SemaOverload.cpp revision b1c2ea5dddc9188e2ea30de7f6546f640b85dead
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, false, SourceLocation()) || 354 OldType->getResultType() != NewType->getResultType())) 355 return true; 356 357 // If the function is a class member, its signature includes the 358 // cv-qualifiers (if any) on the function itself. 359 // 360 // As part of this, also check whether one of the member functions 361 // is static, in which case they are not overloads (C++ 362 // 13.1p2). While not part of the definition of the signature, 363 // this check is important to determine whether these functions 364 // can be overloaded. 365 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 366 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 367 if (OldMethod && NewMethod && 368 !OldMethod->isStatic() && !NewMethod->isStatic() && 369 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 370 return true; 371 372 // The signatures match; this is not an overload. 373 return false; 374 } else { 375 // (C++ 13p1): 376 // Only function declarations can be overloaded; object and type 377 // declarations cannot be overloaded. 378 return false; 379 } 380} 381 382/// TryImplicitConversion - Attempt to perform an implicit conversion 383/// from the given expression (Expr) to the given type (ToType). This 384/// function returns an implicit conversion sequence that can be used 385/// to perform the initialization. Given 386/// 387/// void f(float f); 388/// void g(int i) { f(i); } 389/// 390/// this routine would produce an implicit conversion sequence to 391/// describe the initialization of f from i, which will be a standard 392/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 393/// 4.1) followed by a floating-integral conversion (C++ 4.9). 394// 395/// Note that this routine only determines how the conversion can be 396/// performed; it does not actually perform the conversion. As such, 397/// it will not produce any diagnostics if no conversion is available, 398/// but will instead return an implicit conversion sequence of kind 399/// "BadConversion". 400/// 401/// If @p SuppressUserConversions, then user-defined conversions are 402/// not permitted. 403/// If @p AllowExplicit, then explicit user-defined conversions are 404/// permitted. 405/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 406/// no matter its actual lvalueness. 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 (CXXRecordDecl *ToRecordDecl 1391 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1392 // C++ [over.match.ctor]p1: 1393 // When objects of class type are direct-initialized (8.5), or 1394 // copy-initialized from an expression of the same or a 1395 // derived class type (8.5), overload resolution selects the 1396 // constructor. [...] For copy-initialization, the candidate 1397 // functions are all the converting constructors (12.3.1) of 1398 // that class. The argument list is the expression-list within 1399 // the parentheses of the initializer. 1400 DeclarationName ConstructorName 1401 = Context.DeclarationNames.getCXXConstructorName( 1402 Context.getCanonicalType(ToType).getUnqualifiedType()); 1403 DeclContext::lookup_iterator Con, ConEnd; 1404 for (llvm::tie(Con, ConEnd) 1405 = ToRecordDecl->lookup(ConstructorName); 1406 Con != ConEnd; ++Con) { 1407 // Find the constructor (which may be a template). 1408 CXXConstructorDecl *Constructor = 0; 1409 FunctionTemplateDecl *ConstructorTmpl 1410 = dyn_cast<FunctionTemplateDecl>(*Con); 1411 if (ConstructorTmpl) 1412 Constructor 1413 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1414 else 1415 Constructor = cast<CXXConstructorDecl>(*Con); 1416 1417 if (!Constructor->isInvalidDecl() && 1418 Constructor->isConvertingConstructor(AllowExplicit)) { 1419 if (ConstructorTmpl) 1420 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1421 1, CandidateSet, 1422 /*SuppressUserConversions=*/!UserCast, 1423 ForceRValue); 1424 else 1425 // Allow one user-defined conversion when user specifies a 1426 // From->ToType conversion via an static cast (c-style, etc). 1427 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1428 /*SuppressUserConversions=*/!UserCast, 1429 ForceRValue); 1430 } 1431 } 1432 } 1433 } 1434 1435 if (!AllowConversionFunctions) { 1436 // Don't allow any conversion functions to enter the overload set. 1437 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1438 PDiag(0) 1439 << From->getSourceRange())) { 1440 // No conversion functions from incomplete types. 1441 } else if (const RecordType *FromRecordType 1442 = From->getType()->getAs<RecordType>()) { 1443 if (CXXRecordDecl *FromRecordDecl 1444 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1445 // Add all of the conversion functions as candidates. 1446 OverloadedFunctionDecl *Conversions 1447 = FromRecordDecl->getVisibleConversionFunctions(); 1448 for (OverloadedFunctionDecl::function_iterator Func 1449 = Conversions->function_begin(); 1450 Func != Conversions->function_end(); ++Func) { 1451 CXXConversionDecl *Conv; 1452 FunctionTemplateDecl *ConvTemplate; 1453 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1454 if (ConvTemplate) 1455 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1456 else 1457 Conv = dyn_cast<CXXConversionDecl>(*Func); 1458 1459 if (AllowExplicit || !Conv->isExplicit()) { 1460 if (ConvTemplate) 1461 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1462 CandidateSet); 1463 else 1464 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1465 } 1466 } 1467 } 1468 } 1469 1470 OverloadCandidateSet::iterator Best; 1471 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1472 case OR_Success: 1473 // Record the standard conversion we used and the conversion function. 1474 if (CXXConstructorDecl *Constructor 1475 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1476 // C++ [over.ics.user]p1: 1477 // If the user-defined conversion is specified by a 1478 // constructor (12.3.1), the initial standard conversion 1479 // sequence converts the source type to the type required by 1480 // the argument of the constructor. 1481 // 1482 // FIXME: What about ellipsis conversions? 1483 QualType ThisType = Constructor->getThisType(Context); 1484 User.Before = Best->Conversions[0].Standard; 1485 User.ConversionFunction = Constructor; 1486 User.After.setAsIdentityConversion(); 1487 User.After.FromTypePtr 1488 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1489 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1490 return OR_Success; 1491 } else if (CXXConversionDecl *Conversion 1492 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1493 // C++ [over.ics.user]p1: 1494 // 1495 // [...] If the user-defined conversion is specified by a 1496 // conversion function (12.3.2), the initial standard 1497 // conversion sequence converts the source type to the 1498 // implicit object parameter of the conversion function. 1499 User.Before = Best->Conversions[0].Standard; 1500 User.ConversionFunction = Conversion; 1501 1502 // C++ [over.ics.user]p2: 1503 // The second standard conversion sequence converts the 1504 // result of the user-defined conversion to the target type 1505 // for the sequence. Since an implicit conversion sequence 1506 // is an initialization, the special rules for 1507 // initialization by user-defined conversion apply when 1508 // selecting the best user-defined conversion for a 1509 // user-defined conversion sequence (see 13.3.3 and 1510 // 13.3.3.1). 1511 User.After = Best->FinalConversion; 1512 return OR_Success; 1513 } else { 1514 assert(false && "Not a constructor or conversion function?"); 1515 return OR_No_Viable_Function; 1516 } 1517 1518 case OR_No_Viable_Function: 1519 return OR_No_Viable_Function; 1520 case OR_Deleted: 1521 // No conversion here! We're done. 1522 return OR_Deleted; 1523 1524 case OR_Ambiguous: 1525 return OR_Ambiguous; 1526 } 1527 1528 return OR_No_Viable_Function; 1529} 1530 1531bool 1532Sema::DiagnoseAmbiguousUserDefinedConversion(Expr *From, QualType ToType) { 1533 ImplicitConversionSequence ICS; 1534 OverloadCandidateSet CandidateSet; 1535 OverloadingResult OvResult = 1536 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1537 CandidateSet, true, false, false); 1538 if (OvResult != OR_Ambiguous) 1539 return false; 1540 Diag(From->getSourceRange().getBegin(), 1541 diag::err_typecheck_ambiguous_condition) 1542 << From->getType() << ToType << From->getSourceRange(); 1543 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1544 return true; 1545} 1546 1547/// CompareImplicitConversionSequences - Compare two implicit 1548/// conversion sequences to determine whether one is better than the 1549/// other or if they are indistinguishable (C++ 13.3.3.2). 1550ImplicitConversionSequence::CompareKind 1551Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1552 const ImplicitConversionSequence& ICS2) 1553{ 1554 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1555 // conversion sequences (as defined in 13.3.3.1) 1556 // -- a standard conversion sequence (13.3.3.1.1) is a better 1557 // conversion sequence than a user-defined conversion sequence or 1558 // an ellipsis conversion sequence, and 1559 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1560 // conversion sequence than an ellipsis conversion sequence 1561 // (13.3.3.1.3). 1562 // 1563 if (ICS1.ConversionKind < ICS2.ConversionKind) 1564 return ImplicitConversionSequence::Better; 1565 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1566 return ImplicitConversionSequence::Worse; 1567 1568 // Two implicit conversion sequences of the same form are 1569 // indistinguishable conversion sequences unless one of the 1570 // following rules apply: (C++ 13.3.3.2p3): 1571 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1572 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1573 else if (ICS1.ConversionKind == 1574 ImplicitConversionSequence::UserDefinedConversion) { 1575 // User-defined conversion sequence U1 is a better conversion 1576 // sequence than another user-defined conversion sequence U2 if 1577 // they contain the same user-defined conversion function or 1578 // constructor and if the second standard conversion sequence of 1579 // U1 is better than the second standard conversion sequence of 1580 // U2 (C++ 13.3.3.2p3). 1581 if (ICS1.UserDefined.ConversionFunction == 1582 ICS2.UserDefined.ConversionFunction) 1583 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1584 ICS2.UserDefined.After); 1585 } 1586 1587 return ImplicitConversionSequence::Indistinguishable; 1588} 1589 1590/// CompareStandardConversionSequences - Compare two standard 1591/// conversion sequences to determine whether one is better than the 1592/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1593ImplicitConversionSequence::CompareKind 1594Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1595 const StandardConversionSequence& SCS2) 1596{ 1597 // Standard conversion sequence S1 is a better conversion sequence 1598 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1599 1600 // -- S1 is a proper subsequence of S2 (comparing the conversion 1601 // sequences in the canonical form defined by 13.3.3.1.1, 1602 // excluding any Lvalue Transformation; the identity conversion 1603 // sequence is considered to be a subsequence of any 1604 // non-identity conversion sequence) or, if not that, 1605 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1606 // Neither is a proper subsequence of the other. Do nothing. 1607 ; 1608 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1609 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1610 (SCS1.Second == ICK_Identity && 1611 SCS1.Third == ICK_Identity)) 1612 // SCS1 is a proper subsequence of SCS2. 1613 return ImplicitConversionSequence::Better; 1614 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1615 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1616 (SCS2.Second == ICK_Identity && 1617 SCS2.Third == ICK_Identity)) 1618 // SCS2 is a proper subsequence of SCS1. 1619 return ImplicitConversionSequence::Worse; 1620 1621 // -- the rank of S1 is better than the rank of S2 (by the rules 1622 // defined below), or, if not that, 1623 ImplicitConversionRank Rank1 = SCS1.getRank(); 1624 ImplicitConversionRank Rank2 = SCS2.getRank(); 1625 if (Rank1 < Rank2) 1626 return ImplicitConversionSequence::Better; 1627 else if (Rank2 < Rank1) 1628 return ImplicitConversionSequence::Worse; 1629 1630 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1631 // are indistinguishable unless one of the following rules 1632 // applies: 1633 1634 // A conversion that is not a conversion of a pointer, or 1635 // pointer to member, to bool is better than another conversion 1636 // that is such a conversion. 1637 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1638 return SCS2.isPointerConversionToBool() 1639 ? ImplicitConversionSequence::Better 1640 : ImplicitConversionSequence::Worse; 1641 1642 // C++ [over.ics.rank]p4b2: 1643 // 1644 // If class B is derived directly or indirectly from class A, 1645 // conversion of B* to A* is better than conversion of B* to 1646 // void*, and conversion of A* to void* is better than conversion 1647 // of B* to void*. 1648 bool SCS1ConvertsToVoid 1649 = SCS1.isPointerConversionToVoidPointer(Context); 1650 bool SCS2ConvertsToVoid 1651 = SCS2.isPointerConversionToVoidPointer(Context); 1652 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1653 // Exactly one of the conversion sequences is a conversion to 1654 // a void pointer; it's the worse conversion. 1655 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1656 : ImplicitConversionSequence::Worse; 1657 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1658 // Neither conversion sequence converts to a void pointer; compare 1659 // their derived-to-base conversions. 1660 if (ImplicitConversionSequence::CompareKind DerivedCK 1661 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1662 return DerivedCK; 1663 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1664 // Both conversion sequences are conversions to void 1665 // pointers. Compare the source types to determine if there's an 1666 // inheritance relationship in their sources. 1667 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1668 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1669 1670 // Adjust the types we're converting from via the array-to-pointer 1671 // conversion, if we need to. 1672 if (SCS1.First == ICK_Array_To_Pointer) 1673 FromType1 = Context.getArrayDecayedType(FromType1); 1674 if (SCS2.First == ICK_Array_To_Pointer) 1675 FromType2 = Context.getArrayDecayedType(FromType2); 1676 1677 QualType FromPointee1 1678 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1679 QualType FromPointee2 1680 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1681 1682 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1683 return ImplicitConversionSequence::Better; 1684 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1685 return ImplicitConversionSequence::Worse; 1686 1687 // Objective-C++: If one interface is more specific than the 1688 // other, it is the better one. 1689 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1690 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1691 if (FromIface1 && FromIface1) { 1692 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1693 return ImplicitConversionSequence::Better; 1694 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1695 return ImplicitConversionSequence::Worse; 1696 } 1697 } 1698 1699 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1700 // bullet 3). 1701 if (ImplicitConversionSequence::CompareKind QualCK 1702 = CompareQualificationConversions(SCS1, SCS2)) 1703 return QualCK; 1704 1705 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1706 // C++0x [over.ics.rank]p3b4: 1707 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1708 // implicit object parameter of a non-static member function declared 1709 // without a ref-qualifier, and S1 binds an rvalue reference to an 1710 // rvalue and S2 binds an lvalue reference. 1711 // FIXME: We don't know if we're dealing with the implicit object parameter, 1712 // or if the member function in this case has a ref qualifier. 1713 // (Of course, we don't have ref qualifiers yet.) 1714 if (SCS1.RRefBinding != SCS2.RRefBinding) 1715 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1716 : ImplicitConversionSequence::Worse; 1717 1718 // C++ [over.ics.rank]p3b4: 1719 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1720 // which the references refer are the same type except for 1721 // top-level cv-qualifiers, and the type to which the reference 1722 // initialized by S2 refers is more cv-qualified than the type 1723 // to which the reference initialized by S1 refers. 1724 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1725 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1726 T1 = Context.getCanonicalType(T1); 1727 T2 = Context.getCanonicalType(T2); 1728 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1729 if (T2.isMoreQualifiedThan(T1)) 1730 return ImplicitConversionSequence::Better; 1731 else if (T1.isMoreQualifiedThan(T2)) 1732 return ImplicitConversionSequence::Worse; 1733 } 1734 } 1735 1736 return ImplicitConversionSequence::Indistinguishable; 1737} 1738 1739/// CompareQualificationConversions - Compares two standard conversion 1740/// sequences to determine whether they can be ranked based on their 1741/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1742ImplicitConversionSequence::CompareKind 1743Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1744 const StandardConversionSequence& SCS2) { 1745 // C++ 13.3.3.2p3: 1746 // -- S1 and S2 differ only in their qualification conversion and 1747 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1748 // cv-qualification signature of type T1 is a proper subset of 1749 // the cv-qualification signature of type T2, and S1 is not the 1750 // deprecated string literal array-to-pointer conversion (4.2). 1751 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1752 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1753 return ImplicitConversionSequence::Indistinguishable; 1754 1755 // FIXME: the example in the standard doesn't use a qualification 1756 // conversion (!) 1757 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1758 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1759 T1 = Context.getCanonicalType(T1); 1760 T2 = Context.getCanonicalType(T2); 1761 1762 // If the types are the same, we won't learn anything by unwrapped 1763 // them. 1764 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1765 return ImplicitConversionSequence::Indistinguishable; 1766 1767 ImplicitConversionSequence::CompareKind Result 1768 = ImplicitConversionSequence::Indistinguishable; 1769 while (UnwrapSimilarPointerTypes(T1, T2)) { 1770 // Within each iteration of the loop, we check the qualifiers to 1771 // determine if this still looks like a qualification 1772 // conversion. Then, if all is well, we unwrap one more level of 1773 // pointers or pointers-to-members and do it all again 1774 // until there are no more pointers or pointers-to-members left 1775 // to unwrap. This essentially mimics what 1776 // IsQualificationConversion does, but here we're checking for a 1777 // strict subset of qualifiers. 1778 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1779 // The qualifiers are the same, so this doesn't tell us anything 1780 // about how the sequences rank. 1781 ; 1782 else if (T2.isMoreQualifiedThan(T1)) { 1783 // T1 has fewer qualifiers, so it could be the better sequence. 1784 if (Result == ImplicitConversionSequence::Worse) 1785 // Neither has qualifiers that are a subset of the other's 1786 // qualifiers. 1787 return ImplicitConversionSequence::Indistinguishable; 1788 1789 Result = ImplicitConversionSequence::Better; 1790 } else if (T1.isMoreQualifiedThan(T2)) { 1791 // T2 has fewer qualifiers, so it could be the better sequence. 1792 if (Result == ImplicitConversionSequence::Better) 1793 // Neither has qualifiers that are a subset of the other's 1794 // qualifiers. 1795 return ImplicitConversionSequence::Indistinguishable; 1796 1797 Result = ImplicitConversionSequence::Worse; 1798 } else { 1799 // Qualifiers are disjoint. 1800 return ImplicitConversionSequence::Indistinguishable; 1801 } 1802 1803 // If the types after this point are equivalent, we're done. 1804 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1805 break; 1806 } 1807 1808 // Check that the winning standard conversion sequence isn't using 1809 // the deprecated string literal array to pointer conversion. 1810 switch (Result) { 1811 case ImplicitConversionSequence::Better: 1812 if (SCS1.Deprecated) 1813 Result = ImplicitConversionSequence::Indistinguishable; 1814 break; 1815 1816 case ImplicitConversionSequence::Indistinguishable: 1817 break; 1818 1819 case ImplicitConversionSequence::Worse: 1820 if (SCS2.Deprecated) 1821 Result = ImplicitConversionSequence::Indistinguishable; 1822 break; 1823 } 1824 1825 return Result; 1826} 1827 1828/// CompareDerivedToBaseConversions - Compares two standard conversion 1829/// sequences to determine whether they can be ranked based on their 1830/// various kinds of derived-to-base conversions (C++ 1831/// [over.ics.rank]p4b3). As part of these checks, we also look at 1832/// conversions between Objective-C interface types. 1833ImplicitConversionSequence::CompareKind 1834Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1835 const StandardConversionSequence& SCS2) { 1836 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1837 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1838 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1839 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1840 1841 // Adjust the types we're converting from via the array-to-pointer 1842 // conversion, if we need to. 1843 if (SCS1.First == ICK_Array_To_Pointer) 1844 FromType1 = Context.getArrayDecayedType(FromType1); 1845 if (SCS2.First == ICK_Array_To_Pointer) 1846 FromType2 = Context.getArrayDecayedType(FromType2); 1847 1848 // Canonicalize all of the types. 1849 FromType1 = Context.getCanonicalType(FromType1); 1850 ToType1 = Context.getCanonicalType(ToType1); 1851 FromType2 = Context.getCanonicalType(FromType2); 1852 ToType2 = Context.getCanonicalType(ToType2); 1853 1854 // C++ [over.ics.rank]p4b3: 1855 // 1856 // If class B is derived directly or indirectly from class A and 1857 // class C is derived directly or indirectly from B, 1858 // 1859 // For Objective-C, we let A, B, and C also be Objective-C 1860 // interfaces. 1861 1862 // Compare based on pointer conversions. 1863 if (SCS1.Second == ICK_Pointer_Conversion && 1864 SCS2.Second == ICK_Pointer_Conversion && 1865 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1866 FromType1->isPointerType() && FromType2->isPointerType() && 1867 ToType1->isPointerType() && ToType2->isPointerType()) { 1868 QualType FromPointee1 1869 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1870 QualType ToPointee1 1871 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1872 QualType FromPointee2 1873 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1874 QualType ToPointee2 1875 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1876 1877 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1878 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1879 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1880 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1881 1882 // -- conversion of C* to B* is better than conversion of C* to A*, 1883 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1884 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1885 return ImplicitConversionSequence::Better; 1886 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1887 return ImplicitConversionSequence::Worse; 1888 1889 if (ToIface1 && ToIface2) { 1890 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1891 return ImplicitConversionSequence::Better; 1892 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1893 return ImplicitConversionSequence::Worse; 1894 } 1895 } 1896 1897 // -- conversion of B* to A* is better than conversion of C* to A*, 1898 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1899 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1900 return ImplicitConversionSequence::Better; 1901 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1902 return ImplicitConversionSequence::Worse; 1903 1904 if (FromIface1 && FromIface2) { 1905 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1906 return ImplicitConversionSequence::Better; 1907 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1908 return ImplicitConversionSequence::Worse; 1909 } 1910 } 1911 } 1912 1913 // Compare based on reference bindings. 1914 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1915 SCS1.Second == ICK_Derived_To_Base) { 1916 // -- binding of an expression of type C to a reference of type 1917 // B& is better than binding an expression of type C to a 1918 // reference of type A&, 1919 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1920 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1921 if (IsDerivedFrom(ToType1, ToType2)) 1922 return ImplicitConversionSequence::Better; 1923 else if (IsDerivedFrom(ToType2, ToType1)) 1924 return ImplicitConversionSequence::Worse; 1925 } 1926 1927 // -- binding of an expression of type B to a reference of type 1928 // A& is better than binding an expression of type C to a 1929 // reference of type A&, 1930 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1931 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1932 if (IsDerivedFrom(FromType2, FromType1)) 1933 return ImplicitConversionSequence::Better; 1934 else if (IsDerivedFrom(FromType1, FromType2)) 1935 return ImplicitConversionSequence::Worse; 1936 } 1937 } 1938 1939 // Ranking of member-pointer types. 1940 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 1941 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 1942 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 1943 const MemberPointerType * FromMemPointer1 = 1944 FromType1->getAs<MemberPointerType>(); 1945 const MemberPointerType * ToMemPointer1 = 1946 ToType1->getAs<MemberPointerType>(); 1947 const MemberPointerType * FromMemPointer2 = 1948 FromType2->getAs<MemberPointerType>(); 1949 const MemberPointerType * ToMemPointer2 = 1950 ToType2->getAs<MemberPointerType>(); 1951 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 1952 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 1953 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 1954 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 1955 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 1956 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 1957 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 1958 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 1959 // conversion of A::* to B::* is better than conversion of A::* to C::*, 1960 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1961 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1962 return ImplicitConversionSequence::Worse; 1963 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1964 return ImplicitConversionSequence::Better; 1965 } 1966 // conversion of B::* to C::* is better than conversion of A::* to C::* 1967 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 1968 if (IsDerivedFrom(FromPointee1, FromPointee2)) 1969 return ImplicitConversionSequence::Better; 1970 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 1971 return ImplicitConversionSequence::Worse; 1972 } 1973 } 1974 1975 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1976 SCS1.Second == ICK_Derived_To_Base) { 1977 // -- conversion of C to B is better than conversion of C to A, 1978 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1979 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1980 if (IsDerivedFrom(ToType1, ToType2)) 1981 return ImplicitConversionSequence::Better; 1982 else if (IsDerivedFrom(ToType2, ToType1)) 1983 return ImplicitConversionSequence::Worse; 1984 } 1985 1986 // -- conversion of B to A is better than conversion of C to A. 1987 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1988 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1989 if (IsDerivedFrom(FromType2, FromType1)) 1990 return ImplicitConversionSequence::Better; 1991 else if (IsDerivedFrom(FromType1, FromType2)) 1992 return ImplicitConversionSequence::Worse; 1993 } 1994 } 1995 1996 return ImplicitConversionSequence::Indistinguishable; 1997} 1998 1999/// TryCopyInitialization - Try to copy-initialize a value of type 2000/// ToType from the expression From. Return the implicit conversion 2001/// sequence required to pass this argument, which may be a bad 2002/// conversion sequence (meaning that the argument cannot be passed to 2003/// a parameter of this type). If @p SuppressUserConversions, then we 2004/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2005/// then we treat @p From as an rvalue, even if it is an lvalue. 2006ImplicitConversionSequence 2007Sema::TryCopyInitialization(Expr *From, QualType ToType, 2008 bool SuppressUserConversions, bool ForceRValue, 2009 bool InOverloadResolution) { 2010 if (ToType->isReferenceType()) { 2011 ImplicitConversionSequence ICS; 2012 CheckReferenceInit(From, ToType, 2013 /*FIXME:*/From->getLocStart(), 2014 SuppressUserConversions, 2015 /*AllowExplicit=*/false, 2016 ForceRValue, 2017 &ICS); 2018 return ICS; 2019 } else { 2020 return TryImplicitConversion(From, ToType, 2021 SuppressUserConversions, 2022 /*AllowExplicit=*/false, 2023 ForceRValue, 2024 InOverloadResolution); 2025 } 2026} 2027 2028/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 2029/// the expression @p From. Returns true (and emits a diagnostic) if there was 2030/// an error, returns false if the initialization succeeded. Elidable should 2031/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2032/// differently in C++0x for this case. 2033bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2034 const char* Flavor, bool Elidable) { 2035 if (!getLangOptions().CPlusPlus) { 2036 // In C, argument passing is the same as performing an assignment. 2037 QualType FromType = From->getType(); 2038 2039 AssignConvertType ConvTy = 2040 CheckSingleAssignmentConstraints(ToType, From); 2041 if (ConvTy != Compatible && 2042 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2043 ConvTy = Compatible; 2044 2045 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2046 FromType, From, Flavor); 2047 } 2048 2049 if (ToType->isReferenceType()) 2050 return CheckReferenceInit(From, ToType, 2051 /*FIXME:*/From->getLocStart(), 2052 /*SuppressUserConversions=*/false, 2053 /*AllowExplicit=*/false, 2054 /*ForceRValue=*/false); 2055 2056 if (!PerformImplicitConversion(From, ToType, Flavor, 2057 /*AllowExplicit=*/false, Elidable)) 2058 return false; 2059 if (!DiagnoseAmbiguousUserDefinedConversion(From, ToType)) 2060 return Diag(From->getSourceRange().getBegin(), 2061 diag::err_typecheck_convert_incompatible) 2062 << ToType << From->getType() << Flavor << From->getSourceRange(); 2063 return true; 2064} 2065 2066/// TryObjectArgumentInitialization - Try to initialize the object 2067/// parameter of the given member function (@c Method) from the 2068/// expression @p From. 2069ImplicitConversionSequence 2070Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2071 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2072 QualType ImplicitParamType 2073 = Context.getCVRQualifiedType(ClassType, Method->getTypeQualifiers()); 2074 2075 // Set up the conversion sequence as a "bad" conversion, to allow us 2076 // to exit early. 2077 ImplicitConversionSequence ICS; 2078 ICS.Standard.setAsIdentityConversion(); 2079 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2080 2081 // We need to have an object of class type. 2082 QualType FromType = From->getType(); 2083 if (const PointerType *PT = FromType->getAs<PointerType>()) 2084 FromType = PT->getPointeeType(); 2085 2086 assert(FromType->isRecordType()); 2087 2088 // The implicit object parmeter is has the type "reference to cv X", 2089 // where X is the class of which the function is a member 2090 // (C++ [over.match.funcs]p4). However, when finding an implicit 2091 // conversion sequence for the argument, we are not allowed to 2092 // create temporaries or perform user-defined conversions 2093 // (C++ [over.match.funcs]p5). We perform a simplified version of 2094 // reference binding here, that allows class rvalues to bind to 2095 // non-constant references. 2096 2097 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2098 // with the implicit object parameter (C++ [over.match.funcs]p5). 2099 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2100 if (ImplicitParamType.getCVRQualifiers() != FromTypeCanon.getCVRQualifiers() && 2101 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) 2102 return ICS; 2103 2104 // Check that we have either the same type or a derived type. It 2105 // affects the conversion rank. 2106 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2107 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2108 ICS.Standard.Second = ICK_Identity; 2109 else if (IsDerivedFrom(FromType, ClassType)) 2110 ICS.Standard.Second = ICK_Derived_To_Base; 2111 else 2112 return ICS; 2113 2114 // Success. Mark this as a reference binding. 2115 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2116 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2117 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2118 ICS.Standard.ReferenceBinding = true; 2119 ICS.Standard.DirectBinding = true; 2120 ICS.Standard.RRefBinding = false; 2121 return ICS; 2122} 2123 2124/// PerformObjectArgumentInitialization - Perform initialization of 2125/// the implicit object parameter for the given Method with the given 2126/// expression. 2127bool 2128Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2129 QualType FromRecordType, DestType; 2130 QualType ImplicitParamRecordType = 2131 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2132 2133 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2134 FromRecordType = PT->getPointeeType(); 2135 DestType = Method->getThisType(Context); 2136 } else { 2137 FromRecordType = From->getType(); 2138 DestType = ImplicitParamRecordType; 2139 } 2140 2141 ImplicitConversionSequence ICS 2142 = TryObjectArgumentInitialization(From, Method); 2143 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2144 return Diag(From->getSourceRange().getBegin(), 2145 diag::err_implicit_object_parameter_init) 2146 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2147 2148 if (ICS.Standard.Second == ICK_Derived_To_Base && 2149 CheckDerivedToBaseConversion(FromRecordType, 2150 ImplicitParamRecordType, 2151 From->getSourceRange().getBegin(), 2152 From->getSourceRange())) 2153 return true; 2154 2155 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2156 /*isLvalue=*/true); 2157 return false; 2158} 2159 2160/// TryContextuallyConvertToBool - Attempt to contextually convert the 2161/// expression From to bool (C++0x [conv]p3). 2162ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2163 return TryImplicitConversion(From, Context.BoolTy, 2164 // FIXME: Are these flags correct? 2165 /*SuppressUserConversions=*/false, 2166 /*AllowExplicit=*/true, 2167 /*ForceRValue=*/false, 2168 /*InOverloadResolution=*/false); 2169} 2170 2171/// PerformContextuallyConvertToBool - Perform a contextual conversion 2172/// of the expression From to bool (C++0x [conv]p3). 2173bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2174 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2175 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2176 return false; 2177 2178 if (!DiagnoseAmbiguousUserDefinedConversion(From, Context.BoolTy)) 2179 return Diag(From->getSourceRange().getBegin(), 2180 diag::err_typecheck_bool_condition) 2181 << From->getType() << From->getSourceRange(); 2182 return true; 2183} 2184 2185/// AddOverloadCandidate - Adds the given function to the set of 2186/// candidate functions, using the given function call arguments. If 2187/// @p SuppressUserConversions, then don't allow user-defined 2188/// conversions via constructors or conversion operators. 2189/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2190/// hacky way to implement the overloading rules for elidable copy 2191/// initialization in C++0x (C++0x 12.8p15). 2192/// 2193/// \para PartialOverloading true if we are performing "partial" overloading 2194/// based on an incomplete set of function arguments. This feature is used by 2195/// code completion. 2196void 2197Sema::AddOverloadCandidate(FunctionDecl *Function, 2198 Expr **Args, unsigned NumArgs, 2199 OverloadCandidateSet& CandidateSet, 2200 bool SuppressUserConversions, 2201 bool ForceRValue, 2202 bool PartialOverloading) { 2203 const FunctionProtoType* Proto 2204 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2205 assert(Proto && "Functions without a prototype cannot be overloaded"); 2206 assert(!isa<CXXConversionDecl>(Function) && 2207 "Use AddConversionCandidate for conversion functions"); 2208 assert(!Function->getDescribedFunctionTemplate() && 2209 "Use AddTemplateOverloadCandidate for function templates"); 2210 2211 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2212 if (!isa<CXXConstructorDecl>(Method)) { 2213 // If we get here, it's because we're calling a member function 2214 // that is named without a member access expression (e.g., 2215 // "this->f") that was either written explicitly or created 2216 // implicitly. This can happen with a qualified call to a member 2217 // function, e.g., X::f(). We use a NULL object as the implied 2218 // object argument (C++ [over.call.func]p3). 2219 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2220 SuppressUserConversions, ForceRValue); 2221 return; 2222 } 2223 // We treat a constructor like a non-member function, since its object 2224 // argument doesn't participate in overload resolution. 2225 } 2226 2227 if (!CandidateSet.isNewCandidate(Function)) 2228 return; 2229 2230 // Add this candidate 2231 CandidateSet.push_back(OverloadCandidate()); 2232 OverloadCandidate& Candidate = CandidateSet.back(); 2233 Candidate.Function = Function; 2234 Candidate.Viable = true; 2235 Candidate.IsSurrogate = false; 2236 Candidate.IgnoreObjectArgument = false; 2237 2238 unsigned NumArgsInProto = Proto->getNumArgs(); 2239 2240 // (C++ 13.3.2p2): A candidate function having fewer than m 2241 // parameters is viable only if it has an ellipsis in its parameter 2242 // list (8.3.5). 2243 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2244 !Proto->isVariadic()) { 2245 Candidate.Viable = false; 2246 return; 2247 } 2248 2249 // (C++ 13.3.2p2): A candidate function having more than m parameters 2250 // is viable only if the (m+1)st parameter has a default argument 2251 // (8.3.6). For the purposes of overload resolution, the 2252 // parameter list is truncated on the right, so that there are 2253 // exactly m parameters. 2254 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2255 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2256 // Not enough arguments. 2257 Candidate.Viable = false; 2258 return; 2259 } 2260 2261 // Determine the implicit conversion sequences for each of the 2262 // arguments. 2263 Candidate.Conversions.resize(NumArgs); 2264 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2265 if (ArgIdx < NumArgsInProto) { 2266 // (C++ 13.3.2p3): for F to be a viable function, there shall 2267 // exist for each argument an implicit conversion sequence 2268 // (13.3.3.1) that converts that argument to the corresponding 2269 // parameter of F. 2270 QualType ParamType = Proto->getArgType(ArgIdx); 2271 Candidate.Conversions[ArgIdx] 2272 = TryCopyInitialization(Args[ArgIdx], ParamType, 2273 SuppressUserConversions, ForceRValue, 2274 /*InOverloadResolution=*/true); 2275 if (Candidate.Conversions[ArgIdx].ConversionKind 2276 == ImplicitConversionSequence::BadConversion) { 2277 // 13.3.3.1-p10 If several different sequences of conversions exist that 2278 // each convert the argument to the parameter type, the implicit conversion 2279 // sequence associated with the parameter is defined to be the unique conversion 2280 // sequence designated the ambiguous conversion sequence. For the purpose of 2281 // ranking implicit conversion sequences as described in 13.3.3.2, the ambiguous 2282 // conversion sequence is treated as a user-defined sequence that is 2283 // indistinguishable from any other user-defined conversion sequence 2284 if (!Candidate.Conversions[ArgIdx].ConversionFunctionSet.empty()) { 2285 Candidate.Conversions[ArgIdx].ConversionKind = 2286 ImplicitConversionSequence::UserDefinedConversion; 2287 // Set the conversion function to one of them. As due to ambiguity, 2288 // they carry the same weight and is needed for overload resolution 2289 // later. 2290 Candidate.Conversions[ArgIdx].UserDefined.ConversionFunction = 2291 Candidate.Conversions[ArgIdx].ConversionFunctionSet[0]; 2292 } 2293 else { 2294 Candidate.Viable = false; 2295 break; 2296 } 2297 } 2298 } else { 2299 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2300 // argument for which there is no corresponding parameter is 2301 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2302 Candidate.Conversions[ArgIdx].ConversionKind 2303 = ImplicitConversionSequence::EllipsisConversion; 2304 } 2305 } 2306} 2307 2308/// \brief Add all of the function declarations in the given function set to 2309/// the overload canddiate set. 2310void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2311 Expr **Args, unsigned NumArgs, 2312 OverloadCandidateSet& CandidateSet, 2313 bool SuppressUserConversions) { 2314 for (FunctionSet::const_iterator F = Functions.begin(), 2315 FEnd = Functions.end(); 2316 F != FEnd; ++F) { 2317 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2318 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2319 AddMethodCandidate(cast<CXXMethodDecl>(FD), 2320 Args[0], Args + 1, NumArgs - 1, 2321 CandidateSet, SuppressUserConversions); 2322 else 2323 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2324 SuppressUserConversions); 2325 } else { 2326 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2327 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2328 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2329 AddMethodTemplateCandidate(FunTmpl, 2330 /*FIXME: explicit args */false, 0, 0, 2331 Args[0], Args + 1, NumArgs - 1, 2332 CandidateSet, 2333 SuppressUserConversions); 2334 else 2335 AddTemplateOverloadCandidate(FunTmpl, 2336 /*FIXME: explicit args */false, 0, 0, 2337 Args, NumArgs, CandidateSet, 2338 SuppressUserConversions); 2339 } 2340 } 2341} 2342 2343/// AddMethodCandidate - Adds the given C++ member function to the set 2344/// of candidate functions, using the given function call arguments 2345/// and the object argument (@c Object). For example, in a call 2346/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2347/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2348/// allow user-defined conversions via constructors or conversion 2349/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2350/// a slightly hacky way to implement the overloading rules for elidable copy 2351/// initialization in C++0x (C++0x 12.8p15). 2352void 2353Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2354 Expr **Args, unsigned NumArgs, 2355 OverloadCandidateSet& CandidateSet, 2356 bool SuppressUserConversions, bool ForceRValue) { 2357 const FunctionProtoType* Proto 2358 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2359 assert(Proto && "Methods without a prototype cannot be overloaded"); 2360 assert(!isa<CXXConversionDecl>(Method) && 2361 "Use AddConversionCandidate for conversion functions"); 2362 assert(!isa<CXXConstructorDecl>(Method) && 2363 "Use AddOverloadCandidate for constructors"); 2364 2365 if (!CandidateSet.isNewCandidate(Method)) 2366 return; 2367 2368 // Add this candidate 2369 CandidateSet.push_back(OverloadCandidate()); 2370 OverloadCandidate& Candidate = CandidateSet.back(); 2371 Candidate.Function = Method; 2372 Candidate.IsSurrogate = false; 2373 Candidate.IgnoreObjectArgument = false; 2374 2375 unsigned NumArgsInProto = Proto->getNumArgs(); 2376 2377 // (C++ 13.3.2p2): A candidate function having fewer than m 2378 // parameters is viable only if it has an ellipsis in its parameter 2379 // list (8.3.5). 2380 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2381 Candidate.Viable = false; 2382 return; 2383 } 2384 2385 // (C++ 13.3.2p2): A candidate function having more than m parameters 2386 // is viable only if the (m+1)st parameter has a default argument 2387 // (8.3.6). For the purposes of overload resolution, the 2388 // parameter list is truncated on the right, so that there are 2389 // exactly m parameters. 2390 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2391 if (NumArgs < MinRequiredArgs) { 2392 // Not enough arguments. 2393 Candidate.Viable = false; 2394 return; 2395 } 2396 2397 Candidate.Viable = true; 2398 Candidate.Conversions.resize(NumArgs + 1); 2399 2400 if (Method->isStatic() || !Object) 2401 // The implicit object argument is ignored. 2402 Candidate.IgnoreObjectArgument = true; 2403 else { 2404 // Determine the implicit conversion sequence for the object 2405 // parameter. 2406 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2407 if (Candidate.Conversions[0].ConversionKind 2408 == ImplicitConversionSequence::BadConversion) { 2409 Candidate.Viable = false; 2410 return; 2411 } 2412 } 2413 2414 // Determine the implicit conversion sequences for each of the 2415 // arguments. 2416 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2417 if (ArgIdx < NumArgsInProto) { 2418 // (C++ 13.3.2p3): for F to be a viable function, there shall 2419 // exist for each argument an implicit conversion sequence 2420 // (13.3.3.1) that converts that argument to the corresponding 2421 // parameter of F. 2422 QualType ParamType = Proto->getArgType(ArgIdx); 2423 Candidate.Conversions[ArgIdx + 1] 2424 = TryCopyInitialization(Args[ArgIdx], ParamType, 2425 SuppressUserConversions, ForceRValue, 2426 /*InOverloadResolution=*/true); 2427 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2428 == ImplicitConversionSequence::BadConversion) { 2429 Candidate.Viable = false; 2430 break; 2431 } 2432 } else { 2433 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2434 // argument for which there is no corresponding parameter is 2435 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2436 Candidate.Conversions[ArgIdx + 1].ConversionKind 2437 = ImplicitConversionSequence::EllipsisConversion; 2438 } 2439 } 2440} 2441 2442/// \brief Add a C++ member function template as a candidate to the candidate 2443/// set, using template argument deduction to produce an appropriate member 2444/// function template specialization. 2445void 2446Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2447 bool HasExplicitTemplateArgs, 2448 const TemplateArgumentLoc *ExplicitTemplateArgs, 2449 unsigned NumExplicitTemplateArgs, 2450 Expr *Object, Expr **Args, unsigned NumArgs, 2451 OverloadCandidateSet& CandidateSet, 2452 bool SuppressUserConversions, 2453 bool ForceRValue) { 2454 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2455 return; 2456 2457 // C++ [over.match.funcs]p7: 2458 // In each case where a candidate is a function template, candidate 2459 // function template specializations are generated using template argument 2460 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2461 // candidate functions in the usual way.113) A given name can refer to one 2462 // or more function templates and also to a set of overloaded non-template 2463 // functions. In such a case, the candidate functions generated from each 2464 // function template are combined with the set of non-template candidate 2465 // functions. 2466 TemplateDeductionInfo Info(Context); 2467 FunctionDecl *Specialization = 0; 2468 if (TemplateDeductionResult Result 2469 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2470 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2471 Args, NumArgs, Specialization, Info)) { 2472 // FIXME: Record what happened with template argument deduction, so 2473 // that we can give the user a beautiful diagnostic. 2474 (void)Result; 2475 return; 2476 } 2477 2478 // Add the function template specialization produced by template argument 2479 // deduction as a candidate. 2480 assert(Specialization && "Missing member function template specialization?"); 2481 assert(isa<CXXMethodDecl>(Specialization) && 2482 "Specialization is not a member function?"); 2483 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2484 CandidateSet, SuppressUserConversions, ForceRValue); 2485} 2486 2487/// \brief Add a C++ function template specialization as a candidate 2488/// in the candidate set, using template argument deduction to produce 2489/// an appropriate function template specialization. 2490void 2491Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2492 bool HasExplicitTemplateArgs, 2493 const TemplateArgumentLoc *ExplicitTemplateArgs, 2494 unsigned NumExplicitTemplateArgs, 2495 Expr **Args, unsigned NumArgs, 2496 OverloadCandidateSet& CandidateSet, 2497 bool SuppressUserConversions, 2498 bool ForceRValue) { 2499 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2500 return; 2501 2502 // C++ [over.match.funcs]p7: 2503 // In each case where a candidate is a function template, candidate 2504 // function template specializations are generated using template argument 2505 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2506 // candidate functions in the usual way.113) A given name can refer to one 2507 // or more function templates and also to a set of overloaded non-template 2508 // functions. In such a case, the candidate functions generated from each 2509 // function template are combined with the set of non-template candidate 2510 // functions. 2511 TemplateDeductionInfo Info(Context); 2512 FunctionDecl *Specialization = 0; 2513 if (TemplateDeductionResult Result 2514 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2515 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2516 Args, NumArgs, Specialization, Info)) { 2517 // FIXME: Record what happened with template argument deduction, so 2518 // that we can give the user a beautiful diagnostic. 2519 (void)Result; 2520 return; 2521 } 2522 2523 // Add the function template specialization produced by template argument 2524 // deduction as a candidate. 2525 assert(Specialization && "Missing function template specialization?"); 2526 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2527 SuppressUserConversions, ForceRValue); 2528} 2529 2530/// AddConversionCandidate - Add a C++ conversion function as a 2531/// candidate in the candidate set (C++ [over.match.conv], 2532/// C++ [over.match.copy]). From is the expression we're converting from, 2533/// and ToType is the type that we're eventually trying to convert to 2534/// (which may or may not be the same type as the type that the 2535/// conversion function produces). 2536void 2537Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2538 Expr *From, QualType ToType, 2539 OverloadCandidateSet& CandidateSet) { 2540 assert(!Conversion->getDescribedFunctionTemplate() && 2541 "Conversion function templates use AddTemplateConversionCandidate"); 2542 2543 if (!CandidateSet.isNewCandidate(Conversion)) 2544 return; 2545 2546 // Add this candidate 2547 CandidateSet.push_back(OverloadCandidate()); 2548 OverloadCandidate& Candidate = CandidateSet.back(); 2549 Candidate.Function = Conversion; 2550 Candidate.IsSurrogate = false; 2551 Candidate.IgnoreObjectArgument = false; 2552 Candidate.FinalConversion.setAsIdentityConversion(); 2553 Candidate.FinalConversion.FromTypePtr 2554 = Conversion->getConversionType().getAsOpaquePtr(); 2555 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2556 2557 // Determine the implicit conversion sequence for the implicit 2558 // object parameter. 2559 Candidate.Viable = true; 2560 Candidate.Conversions.resize(1); 2561 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2562 // Conversion functions to a different type in the base class is visible in 2563 // the derived class. So, a derived to base conversion should not participate 2564 // in overload resolution. 2565 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2566 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2567 if (Candidate.Conversions[0].ConversionKind 2568 == ImplicitConversionSequence::BadConversion) { 2569 Candidate.Viable = false; 2570 return; 2571 } 2572 2573 // We won't go through a user-define type conversion function to convert a 2574 // derived to base as such conversions are given Conversion Rank. They only 2575 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2576 QualType FromCanon 2577 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2578 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2579 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2580 Candidate.Viable = false; 2581 return; 2582 } 2583 2584 2585 // To determine what the conversion from the result of calling the 2586 // conversion function to the type we're eventually trying to 2587 // convert to (ToType), we need to synthesize a call to the 2588 // conversion function and attempt copy initialization from it. This 2589 // makes sure that we get the right semantics with respect to 2590 // lvalues/rvalues and the type. Fortunately, we can allocate this 2591 // call on the stack and we don't need its arguments to be 2592 // well-formed. 2593 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2594 SourceLocation()); 2595 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2596 CastExpr::CK_FunctionToPointerDecay, 2597 &ConversionRef, false); 2598 2599 // Note that it is safe to allocate CallExpr on the stack here because 2600 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2601 // allocator). 2602 CallExpr Call(Context, &ConversionFn, 0, 0, 2603 Conversion->getConversionType().getNonReferenceType(), 2604 SourceLocation()); 2605 ImplicitConversionSequence ICS = 2606 TryCopyInitialization(&Call, ToType, 2607 /*SuppressUserConversions=*/true, 2608 /*ForceRValue=*/false, 2609 /*InOverloadResolution=*/false); 2610 2611 switch (ICS.ConversionKind) { 2612 case ImplicitConversionSequence::StandardConversion: 2613 Candidate.FinalConversion = ICS.Standard; 2614 break; 2615 2616 case ImplicitConversionSequence::BadConversion: 2617 Candidate.Viable = false; 2618 break; 2619 2620 default: 2621 assert(false && 2622 "Can only end up with a standard conversion sequence or failure"); 2623 } 2624} 2625 2626/// \brief Adds a conversion function template specialization 2627/// candidate to the overload set, using template argument deduction 2628/// to deduce the template arguments of the conversion function 2629/// template from the type that we are converting to (C++ 2630/// [temp.deduct.conv]). 2631void 2632Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2633 Expr *From, QualType ToType, 2634 OverloadCandidateSet &CandidateSet) { 2635 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2636 "Only conversion function templates permitted here"); 2637 2638 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2639 return; 2640 2641 TemplateDeductionInfo Info(Context); 2642 CXXConversionDecl *Specialization = 0; 2643 if (TemplateDeductionResult Result 2644 = DeduceTemplateArguments(FunctionTemplate, ToType, 2645 Specialization, Info)) { 2646 // FIXME: Record what happened with template argument deduction, so 2647 // that we can give the user a beautiful diagnostic. 2648 (void)Result; 2649 return; 2650 } 2651 2652 // Add the conversion function template specialization produced by 2653 // template argument deduction as a candidate. 2654 assert(Specialization && "Missing function template specialization?"); 2655 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2656} 2657 2658/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2659/// converts the given @c Object to a function pointer via the 2660/// conversion function @c Conversion, and then attempts to call it 2661/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2662/// the type of function that we'll eventually be calling. 2663void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2664 const FunctionProtoType *Proto, 2665 Expr *Object, Expr **Args, unsigned NumArgs, 2666 OverloadCandidateSet& CandidateSet) { 2667 if (!CandidateSet.isNewCandidate(Conversion)) 2668 return; 2669 2670 CandidateSet.push_back(OverloadCandidate()); 2671 OverloadCandidate& Candidate = CandidateSet.back(); 2672 Candidate.Function = 0; 2673 Candidate.Surrogate = Conversion; 2674 Candidate.Viable = true; 2675 Candidate.IsSurrogate = true; 2676 Candidate.IgnoreObjectArgument = false; 2677 Candidate.Conversions.resize(NumArgs + 1); 2678 2679 // Determine the implicit conversion sequence for the implicit 2680 // object parameter. 2681 ImplicitConversionSequence ObjectInit 2682 = TryObjectArgumentInitialization(Object, Conversion); 2683 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2684 Candidate.Viable = false; 2685 return; 2686 } 2687 2688 // The first conversion is actually a user-defined conversion whose 2689 // first conversion is ObjectInit's standard conversion (which is 2690 // effectively a reference binding). Record it as such. 2691 Candidate.Conversions[0].ConversionKind 2692 = ImplicitConversionSequence::UserDefinedConversion; 2693 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2694 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2695 Candidate.Conversions[0].UserDefined.After 2696 = Candidate.Conversions[0].UserDefined.Before; 2697 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2698 2699 // Find the 2700 unsigned NumArgsInProto = Proto->getNumArgs(); 2701 2702 // (C++ 13.3.2p2): A candidate function having fewer than m 2703 // parameters is viable only if it has an ellipsis in its parameter 2704 // list (8.3.5). 2705 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2706 Candidate.Viable = false; 2707 return; 2708 } 2709 2710 // Function types don't have any default arguments, so just check if 2711 // we have enough arguments. 2712 if (NumArgs < NumArgsInProto) { 2713 // Not enough arguments. 2714 Candidate.Viable = false; 2715 return; 2716 } 2717 2718 // Determine the implicit conversion sequences for each of the 2719 // arguments. 2720 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2721 if (ArgIdx < NumArgsInProto) { 2722 // (C++ 13.3.2p3): for F to be a viable function, there shall 2723 // exist for each argument an implicit conversion sequence 2724 // (13.3.3.1) that converts that argument to the corresponding 2725 // parameter of F. 2726 QualType ParamType = Proto->getArgType(ArgIdx); 2727 Candidate.Conversions[ArgIdx + 1] 2728 = TryCopyInitialization(Args[ArgIdx], ParamType, 2729 /*SuppressUserConversions=*/false, 2730 /*ForceRValue=*/false, 2731 /*InOverloadResolution=*/false); 2732 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2733 == ImplicitConversionSequence::BadConversion) { 2734 Candidate.Viable = false; 2735 break; 2736 } 2737 } else { 2738 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2739 // argument for which there is no corresponding parameter is 2740 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2741 Candidate.Conversions[ArgIdx + 1].ConversionKind 2742 = ImplicitConversionSequence::EllipsisConversion; 2743 } 2744 } 2745} 2746 2747// FIXME: This will eventually be removed, once we've migrated all of the 2748// operator overloading logic over to the scheme used by binary operators, which 2749// works for template instantiation. 2750void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2751 SourceLocation OpLoc, 2752 Expr **Args, unsigned NumArgs, 2753 OverloadCandidateSet& CandidateSet, 2754 SourceRange OpRange) { 2755 FunctionSet Functions; 2756 2757 QualType T1 = Args[0]->getType(); 2758 QualType T2; 2759 if (NumArgs > 1) 2760 T2 = Args[1]->getType(); 2761 2762 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2763 if (S) 2764 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2765 ArgumentDependentLookup(OpName, /*Operator*/true, Args, NumArgs, Functions); 2766 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2767 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2768 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 2769} 2770 2771/// \brief Add overload candidates for overloaded operators that are 2772/// member functions. 2773/// 2774/// Add the overloaded operator candidates that are member functions 2775/// for the operator Op that was used in an operator expression such 2776/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2777/// CandidateSet will store the added overload candidates. (C++ 2778/// [over.match.oper]). 2779void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2780 SourceLocation OpLoc, 2781 Expr **Args, unsigned NumArgs, 2782 OverloadCandidateSet& CandidateSet, 2783 SourceRange OpRange) { 2784 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2785 2786 // C++ [over.match.oper]p3: 2787 // For a unary operator @ with an operand of a type whose 2788 // cv-unqualified version is T1, and for a binary operator @ with 2789 // a left operand of a type whose cv-unqualified version is T1 and 2790 // a right operand of a type whose cv-unqualified version is T2, 2791 // three sets of candidate functions, designated member 2792 // candidates, non-member candidates and built-in candidates, are 2793 // constructed as follows: 2794 QualType T1 = Args[0]->getType(); 2795 QualType T2; 2796 if (NumArgs > 1) 2797 T2 = Args[1]->getType(); 2798 2799 // -- If T1 is a class type, the set of member candidates is the 2800 // result of the qualified lookup of T1::operator@ 2801 // (13.3.1.1.1); otherwise, the set of member candidates is 2802 // empty. 2803 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2804 // Complete the type if it can be completed. Otherwise, we're done. 2805 if (RequireCompleteType(OpLoc, T1, PDiag())) 2806 return; 2807 2808 LookupResult Operators; 2809 LookupQualifiedName(Operators, T1Rec->getDecl(), OpName, 2810 LookupOrdinaryName, false); 2811 for (LookupResult::iterator Oper = Operators.begin(), 2812 OperEnd = Operators.end(); 2813 Oper != OperEnd; 2814 ++Oper) { 2815 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Oper)) { 2816 AddMethodCandidate(Method, Args[0], Args+1, NumArgs - 1, CandidateSet, 2817 /*SuppressUserConversions=*/false); 2818 continue; 2819 } 2820 2821 assert(isa<FunctionTemplateDecl>(*Oper) && 2822 isa<CXXMethodDecl>(cast<FunctionTemplateDecl>(*Oper) 2823 ->getTemplatedDecl()) && 2824 "Expected a member function template"); 2825 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Oper), false, 0, 0, 2826 Args[0], Args+1, NumArgs - 1, CandidateSet, 2827 /*SuppressUserConversions=*/false); 2828 } 2829 } 2830} 2831 2832/// AddBuiltinCandidate - Add a candidate for a built-in 2833/// operator. ResultTy and ParamTys are the result and parameter types 2834/// of the built-in candidate, respectively. Args and NumArgs are the 2835/// arguments being passed to the candidate. IsAssignmentOperator 2836/// should be true when this built-in candidate is an assignment 2837/// operator. NumContextualBoolArguments is the number of arguments 2838/// (at the beginning of the argument list) that will be contextually 2839/// converted to bool. 2840void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2841 Expr **Args, unsigned NumArgs, 2842 OverloadCandidateSet& CandidateSet, 2843 bool IsAssignmentOperator, 2844 unsigned NumContextualBoolArguments) { 2845 // Add this candidate 2846 CandidateSet.push_back(OverloadCandidate()); 2847 OverloadCandidate& Candidate = CandidateSet.back(); 2848 Candidate.Function = 0; 2849 Candidate.IsSurrogate = false; 2850 Candidate.IgnoreObjectArgument = false; 2851 Candidate.BuiltinTypes.ResultTy = ResultTy; 2852 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2853 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2854 2855 // Determine the implicit conversion sequences for each of the 2856 // arguments. 2857 Candidate.Viable = true; 2858 Candidate.Conversions.resize(NumArgs); 2859 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2860 // C++ [over.match.oper]p4: 2861 // For the built-in assignment operators, conversions of the 2862 // left operand are restricted as follows: 2863 // -- no temporaries are introduced to hold the left operand, and 2864 // -- no user-defined conversions are applied to the left 2865 // operand to achieve a type match with the left-most 2866 // parameter of a built-in candidate. 2867 // 2868 // We block these conversions by turning off user-defined 2869 // conversions, since that is the only way that initialization of 2870 // a reference to a non-class type can occur from something that 2871 // is not of the same type. 2872 if (ArgIdx < NumContextualBoolArguments) { 2873 assert(ParamTys[ArgIdx] == Context.BoolTy && 2874 "Contextual conversion to bool requires bool type"); 2875 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2876 } else { 2877 Candidate.Conversions[ArgIdx] 2878 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2879 ArgIdx == 0 && IsAssignmentOperator, 2880 /*ForceRValue=*/false, 2881 /*InOverloadResolution=*/false); 2882 } 2883 if (Candidate.Conversions[ArgIdx].ConversionKind 2884 == ImplicitConversionSequence::BadConversion) { 2885 Candidate.Viable = false; 2886 break; 2887 } 2888 } 2889} 2890 2891/// BuiltinCandidateTypeSet - A set of types that will be used for the 2892/// candidate operator functions for built-in operators (C++ 2893/// [over.built]). The types are separated into pointer types and 2894/// enumeration types. 2895class BuiltinCandidateTypeSet { 2896 /// TypeSet - A set of types. 2897 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2898 2899 /// PointerTypes - The set of pointer types that will be used in the 2900 /// built-in candidates. 2901 TypeSet PointerTypes; 2902 2903 /// MemberPointerTypes - The set of member pointer types that will be 2904 /// used in the built-in candidates. 2905 TypeSet MemberPointerTypes; 2906 2907 /// EnumerationTypes - The set of enumeration types that will be 2908 /// used in the built-in candidates. 2909 TypeSet EnumerationTypes; 2910 2911 /// Sema - The semantic analysis instance where we are building the 2912 /// candidate type set. 2913 Sema &SemaRef; 2914 2915 /// Context - The AST context in which we will build the type sets. 2916 ASTContext &Context; 2917 2918 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 2919 const Qualifiers &VisibleQuals); 2920 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2921 2922public: 2923 /// iterator - Iterates through the types that are part of the set. 2924 typedef TypeSet::iterator iterator; 2925 2926 BuiltinCandidateTypeSet(Sema &SemaRef) 2927 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2928 2929 void AddTypesConvertedFrom(QualType Ty, 2930 SourceLocation Loc, 2931 bool AllowUserConversions, 2932 bool AllowExplicitConversions, 2933 const Qualifiers &VisibleTypeConversionsQuals); 2934 2935 /// pointer_begin - First pointer type found; 2936 iterator pointer_begin() { return PointerTypes.begin(); } 2937 2938 /// pointer_end - Past the last pointer type found; 2939 iterator pointer_end() { return PointerTypes.end(); } 2940 2941 /// member_pointer_begin - First member pointer type found; 2942 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2943 2944 /// member_pointer_end - Past the last member pointer type found; 2945 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2946 2947 /// enumeration_begin - First enumeration type found; 2948 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2949 2950 /// enumeration_end - Past the last enumeration type found; 2951 iterator enumeration_end() { return EnumerationTypes.end(); } 2952}; 2953 2954/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2955/// the set of pointer types along with any more-qualified variants of 2956/// that type. For example, if @p Ty is "int const *", this routine 2957/// will add "int const *", "int const volatile *", "int const 2958/// restrict *", and "int const volatile restrict *" to the set of 2959/// pointer types. Returns true if the add of @p Ty itself succeeded, 2960/// false otherwise. 2961/// 2962/// FIXME: what to do about extended qualifiers? 2963bool 2964BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 2965 const Qualifiers &VisibleQuals) { 2966 2967 // Insert this type. 2968 if (!PointerTypes.insert(Ty)) 2969 return false; 2970 2971 const PointerType *PointerTy = Ty->getAs<PointerType>(); 2972 assert(PointerTy && "type was not a pointer type!"); 2973 2974 QualType PointeeTy = PointerTy->getPointeeType(); 2975 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2976 bool hasVolatile = VisibleQuals.hasVolatile(); 2977 bool hasRestrict = VisibleQuals.hasRestrict(); 2978 2979 // Iterate through all strict supersets of BaseCVR. 2980 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2981 if ((CVR | BaseCVR) != CVR) continue; 2982 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 2983 // in the types. 2984 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 2985 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 2986 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2987 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 2988 } 2989 2990 return true; 2991} 2992 2993/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2994/// to the set of pointer types along with any more-qualified variants of 2995/// that type. For example, if @p Ty is "int const *", this routine 2996/// will add "int const *", "int const volatile *", "int const 2997/// restrict *", and "int const volatile restrict *" to the set of 2998/// pointer types. Returns true if the add of @p Ty itself succeeded, 2999/// false otherwise. 3000/// 3001/// FIXME: what to do about extended qualifiers? 3002bool 3003BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3004 QualType Ty) { 3005 // Insert this type. 3006 if (!MemberPointerTypes.insert(Ty)) 3007 return false; 3008 3009 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3010 assert(PointerTy && "type was not a member pointer type!"); 3011 3012 QualType PointeeTy = PointerTy->getPointeeType(); 3013 const Type *ClassTy = PointerTy->getClass(); 3014 3015 // Iterate through all strict supersets of the pointee type's CVR 3016 // qualifiers. 3017 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3018 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3019 if ((CVR | BaseCVR) != CVR) continue; 3020 3021 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3022 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3023 } 3024 3025 return true; 3026} 3027 3028/// AddTypesConvertedFrom - Add each of the types to which the type @p 3029/// Ty can be implicit converted to the given set of @p Types. We're 3030/// primarily interested in pointer types and enumeration types. We also 3031/// take member pointer types, for the conditional operator. 3032/// AllowUserConversions is true if we should look at the conversion 3033/// functions of a class type, and AllowExplicitConversions if we 3034/// should also include the explicit conversion functions of a class 3035/// type. 3036void 3037BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3038 SourceLocation Loc, 3039 bool AllowUserConversions, 3040 bool AllowExplicitConversions, 3041 const Qualifiers &VisibleQuals) { 3042 // Only deal with canonical types. 3043 Ty = Context.getCanonicalType(Ty); 3044 3045 // Look through reference types; they aren't part of the type of an 3046 // expression for the purposes of conversions. 3047 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3048 Ty = RefTy->getPointeeType(); 3049 3050 // We don't care about qualifiers on the type. 3051 Ty = Ty.getUnqualifiedType(); 3052 3053 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3054 QualType PointeeTy = PointerTy->getPointeeType(); 3055 3056 // Insert our type, and its more-qualified variants, into the set 3057 // of types. 3058 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3059 return; 3060 } else if (Ty->isMemberPointerType()) { 3061 // Member pointers are far easier, since the pointee can't be converted. 3062 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3063 return; 3064 } else if (Ty->isEnumeralType()) { 3065 EnumerationTypes.insert(Ty); 3066 } else if (AllowUserConversions) { 3067 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3068 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3069 // No conversion functions in incomplete types. 3070 return; 3071 } 3072 3073 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3074 OverloadedFunctionDecl *Conversions 3075 = ClassDecl->getVisibleConversionFunctions(); 3076 for (OverloadedFunctionDecl::function_iterator Func 3077 = Conversions->function_begin(); 3078 Func != Conversions->function_end(); ++Func) { 3079 CXXConversionDecl *Conv; 3080 FunctionTemplateDecl *ConvTemplate; 3081 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 3082 3083 // Skip conversion function templates; they don't tell us anything 3084 // about which builtin types we can convert to. 3085 if (ConvTemplate) 3086 continue; 3087 3088 if (AllowExplicitConversions || !Conv->isExplicit()) { 3089 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3090 VisibleQuals); 3091 } 3092 } 3093 } 3094 } 3095} 3096 3097/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3098/// the volatile- and non-volatile-qualified assignment operators for the 3099/// given type to the candidate set. 3100static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3101 QualType T, 3102 Expr **Args, 3103 unsigned NumArgs, 3104 OverloadCandidateSet &CandidateSet) { 3105 QualType ParamTypes[2]; 3106 3107 // T& operator=(T&, T) 3108 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3109 ParamTypes[1] = T; 3110 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3111 /*IsAssignmentOperator=*/true); 3112 3113 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3114 // volatile T& operator=(volatile T&, T) 3115 ParamTypes[0] 3116 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3117 ParamTypes[1] = T; 3118 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3119 /*IsAssignmentOperator=*/true); 3120 } 3121} 3122 3123/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3124/// if any, found in visible type conversion functions found in ArgExpr's type. 3125static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3126 Qualifiers VRQuals; 3127 const RecordType *TyRec; 3128 if (const MemberPointerType *RHSMPType = 3129 ArgExpr->getType()->getAs<MemberPointerType>()) 3130 TyRec = cast<RecordType>(RHSMPType->getClass()); 3131 else 3132 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3133 if (!TyRec) { 3134 // Just to be safe, assume the worst case. 3135 VRQuals.addVolatile(); 3136 VRQuals.addRestrict(); 3137 return VRQuals; 3138 } 3139 3140 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3141 OverloadedFunctionDecl *Conversions = 3142 ClassDecl->getVisibleConversionFunctions(); 3143 3144 for (OverloadedFunctionDecl::function_iterator Func 3145 = Conversions->function_begin(); 3146 Func != Conversions->function_end(); ++Func) { 3147 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*Func)) { 3148 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3149 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3150 CanTy = ResTypeRef->getPointeeType(); 3151 // Need to go down the pointer/mempointer chain and add qualifiers 3152 // as see them. 3153 bool done = false; 3154 while (!done) { 3155 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3156 CanTy = ResTypePtr->getPointeeType(); 3157 else if (const MemberPointerType *ResTypeMPtr = 3158 CanTy->getAs<MemberPointerType>()) 3159 CanTy = ResTypeMPtr->getPointeeType(); 3160 else 3161 done = true; 3162 if (CanTy.isVolatileQualified()) 3163 VRQuals.addVolatile(); 3164 if (CanTy.isRestrictQualified()) 3165 VRQuals.addRestrict(); 3166 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3167 return VRQuals; 3168 } 3169 } 3170 } 3171 return VRQuals; 3172} 3173 3174/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3175/// operator overloads to the candidate set (C++ [over.built]), based 3176/// on the operator @p Op and the arguments given. For example, if the 3177/// operator is a binary '+', this routine might add "int 3178/// operator+(int, int)" to cover integer addition. 3179void 3180Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3181 SourceLocation OpLoc, 3182 Expr **Args, unsigned NumArgs, 3183 OverloadCandidateSet& CandidateSet) { 3184 // The set of "promoted arithmetic types", which are the arithmetic 3185 // types are that preserved by promotion (C++ [over.built]p2). Note 3186 // that the first few of these types are the promoted integral 3187 // types; these types need to be first. 3188 // FIXME: What about complex? 3189 const unsigned FirstIntegralType = 0; 3190 const unsigned LastIntegralType = 13; 3191 const unsigned FirstPromotedIntegralType = 7, 3192 LastPromotedIntegralType = 13; 3193 const unsigned FirstPromotedArithmeticType = 7, 3194 LastPromotedArithmeticType = 16; 3195 const unsigned NumArithmeticTypes = 16; 3196 QualType ArithmeticTypes[NumArithmeticTypes] = { 3197 Context.BoolTy, Context.CharTy, Context.WCharTy, 3198// FIXME: Context.Char16Ty, Context.Char32Ty, 3199 Context.SignedCharTy, Context.ShortTy, 3200 Context.UnsignedCharTy, Context.UnsignedShortTy, 3201 Context.IntTy, Context.LongTy, Context.LongLongTy, 3202 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3203 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3204 }; 3205 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3206 "Invalid first promoted integral type"); 3207 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3208 == Context.UnsignedLongLongTy && 3209 "Invalid last promoted integral type"); 3210 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3211 "Invalid first promoted arithmetic type"); 3212 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3213 == Context.LongDoubleTy && 3214 "Invalid last promoted arithmetic type"); 3215 3216 // Find all of the types that the arguments can convert to, but only 3217 // if the operator we're looking at has built-in operator candidates 3218 // that make use of these types. 3219 Qualifiers VisibleTypeConversionsQuals; 3220 VisibleTypeConversionsQuals.addConst(); 3221 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3222 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3223 3224 BuiltinCandidateTypeSet CandidateTypes(*this); 3225 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3226 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3227 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3228 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3229 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3230 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3231 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3232 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3233 OpLoc, 3234 true, 3235 (Op == OO_Exclaim || 3236 Op == OO_AmpAmp || 3237 Op == OO_PipePipe), 3238 VisibleTypeConversionsQuals); 3239 } 3240 3241 bool isComparison = false; 3242 switch (Op) { 3243 case OO_None: 3244 case NUM_OVERLOADED_OPERATORS: 3245 assert(false && "Expected an overloaded operator"); 3246 break; 3247 3248 case OO_Star: // '*' is either unary or binary 3249 if (NumArgs == 1) 3250 goto UnaryStar; 3251 else 3252 goto BinaryStar; 3253 break; 3254 3255 case OO_Plus: // '+' is either unary or binary 3256 if (NumArgs == 1) 3257 goto UnaryPlus; 3258 else 3259 goto BinaryPlus; 3260 break; 3261 3262 case OO_Minus: // '-' is either unary or binary 3263 if (NumArgs == 1) 3264 goto UnaryMinus; 3265 else 3266 goto BinaryMinus; 3267 break; 3268 3269 case OO_Amp: // '&' is either unary or binary 3270 if (NumArgs == 1) 3271 goto UnaryAmp; 3272 else 3273 goto BinaryAmp; 3274 3275 case OO_PlusPlus: 3276 case OO_MinusMinus: 3277 // C++ [over.built]p3: 3278 // 3279 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3280 // is either volatile or empty, there exist candidate operator 3281 // functions of the form 3282 // 3283 // VQ T& operator++(VQ T&); 3284 // T operator++(VQ T&, int); 3285 // 3286 // C++ [over.built]p4: 3287 // 3288 // For every pair (T, VQ), where T is an arithmetic type other 3289 // than bool, and VQ is either volatile or empty, there exist 3290 // candidate operator functions of the form 3291 // 3292 // VQ T& operator--(VQ T&); 3293 // T operator--(VQ T&, int); 3294 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3295 Arith < NumArithmeticTypes; ++Arith) { 3296 QualType ArithTy = ArithmeticTypes[Arith]; 3297 QualType ParamTypes[2] 3298 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3299 3300 // Non-volatile version. 3301 if (NumArgs == 1) 3302 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3303 else 3304 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3305 // heuristic to reduce number of builtin candidates in the set. 3306 // Add volatile version only if there are conversions to a volatile type. 3307 if (VisibleTypeConversionsQuals.hasVolatile()) { 3308 // Volatile version 3309 ParamTypes[0] 3310 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3311 if (NumArgs == 1) 3312 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3313 else 3314 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3315 } 3316 } 3317 3318 // C++ [over.built]p5: 3319 // 3320 // For every pair (T, VQ), where T is a cv-qualified or 3321 // cv-unqualified object type, and VQ is either volatile or 3322 // empty, there exist candidate operator functions of the form 3323 // 3324 // T*VQ& operator++(T*VQ&); 3325 // T*VQ& operator--(T*VQ&); 3326 // T* operator++(T*VQ&, int); 3327 // T* operator--(T*VQ&, int); 3328 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3329 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3330 // Skip pointer types that aren't pointers to object types. 3331 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3332 continue; 3333 3334 QualType ParamTypes[2] = { 3335 Context.getLValueReferenceType(*Ptr), Context.IntTy 3336 }; 3337 3338 // Without volatile 3339 if (NumArgs == 1) 3340 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3341 else 3342 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3343 3344 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3345 VisibleTypeConversionsQuals.hasVolatile()) { 3346 // With volatile 3347 ParamTypes[0] 3348 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3349 if (NumArgs == 1) 3350 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3351 else 3352 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3353 } 3354 } 3355 break; 3356 3357 UnaryStar: 3358 // C++ [over.built]p6: 3359 // For every cv-qualified or cv-unqualified object type T, there 3360 // exist candidate operator functions of the form 3361 // 3362 // T& operator*(T*); 3363 // 3364 // C++ [over.built]p7: 3365 // For every function type T, there exist candidate operator 3366 // functions of the form 3367 // T& operator*(T*); 3368 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3369 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3370 QualType ParamTy = *Ptr; 3371 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3372 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3373 &ParamTy, Args, 1, CandidateSet); 3374 } 3375 break; 3376 3377 UnaryPlus: 3378 // C++ [over.built]p8: 3379 // For every type T, there exist candidate operator functions of 3380 // the form 3381 // 3382 // T* operator+(T*); 3383 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3384 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3385 QualType ParamTy = *Ptr; 3386 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3387 } 3388 3389 // Fall through 3390 3391 UnaryMinus: 3392 // C++ [over.built]p9: 3393 // For every promoted arithmetic type T, there exist candidate 3394 // operator functions of the form 3395 // 3396 // T operator+(T); 3397 // T operator-(T); 3398 for (unsigned Arith = FirstPromotedArithmeticType; 3399 Arith < LastPromotedArithmeticType; ++Arith) { 3400 QualType ArithTy = ArithmeticTypes[Arith]; 3401 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3402 } 3403 break; 3404 3405 case OO_Tilde: 3406 // C++ [over.built]p10: 3407 // For every promoted integral type T, there exist candidate 3408 // operator functions of the form 3409 // 3410 // T operator~(T); 3411 for (unsigned Int = FirstPromotedIntegralType; 3412 Int < LastPromotedIntegralType; ++Int) { 3413 QualType IntTy = ArithmeticTypes[Int]; 3414 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3415 } 3416 break; 3417 3418 case OO_New: 3419 case OO_Delete: 3420 case OO_Array_New: 3421 case OO_Array_Delete: 3422 case OO_Call: 3423 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3424 break; 3425 3426 case OO_Comma: 3427 UnaryAmp: 3428 case OO_Arrow: 3429 // C++ [over.match.oper]p3: 3430 // -- For the operator ',', the unary operator '&', or the 3431 // operator '->', the built-in candidates set is empty. 3432 break; 3433 3434 case OO_EqualEqual: 3435 case OO_ExclaimEqual: 3436 // C++ [over.match.oper]p16: 3437 // For every pointer to member type T, there exist candidate operator 3438 // functions of the form 3439 // 3440 // bool operator==(T,T); 3441 // bool operator!=(T,T); 3442 for (BuiltinCandidateTypeSet::iterator 3443 MemPtr = CandidateTypes.member_pointer_begin(), 3444 MemPtrEnd = CandidateTypes.member_pointer_end(); 3445 MemPtr != MemPtrEnd; 3446 ++MemPtr) { 3447 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3448 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3449 } 3450 3451 // Fall through 3452 3453 case OO_Less: 3454 case OO_Greater: 3455 case OO_LessEqual: 3456 case OO_GreaterEqual: 3457 // C++ [over.built]p15: 3458 // 3459 // For every pointer or enumeration type T, there exist 3460 // candidate operator functions of the form 3461 // 3462 // bool operator<(T, T); 3463 // bool operator>(T, T); 3464 // bool operator<=(T, T); 3465 // bool operator>=(T, T); 3466 // bool operator==(T, T); 3467 // bool operator!=(T, T); 3468 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3469 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3470 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3471 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3472 } 3473 for (BuiltinCandidateTypeSet::iterator Enum 3474 = CandidateTypes.enumeration_begin(); 3475 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3476 QualType ParamTypes[2] = { *Enum, *Enum }; 3477 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3478 } 3479 3480 // Fall through. 3481 isComparison = true; 3482 3483 BinaryPlus: 3484 BinaryMinus: 3485 if (!isComparison) { 3486 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3487 3488 // C++ [over.built]p13: 3489 // 3490 // For every cv-qualified or cv-unqualified object type T 3491 // there exist candidate operator functions of the form 3492 // 3493 // T* operator+(T*, ptrdiff_t); 3494 // T& operator[](T*, ptrdiff_t); [BELOW] 3495 // T* operator-(T*, ptrdiff_t); 3496 // T* operator+(ptrdiff_t, T*); 3497 // T& operator[](ptrdiff_t, T*); [BELOW] 3498 // 3499 // C++ [over.built]p14: 3500 // 3501 // For every T, where T is a pointer to object type, there 3502 // exist candidate operator functions of the form 3503 // 3504 // ptrdiff_t operator-(T, T); 3505 for (BuiltinCandidateTypeSet::iterator Ptr 3506 = CandidateTypes.pointer_begin(); 3507 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3508 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3509 3510 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3511 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3512 3513 if (Op == OO_Plus) { 3514 // T* operator+(ptrdiff_t, T*); 3515 ParamTypes[0] = ParamTypes[1]; 3516 ParamTypes[1] = *Ptr; 3517 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3518 } else { 3519 // ptrdiff_t operator-(T, T); 3520 ParamTypes[1] = *Ptr; 3521 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3522 Args, 2, CandidateSet); 3523 } 3524 } 3525 } 3526 // Fall through 3527 3528 case OO_Slash: 3529 BinaryStar: 3530 Conditional: 3531 // C++ [over.built]p12: 3532 // 3533 // For every pair of promoted arithmetic types L and R, there 3534 // exist candidate operator functions of the form 3535 // 3536 // LR operator*(L, R); 3537 // LR operator/(L, R); 3538 // LR operator+(L, R); 3539 // LR operator-(L, R); 3540 // bool operator<(L, R); 3541 // bool operator>(L, R); 3542 // bool operator<=(L, R); 3543 // bool operator>=(L, R); 3544 // bool operator==(L, R); 3545 // bool operator!=(L, R); 3546 // 3547 // where LR is the result of the usual arithmetic conversions 3548 // between types L and R. 3549 // 3550 // C++ [over.built]p24: 3551 // 3552 // For every pair of promoted arithmetic types L and R, there exist 3553 // candidate operator functions of the form 3554 // 3555 // LR operator?(bool, L, R); 3556 // 3557 // where LR is the result of the usual arithmetic conversions 3558 // between types L and R. 3559 // Our candidates ignore the first parameter. 3560 for (unsigned Left = FirstPromotedArithmeticType; 3561 Left < LastPromotedArithmeticType; ++Left) { 3562 for (unsigned Right = FirstPromotedArithmeticType; 3563 Right < LastPromotedArithmeticType; ++Right) { 3564 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3565 QualType Result 3566 = isComparison 3567 ? Context.BoolTy 3568 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3569 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3570 } 3571 } 3572 break; 3573 3574 case OO_Percent: 3575 BinaryAmp: 3576 case OO_Caret: 3577 case OO_Pipe: 3578 case OO_LessLess: 3579 case OO_GreaterGreater: 3580 // C++ [over.built]p17: 3581 // 3582 // For every pair of promoted integral types L and R, there 3583 // exist candidate operator functions of the form 3584 // 3585 // LR operator%(L, R); 3586 // LR operator&(L, R); 3587 // LR operator^(L, R); 3588 // LR operator|(L, R); 3589 // L operator<<(L, R); 3590 // L operator>>(L, R); 3591 // 3592 // where LR is the result of the usual arithmetic conversions 3593 // between types L and R. 3594 for (unsigned Left = FirstPromotedIntegralType; 3595 Left < LastPromotedIntegralType; ++Left) { 3596 for (unsigned Right = FirstPromotedIntegralType; 3597 Right < LastPromotedIntegralType; ++Right) { 3598 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3599 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3600 ? LandR[0] 3601 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3602 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3603 } 3604 } 3605 break; 3606 3607 case OO_Equal: 3608 // C++ [over.built]p20: 3609 // 3610 // For every pair (T, VQ), where T is an enumeration or 3611 // pointer to member type and VQ is either volatile or 3612 // empty, there exist candidate operator functions of the form 3613 // 3614 // VQ T& operator=(VQ T&, T); 3615 for (BuiltinCandidateTypeSet::iterator 3616 Enum = CandidateTypes.enumeration_begin(), 3617 EnumEnd = CandidateTypes.enumeration_end(); 3618 Enum != EnumEnd; ++Enum) 3619 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3620 CandidateSet); 3621 for (BuiltinCandidateTypeSet::iterator 3622 MemPtr = CandidateTypes.member_pointer_begin(), 3623 MemPtrEnd = CandidateTypes.member_pointer_end(); 3624 MemPtr != MemPtrEnd; ++MemPtr) 3625 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3626 CandidateSet); 3627 // Fall through. 3628 3629 case OO_PlusEqual: 3630 case OO_MinusEqual: 3631 // C++ [over.built]p19: 3632 // 3633 // For every pair (T, VQ), where T is any type and VQ is either 3634 // volatile or empty, there exist candidate operator functions 3635 // of the form 3636 // 3637 // T*VQ& operator=(T*VQ&, T*); 3638 // 3639 // C++ [over.built]p21: 3640 // 3641 // For every pair (T, VQ), where T is a cv-qualified or 3642 // cv-unqualified object type and VQ is either volatile or 3643 // empty, there exist candidate operator functions of the form 3644 // 3645 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3646 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3647 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3648 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3649 QualType ParamTypes[2]; 3650 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3651 3652 // non-volatile version 3653 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3654 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3655 /*IsAssigmentOperator=*/Op == OO_Equal); 3656 3657 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3658 VisibleTypeConversionsQuals.hasVolatile()) { 3659 // volatile version 3660 ParamTypes[0] 3661 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3662 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3663 /*IsAssigmentOperator=*/Op == OO_Equal); 3664 } 3665 } 3666 // Fall through. 3667 3668 case OO_StarEqual: 3669 case OO_SlashEqual: 3670 // C++ [over.built]p18: 3671 // 3672 // For every triple (L, VQ, R), where L is an arithmetic type, 3673 // VQ is either volatile or empty, and R is a promoted 3674 // arithmetic type, there exist candidate operator functions of 3675 // the form 3676 // 3677 // VQ L& operator=(VQ L&, R); 3678 // VQ L& operator*=(VQ L&, R); 3679 // VQ L& operator/=(VQ L&, R); 3680 // VQ L& operator+=(VQ L&, R); 3681 // VQ L& operator-=(VQ L&, R); 3682 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3683 for (unsigned Right = FirstPromotedArithmeticType; 3684 Right < LastPromotedArithmeticType; ++Right) { 3685 QualType ParamTypes[2]; 3686 ParamTypes[1] = ArithmeticTypes[Right]; 3687 3688 // Add this built-in operator as a candidate (VQ is empty). 3689 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3690 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3691 /*IsAssigmentOperator=*/Op == OO_Equal); 3692 3693 // Add this built-in operator as a candidate (VQ is 'volatile'). 3694 if (VisibleTypeConversionsQuals.hasVolatile()) { 3695 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3696 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3697 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3698 /*IsAssigmentOperator=*/Op == OO_Equal); 3699 } 3700 } 3701 } 3702 break; 3703 3704 case OO_PercentEqual: 3705 case OO_LessLessEqual: 3706 case OO_GreaterGreaterEqual: 3707 case OO_AmpEqual: 3708 case OO_CaretEqual: 3709 case OO_PipeEqual: 3710 // C++ [over.built]p22: 3711 // 3712 // For every triple (L, VQ, R), where L is an integral type, VQ 3713 // is either volatile or empty, and R is a promoted integral 3714 // type, there exist candidate operator functions of the form 3715 // 3716 // VQ L& operator%=(VQ L&, R); 3717 // VQ L& operator<<=(VQ L&, R); 3718 // VQ L& operator>>=(VQ L&, R); 3719 // VQ L& operator&=(VQ L&, R); 3720 // VQ L& operator^=(VQ L&, R); 3721 // VQ L& operator|=(VQ L&, R); 3722 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3723 for (unsigned Right = FirstPromotedIntegralType; 3724 Right < LastPromotedIntegralType; ++Right) { 3725 QualType ParamTypes[2]; 3726 ParamTypes[1] = ArithmeticTypes[Right]; 3727 3728 // Add this built-in operator as a candidate (VQ is empty). 3729 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3730 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3731 if (VisibleTypeConversionsQuals.hasVolatile()) { 3732 // Add this built-in operator as a candidate (VQ is 'volatile'). 3733 ParamTypes[0] = ArithmeticTypes[Left]; 3734 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3735 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3736 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3737 } 3738 } 3739 } 3740 break; 3741 3742 case OO_Exclaim: { 3743 // C++ [over.operator]p23: 3744 // 3745 // There also exist candidate operator functions of the form 3746 // 3747 // bool operator!(bool); 3748 // bool operator&&(bool, bool); [BELOW] 3749 // bool operator||(bool, bool); [BELOW] 3750 QualType ParamTy = Context.BoolTy; 3751 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3752 /*IsAssignmentOperator=*/false, 3753 /*NumContextualBoolArguments=*/1); 3754 break; 3755 } 3756 3757 case OO_AmpAmp: 3758 case OO_PipePipe: { 3759 // C++ [over.operator]p23: 3760 // 3761 // There also exist candidate operator functions of the form 3762 // 3763 // bool operator!(bool); [ABOVE] 3764 // bool operator&&(bool, bool); 3765 // bool operator||(bool, bool); 3766 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3767 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3768 /*IsAssignmentOperator=*/false, 3769 /*NumContextualBoolArguments=*/2); 3770 break; 3771 } 3772 3773 case OO_Subscript: 3774 // C++ [over.built]p13: 3775 // 3776 // For every cv-qualified or cv-unqualified object type T there 3777 // exist candidate operator functions of the form 3778 // 3779 // T* operator+(T*, ptrdiff_t); [ABOVE] 3780 // T& operator[](T*, ptrdiff_t); 3781 // T* operator-(T*, ptrdiff_t); [ABOVE] 3782 // T* operator+(ptrdiff_t, T*); [ABOVE] 3783 // T& operator[](ptrdiff_t, T*); 3784 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3785 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3786 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3787 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3788 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3789 3790 // T& operator[](T*, ptrdiff_t) 3791 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3792 3793 // T& operator[](ptrdiff_t, T*); 3794 ParamTypes[0] = ParamTypes[1]; 3795 ParamTypes[1] = *Ptr; 3796 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3797 } 3798 break; 3799 3800 case OO_ArrowStar: 3801 // C++ [over.built]p11: 3802 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 3803 // C1 is the same type as C2 or is a derived class of C2, T is an object 3804 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 3805 // there exist candidate operator functions of the form 3806 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 3807 // where CV12 is the union of CV1 and CV2. 3808 { 3809 for (BuiltinCandidateTypeSet::iterator Ptr = 3810 CandidateTypes.pointer_begin(); 3811 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3812 QualType C1Ty = (*Ptr); 3813 QualType C1; 3814 QualifierCollector Q1; 3815 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 3816 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 3817 if (!isa<RecordType>(C1)) 3818 continue; 3819 // heuristic to reduce number of builtin candidates in the set. 3820 // Add volatile/restrict version only if there are conversions to a 3821 // volatile/restrict type. 3822 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 3823 continue; 3824 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 3825 continue; 3826 } 3827 for (BuiltinCandidateTypeSet::iterator 3828 MemPtr = CandidateTypes.member_pointer_begin(), 3829 MemPtrEnd = CandidateTypes.member_pointer_end(); 3830 MemPtr != MemPtrEnd; ++MemPtr) { 3831 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 3832 QualType C2 = QualType(mptr->getClass(), 0); 3833 C2 = C2.getUnqualifiedType(); 3834 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 3835 break; 3836 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 3837 // build CV12 T& 3838 QualType T = mptr->getPointeeType(); 3839 if (!VisibleTypeConversionsQuals.hasVolatile() && 3840 T.isVolatileQualified()) 3841 continue; 3842 if (!VisibleTypeConversionsQuals.hasRestrict() && 3843 T.isRestrictQualified()) 3844 continue; 3845 T = Q1.apply(T); 3846 QualType ResultTy = Context.getLValueReferenceType(T); 3847 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3848 } 3849 } 3850 } 3851 break; 3852 3853 case OO_Conditional: 3854 // Note that we don't consider the first argument, since it has been 3855 // contextually converted to bool long ago. The candidates below are 3856 // therefore added as binary. 3857 // 3858 // C++ [over.built]p24: 3859 // For every type T, where T is a pointer or pointer-to-member type, 3860 // there exist candidate operator functions of the form 3861 // 3862 // T operator?(bool, T, T); 3863 // 3864 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3865 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3866 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3867 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3868 } 3869 for (BuiltinCandidateTypeSet::iterator Ptr = 3870 CandidateTypes.member_pointer_begin(), 3871 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3872 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3873 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3874 } 3875 goto Conditional; 3876 } 3877} 3878 3879/// \brief Add function candidates found via argument-dependent lookup 3880/// to the set of overloading candidates. 3881/// 3882/// This routine performs argument-dependent name lookup based on the 3883/// given function name (which may also be an operator name) and adds 3884/// all of the overload candidates found by ADL to the overload 3885/// candidate set (C++ [basic.lookup.argdep]). 3886void 3887Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3888 Expr **Args, unsigned NumArgs, 3889 bool HasExplicitTemplateArgs, 3890 const TemplateArgumentLoc *ExplicitTemplateArgs, 3891 unsigned NumExplicitTemplateArgs, 3892 OverloadCandidateSet& CandidateSet, 3893 bool PartialOverloading) { 3894 FunctionSet Functions; 3895 3896 // FIXME: Should we be trafficking in canonical function decls throughout? 3897 3898 // Record all of the function candidates that we've already 3899 // added to the overload set, so that we don't add those same 3900 // candidates a second time. 3901 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3902 CandEnd = CandidateSet.end(); 3903 Cand != CandEnd; ++Cand) 3904 if (Cand->Function) { 3905 Functions.insert(Cand->Function); 3906 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3907 Functions.insert(FunTmpl); 3908 } 3909 3910 // FIXME: Pass in the explicit template arguments? 3911 ArgumentDependentLookup(Name, /*Operator*/false, Args, NumArgs, Functions); 3912 3913 // Erase all of the candidates we already knew about. 3914 // FIXME: This is suboptimal. Is there a better way? 3915 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3916 CandEnd = CandidateSet.end(); 3917 Cand != CandEnd; ++Cand) 3918 if (Cand->Function) { 3919 Functions.erase(Cand->Function); 3920 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3921 Functions.erase(FunTmpl); 3922 } 3923 3924 // For each of the ADL candidates we found, add it to the overload 3925 // set. 3926 for (FunctionSet::iterator Func = Functions.begin(), 3927 FuncEnd = Functions.end(); 3928 Func != FuncEnd; ++Func) { 3929 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3930 if (HasExplicitTemplateArgs) 3931 continue; 3932 3933 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3934 false, false, PartialOverloading); 3935 } else 3936 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3937 HasExplicitTemplateArgs, 3938 ExplicitTemplateArgs, 3939 NumExplicitTemplateArgs, 3940 Args, NumArgs, CandidateSet); 3941 } 3942} 3943 3944/// isBetterOverloadCandidate - Determines whether the first overload 3945/// candidate is a better candidate than the second (C++ 13.3.3p1). 3946bool 3947Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3948 const OverloadCandidate& Cand2) { 3949 // Define viable functions to be better candidates than non-viable 3950 // functions. 3951 if (!Cand2.Viable) 3952 return Cand1.Viable; 3953 else if (!Cand1.Viable) 3954 return false; 3955 3956 // C++ [over.match.best]p1: 3957 // 3958 // -- if F is a static member function, ICS1(F) is defined such 3959 // that ICS1(F) is neither better nor worse than ICS1(G) for 3960 // any function G, and, symmetrically, ICS1(G) is neither 3961 // better nor worse than ICS1(F). 3962 unsigned StartArg = 0; 3963 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3964 StartArg = 1; 3965 3966 // C++ [over.match.best]p1: 3967 // A viable function F1 is defined to be a better function than another 3968 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3969 // conversion sequence than ICSi(F2), and then... 3970 unsigned NumArgs = Cand1.Conversions.size(); 3971 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3972 bool HasBetterConversion = false; 3973 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3974 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3975 Cand2.Conversions[ArgIdx])) { 3976 case ImplicitConversionSequence::Better: 3977 // Cand1 has a better conversion sequence. 3978 HasBetterConversion = true; 3979 break; 3980 3981 case ImplicitConversionSequence::Worse: 3982 // Cand1 can't be better than Cand2. 3983 return false; 3984 3985 case ImplicitConversionSequence::Indistinguishable: 3986 // Do nothing. 3987 break; 3988 } 3989 } 3990 3991 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3992 // ICSj(F2), or, if not that, 3993 if (HasBetterConversion) 3994 return true; 3995 3996 // - F1 is a non-template function and F2 is a function template 3997 // specialization, or, if not that, 3998 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3999 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4000 return true; 4001 4002 // -- F1 and F2 are function template specializations, and the function 4003 // template for F1 is more specialized than the template for F2 4004 // according to the partial ordering rules described in 14.5.5.2, or, 4005 // if not that, 4006 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4007 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4008 if (FunctionTemplateDecl *BetterTemplate 4009 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4010 Cand2.Function->getPrimaryTemplate(), 4011 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4012 : TPOC_Call)) 4013 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4014 4015 // -- the context is an initialization by user-defined conversion 4016 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4017 // from the return type of F1 to the destination type (i.e., 4018 // the type of the entity being initialized) is a better 4019 // conversion sequence than the standard conversion sequence 4020 // from the return type of F2 to the destination type. 4021 if (Cand1.Function && Cand2.Function && 4022 isa<CXXConversionDecl>(Cand1.Function) && 4023 isa<CXXConversionDecl>(Cand2.Function)) { 4024 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4025 Cand2.FinalConversion)) { 4026 case ImplicitConversionSequence::Better: 4027 // Cand1 has a better conversion sequence. 4028 return true; 4029 4030 case ImplicitConversionSequence::Worse: 4031 // Cand1 can't be better than Cand2. 4032 return false; 4033 4034 case ImplicitConversionSequence::Indistinguishable: 4035 // Do nothing 4036 break; 4037 } 4038 } 4039 4040 return false; 4041} 4042 4043/// \brief Computes the best viable function (C++ 13.3.3) 4044/// within an overload candidate set. 4045/// 4046/// \param CandidateSet the set of candidate functions. 4047/// 4048/// \param Loc the location of the function name (or operator symbol) for 4049/// which overload resolution occurs. 4050/// 4051/// \param Best f overload resolution was successful or found a deleted 4052/// function, Best points to the candidate function found. 4053/// 4054/// \returns The result of overload resolution. 4055Sema::OverloadingResult 4056Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4057 SourceLocation Loc, 4058 OverloadCandidateSet::iterator& Best) { 4059 // Find the best viable function. 4060 Best = CandidateSet.end(); 4061 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4062 Cand != CandidateSet.end(); ++Cand) { 4063 if (Cand->Viable) { 4064 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 4065 Best = Cand; 4066 } 4067 } 4068 4069 // If we didn't find any viable functions, abort. 4070 if (Best == CandidateSet.end()) 4071 return OR_No_Viable_Function; 4072 4073 // Make sure that this function is better than every other viable 4074 // function. If not, we have an ambiguity. 4075 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4076 Cand != CandidateSet.end(); ++Cand) { 4077 if (Cand->Viable && 4078 Cand != Best && 4079 !isBetterOverloadCandidate(*Best, *Cand)) { 4080 Best = CandidateSet.end(); 4081 return OR_Ambiguous; 4082 } 4083 } 4084 4085 // Best is the best viable function. 4086 if (Best->Function && 4087 (Best->Function->isDeleted() || 4088 Best->Function->getAttr<UnavailableAttr>())) 4089 return OR_Deleted; 4090 4091 // C++ [basic.def.odr]p2: 4092 // An overloaded function is used if it is selected by overload resolution 4093 // when referred to from a potentially-evaluated expression. [Note: this 4094 // covers calls to named functions (5.2.2), operator overloading 4095 // (clause 13), user-defined conversions (12.3.2), allocation function for 4096 // placement new (5.3.4), as well as non-default initialization (8.5). 4097 if (Best->Function) 4098 MarkDeclarationReferenced(Loc, Best->Function); 4099 return OR_Success; 4100} 4101 4102/// PrintOverloadCandidates - When overload resolution fails, prints 4103/// diagnostic messages containing the candidates in the candidate 4104/// set. If OnlyViable is true, only viable candidates will be printed. 4105void 4106Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4107 bool OnlyViable, 4108 const char *Opc, 4109 SourceLocation OpLoc) { 4110 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4111 LastCand = CandidateSet.end(); 4112 bool Reported = false; 4113 for (; Cand != LastCand; ++Cand) { 4114 if (Cand->Viable || !OnlyViable) { 4115 if (Cand->Function) { 4116 if (Cand->Function->isDeleted() || 4117 Cand->Function->getAttr<UnavailableAttr>()) { 4118 // Deleted or "unavailable" function. 4119 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 4120 << Cand->Function->isDeleted(); 4121 } else if (FunctionTemplateDecl *FunTmpl 4122 = Cand->Function->getPrimaryTemplate()) { 4123 // Function template specialization 4124 // FIXME: Give a better reason! 4125 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 4126 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 4127 *Cand->Function->getTemplateSpecializationArgs()); 4128 } else { 4129 // Normal function 4130 bool errReported = false; 4131 if (!Cand->Viable && Cand->Conversions.size() > 0) { 4132 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 4133 const ImplicitConversionSequence &Conversion = 4134 Cand->Conversions[i]; 4135 if ((Conversion.ConversionKind != 4136 ImplicitConversionSequence::BadConversion) || 4137 Conversion.ConversionFunctionSet.size() == 0) 4138 continue; 4139 Diag(Cand->Function->getLocation(), 4140 diag::err_ovl_candidate_not_viable) << (i+1); 4141 errReported = true; 4142 for (int j = Conversion.ConversionFunctionSet.size()-1; 4143 j >= 0; j--) { 4144 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 4145 Diag(Func->getLocation(), diag::err_ovl_candidate); 4146 } 4147 } 4148 } 4149 if (!errReported) 4150 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 4151 } 4152 } else if (Cand->IsSurrogate) { 4153 // Desugar the type of the surrogate down to a function type, 4154 // retaining as many typedefs as possible while still showing 4155 // the function type (and, therefore, its parameter types). 4156 QualType FnType = Cand->Surrogate->getConversionType(); 4157 bool isLValueReference = false; 4158 bool isRValueReference = false; 4159 bool isPointer = false; 4160 if (const LValueReferenceType *FnTypeRef = 4161 FnType->getAs<LValueReferenceType>()) { 4162 FnType = FnTypeRef->getPointeeType(); 4163 isLValueReference = true; 4164 } else if (const RValueReferenceType *FnTypeRef = 4165 FnType->getAs<RValueReferenceType>()) { 4166 FnType = FnTypeRef->getPointeeType(); 4167 isRValueReference = true; 4168 } 4169 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4170 FnType = FnTypePtr->getPointeeType(); 4171 isPointer = true; 4172 } 4173 // Desugar down to a function type. 4174 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4175 // Reconstruct the pointer/reference as appropriate. 4176 if (isPointer) FnType = Context.getPointerType(FnType); 4177 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 4178 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 4179 4180 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 4181 << FnType; 4182 } else if (OnlyViable) { 4183 assert(Cand->Conversions.size() <= 2 && 4184 "builtin-binary-operator-not-binary"); 4185 std::string TypeStr("operator"); 4186 TypeStr += Opc; 4187 TypeStr += "("; 4188 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4189 if (Cand->Conversions.size() == 1) { 4190 TypeStr += ")"; 4191 Diag(OpLoc, diag::err_ovl_builtin_unary_candidate) << TypeStr; 4192 } 4193 else { 4194 TypeStr += ", "; 4195 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4196 TypeStr += ")"; 4197 Diag(OpLoc, diag::err_ovl_builtin_binary_candidate) << TypeStr; 4198 } 4199 } 4200 else if (!Cand->Viable && !Reported) { 4201 // Non-viability might be due to ambiguous user-defined conversions, 4202 // needed for built-in operators. Report them as well, but only once 4203 // as we have typically many built-in candidates. 4204 unsigned NoOperands = Cand->Conversions.size(); 4205 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4206 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4207 if (ICS.ConversionKind != ImplicitConversionSequence::BadConversion || 4208 ICS.ConversionFunctionSet.empty()) 4209 continue; 4210 if (CXXConversionDecl *Func = dyn_cast<CXXConversionDecl>( 4211 Cand->Conversions[ArgIdx].ConversionFunctionSet[0])) { 4212 QualType FromTy = 4213 QualType( 4214 static_cast<Type*>(ICS.UserDefined.Before.FromTypePtr),0); 4215 Diag(OpLoc,diag::note_ambiguous_type_conversion) 4216 << FromTy << Func->getConversionType(); 4217 } 4218 for (unsigned j = 0; j < ICS.ConversionFunctionSet.size(); j++) { 4219 FunctionDecl *Func = 4220 Cand->Conversions[ArgIdx].ConversionFunctionSet[j]; 4221 Diag(Func->getLocation(),diag::err_ovl_candidate); 4222 } 4223 } 4224 Reported = true; 4225 } 4226 } 4227 } 4228} 4229 4230/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4231/// an overloaded function (C++ [over.over]), where @p From is an 4232/// expression with overloaded function type and @p ToType is the type 4233/// we're trying to resolve to. For example: 4234/// 4235/// @code 4236/// int f(double); 4237/// int f(int); 4238/// 4239/// int (*pfd)(double) = f; // selects f(double) 4240/// @endcode 4241/// 4242/// This routine returns the resulting FunctionDecl if it could be 4243/// resolved, and NULL otherwise. When @p Complain is true, this 4244/// routine will emit diagnostics if there is an error. 4245FunctionDecl * 4246Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4247 bool Complain) { 4248 QualType FunctionType = ToType; 4249 bool IsMember = false; 4250 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4251 FunctionType = ToTypePtr->getPointeeType(); 4252 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4253 FunctionType = ToTypeRef->getPointeeType(); 4254 else if (const MemberPointerType *MemTypePtr = 4255 ToType->getAs<MemberPointerType>()) { 4256 FunctionType = MemTypePtr->getPointeeType(); 4257 IsMember = true; 4258 } 4259 4260 // We only look at pointers or references to functions. 4261 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4262 if (!FunctionType->isFunctionType()) 4263 return 0; 4264 4265 // Find the actual overloaded function declaration. 4266 OverloadedFunctionDecl *Ovl = 0; 4267 4268 // C++ [over.over]p1: 4269 // [...] [Note: any redundant set of parentheses surrounding the 4270 // overloaded function name is ignored (5.1). ] 4271 Expr *OvlExpr = From->IgnoreParens(); 4272 4273 // C++ [over.over]p1: 4274 // [...] The overloaded function name can be preceded by the & 4275 // operator. 4276 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4277 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4278 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4279 } 4280 4281 bool HasExplicitTemplateArgs = false; 4282 const TemplateArgumentLoc *ExplicitTemplateArgs = 0; 4283 unsigned NumExplicitTemplateArgs = 0; 4284 4285 // Try to dig out the overloaded function. 4286 FunctionTemplateDecl *FunctionTemplate = 0; 4287 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4288 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4289 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4290 HasExplicitTemplateArgs = DR->hasExplicitTemplateArgumentList(); 4291 ExplicitTemplateArgs = DR->getTemplateArgs(); 4292 NumExplicitTemplateArgs = DR->getNumTemplateArgs(); 4293 } else if (MemberExpr *ME = dyn_cast<MemberExpr>(OvlExpr)) { 4294 Ovl = dyn_cast<OverloadedFunctionDecl>(ME->getMemberDecl()); 4295 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(ME->getMemberDecl()); 4296 HasExplicitTemplateArgs = ME->hasExplicitTemplateArgumentList(); 4297 ExplicitTemplateArgs = ME->getTemplateArgs(); 4298 NumExplicitTemplateArgs = ME->getNumTemplateArgs(); 4299 } else if (TemplateIdRefExpr *TIRE = dyn_cast<TemplateIdRefExpr>(OvlExpr)) { 4300 TemplateName Name = TIRE->getTemplateName(); 4301 Ovl = Name.getAsOverloadedFunctionDecl(); 4302 FunctionTemplate = 4303 dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl()); 4304 4305 HasExplicitTemplateArgs = true; 4306 ExplicitTemplateArgs = TIRE->getTemplateArgs(); 4307 NumExplicitTemplateArgs = TIRE->getNumTemplateArgs(); 4308 } 4309 4310 // If there's no overloaded function declaration or function template, 4311 // we're done. 4312 if (!Ovl && !FunctionTemplate) 4313 return 0; 4314 4315 OverloadIterator Fun; 4316 if (Ovl) 4317 Fun = Ovl; 4318 else 4319 Fun = FunctionTemplate; 4320 4321 // Look through all of the overloaded functions, searching for one 4322 // whose type matches exactly. 4323 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4324 bool FoundNonTemplateFunction = false; 4325 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4326 // C++ [over.over]p3: 4327 // Non-member functions and static member functions match 4328 // targets of type "pointer-to-function" or "reference-to-function." 4329 // Nonstatic member functions match targets of 4330 // type "pointer-to-member-function." 4331 // Note that according to DR 247, the containing class does not matter. 4332 4333 if (FunctionTemplateDecl *FunctionTemplate 4334 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4335 if (CXXMethodDecl *Method 4336 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4337 // Skip non-static function templates when converting to pointer, and 4338 // static when converting to member pointer. 4339 if (Method->isStatic() == IsMember) 4340 continue; 4341 } else if (IsMember) 4342 continue; 4343 4344 // C++ [over.over]p2: 4345 // If the name is a function template, template argument deduction is 4346 // done (14.8.2.2), and if the argument deduction succeeds, the 4347 // resulting template argument list is used to generate a single 4348 // function template specialization, which is added to the set of 4349 // overloaded functions considered. 4350 // FIXME: We don't really want to build the specialization here, do we? 4351 FunctionDecl *Specialization = 0; 4352 TemplateDeductionInfo Info(Context); 4353 if (TemplateDeductionResult Result 4354 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 4355 ExplicitTemplateArgs, 4356 NumExplicitTemplateArgs, 4357 FunctionType, Specialization, Info)) { 4358 // FIXME: make a note of the failed deduction for diagnostics. 4359 (void)Result; 4360 } else { 4361 // FIXME: If the match isn't exact, shouldn't we just drop this as 4362 // a candidate? Find a testcase before changing the code. 4363 assert(FunctionType 4364 == Context.getCanonicalType(Specialization->getType())); 4365 Matches.insert( 4366 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4367 } 4368 } 4369 4370 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4371 // Skip non-static functions when converting to pointer, and static 4372 // when converting to member pointer. 4373 if (Method->isStatic() == IsMember) 4374 continue; 4375 4376 // If we have explicit template arguments, skip non-templates. 4377 if (HasExplicitTemplateArgs) 4378 continue; 4379 } else if (IsMember) 4380 continue; 4381 4382 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4383 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4384 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4385 FoundNonTemplateFunction = true; 4386 } 4387 } 4388 } 4389 4390 // If there were 0 or 1 matches, we're done. 4391 if (Matches.empty()) 4392 return 0; 4393 else if (Matches.size() == 1) { 4394 FunctionDecl *Result = *Matches.begin(); 4395 MarkDeclarationReferenced(From->getLocStart(), Result); 4396 return Result; 4397 } 4398 4399 // C++ [over.over]p4: 4400 // If more than one function is selected, [...] 4401 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4402 if (!FoundNonTemplateFunction) { 4403 // [...] and any given function template specialization F1 is 4404 // eliminated if the set contains a second function template 4405 // specialization whose function template is more specialized 4406 // than the function template of F1 according to the partial 4407 // ordering rules of 14.5.5.2. 4408 4409 // The algorithm specified above is quadratic. We instead use a 4410 // two-pass algorithm (similar to the one used to identify the 4411 // best viable function in an overload set) that identifies the 4412 // best function template (if it exists). 4413 llvm::SmallVector<FunctionDecl *, 8> TemplateMatches(Matches.begin(), 4414 Matches.end()); 4415 FunctionDecl *Result = 4416 getMostSpecialized(TemplateMatches.data(), TemplateMatches.size(), 4417 TPOC_Other, From->getLocStart(), 4418 PDiag(), 4419 PDiag(diag::err_addr_ovl_ambiguous) 4420 << TemplateMatches[0]->getDeclName(), 4421 PDiag(diag::err_ovl_template_candidate)); 4422 MarkDeclarationReferenced(From->getLocStart(), Result); 4423 return Result; 4424 } 4425 4426 // [...] any function template specializations in the set are 4427 // eliminated if the set also contains a non-template function, [...] 4428 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4429 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4430 if ((*M)->getPrimaryTemplate() == 0) 4431 RemainingMatches.push_back(*M); 4432 4433 // [...] After such eliminations, if any, there shall remain exactly one 4434 // selected function. 4435 if (RemainingMatches.size() == 1) { 4436 FunctionDecl *Result = RemainingMatches.front(); 4437 MarkDeclarationReferenced(From->getLocStart(), Result); 4438 return Result; 4439 } 4440 4441 // FIXME: We should probably return the same thing that BestViableFunction 4442 // returns (even if we issue the diagnostics here). 4443 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4444 << RemainingMatches[0]->getDeclName(); 4445 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4446 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4447 return 0; 4448} 4449 4450/// \brief Add a single candidate to the overload set. 4451static void AddOverloadedCallCandidate(Sema &S, 4452 AnyFunctionDecl Callee, 4453 bool &ArgumentDependentLookup, 4454 bool HasExplicitTemplateArgs, 4455 const TemplateArgumentLoc *ExplicitTemplateArgs, 4456 unsigned NumExplicitTemplateArgs, 4457 Expr **Args, unsigned NumArgs, 4458 OverloadCandidateSet &CandidateSet, 4459 bool PartialOverloading) { 4460 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4461 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4462 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4463 PartialOverloading); 4464 4465 if (Func->getDeclContext()->isRecord() || 4466 Func->getDeclContext()->isFunctionOrMethod()) 4467 ArgumentDependentLookup = false; 4468 return; 4469 } 4470 4471 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4472 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4473 ExplicitTemplateArgs, 4474 NumExplicitTemplateArgs, 4475 Args, NumArgs, CandidateSet); 4476 4477 if (FuncTemplate->getDeclContext()->isRecord()) 4478 ArgumentDependentLookup = false; 4479} 4480 4481/// \brief Add the overload candidates named by callee and/or found by argument 4482/// dependent lookup to the given overload set. 4483void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4484 DeclarationName &UnqualifiedName, 4485 bool &ArgumentDependentLookup, 4486 bool HasExplicitTemplateArgs, 4487 const TemplateArgumentLoc *ExplicitTemplateArgs, 4488 unsigned NumExplicitTemplateArgs, 4489 Expr **Args, unsigned NumArgs, 4490 OverloadCandidateSet &CandidateSet, 4491 bool PartialOverloading) { 4492 // Add the functions denoted by Callee to the set of candidate 4493 // functions. While we're doing so, track whether argument-dependent 4494 // lookup still applies, per: 4495 // 4496 // C++0x [basic.lookup.argdep]p3: 4497 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4498 // and let Y be the lookup set produced by argument dependent 4499 // lookup (defined as follows). If X contains 4500 // 4501 // -- a declaration of a class member, or 4502 // 4503 // -- a block-scope function declaration that is not a 4504 // using-declaration (FIXME: check for using declaration), or 4505 // 4506 // -- a declaration that is neither a function or a function 4507 // template 4508 // 4509 // then Y is empty. 4510 if (!Callee) { 4511 // Nothing to do. 4512 } else if (OverloadedFunctionDecl *Ovl 4513 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4514 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4515 FuncEnd = Ovl->function_end(); 4516 Func != FuncEnd; ++Func) 4517 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4518 HasExplicitTemplateArgs, 4519 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4520 Args, NumArgs, CandidateSet, 4521 PartialOverloading); 4522 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4523 AddOverloadedCallCandidate(*this, 4524 AnyFunctionDecl::getFromNamedDecl(Callee), 4525 ArgumentDependentLookup, 4526 HasExplicitTemplateArgs, 4527 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4528 Args, NumArgs, CandidateSet, 4529 PartialOverloading); 4530 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4531 // checking dynamically. 4532 4533 if (Callee) 4534 UnqualifiedName = Callee->getDeclName(); 4535 4536 if (ArgumentDependentLookup) 4537 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4538 HasExplicitTemplateArgs, 4539 ExplicitTemplateArgs, 4540 NumExplicitTemplateArgs, 4541 CandidateSet, 4542 PartialOverloading); 4543} 4544 4545/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4546/// (which eventually refers to the declaration Func) and the call 4547/// arguments Args/NumArgs, attempt to resolve the function call down 4548/// to a specific function. If overload resolution succeeds, returns 4549/// the function declaration produced by overload 4550/// resolution. Otherwise, emits diagnostics, deletes all of the 4551/// arguments and Fn, and returns NULL. 4552FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4553 DeclarationName UnqualifiedName, 4554 bool HasExplicitTemplateArgs, 4555 const TemplateArgumentLoc *ExplicitTemplateArgs, 4556 unsigned NumExplicitTemplateArgs, 4557 SourceLocation LParenLoc, 4558 Expr **Args, unsigned NumArgs, 4559 SourceLocation *CommaLocs, 4560 SourceLocation RParenLoc, 4561 bool &ArgumentDependentLookup) { 4562 OverloadCandidateSet CandidateSet; 4563 4564 // Add the functions denoted by Callee to the set of candidate 4565 // functions. 4566 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4567 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4568 NumExplicitTemplateArgs, Args, NumArgs, 4569 CandidateSet); 4570 OverloadCandidateSet::iterator Best; 4571 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4572 case OR_Success: 4573 return Best->Function; 4574 4575 case OR_No_Viable_Function: 4576 Diag(Fn->getSourceRange().getBegin(), 4577 diag::err_ovl_no_viable_function_in_call) 4578 << UnqualifiedName << Fn->getSourceRange(); 4579 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4580 break; 4581 4582 case OR_Ambiguous: 4583 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4584 << UnqualifiedName << Fn->getSourceRange(); 4585 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4586 break; 4587 4588 case OR_Deleted: 4589 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4590 << Best->Function->isDeleted() 4591 << UnqualifiedName 4592 << Fn->getSourceRange(); 4593 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4594 break; 4595 } 4596 4597 // Overload resolution failed. Destroy all of the subexpressions and 4598 // return NULL. 4599 Fn->Destroy(Context); 4600 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4601 Args[Arg]->Destroy(Context); 4602 return 0; 4603} 4604 4605/// \brief Create a unary operation that may resolve to an overloaded 4606/// operator. 4607/// 4608/// \param OpLoc The location of the operator itself (e.g., '*'). 4609/// 4610/// \param OpcIn The UnaryOperator::Opcode that describes this 4611/// operator. 4612/// 4613/// \param Functions The set of non-member functions that will be 4614/// considered by overload resolution. The caller needs to build this 4615/// set based on the context using, e.g., 4616/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4617/// set should not contain any member functions; those will be added 4618/// by CreateOverloadedUnaryOp(). 4619/// 4620/// \param input The input argument. 4621Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4622 unsigned OpcIn, 4623 FunctionSet &Functions, 4624 ExprArg input) { 4625 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4626 Expr *Input = (Expr *)input.get(); 4627 4628 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4629 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4630 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4631 4632 Expr *Args[2] = { Input, 0 }; 4633 unsigned NumArgs = 1; 4634 4635 // For post-increment and post-decrement, add the implicit '0' as 4636 // the second argument, so that we know this is a post-increment or 4637 // post-decrement. 4638 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4639 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4640 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4641 SourceLocation()); 4642 NumArgs = 2; 4643 } 4644 4645 if (Input->isTypeDependent()) { 4646 OverloadedFunctionDecl *Overloads 4647 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4648 for (FunctionSet::iterator Func = Functions.begin(), 4649 FuncEnd = Functions.end(); 4650 Func != FuncEnd; ++Func) 4651 Overloads->addOverload(*Func); 4652 4653 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4654 OpLoc, false, false); 4655 4656 input.release(); 4657 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4658 &Args[0], NumArgs, 4659 Context.DependentTy, 4660 OpLoc)); 4661 } 4662 4663 // Build an empty overload set. 4664 OverloadCandidateSet CandidateSet; 4665 4666 // Add the candidates from the given function set. 4667 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4668 4669 // Add operator candidates that are member functions. 4670 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4671 4672 // Add builtin operator candidates. 4673 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4674 4675 // Perform overload resolution. 4676 OverloadCandidateSet::iterator Best; 4677 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4678 case OR_Success: { 4679 // We found a built-in operator or an overloaded operator. 4680 FunctionDecl *FnDecl = Best->Function; 4681 4682 if (FnDecl) { 4683 // We matched an overloaded operator. Build a call to that 4684 // operator. 4685 4686 // Convert the arguments. 4687 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4688 if (PerformObjectArgumentInitialization(Input, Method)) 4689 return ExprError(); 4690 } else { 4691 // Convert the arguments. 4692 if (PerformCopyInitialization(Input, 4693 FnDecl->getParamDecl(0)->getType(), 4694 "passing")) 4695 return ExprError(); 4696 } 4697 4698 // Determine the result type 4699 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 4700 4701 // Build the actual expression node. 4702 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4703 SourceLocation()); 4704 UsualUnaryConversions(FnExpr); 4705 4706 input.release(); 4707 4708 ExprOwningPtr<CallExpr> TheCall(this, 4709 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4710 &Input, 1, ResultTy, OpLoc)); 4711 4712 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4713 FnDecl)) 4714 return ExprError(); 4715 4716 return MaybeBindToTemporary(TheCall.release()); 4717 } else { 4718 // We matched a built-in operator. Convert the arguments, then 4719 // break out so that we will build the appropriate built-in 4720 // operator node. 4721 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4722 Best->Conversions[0], "passing")) 4723 return ExprError(); 4724 4725 break; 4726 } 4727 } 4728 4729 case OR_No_Viable_Function: 4730 // No viable function; fall through to handling this as a 4731 // built-in operator, which will produce an error message for us. 4732 break; 4733 4734 case OR_Ambiguous: 4735 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4736 << UnaryOperator::getOpcodeStr(Opc) 4737 << Input->getSourceRange(); 4738 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4739 UnaryOperator::getOpcodeStr(Opc), OpLoc); 4740 return ExprError(); 4741 4742 case OR_Deleted: 4743 Diag(OpLoc, diag::err_ovl_deleted_oper) 4744 << Best->Function->isDeleted() 4745 << UnaryOperator::getOpcodeStr(Opc) 4746 << Input->getSourceRange(); 4747 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4748 return ExprError(); 4749 } 4750 4751 // Either we found no viable overloaded operator or we matched a 4752 // built-in operator. In either case, fall through to trying to 4753 // build a built-in operation. 4754 input.release(); 4755 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4756} 4757 4758/// \brief Create a binary operation that may resolve to an overloaded 4759/// operator. 4760/// 4761/// \param OpLoc The location of the operator itself (e.g., '+'). 4762/// 4763/// \param OpcIn The BinaryOperator::Opcode that describes this 4764/// operator. 4765/// 4766/// \param Functions The set of non-member functions that will be 4767/// considered by overload resolution. The caller needs to build this 4768/// set based on the context using, e.g., 4769/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4770/// set should not contain any member functions; those will be added 4771/// by CreateOverloadedBinOp(). 4772/// 4773/// \param LHS Left-hand argument. 4774/// \param RHS Right-hand argument. 4775Sema::OwningExprResult 4776Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4777 unsigned OpcIn, 4778 FunctionSet &Functions, 4779 Expr *LHS, Expr *RHS) { 4780 Expr *Args[2] = { LHS, RHS }; 4781 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4782 4783 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4784 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4785 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4786 4787 // If either side is type-dependent, create an appropriate dependent 4788 // expression. 4789 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4790 // .* cannot be overloaded. 4791 if (Opc == BinaryOperator::PtrMemD) 4792 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4793 Context.DependentTy, OpLoc)); 4794 4795 OverloadedFunctionDecl *Overloads 4796 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4797 for (FunctionSet::iterator Func = Functions.begin(), 4798 FuncEnd = Functions.end(); 4799 Func != FuncEnd; ++Func) 4800 Overloads->addOverload(*Func); 4801 4802 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4803 OpLoc, false, false); 4804 4805 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4806 Args, 2, 4807 Context.DependentTy, 4808 OpLoc)); 4809 } 4810 4811 // If this is the .* operator, which is not overloadable, just 4812 // create a built-in binary operator. 4813 if (Opc == BinaryOperator::PtrMemD) 4814 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4815 4816 // If this is one of the assignment operators, we only perform 4817 // overload resolution if the left-hand side is a class or 4818 // enumeration type (C++ [expr.ass]p3). 4819 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4820 !Args[0]->getType()->isOverloadableType()) 4821 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4822 4823 // Build an empty overload set. 4824 OverloadCandidateSet CandidateSet; 4825 4826 // Add the candidates from the given function set. 4827 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4828 4829 // Add operator candidates that are member functions. 4830 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4831 4832 // Add builtin operator candidates. 4833 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4834 4835 // Perform overload resolution. 4836 OverloadCandidateSet::iterator Best; 4837 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4838 case OR_Success: { 4839 // We found a built-in operator or an overloaded operator. 4840 FunctionDecl *FnDecl = Best->Function; 4841 4842 if (FnDecl) { 4843 // We matched an overloaded operator. Build a call to that 4844 // operator. 4845 4846 // Convert the arguments. 4847 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4848 if (PerformObjectArgumentInitialization(Args[0], Method) || 4849 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4850 "passing")) 4851 return ExprError(); 4852 } else { 4853 // Convert the arguments. 4854 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4855 "passing") || 4856 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4857 "passing")) 4858 return ExprError(); 4859 } 4860 4861 // Determine the result type 4862 QualType ResultTy 4863 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4864 ResultTy = ResultTy.getNonReferenceType(); 4865 4866 // Build the actual expression node. 4867 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4868 OpLoc); 4869 UsualUnaryConversions(FnExpr); 4870 4871 ExprOwningPtr<CXXOperatorCallExpr> 4872 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4873 Args, 2, ResultTy, 4874 OpLoc)); 4875 4876 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4877 FnDecl)) 4878 return ExprError(); 4879 4880 return MaybeBindToTemporary(TheCall.release()); 4881 } else { 4882 // We matched a built-in operator. Convert the arguments, then 4883 // break out so that we will build the appropriate built-in 4884 // operator node. 4885 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4886 Best->Conversions[0], "passing") || 4887 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4888 Best->Conversions[1], "passing")) 4889 return ExprError(); 4890 4891 break; 4892 } 4893 } 4894 4895 case OR_No_Viable_Function: { 4896 // C++ [over.match.oper]p9: 4897 // If the operator is the operator , [...] and there are no 4898 // viable functions, then the operator is assumed to be the 4899 // built-in operator and interpreted according to clause 5. 4900 if (Opc == BinaryOperator::Comma) 4901 break; 4902 4903 // For class as left operand for assignment or compound assigment operator 4904 // do not fall through to handling in built-in, but report that no overloaded 4905 // assignment operator found 4906 OwningExprResult Result = ExprError(); 4907 if (Args[0]->getType()->isRecordType() && 4908 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4909 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4910 << BinaryOperator::getOpcodeStr(Opc) 4911 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4912 } else { 4913 // No viable function; try to create a built-in operation, which will 4914 // produce an error. Then, show the non-viable candidates. 4915 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4916 } 4917 assert(Result.isInvalid() && 4918 "C++ binary operator overloading is missing candidates!"); 4919 if (Result.isInvalid()) 4920 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 4921 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4922 return move(Result); 4923 } 4924 4925 case OR_Ambiguous: 4926 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4927 << BinaryOperator::getOpcodeStr(Opc) 4928 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4929 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4930 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4931 return ExprError(); 4932 4933 case OR_Deleted: 4934 Diag(OpLoc, diag::err_ovl_deleted_oper) 4935 << Best->Function->isDeleted() 4936 << BinaryOperator::getOpcodeStr(Opc) 4937 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4938 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4939 return ExprError(); 4940 } 4941 4942 // We matched a built-in operator; build it. 4943 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4944} 4945 4946Action::OwningExprResult 4947Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 4948 SourceLocation RLoc, 4949 ExprArg Base, ExprArg Idx) { 4950 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 4951 static_cast<Expr*>(Idx.get()) }; 4952 DeclarationName OpName = 4953 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 4954 4955 // If either side is type-dependent, create an appropriate dependent 4956 // expression. 4957 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4958 4959 OverloadedFunctionDecl *Overloads 4960 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4961 4962 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4963 LLoc, false, false); 4964 4965 Base.release(); 4966 Idx.release(); 4967 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 4968 Args, 2, 4969 Context.DependentTy, 4970 RLoc)); 4971 } 4972 4973 // Build an empty overload set. 4974 OverloadCandidateSet CandidateSet; 4975 4976 // Subscript can only be overloaded as a member function. 4977 4978 // Add operator candidates that are member functions. 4979 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 4980 4981 // Add builtin operator candidates. 4982 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 4983 4984 // Perform overload resolution. 4985 OverloadCandidateSet::iterator Best; 4986 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 4987 case OR_Success: { 4988 // We found a built-in operator or an overloaded operator. 4989 FunctionDecl *FnDecl = Best->Function; 4990 4991 if (FnDecl) { 4992 // We matched an overloaded operator. Build a call to that 4993 // operator. 4994 4995 // Convert the arguments. 4996 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 4997 if (PerformObjectArgumentInitialization(Args[0], Method) || 4998 PerformCopyInitialization(Args[1], 4999 FnDecl->getParamDecl(0)->getType(), 5000 "passing")) 5001 return ExprError(); 5002 5003 // Determine the result type 5004 QualType ResultTy 5005 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5006 ResultTy = ResultTy.getNonReferenceType(); 5007 5008 // Build the actual expression node. 5009 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5010 LLoc); 5011 UsualUnaryConversions(FnExpr); 5012 5013 Base.release(); 5014 Idx.release(); 5015 ExprOwningPtr<CXXOperatorCallExpr> 5016 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5017 FnExpr, Args, 2, 5018 ResultTy, RLoc)); 5019 5020 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5021 FnDecl)) 5022 return ExprError(); 5023 5024 return MaybeBindToTemporary(TheCall.release()); 5025 } else { 5026 // We matched a built-in operator. Convert the arguments, then 5027 // break out so that we will build the appropriate built-in 5028 // operator node. 5029 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5030 Best->Conversions[0], "passing") || 5031 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5032 Best->Conversions[1], "passing")) 5033 return ExprError(); 5034 5035 break; 5036 } 5037 } 5038 5039 case OR_No_Viable_Function: { 5040 // No viable function; try to create a built-in operation, which will 5041 // produce an error. Then, show the non-viable candidates. 5042 OwningExprResult Result = 5043 CreateBuiltinArraySubscriptExpr(move(Base), LLoc, move(Idx), RLoc); 5044 assert(Result.isInvalid() && 5045 "C++ subscript operator overloading is missing candidates!"); 5046 if (Result.isInvalid()) 5047 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 5048 "[]", LLoc); 5049 return move(Result); 5050 } 5051 5052 case OR_Ambiguous: 5053 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5054 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5055 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 5056 "[]", LLoc); 5057 return ExprError(); 5058 5059 case OR_Deleted: 5060 Diag(LLoc, diag::err_ovl_deleted_oper) 5061 << Best->Function->isDeleted() << "[]" 5062 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5063 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5064 return ExprError(); 5065 } 5066 5067 // We matched a built-in operator; build it. 5068 Base.release(); 5069 Idx.release(); 5070 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 5071 Owned(Args[1]), RLoc); 5072} 5073 5074/// BuildCallToMemberFunction - Build a call to a member 5075/// function. MemExpr is the expression that refers to the member 5076/// function (and includes the object parameter), Args/NumArgs are the 5077/// arguments to the function call (not including the object 5078/// parameter). The caller needs to validate that the member 5079/// expression refers to a member function or an overloaded member 5080/// function. 5081Sema::ExprResult 5082Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 5083 SourceLocation LParenLoc, Expr **Args, 5084 unsigned NumArgs, SourceLocation *CommaLocs, 5085 SourceLocation RParenLoc) { 5086 // Dig out the member expression. This holds both the object 5087 // argument and the member function we're referring to. 5088 MemberExpr *MemExpr = 0; 5089 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 5090 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 5091 else 5092 MemExpr = dyn_cast<MemberExpr>(MemExprE); 5093 assert(MemExpr && "Building member call without member expression"); 5094 5095 // Extract the object argument. 5096 Expr *ObjectArg = MemExpr->getBase(); 5097 5098 CXXMethodDecl *Method = 0; 5099 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 5100 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 5101 // Add overload candidates 5102 OverloadCandidateSet CandidateSet; 5103 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 5104 5105 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 5106 Func != FuncEnd; ++Func) { 5107 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) { 5108 // If explicit template arguments were provided, we can't call a 5109 // non-template member function. 5110 if (MemExpr->hasExplicitTemplateArgumentList()) 5111 continue; 5112 5113 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 5114 /*SuppressUserConversions=*/false); 5115 } else 5116 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 5117 MemExpr->hasExplicitTemplateArgumentList(), 5118 MemExpr->getTemplateArgs(), 5119 MemExpr->getNumTemplateArgs(), 5120 ObjectArg, Args, NumArgs, 5121 CandidateSet, 5122 /*SuppressUsedConversions=*/false); 5123 } 5124 5125 OverloadCandidateSet::iterator Best; 5126 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 5127 case OR_Success: 5128 Method = cast<CXXMethodDecl>(Best->Function); 5129 break; 5130 5131 case OR_No_Viable_Function: 5132 Diag(MemExpr->getSourceRange().getBegin(), 5133 diag::err_ovl_no_viable_member_function_in_call) 5134 << DeclName << MemExprE->getSourceRange(); 5135 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5136 // FIXME: Leaking incoming expressions! 5137 return true; 5138 5139 case OR_Ambiguous: 5140 Diag(MemExpr->getSourceRange().getBegin(), 5141 diag::err_ovl_ambiguous_member_call) 5142 << DeclName << MemExprE->getSourceRange(); 5143 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5144 // FIXME: Leaking incoming expressions! 5145 return true; 5146 5147 case OR_Deleted: 5148 Diag(MemExpr->getSourceRange().getBegin(), 5149 diag::err_ovl_deleted_member_call) 5150 << Best->Function->isDeleted() 5151 << DeclName << MemExprE->getSourceRange(); 5152 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5153 // FIXME: Leaking incoming expressions! 5154 return true; 5155 } 5156 5157 FixOverloadedFunctionReference(MemExpr, Method); 5158 } else { 5159 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 5160 } 5161 5162 assert(Method && "Member call to something that isn't a method?"); 5163 ExprOwningPtr<CXXMemberCallExpr> 5164 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 5165 NumArgs, 5166 Method->getResultType().getNonReferenceType(), 5167 RParenLoc)); 5168 5169 // Check for a valid return type. 5170 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 5171 TheCall.get(), Method)) 5172 return true; 5173 5174 // Convert the object argument (for a non-static member function call). 5175 if (!Method->isStatic() && 5176 PerformObjectArgumentInitialization(ObjectArg, Method)) 5177 return true; 5178 MemExpr->setBase(ObjectArg); 5179 5180 // Convert the rest of the arguments 5181 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 5182 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 5183 RParenLoc)) 5184 return true; 5185 5186 if (CheckFunctionCall(Method, TheCall.get())) 5187 return true; 5188 5189 return MaybeBindToTemporary(TheCall.release()).release(); 5190} 5191 5192/// BuildCallToObjectOfClassType - Build a call to an object of class 5193/// type (C++ [over.call.object]), which can end up invoking an 5194/// overloaded function call operator (@c operator()) or performing a 5195/// user-defined conversion on the object argument. 5196Sema::ExprResult 5197Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 5198 SourceLocation LParenLoc, 5199 Expr **Args, unsigned NumArgs, 5200 SourceLocation *CommaLocs, 5201 SourceLocation RParenLoc) { 5202 assert(Object->getType()->isRecordType() && "Requires object type argument"); 5203 const RecordType *Record = Object->getType()->getAs<RecordType>(); 5204 5205 // C++ [over.call.object]p1: 5206 // If the primary-expression E in the function call syntax 5207 // evaluates to a class object of type "cv T", then the set of 5208 // candidate functions includes at least the function call 5209 // operators of T. The function call operators of T are obtained by 5210 // ordinary lookup of the name operator() in the context of 5211 // (E).operator(). 5212 OverloadCandidateSet CandidateSet; 5213 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 5214 DeclContext::lookup_const_iterator Oper, OperEnd; 5215 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 5216 Oper != OperEnd; ++Oper) 5217 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 5218 CandidateSet, /*SuppressUserConversions=*/false); 5219 5220 if (RequireCompleteType(LParenLoc, Object->getType(), 5221 PartialDiagnostic(diag::err_incomplete_object_call) 5222 << Object->getSourceRange())) 5223 return true; 5224 5225 // C++ [over.call.object]p2: 5226 // In addition, for each conversion function declared in T of the 5227 // form 5228 // 5229 // operator conversion-type-id () cv-qualifier; 5230 // 5231 // where cv-qualifier is the same cv-qualification as, or a 5232 // greater cv-qualification than, cv, and where conversion-type-id 5233 // denotes the type "pointer to function of (P1,...,Pn) returning 5234 // R", or the type "reference to pointer to function of 5235 // (P1,...,Pn) returning R", or the type "reference to function 5236 // of (P1,...,Pn) returning R", a surrogate call function [...] 5237 // is also considered as a candidate function. Similarly, 5238 // surrogate call functions are added to the set of candidate 5239 // functions for each conversion function declared in an 5240 // accessible base class provided the function is not hidden 5241 // within T by another intervening declaration. 5242 // FIXME: Look in base classes for more conversion operators! 5243 OverloadedFunctionDecl *Conversions 5244 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 5245 for (OverloadedFunctionDecl::function_iterator 5246 Func = Conversions->function_begin(), 5247 FuncEnd = Conversions->function_end(); 5248 Func != FuncEnd; ++Func) { 5249 CXXConversionDecl *Conv; 5250 FunctionTemplateDecl *ConvTemplate; 5251 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 5252 5253 // Skip over templated conversion functions; they aren't 5254 // surrogates. 5255 if (ConvTemplate) 5256 continue; 5257 5258 // Strip the reference type (if any) and then the pointer type (if 5259 // any) to get down to what might be a function type. 5260 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 5261 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5262 ConvType = ConvPtrType->getPointeeType(); 5263 5264 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 5265 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 5266 } 5267 5268 // Perform overload resolution. 5269 OverloadCandidateSet::iterator Best; 5270 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 5271 case OR_Success: 5272 // Overload resolution succeeded; we'll build the appropriate call 5273 // below. 5274 break; 5275 5276 case OR_No_Viable_Function: 5277 Diag(Object->getSourceRange().getBegin(), 5278 diag::err_ovl_no_viable_object_call) 5279 << Object->getType() << Object->getSourceRange(); 5280 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5281 break; 5282 5283 case OR_Ambiguous: 5284 Diag(Object->getSourceRange().getBegin(), 5285 diag::err_ovl_ambiguous_object_call) 5286 << Object->getType() << Object->getSourceRange(); 5287 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5288 break; 5289 5290 case OR_Deleted: 5291 Diag(Object->getSourceRange().getBegin(), 5292 diag::err_ovl_deleted_object_call) 5293 << Best->Function->isDeleted() 5294 << Object->getType() << Object->getSourceRange(); 5295 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5296 break; 5297 } 5298 5299 if (Best == CandidateSet.end()) { 5300 // We had an error; delete all of the subexpressions and return 5301 // the error. 5302 Object->Destroy(Context); 5303 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5304 Args[ArgIdx]->Destroy(Context); 5305 return true; 5306 } 5307 5308 if (Best->Function == 0) { 5309 // Since there is no function declaration, this is one of the 5310 // surrogate candidates. Dig out the conversion function. 5311 CXXConversionDecl *Conv 5312 = cast<CXXConversionDecl>( 5313 Best->Conversions[0].UserDefined.ConversionFunction); 5314 5315 // We selected one of the surrogate functions that converts the 5316 // object parameter to a function pointer. Perform the conversion 5317 // on the object argument, then let ActOnCallExpr finish the job. 5318 5319 // Create an implicit member expr to refer to the conversion operator. 5320 // and then call it. 5321 CXXMemberCallExpr *CE = 5322 BuildCXXMemberCallExpr(Object, Conv); 5323 5324 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 5325 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 5326 CommaLocs, RParenLoc).release(); 5327 } 5328 5329 // We found an overloaded operator(). Build a CXXOperatorCallExpr 5330 // that calls this method, using Object for the implicit object 5331 // parameter and passing along the remaining arguments. 5332 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5333 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 5334 5335 unsigned NumArgsInProto = Proto->getNumArgs(); 5336 unsigned NumArgsToCheck = NumArgs; 5337 5338 // Build the full argument list for the method call (the 5339 // implicit object parameter is placed at the beginning of the 5340 // list). 5341 Expr **MethodArgs; 5342 if (NumArgs < NumArgsInProto) { 5343 NumArgsToCheck = NumArgsInProto; 5344 MethodArgs = new Expr*[NumArgsInProto + 1]; 5345 } else { 5346 MethodArgs = new Expr*[NumArgs + 1]; 5347 } 5348 MethodArgs[0] = Object; 5349 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5350 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 5351 5352 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 5353 SourceLocation()); 5354 UsualUnaryConversions(NewFn); 5355 5356 // Once we've built TheCall, all of the expressions are properly 5357 // owned. 5358 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5359 ExprOwningPtr<CXXOperatorCallExpr> 5360 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 5361 MethodArgs, NumArgs + 1, 5362 ResultTy, RParenLoc)); 5363 delete [] MethodArgs; 5364 5365 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 5366 Method)) 5367 return true; 5368 5369 // We may have default arguments. If so, we need to allocate more 5370 // slots in the call for them. 5371 if (NumArgs < NumArgsInProto) 5372 TheCall->setNumArgs(Context, NumArgsInProto + 1); 5373 else if (NumArgs > NumArgsInProto) 5374 NumArgsToCheck = NumArgsInProto; 5375 5376 bool IsError = false; 5377 5378 // Initialize the implicit object parameter. 5379 IsError |= PerformObjectArgumentInitialization(Object, Method); 5380 TheCall->setArg(0, Object); 5381 5382 5383 // Check the argument types. 5384 for (unsigned i = 0; i != NumArgsToCheck; i++) { 5385 Expr *Arg; 5386 if (i < NumArgs) { 5387 Arg = Args[i]; 5388 5389 // Pass the argument. 5390 QualType ProtoArgType = Proto->getArgType(i); 5391 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 5392 } else { 5393 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 5394 } 5395 5396 TheCall->setArg(i + 1, Arg); 5397 } 5398 5399 // If this is a variadic call, handle args passed through "...". 5400 if (Proto->isVariadic()) { 5401 // Promote the arguments (C99 6.5.2.2p7). 5402 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 5403 Expr *Arg = Args[i]; 5404 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 5405 TheCall->setArg(i + 1, Arg); 5406 } 5407 } 5408 5409 if (IsError) return true; 5410 5411 if (CheckFunctionCall(Method, TheCall.get())) 5412 return true; 5413 5414 return MaybeBindToTemporary(TheCall.release()).release(); 5415} 5416 5417/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 5418/// (if one exists), where @c Base is an expression of class type and 5419/// @c Member is the name of the member we're trying to find. 5420Sema::OwningExprResult 5421Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 5422 Expr *Base = static_cast<Expr *>(BaseIn.get()); 5423 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 5424 5425 // C++ [over.ref]p1: 5426 // 5427 // [...] An expression x->m is interpreted as (x.operator->())->m 5428 // for a class object x of type T if T::operator->() exists and if 5429 // the operator is selected as the best match function by the 5430 // overload resolution mechanism (13.3). 5431 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 5432 OverloadCandidateSet CandidateSet; 5433 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 5434 5435 LookupResult R; 5436 LookupQualifiedName(R, BaseRecord->getDecl(), OpName, LookupOrdinaryName); 5437 5438 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5439 Oper != OperEnd; ++Oper) 5440 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 5441 /*SuppressUserConversions=*/false); 5442 5443 // Perform overload resolution. 5444 OverloadCandidateSet::iterator Best; 5445 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5446 case OR_Success: 5447 // Overload resolution succeeded; we'll build the call below. 5448 break; 5449 5450 case OR_No_Viable_Function: 5451 if (CandidateSet.empty()) 5452 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5453 << Base->getType() << Base->getSourceRange(); 5454 else 5455 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5456 << "operator->" << Base->getSourceRange(); 5457 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5458 return ExprError(); 5459 5460 case OR_Ambiguous: 5461 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5462 << "->" << Base->getSourceRange(); 5463 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5464 return ExprError(); 5465 5466 case OR_Deleted: 5467 Diag(OpLoc, diag::err_ovl_deleted_oper) 5468 << Best->Function->isDeleted() 5469 << "->" << Base->getSourceRange(); 5470 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5471 return ExprError(); 5472 } 5473 5474 // Convert the object parameter. 5475 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5476 if (PerformObjectArgumentInitialization(Base, Method)) 5477 return ExprError(); 5478 5479 // No concerns about early exits now. 5480 BaseIn.release(); 5481 5482 // Build the operator call. 5483 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5484 SourceLocation()); 5485 UsualUnaryConversions(FnExpr); 5486 5487 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5488 ExprOwningPtr<CXXOperatorCallExpr> 5489 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 5490 &Base, 1, ResultTy, OpLoc)); 5491 5492 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 5493 Method)) 5494 return ExprError(); 5495 return move(TheCall); 5496} 5497 5498/// FixOverloadedFunctionReference - E is an expression that refers to 5499/// a C++ overloaded function (possibly with some parentheses and 5500/// perhaps a '&' around it). We have resolved the overloaded function 5501/// to the function declaration Fn, so patch up the expression E to 5502/// refer (possibly indirectly) to Fn. Returns the new expr. 5503Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5504 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5505 Expr *NewExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5506 PE->setSubExpr(NewExpr); 5507 PE->setType(NewExpr->getType()); 5508 } else if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 5509 Expr *NewExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 5510 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 5511 NewExpr->getType()) && 5512 "Implicit cast type cannot be determined from overload"); 5513 ICE->setSubExpr(NewExpr); 5514 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5515 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5516 "Can only take the address of an overloaded function"); 5517 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5518 if (Method->isStatic()) { 5519 // Do nothing: static member functions aren't any different 5520 // from non-member functions. 5521 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr())) { 5522 if (DRE->getQualifier()) { 5523 // We have taken the address of a pointer to member 5524 // function. Perform the computation here so that we get the 5525 // appropriate pointer to member type. 5526 DRE->setDecl(Fn); 5527 DRE->setType(Fn->getType()); 5528 QualType ClassType 5529 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5530 E->setType(Context.getMemberPointerType(Fn->getType(), 5531 ClassType.getTypePtr())); 5532 return E; 5533 } 5534 } 5535 // FIXME: TemplateIdRefExpr referring to a member function template 5536 // specialization! 5537 } 5538 Expr *NewExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5539 UnOp->setSubExpr(NewExpr); 5540 UnOp->setType(Context.getPointerType(NewExpr->getType())); 5541 5542 return UnOp; 5543 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5544 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5545 isa<FunctionTemplateDecl>(DR->getDecl()) || 5546 isa<FunctionDecl>(DR->getDecl())) && 5547 "Expected function or function template"); 5548 DR->setDecl(Fn); 5549 E->setType(Fn->getType()); 5550 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5551 MemExpr->setMemberDecl(Fn); 5552 E->setType(Fn->getType()); 5553 } else if (TemplateIdRefExpr *TID = dyn_cast<TemplateIdRefExpr>(E)) { 5554 E = DeclRefExpr::Create(Context, 5555 TID->getQualifier(), TID->getQualifierRange(), 5556 Fn, TID->getTemplateNameLoc(), 5557 true, 5558 TID->getLAngleLoc(), 5559 TID->getTemplateArgs(), 5560 TID->getNumTemplateArgs(), 5561 TID->getRAngleLoc(), 5562 Fn->getType(), 5563 /*FIXME?*/false, /*FIXME?*/false); 5564 5565 // FIXME: Don't destroy TID here, since we need its template arguments 5566 // to survive. 5567 // TID->Destroy(Context); 5568 } else if (isa<UnresolvedFunctionNameExpr>(E)) { 5569 return DeclRefExpr::Create(Context, 5570 /*Qualifier=*/0, 5571 /*QualifierRange=*/SourceRange(), 5572 Fn, E->getLocStart(), 5573 Fn->getType(), false, false); 5574 } else { 5575 assert(false && "Invalid reference to overloaded function"); 5576 } 5577 5578 return E; 5579} 5580 5581} // end namespace clang 5582