SemaOverload.cpp revision 7d384dd5ace9ae9a22a69e700d2cacb256bc6c69
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 "Lookup.h" 16#include "clang/Basic/Diagnostic.h" 17#include "clang/Lex/Preprocessor.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/CXXInheritance.h" 20#include "clang/AST/Expr.h" 21#include "clang/AST/ExprCXX.h" 22#include "clang/AST/TypeOrdering.h" 23#include "clang/Basic/PartialDiagnostic.h" 24#include "llvm/ADT/SmallPtrSet.h" 25#include "llvm/ADT/STLExtras.h" 26#include "llvm/Support/Compiler.h" 27#include <algorithm> 28#include <cstdio> 29 30namespace clang { 31 32/// GetConversionCategory - Retrieve the implicit conversion 33/// category corresponding to the given implicit conversion kind. 34ImplicitConversionCategory 35GetConversionCategory(ImplicitConversionKind Kind) { 36 static const ImplicitConversionCategory 37 Category[(int)ICK_Num_Conversion_Kinds] = { 38 ICC_Identity, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Lvalue_Transformation, 42 ICC_Qualification_Adjustment, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Promotion, 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 ICC_Conversion 56 }; 57 return Category[(int)Kind]; 58} 59 60/// GetConversionRank - Retrieve the implicit conversion rank 61/// corresponding to the given implicit conversion kind. 62ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 63 static const ImplicitConversionRank 64 Rank[(int)ICK_Num_Conversion_Kinds] = { 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Exact_Match, 70 ICR_Promotion, 71 ICR_Promotion, 72 ICR_Promotion, 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 ICR_Conversion 83 }; 84 return Rank[(int)Kind]; 85} 86 87/// GetImplicitConversionName - Return the name of this kind of 88/// implicit conversion. 89const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 90 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 91 "No conversion", 92 "Lvalue-to-rvalue", 93 "Array-to-pointer", 94 "Function-to-pointer", 95 "Qualification", 96 "Integral promotion", 97 "Floating point promotion", 98 "Complex promotion", 99 "Integral conversion", 100 "Floating conversion", 101 "Complex conversion", 102 "Floating-integral conversion", 103 "Complex-real conversion", 104 "Pointer conversion", 105 "Pointer-to-member conversion", 106 "Boolean conversion", 107 "Compatible-types conversion", 108 "Derived-to-base conversion" 109 }; 110 return Name[Kind]; 111} 112 113/// StandardConversionSequence - Set the standard conversion 114/// sequence to the identity conversion. 115void StandardConversionSequence::setAsIdentityConversion() { 116 First = ICK_Identity; 117 Second = ICK_Identity; 118 Third = ICK_Identity; 119 Deprecated = false; 120 ReferenceBinding = false; 121 DirectBinding = false; 122 RRefBinding = false; 123 CopyConstructor = 0; 124} 125 126/// getRank - Retrieve the rank of this standard conversion sequence 127/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 128/// implicit conversions. 129ImplicitConversionRank StandardConversionSequence::getRank() const { 130 ImplicitConversionRank Rank = ICR_Exact_Match; 131 if (GetConversionRank(First) > Rank) 132 Rank = GetConversionRank(First); 133 if (GetConversionRank(Second) > Rank) 134 Rank = GetConversionRank(Second); 135 if (GetConversionRank(Third) > Rank) 136 Rank = GetConversionRank(Third); 137 return Rank; 138} 139 140/// isPointerConversionToBool - Determines whether this conversion is 141/// a conversion of a pointer or pointer-to-member to bool. This is 142/// used as part of the ranking of standard conversion sequences 143/// (C++ 13.3.3.2p4). 144bool StandardConversionSequence::isPointerConversionToBool() const { 145 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 146 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 147 148 // Note that FromType has not necessarily been transformed by the 149 // array-to-pointer or function-to-pointer implicit conversions, so 150 // check for their presence as well as checking whether FromType is 151 // a pointer. 152 if (ToType->isBooleanType() && 153 (FromType->isPointerType() || FromType->isBlockPointerType() || 154 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 155 return true; 156 157 return false; 158} 159 160/// isPointerConversionToVoidPointer - Determines whether this 161/// conversion is a conversion of a pointer to a void pointer. This is 162/// used as part of the ranking of standard conversion sequences (C++ 163/// 13.3.3.2p4). 164bool 165StandardConversionSequence:: 166isPointerConversionToVoidPointer(ASTContext& Context) const { 167 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 168 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 169 170 // Note that FromType has not necessarily been transformed by the 171 // array-to-pointer implicit conversion, so check for its presence 172 // and redo the conversion to get a pointer. 173 if (First == ICK_Array_To_Pointer) 174 FromType = Context.getArrayDecayedType(FromType); 175 176 if (Second == ICK_Pointer_Conversion) 177 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 178 return ToPtrType->getPointeeType()->isVoidType(); 179 180 return false; 181} 182 183/// DebugPrint - Print this standard conversion sequence to standard 184/// error. Useful for debugging overloading issues. 185void StandardConversionSequence::DebugPrint() const { 186 bool PrintedSomething = false; 187 if (First != ICK_Identity) { 188 fprintf(stderr, "%s", GetImplicitConversionName(First)); 189 PrintedSomething = true; 190 } 191 192 if (Second != ICK_Identity) { 193 if (PrintedSomething) { 194 fprintf(stderr, " -> "); 195 } 196 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 197 198 if (CopyConstructor) { 199 fprintf(stderr, " (by copy constructor)"); 200 } else if (DirectBinding) { 201 fprintf(stderr, " (direct reference binding)"); 202 } else if (ReferenceBinding) { 203 fprintf(stderr, " (reference binding)"); 204 } 205 PrintedSomething = true; 206 } 207 208 if (Third != ICK_Identity) { 209 if (PrintedSomething) { 210 fprintf(stderr, " -> "); 211 } 212 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 213 PrintedSomething = true; 214 } 215 216 if (!PrintedSomething) { 217 fprintf(stderr, "No conversions required"); 218 } 219} 220 221/// DebugPrint - Print this user-defined conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void UserDefinedConversionSequence::DebugPrint() const { 224 if (Before.First || Before.Second || Before.Third) { 225 Before.DebugPrint(); 226 fprintf(stderr, " -> "); 227 } 228 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 229 if (After.First || After.Second || After.Third) { 230 fprintf(stderr, " -> "); 231 After.DebugPrint(); 232 } 233} 234 235/// DebugPrint - Print this implicit conversion sequence to standard 236/// error. Useful for debugging overloading issues. 237void ImplicitConversionSequence::DebugPrint() const { 238 switch (ConversionKind) { 239 case StandardConversion: 240 fprintf(stderr, "Standard conversion: "); 241 Standard.DebugPrint(); 242 break; 243 case UserDefinedConversion: 244 fprintf(stderr, "User-defined conversion: "); 245 UserDefined.DebugPrint(); 246 break; 247 case EllipsisConversion: 248 fprintf(stderr, "Ellipsis conversion"); 249 break; 250 case BadConversion: 251 fprintf(stderr, "Bad conversion"); 252 break; 253 } 254 255 fprintf(stderr, "\n"); 256} 257 258// IsOverload - Determine whether the given New declaration is an 259// overload of the Old declaration. This routine returns false if New 260// and Old cannot be overloaded, e.g., if they are functions with the 261// same signature (C++ 1.3.10) or if the Old declaration isn't a 262// function (or overload set). When it does return false and Old is an 263// OverloadedFunctionDecl, MatchedDecl will be set to point to the 264// FunctionDecl that New cannot be overloaded with. 265// 266// Example: Given the following input: 267// 268// void f(int, float); // #1 269// void f(int, int); // #2 270// int f(int, int); // #3 271// 272// When we process #1, there is no previous declaration of "f", 273// so IsOverload will not be used. 274// 275// When we process #2, Old is a FunctionDecl for #1. By comparing the 276// parameter types, we see that #1 and #2 are overloaded (since they 277// have different signatures), so this routine returns false; 278// MatchedDecl is unchanged. 279// 280// When we process #3, Old is an OverloadedFunctionDecl containing #1 281// and #2. We compare the signatures of #3 to #1 (they're overloaded, 282// so we do nothing) and then #3 to #2. Since the signatures of #3 and 283// #2 are identical (return types of functions are not part of the 284// signature), IsOverload returns false and MatchedDecl will be set to 285// point to the FunctionDecl for #2. 286bool 287Sema::IsOverload(FunctionDecl *New, Decl* OldD, 288 OverloadedFunctionDecl::function_iterator& MatchedDecl) { 289 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 290 // Is this new function an overload of every function in the 291 // overload set? 292 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 293 FuncEnd = Ovl->function_end(); 294 for (; Func != FuncEnd; ++Func) { 295 if (!IsOverload(New, *Func, MatchedDecl)) { 296 MatchedDecl = Func; 297 return false; 298 } 299 } 300 301 // This function overloads every function in the overload set. 302 return true; 303 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 304 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 305 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 306 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 307 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 308 309 // C++ [temp.fct]p2: 310 // A function template can be overloaded with other function templates 311 // and with normal (non-template) functions. 312 if ((OldTemplate == 0) != (NewTemplate == 0)) 313 return true; 314 315 // Is the function New an overload of the function Old? 316 QualType OldQType = Context.getCanonicalType(Old->getType()); 317 QualType NewQType = Context.getCanonicalType(New->getType()); 318 319 // Compare the signatures (C++ 1.3.10) of the two functions to 320 // determine whether they are overloads. If we find any mismatch 321 // in the signature, they are overloads. 322 323 // If either of these functions is a K&R-style function (no 324 // prototype), then we consider them to have matching signatures. 325 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 326 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 327 return false; 328 329 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 330 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 331 332 // The signature of a function includes the types of its 333 // parameters (C++ 1.3.10), which includes the presence or absence 334 // of the ellipsis; see C++ DR 357). 335 if (OldQType != NewQType && 336 (OldType->getNumArgs() != NewType->getNumArgs() || 337 OldType->isVariadic() != NewType->isVariadic() || 338 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 339 NewType->arg_type_begin()))) 340 return true; 341 342 // C++ [temp.over.link]p4: 343 // The signature of a function template consists of its function 344 // signature, its return type and its template parameter list. The names 345 // of the template parameters are significant only for establishing the 346 // relationship between the template parameters and the rest of the 347 // signature. 348 // 349 // We check the return type and template parameter lists for function 350 // templates first; the remaining checks follow. 351 if (NewTemplate && 352 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 353 OldTemplate->getTemplateParameters(), 354 false, TPL_TemplateMatch) || 355 OldType->getResultType() != NewType->getResultType())) 356 return true; 357 358 // If the function is a class member, its signature includes the 359 // cv-qualifiers (if any) on the function itself. 360 // 361 // As part of this, also check whether one of the member functions 362 // is static, in which case they are not overloads (C++ 363 // 13.1p2). While not part of the definition of the signature, 364 // this check is important to determine whether these functions 365 // can be overloaded. 366 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 367 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 368 if (OldMethod && NewMethod && 369 !OldMethod->isStatic() && !NewMethod->isStatic() && 370 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 371 return true; 372 373 // The signatures match; this is not an overload. 374 return false; 375 } else { 376 // (C++ 13p1): 377 // Only function declarations can be overloaded; object and type 378 // declarations cannot be overloaded. 379 return false; 380 } 381} 382 383/// TryImplicitConversion - Attempt to perform an implicit conversion 384/// from the given expression (Expr) to the given type (ToType). This 385/// function returns an implicit conversion sequence that can be used 386/// to perform the initialization. Given 387/// 388/// void f(float f); 389/// void g(int i) { f(i); } 390/// 391/// this routine would produce an implicit conversion sequence to 392/// describe the initialization of f from i, which will be a standard 393/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 394/// 4.1) followed by a floating-integral conversion (C++ 4.9). 395// 396/// Note that this routine only determines how the conversion can be 397/// performed; it does not actually perform the conversion. As such, 398/// it will not produce any diagnostics if no conversion is available, 399/// but will instead return an implicit conversion sequence of kind 400/// "BadConversion". 401/// 402/// If @p SuppressUserConversions, then user-defined conversions are 403/// not permitted. 404/// If @p AllowExplicit, then explicit user-defined conversions are 405/// permitted. 406/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 407/// no matter its actual lvalueness. 408/// If @p UserCast, the implicit conversion is being done for a user-specified 409/// cast. 410ImplicitConversionSequence 411Sema::TryImplicitConversion(Expr* From, QualType ToType, 412 bool SuppressUserConversions, 413 bool AllowExplicit, bool ForceRValue, 414 bool InOverloadResolution, 415 bool UserCast) { 416 ImplicitConversionSequence ICS; 417 OverloadCandidateSet Conversions; 418 OverloadingResult UserDefResult = OR_Success; 419 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 420 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 421 else if (getLangOptions().CPlusPlus && 422 (UserDefResult = IsUserDefinedConversion(From, ToType, 423 ICS.UserDefined, 424 Conversions, 425 !SuppressUserConversions, AllowExplicit, 426 ForceRValue, UserCast)) == OR_Success) { 427 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 428 // C++ [over.ics.user]p4: 429 // A conversion of an expression of class type to the same class 430 // type is given Exact Match rank, and a conversion of an 431 // expression of class type to a base class of that type is 432 // given Conversion rank, in spite of the fact that a copy 433 // constructor (i.e., a user-defined conversion function) is 434 // called for those cases. 435 if (CXXConstructorDecl *Constructor 436 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 437 QualType FromCanon 438 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 439 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 440 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 441 // Turn this into a "standard" conversion sequence, so that it 442 // gets ranked with standard conversion sequences. 443 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 444 ICS.Standard.setAsIdentityConversion(); 445 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 446 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 447 ICS.Standard.CopyConstructor = Constructor; 448 if (ToCanon != FromCanon) 449 ICS.Standard.Second = ICK_Derived_To_Base; 450 } 451 } 452 453 // C++ [over.best.ics]p4: 454 // However, when considering the argument of a user-defined 455 // conversion function that is a candidate by 13.3.1.3 when 456 // invoked for the copying of the temporary in the second step 457 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 458 // 13.3.1.6 in all cases, only standard conversion sequences and 459 // ellipsis conversion sequences are allowed. 460 if (SuppressUserConversions && 461 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 462 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 463 } else { 464 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 465 if (UserDefResult == OR_Ambiguous) { 466 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 467 Cand != Conversions.end(); ++Cand) 468 if (Cand->Viable) 469 ICS.ConversionFunctionSet.push_back(Cand->Function); 470 } 471 } 472 473 return ICS; 474} 475 476/// IsStandardConversion - Determines whether there is a standard 477/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 478/// expression From to the type ToType. Standard conversion sequences 479/// only consider non-class types; for conversions that involve class 480/// types, use TryImplicitConversion. If a conversion exists, SCS will 481/// contain the standard conversion sequence required to perform this 482/// conversion and this routine will return true. Otherwise, this 483/// routine will return false and the value of SCS is unspecified. 484bool 485Sema::IsStandardConversion(Expr* From, QualType ToType, 486 bool InOverloadResolution, 487 StandardConversionSequence &SCS) { 488 QualType FromType = From->getType(); 489 490 // Standard conversions (C++ [conv]) 491 SCS.setAsIdentityConversion(); 492 SCS.Deprecated = false; 493 SCS.IncompatibleObjC = false; 494 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 495 SCS.CopyConstructor = 0; 496 497 // There are no standard conversions for class types in C++, so 498 // abort early. When overloading in C, however, we do permit 499 if (FromType->isRecordType() || ToType->isRecordType()) { 500 if (getLangOptions().CPlusPlus) 501 return false; 502 503 // When we're overloading in C, we allow, as standard conversions, 504 } 505 506 // The first conversion can be an lvalue-to-rvalue conversion, 507 // array-to-pointer conversion, or function-to-pointer conversion 508 // (C++ 4p1). 509 510 // Lvalue-to-rvalue conversion (C++ 4.1): 511 // An lvalue (3.10) of a non-function, non-array type T can be 512 // converted to an rvalue. 513 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 514 if (argIsLvalue == Expr::LV_Valid && 515 !FromType->isFunctionType() && !FromType->isArrayType() && 516 Context.getCanonicalType(FromType) != Context.OverloadTy) { 517 SCS.First = ICK_Lvalue_To_Rvalue; 518 519 // If T is a non-class type, the type of the rvalue is the 520 // cv-unqualified version of T. Otherwise, the type of the rvalue 521 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 522 // just strip the qualifiers because they don't matter. 523 FromType = FromType.getUnqualifiedType(); 524 } else if (FromType->isArrayType()) { 525 // Array-to-pointer conversion (C++ 4.2) 526 SCS.First = ICK_Array_To_Pointer; 527 528 // An lvalue or rvalue of type "array of N T" or "array of unknown 529 // bound of T" can be converted to an rvalue of type "pointer to 530 // T" (C++ 4.2p1). 531 FromType = Context.getArrayDecayedType(FromType); 532 533 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 534 // This conversion is deprecated. (C++ D.4). 535 SCS.Deprecated = true; 536 537 // For the purpose of ranking in overload resolution 538 // (13.3.3.1.1), this conversion is considered an 539 // array-to-pointer conversion followed by a qualification 540 // conversion (4.4). (C++ 4.2p2) 541 SCS.Second = ICK_Identity; 542 SCS.Third = ICK_Qualification; 543 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 544 return true; 545 } 546 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 547 // Function-to-pointer conversion (C++ 4.3). 548 SCS.First = ICK_Function_To_Pointer; 549 550 // An lvalue of function type T can be converted to an rvalue of 551 // type "pointer to T." The result is a pointer to the 552 // function. (C++ 4.3p1). 553 FromType = Context.getPointerType(FromType); 554 } else if (FunctionDecl *Fn 555 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 556 // Address of overloaded function (C++ [over.over]). 557 SCS.First = ICK_Function_To_Pointer; 558 559 // We were able to resolve the address of the overloaded function, 560 // so we can convert to the type of that function. 561 FromType = Fn->getType(); 562 if (ToType->isLValueReferenceType()) 563 FromType = Context.getLValueReferenceType(FromType); 564 else if (ToType->isRValueReferenceType()) 565 FromType = Context.getRValueReferenceType(FromType); 566 else if (ToType->isMemberPointerType()) { 567 // Resolve address only succeeds if both sides are member pointers, 568 // but it doesn't have to be the same class. See DR 247. 569 // Note that this means that the type of &Derived::fn can be 570 // Ret (Base::*)(Args) if the fn overload actually found is from the 571 // base class, even if it was brought into the derived class via a 572 // using declaration. The standard isn't clear on this issue at all. 573 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 574 FromType = Context.getMemberPointerType(FromType, 575 Context.getTypeDeclType(M->getParent()).getTypePtr()); 576 } else 577 FromType = Context.getPointerType(FromType); 578 } else { 579 // We don't require any conversions for the first step. 580 SCS.First = ICK_Identity; 581 } 582 583 // The second conversion can be an integral promotion, floating 584 // point promotion, integral conversion, floating point conversion, 585 // floating-integral conversion, pointer conversion, 586 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 587 // For overloading in C, this can also be a "compatible-type" 588 // conversion. 589 bool IncompatibleObjC = false; 590 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 591 // The unqualified versions of the types are the same: there's no 592 // conversion to do. 593 SCS.Second = ICK_Identity; 594 } else if (IsIntegralPromotion(From, FromType, ToType)) { 595 // Integral promotion (C++ 4.5). 596 SCS.Second = ICK_Integral_Promotion; 597 FromType = ToType.getUnqualifiedType(); 598 } else if (IsFloatingPointPromotion(FromType, ToType)) { 599 // Floating point promotion (C++ 4.6). 600 SCS.Second = ICK_Floating_Promotion; 601 FromType = ToType.getUnqualifiedType(); 602 } else if (IsComplexPromotion(FromType, ToType)) { 603 // Complex promotion (Clang extension) 604 SCS.Second = ICK_Complex_Promotion; 605 FromType = ToType.getUnqualifiedType(); 606 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 607 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 608 // Integral conversions (C++ 4.7). 609 // FIXME: isIntegralType shouldn't be true for enums in C++. 610 SCS.Second = ICK_Integral_Conversion; 611 FromType = ToType.getUnqualifiedType(); 612 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 613 // Floating point conversions (C++ 4.8). 614 SCS.Second = ICK_Floating_Conversion; 615 FromType = ToType.getUnqualifiedType(); 616 } else if (FromType->isComplexType() && ToType->isComplexType()) { 617 // Complex conversions (C99 6.3.1.6) 618 SCS.Second = ICK_Complex_Conversion; 619 FromType = ToType.getUnqualifiedType(); 620 } else if ((FromType->isFloatingType() && 621 ToType->isIntegralType() && (!ToType->isBooleanType() && 622 !ToType->isEnumeralType())) || 623 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 624 ToType->isFloatingType())) { 625 // Floating-integral conversions (C++ 4.9). 626 // FIXME: isIntegralType shouldn't be true for enums in C++. 627 SCS.Second = ICK_Floating_Integral; 628 FromType = ToType.getUnqualifiedType(); 629 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 630 (ToType->isComplexType() && FromType->isArithmeticType())) { 631 // Complex-real conversions (C99 6.3.1.7) 632 SCS.Second = ICK_Complex_Real; 633 FromType = ToType.getUnqualifiedType(); 634 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 635 FromType, IncompatibleObjC)) { 636 // Pointer conversions (C++ 4.10). 637 SCS.Second = ICK_Pointer_Conversion; 638 SCS.IncompatibleObjC = IncompatibleObjC; 639 } else if (IsMemberPointerConversion(From, FromType, ToType, 640 InOverloadResolution, FromType)) { 641 // Pointer to member conversions (4.11). 642 SCS.Second = ICK_Pointer_Member; 643 } else if (ToType->isBooleanType() && 644 (FromType->isArithmeticType() || 645 FromType->isEnumeralType() || 646 FromType->isPointerType() || 647 FromType->isBlockPointerType() || 648 FromType->isMemberPointerType() || 649 FromType->isNullPtrType())) { 650 // Boolean conversions (C++ 4.12). 651 SCS.Second = ICK_Boolean_Conversion; 652 FromType = Context.BoolTy; 653 } else if (!getLangOptions().CPlusPlus && 654 Context.typesAreCompatible(ToType, FromType)) { 655 // Compatible conversions (Clang extension for C function overloading) 656 SCS.Second = ICK_Compatible_Conversion; 657 } else { 658 // No second conversion required. 659 SCS.Second = ICK_Identity; 660 } 661 662 QualType CanonFrom; 663 QualType CanonTo; 664 // The third conversion can be a qualification conversion (C++ 4p1). 665 if (IsQualificationConversion(FromType, ToType)) { 666 SCS.Third = ICK_Qualification; 667 FromType = ToType; 668 CanonFrom = Context.getCanonicalType(FromType); 669 CanonTo = Context.getCanonicalType(ToType); 670 } else { 671 // No conversion required 672 SCS.Third = ICK_Identity; 673 674 // C++ [over.best.ics]p6: 675 // [...] Any difference in top-level cv-qualification is 676 // subsumed by the initialization itself and does not constitute 677 // a conversion. [...] 678 CanonFrom = Context.getCanonicalType(FromType); 679 CanonTo = Context.getCanonicalType(ToType); 680 if (CanonFrom.getLocalUnqualifiedType() 681 == CanonTo.getLocalUnqualifiedType() && 682 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 683 FromType = ToType; 684 CanonFrom = CanonTo; 685 } 686 } 687 688 // If we have not converted the argument type to the parameter type, 689 // this is a bad conversion sequence. 690 if (CanonFrom != CanonTo) 691 return false; 692 693 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 694 return true; 695} 696 697/// IsIntegralPromotion - Determines whether the conversion from the 698/// expression From (whose potentially-adjusted type is FromType) to 699/// ToType is an integral promotion (C++ 4.5). If so, returns true and 700/// sets PromotedType to the promoted type. 701bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 702 const BuiltinType *To = ToType->getAs<BuiltinType>(); 703 // All integers are built-in. 704 if (!To) { 705 return false; 706 } 707 708 // An rvalue of type char, signed char, unsigned char, short int, or 709 // unsigned short int can be converted to an rvalue of type int if 710 // int can represent all the values of the source type; otherwise, 711 // the source rvalue can be converted to an rvalue of type unsigned 712 // int (C++ 4.5p1). 713 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 714 if (// We can promote any signed, promotable integer type to an int 715 (FromType->isSignedIntegerType() || 716 // We can promote any unsigned integer type whose size is 717 // less than int to an int. 718 (!FromType->isSignedIntegerType() && 719 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 720 return To->getKind() == BuiltinType::Int; 721 } 722 723 return To->getKind() == BuiltinType::UInt; 724 } 725 726 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 727 // can be converted to an rvalue of the first of the following types 728 // that can represent all the values of its underlying type: int, 729 // unsigned int, long, or unsigned long (C++ 4.5p2). 730 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 731 && ToType->isIntegerType()) { 732 // Determine whether the type we're converting from is signed or 733 // unsigned. 734 bool FromIsSigned; 735 uint64_t FromSize = Context.getTypeSize(FromType); 736 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 737 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 738 FromIsSigned = UnderlyingType->isSignedIntegerType(); 739 } else { 740 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 741 FromIsSigned = true; 742 } 743 744 // The types we'll try to promote to, in the appropriate 745 // order. Try each of these types. 746 QualType PromoteTypes[6] = { 747 Context.IntTy, Context.UnsignedIntTy, 748 Context.LongTy, Context.UnsignedLongTy , 749 Context.LongLongTy, Context.UnsignedLongLongTy 750 }; 751 for (int Idx = 0; Idx < 6; ++Idx) { 752 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 753 if (FromSize < ToSize || 754 (FromSize == ToSize && 755 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 756 // We found the type that we can promote to. If this is the 757 // type we wanted, we have a promotion. Otherwise, no 758 // promotion. 759 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 760 } 761 } 762 } 763 764 // An rvalue for an integral bit-field (9.6) can be converted to an 765 // rvalue of type int if int can represent all the values of the 766 // bit-field; otherwise, it can be converted to unsigned int if 767 // unsigned int can represent all the values of the bit-field. If 768 // the bit-field is larger yet, no integral promotion applies to 769 // it. If the bit-field has an enumerated type, it is treated as any 770 // other value of that type for promotion purposes (C++ 4.5p3). 771 // FIXME: We should delay checking of bit-fields until we actually perform the 772 // conversion. 773 using llvm::APSInt; 774 if (From) 775 if (FieldDecl *MemberDecl = From->getBitField()) { 776 APSInt BitWidth; 777 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 778 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 779 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 780 ToSize = Context.getTypeSize(ToType); 781 782 // Are we promoting to an int from a bitfield that fits in an int? 783 if (BitWidth < ToSize || 784 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 785 return To->getKind() == BuiltinType::Int; 786 } 787 788 // Are we promoting to an unsigned int from an unsigned bitfield 789 // that fits into an unsigned int? 790 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 791 return To->getKind() == BuiltinType::UInt; 792 } 793 794 return false; 795 } 796 } 797 798 // An rvalue of type bool can be converted to an rvalue of type int, 799 // with false becoming zero and true becoming one (C++ 4.5p4). 800 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 801 return true; 802 } 803 804 return false; 805} 806 807/// IsFloatingPointPromotion - Determines whether the conversion from 808/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 809/// returns true and sets PromotedType to the promoted type. 810bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 811 /// An rvalue of type float can be converted to an rvalue of type 812 /// double. (C++ 4.6p1). 813 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 814 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 815 if (FromBuiltin->getKind() == BuiltinType::Float && 816 ToBuiltin->getKind() == BuiltinType::Double) 817 return true; 818 819 // C99 6.3.1.5p1: 820 // When a float is promoted to double or long double, or a 821 // double is promoted to long double [...]. 822 if (!getLangOptions().CPlusPlus && 823 (FromBuiltin->getKind() == BuiltinType::Float || 824 FromBuiltin->getKind() == BuiltinType::Double) && 825 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 826 return true; 827 } 828 829 return false; 830} 831 832/// \brief Determine if a conversion is a complex promotion. 833/// 834/// A complex promotion is defined as a complex -> complex conversion 835/// where the conversion between the underlying real types is a 836/// floating-point or integral promotion. 837bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 838 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 839 if (!FromComplex) 840 return false; 841 842 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 843 if (!ToComplex) 844 return false; 845 846 return IsFloatingPointPromotion(FromComplex->getElementType(), 847 ToComplex->getElementType()) || 848 IsIntegralPromotion(0, FromComplex->getElementType(), 849 ToComplex->getElementType()); 850} 851 852/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 853/// the pointer type FromPtr to a pointer to type ToPointee, with the 854/// same type qualifiers as FromPtr has on its pointee type. ToType, 855/// if non-empty, will be a pointer to ToType that may or may not have 856/// the right set of qualifiers on its pointee. 857static QualType 858BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 859 QualType ToPointee, QualType ToType, 860 ASTContext &Context) { 861 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 862 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 863 Qualifiers Quals = CanonFromPointee.getQualifiers(); 864 865 // Exact qualifier match -> return the pointer type we're converting to. 866 if (CanonToPointee.getLocalQualifiers() == Quals) { 867 // ToType is exactly what we need. Return it. 868 if (!ToType.isNull()) 869 return ToType; 870 871 // Build a pointer to ToPointee. It has the right qualifiers 872 // already. 873 return Context.getPointerType(ToPointee); 874 } 875 876 // Just build a canonical type that has the right qualifiers. 877 return Context.getPointerType( 878 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 879 Quals)); 880} 881 882static bool isNullPointerConstantForConversion(Expr *Expr, 883 bool InOverloadResolution, 884 ASTContext &Context) { 885 // Handle value-dependent integral null pointer constants correctly. 886 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 887 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 888 Expr->getType()->isIntegralType()) 889 return !InOverloadResolution; 890 891 return Expr->isNullPointerConstant(Context, 892 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 893 : Expr::NPC_ValueDependentIsNull); 894} 895 896/// IsPointerConversion - Determines whether the conversion of the 897/// expression From, which has the (possibly adjusted) type FromType, 898/// can be converted to the type ToType via a pointer conversion (C++ 899/// 4.10). If so, returns true and places the converted type (that 900/// might differ from ToType in its cv-qualifiers at some level) into 901/// ConvertedType. 902/// 903/// This routine also supports conversions to and from block pointers 904/// and conversions with Objective-C's 'id', 'id<protocols...>', and 905/// pointers to interfaces. FIXME: Once we've determined the 906/// appropriate overloading rules for Objective-C, we may want to 907/// split the Objective-C checks into a different routine; however, 908/// GCC seems to consider all of these conversions to be pointer 909/// conversions, so for now they live here. IncompatibleObjC will be 910/// set if the conversion is an allowed Objective-C conversion that 911/// should result in a warning. 912bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 913 bool InOverloadResolution, 914 QualType& ConvertedType, 915 bool &IncompatibleObjC) { 916 IncompatibleObjC = false; 917 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 918 return true; 919 920 // Conversion from a null pointer constant to any Objective-C pointer type. 921 if (ToType->isObjCObjectPointerType() && 922 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 923 ConvertedType = ToType; 924 return true; 925 } 926 927 // Blocks: Block pointers can be converted to void*. 928 if (FromType->isBlockPointerType() && ToType->isPointerType() && 929 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 930 ConvertedType = ToType; 931 return true; 932 } 933 // Blocks: A null pointer constant can be converted to a block 934 // pointer type. 935 if (ToType->isBlockPointerType() && 936 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 937 ConvertedType = ToType; 938 return true; 939 } 940 941 // If the left-hand-side is nullptr_t, the right side can be a null 942 // pointer constant. 943 if (ToType->isNullPtrType() && 944 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 945 ConvertedType = ToType; 946 return true; 947 } 948 949 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 950 if (!ToTypePtr) 951 return false; 952 953 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 954 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 955 ConvertedType = ToType; 956 return true; 957 } 958 959 // Beyond this point, both types need to be pointers. 960 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 961 if (!FromTypePtr) 962 return false; 963 964 QualType FromPointeeType = FromTypePtr->getPointeeType(); 965 QualType ToPointeeType = ToTypePtr->getPointeeType(); 966 967 // An rvalue of type "pointer to cv T," where T is an object type, 968 // can be converted to an rvalue of type "pointer to cv void" (C++ 969 // 4.10p2). 970 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 971 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 972 ToPointeeType, 973 ToType, Context); 974 return true; 975 } 976 977 // When we're overloading in C, we allow a special kind of pointer 978 // conversion for compatible-but-not-identical pointee types. 979 if (!getLangOptions().CPlusPlus && 980 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 981 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 982 ToPointeeType, 983 ToType, Context); 984 return true; 985 } 986 987 // C++ [conv.ptr]p3: 988 // 989 // An rvalue of type "pointer to cv D," where D is a class type, 990 // can be converted to an rvalue of type "pointer to cv B," where 991 // B is a base class (clause 10) of D. If B is an inaccessible 992 // (clause 11) or ambiguous (10.2) base class of D, a program that 993 // necessitates this conversion is ill-formed. The result of the 994 // conversion is a pointer to the base class sub-object of the 995 // derived class object. The null pointer value is converted to 996 // the null pointer value of the destination type. 997 // 998 // Note that we do not check for ambiguity or inaccessibility 999 // here. That is handled by CheckPointerConversion. 1000 if (getLangOptions().CPlusPlus && 1001 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1002 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1003 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1004 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1005 ToPointeeType, 1006 ToType, Context); 1007 return true; 1008 } 1009 1010 return false; 1011} 1012 1013/// isObjCPointerConversion - Determines whether this is an 1014/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1015/// with the same arguments and return values. 1016bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1017 QualType& ConvertedType, 1018 bool &IncompatibleObjC) { 1019 if (!getLangOptions().ObjC1) 1020 return false; 1021 1022 // First, we handle all conversions on ObjC object pointer types. 1023 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1024 const ObjCObjectPointerType *FromObjCPtr = 1025 FromType->getAs<ObjCObjectPointerType>(); 1026 1027 if (ToObjCPtr && FromObjCPtr) { 1028 // Objective C++: We're able to convert between "id" or "Class" and a 1029 // pointer to any interface (in both directions). 1030 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1031 ConvertedType = ToType; 1032 return true; 1033 } 1034 // Conversions with Objective-C's id<...>. 1035 if ((FromObjCPtr->isObjCQualifiedIdType() || 1036 ToObjCPtr->isObjCQualifiedIdType()) && 1037 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1038 /*compare=*/false)) { 1039 ConvertedType = ToType; 1040 return true; 1041 } 1042 // Objective C++: We're able to convert from a pointer to an 1043 // interface to a pointer to a different interface. 1044 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1045 ConvertedType = ToType; 1046 return true; 1047 } 1048 1049 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1050 // Okay: this is some kind of implicit downcast of Objective-C 1051 // interfaces, which is permitted. However, we're going to 1052 // complain about it. 1053 IncompatibleObjC = true; 1054 ConvertedType = FromType; 1055 return true; 1056 } 1057 } 1058 // Beyond this point, both types need to be C pointers or block pointers. 1059 QualType ToPointeeType; 1060 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1061 ToPointeeType = ToCPtr->getPointeeType(); 1062 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1063 ToPointeeType = ToBlockPtr->getPointeeType(); 1064 else 1065 return false; 1066 1067 QualType FromPointeeType; 1068 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1069 FromPointeeType = FromCPtr->getPointeeType(); 1070 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1071 FromPointeeType = FromBlockPtr->getPointeeType(); 1072 else 1073 return false; 1074 1075 // If we have pointers to pointers, recursively check whether this 1076 // is an Objective-C conversion. 1077 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1078 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1079 IncompatibleObjC)) { 1080 // We always complain about this conversion. 1081 IncompatibleObjC = true; 1082 ConvertedType = ToType; 1083 return true; 1084 } 1085 // If we have pointers to functions or blocks, check whether the only 1086 // differences in the argument and result types are in Objective-C 1087 // pointer conversions. If so, we permit the conversion (but 1088 // complain about it). 1089 const FunctionProtoType *FromFunctionType 1090 = FromPointeeType->getAs<FunctionProtoType>(); 1091 const FunctionProtoType *ToFunctionType 1092 = ToPointeeType->getAs<FunctionProtoType>(); 1093 if (FromFunctionType && ToFunctionType) { 1094 // If the function types are exactly the same, this isn't an 1095 // Objective-C pointer conversion. 1096 if (Context.getCanonicalType(FromPointeeType) 1097 == Context.getCanonicalType(ToPointeeType)) 1098 return false; 1099 1100 // Perform the quick checks that will tell us whether these 1101 // function types are obviously different. 1102 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1103 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1104 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1105 return false; 1106 1107 bool HasObjCConversion = false; 1108 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1109 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1110 // Okay, the types match exactly. Nothing to do. 1111 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1112 ToFunctionType->getResultType(), 1113 ConvertedType, IncompatibleObjC)) { 1114 // Okay, we have an Objective-C pointer conversion. 1115 HasObjCConversion = true; 1116 } else { 1117 // Function types are too different. Abort. 1118 return false; 1119 } 1120 1121 // Check argument types. 1122 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1123 ArgIdx != NumArgs; ++ArgIdx) { 1124 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1125 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1126 if (Context.getCanonicalType(FromArgType) 1127 == Context.getCanonicalType(ToArgType)) { 1128 // Okay, the types match exactly. Nothing to do. 1129 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1130 ConvertedType, IncompatibleObjC)) { 1131 // Okay, we have an Objective-C pointer conversion. 1132 HasObjCConversion = true; 1133 } else { 1134 // Argument types are too different. Abort. 1135 return false; 1136 } 1137 } 1138 1139 if (HasObjCConversion) { 1140 // We had an Objective-C conversion. Allow this pointer 1141 // conversion, but complain about it. 1142 ConvertedType = ToType; 1143 IncompatibleObjC = true; 1144 return true; 1145 } 1146 } 1147 1148 return false; 1149} 1150 1151/// CheckPointerConversion - Check the pointer conversion from the 1152/// expression From to the type ToType. This routine checks for 1153/// ambiguous or inaccessible derived-to-base pointer 1154/// conversions for which IsPointerConversion has already returned 1155/// true. It returns true and produces a diagnostic if there was an 1156/// error, or returns false otherwise. 1157bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1158 CastExpr::CastKind &Kind, 1159 bool IgnoreBaseAccess) { 1160 QualType FromType = From->getType(); 1161 1162 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1163 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1164 QualType FromPointeeType = FromPtrType->getPointeeType(), 1165 ToPointeeType = ToPtrType->getPointeeType(); 1166 1167 if (FromPointeeType->isRecordType() && 1168 ToPointeeType->isRecordType()) { 1169 // We must have a derived-to-base conversion. Check an 1170 // ambiguous or inaccessible conversion. 1171 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1172 From->getExprLoc(), 1173 From->getSourceRange(), 1174 IgnoreBaseAccess)) 1175 return true; 1176 1177 // The conversion was successful. 1178 Kind = CastExpr::CK_DerivedToBase; 1179 } 1180 } 1181 if (const ObjCObjectPointerType *FromPtrType = 1182 FromType->getAs<ObjCObjectPointerType>()) 1183 if (const ObjCObjectPointerType *ToPtrType = 1184 ToType->getAs<ObjCObjectPointerType>()) { 1185 // Objective-C++ conversions are always okay. 1186 // FIXME: We should have a different class of conversions for the 1187 // Objective-C++ implicit conversions. 1188 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1189 return false; 1190 1191 } 1192 return false; 1193} 1194 1195/// IsMemberPointerConversion - Determines whether the conversion of the 1196/// expression From, which has the (possibly adjusted) type FromType, can be 1197/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1198/// If so, returns true and places the converted type (that might differ from 1199/// ToType in its cv-qualifiers at some level) into ConvertedType. 1200bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1201 QualType ToType, 1202 bool InOverloadResolution, 1203 QualType &ConvertedType) { 1204 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1205 if (!ToTypePtr) 1206 return false; 1207 1208 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1209 if (From->isNullPointerConstant(Context, 1210 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1211 : Expr::NPC_ValueDependentIsNull)) { 1212 ConvertedType = ToType; 1213 return true; 1214 } 1215 1216 // Otherwise, both types have to be member pointers. 1217 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1218 if (!FromTypePtr) 1219 return false; 1220 1221 // A pointer to member of B can be converted to a pointer to member of D, 1222 // where D is derived from B (C++ 4.11p2). 1223 QualType FromClass(FromTypePtr->getClass(), 0); 1224 QualType ToClass(ToTypePtr->getClass(), 0); 1225 // FIXME: What happens when these are dependent? Is this function even called? 1226 1227 if (IsDerivedFrom(ToClass, FromClass)) { 1228 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1229 ToClass.getTypePtr()); 1230 return true; 1231 } 1232 1233 return false; 1234} 1235 1236/// CheckMemberPointerConversion - Check the member pointer conversion from the 1237/// expression From to the type ToType. This routine checks for ambiguous or 1238/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1239/// for which IsMemberPointerConversion has already returned true. It returns 1240/// true and produces a diagnostic if there was an error, or returns false 1241/// otherwise. 1242bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1243 CastExpr::CastKind &Kind, 1244 bool IgnoreBaseAccess) { 1245 (void)IgnoreBaseAccess; 1246 QualType FromType = From->getType(); 1247 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1248 if (!FromPtrType) { 1249 // This must be a null pointer to member pointer conversion 1250 assert(From->isNullPointerConstant(Context, 1251 Expr::NPC_ValueDependentIsNull) && 1252 "Expr must be null pointer constant!"); 1253 Kind = CastExpr::CK_NullToMemberPointer; 1254 return false; 1255 } 1256 1257 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1258 assert(ToPtrType && "No member pointer cast has a target type " 1259 "that is not a member pointer."); 1260 1261 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1262 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1263 1264 // FIXME: What about dependent types? 1265 assert(FromClass->isRecordType() && "Pointer into non-class."); 1266 assert(ToClass->isRecordType() && "Pointer into non-class."); 1267 1268 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1269 /*DetectVirtual=*/true); 1270 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1271 assert(DerivationOkay && 1272 "Should not have been called if derivation isn't OK."); 1273 (void)DerivationOkay; 1274 1275 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1276 getUnqualifiedType())) { 1277 // Derivation is ambiguous. Redo the check to find the exact paths. 1278 Paths.clear(); 1279 Paths.setRecordingPaths(true); 1280 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1281 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1282 (void)StillOkay; 1283 1284 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1285 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1286 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1287 return true; 1288 } 1289 1290 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1291 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1292 << FromClass << ToClass << QualType(VBase, 0) 1293 << From->getSourceRange(); 1294 return true; 1295 } 1296 1297 // Must be a base to derived member conversion. 1298 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1299 return false; 1300} 1301 1302/// IsQualificationConversion - Determines whether the conversion from 1303/// an rvalue of type FromType to ToType is a qualification conversion 1304/// (C++ 4.4). 1305bool 1306Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1307 FromType = Context.getCanonicalType(FromType); 1308 ToType = Context.getCanonicalType(ToType); 1309 1310 // If FromType and ToType are the same type, this is not a 1311 // qualification conversion. 1312 if (FromType == ToType) 1313 return false; 1314 1315 // (C++ 4.4p4): 1316 // A conversion can add cv-qualifiers at levels other than the first 1317 // in multi-level pointers, subject to the following rules: [...] 1318 bool PreviousToQualsIncludeConst = true; 1319 bool UnwrappedAnyPointer = false; 1320 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1321 // Within each iteration of the loop, we check the qualifiers to 1322 // determine if this still looks like a qualification 1323 // conversion. Then, if all is well, we unwrap one more level of 1324 // pointers or pointers-to-members and do it all again 1325 // until there are no more pointers or pointers-to-members left to 1326 // unwrap. 1327 UnwrappedAnyPointer = true; 1328 1329 // -- for every j > 0, if const is in cv 1,j then const is in cv 1330 // 2,j, and similarly for volatile. 1331 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1332 return false; 1333 1334 // -- if the cv 1,j and cv 2,j are different, then const is in 1335 // every cv for 0 < k < j. 1336 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1337 && !PreviousToQualsIncludeConst) 1338 return false; 1339 1340 // Keep track of whether all prior cv-qualifiers in the "to" type 1341 // include const. 1342 PreviousToQualsIncludeConst 1343 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1344 } 1345 1346 // We are left with FromType and ToType being the pointee types 1347 // after unwrapping the original FromType and ToType the same number 1348 // of types. If we unwrapped any pointers, and if FromType and 1349 // ToType have the same unqualified type (since we checked 1350 // qualifiers above), then this is a qualification conversion. 1351 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1352} 1353 1354/// \brief Given a function template or function, extract the function template 1355/// declaration (if any) and the underlying function declaration. 1356template<typename T> 1357static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1358 FunctionTemplateDecl *&FunctionTemplate) { 1359 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1360 if (FunctionTemplate) 1361 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1362 else 1363 Function = cast<T>(Orig); 1364} 1365 1366/// Determines whether there is a user-defined conversion sequence 1367/// (C++ [over.ics.user]) that converts expression From to the type 1368/// ToType. If such a conversion exists, User will contain the 1369/// user-defined conversion sequence that performs such a conversion 1370/// and this routine will return true. Otherwise, this routine returns 1371/// false and User is unspecified. 1372/// 1373/// \param AllowConversionFunctions true if the conversion should 1374/// consider conversion functions at all. If false, only constructors 1375/// will be considered. 1376/// 1377/// \param AllowExplicit true if the conversion should consider C++0x 1378/// "explicit" conversion functions as well as non-explicit conversion 1379/// functions (C++0x [class.conv.fct]p2). 1380/// 1381/// \param ForceRValue true if the expression should be treated as an rvalue 1382/// for overload resolution. 1383/// \param UserCast true if looking for user defined conversion for a static 1384/// cast. 1385Sema::OverloadingResult Sema::IsUserDefinedConversion( 1386 Expr *From, QualType ToType, 1387 UserDefinedConversionSequence& User, 1388 OverloadCandidateSet& CandidateSet, 1389 bool AllowConversionFunctions, 1390 bool AllowExplicit, bool ForceRValue, 1391 bool UserCast) { 1392 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1393 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1394 // We're not going to find any constructors. 1395 } else if (CXXRecordDecl *ToRecordDecl 1396 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1397 // C++ [over.match.ctor]p1: 1398 // When objects of class type are direct-initialized (8.5), or 1399 // copy-initialized from an expression of the same or a 1400 // derived class type (8.5), overload resolution selects the 1401 // constructor. [...] For copy-initialization, the candidate 1402 // functions are all the converting constructors (12.3.1) of 1403 // that class. The argument list is the expression-list within 1404 // the parentheses of the initializer. 1405 bool SuppressUserConversions = !UserCast; 1406 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1407 IsDerivedFrom(From->getType(), ToType)) { 1408 SuppressUserConversions = false; 1409 AllowConversionFunctions = false; 1410 } 1411 1412 DeclarationName ConstructorName 1413 = Context.DeclarationNames.getCXXConstructorName( 1414 Context.getCanonicalType(ToType).getUnqualifiedType()); 1415 DeclContext::lookup_iterator Con, ConEnd; 1416 for (llvm::tie(Con, ConEnd) 1417 = ToRecordDecl->lookup(ConstructorName); 1418 Con != ConEnd; ++Con) { 1419 // Find the constructor (which may be a template). 1420 CXXConstructorDecl *Constructor = 0; 1421 FunctionTemplateDecl *ConstructorTmpl 1422 = dyn_cast<FunctionTemplateDecl>(*Con); 1423 if (ConstructorTmpl) 1424 Constructor 1425 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1426 else 1427 Constructor = cast<CXXConstructorDecl>(*Con); 1428 1429 if (!Constructor->isInvalidDecl() && 1430 Constructor->isConvertingConstructor(AllowExplicit)) { 1431 if (ConstructorTmpl) 1432 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1433 1, CandidateSet, 1434 SuppressUserConversions, ForceRValue); 1435 else 1436 // Allow one user-defined conversion when user specifies a 1437 // From->ToType conversion via an static cast (c-style, etc). 1438 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1439 SuppressUserConversions, ForceRValue); 1440 } 1441 } 1442 } 1443 } 1444 1445 if (!AllowConversionFunctions) { 1446 // Don't allow any conversion functions to enter the overload set. 1447 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1448 PDiag(0) 1449 << From->getSourceRange())) { 1450 // No conversion functions from incomplete types. 1451 } else if (const RecordType *FromRecordType 1452 = From->getType()->getAs<RecordType>()) { 1453 if (CXXRecordDecl *FromRecordDecl 1454 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1455 // Add all of the conversion functions as candidates. 1456 OverloadedFunctionDecl *Conversions 1457 = FromRecordDecl->getVisibleConversionFunctions(); 1458 for (OverloadedFunctionDecl::function_iterator Func 1459 = Conversions->function_begin(); 1460 Func != Conversions->function_end(); ++Func) { 1461 CXXConversionDecl *Conv; 1462 FunctionTemplateDecl *ConvTemplate; 1463 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1464 if (ConvTemplate) 1465 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1466 else 1467 Conv = dyn_cast<CXXConversionDecl>(*Func); 1468 1469 if (AllowExplicit || !Conv->isExplicit()) { 1470 if (ConvTemplate) 1471 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1472 CandidateSet); 1473 else 1474 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1475 } 1476 } 1477 } 1478 } 1479 1480 OverloadCandidateSet::iterator Best; 1481 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1482 case OR_Success: 1483 // Record the standard conversion we used and the conversion function. 1484 if (CXXConstructorDecl *Constructor 1485 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1486 // C++ [over.ics.user]p1: 1487 // If the user-defined conversion is specified by a 1488 // constructor (12.3.1), the initial standard conversion 1489 // sequence converts the source type to the type required by 1490 // the argument of the constructor. 1491 // 1492 QualType ThisType = Constructor->getThisType(Context); 1493 if (Best->Conversions[0].ConversionKind == 1494 ImplicitConversionSequence::EllipsisConversion) 1495 User.EllipsisConversion = true; 1496 else { 1497 User.Before = Best->Conversions[0].Standard; 1498 User.EllipsisConversion = false; 1499 } 1500 User.ConversionFunction = Constructor; 1501 User.After.setAsIdentityConversion(); 1502 User.After.FromTypePtr 1503 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1504 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1505 return OR_Success; 1506 } else if (CXXConversionDecl *Conversion 1507 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1508 // C++ [over.ics.user]p1: 1509 // 1510 // [...] If the user-defined conversion is specified by a 1511 // conversion function (12.3.2), the initial standard 1512 // conversion sequence converts the source type to the 1513 // implicit object parameter of the conversion function. 1514 User.Before = Best->Conversions[0].Standard; 1515 User.ConversionFunction = Conversion; 1516 User.EllipsisConversion = false; 1517 1518 // C++ [over.ics.user]p2: 1519 // The second standard conversion sequence converts the 1520 // result of the user-defined conversion to the target type 1521 // for the sequence. Since an implicit conversion sequence 1522 // is an initialization, the special rules for 1523 // initialization by user-defined conversion apply when 1524 // selecting the best user-defined conversion for a 1525 // user-defined conversion sequence (see 13.3.3 and 1526 // 13.3.3.1). 1527 User.After = Best->FinalConversion; 1528 return OR_Success; 1529 } else { 1530 assert(false && "Not a constructor or conversion function?"); 1531 return OR_No_Viable_Function; 1532 } 1533 1534 case OR_No_Viable_Function: 1535 return OR_No_Viable_Function; 1536 case OR_Deleted: 1537 // No conversion here! We're done. 1538 return OR_Deleted; 1539 1540 case OR_Ambiguous: 1541 return OR_Ambiguous; 1542 } 1543 1544 return OR_No_Viable_Function; 1545} 1546 1547bool 1548Sema::DiagnoseAmbiguousUserDefinedConversion(Expr *From, QualType ToType) { 1549 ImplicitConversionSequence ICS; 1550 OverloadCandidateSet CandidateSet; 1551 OverloadingResult OvResult = 1552 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1553 CandidateSet, true, false, false); 1554 if (OvResult != OR_Ambiguous) 1555 return false; 1556 Diag(From->getSourceRange().getBegin(), 1557 diag::err_typecheck_ambiguous_condition) 1558 << From->getType() << ToType << From->getSourceRange(); 1559 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1560 return true; 1561} 1562 1563/// CompareImplicitConversionSequences - Compare two implicit 1564/// conversion sequences to determine whether one is better than the 1565/// other or if they are indistinguishable (C++ 13.3.3.2). 1566ImplicitConversionSequence::CompareKind 1567Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1568 const ImplicitConversionSequence& ICS2) 1569{ 1570 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1571 // conversion sequences (as defined in 13.3.3.1) 1572 // -- a standard conversion sequence (13.3.3.1.1) is a better 1573 // conversion sequence than a user-defined conversion sequence or 1574 // an ellipsis conversion sequence, and 1575 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1576 // conversion sequence than an ellipsis conversion sequence 1577 // (13.3.3.1.3). 1578 // 1579 if (ICS1.ConversionKind < ICS2.ConversionKind) 1580 return ImplicitConversionSequence::Better; 1581 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1582 return ImplicitConversionSequence::Worse; 1583 1584 // Two implicit conversion sequences of the same form are 1585 // indistinguishable conversion sequences unless one of the 1586 // following rules apply: (C++ 13.3.3.2p3): 1587 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1588 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1589 else if (ICS1.ConversionKind == 1590 ImplicitConversionSequence::UserDefinedConversion) { 1591 // User-defined conversion sequence U1 is a better conversion 1592 // sequence than another user-defined conversion sequence U2 if 1593 // they contain the same user-defined conversion function or 1594 // constructor and if the second standard conversion sequence of 1595 // U1 is better than the second standard conversion sequence of 1596 // U2 (C++ 13.3.3.2p3). 1597 if (ICS1.UserDefined.ConversionFunction == 1598 ICS2.UserDefined.ConversionFunction) 1599 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1600 ICS2.UserDefined.After); 1601 } 1602 1603 return ImplicitConversionSequence::Indistinguishable; 1604} 1605 1606/// CompareStandardConversionSequences - Compare two standard 1607/// conversion sequences to determine whether one is better than the 1608/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1609ImplicitConversionSequence::CompareKind 1610Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1611 const StandardConversionSequence& SCS2) 1612{ 1613 // Standard conversion sequence S1 is a better conversion sequence 1614 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1615 1616 // -- S1 is a proper subsequence of S2 (comparing the conversion 1617 // sequences in the canonical form defined by 13.3.3.1.1, 1618 // excluding any Lvalue Transformation; the identity conversion 1619 // sequence is considered to be a subsequence of any 1620 // non-identity conversion sequence) or, if not that, 1621 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1622 // Neither is a proper subsequence of the other. Do nothing. 1623 ; 1624 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1625 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1626 (SCS1.Second == ICK_Identity && 1627 SCS1.Third == ICK_Identity)) 1628 // SCS1 is a proper subsequence of SCS2. 1629 return ImplicitConversionSequence::Better; 1630 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1631 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1632 (SCS2.Second == ICK_Identity && 1633 SCS2.Third == ICK_Identity)) 1634 // SCS2 is a proper subsequence of SCS1. 1635 return ImplicitConversionSequence::Worse; 1636 1637 // -- the rank of S1 is better than the rank of S2 (by the rules 1638 // defined below), or, if not that, 1639 ImplicitConversionRank Rank1 = SCS1.getRank(); 1640 ImplicitConversionRank Rank2 = SCS2.getRank(); 1641 if (Rank1 < Rank2) 1642 return ImplicitConversionSequence::Better; 1643 else if (Rank2 < Rank1) 1644 return ImplicitConversionSequence::Worse; 1645 1646 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1647 // are indistinguishable unless one of the following rules 1648 // applies: 1649 1650 // A conversion that is not a conversion of a pointer, or 1651 // pointer to member, to bool is better than another conversion 1652 // that is such a conversion. 1653 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1654 return SCS2.isPointerConversionToBool() 1655 ? ImplicitConversionSequence::Better 1656 : ImplicitConversionSequence::Worse; 1657 1658 // C++ [over.ics.rank]p4b2: 1659 // 1660 // If class B is derived directly or indirectly from class A, 1661 // conversion of B* to A* is better than conversion of B* to 1662 // void*, and conversion of A* to void* is better than conversion 1663 // of B* to void*. 1664 bool SCS1ConvertsToVoid 1665 = SCS1.isPointerConversionToVoidPointer(Context); 1666 bool SCS2ConvertsToVoid 1667 = SCS2.isPointerConversionToVoidPointer(Context); 1668 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1669 // Exactly one of the conversion sequences is a conversion to 1670 // a void pointer; it's the worse conversion. 1671 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1672 : ImplicitConversionSequence::Worse; 1673 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1674 // Neither conversion sequence converts to a void pointer; compare 1675 // their derived-to-base conversions. 1676 if (ImplicitConversionSequence::CompareKind DerivedCK 1677 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1678 return DerivedCK; 1679 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1680 // Both conversion sequences are conversions to void 1681 // pointers. Compare the source types to determine if there's an 1682 // inheritance relationship in their sources. 1683 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1684 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1685 1686 // Adjust the types we're converting from via the array-to-pointer 1687 // conversion, if we need to. 1688 if (SCS1.First == ICK_Array_To_Pointer) 1689 FromType1 = Context.getArrayDecayedType(FromType1); 1690 if (SCS2.First == ICK_Array_To_Pointer) 1691 FromType2 = Context.getArrayDecayedType(FromType2); 1692 1693 QualType FromPointee1 1694 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1695 QualType FromPointee2 1696 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1697 1698 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1699 return ImplicitConversionSequence::Better; 1700 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1701 return ImplicitConversionSequence::Worse; 1702 1703 // Objective-C++: If one interface is more specific than the 1704 // other, it is the better one. 1705 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1706 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1707 if (FromIface1 && FromIface1) { 1708 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1709 return ImplicitConversionSequence::Better; 1710 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1711 return ImplicitConversionSequence::Worse; 1712 } 1713 } 1714 1715 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1716 // bullet 3). 1717 if (ImplicitConversionSequence::CompareKind QualCK 1718 = CompareQualificationConversions(SCS1, SCS2)) 1719 return QualCK; 1720 1721 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1722 // C++0x [over.ics.rank]p3b4: 1723 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1724 // implicit object parameter of a non-static member function declared 1725 // without a ref-qualifier, and S1 binds an rvalue reference to an 1726 // rvalue and S2 binds an lvalue reference. 1727 // FIXME: We don't know if we're dealing with the implicit object parameter, 1728 // or if the member function in this case has a ref qualifier. 1729 // (Of course, we don't have ref qualifiers yet.) 1730 if (SCS1.RRefBinding != SCS2.RRefBinding) 1731 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1732 : ImplicitConversionSequence::Worse; 1733 1734 // C++ [over.ics.rank]p3b4: 1735 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1736 // which the references refer are the same type except for 1737 // top-level cv-qualifiers, and the type to which the reference 1738 // initialized by S2 refers is more cv-qualified than the type 1739 // to which the reference initialized by S1 refers. 1740 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1741 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1742 T1 = Context.getCanonicalType(T1); 1743 T2 = Context.getCanonicalType(T2); 1744 if (Context.hasSameUnqualifiedType(T1, T2)) { 1745 if (T2.isMoreQualifiedThan(T1)) 1746 return ImplicitConversionSequence::Better; 1747 else if (T1.isMoreQualifiedThan(T2)) 1748 return ImplicitConversionSequence::Worse; 1749 } 1750 } 1751 1752 return ImplicitConversionSequence::Indistinguishable; 1753} 1754 1755/// CompareQualificationConversions - Compares two standard conversion 1756/// sequences to determine whether they can be ranked based on their 1757/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1758ImplicitConversionSequence::CompareKind 1759Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1760 const StandardConversionSequence& SCS2) { 1761 // C++ 13.3.3.2p3: 1762 // -- S1 and S2 differ only in their qualification conversion and 1763 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1764 // cv-qualification signature of type T1 is a proper subset of 1765 // the cv-qualification signature of type T2, and S1 is not the 1766 // deprecated string literal array-to-pointer conversion (4.2). 1767 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1768 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1769 return ImplicitConversionSequence::Indistinguishable; 1770 1771 // FIXME: the example in the standard doesn't use a qualification 1772 // conversion (!) 1773 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1774 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1775 T1 = Context.getCanonicalType(T1); 1776 T2 = Context.getCanonicalType(T2); 1777 1778 // If the types are the same, we won't learn anything by unwrapped 1779 // them. 1780 if (Context.hasSameUnqualifiedType(T1, T2)) 1781 return ImplicitConversionSequence::Indistinguishable; 1782 1783 ImplicitConversionSequence::CompareKind Result 1784 = ImplicitConversionSequence::Indistinguishable; 1785 while (UnwrapSimilarPointerTypes(T1, T2)) { 1786 // Within each iteration of the loop, we check the qualifiers to 1787 // determine if this still looks like a qualification 1788 // conversion. Then, if all is well, we unwrap one more level of 1789 // pointers or pointers-to-members and do it all again 1790 // until there are no more pointers or pointers-to-members left 1791 // to unwrap. This essentially mimics what 1792 // IsQualificationConversion does, but here we're checking for a 1793 // strict subset of qualifiers. 1794 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1795 // The qualifiers are the same, so this doesn't tell us anything 1796 // about how the sequences rank. 1797 ; 1798 else if (T2.isMoreQualifiedThan(T1)) { 1799 // T1 has fewer qualifiers, so it could be the better sequence. 1800 if (Result == ImplicitConversionSequence::Worse) 1801 // Neither has qualifiers that are a subset of the other's 1802 // qualifiers. 1803 return ImplicitConversionSequence::Indistinguishable; 1804 1805 Result = ImplicitConversionSequence::Better; 1806 } else if (T1.isMoreQualifiedThan(T2)) { 1807 // T2 has fewer qualifiers, so it could be the better sequence. 1808 if (Result == ImplicitConversionSequence::Better) 1809 // Neither has qualifiers that are a subset of the other's 1810 // qualifiers. 1811 return ImplicitConversionSequence::Indistinguishable; 1812 1813 Result = ImplicitConversionSequence::Worse; 1814 } else { 1815 // Qualifiers are disjoint. 1816 return ImplicitConversionSequence::Indistinguishable; 1817 } 1818 1819 // If the types after this point are equivalent, we're done. 1820 if (Context.hasSameUnqualifiedType(T1, T2)) 1821 break; 1822 } 1823 1824 // Check that the winning standard conversion sequence isn't using 1825 // the deprecated string literal array to pointer conversion. 1826 switch (Result) { 1827 case ImplicitConversionSequence::Better: 1828 if (SCS1.Deprecated) 1829 Result = ImplicitConversionSequence::Indistinguishable; 1830 break; 1831 1832 case ImplicitConversionSequence::Indistinguishable: 1833 break; 1834 1835 case ImplicitConversionSequence::Worse: 1836 if (SCS2.Deprecated) 1837 Result = ImplicitConversionSequence::Indistinguishable; 1838 break; 1839 } 1840 1841 return Result; 1842} 1843 1844/// CompareDerivedToBaseConversions - Compares two standard conversion 1845/// sequences to determine whether they can be ranked based on their 1846/// various kinds of derived-to-base conversions (C++ 1847/// [over.ics.rank]p4b3). As part of these checks, we also look at 1848/// conversions between Objective-C interface types. 1849ImplicitConversionSequence::CompareKind 1850Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1851 const StandardConversionSequence& SCS2) { 1852 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1853 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1854 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1855 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1856 1857 // Adjust the types we're converting from via the array-to-pointer 1858 // conversion, if we need to. 1859 if (SCS1.First == ICK_Array_To_Pointer) 1860 FromType1 = Context.getArrayDecayedType(FromType1); 1861 if (SCS2.First == ICK_Array_To_Pointer) 1862 FromType2 = Context.getArrayDecayedType(FromType2); 1863 1864 // Canonicalize all of the types. 1865 FromType1 = Context.getCanonicalType(FromType1); 1866 ToType1 = Context.getCanonicalType(ToType1); 1867 FromType2 = Context.getCanonicalType(FromType2); 1868 ToType2 = Context.getCanonicalType(ToType2); 1869 1870 // C++ [over.ics.rank]p4b3: 1871 // 1872 // If class B is derived directly or indirectly from class A and 1873 // class C is derived directly or indirectly from B, 1874 // 1875 // For Objective-C, we let A, B, and C also be Objective-C 1876 // interfaces. 1877 1878 // Compare based on pointer conversions. 1879 if (SCS1.Second == ICK_Pointer_Conversion && 1880 SCS2.Second == ICK_Pointer_Conversion && 1881 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1882 FromType1->isPointerType() && FromType2->isPointerType() && 1883 ToType1->isPointerType() && ToType2->isPointerType()) { 1884 QualType FromPointee1 1885 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1886 QualType ToPointee1 1887 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1888 QualType FromPointee2 1889 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1890 QualType ToPointee2 1891 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1892 1893 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1894 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1895 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1896 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1897 1898 // -- conversion of C* to B* is better than conversion of C* to A*, 1899 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1900 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1901 return ImplicitConversionSequence::Better; 1902 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1903 return ImplicitConversionSequence::Worse; 1904 1905 if (ToIface1 && ToIface2) { 1906 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1907 return ImplicitConversionSequence::Better; 1908 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1909 return ImplicitConversionSequence::Worse; 1910 } 1911 } 1912 1913 // -- conversion of B* to A* is better than conversion of C* to A*, 1914 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1915 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1916 return ImplicitConversionSequence::Better; 1917 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1918 return ImplicitConversionSequence::Worse; 1919 1920 if (FromIface1 && FromIface2) { 1921 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1922 return ImplicitConversionSequence::Better; 1923 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1924 return ImplicitConversionSequence::Worse; 1925 } 1926 } 1927 } 1928 1929 // Compare based on reference bindings. 1930 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1931 SCS1.Second == ICK_Derived_To_Base) { 1932 // -- binding of an expression of type C to a reference of type 1933 // B& is better than binding an expression of type C to a 1934 // reference of type A&, 1935 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 1936 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 1937 if (IsDerivedFrom(ToType1, ToType2)) 1938 return ImplicitConversionSequence::Better; 1939 else if (IsDerivedFrom(ToType2, ToType1)) 1940 return ImplicitConversionSequence::Worse; 1941 } 1942 1943 // -- binding of an expression of type B to a reference of type 1944 // A& is better than binding an expression of type C to a 1945 // reference of type A&, 1946 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 1947 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 1948 if (IsDerivedFrom(FromType2, FromType1)) 1949 return ImplicitConversionSequence::Better; 1950 else if (IsDerivedFrom(FromType1, FromType2)) 1951 return ImplicitConversionSequence::Worse; 1952 } 1953 } 1954 1955 // Ranking of member-pointer types. 1956 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 1957 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 1958 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 1959 const MemberPointerType * FromMemPointer1 = 1960 FromType1->getAs<MemberPointerType>(); 1961 const MemberPointerType * ToMemPointer1 = 1962 ToType1->getAs<MemberPointerType>(); 1963 const MemberPointerType * FromMemPointer2 = 1964 FromType2->getAs<MemberPointerType>(); 1965 const MemberPointerType * ToMemPointer2 = 1966 ToType2->getAs<MemberPointerType>(); 1967 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 1968 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 1969 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 1970 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 1971 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 1972 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 1973 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 1974 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 1975 // conversion of A::* to B::* is better than conversion of A::* to C::*, 1976 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1977 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1978 return ImplicitConversionSequence::Worse; 1979 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1980 return ImplicitConversionSequence::Better; 1981 } 1982 // conversion of B::* to C::* is better than conversion of A::* to C::* 1983 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 1984 if (IsDerivedFrom(FromPointee1, FromPointee2)) 1985 return ImplicitConversionSequence::Better; 1986 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 1987 return ImplicitConversionSequence::Worse; 1988 } 1989 } 1990 1991 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1992 SCS1.Second == ICK_Derived_To_Base) { 1993 // -- conversion of C to B is better than conversion of C to A, 1994 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 1995 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 1996 if (IsDerivedFrom(ToType1, ToType2)) 1997 return ImplicitConversionSequence::Better; 1998 else if (IsDerivedFrom(ToType2, ToType1)) 1999 return ImplicitConversionSequence::Worse; 2000 } 2001 2002 // -- conversion of B to A is better than conversion of C to A. 2003 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2004 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2005 if (IsDerivedFrom(FromType2, FromType1)) 2006 return ImplicitConversionSequence::Better; 2007 else if (IsDerivedFrom(FromType1, FromType2)) 2008 return ImplicitConversionSequence::Worse; 2009 } 2010 } 2011 2012 return ImplicitConversionSequence::Indistinguishable; 2013} 2014 2015/// TryCopyInitialization - Try to copy-initialize a value of type 2016/// ToType from the expression From. Return the implicit conversion 2017/// sequence required to pass this argument, which may be a bad 2018/// conversion sequence (meaning that the argument cannot be passed to 2019/// a parameter of this type). If @p SuppressUserConversions, then we 2020/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2021/// then we treat @p From as an rvalue, even if it is an lvalue. 2022ImplicitConversionSequence 2023Sema::TryCopyInitialization(Expr *From, QualType ToType, 2024 bool SuppressUserConversions, bool ForceRValue, 2025 bool InOverloadResolution) { 2026 if (ToType->isReferenceType()) { 2027 ImplicitConversionSequence ICS; 2028 CheckReferenceInit(From, ToType, 2029 /*FIXME:*/From->getLocStart(), 2030 SuppressUserConversions, 2031 /*AllowExplicit=*/false, 2032 ForceRValue, 2033 &ICS); 2034 return ICS; 2035 } else { 2036 return TryImplicitConversion(From, ToType, 2037 SuppressUserConversions, 2038 /*AllowExplicit=*/false, 2039 ForceRValue, 2040 InOverloadResolution); 2041 } 2042} 2043 2044/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 2045/// the expression @p From. Returns true (and emits a diagnostic) if there was 2046/// an error, returns false if the initialization succeeded. Elidable should 2047/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2048/// differently in C++0x for this case. 2049bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2050 const char* Flavor, bool Elidable) { 2051 if (!getLangOptions().CPlusPlus) { 2052 // In C, argument passing is the same as performing an assignment. 2053 QualType FromType = From->getType(); 2054 2055 AssignConvertType ConvTy = 2056 CheckSingleAssignmentConstraints(ToType, From); 2057 if (ConvTy != Compatible && 2058 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2059 ConvTy = Compatible; 2060 2061 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2062 FromType, From, Flavor); 2063 } 2064 2065 if (ToType->isReferenceType()) 2066 return CheckReferenceInit(From, ToType, 2067 /*FIXME:*/From->getLocStart(), 2068 /*SuppressUserConversions=*/false, 2069 /*AllowExplicit=*/false, 2070 /*ForceRValue=*/false); 2071 2072 if (!PerformImplicitConversion(From, ToType, Flavor, 2073 /*AllowExplicit=*/false, Elidable)) 2074 return false; 2075 if (!DiagnoseAmbiguousUserDefinedConversion(From, ToType)) 2076 return Diag(From->getSourceRange().getBegin(), 2077 diag::err_typecheck_convert_incompatible) 2078 << ToType << From->getType() << Flavor << From->getSourceRange(); 2079 return true; 2080} 2081 2082/// TryObjectArgumentInitialization - Try to initialize the object 2083/// parameter of the given member function (@c Method) from the 2084/// expression @p From. 2085ImplicitConversionSequence 2086Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2087 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2088 QualType ImplicitParamType 2089 = Context.getCVRQualifiedType(ClassType, Method->getTypeQualifiers()); 2090 2091 // Set up the conversion sequence as a "bad" conversion, to allow us 2092 // to exit early. 2093 ImplicitConversionSequence ICS; 2094 ICS.Standard.setAsIdentityConversion(); 2095 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2096 2097 // We need to have an object of class type. 2098 QualType FromType = From->getType(); 2099 if (const PointerType *PT = FromType->getAs<PointerType>()) 2100 FromType = PT->getPointeeType(); 2101 2102 assert(FromType->isRecordType()); 2103 2104 // The implicit object parmeter is has the type "reference to cv X", 2105 // where X is the class of which the function is a member 2106 // (C++ [over.match.funcs]p4). However, when finding an implicit 2107 // conversion sequence for the argument, we are not allowed to 2108 // create temporaries or perform user-defined conversions 2109 // (C++ [over.match.funcs]p5). We perform a simplified version of 2110 // reference binding here, that allows class rvalues to bind to 2111 // non-constant references. 2112 2113 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2114 // with the implicit object parameter (C++ [over.match.funcs]p5). 2115 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2116 if (ImplicitParamType.getCVRQualifiers() 2117 != FromTypeCanon.getLocalCVRQualifiers() && 2118 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) 2119 return ICS; 2120 2121 // Check that we have either the same type or a derived type. It 2122 // affects the conversion rank. 2123 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2124 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) 2125 ICS.Standard.Second = ICK_Identity; 2126 else if (IsDerivedFrom(FromType, ClassType)) 2127 ICS.Standard.Second = ICK_Derived_To_Base; 2128 else 2129 return ICS; 2130 2131 // Success. Mark this as a reference binding. 2132 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2133 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2134 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2135 ICS.Standard.ReferenceBinding = true; 2136 ICS.Standard.DirectBinding = true; 2137 ICS.Standard.RRefBinding = false; 2138 return ICS; 2139} 2140 2141/// PerformObjectArgumentInitialization - Perform initialization of 2142/// the implicit object parameter for the given Method with the given 2143/// expression. 2144bool 2145Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2146 QualType FromRecordType, DestType; 2147 QualType ImplicitParamRecordType = 2148 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2149 2150 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2151 FromRecordType = PT->getPointeeType(); 2152 DestType = Method->getThisType(Context); 2153 } else { 2154 FromRecordType = From->getType(); 2155 DestType = ImplicitParamRecordType; 2156 } 2157 2158 ImplicitConversionSequence ICS 2159 = TryObjectArgumentInitialization(From, Method); 2160 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2161 return Diag(From->getSourceRange().getBegin(), 2162 diag::err_implicit_object_parameter_init) 2163 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2164 2165 if (ICS.Standard.Second == ICK_Derived_To_Base && 2166 CheckDerivedToBaseConversion(FromRecordType, 2167 ImplicitParamRecordType, 2168 From->getSourceRange().getBegin(), 2169 From->getSourceRange())) 2170 return true; 2171 2172 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2173 /*isLvalue=*/true); 2174 return false; 2175} 2176 2177/// TryContextuallyConvertToBool - Attempt to contextually convert the 2178/// expression From to bool (C++0x [conv]p3). 2179ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2180 return TryImplicitConversion(From, Context.BoolTy, 2181 // FIXME: Are these flags correct? 2182 /*SuppressUserConversions=*/false, 2183 /*AllowExplicit=*/true, 2184 /*ForceRValue=*/false, 2185 /*InOverloadResolution=*/false); 2186} 2187 2188/// PerformContextuallyConvertToBool - Perform a contextual conversion 2189/// of the expression From to bool (C++0x [conv]p3). 2190bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2191 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2192 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2193 return false; 2194 2195 if (!DiagnoseAmbiguousUserDefinedConversion(From, Context.BoolTy)) 2196 return Diag(From->getSourceRange().getBegin(), 2197 diag::err_typecheck_bool_condition) 2198 << From->getType() << From->getSourceRange(); 2199 return true; 2200} 2201 2202/// AddOverloadCandidate - Adds the given function to the set of 2203/// candidate functions, using the given function call arguments. If 2204/// @p SuppressUserConversions, then don't allow user-defined 2205/// conversions via constructors or conversion operators. 2206/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2207/// hacky way to implement the overloading rules for elidable copy 2208/// initialization in C++0x (C++0x 12.8p15). 2209/// 2210/// \para PartialOverloading true if we are performing "partial" overloading 2211/// based on an incomplete set of function arguments. This feature is used by 2212/// code completion. 2213void 2214Sema::AddOverloadCandidate(FunctionDecl *Function, 2215 Expr **Args, unsigned NumArgs, 2216 OverloadCandidateSet& CandidateSet, 2217 bool SuppressUserConversions, 2218 bool ForceRValue, 2219 bool PartialOverloading) { 2220 const FunctionProtoType* Proto 2221 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2222 assert(Proto && "Functions without a prototype cannot be overloaded"); 2223 assert(!isa<CXXConversionDecl>(Function) && 2224 "Use AddConversionCandidate for conversion functions"); 2225 assert(!Function->getDescribedFunctionTemplate() && 2226 "Use AddTemplateOverloadCandidate for function templates"); 2227 2228 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2229 if (!isa<CXXConstructorDecl>(Method)) { 2230 // If we get here, it's because we're calling a member function 2231 // that is named without a member access expression (e.g., 2232 // "this->f") that was either written explicitly or created 2233 // implicitly. This can happen with a qualified call to a member 2234 // function, e.g., X::f(). We use a NULL object as the implied 2235 // object argument (C++ [over.call.func]p3). 2236 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2237 SuppressUserConversions, ForceRValue); 2238 return; 2239 } 2240 // We treat a constructor like a non-member function, since its object 2241 // argument doesn't participate in overload resolution. 2242 } 2243 2244 if (!CandidateSet.isNewCandidate(Function)) 2245 return; 2246 2247 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2248 // C++ [class.copy]p3: 2249 // A member function template is never instantiated to perform the copy 2250 // of a class object to an object of its class type. 2251 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2252 if (NumArgs == 1 && 2253 Constructor->isCopyConstructorLikeSpecialization() && 2254 Context.hasSameUnqualifiedType(ClassType, Args[0]->getType())) 2255 return; 2256 } 2257 2258 // Add this candidate 2259 CandidateSet.push_back(OverloadCandidate()); 2260 OverloadCandidate& Candidate = CandidateSet.back(); 2261 Candidate.Function = Function; 2262 Candidate.Viable = true; 2263 Candidate.IsSurrogate = false; 2264 Candidate.IgnoreObjectArgument = false; 2265 2266 unsigned NumArgsInProto = Proto->getNumArgs(); 2267 2268 // (C++ 13.3.2p2): A candidate function having fewer than m 2269 // parameters is viable only if it has an ellipsis in its parameter 2270 // list (8.3.5). 2271 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2272 !Proto->isVariadic()) { 2273 Candidate.Viable = false; 2274 return; 2275 } 2276 2277 // (C++ 13.3.2p2): A candidate function having more than m parameters 2278 // is viable only if the (m+1)st parameter has a default argument 2279 // (8.3.6). For the purposes of overload resolution, the 2280 // parameter list is truncated on the right, so that there are 2281 // exactly m parameters. 2282 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2283 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2284 // Not enough arguments. 2285 Candidate.Viable = false; 2286 return; 2287 } 2288 2289 // Determine the implicit conversion sequences for each of the 2290 // arguments. 2291 Candidate.Conversions.resize(NumArgs); 2292 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2293 if (ArgIdx < NumArgsInProto) { 2294 // (C++ 13.3.2p3): for F to be a viable function, there shall 2295 // exist for each argument an implicit conversion sequence 2296 // (13.3.3.1) that converts that argument to the corresponding 2297 // parameter of F. 2298 QualType ParamType = Proto->getArgType(ArgIdx); 2299 Candidate.Conversions[ArgIdx] 2300 = TryCopyInitialization(Args[ArgIdx], ParamType, 2301 SuppressUserConversions, ForceRValue, 2302 /*InOverloadResolution=*/true); 2303 if (Candidate.Conversions[ArgIdx].ConversionKind 2304 == ImplicitConversionSequence::BadConversion) { 2305 // 13.3.3.1-p10 If several different sequences of conversions exist that 2306 // each convert the argument to the parameter type, the implicit conversion 2307 // sequence associated with the parameter is defined to be the unique conversion 2308 // sequence designated the ambiguous conversion sequence. For the purpose of 2309 // ranking implicit conversion sequences as described in 13.3.3.2, the ambiguous 2310 // conversion sequence is treated as a user-defined sequence that is 2311 // indistinguishable from any other user-defined conversion sequence 2312 if (!Candidate.Conversions[ArgIdx].ConversionFunctionSet.empty()) { 2313 Candidate.Conversions[ArgIdx].ConversionKind = 2314 ImplicitConversionSequence::UserDefinedConversion; 2315 // Set the conversion function to one of them. As due to ambiguity, 2316 // they carry the same weight and is needed for overload resolution 2317 // later. 2318 Candidate.Conversions[ArgIdx].UserDefined.ConversionFunction = 2319 Candidate.Conversions[ArgIdx].ConversionFunctionSet[0]; 2320 } 2321 else { 2322 Candidate.Viable = false; 2323 break; 2324 } 2325 } 2326 } else { 2327 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2328 // argument for which there is no corresponding parameter is 2329 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2330 Candidate.Conversions[ArgIdx].ConversionKind 2331 = ImplicitConversionSequence::EllipsisConversion; 2332 } 2333 } 2334} 2335 2336/// \brief Add all of the function declarations in the given function set to 2337/// the overload canddiate set. 2338void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2339 Expr **Args, unsigned NumArgs, 2340 OverloadCandidateSet& CandidateSet, 2341 bool SuppressUserConversions) { 2342 for (FunctionSet::const_iterator F = Functions.begin(), 2343 FEnd = Functions.end(); 2344 F != FEnd; ++F) { 2345 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2346 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2347 AddMethodCandidate(cast<CXXMethodDecl>(FD), 2348 Args[0], Args + 1, NumArgs - 1, 2349 CandidateSet, SuppressUserConversions); 2350 else 2351 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2352 SuppressUserConversions); 2353 } else { 2354 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2355 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2356 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2357 AddMethodTemplateCandidate(FunTmpl, 2358 /*FIXME: explicit args */false, 0, 0, 2359 Args[0], Args + 1, NumArgs - 1, 2360 CandidateSet, 2361 SuppressUserConversions); 2362 else 2363 AddTemplateOverloadCandidate(FunTmpl, 2364 /*FIXME: explicit args */false, 0, 0, 2365 Args, NumArgs, CandidateSet, 2366 SuppressUserConversions); 2367 } 2368 } 2369} 2370 2371/// AddMethodCandidate - Adds a named decl (which is some kind of 2372/// method) as a method candidate to the given overload set. 2373void Sema::AddMethodCandidate(NamedDecl *Decl, Expr *Object, 2374 Expr **Args, unsigned NumArgs, 2375 OverloadCandidateSet& CandidateSet, 2376 bool SuppressUserConversions, bool ForceRValue) { 2377 2378 // FIXME: use this 2379 //DeclContext *ActingContext = Decl->getDeclContext(); 2380 2381 if (isa<UsingShadowDecl>(Decl)) 2382 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2383 2384 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2385 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2386 "Expected a member function template"); 2387 AddMethodTemplateCandidate(TD, false, 0, 0, 2388 Object, Args, NumArgs, 2389 CandidateSet, 2390 SuppressUserConversions, 2391 ForceRValue); 2392 } else { 2393 AddMethodCandidate(cast<CXXMethodDecl>(Decl), Object, Args, NumArgs, 2394 CandidateSet, SuppressUserConversions, ForceRValue); 2395 } 2396} 2397 2398/// AddMethodCandidate - Adds the given C++ member function to the set 2399/// of candidate functions, using the given function call arguments 2400/// and the object argument (@c Object). For example, in a call 2401/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2402/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2403/// allow user-defined conversions via constructors or conversion 2404/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2405/// a slightly hacky way to implement the overloading rules for elidable copy 2406/// initialization in C++0x (C++0x 12.8p15). 2407void 2408Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2409 Expr **Args, unsigned NumArgs, 2410 OverloadCandidateSet& CandidateSet, 2411 bool SuppressUserConversions, bool ForceRValue) { 2412 const FunctionProtoType* Proto 2413 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2414 assert(Proto && "Methods without a prototype cannot be overloaded"); 2415 assert(!isa<CXXConversionDecl>(Method) && 2416 "Use AddConversionCandidate for conversion functions"); 2417 assert(!isa<CXXConstructorDecl>(Method) && 2418 "Use AddOverloadCandidate for constructors"); 2419 2420 if (!CandidateSet.isNewCandidate(Method)) 2421 return; 2422 2423 // Add this candidate 2424 CandidateSet.push_back(OverloadCandidate()); 2425 OverloadCandidate& Candidate = CandidateSet.back(); 2426 Candidate.Function = Method; 2427 Candidate.IsSurrogate = false; 2428 Candidate.IgnoreObjectArgument = false; 2429 2430 unsigned NumArgsInProto = Proto->getNumArgs(); 2431 2432 // (C++ 13.3.2p2): A candidate function having fewer than m 2433 // parameters is viable only if it has an ellipsis in its parameter 2434 // list (8.3.5). 2435 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2436 Candidate.Viable = false; 2437 return; 2438 } 2439 2440 // (C++ 13.3.2p2): A candidate function having more than m parameters 2441 // is viable only if the (m+1)st parameter has a default argument 2442 // (8.3.6). For the purposes of overload resolution, the 2443 // parameter list is truncated on the right, so that there are 2444 // exactly m parameters. 2445 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2446 if (NumArgs < MinRequiredArgs) { 2447 // Not enough arguments. 2448 Candidate.Viable = false; 2449 return; 2450 } 2451 2452 Candidate.Viable = true; 2453 Candidate.Conversions.resize(NumArgs + 1); 2454 2455 if (Method->isStatic() || !Object) 2456 // The implicit object argument is ignored. 2457 Candidate.IgnoreObjectArgument = true; 2458 else { 2459 // Determine the implicit conversion sequence for the object 2460 // parameter. 2461 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2462 if (Candidate.Conversions[0].ConversionKind 2463 == ImplicitConversionSequence::BadConversion) { 2464 Candidate.Viable = false; 2465 return; 2466 } 2467 } 2468 2469 // Determine the implicit conversion sequences for each of the 2470 // arguments. 2471 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2472 if (ArgIdx < NumArgsInProto) { 2473 // (C++ 13.3.2p3): for F to be a viable function, there shall 2474 // exist for each argument an implicit conversion sequence 2475 // (13.3.3.1) that converts that argument to the corresponding 2476 // parameter of F. 2477 QualType ParamType = Proto->getArgType(ArgIdx); 2478 Candidate.Conversions[ArgIdx + 1] 2479 = TryCopyInitialization(Args[ArgIdx], ParamType, 2480 SuppressUserConversions, ForceRValue, 2481 /*InOverloadResolution=*/true); 2482 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2483 == ImplicitConversionSequence::BadConversion) { 2484 Candidate.Viable = false; 2485 break; 2486 } 2487 } else { 2488 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2489 // argument for which there is no corresponding parameter is 2490 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2491 Candidate.Conversions[ArgIdx + 1].ConversionKind 2492 = ImplicitConversionSequence::EllipsisConversion; 2493 } 2494 } 2495} 2496 2497/// \brief Add a C++ member function template as a candidate to the candidate 2498/// set, using template argument deduction to produce an appropriate member 2499/// function template specialization. 2500void 2501Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2502 bool HasExplicitTemplateArgs, 2503 const TemplateArgumentLoc *ExplicitTemplateArgs, 2504 unsigned NumExplicitTemplateArgs, 2505 Expr *Object, Expr **Args, unsigned NumArgs, 2506 OverloadCandidateSet& CandidateSet, 2507 bool SuppressUserConversions, 2508 bool ForceRValue) { 2509 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2510 return; 2511 2512 // C++ [over.match.funcs]p7: 2513 // In each case where a candidate is a function template, candidate 2514 // function template specializations are generated using template argument 2515 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2516 // candidate functions in the usual way.113) A given name can refer to one 2517 // or more function templates and also to a set of overloaded non-template 2518 // functions. In such a case, the candidate functions generated from each 2519 // function template are combined with the set of non-template candidate 2520 // functions. 2521 TemplateDeductionInfo Info(Context); 2522 FunctionDecl *Specialization = 0; 2523 if (TemplateDeductionResult Result 2524 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2525 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2526 Args, NumArgs, Specialization, Info)) { 2527 // FIXME: Record what happened with template argument deduction, so 2528 // that we can give the user a beautiful diagnostic. 2529 (void)Result; 2530 return; 2531 } 2532 2533 // Add the function template specialization produced by template argument 2534 // deduction as a candidate. 2535 assert(Specialization && "Missing member function template specialization?"); 2536 assert(isa<CXXMethodDecl>(Specialization) && 2537 "Specialization is not a member function?"); 2538 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2539 CandidateSet, SuppressUserConversions, ForceRValue); 2540} 2541 2542/// \brief Add a C++ function template specialization as a candidate 2543/// in the candidate set, using template argument deduction to produce 2544/// an appropriate function template specialization. 2545void 2546Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2547 bool HasExplicitTemplateArgs, 2548 const TemplateArgumentLoc *ExplicitTemplateArgs, 2549 unsigned NumExplicitTemplateArgs, 2550 Expr **Args, unsigned NumArgs, 2551 OverloadCandidateSet& CandidateSet, 2552 bool SuppressUserConversions, 2553 bool ForceRValue) { 2554 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2555 return; 2556 2557 // C++ [over.match.funcs]p7: 2558 // In each case where a candidate is a function template, candidate 2559 // function template specializations are generated using template argument 2560 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2561 // candidate functions in the usual way.113) A given name can refer to one 2562 // or more function templates and also to a set of overloaded non-template 2563 // functions. In such a case, the candidate functions generated from each 2564 // function template are combined with the set of non-template candidate 2565 // functions. 2566 TemplateDeductionInfo Info(Context); 2567 FunctionDecl *Specialization = 0; 2568 if (TemplateDeductionResult Result 2569 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2570 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2571 Args, NumArgs, Specialization, Info)) { 2572 // FIXME: Record what happened with template argument deduction, so 2573 // that we can give the user a beautiful diagnostic. 2574 (void)Result; 2575 return; 2576 } 2577 2578 // Add the function template specialization produced by template argument 2579 // deduction as a candidate. 2580 assert(Specialization && "Missing function template specialization?"); 2581 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2582 SuppressUserConversions, ForceRValue); 2583} 2584 2585/// AddConversionCandidate - Add a C++ conversion function as a 2586/// candidate in the candidate set (C++ [over.match.conv], 2587/// C++ [over.match.copy]). From is the expression we're converting from, 2588/// and ToType is the type that we're eventually trying to convert to 2589/// (which may or may not be the same type as the type that the 2590/// conversion function produces). 2591void 2592Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2593 Expr *From, QualType ToType, 2594 OverloadCandidateSet& CandidateSet) { 2595 assert(!Conversion->getDescribedFunctionTemplate() && 2596 "Conversion function templates use AddTemplateConversionCandidate"); 2597 2598 if (!CandidateSet.isNewCandidate(Conversion)) 2599 return; 2600 2601 // Add this candidate 2602 CandidateSet.push_back(OverloadCandidate()); 2603 OverloadCandidate& Candidate = CandidateSet.back(); 2604 Candidate.Function = Conversion; 2605 Candidate.IsSurrogate = false; 2606 Candidate.IgnoreObjectArgument = false; 2607 Candidate.FinalConversion.setAsIdentityConversion(); 2608 Candidate.FinalConversion.FromTypePtr 2609 = Conversion->getConversionType().getAsOpaquePtr(); 2610 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2611 2612 // Determine the implicit conversion sequence for the implicit 2613 // object parameter. 2614 Candidate.Viable = true; 2615 Candidate.Conversions.resize(1); 2616 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2617 // Conversion functions to a different type in the base class is visible in 2618 // the derived class. So, a derived to base conversion should not participate 2619 // in overload resolution. 2620 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2621 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2622 if (Candidate.Conversions[0].ConversionKind 2623 == ImplicitConversionSequence::BadConversion) { 2624 Candidate.Viable = false; 2625 return; 2626 } 2627 2628 // We won't go through a user-define type conversion function to convert a 2629 // derived to base as such conversions are given Conversion Rank. They only 2630 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2631 QualType FromCanon 2632 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2633 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2634 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2635 Candidate.Viable = false; 2636 return; 2637 } 2638 2639 2640 // To determine what the conversion from the result of calling the 2641 // conversion function to the type we're eventually trying to 2642 // convert to (ToType), we need to synthesize a call to the 2643 // conversion function and attempt copy initialization from it. This 2644 // makes sure that we get the right semantics with respect to 2645 // lvalues/rvalues and the type. Fortunately, we can allocate this 2646 // call on the stack and we don't need its arguments to be 2647 // well-formed. 2648 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2649 From->getLocStart()); 2650 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2651 CastExpr::CK_FunctionToPointerDecay, 2652 &ConversionRef, false); 2653 2654 // Note that it is safe to allocate CallExpr on the stack here because 2655 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2656 // allocator). 2657 CallExpr Call(Context, &ConversionFn, 0, 0, 2658 Conversion->getConversionType().getNonReferenceType(), 2659 From->getLocStart()); 2660 ImplicitConversionSequence ICS = 2661 TryCopyInitialization(&Call, ToType, 2662 /*SuppressUserConversions=*/true, 2663 /*ForceRValue=*/false, 2664 /*InOverloadResolution=*/false); 2665 2666 switch (ICS.ConversionKind) { 2667 case ImplicitConversionSequence::StandardConversion: 2668 Candidate.FinalConversion = ICS.Standard; 2669 break; 2670 2671 case ImplicitConversionSequence::BadConversion: 2672 Candidate.Viable = false; 2673 break; 2674 2675 default: 2676 assert(false && 2677 "Can only end up with a standard conversion sequence or failure"); 2678 } 2679} 2680 2681/// \brief Adds a conversion function template specialization 2682/// candidate to the overload set, using template argument deduction 2683/// to deduce the template arguments of the conversion function 2684/// template from the type that we are converting to (C++ 2685/// [temp.deduct.conv]). 2686void 2687Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2688 Expr *From, QualType ToType, 2689 OverloadCandidateSet &CandidateSet) { 2690 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2691 "Only conversion function templates permitted here"); 2692 2693 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2694 return; 2695 2696 TemplateDeductionInfo Info(Context); 2697 CXXConversionDecl *Specialization = 0; 2698 if (TemplateDeductionResult Result 2699 = DeduceTemplateArguments(FunctionTemplate, ToType, 2700 Specialization, Info)) { 2701 // FIXME: Record what happened with template argument deduction, so 2702 // that we can give the user a beautiful diagnostic. 2703 (void)Result; 2704 return; 2705 } 2706 2707 // Add the conversion function template specialization produced by 2708 // template argument deduction as a candidate. 2709 assert(Specialization && "Missing function template specialization?"); 2710 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2711} 2712 2713/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2714/// converts the given @c Object to a function pointer via the 2715/// conversion function @c Conversion, and then attempts to call it 2716/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2717/// the type of function that we'll eventually be calling. 2718void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2719 const FunctionProtoType *Proto, 2720 Expr *Object, Expr **Args, unsigned NumArgs, 2721 OverloadCandidateSet& CandidateSet) { 2722 if (!CandidateSet.isNewCandidate(Conversion)) 2723 return; 2724 2725 CandidateSet.push_back(OverloadCandidate()); 2726 OverloadCandidate& Candidate = CandidateSet.back(); 2727 Candidate.Function = 0; 2728 Candidate.Surrogate = Conversion; 2729 Candidate.Viable = true; 2730 Candidate.IsSurrogate = true; 2731 Candidate.IgnoreObjectArgument = false; 2732 Candidate.Conversions.resize(NumArgs + 1); 2733 2734 // Determine the implicit conversion sequence for the implicit 2735 // object parameter. 2736 ImplicitConversionSequence ObjectInit 2737 = TryObjectArgumentInitialization(Object, Conversion); 2738 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2739 Candidate.Viable = false; 2740 return; 2741 } 2742 2743 // The first conversion is actually a user-defined conversion whose 2744 // first conversion is ObjectInit's standard conversion (which is 2745 // effectively a reference binding). Record it as such. 2746 Candidate.Conversions[0].ConversionKind 2747 = ImplicitConversionSequence::UserDefinedConversion; 2748 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2749 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2750 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2751 Candidate.Conversions[0].UserDefined.After 2752 = Candidate.Conversions[0].UserDefined.Before; 2753 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2754 2755 // Find the 2756 unsigned NumArgsInProto = Proto->getNumArgs(); 2757 2758 // (C++ 13.3.2p2): A candidate function having fewer than m 2759 // parameters is viable only if it has an ellipsis in its parameter 2760 // list (8.3.5). 2761 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2762 Candidate.Viable = false; 2763 return; 2764 } 2765 2766 // Function types don't have any default arguments, so just check if 2767 // we have enough arguments. 2768 if (NumArgs < NumArgsInProto) { 2769 // Not enough arguments. 2770 Candidate.Viable = false; 2771 return; 2772 } 2773 2774 // Determine the implicit conversion sequences for each of the 2775 // arguments. 2776 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2777 if (ArgIdx < NumArgsInProto) { 2778 // (C++ 13.3.2p3): for F to be a viable function, there shall 2779 // exist for each argument an implicit conversion sequence 2780 // (13.3.3.1) that converts that argument to the corresponding 2781 // parameter of F. 2782 QualType ParamType = Proto->getArgType(ArgIdx); 2783 Candidate.Conversions[ArgIdx + 1] 2784 = TryCopyInitialization(Args[ArgIdx], ParamType, 2785 /*SuppressUserConversions=*/false, 2786 /*ForceRValue=*/false, 2787 /*InOverloadResolution=*/false); 2788 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2789 == ImplicitConversionSequence::BadConversion) { 2790 Candidate.Viable = false; 2791 break; 2792 } 2793 } else { 2794 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2795 // argument for which there is no corresponding parameter is 2796 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2797 Candidate.Conversions[ArgIdx + 1].ConversionKind 2798 = ImplicitConversionSequence::EllipsisConversion; 2799 } 2800 } 2801} 2802 2803// FIXME: This will eventually be removed, once we've migrated all of the 2804// operator overloading logic over to the scheme used by binary operators, which 2805// works for template instantiation. 2806void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2807 SourceLocation OpLoc, 2808 Expr **Args, unsigned NumArgs, 2809 OverloadCandidateSet& CandidateSet, 2810 SourceRange OpRange) { 2811 FunctionSet Functions; 2812 2813 QualType T1 = Args[0]->getType(); 2814 QualType T2; 2815 if (NumArgs > 1) 2816 T2 = Args[1]->getType(); 2817 2818 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2819 if (S) 2820 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2821 ArgumentDependentLookup(OpName, /*Operator*/true, Args, NumArgs, Functions); 2822 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2823 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2824 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 2825} 2826 2827/// \brief Add overload candidates for overloaded operators that are 2828/// member functions. 2829/// 2830/// Add the overloaded operator candidates that are member functions 2831/// for the operator Op that was used in an operator expression such 2832/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2833/// CandidateSet will store the added overload candidates. (C++ 2834/// [over.match.oper]). 2835void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2836 SourceLocation OpLoc, 2837 Expr **Args, unsigned NumArgs, 2838 OverloadCandidateSet& CandidateSet, 2839 SourceRange OpRange) { 2840 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2841 2842 // C++ [over.match.oper]p3: 2843 // For a unary operator @ with an operand of a type whose 2844 // cv-unqualified version is T1, and for a binary operator @ with 2845 // a left operand of a type whose cv-unqualified version is T1 and 2846 // a right operand of a type whose cv-unqualified version is T2, 2847 // three sets of candidate functions, designated member 2848 // candidates, non-member candidates and built-in candidates, are 2849 // constructed as follows: 2850 QualType T1 = Args[0]->getType(); 2851 QualType T2; 2852 if (NumArgs > 1) 2853 T2 = Args[1]->getType(); 2854 2855 // -- If T1 is a class type, the set of member candidates is the 2856 // result of the qualified lookup of T1::operator@ 2857 // (13.3.1.1.1); otherwise, the set of member candidates is 2858 // empty. 2859 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2860 // Complete the type if it can be completed. Otherwise, we're done. 2861 if (RequireCompleteType(OpLoc, T1, PDiag())) 2862 return; 2863 2864 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 2865 LookupQualifiedName(Operators, T1Rec->getDecl()); 2866 Operators.suppressDiagnostics(); 2867 2868 for (LookupResult::iterator Oper = Operators.begin(), 2869 OperEnd = Operators.end(); 2870 Oper != OperEnd; 2871 ++Oper) 2872 AddMethodCandidate(*Oper, Args[0], Args + 1, NumArgs - 1, CandidateSet, 2873 /* SuppressUserConversions = */ false); 2874 } 2875} 2876 2877/// AddBuiltinCandidate - Add a candidate for a built-in 2878/// operator. ResultTy and ParamTys are the result and parameter types 2879/// of the built-in candidate, respectively. Args and NumArgs are the 2880/// arguments being passed to the candidate. IsAssignmentOperator 2881/// should be true when this built-in candidate is an assignment 2882/// operator. NumContextualBoolArguments is the number of arguments 2883/// (at the beginning of the argument list) that will be contextually 2884/// converted to bool. 2885void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2886 Expr **Args, unsigned NumArgs, 2887 OverloadCandidateSet& CandidateSet, 2888 bool IsAssignmentOperator, 2889 unsigned NumContextualBoolArguments) { 2890 // Add this candidate 2891 CandidateSet.push_back(OverloadCandidate()); 2892 OverloadCandidate& Candidate = CandidateSet.back(); 2893 Candidate.Function = 0; 2894 Candidate.IsSurrogate = false; 2895 Candidate.IgnoreObjectArgument = false; 2896 Candidate.BuiltinTypes.ResultTy = ResultTy; 2897 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2898 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2899 2900 // Determine the implicit conversion sequences for each of the 2901 // arguments. 2902 Candidate.Viable = true; 2903 Candidate.Conversions.resize(NumArgs); 2904 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2905 // C++ [over.match.oper]p4: 2906 // For the built-in assignment operators, conversions of the 2907 // left operand are restricted as follows: 2908 // -- no temporaries are introduced to hold the left operand, and 2909 // -- no user-defined conversions are applied to the left 2910 // operand to achieve a type match with the left-most 2911 // parameter of a built-in candidate. 2912 // 2913 // We block these conversions by turning off user-defined 2914 // conversions, since that is the only way that initialization of 2915 // a reference to a non-class type can occur from something that 2916 // is not of the same type. 2917 if (ArgIdx < NumContextualBoolArguments) { 2918 assert(ParamTys[ArgIdx] == Context.BoolTy && 2919 "Contextual conversion to bool requires bool type"); 2920 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2921 } else { 2922 Candidate.Conversions[ArgIdx] 2923 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2924 ArgIdx == 0 && IsAssignmentOperator, 2925 /*ForceRValue=*/false, 2926 /*InOverloadResolution=*/false); 2927 } 2928 if (Candidate.Conversions[ArgIdx].ConversionKind 2929 == ImplicitConversionSequence::BadConversion) { 2930 Candidate.Viable = false; 2931 break; 2932 } 2933 } 2934} 2935 2936/// BuiltinCandidateTypeSet - A set of types that will be used for the 2937/// candidate operator functions for built-in operators (C++ 2938/// [over.built]). The types are separated into pointer types and 2939/// enumeration types. 2940class BuiltinCandidateTypeSet { 2941 /// TypeSet - A set of types. 2942 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2943 2944 /// PointerTypes - The set of pointer types that will be used in the 2945 /// built-in candidates. 2946 TypeSet PointerTypes; 2947 2948 /// MemberPointerTypes - The set of member pointer types that will be 2949 /// used in the built-in candidates. 2950 TypeSet MemberPointerTypes; 2951 2952 /// EnumerationTypes - The set of enumeration types that will be 2953 /// used in the built-in candidates. 2954 TypeSet EnumerationTypes; 2955 2956 /// Sema - The semantic analysis instance where we are building the 2957 /// candidate type set. 2958 Sema &SemaRef; 2959 2960 /// Context - The AST context in which we will build the type sets. 2961 ASTContext &Context; 2962 2963 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 2964 const Qualifiers &VisibleQuals); 2965 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2966 2967public: 2968 /// iterator - Iterates through the types that are part of the set. 2969 typedef TypeSet::iterator iterator; 2970 2971 BuiltinCandidateTypeSet(Sema &SemaRef) 2972 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2973 2974 void AddTypesConvertedFrom(QualType Ty, 2975 SourceLocation Loc, 2976 bool AllowUserConversions, 2977 bool AllowExplicitConversions, 2978 const Qualifiers &VisibleTypeConversionsQuals); 2979 2980 /// pointer_begin - First pointer type found; 2981 iterator pointer_begin() { return PointerTypes.begin(); } 2982 2983 /// pointer_end - Past the last pointer type found; 2984 iterator pointer_end() { return PointerTypes.end(); } 2985 2986 /// member_pointer_begin - First member pointer type found; 2987 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2988 2989 /// member_pointer_end - Past the last member pointer type found; 2990 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2991 2992 /// enumeration_begin - First enumeration type found; 2993 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2994 2995 /// enumeration_end - Past the last enumeration type found; 2996 iterator enumeration_end() { return EnumerationTypes.end(); } 2997}; 2998 2999/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3000/// the set of pointer types along with any more-qualified variants of 3001/// that type. For example, if @p Ty is "int const *", this routine 3002/// will add "int const *", "int const volatile *", "int const 3003/// restrict *", and "int const volatile restrict *" to the set of 3004/// pointer types. Returns true if the add of @p Ty itself succeeded, 3005/// false otherwise. 3006/// 3007/// FIXME: what to do about extended qualifiers? 3008bool 3009BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3010 const Qualifiers &VisibleQuals) { 3011 3012 // Insert this type. 3013 if (!PointerTypes.insert(Ty)) 3014 return false; 3015 3016 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3017 assert(PointerTy && "type was not a pointer type!"); 3018 3019 QualType PointeeTy = PointerTy->getPointeeType(); 3020 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3021 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3022 BaseCVR = Array->getElementType().getCVRQualifiers(); 3023 bool hasVolatile = VisibleQuals.hasVolatile(); 3024 bool hasRestrict = VisibleQuals.hasRestrict(); 3025 3026 // Iterate through all strict supersets of BaseCVR. 3027 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3028 if ((CVR | BaseCVR) != CVR) continue; 3029 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3030 // in the types. 3031 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3032 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3033 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3034 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3035 } 3036 3037 return true; 3038} 3039 3040/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3041/// to the set of pointer types along with any more-qualified variants of 3042/// that type. For example, if @p Ty is "int const *", this routine 3043/// will add "int const *", "int const volatile *", "int const 3044/// restrict *", and "int const volatile restrict *" to the set of 3045/// pointer types. Returns true if the add of @p Ty itself succeeded, 3046/// false otherwise. 3047/// 3048/// FIXME: what to do about extended qualifiers? 3049bool 3050BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3051 QualType Ty) { 3052 // Insert this type. 3053 if (!MemberPointerTypes.insert(Ty)) 3054 return false; 3055 3056 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3057 assert(PointerTy && "type was not a member pointer type!"); 3058 3059 QualType PointeeTy = PointerTy->getPointeeType(); 3060 const Type *ClassTy = PointerTy->getClass(); 3061 3062 // Iterate through all strict supersets of the pointee type's CVR 3063 // qualifiers. 3064 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3065 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3066 if ((CVR | BaseCVR) != CVR) continue; 3067 3068 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3069 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3070 } 3071 3072 return true; 3073} 3074 3075/// AddTypesConvertedFrom - Add each of the types to which the type @p 3076/// Ty can be implicit converted to the given set of @p Types. We're 3077/// primarily interested in pointer types and enumeration types. We also 3078/// take member pointer types, for the conditional operator. 3079/// AllowUserConversions is true if we should look at the conversion 3080/// functions of a class type, and AllowExplicitConversions if we 3081/// should also include the explicit conversion functions of a class 3082/// type. 3083void 3084BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3085 SourceLocation Loc, 3086 bool AllowUserConversions, 3087 bool AllowExplicitConversions, 3088 const Qualifiers &VisibleQuals) { 3089 // Only deal with canonical types. 3090 Ty = Context.getCanonicalType(Ty); 3091 3092 // Look through reference types; they aren't part of the type of an 3093 // expression for the purposes of conversions. 3094 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3095 Ty = RefTy->getPointeeType(); 3096 3097 // We don't care about qualifiers on the type. 3098 Ty = Ty.getLocalUnqualifiedType(); 3099 3100 // If we're dealing with an array type, decay to the pointer. 3101 if (Ty->isArrayType()) 3102 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3103 3104 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3105 QualType PointeeTy = PointerTy->getPointeeType(); 3106 3107 // Insert our type, and its more-qualified variants, into the set 3108 // of types. 3109 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3110 return; 3111 } else if (Ty->isMemberPointerType()) { 3112 // Member pointers are far easier, since the pointee can't be converted. 3113 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3114 return; 3115 } else if (Ty->isEnumeralType()) { 3116 EnumerationTypes.insert(Ty); 3117 } else if (AllowUserConversions) { 3118 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3119 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3120 // No conversion functions in incomplete types. 3121 return; 3122 } 3123 3124 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3125 OverloadedFunctionDecl *Conversions 3126 = ClassDecl->getVisibleConversionFunctions(); 3127 for (OverloadedFunctionDecl::function_iterator Func 3128 = Conversions->function_begin(); 3129 Func != Conversions->function_end(); ++Func) { 3130 CXXConversionDecl *Conv; 3131 FunctionTemplateDecl *ConvTemplate; 3132 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 3133 3134 // Skip conversion function templates; they don't tell us anything 3135 // about which builtin types we can convert to. 3136 if (ConvTemplate) 3137 continue; 3138 3139 if (AllowExplicitConversions || !Conv->isExplicit()) { 3140 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3141 VisibleQuals); 3142 } 3143 } 3144 } 3145 } 3146} 3147 3148/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3149/// the volatile- and non-volatile-qualified assignment operators for the 3150/// given type to the candidate set. 3151static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3152 QualType T, 3153 Expr **Args, 3154 unsigned NumArgs, 3155 OverloadCandidateSet &CandidateSet) { 3156 QualType ParamTypes[2]; 3157 3158 // T& operator=(T&, T) 3159 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3160 ParamTypes[1] = T; 3161 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3162 /*IsAssignmentOperator=*/true); 3163 3164 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3165 // volatile T& operator=(volatile T&, T) 3166 ParamTypes[0] 3167 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3168 ParamTypes[1] = T; 3169 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3170 /*IsAssignmentOperator=*/true); 3171 } 3172} 3173 3174/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3175/// if any, found in visible type conversion functions found in ArgExpr's type. 3176static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3177 Qualifiers VRQuals; 3178 const RecordType *TyRec; 3179 if (const MemberPointerType *RHSMPType = 3180 ArgExpr->getType()->getAs<MemberPointerType>()) 3181 TyRec = cast<RecordType>(RHSMPType->getClass()); 3182 else 3183 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3184 if (!TyRec) { 3185 // Just to be safe, assume the worst case. 3186 VRQuals.addVolatile(); 3187 VRQuals.addRestrict(); 3188 return VRQuals; 3189 } 3190 3191 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3192 OverloadedFunctionDecl *Conversions = 3193 ClassDecl->getVisibleConversionFunctions(); 3194 3195 for (OverloadedFunctionDecl::function_iterator Func 3196 = Conversions->function_begin(); 3197 Func != Conversions->function_end(); ++Func) { 3198 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*Func)) { 3199 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3200 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3201 CanTy = ResTypeRef->getPointeeType(); 3202 // Need to go down the pointer/mempointer chain and add qualifiers 3203 // as see them. 3204 bool done = false; 3205 while (!done) { 3206 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3207 CanTy = ResTypePtr->getPointeeType(); 3208 else if (const MemberPointerType *ResTypeMPtr = 3209 CanTy->getAs<MemberPointerType>()) 3210 CanTy = ResTypeMPtr->getPointeeType(); 3211 else 3212 done = true; 3213 if (CanTy.isVolatileQualified()) 3214 VRQuals.addVolatile(); 3215 if (CanTy.isRestrictQualified()) 3216 VRQuals.addRestrict(); 3217 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3218 return VRQuals; 3219 } 3220 } 3221 } 3222 return VRQuals; 3223} 3224 3225/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3226/// operator overloads to the candidate set (C++ [over.built]), based 3227/// on the operator @p Op and the arguments given. For example, if the 3228/// operator is a binary '+', this routine might add "int 3229/// operator+(int, int)" to cover integer addition. 3230void 3231Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3232 SourceLocation OpLoc, 3233 Expr **Args, unsigned NumArgs, 3234 OverloadCandidateSet& CandidateSet) { 3235 // The set of "promoted arithmetic types", which are the arithmetic 3236 // types are that preserved by promotion (C++ [over.built]p2). Note 3237 // that the first few of these types are the promoted integral 3238 // types; these types need to be first. 3239 // FIXME: What about complex? 3240 const unsigned FirstIntegralType = 0; 3241 const unsigned LastIntegralType = 13; 3242 const unsigned FirstPromotedIntegralType = 7, 3243 LastPromotedIntegralType = 13; 3244 const unsigned FirstPromotedArithmeticType = 7, 3245 LastPromotedArithmeticType = 16; 3246 const unsigned NumArithmeticTypes = 16; 3247 QualType ArithmeticTypes[NumArithmeticTypes] = { 3248 Context.BoolTy, Context.CharTy, Context.WCharTy, 3249// FIXME: Context.Char16Ty, Context.Char32Ty, 3250 Context.SignedCharTy, Context.ShortTy, 3251 Context.UnsignedCharTy, Context.UnsignedShortTy, 3252 Context.IntTy, Context.LongTy, Context.LongLongTy, 3253 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3254 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3255 }; 3256 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3257 "Invalid first promoted integral type"); 3258 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3259 == Context.UnsignedLongLongTy && 3260 "Invalid last promoted integral type"); 3261 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3262 "Invalid first promoted arithmetic type"); 3263 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3264 == Context.LongDoubleTy && 3265 "Invalid last promoted arithmetic type"); 3266 3267 // Find all of the types that the arguments can convert to, but only 3268 // if the operator we're looking at has built-in operator candidates 3269 // that make use of these types. 3270 Qualifiers VisibleTypeConversionsQuals; 3271 VisibleTypeConversionsQuals.addConst(); 3272 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3273 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3274 3275 BuiltinCandidateTypeSet CandidateTypes(*this); 3276 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3277 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3278 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3279 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3280 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3281 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3282 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3283 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3284 OpLoc, 3285 true, 3286 (Op == OO_Exclaim || 3287 Op == OO_AmpAmp || 3288 Op == OO_PipePipe), 3289 VisibleTypeConversionsQuals); 3290 } 3291 3292 bool isComparison = false; 3293 switch (Op) { 3294 case OO_None: 3295 case NUM_OVERLOADED_OPERATORS: 3296 assert(false && "Expected an overloaded operator"); 3297 break; 3298 3299 case OO_Star: // '*' is either unary or binary 3300 if (NumArgs == 1) 3301 goto UnaryStar; 3302 else 3303 goto BinaryStar; 3304 break; 3305 3306 case OO_Plus: // '+' is either unary or binary 3307 if (NumArgs == 1) 3308 goto UnaryPlus; 3309 else 3310 goto BinaryPlus; 3311 break; 3312 3313 case OO_Minus: // '-' is either unary or binary 3314 if (NumArgs == 1) 3315 goto UnaryMinus; 3316 else 3317 goto BinaryMinus; 3318 break; 3319 3320 case OO_Amp: // '&' is either unary or binary 3321 if (NumArgs == 1) 3322 goto UnaryAmp; 3323 else 3324 goto BinaryAmp; 3325 3326 case OO_PlusPlus: 3327 case OO_MinusMinus: 3328 // C++ [over.built]p3: 3329 // 3330 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3331 // is either volatile or empty, there exist candidate operator 3332 // functions of the form 3333 // 3334 // VQ T& operator++(VQ T&); 3335 // T operator++(VQ T&, int); 3336 // 3337 // C++ [over.built]p4: 3338 // 3339 // For every pair (T, VQ), where T is an arithmetic type other 3340 // than bool, and VQ is either volatile or empty, there exist 3341 // candidate operator functions of the form 3342 // 3343 // VQ T& operator--(VQ T&); 3344 // T operator--(VQ T&, int); 3345 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3346 Arith < NumArithmeticTypes; ++Arith) { 3347 QualType ArithTy = ArithmeticTypes[Arith]; 3348 QualType ParamTypes[2] 3349 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3350 3351 // Non-volatile version. 3352 if (NumArgs == 1) 3353 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3354 else 3355 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3356 // heuristic to reduce number of builtin candidates in the set. 3357 // Add volatile version only if there are conversions to a volatile type. 3358 if (VisibleTypeConversionsQuals.hasVolatile()) { 3359 // Volatile version 3360 ParamTypes[0] 3361 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3362 if (NumArgs == 1) 3363 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3364 else 3365 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3366 } 3367 } 3368 3369 // C++ [over.built]p5: 3370 // 3371 // For every pair (T, VQ), where T is a cv-qualified or 3372 // cv-unqualified object type, and VQ is either volatile or 3373 // empty, there exist candidate operator functions of the form 3374 // 3375 // T*VQ& operator++(T*VQ&); 3376 // T*VQ& operator--(T*VQ&); 3377 // T* operator++(T*VQ&, int); 3378 // T* operator--(T*VQ&, int); 3379 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3380 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3381 // Skip pointer types that aren't pointers to object types. 3382 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3383 continue; 3384 3385 QualType ParamTypes[2] = { 3386 Context.getLValueReferenceType(*Ptr), Context.IntTy 3387 }; 3388 3389 // Without volatile 3390 if (NumArgs == 1) 3391 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3392 else 3393 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3394 3395 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3396 VisibleTypeConversionsQuals.hasVolatile()) { 3397 // With volatile 3398 ParamTypes[0] 3399 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3400 if (NumArgs == 1) 3401 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3402 else 3403 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3404 } 3405 } 3406 break; 3407 3408 UnaryStar: 3409 // C++ [over.built]p6: 3410 // For every cv-qualified or cv-unqualified object type T, there 3411 // exist candidate operator functions of the form 3412 // 3413 // T& operator*(T*); 3414 // 3415 // C++ [over.built]p7: 3416 // For every function type T, there exist candidate operator 3417 // functions of the form 3418 // T& operator*(T*); 3419 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3420 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3421 QualType ParamTy = *Ptr; 3422 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3423 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3424 &ParamTy, Args, 1, CandidateSet); 3425 } 3426 break; 3427 3428 UnaryPlus: 3429 // C++ [over.built]p8: 3430 // For every type T, there exist candidate operator functions of 3431 // the form 3432 // 3433 // T* operator+(T*); 3434 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3435 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3436 QualType ParamTy = *Ptr; 3437 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3438 } 3439 3440 // Fall through 3441 3442 UnaryMinus: 3443 // C++ [over.built]p9: 3444 // For every promoted arithmetic type T, there exist candidate 3445 // operator functions of the form 3446 // 3447 // T operator+(T); 3448 // T operator-(T); 3449 for (unsigned Arith = FirstPromotedArithmeticType; 3450 Arith < LastPromotedArithmeticType; ++Arith) { 3451 QualType ArithTy = ArithmeticTypes[Arith]; 3452 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3453 } 3454 break; 3455 3456 case OO_Tilde: 3457 // C++ [over.built]p10: 3458 // For every promoted integral type T, there exist candidate 3459 // operator functions of the form 3460 // 3461 // T operator~(T); 3462 for (unsigned Int = FirstPromotedIntegralType; 3463 Int < LastPromotedIntegralType; ++Int) { 3464 QualType IntTy = ArithmeticTypes[Int]; 3465 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3466 } 3467 break; 3468 3469 case OO_New: 3470 case OO_Delete: 3471 case OO_Array_New: 3472 case OO_Array_Delete: 3473 case OO_Call: 3474 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3475 break; 3476 3477 case OO_Comma: 3478 UnaryAmp: 3479 case OO_Arrow: 3480 // C++ [over.match.oper]p3: 3481 // -- For the operator ',', the unary operator '&', or the 3482 // operator '->', the built-in candidates set is empty. 3483 break; 3484 3485 case OO_EqualEqual: 3486 case OO_ExclaimEqual: 3487 // C++ [over.match.oper]p16: 3488 // For every pointer to member type T, there exist candidate operator 3489 // functions of the form 3490 // 3491 // bool operator==(T,T); 3492 // bool operator!=(T,T); 3493 for (BuiltinCandidateTypeSet::iterator 3494 MemPtr = CandidateTypes.member_pointer_begin(), 3495 MemPtrEnd = CandidateTypes.member_pointer_end(); 3496 MemPtr != MemPtrEnd; 3497 ++MemPtr) { 3498 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3499 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3500 } 3501 3502 // Fall through 3503 3504 case OO_Less: 3505 case OO_Greater: 3506 case OO_LessEqual: 3507 case OO_GreaterEqual: 3508 // C++ [over.built]p15: 3509 // 3510 // For every pointer or enumeration type T, there exist 3511 // candidate operator functions of the form 3512 // 3513 // bool operator<(T, T); 3514 // bool operator>(T, T); 3515 // bool operator<=(T, T); 3516 // bool operator>=(T, T); 3517 // bool operator==(T, T); 3518 // bool operator!=(T, T); 3519 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3520 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3521 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3522 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3523 } 3524 for (BuiltinCandidateTypeSet::iterator Enum 3525 = CandidateTypes.enumeration_begin(); 3526 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3527 QualType ParamTypes[2] = { *Enum, *Enum }; 3528 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3529 } 3530 3531 // Fall through. 3532 isComparison = true; 3533 3534 BinaryPlus: 3535 BinaryMinus: 3536 if (!isComparison) { 3537 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3538 3539 // C++ [over.built]p13: 3540 // 3541 // For every cv-qualified or cv-unqualified object type T 3542 // there exist candidate operator functions of the form 3543 // 3544 // T* operator+(T*, ptrdiff_t); 3545 // T& operator[](T*, ptrdiff_t); [BELOW] 3546 // T* operator-(T*, ptrdiff_t); 3547 // T* operator+(ptrdiff_t, T*); 3548 // T& operator[](ptrdiff_t, T*); [BELOW] 3549 // 3550 // C++ [over.built]p14: 3551 // 3552 // For every T, where T is a pointer to object type, there 3553 // exist candidate operator functions of the form 3554 // 3555 // ptrdiff_t operator-(T, T); 3556 for (BuiltinCandidateTypeSet::iterator Ptr 3557 = CandidateTypes.pointer_begin(); 3558 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3559 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3560 3561 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3562 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3563 3564 if (Op == OO_Plus) { 3565 // T* operator+(ptrdiff_t, T*); 3566 ParamTypes[0] = ParamTypes[1]; 3567 ParamTypes[1] = *Ptr; 3568 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3569 } else { 3570 // ptrdiff_t operator-(T, T); 3571 ParamTypes[1] = *Ptr; 3572 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3573 Args, 2, CandidateSet); 3574 } 3575 } 3576 } 3577 // Fall through 3578 3579 case OO_Slash: 3580 BinaryStar: 3581 Conditional: 3582 // C++ [over.built]p12: 3583 // 3584 // For every pair of promoted arithmetic types L and R, there 3585 // exist candidate operator functions of the form 3586 // 3587 // LR operator*(L, R); 3588 // LR operator/(L, R); 3589 // LR operator+(L, R); 3590 // LR operator-(L, R); 3591 // bool operator<(L, R); 3592 // bool operator>(L, R); 3593 // bool operator<=(L, R); 3594 // bool operator>=(L, R); 3595 // bool operator==(L, R); 3596 // bool operator!=(L, R); 3597 // 3598 // where LR is the result of the usual arithmetic conversions 3599 // between types L and R. 3600 // 3601 // C++ [over.built]p24: 3602 // 3603 // For every pair of promoted arithmetic types L and R, there exist 3604 // candidate operator functions of the form 3605 // 3606 // LR operator?(bool, L, R); 3607 // 3608 // where LR is the result of the usual arithmetic conversions 3609 // between types L and R. 3610 // Our candidates ignore the first parameter. 3611 for (unsigned Left = FirstPromotedArithmeticType; 3612 Left < LastPromotedArithmeticType; ++Left) { 3613 for (unsigned Right = FirstPromotedArithmeticType; 3614 Right < LastPromotedArithmeticType; ++Right) { 3615 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3616 QualType Result 3617 = isComparison 3618 ? Context.BoolTy 3619 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3620 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3621 } 3622 } 3623 break; 3624 3625 case OO_Percent: 3626 BinaryAmp: 3627 case OO_Caret: 3628 case OO_Pipe: 3629 case OO_LessLess: 3630 case OO_GreaterGreater: 3631 // C++ [over.built]p17: 3632 // 3633 // For every pair of promoted integral types L and R, there 3634 // exist candidate operator functions of the form 3635 // 3636 // LR operator%(L, R); 3637 // LR operator&(L, R); 3638 // LR operator^(L, R); 3639 // LR operator|(L, R); 3640 // L operator<<(L, R); 3641 // L operator>>(L, R); 3642 // 3643 // where LR is the result of the usual arithmetic conversions 3644 // between types L and R. 3645 for (unsigned Left = FirstPromotedIntegralType; 3646 Left < LastPromotedIntegralType; ++Left) { 3647 for (unsigned Right = FirstPromotedIntegralType; 3648 Right < LastPromotedIntegralType; ++Right) { 3649 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3650 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3651 ? LandR[0] 3652 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3653 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3654 } 3655 } 3656 break; 3657 3658 case OO_Equal: 3659 // C++ [over.built]p20: 3660 // 3661 // For every pair (T, VQ), where T is an enumeration or 3662 // pointer to member type and VQ is either volatile or 3663 // empty, there exist candidate operator functions of the form 3664 // 3665 // VQ T& operator=(VQ T&, T); 3666 for (BuiltinCandidateTypeSet::iterator 3667 Enum = CandidateTypes.enumeration_begin(), 3668 EnumEnd = CandidateTypes.enumeration_end(); 3669 Enum != EnumEnd; ++Enum) 3670 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3671 CandidateSet); 3672 for (BuiltinCandidateTypeSet::iterator 3673 MemPtr = CandidateTypes.member_pointer_begin(), 3674 MemPtrEnd = CandidateTypes.member_pointer_end(); 3675 MemPtr != MemPtrEnd; ++MemPtr) 3676 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3677 CandidateSet); 3678 // Fall through. 3679 3680 case OO_PlusEqual: 3681 case OO_MinusEqual: 3682 // C++ [over.built]p19: 3683 // 3684 // For every pair (T, VQ), where T is any type and VQ is either 3685 // volatile or empty, there exist candidate operator functions 3686 // of the form 3687 // 3688 // T*VQ& operator=(T*VQ&, T*); 3689 // 3690 // C++ [over.built]p21: 3691 // 3692 // For every pair (T, VQ), where T is a cv-qualified or 3693 // cv-unqualified object type and VQ is either volatile or 3694 // empty, there exist candidate operator functions of the form 3695 // 3696 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3697 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3698 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3699 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3700 QualType ParamTypes[2]; 3701 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3702 3703 // non-volatile version 3704 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3705 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3706 /*IsAssigmentOperator=*/Op == OO_Equal); 3707 3708 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3709 VisibleTypeConversionsQuals.hasVolatile()) { 3710 // volatile version 3711 ParamTypes[0] 3712 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3713 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3714 /*IsAssigmentOperator=*/Op == OO_Equal); 3715 } 3716 } 3717 // Fall through. 3718 3719 case OO_StarEqual: 3720 case OO_SlashEqual: 3721 // C++ [over.built]p18: 3722 // 3723 // For every triple (L, VQ, R), where L is an arithmetic type, 3724 // VQ is either volatile or empty, and R is a promoted 3725 // arithmetic type, there exist candidate operator functions of 3726 // the form 3727 // 3728 // VQ L& operator=(VQ L&, R); 3729 // VQ L& operator*=(VQ L&, R); 3730 // VQ L& operator/=(VQ L&, R); 3731 // VQ L& operator+=(VQ L&, R); 3732 // VQ L& operator-=(VQ L&, R); 3733 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3734 for (unsigned Right = FirstPromotedArithmeticType; 3735 Right < LastPromotedArithmeticType; ++Right) { 3736 QualType ParamTypes[2]; 3737 ParamTypes[1] = ArithmeticTypes[Right]; 3738 3739 // Add this built-in operator as a candidate (VQ is empty). 3740 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3741 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3742 /*IsAssigmentOperator=*/Op == OO_Equal); 3743 3744 // Add this built-in operator as a candidate (VQ is 'volatile'). 3745 if (VisibleTypeConversionsQuals.hasVolatile()) { 3746 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3747 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3748 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3749 /*IsAssigmentOperator=*/Op == OO_Equal); 3750 } 3751 } 3752 } 3753 break; 3754 3755 case OO_PercentEqual: 3756 case OO_LessLessEqual: 3757 case OO_GreaterGreaterEqual: 3758 case OO_AmpEqual: 3759 case OO_CaretEqual: 3760 case OO_PipeEqual: 3761 // C++ [over.built]p22: 3762 // 3763 // For every triple (L, VQ, R), where L is an integral type, VQ 3764 // is either volatile or empty, and R is a promoted integral 3765 // type, there exist candidate operator functions of the form 3766 // 3767 // VQ L& operator%=(VQ L&, R); 3768 // VQ L& operator<<=(VQ L&, R); 3769 // VQ L& operator>>=(VQ L&, R); 3770 // VQ L& operator&=(VQ L&, R); 3771 // VQ L& operator^=(VQ L&, R); 3772 // VQ L& operator|=(VQ L&, R); 3773 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3774 for (unsigned Right = FirstPromotedIntegralType; 3775 Right < LastPromotedIntegralType; ++Right) { 3776 QualType ParamTypes[2]; 3777 ParamTypes[1] = ArithmeticTypes[Right]; 3778 3779 // Add this built-in operator as a candidate (VQ is empty). 3780 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3781 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3782 if (VisibleTypeConversionsQuals.hasVolatile()) { 3783 // Add this built-in operator as a candidate (VQ is 'volatile'). 3784 ParamTypes[0] = ArithmeticTypes[Left]; 3785 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3786 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3787 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3788 } 3789 } 3790 } 3791 break; 3792 3793 case OO_Exclaim: { 3794 // C++ [over.operator]p23: 3795 // 3796 // There also exist candidate operator functions of the form 3797 // 3798 // bool operator!(bool); 3799 // bool operator&&(bool, bool); [BELOW] 3800 // bool operator||(bool, bool); [BELOW] 3801 QualType ParamTy = Context.BoolTy; 3802 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3803 /*IsAssignmentOperator=*/false, 3804 /*NumContextualBoolArguments=*/1); 3805 break; 3806 } 3807 3808 case OO_AmpAmp: 3809 case OO_PipePipe: { 3810 // C++ [over.operator]p23: 3811 // 3812 // There also exist candidate operator functions of the form 3813 // 3814 // bool operator!(bool); [ABOVE] 3815 // bool operator&&(bool, bool); 3816 // bool operator||(bool, bool); 3817 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3818 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3819 /*IsAssignmentOperator=*/false, 3820 /*NumContextualBoolArguments=*/2); 3821 break; 3822 } 3823 3824 case OO_Subscript: 3825 // C++ [over.built]p13: 3826 // 3827 // For every cv-qualified or cv-unqualified object type T there 3828 // exist candidate operator functions of the form 3829 // 3830 // T* operator+(T*, ptrdiff_t); [ABOVE] 3831 // T& operator[](T*, ptrdiff_t); 3832 // T* operator-(T*, ptrdiff_t); [ABOVE] 3833 // T* operator+(ptrdiff_t, T*); [ABOVE] 3834 // T& operator[](ptrdiff_t, T*); 3835 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3836 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3837 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3838 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3839 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3840 3841 // T& operator[](T*, ptrdiff_t) 3842 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3843 3844 // T& operator[](ptrdiff_t, T*); 3845 ParamTypes[0] = ParamTypes[1]; 3846 ParamTypes[1] = *Ptr; 3847 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3848 } 3849 break; 3850 3851 case OO_ArrowStar: 3852 // C++ [over.built]p11: 3853 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 3854 // C1 is the same type as C2 or is a derived class of C2, T is an object 3855 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 3856 // there exist candidate operator functions of the form 3857 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 3858 // where CV12 is the union of CV1 and CV2. 3859 { 3860 for (BuiltinCandidateTypeSet::iterator Ptr = 3861 CandidateTypes.pointer_begin(); 3862 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3863 QualType C1Ty = (*Ptr); 3864 QualType C1; 3865 QualifierCollector Q1; 3866 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 3867 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 3868 if (!isa<RecordType>(C1)) 3869 continue; 3870 // heuristic to reduce number of builtin candidates in the set. 3871 // Add volatile/restrict version only if there are conversions to a 3872 // volatile/restrict type. 3873 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 3874 continue; 3875 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 3876 continue; 3877 } 3878 for (BuiltinCandidateTypeSet::iterator 3879 MemPtr = CandidateTypes.member_pointer_begin(), 3880 MemPtrEnd = CandidateTypes.member_pointer_end(); 3881 MemPtr != MemPtrEnd; ++MemPtr) { 3882 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 3883 QualType C2 = QualType(mptr->getClass(), 0); 3884 C2 = C2.getUnqualifiedType(); 3885 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 3886 break; 3887 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 3888 // build CV12 T& 3889 QualType T = mptr->getPointeeType(); 3890 if (!VisibleTypeConversionsQuals.hasVolatile() && 3891 T.isVolatileQualified()) 3892 continue; 3893 if (!VisibleTypeConversionsQuals.hasRestrict() && 3894 T.isRestrictQualified()) 3895 continue; 3896 T = Q1.apply(T); 3897 QualType ResultTy = Context.getLValueReferenceType(T); 3898 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3899 } 3900 } 3901 } 3902 break; 3903 3904 case OO_Conditional: 3905 // Note that we don't consider the first argument, since it has been 3906 // contextually converted to bool long ago. The candidates below are 3907 // therefore added as binary. 3908 // 3909 // C++ [over.built]p24: 3910 // For every type T, where T is a pointer or pointer-to-member type, 3911 // there exist candidate operator functions of the form 3912 // 3913 // T operator?(bool, T, T); 3914 // 3915 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3916 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3917 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3918 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3919 } 3920 for (BuiltinCandidateTypeSet::iterator Ptr = 3921 CandidateTypes.member_pointer_begin(), 3922 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3923 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3924 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3925 } 3926 goto Conditional; 3927 } 3928} 3929 3930/// \brief Add function candidates found via argument-dependent lookup 3931/// to the set of overloading candidates. 3932/// 3933/// This routine performs argument-dependent name lookup based on the 3934/// given function name (which may also be an operator name) and adds 3935/// all of the overload candidates found by ADL to the overload 3936/// candidate set (C++ [basic.lookup.argdep]). 3937void 3938Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3939 Expr **Args, unsigned NumArgs, 3940 bool HasExplicitTemplateArgs, 3941 const TemplateArgumentLoc *ExplicitTemplateArgs, 3942 unsigned NumExplicitTemplateArgs, 3943 OverloadCandidateSet& CandidateSet, 3944 bool PartialOverloading) { 3945 FunctionSet Functions; 3946 3947 // FIXME: Should we be trafficking in canonical function decls throughout? 3948 3949 // Record all of the function candidates that we've already 3950 // added to the overload set, so that we don't add those same 3951 // candidates a second time. 3952 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3953 CandEnd = CandidateSet.end(); 3954 Cand != CandEnd; ++Cand) 3955 if (Cand->Function) { 3956 Functions.insert(Cand->Function); 3957 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3958 Functions.insert(FunTmpl); 3959 } 3960 3961 // FIXME: Pass in the explicit template arguments? 3962 ArgumentDependentLookup(Name, /*Operator*/false, Args, NumArgs, Functions); 3963 3964 // Erase all of the candidates we already knew about. 3965 // FIXME: This is suboptimal. Is there a better way? 3966 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3967 CandEnd = CandidateSet.end(); 3968 Cand != CandEnd; ++Cand) 3969 if (Cand->Function) { 3970 Functions.erase(Cand->Function); 3971 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3972 Functions.erase(FunTmpl); 3973 } 3974 3975 // For each of the ADL candidates we found, add it to the overload 3976 // set. 3977 for (FunctionSet::iterator Func = Functions.begin(), 3978 FuncEnd = Functions.end(); 3979 Func != FuncEnd; ++Func) { 3980 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3981 if (HasExplicitTemplateArgs) 3982 continue; 3983 3984 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3985 false, false, PartialOverloading); 3986 } else 3987 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3988 HasExplicitTemplateArgs, 3989 ExplicitTemplateArgs, 3990 NumExplicitTemplateArgs, 3991 Args, NumArgs, CandidateSet); 3992 } 3993} 3994 3995/// isBetterOverloadCandidate - Determines whether the first overload 3996/// candidate is a better candidate than the second (C++ 13.3.3p1). 3997bool 3998Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3999 const OverloadCandidate& Cand2) { 4000 // Define viable functions to be better candidates than non-viable 4001 // functions. 4002 if (!Cand2.Viable) 4003 return Cand1.Viable; 4004 else if (!Cand1.Viable) 4005 return false; 4006 4007 // C++ [over.match.best]p1: 4008 // 4009 // -- if F is a static member function, ICS1(F) is defined such 4010 // that ICS1(F) is neither better nor worse than ICS1(G) for 4011 // any function G, and, symmetrically, ICS1(G) is neither 4012 // better nor worse than ICS1(F). 4013 unsigned StartArg = 0; 4014 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4015 StartArg = 1; 4016 4017 // C++ [over.match.best]p1: 4018 // A viable function F1 is defined to be a better function than another 4019 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4020 // conversion sequence than ICSi(F2), and then... 4021 unsigned NumArgs = Cand1.Conversions.size(); 4022 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4023 bool HasBetterConversion = false; 4024 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4025 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4026 Cand2.Conversions[ArgIdx])) { 4027 case ImplicitConversionSequence::Better: 4028 // Cand1 has a better conversion sequence. 4029 HasBetterConversion = true; 4030 break; 4031 4032 case ImplicitConversionSequence::Worse: 4033 // Cand1 can't be better than Cand2. 4034 return false; 4035 4036 case ImplicitConversionSequence::Indistinguishable: 4037 // Do nothing. 4038 break; 4039 } 4040 } 4041 4042 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4043 // ICSj(F2), or, if not that, 4044 if (HasBetterConversion) 4045 return true; 4046 4047 // - F1 is a non-template function and F2 is a function template 4048 // specialization, or, if not that, 4049 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4050 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4051 return true; 4052 4053 // -- F1 and F2 are function template specializations, and the function 4054 // template for F1 is more specialized than the template for F2 4055 // according to the partial ordering rules described in 14.5.5.2, or, 4056 // if not that, 4057 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4058 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4059 if (FunctionTemplateDecl *BetterTemplate 4060 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4061 Cand2.Function->getPrimaryTemplate(), 4062 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4063 : TPOC_Call)) 4064 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4065 4066 // -- the context is an initialization by user-defined conversion 4067 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4068 // from the return type of F1 to the destination type (i.e., 4069 // the type of the entity being initialized) is a better 4070 // conversion sequence than the standard conversion sequence 4071 // from the return type of F2 to the destination type. 4072 if (Cand1.Function && Cand2.Function && 4073 isa<CXXConversionDecl>(Cand1.Function) && 4074 isa<CXXConversionDecl>(Cand2.Function)) { 4075 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4076 Cand2.FinalConversion)) { 4077 case ImplicitConversionSequence::Better: 4078 // Cand1 has a better conversion sequence. 4079 return true; 4080 4081 case ImplicitConversionSequence::Worse: 4082 // Cand1 can't be better than Cand2. 4083 return false; 4084 4085 case ImplicitConversionSequence::Indistinguishable: 4086 // Do nothing 4087 break; 4088 } 4089 } 4090 4091 return false; 4092} 4093 4094/// \brief Computes the best viable function (C++ 13.3.3) 4095/// within an overload candidate set. 4096/// 4097/// \param CandidateSet the set of candidate functions. 4098/// 4099/// \param Loc the location of the function name (or operator symbol) for 4100/// which overload resolution occurs. 4101/// 4102/// \param Best f overload resolution was successful or found a deleted 4103/// function, Best points to the candidate function found. 4104/// 4105/// \returns The result of overload resolution. 4106Sema::OverloadingResult 4107Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4108 SourceLocation Loc, 4109 OverloadCandidateSet::iterator& Best) { 4110 // Find the best viable function. 4111 Best = CandidateSet.end(); 4112 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4113 Cand != CandidateSet.end(); ++Cand) { 4114 if (Cand->Viable) { 4115 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 4116 Best = Cand; 4117 } 4118 } 4119 4120 // If we didn't find any viable functions, abort. 4121 if (Best == CandidateSet.end()) 4122 return OR_No_Viable_Function; 4123 4124 // Make sure that this function is better than every other viable 4125 // function. If not, we have an ambiguity. 4126 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4127 Cand != CandidateSet.end(); ++Cand) { 4128 if (Cand->Viable && 4129 Cand != Best && 4130 !isBetterOverloadCandidate(*Best, *Cand)) { 4131 Best = CandidateSet.end(); 4132 return OR_Ambiguous; 4133 } 4134 } 4135 4136 // Best is the best viable function. 4137 if (Best->Function && 4138 (Best->Function->isDeleted() || 4139 Best->Function->getAttr<UnavailableAttr>())) 4140 return OR_Deleted; 4141 4142 // C++ [basic.def.odr]p2: 4143 // An overloaded function is used if it is selected by overload resolution 4144 // when referred to from a potentially-evaluated expression. [Note: this 4145 // covers calls to named functions (5.2.2), operator overloading 4146 // (clause 13), user-defined conversions (12.3.2), allocation function for 4147 // placement new (5.3.4), as well as non-default initialization (8.5). 4148 if (Best->Function) 4149 MarkDeclarationReferenced(Loc, Best->Function); 4150 return OR_Success; 4151} 4152 4153/// PrintOverloadCandidates - When overload resolution fails, prints 4154/// diagnostic messages containing the candidates in the candidate 4155/// set. If OnlyViable is true, only viable candidates will be printed. 4156void 4157Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4158 bool OnlyViable, 4159 const char *Opc, 4160 SourceLocation OpLoc) { 4161 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4162 LastCand = CandidateSet.end(); 4163 bool Reported = false; 4164 for (; Cand != LastCand; ++Cand) { 4165 if (Cand->Viable || !OnlyViable) { 4166 if (Cand->Function) { 4167 if (Cand->Function->isDeleted() || 4168 Cand->Function->getAttr<UnavailableAttr>()) { 4169 // Deleted or "unavailable" function. 4170 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 4171 << Cand->Function->isDeleted(); 4172 } else if (FunctionTemplateDecl *FunTmpl 4173 = Cand->Function->getPrimaryTemplate()) { 4174 // Function template specialization 4175 // FIXME: Give a better reason! 4176 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 4177 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 4178 *Cand->Function->getTemplateSpecializationArgs()); 4179 } else { 4180 // Normal function 4181 bool errReported = false; 4182 if (!Cand->Viable && Cand->Conversions.size() > 0) { 4183 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 4184 const ImplicitConversionSequence &Conversion = 4185 Cand->Conversions[i]; 4186 if ((Conversion.ConversionKind != 4187 ImplicitConversionSequence::BadConversion) || 4188 Conversion.ConversionFunctionSet.size() == 0) 4189 continue; 4190 Diag(Cand->Function->getLocation(), 4191 diag::err_ovl_candidate_not_viable) << (i+1); 4192 errReported = true; 4193 for (int j = Conversion.ConversionFunctionSet.size()-1; 4194 j >= 0; j--) { 4195 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 4196 Diag(Func->getLocation(), diag::err_ovl_candidate); 4197 } 4198 } 4199 } 4200 if (!errReported) 4201 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 4202 } 4203 } else if (Cand->IsSurrogate) { 4204 // Desugar the type of the surrogate down to a function type, 4205 // retaining as many typedefs as possible while still showing 4206 // the function type (and, therefore, its parameter types). 4207 QualType FnType = Cand->Surrogate->getConversionType(); 4208 bool isLValueReference = false; 4209 bool isRValueReference = false; 4210 bool isPointer = false; 4211 if (const LValueReferenceType *FnTypeRef = 4212 FnType->getAs<LValueReferenceType>()) { 4213 FnType = FnTypeRef->getPointeeType(); 4214 isLValueReference = true; 4215 } else if (const RValueReferenceType *FnTypeRef = 4216 FnType->getAs<RValueReferenceType>()) { 4217 FnType = FnTypeRef->getPointeeType(); 4218 isRValueReference = true; 4219 } 4220 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4221 FnType = FnTypePtr->getPointeeType(); 4222 isPointer = true; 4223 } 4224 // Desugar down to a function type. 4225 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4226 // Reconstruct the pointer/reference as appropriate. 4227 if (isPointer) FnType = Context.getPointerType(FnType); 4228 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 4229 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 4230 4231 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 4232 << FnType; 4233 } else if (OnlyViable) { 4234 assert(Cand->Conversions.size() <= 2 && 4235 "builtin-binary-operator-not-binary"); 4236 std::string TypeStr("operator"); 4237 TypeStr += Opc; 4238 TypeStr += "("; 4239 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4240 if (Cand->Conversions.size() == 1) { 4241 TypeStr += ")"; 4242 Diag(OpLoc, diag::err_ovl_builtin_unary_candidate) << TypeStr; 4243 } 4244 else { 4245 TypeStr += ", "; 4246 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4247 TypeStr += ")"; 4248 Diag(OpLoc, diag::err_ovl_builtin_binary_candidate) << TypeStr; 4249 } 4250 } 4251 else if (!Cand->Viable && !Reported) { 4252 // Non-viability might be due to ambiguous user-defined conversions, 4253 // needed for built-in operators. Report them as well, but only once 4254 // as we have typically many built-in candidates. 4255 unsigned NoOperands = Cand->Conversions.size(); 4256 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4257 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4258 if (ICS.ConversionKind != ImplicitConversionSequence::BadConversion || 4259 ICS.ConversionFunctionSet.empty()) 4260 continue; 4261 if (CXXConversionDecl *Func = dyn_cast<CXXConversionDecl>( 4262 Cand->Conversions[ArgIdx].ConversionFunctionSet[0])) { 4263 QualType FromTy = 4264 QualType( 4265 static_cast<Type*>(ICS.UserDefined.Before.FromTypePtr),0); 4266 Diag(OpLoc,diag::note_ambiguous_type_conversion) 4267 << FromTy << Func->getConversionType(); 4268 } 4269 for (unsigned j = 0; j < ICS.ConversionFunctionSet.size(); j++) { 4270 FunctionDecl *Func = 4271 Cand->Conversions[ArgIdx].ConversionFunctionSet[j]; 4272 Diag(Func->getLocation(),diag::err_ovl_candidate); 4273 } 4274 } 4275 Reported = true; 4276 } 4277 } 4278 } 4279} 4280 4281/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4282/// an overloaded function (C++ [over.over]), where @p From is an 4283/// expression with overloaded function type and @p ToType is the type 4284/// we're trying to resolve to. For example: 4285/// 4286/// @code 4287/// int f(double); 4288/// int f(int); 4289/// 4290/// int (*pfd)(double) = f; // selects f(double) 4291/// @endcode 4292/// 4293/// This routine returns the resulting FunctionDecl if it could be 4294/// resolved, and NULL otherwise. When @p Complain is true, this 4295/// routine will emit diagnostics if there is an error. 4296FunctionDecl * 4297Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4298 bool Complain) { 4299 QualType FunctionType = ToType; 4300 bool IsMember = false; 4301 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4302 FunctionType = ToTypePtr->getPointeeType(); 4303 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4304 FunctionType = ToTypeRef->getPointeeType(); 4305 else if (const MemberPointerType *MemTypePtr = 4306 ToType->getAs<MemberPointerType>()) { 4307 FunctionType = MemTypePtr->getPointeeType(); 4308 IsMember = true; 4309 } 4310 4311 // We only look at pointers or references to functions. 4312 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4313 if (!FunctionType->isFunctionType()) 4314 return 0; 4315 4316 // Find the actual overloaded function declaration. 4317 OverloadedFunctionDecl *Ovl = 0; 4318 4319 // C++ [over.over]p1: 4320 // [...] [Note: any redundant set of parentheses surrounding the 4321 // overloaded function name is ignored (5.1). ] 4322 Expr *OvlExpr = From->IgnoreParens(); 4323 4324 // C++ [over.over]p1: 4325 // [...] The overloaded function name can be preceded by the & 4326 // operator. 4327 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4328 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4329 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4330 } 4331 4332 bool HasExplicitTemplateArgs = false; 4333 const TemplateArgumentLoc *ExplicitTemplateArgs = 0; 4334 unsigned NumExplicitTemplateArgs = 0; 4335 4336 // Try to dig out the overloaded function. 4337 FunctionTemplateDecl *FunctionTemplate = 0; 4338 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4339 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4340 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4341 HasExplicitTemplateArgs = DR->hasExplicitTemplateArgumentList(); 4342 ExplicitTemplateArgs = DR->getTemplateArgs(); 4343 NumExplicitTemplateArgs = DR->getNumTemplateArgs(); 4344 } else if (MemberExpr *ME = dyn_cast<MemberExpr>(OvlExpr)) { 4345 Ovl = dyn_cast<OverloadedFunctionDecl>(ME->getMemberDecl()); 4346 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(ME->getMemberDecl()); 4347 HasExplicitTemplateArgs = ME->hasExplicitTemplateArgumentList(); 4348 ExplicitTemplateArgs = ME->getTemplateArgs(); 4349 NumExplicitTemplateArgs = ME->getNumTemplateArgs(); 4350 } else if (TemplateIdRefExpr *TIRE = dyn_cast<TemplateIdRefExpr>(OvlExpr)) { 4351 TemplateName Name = TIRE->getTemplateName(); 4352 Ovl = Name.getAsOverloadedFunctionDecl(); 4353 FunctionTemplate = 4354 dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl()); 4355 4356 HasExplicitTemplateArgs = true; 4357 ExplicitTemplateArgs = TIRE->getTemplateArgs(); 4358 NumExplicitTemplateArgs = TIRE->getNumTemplateArgs(); 4359 } 4360 4361 // If there's no overloaded function declaration or function template, 4362 // we're done. 4363 if (!Ovl && !FunctionTemplate) 4364 return 0; 4365 4366 OverloadIterator Fun; 4367 if (Ovl) 4368 Fun = Ovl; 4369 else 4370 Fun = FunctionTemplate; 4371 4372 // Look through all of the overloaded functions, searching for one 4373 // whose type matches exactly. 4374 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4375 bool FoundNonTemplateFunction = false; 4376 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4377 // C++ [over.over]p3: 4378 // Non-member functions and static member functions match 4379 // targets of type "pointer-to-function" or "reference-to-function." 4380 // Nonstatic member functions match targets of 4381 // type "pointer-to-member-function." 4382 // Note that according to DR 247, the containing class does not matter. 4383 4384 if (FunctionTemplateDecl *FunctionTemplate 4385 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4386 if (CXXMethodDecl *Method 4387 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4388 // Skip non-static function templates when converting to pointer, and 4389 // static when converting to member pointer. 4390 if (Method->isStatic() == IsMember) 4391 continue; 4392 } else if (IsMember) 4393 continue; 4394 4395 // C++ [over.over]p2: 4396 // If the name is a function template, template argument deduction is 4397 // done (14.8.2.2), and if the argument deduction succeeds, the 4398 // resulting template argument list is used to generate a single 4399 // function template specialization, which is added to the set of 4400 // overloaded functions considered. 4401 // FIXME: We don't really want to build the specialization here, do we? 4402 FunctionDecl *Specialization = 0; 4403 TemplateDeductionInfo Info(Context); 4404 if (TemplateDeductionResult Result 4405 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 4406 ExplicitTemplateArgs, 4407 NumExplicitTemplateArgs, 4408 FunctionType, Specialization, Info)) { 4409 // FIXME: make a note of the failed deduction for diagnostics. 4410 (void)Result; 4411 } else { 4412 // FIXME: If the match isn't exact, shouldn't we just drop this as 4413 // a candidate? Find a testcase before changing the code. 4414 assert(FunctionType 4415 == Context.getCanonicalType(Specialization->getType())); 4416 Matches.insert( 4417 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4418 } 4419 } 4420 4421 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4422 // Skip non-static functions when converting to pointer, and static 4423 // when converting to member pointer. 4424 if (Method->isStatic() == IsMember) 4425 continue; 4426 4427 // If we have explicit template arguments, skip non-templates. 4428 if (HasExplicitTemplateArgs) 4429 continue; 4430 } else if (IsMember) 4431 continue; 4432 4433 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4434 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4435 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4436 FoundNonTemplateFunction = true; 4437 } 4438 } 4439 } 4440 4441 // If there were 0 or 1 matches, we're done. 4442 if (Matches.empty()) 4443 return 0; 4444 else if (Matches.size() == 1) { 4445 FunctionDecl *Result = *Matches.begin(); 4446 MarkDeclarationReferenced(From->getLocStart(), Result); 4447 return Result; 4448 } 4449 4450 // C++ [over.over]p4: 4451 // If more than one function is selected, [...] 4452 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4453 if (!FoundNonTemplateFunction) { 4454 // [...] and any given function template specialization F1 is 4455 // eliminated if the set contains a second function template 4456 // specialization whose function template is more specialized 4457 // than the function template of F1 according to the partial 4458 // ordering rules of 14.5.5.2. 4459 4460 // The algorithm specified above is quadratic. We instead use a 4461 // two-pass algorithm (similar to the one used to identify the 4462 // best viable function in an overload set) that identifies the 4463 // best function template (if it exists). 4464 llvm::SmallVector<FunctionDecl *, 8> TemplateMatches(Matches.begin(), 4465 Matches.end()); 4466 FunctionDecl *Result = 4467 getMostSpecialized(TemplateMatches.data(), TemplateMatches.size(), 4468 TPOC_Other, From->getLocStart(), 4469 PDiag(), 4470 PDiag(diag::err_addr_ovl_ambiguous) 4471 << TemplateMatches[0]->getDeclName(), 4472 PDiag(diag::err_ovl_template_candidate)); 4473 MarkDeclarationReferenced(From->getLocStart(), Result); 4474 return Result; 4475 } 4476 4477 // [...] any function template specializations in the set are 4478 // eliminated if the set also contains a non-template function, [...] 4479 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4480 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4481 if ((*M)->getPrimaryTemplate() == 0) 4482 RemainingMatches.push_back(*M); 4483 4484 // [...] After such eliminations, if any, there shall remain exactly one 4485 // selected function. 4486 if (RemainingMatches.size() == 1) { 4487 FunctionDecl *Result = RemainingMatches.front(); 4488 MarkDeclarationReferenced(From->getLocStart(), Result); 4489 return Result; 4490 } 4491 4492 // FIXME: We should probably return the same thing that BestViableFunction 4493 // returns (even if we issue the diagnostics here). 4494 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4495 << RemainingMatches[0]->getDeclName(); 4496 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4497 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4498 return 0; 4499} 4500 4501/// \brief Add a single candidate to the overload set. 4502static void AddOverloadedCallCandidate(Sema &S, 4503 AnyFunctionDecl Callee, 4504 bool &ArgumentDependentLookup, 4505 bool HasExplicitTemplateArgs, 4506 const TemplateArgumentLoc *ExplicitTemplateArgs, 4507 unsigned NumExplicitTemplateArgs, 4508 Expr **Args, unsigned NumArgs, 4509 OverloadCandidateSet &CandidateSet, 4510 bool PartialOverloading) { 4511 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4512 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4513 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4514 PartialOverloading); 4515 4516 if (Func->getDeclContext()->isRecord() || 4517 Func->getDeclContext()->isFunctionOrMethod()) 4518 ArgumentDependentLookup = false; 4519 return; 4520 } 4521 4522 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4523 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4524 ExplicitTemplateArgs, 4525 NumExplicitTemplateArgs, 4526 Args, NumArgs, CandidateSet); 4527 4528 if (FuncTemplate->getDeclContext()->isRecord()) 4529 ArgumentDependentLookup = false; 4530} 4531 4532/// \brief Add the overload candidates named by callee and/or found by argument 4533/// dependent lookup to the given overload set. 4534void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4535 DeclarationName &UnqualifiedName, 4536 bool &ArgumentDependentLookup, 4537 bool HasExplicitTemplateArgs, 4538 const TemplateArgumentLoc *ExplicitTemplateArgs, 4539 unsigned NumExplicitTemplateArgs, 4540 Expr **Args, unsigned NumArgs, 4541 OverloadCandidateSet &CandidateSet, 4542 bool PartialOverloading) { 4543 // Add the functions denoted by Callee to the set of candidate 4544 // functions. While we're doing so, track whether argument-dependent 4545 // lookup still applies, per: 4546 // 4547 // C++0x [basic.lookup.argdep]p3: 4548 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4549 // and let Y be the lookup set produced by argument dependent 4550 // lookup (defined as follows). If X contains 4551 // 4552 // -- a declaration of a class member, or 4553 // 4554 // -- a block-scope function declaration that is not a 4555 // using-declaration (FIXME: check for using declaration), or 4556 // 4557 // -- a declaration that is neither a function or a function 4558 // template 4559 // 4560 // then Y is empty. 4561 if (!Callee) { 4562 // Nothing to do. 4563 } else if (OverloadedFunctionDecl *Ovl 4564 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4565 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4566 FuncEnd = Ovl->function_end(); 4567 Func != FuncEnd; ++Func) 4568 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4569 HasExplicitTemplateArgs, 4570 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4571 Args, NumArgs, CandidateSet, 4572 PartialOverloading); 4573 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4574 AddOverloadedCallCandidate(*this, 4575 AnyFunctionDecl::getFromNamedDecl(Callee), 4576 ArgumentDependentLookup, 4577 HasExplicitTemplateArgs, 4578 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4579 Args, NumArgs, CandidateSet, 4580 PartialOverloading); 4581 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4582 // checking dynamically. 4583 4584 if (Callee) 4585 UnqualifiedName = Callee->getDeclName(); 4586 4587 if (ArgumentDependentLookup) 4588 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4589 HasExplicitTemplateArgs, 4590 ExplicitTemplateArgs, 4591 NumExplicitTemplateArgs, 4592 CandidateSet, 4593 PartialOverloading); 4594} 4595 4596/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4597/// (which eventually refers to the declaration Func) and the call 4598/// arguments Args/NumArgs, attempt to resolve the function call down 4599/// to a specific function. If overload resolution succeeds, returns 4600/// the function declaration produced by overload 4601/// resolution. Otherwise, emits diagnostics, deletes all of the 4602/// arguments and Fn, and returns NULL. 4603FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4604 DeclarationName UnqualifiedName, 4605 bool HasExplicitTemplateArgs, 4606 const TemplateArgumentLoc *ExplicitTemplateArgs, 4607 unsigned NumExplicitTemplateArgs, 4608 SourceLocation LParenLoc, 4609 Expr **Args, unsigned NumArgs, 4610 SourceLocation *CommaLocs, 4611 SourceLocation RParenLoc, 4612 bool &ArgumentDependentLookup) { 4613 OverloadCandidateSet CandidateSet; 4614 4615 // Add the functions denoted by Callee to the set of candidate 4616 // functions. 4617 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4618 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4619 NumExplicitTemplateArgs, Args, NumArgs, 4620 CandidateSet); 4621 OverloadCandidateSet::iterator Best; 4622 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4623 case OR_Success: 4624 return Best->Function; 4625 4626 case OR_No_Viable_Function: 4627 Diag(Fn->getSourceRange().getBegin(), 4628 diag::err_ovl_no_viable_function_in_call) 4629 << UnqualifiedName << Fn->getSourceRange(); 4630 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4631 break; 4632 4633 case OR_Ambiguous: 4634 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4635 << UnqualifiedName << Fn->getSourceRange(); 4636 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4637 break; 4638 4639 case OR_Deleted: 4640 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4641 << Best->Function->isDeleted() 4642 << UnqualifiedName 4643 << Fn->getSourceRange(); 4644 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4645 break; 4646 } 4647 4648 // Overload resolution failed. Destroy all of the subexpressions and 4649 // return NULL. 4650 Fn->Destroy(Context); 4651 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4652 Args[Arg]->Destroy(Context); 4653 return 0; 4654} 4655 4656/// \brief Create a unary operation that may resolve to an overloaded 4657/// operator. 4658/// 4659/// \param OpLoc The location of the operator itself (e.g., '*'). 4660/// 4661/// \param OpcIn The UnaryOperator::Opcode that describes this 4662/// operator. 4663/// 4664/// \param Functions The set of non-member functions that will be 4665/// considered by overload resolution. The caller needs to build this 4666/// set based on the context using, e.g., 4667/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4668/// set should not contain any member functions; those will be added 4669/// by CreateOverloadedUnaryOp(). 4670/// 4671/// \param input The input argument. 4672Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4673 unsigned OpcIn, 4674 FunctionSet &Functions, 4675 ExprArg input) { 4676 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4677 Expr *Input = (Expr *)input.get(); 4678 4679 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4680 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4681 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4682 4683 Expr *Args[2] = { Input, 0 }; 4684 unsigned NumArgs = 1; 4685 4686 // For post-increment and post-decrement, add the implicit '0' as 4687 // the second argument, so that we know this is a post-increment or 4688 // post-decrement. 4689 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4690 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4691 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4692 SourceLocation()); 4693 NumArgs = 2; 4694 } 4695 4696 if (Input->isTypeDependent()) { 4697 OverloadedFunctionDecl *Overloads 4698 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4699 for (FunctionSet::iterator Func = Functions.begin(), 4700 FuncEnd = Functions.end(); 4701 Func != FuncEnd; ++Func) 4702 Overloads->addOverload(*Func); 4703 4704 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4705 OpLoc, false, false); 4706 4707 input.release(); 4708 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4709 &Args[0], NumArgs, 4710 Context.DependentTy, 4711 OpLoc)); 4712 } 4713 4714 // Build an empty overload set. 4715 OverloadCandidateSet CandidateSet; 4716 4717 // Add the candidates from the given function set. 4718 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4719 4720 // Add operator candidates that are member functions. 4721 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4722 4723 // Add builtin operator candidates. 4724 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4725 4726 // Perform overload resolution. 4727 OverloadCandidateSet::iterator Best; 4728 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4729 case OR_Success: { 4730 // We found a built-in operator or an overloaded operator. 4731 FunctionDecl *FnDecl = Best->Function; 4732 4733 if (FnDecl) { 4734 // We matched an overloaded operator. Build a call to that 4735 // operator. 4736 4737 // Convert the arguments. 4738 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4739 if (PerformObjectArgumentInitialization(Input, Method)) 4740 return ExprError(); 4741 } else { 4742 // Convert the arguments. 4743 if (PerformCopyInitialization(Input, 4744 FnDecl->getParamDecl(0)->getType(), 4745 "passing")) 4746 return ExprError(); 4747 } 4748 4749 // Determine the result type 4750 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 4751 4752 // Build the actual expression node. 4753 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4754 SourceLocation()); 4755 UsualUnaryConversions(FnExpr); 4756 4757 input.release(); 4758 Args[0] = Input; 4759 ExprOwningPtr<CallExpr> TheCall(this, 4760 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4761 Args, NumArgs, ResultTy, OpLoc)); 4762 4763 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4764 FnDecl)) 4765 return ExprError(); 4766 4767 return MaybeBindToTemporary(TheCall.release()); 4768 } else { 4769 // We matched a built-in operator. Convert the arguments, then 4770 // break out so that we will build the appropriate built-in 4771 // operator node. 4772 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4773 Best->Conversions[0], "passing")) 4774 return ExprError(); 4775 4776 break; 4777 } 4778 } 4779 4780 case OR_No_Viable_Function: 4781 // No viable function; fall through to handling this as a 4782 // built-in operator, which will produce an error message for us. 4783 break; 4784 4785 case OR_Ambiguous: 4786 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4787 << UnaryOperator::getOpcodeStr(Opc) 4788 << Input->getSourceRange(); 4789 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4790 UnaryOperator::getOpcodeStr(Opc), OpLoc); 4791 return ExprError(); 4792 4793 case OR_Deleted: 4794 Diag(OpLoc, diag::err_ovl_deleted_oper) 4795 << Best->Function->isDeleted() 4796 << UnaryOperator::getOpcodeStr(Opc) 4797 << Input->getSourceRange(); 4798 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4799 return ExprError(); 4800 } 4801 4802 // Either we found no viable overloaded operator or we matched a 4803 // built-in operator. In either case, fall through to trying to 4804 // build a built-in operation. 4805 input.release(); 4806 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4807} 4808 4809/// \brief Create a binary operation that may resolve to an overloaded 4810/// operator. 4811/// 4812/// \param OpLoc The location of the operator itself (e.g., '+'). 4813/// 4814/// \param OpcIn The BinaryOperator::Opcode that describes this 4815/// operator. 4816/// 4817/// \param Functions The set of non-member functions that will be 4818/// considered by overload resolution. The caller needs to build this 4819/// set based on the context using, e.g., 4820/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4821/// set should not contain any member functions; those will be added 4822/// by CreateOverloadedBinOp(). 4823/// 4824/// \param LHS Left-hand argument. 4825/// \param RHS Right-hand argument. 4826Sema::OwningExprResult 4827Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4828 unsigned OpcIn, 4829 FunctionSet &Functions, 4830 Expr *LHS, Expr *RHS) { 4831 Expr *Args[2] = { LHS, RHS }; 4832 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4833 4834 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4835 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4836 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4837 4838 // If either side is type-dependent, create an appropriate dependent 4839 // expression. 4840 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4841 if (Functions.empty()) { 4842 // If there are no functions to store, just build a dependent 4843 // BinaryOperator or CompoundAssignment. 4844 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 4845 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4846 Context.DependentTy, OpLoc)); 4847 4848 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 4849 Context.DependentTy, 4850 Context.DependentTy, 4851 Context.DependentTy, 4852 OpLoc)); 4853 } 4854 4855 OverloadedFunctionDecl *Overloads 4856 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4857 for (FunctionSet::iterator Func = Functions.begin(), 4858 FuncEnd = Functions.end(); 4859 Func != FuncEnd; ++Func) 4860 Overloads->addOverload(*Func); 4861 4862 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4863 OpLoc, false, false); 4864 4865 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4866 Args, 2, 4867 Context.DependentTy, 4868 OpLoc)); 4869 } 4870 4871 // If this is the .* operator, which is not overloadable, just 4872 // create a built-in binary operator. 4873 if (Opc == BinaryOperator::PtrMemD) 4874 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4875 4876 // If this is one of the assignment operators, we only perform 4877 // overload resolution if the left-hand side is a class or 4878 // enumeration type (C++ [expr.ass]p3). 4879 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4880 !Args[0]->getType()->isOverloadableType()) 4881 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4882 4883 // Build an empty overload set. 4884 OverloadCandidateSet CandidateSet; 4885 4886 // Add the candidates from the given function set. 4887 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4888 4889 // Add operator candidates that are member functions. 4890 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4891 4892 // Add builtin operator candidates. 4893 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4894 4895 // Perform overload resolution. 4896 OverloadCandidateSet::iterator Best; 4897 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4898 case OR_Success: { 4899 // We found a built-in operator or an overloaded operator. 4900 FunctionDecl *FnDecl = Best->Function; 4901 4902 if (FnDecl) { 4903 // We matched an overloaded operator. Build a call to that 4904 // operator. 4905 4906 // Convert the arguments. 4907 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4908 if (PerformObjectArgumentInitialization(Args[0], Method) || 4909 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4910 "passing")) 4911 return ExprError(); 4912 } else { 4913 // Convert the arguments. 4914 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4915 "passing") || 4916 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4917 "passing")) 4918 return ExprError(); 4919 } 4920 4921 // Determine the result type 4922 QualType ResultTy 4923 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4924 ResultTy = ResultTy.getNonReferenceType(); 4925 4926 // Build the actual expression node. 4927 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4928 OpLoc); 4929 UsualUnaryConversions(FnExpr); 4930 4931 ExprOwningPtr<CXXOperatorCallExpr> 4932 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4933 Args, 2, ResultTy, 4934 OpLoc)); 4935 4936 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4937 FnDecl)) 4938 return ExprError(); 4939 4940 return MaybeBindToTemporary(TheCall.release()); 4941 } else { 4942 // We matched a built-in operator. Convert the arguments, then 4943 // break out so that we will build the appropriate built-in 4944 // operator node. 4945 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4946 Best->Conversions[0], "passing") || 4947 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4948 Best->Conversions[1], "passing")) 4949 return ExprError(); 4950 4951 break; 4952 } 4953 } 4954 4955 case OR_No_Viable_Function: { 4956 // C++ [over.match.oper]p9: 4957 // If the operator is the operator , [...] and there are no 4958 // viable functions, then the operator is assumed to be the 4959 // built-in operator and interpreted according to clause 5. 4960 if (Opc == BinaryOperator::Comma) 4961 break; 4962 4963 // For class as left operand for assignment or compound assigment operator 4964 // do not fall through to handling in built-in, but report that no overloaded 4965 // assignment operator found 4966 OwningExprResult Result = ExprError(); 4967 if (Args[0]->getType()->isRecordType() && 4968 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4969 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4970 << BinaryOperator::getOpcodeStr(Opc) 4971 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4972 } else { 4973 // No viable function; try to create a built-in operation, which will 4974 // produce an error. Then, show the non-viable candidates. 4975 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4976 } 4977 assert(Result.isInvalid() && 4978 "C++ binary operator overloading is missing candidates!"); 4979 if (Result.isInvalid()) 4980 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 4981 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4982 return move(Result); 4983 } 4984 4985 case OR_Ambiguous: 4986 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4987 << BinaryOperator::getOpcodeStr(Opc) 4988 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4989 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4990 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4991 return ExprError(); 4992 4993 case OR_Deleted: 4994 Diag(OpLoc, diag::err_ovl_deleted_oper) 4995 << Best->Function->isDeleted() 4996 << BinaryOperator::getOpcodeStr(Opc) 4997 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4998 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4999 return ExprError(); 5000 } 5001 5002 // We matched a built-in operator; build it. 5003 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5004} 5005 5006Action::OwningExprResult 5007Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 5008 SourceLocation RLoc, 5009 ExprArg Base, ExprArg Idx) { 5010 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 5011 static_cast<Expr*>(Idx.get()) }; 5012 DeclarationName OpName = 5013 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 5014 5015 // If either side is type-dependent, create an appropriate dependent 5016 // expression. 5017 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5018 5019 OverloadedFunctionDecl *Overloads 5020 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 5021 5022 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 5023 LLoc, false, false); 5024 5025 Base.release(); 5026 Idx.release(); 5027 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5028 Args, 2, 5029 Context.DependentTy, 5030 RLoc)); 5031 } 5032 5033 // Build an empty overload set. 5034 OverloadCandidateSet CandidateSet; 5035 5036 // Subscript can only be overloaded as a member function. 5037 5038 // Add operator candidates that are member functions. 5039 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5040 5041 // Add builtin operator candidates. 5042 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5043 5044 // Perform overload resolution. 5045 OverloadCandidateSet::iterator Best; 5046 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5047 case OR_Success: { 5048 // We found a built-in operator or an overloaded operator. 5049 FunctionDecl *FnDecl = Best->Function; 5050 5051 if (FnDecl) { 5052 // We matched an overloaded operator. Build a call to that 5053 // operator. 5054 5055 // Convert the arguments. 5056 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5057 if (PerformObjectArgumentInitialization(Args[0], Method) || 5058 PerformCopyInitialization(Args[1], 5059 FnDecl->getParamDecl(0)->getType(), 5060 "passing")) 5061 return ExprError(); 5062 5063 // Determine the result type 5064 QualType ResultTy 5065 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5066 ResultTy = ResultTy.getNonReferenceType(); 5067 5068 // Build the actual expression node. 5069 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5070 LLoc); 5071 UsualUnaryConversions(FnExpr); 5072 5073 Base.release(); 5074 Idx.release(); 5075 ExprOwningPtr<CXXOperatorCallExpr> 5076 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5077 FnExpr, Args, 2, 5078 ResultTy, RLoc)); 5079 5080 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5081 FnDecl)) 5082 return ExprError(); 5083 5084 return MaybeBindToTemporary(TheCall.release()); 5085 } else { 5086 // We matched a built-in operator. Convert the arguments, then 5087 // break out so that we will build the appropriate built-in 5088 // operator node. 5089 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5090 Best->Conversions[0], "passing") || 5091 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5092 Best->Conversions[1], "passing")) 5093 return ExprError(); 5094 5095 break; 5096 } 5097 } 5098 5099 case OR_No_Viable_Function: { 5100 // No viable function; try to create a built-in operation, which will 5101 // produce an error. Then, show the non-viable candidates. 5102 OwningExprResult Result = 5103 CreateBuiltinArraySubscriptExpr(move(Base), LLoc, move(Idx), RLoc); 5104 assert(Result.isInvalid() && 5105 "C++ subscript operator overloading is missing candidates!"); 5106 if (Result.isInvalid()) 5107 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 5108 "[]", LLoc); 5109 return move(Result); 5110 } 5111 5112 case OR_Ambiguous: 5113 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5114 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5115 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 5116 "[]", LLoc); 5117 return ExprError(); 5118 5119 case OR_Deleted: 5120 Diag(LLoc, diag::err_ovl_deleted_oper) 5121 << Best->Function->isDeleted() << "[]" 5122 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5123 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5124 return ExprError(); 5125 } 5126 5127 // We matched a built-in operator; build it. 5128 Base.release(); 5129 Idx.release(); 5130 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 5131 Owned(Args[1]), RLoc); 5132} 5133 5134/// BuildCallToMemberFunction - Build a call to a member 5135/// function. MemExpr is the expression that refers to the member 5136/// function (and includes the object parameter), Args/NumArgs are the 5137/// arguments to the function call (not including the object 5138/// parameter). The caller needs to validate that the member 5139/// expression refers to a member function or an overloaded member 5140/// function. 5141Sema::ExprResult 5142Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 5143 SourceLocation LParenLoc, Expr **Args, 5144 unsigned NumArgs, SourceLocation *CommaLocs, 5145 SourceLocation RParenLoc) { 5146 // Dig out the member expression. This holds both the object 5147 // argument and the member function we're referring to. 5148 MemberExpr *MemExpr = 0; 5149 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 5150 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 5151 else 5152 MemExpr = dyn_cast<MemberExpr>(MemExprE); 5153 assert(MemExpr && "Building member call without member expression"); 5154 5155 // Extract the object argument. 5156 Expr *ObjectArg = MemExpr->getBase(); 5157 5158 CXXMethodDecl *Method = 0; 5159 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 5160 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 5161 // Add overload candidates 5162 OverloadCandidateSet CandidateSet; 5163 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 5164 5165 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 5166 Func != FuncEnd; ++Func) { 5167 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) { 5168 // If explicit template arguments were provided, we can't call a 5169 // non-template member function. 5170 if (MemExpr->hasExplicitTemplateArgumentList()) 5171 continue; 5172 5173 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 5174 /*SuppressUserConversions=*/false); 5175 } else 5176 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 5177 MemExpr->hasExplicitTemplateArgumentList(), 5178 MemExpr->getTemplateArgs(), 5179 MemExpr->getNumTemplateArgs(), 5180 ObjectArg, Args, NumArgs, 5181 CandidateSet, 5182 /*SuppressUsedConversions=*/false); 5183 } 5184 5185 OverloadCandidateSet::iterator Best; 5186 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 5187 case OR_Success: 5188 Method = cast<CXXMethodDecl>(Best->Function); 5189 break; 5190 5191 case OR_No_Viable_Function: 5192 Diag(MemExpr->getSourceRange().getBegin(), 5193 diag::err_ovl_no_viable_member_function_in_call) 5194 << DeclName << MemExprE->getSourceRange(); 5195 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5196 // FIXME: Leaking incoming expressions! 5197 return true; 5198 5199 case OR_Ambiguous: 5200 Diag(MemExpr->getSourceRange().getBegin(), 5201 diag::err_ovl_ambiguous_member_call) 5202 << DeclName << MemExprE->getSourceRange(); 5203 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5204 // FIXME: Leaking incoming expressions! 5205 return true; 5206 5207 case OR_Deleted: 5208 Diag(MemExpr->getSourceRange().getBegin(), 5209 diag::err_ovl_deleted_member_call) 5210 << Best->Function->isDeleted() 5211 << DeclName << MemExprE->getSourceRange(); 5212 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5213 // FIXME: Leaking incoming expressions! 5214 return true; 5215 } 5216 5217 FixOverloadedFunctionReference(MemExpr, Method); 5218 } else { 5219 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 5220 } 5221 5222 assert(Method && "Member call to something that isn't a method?"); 5223 ExprOwningPtr<CXXMemberCallExpr> 5224 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 5225 NumArgs, 5226 Method->getResultType().getNonReferenceType(), 5227 RParenLoc)); 5228 5229 // Check for a valid return type. 5230 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 5231 TheCall.get(), Method)) 5232 return true; 5233 5234 // Convert the object argument (for a non-static member function call). 5235 if (!Method->isStatic() && 5236 PerformObjectArgumentInitialization(ObjectArg, Method)) 5237 return true; 5238 MemExpr->setBase(ObjectArg); 5239 5240 // Convert the rest of the arguments 5241 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 5242 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 5243 RParenLoc)) 5244 return true; 5245 5246 if (CheckFunctionCall(Method, TheCall.get())) 5247 return true; 5248 5249 return MaybeBindToTemporary(TheCall.release()).release(); 5250} 5251 5252/// BuildCallToObjectOfClassType - Build a call to an object of class 5253/// type (C++ [over.call.object]), which can end up invoking an 5254/// overloaded function call operator (@c operator()) or performing a 5255/// user-defined conversion on the object argument. 5256Sema::ExprResult 5257Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 5258 SourceLocation LParenLoc, 5259 Expr **Args, unsigned NumArgs, 5260 SourceLocation *CommaLocs, 5261 SourceLocation RParenLoc) { 5262 assert(Object->getType()->isRecordType() && "Requires object type argument"); 5263 const RecordType *Record = Object->getType()->getAs<RecordType>(); 5264 5265 // C++ [over.call.object]p1: 5266 // If the primary-expression E in the function call syntax 5267 // evaluates to a class object of type "cv T", then the set of 5268 // candidate functions includes at least the function call 5269 // operators of T. The function call operators of T are obtained by 5270 // ordinary lookup of the name operator() in the context of 5271 // (E).operator(). 5272 OverloadCandidateSet CandidateSet; 5273 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 5274 5275 if (RequireCompleteType(LParenLoc, Object->getType(), 5276 PartialDiagnostic(diag::err_incomplete_object_call) 5277 << Object->getSourceRange())) 5278 return true; 5279 5280 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 5281 LookupQualifiedName(R, Record->getDecl()); 5282 R.suppressDiagnostics(); 5283 5284 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5285 Oper != OperEnd; ++Oper) { 5286 AddMethodCandidate(*Oper, Object, Args, NumArgs, CandidateSet, 5287 /*SuppressUserConversions=*/ false); 5288 } 5289 5290 // C++ [over.call.object]p2: 5291 // In addition, for each conversion function declared in T of the 5292 // form 5293 // 5294 // operator conversion-type-id () cv-qualifier; 5295 // 5296 // where cv-qualifier is the same cv-qualification as, or a 5297 // greater cv-qualification than, cv, and where conversion-type-id 5298 // denotes the type "pointer to function of (P1,...,Pn) returning 5299 // R", or the type "reference to pointer to function of 5300 // (P1,...,Pn) returning R", or the type "reference to function 5301 // of (P1,...,Pn) returning R", a surrogate call function [...] 5302 // is also considered as a candidate function. Similarly, 5303 // surrogate call functions are added to the set of candidate 5304 // functions for each conversion function declared in an 5305 // accessible base class provided the function is not hidden 5306 // within T by another intervening declaration. 5307 // FIXME: Look in base classes for more conversion operators! 5308 OverloadedFunctionDecl *Conversions 5309 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 5310 for (OverloadedFunctionDecl::function_iterator 5311 Func = Conversions->function_begin(), 5312 FuncEnd = Conversions->function_end(); 5313 Func != FuncEnd; ++Func) { 5314 CXXConversionDecl *Conv; 5315 FunctionTemplateDecl *ConvTemplate; 5316 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 5317 5318 // Skip over templated conversion functions; they aren't 5319 // surrogates. 5320 if (ConvTemplate) 5321 continue; 5322 5323 // Strip the reference type (if any) and then the pointer type (if 5324 // any) to get down to what might be a function type. 5325 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 5326 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5327 ConvType = ConvPtrType->getPointeeType(); 5328 5329 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 5330 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 5331 } 5332 5333 // Perform overload resolution. 5334 OverloadCandidateSet::iterator Best; 5335 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 5336 case OR_Success: 5337 // Overload resolution succeeded; we'll build the appropriate call 5338 // below. 5339 break; 5340 5341 case OR_No_Viable_Function: 5342 Diag(Object->getSourceRange().getBegin(), 5343 diag::err_ovl_no_viable_object_call) 5344 << Object->getType() << Object->getSourceRange(); 5345 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5346 break; 5347 5348 case OR_Ambiguous: 5349 Diag(Object->getSourceRange().getBegin(), 5350 diag::err_ovl_ambiguous_object_call) 5351 << Object->getType() << Object->getSourceRange(); 5352 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5353 break; 5354 5355 case OR_Deleted: 5356 Diag(Object->getSourceRange().getBegin(), 5357 diag::err_ovl_deleted_object_call) 5358 << Best->Function->isDeleted() 5359 << Object->getType() << Object->getSourceRange(); 5360 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5361 break; 5362 } 5363 5364 if (Best == CandidateSet.end()) { 5365 // We had an error; delete all of the subexpressions and return 5366 // the error. 5367 Object->Destroy(Context); 5368 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5369 Args[ArgIdx]->Destroy(Context); 5370 return true; 5371 } 5372 5373 if (Best->Function == 0) { 5374 // Since there is no function declaration, this is one of the 5375 // surrogate candidates. Dig out the conversion function. 5376 CXXConversionDecl *Conv 5377 = cast<CXXConversionDecl>( 5378 Best->Conversions[0].UserDefined.ConversionFunction); 5379 5380 // We selected one of the surrogate functions that converts the 5381 // object parameter to a function pointer. Perform the conversion 5382 // on the object argument, then let ActOnCallExpr finish the job. 5383 5384 // Create an implicit member expr to refer to the conversion operator. 5385 // and then call it. 5386 CXXMemberCallExpr *CE = 5387 BuildCXXMemberCallExpr(Object, Conv); 5388 5389 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 5390 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 5391 CommaLocs, RParenLoc).release(); 5392 } 5393 5394 // We found an overloaded operator(). Build a CXXOperatorCallExpr 5395 // that calls this method, using Object for the implicit object 5396 // parameter and passing along the remaining arguments. 5397 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5398 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 5399 5400 unsigned NumArgsInProto = Proto->getNumArgs(); 5401 unsigned NumArgsToCheck = NumArgs; 5402 5403 // Build the full argument list for the method call (the 5404 // implicit object parameter is placed at the beginning of the 5405 // list). 5406 Expr **MethodArgs; 5407 if (NumArgs < NumArgsInProto) { 5408 NumArgsToCheck = NumArgsInProto; 5409 MethodArgs = new Expr*[NumArgsInProto + 1]; 5410 } else { 5411 MethodArgs = new Expr*[NumArgs + 1]; 5412 } 5413 MethodArgs[0] = Object; 5414 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5415 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 5416 5417 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 5418 SourceLocation()); 5419 UsualUnaryConversions(NewFn); 5420 5421 // Once we've built TheCall, all of the expressions are properly 5422 // owned. 5423 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5424 ExprOwningPtr<CXXOperatorCallExpr> 5425 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 5426 MethodArgs, NumArgs + 1, 5427 ResultTy, RParenLoc)); 5428 delete [] MethodArgs; 5429 5430 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 5431 Method)) 5432 return true; 5433 5434 // We may have default arguments. If so, we need to allocate more 5435 // slots in the call for them. 5436 if (NumArgs < NumArgsInProto) 5437 TheCall->setNumArgs(Context, NumArgsInProto + 1); 5438 else if (NumArgs > NumArgsInProto) 5439 NumArgsToCheck = NumArgsInProto; 5440 5441 bool IsError = false; 5442 5443 // Initialize the implicit object parameter. 5444 IsError |= PerformObjectArgumentInitialization(Object, Method); 5445 TheCall->setArg(0, Object); 5446 5447 5448 // Check the argument types. 5449 for (unsigned i = 0; i != NumArgsToCheck; i++) { 5450 Expr *Arg; 5451 if (i < NumArgs) { 5452 Arg = Args[i]; 5453 5454 // Pass the argument. 5455 QualType ProtoArgType = Proto->getArgType(i); 5456 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 5457 } else { 5458 OwningExprResult DefArg 5459 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 5460 if (DefArg.isInvalid()) { 5461 IsError = true; 5462 break; 5463 } 5464 5465 Arg = DefArg.takeAs<Expr>(); 5466 } 5467 5468 TheCall->setArg(i + 1, Arg); 5469 } 5470 5471 // If this is a variadic call, handle args passed through "...". 5472 if (Proto->isVariadic()) { 5473 // Promote the arguments (C99 6.5.2.2p7). 5474 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 5475 Expr *Arg = Args[i]; 5476 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 5477 TheCall->setArg(i + 1, Arg); 5478 } 5479 } 5480 5481 if (IsError) return true; 5482 5483 if (CheckFunctionCall(Method, TheCall.get())) 5484 return true; 5485 5486 return MaybeBindToTemporary(TheCall.release()).release(); 5487} 5488 5489/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 5490/// (if one exists), where @c Base is an expression of class type and 5491/// @c Member is the name of the member we're trying to find. 5492Sema::OwningExprResult 5493Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 5494 Expr *Base = static_cast<Expr *>(BaseIn.get()); 5495 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 5496 5497 // C++ [over.ref]p1: 5498 // 5499 // [...] An expression x->m is interpreted as (x.operator->())->m 5500 // for a class object x of type T if T::operator->() exists and if 5501 // the operator is selected as the best match function by the 5502 // overload resolution mechanism (13.3). 5503 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 5504 OverloadCandidateSet CandidateSet; 5505 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 5506 5507 if (RequireCompleteType(Base->getLocStart(), Base->getType(), 5508 PDiag(diag::err_typecheck_incomplete_tag) 5509 << Base->getSourceRange())) 5510 return ExprError(); 5511 5512 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 5513 LookupQualifiedName(R, BaseRecord->getDecl()); 5514 R.suppressDiagnostics(); 5515 5516 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5517 Oper != OperEnd; ++Oper) 5518 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 5519 /*SuppressUserConversions=*/false); 5520 5521 // Perform overload resolution. 5522 OverloadCandidateSet::iterator Best; 5523 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5524 case OR_Success: 5525 // Overload resolution succeeded; we'll build the call below. 5526 break; 5527 5528 case OR_No_Viable_Function: 5529 if (CandidateSet.empty()) 5530 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5531 << Base->getType() << Base->getSourceRange(); 5532 else 5533 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5534 << "operator->" << Base->getSourceRange(); 5535 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5536 return ExprError(); 5537 5538 case OR_Ambiguous: 5539 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5540 << "->" << Base->getSourceRange(); 5541 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5542 return ExprError(); 5543 5544 case OR_Deleted: 5545 Diag(OpLoc, diag::err_ovl_deleted_oper) 5546 << Best->Function->isDeleted() 5547 << "->" << Base->getSourceRange(); 5548 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5549 return ExprError(); 5550 } 5551 5552 // Convert the object parameter. 5553 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5554 if (PerformObjectArgumentInitialization(Base, Method)) 5555 return ExprError(); 5556 5557 // No concerns about early exits now. 5558 BaseIn.release(); 5559 5560 // Build the operator call. 5561 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5562 SourceLocation()); 5563 UsualUnaryConversions(FnExpr); 5564 5565 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5566 ExprOwningPtr<CXXOperatorCallExpr> 5567 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 5568 &Base, 1, ResultTy, OpLoc)); 5569 5570 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 5571 Method)) 5572 return ExprError(); 5573 return move(TheCall); 5574} 5575 5576/// FixOverloadedFunctionReference - E is an expression that refers to 5577/// a C++ overloaded function (possibly with some parentheses and 5578/// perhaps a '&' around it). We have resolved the overloaded function 5579/// to the function declaration Fn, so patch up the expression E to 5580/// refer (possibly indirectly) to Fn. Returns the new expr. 5581Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5582 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5583 Expr *NewExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5584 PE->setSubExpr(NewExpr); 5585 PE->setType(NewExpr->getType()); 5586 } else if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 5587 Expr *NewExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 5588 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 5589 NewExpr->getType()) && 5590 "Implicit cast type cannot be determined from overload"); 5591 ICE->setSubExpr(NewExpr); 5592 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5593 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5594 "Can only take the address of an overloaded function"); 5595 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5596 if (Method->isStatic()) { 5597 // Do nothing: static member functions aren't any different 5598 // from non-member functions. 5599 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr())) { 5600 if (DRE->getQualifier()) { 5601 // We have taken the address of a pointer to member 5602 // function. Perform the computation here so that we get the 5603 // appropriate pointer to member type. 5604 DRE->setDecl(Fn); 5605 DRE->setType(Fn->getType()); 5606 QualType ClassType 5607 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5608 E->setType(Context.getMemberPointerType(Fn->getType(), 5609 ClassType.getTypePtr())); 5610 return E; 5611 } 5612 } 5613 // FIXME: TemplateIdRefExpr referring to a member function template 5614 // specialization! 5615 } 5616 Expr *NewExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5617 UnOp->setSubExpr(NewExpr); 5618 UnOp->setType(Context.getPointerType(NewExpr->getType())); 5619 5620 return UnOp; 5621 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5622 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5623 isa<FunctionTemplateDecl>(DR->getDecl()) || 5624 isa<FunctionDecl>(DR->getDecl())) && 5625 "Expected function or function template"); 5626 DR->setDecl(Fn); 5627 E->setType(Fn->getType()); 5628 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5629 MemExpr->setMemberDecl(Fn); 5630 E->setType(Fn->getType()); 5631 } else if (TemplateIdRefExpr *TID = dyn_cast<TemplateIdRefExpr>(E)) { 5632 E = DeclRefExpr::Create(Context, 5633 TID->getQualifier(), TID->getQualifierRange(), 5634 Fn, TID->getTemplateNameLoc(), 5635 true, 5636 TID->getLAngleLoc(), 5637 TID->getTemplateArgs(), 5638 TID->getNumTemplateArgs(), 5639 TID->getRAngleLoc(), 5640 Fn->getType(), 5641 /*FIXME?*/false, /*FIXME?*/false); 5642 5643 // FIXME: Don't destroy TID here, since we need its template arguments 5644 // to survive. 5645 // TID->Destroy(Context); 5646 } else if (isa<UnresolvedFunctionNameExpr>(E)) { 5647 return DeclRefExpr::Create(Context, 5648 /*Qualifier=*/0, 5649 /*QualifierRange=*/SourceRange(), 5650 Fn, E->getLocStart(), 5651 Fn->getType(), false, false); 5652 } else { 5653 assert(false && "Invalid reference to overloaded function"); 5654 } 5655 5656 return E; 5657} 5658 5659} // end namespace clang 5660