SemaOverload.cpp revision 5d7d37506319d432f8f5e3952b7427e1e4aacd2e
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInherit.h" 16#include "clang/Basic/Diagnostic.h" 17#include "clang/Lex/Preprocessor.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/TypeOrdering.h" 22#include "clang/Basic/PartialDiagnostic.h" 23#include "llvm/ADT/SmallPtrSet.h" 24#include "llvm/ADT/STLExtras.h" 25#include "llvm/Support/Compiler.h" 26#include <algorithm> 27#include <cstdio> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Qualification_Adjustment, 42 ICC_Promotion, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Conversion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion 55 }; 56 return Category[(int)Kind]; 57} 58 59/// GetConversionRank - Retrieve the implicit conversion rank 60/// corresponding to the given implicit conversion kind. 61ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 62 static const ImplicitConversionRank 63 Rank[(int)ICK_Num_Conversion_Kinds] = { 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Promotion, 70 ICR_Promotion, 71 ICR_Promotion, 72 ICR_Conversion, 73 ICR_Conversion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion 82 }; 83 return Rank[(int)Kind]; 84} 85 86/// GetImplicitConversionName - Return the name of this kind of 87/// implicit conversion. 88const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 89 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 90 "No conversion", 91 "Lvalue-to-rvalue", 92 "Array-to-pointer", 93 "Function-to-pointer", 94 "Qualification", 95 "Integral promotion", 96 "Floating point promotion", 97 "Complex promotion", 98 "Integral conversion", 99 "Floating conversion", 100 "Complex conversion", 101 "Floating-integral conversion", 102 "Complex-real conversion", 103 "Pointer conversion", 104 "Pointer-to-member conversion", 105 "Boolean conversion", 106 "Compatible-types conversion", 107 "Derived-to-base conversion" 108 }; 109 return Name[Kind]; 110} 111 112/// StandardConversionSequence - Set the standard conversion 113/// sequence to the identity conversion. 114void StandardConversionSequence::setAsIdentityConversion() { 115 First = ICK_Identity; 116 Second = ICK_Identity; 117 Third = ICK_Identity; 118 Deprecated = false; 119 ReferenceBinding = false; 120 DirectBinding = false; 121 RRefBinding = false; 122 CopyConstructor = 0; 123} 124 125/// getRank - Retrieve the rank of this standard conversion sequence 126/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 127/// implicit conversions. 128ImplicitConversionRank StandardConversionSequence::getRank() const { 129 ImplicitConversionRank Rank = ICR_Exact_Match; 130 if (GetConversionRank(First) > Rank) 131 Rank = GetConversionRank(First); 132 if (GetConversionRank(Second) > Rank) 133 Rank = GetConversionRank(Second); 134 if (GetConversionRank(Third) > Rank) 135 Rank = GetConversionRank(Third); 136 return Rank; 137} 138 139/// isPointerConversionToBool - Determines whether this conversion is 140/// a conversion of a pointer or pointer-to-member to bool. This is 141/// used as part of the ranking of standard conversion sequences 142/// (C++ 13.3.3.2p4). 143bool StandardConversionSequence::isPointerConversionToBool() const { 144 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 145 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 146 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (ToType->isBooleanType() && 152 (FromType->isPointerType() || FromType->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 167 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 bool PrintedSomething = false; 186 if (First != ICK_Identity) { 187 fprintf(stderr, "%s", GetImplicitConversionName(First)); 188 PrintedSomething = true; 189 } 190 191 if (Second != ICK_Identity) { 192 if (PrintedSomething) { 193 fprintf(stderr, " -> "); 194 } 195 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 196 197 if (CopyConstructor) { 198 fprintf(stderr, " (by copy constructor)"); 199 } else if (DirectBinding) { 200 fprintf(stderr, " (direct reference binding)"); 201 } else if (ReferenceBinding) { 202 fprintf(stderr, " (reference binding)"); 203 } 204 PrintedSomething = true; 205 } 206 207 if (Third != ICK_Identity) { 208 if (PrintedSomething) { 209 fprintf(stderr, " -> "); 210 } 211 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 212 PrintedSomething = true; 213 } 214 215 if (!PrintedSomething) { 216 fprintf(stderr, "No conversions required"); 217 } 218} 219 220/// DebugPrint - Print this user-defined conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void UserDefinedConversionSequence::DebugPrint() const { 223 if (Before.First || Before.Second || Before.Third) { 224 Before.DebugPrint(); 225 fprintf(stderr, " -> "); 226 } 227 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 228 if (After.First || After.Second || After.Third) { 229 fprintf(stderr, " -> "); 230 After.DebugPrint(); 231 } 232} 233 234/// DebugPrint - Print this implicit conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void ImplicitConversionSequence::DebugPrint() const { 237 switch (ConversionKind) { 238 case StandardConversion: 239 fprintf(stderr, "Standard conversion: "); 240 Standard.DebugPrint(); 241 break; 242 case UserDefinedConversion: 243 fprintf(stderr, "User-defined conversion: "); 244 UserDefined.DebugPrint(); 245 break; 246 case EllipsisConversion: 247 fprintf(stderr, "Ellipsis conversion"); 248 break; 249 case BadConversion: 250 fprintf(stderr, "Bad conversion"); 251 break; 252 } 253 254 fprintf(stderr, "\n"); 255} 256 257// IsOverload - Determine whether the given New declaration is an 258// overload of the Old declaration. This routine returns false if New 259// and Old cannot be overloaded, e.g., if they are functions with the 260// same signature (C++ 1.3.10) or if the Old declaration isn't a 261// function (or overload set). When it does return false and Old is an 262// OverloadedFunctionDecl, MatchedDecl will be set to point to the 263// FunctionDecl that New cannot be overloaded with. 264// 265// Example: Given the following input: 266// 267// void f(int, float); // #1 268// void f(int, int); // #2 269// int f(int, int); // #3 270// 271// When we process #1, there is no previous declaration of "f", 272// so IsOverload will not be used. 273// 274// When we process #2, Old is a FunctionDecl for #1. By comparing the 275// parameter types, we see that #1 and #2 are overloaded (since they 276// have different signatures), so this routine returns false; 277// MatchedDecl is unchanged. 278// 279// When we process #3, Old is an OverloadedFunctionDecl containing #1 280// and #2. We compare the signatures of #3 to #1 (they're overloaded, 281// so we do nothing) and then #3 to #2. Since the signatures of #3 and 282// #2 are identical (return types of functions are not part of the 283// signature), IsOverload returns false and MatchedDecl will be set to 284// point to the FunctionDecl for #2. 285bool 286Sema::IsOverload(FunctionDecl *New, Decl* OldD, 287 OverloadedFunctionDecl::function_iterator& MatchedDecl) { 288 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 289 // Is this new function an overload of every function in the 290 // overload set? 291 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 292 FuncEnd = Ovl->function_end(); 293 for (; Func != FuncEnd; ++Func) { 294 if (!IsOverload(New, *Func, MatchedDecl)) { 295 MatchedDecl = Func; 296 return false; 297 } 298 } 299 300 // This function overloads every function in the overload set. 301 return true; 302 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 303 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 304 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 305 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 306 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 307 308 // C++ [temp.fct]p2: 309 // A function template can be overloaded with other function templates 310 // and with normal (non-template) functions. 311 if ((OldTemplate == 0) != (NewTemplate == 0)) 312 return true; 313 314 // Is the function New an overload of the function Old? 315 QualType OldQType = Context.getCanonicalType(Old->getType()); 316 QualType NewQType = Context.getCanonicalType(New->getType()); 317 318 // Compare the signatures (C++ 1.3.10) of the two functions to 319 // determine whether they are overloads. If we find any mismatch 320 // in the signature, they are overloads. 321 322 // If either of these functions is a K&R-style function (no 323 // prototype), then we consider them to have matching signatures. 324 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 325 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 326 return false; 327 328 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 329 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 330 331 // The signature of a function includes the types of its 332 // parameters (C++ 1.3.10), which includes the presence or absence 333 // of the ellipsis; see C++ DR 357). 334 if (OldQType != NewQType && 335 (OldType->getNumArgs() != NewType->getNumArgs() || 336 OldType->isVariadic() != NewType->isVariadic() || 337 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 338 NewType->arg_type_begin()))) 339 return true; 340 341 // C++ [temp.over.link]p4: 342 // The signature of a function template consists of its function 343 // signature, its return type and its template parameter list. The names 344 // of the template parameters are significant only for establishing the 345 // relationship between the template parameters and the rest of the 346 // signature. 347 // 348 // We check the return type and template parameter lists for function 349 // templates first; the remaining checks follow. 350 if (NewTemplate && 351 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 352 OldTemplate->getTemplateParameters(), 353 false, false, SourceLocation()) || 354 OldType->getResultType() != NewType->getResultType())) 355 return true; 356 357 // If the function is a class member, its signature includes the 358 // cv-qualifiers (if any) on the function itself. 359 // 360 // As part of this, also check whether one of the member functions 361 // is static, in which case they are not overloads (C++ 362 // 13.1p2). While not part of the definition of the signature, 363 // this check is important to determine whether these functions 364 // can be overloaded. 365 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 366 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 367 if (OldMethod && NewMethod && 368 !OldMethod->isStatic() && !NewMethod->isStatic() && 369 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 370 return true; 371 372 // The signatures match; this is not an overload. 373 return false; 374 } else { 375 // (C++ 13p1): 376 // Only function declarations can be overloaded; object and type 377 // declarations cannot be overloaded. 378 return false; 379 } 380} 381 382/// TryImplicitConversion - Attempt to perform an implicit conversion 383/// from the given expression (Expr) to the given type (ToType). This 384/// function returns an implicit conversion sequence that can be used 385/// to perform the initialization. Given 386/// 387/// void f(float f); 388/// void g(int i) { f(i); } 389/// 390/// this routine would produce an implicit conversion sequence to 391/// describe the initialization of f from i, which will be a standard 392/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 393/// 4.1) followed by a floating-integral conversion (C++ 4.9). 394// 395/// Note that this routine only determines how the conversion can be 396/// performed; it does not actually perform the conversion. As such, 397/// it will not produce any diagnostics if no conversion is available, 398/// but will instead return an implicit conversion sequence of kind 399/// "BadConversion". 400/// 401/// If @p SuppressUserConversions, then user-defined conversions are 402/// not permitted. 403/// If @p AllowExplicit, then explicit user-defined conversions are 404/// permitted. 405/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 406/// no matter its actual lvalueness. 407ImplicitConversionSequence 408Sema::TryImplicitConversion(Expr* From, QualType ToType, 409 bool SuppressUserConversions, 410 bool AllowExplicit, bool ForceRValue, 411 bool InOverloadResolution) { 412 ImplicitConversionSequence ICS; 413 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 414 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 415 else if (getLangOptions().CPlusPlus && 416 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 417 !SuppressUserConversions, AllowExplicit, 418 ForceRValue)) { 419 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 420 // C++ [over.ics.user]p4: 421 // A conversion of an expression of class type to the same class 422 // type is given Exact Match rank, and a conversion of an 423 // expression of class type to a base class of that type is 424 // given Conversion rank, in spite of the fact that a copy 425 // constructor (i.e., a user-defined conversion function) is 426 // called for those cases. 427 if (CXXConstructorDecl *Constructor 428 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 429 QualType FromCanon 430 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 431 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 432 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 433 // Turn this into a "standard" conversion sequence, so that it 434 // gets ranked with standard conversion sequences. 435 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 436 ICS.Standard.setAsIdentityConversion(); 437 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 438 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 439 ICS.Standard.CopyConstructor = Constructor; 440 if (ToCanon != FromCanon) 441 ICS.Standard.Second = ICK_Derived_To_Base; 442 } 443 } 444 445 // C++ [over.best.ics]p4: 446 // However, when considering the argument of a user-defined 447 // conversion function that is a candidate by 13.3.1.3 when 448 // invoked for the copying of the temporary in the second step 449 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 450 // 13.3.1.6 in all cases, only standard conversion sequences and 451 // ellipsis conversion sequences are allowed. 452 if (SuppressUserConversions && 453 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 454 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 455 } else 456 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 457 458 return ICS; 459} 460 461/// IsStandardConversion - Determines whether there is a standard 462/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 463/// expression From to the type ToType. Standard conversion sequences 464/// only consider non-class types; for conversions that involve class 465/// types, use TryImplicitConversion. If a conversion exists, SCS will 466/// contain the standard conversion sequence required to perform this 467/// conversion and this routine will return true. Otherwise, this 468/// routine will return false and the value of SCS is unspecified. 469bool 470Sema::IsStandardConversion(Expr* From, QualType ToType, 471 bool InOverloadResolution, 472 StandardConversionSequence &SCS) { 473 QualType FromType = From->getType(); 474 475 // Standard conversions (C++ [conv]) 476 SCS.setAsIdentityConversion(); 477 SCS.Deprecated = false; 478 SCS.IncompatibleObjC = false; 479 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 480 SCS.CopyConstructor = 0; 481 482 // There are no standard conversions for class types in C++, so 483 // abort early. When overloading in C, however, we do permit 484 if (FromType->isRecordType() || ToType->isRecordType()) { 485 if (getLangOptions().CPlusPlus) 486 return false; 487 488 // When we're overloading in C, we allow, as standard conversions, 489 } 490 491 // The first conversion can be an lvalue-to-rvalue conversion, 492 // array-to-pointer conversion, or function-to-pointer conversion 493 // (C++ 4p1). 494 495 // Lvalue-to-rvalue conversion (C++ 4.1): 496 // An lvalue (3.10) of a non-function, non-array type T can be 497 // converted to an rvalue. 498 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 499 if (argIsLvalue == Expr::LV_Valid && 500 !FromType->isFunctionType() && !FromType->isArrayType() && 501 Context.getCanonicalType(FromType) != Context.OverloadTy) { 502 SCS.First = ICK_Lvalue_To_Rvalue; 503 504 // If T is a non-class type, the type of the rvalue is the 505 // cv-unqualified version of T. Otherwise, the type of the rvalue 506 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 507 // just strip the qualifiers because they don't matter. 508 509 // FIXME: Doesn't see through to qualifiers behind a typedef! 510 FromType = FromType.getUnqualifiedType(); 511 } else if (FromType->isArrayType()) { 512 // Array-to-pointer conversion (C++ 4.2) 513 SCS.First = ICK_Array_To_Pointer; 514 515 // An lvalue or rvalue of type "array of N T" or "array of unknown 516 // bound of T" can be converted to an rvalue of type "pointer to 517 // T" (C++ 4.2p1). 518 FromType = Context.getArrayDecayedType(FromType); 519 520 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 521 // This conversion is deprecated. (C++ D.4). 522 SCS.Deprecated = true; 523 524 // For the purpose of ranking in overload resolution 525 // (13.3.3.1.1), this conversion is considered an 526 // array-to-pointer conversion followed by a qualification 527 // conversion (4.4). (C++ 4.2p2) 528 SCS.Second = ICK_Identity; 529 SCS.Third = ICK_Qualification; 530 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 531 return true; 532 } 533 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 534 // Function-to-pointer conversion (C++ 4.3). 535 SCS.First = ICK_Function_To_Pointer; 536 537 // An lvalue of function type T can be converted to an rvalue of 538 // type "pointer to T." The result is a pointer to the 539 // function. (C++ 4.3p1). 540 FromType = Context.getPointerType(FromType); 541 } else if (FunctionDecl *Fn 542 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 543 // Address of overloaded function (C++ [over.over]). 544 SCS.First = ICK_Function_To_Pointer; 545 546 // We were able to resolve the address of the overloaded function, 547 // so we can convert to the type of that function. 548 FromType = Fn->getType(); 549 if (ToType->isLValueReferenceType()) 550 FromType = Context.getLValueReferenceType(FromType); 551 else if (ToType->isRValueReferenceType()) 552 FromType = Context.getRValueReferenceType(FromType); 553 else if (ToType->isMemberPointerType()) { 554 // Resolve address only succeeds if both sides are member pointers, 555 // but it doesn't have to be the same class. See DR 247. 556 // Note that this means that the type of &Derived::fn can be 557 // Ret (Base::*)(Args) if the fn overload actually found is from the 558 // base class, even if it was brought into the derived class via a 559 // using declaration. The standard isn't clear on this issue at all. 560 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 561 FromType = Context.getMemberPointerType(FromType, 562 Context.getTypeDeclType(M->getParent()).getTypePtr()); 563 } else 564 FromType = Context.getPointerType(FromType); 565 } else { 566 // We don't require any conversions for the first step. 567 SCS.First = ICK_Identity; 568 } 569 570 // The second conversion can be an integral promotion, floating 571 // point promotion, integral conversion, floating point conversion, 572 // floating-integral conversion, pointer conversion, 573 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 574 // For overloading in C, this can also be a "compatible-type" 575 // conversion. 576 bool IncompatibleObjC = false; 577 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 578 // The unqualified versions of the types are the same: there's no 579 // conversion to do. 580 SCS.Second = ICK_Identity; 581 } else if (IsIntegralPromotion(From, FromType, ToType)) { 582 // Integral promotion (C++ 4.5). 583 SCS.Second = ICK_Integral_Promotion; 584 FromType = ToType.getUnqualifiedType(); 585 } else if (IsFloatingPointPromotion(FromType, ToType)) { 586 // Floating point promotion (C++ 4.6). 587 SCS.Second = ICK_Floating_Promotion; 588 FromType = ToType.getUnqualifiedType(); 589 } else if (IsComplexPromotion(FromType, ToType)) { 590 // Complex promotion (Clang extension) 591 SCS.Second = ICK_Complex_Promotion; 592 FromType = ToType.getUnqualifiedType(); 593 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 594 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 595 // Integral conversions (C++ 4.7). 596 // FIXME: isIntegralType shouldn't be true for enums in C++. 597 SCS.Second = ICK_Integral_Conversion; 598 FromType = ToType.getUnqualifiedType(); 599 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 600 // Floating point conversions (C++ 4.8). 601 SCS.Second = ICK_Floating_Conversion; 602 FromType = ToType.getUnqualifiedType(); 603 } else if (FromType->isComplexType() && ToType->isComplexType()) { 604 // Complex conversions (C99 6.3.1.6) 605 SCS.Second = ICK_Complex_Conversion; 606 FromType = ToType.getUnqualifiedType(); 607 } else if ((FromType->isFloatingType() && 608 ToType->isIntegralType() && (!ToType->isBooleanType() && 609 !ToType->isEnumeralType())) || 610 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 611 ToType->isFloatingType())) { 612 // Floating-integral conversions (C++ 4.9). 613 // FIXME: isIntegralType shouldn't be true for enums in C++. 614 SCS.Second = ICK_Floating_Integral; 615 FromType = ToType.getUnqualifiedType(); 616 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 617 (ToType->isComplexType() && FromType->isArithmeticType())) { 618 // Complex-real conversions (C99 6.3.1.7) 619 SCS.Second = ICK_Complex_Real; 620 FromType = ToType.getUnqualifiedType(); 621 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 622 FromType, IncompatibleObjC)) { 623 // Pointer conversions (C++ 4.10). 624 SCS.Second = ICK_Pointer_Conversion; 625 SCS.IncompatibleObjC = IncompatibleObjC; 626 } else if (IsMemberPointerConversion(From, FromType, ToType, FromType)) { 627 // Pointer to member conversions (4.11). 628 SCS.Second = ICK_Pointer_Member; 629 } else if (ToType->isBooleanType() && 630 (FromType->isArithmeticType() || 631 FromType->isEnumeralType() || 632 FromType->isPointerType() || 633 FromType->isBlockPointerType() || 634 FromType->isMemberPointerType() || 635 FromType->isNullPtrType())) { 636 // Boolean conversions (C++ 4.12). 637 SCS.Second = ICK_Boolean_Conversion; 638 FromType = Context.BoolTy; 639 } else if (!getLangOptions().CPlusPlus && 640 Context.typesAreCompatible(ToType, FromType)) { 641 // Compatible conversions (Clang extension for C function overloading) 642 SCS.Second = ICK_Compatible_Conversion; 643 } else { 644 // No second conversion required. 645 SCS.Second = ICK_Identity; 646 } 647 648 QualType CanonFrom; 649 QualType CanonTo; 650 // The third conversion can be a qualification conversion (C++ 4p1). 651 if (IsQualificationConversion(FromType, ToType)) { 652 SCS.Third = ICK_Qualification; 653 FromType = ToType; 654 CanonFrom = Context.getCanonicalType(FromType); 655 CanonTo = Context.getCanonicalType(ToType); 656 } else { 657 // No conversion required 658 SCS.Third = ICK_Identity; 659 660 // C++ [over.best.ics]p6: 661 // [...] Any difference in top-level cv-qualification is 662 // subsumed by the initialization itself and does not constitute 663 // a conversion. [...] 664 CanonFrom = Context.getCanonicalType(FromType); 665 CanonTo = Context.getCanonicalType(ToType); 666 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 667 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 668 FromType = ToType; 669 CanonFrom = CanonTo; 670 } 671 } 672 673 // If we have not converted the argument type to the parameter type, 674 // this is a bad conversion sequence. 675 if (CanonFrom != CanonTo) 676 return false; 677 678 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 679 return true; 680} 681 682/// IsIntegralPromotion - Determines whether the conversion from the 683/// expression From (whose potentially-adjusted type is FromType) to 684/// ToType is an integral promotion (C++ 4.5). If so, returns true and 685/// sets PromotedType to the promoted type. 686bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 687 const BuiltinType *To = ToType->getAsBuiltinType(); 688 // All integers are built-in. 689 if (!To) { 690 return false; 691 } 692 693 // An rvalue of type char, signed char, unsigned char, short int, or 694 // unsigned short int can be converted to an rvalue of type int if 695 // int can represent all the values of the source type; otherwise, 696 // the source rvalue can be converted to an rvalue of type unsigned 697 // int (C++ 4.5p1). 698 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 699 if (// We can promote any signed, promotable integer type to an int 700 (FromType->isSignedIntegerType() || 701 // We can promote any unsigned integer type whose size is 702 // less than int to an int. 703 (!FromType->isSignedIntegerType() && 704 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 705 return To->getKind() == BuiltinType::Int; 706 } 707 708 return To->getKind() == BuiltinType::UInt; 709 } 710 711 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 712 // can be converted to an rvalue of the first of the following types 713 // that can represent all the values of its underlying type: int, 714 // unsigned int, long, or unsigned long (C++ 4.5p2). 715 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 716 && ToType->isIntegerType()) { 717 // Determine whether the type we're converting from is signed or 718 // unsigned. 719 bool FromIsSigned; 720 uint64_t FromSize = Context.getTypeSize(FromType); 721 if (const EnumType *FromEnumType = FromType->getAsEnumType()) { 722 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 723 FromIsSigned = UnderlyingType->isSignedIntegerType(); 724 } else { 725 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 726 FromIsSigned = true; 727 } 728 729 // The types we'll try to promote to, in the appropriate 730 // order. Try each of these types. 731 QualType PromoteTypes[6] = { 732 Context.IntTy, Context.UnsignedIntTy, 733 Context.LongTy, Context.UnsignedLongTy , 734 Context.LongLongTy, Context.UnsignedLongLongTy 735 }; 736 for (int Idx = 0; Idx < 6; ++Idx) { 737 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 738 if (FromSize < ToSize || 739 (FromSize == ToSize && 740 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 741 // We found the type that we can promote to. If this is the 742 // type we wanted, we have a promotion. Otherwise, no 743 // promotion. 744 return Context.getCanonicalType(ToType).getUnqualifiedType() 745 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 746 } 747 } 748 } 749 750 // An rvalue for an integral bit-field (9.6) can be converted to an 751 // rvalue of type int if int can represent all the values of the 752 // bit-field; otherwise, it can be converted to unsigned int if 753 // unsigned int can represent all the values of the bit-field. If 754 // the bit-field is larger yet, no integral promotion applies to 755 // it. If the bit-field has an enumerated type, it is treated as any 756 // other value of that type for promotion purposes (C++ 4.5p3). 757 // FIXME: We should delay checking of bit-fields until we actually perform the 758 // conversion. 759 using llvm::APSInt; 760 if (From) 761 if (FieldDecl *MemberDecl = From->getBitField()) { 762 APSInt BitWidth; 763 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 764 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 765 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 766 ToSize = Context.getTypeSize(ToType); 767 768 // Are we promoting to an int from a bitfield that fits in an int? 769 if (BitWidth < ToSize || 770 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 771 return To->getKind() == BuiltinType::Int; 772 } 773 774 // Are we promoting to an unsigned int from an unsigned bitfield 775 // that fits into an unsigned int? 776 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 777 return To->getKind() == BuiltinType::UInt; 778 } 779 780 return false; 781 } 782 } 783 784 // An rvalue of type bool can be converted to an rvalue of type int, 785 // with false becoming zero and true becoming one (C++ 4.5p4). 786 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 787 return true; 788 } 789 790 return false; 791} 792 793/// IsFloatingPointPromotion - Determines whether the conversion from 794/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 795/// returns true and sets PromotedType to the promoted type. 796bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 797 /// An rvalue of type float can be converted to an rvalue of type 798 /// double. (C++ 4.6p1). 799 if (const BuiltinType *FromBuiltin = FromType->getAsBuiltinType()) 800 if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType()) { 801 if (FromBuiltin->getKind() == BuiltinType::Float && 802 ToBuiltin->getKind() == BuiltinType::Double) 803 return true; 804 805 // C99 6.3.1.5p1: 806 // When a float is promoted to double or long double, or a 807 // double is promoted to long double [...]. 808 if (!getLangOptions().CPlusPlus && 809 (FromBuiltin->getKind() == BuiltinType::Float || 810 FromBuiltin->getKind() == BuiltinType::Double) && 811 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 812 return true; 813 } 814 815 return false; 816} 817 818/// \brief Determine if a conversion is a complex promotion. 819/// 820/// A complex promotion is defined as a complex -> complex conversion 821/// where the conversion between the underlying real types is a 822/// floating-point or integral promotion. 823bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 824 const ComplexType *FromComplex = FromType->getAsComplexType(); 825 if (!FromComplex) 826 return false; 827 828 const ComplexType *ToComplex = ToType->getAsComplexType(); 829 if (!ToComplex) 830 return false; 831 832 return IsFloatingPointPromotion(FromComplex->getElementType(), 833 ToComplex->getElementType()) || 834 IsIntegralPromotion(0, FromComplex->getElementType(), 835 ToComplex->getElementType()); 836} 837 838/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 839/// the pointer type FromPtr to a pointer to type ToPointee, with the 840/// same type qualifiers as FromPtr has on its pointee type. ToType, 841/// if non-empty, will be a pointer to ToType that may or may not have 842/// the right set of qualifiers on its pointee. 843static QualType 844BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 845 QualType ToPointee, QualType ToType, 846 ASTContext &Context) { 847 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 848 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 849 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 850 851 // Exact qualifier match -> return the pointer type we're converting to. 852 if (CanonToPointee.getCVRQualifiers() == Quals) { 853 // ToType is exactly what we need. Return it. 854 if (ToType.getTypePtr()) 855 return ToType; 856 857 // Build a pointer to ToPointee. It has the right qualifiers 858 // already. 859 return Context.getPointerType(ToPointee); 860 } 861 862 // Just build a canonical type that has the right qualifiers. 863 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 864} 865 866static bool isNullPointerConstantForConversion(Expr *Expr, 867 bool InOverloadResolution, 868 ASTContext &Context) { 869 // Handle value-dependent integral null pointer constants correctly. 870 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 871 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 872 Expr->getType()->isIntegralType()) 873 return !InOverloadResolution; 874 875 return Expr->isNullPointerConstant(Context); 876} 877 878/// IsPointerConversion - Determines whether the conversion of the 879/// expression From, which has the (possibly adjusted) type FromType, 880/// can be converted to the type ToType via a pointer conversion (C++ 881/// 4.10). If so, returns true and places the converted type (that 882/// might differ from ToType in its cv-qualifiers at some level) into 883/// ConvertedType. 884/// 885/// This routine also supports conversions to and from block pointers 886/// and conversions with Objective-C's 'id', 'id<protocols...>', and 887/// pointers to interfaces. FIXME: Once we've determined the 888/// appropriate overloading rules for Objective-C, we may want to 889/// split the Objective-C checks into a different routine; however, 890/// GCC seems to consider all of these conversions to be pointer 891/// conversions, so for now they live here. IncompatibleObjC will be 892/// set if the conversion is an allowed Objective-C conversion that 893/// should result in a warning. 894bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 895 bool InOverloadResolution, 896 QualType& ConvertedType, 897 bool &IncompatibleObjC) { 898 IncompatibleObjC = false; 899 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 900 return true; 901 902 // Conversion from a null pointer constant to any Objective-C pointer type. 903 if (ToType->isObjCObjectPointerType() && 904 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 905 ConvertedType = ToType; 906 return true; 907 } 908 909 // Blocks: Block pointers can be converted to void*. 910 if (FromType->isBlockPointerType() && ToType->isPointerType() && 911 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 912 ConvertedType = ToType; 913 return true; 914 } 915 // Blocks: A null pointer constant can be converted to a block 916 // pointer type. 917 if (ToType->isBlockPointerType() && 918 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 919 ConvertedType = ToType; 920 return true; 921 } 922 923 // If the left-hand-side is nullptr_t, the right side can be a null 924 // pointer constant. 925 if (ToType->isNullPtrType() && 926 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 927 ConvertedType = ToType; 928 return true; 929 } 930 931 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 932 if (!ToTypePtr) 933 return false; 934 935 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 936 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 937 ConvertedType = ToType; 938 return true; 939 } 940 941 // Beyond this point, both types need to be pointers. 942 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 943 if (!FromTypePtr) 944 return false; 945 946 QualType FromPointeeType = FromTypePtr->getPointeeType(); 947 QualType ToPointeeType = ToTypePtr->getPointeeType(); 948 949 // An rvalue of type "pointer to cv T," where T is an object type, 950 // can be converted to an rvalue of type "pointer to cv void" (C++ 951 // 4.10p2). 952 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 953 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 954 ToPointeeType, 955 ToType, Context); 956 return true; 957 } 958 959 // When we're overloading in C, we allow a special kind of pointer 960 // conversion for compatible-but-not-identical pointee types. 961 if (!getLangOptions().CPlusPlus && 962 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 963 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 964 ToPointeeType, 965 ToType, Context); 966 return true; 967 } 968 969 // C++ [conv.ptr]p3: 970 // 971 // An rvalue of type "pointer to cv D," where D is a class type, 972 // can be converted to an rvalue of type "pointer to cv B," where 973 // B is a base class (clause 10) of D. If B is an inaccessible 974 // (clause 11) or ambiguous (10.2) base class of D, a program that 975 // necessitates this conversion is ill-formed. The result of the 976 // conversion is a pointer to the base class sub-object of the 977 // derived class object. The null pointer value is converted to 978 // the null pointer value of the destination type. 979 // 980 // Note that we do not check for ambiguity or inaccessibility 981 // here. That is handled by CheckPointerConversion. 982 if (getLangOptions().CPlusPlus && 983 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 984 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 985 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 986 ToPointeeType, 987 ToType, Context); 988 return true; 989 } 990 991 return false; 992} 993 994/// isObjCPointerConversion - Determines whether this is an 995/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 996/// with the same arguments and return values. 997bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 998 QualType& ConvertedType, 999 bool &IncompatibleObjC) { 1000 if (!getLangOptions().ObjC1) 1001 return false; 1002 1003 // First, we handle all conversions on ObjC object pointer types. 1004 const ObjCObjectPointerType* ToObjCPtr = ToType->getAsObjCObjectPointerType(); 1005 const ObjCObjectPointerType *FromObjCPtr = 1006 FromType->getAsObjCObjectPointerType(); 1007 1008 if (ToObjCPtr && FromObjCPtr) { 1009 // Objective C++: We're able to convert between "id" or "Class" and a 1010 // pointer to any interface (in both directions). 1011 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1012 ConvertedType = ToType; 1013 return true; 1014 } 1015 // Conversions with Objective-C's id<...>. 1016 if ((FromObjCPtr->isObjCQualifiedIdType() || 1017 ToObjCPtr->isObjCQualifiedIdType()) && 1018 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1019 /*compare=*/false)) { 1020 ConvertedType = ToType; 1021 return true; 1022 } 1023 // Objective C++: We're able to convert from a pointer to an 1024 // interface to a pointer to a different interface. 1025 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1026 ConvertedType = ToType; 1027 return true; 1028 } 1029 1030 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1031 // Okay: this is some kind of implicit downcast of Objective-C 1032 // interfaces, which is permitted. However, we're going to 1033 // complain about it. 1034 IncompatibleObjC = true; 1035 ConvertedType = FromType; 1036 return true; 1037 } 1038 } 1039 // Beyond this point, both types need to be C pointers or block pointers. 1040 QualType ToPointeeType; 1041 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1042 ToPointeeType = ToCPtr->getPointeeType(); 1043 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1044 ToPointeeType = ToBlockPtr->getPointeeType(); 1045 else 1046 return false; 1047 1048 QualType FromPointeeType; 1049 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1050 FromPointeeType = FromCPtr->getPointeeType(); 1051 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1052 FromPointeeType = FromBlockPtr->getPointeeType(); 1053 else 1054 return false; 1055 1056 // If we have pointers to pointers, recursively check whether this 1057 // is an Objective-C conversion. 1058 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1059 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1060 IncompatibleObjC)) { 1061 // We always complain about this conversion. 1062 IncompatibleObjC = true; 1063 ConvertedType = ToType; 1064 return true; 1065 } 1066 // If we have pointers to functions or blocks, check whether the only 1067 // differences in the argument and result types are in Objective-C 1068 // pointer conversions. If so, we permit the conversion (but 1069 // complain about it). 1070 const FunctionProtoType *FromFunctionType 1071 = FromPointeeType->getAsFunctionProtoType(); 1072 const FunctionProtoType *ToFunctionType 1073 = ToPointeeType->getAsFunctionProtoType(); 1074 if (FromFunctionType && ToFunctionType) { 1075 // If the function types are exactly the same, this isn't an 1076 // Objective-C pointer conversion. 1077 if (Context.getCanonicalType(FromPointeeType) 1078 == Context.getCanonicalType(ToPointeeType)) 1079 return false; 1080 1081 // Perform the quick checks that will tell us whether these 1082 // function types are obviously different. 1083 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1084 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1085 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1086 return false; 1087 1088 bool HasObjCConversion = false; 1089 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1090 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1091 // Okay, the types match exactly. Nothing to do. 1092 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1093 ToFunctionType->getResultType(), 1094 ConvertedType, IncompatibleObjC)) { 1095 // Okay, we have an Objective-C pointer conversion. 1096 HasObjCConversion = true; 1097 } else { 1098 // Function types are too different. Abort. 1099 return false; 1100 } 1101 1102 // Check argument types. 1103 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1104 ArgIdx != NumArgs; ++ArgIdx) { 1105 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1106 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1107 if (Context.getCanonicalType(FromArgType) 1108 == Context.getCanonicalType(ToArgType)) { 1109 // Okay, the types match exactly. Nothing to do. 1110 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1111 ConvertedType, IncompatibleObjC)) { 1112 // Okay, we have an Objective-C pointer conversion. 1113 HasObjCConversion = true; 1114 } else { 1115 // Argument types are too different. Abort. 1116 return false; 1117 } 1118 } 1119 1120 if (HasObjCConversion) { 1121 // We had an Objective-C conversion. Allow this pointer 1122 // conversion, but complain about it. 1123 ConvertedType = ToType; 1124 IncompatibleObjC = true; 1125 return true; 1126 } 1127 } 1128 1129 return false; 1130} 1131 1132/// CheckPointerConversion - Check the pointer conversion from the 1133/// expression From to the type ToType. This routine checks for 1134/// ambiguous or inaccessible derived-to-base pointer 1135/// conversions for which IsPointerConversion has already returned 1136/// true. It returns true and produces a diagnostic if there was an 1137/// error, or returns false otherwise. 1138bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1139 CastExpr::CastKind &Kind) { 1140 QualType FromType = From->getType(); 1141 1142 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1143 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1144 QualType FromPointeeType = FromPtrType->getPointeeType(), 1145 ToPointeeType = ToPtrType->getPointeeType(); 1146 1147 if (FromPointeeType->isRecordType() && 1148 ToPointeeType->isRecordType()) { 1149 // We must have a derived-to-base conversion. Check an 1150 // ambiguous or inaccessible conversion. 1151 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1152 From->getExprLoc(), 1153 From->getSourceRange())) 1154 return true; 1155 1156 // The conversion was successful. 1157 Kind = CastExpr::CK_DerivedToBase; 1158 } 1159 } 1160 if (const ObjCObjectPointerType *FromPtrType = 1161 FromType->getAsObjCObjectPointerType()) 1162 if (const ObjCObjectPointerType *ToPtrType = 1163 ToType->getAsObjCObjectPointerType()) { 1164 // Objective-C++ conversions are always okay. 1165 // FIXME: We should have a different class of conversions for the 1166 // Objective-C++ implicit conversions. 1167 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1168 return false; 1169 1170 } 1171 return false; 1172} 1173 1174/// IsMemberPointerConversion - Determines whether the conversion of the 1175/// expression From, which has the (possibly adjusted) type FromType, can be 1176/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1177/// If so, returns true and places the converted type (that might differ from 1178/// ToType in its cv-qualifiers at some level) into ConvertedType. 1179bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1180 QualType ToType, QualType &ConvertedType) { 1181 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1182 if (!ToTypePtr) 1183 return false; 1184 1185 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1186 if (From->isNullPointerConstant(Context)) { 1187 ConvertedType = ToType; 1188 return true; 1189 } 1190 1191 // Otherwise, both types have to be member pointers. 1192 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1193 if (!FromTypePtr) 1194 return false; 1195 1196 // A pointer to member of B can be converted to a pointer to member of D, 1197 // where D is derived from B (C++ 4.11p2). 1198 QualType FromClass(FromTypePtr->getClass(), 0); 1199 QualType ToClass(ToTypePtr->getClass(), 0); 1200 // FIXME: What happens when these are dependent? Is this function even called? 1201 1202 if (IsDerivedFrom(ToClass, FromClass)) { 1203 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1204 ToClass.getTypePtr()); 1205 return true; 1206 } 1207 1208 return false; 1209} 1210 1211/// CheckMemberPointerConversion - Check the member pointer conversion from the 1212/// expression From to the type ToType. This routine checks for ambiguous or 1213/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1214/// for which IsMemberPointerConversion has already returned true. It returns 1215/// true and produces a diagnostic if there was an error, or returns false 1216/// otherwise. 1217bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1218 CastExpr::CastKind &Kind) { 1219 QualType FromType = From->getType(); 1220 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1221 if (!FromPtrType) { 1222 // This must be a null pointer to member pointer conversion 1223 assert(From->isNullPointerConstant(Context) && 1224 "Expr must be null pointer constant!"); 1225 Kind = CastExpr::CK_NullToMemberPointer; 1226 return false; 1227 } 1228 1229 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1230 assert(ToPtrType && "No member pointer cast has a target type " 1231 "that is not a member pointer."); 1232 1233 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1234 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1235 1236 // FIXME: What about dependent types? 1237 assert(FromClass->isRecordType() && "Pointer into non-class."); 1238 assert(ToClass->isRecordType() && "Pointer into non-class."); 1239 1240 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1241 /*DetectVirtual=*/true); 1242 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1243 assert(DerivationOkay && 1244 "Should not have been called if derivation isn't OK."); 1245 (void)DerivationOkay; 1246 1247 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1248 getUnqualifiedType())) { 1249 // Derivation is ambiguous. Redo the check to find the exact paths. 1250 Paths.clear(); 1251 Paths.setRecordingPaths(true); 1252 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1253 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1254 (void)StillOkay; 1255 1256 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1257 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1258 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1259 return true; 1260 } 1261 1262 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1263 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1264 << FromClass << ToClass << QualType(VBase, 0) 1265 << From->getSourceRange(); 1266 return true; 1267 } 1268 1269 // Must be a base to derived member conversion. 1270 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1271 return false; 1272} 1273 1274/// IsQualificationConversion - Determines whether the conversion from 1275/// an rvalue of type FromType to ToType is a qualification conversion 1276/// (C++ 4.4). 1277bool 1278Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1279 FromType = Context.getCanonicalType(FromType); 1280 ToType = Context.getCanonicalType(ToType); 1281 1282 // If FromType and ToType are the same type, this is not a 1283 // qualification conversion. 1284 if (FromType == ToType) 1285 return false; 1286 1287 // (C++ 4.4p4): 1288 // A conversion can add cv-qualifiers at levels other than the first 1289 // in multi-level pointers, subject to the following rules: [...] 1290 bool PreviousToQualsIncludeConst = true; 1291 bool UnwrappedAnyPointer = false; 1292 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1293 // Within each iteration of the loop, we check the qualifiers to 1294 // determine if this still looks like a qualification 1295 // conversion. Then, if all is well, we unwrap one more level of 1296 // pointers or pointers-to-members and do it all again 1297 // until there are no more pointers or pointers-to-members left to 1298 // unwrap. 1299 UnwrappedAnyPointer = true; 1300 1301 // -- for every j > 0, if const is in cv 1,j then const is in cv 1302 // 2,j, and similarly for volatile. 1303 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1304 return false; 1305 1306 // -- if the cv 1,j and cv 2,j are different, then const is in 1307 // every cv for 0 < k < j. 1308 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1309 && !PreviousToQualsIncludeConst) 1310 return false; 1311 1312 // Keep track of whether all prior cv-qualifiers in the "to" type 1313 // include const. 1314 PreviousToQualsIncludeConst 1315 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1316 } 1317 1318 // We are left with FromType and ToType being the pointee types 1319 // after unwrapping the original FromType and ToType the same number 1320 // of types. If we unwrapped any pointers, and if FromType and 1321 // ToType have the same unqualified type (since we checked 1322 // qualifiers above), then this is a qualification conversion. 1323 return UnwrappedAnyPointer && 1324 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1325} 1326 1327/// \brief Given a function template or function, extract the function template 1328/// declaration (if any) and the underlying function declaration. 1329template<typename T> 1330static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1331 FunctionTemplateDecl *&FunctionTemplate) { 1332 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1333 if (FunctionTemplate) 1334 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1335 else 1336 Function = cast<T>(Orig); 1337} 1338 1339/// Determines whether there is a user-defined conversion sequence 1340/// (C++ [over.ics.user]) that converts expression From to the type 1341/// ToType. If such a conversion exists, User will contain the 1342/// user-defined conversion sequence that performs such a conversion 1343/// and this routine will return true. Otherwise, this routine returns 1344/// false and User is unspecified. 1345/// 1346/// \param AllowConversionFunctions true if the conversion should 1347/// consider conversion functions at all. If false, only constructors 1348/// will be considered. 1349/// 1350/// \param AllowExplicit true if the conversion should consider C++0x 1351/// "explicit" conversion functions as well as non-explicit conversion 1352/// functions (C++0x [class.conv.fct]p2). 1353/// 1354/// \param ForceRValue true if the expression should be treated as an rvalue 1355/// for overload resolution. 1356bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1357 UserDefinedConversionSequence& User, 1358 bool AllowConversionFunctions, 1359 bool AllowExplicit, bool ForceRValue) { 1360 OverloadCandidateSet CandidateSet; 1361 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1362 if (CXXRecordDecl *ToRecordDecl 1363 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1364 // C++ [over.match.ctor]p1: 1365 // When objects of class type are direct-initialized (8.5), or 1366 // copy-initialized from an expression of the same or a 1367 // derived class type (8.5), overload resolution selects the 1368 // constructor. [...] For copy-initialization, the candidate 1369 // functions are all the converting constructors (12.3.1) of 1370 // that class. The argument list is the expression-list within 1371 // the parentheses of the initializer. 1372 DeclarationName ConstructorName 1373 = Context.DeclarationNames.getCXXConstructorName( 1374 Context.getCanonicalType(ToType).getUnqualifiedType()); 1375 DeclContext::lookup_iterator Con, ConEnd; 1376 for (llvm::tie(Con, ConEnd) 1377 = ToRecordDecl->lookup(ConstructorName); 1378 Con != ConEnd; ++Con) { 1379 // Find the constructor (which may be a template). 1380 CXXConstructorDecl *Constructor = 0; 1381 FunctionTemplateDecl *ConstructorTmpl 1382 = dyn_cast<FunctionTemplateDecl>(*Con); 1383 if (ConstructorTmpl) 1384 Constructor 1385 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1386 else 1387 Constructor = cast<CXXConstructorDecl>(*Con); 1388 1389 if (!Constructor->isInvalidDecl() && 1390 Constructor->isConvertingConstructor(AllowExplicit)) { 1391 if (ConstructorTmpl) 1392 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1393 1, CandidateSet, 1394 /*SuppressUserConversions=*/true, 1395 ForceRValue); 1396 else 1397 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1398 /*SuppressUserConversions=*/true, ForceRValue); 1399 } 1400 } 1401 } 1402 } 1403 1404 if (!AllowConversionFunctions) { 1405 // Don't allow any conversion functions to enter the overload set. 1406 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1407 PDiag(0) 1408 << From->getSourceRange())) { 1409 // No conversion functions from incomplete types. 1410 } else if (const RecordType *FromRecordType 1411 = From->getType()->getAs<RecordType>()) { 1412 if (CXXRecordDecl *FromRecordDecl 1413 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1414 // Add all of the conversion functions as candidates. 1415 OverloadedFunctionDecl *Conversions 1416 = FromRecordDecl->getVisibleConversionFunctions(); 1417 for (OverloadedFunctionDecl::function_iterator Func 1418 = Conversions->function_begin(); 1419 Func != Conversions->function_end(); ++Func) { 1420 CXXConversionDecl *Conv; 1421 FunctionTemplateDecl *ConvTemplate; 1422 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1423 if (ConvTemplate) 1424 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1425 else 1426 Conv = dyn_cast<CXXConversionDecl>(*Func); 1427 1428 if (AllowExplicit || !Conv->isExplicit()) { 1429 if (ConvTemplate) 1430 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1431 CandidateSet); 1432 else 1433 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1434 } 1435 } 1436 } 1437 } 1438 1439 OverloadCandidateSet::iterator Best; 1440 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1441 case OR_Success: 1442 // Record the standard conversion we used and the conversion function. 1443 if (CXXConstructorDecl *Constructor 1444 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1445 // C++ [over.ics.user]p1: 1446 // If the user-defined conversion is specified by a 1447 // constructor (12.3.1), the initial standard conversion 1448 // sequence converts the source type to the type required by 1449 // the argument of the constructor. 1450 // 1451 // FIXME: What about ellipsis conversions? 1452 QualType ThisType = Constructor->getThisType(Context); 1453 User.Before = Best->Conversions[0].Standard; 1454 User.ConversionFunction = Constructor; 1455 User.After.setAsIdentityConversion(); 1456 User.After.FromTypePtr 1457 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1458 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1459 return true; 1460 } else if (CXXConversionDecl *Conversion 1461 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1462 // C++ [over.ics.user]p1: 1463 // 1464 // [...] If the user-defined conversion is specified by a 1465 // conversion function (12.3.2), the initial standard 1466 // conversion sequence converts the source type to the 1467 // implicit object parameter of the conversion function. 1468 User.Before = Best->Conversions[0].Standard; 1469 User.ConversionFunction = Conversion; 1470 1471 // C++ [over.ics.user]p2: 1472 // The second standard conversion sequence converts the 1473 // result of the user-defined conversion to the target type 1474 // for the sequence. Since an implicit conversion sequence 1475 // is an initialization, the special rules for 1476 // initialization by user-defined conversion apply when 1477 // selecting the best user-defined conversion for a 1478 // user-defined conversion sequence (see 13.3.3 and 1479 // 13.3.3.1). 1480 User.After = Best->FinalConversion; 1481 return true; 1482 } else { 1483 assert(false && "Not a constructor or conversion function?"); 1484 return false; 1485 } 1486 1487 case OR_No_Viable_Function: 1488 case OR_Deleted: 1489 // No conversion here! We're done. 1490 return false; 1491 1492 case OR_Ambiguous: 1493 // FIXME: See C++ [over.best.ics]p10 for the handling of 1494 // ambiguous conversion sequences. 1495 return false; 1496 } 1497 1498 return false; 1499} 1500 1501/// CompareImplicitConversionSequences - Compare two implicit 1502/// conversion sequences to determine whether one is better than the 1503/// other or if they are indistinguishable (C++ 13.3.3.2). 1504ImplicitConversionSequence::CompareKind 1505Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1506 const ImplicitConversionSequence& ICS2) 1507{ 1508 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1509 // conversion sequences (as defined in 13.3.3.1) 1510 // -- a standard conversion sequence (13.3.3.1.1) is a better 1511 // conversion sequence than a user-defined conversion sequence or 1512 // an ellipsis conversion sequence, and 1513 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1514 // conversion sequence than an ellipsis conversion sequence 1515 // (13.3.3.1.3). 1516 // 1517 if (ICS1.ConversionKind < ICS2.ConversionKind) 1518 return ImplicitConversionSequence::Better; 1519 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1520 return ImplicitConversionSequence::Worse; 1521 1522 // Two implicit conversion sequences of the same form are 1523 // indistinguishable conversion sequences unless one of the 1524 // following rules apply: (C++ 13.3.3.2p3): 1525 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1526 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1527 else if (ICS1.ConversionKind == 1528 ImplicitConversionSequence::UserDefinedConversion) { 1529 // User-defined conversion sequence U1 is a better conversion 1530 // sequence than another user-defined conversion sequence U2 if 1531 // they contain the same user-defined conversion function or 1532 // constructor and if the second standard conversion sequence of 1533 // U1 is better than the second standard conversion sequence of 1534 // U2 (C++ 13.3.3.2p3). 1535 if (ICS1.UserDefined.ConversionFunction == 1536 ICS2.UserDefined.ConversionFunction) 1537 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1538 ICS2.UserDefined.After); 1539 } 1540 1541 return ImplicitConversionSequence::Indistinguishable; 1542} 1543 1544/// CompareStandardConversionSequences - Compare two standard 1545/// conversion sequences to determine whether one is better than the 1546/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1547ImplicitConversionSequence::CompareKind 1548Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1549 const StandardConversionSequence& SCS2) 1550{ 1551 // Standard conversion sequence S1 is a better conversion sequence 1552 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1553 1554 // -- S1 is a proper subsequence of S2 (comparing the conversion 1555 // sequences in the canonical form defined by 13.3.3.1.1, 1556 // excluding any Lvalue Transformation; the identity conversion 1557 // sequence is considered to be a subsequence of any 1558 // non-identity conversion sequence) or, if not that, 1559 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1560 // Neither is a proper subsequence of the other. Do nothing. 1561 ; 1562 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1563 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1564 (SCS1.Second == ICK_Identity && 1565 SCS1.Third == ICK_Identity)) 1566 // SCS1 is a proper subsequence of SCS2. 1567 return ImplicitConversionSequence::Better; 1568 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1569 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1570 (SCS2.Second == ICK_Identity && 1571 SCS2.Third == ICK_Identity)) 1572 // SCS2 is a proper subsequence of SCS1. 1573 return ImplicitConversionSequence::Worse; 1574 1575 // -- the rank of S1 is better than the rank of S2 (by the rules 1576 // defined below), or, if not that, 1577 ImplicitConversionRank Rank1 = SCS1.getRank(); 1578 ImplicitConversionRank Rank2 = SCS2.getRank(); 1579 if (Rank1 < Rank2) 1580 return ImplicitConversionSequence::Better; 1581 else if (Rank2 < Rank1) 1582 return ImplicitConversionSequence::Worse; 1583 1584 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1585 // are indistinguishable unless one of the following rules 1586 // applies: 1587 1588 // A conversion that is not a conversion of a pointer, or 1589 // pointer to member, to bool is better than another conversion 1590 // that is such a conversion. 1591 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1592 return SCS2.isPointerConversionToBool() 1593 ? ImplicitConversionSequence::Better 1594 : ImplicitConversionSequence::Worse; 1595 1596 // C++ [over.ics.rank]p4b2: 1597 // 1598 // If class B is derived directly or indirectly from class A, 1599 // conversion of B* to A* is better than conversion of B* to 1600 // void*, and conversion of A* to void* is better than conversion 1601 // of B* to void*. 1602 bool SCS1ConvertsToVoid 1603 = SCS1.isPointerConversionToVoidPointer(Context); 1604 bool SCS2ConvertsToVoid 1605 = SCS2.isPointerConversionToVoidPointer(Context); 1606 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1607 // Exactly one of the conversion sequences is a conversion to 1608 // a void pointer; it's the worse conversion. 1609 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1610 : ImplicitConversionSequence::Worse; 1611 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1612 // Neither conversion sequence converts to a void pointer; compare 1613 // their derived-to-base conversions. 1614 if (ImplicitConversionSequence::CompareKind DerivedCK 1615 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1616 return DerivedCK; 1617 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1618 // Both conversion sequences are conversions to void 1619 // pointers. Compare the source types to determine if there's an 1620 // inheritance relationship in their sources. 1621 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1622 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1623 1624 // Adjust the types we're converting from via the array-to-pointer 1625 // conversion, if we need to. 1626 if (SCS1.First == ICK_Array_To_Pointer) 1627 FromType1 = Context.getArrayDecayedType(FromType1); 1628 if (SCS2.First == ICK_Array_To_Pointer) 1629 FromType2 = Context.getArrayDecayedType(FromType2); 1630 1631 QualType FromPointee1 1632 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1633 QualType FromPointee2 1634 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1635 1636 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1637 return ImplicitConversionSequence::Better; 1638 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1639 return ImplicitConversionSequence::Worse; 1640 1641 // Objective-C++: If one interface is more specific than the 1642 // other, it is the better one. 1643 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1644 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1645 if (FromIface1 && FromIface1) { 1646 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1647 return ImplicitConversionSequence::Better; 1648 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1649 return ImplicitConversionSequence::Worse; 1650 } 1651 } 1652 1653 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1654 // bullet 3). 1655 if (ImplicitConversionSequence::CompareKind QualCK 1656 = CompareQualificationConversions(SCS1, SCS2)) 1657 return QualCK; 1658 1659 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1660 // C++0x [over.ics.rank]p3b4: 1661 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1662 // implicit object parameter of a non-static member function declared 1663 // without a ref-qualifier, and S1 binds an rvalue reference to an 1664 // rvalue and S2 binds an lvalue reference. 1665 // FIXME: We don't know if we're dealing with the implicit object parameter, 1666 // or if the member function in this case has a ref qualifier. 1667 // (Of course, we don't have ref qualifiers yet.) 1668 if (SCS1.RRefBinding != SCS2.RRefBinding) 1669 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1670 : ImplicitConversionSequence::Worse; 1671 1672 // C++ [over.ics.rank]p3b4: 1673 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1674 // which the references refer are the same type except for 1675 // top-level cv-qualifiers, and the type to which the reference 1676 // initialized by S2 refers is more cv-qualified than the type 1677 // to which the reference initialized by S1 refers. 1678 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1679 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1680 T1 = Context.getCanonicalType(T1); 1681 T2 = Context.getCanonicalType(T2); 1682 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1683 if (T2.isMoreQualifiedThan(T1)) 1684 return ImplicitConversionSequence::Better; 1685 else if (T1.isMoreQualifiedThan(T2)) 1686 return ImplicitConversionSequence::Worse; 1687 } 1688 } 1689 1690 return ImplicitConversionSequence::Indistinguishable; 1691} 1692 1693/// CompareQualificationConversions - Compares two standard conversion 1694/// sequences to determine whether they can be ranked based on their 1695/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1696ImplicitConversionSequence::CompareKind 1697Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1698 const StandardConversionSequence& SCS2) { 1699 // C++ 13.3.3.2p3: 1700 // -- S1 and S2 differ only in their qualification conversion and 1701 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1702 // cv-qualification signature of type T1 is a proper subset of 1703 // the cv-qualification signature of type T2, and S1 is not the 1704 // deprecated string literal array-to-pointer conversion (4.2). 1705 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1706 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1707 return ImplicitConversionSequence::Indistinguishable; 1708 1709 // FIXME: the example in the standard doesn't use a qualification 1710 // conversion (!) 1711 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1712 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1713 T1 = Context.getCanonicalType(T1); 1714 T2 = Context.getCanonicalType(T2); 1715 1716 // If the types are the same, we won't learn anything by unwrapped 1717 // them. 1718 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1719 return ImplicitConversionSequence::Indistinguishable; 1720 1721 ImplicitConversionSequence::CompareKind Result 1722 = ImplicitConversionSequence::Indistinguishable; 1723 while (UnwrapSimilarPointerTypes(T1, T2)) { 1724 // Within each iteration of the loop, we check the qualifiers to 1725 // determine if this still looks like a qualification 1726 // conversion. Then, if all is well, we unwrap one more level of 1727 // pointers or pointers-to-members and do it all again 1728 // until there are no more pointers or pointers-to-members left 1729 // to unwrap. This essentially mimics what 1730 // IsQualificationConversion does, but here we're checking for a 1731 // strict subset of qualifiers. 1732 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1733 // The qualifiers are the same, so this doesn't tell us anything 1734 // about how the sequences rank. 1735 ; 1736 else if (T2.isMoreQualifiedThan(T1)) { 1737 // T1 has fewer qualifiers, so it could be the better sequence. 1738 if (Result == ImplicitConversionSequence::Worse) 1739 // Neither has qualifiers that are a subset of the other's 1740 // qualifiers. 1741 return ImplicitConversionSequence::Indistinguishable; 1742 1743 Result = ImplicitConversionSequence::Better; 1744 } else if (T1.isMoreQualifiedThan(T2)) { 1745 // T2 has fewer qualifiers, so it could be the better sequence. 1746 if (Result == ImplicitConversionSequence::Better) 1747 // Neither has qualifiers that are a subset of the other's 1748 // qualifiers. 1749 return ImplicitConversionSequence::Indistinguishable; 1750 1751 Result = ImplicitConversionSequence::Worse; 1752 } else { 1753 // Qualifiers are disjoint. 1754 return ImplicitConversionSequence::Indistinguishable; 1755 } 1756 1757 // If the types after this point are equivalent, we're done. 1758 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1759 break; 1760 } 1761 1762 // Check that the winning standard conversion sequence isn't using 1763 // the deprecated string literal array to pointer conversion. 1764 switch (Result) { 1765 case ImplicitConversionSequence::Better: 1766 if (SCS1.Deprecated) 1767 Result = ImplicitConversionSequence::Indistinguishable; 1768 break; 1769 1770 case ImplicitConversionSequence::Indistinguishable: 1771 break; 1772 1773 case ImplicitConversionSequence::Worse: 1774 if (SCS2.Deprecated) 1775 Result = ImplicitConversionSequence::Indistinguishable; 1776 break; 1777 } 1778 1779 return Result; 1780} 1781 1782/// CompareDerivedToBaseConversions - Compares two standard conversion 1783/// sequences to determine whether they can be ranked based on their 1784/// various kinds of derived-to-base conversions (C++ 1785/// [over.ics.rank]p4b3). As part of these checks, we also look at 1786/// conversions between Objective-C interface types. 1787ImplicitConversionSequence::CompareKind 1788Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1789 const StandardConversionSequence& SCS2) { 1790 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1791 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1792 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1793 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1794 1795 // Adjust the types we're converting from via the array-to-pointer 1796 // conversion, if we need to. 1797 if (SCS1.First == ICK_Array_To_Pointer) 1798 FromType1 = Context.getArrayDecayedType(FromType1); 1799 if (SCS2.First == ICK_Array_To_Pointer) 1800 FromType2 = Context.getArrayDecayedType(FromType2); 1801 1802 // Canonicalize all of the types. 1803 FromType1 = Context.getCanonicalType(FromType1); 1804 ToType1 = Context.getCanonicalType(ToType1); 1805 FromType2 = Context.getCanonicalType(FromType2); 1806 ToType2 = Context.getCanonicalType(ToType2); 1807 1808 // C++ [over.ics.rank]p4b3: 1809 // 1810 // If class B is derived directly or indirectly from class A and 1811 // class C is derived directly or indirectly from B, 1812 // 1813 // For Objective-C, we let A, B, and C also be Objective-C 1814 // interfaces. 1815 1816 // Compare based on pointer conversions. 1817 if (SCS1.Second == ICK_Pointer_Conversion && 1818 SCS2.Second == ICK_Pointer_Conversion && 1819 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1820 FromType1->isPointerType() && FromType2->isPointerType() && 1821 ToType1->isPointerType() && ToType2->isPointerType()) { 1822 QualType FromPointee1 1823 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1824 QualType ToPointee1 1825 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1826 QualType FromPointee2 1827 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1828 QualType ToPointee2 1829 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1830 1831 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1832 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1833 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1834 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1835 1836 // -- conversion of C* to B* is better than conversion of C* to A*, 1837 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1838 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1839 return ImplicitConversionSequence::Better; 1840 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1841 return ImplicitConversionSequence::Worse; 1842 1843 if (ToIface1 && ToIface2) { 1844 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1845 return ImplicitConversionSequence::Better; 1846 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1847 return ImplicitConversionSequence::Worse; 1848 } 1849 } 1850 1851 // -- conversion of B* to A* is better than conversion of C* to A*, 1852 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1853 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1854 return ImplicitConversionSequence::Better; 1855 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1856 return ImplicitConversionSequence::Worse; 1857 1858 if (FromIface1 && FromIface2) { 1859 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1860 return ImplicitConversionSequence::Better; 1861 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1862 return ImplicitConversionSequence::Worse; 1863 } 1864 } 1865 } 1866 1867 // Compare based on reference bindings. 1868 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1869 SCS1.Second == ICK_Derived_To_Base) { 1870 // -- binding of an expression of type C to a reference of type 1871 // B& is better than binding an expression of type C to a 1872 // reference of type A&, 1873 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1874 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1875 if (IsDerivedFrom(ToType1, ToType2)) 1876 return ImplicitConversionSequence::Better; 1877 else if (IsDerivedFrom(ToType2, ToType1)) 1878 return ImplicitConversionSequence::Worse; 1879 } 1880 1881 // -- binding of an expression of type B to a reference of type 1882 // A& is better than binding an expression of type C to a 1883 // reference of type A&, 1884 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1885 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1886 if (IsDerivedFrom(FromType2, FromType1)) 1887 return ImplicitConversionSequence::Better; 1888 else if (IsDerivedFrom(FromType1, FromType2)) 1889 return ImplicitConversionSequence::Worse; 1890 } 1891 } 1892 1893 1894 // FIXME: conversion of A::* to B::* is better than conversion of 1895 // A::* to C::*, 1896 1897 // FIXME: conversion of B::* to C::* is better than conversion of 1898 // A::* to C::*, and 1899 1900 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1901 SCS1.Second == ICK_Derived_To_Base) { 1902 // -- conversion of C to B is better than conversion of C to A, 1903 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1904 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1905 if (IsDerivedFrom(ToType1, ToType2)) 1906 return ImplicitConversionSequence::Better; 1907 else if (IsDerivedFrom(ToType2, ToType1)) 1908 return ImplicitConversionSequence::Worse; 1909 } 1910 1911 // -- conversion of B to A is better than conversion of C to A. 1912 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1913 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1914 if (IsDerivedFrom(FromType2, FromType1)) 1915 return ImplicitConversionSequence::Better; 1916 else if (IsDerivedFrom(FromType1, FromType2)) 1917 return ImplicitConversionSequence::Worse; 1918 } 1919 } 1920 1921 return ImplicitConversionSequence::Indistinguishable; 1922} 1923 1924/// TryCopyInitialization - Try to copy-initialize a value of type 1925/// ToType from the expression From. Return the implicit conversion 1926/// sequence required to pass this argument, which may be a bad 1927/// conversion sequence (meaning that the argument cannot be passed to 1928/// a parameter of this type). If @p SuppressUserConversions, then we 1929/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1930/// then we treat @p From as an rvalue, even if it is an lvalue. 1931ImplicitConversionSequence 1932Sema::TryCopyInitialization(Expr *From, QualType ToType, 1933 bool SuppressUserConversions, bool ForceRValue, 1934 bool InOverloadResolution) { 1935 if (ToType->isReferenceType()) { 1936 ImplicitConversionSequence ICS; 1937 CheckReferenceInit(From, ToType, 1938 SuppressUserConversions, 1939 /*AllowExplicit=*/false, 1940 ForceRValue, 1941 &ICS); 1942 return ICS; 1943 } else { 1944 return TryImplicitConversion(From, ToType, 1945 SuppressUserConversions, 1946 /*AllowExplicit=*/false, 1947 ForceRValue, 1948 InOverloadResolution); 1949 } 1950} 1951 1952/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1953/// the expression @p From. Returns true (and emits a diagnostic) if there was 1954/// an error, returns false if the initialization succeeded. Elidable should 1955/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1956/// differently in C++0x for this case. 1957bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1958 const char* Flavor, bool Elidable) { 1959 if (!getLangOptions().CPlusPlus) { 1960 // In C, argument passing is the same as performing an assignment. 1961 QualType FromType = From->getType(); 1962 1963 AssignConvertType ConvTy = 1964 CheckSingleAssignmentConstraints(ToType, From); 1965 if (ConvTy != Compatible && 1966 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1967 ConvTy = Compatible; 1968 1969 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1970 FromType, From, Flavor); 1971 } 1972 1973 if (ToType->isReferenceType()) 1974 return CheckReferenceInit(From, ToType, 1975 /*SuppressUserConversions=*/false, 1976 /*AllowExplicit=*/false, 1977 /*ForceRValue=*/false); 1978 1979 if (!PerformImplicitConversion(From, ToType, Flavor, 1980 /*AllowExplicit=*/false, Elidable)) 1981 return false; 1982 1983 return Diag(From->getSourceRange().getBegin(), 1984 diag::err_typecheck_convert_incompatible) 1985 << ToType << From->getType() << Flavor << From->getSourceRange(); 1986} 1987 1988/// TryObjectArgumentInitialization - Try to initialize the object 1989/// parameter of the given member function (@c Method) from the 1990/// expression @p From. 1991ImplicitConversionSequence 1992Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1993 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1994 unsigned MethodQuals = Method->getTypeQualifiers(); 1995 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 1996 1997 // Set up the conversion sequence as a "bad" conversion, to allow us 1998 // to exit early. 1999 ImplicitConversionSequence ICS; 2000 ICS.Standard.setAsIdentityConversion(); 2001 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2002 2003 // We need to have an object of class type. 2004 QualType FromType = From->getType(); 2005 if (const PointerType *PT = FromType->getAs<PointerType>()) 2006 FromType = PT->getPointeeType(); 2007 2008 assert(FromType->isRecordType()); 2009 2010 // The implicit object parmeter is has the type "reference to cv X", 2011 // where X is the class of which the function is a member 2012 // (C++ [over.match.funcs]p4). However, when finding an implicit 2013 // conversion sequence for the argument, we are not allowed to 2014 // create temporaries or perform user-defined conversions 2015 // (C++ [over.match.funcs]p5). We perform a simplified version of 2016 // reference binding here, that allows class rvalues to bind to 2017 // non-constant references. 2018 2019 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2020 // with the implicit object parameter (C++ [over.match.funcs]p5). 2021 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2022 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 2023 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 2024 return ICS; 2025 2026 // Check that we have either the same type or a derived type. It 2027 // affects the conversion rank. 2028 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2029 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2030 ICS.Standard.Second = ICK_Identity; 2031 else if (IsDerivedFrom(FromType, ClassType)) 2032 ICS.Standard.Second = ICK_Derived_To_Base; 2033 else 2034 return ICS; 2035 2036 // Success. Mark this as a reference binding. 2037 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2038 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2039 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2040 ICS.Standard.ReferenceBinding = true; 2041 ICS.Standard.DirectBinding = true; 2042 ICS.Standard.RRefBinding = false; 2043 return ICS; 2044} 2045 2046/// PerformObjectArgumentInitialization - Perform initialization of 2047/// the implicit object parameter for the given Method with the given 2048/// expression. 2049bool 2050Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2051 QualType FromRecordType, DestType; 2052 QualType ImplicitParamRecordType = 2053 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2054 2055 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2056 FromRecordType = PT->getPointeeType(); 2057 DestType = Method->getThisType(Context); 2058 } else { 2059 FromRecordType = From->getType(); 2060 DestType = ImplicitParamRecordType; 2061 } 2062 2063 ImplicitConversionSequence ICS 2064 = TryObjectArgumentInitialization(From, Method); 2065 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2066 return Diag(From->getSourceRange().getBegin(), 2067 diag::err_implicit_object_parameter_init) 2068 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2069 2070 if (ICS.Standard.Second == ICK_Derived_To_Base && 2071 CheckDerivedToBaseConversion(FromRecordType, 2072 ImplicitParamRecordType, 2073 From->getSourceRange().getBegin(), 2074 From->getSourceRange())) 2075 return true; 2076 2077 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2078 /*isLvalue=*/true); 2079 return false; 2080} 2081 2082/// TryContextuallyConvertToBool - Attempt to contextually convert the 2083/// expression From to bool (C++0x [conv]p3). 2084ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2085 return TryImplicitConversion(From, Context.BoolTy, 2086 // FIXME: Are these flags correct? 2087 /*SuppressUserConversions=*/false, 2088 /*AllowExplicit=*/true, 2089 /*ForceRValue=*/false, 2090 /*InOverloadResolution=*/false); 2091} 2092 2093/// PerformContextuallyConvertToBool - Perform a contextual conversion 2094/// of the expression From to bool (C++0x [conv]p3). 2095bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2096 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2097 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2098 return false; 2099 2100 return Diag(From->getSourceRange().getBegin(), 2101 diag::err_typecheck_bool_condition) 2102 << From->getType() << From->getSourceRange(); 2103} 2104 2105/// AddOverloadCandidate - Adds the given function to the set of 2106/// candidate functions, using the given function call arguments. If 2107/// @p SuppressUserConversions, then don't allow user-defined 2108/// conversions via constructors or conversion operators. 2109/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2110/// hacky way to implement the overloading rules for elidable copy 2111/// initialization in C++0x (C++0x 12.8p15). 2112void 2113Sema::AddOverloadCandidate(FunctionDecl *Function, 2114 Expr **Args, unsigned NumArgs, 2115 OverloadCandidateSet& CandidateSet, 2116 bool SuppressUserConversions, 2117 bool ForceRValue) { 2118 const FunctionProtoType* Proto 2119 = dyn_cast<FunctionProtoType>(Function->getType()->getAsFunctionType()); 2120 assert(Proto && "Functions without a prototype cannot be overloaded"); 2121 assert(!isa<CXXConversionDecl>(Function) && 2122 "Use AddConversionCandidate for conversion functions"); 2123 assert(!Function->getDescribedFunctionTemplate() && 2124 "Use AddTemplateOverloadCandidate for function templates"); 2125 2126 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2127 if (!isa<CXXConstructorDecl>(Method)) { 2128 // If we get here, it's because we're calling a member function 2129 // that is named without a member access expression (e.g., 2130 // "this->f") that was either written explicitly or created 2131 // implicitly. This can happen with a qualified call to a member 2132 // function, e.g., X::f(). We use a NULL object as the implied 2133 // object argument (C++ [over.call.func]p3). 2134 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2135 SuppressUserConversions, ForceRValue); 2136 return; 2137 } 2138 // We treat a constructor like a non-member function, since its object 2139 // argument doesn't participate in overload resolution. 2140 } 2141 2142 2143 // Add this candidate 2144 CandidateSet.push_back(OverloadCandidate()); 2145 OverloadCandidate& Candidate = CandidateSet.back(); 2146 Candidate.Function = Function; 2147 Candidate.Viable = true; 2148 Candidate.IsSurrogate = false; 2149 Candidate.IgnoreObjectArgument = false; 2150 2151 unsigned NumArgsInProto = Proto->getNumArgs(); 2152 2153 // (C++ 13.3.2p2): A candidate function having fewer than m 2154 // parameters is viable only if it has an ellipsis in its parameter 2155 // list (8.3.5). 2156 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2157 Candidate.Viable = false; 2158 return; 2159 } 2160 2161 // (C++ 13.3.2p2): A candidate function having more than m parameters 2162 // is viable only if the (m+1)st parameter has a default argument 2163 // (8.3.6). For the purposes of overload resolution, the 2164 // parameter list is truncated on the right, so that there are 2165 // exactly m parameters. 2166 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2167 if (NumArgs < MinRequiredArgs) { 2168 // Not enough arguments. 2169 Candidate.Viable = false; 2170 return; 2171 } 2172 2173 // Determine the implicit conversion sequences for each of the 2174 // arguments. 2175 Candidate.Conversions.resize(NumArgs); 2176 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2177 if (ArgIdx < NumArgsInProto) { 2178 // (C++ 13.3.2p3): for F to be a viable function, there shall 2179 // exist for each argument an implicit conversion sequence 2180 // (13.3.3.1) that converts that argument to the corresponding 2181 // parameter of F. 2182 QualType ParamType = Proto->getArgType(ArgIdx); 2183 Candidate.Conversions[ArgIdx] 2184 = TryCopyInitialization(Args[ArgIdx], ParamType, 2185 SuppressUserConversions, ForceRValue, 2186 /*InOverloadResolution=*/true); 2187 if (Candidate.Conversions[ArgIdx].ConversionKind 2188 == ImplicitConversionSequence::BadConversion) { 2189 Candidate.Viable = false; 2190 break; 2191 } 2192 } else { 2193 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2194 // argument for which there is no corresponding parameter is 2195 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2196 Candidate.Conversions[ArgIdx].ConversionKind 2197 = ImplicitConversionSequence::EllipsisConversion; 2198 } 2199 } 2200} 2201 2202/// \brief Add all of the function declarations in the given function set to 2203/// the overload canddiate set. 2204void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2205 Expr **Args, unsigned NumArgs, 2206 OverloadCandidateSet& CandidateSet, 2207 bool SuppressUserConversions) { 2208 for (FunctionSet::const_iterator F = Functions.begin(), 2209 FEnd = Functions.end(); 2210 F != FEnd; ++F) { 2211 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) 2212 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2213 SuppressUserConversions); 2214 else 2215 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*F), 2216 /*FIXME: explicit args */false, 0, 0, 2217 Args, NumArgs, CandidateSet, 2218 SuppressUserConversions); 2219 } 2220} 2221 2222/// AddMethodCandidate - Adds the given C++ member function to the set 2223/// of candidate functions, using the given function call arguments 2224/// and the object argument (@c Object). For example, in a call 2225/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2226/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2227/// allow user-defined conversions via constructors or conversion 2228/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2229/// a slightly hacky way to implement the overloading rules for elidable copy 2230/// initialization in C++0x (C++0x 12.8p15). 2231void 2232Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2233 Expr **Args, unsigned NumArgs, 2234 OverloadCandidateSet& CandidateSet, 2235 bool SuppressUserConversions, bool ForceRValue) { 2236 const FunctionProtoType* Proto 2237 = dyn_cast<FunctionProtoType>(Method->getType()->getAsFunctionType()); 2238 assert(Proto && "Methods without a prototype cannot be overloaded"); 2239 assert(!isa<CXXConversionDecl>(Method) && 2240 "Use AddConversionCandidate for conversion functions"); 2241 assert(!isa<CXXConstructorDecl>(Method) && 2242 "Use AddOverloadCandidate for constructors"); 2243 2244 // Add this candidate 2245 CandidateSet.push_back(OverloadCandidate()); 2246 OverloadCandidate& Candidate = CandidateSet.back(); 2247 Candidate.Function = Method; 2248 Candidate.IsSurrogate = false; 2249 Candidate.IgnoreObjectArgument = false; 2250 2251 unsigned NumArgsInProto = Proto->getNumArgs(); 2252 2253 // (C++ 13.3.2p2): A candidate function having fewer than m 2254 // parameters is viable only if it has an ellipsis in its parameter 2255 // list (8.3.5). 2256 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2257 Candidate.Viable = false; 2258 return; 2259 } 2260 2261 // (C++ 13.3.2p2): A candidate function having more than m parameters 2262 // is viable only if the (m+1)st parameter has a default argument 2263 // (8.3.6). For the purposes of overload resolution, the 2264 // parameter list is truncated on the right, so that there are 2265 // exactly m parameters. 2266 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2267 if (NumArgs < MinRequiredArgs) { 2268 // Not enough arguments. 2269 Candidate.Viable = false; 2270 return; 2271 } 2272 2273 Candidate.Viable = true; 2274 Candidate.Conversions.resize(NumArgs + 1); 2275 2276 if (Method->isStatic() || !Object) 2277 // The implicit object argument is ignored. 2278 Candidate.IgnoreObjectArgument = true; 2279 else { 2280 // Determine the implicit conversion sequence for the object 2281 // parameter. 2282 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2283 if (Candidate.Conversions[0].ConversionKind 2284 == ImplicitConversionSequence::BadConversion) { 2285 Candidate.Viable = false; 2286 return; 2287 } 2288 } 2289 2290 // Determine the implicit conversion sequences for each of the 2291 // arguments. 2292 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2293 if (ArgIdx < NumArgsInProto) { 2294 // (C++ 13.3.2p3): for F to be a viable function, there shall 2295 // exist for each argument an implicit conversion sequence 2296 // (13.3.3.1) that converts that argument to the corresponding 2297 // parameter of F. 2298 QualType ParamType = Proto->getArgType(ArgIdx); 2299 Candidate.Conversions[ArgIdx + 1] 2300 = TryCopyInitialization(Args[ArgIdx], ParamType, 2301 SuppressUserConversions, ForceRValue, 2302 /*InOverloadResolution=*/true); 2303 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2304 == ImplicitConversionSequence::BadConversion) { 2305 Candidate.Viable = false; 2306 break; 2307 } 2308 } else { 2309 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2310 // argument for which there is no corresponding parameter is 2311 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2312 Candidate.Conversions[ArgIdx + 1].ConversionKind 2313 = ImplicitConversionSequence::EllipsisConversion; 2314 } 2315 } 2316} 2317 2318/// \brief Add a C++ member function template as a candidate to the candidate 2319/// set, using template argument deduction to produce an appropriate member 2320/// function template specialization. 2321void 2322Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2323 bool HasExplicitTemplateArgs, 2324 const TemplateArgument *ExplicitTemplateArgs, 2325 unsigned NumExplicitTemplateArgs, 2326 Expr *Object, Expr **Args, unsigned NumArgs, 2327 OverloadCandidateSet& CandidateSet, 2328 bool SuppressUserConversions, 2329 bool ForceRValue) { 2330 // C++ [over.match.funcs]p7: 2331 // In each case where a candidate is a function template, candidate 2332 // function template specializations are generated using template argument 2333 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2334 // candidate functions in the usual way.113) A given name can refer to one 2335 // or more function templates and also to a set of overloaded non-template 2336 // functions. In such a case, the candidate functions generated from each 2337 // function template are combined with the set of non-template candidate 2338 // functions. 2339 TemplateDeductionInfo Info(Context); 2340 FunctionDecl *Specialization = 0; 2341 if (TemplateDeductionResult Result 2342 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2343 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2344 Args, NumArgs, Specialization, Info)) { 2345 // FIXME: Record what happened with template argument deduction, so 2346 // that we can give the user a beautiful diagnostic. 2347 (void)Result; 2348 return; 2349 } 2350 2351 // Add the function template specialization produced by template argument 2352 // deduction as a candidate. 2353 assert(Specialization && "Missing member function template specialization?"); 2354 assert(isa<CXXMethodDecl>(Specialization) && 2355 "Specialization is not a member function?"); 2356 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2357 CandidateSet, SuppressUserConversions, ForceRValue); 2358} 2359 2360/// \brief Add a C++ function template specialization as a candidate 2361/// in the candidate set, using template argument deduction to produce 2362/// an appropriate function template specialization. 2363void 2364Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2365 bool HasExplicitTemplateArgs, 2366 const TemplateArgument *ExplicitTemplateArgs, 2367 unsigned NumExplicitTemplateArgs, 2368 Expr **Args, unsigned NumArgs, 2369 OverloadCandidateSet& CandidateSet, 2370 bool SuppressUserConversions, 2371 bool ForceRValue) { 2372 // C++ [over.match.funcs]p7: 2373 // In each case where a candidate is a function template, candidate 2374 // function template specializations are generated using template argument 2375 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2376 // candidate functions in the usual way.113) A given name can refer to one 2377 // or more function templates and also to a set of overloaded non-template 2378 // functions. In such a case, the candidate functions generated from each 2379 // function template are combined with the set of non-template candidate 2380 // functions. 2381 TemplateDeductionInfo Info(Context); 2382 FunctionDecl *Specialization = 0; 2383 if (TemplateDeductionResult Result 2384 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2385 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2386 Args, NumArgs, Specialization, Info)) { 2387 // FIXME: Record what happened with template argument deduction, so 2388 // that we can give the user a beautiful diagnostic. 2389 (void)Result; 2390 return; 2391 } 2392 2393 // Add the function template specialization produced by template argument 2394 // deduction as a candidate. 2395 assert(Specialization && "Missing function template specialization?"); 2396 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2397 SuppressUserConversions, ForceRValue); 2398} 2399 2400/// AddConversionCandidate - Add a C++ conversion function as a 2401/// candidate in the candidate set (C++ [over.match.conv], 2402/// C++ [over.match.copy]). From is the expression we're converting from, 2403/// and ToType is the type that we're eventually trying to convert to 2404/// (which may or may not be the same type as the type that the 2405/// conversion function produces). 2406void 2407Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2408 Expr *From, QualType ToType, 2409 OverloadCandidateSet& CandidateSet) { 2410 assert(!Conversion->getDescribedFunctionTemplate() && 2411 "Conversion function templates use AddTemplateConversionCandidate"); 2412 2413 // Add this candidate 2414 CandidateSet.push_back(OverloadCandidate()); 2415 OverloadCandidate& Candidate = CandidateSet.back(); 2416 Candidate.Function = Conversion; 2417 Candidate.IsSurrogate = false; 2418 Candidate.IgnoreObjectArgument = false; 2419 Candidate.FinalConversion.setAsIdentityConversion(); 2420 Candidate.FinalConversion.FromTypePtr 2421 = Conversion->getConversionType().getAsOpaquePtr(); 2422 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2423 2424 // Determine the implicit conversion sequence for the implicit 2425 // object parameter. 2426 Candidate.Viable = true; 2427 Candidate.Conversions.resize(1); 2428 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2429 // Conversion functions to a different type in the base class is visible in 2430 // the derived class. So, a derived to base conversion should not participate 2431 // in overload resolution. 2432 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2433 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2434 if (Candidate.Conversions[0].ConversionKind 2435 == ImplicitConversionSequence::BadConversion) { 2436 Candidate.Viable = false; 2437 return; 2438 } 2439 2440 // To determine what the conversion from the result of calling the 2441 // conversion function to the type we're eventually trying to 2442 // convert to (ToType), we need to synthesize a call to the 2443 // conversion function and attempt copy initialization from it. This 2444 // makes sure that we get the right semantics with respect to 2445 // lvalues/rvalues and the type. Fortunately, we can allocate this 2446 // call on the stack and we don't need its arguments to be 2447 // well-formed. 2448 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2449 SourceLocation()); 2450 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2451 CastExpr::CK_Unknown, 2452 &ConversionRef, false); 2453 2454 // Note that it is safe to allocate CallExpr on the stack here because 2455 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2456 // allocator). 2457 CallExpr Call(Context, &ConversionFn, 0, 0, 2458 Conversion->getConversionType().getNonReferenceType(), 2459 SourceLocation()); 2460 ImplicitConversionSequence ICS = 2461 TryCopyInitialization(&Call, ToType, 2462 /*SuppressUserConversions=*/true, 2463 /*ForceRValue=*/false, 2464 /*InOverloadResolution=*/false); 2465 2466 switch (ICS.ConversionKind) { 2467 case ImplicitConversionSequence::StandardConversion: 2468 Candidate.FinalConversion = ICS.Standard; 2469 break; 2470 2471 case ImplicitConversionSequence::BadConversion: 2472 Candidate.Viable = false; 2473 break; 2474 2475 default: 2476 assert(false && 2477 "Can only end up with a standard conversion sequence or failure"); 2478 } 2479} 2480 2481/// \brief Adds a conversion function template specialization 2482/// candidate to the overload set, using template argument deduction 2483/// to deduce the template arguments of the conversion function 2484/// template from the type that we are converting to (C++ 2485/// [temp.deduct.conv]). 2486void 2487Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2488 Expr *From, QualType ToType, 2489 OverloadCandidateSet &CandidateSet) { 2490 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2491 "Only conversion function templates permitted here"); 2492 2493 TemplateDeductionInfo Info(Context); 2494 CXXConversionDecl *Specialization = 0; 2495 if (TemplateDeductionResult Result 2496 = DeduceTemplateArguments(FunctionTemplate, ToType, 2497 Specialization, Info)) { 2498 // FIXME: Record what happened with template argument deduction, so 2499 // that we can give the user a beautiful diagnostic. 2500 (void)Result; 2501 return; 2502 } 2503 2504 // Add the conversion function template specialization produced by 2505 // template argument deduction as a candidate. 2506 assert(Specialization && "Missing function template specialization?"); 2507 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2508} 2509 2510/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2511/// converts the given @c Object to a function pointer via the 2512/// conversion function @c Conversion, and then attempts to call it 2513/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2514/// the type of function that we'll eventually be calling. 2515void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2516 const FunctionProtoType *Proto, 2517 Expr *Object, Expr **Args, unsigned NumArgs, 2518 OverloadCandidateSet& CandidateSet) { 2519 CandidateSet.push_back(OverloadCandidate()); 2520 OverloadCandidate& Candidate = CandidateSet.back(); 2521 Candidate.Function = 0; 2522 Candidate.Surrogate = Conversion; 2523 Candidate.Viable = true; 2524 Candidate.IsSurrogate = true; 2525 Candidate.IgnoreObjectArgument = false; 2526 Candidate.Conversions.resize(NumArgs + 1); 2527 2528 // Determine the implicit conversion sequence for the implicit 2529 // object parameter. 2530 ImplicitConversionSequence ObjectInit 2531 = TryObjectArgumentInitialization(Object, Conversion); 2532 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2533 Candidate.Viable = false; 2534 return; 2535 } 2536 2537 // The first conversion is actually a user-defined conversion whose 2538 // first conversion is ObjectInit's standard conversion (which is 2539 // effectively a reference binding). Record it as such. 2540 Candidate.Conversions[0].ConversionKind 2541 = ImplicitConversionSequence::UserDefinedConversion; 2542 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2543 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2544 Candidate.Conversions[0].UserDefined.After 2545 = Candidate.Conversions[0].UserDefined.Before; 2546 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2547 2548 // Find the 2549 unsigned NumArgsInProto = Proto->getNumArgs(); 2550 2551 // (C++ 13.3.2p2): A candidate function having fewer than m 2552 // parameters is viable only if it has an ellipsis in its parameter 2553 // list (8.3.5). 2554 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2555 Candidate.Viable = false; 2556 return; 2557 } 2558 2559 // Function types don't have any default arguments, so just check if 2560 // we have enough arguments. 2561 if (NumArgs < NumArgsInProto) { 2562 // Not enough arguments. 2563 Candidate.Viable = false; 2564 return; 2565 } 2566 2567 // Determine the implicit conversion sequences for each of the 2568 // arguments. 2569 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2570 if (ArgIdx < NumArgsInProto) { 2571 // (C++ 13.3.2p3): for F to be a viable function, there shall 2572 // exist for each argument an implicit conversion sequence 2573 // (13.3.3.1) that converts that argument to the corresponding 2574 // parameter of F. 2575 QualType ParamType = Proto->getArgType(ArgIdx); 2576 Candidate.Conversions[ArgIdx + 1] 2577 = TryCopyInitialization(Args[ArgIdx], ParamType, 2578 /*SuppressUserConversions=*/false, 2579 /*ForceRValue=*/false, 2580 /*InOverloadResolution=*/false); 2581 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2582 == ImplicitConversionSequence::BadConversion) { 2583 Candidate.Viable = false; 2584 break; 2585 } 2586 } else { 2587 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2588 // argument for which there is no corresponding parameter is 2589 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2590 Candidate.Conversions[ArgIdx + 1].ConversionKind 2591 = ImplicitConversionSequence::EllipsisConversion; 2592 } 2593 } 2594} 2595 2596// FIXME: This will eventually be removed, once we've migrated all of the 2597// operator overloading logic over to the scheme used by binary operators, which 2598// works for template instantiation. 2599void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2600 SourceLocation OpLoc, 2601 Expr **Args, unsigned NumArgs, 2602 OverloadCandidateSet& CandidateSet, 2603 SourceRange OpRange) { 2604 2605 FunctionSet Functions; 2606 2607 QualType T1 = Args[0]->getType(); 2608 QualType T2; 2609 if (NumArgs > 1) 2610 T2 = Args[1]->getType(); 2611 2612 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2613 if (S) 2614 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2615 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2616 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2617 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2618 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2619} 2620 2621/// \brief Add overload candidates for overloaded operators that are 2622/// member functions. 2623/// 2624/// Add the overloaded operator candidates that are member functions 2625/// for the operator Op that was used in an operator expression such 2626/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2627/// CandidateSet will store the added overload candidates. (C++ 2628/// [over.match.oper]). 2629void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2630 SourceLocation OpLoc, 2631 Expr **Args, unsigned NumArgs, 2632 OverloadCandidateSet& CandidateSet, 2633 SourceRange OpRange) { 2634 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2635 2636 // C++ [over.match.oper]p3: 2637 // For a unary operator @ with an operand of a type whose 2638 // cv-unqualified version is T1, and for a binary operator @ with 2639 // a left operand of a type whose cv-unqualified version is T1 and 2640 // a right operand of a type whose cv-unqualified version is T2, 2641 // three sets of candidate functions, designated member 2642 // candidates, non-member candidates and built-in candidates, are 2643 // constructed as follows: 2644 QualType T1 = Args[0]->getType(); 2645 QualType T2; 2646 if (NumArgs > 1) 2647 T2 = Args[1]->getType(); 2648 2649 // -- If T1 is a class type, the set of member candidates is the 2650 // result of the qualified lookup of T1::operator@ 2651 // (13.3.1.1.1); otherwise, the set of member candidates is 2652 // empty. 2653 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2654 // Complete the type if it can be completed. Otherwise, we're done. 2655 if (RequireCompleteType(OpLoc, T1, PartialDiagnostic(0))) 2656 return; 2657 2658 LookupResult Operators = LookupQualifiedName(T1Rec->getDecl(), OpName, 2659 LookupOrdinaryName, false); 2660 for (LookupResult::iterator Oper = Operators.begin(), 2661 OperEnd = Operators.end(); 2662 Oper != OperEnd; 2663 ++Oper) 2664 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2665 Args+1, NumArgs - 1, CandidateSet, 2666 /*SuppressUserConversions=*/false); 2667 } 2668} 2669 2670/// AddBuiltinCandidate - Add a candidate for a built-in 2671/// operator. ResultTy and ParamTys are the result and parameter types 2672/// of the built-in candidate, respectively. Args and NumArgs are the 2673/// arguments being passed to the candidate. IsAssignmentOperator 2674/// should be true when this built-in candidate is an assignment 2675/// operator. NumContextualBoolArguments is the number of arguments 2676/// (at the beginning of the argument list) that will be contextually 2677/// converted to bool. 2678void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2679 Expr **Args, unsigned NumArgs, 2680 OverloadCandidateSet& CandidateSet, 2681 bool IsAssignmentOperator, 2682 unsigned NumContextualBoolArguments) { 2683 // Add this candidate 2684 CandidateSet.push_back(OverloadCandidate()); 2685 OverloadCandidate& Candidate = CandidateSet.back(); 2686 Candidate.Function = 0; 2687 Candidate.IsSurrogate = false; 2688 Candidate.IgnoreObjectArgument = false; 2689 Candidate.BuiltinTypes.ResultTy = ResultTy; 2690 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2691 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2692 2693 // Determine the implicit conversion sequences for each of the 2694 // arguments. 2695 Candidate.Viable = true; 2696 Candidate.Conversions.resize(NumArgs); 2697 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2698 // C++ [over.match.oper]p4: 2699 // For the built-in assignment operators, conversions of the 2700 // left operand are restricted as follows: 2701 // -- no temporaries are introduced to hold the left operand, and 2702 // -- no user-defined conversions are applied to the left 2703 // operand to achieve a type match with the left-most 2704 // parameter of a built-in candidate. 2705 // 2706 // We block these conversions by turning off user-defined 2707 // conversions, since that is the only way that initialization of 2708 // a reference to a non-class type can occur from something that 2709 // is not of the same type. 2710 if (ArgIdx < NumContextualBoolArguments) { 2711 assert(ParamTys[ArgIdx] == Context.BoolTy && 2712 "Contextual conversion to bool requires bool type"); 2713 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2714 } else { 2715 Candidate.Conversions[ArgIdx] 2716 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2717 ArgIdx == 0 && IsAssignmentOperator, 2718 /*ForceRValue=*/false, 2719 /*InOverloadResolution=*/false); 2720 } 2721 if (Candidate.Conversions[ArgIdx].ConversionKind 2722 == ImplicitConversionSequence::BadConversion) { 2723 Candidate.Viable = false; 2724 break; 2725 } 2726 } 2727} 2728 2729/// BuiltinCandidateTypeSet - A set of types that will be used for the 2730/// candidate operator functions for built-in operators (C++ 2731/// [over.built]). The types are separated into pointer types and 2732/// enumeration types. 2733class BuiltinCandidateTypeSet { 2734 /// TypeSet - A set of types. 2735 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2736 2737 /// PointerTypes - The set of pointer types that will be used in the 2738 /// built-in candidates. 2739 TypeSet PointerTypes; 2740 2741 /// MemberPointerTypes - The set of member pointer types that will be 2742 /// used in the built-in candidates. 2743 TypeSet MemberPointerTypes; 2744 2745 /// EnumerationTypes - The set of enumeration types that will be 2746 /// used in the built-in candidates. 2747 TypeSet EnumerationTypes; 2748 2749 /// Sema - The semantic analysis instance where we are building the 2750 /// candidate type set. 2751 Sema &SemaRef; 2752 2753 /// Context - The AST context in which we will build the type sets. 2754 ASTContext &Context; 2755 2756 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2757 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2758 2759public: 2760 /// iterator - Iterates through the types that are part of the set. 2761 typedef TypeSet::iterator iterator; 2762 2763 BuiltinCandidateTypeSet(Sema &SemaRef) 2764 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2765 2766 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2767 bool AllowExplicitConversions); 2768 2769 /// pointer_begin - First pointer type found; 2770 iterator pointer_begin() { return PointerTypes.begin(); } 2771 2772 /// pointer_end - Past the last pointer type found; 2773 iterator pointer_end() { return PointerTypes.end(); } 2774 2775 /// member_pointer_begin - First member pointer type found; 2776 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2777 2778 /// member_pointer_end - Past the last member pointer type found; 2779 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2780 2781 /// enumeration_begin - First enumeration type found; 2782 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2783 2784 /// enumeration_end - Past the last enumeration type found; 2785 iterator enumeration_end() { return EnumerationTypes.end(); } 2786}; 2787 2788/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2789/// the set of pointer types along with any more-qualified variants of 2790/// that type. For example, if @p Ty is "int const *", this routine 2791/// will add "int const *", "int const volatile *", "int const 2792/// restrict *", and "int const volatile restrict *" to the set of 2793/// pointer types. Returns true if the add of @p Ty itself succeeded, 2794/// false otherwise. 2795bool 2796BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2797 // Insert this type. 2798 if (!PointerTypes.insert(Ty)) 2799 return false; 2800 2801 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2802 QualType PointeeTy = PointerTy->getPointeeType(); 2803 // FIXME: Optimize this so that we don't keep trying to add the same types. 2804 2805 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal with all 2806 // pointer conversions that don't cast away constness? 2807 if (!PointeeTy.isConstQualified()) 2808 AddPointerWithMoreQualifiedTypeVariants 2809 (Context.getPointerType(PointeeTy.withConst())); 2810 if (!PointeeTy.isVolatileQualified()) 2811 AddPointerWithMoreQualifiedTypeVariants 2812 (Context.getPointerType(PointeeTy.withVolatile())); 2813 if (!PointeeTy.isRestrictQualified()) 2814 AddPointerWithMoreQualifiedTypeVariants 2815 (Context.getPointerType(PointeeTy.withRestrict())); 2816 } 2817 2818 return true; 2819} 2820 2821/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2822/// to the set of pointer types along with any more-qualified variants of 2823/// that type. For example, if @p Ty is "int const *", this routine 2824/// will add "int const *", "int const volatile *", "int const 2825/// restrict *", and "int const volatile restrict *" to the set of 2826/// pointer types. Returns true if the add of @p Ty itself succeeded, 2827/// false otherwise. 2828bool 2829BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2830 QualType Ty) { 2831 // Insert this type. 2832 if (!MemberPointerTypes.insert(Ty)) 2833 return false; 2834 2835 if (const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>()) { 2836 QualType PointeeTy = PointerTy->getPointeeType(); 2837 const Type *ClassTy = PointerTy->getClass(); 2838 // FIXME: Optimize this so that we don't keep trying to add the same types. 2839 2840 if (!PointeeTy.isConstQualified()) 2841 AddMemberPointerWithMoreQualifiedTypeVariants 2842 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2843 if (!PointeeTy.isVolatileQualified()) 2844 AddMemberPointerWithMoreQualifiedTypeVariants 2845 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2846 if (!PointeeTy.isRestrictQualified()) 2847 AddMemberPointerWithMoreQualifiedTypeVariants 2848 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2849 } 2850 2851 return true; 2852} 2853 2854/// AddTypesConvertedFrom - Add each of the types to which the type @p 2855/// Ty can be implicit converted to the given set of @p Types. We're 2856/// primarily interested in pointer types and enumeration types. We also 2857/// take member pointer types, for the conditional operator. 2858/// AllowUserConversions is true if we should look at the conversion 2859/// functions of a class type, and AllowExplicitConversions if we 2860/// should also include the explicit conversion functions of a class 2861/// type. 2862void 2863BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2864 bool AllowUserConversions, 2865 bool AllowExplicitConversions) { 2866 // Only deal with canonical types. 2867 Ty = Context.getCanonicalType(Ty); 2868 2869 // Look through reference types; they aren't part of the type of an 2870 // expression for the purposes of conversions. 2871 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 2872 Ty = RefTy->getPointeeType(); 2873 2874 // We don't care about qualifiers on the type. 2875 Ty = Ty.getUnqualifiedType(); 2876 2877 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2878 QualType PointeeTy = PointerTy->getPointeeType(); 2879 2880 // Insert our type, and its more-qualified variants, into the set 2881 // of types. 2882 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2883 return; 2884 2885 // Add 'cv void*' to our set of types. 2886 if (!Ty->isVoidType()) { 2887 QualType QualVoid 2888 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2889 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2890 } 2891 2892 // If this is a pointer to a class type, add pointers to its bases 2893 // (with the same level of cv-qualification as the original 2894 // derived class, of course). 2895 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 2896 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2897 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2898 Base != ClassDecl->bases_end(); ++Base) { 2899 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2900 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2901 2902 // Add the pointer type, recursively, so that we get all of 2903 // the indirect base classes, too. 2904 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2905 } 2906 } 2907 } else if (Ty->isMemberPointerType()) { 2908 // Member pointers are far easier, since the pointee can't be converted. 2909 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2910 return; 2911 } else if (Ty->isEnumeralType()) { 2912 EnumerationTypes.insert(Ty); 2913 } else if (AllowUserConversions) { 2914 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 2915 if (SemaRef.RequireCompleteType(SourceLocation(), Ty, 0)) { 2916 // No conversion functions in incomplete types. 2917 return; 2918 } 2919 2920 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2921 // FIXME: Visit conversion functions in the base classes, too. 2922 OverloadedFunctionDecl *Conversions 2923 = ClassDecl->getConversionFunctions(); 2924 for (OverloadedFunctionDecl::function_iterator Func 2925 = Conversions->function_begin(); 2926 Func != Conversions->function_end(); ++Func) { 2927 CXXConversionDecl *Conv; 2928 FunctionTemplateDecl *ConvTemplate; 2929 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 2930 2931 // Skip conversion function templates; they don't tell us anything 2932 // about which builtin types we can convert to. 2933 if (ConvTemplate) 2934 continue; 2935 2936 if (AllowExplicitConversions || !Conv->isExplicit()) 2937 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2938 } 2939 } 2940 } 2941} 2942 2943/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 2944/// the volatile- and non-volatile-qualified assignment operators for the 2945/// given type to the candidate set. 2946static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 2947 QualType T, 2948 Expr **Args, 2949 unsigned NumArgs, 2950 OverloadCandidateSet &CandidateSet) { 2951 QualType ParamTypes[2]; 2952 2953 // T& operator=(T&, T) 2954 ParamTypes[0] = S.Context.getLValueReferenceType(T); 2955 ParamTypes[1] = T; 2956 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 2957 /*IsAssignmentOperator=*/true); 2958 2959 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 2960 // volatile T& operator=(volatile T&, T) 2961 ParamTypes[0] = S.Context.getLValueReferenceType(T.withVolatile()); 2962 ParamTypes[1] = T; 2963 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 2964 /*IsAssignmentOperator=*/true); 2965 } 2966} 2967 2968/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2969/// operator overloads to the candidate set (C++ [over.built]), based 2970/// on the operator @p Op and the arguments given. For example, if the 2971/// operator is a binary '+', this routine might add "int 2972/// operator+(int, int)" to cover integer addition. 2973void 2974Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2975 Expr **Args, unsigned NumArgs, 2976 OverloadCandidateSet& CandidateSet) { 2977 // The set of "promoted arithmetic types", which are the arithmetic 2978 // types are that preserved by promotion (C++ [over.built]p2). Note 2979 // that the first few of these types are the promoted integral 2980 // types; these types need to be first. 2981 // FIXME: What about complex? 2982 const unsigned FirstIntegralType = 0; 2983 const unsigned LastIntegralType = 13; 2984 const unsigned FirstPromotedIntegralType = 7, 2985 LastPromotedIntegralType = 13; 2986 const unsigned FirstPromotedArithmeticType = 7, 2987 LastPromotedArithmeticType = 16; 2988 const unsigned NumArithmeticTypes = 16; 2989 QualType ArithmeticTypes[NumArithmeticTypes] = { 2990 Context.BoolTy, Context.CharTy, Context.WCharTy, 2991// FIXME: Context.Char16Ty, Context.Char32Ty, 2992 Context.SignedCharTy, Context.ShortTy, 2993 Context.UnsignedCharTy, Context.UnsignedShortTy, 2994 Context.IntTy, Context.LongTy, Context.LongLongTy, 2995 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 2996 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 2997 }; 2998 2999 // Find all of the types that the arguments can convert to, but only 3000 // if the operator we're looking at has built-in operator candidates 3001 // that make use of these types. 3002 BuiltinCandidateTypeSet CandidateTypes(*this); 3003 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3004 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3005 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3006 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3007 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3008 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3009 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3010 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3011 true, 3012 (Op == OO_Exclaim || 3013 Op == OO_AmpAmp || 3014 Op == OO_PipePipe)); 3015 } 3016 3017 bool isComparison = false; 3018 switch (Op) { 3019 case OO_None: 3020 case NUM_OVERLOADED_OPERATORS: 3021 assert(false && "Expected an overloaded operator"); 3022 break; 3023 3024 case OO_Star: // '*' is either unary or binary 3025 if (NumArgs == 1) 3026 goto UnaryStar; 3027 else 3028 goto BinaryStar; 3029 break; 3030 3031 case OO_Plus: // '+' is either unary or binary 3032 if (NumArgs == 1) 3033 goto UnaryPlus; 3034 else 3035 goto BinaryPlus; 3036 break; 3037 3038 case OO_Minus: // '-' is either unary or binary 3039 if (NumArgs == 1) 3040 goto UnaryMinus; 3041 else 3042 goto BinaryMinus; 3043 break; 3044 3045 case OO_Amp: // '&' is either unary or binary 3046 if (NumArgs == 1) 3047 goto UnaryAmp; 3048 else 3049 goto BinaryAmp; 3050 3051 case OO_PlusPlus: 3052 case OO_MinusMinus: 3053 // C++ [over.built]p3: 3054 // 3055 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3056 // is either volatile or empty, there exist candidate operator 3057 // functions of the form 3058 // 3059 // VQ T& operator++(VQ T&); 3060 // T operator++(VQ T&, int); 3061 // 3062 // C++ [over.built]p4: 3063 // 3064 // For every pair (T, VQ), where T is an arithmetic type other 3065 // than bool, and VQ is either volatile or empty, there exist 3066 // candidate operator functions of the form 3067 // 3068 // VQ T& operator--(VQ T&); 3069 // T operator--(VQ T&, int); 3070 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3071 Arith < NumArithmeticTypes; ++Arith) { 3072 QualType ArithTy = ArithmeticTypes[Arith]; 3073 QualType ParamTypes[2] 3074 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3075 3076 // Non-volatile version. 3077 if (NumArgs == 1) 3078 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3079 else 3080 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3081 3082 // Volatile version 3083 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 3084 if (NumArgs == 1) 3085 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3086 else 3087 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3088 } 3089 3090 // C++ [over.built]p5: 3091 // 3092 // For every pair (T, VQ), where T is a cv-qualified or 3093 // cv-unqualified object type, and VQ is either volatile or 3094 // empty, there exist candidate operator functions of the form 3095 // 3096 // T*VQ& operator++(T*VQ&); 3097 // T*VQ& operator--(T*VQ&); 3098 // T* operator++(T*VQ&, int); 3099 // T* operator--(T*VQ&, int); 3100 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3101 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3102 // Skip pointer types that aren't pointers to object types. 3103 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3104 continue; 3105 3106 QualType ParamTypes[2] = { 3107 Context.getLValueReferenceType(*Ptr), Context.IntTy 3108 }; 3109 3110 // Without volatile 3111 if (NumArgs == 1) 3112 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3113 else 3114 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3115 3116 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3117 // With volatile 3118 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3119 if (NumArgs == 1) 3120 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3121 else 3122 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3123 } 3124 } 3125 break; 3126 3127 UnaryStar: 3128 // C++ [over.built]p6: 3129 // For every cv-qualified or cv-unqualified object type T, there 3130 // exist candidate operator functions of the form 3131 // 3132 // T& operator*(T*); 3133 // 3134 // C++ [over.built]p7: 3135 // For every function type T, there exist candidate operator 3136 // functions of the form 3137 // T& operator*(T*); 3138 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3139 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3140 QualType ParamTy = *Ptr; 3141 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3142 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3143 &ParamTy, Args, 1, CandidateSet); 3144 } 3145 break; 3146 3147 UnaryPlus: 3148 // C++ [over.built]p8: 3149 // For every type T, there exist candidate operator functions of 3150 // the form 3151 // 3152 // T* operator+(T*); 3153 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3154 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3155 QualType ParamTy = *Ptr; 3156 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3157 } 3158 3159 // Fall through 3160 3161 UnaryMinus: 3162 // C++ [over.built]p9: 3163 // For every promoted arithmetic type T, there exist candidate 3164 // operator functions of the form 3165 // 3166 // T operator+(T); 3167 // T operator-(T); 3168 for (unsigned Arith = FirstPromotedArithmeticType; 3169 Arith < LastPromotedArithmeticType; ++Arith) { 3170 QualType ArithTy = ArithmeticTypes[Arith]; 3171 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3172 } 3173 break; 3174 3175 case OO_Tilde: 3176 // C++ [over.built]p10: 3177 // For every promoted integral type T, there exist candidate 3178 // operator functions of the form 3179 // 3180 // T operator~(T); 3181 for (unsigned Int = FirstPromotedIntegralType; 3182 Int < LastPromotedIntegralType; ++Int) { 3183 QualType IntTy = ArithmeticTypes[Int]; 3184 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3185 } 3186 break; 3187 3188 case OO_New: 3189 case OO_Delete: 3190 case OO_Array_New: 3191 case OO_Array_Delete: 3192 case OO_Call: 3193 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3194 break; 3195 3196 case OO_Comma: 3197 UnaryAmp: 3198 case OO_Arrow: 3199 // C++ [over.match.oper]p3: 3200 // -- For the operator ',', the unary operator '&', or the 3201 // operator '->', the built-in candidates set is empty. 3202 break; 3203 3204 case OO_EqualEqual: 3205 case OO_ExclaimEqual: 3206 // C++ [over.match.oper]p16: 3207 // For every pointer to member type T, there exist candidate operator 3208 // functions of the form 3209 // 3210 // bool operator==(T,T); 3211 // bool operator!=(T,T); 3212 for (BuiltinCandidateTypeSet::iterator 3213 MemPtr = CandidateTypes.member_pointer_begin(), 3214 MemPtrEnd = CandidateTypes.member_pointer_end(); 3215 MemPtr != MemPtrEnd; 3216 ++MemPtr) { 3217 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3218 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3219 } 3220 3221 // Fall through 3222 3223 case OO_Less: 3224 case OO_Greater: 3225 case OO_LessEqual: 3226 case OO_GreaterEqual: 3227 // C++ [over.built]p15: 3228 // 3229 // For every pointer or enumeration type T, there exist 3230 // candidate operator functions of the form 3231 // 3232 // bool operator<(T, T); 3233 // bool operator>(T, T); 3234 // bool operator<=(T, T); 3235 // bool operator>=(T, T); 3236 // bool operator==(T, T); 3237 // bool operator!=(T, T); 3238 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3239 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3240 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3241 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3242 } 3243 for (BuiltinCandidateTypeSet::iterator Enum 3244 = CandidateTypes.enumeration_begin(); 3245 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3246 QualType ParamTypes[2] = { *Enum, *Enum }; 3247 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3248 } 3249 3250 // Fall through. 3251 isComparison = true; 3252 3253 BinaryPlus: 3254 BinaryMinus: 3255 if (!isComparison) { 3256 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3257 3258 // C++ [over.built]p13: 3259 // 3260 // For every cv-qualified or cv-unqualified object type T 3261 // there exist candidate operator functions of the form 3262 // 3263 // T* operator+(T*, ptrdiff_t); 3264 // T& operator[](T*, ptrdiff_t); [BELOW] 3265 // T* operator-(T*, ptrdiff_t); 3266 // T* operator+(ptrdiff_t, T*); 3267 // T& operator[](ptrdiff_t, T*); [BELOW] 3268 // 3269 // C++ [over.built]p14: 3270 // 3271 // For every T, where T is a pointer to object type, there 3272 // exist candidate operator functions of the form 3273 // 3274 // ptrdiff_t operator-(T, T); 3275 for (BuiltinCandidateTypeSet::iterator Ptr 3276 = CandidateTypes.pointer_begin(); 3277 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3278 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3279 3280 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3281 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3282 3283 if (Op == OO_Plus) { 3284 // T* operator+(ptrdiff_t, T*); 3285 ParamTypes[0] = ParamTypes[1]; 3286 ParamTypes[1] = *Ptr; 3287 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3288 } else { 3289 // ptrdiff_t operator-(T, T); 3290 ParamTypes[1] = *Ptr; 3291 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3292 Args, 2, CandidateSet); 3293 } 3294 } 3295 } 3296 // Fall through 3297 3298 case OO_Slash: 3299 BinaryStar: 3300 Conditional: 3301 // C++ [over.built]p12: 3302 // 3303 // For every pair of promoted arithmetic types L and R, there 3304 // exist candidate operator functions of the form 3305 // 3306 // LR operator*(L, R); 3307 // LR operator/(L, R); 3308 // LR operator+(L, R); 3309 // LR operator-(L, R); 3310 // bool operator<(L, R); 3311 // bool operator>(L, R); 3312 // bool operator<=(L, R); 3313 // bool operator>=(L, R); 3314 // bool operator==(L, R); 3315 // bool operator!=(L, R); 3316 // 3317 // where LR is the result of the usual arithmetic conversions 3318 // between types L and R. 3319 // 3320 // C++ [over.built]p24: 3321 // 3322 // For every pair of promoted arithmetic types L and R, there exist 3323 // candidate operator functions of the form 3324 // 3325 // LR operator?(bool, L, R); 3326 // 3327 // where LR is the result of the usual arithmetic conversions 3328 // between types L and R. 3329 // Our candidates ignore the first parameter. 3330 for (unsigned Left = FirstPromotedArithmeticType; 3331 Left < LastPromotedArithmeticType; ++Left) { 3332 for (unsigned Right = FirstPromotedArithmeticType; 3333 Right < LastPromotedArithmeticType; ++Right) { 3334 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3335 QualType Result 3336 = isComparison 3337 ? Context.BoolTy 3338 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3339 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3340 } 3341 } 3342 break; 3343 3344 case OO_Percent: 3345 BinaryAmp: 3346 case OO_Caret: 3347 case OO_Pipe: 3348 case OO_LessLess: 3349 case OO_GreaterGreater: 3350 // C++ [over.built]p17: 3351 // 3352 // For every pair of promoted integral types L and R, there 3353 // exist candidate operator functions of the form 3354 // 3355 // LR operator%(L, R); 3356 // LR operator&(L, R); 3357 // LR operator^(L, R); 3358 // LR operator|(L, R); 3359 // L operator<<(L, R); 3360 // L operator>>(L, R); 3361 // 3362 // where LR is the result of the usual arithmetic conversions 3363 // between types L and R. 3364 for (unsigned Left = FirstPromotedIntegralType; 3365 Left < LastPromotedIntegralType; ++Left) { 3366 for (unsigned Right = FirstPromotedIntegralType; 3367 Right < LastPromotedIntegralType; ++Right) { 3368 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3369 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3370 ? LandR[0] 3371 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3372 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3373 } 3374 } 3375 break; 3376 3377 case OO_Equal: 3378 // C++ [over.built]p20: 3379 // 3380 // For every pair (T, VQ), where T is an enumeration or 3381 // pointer to member type and VQ is either volatile or 3382 // empty, there exist candidate operator functions of the form 3383 // 3384 // VQ T& operator=(VQ T&, T); 3385 for (BuiltinCandidateTypeSet::iterator 3386 Enum = CandidateTypes.enumeration_begin(), 3387 EnumEnd = CandidateTypes.enumeration_end(); 3388 Enum != EnumEnd; ++Enum) 3389 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3390 CandidateSet); 3391 for (BuiltinCandidateTypeSet::iterator 3392 MemPtr = CandidateTypes.member_pointer_begin(), 3393 MemPtrEnd = CandidateTypes.member_pointer_end(); 3394 MemPtr != MemPtrEnd; ++MemPtr) 3395 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3396 CandidateSet); 3397 // Fall through. 3398 3399 case OO_PlusEqual: 3400 case OO_MinusEqual: 3401 // C++ [over.built]p19: 3402 // 3403 // For every pair (T, VQ), where T is any type and VQ is either 3404 // volatile or empty, there exist candidate operator functions 3405 // of the form 3406 // 3407 // T*VQ& operator=(T*VQ&, T*); 3408 // 3409 // C++ [over.built]p21: 3410 // 3411 // For every pair (T, VQ), where T is a cv-qualified or 3412 // cv-unqualified object type and VQ is either volatile or 3413 // empty, there exist candidate operator functions of the form 3414 // 3415 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3416 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3417 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3418 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3419 QualType ParamTypes[2]; 3420 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3421 3422 // non-volatile version 3423 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3424 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3425 /*IsAssigmentOperator=*/Op == OO_Equal); 3426 3427 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3428 // volatile version 3429 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3430 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3431 /*IsAssigmentOperator=*/Op == OO_Equal); 3432 } 3433 } 3434 // Fall through. 3435 3436 case OO_StarEqual: 3437 case OO_SlashEqual: 3438 // C++ [over.built]p18: 3439 // 3440 // For every triple (L, VQ, R), where L is an arithmetic type, 3441 // VQ is either volatile or empty, and R is a promoted 3442 // arithmetic type, there exist candidate operator functions of 3443 // the form 3444 // 3445 // VQ L& operator=(VQ L&, R); 3446 // VQ L& operator*=(VQ L&, R); 3447 // VQ L& operator/=(VQ L&, R); 3448 // VQ L& operator+=(VQ L&, R); 3449 // VQ L& operator-=(VQ L&, R); 3450 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3451 for (unsigned Right = FirstPromotedArithmeticType; 3452 Right < LastPromotedArithmeticType; ++Right) { 3453 QualType ParamTypes[2]; 3454 ParamTypes[1] = ArithmeticTypes[Right]; 3455 3456 // Add this built-in operator as a candidate (VQ is empty). 3457 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3458 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3459 /*IsAssigmentOperator=*/Op == OO_Equal); 3460 3461 // Add this built-in operator as a candidate (VQ is 'volatile'). 3462 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3463 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3464 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3465 /*IsAssigmentOperator=*/Op == OO_Equal); 3466 } 3467 } 3468 break; 3469 3470 case OO_PercentEqual: 3471 case OO_LessLessEqual: 3472 case OO_GreaterGreaterEqual: 3473 case OO_AmpEqual: 3474 case OO_CaretEqual: 3475 case OO_PipeEqual: 3476 // C++ [over.built]p22: 3477 // 3478 // For every triple (L, VQ, R), where L is an integral type, VQ 3479 // is either volatile or empty, and R is a promoted integral 3480 // type, there exist candidate operator functions of the form 3481 // 3482 // VQ L& operator%=(VQ L&, R); 3483 // VQ L& operator<<=(VQ L&, R); 3484 // VQ L& operator>>=(VQ L&, R); 3485 // VQ L& operator&=(VQ L&, R); 3486 // VQ L& operator^=(VQ L&, R); 3487 // VQ L& operator|=(VQ L&, R); 3488 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3489 for (unsigned Right = FirstPromotedIntegralType; 3490 Right < LastPromotedIntegralType; ++Right) { 3491 QualType ParamTypes[2]; 3492 ParamTypes[1] = ArithmeticTypes[Right]; 3493 3494 // Add this built-in operator as a candidate (VQ is empty). 3495 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3496 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3497 3498 // Add this built-in operator as a candidate (VQ is 'volatile'). 3499 ParamTypes[0] = ArithmeticTypes[Left]; 3500 ParamTypes[0].addVolatile(); 3501 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3502 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3503 } 3504 } 3505 break; 3506 3507 case OO_Exclaim: { 3508 // C++ [over.operator]p23: 3509 // 3510 // There also exist candidate operator functions of the form 3511 // 3512 // bool operator!(bool); 3513 // bool operator&&(bool, bool); [BELOW] 3514 // bool operator||(bool, bool); [BELOW] 3515 QualType ParamTy = Context.BoolTy; 3516 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3517 /*IsAssignmentOperator=*/false, 3518 /*NumContextualBoolArguments=*/1); 3519 break; 3520 } 3521 3522 case OO_AmpAmp: 3523 case OO_PipePipe: { 3524 // C++ [over.operator]p23: 3525 // 3526 // There also exist candidate operator functions of the form 3527 // 3528 // bool operator!(bool); [ABOVE] 3529 // bool operator&&(bool, bool); 3530 // bool operator||(bool, bool); 3531 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3532 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3533 /*IsAssignmentOperator=*/false, 3534 /*NumContextualBoolArguments=*/2); 3535 break; 3536 } 3537 3538 case OO_Subscript: 3539 // C++ [over.built]p13: 3540 // 3541 // For every cv-qualified or cv-unqualified object type T there 3542 // exist candidate operator functions of the form 3543 // 3544 // T* operator+(T*, ptrdiff_t); [ABOVE] 3545 // T& operator[](T*, ptrdiff_t); 3546 // T* operator-(T*, ptrdiff_t); [ABOVE] 3547 // T* operator+(ptrdiff_t, T*); [ABOVE] 3548 // T& operator[](ptrdiff_t, T*); 3549 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3550 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3551 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3552 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3553 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3554 3555 // T& operator[](T*, ptrdiff_t) 3556 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3557 3558 // T& operator[](ptrdiff_t, T*); 3559 ParamTypes[0] = ParamTypes[1]; 3560 ParamTypes[1] = *Ptr; 3561 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3562 } 3563 break; 3564 3565 case OO_ArrowStar: 3566 // FIXME: No support for pointer-to-members yet. 3567 break; 3568 3569 case OO_Conditional: 3570 // Note that we don't consider the first argument, since it has been 3571 // contextually converted to bool long ago. The candidates below are 3572 // therefore added as binary. 3573 // 3574 // C++ [over.built]p24: 3575 // For every type T, where T is a pointer or pointer-to-member type, 3576 // there exist candidate operator functions of the form 3577 // 3578 // T operator?(bool, T, T); 3579 // 3580 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3581 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3582 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3583 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3584 } 3585 for (BuiltinCandidateTypeSet::iterator Ptr = 3586 CandidateTypes.member_pointer_begin(), 3587 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3588 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3589 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3590 } 3591 goto Conditional; 3592 } 3593} 3594 3595/// \brief Add function candidates found via argument-dependent lookup 3596/// to the set of overloading candidates. 3597/// 3598/// This routine performs argument-dependent name lookup based on the 3599/// given function name (which may also be an operator name) and adds 3600/// all of the overload candidates found by ADL to the overload 3601/// candidate set (C++ [basic.lookup.argdep]). 3602void 3603Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3604 Expr **Args, unsigned NumArgs, 3605 OverloadCandidateSet& CandidateSet) { 3606 FunctionSet Functions; 3607 3608 // Record all of the function candidates that we've already 3609 // added to the overload set, so that we don't add those same 3610 // candidates a second time. 3611 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3612 CandEnd = CandidateSet.end(); 3613 Cand != CandEnd; ++Cand) 3614 if (Cand->Function) { 3615 Functions.insert(Cand->Function); 3616 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3617 Functions.insert(FunTmpl); 3618 } 3619 3620 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3621 3622 // Erase all of the candidates we already knew about. 3623 // FIXME: This is suboptimal. Is there a better way? 3624 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3625 CandEnd = CandidateSet.end(); 3626 Cand != CandEnd; ++Cand) 3627 if (Cand->Function) { 3628 Functions.erase(Cand->Function); 3629 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3630 Functions.erase(FunTmpl); 3631 } 3632 3633 // For each of the ADL candidates we found, add it to the overload 3634 // set. 3635 for (FunctionSet::iterator Func = Functions.begin(), 3636 FuncEnd = Functions.end(); 3637 Func != FuncEnd; ++Func) { 3638 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) 3639 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet); 3640 else 3641 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3642 /*FIXME: explicit args */false, 0, 0, 3643 Args, NumArgs, CandidateSet); 3644 } 3645} 3646 3647/// isBetterOverloadCandidate - Determines whether the first overload 3648/// candidate is a better candidate than the second (C++ 13.3.3p1). 3649bool 3650Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3651 const OverloadCandidate& Cand2) { 3652 // Define viable functions to be better candidates than non-viable 3653 // functions. 3654 if (!Cand2.Viable) 3655 return Cand1.Viable; 3656 else if (!Cand1.Viable) 3657 return false; 3658 3659 // C++ [over.match.best]p1: 3660 // 3661 // -- if F is a static member function, ICS1(F) is defined such 3662 // that ICS1(F) is neither better nor worse than ICS1(G) for 3663 // any function G, and, symmetrically, ICS1(G) is neither 3664 // better nor worse than ICS1(F). 3665 unsigned StartArg = 0; 3666 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3667 StartArg = 1; 3668 3669 // C++ [over.match.best]p1: 3670 // A viable function F1 is defined to be a better function than another 3671 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3672 // conversion sequence than ICSi(F2), and then... 3673 unsigned NumArgs = Cand1.Conversions.size(); 3674 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3675 bool HasBetterConversion = false; 3676 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3677 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3678 Cand2.Conversions[ArgIdx])) { 3679 case ImplicitConversionSequence::Better: 3680 // Cand1 has a better conversion sequence. 3681 HasBetterConversion = true; 3682 break; 3683 3684 case ImplicitConversionSequence::Worse: 3685 // Cand1 can't be better than Cand2. 3686 return false; 3687 3688 case ImplicitConversionSequence::Indistinguishable: 3689 // Do nothing. 3690 break; 3691 } 3692 } 3693 3694 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3695 // ICSj(F2), or, if not that, 3696 if (HasBetterConversion) 3697 return true; 3698 3699 // - F1 is a non-template function and F2 is a function template 3700 // specialization, or, if not that, 3701 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3702 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3703 return true; 3704 3705 // -- F1 and F2 are function template specializations, and the function 3706 // template for F1 is more specialized than the template for F2 3707 // according to the partial ordering rules described in 14.5.5.2, or, 3708 // if not that, 3709 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3710 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3711 if (FunctionTemplateDecl *BetterTemplate 3712 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 3713 Cand2.Function->getPrimaryTemplate(), 3714 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 3715 : TPOC_Call)) 3716 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 3717 3718 // -- the context is an initialization by user-defined conversion 3719 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3720 // from the return type of F1 to the destination type (i.e., 3721 // the type of the entity being initialized) is a better 3722 // conversion sequence than the standard conversion sequence 3723 // from the return type of F2 to the destination type. 3724 if (Cand1.Function && Cand2.Function && 3725 isa<CXXConversionDecl>(Cand1.Function) && 3726 isa<CXXConversionDecl>(Cand2.Function)) { 3727 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3728 Cand2.FinalConversion)) { 3729 case ImplicitConversionSequence::Better: 3730 // Cand1 has a better conversion sequence. 3731 return true; 3732 3733 case ImplicitConversionSequence::Worse: 3734 // Cand1 can't be better than Cand2. 3735 return false; 3736 3737 case ImplicitConversionSequence::Indistinguishable: 3738 // Do nothing 3739 break; 3740 } 3741 } 3742 3743 return false; 3744} 3745 3746/// \brief Computes the best viable function (C++ 13.3.3) 3747/// within an overload candidate set. 3748/// 3749/// \param CandidateSet the set of candidate functions. 3750/// 3751/// \param Loc the location of the function name (or operator symbol) for 3752/// which overload resolution occurs. 3753/// 3754/// \param Best f overload resolution was successful or found a deleted 3755/// function, Best points to the candidate function found. 3756/// 3757/// \returns The result of overload resolution. 3758Sema::OverloadingResult 3759Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3760 SourceLocation Loc, 3761 OverloadCandidateSet::iterator& Best) { 3762 // Find the best viable function. 3763 Best = CandidateSet.end(); 3764 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3765 Cand != CandidateSet.end(); ++Cand) { 3766 if (Cand->Viable) { 3767 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3768 Best = Cand; 3769 } 3770 } 3771 3772 // If we didn't find any viable functions, abort. 3773 if (Best == CandidateSet.end()) 3774 return OR_No_Viable_Function; 3775 3776 // Make sure that this function is better than every other viable 3777 // function. If not, we have an ambiguity. 3778 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3779 Cand != CandidateSet.end(); ++Cand) { 3780 if (Cand->Viable && 3781 Cand != Best && 3782 !isBetterOverloadCandidate(*Best, *Cand)) { 3783 Best = CandidateSet.end(); 3784 return OR_Ambiguous; 3785 } 3786 } 3787 3788 // Best is the best viable function. 3789 if (Best->Function && 3790 (Best->Function->isDeleted() || 3791 Best->Function->getAttr<UnavailableAttr>())) 3792 return OR_Deleted; 3793 3794 // C++ [basic.def.odr]p2: 3795 // An overloaded function is used if it is selected by overload resolution 3796 // when referred to from a potentially-evaluated expression. [Note: this 3797 // covers calls to named functions (5.2.2), operator overloading 3798 // (clause 13), user-defined conversions (12.3.2), allocation function for 3799 // placement new (5.3.4), as well as non-default initialization (8.5). 3800 if (Best->Function) 3801 MarkDeclarationReferenced(Loc, Best->Function); 3802 return OR_Success; 3803} 3804 3805/// PrintOverloadCandidates - When overload resolution fails, prints 3806/// diagnostic messages containing the candidates in the candidate 3807/// set. If OnlyViable is true, only viable candidates will be printed. 3808void 3809Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3810 bool OnlyViable) { 3811 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3812 LastCand = CandidateSet.end(); 3813 for (; Cand != LastCand; ++Cand) { 3814 if (Cand->Viable || !OnlyViable) { 3815 if (Cand->Function) { 3816 if (Cand->Function->isDeleted() || 3817 Cand->Function->getAttr<UnavailableAttr>()) { 3818 // Deleted or "unavailable" function. 3819 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3820 << Cand->Function->isDeleted(); 3821 } else { 3822 // Normal function 3823 // FIXME: Give a better reason! 3824 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3825 } 3826 } else if (Cand->IsSurrogate) { 3827 // Desugar the type of the surrogate down to a function type, 3828 // retaining as many typedefs as possible while still showing 3829 // the function type (and, therefore, its parameter types). 3830 QualType FnType = Cand->Surrogate->getConversionType(); 3831 bool isLValueReference = false; 3832 bool isRValueReference = false; 3833 bool isPointer = false; 3834 if (const LValueReferenceType *FnTypeRef = 3835 FnType->getAs<LValueReferenceType>()) { 3836 FnType = FnTypeRef->getPointeeType(); 3837 isLValueReference = true; 3838 } else if (const RValueReferenceType *FnTypeRef = 3839 FnType->getAs<RValueReferenceType>()) { 3840 FnType = FnTypeRef->getPointeeType(); 3841 isRValueReference = true; 3842 } 3843 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 3844 FnType = FnTypePtr->getPointeeType(); 3845 isPointer = true; 3846 } 3847 // Desugar down to a function type. 3848 FnType = QualType(FnType->getAsFunctionType(), 0); 3849 // Reconstruct the pointer/reference as appropriate. 3850 if (isPointer) FnType = Context.getPointerType(FnType); 3851 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3852 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3853 3854 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3855 << FnType; 3856 } else { 3857 // FIXME: We need to get the identifier in here 3858 // FIXME: Do we want the error message to point at the operator? 3859 // (built-ins won't have a location) 3860 QualType FnType 3861 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3862 Cand->BuiltinTypes.ParamTypes, 3863 Cand->Conversions.size(), 3864 false, 0); 3865 3866 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3867 } 3868 } 3869 } 3870} 3871 3872/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3873/// an overloaded function (C++ [over.over]), where @p From is an 3874/// expression with overloaded function type and @p ToType is the type 3875/// we're trying to resolve to. For example: 3876/// 3877/// @code 3878/// int f(double); 3879/// int f(int); 3880/// 3881/// int (*pfd)(double) = f; // selects f(double) 3882/// @endcode 3883/// 3884/// This routine returns the resulting FunctionDecl if it could be 3885/// resolved, and NULL otherwise. When @p Complain is true, this 3886/// routine will emit diagnostics if there is an error. 3887FunctionDecl * 3888Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3889 bool Complain) { 3890 QualType FunctionType = ToType; 3891 bool IsMember = false; 3892 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 3893 FunctionType = ToTypePtr->getPointeeType(); 3894 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 3895 FunctionType = ToTypeRef->getPointeeType(); 3896 else if (const MemberPointerType *MemTypePtr = 3897 ToType->getAs<MemberPointerType>()) { 3898 FunctionType = MemTypePtr->getPointeeType(); 3899 IsMember = true; 3900 } 3901 3902 // We only look at pointers or references to functions. 3903 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 3904 if (!FunctionType->isFunctionType()) 3905 return 0; 3906 3907 // Find the actual overloaded function declaration. 3908 OverloadedFunctionDecl *Ovl = 0; 3909 3910 // C++ [over.over]p1: 3911 // [...] [Note: any redundant set of parentheses surrounding the 3912 // overloaded function name is ignored (5.1). ] 3913 Expr *OvlExpr = From->IgnoreParens(); 3914 3915 // C++ [over.over]p1: 3916 // [...] The overloaded function name can be preceded by the & 3917 // operator. 3918 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3919 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3920 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3921 } 3922 3923 // Try to dig out the overloaded function. 3924 FunctionTemplateDecl *FunctionTemplate = 0; 3925 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 3926 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3927 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 3928 } 3929 3930 // If there's no overloaded function declaration or function template, 3931 // we're done. 3932 if (!Ovl && !FunctionTemplate) 3933 return 0; 3934 3935 OverloadIterator Fun; 3936 if (Ovl) 3937 Fun = Ovl; 3938 else 3939 Fun = FunctionTemplate; 3940 3941 // Look through all of the overloaded functions, searching for one 3942 // whose type matches exactly. 3943 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 3944 3945 bool FoundNonTemplateFunction = false; 3946 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 3947 // C++ [over.over]p3: 3948 // Non-member functions and static member functions match 3949 // targets of type "pointer-to-function" or "reference-to-function." 3950 // Nonstatic member functions match targets of 3951 // type "pointer-to-member-function." 3952 // Note that according to DR 247, the containing class does not matter. 3953 3954 if (FunctionTemplateDecl *FunctionTemplate 3955 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 3956 if (CXXMethodDecl *Method 3957 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 3958 // Skip non-static function templates when converting to pointer, and 3959 // static when converting to member pointer. 3960 if (Method->isStatic() == IsMember) 3961 continue; 3962 } else if (IsMember) 3963 continue; 3964 3965 // C++ [over.over]p2: 3966 // If the name is a function template, template argument deduction is 3967 // done (14.8.2.2), and if the argument deduction succeeds, the 3968 // resulting template argument list is used to generate a single 3969 // function template specialization, which is added to the set of 3970 // overloaded functions considered. 3971 FunctionDecl *Specialization = 0; 3972 TemplateDeductionInfo Info(Context); 3973 if (TemplateDeductionResult Result 3974 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 3975 /*FIXME:*/0, /*FIXME:*/0, 3976 FunctionType, Specialization, Info)) { 3977 // FIXME: make a note of the failed deduction for diagnostics. 3978 (void)Result; 3979 } else { 3980 assert(FunctionType 3981 == Context.getCanonicalType(Specialization->getType())); 3982 Matches.insert( 3983 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 3984 } 3985 } 3986 3987 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 3988 // Skip non-static functions when converting to pointer, and static 3989 // when converting to member pointer. 3990 if (Method->isStatic() == IsMember) 3991 continue; 3992 } else if (IsMember) 3993 continue; 3994 3995 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 3996 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 3997 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 3998 FoundNonTemplateFunction = true; 3999 } 4000 } 4001 } 4002 4003 // If there were 0 or 1 matches, we're done. 4004 if (Matches.empty()) 4005 return 0; 4006 else if (Matches.size() == 1) 4007 return *Matches.begin(); 4008 4009 // C++ [over.over]p4: 4010 // If more than one function is selected, [...] 4011 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4012 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4013 if (FoundNonTemplateFunction) { 4014 // [...] any function template specializations in the set are 4015 // eliminated if the set also contains a non-template function, [...] 4016 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4017 if ((*M)->getPrimaryTemplate() == 0) 4018 RemainingMatches.push_back(*M); 4019 } else { 4020 // [...] and any given function template specialization F1 is 4021 // eliminated if the set contains a second function template 4022 // specialization whose function template is more specialized 4023 // than the function template of F1 according to the partial 4024 // ordering rules of 14.5.5.2. 4025 4026 // The algorithm specified above is quadratic. We instead use a 4027 // two-pass algorithm (similar to the one used to identify the 4028 // best viable function in an overload set) that identifies the 4029 // best function template (if it exists). 4030 MatchIter Best = Matches.begin(); 4031 MatchIter M = Best, MEnd = Matches.end(); 4032 // Find the most specialized function. 4033 for (++M; M != MEnd; ++M) 4034 if (getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4035 (*Best)->getPrimaryTemplate(), 4036 TPOC_Other) 4037 == (*M)->getPrimaryTemplate()) 4038 Best = M; 4039 4040 // Determine whether this function template is more specialized 4041 // that all of the others. 4042 bool Ambiguous = false; 4043 for (M = Matches.begin(); M != MEnd; ++M) { 4044 if (M != Best && 4045 getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4046 (*Best)->getPrimaryTemplate(), 4047 TPOC_Other) 4048 != (*Best)->getPrimaryTemplate()) { 4049 Ambiguous = true; 4050 break; 4051 } 4052 } 4053 4054 // If one function template was more specialized than all of the 4055 // others, return it. 4056 if (!Ambiguous) 4057 return *Best; 4058 4059 // We could not find a most-specialized function template, which 4060 // is equivalent to having a set of function templates with more 4061 // than one such template. So, we place all of the function 4062 // templates into the set of remaining matches and produce a 4063 // diagnostic below. FIXME: we could perform the quadratic 4064 // algorithm here, pruning the result set to limit the number of 4065 // candidates output later. 4066 RemainingMatches.append(Matches.begin(), Matches.end()); 4067 } 4068 4069 // [...] After such eliminations, if any, there shall remain exactly one 4070 // selected function. 4071 if (RemainingMatches.size() == 1) 4072 return RemainingMatches.front(); 4073 4074 // FIXME: We should probably return the same thing that BestViableFunction 4075 // returns (even if we issue the diagnostics here). 4076 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4077 << RemainingMatches[0]->getDeclName(); 4078 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4079 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4080 return 0; 4081} 4082 4083/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4084/// (which eventually refers to the declaration Func) and the call 4085/// arguments Args/NumArgs, attempt to resolve the function call down 4086/// to a specific function. If overload resolution succeeds, returns 4087/// the function declaration produced by overload 4088/// resolution. Otherwise, emits diagnostics, deletes all of the 4089/// arguments and Fn, and returns NULL. 4090FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4091 DeclarationName UnqualifiedName, 4092 bool HasExplicitTemplateArgs, 4093 const TemplateArgument *ExplicitTemplateArgs, 4094 unsigned NumExplicitTemplateArgs, 4095 SourceLocation LParenLoc, 4096 Expr **Args, unsigned NumArgs, 4097 SourceLocation *CommaLocs, 4098 SourceLocation RParenLoc, 4099 bool &ArgumentDependentLookup) { 4100 OverloadCandidateSet CandidateSet; 4101 4102 // Add the functions denoted by Callee to the set of candidate 4103 // functions. While we're doing so, track whether argument-dependent 4104 // lookup still applies, per: 4105 // 4106 // C++0x [basic.lookup.argdep]p3: 4107 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4108 // and let Y be the lookup set produced by argument dependent 4109 // lookup (defined as follows). If X contains 4110 // 4111 // -- a declaration of a class member, or 4112 // 4113 // -- a block-scope function declaration that is not a 4114 // using-declaration, or 4115 // 4116 // -- a declaration that is neither a function or a function 4117 // template 4118 // 4119 // then Y is empty. 4120 if (OverloadedFunctionDecl *Ovl 4121 = dyn_cast_or_null<OverloadedFunctionDecl>(Callee)) { 4122 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4123 FuncEnd = Ovl->function_end(); 4124 Func != FuncEnd; ++Func) { 4125 DeclContext *Ctx = 0; 4126 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Func)) { 4127 if (HasExplicitTemplateArgs) 4128 continue; 4129 4130 AddOverloadCandidate(FunDecl, Args, NumArgs, CandidateSet); 4131 Ctx = FunDecl->getDeclContext(); 4132 } else { 4133 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*Func); 4134 AddTemplateOverloadCandidate(FunTmpl, HasExplicitTemplateArgs, 4135 ExplicitTemplateArgs, 4136 NumExplicitTemplateArgs, 4137 Args, NumArgs, CandidateSet); 4138 Ctx = FunTmpl->getDeclContext(); 4139 } 4140 4141 4142 if (Ctx->isRecord() || Ctx->isFunctionOrMethod()) 4143 ArgumentDependentLookup = false; 4144 } 4145 } else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee)) { 4146 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4147 AddOverloadCandidate(Func, Args, NumArgs, CandidateSet); 4148 4149 if (Func->getDeclContext()->isRecord() || 4150 Func->getDeclContext()->isFunctionOrMethod()) 4151 ArgumentDependentLookup = false; 4152 } else if (FunctionTemplateDecl *FuncTemplate 4153 = dyn_cast_or_null<FunctionTemplateDecl>(Callee)) { 4154 AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4155 ExplicitTemplateArgs, 4156 NumExplicitTemplateArgs, 4157 Args, NumArgs, CandidateSet); 4158 4159 if (FuncTemplate->getDeclContext()->isRecord()) 4160 ArgumentDependentLookup = false; 4161 } 4162 4163 if (Callee) 4164 UnqualifiedName = Callee->getDeclName(); 4165 4166 // FIXME: Pass explicit template arguments through for ADL 4167 if (ArgumentDependentLookup) 4168 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4169 CandidateSet); 4170 4171 OverloadCandidateSet::iterator Best; 4172 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4173 case OR_Success: 4174 return Best->Function; 4175 4176 case OR_No_Viable_Function: 4177 Diag(Fn->getSourceRange().getBegin(), 4178 diag::err_ovl_no_viable_function_in_call) 4179 << UnqualifiedName << Fn->getSourceRange(); 4180 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4181 break; 4182 4183 case OR_Ambiguous: 4184 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4185 << UnqualifiedName << Fn->getSourceRange(); 4186 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4187 break; 4188 4189 case OR_Deleted: 4190 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4191 << Best->Function->isDeleted() 4192 << UnqualifiedName 4193 << Fn->getSourceRange(); 4194 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4195 break; 4196 } 4197 4198 // Overload resolution failed. Destroy all of the subexpressions and 4199 // return NULL. 4200 Fn->Destroy(Context); 4201 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4202 Args[Arg]->Destroy(Context); 4203 return 0; 4204} 4205 4206/// \brief Create a unary operation that may resolve to an overloaded 4207/// operator. 4208/// 4209/// \param OpLoc The location of the operator itself (e.g., '*'). 4210/// 4211/// \param OpcIn The UnaryOperator::Opcode that describes this 4212/// operator. 4213/// 4214/// \param Functions The set of non-member functions that will be 4215/// considered by overload resolution. The caller needs to build this 4216/// set based on the context using, e.g., 4217/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4218/// set should not contain any member functions; those will be added 4219/// by CreateOverloadedUnaryOp(). 4220/// 4221/// \param input The input argument. 4222Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4223 unsigned OpcIn, 4224 FunctionSet &Functions, 4225 ExprArg input) { 4226 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4227 Expr *Input = (Expr *)input.get(); 4228 4229 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4230 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4231 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4232 4233 Expr *Args[2] = { Input, 0 }; 4234 unsigned NumArgs = 1; 4235 4236 // For post-increment and post-decrement, add the implicit '0' as 4237 // the second argument, so that we know this is a post-increment or 4238 // post-decrement. 4239 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4240 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4241 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4242 SourceLocation()); 4243 NumArgs = 2; 4244 } 4245 4246 if (Input->isTypeDependent()) { 4247 OverloadedFunctionDecl *Overloads 4248 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4249 for (FunctionSet::iterator Func = Functions.begin(), 4250 FuncEnd = Functions.end(); 4251 Func != FuncEnd; ++Func) 4252 Overloads->addOverload(*Func); 4253 4254 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4255 OpLoc, false, false); 4256 4257 input.release(); 4258 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4259 &Args[0], NumArgs, 4260 Context.DependentTy, 4261 OpLoc)); 4262 } 4263 4264 // Build an empty overload set. 4265 OverloadCandidateSet CandidateSet; 4266 4267 // Add the candidates from the given function set. 4268 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4269 4270 // Add operator candidates that are member functions. 4271 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4272 4273 // Add builtin operator candidates. 4274 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4275 4276 // Perform overload resolution. 4277 OverloadCandidateSet::iterator Best; 4278 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4279 case OR_Success: { 4280 // We found a built-in operator or an overloaded operator. 4281 FunctionDecl *FnDecl = Best->Function; 4282 4283 if (FnDecl) { 4284 // We matched an overloaded operator. Build a call to that 4285 // operator. 4286 4287 // Convert the arguments. 4288 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4289 if (PerformObjectArgumentInitialization(Input, Method)) 4290 return ExprError(); 4291 } else { 4292 // Convert the arguments. 4293 if (PerformCopyInitialization(Input, 4294 FnDecl->getParamDecl(0)->getType(), 4295 "passing")) 4296 return ExprError(); 4297 } 4298 4299 // Determine the result type 4300 QualType ResultTy 4301 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4302 ResultTy = ResultTy.getNonReferenceType(); 4303 4304 // Build the actual expression node. 4305 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4306 SourceLocation()); 4307 UsualUnaryConversions(FnExpr); 4308 4309 input.release(); 4310 4311 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4312 &Input, 1, ResultTy, OpLoc); 4313 return MaybeBindToTemporary(CE); 4314 } else { 4315 // We matched a built-in operator. Convert the arguments, then 4316 // break out so that we will build the appropriate built-in 4317 // operator node. 4318 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4319 Best->Conversions[0], "passing")) 4320 return ExprError(); 4321 4322 break; 4323 } 4324 } 4325 4326 case OR_No_Viable_Function: 4327 // No viable function; fall through to handling this as a 4328 // built-in operator, which will produce an error message for us. 4329 break; 4330 4331 case OR_Ambiguous: 4332 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4333 << UnaryOperator::getOpcodeStr(Opc) 4334 << Input->getSourceRange(); 4335 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4336 return ExprError(); 4337 4338 case OR_Deleted: 4339 Diag(OpLoc, diag::err_ovl_deleted_oper) 4340 << Best->Function->isDeleted() 4341 << UnaryOperator::getOpcodeStr(Opc) 4342 << Input->getSourceRange(); 4343 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4344 return ExprError(); 4345 } 4346 4347 // Either we found no viable overloaded operator or we matched a 4348 // built-in operator. In either case, fall through to trying to 4349 // build a built-in operation. 4350 input.release(); 4351 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4352} 4353 4354/// \brief Create a binary operation that may resolve to an overloaded 4355/// operator. 4356/// 4357/// \param OpLoc The location of the operator itself (e.g., '+'). 4358/// 4359/// \param OpcIn The BinaryOperator::Opcode that describes this 4360/// operator. 4361/// 4362/// \param Functions The set of non-member functions that will be 4363/// considered by overload resolution. The caller needs to build this 4364/// set based on the context using, e.g., 4365/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4366/// set should not contain any member functions; those will be added 4367/// by CreateOverloadedBinOp(). 4368/// 4369/// \param LHS Left-hand argument. 4370/// \param RHS Right-hand argument. 4371Sema::OwningExprResult 4372Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4373 unsigned OpcIn, 4374 FunctionSet &Functions, 4375 Expr *LHS, Expr *RHS) { 4376 Expr *Args[2] = { LHS, RHS }; 4377 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4378 4379 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4380 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4381 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4382 4383 // If either side is type-dependent, create an appropriate dependent 4384 // expression. 4385 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4386 // .* cannot be overloaded. 4387 if (Opc == BinaryOperator::PtrMemD) 4388 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4389 Context.DependentTy, OpLoc)); 4390 4391 OverloadedFunctionDecl *Overloads 4392 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4393 for (FunctionSet::iterator Func = Functions.begin(), 4394 FuncEnd = Functions.end(); 4395 Func != FuncEnd; ++Func) 4396 Overloads->addOverload(*Func); 4397 4398 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4399 OpLoc, false, false); 4400 4401 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4402 Args, 2, 4403 Context.DependentTy, 4404 OpLoc)); 4405 } 4406 4407 // If this is the .* operator, which is not overloadable, just 4408 // create a built-in binary operator. 4409 if (Opc == BinaryOperator::PtrMemD) 4410 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4411 4412 // If this is one of the assignment operators, we only perform 4413 // overload resolution if the left-hand side is a class or 4414 // enumeration type (C++ [expr.ass]p3). 4415 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4416 !Args[0]->getType()->isOverloadableType()) 4417 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4418 4419 // Build an empty overload set. 4420 OverloadCandidateSet CandidateSet; 4421 4422 // Add the candidates from the given function set. 4423 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4424 4425 // Add operator candidates that are member functions. 4426 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4427 4428 // Add builtin operator candidates. 4429 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4430 4431 // Perform overload resolution. 4432 OverloadCandidateSet::iterator Best; 4433 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4434 case OR_Success: { 4435 // We found a built-in operator or an overloaded operator. 4436 FunctionDecl *FnDecl = Best->Function; 4437 4438 if (FnDecl) { 4439 // We matched an overloaded operator. Build a call to that 4440 // operator. 4441 4442 // Convert the arguments. 4443 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4444 if (PerformObjectArgumentInitialization(Args[0], Method) || 4445 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4446 "passing")) 4447 return ExprError(); 4448 } else { 4449 // Convert the arguments. 4450 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4451 "passing") || 4452 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4453 "passing")) 4454 return ExprError(); 4455 } 4456 4457 // Determine the result type 4458 QualType ResultTy 4459 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4460 ResultTy = ResultTy.getNonReferenceType(); 4461 4462 // Build the actual expression node. 4463 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4464 OpLoc); 4465 UsualUnaryConversions(FnExpr); 4466 4467 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4468 Args, 2, ResultTy, OpLoc); 4469 return MaybeBindToTemporary(CE); 4470 } else { 4471 // We matched a built-in operator. Convert the arguments, then 4472 // break out so that we will build the appropriate built-in 4473 // operator node. 4474 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4475 Best->Conversions[0], "passing") || 4476 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4477 Best->Conversions[1], "passing")) 4478 return ExprError(); 4479 4480 break; 4481 } 4482 } 4483 4484 case OR_No_Viable_Function: 4485 // For class as left operand for assignment or compound assigment operator 4486 // do not fall through to handling in built-in, but report that no overloaded 4487 // assignment operator found 4488 if (Args[0]->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4489 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4490 << BinaryOperator::getOpcodeStr(Opc) 4491 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4492 return ExprError(); 4493 } 4494 // No viable function; fall through to handling this as a 4495 // built-in operator, which will produce an error message for us. 4496 break; 4497 4498 case OR_Ambiguous: 4499 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4500 << BinaryOperator::getOpcodeStr(Opc) 4501 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4502 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4503 return ExprError(); 4504 4505 case OR_Deleted: 4506 Diag(OpLoc, diag::err_ovl_deleted_oper) 4507 << Best->Function->isDeleted() 4508 << BinaryOperator::getOpcodeStr(Opc) 4509 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4510 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4511 return ExprError(); 4512 } 4513 4514 // Either we found no viable overloaded operator or we matched a 4515 // built-in operator. In either case, try to build a built-in 4516 // operation. 4517 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4518} 4519 4520/// BuildCallToMemberFunction - Build a call to a member 4521/// function. MemExpr is the expression that refers to the member 4522/// function (and includes the object parameter), Args/NumArgs are the 4523/// arguments to the function call (not including the object 4524/// parameter). The caller needs to validate that the member 4525/// expression refers to a member function or an overloaded member 4526/// function. 4527Sema::ExprResult 4528Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4529 SourceLocation LParenLoc, Expr **Args, 4530 unsigned NumArgs, SourceLocation *CommaLocs, 4531 SourceLocation RParenLoc) { 4532 // Dig out the member expression. This holds both the object 4533 // argument and the member function we're referring to. 4534 MemberExpr *MemExpr = 0; 4535 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4536 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4537 else 4538 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4539 assert(MemExpr && "Building member call without member expression"); 4540 4541 // Extract the object argument. 4542 Expr *ObjectArg = MemExpr->getBase(); 4543 4544 CXXMethodDecl *Method = 0; 4545 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 4546 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 4547 // Add overload candidates 4548 OverloadCandidateSet CandidateSet; 4549 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 4550 4551 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 4552 Func != FuncEnd; ++Func) { 4553 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) 4554 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4555 /*SuppressUserConversions=*/false); 4556 else 4557 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 4558 MemExpr->hasExplicitTemplateArgumentList(), 4559 MemExpr->getTemplateArgs(), 4560 MemExpr->getNumTemplateArgs(), 4561 ObjectArg, Args, NumArgs, 4562 CandidateSet, 4563 /*SuppressUsedConversions=*/false); 4564 } 4565 4566 OverloadCandidateSet::iterator Best; 4567 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4568 case OR_Success: 4569 Method = cast<CXXMethodDecl>(Best->Function); 4570 break; 4571 4572 case OR_No_Viable_Function: 4573 Diag(MemExpr->getSourceRange().getBegin(), 4574 diag::err_ovl_no_viable_member_function_in_call) 4575 << DeclName << MemExprE->getSourceRange(); 4576 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4577 // FIXME: Leaking incoming expressions! 4578 return true; 4579 4580 case OR_Ambiguous: 4581 Diag(MemExpr->getSourceRange().getBegin(), 4582 diag::err_ovl_ambiguous_member_call) 4583 << DeclName << MemExprE->getSourceRange(); 4584 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4585 // FIXME: Leaking incoming expressions! 4586 return true; 4587 4588 case OR_Deleted: 4589 Diag(MemExpr->getSourceRange().getBegin(), 4590 diag::err_ovl_deleted_member_call) 4591 << Best->Function->isDeleted() 4592 << DeclName << MemExprE->getSourceRange(); 4593 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4594 // FIXME: Leaking incoming expressions! 4595 return true; 4596 } 4597 4598 FixOverloadedFunctionReference(MemExpr, Method); 4599 } else { 4600 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4601 } 4602 4603 assert(Method && "Member call to something that isn't a method?"); 4604 ExprOwningPtr<CXXMemberCallExpr> 4605 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4606 NumArgs, 4607 Method->getResultType().getNonReferenceType(), 4608 RParenLoc)); 4609 4610 // Convert the object argument (for a non-static member function call). 4611 if (!Method->isStatic() && 4612 PerformObjectArgumentInitialization(ObjectArg, Method)) 4613 return true; 4614 MemExpr->setBase(ObjectArg); 4615 4616 // Convert the rest of the arguments 4617 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4618 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4619 RParenLoc)) 4620 return true; 4621 4622 if (CheckFunctionCall(Method, TheCall.get())) 4623 return true; 4624 4625 return MaybeBindToTemporary(TheCall.release()).release(); 4626} 4627 4628/// BuildCallToObjectOfClassType - Build a call to an object of class 4629/// type (C++ [over.call.object]), which can end up invoking an 4630/// overloaded function call operator (@c operator()) or performing a 4631/// user-defined conversion on the object argument. 4632Sema::ExprResult 4633Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4634 SourceLocation LParenLoc, 4635 Expr **Args, unsigned NumArgs, 4636 SourceLocation *CommaLocs, 4637 SourceLocation RParenLoc) { 4638 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4639 const RecordType *Record = Object->getType()->getAs<RecordType>(); 4640 4641 // C++ [over.call.object]p1: 4642 // If the primary-expression E in the function call syntax 4643 // evaluates to a class object of type "cv T", then the set of 4644 // candidate functions includes at least the function call 4645 // operators of T. The function call operators of T are obtained by 4646 // ordinary lookup of the name operator() in the context of 4647 // (E).operator(). 4648 OverloadCandidateSet CandidateSet; 4649 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4650 DeclContext::lookup_const_iterator Oper, OperEnd; 4651 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4652 Oper != OperEnd; ++Oper) 4653 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4654 CandidateSet, /*SuppressUserConversions=*/false); 4655 4656 // C++ [over.call.object]p2: 4657 // In addition, for each conversion function declared in T of the 4658 // form 4659 // 4660 // operator conversion-type-id () cv-qualifier; 4661 // 4662 // where cv-qualifier is the same cv-qualification as, or a 4663 // greater cv-qualification than, cv, and where conversion-type-id 4664 // denotes the type "pointer to function of (P1,...,Pn) returning 4665 // R", or the type "reference to pointer to function of 4666 // (P1,...,Pn) returning R", or the type "reference to function 4667 // of (P1,...,Pn) returning R", a surrogate call function [...] 4668 // is also considered as a candidate function. Similarly, 4669 // surrogate call functions are added to the set of candidate 4670 // functions for each conversion function declared in an 4671 // accessible base class provided the function is not hidden 4672 // within T by another intervening declaration. 4673 4674 if (!RequireCompleteType(SourceLocation(), Object->getType(), 0)) { 4675 // FIXME: Look in base classes for more conversion operators! 4676 OverloadedFunctionDecl *Conversions 4677 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4678 for (OverloadedFunctionDecl::function_iterator 4679 Func = Conversions->function_begin(), 4680 FuncEnd = Conversions->function_end(); 4681 Func != FuncEnd; ++Func) { 4682 CXXConversionDecl *Conv; 4683 FunctionTemplateDecl *ConvTemplate; 4684 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 4685 4686 // Skip over templated conversion functions; they aren't 4687 // surrogates. 4688 if (ConvTemplate) 4689 continue; 4690 4691 // Strip the reference type (if any) and then the pointer type (if 4692 // any) to get down to what might be a function type. 4693 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4694 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4695 ConvType = ConvPtrType->getPointeeType(); 4696 4697 if (const FunctionProtoType *Proto = ConvType->getAsFunctionProtoType()) 4698 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4699 } 4700 } 4701 4702 // Perform overload resolution. 4703 OverloadCandidateSet::iterator Best; 4704 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4705 case OR_Success: 4706 // Overload resolution succeeded; we'll build the appropriate call 4707 // below. 4708 break; 4709 4710 case OR_No_Viable_Function: 4711 Diag(Object->getSourceRange().getBegin(), 4712 diag::err_ovl_no_viable_object_call) 4713 << Object->getType() << Object->getSourceRange(); 4714 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4715 break; 4716 4717 case OR_Ambiguous: 4718 Diag(Object->getSourceRange().getBegin(), 4719 diag::err_ovl_ambiguous_object_call) 4720 << Object->getType() << Object->getSourceRange(); 4721 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4722 break; 4723 4724 case OR_Deleted: 4725 Diag(Object->getSourceRange().getBegin(), 4726 diag::err_ovl_deleted_object_call) 4727 << Best->Function->isDeleted() 4728 << Object->getType() << Object->getSourceRange(); 4729 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4730 break; 4731 } 4732 4733 if (Best == CandidateSet.end()) { 4734 // We had an error; delete all of the subexpressions and return 4735 // the error. 4736 Object->Destroy(Context); 4737 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4738 Args[ArgIdx]->Destroy(Context); 4739 return true; 4740 } 4741 4742 if (Best->Function == 0) { 4743 // Since there is no function declaration, this is one of the 4744 // surrogate candidates. Dig out the conversion function. 4745 CXXConversionDecl *Conv 4746 = cast<CXXConversionDecl>( 4747 Best->Conversions[0].UserDefined.ConversionFunction); 4748 4749 // We selected one of the surrogate functions that converts the 4750 // object parameter to a function pointer. Perform the conversion 4751 // on the object argument, then let ActOnCallExpr finish the job. 4752 // FIXME: Represent the user-defined conversion in the AST! 4753 ImpCastExprToType(Object, 4754 Conv->getConversionType().getNonReferenceType(), 4755 CastExpr::CK_Unknown, 4756 Conv->getConversionType()->isLValueReferenceType()); 4757 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4758 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4759 CommaLocs, RParenLoc).release(); 4760 } 4761 4762 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4763 // that calls this method, using Object for the implicit object 4764 // parameter and passing along the remaining arguments. 4765 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4766 const FunctionProtoType *Proto = Method->getType()->getAsFunctionProtoType(); 4767 4768 unsigned NumArgsInProto = Proto->getNumArgs(); 4769 unsigned NumArgsToCheck = NumArgs; 4770 4771 // Build the full argument list for the method call (the 4772 // implicit object parameter is placed at the beginning of the 4773 // list). 4774 Expr **MethodArgs; 4775 if (NumArgs < NumArgsInProto) { 4776 NumArgsToCheck = NumArgsInProto; 4777 MethodArgs = new Expr*[NumArgsInProto + 1]; 4778 } else { 4779 MethodArgs = new Expr*[NumArgs + 1]; 4780 } 4781 MethodArgs[0] = Object; 4782 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4783 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4784 4785 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4786 SourceLocation()); 4787 UsualUnaryConversions(NewFn); 4788 4789 // Once we've built TheCall, all of the expressions are properly 4790 // owned. 4791 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4792 ExprOwningPtr<CXXOperatorCallExpr> 4793 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4794 MethodArgs, NumArgs + 1, 4795 ResultTy, RParenLoc)); 4796 delete [] MethodArgs; 4797 4798 // We may have default arguments. If so, we need to allocate more 4799 // slots in the call for them. 4800 if (NumArgs < NumArgsInProto) 4801 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4802 else if (NumArgs > NumArgsInProto) 4803 NumArgsToCheck = NumArgsInProto; 4804 4805 bool IsError = false; 4806 4807 // Initialize the implicit object parameter. 4808 IsError |= PerformObjectArgumentInitialization(Object, Method); 4809 TheCall->setArg(0, Object); 4810 4811 4812 // Check the argument types. 4813 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4814 Expr *Arg; 4815 if (i < NumArgs) { 4816 Arg = Args[i]; 4817 4818 // Pass the argument. 4819 QualType ProtoArgType = Proto->getArgType(i); 4820 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4821 } else { 4822 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 4823 } 4824 4825 TheCall->setArg(i + 1, Arg); 4826 } 4827 4828 // If this is a variadic call, handle args passed through "...". 4829 if (Proto->isVariadic()) { 4830 // Promote the arguments (C99 6.5.2.2p7). 4831 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4832 Expr *Arg = Args[i]; 4833 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4834 TheCall->setArg(i + 1, Arg); 4835 } 4836 } 4837 4838 if (IsError) return true; 4839 4840 if (CheckFunctionCall(Method, TheCall.get())) 4841 return true; 4842 4843 return MaybeBindToTemporary(TheCall.release()).release(); 4844} 4845 4846/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4847/// (if one exists), where @c Base is an expression of class type and 4848/// @c Member is the name of the member we're trying to find. 4849Sema::OwningExprResult 4850Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 4851 Expr *Base = static_cast<Expr *>(BaseIn.get()); 4852 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4853 4854 // C++ [over.ref]p1: 4855 // 4856 // [...] An expression x->m is interpreted as (x.operator->())->m 4857 // for a class object x of type T if T::operator->() exists and if 4858 // the operator is selected as the best match function by the 4859 // overload resolution mechanism (13.3). 4860 // FIXME: look in base classes. 4861 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4862 OverloadCandidateSet CandidateSet; 4863 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 4864 4865 LookupResult R = LookupQualifiedName(BaseRecord->getDecl(), OpName, 4866 LookupOrdinaryName); 4867 4868 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 4869 Oper != OperEnd; ++Oper) 4870 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4871 /*SuppressUserConversions=*/false); 4872 4873 // Perform overload resolution. 4874 OverloadCandidateSet::iterator Best; 4875 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4876 case OR_Success: 4877 // Overload resolution succeeded; we'll build the call below. 4878 break; 4879 4880 case OR_No_Viable_Function: 4881 if (CandidateSet.empty()) 4882 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4883 << Base->getType() << Base->getSourceRange(); 4884 else 4885 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4886 << "operator->" << Base->getSourceRange(); 4887 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4888 return ExprError(); 4889 4890 case OR_Ambiguous: 4891 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4892 << "->" << Base->getSourceRange(); 4893 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4894 return ExprError(); 4895 4896 case OR_Deleted: 4897 Diag(OpLoc, diag::err_ovl_deleted_oper) 4898 << Best->Function->isDeleted() 4899 << "->" << Base->getSourceRange(); 4900 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4901 return ExprError(); 4902 } 4903 4904 // Convert the object parameter. 4905 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4906 if (PerformObjectArgumentInitialization(Base, Method)) 4907 return ExprError(); 4908 4909 // No concerns about early exits now. 4910 BaseIn.release(); 4911 4912 // Build the operator call. 4913 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 4914 SourceLocation()); 4915 UsualUnaryConversions(FnExpr); 4916 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 4917 Method->getResultType().getNonReferenceType(), 4918 OpLoc); 4919 return Owned(Base); 4920} 4921 4922/// FixOverloadedFunctionReference - E is an expression that refers to 4923/// a C++ overloaded function (possibly with some parentheses and 4924/// perhaps a '&' around it). We have resolved the overloaded function 4925/// to the function declaration Fn, so patch up the expression E to 4926/// refer (possibly indirectly) to Fn. 4927void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 4928 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4929 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 4930 E->setType(PE->getSubExpr()->getType()); 4931 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 4932 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 4933 "Can only take the address of an overloaded function"); 4934 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4935 if (Method->isStatic()) { 4936 // Do nothing: static member functions aren't any different 4937 // from non-member functions. 4938 } else if (QualifiedDeclRefExpr *DRE 4939 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 4940 // We have taken the address of a pointer to member 4941 // function. Perform the computation here so that we get the 4942 // appropriate pointer to member type. 4943 DRE->setDecl(Fn); 4944 DRE->setType(Fn->getType()); 4945 QualType ClassType 4946 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 4947 E->setType(Context.getMemberPointerType(Fn->getType(), 4948 ClassType.getTypePtr())); 4949 return; 4950 } 4951 } 4952 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 4953 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 4954 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 4955 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 4956 isa<FunctionTemplateDecl>(DR->getDecl())) && 4957 "Expected overloaded function or function template"); 4958 DR->setDecl(Fn); 4959 E->setType(Fn->getType()); 4960 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 4961 MemExpr->setMemberDecl(Fn); 4962 E->setType(Fn->getType()); 4963 } else { 4964 assert(false && "Invalid reference to overloaded function"); 4965 } 4966} 4967 4968} // end namespace clang 4969