SemaOverload.cpp revision 1fdd89ba1d14ee11fda5b9e1c171db428b1acb23
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInherit.h" 16#include "clang/Basic/Diagnostic.h" 17#include "clang/Lex/Preprocessor.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/TypeOrdering.h" 22#include "clang/Basic/PartialDiagnostic.h" 23#include "llvm/ADT/SmallPtrSet.h" 24#include "llvm/ADT/STLExtras.h" 25#include "llvm/Support/Compiler.h" 26#include <algorithm> 27#include <cstdio> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Qualification_Adjustment, 42 ICC_Promotion, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Conversion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion 55 }; 56 return Category[(int)Kind]; 57} 58 59/// GetConversionRank - Retrieve the implicit conversion rank 60/// corresponding to the given implicit conversion kind. 61ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 62 static const ImplicitConversionRank 63 Rank[(int)ICK_Num_Conversion_Kinds] = { 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Promotion, 70 ICR_Promotion, 71 ICR_Promotion, 72 ICR_Conversion, 73 ICR_Conversion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion 82 }; 83 return Rank[(int)Kind]; 84} 85 86/// GetImplicitConversionName - Return the name of this kind of 87/// implicit conversion. 88const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 89 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 90 "No conversion", 91 "Lvalue-to-rvalue", 92 "Array-to-pointer", 93 "Function-to-pointer", 94 "Qualification", 95 "Integral promotion", 96 "Floating point promotion", 97 "Complex promotion", 98 "Integral conversion", 99 "Floating conversion", 100 "Complex conversion", 101 "Floating-integral conversion", 102 "Complex-real conversion", 103 "Pointer conversion", 104 "Pointer-to-member conversion", 105 "Boolean conversion", 106 "Compatible-types conversion", 107 "Derived-to-base conversion" 108 }; 109 return Name[Kind]; 110} 111 112/// StandardConversionSequence - Set the standard conversion 113/// sequence to the identity conversion. 114void StandardConversionSequence::setAsIdentityConversion() { 115 First = ICK_Identity; 116 Second = ICK_Identity; 117 Third = ICK_Identity; 118 Deprecated = false; 119 ReferenceBinding = false; 120 DirectBinding = false; 121 RRefBinding = false; 122 CopyConstructor = 0; 123} 124 125/// getRank - Retrieve the rank of this standard conversion sequence 126/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 127/// implicit conversions. 128ImplicitConversionRank StandardConversionSequence::getRank() const { 129 ImplicitConversionRank Rank = ICR_Exact_Match; 130 if (GetConversionRank(First) > Rank) 131 Rank = GetConversionRank(First); 132 if (GetConversionRank(Second) > Rank) 133 Rank = GetConversionRank(Second); 134 if (GetConversionRank(Third) > Rank) 135 Rank = GetConversionRank(Third); 136 return Rank; 137} 138 139/// isPointerConversionToBool - Determines whether this conversion is 140/// a conversion of a pointer or pointer-to-member to bool. This is 141/// used as part of the ranking of standard conversion sequences 142/// (C++ 13.3.3.2p4). 143bool StandardConversionSequence::isPointerConversionToBool() const { 144 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 145 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 146 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (ToType->isBooleanType() && 152 (FromType->isPointerType() || FromType->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 167 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 bool PrintedSomething = false; 186 if (First != ICK_Identity) { 187 fprintf(stderr, "%s", GetImplicitConversionName(First)); 188 PrintedSomething = true; 189 } 190 191 if (Second != ICK_Identity) { 192 if (PrintedSomething) { 193 fprintf(stderr, " -> "); 194 } 195 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 196 197 if (CopyConstructor) { 198 fprintf(stderr, " (by copy constructor)"); 199 } else if (DirectBinding) { 200 fprintf(stderr, " (direct reference binding)"); 201 } else if (ReferenceBinding) { 202 fprintf(stderr, " (reference binding)"); 203 } 204 PrintedSomething = true; 205 } 206 207 if (Third != ICK_Identity) { 208 if (PrintedSomething) { 209 fprintf(stderr, " -> "); 210 } 211 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 212 PrintedSomething = true; 213 } 214 215 if (!PrintedSomething) { 216 fprintf(stderr, "No conversions required"); 217 } 218} 219 220/// DebugPrint - Print this user-defined conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void UserDefinedConversionSequence::DebugPrint() const { 223 if (Before.First || Before.Second || Before.Third) { 224 Before.DebugPrint(); 225 fprintf(stderr, " -> "); 226 } 227 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 228 if (After.First || After.Second || After.Third) { 229 fprintf(stderr, " -> "); 230 After.DebugPrint(); 231 } 232} 233 234/// DebugPrint - Print this implicit conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void ImplicitConversionSequence::DebugPrint() const { 237 switch (ConversionKind) { 238 case StandardConversion: 239 fprintf(stderr, "Standard conversion: "); 240 Standard.DebugPrint(); 241 break; 242 case UserDefinedConversion: 243 fprintf(stderr, "User-defined conversion: "); 244 UserDefined.DebugPrint(); 245 break; 246 case EllipsisConversion: 247 fprintf(stderr, "Ellipsis conversion"); 248 break; 249 case BadConversion: 250 fprintf(stderr, "Bad conversion"); 251 break; 252 } 253 254 fprintf(stderr, "\n"); 255} 256 257// IsOverload - Determine whether the given New declaration is an 258// overload of the Old declaration. This routine returns false if New 259// and Old cannot be overloaded, e.g., if they are functions with the 260// same signature (C++ 1.3.10) or if the Old declaration isn't a 261// function (or overload set). When it does return false and Old is an 262// OverloadedFunctionDecl, MatchedDecl will be set to point to the 263// FunctionDecl that New cannot be overloaded with. 264// 265// Example: Given the following input: 266// 267// void f(int, float); // #1 268// void f(int, int); // #2 269// int f(int, int); // #3 270// 271// When we process #1, there is no previous declaration of "f", 272// so IsOverload will not be used. 273// 274// When we process #2, Old is a FunctionDecl for #1. By comparing the 275// parameter types, we see that #1 and #2 are overloaded (since they 276// have different signatures), so this routine returns false; 277// MatchedDecl is unchanged. 278// 279// When we process #3, Old is an OverloadedFunctionDecl containing #1 280// and #2. We compare the signatures of #3 to #1 (they're overloaded, 281// so we do nothing) and then #3 to #2. Since the signatures of #3 and 282// #2 are identical (return types of functions are not part of the 283// signature), IsOverload returns false and MatchedDecl will be set to 284// point to the FunctionDecl for #2. 285bool 286Sema::IsOverload(FunctionDecl *New, Decl* OldD, 287 OverloadedFunctionDecl::function_iterator& MatchedDecl) { 288 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 289 // Is this new function an overload of every function in the 290 // overload set? 291 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 292 FuncEnd = Ovl->function_end(); 293 for (; Func != FuncEnd; ++Func) { 294 if (!IsOverload(New, *Func, MatchedDecl)) { 295 MatchedDecl = Func; 296 return false; 297 } 298 } 299 300 // This function overloads every function in the overload set. 301 return true; 302 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 303 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 304 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 305 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 306 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 307 308 // C++ [temp.fct]p2: 309 // A function template can be overloaded with other function templates 310 // and with normal (non-template) functions. 311 if ((OldTemplate == 0) != (NewTemplate == 0)) 312 return true; 313 314 // Is the function New an overload of the function Old? 315 QualType OldQType = Context.getCanonicalType(Old->getType()); 316 QualType NewQType = Context.getCanonicalType(New->getType()); 317 318 // Compare the signatures (C++ 1.3.10) of the two functions to 319 // determine whether they are overloads. If we find any mismatch 320 // in the signature, they are overloads. 321 322 // If either of these functions is a K&R-style function (no 323 // prototype), then we consider them to have matching signatures. 324 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 325 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 326 return false; 327 328 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 329 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 330 331 // The signature of a function includes the types of its 332 // parameters (C++ 1.3.10), which includes the presence or absence 333 // of the ellipsis; see C++ DR 357). 334 if (OldQType != NewQType && 335 (OldType->getNumArgs() != NewType->getNumArgs() || 336 OldType->isVariadic() != NewType->isVariadic() || 337 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 338 NewType->arg_type_begin()))) 339 return true; 340 341 // C++ [temp.over.link]p4: 342 // The signature of a function template consists of its function 343 // signature, its return type and its template parameter list. The names 344 // of the template parameters are significant only for establishing the 345 // relationship between the template parameters and the rest of the 346 // signature. 347 // 348 // We check the return type and template parameter lists for function 349 // templates first; the remaining checks follow. 350 if (NewTemplate && 351 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 352 OldTemplate->getTemplateParameters(), 353 false, false, SourceLocation()) || 354 OldType->getResultType() != NewType->getResultType())) 355 return true; 356 357 // If the function is a class member, its signature includes the 358 // cv-qualifiers (if any) on the function itself. 359 // 360 // As part of this, also check whether one of the member functions 361 // is static, in which case they are not overloads (C++ 362 // 13.1p2). While not part of the definition of the signature, 363 // this check is important to determine whether these functions 364 // can be overloaded. 365 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 366 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 367 if (OldMethod && NewMethod && 368 !OldMethod->isStatic() && !NewMethod->isStatic() && 369 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 370 return true; 371 372 // The signatures match; this is not an overload. 373 return false; 374 } else { 375 // (C++ 13p1): 376 // Only function declarations can be overloaded; object and type 377 // declarations cannot be overloaded. 378 return false; 379 } 380} 381 382/// TryImplicitConversion - Attempt to perform an implicit conversion 383/// from the given expression (Expr) to the given type (ToType). This 384/// function returns an implicit conversion sequence that can be used 385/// to perform the initialization. Given 386/// 387/// void f(float f); 388/// void g(int i) { f(i); } 389/// 390/// this routine would produce an implicit conversion sequence to 391/// describe the initialization of f from i, which will be a standard 392/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 393/// 4.1) followed by a floating-integral conversion (C++ 4.9). 394// 395/// Note that this routine only determines how the conversion can be 396/// performed; it does not actually perform the conversion. As such, 397/// it will not produce any diagnostics if no conversion is available, 398/// but will instead return an implicit conversion sequence of kind 399/// "BadConversion". 400/// 401/// If @p SuppressUserConversions, then user-defined conversions are 402/// not permitted. 403/// If @p AllowExplicit, then explicit user-defined conversions are 404/// permitted. 405/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 406/// no matter its actual lvalueness. 407ImplicitConversionSequence 408Sema::TryImplicitConversion(Expr* From, QualType ToType, 409 bool SuppressUserConversions, 410 bool AllowExplicit, bool ForceRValue, 411 bool InOverloadResolution) { 412 ImplicitConversionSequence ICS; 413 OverloadCandidateSet Conversions; 414 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 415 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 416 else if (getLangOptions().CPlusPlus && 417 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 418 Conversions, 419 !SuppressUserConversions, AllowExplicit, 420 ForceRValue) == OR_Success) { 421 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 422 // C++ [over.ics.user]p4: 423 // A conversion of an expression of class type to the same class 424 // type is given Exact Match rank, and a conversion of an 425 // expression of class type to a base class of that type is 426 // given Conversion rank, in spite of the fact that a copy 427 // constructor (i.e., a user-defined conversion function) is 428 // called for those cases. 429 if (CXXConstructorDecl *Constructor 430 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 431 QualType FromCanon 432 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 433 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 434 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 435 // Turn this into a "standard" conversion sequence, so that it 436 // gets ranked with standard conversion sequences. 437 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 438 ICS.Standard.setAsIdentityConversion(); 439 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 440 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 441 ICS.Standard.CopyConstructor = Constructor; 442 if (ToCanon != FromCanon) 443 ICS.Standard.Second = ICK_Derived_To_Base; 444 } 445 } 446 447 // C++ [over.best.ics]p4: 448 // However, when considering the argument of a user-defined 449 // conversion function that is a candidate by 13.3.1.3 when 450 // invoked for the copying of the temporary in the second step 451 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 452 // 13.3.1.6 in all cases, only standard conversion sequences and 453 // ellipsis conversion sequences are allowed. 454 if (SuppressUserConversions && 455 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 456 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 457 } else 458 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 459 460 return ICS; 461} 462 463/// IsStandardConversion - Determines whether there is a standard 464/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 465/// expression From to the type ToType. Standard conversion sequences 466/// only consider non-class types; for conversions that involve class 467/// types, use TryImplicitConversion. If a conversion exists, SCS will 468/// contain the standard conversion sequence required to perform this 469/// conversion and this routine will return true. Otherwise, this 470/// routine will return false and the value of SCS is unspecified. 471bool 472Sema::IsStandardConversion(Expr* From, QualType ToType, 473 bool InOverloadResolution, 474 StandardConversionSequence &SCS) { 475 QualType FromType = From->getType(); 476 477 // Standard conversions (C++ [conv]) 478 SCS.setAsIdentityConversion(); 479 SCS.Deprecated = false; 480 SCS.IncompatibleObjC = false; 481 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 482 SCS.CopyConstructor = 0; 483 484 // There are no standard conversions for class types in C++, so 485 // abort early. When overloading in C, however, we do permit 486 if (FromType->isRecordType() || ToType->isRecordType()) { 487 if (getLangOptions().CPlusPlus) 488 return false; 489 490 // When we're overloading in C, we allow, as standard conversions, 491 } 492 493 // The first conversion can be an lvalue-to-rvalue conversion, 494 // array-to-pointer conversion, or function-to-pointer conversion 495 // (C++ 4p1). 496 497 // Lvalue-to-rvalue conversion (C++ 4.1): 498 // An lvalue (3.10) of a non-function, non-array type T can be 499 // converted to an rvalue. 500 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 501 if (argIsLvalue == Expr::LV_Valid && 502 !FromType->isFunctionType() && !FromType->isArrayType() && 503 Context.getCanonicalType(FromType) != Context.OverloadTy) { 504 SCS.First = ICK_Lvalue_To_Rvalue; 505 506 // If T is a non-class type, the type of the rvalue is the 507 // cv-unqualified version of T. Otherwise, the type of the rvalue 508 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 509 // just strip the qualifiers because they don't matter. 510 511 // FIXME: Doesn't see through to qualifiers behind a typedef! 512 FromType = FromType.getUnqualifiedType(); 513 } else if (FromType->isArrayType()) { 514 // Array-to-pointer conversion (C++ 4.2) 515 SCS.First = ICK_Array_To_Pointer; 516 517 // An lvalue or rvalue of type "array of N T" or "array of unknown 518 // bound of T" can be converted to an rvalue of type "pointer to 519 // T" (C++ 4.2p1). 520 FromType = Context.getArrayDecayedType(FromType); 521 522 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 523 // This conversion is deprecated. (C++ D.4). 524 SCS.Deprecated = true; 525 526 // For the purpose of ranking in overload resolution 527 // (13.3.3.1.1), this conversion is considered an 528 // array-to-pointer conversion followed by a qualification 529 // conversion (4.4). (C++ 4.2p2) 530 SCS.Second = ICK_Identity; 531 SCS.Third = ICK_Qualification; 532 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 533 return true; 534 } 535 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 536 // Function-to-pointer conversion (C++ 4.3). 537 SCS.First = ICK_Function_To_Pointer; 538 539 // An lvalue of function type T can be converted to an rvalue of 540 // type "pointer to T." The result is a pointer to the 541 // function. (C++ 4.3p1). 542 FromType = Context.getPointerType(FromType); 543 } else if (FunctionDecl *Fn 544 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 545 // Address of overloaded function (C++ [over.over]). 546 SCS.First = ICK_Function_To_Pointer; 547 548 // We were able to resolve the address of the overloaded function, 549 // so we can convert to the type of that function. 550 FromType = Fn->getType(); 551 if (ToType->isLValueReferenceType()) 552 FromType = Context.getLValueReferenceType(FromType); 553 else if (ToType->isRValueReferenceType()) 554 FromType = Context.getRValueReferenceType(FromType); 555 else if (ToType->isMemberPointerType()) { 556 // Resolve address only succeeds if both sides are member pointers, 557 // but it doesn't have to be the same class. See DR 247. 558 // Note that this means that the type of &Derived::fn can be 559 // Ret (Base::*)(Args) if the fn overload actually found is from the 560 // base class, even if it was brought into the derived class via a 561 // using declaration. The standard isn't clear on this issue at all. 562 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 563 FromType = Context.getMemberPointerType(FromType, 564 Context.getTypeDeclType(M->getParent()).getTypePtr()); 565 } else 566 FromType = Context.getPointerType(FromType); 567 } else { 568 // We don't require any conversions for the first step. 569 SCS.First = ICK_Identity; 570 } 571 572 // The second conversion can be an integral promotion, floating 573 // point promotion, integral conversion, floating point conversion, 574 // floating-integral conversion, pointer conversion, 575 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 576 // For overloading in C, this can also be a "compatible-type" 577 // conversion. 578 bool IncompatibleObjC = false; 579 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 580 // The unqualified versions of the types are the same: there's no 581 // conversion to do. 582 SCS.Second = ICK_Identity; 583 } else if (IsIntegralPromotion(From, FromType, ToType)) { 584 // Integral promotion (C++ 4.5). 585 SCS.Second = ICK_Integral_Promotion; 586 FromType = ToType.getUnqualifiedType(); 587 } else if (IsFloatingPointPromotion(FromType, ToType)) { 588 // Floating point promotion (C++ 4.6). 589 SCS.Second = ICK_Floating_Promotion; 590 FromType = ToType.getUnqualifiedType(); 591 } else if (IsComplexPromotion(FromType, ToType)) { 592 // Complex promotion (Clang extension) 593 SCS.Second = ICK_Complex_Promotion; 594 FromType = ToType.getUnqualifiedType(); 595 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 596 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 597 // Integral conversions (C++ 4.7). 598 // FIXME: isIntegralType shouldn't be true for enums in C++. 599 SCS.Second = ICK_Integral_Conversion; 600 FromType = ToType.getUnqualifiedType(); 601 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 602 // Floating point conversions (C++ 4.8). 603 SCS.Second = ICK_Floating_Conversion; 604 FromType = ToType.getUnqualifiedType(); 605 } else if (FromType->isComplexType() && ToType->isComplexType()) { 606 // Complex conversions (C99 6.3.1.6) 607 SCS.Second = ICK_Complex_Conversion; 608 FromType = ToType.getUnqualifiedType(); 609 } else if ((FromType->isFloatingType() && 610 ToType->isIntegralType() && (!ToType->isBooleanType() && 611 !ToType->isEnumeralType())) || 612 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 613 ToType->isFloatingType())) { 614 // Floating-integral conversions (C++ 4.9). 615 // FIXME: isIntegralType shouldn't be true for enums in C++. 616 SCS.Second = ICK_Floating_Integral; 617 FromType = ToType.getUnqualifiedType(); 618 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 619 (ToType->isComplexType() && FromType->isArithmeticType())) { 620 // Complex-real conversions (C99 6.3.1.7) 621 SCS.Second = ICK_Complex_Real; 622 FromType = ToType.getUnqualifiedType(); 623 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 624 FromType, IncompatibleObjC)) { 625 // Pointer conversions (C++ 4.10). 626 SCS.Second = ICK_Pointer_Conversion; 627 SCS.IncompatibleObjC = IncompatibleObjC; 628 } else if (IsMemberPointerConversion(From, FromType, ToType, FromType)) { 629 // Pointer to member conversions (4.11). 630 SCS.Second = ICK_Pointer_Member; 631 } else if (ToType->isBooleanType() && 632 (FromType->isArithmeticType() || 633 FromType->isEnumeralType() || 634 FromType->isPointerType() || 635 FromType->isBlockPointerType() || 636 FromType->isMemberPointerType() || 637 FromType->isNullPtrType())) { 638 // Boolean conversions (C++ 4.12). 639 SCS.Second = ICK_Boolean_Conversion; 640 FromType = Context.BoolTy; 641 } else if (!getLangOptions().CPlusPlus && 642 Context.typesAreCompatible(ToType, FromType)) { 643 // Compatible conversions (Clang extension for C function overloading) 644 SCS.Second = ICK_Compatible_Conversion; 645 } else { 646 // No second conversion required. 647 SCS.Second = ICK_Identity; 648 } 649 650 QualType CanonFrom; 651 QualType CanonTo; 652 // The third conversion can be a qualification conversion (C++ 4p1). 653 if (IsQualificationConversion(FromType, ToType)) { 654 SCS.Third = ICK_Qualification; 655 FromType = ToType; 656 CanonFrom = Context.getCanonicalType(FromType); 657 CanonTo = Context.getCanonicalType(ToType); 658 } else { 659 // No conversion required 660 SCS.Third = ICK_Identity; 661 662 // C++ [over.best.ics]p6: 663 // [...] Any difference in top-level cv-qualification is 664 // subsumed by the initialization itself and does not constitute 665 // a conversion. [...] 666 CanonFrom = Context.getCanonicalType(FromType); 667 CanonTo = Context.getCanonicalType(ToType); 668 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 669 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 670 FromType = ToType; 671 CanonFrom = CanonTo; 672 } 673 } 674 675 // If we have not converted the argument type to the parameter type, 676 // this is a bad conversion sequence. 677 if (CanonFrom != CanonTo) 678 return false; 679 680 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 681 return true; 682} 683 684/// IsIntegralPromotion - Determines whether the conversion from the 685/// expression From (whose potentially-adjusted type is FromType) to 686/// ToType is an integral promotion (C++ 4.5). If so, returns true and 687/// sets PromotedType to the promoted type. 688bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 689 const BuiltinType *To = ToType->getAsBuiltinType(); 690 // All integers are built-in. 691 if (!To) { 692 return false; 693 } 694 695 // An rvalue of type char, signed char, unsigned char, short int, or 696 // unsigned short int can be converted to an rvalue of type int if 697 // int can represent all the values of the source type; otherwise, 698 // the source rvalue can be converted to an rvalue of type unsigned 699 // int (C++ 4.5p1). 700 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 701 if (// We can promote any signed, promotable integer type to an int 702 (FromType->isSignedIntegerType() || 703 // We can promote any unsigned integer type whose size is 704 // less than int to an int. 705 (!FromType->isSignedIntegerType() && 706 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 707 return To->getKind() == BuiltinType::Int; 708 } 709 710 return To->getKind() == BuiltinType::UInt; 711 } 712 713 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 714 // can be converted to an rvalue of the first of the following types 715 // that can represent all the values of its underlying type: int, 716 // unsigned int, long, or unsigned long (C++ 4.5p2). 717 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 718 && ToType->isIntegerType()) { 719 // Determine whether the type we're converting from is signed or 720 // unsigned. 721 bool FromIsSigned; 722 uint64_t FromSize = Context.getTypeSize(FromType); 723 if (const EnumType *FromEnumType = FromType->getAsEnumType()) { 724 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 725 FromIsSigned = UnderlyingType->isSignedIntegerType(); 726 } else { 727 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 728 FromIsSigned = true; 729 } 730 731 // The types we'll try to promote to, in the appropriate 732 // order. Try each of these types. 733 QualType PromoteTypes[6] = { 734 Context.IntTy, Context.UnsignedIntTy, 735 Context.LongTy, Context.UnsignedLongTy , 736 Context.LongLongTy, Context.UnsignedLongLongTy 737 }; 738 for (int Idx = 0; Idx < 6; ++Idx) { 739 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 740 if (FromSize < ToSize || 741 (FromSize == ToSize && 742 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 743 // We found the type that we can promote to. If this is the 744 // type we wanted, we have a promotion. Otherwise, no 745 // promotion. 746 return Context.getCanonicalType(ToType).getUnqualifiedType() 747 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 748 } 749 } 750 } 751 752 // An rvalue for an integral bit-field (9.6) can be converted to an 753 // rvalue of type int if int can represent all the values of the 754 // bit-field; otherwise, it can be converted to unsigned int if 755 // unsigned int can represent all the values of the bit-field. If 756 // the bit-field is larger yet, no integral promotion applies to 757 // it. If the bit-field has an enumerated type, it is treated as any 758 // other value of that type for promotion purposes (C++ 4.5p3). 759 // FIXME: We should delay checking of bit-fields until we actually perform the 760 // conversion. 761 using llvm::APSInt; 762 if (From) 763 if (FieldDecl *MemberDecl = From->getBitField()) { 764 APSInt BitWidth; 765 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 766 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 767 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 768 ToSize = Context.getTypeSize(ToType); 769 770 // Are we promoting to an int from a bitfield that fits in an int? 771 if (BitWidth < ToSize || 772 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 773 return To->getKind() == BuiltinType::Int; 774 } 775 776 // Are we promoting to an unsigned int from an unsigned bitfield 777 // that fits into an unsigned int? 778 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 779 return To->getKind() == BuiltinType::UInt; 780 } 781 782 return false; 783 } 784 } 785 786 // An rvalue of type bool can be converted to an rvalue of type int, 787 // with false becoming zero and true becoming one (C++ 4.5p4). 788 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 789 return true; 790 } 791 792 return false; 793} 794 795/// IsFloatingPointPromotion - Determines whether the conversion from 796/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 797/// returns true and sets PromotedType to the promoted type. 798bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 799 /// An rvalue of type float can be converted to an rvalue of type 800 /// double. (C++ 4.6p1). 801 if (const BuiltinType *FromBuiltin = FromType->getAsBuiltinType()) 802 if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType()) { 803 if (FromBuiltin->getKind() == BuiltinType::Float && 804 ToBuiltin->getKind() == BuiltinType::Double) 805 return true; 806 807 // C99 6.3.1.5p1: 808 // When a float is promoted to double or long double, or a 809 // double is promoted to long double [...]. 810 if (!getLangOptions().CPlusPlus && 811 (FromBuiltin->getKind() == BuiltinType::Float || 812 FromBuiltin->getKind() == BuiltinType::Double) && 813 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 814 return true; 815 } 816 817 return false; 818} 819 820/// \brief Determine if a conversion is a complex promotion. 821/// 822/// A complex promotion is defined as a complex -> complex conversion 823/// where the conversion between the underlying real types is a 824/// floating-point or integral promotion. 825bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 826 const ComplexType *FromComplex = FromType->getAsComplexType(); 827 if (!FromComplex) 828 return false; 829 830 const ComplexType *ToComplex = ToType->getAsComplexType(); 831 if (!ToComplex) 832 return false; 833 834 return IsFloatingPointPromotion(FromComplex->getElementType(), 835 ToComplex->getElementType()) || 836 IsIntegralPromotion(0, FromComplex->getElementType(), 837 ToComplex->getElementType()); 838} 839 840/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 841/// the pointer type FromPtr to a pointer to type ToPointee, with the 842/// same type qualifiers as FromPtr has on its pointee type. ToType, 843/// if non-empty, will be a pointer to ToType that may or may not have 844/// the right set of qualifiers on its pointee. 845static QualType 846BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 847 QualType ToPointee, QualType ToType, 848 ASTContext &Context) { 849 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 850 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 851 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 852 853 // Exact qualifier match -> return the pointer type we're converting to. 854 if (CanonToPointee.getCVRQualifiers() == Quals) { 855 // ToType is exactly what we need. Return it. 856 if (ToType.getTypePtr()) 857 return ToType; 858 859 // Build a pointer to ToPointee. It has the right qualifiers 860 // already. 861 return Context.getPointerType(ToPointee); 862 } 863 864 // Just build a canonical type that has the right qualifiers. 865 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 866} 867 868static bool isNullPointerConstantForConversion(Expr *Expr, 869 bool InOverloadResolution, 870 ASTContext &Context) { 871 // Handle value-dependent integral null pointer constants correctly. 872 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 873 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 874 Expr->getType()->isIntegralType()) 875 return !InOverloadResolution; 876 877 return Expr->isNullPointerConstant(Context); 878} 879 880/// IsPointerConversion - Determines whether the conversion of the 881/// expression From, which has the (possibly adjusted) type FromType, 882/// can be converted to the type ToType via a pointer conversion (C++ 883/// 4.10). If so, returns true and places the converted type (that 884/// might differ from ToType in its cv-qualifiers at some level) into 885/// ConvertedType. 886/// 887/// This routine also supports conversions to and from block pointers 888/// and conversions with Objective-C's 'id', 'id<protocols...>', and 889/// pointers to interfaces. FIXME: Once we've determined the 890/// appropriate overloading rules for Objective-C, we may want to 891/// split the Objective-C checks into a different routine; however, 892/// GCC seems to consider all of these conversions to be pointer 893/// conversions, so for now they live here. IncompatibleObjC will be 894/// set if the conversion is an allowed Objective-C conversion that 895/// should result in a warning. 896bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 897 bool InOverloadResolution, 898 QualType& ConvertedType, 899 bool &IncompatibleObjC) { 900 IncompatibleObjC = false; 901 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 902 return true; 903 904 // Conversion from a null pointer constant to any Objective-C pointer type. 905 if (ToType->isObjCObjectPointerType() && 906 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 907 ConvertedType = ToType; 908 return true; 909 } 910 911 // Blocks: Block pointers can be converted to void*. 912 if (FromType->isBlockPointerType() && ToType->isPointerType() && 913 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 914 ConvertedType = ToType; 915 return true; 916 } 917 // Blocks: A null pointer constant can be converted to a block 918 // pointer type. 919 if (ToType->isBlockPointerType() && 920 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 921 ConvertedType = ToType; 922 return true; 923 } 924 925 // If the left-hand-side is nullptr_t, the right side can be a null 926 // pointer constant. 927 if (ToType->isNullPtrType() && 928 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 929 ConvertedType = ToType; 930 return true; 931 } 932 933 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 934 if (!ToTypePtr) 935 return false; 936 937 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 938 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 939 ConvertedType = ToType; 940 return true; 941 } 942 943 // Beyond this point, both types need to be pointers. 944 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 945 if (!FromTypePtr) 946 return false; 947 948 QualType FromPointeeType = FromTypePtr->getPointeeType(); 949 QualType ToPointeeType = ToTypePtr->getPointeeType(); 950 951 // An rvalue of type "pointer to cv T," where T is an object type, 952 // can be converted to an rvalue of type "pointer to cv void" (C++ 953 // 4.10p2). 954 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 955 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 956 ToPointeeType, 957 ToType, Context); 958 return true; 959 } 960 961 // When we're overloading in C, we allow a special kind of pointer 962 // conversion for compatible-but-not-identical pointee types. 963 if (!getLangOptions().CPlusPlus && 964 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 965 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 966 ToPointeeType, 967 ToType, Context); 968 return true; 969 } 970 971 // C++ [conv.ptr]p3: 972 // 973 // An rvalue of type "pointer to cv D," where D is a class type, 974 // can be converted to an rvalue of type "pointer to cv B," where 975 // B is a base class (clause 10) of D. If B is an inaccessible 976 // (clause 11) or ambiguous (10.2) base class of D, a program that 977 // necessitates this conversion is ill-formed. The result of the 978 // conversion is a pointer to the base class sub-object of the 979 // derived class object. The null pointer value is converted to 980 // the null pointer value of the destination type. 981 // 982 // Note that we do not check for ambiguity or inaccessibility 983 // here. That is handled by CheckPointerConversion. 984 if (getLangOptions().CPlusPlus && 985 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 986 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 987 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 988 ToPointeeType, 989 ToType, Context); 990 return true; 991 } 992 993 return false; 994} 995 996/// isObjCPointerConversion - Determines whether this is an 997/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 998/// with the same arguments and return values. 999bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1000 QualType& ConvertedType, 1001 bool &IncompatibleObjC) { 1002 if (!getLangOptions().ObjC1) 1003 return false; 1004 1005 // First, we handle all conversions on ObjC object pointer types. 1006 const ObjCObjectPointerType* ToObjCPtr = ToType->getAsObjCObjectPointerType(); 1007 const ObjCObjectPointerType *FromObjCPtr = 1008 FromType->getAsObjCObjectPointerType(); 1009 1010 if (ToObjCPtr && FromObjCPtr) { 1011 // Objective C++: We're able to convert between "id" or "Class" and a 1012 // pointer to any interface (in both directions). 1013 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1014 ConvertedType = ToType; 1015 return true; 1016 } 1017 // Conversions with Objective-C's id<...>. 1018 if ((FromObjCPtr->isObjCQualifiedIdType() || 1019 ToObjCPtr->isObjCQualifiedIdType()) && 1020 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1021 /*compare=*/false)) { 1022 ConvertedType = ToType; 1023 return true; 1024 } 1025 // Objective C++: We're able to convert from a pointer to an 1026 // interface to a pointer to a different interface. 1027 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1028 ConvertedType = ToType; 1029 return true; 1030 } 1031 1032 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1033 // Okay: this is some kind of implicit downcast of Objective-C 1034 // interfaces, which is permitted. However, we're going to 1035 // complain about it. 1036 IncompatibleObjC = true; 1037 ConvertedType = FromType; 1038 return true; 1039 } 1040 } 1041 // Beyond this point, both types need to be C pointers or block pointers. 1042 QualType ToPointeeType; 1043 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1044 ToPointeeType = ToCPtr->getPointeeType(); 1045 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1046 ToPointeeType = ToBlockPtr->getPointeeType(); 1047 else 1048 return false; 1049 1050 QualType FromPointeeType; 1051 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1052 FromPointeeType = FromCPtr->getPointeeType(); 1053 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1054 FromPointeeType = FromBlockPtr->getPointeeType(); 1055 else 1056 return false; 1057 1058 // If we have pointers to pointers, recursively check whether this 1059 // is an Objective-C conversion. 1060 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1061 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1062 IncompatibleObjC)) { 1063 // We always complain about this conversion. 1064 IncompatibleObjC = true; 1065 ConvertedType = ToType; 1066 return true; 1067 } 1068 // If we have pointers to functions or blocks, check whether the only 1069 // differences in the argument and result types are in Objective-C 1070 // pointer conversions. If so, we permit the conversion (but 1071 // complain about it). 1072 const FunctionProtoType *FromFunctionType 1073 = FromPointeeType->getAsFunctionProtoType(); 1074 const FunctionProtoType *ToFunctionType 1075 = ToPointeeType->getAsFunctionProtoType(); 1076 if (FromFunctionType && ToFunctionType) { 1077 // If the function types are exactly the same, this isn't an 1078 // Objective-C pointer conversion. 1079 if (Context.getCanonicalType(FromPointeeType) 1080 == Context.getCanonicalType(ToPointeeType)) 1081 return false; 1082 1083 // Perform the quick checks that will tell us whether these 1084 // function types are obviously different. 1085 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1086 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1087 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1088 return false; 1089 1090 bool HasObjCConversion = false; 1091 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1092 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1093 // Okay, the types match exactly. Nothing to do. 1094 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1095 ToFunctionType->getResultType(), 1096 ConvertedType, IncompatibleObjC)) { 1097 // Okay, we have an Objective-C pointer conversion. 1098 HasObjCConversion = true; 1099 } else { 1100 // Function types are too different. Abort. 1101 return false; 1102 } 1103 1104 // Check argument types. 1105 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1106 ArgIdx != NumArgs; ++ArgIdx) { 1107 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1108 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1109 if (Context.getCanonicalType(FromArgType) 1110 == Context.getCanonicalType(ToArgType)) { 1111 // Okay, the types match exactly. Nothing to do. 1112 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1113 ConvertedType, IncompatibleObjC)) { 1114 // Okay, we have an Objective-C pointer conversion. 1115 HasObjCConversion = true; 1116 } else { 1117 // Argument types are too different. Abort. 1118 return false; 1119 } 1120 } 1121 1122 if (HasObjCConversion) { 1123 // We had an Objective-C conversion. Allow this pointer 1124 // conversion, but complain about it. 1125 ConvertedType = ToType; 1126 IncompatibleObjC = true; 1127 return true; 1128 } 1129 } 1130 1131 return false; 1132} 1133 1134/// CheckPointerConversion - Check the pointer conversion from the 1135/// expression From to the type ToType. This routine checks for 1136/// ambiguous or inaccessible derived-to-base pointer 1137/// conversions for which IsPointerConversion has already returned 1138/// true. It returns true and produces a diagnostic if there was an 1139/// error, or returns false otherwise. 1140bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1141 CastExpr::CastKind &Kind) { 1142 QualType FromType = From->getType(); 1143 1144 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1145 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1146 QualType FromPointeeType = FromPtrType->getPointeeType(), 1147 ToPointeeType = ToPtrType->getPointeeType(); 1148 1149 if (FromPointeeType->isRecordType() && 1150 ToPointeeType->isRecordType()) { 1151 // We must have a derived-to-base conversion. Check an 1152 // ambiguous or inaccessible conversion. 1153 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1154 From->getExprLoc(), 1155 From->getSourceRange())) 1156 return true; 1157 1158 // The conversion was successful. 1159 Kind = CastExpr::CK_DerivedToBase; 1160 } 1161 } 1162 if (const ObjCObjectPointerType *FromPtrType = 1163 FromType->getAsObjCObjectPointerType()) 1164 if (const ObjCObjectPointerType *ToPtrType = 1165 ToType->getAsObjCObjectPointerType()) { 1166 // Objective-C++ conversions are always okay. 1167 // FIXME: We should have a different class of conversions for the 1168 // Objective-C++ implicit conversions. 1169 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1170 return false; 1171 1172 } 1173 return false; 1174} 1175 1176/// IsMemberPointerConversion - Determines whether the conversion of the 1177/// expression From, which has the (possibly adjusted) type FromType, can be 1178/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1179/// If so, returns true and places the converted type (that might differ from 1180/// ToType in its cv-qualifiers at some level) into ConvertedType. 1181bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1182 QualType ToType, QualType &ConvertedType) { 1183 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1184 if (!ToTypePtr) 1185 return false; 1186 1187 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1188 if (From->isNullPointerConstant(Context)) { 1189 ConvertedType = ToType; 1190 return true; 1191 } 1192 1193 // Otherwise, both types have to be member pointers. 1194 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1195 if (!FromTypePtr) 1196 return false; 1197 1198 // A pointer to member of B can be converted to a pointer to member of D, 1199 // where D is derived from B (C++ 4.11p2). 1200 QualType FromClass(FromTypePtr->getClass(), 0); 1201 QualType ToClass(ToTypePtr->getClass(), 0); 1202 // FIXME: What happens when these are dependent? Is this function even called? 1203 1204 if (IsDerivedFrom(ToClass, FromClass)) { 1205 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1206 ToClass.getTypePtr()); 1207 return true; 1208 } 1209 1210 return false; 1211} 1212 1213/// CheckMemberPointerConversion - Check the member pointer conversion from the 1214/// expression From to the type ToType. This routine checks for ambiguous or 1215/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1216/// for which IsMemberPointerConversion has already returned true. It returns 1217/// true and produces a diagnostic if there was an error, or returns false 1218/// otherwise. 1219bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1220 CastExpr::CastKind &Kind) { 1221 QualType FromType = From->getType(); 1222 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1223 if (!FromPtrType) { 1224 // This must be a null pointer to member pointer conversion 1225 assert(From->isNullPointerConstant(Context) && 1226 "Expr must be null pointer constant!"); 1227 Kind = CastExpr::CK_NullToMemberPointer; 1228 return false; 1229 } 1230 1231 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1232 assert(ToPtrType && "No member pointer cast has a target type " 1233 "that is not a member pointer."); 1234 1235 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1236 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1237 1238 // FIXME: What about dependent types? 1239 assert(FromClass->isRecordType() && "Pointer into non-class."); 1240 assert(ToClass->isRecordType() && "Pointer into non-class."); 1241 1242 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1243 /*DetectVirtual=*/true); 1244 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1245 assert(DerivationOkay && 1246 "Should not have been called if derivation isn't OK."); 1247 (void)DerivationOkay; 1248 1249 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1250 getUnqualifiedType())) { 1251 // Derivation is ambiguous. Redo the check to find the exact paths. 1252 Paths.clear(); 1253 Paths.setRecordingPaths(true); 1254 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1255 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1256 (void)StillOkay; 1257 1258 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1259 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1260 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1261 return true; 1262 } 1263 1264 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1265 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1266 << FromClass << ToClass << QualType(VBase, 0) 1267 << From->getSourceRange(); 1268 return true; 1269 } 1270 1271 // Must be a base to derived member conversion. 1272 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1273 return false; 1274} 1275 1276/// IsQualificationConversion - Determines whether the conversion from 1277/// an rvalue of type FromType to ToType is a qualification conversion 1278/// (C++ 4.4). 1279bool 1280Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1281 FromType = Context.getCanonicalType(FromType); 1282 ToType = Context.getCanonicalType(ToType); 1283 1284 // If FromType and ToType are the same type, this is not a 1285 // qualification conversion. 1286 if (FromType == ToType) 1287 return false; 1288 1289 // (C++ 4.4p4): 1290 // A conversion can add cv-qualifiers at levels other than the first 1291 // in multi-level pointers, subject to the following rules: [...] 1292 bool PreviousToQualsIncludeConst = true; 1293 bool UnwrappedAnyPointer = false; 1294 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1295 // Within each iteration of the loop, we check the qualifiers to 1296 // determine if this still looks like a qualification 1297 // conversion. Then, if all is well, we unwrap one more level of 1298 // pointers or pointers-to-members and do it all again 1299 // until there are no more pointers or pointers-to-members left to 1300 // unwrap. 1301 UnwrappedAnyPointer = true; 1302 1303 // -- for every j > 0, if const is in cv 1,j then const is in cv 1304 // 2,j, and similarly for volatile. 1305 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1306 return false; 1307 1308 // -- if the cv 1,j and cv 2,j are different, then const is in 1309 // every cv for 0 < k < j. 1310 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1311 && !PreviousToQualsIncludeConst) 1312 return false; 1313 1314 // Keep track of whether all prior cv-qualifiers in the "to" type 1315 // include const. 1316 PreviousToQualsIncludeConst 1317 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1318 } 1319 1320 // We are left with FromType and ToType being the pointee types 1321 // after unwrapping the original FromType and ToType the same number 1322 // of types. If we unwrapped any pointers, and if FromType and 1323 // ToType have the same unqualified type (since we checked 1324 // qualifiers above), then this is a qualification conversion. 1325 return UnwrappedAnyPointer && 1326 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1327} 1328 1329/// \brief Given a function template or function, extract the function template 1330/// declaration (if any) and the underlying function declaration. 1331template<typename T> 1332static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1333 FunctionTemplateDecl *&FunctionTemplate) { 1334 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1335 if (FunctionTemplate) 1336 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1337 else 1338 Function = cast<T>(Orig); 1339} 1340 1341/// Determines whether there is a user-defined conversion sequence 1342/// (C++ [over.ics.user]) that converts expression From to the type 1343/// ToType. If such a conversion exists, User will contain the 1344/// user-defined conversion sequence that performs such a conversion 1345/// and this routine will return true. Otherwise, this routine returns 1346/// false and User is unspecified. 1347/// 1348/// \param AllowConversionFunctions true if the conversion should 1349/// consider conversion functions at all. If false, only constructors 1350/// will be considered. 1351/// 1352/// \param AllowExplicit true if the conversion should consider C++0x 1353/// "explicit" conversion functions as well as non-explicit conversion 1354/// functions (C++0x [class.conv.fct]p2). 1355/// 1356/// \param ForceRValue true if the expression should be treated as an rvalue 1357/// for overload resolution. 1358Sema::OverloadingResult Sema::IsUserDefinedConversion( 1359 Expr *From, QualType ToType, 1360 UserDefinedConversionSequence& User, 1361 OverloadCandidateSet& CandidateSet, 1362 bool AllowConversionFunctions, 1363 bool AllowExplicit, bool ForceRValue) { 1364 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1365 if (CXXRecordDecl *ToRecordDecl 1366 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1367 // C++ [over.match.ctor]p1: 1368 // When objects of class type are direct-initialized (8.5), or 1369 // copy-initialized from an expression of the same or a 1370 // derived class type (8.5), overload resolution selects the 1371 // constructor. [...] For copy-initialization, the candidate 1372 // functions are all the converting constructors (12.3.1) of 1373 // that class. The argument list is the expression-list within 1374 // the parentheses of the initializer. 1375 DeclarationName ConstructorName 1376 = Context.DeclarationNames.getCXXConstructorName( 1377 Context.getCanonicalType(ToType).getUnqualifiedType()); 1378 DeclContext::lookup_iterator Con, ConEnd; 1379 for (llvm::tie(Con, ConEnd) 1380 = ToRecordDecl->lookup(ConstructorName); 1381 Con != ConEnd; ++Con) { 1382 // Find the constructor (which may be a template). 1383 CXXConstructorDecl *Constructor = 0; 1384 FunctionTemplateDecl *ConstructorTmpl 1385 = dyn_cast<FunctionTemplateDecl>(*Con); 1386 if (ConstructorTmpl) 1387 Constructor 1388 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1389 else 1390 Constructor = cast<CXXConstructorDecl>(*Con); 1391 1392 if (!Constructor->isInvalidDecl() && 1393 Constructor->isConvertingConstructor(AllowExplicit)) { 1394 if (ConstructorTmpl) 1395 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1396 1, CandidateSet, 1397 /*SuppressUserConversions=*/true, 1398 ForceRValue); 1399 else 1400 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1401 /*SuppressUserConversions=*/true, ForceRValue); 1402 } 1403 } 1404 } 1405 } 1406 1407 if (!AllowConversionFunctions) { 1408 // Don't allow any conversion functions to enter the overload set. 1409 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1410 PDiag(0) 1411 << From->getSourceRange())) { 1412 // No conversion functions from incomplete types. 1413 } else if (const RecordType *FromRecordType 1414 = From->getType()->getAs<RecordType>()) { 1415 if (CXXRecordDecl *FromRecordDecl 1416 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1417 // Add all of the conversion functions as candidates. 1418 OverloadedFunctionDecl *Conversions 1419 = FromRecordDecl->getVisibleConversionFunctions(); 1420 for (OverloadedFunctionDecl::function_iterator Func 1421 = Conversions->function_begin(); 1422 Func != Conversions->function_end(); ++Func) { 1423 CXXConversionDecl *Conv; 1424 FunctionTemplateDecl *ConvTemplate; 1425 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1426 if (ConvTemplate) 1427 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1428 else 1429 Conv = dyn_cast<CXXConversionDecl>(*Func); 1430 1431 if (AllowExplicit || !Conv->isExplicit()) { 1432 if (ConvTemplate) 1433 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1434 CandidateSet); 1435 else 1436 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1437 } 1438 } 1439 } 1440 } 1441 1442 OverloadCandidateSet::iterator Best; 1443 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1444 case OR_Success: 1445 // Record the standard conversion we used and the conversion function. 1446 if (CXXConstructorDecl *Constructor 1447 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1448 // C++ [over.ics.user]p1: 1449 // If the user-defined conversion is specified by a 1450 // constructor (12.3.1), the initial standard conversion 1451 // sequence converts the source type to the type required by 1452 // the argument of the constructor. 1453 // 1454 // FIXME: What about ellipsis conversions? 1455 QualType ThisType = Constructor->getThisType(Context); 1456 User.Before = Best->Conversions[0].Standard; 1457 User.ConversionFunction = Constructor; 1458 User.After.setAsIdentityConversion(); 1459 User.After.FromTypePtr 1460 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1461 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1462 return OR_Success; 1463 } else if (CXXConversionDecl *Conversion 1464 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1465 // C++ [over.ics.user]p1: 1466 // 1467 // [...] If the user-defined conversion is specified by a 1468 // conversion function (12.3.2), the initial standard 1469 // conversion sequence converts the source type to the 1470 // implicit object parameter of the conversion function. 1471 User.Before = Best->Conversions[0].Standard; 1472 User.ConversionFunction = Conversion; 1473 1474 // C++ [over.ics.user]p2: 1475 // The second standard conversion sequence converts the 1476 // result of the user-defined conversion to the target type 1477 // for the sequence. Since an implicit conversion sequence 1478 // is an initialization, the special rules for 1479 // initialization by user-defined conversion apply when 1480 // selecting the best user-defined conversion for a 1481 // user-defined conversion sequence (see 13.3.3 and 1482 // 13.3.3.1). 1483 User.After = Best->FinalConversion; 1484 return OR_Success; 1485 } else { 1486 assert(false && "Not a constructor or conversion function?"); 1487 return OR_No_Viable_Function; 1488 } 1489 1490 case OR_No_Viable_Function: 1491 return OR_No_Viable_Function; 1492 case OR_Deleted: 1493 // No conversion here! We're done. 1494 return OR_Deleted; 1495 1496 case OR_Ambiguous: 1497 // FIXME: See C++ [over.best.ics]p10 for the handling of 1498 // ambiguous conversion sequences. 1499 return OR_Ambiguous; 1500 } 1501 1502 return OR_No_Viable_Function; 1503} 1504 1505/// CompareImplicitConversionSequences - Compare two implicit 1506/// conversion sequences to determine whether one is better than the 1507/// other or if they are indistinguishable (C++ 13.3.3.2). 1508ImplicitConversionSequence::CompareKind 1509Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1510 const ImplicitConversionSequence& ICS2) 1511{ 1512 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1513 // conversion sequences (as defined in 13.3.3.1) 1514 // -- a standard conversion sequence (13.3.3.1.1) is a better 1515 // conversion sequence than a user-defined conversion sequence or 1516 // an ellipsis conversion sequence, and 1517 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1518 // conversion sequence than an ellipsis conversion sequence 1519 // (13.3.3.1.3). 1520 // 1521 if (ICS1.ConversionKind < ICS2.ConversionKind) 1522 return ImplicitConversionSequence::Better; 1523 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1524 return ImplicitConversionSequence::Worse; 1525 1526 // Two implicit conversion sequences of the same form are 1527 // indistinguishable conversion sequences unless one of the 1528 // following rules apply: (C++ 13.3.3.2p3): 1529 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1530 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1531 else if (ICS1.ConversionKind == 1532 ImplicitConversionSequence::UserDefinedConversion) { 1533 // User-defined conversion sequence U1 is a better conversion 1534 // sequence than another user-defined conversion sequence U2 if 1535 // they contain the same user-defined conversion function or 1536 // constructor and if the second standard conversion sequence of 1537 // U1 is better than the second standard conversion sequence of 1538 // U2 (C++ 13.3.3.2p3). 1539 if (ICS1.UserDefined.ConversionFunction == 1540 ICS2.UserDefined.ConversionFunction) 1541 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1542 ICS2.UserDefined.After); 1543 } 1544 1545 return ImplicitConversionSequence::Indistinguishable; 1546} 1547 1548/// CompareStandardConversionSequences - Compare two standard 1549/// conversion sequences to determine whether one is better than the 1550/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1551ImplicitConversionSequence::CompareKind 1552Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1553 const StandardConversionSequence& SCS2) 1554{ 1555 // Standard conversion sequence S1 is a better conversion sequence 1556 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1557 1558 // -- S1 is a proper subsequence of S2 (comparing the conversion 1559 // sequences in the canonical form defined by 13.3.3.1.1, 1560 // excluding any Lvalue Transformation; the identity conversion 1561 // sequence is considered to be a subsequence of any 1562 // non-identity conversion sequence) or, if not that, 1563 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1564 // Neither is a proper subsequence of the other. Do nothing. 1565 ; 1566 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1567 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1568 (SCS1.Second == ICK_Identity && 1569 SCS1.Third == ICK_Identity)) 1570 // SCS1 is a proper subsequence of SCS2. 1571 return ImplicitConversionSequence::Better; 1572 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1573 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1574 (SCS2.Second == ICK_Identity && 1575 SCS2.Third == ICK_Identity)) 1576 // SCS2 is a proper subsequence of SCS1. 1577 return ImplicitConversionSequence::Worse; 1578 1579 // -- the rank of S1 is better than the rank of S2 (by the rules 1580 // defined below), or, if not that, 1581 ImplicitConversionRank Rank1 = SCS1.getRank(); 1582 ImplicitConversionRank Rank2 = SCS2.getRank(); 1583 if (Rank1 < Rank2) 1584 return ImplicitConversionSequence::Better; 1585 else if (Rank2 < Rank1) 1586 return ImplicitConversionSequence::Worse; 1587 1588 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1589 // are indistinguishable unless one of the following rules 1590 // applies: 1591 1592 // A conversion that is not a conversion of a pointer, or 1593 // pointer to member, to bool is better than another conversion 1594 // that is such a conversion. 1595 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1596 return SCS2.isPointerConversionToBool() 1597 ? ImplicitConversionSequence::Better 1598 : ImplicitConversionSequence::Worse; 1599 1600 // C++ [over.ics.rank]p4b2: 1601 // 1602 // If class B is derived directly or indirectly from class A, 1603 // conversion of B* to A* is better than conversion of B* to 1604 // void*, and conversion of A* to void* is better than conversion 1605 // of B* to void*. 1606 bool SCS1ConvertsToVoid 1607 = SCS1.isPointerConversionToVoidPointer(Context); 1608 bool SCS2ConvertsToVoid 1609 = SCS2.isPointerConversionToVoidPointer(Context); 1610 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1611 // Exactly one of the conversion sequences is a conversion to 1612 // a void pointer; it's the worse conversion. 1613 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1614 : ImplicitConversionSequence::Worse; 1615 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1616 // Neither conversion sequence converts to a void pointer; compare 1617 // their derived-to-base conversions. 1618 if (ImplicitConversionSequence::CompareKind DerivedCK 1619 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1620 return DerivedCK; 1621 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1622 // Both conversion sequences are conversions to void 1623 // pointers. Compare the source types to determine if there's an 1624 // inheritance relationship in their sources. 1625 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1626 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1627 1628 // Adjust the types we're converting from via the array-to-pointer 1629 // conversion, if we need to. 1630 if (SCS1.First == ICK_Array_To_Pointer) 1631 FromType1 = Context.getArrayDecayedType(FromType1); 1632 if (SCS2.First == ICK_Array_To_Pointer) 1633 FromType2 = Context.getArrayDecayedType(FromType2); 1634 1635 QualType FromPointee1 1636 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1637 QualType FromPointee2 1638 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1639 1640 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1641 return ImplicitConversionSequence::Better; 1642 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1643 return ImplicitConversionSequence::Worse; 1644 1645 // Objective-C++: If one interface is more specific than the 1646 // other, it is the better one. 1647 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1648 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1649 if (FromIface1 && FromIface1) { 1650 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1651 return ImplicitConversionSequence::Better; 1652 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1653 return ImplicitConversionSequence::Worse; 1654 } 1655 } 1656 1657 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1658 // bullet 3). 1659 if (ImplicitConversionSequence::CompareKind QualCK 1660 = CompareQualificationConversions(SCS1, SCS2)) 1661 return QualCK; 1662 1663 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1664 // C++0x [over.ics.rank]p3b4: 1665 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1666 // implicit object parameter of a non-static member function declared 1667 // without a ref-qualifier, and S1 binds an rvalue reference to an 1668 // rvalue and S2 binds an lvalue reference. 1669 // FIXME: We don't know if we're dealing with the implicit object parameter, 1670 // or if the member function in this case has a ref qualifier. 1671 // (Of course, we don't have ref qualifiers yet.) 1672 if (SCS1.RRefBinding != SCS2.RRefBinding) 1673 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1674 : ImplicitConversionSequence::Worse; 1675 1676 // C++ [over.ics.rank]p3b4: 1677 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1678 // which the references refer are the same type except for 1679 // top-level cv-qualifiers, and the type to which the reference 1680 // initialized by S2 refers is more cv-qualified than the type 1681 // to which the reference initialized by S1 refers. 1682 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1683 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1684 T1 = Context.getCanonicalType(T1); 1685 T2 = Context.getCanonicalType(T2); 1686 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1687 if (T2.isMoreQualifiedThan(T1)) 1688 return ImplicitConversionSequence::Better; 1689 else if (T1.isMoreQualifiedThan(T2)) 1690 return ImplicitConversionSequence::Worse; 1691 } 1692 } 1693 1694 return ImplicitConversionSequence::Indistinguishable; 1695} 1696 1697/// CompareQualificationConversions - Compares two standard conversion 1698/// sequences to determine whether they can be ranked based on their 1699/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1700ImplicitConversionSequence::CompareKind 1701Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1702 const StandardConversionSequence& SCS2) { 1703 // C++ 13.3.3.2p3: 1704 // -- S1 and S2 differ only in their qualification conversion and 1705 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1706 // cv-qualification signature of type T1 is a proper subset of 1707 // the cv-qualification signature of type T2, and S1 is not the 1708 // deprecated string literal array-to-pointer conversion (4.2). 1709 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1710 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1711 return ImplicitConversionSequence::Indistinguishable; 1712 1713 // FIXME: the example in the standard doesn't use a qualification 1714 // conversion (!) 1715 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1716 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1717 T1 = Context.getCanonicalType(T1); 1718 T2 = Context.getCanonicalType(T2); 1719 1720 // If the types are the same, we won't learn anything by unwrapped 1721 // them. 1722 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1723 return ImplicitConversionSequence::Indistinguishable; 1724 1725 ImplicitConversionSequence::CompareKind Result 1726 = ImplicitConversionSequence::Indistinguishable; 1727 while (UnwrapSimilarPointerTypes(T1, T2)) { 1728 // Within each iteration of the loop, we check the qualifiers to 1729 // determine if this still looks like a qualification 1730 // conversion. Then, if all is well, we unwrap one more level of 1731 // pointers or pointers-to-members and do it all again 1732 // until there are no more pointers or pointers-to-members left 1733 // to unwrap. This essentially mimics what 1734 // IsQualificationConversion does, but here we're checking for a 1735 // strict subset of qualifiers. 1736 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1737 // The qualifiers are the same, so this doesn't tell us anything 1738 // about how the sequences rank. 1739 ; 1740 else if (T2.isMoreQualifiedThan(T1)) { 1741 // T1 has fewer qualifiers, so it could be the better sequence. 1742 if (Result == ImplicitConversionSequence::Worse) 1743 // Neither has qualifiers that are a subset of the other's 1744 // qualifiers. 1745 return ImplicitConversionSequence::Indistinguishable; 1746 1747 Result = ImplicitConversionSequence::Better; 1748 } else if (T1.isMoreQualifiedThan(T2)) { 1749 // T2 has fewer qualifiers, so it could be the better sequence. 1750 if (Result == ImplicitConversionSequence::Better) 1751 // Neither has qualifiers that are a subset of the other's 1752 // qualifiers. 1753 return ImplicitConversionSequence::Indistinguishable; 1754 1755 Result = ImplicitConversionSequence::Worse; 1756 } else { 1757 // Qualifiers are disjoint. 1758 return ImplicitConversionSequence::Indistinguishable; 1759 } 1760 1761 // If the types after this point are equivalent, we're done. 1762 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1763 break; 1764 } 1765 1766 // Check that the winning standard conversion sequence isn't using 1767 // the deprecated string literal array to pointer conversion. 1768 switch (Result) { 1769 case ImplicitConversionSequence::Better: 1770 if (SCS1.Deprecated) 1771 Result = ImplicitConversionSequence::Indistinguishable; 1772 break; 1773 1774 case ImplicitConversionSequence::Indistinguishable: 1775 break; 1776 1777 case ImplicitConversionSequence::Worse: 1778 if (SCS2.Deprecated) 1779 Result = ImplicitConversionSequence::Indistinguishable; 1780 break; 1781 } 1782 1783 return Result; 1784} 1785 1786/// CompareDerivedToBaseConversions - Compares two standard conversion 1787/// sequences to determine whether they can be ranked based on their 1788/// various kinds of derived-to-base conversions (C++ 1789/// [over.ics.rank]p4b3). As part of these checks, we also look at 1790/// conversions between Objective-C interface types. 1791ImplicitConversionSequence::CompareKind 1792Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1793 const StandardConversionSequence& SCS2) { 1794 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1795 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1796 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1797 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1798 1799 // Adjust the types we're converting from via the array-to-pointer 1800 // conversion, if we need to. 1801 if (SCS1.First == ICK_Array_To_Pointer) 1802 FromType1 = Context.getArrayDecayedType(FromType1); 1803 if (SCS2.First == ICK_Array_To_Pointer) 1804 FromType2 = Context.getArrayDecayedType(FromType2); 1805 1806 // Canonicalize all of the types. 1807 FromType1 = Context.getCanonicalType(FromType1); 1808 ToType1 = Context.getCanonicalType(ToType1); 1809 FromType2 = Context.getCanonicalType(FromType2); 1810 ToType2 = Context.getCanonicalType(ToType2); 1811 1812 // C++ [over.ics.rank]p4b3: 1813 // 1814 // If class B is derived directly or indirectly from class A and 1815 // class C is derived directly or indirectly from B, 1816 // 1817 // For Objective-C, we let A, B, and C also be Objective-C 1818 // interfaces. 1819 1820 // Compare based on pointer conversions. 1821 if (SCS1.Second == ICK_Pointer_Conversion && 1822 SCS2.Second == ICK_Pointer_Conversion && 1823 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1824 FromType1->isPointerType() && FromType2->isPointerType() && 1825 ToType1->isPointerType() && ToType2->isPointerType()) { 1826 QualType FromPointee1 1827 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1828 QualType ToPointee1 1829 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1830 QualType FromPointee2 1831 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1832 QualType ToPointee2 1833 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1834 1835 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1836 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1837 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1838 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1839 1840 // -- conversion of C* to B* is better than conversion of C* to A*, 1841 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1842 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1843 return ImplicitConversionSequence::Better; 1844 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1845 return ImplicitConversionSequence::Worse; 1846 1847 if (ToIface1 && ToIface2) { 1848 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1849 return ImplicitConversionSequence::Better; 1850 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1851 return ImplicitConversionSequence::Worse; 1852 } 1853 } 1854 1855 // -- conversion of B* to A* is better than conversion of C* to A*, 1856 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1857 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1858 return ImplicitConversionSequence::Better; 1859 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1860 return ImplicitConversionSequence::Worse; 1861 1862 if (FromIface1 && FromIface2) { 1863 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1864 return ImplicitConversionSequence::Better; 1865 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1866 return ImplicitConversionSequence::Worse; 1867 } 1868 } 1869 } 1870 1871 // Compare based on reference bindings. 1872 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1873 SCS1.Second == ICK_Derived_To_Base) { 1874 // -- binding of an expression of type C to a reference of type 1875 // B& is better than binding an expression of type C to a 1876 // reference of type A&, 1877 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1878 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1879 if (IsDerivedFrom(ToType1, ToType2)) 1880 return ImplicitConversionSequence::Better; 1881 else if (IsDerivedFrom(ToType2, ToType1)) 1882 return ImplicitConversionSequence::Worse; 1883 } 1884 1885 // -- binding of an expression of type B to a reference of type 1886 // A& is better than binding an expression of type C to a 1887 // reference of type A&, 1888 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1889 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1890 if (IsDerivedFrom(FromType2, FromType1)) 1891 return ImplicitConversionSequence::Better; 1892 else if (IsDerivedFrom(FromType1, FromType2)) 1893 return ImplicitConversionSequence::Worse; 1894 } 1895 } 1896 1897 1898 // FIXME: conversion of A::* to B::* is better than conversion of 1899 // A::* to C::*, 1900 1901 // FIXME: conversion of B::* to C::* is better than conversion of 1902 // A::* to C::*, and 1903 1904 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1905 SCS1.Second == ICK_Derived_To_Base) { 1906 // -- conversion of C to B is better than conversion of C to A, 1907 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1908 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1909 if (IsDerivedFrom(ToType1, ToType2)) 1910 return ImplicitConversionSequence::Better; 1911 else if (IsDerivedFrom(ToType2, ToType1)) 1912 return ImplicitConversionSequence::Worse; 1913 } 1914 1915 // -- conversion of B to A is better than conversion of C to A. 1916 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1917 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1918 if (IsDerivedFrom(FromType2, FromType1)) 1919 return ImplicitConversionSequence::Better; 1920 else if (IsDerivedFrom(FromType1, FromType2)) 1921 return ImplicitConversionSequence::Worse; 1922 } 1923 } 1924 1925 return ImplicitConversionSequence::Indistinguishable; 1926} 1927 1928/// TryCopyInitialization - Try to copy-initialize a value of type 1929/// ToType from the expression From. Return the implicit conversion 1930/// sequence required to pass this argument, which may be a bad 1931/// conversion sequence (meaning that the argument cannot be passed to 1932/// a parameter of this type). If @p SuppressUserConversions, then we 1933/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1934/// then we treat @p From as an rvalue, even if it is an lvalue. 1935ImplicitConversionSequence 1936Sema::TryCopyInitialization(Expr *From, QualType ToType, 1937 bool SuppressUserConversions, bool ForceRValue, 1938 bool InOverloadResolution) { 1939 if (ToType->isReferenceType()) { 1940 ImplicitConversionSequence ICS; 1941 CheckReferenceInit(From, ToType, 1942 SuppressUserConversions, 1943 /*AllowExplicit=*/false, 1944 ForceRValue, 1945 &ICS); 1946 return ICS; 1947 } else { 1948 return TryImplicitConversion(From, ToType, 1949 SuppressUserConversions, 1950 /*AllowExplicit=*/false, 1951 ForceRValue, 1952 InOverloadResolution); 1953 } 1954} 1955 1956/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1957/// the expression @p From. Returns true (and emits a diagnostic) if there was 1958/// an error, returns false if the initialization succeeded. Elidable should 1959/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1960/// differently in C++0x for this case. 1961bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1962 const char* Flavor, bool Elidable) { 1963 if (!getLangOptions().CPlusPlus) { 1964 // In C, argument passing is the same as performing an assignment. 1965 QualType FromType = From->getType(); 1966 1967 AssignConvertType ConvTy = 1968 CheckSingleAssignmentConstraints(ToType, From); 1969 if (ConvTy != Compatible && 1970 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1971 ConvTy = Compatible; 1972 1973 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1974 FromType, From, Flavor); 1975 } 1976 1977 if (ToType->isReferenceType()) 1978 return CheckReferenceInit(From, ToType, 1979 /*SuppressUserConversions=*/false, 1980 /*AllowExplicit=*/false, 1981 /*ForceRValue=*/false); 1982 1983 if (!PerformImplicitConversion(From, ToType, Flavor, 1984 /*AllowExplicit=*/false, Elidable)) 1985 return false; 1986 1987 return Diag(From->getSourceRange().getBegin(), 1988 diag::err_typecheck_convert_incompatible) 1989 << ToType << From->getType() << Flavor << From->getSourceRange(); 1990} 1991 1992/// TryObjectArgumentInitialization - Try to initialize the object 1993/// parameter of the given member function (@c Method) from the 1994/// expression @p From. 1995ImplicitConversionSequence 1996Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1997 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1998 unsigned MethodQuals = Method->getTypeQualifiers(); 1999 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 2000 2001 // Set up the conversion sequence as a "bad" conversion, to allow us 2002 // to exit early. 2003 ImplicitConversionSequence ICS; 2004 ICS.Standard.setAsIdentityConversion(); 2005 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2006 2007 // We need to have an object of class type. 2008 QualType FromType = From->getType(); 2009 if (const PointerType *PT = FromType->getAs<PointerType>()) 2010 FromType = PT->getPointeeType(); 2011 2012 assert(FromType->isRecordType()); 2013 2014 // The implicit object parmeter is has the type "reference to cv X", 2015 // where X is the class of which the function is a member 2016 // (C++ [over.match.funcs]p4). However, when finding an implicit 2017 // conversion sequence for the argument, we are not allowed to 2018 // create temporaries or perform user-defined conversions 2019 // (C++ [over.match.funcs]p5). We perform a simplified version of 2020 // reference binding here, that allows class rvalues to bind to 2021 // non-constant references. 2022 2023 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2024 // with the implicit object parameter (C++ [over.match.funcs]p5). 2025 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2026 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 2027 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 2028 return ICS; 2029 2030 // Check that we have either the same type or a derived type. It 2031 // affects the conversion rank. 2032 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2033 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2034 ICS.Standard.Second = ICK_Identity; 2035 else if (IsDerivedFrom(FromType, ClassType)) 2036 ICS.Standard.Second = ICK_Derived_To_Base; 2037 else 2038 return ICS; 2039 2040 // Success. Mark this as a reference binding. 2041 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2042 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2043 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2044 ICS.Standard.ReferenceBinding = true; 2045 ICS.Standard.DirectBinding = true; 2046 ICS.Standard.RRefBinding = false; 2047 return ICS; 2048} 2049 2050/// PerformObjectArgumentInitialization - Perform initialization of 2051/// the implicit object parameter for the given Method with the given 2052/// expression. 2053bool 2054Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2055 QualType FromRecordType, DestType; 2056 QualType ImplicitParamRecordType = 2057 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2058 2059 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2060 FromRecordType = PT->getPointeeType(); 2061 DestType = Method->getThisType(Context); 2062 } else { 2063 FromRecordType = From->getType(); 2064 DestType = ImplicitParamRecordType; 2065 } 2066 2067 ImplicitConversionSequence ICS 2068 = TryObjectArgumentInitialization(From, Method); 2069 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2070 return Diag(From->getSourceRange().getBegin(), 2071 diag::err_implicit_object_parameter_init) 2072 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2073 2074 if (ICS.Standard.Second == ICK_Derived_To_Base && 2075 CheckDerivedToBaseConversion(FromRecordType, 2076 ImplicitParamRecordType, 2077 From->getSourceRange().getBegin(), 2078 From->getSourceRange())) 2079 return true; 2080 2081 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2082 /*isLvalue=*/true); 2083 return false; 2084} 2085 2086/// TryContextuallyConvertToBool - Attempt to contextually convert the 2087/// expression From to bool (C++0x [conv]p3). 2088ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2089 return TryImplicitConversion(From, Context.BoolTy, 2090 // FIXME: Are these flags correct? 2091 /*SuppressUserConversions=*/false, 2092 /*AllowExplicit=*/true, 2093 /*ForceRValue=*/false, 2094 /*InOverloadResolution=*/false); 2095} 2096 2097/// PerformContextuallyConvertToBool - Perform a contextual conversion 2098/// of the expression From to bool (C++0x [conv]p3). 2099bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2100 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2101 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2102 return false; 2103 2104 OverloadCandidateSet CandidateSet; 2105 if (IsUserDefinedConversion(From, Context.BoolTy, ICS.UserDefined, 2106 CandidateSet, 2107 true, true, false) != OR_Ambiguous) 2108 return Diag(From->getSourceRange().getBegin(), 2109 diag::err_typecheck_bool_condition) 2110 << From->getType() << From->getSourceRange(); 2111 Diag(From->getSourceRange().getBegin(), 2112 diag::err_typecheck_ambiguous_bool_condition) 2113 << From->getType() << From->getSourceRange(); 2114 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 2115 return true; 2116} 2117 2118/// AddOverloadCandidate - Adds the given function to the set of 2119/// candidate functions, using the given function call arguments. If 2120/// @p SuppressUserConversions, then don't allow user-defined 2121/// conversions via constructors or conversion operators. 2122/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2123/// hacky way to implement the overloading rules for elidable copy 2124/// initialization in C++0x (C++0x 12.8p15). 2125void 2126Sema::AddOverloadCandidate(FunctionDecl *Function, 2127 Expr **Args, unsigned NumArgs, 2128 OverloadCandidateSet& CandidateSet, 2129 bool SuppressUserConversions, 2130 bool ForceRValue) { 2131 const FunctionProtoType* Proto 2132 = dyn_cast<FunctionProtoType>(Function->getType()->getAsFunctionType()); 2133 assert(Proto && "Functions without a prototype cannot be overloaded"); 2134 assert(!isa<CXXConversionDecl>(Function) && 2135 "Use AddConversionCandidate for conversion functions"); 2136 assert(!Function->getDescribedFunctionTemplate() && 2137 "Use AddTemplateOverloadCandidate for function templates"); 2138 2139 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2140 if (!isa<CXXConstructorDecl>(Method)) { 2141 // If we get here, it's because we're calling a member function 2142 // that is named without a member access expression (e.g., 2143 // "this->f") that was either written explicitly or created 2144 // implicitly. This can happen with a qualified call to a member 2145 // function, e.g., X::f(). We use a NULL object as the implied 2146 // object argument (C++ [over.call.func]p3). 2147 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2148 SuppressUserConversions, ForceRValue); 2149 return; 2150 } 2151 // We treat a constructor like a non-member function, since its object 2152 // argument doesn't participate in overload resolution. 2153 } 2154 2155 2156 // Add this candidate 2157 CandidateSet.push_back(OverloadCandidate()); 2158 OverloadCandidate& Candidate = CandidateSet.back(); 2159 Candidate.Function = Function; 2160 Candidate.Viable = true; 2161 Candidate.IsSurrogate = false; 2162 Candidate.IgnoreObjectArgument = false; 2163 2164 unsigned NumArgsInProto = Proto->getNumArgs(); 2165 2166 // (C++ 13.3.2p2): A candidate function having fewer than m 2167 // parameters is viable only if it has an ellipsis in its parameter 2168 // list (8.3.5). 2169 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2170 Candidate.Viable = false; 2171 return; 2172 } 2173 2174 // (C++ 13.3.2p2): A candidate function having more than m parameters 2175 // is viable only if the (m+1)st parameter has a default argument 2176 // (8.3.6). For the purposes of overload resolution, the 2177 // parameter list is truncated on the right, so that there are 2178 // exactly m parameters. 2179 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2180 if (NumArgs < MinRequiredArgs) { 2181 // Not enough arguments. 2182 Candidate.Viable = false; 2183 return; 2184 } 2185 2186 // Determine the implicit conversion sequences for each of the 2187 // arguments. 2188 Candidate.Conversions.resize(NumArgs); 2189 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2190 if (ArgIdx < NumArgsInProto) { 2191 // (C++ 13.3.2p3): for F to be a viable function, there shall 2192 // exist for each argument an implicit conversion sequence 2193 // (13.3.3.1) that converts that argument to the corresponding 2194 // parameter of F. 2195 QualType ParamType = Proto->getArgType(ArgIdx); 2196 Candidate.Conversions[ArgIdx] 2197 = TryCopyInitialization(Args[ArgIdx], ParamType, 2198 SuppressUserConversions, ForceRValue, 2199 /*InOverloadResolution=*/true); 2200 if (Candidate.Conversions[ArgIdx].ConversionKind 2201 == ImplicitConversionSequence::BadConversion) { 2202 Candidate.Viable = false; 2203 break; 2204 } 2205 } else { 2206 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2207 // argument for which there is no corresponding parameter is 2208 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2209 Candidate.Conversions[ArgIdx].ConversionKind 2210 = ImplicitConversionSequence::EllipsisConversion; 2211 } 2212 } 2213} 2214 2215/// \brief Add all of the function declarations in the given function set to 2216/// the overload canddiate set. 2217void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2218 Expr **Args, unsigned NumArgs, 2219 OverloadCandidateSet& CandidateSet, 2220 bool SuppressUserConversions) { 2221 for (FunctionSet::const_iterator F = Functions.begin(), 2222 FEnd = Functions.end(); 2223 F != FEnd; ++F) { 2224 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) 2225 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2226 SuppressUserConversions); 2227 else 2228 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*F), 2229 /*FIXME: explicit args */false, 0, 0, 2230 Args, NumArgs, CandidateSet, 2231 SuppressUserConversions); 2232 } 2233} 2234 2235/// AddMethodCandidate - Adds the given C++ member function to the set 2236/// of candidate functions, using the given function call arguments 2237/// and the object argument (@c Object). For example, in a call 2238/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2239/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2240/// allow user-defined conversions via constructors or conversion 2241/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2242/// a slightly hacky way to implement the overloading rules for elidable copy 2243/// initialization in C++0x (C++0x 12.8p15). 2244void 2245Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2246 Expr **Args, unsigned NumArgs, 2247 OverloadCandidateSet& CandidateSet, 2248 bool SuppressUserConversions, bool ForceRValue) { 2249 const FunctionProtoType* Proto 2250 = dyn_cast<FunctionProtoType>(Method->getType()->getAsFunctionType()); 2251 assert(Proto && "Methods without a prototype cannot be overloaded"); 2252 assert(!isa<CXXConversionDecl>(Method) && 2253 "Use AddConversionCandidate for conversion functions"); 2254 assert(!isa<CXXConstructorDecl>(Method) && 2255 "Use AddOverloadCandidate for constructors"); 2256 2257 // Add this candidate 2258 CandidateSet.push_back(OverloadCandidate()); 2259 OverloadCandidate& Candidate = CandidateSet.back(); 2260 Candidate.Function = Method; 2261 Candidate.IsSurrogate = false; 2262 Candidate.IgnoreObjectArgument = false; 2263 2264 unsigned NumArgsInProto = Proto->getNumArgs(); 2265 2266 // (C++ 13.3.2p2): A candidate function having fewer than m 2267 // parameters is viable only if it has an ellipsis in its parameter 2268 // list (8.3.5). 2269 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2270 Candidate.Viable = false; 2271 return; 2272 } 2273 2274 // (C++ 13.3.2p2): A candidate function having more than m parameters 2275 // is viable only if the (m+1)st parameter has a default argument 2276 // (8.3.6). For the purposes of overload resolution, the 2277 // parameter list is truncated on the right, so that there are 2278 // exactly m parameters. 2279 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2280 if (NumArgs < MinRequiredArgs) { 2281 // Not enough arguments. 2282 Candidate.Viable = false; 2283 return; 2284 } 2285 2286 Candidate.Viable = true; 2287 Candidate.Conversions.resize(NumArgs + 1); 2288 2289 if (Method->isStatic() || !Object) 2290 // The implicit object argument is ignored. 2291 Candidate.IgnoreObjectArgument = true; 2292 else { 2293 // Determine the implicit conversion sequence for the object 2294 // parameter. 2295 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2296 if (Candidate.Conversions[0].ConversionKind 2297 == ImplicitConversionSequence::BadConversion) { 2298 Candidate.Viable = false; 2299 return; 2300 } 2301 } 2302 2303 // Determine the implicit conversion sequences for each of the 2304 // arguments. 2305 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2306 if (ArgIdx < NumArgsInProto) { 2307 // (C++ 13.3.2p3): for F to be a viable function, there shall 2308 // exist for each argument an implicit conversion sequence 2309 // (13.3.3.1) that converts that argument to the corresponding 2310 // parameter of F. 2311 QualType ParamType = Proto->getArgType(ArgIdx); 2312 Candidate.Conversions[ArgIdx + 1] 2313 = TryCopyInitialization(Args[ArgIdx], ParamType, 2314 SuppressUserConversions, ForceRValue, 2315 /*InOverloadResolution=*/true); 2316 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2317 == ImplicitConversionSequence::BadConversion) { 2318 Candidate.Viable = false; 2319 break; 2320 } 2321 } else { 2322 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2323 // argument for which there is no corresponding parameter is 2324 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2325 Candidate.Conversions[ArgIdx + 1].ConversionKind 2326 = ImplicitConversionSequence::EllipsisConversion; 2327 } 2328 } 2329} 2330 2331/// \brief Add a C++ member function template as a candidate to the candidate 2332/// set, using template argument deduction to produce an appropriate member 2333/// function template specialization. 2334void 2335Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2336 bool HasExplicitTemplateArgs, 2337 const TemplateArgument *ExplicitTemplateArgs, 2338 unsigned NumExplicitTemplateArgs, 2339 Expr *Object, Expr **Args, unsigned NumArgs, 2340 OverloadCandidateSet& CandidateSet, 2341 bool SuppressUserConversions, 2342 bool ForceRValue) { 2343 // C++ [over.match.funcs]p7: 2344 // In each case where a candidate is a function template, candidate 2345 // function template specializations are generated using template argument 2346 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2347 // candidate functions in the usual way.113) A given name can refer to one 2348 // or more function templates and also to a set of overloaded non-template 2349 // functions. In such a case, the candidate functions generated from each 2350 // function template are combined with the set of non-template candidate 2351 // functions. 2352 TemplateDeductionInfo Info(Context); 2353 FunctionDecl *Specialization = 0; 2354 if (TemplateDeductionResult Result 2355 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2356 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2357 Args, NumArgs, Specialization, Info)) { 2358 // FIXME: Record what happened with template argument deduction, so 2359 // that we can give the user a beautiful diagnostic. 2360 (void)Result; 2361 return; 2362 } 2363 2364 // Add the function template specialization produced by template argument 2365 // deduction as a candidate. 2366 assert(Specialization && "Missing member function template specialization?"); 2367 assert(isa<CXXMethodDecl>(Specialization) && 2368 "Specialization is not a member function?"); 2369 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2370 CandidateSet, SuppressUserConversions, ForceRValue); 2371} 2372 2373/// \brief Add a C++ function template specialization as a candidate 2374/// in the candidate set, using template argument deduction to produce 2375/// an appropriate function template specialization. 2376void 2377Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2378 bool HasExplicitTemplateArgs, 2379 const TemplateArgument *ExplicitTemplateArgs, 2380 unsigned NumExplicitTemplateArgs, 2381 Expr **Args, unsigned NumArgs, 2382 OverloadCandidateSet& CandidateSet, 2383 bool SuppressUserConversions, 2384 bool ForceRValue) { 2385 // C++ [over.match.funcs]p7: 2386 // In each case where a candidate is a function template, candidate 2387 // function template specializations are generated using template argument 2388 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2389 // candidate functions in the usual way.113) A given name can refer to one 2390 // or more function templates and also to a set of overloaded non-template 2391 // functions. In such a case, the candidate functions generated from each 2392 // function template are combined with the set of non-template candidate 2393 // functions. 2394 TemplateDeductionInfo Info(Context); 2395 FunctionDecl *Specialization = 0; 2396 if (TemplateDeductionResult Result 2397 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2398 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2399 Args, NumArgs, Specialization, Info)) { 2400 // FIXME: Record what happened with template argument deduction, so 2401 // that we can give the user a beautiful diagnostic. 2402 (void)Result; 2403 return; 2404 } 2405 2406 // Add the function template specialization produced by template argument 2407 // deduction as a candidate. 2408 assert(Specialization && "Missing function template specialization?"); 2409 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2410 SuppressUserConversions, ForceRValue); 2411} 2412 2413/// AddConversionCandidate - Add a C++ conversion function as a 2414/// candidate in the candidate set (C++ [over.match.conv], 2415/// C++ [over.match.copy]). From is the expression we're converting from, 2416/// and ToType is the type that we're eventually trying to convert to 2417/// (which may or may not be the same type as the type that the 2418/// conversion function produces). 2419void 2420Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2421 Expr *From, QualType ToType, 2422 OverloadCandidateSet& CandidateSet) { 2423 assert(!Conversion->getDescribedFunctionTemplate() && 2424 "Conversion function templates use AddTemplateConversionCandidate"); 2425 2426 // Add this candidate 2427 CandidateSet.push_back(OverloadCandidate()); 2428 OverloadCandidate& Candidate = CandidateSet.back(); 2429 Candidate.Function = Conversion; 2430 Candidate.IsSurrogate = false; 2431 Candidate.IgnoreObjectArgument = false; 2432 Candidate.FinalConversion.setAsIdentityConversion(); 2433 Candidate.FinalConversion.FromTypePtr 2434 = Conversion->getConversionType().getAsOpaquePtr(); 2435 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2436 2437 // Determine the implicit conversion sequence for the implicit 2438 // object parameter. 2439 Candidate.Viable = true; 2440 Candidate.Conversions.resize(1); 2441 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2442 // Conversion functions to a different type in the base class is visible in 2443 // the derived class. So, a derived to base conversion should not participate 2444 // in overload resolution. 2445 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2446 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2447 if (Candidate.Conversions[0].ConversionKind 2448 == ImplicitConversionSequence::BadConversion) { 2449 Candidate.Viable = false; 2450 return; 2451 } 2452 2453 // To determine what the conversion from the result of calling the 2454 // conversion function to the type we're eventually trying to 2455 // convert to (ToType), we need to synthesize a call to the 2456 // conversion function and attempt copy initialization from it. This 2457 // makes sure that we get the right semantics with respect to 2458 // lvalues/rvalues and the type. Fortunately, we can allocate this 2459 // call on the stack and we don't need its arguments to be 2460 // well-formed. 2461 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2462 SourceLocation()); 2463 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2464 CastExpr::CK_Unknown, 2465 &ConversionRef, false); 2466 2467 // Note that it is safe to allocate CallExpr on the stack here because 2468 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2469 // allocator). 2470 CallExpr Call(Context, &ConversionFn, 0, 0, 2471 Conversion->getConversionType().getNonReferenceType(), 2472 SourceLocation()); 2473 ImplicitConversionSequence ICS = 2474 TryCopyInitialization(&Call, ToType, 2475 /*SuppressUserConversions=*/true, 2476 /*ForceRValue=*/false, 2477 /*InOverloadResolution=*/false); 2478 2479 switch (ICS.ConversionKind) { 2480 case ImplicitConversionSequence::StandardConversion: 2481 Candidate.FinalConversion = ICS.Standard; 2482 break; 2483 2484 case ImplicitConversionSequence::BadConversion: 2485 Candidate.Viable = false; 2486 break; 2487 2488 default: 2489 assert(false && 2490 "Can only end up with a standard conversion sequence or failure"); 2491 } 2492} 2493 2494/// \brief Adds a conversion function template specialization 2495/// candidate to the overload set, using template argument deduction 2496/// to deduce the template arguments of the conversion function 2497/// template from the type that we are converting to (C++ 2498/// [temp.deduct.conv]). 2499void 2500Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2501 Expr *From, QualType ToType, 2502 OverloadCandidateSet &CandidateSet) { 2503 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2504 "Only conversion function templates permitted here"); 2505 2506 TemplateDeductionInfo Info(Context); 2507 CXXConversionDecl *Specialization = 0; 2508 if (TemplateDeductionResult Result 2509 = DeduceTemplateArguments(FunctionTemplate, ToType, 2510 Specialization, Info)) { 2511 // FIXME: Record what happened with template argument deduction, so 2512 // that we can give the user a beautiful diagnostic. 2513 (void)Result; 2514 return; 2515 } 2516 2517 // Add the conversion function template specialization produced by 2518 // template argument deduction as a candidate. 2519 assert(Specialization && "Missing function template specialization?"); 2520 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2521} 2522 2523/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2524/// converts the given @c Object to a function pointer via the 2525/// conversion function @c Conversion, and then attempts to call it 2526/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2527/// the type of function that we'll eventually be calling. 2528void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2529 const FunctionProtoType *Proto, 2530 Expr *Object, Expr **Args, unsigned NumArgs, 2531 OverloadCandidateSet& CandidateSet) { 2532 CandidateSet.push_back(OverloadCandidate()); 2533 OverloadCandidate& Candidate = CandidateSet.back(); 2534 Candidate.Function = 0; 2535 Candidate.Surrogate = Conversion; 2536 Candidate.Viable = true; 2537 Candidate.IsSurrogate = true; 2538 Candidate.IgnoreObjectArgument = false; 2539 Candidate.Conversions.resize(NumArgs + 1); 2540 2541 // Determine the implicit conversion sequence for the implicit 2542 // object parameter. 2543 ImplicitConversionSequence ObjectInit 2544 = TryObjectArgumentInitialization(Object, Conversion); 2545 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2546 Candidate.Viable = false; 2547 return; 2548 } 2549 2550 // The first conversion is actually a user-defined conversion whose 2551 // first conversion is ObjectInit's standard conversion (which is 2552 // effectively a reference binding). Record it as such. 2553 Candidate.Conversions[0].ConversionKind 2554 = ImplicitConversionSequence::UserDefinedConversion; 2555 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2556 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2557 Candidate.Conversions[0].UserDefined.After 2558 = Candidate.Conversions[0].UserDefined.Before; 2559 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2560 2561 // Find the 2562 unsigned NumArgsInProto = Proto->getNumArgs(); 2563 2564 // (C++ 13.3.2p2): A candidate function having fewer than m 2565 // parameters is viable only if it has an ellipsis in its parameter 2566 // list (8.3.5). 2567 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2568 Candidate.Viable = false; 2569 return; 2570 } 2571 2572 // Function types don't have any default arguments, so just check if 2573 // we have enough arguments. 2574 if (NumArgs < NumArgsInProto) { 2575 // Not enough arguments. 2576 Candidate.Viable = false; 2577 return; 2578 } 2579 2580 // Determine the implicit conversion sequences for each of the 2581 // arguments. 2582 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2583 if (ArgIdx < NumArgsInProto) { 2584 // (C++ 13.3.2p3): for F to be a viable function, there shall 2585 // exist for each argument an implicit conversion sequence 2586 // (13.3.3.1) that converts that argument to the corresponding 2587 // parameter of F. 2588 QualType ParamType = Proto->getArgType(ArgIdx); 2589 Candidate.Conversions[ArgIdx + 1] 2590 = TryCopyInitialization(Args[ArgIdx], ParamType, 2591 /*SuppressUserConversions=*/false, 2592 /*ForceRValue=*/false, 2593 /*InOverloadResolution=*/false); 2594 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2595 == ImplicitConversionSequence::BadConversion) { 2596 Candidate.Viable = false; 2597 break; 2598 } 2599 } else { 2600 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2601 // argument for which there is no corresponding parameter is 2602 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2603 Candidate.Conversions[ArgIdx + 1].ConversionKind 2604 = ImplicitConversionSequence::EllipsisConversion; 2605 } 2606 } 2607} 2608 2609// FIXME: This will eventually be removed, once we've migrated all of the 2610// operator overloading logic over to the scheme used by binary operators, which 2611// works for template instantiation. 2612void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2613 SourceLocation OpLoc, 2614 Expr **Args, unsigned NumArgs, 2615 OverloadCandidateSet& CandidateSet, 2616 SourceRange OpRange) { 2617 2618 FunctionSet Functions; 2619 2620 QualType T1 = Args[0]->getType(); 2621 QualType T2; 2622 if (NumArgs > 1) 2623 T2 = Args[1]->getType(); 2624 2625 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2626 if (S) 2627 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2628 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2629 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2630 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2631 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2632} 2633 2634/// \brief Add overload candidates for overloaded operators that are 2635/// member functions. 2636/// 2637/// Add the overloaded operator candidates that are member functions 2638/// for the operator Op that was used in an operator expression such 2639/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2640/// CandidateSet will store the added overload candidates. (C++ 2641/// [over.match.oper]). 2642void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2643 SourceLocation OpLoc, 2644 Expr **Args, unsigned NumArgs, 2645 OverloadCandidateSet& CandidateSet, 2646 SourceRange OpRange) { 2647 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2648 2649 // C++ [over.match.oper]p3: 2650 // For a unary operator @ with an operand of a type whose 2651 // cv-unqualified version is T1, and for a binary operator @ with 2652 // a left operand of a type whose cv-unqualified version is T1 and 2653 // a right operand of a type whose cv-unqualified version is T2, 2654 // three sets of candidate functions, designated member 2655 // candidates, non-member candidates and built-in candidates, are 2656 // constructed as follows: 2657 QualType T1 = Args[0]->getType(); 2658 QualType T2; 2659 if (NumArgs > 1) 2660 T2 = Args[1]->getType(); 2661 2662 // -- If T1 is a class type, the set of member candidates is the 2663 // result of the qualified lookup of T1::operator@ 2664 // (13.3.1.1.1); otherwise, the set of member candidates is 2665 // empty. 2666 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2667 // Complete the type if it can be completed. Otherwise, we're done. 2668 if (RequireCompleteType(OpLoc, T1, PartialDiagnostic(0))) 2669 return; 2670 2671 LookupResult Operators = LookupQualifiedName(T1Rec->getDecl(), OpName, 2672 LookupOrdinaryName, false); 2673 for (LookupResult::iterator Oper = Operators.begin(), 2674 OperEnd = Operators.end(); 2675 Oper != OperEnd; 2676 ++Oper) 2677 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2678 Args+1, NumArgs - 1, CandidateSet, 2679 /*SuppressUserConversions=*/false); 2680 } 2681} 2682 2683/// AddBuiltinCandidate - Add a candidate for a built-in 2684/// operator. ResultTy and ParamTys are the result and parameter types 2685/// of the built-in candidate, respectively. Args and NumArgs are the 2686/// arguments being passed to the candidate. IsAssignmentOperator 2687/// should be true when this built-in candidate is an assignment 2688/// operator. NumContextualBoolArguments is the number of arguments 2689/// (at the beginning of the argument list) that will be contextually 2690/// converted to bool. 2691void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2692 Expr **Args, unsigned NumArgs, 2693 OverloadCandidateSet& CandidateSet, 2694 bool IsAssignmentOperator, 2695 unsigned NumContextualBoolArguments) { 2696 // Add this candidate 2697 CandidateSet.push_back(OverloadCandidate()); 2698 OverloadCandidate& Candidate = CandidateSet.back(); 2699 Candidate.Function = 0; 2700 Candidate.IsSurrogate = false; 2701 Candidate.IgnoreObjectArgument = false; 2702 Candidate.BuiltinTypes.ResultTy = ResultTy; 2703 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2704 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2705 2706 // Determine the implicit conversion sequences for each of the 2707 // arguments. 2708 Candidate.Viable = true; 2709 Candidate.Conversions.resize(NumArgs); 2710 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2711 // C++ [over.match.oper]p4: 2712 // For the built-in assignment operators, conversions of the 2713 // left operand are restricted as follows: 2714 // -- no temporaries are introduced to hold the left operand, and 2715 // -- no user-defined conversions are applied to the left 2716 // operand to achieve a type match with the left-most 2717 // parameter of a built-in candidate. 2718 // 2719 // We block these conversions by turning off user-defined 2720 // conversions, since that is the only way that initialization of 2721 // a reference to a non-class type can occur from something that 2722 // is not of the same type. 2723 if (ArgIdx < NumContextualBoolArguments) { 2724 assert(ParamTys[ArgIdx] == Context.BoolTy && 2725 "Contextual conversion to bool requires bool type"); 2726 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2727 } else { 2728 Candidate.Conversions[ArgIdx] 2729 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2730 ArgIdx == 0 && IsAssignmentOperator, 2731 /*ForceRValue=*/false, 2732 /*InOverloadResolution=*/false); 2733 } 2734 if (Candidate.Conversions[ArgIdx].ConversionKind 2735 == ImplicitConversionSequence::BadConversion) { 2736 Candidate.Viable = false; 2737 break; 2738 } 2739 } 2740} 2741 2742/// BuiltinCandidateTypeSet - A set of types that will be used for the 2743/// candidate operator functions for built-in operators (C++ 2744/// [over.built]). The types are separated into pointer types and 2745/// enumeration types. 2746class BuiltinCandidateTypeSet { 2747 /// TypeSet - A set of types. 2748 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2749 2750 /// PointerTypes - The set of pointer types that will be used in the 2751 /// built-in candidates. 2752 TypeSet PointerTypes; 2753 2754 /// MemberPointerTypes - The set of member pointer types that will be 2755 /// used in the built-in candidates. 2756 TypeSet MemberPointerTypes; 2757 2758 /// EnumerationTypes - The set of enumeration types that will be 2759 /// used in the built-in candidates. 2760 TypeSet EnumerationTypes; 2761 2762 /// Sema - The semantic analysis instance where we are building the 2763 /// candidate type set. 2764 Sema &SemaRef; 2765 2766 /// Context - The AST context in which we will build the type sets. 2767 ASTContext &Context; 2768 2769 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2770 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2771 2772public: 2773 /// iterator - Iterates through the types that are part of the set. 2774 typedef TypeSet::iterator iterator; 2775 2776 BuiltinCandidateTypeSet(Sema &SemaRef) 2777 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2778 2779 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2780 bool AllowExplicitConversions); 2781 2782 /// pointer_begin - First pointer type found; 2783 iterator pointer_begin() { return PointerTypes.begin(); } 2784 2785 /// pointer_end - Past the last pointer type found; 2786 iterator pointer_end() { return PointerTypes.end(); } 2787 2788 /// member_pointer_begin - First member pointer type found; 2789 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2790 2791 /// member_pointer_end - Past the last member pointer type found; 2792 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2793 2794 /// enumeration_begin - First enumeration type found; 2795 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2796 2797 /// enumeration_end - Past the last enumeration type found; 2798 iterator enumeration_end() { return EnumerationTypes.end(); } 2799}; 2800 2801/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2802/// the set of pointer types along with any more-qualified variants of 2803/// that type. For example, if @p Ty is "int const *", this routine 2804/// will add "int const *", "int const volatile *", "int const 2805/// restrict *", and "int const volatile restrict *" to the set of 2806/// pointer types. Returns true if the add of @p Ty itself succeeded, 2807/// false otherwise. 2808bool 2809BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2810 // Insert this type. 2811 if (!PointerTypes.insert(Ty)) 2812 return false; 2813 2814 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2815 QualType PointeeTy = PointerTy->getPointeeType(); 2816 // FIXME: Optimize this so that we don't keep trying to add the same types. 2817 2818 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal with all 2819 // pointer conversions that don't cast away constness? 2820 if (!PointeeTy.isConstQualified()) 2821 AddPointerWithMoreQualifiedTypeVariants 2822 (Context.getPointerType(PointeeTy.withConst())); 2823 if (!PointeeTy.isVolatileQualified()) 2824 AddPointerWithMoreQualifiedTypeVariants 2825 (Context.getPointerType(PointeeTy.withVolatile())); 2826 if (!PointeeTy.isRestrictQualified()) 2827 AddPointerWithMoreQualifiedTypeVariants 2828 (Context.getPointerType(PointeeTy.withRestrict())); 2829 } 2830 2831 return true; 2832} 2833 2834/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2835/// to the set of pointer types along with any more-qualified variants of 2836/// that type. For example, if @p Ty is "int const *", this routine 2837/// will add "int const *", "int const volatile *", "int const 2838/// restrict *", and "int const volatile restrict *" to the set of 2839/// pointer types. Returns true if the add of @p Ty itself succeeded, 2840/// false otherwise. 2841bool 2842BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2843 QualType Ty) { 2844 // Insert this type. 2845 if (!MemberPointerTypes.insert(Ty)) 2846 return false; 2847 2848 if (const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>()) { 2849 QualType PointeeTy = PointerTy->getPointeeType(); 2850 const Type *ClassTy = PointerTy->getClass(); 2851 // FIXME: Optimize this so that we don't keep trying to add the same types. 2852 2853 if (!PointeeTy.isConstQualified()) 2854 AddMemberPointerWithMoreQualifiedTypeVariants 2855 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2856 if (!PointeeTy.isVolatileQualified()) 2857 AddMemberPointerWithMoreQualifiedTypeVariants 2858 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2859 if (!PointeeTy.isRestrictQualified()) 2860 AddMemberPointerWithMoreQualifiedTypeVariants 2861 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2862 } 2863 2864 return true; 2865} 2866 2867/// AddTypesConvertedFrom - Add each of the types to which the type @p 2868/// Ty can be implicit converted to the given set of @p Types. We're 2869/// primarily interested in pointer types and enumeration types. We also 2870/// take member pointer types, for the conditional operator. 2871/// AllowUserConversions is true if we should look at the conversion 2872/// functions of a class type, and AllowExplicitConversions if we 2873/// should also include the explicit conversion functions of a class 2874/// type. 2875void 2876BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2877 bool AllowUserConversions, 2878 bool AllowExplicitConversions) { 2879 // Only deal with canonical types. 2880 Ty = Context.getCanonicalType(Ty); 2881 2882 // Look through reference types; they aren't part of the type of an 2883 // expression for the purposes of conversions. 2884 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 2885 Ty = RefTy->getPointeeType(); 2886 2887 // We don't care about qualifiers on the type. 2888 Ty = Ty.getUnqualifiedType(); 2889 2890 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2891 QualType PointeeTy = PointerTy->getPointeeType(); 2892 2893 // Insert our type, and its more-qualified variants, into the set 2894 // of types. 2895 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2896 return; 2897 2898 // Add 'cv void*' to our set of types. 2899 if (!Ty->isVoidType()) { 2900 QualType QualVoid 2901 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2902 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2903 } 2904 2905 // If this is a pointer to a class type, add pointers to its bases 2906 // (with the same level of cv-qualification as the original 2907 // derived class, of course). 2908 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 2909 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2910 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2911 Base != ClassDecl->bases_end(); ++Base) { 2912 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2913 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2914 2915 // Add the pointer type, recursively, so that we get all of 2916 // the indirect base classes, too. 2917 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2918 } 2919 } 2920 } else if (Ty->isMemberPointerType()) { 2921 // Member pointers are far easier, since the pointee can't be converted. 2922 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2923 return; 2924 } else if (Ty->isEnumeralType()) { 2925 EnumerationTypes.insert(Ty); 2926 } else if (AllowUserConversions) { 2927 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 2928 if (SemaRef.RequireCompleteType(SourceLocation(), Ty, 0)) { 2929 // No conversion functions in incomplete types. 2930 return; 2931 } 2932 2933 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2934 // FIXME: Visit conversion functions in the base classes, too. 2935 OverloadedFunctionDecl *Conversions 2936 = ClassDecl->getConversionFunctions(); 2937 for (OverloadedFunctionDecl::function_iterator Func 2938 = Conversions->function_begin(); 2939 Func != Conversions->function_end(); ++Func) { 2940 CXXConversionDecl *Conv; 2941 FunctionTemplateDecl *ConvTemplate; 2942 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 2943 2944 // Skip conversion function templates; they don't tell us anything 2945 // about which builtin types we can convert to. 2946 if (ConvTemplate) 2947 continue; 2948 2949 if (AllowExplicitConversions || !Conv->isExplicit()) 2950 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2951 } 2952 } 2953 } 2954} 2955 2956/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 2957/// the volatile- and non-volatile-qualified assignment operators for the 2958/// given type to the candidate set. 2959static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 2960 QualType T, 2961 Expr **Args, 2962 unsigned NumArgs, 2963 OverloadCandidateSet &CandidateSet) { 2964 QualType ParamTypes[2]; 2965 2966 // T& operator=(T&, T) 2967 ParamTypes[0] = S.Context.getLValueReferenceType(T); 2968 ParamTypes[1] = T; 2969 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 2970 /*IsAssignmentOperator=*/true); 2971 2972 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 2973 // volatile T& operator=(volatile T&, T) 2974 ParamTypes[0] = S.Context.getLValueReferenceType(T.withVolatile()); 2975 ParamTypes[1] = T; 2976 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 2977 /*IsAssignmentOperator=*/true); 2978 } 2979} 2980 2981/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2982/// operator overloads to the candidate set (C++ [over.built]), based 2983/// on the operator @p Op and the arguments given. For example, if the 2984/// operator is a binary '+', this routine might add "int 2985/// operator+(int, int)" to cover integer addition. 2986void 2987Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2988 Expr **Args, unsigned NumArgs, 2989 OverloadCandidateSet& CandidateSet) { 2990 // The set of "promoted arithmetic types", which are the arithmetic 2991 // types are that preserved by promotion (C++ [over.built]p2). Note 2992 // that the first few of these types are the promoted integral 2993 // types; these types need to be first. 2994 // FIXME: What about complex? 2995 const unsigned FirstIntegralType = 0; 2996 const unsigned LastIntegralType = 13; 2997 const unsigned FirstPromotedIntegralType = 7, 2998 LastPromotedIntegralType = 13; 2999 const unsigned FirstPromotedArithmeticType = 7, 3000 LastPromotedArithmeticType = 16; 3001 const unsigned NumArithmeticTypes = 16; 3002 QualType ArithmeticTypes[NumArithmeticTypes] = { 3003 Context.BoolTy, Context.CharTy, Context.WCharTy, 3004// FIXME: Context.Char16Ty, Context.Char32Ty, 3005 Context.SignedCharTy, Context.ShortTy, 3006 Context.UnsignedCharTy, Context.UnsignedShortTy, 3007 Context.IntTy, Context.LongTy, Context.LongLongTy, 3008 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3009 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3010 }; 3011 3012 // Find all of the types that the arguments can convert to, but only 3013 // if the operator we're looking at has built-in operator candidates 3014 // that make use of these types. 3015 BuiltinCandidateTypeSet CandidateTypes(*this); 3016 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3017 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3018 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3019 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3020 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3021 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3022 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3023 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3024 true, 3025 (Op == OO_Exclaim || 3026 Op == OO_AmpAmp || 3027 Op == OO_PipePipe)); 3028 } 3029 3030 bool isComparison = false; 3031 switch (Op) { 3032 case OO_None: 3033 case NUM_OVERLOADED_OPERATORS: 3034 assert(false && "Expected an overloaded operator"); 3035 break; 3036 3037 case OO_Star: // '*' is either unary or binary 3038 if (NumArgs == 1) 3039 goto UnaryStar; 3040 else 3041 goto BinaryStar; 3042 break; 3043 3044 case OO_Plus: // '+' is either unary or binary 3045 if (NumArgs == 1) 3046 goto UnaryPlus; 3047 else 3048 goto BinaryPlus; 3049 break; 3050 3051 case OO_Minus: // '-' is either unary or binary 3052 if (NumArgs == 1) 3053 goto UnaryMinus; 3054 else 3055 goto BinaryMinus; 3056 break; 3057 3058 case OO_Amp: // '&' is either unary or binary 3059 if (NumArgs == 1) 3060 goto UnaryAmp; 3061 else 3062 goto BinaryAmp; 3063 3064 case OO_PlusPlus: 3065 case OO_MinusMinus: 3066 // C++ [over.built]p3: 3067 // 3068 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3069 // is either volatile or empty, there exist candidate operator 3070 // functions of the form 3071 // 3072 // VQ T& operator++(VQ T&); 3073 // T operator++(VQ T&, int); 3074 // 3075 // C++ [over.built]p4: 3076 // 3077 // For every pair (T, VQ), where T is an arithmetic type other 3078 // than bool, and VQ is either volatile or empty, there exist 3079 // candidate operator functions of the form 3080 // 3081 // VQ T& operator--(VQ T&); 3082 // T operator--(VQ T&, int); 3083 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3084 Arith < NumArithmeticTypes; ++Arith) { 3085 QualType ArithTy = ArithmeticTypes[Arith]; 3086 QualType ParamTypes[2] 3087 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3088 3089 // Non-volatile version. 3090 if (NumArgs == 1) 3091 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3092 else 3093 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3094 3095 // Volatile version 3096 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 3097 if (NumArgs == 1) 3098 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3099 else 3100 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3101 } 3102 3103 // C++ [over.built]p5: 3104 // 3105 // For every pair (T, VQ), where T is a cv-qualified or 3106 // cv-unqualified object type, and VQ is either volatile or 3107 // empty, there exist candidate operator functions of the form 3108 // 3109 // T*VQ& operator++(T*VQ&); 3110 // T*VQ& operator--(T*VQ&); 3111 // T* operator++(T*VQ&, int); 3112 // T* operator--(T*VQ&, int); 3113 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3114 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3115 // Skip pointer types that aren't pointers to object types. 3116 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3117 continue; 3118 3119 QualType ParamTypes[2] = { 3120 Context.getLValueReferenceType(*Ptr), Context.IntTy 3121 }; 3122 3123 // Without volatile 3124 if (NumArgs == 1) 3125 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3126 else 3127 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3128 3129 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3130 // With volatile 3131 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3132 if (NumArgs == 1) 3133 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3134 else 3135 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3136 } 3137 } 3138 break; 3139 3140 UnaryStar: 3141 // C++ [over.built]p6: 3142 // For every cv-qualified or cv-unqualified object type T, there 3143 // exist candidate operator functions of the form 3144 // 3145 // T& operator*(T*); 3146 // 3147 // C++ [over.built]p7: 3148 // For every function type T, there exist candidate operator 3149 // functions of the form 3150 // T& operator*(T*); 3151 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3152 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3153 QualType ParamTy = *Ptr; 3154 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3155 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3156 &ParamTy, Args, 1, CandidateSet); 3157 } 3158 break; 3159 3160 UnaryPlus: 3161 // C++ [over.built]p8: 3162 // For every type T, there exist candidate operator functions of 3163 // the form 3164 // 3165 // T* operator+(T*); 3166 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3167 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3168 QualType ParamTy = *Ptr; 3169 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3170 } 3171 3172 // Fall through 3173 3174 UnaryMinus: 3175 // C++ [over.built]p9: 3176 // For every promoted arithmetic type T, there exist candidate 3177 // operator functions of the form 3178 // 3179 // T operator+(T); 3180 // T operator-(T); 3181 for (unsigned Arith = FirstPromotedArithmeticType; 3182 Arith < LastPromotedArithmeticType; ++Arith) { 3183 QualType ArithTy = ArithmeticTypes[Arith]; 3184 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3185 } 3186 break; 3187 3188 case OO_Tilde: 3189 // C++ [over.built]p10: 3190 // For every promoted integral type T, there exist candidate 3191 // operator functions of the form 3192 // 3193 // T operator~(T); 3194 for (unsigned Int = FirstPromotedIntegralType; 3195 Int < LastPromotedIntegralType; ++Int) { 3196 QualType IntTy = ArithmeticTypes[Int]; 3197 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3198 } 3199 break; 3200 3201 case OO_New: 3202 case OO_Delete: 3203 case OO_Array_New: 3204 case OO_Array_Delete: 3205 case OO_Call: 3206 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3207 break; 3208 3209 case OO_Comma: 3210 UnaryAmp: 3211 case OO_Arrow: 3212 // C++ [over.match.oper]p3: 3213 // -- For the operator ',', the unary operator '&', or the 3214 // operator '->', the built-in candidates set is empty. 3215 break; 3216 3217 case OO_EqualEqual: 3218 case OO_ExclaimEqual: 3219 // C++ [over.match.oper]p16: 3220 // For every pointer to member type T, there exist candidate operator 3221 // functions of the form 3222 // 3223 // bool operator==(T,T); 3224 // bool operator!=(T,T); 3225 for (BuiltinCandidateTypeSet::iterator 3226 MemPtr = CandidateTypes.member_pointer_begin(), 3227 MemPtrEnd = CandidateTypes.member_pointer_end(); 3228 MemPtr != MemPtrEnd; 3229 ++MemPtr) { 3230 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3231 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3232 } 3233 3234 // Fall through 3235 3236 case OO_Less: 3237 case OO_Greater: 3238 case OO_LessEqual: 3239 case OO_GreaterEqual: 3240 // C++ [over.built]p15: 3241 // 3242 // For every pointer or enumeration type T, there exist 3243 // candidate operator functions of the form 3244 // 3245 // bool operator<(T, T); 3246 // bool operator>(T, T); 3247 // bool operator<=(T, T); 3248 // bool operator>=(T, T); 3249 // bool operator==(T, T); 3250 // bool operator!=(T, T); 3251 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3252 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3253 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3254 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3255 } 3256 for (BuiltinCandidateTypeSet::iterator Enum 3257 = CandidateTypes.enumeration_begin(); 3258 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3259 QualType ParamTypes[2] = { *Enum, *Enum }; 3260 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3261 } 3262 3263 // Fall through. 3264 isComparison = true; 3265 3266 BinaryPlus: 3267 BinaryMinus: 3268 if (!isComparison) { 3269 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3270 3271 // C++ [over.built]p13: 3272 // 3273 // For every cv-qualified or cv-unqualified object type T 3274 // there exist candidate operator functions of the form 3275 // 3276 // T* operator+(T*, ptrdiff_t); 3277 // T& operator[](T*, ptrdiff_t); [BELOW] 3278 // T* operator-(T*, ptrdiff_t); 3279 // T* operator+(ptrdiff_t, T*); 3280 // T& operator[](ptrdiff_t, T*); [BELOW] 3281 // 3282 // C++ [over.built]p14: 3283 // 3284 // For every T, where T is a pointer to object type, there 3285 // exist candidate operator functions of the form 3286 // 3287 // ptrdiff_t operator-(T, T); 3288 for (BuiltinCandidateTypeSet::iterator Ptr 3289 = CandidateTypes.pointer_begin(); 3290 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3291 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3292 3293 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3294 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3295 3296 if (Op == OO_Plus) { 3297 // T* operator+(ptrdiff_t, T*); 3298 ParamTypes[0] = ParamTypes[1]; 3299 ParamTypes[1] = *Ptr; 3300 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3301 } else { 3302 // ptrdiff_t operator-(T, T); 3303 ParamTypes[1] = *Ptr; 3304 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3305 Args, 2, CandidateSet); 3306 } 3307 } 3308 } 3309 // Fall through 3310 3311 case OO_Slash: 3312 BinaryStar: 3313 Conditional: 3314 // C++ [over.built]p12: 3315 // 3316 // For every pair of promoted arithmetic types L and R, there 3317 // exist candidate operator functions of the form 3318 // 3319 // LR operator*(L, R); 3320 // LR operator/(L, R); 3321 // LR operator+(L, R); 3322 // LR operator-(L, R); 3323 // bool operator<(L, R); 3324 // bool operator>(L, R); 3325 // bool operator<=(L, R); 3326 // bool operator>=(L, R); 3327 // bool operator==(L, R); 3328 // bool operator!=(L, R); 3329 // 3330 // where LR is the result of the usual arithmetic conversions 3331 // between types L and R. 3332 // 3333 // C++ [over.built]p24: 3334 // 3335 // For every pair of promoted arithmetic types L and R, there exist 3336 // candidate operator functions of the form 3337 // 3338 // LR operator?(bool, L, R); 3339 // 3340 // where LR is the result of the usual arithmetic conversions 3341 // between types L and R. 3342 // Our candidates ignore the first parameter. 3343 for (unsigned Left = FirstPromotedArithmeticType; 3344 Left < LastPromotedArithmeticType; ++Left) { 3345 for (unsigned Right = FirstPromotedArithmeticType; 3346 Right < LastPromotedArithmeticType; ++Right) { 3347 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3348 QualType Result 3349 = isComparison 3350 ? Context.BoolTy 3351 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3352 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3353 } 3354 } 3355 break; 3356 3357 case OO_Percent: 3358 BinaryAmp: 3359 case OO_Caret: 3360 case OO_Pipe: 3361 case OO_LessLess: 3362 case OO_GreaterGreater: 3363 // C++ [over.built]p17: 3364 // 3365 // For every pair of promoted integral types L and R, there 3366 // exist candidate operator functions of the form 3367 // 3368 // LR operator%(L, R); 3369 // LR operator&(L, R); 3370 // LR operator^(L, R); 3371 // LR operator|(L, R); 3372 // L operator<<(L, R); 3373 // L operator>>(L, R); 3374 // 3375 // where LR is the result of the usual arithmetic conversions 3376 // between types L and R. 3377 for (unsigned Left = FirstPromotedIntegralType; 3378 Left < LastPromotedIntegralType; ++Left) { 3379 for (unsigned Right = FirstPromotedIntegralType; 3380 Right < LastPromotedIntegralType; ++Right) { 3381 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3382 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3383 ? LandR[0] 3384 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3385 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3386 } 3387 } 3388 break; 3389 3390 case OO_Equal: 3391 // C++ [over.built]p20: 3392 // 3393 // For every pair (T, VQ), where T is an enumeration or 3394 // pointer to member type and VQ is either volatile or 3395 // empty, there exist candidate operator functions of the form 3396 // 3397 // VQ T& operator=(VQ T&, T); 3398 for (BuiltinCandidateTypeSet::iterator 3399 Enum = CandidateTypes.enumeration_begin(), 3400 EnumEnd = CandidateTypes.enumeration_end(); 3401 Enum != EnumEnd; ++Enum) 3402 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3403 CandidateSet); 3404 for (BuiltinCandidateTypeSet::iterator 3405 MemPtr = CandidateTypes.member_pointer_begin(), 3406 MemPtrEnd = CandidateTypes.member_pointer_end(); 3407 MemPtr != MemPtrEnd; ++MemPtr) 3408 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3409 CandidateSet); 3410 // Fall through. 3411 3412 case OO_PlusEqual: 3413 case OO_MinusEqual: 3414 // C++ [over.built]p19: 3415 // 3416 // For every pair (T, VQ), where T is any type and VQ is either 3417 // volatile or empty, there exist candidate operator functions 3418 // of the form 3419 // 3420 // T*VQ& operator=(T*VQ&, T*); 3421 // 3422 // C++ [over.built]p21: 3423 // 3424 // For every pair (T, VQ), where T is a cv-qualified or 3425 // cv-unqualified object type and VQ is either volatile or 3426 // empty, there exist candidate operator functions of the form 3427 // 3428 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3429 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3430 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3431 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3432 QualType ParamTypes[2]; 3433 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3434 3435 // non-volatile version 3436 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3437 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3438 /*IsAssigmentOperator=*/Op == OO_Equal); 3439 3440 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3441 // volatile version 3442 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3443 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3444 /*IsAssigmentOperator=*/Op == OO_Equal); 3445 } 3446 } 3447 // Fall through. 3448 3449 case OO_StarEqual: 3450 case OO_SlashEqual: 3451 // C++ [over.built]p18: 3452 // 3453 // For every triple (L, VQ, R), where L is an arithmetic type, 3454 // VQ is either volatile or empty, and R is a promoted 3455 // arithmetic type, there exist candidate operator functions of 3456 // the form 3457 // 3458 // VQ L& operator=(VQ L&, R); 3459 // VQ L& operator*=(VQ L&, R); 3460 // VQ L& operator/=(VQ L&, R); 3461 // VQ L& operator+=(VQ L&, R); 3462 // VQ L& operator-=(VQ L&, R); 3463 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3464 for (unsigned Right = FirstPromotedArithmeticType; 3465 Right < LastPromotedArithmeticType; ++Right) { 3466 QualType ParamTypes[2]; 3467 ParamTypes[1] = ArithmeticTypes[Right]; 3468 3469 // Add this built-in operator as a candidate (VQ is empty). 3470 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3471 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3472 /*IsAssigmentOperator=*/Op == OO_Equal); 3473 3474 // Add this built-in operator as a candidate (VQ is 'volatile'). 3475 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3476 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3477 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3478 /*IsAssigmentOperator=*/Op == OO_Equal); 3479 } 3480 } 3481 break; 3482 3483 case OO_PercentEqual: 3484 case OO_LessLessEqual: 3485 case OO_GreaterGreaterEqual: 3486 case OO_AmpEqual: 3487 case OO_CaretEqual: 3488 case OO_PipeEqual: 3489 // C++ [over.built]p22: 3490 // 3491 // For every triple (L, VQ, R), where L is an integral type, VQ 3492 // is either volatile or empty, and R is a promoted integral 3493 // type, there exist candidate operator functions of the form 3494 // 3495 // VQ L& operator%=(VQ L&, R); 3496 // VQ L& operator<<=(VQ L&, R); 3497 // VQ L& operator>>=(VQ L&, R); 3498 // VQ L& operator&=(VQ L&, R); 3499 // VQ L& operator^=(VQ L&, R); 3500 // VQ L& operator|=(VQ L&, R); 3501 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3502 for (unsigned Right = FirstPromotedIntegralType; 3503 Right < LastPromotedIntegralType; ++Right) { 3504 QualType ParamTypes[2]; 3505 ParamTypes[1] = ArithmeticTypes[Right]; 3506 3507 // Add this built-in operator as a candidate (VQ is empty). 3508 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3509 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3510 3511 // Add this built-in operator as a candidate (VQ is 'volatile'). 3512 ParamTypes[0] = ArithmeticTypes[Left]; 3513 ParamTypes[0].addVolatile(); 3514 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3515 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3516 } 3517 } 3518 break; 3519 3520 case OO_Exclaim: { 3521 // C++ [over.operator]p23: 3522 // 3523 // There also exist candidate operator functions of the form 3524 // 3525 // bool operator!(bool); 3526 // bool operator&&(bool, bool); [BELOW] 3527 // bool operator||(bool, bool); [BELOW] 3528 QualType ParamTy = Context.BoolTy; 3529 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3530 /*IsAssignmentOperator=*/false, 3531 /*NumContextualBoolArguments=*/1); 3532 break; 3533 } 3534 3535 case OO_AmpAmp: 3536 case OO_PipePipe: { 3537 // C++ [over.operator]p23: 3538 // 3539 // There also exist candidate operator functions of the form 3540 // 3541 // bool operator!(bool); [ABOVE] 3542 // bool operator&&(bool, bool); 3543 // bool operator||(bool, bool); 3544 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3545 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3546 /*IsAssignmentOperator=*/false, 3547 /*NumContextualBoolArguments=*/2); 3548 break; 3549 } 3550 3551 case OO_Subscript: 3552 // C++ [over.built]p13: 3553 // 3554 // For every cv-qualified or cv-unqualified object type T there 3555 // exist candidate operator functions of the form 3556 // 3557 // T* operator+(T*, ptrdiff_t); [ABOVE] 3558 // T& operator[](T*, ptrdiff_t); 3559 // T* operator-(T*, ptrdiff_t); [ABOVE] 3560 // T* operator+(ptrdiff_t, T*); [ABOVE] 3561 // T& operator[](ptrdiff_t, T*); 3562 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3563 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3564 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3565 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3566 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3567 3568 // T& operator[](T*, ptrdiff_t) 3569 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3570 3571 // T& operator[](ptrdiff_t, T*); 3572 ParamTypes[0] = ParamTypes[1]; 3573 ParamTypes[1] = *Ptr; 3574 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3575 } 3576 break; 3577 3578 case OO_ArrowStar: 3579 // FIXME: No support for pointer-to-members yet. 3580 break; 3581 3582 case OO_Conditional: 3583 // Note that we don't consider the first argument, since it has been 3584 // contextually converted to bool long ago. The candidates below are 3585 // therefore added as binary. 3586 // 3587 // C++ [over.built]p24: 3588 // For every type T, where T is a pointer or pointer-to-member type, 3589 // there exist candidate operator functions of the form 3590 // 3591 // T operator?(bool, T, T); 3592 // 3593 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3594 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3595 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3596 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3597 } 3598 for (BuiltinCandidateTypeSet::iterator Ptr = 3599 CandidateTypes.member_pointer_begin(), 3600 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3601 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3602 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3603 } 3604 goto Conditional; 3605 } 3606} 3607 3608/// \brief Add function candidates found via argument-dependent lookup 3609/// to the set of overloading candidates. 3610/// 3611/// This routine performs argument-dependent name lookup based on the 3612/// given function name (which may also be an operator name) and adds 3613/// all of the overload candidates found by ADL to the overload 3614/// candidate set (C++ [basic.lookup.argdep]). 3615void 3616Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3617 Expr **Args, unsigned NumArgs, 3618 OverloadCandidateSet& CandidateSet) { 3619 FunctionSet Functions; 3620 3621 // Record all of the function candidates that we've already 3622 // added to the overload set, so that we don't add those same 3623 // candidates a second time. 3624 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3625 CandEnd = CandidateSet.end(); 3626 Cand != CandEnd; ++Cand) 3627 if (Cand->Function) { 3628 Functions.insert(Cand->Function); 3629 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3630 Functions.insert(FunTmpl); 3631 } 3632 3633 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3634 3635 // Erase all of the candidates we already knew about. 3636 // FIXME: This is suboptimal. Is there a better way? 3637 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3638 CandEnd = CandidateSet.end(); 3639 Cand != CandEnd; ++Cand) 3640 if (Cand->Function) { 3641 Functions.erase(Cand->Function); 3642 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3643 Functions.erase(FunTmpl); 3644 } 3645 3646 // For each of the ADL candidates we found, add it to the overload 3647 // set. 3648 for (FunctionSet::iterator Func = Functions.begin(), 3649 FuncEnd = Functions.end(); 3650 Func != FuncEnd; ++Func) { 3651 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) 3652 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet); 3653 else 3654 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3655 /*FIXME: explicit args */false, 0, 0, 3656 Args, NumArgs, CandidateSet); 3657 } 3658} 3659 3660/// isBetterOverloadCandidate - Determines whether the first overload 3661/// candidate is a better candidate than the second (C++ 13.3.3p1). 3662bool 3663Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3664 const OverloadCandidate& Cand2) { 3665 // Define viable functions to be better candidates than non-viable 3666 // functions. 3667 if (!Cand2.Viable) 3668 return Cand1.Viable; 3669 else if (!Cand1.Viable) 3670 return false; 3671 3672 // C++ [over.match.best]p1: 3673 // 3674 // -- if F is a static member function, ICS1(F) is defined such 3675 // that ICS1(F) is neither better nor worse than ICS1(G) for 3676 // any function G, and, symmetrically, ICS1(G) is neither 3677 // better nor worse than ICS1(F). 3678 unsigned StartArg = 0; 3679 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3680 StartArg = 1; 3681 3682 // C++ [over.match.best]p1: 3683 // A viable function F1 is defined to be a better function than another 3684 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3685 // conversion sequence than ICSi(F2), and then... 3686 unsigned NumArgs = Cand1.Conversions.size(); 3687 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3688 bool HasBetterConversion = false; 3689 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3690 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3691 Cand2.Conversions[ArgIdx])) { 3692 case ImplicitConversionSequence::Better: 3693 // Cand1 has a better conversion sequence. 3694 HasBetterConversion = true; 3695 break; 3696 3697 case ImplicitConversionSequence::Worse: 3698 // Cand1 can't be better than Cand2. 3699 return false; 3700 3701 case ImplicitConversionSequence::Indistinguishable: 3702 // Do nothing. 3703 break; 3704 } 3705 } 3706 3707 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3708 // ICSj(F2), or, if not that, 3709 if (HasBetterConversion) 3710 return true; 3711 3712 // - F1 is a non-template function and F2 is a function template 3713 // specialization, or, if not that, 3714 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3715 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3716 return true; 3717 3718 // -- F1 and F2 are function template specializations, and the function 3719 // template for F1 is more specialized than the template for F2 3720 // according to the partial ordering rules described in 14.5.5.2, or, 3721 // if not that, 3722 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3723 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3724 if (FunctionTemplateDecl *BetterTemplate 3725 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 3726 Cand2.Function->getPrimaryTemplate(), 3727 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 3728 : TPOC_Call)) 3729 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 3730 3731 // -- the context is an initialization by user-defined conversion 3732 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3733 // from the return type of F1 to the destination type (i.e., 3734 // the type of the entity being initialized) is a better 3735 // conversion sequence than the standard conversion sequence 3736 // from the return type of F2 to the destination type. 3737 if (Cand1.Function && Cand2.Function && 3738 isa<CXXConversionDecl>(Cand1.Function) && 3739 isa<CXXConversionDecl>(Cand2.Function)) { 3740 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3741 Cand2.FinalConversion)) { 3742 case ImplicitConversionSequence::Better: 3743 // Cand1 has a better conversion sequence. 3744 return true; 3745 3746 case ImplicitConversionSequence::Worse: 3747 // Cand1 can't be better than Cand2. 3748 return false; 3749 3750 case ImplicitConversionSequence::Indistinguishable: 3751 // Do nothing 3752 break; 3753 } 3754 } 3755 3756 return false; 3757} 3758 3759/// \brief Computes the best viable function (C++ 13.3.3) 3760/// within an overload candidate set. 3761/// 3762/// \param CandidateSet the set of candidate functions. 3763/// 3764/// \param Loc the location of the function name (or operator symbol) for 3765/// which overload resolution occurs. 3766/// 3767/// \param Best f overload resolution was successful or found a deleted 3768/// function, Best points to the candidate function found. 3769/// 3770/// \returns The result of overload resolution. 3771Sema::OverloadingResult 3772Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3773 SourceLocation Loc, 3774 OverloadCandidateSet::iterator& Best) { 3775 // Find the best viable function. 3776 Best = CandidateSet.end(); 3777 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3778 Cand != CandidateSet.end(); ++Cand) { 3779 if (Cand->Viable) { 3780 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3781 Best = Cand; 3782 } 3783 } 3784 3785 // If we didn't find any viable functions, abort. 3786 if (Best == CandidateSet.end()) 3787 return OR_No_Viable_Function; 3788 3789 // Make sure that this function is better than every other viable 3790 // function. If not, we have an ambiguity. 3791 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3792 Cand != CandidateSet.end(); ++Cand) { 3793 if (Cand->Viable && 3794 Cand != Best && 3795 !isBetterOverloadCandidate(*Best, *Cand)) { 3796 Best = CandidateSet.end(); 3797 return OR_Ambiguous; 3798 } 3799 } 3800 3801 // Best is the best viable function. 3802 if (Best->Function && 3803 (Best->Function->isDeleted() || 3804 Best->Function->getAttr<UnavailableAttr>())) 3805 return OR_Deleted; 3806 3807 // C++ [basic.def.odr]p2: 3808 // An overloaded function is used if it is selected by overload resolution 3809 // when referred to from a potentially-evaluated expression. [Note: this 3810 // covers calls to named functions (5.2.2), operator overloading 3811 // (clause 13), user-defined conversions (12.3.2), allocation function for 3812 // placement new (5.3.4), as well as non-default initialization (8.5). 3813 if (Best->Function) 3814 MarkDeclarationReferenced(Loc, Best->Function); 3815 return OR_Success; 3816} 3817 3818/// PrintOverloadCandidates - When overload resolution fails, prints 3819/// diagnostic messages containing the candidates in the candidate 3820/// set. If OnlyViable is true, only viable candidates will be printed. 3821void 3822Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3823 bool OnlyViable) { 3824 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3825 LastCand = CandidateSet.end(); 3826 for (; Cand != LastCand; ++Cand) { 3827 if (Cand->Viable || !OnlyViable) { 3828 if (Cand->Function) { 3829 if (Cand->Function->isDeleted() || 3830 Cand->Function->getAttr<UnavailableAttr>()) { 3831 // Deleted or "unavailable" function. 3832 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3833 << Cand->Function->isDeleted(); 3834 } else if (FunctionTemplateDecl *FunTmpl 3835 = Cand->Function->getPrimaryTemplate()) { 3836 // Function template specialization 3837 // FIXME: Give a better reason! 3838 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 3839 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 3840 *Cand->Function->getTemplateSpecializationArgs()); 3841 } else { 3842 // Normal function 3843 // FIXME: Give a better reason! 3844 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3845 } 3846 } else if (Cand->IsSurrogate) { 3847 // Desugar the type of the surrogate down to a function type, 3848 // retaining as many typedefs as possible while still showing 3849 // the function type (and, therefore, its parameter types). 3850 QualType FnType = Cand->Surrogate->getConversionType(); 3851 bool isLValueReference = false; 3852 bool isRValueReference = false; 3853 bool isPointer = false; 3854 if (const LValueReferenceType *FnTypeRef = 3855 FnType->getAs<LValueReferenceType>()) { 3856 FnType = FnTypeRef->getPointeeType(); 3857 isLValueReference = true; 3858 } else if (const RValueReferenceType *FnTypeRef = 3859 FnType->getAs<RValueReferenceType>()) { 3860 FnType = FnTypeRef->getPointeeType(); 3861 isRValueReference = true; 3862 } 3863 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 3864 FnType = FnTypePtr->getPointeeType(); 3865 isPointer = true; 3866 } 3867 // Desugar down to a function type. 3868 FnType = QualType(FnType->getAsFunctionType(), 0); 3869 // Reconstruct the pointer/reference as appropriate. 3870 if (isPointer) FnType = Context.getPointerType(FnType); 3871 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3872 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3873 3874 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3875 << FnType; 3876 } else { 3877 // FIXME: We need to get the identifier in here 3878 // FIXME: Do we want the error message to point at the operator? 3879 // (built-ins won't have a location) 3880 QualType FnType 3881 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3882 Cand->BuiltinTypes.ParamTypes, 3883 Cand->Conversions.size(), 3884 false, 0); 3885 3886 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3887 } 3888 } 3889 } 3890} 3891 3892/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3893/// an overloaded function (C++ [over.over]), where @p From is an 3894/// expression with overloaded function type and @p ToType is the type 3895/// we're trying to resolve to. For example: 3896/// 3897/// @code 3898/// int f(double); 3899/// int f(int); 3900/// 3901/// int (*pfd)(double) = f; // selects f(double) 3902/// @endcode 3903/// 3904/// This routine returns the resulting FunctionDecl if it could be 3905/// resolved, and NULL otherwise. When @p Complain is true, this 3906/// routine will emit diagnostics if there is an error. 3907FunctionDecl * 3908Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3909 bool Complain) { 3910 QualType FunctionType = ToType; 3911 bool IsMember = false; 3912 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 3913 FunctionType = ToTypePtr->getPointeeType(); 3914 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 3915 FunctionType = ToTypeRef->getPointeeType(); 3916 else if (const MemberPointerType *MemTypePtr = 3917 ToType->getAs<MemberPointerType>()) { 3918 FunctionType = MemTypePtr->getPointeeType(); 3919 IsMember = true; 3920 } 3921 3922 // We only look at pointers or references to functions. 3923 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 3924 if (!FunctionType->isFunctionType()) 3925 return 0; 3926 3927 // Find the actual overloaded function declaration. 3928 OverloadedFunctionDecl *Ovl = 0; 3929 3930 // C++ [over.over]p1: 3931 // [...] [Note: any redundant set of parentheses surrounding the 3932 // overloaded function name is ignored (5.1). ] 3933 Expr *OvlExpr = From->IgnoreParens(); 3934 3935 // C++ [over.over]p1: 3936 // [...] The overloaded function name can be preceded by the & 3937 // operator. 3938 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3939 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3940 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3941 } 3942 3943 // Try to dig out the overloaded function. 3944 FunctionTemplateDecl *FunctionTemplate = 0; 3945 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 3946 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3947 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 3948 } 3949 3950 // If there's no overloaded function declaration or function template, 3951 // we're done. 3952 if (!Ovl && !FunctionTemplate) 3953 return 0; 3954 3955 OverloadIterator Fun; 3956 if (Ovl) 3957 Fun = Ovl; 3958 else 3959 Fun = FunctionTemplate; 3960 3961 // Look through all of the overloaded functions, searching for one 3962 // whose type matches exactly. 3963 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 3964 3965 bool FoundNonTemplateFunction = false; 3966 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 3967 // C++ [over.over]p3: 3968 // Non-member functions and static member functions match 3969 // targets of type "pointer-to-function" or "reference-to-function." 3970 // Nonstatic member functions match targets of 3971 // type "pointer-to-member-function." 3972 // Note that according to DR 247, the containing class does not matter. 3973 3974 if (FunctionTemplateDecl *FunctionTemplate 3975 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 3976 if (CXXMethodDecl *Method 3977 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 3978 // Skip non-static function templates when converting to pointer, and 3979 // static when converting to member pointer. 3980 if (Method->isStatic() == IsMember) 3981 continue; 3982 } else if (IsMember) 3983 continue; 3984 3985 // C++ [over.over]p2: 3986 // If the name is a function template, template argument deduction is 3987 // done (14.8.2.2), and if the argument deduction succeeds, the 3988 // resulting template argument list is used to generate a single 3989 // function template specialization, which is added to the set of 3990 // overloaded functions considered. 3991 FunctionDecl *Specialization = 0; 3992 TemplateDeductionInfo Info(Context); 3993 if (TemplateDeductionResult Result 3994 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 3995 /*FIXME:*/0, /*FIXME:*/0, 3996 FunctionType, Specialization, Info)) { 3997 // FIXME: make a note of the failed deduction for diagnostics. 3998 (void)Result; 3999 } else { 4000 assert(FunctionType 4001 == Context.getCanonicalType(Specialization->getType())); 4002 Matches.insert( 4003 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4004 } 4005 } 4006 4007 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4008 // Skip non-static functions when converting to pointer, and static 4009 // when converting to member pointer. 4010 if (Method->isStatic() == IsMember) 4011 continue; 4012 } else if (IsMember) 4013 continue; 4014 4015 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4016 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4017 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4018 FoundNonTemplateFunction = true; 4019 } 4020 } 4021 } 4022 4023 // If there were 0 or 1 matches, we're done. 4024 if (Matches.empty()) 4025 return 0; 4026 else if (Matches.size() == 1) 4027 return *Matches.begin(); 4028 4029 // C++ [over.over]p4: 4030 // If more than one function is selected, [...] 4031 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4032 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4033 if (FoundNonTemplateFunction) { 4034 // [...] any function template specializations in the set are 4035 // eliminated if the set also contains a non-template function, [...] 4036 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4037 if ((*M)->getPrimaryTemplate() == 0) 4038 RemainingMatches.push_back(*M); 4039 } else { 4040 // [...] and any given function template specialization F1 is 4041 // eliminated if the set contains a second function template 4042 // specialization whose function template is more specialized 4043 // than the function template of F1 according to the partial 4044 // ordering rules of 14.5.5.2. 4045 4046 // The algorithm specified above is quadratic. We instead use a 4047 // two-pass algorithm (similar to the one used to identify the 4048 // best viable function in an overload set) that identifies the 4049 // best function template (if it exists). 4050 MatchIter Best = Matches.begin(); 4051 MatchIter M = Best, MEnd = Matches.end(); 4052 // Find the most specialized function. 4053 for (++M; M != MEnd; ++M) 4054 if (getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4055 (*Best)->getPrimaryTemplate(), 4056 TPOC_Other) 4057 == (*M)->getPrimaryTemplate()) 4058 Best = M; 4059 4060 // Determine whether this function template is more specialized 4061 // that all of the others. 4062 bool Ambiguous = false; 4063 for (M = Matches.begin(); M != MEnd; ++M) { 4064 if (M != Best && 4065 getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4066 (*Best)->getPrimaryTemplate(), 4067 TPOC_Other) 4068 != (*Best)->getPrimaryTemplate()) { 4069 Ambiguous = true; 4070 break; 4071 } 4072 } 4073 4074 // If one function template was more specialized than all of the 4075 // others, return it. 4076 if (!Ambiguous) 4077 return *Best; 4078 4079 // We could not find a most-specialized function template, which 4080 // is equivalent to having a set of function templates with more 4081 // than one such template. So, we place all of the function 4082 // templates into the set of remaining matches and produce a 4083 // diagnostic below. FIXME: we could perform the quadratic 4084 // algorithm here, pruning the result set to limit the number of 4085 // candidates output later. 4086 RemainingMatches.append(Matches.begin(), Matches.end()); 4087 } 4088 4089 // [...] After such eliminations, if any, there shall remain exactly one 4090 // selected function. 4091 if (RemainingMatches.size() == 1) 4092 return RemainingMatches.front(); 4093 4094 // FIXME: We should probably return the same thing that BestViableFunction 4095 // returns (even if we issue the diagnostics here). 4096 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4097 << RemainingMatches[0]->getDeclName(); 4098 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4099 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4100 return 0; 4101} 4102 4103/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4104/// (which eventually refers to the declaration Func) and the call 4105/// arguments Args/NumArgs, attempt to resolve the function call down 4106/// to a specific function. If overload resolution succeeds, returns 4107/// the function declaration produced by overload 4108/// resolution. Otherwise, emits diagnostics, deletes all of the 4109/// arguments and Fn, and returns NULL. 4110FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4111 DeclarationName UnqualifiedName, 4112 bool HasExplicitTemplateArgs, 4113 const TemplateArgument *ExplicitTemplateArgs, 4114 unsigned NumExplicitTemplateArgs, 4115 SourceLocation LParenLoc, 4116 Expr **Args, unsigned NumArgs, 4117 SourceLocation *CommaLocs, 4118 SourceLocation RParenLoc, 4119 bool &ArgumentDependentLookup) { 4120 OverloadCandidateSet CandidateSet; 4121 4122 // Add the functions denoted by Callee to the set of candidate 4123 // functions. While we're doing so, track whether argument-dependent 4124 // lookup still applies, per: 4125 // 4126 // C++0x [basic.lookup.argdep]p3: 4127 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4128 // and let Y be the lookup set produced by argument dependent 4129 // lookup (defined as follows). If X contains 4130 // 4131 // -- a declaration of a class member, or 4132 // 4133 // -- a block-scope function declaration that is not a 4134 // using-declaration, or 4135 // 4136 // -- a declaration that is neither a function or a function 4137 // template 4138 // 4139 // then Y is empty. 4140 if (OverloadedFunctionDecl *Ovl 4141 = dyn_cast_or_null<OverloadedFunctionDecl>(Callee)) { 4142 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4143 FuncEnd = Ovl->function_end(); 4144 Func != FuncEnd; ++Func) { 4145 DeclContext *Ctx = 0; 4146 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Func)) { 4147 if (HasExplicitTemplateArgs) 4148 continue; 4149 4150 AddOverloadCandidate(FunDecl, Args, NumArgs, CandidateSet); 4151 Ctx = FunDecl->getDeclContext(); 4152 } else { 4153 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*Func); 4154 AddTemplateOverloadCandidate(FunTmpl, HasExplicitTemplateArgs, 4155 ExplicitTemplateArgs, 4156 NumExplicitTemplateArgs, 4157 Args, NumArgs, CandidateSet); 4158 Ctx = FunTmpl->getDeclContext(); 4159 } 4160 4161 4162 if (Ctx->isRecord() || Ctx->isFunctionOrMethod()) 4163 ArgumentDependentLookup = false; 4164 } 4165 } else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee)) { 4166 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4167 AddOverloadCandidate(Func, Args, NumArgs, CandidateSet); 4168 4169 if (Func->getDeclContext()->isRecord() || 4170 Func->getDeclContext()->isFunctionOrMethod()) 4171 ArgumentDependentLookup = false; 4172 } else if (FunctionTemplateDecl *FuncTemplate 4173 = dyn_cast_or_null<FunctionTemplateDecl>(Callee)) { 4174 AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4175 ExplicitTemplateArgs, 4176 NumExplicitTemplateArgs, 4177 Args, NumArgs, CandidateSet); 4178 4179 if (FuncTemplate->getDeclContext()->isRecord()) 4180 ArgumentDependentLookup = false; 4181 } 4182 4183 if (Callee) 4184 UnqualifiedName = Callee->getDeclName(); 4185 4186 // FIXME: Pass explicit template arguments through for ADL 4187 if (ArgumentDependentLookup) 4188 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4189 CandidateSet); 4190 4191 OverloadCandidateSet::iterator Best; 4192 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4193 case OR_Success: 4194 return Best->Function; 4195 4196 case OR_No_Viable_Function: 4197 Diag(Fn->getSourceRange().getBegin(), 4198 diag::err_ovl_no_viable_function_in_call) 4199 << UnqualifiedName << Fn->getSourceRange(); 4200 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4201 break; 4202 4203 case OR_Ambiguous: 4204 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4205 << UnqualifiedName << Fn->getSourceRange(); 4206 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4207 break; 4208 4209 case OR_Deleted: 4210 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4211 << Best->Function->isDeleted() 4212 << UnqualifiedName 4213 << Fn->getSourceRange(); 4214 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4215 break; 4216 } 4217 4218 // Overload resolution failed. Destroy all of the subexpressions and 4219 // return NULL. 4220 Fn->Destroy(Context); 4221 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4222 Args[Arg]->Destroy(Context); 4223 return 0; 4224} 4225 4226/// \brief Create a unary operation that may resolve to an overloaded 4227/// operator. 4228/// 4229/// \param OpLoc The location of the operator itself (e.g., '*'). 4230/// 4231/// \param OpcIn The UnaryOperator::Opcode that describes this 4232/// operator. 4233/// 4234/// \param Functions The set of non-member functions that will be 4235/// considered by overload resolution. The caller needs to build this 4236/// set based on the context using, e.g., 4237/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4238/// set should not contain any member functions; those will be added 4239/// by CreateOverloadedUnaryOp(). 4240/// 4241/// \param input The input argument. 4242Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4243 unsigned OpcIn, 4244 FunctionSet &Functions, 4245 ExprArg input) { 4246 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4247 Expr *Input = (Expr *)input.get(); 4248 4249 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4250 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4251 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4252 4253 Expr *Args[2] = { Input, 0 }; 4254 unsigned NumArgs = 1; 4255 4256 // For post-increment and post-decrement, add the implicit '0' as 4257 // the second argument, so that we know this is a post-increment or 4258 // post-decrement. 4259 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4260 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4261 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4262 SourceLocation()); 4263 NumArgs = 2; 4264 } 4265 4266 if (Input->isTypeDependent()) { 4267 OverloadedFunctionDecl *Overloads 4268 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4269 for (FunctionSet::iterator Func = Functions.begin(), 4270 FuncEnd = Functions.end(); 4271 Func != FuncEnd; ++Func) 4272 Overloads->addOverload(*Func); 4273 4274 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4275 OpLoc, false, false); 4276 4277 input.release(); 4278 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4279 &Args[0], NumArgs, 4280 Context.DependentTy, 4281 OpLoc)); 4282 } 4283 4284 // Build an empty overload set. 4285 OverloadCandidateSet CandidateSet; 4286 4287 // Add the candidates from the given function set. 4288 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4289 4290 // Add operator candidates that are member functions. 4291 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4292 4293 // Add builtin operator candidates. 4294 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4295 4296 // Perform overload resolution. 4297 OverloadCandidateSet::iterator Best; 4298 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4299 case OR_Success: { 4300 // We found a built-in operator or an overloaded operator. 4301 FunctionDecl *FnDecl = Best->Function; 4302 4303 if (FnDecl) { 4304 // We matched an overloaded operator. Build a call to that 4305 // operator. 4306 4307 // Convert the arguments. 4308 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4309 if (PerformObjectArgumentInitialization(Input, Method)) 4310 return ExprError(); 4311 } else { 4312 // Convert the arguments. 4313 if (PerformCopyInitialization(Input, 4314 FnDecl->getParamDecl(0)->getType(), 4315 "passing")) 4316 return ExprError(); 4317 } 4318 4319 // Determine the result type 4320 QualType ResultTy 4321 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4322 ResultTy = ResultTy.getNonReferenceType(); 4323 4324 // Build the actual expression node. 4325 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4326 SourceLocation()); 4327 UsualUnaryConversions(FnExpr); 4328 4329 input.release(); 4330 4331 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4332 &Input, 1, ResultTy, OpLoc); 4333 return MaybeBindToTemporary(CE); 4334 } else { 4335 // We matched a built-in operator. Convert the arguments, then 4336 // break out so that we will build the appropriate built-in 4337 // operator node. 4338 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4339 Best->Conversions[0], "passing")) 4340 return ExprError(); 4341 4342 break; 4343 } 4344 } 4345 4346 case OR_No_Viable_Function: 4347 // No viable function; fall through to handling this as a 4348 // built-in operator, which will produce an error message for us. 4349 break; 4350 4351 case OR_Ambiguous: 4352 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4353 << UnaryOperator::getOpcodeStr(Opc) 4354 << Input->getSourceRange(); 4355 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4356 return ExprError(); 4357 4358 case OR_Deleted: 4359 Diag(OpLoc, diag::err_ovl_deleted_oper) 4360 << Best->Function->isDeleted() 4361 << UnaryOperator::getOpcodeStr(Opc) 4362 << Input->getSourceRange(); 4363 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4364 return ExprError(); 4365 } 4366 4367 // Either we found no viable overloaded operator or we matched a 4368 // built-in operator. In either case, fall through to trying to 4369 // build a built-in operation. 4370 input.release(); 4371 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4372} 4373 4374/// \brief Create a binary operation that may resolve to an overloaded 4375/// operator. 4376/// 4377/// \param OpLoc The location of the operator itself (e.g., '+'). 4378/// 4379/// \param OpcIn The BinaryOperator::Opcode that describes this 4380/// operator. 4381/// 4382/// \param Functions The set of non-member functions that will be 4383/// considered by overload resolution. The caller needs to build this 4384/// set based on the context using, e.g., 4385/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4386/// set should not contain any member functions; those will be added 4387/// by CreateOverloadedBinOp(). 4388/// 4389/// \param LHS Left-hand argument. 4390/// \param RHS Right-hand argument. 4391Sema::OwningExprResult 4392Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4393 unsigned OpcIn, 4394 FunctionSet &Functions, 4395 Expr *LHS, Expr *RHS) { 4396 Expr *Args[2] = { LHS, RHS }; 4397 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4398 4399 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4400 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4401 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4402 4403 // If either side is type-dependent, create an appropriate dependent 4404 // expression. 4405 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4406 // .* cannot be overloaded. 4407 if (Opc == BinaryOperator::PtrMemD) 4408 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4409 Context.DependentTy, OpLoc)); 4410 4411 OverloadedFunctionDecl *Overloads 4412 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4413 for (FunctionSet::iterator Func = Functions.begin(), 4414 FuncEnd = Functions.end(); 4415 Func != FuncEnd; ++Func) 4416 Overloads->addOverload(*Func); 4417 4418 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4419 OpLoc, false, false); 4420 4421 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4422 Args, 2, 4423 Context.DependentTy, 4424 OpLoc)); 4425 } 4426 4427 // If this is the .* operator, which is not overloadable, just 4428 // create a built-in binary operator. 4429 if (Opc == BinaryOperator::PtrMemD) 4430 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4431 4432 // If this is one of the assignment operators, we only perform 4433 // overload resolution if the left-hand side is a class or 4434 // enumeration type (C++ [expr.ass]p3). 4435 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4436 !Args[0]->getType()->isOverloadableType()) 4437 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4438 4439 // Build an empty overload set. 4440 OverloadCandidateSet CandidateSet; 4441 4442 // Add the candidates from the given function set. 4443 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4444 4445 // Add operator candidates that are member functions. 4446 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4447 4448 // Add builtin operator candidates. 4449 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4450 4451 // Perform overload resolution. 4452 OverloadCandidateSet::iterator Best; 4453 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4454 case OR_Success: { 4455 // We found a built-in operator or an overloaded operator. 4456 FunctionDecl *FnDecl = Best->Function; 4457 4458 if (FnDecl) { 4459 // We matched an overloaded operator. Build a call to that 4460 // operator. 4461 4462 // Convert the arguments. 4463 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4464 if (PerformObjectArgumentInitialization(Args[0], Method) || 4465 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4466 "passing")) 4467 return ExprError(); 4468 } else { 4469 // Convert the arguments. 4470 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4471 "passing") || 4472 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4473 "passing")) 4474 return ExprError(); 4475 } 4476 4477 // Determine the result type 4478 QualType ResultTy 4479 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4480 ResultTy = ResultTy.getNonReferenceType(); 4481 4482 // Build the actual expression node. 4483 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4484 OpLoc); 4485 UsualUnaryConversions(FnExpr); 4486 4487 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4488 Args, 2, ResultTy, OpLoc); 4489 return MaybeBindToTemporary(CE); 4490 } else { 4491 // We matched a built-in operator. Convert the arguments, then 4492 // break out so that we will build the appropriate built-in 4493 // operator node. 4494 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4495 Best->Conversions[0], "passing") || 4496 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4497 Best->Conversions[1], "passing")) 4498 return ExprError(); 4499 4500 break; 4501 } 4502 } 4503 4504 case OR_No_Viable_Function: 4505 // For class as left operand for assignment or compound assigment operator 4506 // do not fall through to handling in built-in, but report that no overloaded 4507 // assignment operator found 4508 if (Args[0]->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4509 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4510 << BinaryOperator::getOpcodeStr(Opc) 4511 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4512 return ExprError(); 4513 } 4514 // No viable function; fall through to handling this as a 4515 // built-in operator, which will produce an error message for us. 4516 break; 4517 4518 case OR_Ambiguous: 4519 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4520 << BinaryOperator::getOpcodeStr(Opc) 4521 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4522 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4523 return ExprError(); 4524 4525 case OR_Deleted: 4526 Diag(OpLoc, diag::err_ovl_deleted_oper) 4527 << Best->Function->isDeleted() 4528 << BinaryOperator::getOpcodeStr(Opc) 4529 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4530 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4531 return ExprError(); 4532 } 4533 4534 // Either we found no viable overloaded operator or we matched a 4535 // built-in operator. In either case, try to build a built-in 4536 // operation. 4537 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4538} 4539 4540/// BuildCallToMemberFunction - Build a call to a member 4541/// function. MemExpr is the expression that refers to the member 4542/// function (and includes the object parameter), Args/NumArgs are the 4543/// arguments to the function call (not including the object 4544/// parameter). The caller needs to validate that the member 4545/// expression refers to a member function or an overloaded member 4546/// function. 4547Sema::ExprResult 4548Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4549 SourceLocation LParenLoc, Expr **Args, 4550 unsigned NumArgs, SourceLocation *CommaLocs, 4551 SourceLocation RParenLoc) { 4552 // Dig out the member expression. This holds both the object 4553 // argument and the member function we're referring to. 4554 MemberExpr *MemExpr = 0; 4555 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4556 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4557 else 4558 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4559 assert(MemExpr && "Building member call without member expression"); 4560 4561 // Extract the object argument. 4562 Expr *ObjectArg = MemExpr->getBase(); 4563 4564 CXXMethodDecl *Method = 0; 4565 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 4566 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 4567 // Add overload candidates 4568 OverloadCandidateSet CandidateSet; 4569 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 4570 4571 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 4572 Func != FuncEnd; ++Func) { 4573 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) 4574 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4575 /*SuppressUserConversions=*/false); 4576 else 4577 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 4578 MemExpr->hasExplicitTemplateArgumentList(), 4579 MemExpr->getTemplateArgs(), 4580 MemExpr->getNumTemplateArgs(), 4581 ObjectArg, Args, NumArgs, 4582 CandidateSet, 4583 /*SuppressUsedConversions=*/false); 4584 } 4585 4586 OverloadCandidateSet::iterator Best; 4587 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4588 case OR_Success: 4589 Method = cast<CXXMethodDecl>(Best->Function); 4590 break; 4591 4592 case OR_No_Viable_Function: 4593 Diag(MemExpr->getSourceRange().getBegin(), 4594 diag::err_ovl_no_viable_member_function_in_call) 4595 << DeclName << MemExprE->getSourceRange(); 4596 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4597 // FIXME: Leaking incoming expressions! 4598 return true; 4599 4600 case OR_Ambiguous: 4601 Diag(MemExpr->getSourceRange().getBegin(), 4602 diag::err_ovl_ambiguous_member_call) 4603 << DeclName << MemExprE->getSourceRange(); 4604 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4605 // FIXME: Leaking incoming expressions! 4606 return true; 4607 4608 case OR_Deleted: 4609 Diag(MemExpr->getSourceRange().getBegin(), 4610 diag::err_ovl_deleted_member_call) 4611 << Best->Function->isDeleted() 4612 << DeclName << MemExprE->getSourceRange(); 4613 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4614 // FIXME: Leaking incoming expressions! 4615 return true; 4616 } 4617 4618 FixOverloadedFunctionReference(MemExpr, Method); 4619 } else { 4620 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4621 } 4622 4623 assert(Method && "Member call to something that isn't a method?"); 4624 ExprOwningPtr<CXXMemberCallExpr> 4625 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4626 NumArgs, 4627 Method->getResultType().getNonReferenceType(), 4628 RParenLoc)); 4629 4630 // Convert the object argument (for a non-static member function call). 4631 if (!Method->isStatic() && 4632 PerformObjectArgumentInitialization(ObjectArg, Method)) 4633 return true; 4634 MemExpr->setBase(ObjectArg); 4635 4636 // Convert the rest of the arguments 4637 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4638 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4639 RParenLoc)) 4640 return true; 4641 4642 if (CheckFunctionCall(Method, TheCall.get())) 4643 return true; 4644 4645 return MaybeBindToTemporary(TheCall.release()).release(); 4646} 4647 4648/// BuildCallToObjectOfClassType - Build a call to an object of class 4649/// type (C++ [over.call.object]), which can end up invoking an 4650/// overloaded function call operator (@c operator()) or performing a 4651/// user-defined conversion on the object argument. 4652Sema::ExprResult 4653Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4654 SourceLocation LParenLoc, 4655 Expr **Args, unsigned NumArgs, 4656 SourceLocation *CommaLocs, 4657 SourceLocation RParenLoc) { 4658 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4659 const RecordType *Record = Object->getType()->getAs<RecordType>(); 4660 4661 // C++ [over.call.object]p1: 4662 // If the primary-expression E in the function call syntax 4663 // evaluates to a class object of type "cv T", then the set of 4664 // candidate functions includes at least the function call 4665 // operators of T. The function call operators of T are obtained by 4666 // ordinary lookup of the name operator() in the context of 4667 // (E).operator(). 4668 OverloadCandidateSet CandidateSet; 4669 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4670 DeclContext::lookup_const_iterator Oper, OperEnd; 4671 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4672 Oper != OperEnd; ++Oper) 4673 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4674 CandidateSet, /*SuppressUserConversions=*/false); 4675 4676 // C++ [over.call.object]p2: 4677 // In addition, for each conversion function declared in T of the 4678 // form 4679 // 4680 // operator conversion-type-id () cv-qualifier; 4681 // 4682 // where cv-qualifier is the same cv-qualification as, or a 4683 // greater cv-qualification than, cv, and where conversion-type-id 4684 // denotes the type "pointer to function of (P1,...,Pn) returning 4685 // R", or the type "reference to pointer to function of 4686 // (P1,...,Pn) returning R", or the type "reference to function 4687 // of (P1,...,Pn) returning R", a surrogate call function [...] 4688 // is also considered as a candidate function. Similarly, 4689 // surrogate call functions are added to the set of candidate 4690 // functions for each conversion function declared in an 4691 // accessible base class provided the function is not hidden 4692 // within T by another intervening declaration. 4693 4694 if (!RequireCompleteType(SourceLocation(), Object->getType(), 0)) { 4695 // FIXME: Look in base classes for more conversion operators! 4696 OverloadedFunctionDecl *Conversions 4697 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4698 for (OverloadedFunctionDecl::function_iterator 4699 Func = Conversions->function_begin(), 4700 FuncEnd = Conversions->function_end(); 4701 Func != FuncEnd; ++Func) { 4702 CXXConversionDecl *Conv; 4703 FunctionTemplateDecl *ConvTemplate; 4704 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 4705 4706 // Skip over templated conversion functions; they aren't 4707 // surrogates. 4708 if (ConvTemplate) 4709 continue; 4710 4711 // Strip the reference type (if any) and then the pointer type (if 4712 // any) to get down to what might be a function type. 4713 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4714 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4715 ConvType = ConvPtrType->getPointeeType(); 4716 4717 if (const FunctionProtoType *Proto = ConvType->getAsFunctionProtoType()) 4718 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4719 } 4720 } 4721 4722 // Perform overload resolution. 4723 OverloadCandidateSet::iterator Best; 4724 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4725 case OR_Success: 4726 // Overload resolution succeeded; we'll build the appropriate call 4727 // below. 4728 break; 4729 4730 case OR_No_Viable_Function: 4731 Diag(Object->getSourceRange().getBegin(), 4732 diag::err_ovl_no_viable_object_call) 4733 << Object->getType() << Object->getSourceRange(); 4734 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4735 break; 4736 4737 case OR_Ambiguous: 4738 Diag(Object->getSourceRange().getBegin(), 4739 diag::err_ovl_ambiguous_object_call) 4740 << Object->getType() << Object->getSourceRange(); 4741 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4742 break; 4743 4744 case OR_Deleted: 4745 Diag(Object->getSourceRange().getBegin(), 4746 diag::err_ovl_deleted_object_call) 4747 << Best->Function->isDeleted() 4748 << Object->getType() << Object->getSourceRange(); 4749 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4750 break; 4751 } 4752 4753 if (Best == CandidateSet.end()) { 4754 // We had an error; delete all of the subexpressions and return 4755 // the error. 4756 Object->Destroy(Context); 4757 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4758 Args[ArgIdx]->Destroy(Context); 4759 return true; 4760 } 4761 4762 if (Best->Function == 0) { 4763 // Since there is no function declaration, this is one of the 4764 // surrogate candidates. Dig out the conversion function. 4765 CXXConversionDecl *Conv 4766 = cast<CXXConversionDecl>( 4767 Best->Conversions[0].UserDefined.ConversionFunction); 4768 4769 // We selected one of the surrogate functions that converts the 4770 // object parameter to a function pointer. Perform the conversion 4771 // on the object argument, then let ActOnCallExpr finish the job. 4772 // FIXME: Represent the user-defined conversion in the AST! 4773 ImpCastExprToType(Object, 4774 Conv->getConversionType().getNonReferenceType(), 4775 CastExpr::CK_Unknown, 4776 Conv->getConversionType()->isLValueReferenceType()); 4777 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4778 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4779 CommaLocs, RParenLoc).release(); 4780 } 4781 4782 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4783 // that calls this method, using Object for the implicit object 4784 // parameter and passing along the remaining arguments. 4785 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4786 const FunctionProtoType *Proto = Method->getType()->getAsFunctionProtoType(); 4787 4788 unsigned NumArgsInProto = Proto->getNumArgs(); 4789 unsigned NumArgsToCheck = NumArgs; 4790 4791 // Build the full argument list for the method call (the 4792 // implicit object parameter is placed at the beginning of the 4793 // list). 4794 Expr **MethodArgs; 4795 if (NumArgs < NumArgsInProto) { 4796 NumArgsToCheck = NumArgsInProto; 4797 MethodArgs = new Expr*[NumArgsInProto + 1]; 4798 } else { 4799 MethodArgs = new Expr*[NumArgs + 1]; 4800 } 4801 MethodArgs[0] = Object; 4802 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4803 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4804 4805 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4806 SourceLocation()); 4807 UsualUnaryConversions(NewFn); 4808 4809 // Once we've built TheCall, all of the expressions are properly 4810 // owned. 4811 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4812 ExprOwningPtr<CXXOperatorCallExpr> 4813 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4814 MethodArgs, NumArgs + 1, 4815 ResultTy, RParenLoc)); 4816 delete [] MethodArgs; 4817 4818 // We may have default arguments. If so, we need to allocate more 4819 // slots in the call for them. 4820 if (NumArgs < NumArgsInProto) 4821 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4822 else if (NumArgs > NumArgsInProto) 4823 NumArgsToCheck = NumArgsInProto; 4824 4825 bool IsError = false; 4826 4827 // Initialize the implicit object parameter. 4828 IsError |= PerformObjectArgumentInitialization(Object, Method); 4829 TheCall->setArg(0, Object); 4830 4831 4832 // Check the argument types. 4833 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4834 Expr *Arg; 4835 if (i < NumArgs) { 4836 Arg = Args[i]; 4837 4838 // Pass the argument. 4839 QualType ProtoArgType = Proto->getArgType(i); 4840 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4841 } else { 4842 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 4843 } 4844 4845 TheCall->setArg(i + 1, Arg); 4846 } 4847 4848 // If this is a variadic call, handle args passed through "...". 4849 if (Proto->isVariadic()) { 4850 // Promote the arguments (C99 6.5.2.2p7). 4851 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4852 Expr *Arg = Args[i]; 4853 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4854 TheCall->setArg(i + 1, Arg); 4855 } 4856 } 4857 4858 if (IsError) return true; 4859 4860 if (CheckFunctionCall(Method, TheCall.get())) 4861 return true; 4862 4863 return MaybeBindToTemporary(TheCall.release()).release(); 4864} 4865 4866/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4867/// (if one exists), where @c Base is an expression of class type and 4868/// @c Member is the name of the member we're trying to find. 4869Sema::OwningExprResult 4870Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 4871 Expr *Base = static_cast<Expr *>(BaseIn.get()); 4872 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4873 4874 // C++ [over.ref]p1: 4875 // 4876 // [...] An expression x->m is interpreted as (x.operator->())->m 4877 // for a class object x of type T if T::operator->() exists and if 4878 // the operator is selected as the best match function by the 4879 // overload resolution mechanism (13.3). 4880 // FIXME: look in base classes. 4881 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4882 OverloadCandidateSet CandidateSet; 4883 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 4884 4885 LookupResult R = LookupQualifiedName(BaseRecord->getDecl(), OpName, 4886 LookupOrdinaryName); 4887 4888 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 4889 Oper != OperEnd; ++Oper) 4890 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4891 /*SuppressUserConversions=*/false); 4892 4893 // Perform overload resolution. 4894 OverloadCandidateSet::iterator Best; 4895 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4896 case OR_Success: 4897 // Overload resolution succeeded; we'll build the call below. 4898 break; 4899 4900 case OR_No_Viable_Function: 4901 if (CandidateSet.empty()) 4902 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4903 << Base->getType() << Base->getSourceRange(); 4904 else 4905 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4906 << "operator->" << Base->getSourceRange(); 4907 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4908 return ExprError(); 4909 4910 case OR_Ambiguous: 4911 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4912 << "->" << Base->getSourceRange(); 4913 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4914 return ExprError(); 4915 4916 case OR_Deleted: 4917 Diag(OpLoc, diag::err_ovl_deleted_oper) 4918 << Best->Function->isDeleted() 4919 << "->" << Base->getSourceRange(); 4920 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4921 return ExprError(); 4922 } 4923 4924 // Convert the object parameter. 4925 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4926 if (PerformObjectArgumentInitialization(Base, Method)) 4927 return ExprError(); 4928 4929 // No concerns about early exits now. 4930 BaseIn.release(); 4931 4932 // Build the operator call. 4933 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 4934 SourceLocation()); 4935 UsualUnaryConversions(FnExpr); 4936 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 4937 Method->getResultType().getNonReferenceType(), 4938 OpLoc); 4939 return Owned(Base); 4940} 4941 4942/// FixOverloadedFunctionReference - E is an expression that refers to 4943/// a C++ overloaded function (possibly with some parentheses and 4944/// perhaps a '&' around it). We have resolved the overloaded function 4945/// to the function declaration Fn, so patch up the expression E to 4946/// refer (possibly indirectly) to Fn. 4947void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 4948 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4949 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 4950 E->setType(PE->getSubExpr()->getType()); 4951 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 4952 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 4953 "Can only take the address of an overloaded function"); 4954 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4955 if (Method->isStatic()) { 4956 // Do nothing: static member functions aren't any different 4957 // from non-member functions. 4958 } else if (QualifiedDeclRefExpr *DRE 4959 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 4960 // We have taken the address of a pointer to member 4961 // function. Perform the computation here so that we get the 4962 // appropriate pointer to member type. 4963 DRE->setDecl(Fn); 4964 DRE->setType(Fn->getType()); 4965 QualType ClassType 4966 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 4967 E->setType(Context.getMemberPointerType(Fn->getType(), 4968 ClassType.getTypePtr())); 4969 return; 4970 } 4971 } 4972 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 4973 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 4974 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 4975 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 4976 isa<FunctionTemplateDecl>(DR->getDecl())) && 4977 "Expected overloaded function or function template"); 4978 DR->setDecl(Fn); 4979 E->setType(Fn->getType()); 4980 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 4981 MemExpr->setMemberDecl(Fn); 4982 E->setType(Fn->getType()); 4983 } else { 4984 assert(false && "Invalid reference to overloaded function"); 4985 } 4986} 4987 4988} // end namespace clang 4989