3957 } else 3958 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3959 HasExplicitTemplateArgs, 3960 ExplicitTemplateArgs, 3961 NumExplicitTemplateArgs, 3962 Args, NumArgs, CandidateSet); 3963 } 3964} 3965 3966/// isBetterOverloadCandidate - Determines whether the first overload 3967/// candidate is a better candidate than the second (C++ 13.3.3p1). 3968bool 3969Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3970 const OverloadCandidate& Cand2) { 3971 // Define viable functions to be better candidates than non-viable 3972 // functions. 3973 if (!Cand2.Viable) 3974 return Cand1.Viable; 3975 else if (!Cand1.Viable) 3976 return false; 3977 3978 // C++ [over.match.best]p1: 3979 // 3980 // -- if F is a static member function, ICS1(F) is defined such 3981 // that ICS1(F) is neither better nor worse than ICS1(G) for 3982 // any function G, and, symmetrically, ICS1(G) is neither 3983 // better nor worse than ICS1(F). 3984 unsigned StartArg = 0; 3985 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3986 StartArg = 1; 3987 3988 // C++ [over.match.best]p1: 3989 // A viable function F1 is defined to be a better function than another 3990 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3991 // conversion sequence than ICSi(F2), and then... 3992 unsigned NumArgs = Cand1.Conversions.size(); 3993 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3994 bool HasBetterConversion = false; 3995 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3996 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3997 Cand2.Conversions[ArgIdx])) { 3998 case ImplicitConversionSequence::Better: 3999 // Cand1 has a better conversion sequence. 4000 HasBetterConversion = true; 4001 break; 4002 4003 case ImplicitConversionSequence::Worse: 4004 // Cand1 can't be better than Cand2. 4005 return false; 4006 4007 case ImplicitConversionSequence::Indistinguishable: 4008 // Do nothing. 4009 break; 4010 } 4011 } 4012 4013 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4014 // ICSj(F2), or, if not that, 4015 if (HasBetterConversion) 4016 return true; 4017 4018 // - F1 is a non-template function and F2 is a function template 4019 // specialization, or, if not that, 4020 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4021 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4022 return true; 4023 4024 // -- F1 and F2 are function template specializations, and the function 4025 // template for F1 is more specialized than the template for F2 4026 // according to the partial ordering rules described in 14.5.5.2, or, 4027 // if not that, 4028 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4029 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4030 if (FunctionTemplateDecl *BetterTemplate 4031 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4032 Cand2.Function->getPrimaryTemplate(), 4033 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4034 : TPOC_Call)) 4035 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4036 4037 // -- the context is an initialization by user-defined conversion 4038 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4039 // from the return type of F1 to the destination type (i.e., 4040 // the type of the entity being initialized) is a better 4041 // conversion sequence than the standard conversion sequence 4042 // from the return type of F2 to the destination type. 4043 if (Cand1.Function && Cand2.Function && 4044 isa<CXXConversionDecl>(Cand1.Function) && 4045 isa<CXXConversionDecl>(Cand2.Function)) { 4046 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4047 Cand2.FinalConversion)) { 4048 case ImplicitConversionSequence::Better: 4049 // Cand1 has a better conversion sequence. 4050 return true; 4051 4052 case ImplicitConversionSequence::Worse: 4053 // Cand1 can't be better than Cand2. 4054 return false; 4055 4056 case ImplicitConversionSequence::Indistinguishable: 4057 // Do nothing 4058 break; 4059 } 4060 } 4061 4062 return false; 4063} 4064 4065/// \brief Computes the best viable function (C++ 13.3.3) 4066/// within an overload candidate set. 4067/// 4068/// \param CandidateSet the set of candidate functions. 4069/// 4070/// \param Loc the location of the function name (or operator symbol) for 4071/// which overload resolution occurs. 4072/// 4073/// \param Best f overload resolution was successful or found a deleted 4074/// function, Best points to the candidate function found. 4075/// 4076/// \returns The result of overload resolution. 4077Sema::OverloadingResult 4078Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4079 SourceLocation Loc, 4080 OverloadCandidateSet::iterator& Best) { 4081 // Find the best viable function. 4082 Best = CandidateSet.end(); 4083 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4084 Cand != CandidateSet.end(); ++Cand) { 4085 if (Cand->Viable) { 4086 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 4087 Best = Cand; 4088 } 4089 } 4090 4091 // If we didn't find any viable functions, abort. 4092 if (Best == CandidateSet.end()) 4093 return OR_No_Viable_Function; 4094 4095 // Make sure that this function is better than every other viable 4096 // function. If not, we have an ambiguity. 4097 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4098 Cand != CandidateSet.end(); ++Cand) { 4099 if (Cand->Viable && 4100 Cand != Best && 4101 !isBetterOverloadCandidate(*Best, *Cand)) { 4102 Best = CandidateSet.end(); 4103 return OR_Ambiguous; 4104 } 4105 } 4106 4107 // Best is the best viable function. 4108 if (Best->Function && 4109 (Best->Function->isDeleted() || 4110 Best->Function->getAttr<UnavailableAttr>())) 4111 return OR_Deleted; 4112 4113 // C++ [basic.def.odr]p2: 4114 // An overloaded function is used if it is selected by overload resolution 4115 // when referred to from a potentially-evaluated expression. [Note: this 4116 // covers calls to named functions (5.2.2), operator overloading 4117 // (clause 13), user-defined conversions (12.3.2), allocation function for 4118 // placement new (5.3.4), as well as non-default initialization (8.5). 4119 if (Best->Function) 4120 MarkDeclarationReferenced(Loc, Best->Function); 4121 return OR_Success; 4122} 4123 4124/// PrintOverloadCandidates - When overload resolution fails, prints 4125/// diagnostic messages containing the candidates in the candidate 4126/// set. If OnlyViable is true, only viable candidates will be printed. 4127void 4128Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4129 bool OnlyViable, 4130 const char *Opc, 4131 SourceLocation OpLoc) { 4132 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4133 LastCand = CandidateSet.end(); 4134 bool Reported = false; 4135 for (; Cand != LastCand; ++Cand) { 4136 if (Cand->Viable || !OnlyViable) { 4137 if (Cand->Function) { 4138 if (Cand->Function->isDeleted() || 4139 Cand->Function->getAttr<UnavailableAttr>()) { 4140 // Deleted or "unavailable" function. 4141 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 4142 << Cand->Function->isDeleted(); 4143 } else if (FunctionTemplateDecl *FunTmpl 4144 = Cand->Function->getPrimaryTemplate()) { 4145 // Function template specialization 4146 // FIXME: Give a better reason! 4147 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 4148 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 4149 *Cand->Function->getTemplateSpecializationArgs()); 4150 } else { 4151 // Normal function 4152 bool errReported = false; 4153 if (!Cand->Viable && Cand->Conversions.size() > 0) { 4154 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 4155 const ImplicitConversionSequence &Conversion = 4156 Cand->Conversions[i]; 4157 if ((Conversion.ConversionKind != 4158 ImplicitConversionSequence::BadConversion) || 4159 Conversion.ConversionFunctionSet.size() == 0) 4160 continue; 4161 Diag(Cand->Function->getLocation(), 4162 diag::err_ovl_candidate_not_viable) << (i+1); 4163 errReported = true; 4164 for (int j = Conversion.ConversionFunctionSet.size()-1; 4165 j >= 0; j--) { 4166 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 4167 Diag(Func->getLocation(), diag::err_ovl_candidate); 4168 } 4169 } 4170 } 4171 if (!errReported) 4172 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 4173 } 4174 } else if (Cand->IsSurrogate) { 4175 // Desugar the type of the surrogate down to a function type, 4176 // retaining as many typedefs as possible while still showing 4177 // the function type (and, therefore, its parameter types). 4178 QualType FnType = Cand->Surrogate->getConversionType(); 4179 bool isLValueReference = false; 4180 bool isRValueReference = false; 4181 bool isPointer = false; 4182 if (const LValueReferenceType *FnTypeRef = 4183 FnType->getAs<LValueReferenceType>()) { 4184 FnType = FnTypeRef->getPointeeType(); 4185 isLValueReference = true; 4186 } else if (const RValueReferenceType *FnTypeRef = 4187 FnType->getAs<RValueReferenceType>()) { 4188 FnType = FnTypeRef->getPointeeType(); 4189 isRValueReference = true; 4190 } 4191 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4192 FnType = FnTypePtr->getPointeeType(); 4193 isPointer = true; 4194 } 4195 // Desugar down to a function type. 4196 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4197 // Reconstruct the pointer/reference as appropriate. 4198 if (isPointer) FnType = Context.getPointerType(FnType); 4199 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 4200 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 4201 4202 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 4203 << FnType; 4204 } else if (OnlyViable) { 4205 assert(Cand->Conversions.size() <= 2 && 4206 "builtin-binary-operator-not-binary"); 4207 std::string TypeStr("operator"); 4208 TypeStr += Opc; 4209 TypeStr += "("; 4210 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4211 if (Cand->Conversions.size() == 1) { 4212 TypeStr += ")"; 4213 Diag(OpLoc, diag::err_ovl_builtin_unary_candidate) << TypeStr; 4214 } 4215 else { 4216 TypeStr += ", "; 4217 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4218 TypeStr += ")"; 4219 Diag(OpLoc, diag::err_ovl_builtin_binary_candidate) << TypeStr; 4220 } 4221 } 4222 else if (!Cand->Viable && !Reported) { 4223 // Non-viability might be due to ambiguous user-defined conversions, 4224 // needed for built-in operators. Report them as well, but only once 4225 // as we have typically many built-in candidates. 4226 unsigned NoOperands = Cand->Conversions.size(); 4227 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4228 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4229 if (ICS.ConversionKind != ImplicitConversionSequence::BadConversion || 4230 ICS.ConversionFunctionSet.empty()) 4231 continue; 4232 if (CXXConversionDecl *Func = dyn_cast<CXXConversionDecl>( 4233 Cand->Conversions[ArgIdx].ConversionFunctionSet[0])) { 4234 QualType FromTy = 4235 QualType( 4236 static_cast<Type*>(ICS.UserDefined.Before.FromTypePtr),0); 4237 Diag(OpLoc,diag::note_ambiguous_type_conversion) 4238 << FromTy << Func->getConversionType(); 4239 } 4240 for (unsigned j = 0; j < ICS.ConversionFunctionSet.size(); j++) { 4241 FunctionDecl *Func = 4242 Cand->Conversions[ArgIdx].ConversionFunctionSet[j]; 4243 Diag(Func->getLocation(),diag::err_ovl_candidate); 4244 } 4245 } 4246 Reported = true; 4247 } 4248 } 4249 } 4250} 4251 4252/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4253/// an overloaded function (C++ [over.over]), where @p From is an 4254/// expression with overloaded function type and @p ToType is the type 4255/// we're trying to resolve to. For example: 4256/// 4257/// @code 4258/// int f(double); 4259/// int f(int); 4260/// 4261/// int (*pfd)(double) = f; // selects f(double) 4262/// @endcode 4263/// 4264/// This routine returns the resulting FunctionDecl if it could be 4265/// resolved, and NULL otherwise. When @p Complain is true, this 4266/// routine will emit diagnostics if there is an error. 4267FunctionDecl * 4268Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4269 bool Complain) { 4270 QualType FunctionType = ToType; 4271 bool IsMember = false; 4272 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4273 FunctionType = ToTypePtr->getPointeeType(); 4274 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4275 FunctionType = ToTypeRef->getPointeeType(); 4276 else if (const MemberPointerType *MemTypePtr = 4277 ToType->getAs<MemberPointerType>()) { 4278 FunctionType = MemTypePtr->getPointeeType(); 4279 IsMember = true; 4280 } 4281 4282 // We only look at pointers or references to functions. 4283 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4284 if (!FunctionType->isFunctionType()) 4285 return 0; 4286 4287 // Find the actual overloaded function declaration. 4288 OverloadedFunctionDecl *Ovl = 0; 4289 4290 // C++ [over.over]p1: 4291 // [...] [Note: any redundant set of parentheses surrounding the 4292 // overloaded function name is ignored (5.1). ] 4293 Expr *OvlExpr = From->IgnoreParens(); 4294 4295 // C++ [over.over]p1: 4296 // [...] The overloaded function name can be preceded by the & 4297 // operator. 4298 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4299 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4300 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4301 } 4302 4303 bool HasExplicitTemplateArgs = false; 4304 const TemplateArgumentLoc *ExplicitTemplateArgs = 0; 4305 unsigned NumExplicitTemplateArgs = 0; 4306 4307 // Try to dig out the overloaded function. 4308 FunctionTemplateDecl *FunctionTemplate = 0; 4309 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4310 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4311 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4312 HasExplicitTemplateArgs = DR->hasExplicitTemplateArgumentList(); 4313 ExplicitTemplateArgs = DR->getTemplateArgs(); 4314 NumExplicitTemplateArgs = DR->getNumTemplateArgs(); 4315 } else if (MemberExpr *ME = dyn_cast<MemberExpr>(OvlExpr)) { 4316 Ovl = dyn_cast<OverloadedFunctionDecl>(ME->getMemberDecl()); 4317 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(ME->getMemberDecl()); 4318 HasExplicitTemplateArgs = ME->hasExplicitTemplateArgumentList(); 4319 ExplicitTemplateArgs = ME->getTemplateArgs(); 4320 NumExplicitTemplateArgs = ME->getNumTemplateArgs(); 4321 } else if (TemplateIdRefExpr *TIRE = dyn_cast<TemplateIdRefExpr>(OvlExpr)) { 4322 TemplateName Name = TIRE->getTemplateName(); 4323 Ovl = Name.getAsOverloadedFunctionDecl(); 4324 FunctionTemplate = 4325 dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl()); 4326 4327 HasExplicitTemplateArgs = true; 4328 ExplicitTemplateArgs = TIRE->getTemplateArgs(); 4329 NumExplicitTemplateArgs = TIRE->getNumTemplateArgs(); 4330 } 4331 4332 // If there's no overloaded function declaration or function template, 4333 // we're done. 4334 if (!Ovl && !FunctionTemplate) 4335 return 0; 4336 4337 OverloadIterator Fun; 4338 if (Ovl) 4339 Fun = Ovl; 4340 else 4341 Fun = FunctionTemplate; 4342 4343 // Look through all of the overloaded functions, searching for one 4344 // whose type matches exactly. 4345 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4346 bool FoundNonTemplateFunction = false; 4347 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4348 // C++ [over.over]p3: 4349 // Non-member functions and static member functions match 4350 // targets of type "pointer-to-function" or "reference-to-function." 4351 // Nonstatic member functions match targets of 4352 // type "pointer-to-member-function." 4353 // Note that according to DR 247, the containing class does not matter. 4354 4355 if (FunctionTemplateDecl *FunctionTemplate 4356 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4357 if (CXXMethodDecl *Method 4358 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4359 // Skip non-static function templates when converting to pointer, and 4360 // static when converting to member pointer. 4361 if (Method->isStatic() == IsMember) 4362 continue; 4363 } else if (IsMember) 4364 continue; 4365 4366 // C++ [over.over]p2: 4367 // If the name is a function template, template argument deduction is 4368 // done (14.8.2.2), and if the argument deduction succeeds, the 4369 // resulting template argument list is used to generate a single 4370 // function template specialization, which is added to the set of 4371 // overloaded functions considered. 4372 // FIXME: We don't really want to build the specialization here, do we? 4373 FunctionDecl *Specialization = 0; 4374 TemplateDeductionInfo Info(Context); 4375 if (TemplateDeductionResult Result 4376 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 4377 ExplicitTemplateArgs, 4378 NumExplicitTemplateArgs, 4379 FunctionType, Specialization, Info)) { 4380 // FIXME: make a note of the failed deduction for diagnostics. 4381 (void)Result; 4382 } else { 4383 // FIXME: If the match isn't exact, shouldn't we just drop this as 4384 // a candidate? Find a testcase before changing the code. 4385 assert(FunctionType 4386 == Context.getCanonicalType(Specialization->getType())); 4387 Matches.insert( 4388 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4389 } 4390 } 4391 4392 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4393 // Skip non-static functions when converting to pointer, and static 4394 // when converting to member pointer. 4395 if (Method->isStatic() == IsMember) 4396 continue; 4397 4398 // If we have explicit template arguments, skip non-templates. 4399 if (HasExplicitTemplateArgs) 4400 continue; 4401 } else if (IsMember) 4402 continue; 4403 4404 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4405 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4406 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4407 FoundNonTemplateFunction = true; 4408 } 4409 } 4410 } 4411 4412 // If there were 0 or 1 matches, we're done. 4413 if (Matches.empty()) 4414 return 0; 4415 else if (Matches.size() == 1) { 4416 FunctionDecl *Result = *Matches.begin(); 4417 MarkDeclarationReferenced(From->getLocStart(), Result); 4418 return Result; 4419 } 4420 4421 // C++ [over.over]p4: 4422 // If more than one function is selected, [...] 4423 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4424 if (!FoundNonTemplateFunction) { 4425 // [...] and any given function template specialization F1 is 4426 // eliminated if the set contains a second function template 4427 // specialization whose function template is more specialized 4428 // than the function template of F1 according to the partial 4429 // ordering rules of 14.5.5.2. 4430 4431 // The algorithm specified above is quadratic. We instead use a 4432 // two-pass algorithm (similar to the one used to identify the 4433 // best viable function in an overload set) that identifies the 4434 // best function template (if it exists). 4435 llvm::SmallVector<FunctionDecl *, 8> TemplateMatches(Matches.begin(), 4436 Matches.end()); 4437 FunctionDecl *Result = 4438 getMostSpecialized(TemplateMatches.data(), TemplateMatches.size(), 4439 TPOC_Other, From->getLocStart(), 4440 PDiag(), 4441 PDiag(diag::err_addr_ovl_ambiguous) 4442 << TemplateMatches[0]->getDeclName(), 4443 PDiag(diag::err_ovl_template_candidate)); 4444 MarkDeclarationReferenced(From->getLocStart(), Result); 4445 return Result; 4446 } 4447 4448 // [...] any function template specializations in the set are 4449 // eliminated if the set also contains a non-template function, [...] 4450 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4451 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4452 if ((*M)->getPrimaryTemplate() == 0) 4453 RemainingMatches.push_back(*M); 4454 4455 // [...] After such eliminations, if any, there shall remain exactly one 4456 // selected function. 4457 if (RemainingMatches.size() == 1) { 4458 FunctionDecl *Result = RemainingMatches.front(); 4459 MarkDeclarationReferenced(From->getLocStart(), Result); 4460 return Result; 4461 } 4462 4463 // FIXME: We should probably return the same thing that BestViableFunction 4464 // returns (even if we issue the diagnostics here). 4465 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4466 << RemainingMatches[0]->getDeclName(); 4467 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4468 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4469 return 0; 4470} 4471 4472/// \brief Add a single candidate to the overload set. 4473static void AddOverloadedCallCandidate(Sema &S, 4474 AnyFunctionDecl Callee, 4475 bool &ArgumentDependentLookup, 4476 bool HasExplicitTemplateArgs, 4477 const TemplateArgumentLoc *ExplicitTemplateArgs, 4478 unsigned NumExplicitTemplateArgs, 4479 Expr **Args, unsigned NumArgs, 4480 OverloadCandidateSet &CandidateSet, 4481 bool PartialOverloading) { 4482 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4483 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4484 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4485 PartialOverloading); 4486 4487 if (Func->getDeclContext()->isRecord() || 4488 Func->getDeclContext()->isFunctionOrMethod()) 4489 ArgumentDependentLookup = false; 4490 return; 4491 } 4492 4493 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4494 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4495 ExplicitTemplateArgs, 4496 NumExplicitTemplateArgs, 4497 Args, NumArgs, CandidateSet); 4498 4499 if (FuncTemplate->getDeclContext()->isRecord()) 4500 ArgumentDependentLookup = false; 4501} 4502 4503/// \brief Add the overload candidates named by callee and/or found by argument 4504/// dependent lookup to the given overload set. 4505void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4506 DeclarationName &UnqualifiedName, 4507 bool &ArgumentDependentLookup, 4508 bool HasExplicitTemplateArgs, 4509 const TemplateArgumentLoc *ExplicitTemplateArgs, 4510 unsigned NumExplicitTemplateArgs, 4511 Expr **Args, unsigned NumArgs, 4512 OverloadCandidateSet &CandidateSet, 4513 bool PartialOverloading) { 4514 // Add the functions denoted by Callee to the set of candidate 4515 // functions. While we're doing so, track whether argument-dependent 4516 // lookup still applies, per: 4517 // 4518 // C++0x [basic.lookup.argdep]p3: 4519 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4520 // and let Y be the lookup set produced by argument dependent 4521 // lookup (defined as follows). If X contains 4522 // 4523 // -- a declaration of a class member, or 4524 // 4525 // -- a block-scope function declaration that is not a 4526 // using-declaration (FIXME: check for using declaration), or 4527 // 4528 // -- a declaration that is neither a function or a function 4529 // template 4530 // 4531 // then Y is empty. 4532 if (!Callee) { 4533 // Nothing to do. 4534 } else if (OverloadedFunctionDecl *Ovl 4535 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4536 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4537 FuncEnd = Ovl->function_end(); 4538 Func != FuncEnd; ++Func) 4539 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4540 HasExplicitTemplateArgs, 4541 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4542 Args, NumArgs, CandidateSet, 4543 PartialOverloading); 4544 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4545 AddOverloadedCallCandidate(*this, 4546 AnyFunctionDecl::getFromNamedDecl(Callee), 4547 ArgumentDependentLookup, 4548 HasExplicitTemplateArgs, 4549 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4550 Args, NumArgs, CandidateSet, 4551 PartialOverloading); 4552 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4553 // checking dynamically. 4554 4555 if (Callee) 4556 UnqualifiedName = Callee->getDeclName(); 4557 4558 if (ArgumentDependentLookup) 4559 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4560 HasExplicitTemplateArgs, 4561 ExplicitTemplateArgs, 4562 NumExplicitTemplateArgs, 4563 CandidateSet, 4564 PartialOverloading); 4565} 4566 4567/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4568/// (which eventually refers to the declaration Func) and the call 4569/// arguments Args/NumArgs, attempt to resolve the function call down 4570/// to a specific function. If overload resolution succeeds, returns 4571/// the function declaration produced by overload 4572/// resolution. Otherwise, emits diagnostics, deletes all of the 4573/// arguments and Fn, and returns NULL. 4574FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4575 DeclarationName UnqualifiedName, 4576 bool HasExplicitTemplateArgs, 4577 const TemplateArgumentLoc *ExplicitTemplateArgs, 4578 unsigned NumExplicitTemplateArgs, 4579 SourceLocation LParenLoc, 4580 Expr **Args, unsigned NumArgs, 4581 SourceLocation *CommaLocs, 4582 SourceLocation RParenLoc, 4583 bool &ArgumentDependentLookup) { 4584 OverloadCandidateSet CandidateSet; 4585 4586 // Add the functions denoted by Callee to the set of candidate 4587 // functions. 4588 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4589 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4590 NumExplicitTemplateArgs, Args, NumArgs, 4591 CandidateSet); 4592 OverloadCandidateSet::iterator Best; 4593 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4594 case OR_Success: 4595 return Best->Function; 4596 4597 case OR_No_Viable_Function: 4598 Diag(Fn->getSourceRange().getBegin(), 4599 diag::err_ovl_no_viable_function_in_call) 4600 << UnqualifiedName << Fn->getSourceRange(); 4601 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4602 break; 4603 4604 case OR_Ambiguous: 4605 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4606 << UnqualifiedName << Fn->getSourceRange(); 4607 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4608 break; 4609 4610 case OR_Deleted: 4611 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4612 << Best->Function->isDeleted() 4613 << UnqualifiedName 4614 << Fn->getSourceRange(); 4615 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4616 break; 4617 } 4618 4619 // Overload resolution failed. Destroy all of the subexpressions and 4620 // return NULL. 4621 Fn->Destroy(Context); 4622 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4623 Args[Arg]->Destroy(Context); 4624 return 0; 4625} 4626 4627/// \brief Create a unary operation that may resolve to an overloaded 4628/// operator. 4629/// 4630/// \param OpLoc The location of the operator itself (e.g., '*'). 4631/// 4632/// \param OpcIn The UnaryOperator::Opcode that describes this 4633/// operator. 4634/// 4635/// \param Functions The set of non-member functions that will be 4636/// considered by overload resolution. The caller needs to build this 4637/// set based on the context using, e.g., 4638/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4639/// set should not contain any member functions; those will be added 4640/// by CreateOverloadedUnaryOp(). 4641/// 4642/// \param input The input argument. 4643Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4644 unsigned OpcIn, 4645 FunctionSet &Functions, 4646 ExprArg input) { 4647 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4648 Expr *Input = (Expr *)input.get(); 4649 4650 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4651 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4652 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4653 4654 Expr *Args[2] = { Input, 0 }; 4655 unsigned NumArgs = 1; 4656 4657 // For post-increment and post-decrement, add the implicit '0' as 4658 // the second argument, so that we know this is a post-increment or 4659 // post-decrement. 4660 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4661 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4662 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4663 SourceLocation()); 4664 NumArgs = 2; 4665 } 4666 4667 if (Input->isTypeDependent()) { 4668 OverloadedFunctionDecl *Overloads 4669 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4670 for (FunctionSet::iterator Func = Functions.begin(), 4671 FuncEnd = Functions.end(); 4672 Func != FuncEnd; ++Func) 4673 Overloads->addOverload(*Func); 4674 4675 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4676 OpLoc, false, false); 4677 4678 input.release(); 4679 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4680 &Args[0], NumArgs, 4681 Context.DependentTy, 4682 OpLoc)); 4683 } 4684 4685 // Build an empty overload set. 4686 OverloadCandidateSet CandidateSet; 4687 4688 // Add the candidates from the given function set. 4689 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4690 4691 // Add operator candidates that are member functions. 4692 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4693 4694 // Add builtin operator candidates. 4695 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4696 4697 // Perform overload resolution. 4698 OverloadCandidateSet::iterator Best; 4699 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4700 case OR_Success: { 4701 // We found a built-in operator or an overloaded operator. 4702 FunctionDecl *FnDecl = Best->Function; 4703 4704 if (FnDecl) { 4705 // We matched an overloaded operator. Build a call to that 4706 // operator. 4707 4708 // Convert the arguments. 4709 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4710 if (PerformObjectArgumentInitialization(Input, Method)) 4711 return ExprError(); 4712 } else { 4713 // Convert the arguments. 4714 if (PerformCopyInitialization(Input, 4715 FnDecl->getParamDecl(0)->getType(), 4716 "passing")) 4717 return ExprError(); 4718 } 4719 4720 // Determine the result type 4721 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 4722 4723 // Build the actual expression node. 4724 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4725 SourceLocation()); 4726 UsualUnaryConversions(FnExpr); 4727 4728 input.release(); 4729 4730 ExprOwningPtr<CallExpr> TheCall(this, 4731 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4732 &Input, 1, ResultTy, OpLoc)); 4733 4734 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4735 FnDecl)) 4736 return ExprError(); 4737 4738 return MaybeBindToTemporary(TheCall.release()); 4739 } else { 4740 // We matched a built-in operator. Convert the arguments, then 4741 // break out so that we will build the appropriate built-in 4742 // operator node. 4743 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4744 Best->Conversions[0], "passing")) 4745 return ExprError(); 4746 4747 break; 4748 } 4749 } 4750 4751 case OR_No_Viable_Function: 4752 // No viable function; fall through to handling this as a 4753 // built-in operator, which will produce an error message for us. 4754 break; 4755 4756 case OR_Ambiguous: 4757 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4758 << UnaryOperator::getOpcodeStr(Opc) 4759 << Input->getSourceRange(); 4760 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4761 UnaryOperator::getOpcodeStr(Opc), OpLoc); 4762 return ExprError(); 4763 4764 case OR_Deleted: 4765 Diag(OpLoc, diag::err_ovl_deleted_oper) 4766 << Best->Function->isDeleted() 4767 << UnaryOperator::getOpcodeStr(Opc) 4768 << Input->getSourceRange(); 4769 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4770 return ExprError(); 4771 } 4772 4773 // Either we found no viable overloaded operator or we matched a 4774 // built-in operator. In either case, fall through to trying to 4775 // build a built-in operation. 4776 input.release(); 4777 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4778} 4779 4780/// \brief Create a binary operation that may resolve to an overloaded 4781/// operator. 4782/// 4783/// \param OpLoc The location of the operator itself (e.g., '+'). 4784/// 4785/// \param OpcIn The BinaryOperator::Opcode that describes this 4786/// operator. 4787/// 4788/// \param Functions The set of non-member functions that will be 4789/// considered by overload resolution. The caller needs to build this 4790/// set based on the context using, e.g., 4791/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4792/// set should not contain any member functions; those will be added 4793/// by CreateOverloadedBinOp(). 4794/// 4795/// \param LHS Left-hand argument. 4796/// \param RHS Right-hand argument. 4797Sema::OwningExprResult 4798Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4799 unsigned OpcIn, 4800 FunctionSet &Functions, 4801 Expr *LHS, Expr *RHS) { 4802 Expr *Args[2] = { LHS, RHS }; 4803 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4804 4805 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4806 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4807 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4808 4809 // If either side is type-dependent, create an appropriate dependent 4810 // expression. 4811 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4812 if (Functions.empty()) { 4813 // If there are no functions to store, just build a dependent 4814 // BinaryOperator or CompoundAssignment. 4815 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 4816 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4817 Context.DependentTy, OpLoc)); 4818 4819 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 4820 Context.DependentTy, 4821 Context.DependentTy, 4822 Context.DependentTy, 4823 OpLoc)); 4824 } 4825 4826 OverloadedFunctionDecl *Overloads 4827 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4828 for (FunctionSet::iterator Func = Functions.begin(), 4829 FuncEnd = Functions.end(); 4830 Func != FuncEnd; ++Func) 4831 Overloads->addOverload(*Func); 4832 4833 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4834 OpLoc, false, false); 4835 4836 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4837 Args, 2, 4838 Context.DependentTy, 4839 OpLoc)); 4840 } 4841 4842 // If this is the .* operator, which is not overloadable, just 4843 // create a built-in binary operator. 4844 if (Opc == BinaryOperator::PtrMemD) 4845 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4846 4847 // If this is one of the assignment operators, we only perform 4848 // overload resolution if the left-hand side is a class or 4849 // enumeration type (C++ [expr.ass]p3). 4850 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4851 !Args[0]->getType()->isOverloadableType()) 4852 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4853 4854 // Build an empty overload set. 4855 OverloadCandidateSet CandidateSet; 4856 4857 // Add the candidates from the given function set. 4858 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4859 4860 // Add operator candidates that are member functions. 4861 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4862 4863 // Add builtin operator candidates. 4864 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4865 4866 // Perform overload resolution. 4867 OverloadCandidateSet::iterator Best; 4868 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4869 case OR_Success: { 4870 // We found a built-in operator or an overloaded operator. 4871 FunctionDecl *FnDecl = Best->Function; 4872 4873 if (FnDecl) { 4874 // We matched an overloaded operator. Build a call to that 4875 // operator. 4876 4877 // Convert the arguments. 4878 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4879 if (PerformObjectArgumentInitialization(Args[0], Method) || 4880 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4881 "passing")) 4882 return ExprError(); 4883 } else { 4884 // Convert the arguments. 4885 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4886 "passing") || 4887 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4888 "passing")) 4889 return ExprError(); 4890 } 4891 4892 // Determine the result type 4893 QualType ResultTy 4894 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4895 ResultTy = ResultTy.getNonReferenceType(); 4896 4897 // Build the actual expression node. 4898 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4899 OpLoc); 4900 UsualUnaryConversions(FnExpr); 4901 4902 ExprOwningPtr<CXXOperatorCallExpr> 4903 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4904 Args, 2, ResultTy, 4905 OpLoc)); 4906 4907 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4908 FnDecl)) 4909 return ExprError(); 4910 4911 return MaybeBindToTemporary(TheCall.release()); 4912 } else { 4913 // We matched a built-in operator. Convert the arguments, then 4914 // break out so that we will build the appropriate built-in 4915 // operator node. 4916 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4917 Best->Conversions[0], "passing") || 4918 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4919 Best->Conversions[1], "passing")) 4920 return ExprError(); 4921 4922 break; 4923 } 4924 } 4925 4926 case OR_No_Viable_Function: { 4927 // C++ [over.match.oper]p9: 4928 // If the operator is the operator , [...] and there are no 4929 // viable functions, then the operator is assumed to be the 4930 // built-in operator and interpreted according to clause 5. 4931 if (Opc == BinaryOperator::Comma) 4932 break; 4933 4934 // For class as left operand for assignment or compound assigment operator 4935 // do not fall through to handling in built-in, but report that no overloaded 4936 // assignment operator found 4937 OwningExprResult Result = ExprError(); 4938 if (Args[0]->getType()->isRecordType() && 4939 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4940 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4941 << BinaryOperator::getOpcodeStr(Opc) 4942 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4943 } else { 4944 // No viable function; try to create a built-in operation, which will 4945 // produce an error. Then, show the non-viable candidates. 4946 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4947 } 4948 assert(Result.isInvalid() && 4949 "C++ binary operator overloading is missing candidates!"); 4950 if (Result.isInvalid()) 4951 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 4952 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4953 return move(Result); 4954 } 4955 4956 case OR_Ambiguous: 4957 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4958 << BinaryOperator::getOpcodeStr(Opc) 4959 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4960 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4961 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4962 return ExprError(); 4963 4964 case OR_Deleted: 4965 Diag(OpLoc, diag::err_ovl_deleted_oper) 4966 << Best->Function->isDeleted() 4967 << BinaryOperator::getOpcodeStr(Opc) 4968 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4969 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4970 return ExprError(); 4971 } 4972 4973 // We matched a built-in operator; build it. 4974 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4975} 4976 4977Action::OwningExprResult 4978Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 4979 SourceLocation RLoc, 4980 ExprArg Base, ExprArg Idx) { 4981 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 4982 static_cast<Expr*>(Idx.get()) }; 4983 DeclarationName OpName = 4984 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 4985 4986 // If either side is type-dependent, create an appropriate dependent 4987 // expression. 4988 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4989 4990 OverloadedFunctionDecl *Overloads 4991 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4992 4993 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4994 LLoc, false, false); 4995 4996 Base.release(); 4997 Idx.release(); 4998 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 4999 Args, 2, 5000 Context.DependentTy, 5001 RLoc)); 5002 } 5003 5004 // Build an empty overload set. 5005 OverloadCandidateSet CandidateSet; 5006 5007 // Subscript can only be overloaded as a member function. 5008 5009 // Add operator candidates that are member functions. 5010 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5011 5012 // Add builtin operator candidates. 5013 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5014 5015 // Perform overload resolution. 5016 OverloadCandidateSet::iterator Best; 5017 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5018 case OR_Success: { 5019 // We found a built-in operator or an overloaded operator. 5020 FunctionDecl *FnDecl = Best->Function; 5021 5022 if (FnDecl) { 5023 // We matched an overloaded operator. Build a call to that 5024 // operator. 5025 5026 // Convert the arguments. 5027 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5028 if (PerformObjectArgumentInitialization(Args[0], Method) || 5029 PerformCopyInitialization(Args[1], 5030 FnDecl->getParamDecl(0)->getType(), 5031 "passing")) 5032 return ExprError(); 5033 5034 // Determine the result type 5035 QualType ResultTy 5036 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5037 ResultTy = ResultTy.getNonReferenceType(); 5038 5039 // Build the actual expression node. 5040 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5041 LLoc); 5042 UsualUnaryConversions(FnExpr); 5043 5044 Base.release(); 5045 Idx.release(); 5046 ExprOwningPtr<CXXOperatorCallExpr> 5047 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5048 FnExpr, Args, 2, 5049 ResultTy, RLoc)); 5050 5051 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5052 FnDecl)) 5053 return ExprError(); 5054 5055 return MaybeBindToTemporary(TheCall.release()); 5056 } else { 5057 // We matched a built-in operator. Convert the arguments, then 5058 // break out so that we will build the appropriate built-in 5059 // operator node. 5060 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5061 Best->Conversions[0], "passing") || 5062 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5063 Best->Conversions[1], "passing")) 5064 return ExprError(); 5065 5066 break; 5067 } 5068 } 5069 5070 case OR_No_Viable_Function: { 5071 // No viable function; try to create a built-in operation, which will 5072 // produce an error. Then, show the non-viable candidates. 5073 OwningExprResult Result = 5074 CreateBuiltinArraySubscriptExpr(move(Base), LLoc, move(Idx), RLoc); 5075 assert(Result.isInvalid() && 5076 "C++ subscript operator overloading is missing candidates!"); 5077 if (Result.isInvalid()) 5078 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 5079 "[]", LLoc); 5080 return move(Result); 5081 } 5082 5083 case OR_Ambiguous: 5084 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5085 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5086 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 5087 "[]", LLoc); 5088 return ExprError(); 5089 5090 case OR_Deleted: 5091 Diag(LLoc, diag::err_ovl_deleted_oper) 5092 << Best->Function->isDeleted() << "[]" 5093 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5094 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5095 return ExprError(); 5096 } 5097 5098 // We matched a built-in operator; build it. 5099 Base.release(); 5100 Idx.release(); 5101 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 5102 Owned(Args[1]), RLoc); 5103} 5104 5105/// BuildCallToMemberFunction - Build a call to a member 5106/// function. MemExpr is the expression that refers to the member 5107/// function (and includes the object parameter), Args/NumArgs are the 5108/// arguments to the function call (not including the object 5109/// parameter). The caller needs to validate that the member 5110/// expression refers to a member function or an overloaded member 5111/// function. 5112Sema::ExprResult 5113Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 5114 SourceLocation LParenLoc, Expr **Args, 5115 unsigned NumArgs, SourceLocation *CommaLocs, 5116 SourceLocation RParenLoc) { 5117 // Dig out the member expression. This holds both the object 5118 // argument and the member function we're referring to. 5119 MemberExpr *MemExpr = 0; 5120 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 5121 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 5122 else 5123 MemExpr = dyn_cast<MemberExpr>(MemExprE); 5124 assert(MemExpr && "Building member call without member expression"); 5125 5126 // Extract the object argument. 5127 Expr *ObjectArg = MemExpr->getBase(); 5128 5129 CXXMethodDecl *Method = 0; 5130 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 5131 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 5132 // Add overload candidates 5133 OverloadCandidateSet CandidateSet; 5134 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 5135 5136 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 5137 Func != FuncEnd; ++Func) { 5138 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) { 5139 // If explicit template arguments were provided, we can't call a 5140 // non-template member function. 5141 if (MemExpr->hasExplicitTemplateArgumentList()) 5142 continue; 5143 5144 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 5145 /*SuppressUserConversions=*/false); 5146 } else 5147 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 5148 MemExpr->hasExplicitTemplateArgumentList(), 5149 MemExpr->getTemplateArgs(), 5150 MemExpr->getNumTemplateArgs(), 5151 ObjectArg, Args, NumArgs, 5152 CandidateSet, 5153 /*SuppressUsedConversions=*/false); 5154 } 5155 5156 OverloadCandidateSet::iterator Best; 5157 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 5158 case OR_Success: 5159 Method = cast<CXXMethodDecl>(Best->Function); 5160 break; 5161 5162 case OR_No_Viable_Function: 5163 Diag(MemExpr->getSourceRange().getBegin(), 5164 diag::err_ovl_no_viable_member_function_in_call) 5165 << DeclName << MemExprE->getSourceRange(); 5166 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5167 // FIXME: Leaking incoming expressions! 5168 return true; 5169 5170 case OR_Ambiguous: 5171 Diag(MemExpr->getSourceRange().getBegin(), 5172 diag::err_ovl_ambiguous_member_call) 5173 << DeclName << MemExprE->getSourceRange(); 5174 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5175 // FIXME: Leaking incoming expressions! 5176 return true; 5177 5178 case OR_Deleted: 5179 Diag(MemExpr->getSourceRange().getBegin(), 5180 diag::err_ovl_deleted_member_call) 5181 << Best->Function->isDeleted() 5182 << DeclName << MemExprE->getSourceRange(); 5183 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5184 // FIXME: Leaking incoming expressions! 5185 return true; 5186 } 5187 5188 FixOverloadedFunctionReference(MemExpr, Method); 5189 } else { 5190 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 5191 } 5192 5193 assert(Method && "Member call to something that isn't a method?"); 5194 ExprOwningPtr<CXXMemberCallExpr> 5195 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 5196 NumArgs, 5197 Method->getResultType().getNonReferenceType(), 5198 RParenLoc)); 5199 5200 // Check for a valid return type. 5201 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 5202 TheCall.get(), Method)) 5203 return true; 5204 5205 // Convert the object argument (for a non-static member function call). 5206 if (!Method->isStatic() && 5207 PerformObjectArgumentInitialization(ObjectArg, Method)) 5208 return true; 5209 MemExpr->setBase(ObjectArg); 5210 5211 // Convert the rest of the arguments 5212 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 5213 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 5214 RParenLoc)) 5215 return true; 5216 5217 if (CheckFunctionCall(Method, TheCall.get())) 5218 return true; 5219 5220 return MaybeBindToTemporary(TheCall.release()).release(); 5221} 5222 5223/// BuildCallToObjectOfClassType - Build a call to an object of class 5224/// type (C++ [over.call.object]), which can end up invoking an 5225/// overloaded function call operator (@c operator()) or performing a 5226/// user-defined conversion on the object argument. 5227Sema::ExprResult 5228Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 5229 SourceLocation LParenLoc, 5230 Expr **Args, unsigned NumArgs, 5231 SourceLocation *CommaLocs, 5232 SourceLocation RParenLoc) { 5233 assert(Object->getType()->isRecordType() && "Requires object type argument"); 5234 const RecordType *Record = Object->getType()->getAs<RecordType>(); 5235 5236 // C++ [over.call.object]p1: 5237 // If the primary-expression E in the function call syntax 5238 // evaluates to a class object of type "cv T", then the set of 5239 // candidate functions includes at least the function call 5240 // operators of T. The function call operators of T are obtained by 5241 // ordinary lookup of the name operator() in the context of 5242 // (E).operator(). 5243 OverloadCandidateSet CandidateSet; 5244 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 5245 DeclContext::lookup_const_iterator Oper, OperEnd; 5246 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 5247 Oper != OperEnd; ++Oper) { 5248 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(*Oper)) { 5249 AddMethodTemplateCandidate(FunTmpl, false, 0, 0, Object, Args, NumArgs, 5250 CandidateSet, 5251 /*SuppressUserConversions=*/false); 5252 continue; 5253 } 5254 5255 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 5256 CandidateSet, /*SuppressUserConversions=*/false); 5257 } 5258 5259 if (RequireCompleteType(LParenLoc, Object->getType(), 5260 PartialDiagnostic(diag::err_incomplete_object_call) 5261 << Object->getSourceRange())) 5262 return true; 5263 5264 // C++ [over.call.object]p2: 5265 // In addition, for each conversion function declared in T of the 5266 // form 5267 // 5268 // operator conversion-type-id () cv-qualifier; 5269 // 5270 // where cv-qualifier is the same cv-qualification as, or a 5271 // greater cv-qualification than, cv, and where conversion-type-id 5272 // denotes the type "pointer to function of (P1,...,Pn) returning 5273 // R", or the type "reference to pointer to function of 5274 // (P1,...,Pn) returning R", or the type "reference to function 5275 // of (P1,...,Pn) returning R", a surrogate call function [...] 5276 // is also considered as a candidate function. Similarly, 5277 // surrogate call functions are added to the set of candidate 5278 // functions for each conversion function declared in an 5279 // accessible base class provided the function is not hidden 5280 // within T by another intervening declaration. 5281 // FIXME: Look in base classes for more conversion operators! 5282 OverloadedFunctionDecl *Conversions 5283 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 5284 for (OverloadedFunctionDecl::function_iterator 5285 Func = Conversions->function_begin(), 5286 FuncEnd = Conversions->function_end(); 5287 Func != FuncEnd; ++Func) { 5288 CXXConversionDecl *Conv; 5289 FunctionTemplateDecl *ConvTemplate; 5290 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 5291 5292 // Skip over templated conversion functions; they aren't 5293 // surrogates. 5294 if (ConvTemplate) 5295 continue; 5296 5297 // Strip the reference type (if any) and then the pointer type (if 5298 // any) to get down to what might be a function type. 5299 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 5300 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5301 ConvType = ConvPtrType->getPointeeType(); 5302 5303 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 5304 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 5305 } 5306 5307 // Perform overload resolution. 5308 OverloadCandidateSet::iterator Best; 5309 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 5310 case OR_Success: 5311 // Overload resolution succeeded; we'll build the appropriate call 5312 // below. 5313 break; 5314 5315 case OR_No_Viable_Function: 5316 Diag(Object->getSourceRange().getBegin(), 5317 diag::err_ovl_no_viable_object_call) 5318 << Object->getType() << Object->getSourceRange(); 5319 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5320 break; 5321 5322 case OR_Ambiguous: 5323 Diag(Object->getSourceRange().getBegin(), 5324 diag::err_ovl_ambiguous_object_call) 5325 << Object->getType() << Object->getSourceRange(); 5326 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5327 break; 5328 5329 case OR_Deleted: 5330 Diag(Object->getSourceRange().getBegin(), 5331 diag::err_ovl_deleted_object_call) 5332 << Best->Function->isDeleted() 5333 << Object->getType() << Object->getSourceRange(); 5334 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5335 break; 5336 } 5337 5338 if (Best == CandidateSet.end()) { 5339 // We had an error; delete all of the subexpressions and return 5340 // the error. 5341 Object->Destroy(Context); 5342 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5343 Args[ArgIdx]->Destroy(Context); 5344 return true; 5345 } 5346 5347 if (Best->Function == 0) { 5348 // Since there is no function declaration, this is one of the 5349 // surrogate candidates. Dig out the conversion function. 5350 CXXConversionDecl *Conv 5351 = cast<CXXConversionDecl>( 5352 Best->Conversions[0].UserDefined.ConversionFunction); 5353 5354 // We selected one of the surrogate functions that converts the 5355 // object parameter to a function pointer. Perform the conversion 5356 // on the object argument, then let ActOnCallExpr finish the job. 5357 5358 // Create an implicit member expr to refer to the conversion operator. 5359 // and then call it. 5360 CXXMemberCallExpr *CE = 5361 BuildCXXMemberCallExpr(Object, Conv); 5362 5363 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 5364 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 5365 CommaLocs, RParenLoc).release(); 5366 } 5367 5368 // We found an overloaded operator(). Build a CXXOperatorCallExpr 5369 // that calls this method, using Object for the implicit object 5370 // parameter and passing along the remaining arguments. 5371 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5372 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 5373 5374 unsigned NumArgsInProto = Proto->getNumArgs(); 5375 unsigned NumArgsToCheck = NumArgs; 5376 5377 // Build the full argument list for the method call (the 5378 // implicit object parameter is placed at the beginning of the 5379 // list). 5380 Expr **MethodArgs; 5381 if (NumArgs < NumArgsInProto) { 5382 NumArgsToCheck = NumArgsInProto; 5383 MethodArgs = new Expr*[NumArgsInProto + 1]; 5384 } else { 5385 MethodArgs = new Expr*[NumArgs + 1]; 5386 } 5387 MethodArgs[0] = Object; 5388 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5389 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 5390 5391 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 5392 SourceLocation()); 5393 UsualUnaryConversions(NewFn); 5394 5395 // Once we've built TheCall, all of the expressions are properly 5396 // owned. 5397 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5398 ExprOwningPtr<CXXOperatorCallExpr> 5399 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 5400 MethodArgs, NumArgs + 1, 5401 ResultTy, RParenLoc)); 5402 delete [] MethodArgs; 5403 5404 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 5405 Method)) 5406 return true; 5407 5408 // We may have default arguments. If so, we need to allocate more 5409 // slots in the call for them. 5410 if (NumArgs < NumArgsInProto) 5411 TheCall->setNumArgs(Context, NumArgsInProto + 1); 5412 else if (NumArgs > NumArgsInProto) 5413 NumArgsToCheck = NumArgsInProto; 5414 5415 bool IsError = false; 5416 5417 // Initialize the implicit object parameter. 5418 IsError |= PerformObjectArgumentInitialization(Object, Method); 5419 TheCall->setArg(0, Object); 5420 5421 5422 // Check the argument types. 5423 for (unsigned i = 0; i != NumArgsToCheck; i++) { 5424 Expr *Arg; 5425 if (i < NumArgs) { 5426 Arg = Args[i]; 5427 5428 // Pass the argument. 5429 QualType ProtoArgType = Proto->getArgType(i); 5430 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 5431 } else { 5432 OwningExprResult DefArg 5433 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 5434 if (DefArg.isInvalid()) { 5435 IsError = true; 5436 break; 5437 } 5438 5439 Arg = DefArg.takeAs<Expr>(); 5440 } 5441 5442 TheCall->setArg(i + 1, Arg); 5443 } 5444 5445 // If this is a variadic call, handle args passed through "...". 5446 if (Proto->isVariadic()) { 5447 // Promote the arguments (C99 6.5.2.2p7). 5448 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 5449 Expr *Arg = Args[i]; 5450 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 5451 TheCall->setArg(i + 1, Arg); 5452 } 5453 } 5454 5455 if (IsError) return true; 5456 5457 if (CheckFunctionCall(Method, TheCall.get())) 5458 return true; 5459 5460 return MaybeBindToTemporary(TheCall.release()).release(); 5461} 5462 5463/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 5464/// (if one exists), where @c Base is an expression of class type and 5465/// @c Member is the name of the member we're trying to find. 5466Sema::OwningExprResult 5467Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 5468 Expr *Base = static_cast<Expr *>(BaseIn.get()); 5469 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 5470 5471 // C++ [over.ref]p1: 5472 // 5473 // [...] An expression x->m is interpreted as (x.operator->())->m 5474 // for a class object x of type T if T::operator->() exists and if 5475 // the operator is selected as the best match function by the 5476 // overload resolution mechanism (13.3). 5477 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 5478 OverloadCandidateSet CandidateSet; 5479 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 5480 5481 LookupResult R; 5482 LookupQualifiedName(R, BaseRecord->getDecl(), OpName, LookupOrdinaryName); 5483 5484 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5485 Oper != OperEnd; ++Oper) 5486 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 5487 /*SuppressUserConversions=*/false); 5488 5489 // Perform overload resolution. 5490 OverloadCandidateSet::iterator Best; 5491 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5492 case OR_Success: 5493 // Overload resolution succeeded; we'll build the call below. 5494 break; 5495 5496 case OR_No_Viable_Function: 5497 if (CandidateSet.empty()) 5498 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5499 << Base->getType() << Base->getSourceRange(); 5500 else 5501 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5502 << "operator->" << Base->getSourceRange(); 5503 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5504 return ExprError(); 5505 5506 case OR_Ambiguous: 5507 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5508 << "->" << Base->getSourceRange(); 5509 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5510 return ExprError(); 5511 5512 case OR_Deleted: 5513 Diag(OpLoc, diag::err_ovl_deleted_oper) 5514 << Best->Function->isDeleted() 5515 << "->" << Base->getSourceRange(); 5516 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5517 return ExprError(); 5518 } 5519 5520 // Convert the object parameter. 5521 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5522 if (PerformObjectArgumentInitialization(Base, Method)) 5523 return ExprError(); 5524 5525 // No concerns about early exits now. 5526 BaseIn.release(); 5527 5528 // Build the operator call. 5529 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5530 SourceLocation()); 5531 UsualUnaryConversions(FnExpr); 5532 5533 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5534 ExprOwningPtr<CXXOperatorCallExpr> 5535 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 5536 &Base, 1, ResultTy, OpLoc)); 5537 5538 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 5539 Method)) 5540 return ExprError(); 5541 return move(TheCall); 5542} 5543 5544/// FixOverloadedFunctionReference - E is an expression that refers to 5545/// a C++ overloaded function (possibly with some parentheses and 5546/// perhaps a '&' around it). We have resolved the overloaded function 5547/// to the function declaration Fn, so patch up the expression E to 5548/// refer (possibly indirectly) to Fn. Returns the new expr. 5549Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5550 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5551 Expr *NewExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5552 PE->setSubExpr(NewExpr); 5553 PE->setType(NewExpr->getType()); 5554 } else if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 5555 Expr *NewExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 5556 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 5557 NewExpr->getType()) && 5558 "Implicit cast type cannot be determined from overload"); 5559 ICE->setSubExpr(NewExpr); 5560 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5561 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5562 "Can only take the address of an overloaded function"); 5563 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5564 if (Method->isStatic()) { 5565 // Do nothing: static member functions aren't any different 5566 // from non-member functions. 5567 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr())) { 5568 if (DRE->getQualifier()) { 5569 // We have taken the address of a pointer to member 5570 // function. Perform the computation here so that we get the 5571 // appropriate pointer to member type. 5572 DRE->setDecl(Fn); 5573 DRE->setType(Fn->getType()); 5574 QualType ClassType 5575 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5576 E->setType(Context.getMemberPointerType(Fn->getType(), 5577 ClassType.getTypePtr())); 5578 return E; 5579 } 5580 } 5581 // FIXME: TemplateIdRefExpr referring to a member function template 5582 // specialization! 5583 } 5584 Expr *NewExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5585 UnOp->setSubExpr(NewExpr); 5586 UnOp->setType(Context.getPointerType(NewExpr->getType())); 5587 5588 return UnOp; 5589 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5590 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5591 isa<FunctionTemplateDecl>(DR->getDecl()) || 5592 isa<FunctionDecl>(DR->getDecl())) && 5593 "Expected function or function template"); 5594 DR->setDecl(Fn); 5595 E->setType(Fn->getType()); 5596 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5597 MemExpr->setMemberDecl(Fn); 5598 E->setType(Fn->getType()); 5599 } else if (TemplateIdRefExpr *TID = dyn_cast<TemplateIdRefExpr>(E)) { 5600 E = DeclRefExpr::Create(Context, 5601 TID->getQualifier(), TID->getQualifierRange(), 5602 Fn, TID->getTemplateNameLoc(), 5603 true, 5604 TID->getLAngleLoc(), 5605 TID->getTemplateArgs(), 5606 TID->getNumTemplateArgs(), 5607 TID->getRAngleLoc(), 5608 Fn->getType(), 5609 /*FIXME?*/false, /*FIXME?*/false); 5610 5611 // FIXME: Don't destroy TID here, since we need its template arguments 5612 // to survive. 5613 // TID->Destroy(Context); 5614 } else if (isa<UnresolvedFunctionNameExpr>(E)) { 5615 return DeclRefExpr::Create(Context, 5616 /*Qualifier=*/0, 5617 /*QualifierRange=*/SourceRange(), 5618 Fn, E->getLocStart(), 5619 Fn->getType(), false, false); 5620 } else { 5621 assert(false && "Invalid reference to overloaded function"); 5622 } 5623 5624 return E; 5625} 5626 5627} // end namespace clang 5628