SemaOverload.cpp revision 52ab92bee00eb14e38dcbefc091d6b9aa5157506
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInherit.h" 16#include "clang/Basic/Diagnostic.h" 17#include "clang/Lex/Preprocessor.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/TypeOrdering.h" 22#include "llvm/ADT/SmallPtrSet.h" 23#include "llvm/ADT/STLExtras.h" 24#include "llvm/Support/Compiler.h" 25#include <algorithm> 26 27namespace clang { 28 29/// GetConversionCategory - Retrieve the implicit conversion 30/// category corresponding to the given implicit conversion kind. 31ImplicitConversionCategory 32GetConversionCategory(ImplicitConversionKind Kind) { 33 static const ImplicitConversionCategory 34 Category[(int)ICK_Num_Conversion_Kinds] = { 35 ICC_Identity, 36 ICC_Lvalue_Transformation, 37 ICC_Lvalue_Transformation, 38 ICC_Lvalue_Transformation, 39 ICC_Qualification_Adjustment, 40 ICC_Promotion, 41 ICC_Promotion, 42 ICC_Promotion, 43 ICC_Conversion, 44 ICC_Conversion, 45 ICC_Conversion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion 53 }; 54 return Category[(int)Kind]; 55} 56 57/// GetConversionRank - Retrieve the implicit conversion rank 58/// corresponding to the given implicit conversion kind. 59ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 60 static const ImplicitConversionRank 61 Rank[(int)ICK_Num_Conversion_Kinds] = { 62 ICR_Exact_Match, 63 ICR_Exact_Match, 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Promotion, 68 ICR_Promotion, 69 ICR_Promotion, 70 ICR_Conversion, 71 ICR_Conversion, 72 ICR_Conversion, 73 ICR_Conversion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion 80 }; 81 return Rank[(int)Kind]; 82} 83 84/// GetImplicitConversionName - Return the name of this kind of 85/// implicit conversion. 86const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 87 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 88 "No conversion", 89 "Lvalue-to-rvalue", 90 "Array-to-pointer", 91 "Function-to-pointer", 92 "Qualification", 93 "Integral promotion", 94 "Floating point promotion", 95 "Complex promotion", 96 "Integral conversion", 97 "Floating conversion", 98 "Complex conversion", 99 "Floating-integral conversion", 100 "Complex-real conversion", 101 "Pointer conversion", 102 "Pointer-to-member conversion", 103 "Boolean conversion", 104 "Compatible-types conversion", 105 "Derived-to-base conversion" 106 }; 107 return Name[Kind]; 108} 109 110/// StandardConversionSequence - Set the standard conversion 111/// sequence to the identity conversion. 112void StandardConversionSequence::setAsIdentityConversion() { 113 First = ICK_Identity; 114 Second = ICK_Identity; 115 Third = ICK_Identity; 116 Deprecated = false; 117 ReferenceBinding = false; 118 DirectBinding = false; 119 RRefBinding = false; 120 CopyConstructor = 0; 121} 122 123/// getRank - Retrieve the rank of this standard conversion sequence 124/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 125/// implicit conversions. 126ImplicitConversionRank StandardConversionSequence::getRank() const { 127 ImplicitConversionRank Rank = ICR_Exact_Match; 128 if (GetConversionRank(First) > Rank) 129 Rank = GetConversionRank(First); 130 if (GetConversionRank(Second) > Rank) 131 Rank = GetConversionRank(Second); 132 if (GetConversionRank(Third) > Rank) 133 Rank = GetConversionRank(Third); 134 return Rank; 135} 136 137/// isPointerConversionToBool - Determines whether this conversion is 138/// a conversion of a pointer or pointer-to-member to bool. This is 139/// used as part of the ranking of standard conversion sequences 140/// (C++ 13.3.3.2p4). 141bool StandardConversionSequence::isPointerConversionToBool() const 142{ 143 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 144 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 145 146 // Note that FromType has not necessarily been transformed by the 147 // array-to-pointer or function-to-pointer implicit conversions, so 148 // check for their presence as well as checking whether FromType is 149 // a pointer. 150 if (ToType->isBooleanType() && 151 (FromType->isPointerType() || FromType->isBlockPointerType() || 152 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 153 return true; 154 155 return false; 156} 157 158/// isPointerConversionToVoidPointer - Determines whether this 159/// conversion is a conversion of a pointer to a void pointer. This is 160/// used as part of the ranking of standard conversion sequences (C++ 161/// 13.3.3.2p4). 162bool 163StandardConversionSequence:: 164isPointerConversionToVoidPointer(ASTContext& Context) const 165{ 166 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 167 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 bool PrintedSomething = false; 186 if (First != ICK_Identity) { 187 fprintf(stderr, "%s", GetImplicitConversionName(First)); 188 PrintedSomething = true; 189 } 190 191 if (Second != ICK_Identity) { 192 if (PrintedSomething) { 193 fprintf(stderr, " -> "); 194 } 195 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 196 197 if (CopyConstructor) { 198 fprintf(stderr, " (by copy constructor)"); 199 } else if (DirectBinding) { 200 fprintf(stderr, " (direct reference binding)"); 201 } else if (ReferenceBinding) { 202 fprintf(stderr, " (reference binding)"); 203 } 204 PrintedSomething = true; 205 } 206 207 if (Third != ICK_Identity) { 208 if (PrintedSomething) { 209 fprintf(stderr, " -> "); 210 } 211 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 212 PrintedSomething = true; 213 } 214 215 if (!PrintedSomething) { 216 fprintf(stderr, "No conversions required"); 217 } 218} 219 220/// DebugPrint - Print this user-defined conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void UserDefinedConversionSequence::DebugPrint() const { 223 if (Before.First || Before.Second || Before.Third) { 224 Before.DebugPrint(); 225 fprintf(stderr, " -> "); 226 } 227 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 228 if (After.First || After.Second || After.Third) { 229 fprintf(stderr, " -> "); 230 After.DebugPrint(); 231 } 232} 233 234/// DebugPrint - Print this implicit conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void ImplicitConversionSequence::DebugPrint() const { 237 switch (ConversionKind) { 238 case StandardConversion: 239 fprintf(stderr, "Standard conversion: "); 240 Standard.DebugPrint(); 241 break; 242 case UserDefinedConversion: 243 fprintf(stderr, "User-defined conversion: "); 244 UserDefined.DebugPrint(); 245 break; 246 case EllipsisConversion: 247 fprintf(stderr, "Ellipsis conversion"); 248 break; 249 case BadConversion: 250 fprintf(stderr, "Bad conversion"); 251 break; 252 } 253 254 fprintf(stderr, "\n"); 255} 256 257// IsOverload - Determine whether the given New declaration is an 258// overload of the Old declaration. This routine returns false if New 259// and Old cannot be overloaded, e.g., if they are functions with the 260// same signature (C++ 1.3.10) or if the Old declaration isn't a 261// function (or overload set). When it does return false and Old is an 262// OverloadedFunctionDecl, MatchedDecl will be set to point to the 263// FunctionDecl that New cannot be overloaded with. 264// 265// Example: Given the following input: 266// 267// void f(int, float); // #1 268// void f(int, int); // #2 269// int f(int, int); // #3 270// 271// When we process #1, there is no previous declaration of "f", 272// so IsOverload will not be used. 273// 274// When we process #2, Old is a FunctionDecl for #1. By comparing the 275// parameter types, we see that #1 and #2 are overloaded (since they 276// have different signatures), so this routine returns false; 277// MatchedDecl is unchanged. 278// 279// When we process #3, Old is an OverloadedFunctionDecl containing #1 280// and #2. We compare the signatures of #3 to #1 (they're overloaded, 281// so we do nothing) and then #3 to #2. Since the signatures of #3 and 282// #2 are identical (return types of functions are not part of the 283// signature), IsOverload returns false and MatchedDecl will be set to 284// point to the FunctionDecl for #2. 285bool 286Sema::IsOverload(FunctionDecl *New, Decl* OldD, 287 OverloadedFunctionDecl::function_iterator& MatchedDecl) 288{ 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, false, SourceLocation()) || 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. 408ImplicitConversionSequence 409Sema::TryImplicitConversion(Expr* From, QualType ToType, 410 bool SuppressUserConversions, 411 bool AllowExplicit, bool ForceRValue) 412{ 413 ImplicitConversionSequence ICS; 414 if (IsStandardConversion(From, ToType, ICS.Standard)) 415 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 416 else if (getLangOptions().CPlusPlus && 417 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 418 !SuppressUserConversions, AllowExplicit, 419 ForceRValue)) { 420 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 421 // C++ [over.ics.user]p4: 422 // A conversion of an expression of class type to the same class 423 // type is given Exact Match rank, and a conversion of an 424 // expression of class type to a base class of that type is 425 // given Conversion rank, in spite of the fact that a copy 426 // constructor (i.e., a user-defined conversion function) is 427 // called for those cases. 428 if (CXXConstructorDecl *Constructor 429 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 430 QualType FromCanon 431 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 432 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 433 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 434 // Turn this into a "standard" conversion sequence, so that it 435 // gets ranked with standard conversion sequences. 436 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 437 ICS.Standard.setAsIdentityConversion(); 438 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 439 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 440 ICS.Standard.CopyConstructor = Constructor; 441 if (ToCanon != FromCanon) 442 ICS.Standard.Second = ICK_Derived_To_Base; 443 } 444 } 445 446 // C++ [over.best.ics]p4: 447 // However, when considering the argument of a user-defined 448 // conversion function that is a candidate by 13.3.1.3 when 449 // invoked for the copying of the temporary in the second step 450 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 451 // 13.3.1.6 in all cases, only standard conversion sequences and 452 // ellipsis conversion sequences are allowed. 453 if (SuppressUserConversions && 454 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 455 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 456 } else 457 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 458 459 return ICS; 460} 461 462/// IsStandardConversion - Determines whether there is a standard 463/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 464/// expression From to the type ToType. Standard conversion sequences 465/// only consider non-class types; for conversions that involve class 466/// types, use TryImplicitConversion. If a conversion exists, SCS will 467/// contain the standard conversion sequence required to perform this 468/// conversion and this routine will return true. Otherwise, this 469/// routine will return false and the value of SCS is unspecified. 470bool 471Sema::IsStandardConversion(Expr* From, QualType ToType, 472 StandardConversionSequence &SCS) 473{ 474 QualType FromType = From->getType(); 475 476 // Standard conversions (C++ [conv]) 477 SCS.setAsIdentityConversion(); 478 SCS.Deprecated = false; 479 SCS.IncompatibleObjC = false; 480 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 481 SCS.CopyConstructor = 0; 482 483 // There are no standard conversions for class types in C++, so 484 // abort early. When overloading in C, however, we do permit 485 if (FromType->isRecordType() || ToType->isRecordType()) { 486 if (getLangOptions().CPlusPlus) 487 return false; 488 489 // When we're overloading in C, we allow, as standard conversions, 490 } 491 492 // The first conversion can be an lvalue-to-rvalue conversion, 493 // array-to-pointer conversion, or function-to-pointer conversion 494 // (C++ 4p1). 495 496 // Lvalue-to-rvalue conversion (C++ 4.1): 497 // An lvalue (3.10) of a non-function, non-array type T can be 498 // converted to an rvalue. 499 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 500 if (argIsLvalue == Expr::LV_Valid && 501 !FromType->isFunctionType() && !FromType->isArrayType() && 502 Context.getCanonicalType(FromType) != Context.OverloadTy) { 503 SCS.First = ICK_Lvalue_To_Rvalue; 504 505 // If T is a non-class type, the type of the rvalue is the 506 // cv-unqualified version of T. Otherwise, the type of the rvalue 507 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 508 // just strip the qualifiers because they don't matter. 509 510 // FIXME: Doesn't see through to qualifiers behind a typedef! 511 FromType = FromType.getUnqualifiedType(); 512 } else if (FromType->isArrayType()) { 513 // Array-to-pointer conversion (C++ 4.2) 514 SCS.First = ICK_Array_To_Pointer; 515 516 // An lvalue or rvalue of type "array of N T" or "array of unknown 517 // bound of T" can be converted to an rvalue of type "pointer to 518 // T" (C++ 4.2p1). 519 FromType = Context.getArrayDecayedType(FromType); 520 521 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 522 // This conversion is deprecated. (C++ D.4). 523 SCS.Deprecated = true; 524 525 // For the purpose of ranking in overload resolution 526 // (13.3.3.1.1), this conversion is considered an 527 // array-to-pointer conversion followed by a qualification 528 // conversion (4.4). (C++ 4.2p2) 529 SCS.Second = ICK_Identity; 530 SCS.Third = ICK_Qualification; 531 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 532 return true; 533 } 534 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 535 // Function-to-pointer conversion (C++ 4.3). 536 SCS.First = ICK_Function_To_Pointer; 537 538 // An lvalue of function type T can be converted to an rvalue of 539 // type "pointer to T." The result is a pointer to the 540 // function. (C++ 4.3p1). 541 FromType = Context.getPointerType(FromType); 542 } else if (FunctionDecl *Fn 543 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 544 // Address of overloaded function (C++ [over.over]). 545 SCS.First = ICK_Function_To_Pointer; 546 547 // We were able to resolve the address of the overloaded function, 548 // so we can convert to the type of that function. 549 FromType = Fn->getType(); 550 if (ToType->isLValueReferenceType()) 551 FromType = Context.getLValueReferenceType(FromType); 552 else if (ToType->isRValueReferenceType()) 553 FromType = Context.getRValueReferenceType(FromType); 554 else if (ToType->isMemberPointerType()) { 555 // Resolve address only succeeds if both sides are member pointers, 556 // but it doesn't have to be the same class. See DR 247. 557 // Note that this means that the type of &Derived::fn can be 558 // Ret (Base::*)(Args) if the fn overload actually found is from the 559 // base class, even if it was brought into the derived class via a 560 // using declaration. The standard isn't clear on this issue at all. 561 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 562 FromType = Context.getMemberPointerType(FromType, 563 Context.getTypeDeclType(M->getParent()).getTypePtr()); 564 } else 565 FromType = Context.getPointerType(FromType); 566 } else { 567 // We don't require any conversions for the first step. 568 SCS.First = ICK_Identity; 569 } 570 571 // The second conversion can be an integral promotion, floating 572 // point promotion, integral conversion, floating point conversion, 573 // floating-integral conversion, pointer conversion, 574 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 575 // For overloading in C, this can also be a "compatible-type" 576 // conversion. 577 bool IncompatibleObjC = false; 578 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 579 // The unqualified versions of the types are the same: there's no 580 // conversion to do. 581 SCS.Second = ICK_Identity; 582 } else if (IsIntegralPromotion(From, FromType, ToType)) { 583 // Integral promotion (C++ 4.5). 584 SCS.Second = ICK_Integral_Promotion; 585 FromType = ToType.getUnqualifiedType(); 586 } else if (IsFloatingPointPromotion(FromType, ToType)) { 587 // Floating point promotion (C++ 4.6). 588 SCS.Second = ICK_Floating_Promotion; 589 FromType = ToType.getUnqualifiedType(); 590 } else if (IsComplexPromotion(FromType, ToType)) { 591 // Complex promotion (Clang extension) 592 SCS.Second = ICK_Complex_Promotion; 593 FromType = ToType.getUnqualifiedType(); 594 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 595 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 596 // Integral conversions (C++ 4.7). 597 // FIXME: isIntegralType shouldn't be true for enums in C++. 598 SCS.Second = ICK_Integral_Conversion; 599 FromType = ToType.getUnqualifiedType(); 600 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 601 // Floating point conversions (C++ 4.8). 602 SCS.Second = ICK_Floating_Conversion; 603 FromType = ToType.getUnqualifiedType(); 604 } else if (FromType->isComplexType() && ToType->isComplexType()) { 605 // Complex conversions (C99 6.3.1.6) 606 SCS.Second = ICK_Complex_Conversion; 607 FromType = ToType.getUnqualifiedType(); 608 } else if ((FromType->isFloatingType() && 609 ToType->isIntegralType() && (!ToType->isBooleanType() && 610 !ToType->isEnumeralType())) || 611 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 612 ToType->isFloatingType())) { 613 // Floating-integral conversions (C++ 4.9). 614 // FIXME: isIntegralType shouldn't be true for enums in C++. 615 SCS.Second = ICK_Floating_Integral; 616 FromType = ToType.getUnqualifiedType(); 617 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 618 (ToType->isComplexType() && FromType->isArithmeticType())) { 619 // Complex-real conversions (C99 6.3.1.7) 620 SCS.Second = ICK_Complex_Real; 621 FromType = ToType.getUnqualifiedType(); 622 } else if (IsPointerConversion(From, FromType, ToType, FromType, 623 IncompatibleObjC)) { 624 // Pointer conversions (C++ 4.10). 625 SCS.Second = ICK_Pointer_Conversion; 626 SCS.IncompatibleObjC = IncompatibleObjC; 627 } else if (IsMemberPointerConversion(From, FromType, ToType, FromType)) { 628 // Pointer to member conversions (4.11). 629 SCS.Second = ICK_Pointer_Member; 630 } else if (ToType->isBooleanType() && 631 (FromType->isArithmeticType() || 632 FromType->isEnumeralType() || 633 FromType->isPointerType() || 634 FromType->isBlockPointerType() || 635 FromType->isMemberPointerType() || 636 FromType->isNullPtrType())) { 637 // Boolean conversions (C++ 4.12). 638 SCS.Second = ICK_Boolean_Conversion; 639 FromType = Context.BoolTy; 640 } else if (!getLangOptions().CPlusPlus && 641 Context.typesAreCompatible(ToType, FromType)) { 642 // Compatible conversions (Clang extension for C function overloading) 643 SCS.Second = ICK_Compatible_Conversion; 644 } else { 645 // No second conversion required. 646 SCS.Second = ICK_Identity; 647 } 648 649 QualType CanonFrom; 650 QualType CanonTo; 651 // The third conversion can be a qualification conversion (C++ 4p1). 652 if (IsQualificationConversion(FromType, ToType)) { 653 SCS.Third = ICK_Qualification; 654 FromType = ToType; 655 CanonFrom = Context.getCanonicalType(FromType); 656 CanonTo = Context.getCanonicalType(ToType); 657 } else { 658 // No conversion required 659 SCS.Third = ICK_Identity; 660 661 // C++ [over.best.ics]p6: 662 // [...] Any difference in top-level cv-qualification is 663 // subsumed by the initialization itself and does not constitute 664 // a conversion. [...] 665 CanonFrom = Context.getCanonicalType(FromType); 666 CanonTo = Context.getCanonicalType(ToType); 667 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 668 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 669 FromType = ToType; 670 CanonFrom = CanonTo; 671 } 672 } 673 674 // If we have not converted the argument type to the parameter type, 675 // this is a bad conversion sequence. 676 if (CanonFrom != CanonTo) 677 return false; 678 679 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 680 return true; 681} 682 683/// IsIntegralPromotion - Determines whether the conversion from the 684/// expression From (whose potentially-adjusted type is FromType) to 685/// ToType is an integral promotion (C++ 4.5). If so, returns true and 686/// sets PromotedType to the promoted type. 687bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) 688{ 689 const BuiltinType *To = ToType->getAsBuiltinType(); 690 // All integers are built-in. 691 if (!To) { 692 return false; 693 } 694 695 // An rvalue of type char, signed char, unsigned char, short int, or 696 // unsigned short int can be converted to an rvalue of type int if 697 // int can represent all the values of the source type; otherwise, 698 // the source rvalue can be converted to an rvalue of type unsigned 699 // int (C++ 4.5p1). 700 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 701 if (// We can promote any signed, promotable integer type to an int 702 (FromType->isSignedIntegerType() || 703 // We can promote any unsigned integer type whose size is 704 // less than int to an int. 705 (!FromType->isSignedIntegerType() && 706 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 707 return To->getKind() == BuiltinType::Int; 708 } 709 710 return To->getKind() == BuiltinType::UInt; 711 } 712 713 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 714 // can be converted to an rvalue of the first of the following types 715 // that can represent all the values of its underlying type: int, 716 // unsigned int, long, or unsigned long (C++ 4.5p2). 717 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 718 && ToType->isIntegerType()) { 719 // Determine whether the type we're converting from is signed or 720 // unsigned. 721 bool FromIsSigned; 722 uint64_t FromSize = Context.getTypeSize(FromType); 723 if (const EnumType *FromEnumType = FromType->getAsEnumType()) { 724 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 725 FromIsSigned = UnderlyingType->isSignedIntegerType(); 726 } else { 727 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 728 FromIsSigned = true; 729 } 730 731 // The types we'll try to promote to, in the appropriate 732 // order. Try each of these types. 733 QualType PromoteTypes[6] = { 734 Context.IntTy, Context.UnsignedIntTy, 735 Context.LongTy, Context.UnsignedLongTy , 736 Context.LongLongTy, Context.UnsignedLongLongTy 737 }; 738 for (int Idx = 0; Idx < 6; ++Idx) { 739 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 740 if (FromSize < ToSize || 741 (FromSize == ToSize && 742 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 743 // We found the type that we can promote to. If this is the 744 // type we wanted, we have a promotion. Otherwise, no 745 // promotion. 746 return Context.getCanonicalType(ToType).getUnqualifiedType() 747 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 748 } 749 } 750 } 751 752 // An rvalue for an integral bit-field (9.6) can be converted to an 753 // rvalue of type int if int can represent all the values of the 754 // bit-field; otherwise, it can be converted to unsigned int if 755 // unsigned int can represent all the values of the bit-field. If 756 // the bit-field is larger yet, no integral promotion applies to 757 // it. If the bit-field has an enumerated type, it is treated as any 758 // other value of that type for promotion purposes (C++ 4.5p3). 759 // FIXME: We should delay checking of bit-fields until we actually perform the 760 // conversion. 761 using llvm::APSInt; 762 if (From) 763 if (FieldDecl *MemberDecl = From->getBitField()) { 764 APSInt BitWidth; 765 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 766 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 767 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 768 ToSize = Context.getTypeSize(ToType); 769 770 // Are we promoting to an int from a bitfield that fits in an int? 771 if (BitWidth < ToSize || 772 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 773 return To->getKind() == BuiltinType::Int; 774 } 775 776 // Are we promoting to an unsigned int from an unsigned bitfield 777 // that fits into an unsigned int? 778 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 779 return To->getKind() == BuiltinType::UInt; 780 } 781 782 return false; 783 } 784 } 785 786 // An rvalue of type bool can be converted to an rvalue of type int, 787 // with false becoming zero and true becoming one (C++ 4.5p4). 788 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 789 return true; 790 } 791 792 return false; 793} 794 795/// IsFloatingPointPromotion - Determines whether the conversion from 796/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 797/// returns true and sets PromotedType to the promoted type. 798bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) 799{ 800 /// An rvalue of type float can be converted to an rvalue of type 801 /// double. (C++ 4.6p1). 802 if (const BuiltinType *FromBuiltin = FromType->getAsBuiltinType()) 803 if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType()) { 804 if (FromBuiltin->getKind() == BuiltinType::Float && 805 ToBuiltin->getKind() == BuiltinType::Double) 806 return true; 807 808 // C99 6.3.1.5p1: 809 // When a float is promoted to double or long double, or a 810 // double is promoted to long double [...]. 811 if (!getLangOptions().CPlusPlus && 812 (FromBuiltin->getKind() == BuiltinType::Float || 813 FromBuiltin->getKind() == BuiltinType::Double) && 814 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 815 return true; 816 } 817 818 return false; 819} 820 821/// \brief Determine if a conversion is a complex promotion. 822/// 823/// A complex promotion is defined as a complex -> complex conversion 824/// where the conversion between the underlying real types is a 825/// floating-point or integral promotion. 826bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 827 const ComplexType *FromComplex = FromType->getAsComplexType(); 828 if (!FromComplex) 829 return false; 830 831 const ComplexType *ToComplex = ToType->getAsComplexType(); 832 if (!ToComplex) 833 return false; 834 835 return IsFloatingPointPromotion(FromComplex->getElementType(), 836 ToComplex->getElementType()) || 837 IsIntegralPromotion(0, FromComplex->getElementType(), 838 ToComplex->getElementType()); 839} 840 841/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 842/// the pointer type FromPtr to a pointer to type ToPointee, with the 843/// same type qualifiers as FromPtr has on its pointee type. ToType, 844/// if non-empty, will be a pointer to ToType that may or may not have 845/// the right set of qualifiers on its pointee. 846static QualType 847BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 848 QualType ToPointee, QualType ToType, 849 ASTContext &Context) { 850 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 851 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 852 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 853 854 // Exact qualifier match -> return the pointer type we're converting to. 855 if (CanonToPointee.getCVRQualifiers() == Quals) { 856 // ToType is exactly what we need. Return it. 857 if (ToType.getTypePtr()) 858 return ToType; 859 860 // Build a pointer to ToPointee. It has the right qualifiers 861 // already. 862 return Context.getPointerType(ToPointee); 863 } 864 865 // Just build a canonical type that has the right qualifiers. 866 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 867} 868 869/// IsPointerConversion - Determines whether the conversion of the 870/// expression From, which has the (possibly adjusted) type FromType, 871/// can be converted to the type ToType via a pointer conversion (C++ 872/// 4.10). If so, returns true and places the converted type (that 873/// might differ from ToType in its cv-qualifiers at some level) into 874/// ConvertedType. 875/// 876/// This routine also supports conversions to and from block pointers 877/// and conversions with Objective-C's 'id', 'id<protocols...>', and 878/// pointers to interfaces. FIXME: Once we've determined the 879/// appropriate overloading rules for Objective-C, we may want to 880/// split the Objective-C checks into a different routine; however, 881/// GCC seems to consider all of these conversions to be pointer 882/// conversions, so for now they live here. IncompatibleObjC will be 883/// set if the conversion is an allowed Objective-C conversion that 884/// should result in a warning. 885bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 886 QualType& ConvertedType, 887 bool &IncompatibleObjC) 888{ 889 IncompatibleObjC = false; 890 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 891 return true; 892 893 // Conversion from a null pointer constant to any Objective-C pointer type. 894 if (ToType->isObjCObjectPointerType() && 895 From->isNullPointerConstant(Context)) { 896 ConvertedType = ToType; 897 return true; 898 } 899 900 // Blocks: Block pointers can be converted to void*. 901 if (FromType->isBlockPointerType() && ToType->isPointerType() && 902 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 903 ConvertedType = ToType; 904 return true; 905 } 906 // Blocks: A null pointer constant can be converted to a block 907 // pointer type. 908 if (ToType->isBlockPointerType() && From->isNullPointerConstant(Context)) { 909 ConvertedType = ToType; 910 return true; 911 } 912 913 // If the left-hand-side is nullptr_t, the right side can be a null 914 // pointer constant. 915 if (ToType->isNullPtrType() && From->isNullPointerConstant(Context)) { 916 ConvertedType = ToType; 917 return true; 918 } 919 920 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 921 if (!ToTypePtr) 922 return false; 923 924 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 925 if (From->isNullPointerConstant(Context)) { 926 ConvertedType = ToType; 927 return true; 928 } 929 930 // Beyond this point, both types need to be pointers. 931 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 932 if (!FromTypePtr) 933 return false; 934 935 QualType FromPointeeType = FromTypePtr->getPointeeType(); 936 QualType ToPointeeType = ToTypePtr->getPointeeType(); 937 938 // An rvalue of type "pointer to cv T," where T is an object type, 939 // can be converted to an rvalue of type "pointer to cv void" (C++ 940 // 4.10p2). 941 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 942 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 943 ToPointeeType, 944 ToType, Context); 945 return true; 946 } 947 948 // When we're overloading in C, we allow a special kind of pointer 949 // conversion for compatible-but-not-identical pointee types. 950 if (!getLangOptions().CPlusPlus && 951 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 952 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 953 ToPointeeType, 954 ToType, Context); 955 return true; 956 } 957 958 // C++ [conv.ptr]p3: 959 // 960 // An rvalue of type "pointer to cv D," where D is a class type, 961 // can be converted to an rvalue of type "pointer to cv B," where 962 // B is a base class (clause 10) of D. If B is an inaccessible 963 // (clause 11) or ambiguous (10.2) base class of D, a program that 964 // necessitates this conversion is ill-formed. The result of the 965 // conversion is a pointer to the base class sub-object of the 966 // derived class object. The null pointer value is converted to 967 // the null pointer value of the destination type. 968 // 969 // Note that we do not check for ambiguity or inaccessibility 970 // here. That is handled by CheckPointerConversion. 971 if (getLangOptions().CPlusPlus && 972 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 973 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 974 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 975 ToPointeeType, 976 ToType, Context); 977 return true; 978 } 979 980 return false; 981} 982 983/// isObjCPointerConversion - Determines whether this is an 984/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 985/// with the same arguments and return values. 986bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 987 QualType& ConvertedType, 988 bool &IncompatibleObjC) { 989 if (!getLangOptions().ObjC1) 990 return false; 991 992 // First, we handle all conversions on ObjC object pointer types. 993 const ObjCObjectPointerType* ToObjCPtr = ToType->getAsObjCObjectPointerType(); 994 const ObjCObjectPointerType *FromObjCPtr = 995 FromType->getAsObjCObjectPointerType(); 996 997 if (ToObjCPtr && FromObjCPtr) { 998 // Objective C++: We're able to convert between "id" or "Class" and a 999 // pointer to any interface (in both directions). 1000 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1001 ConvertedType = ToType; 1002 return true; 1003 } 1004 // Conversions with Objective-C's id<...>. 1005 if ((FromObjCPtr->isObjCQualifiedIdType() || 1006 ToObjCPtr->isObjCQualifiedIdType()) && 1007 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1008 /*compare=*/false)) { 1009 ConvertedType = ToType; 1010 return true; 1011 } 1012 // Objective C++: We're able to convert from a pointer to an 1013 // interface to a pointer to a different interface. 1014 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1015 ConvertedType = ToType; 1016 return true; 1017 } 1018 1019 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1020 // Okay: this is some kind of implicit downcast of Objective-C 1021 // interfaces, which is permitted. However, we're going to 1022 // complain about it. 1023 IncompatibleObjC = true; 1024 ConvertedType = FromType; 1025 return true; 1026 } 1027 } 1028 // Beyond this point, both types need to be C pointers or block pointers. 1029 QualType ToPointeeType; 1030 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1031 ToPointeeType = ToCPtr->getPointeeType(); 1032 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1033 ToPointeeType = ToBlockPtr->getPointeeType(); 1034 else 1035 return false; 1036 1037 QualType FromPointeeType; 1038 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1039 FromPointeeType = FromCPtr->getPointeeType(); 1040 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1041 FromPointeeType = FromBlockPtr->getPointeeType(); 1042 else 1043 return false; 1044 1045 // If we have pointers to pointers, recursively check whether this 1046 // is an Objective-C conversion. 1047 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1048 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1049 IncompatibleObjC)) { 1050 // We always complain about this conversion. 1051 IncompatibleObjC = true; 1052 ConvertedType = ToType; 1053 return true; 1054 } 1055 // If we have pointers to functions or blocks, check whether the only 1056 // differences in the argument and result types are in Objective-C 1057 // pointer conversions. If so, we permit the conversion (but 1058 // complain about it). 1059 const FunctionProtoType *FromFunctionType 1060 = FromPointeeType->getAsFunctionProtoType(); 1061 const FunctionProtoType *ToFunctionType 1062 = ToPointeeType->getAsFunctionProtoType(); 1063 if (FromFunctionType && ToFunctionType) { 1064 // If the function types are exactly the same, this isn't an 1065 // Objective-C pointer conversion. 1066 if (Context.getCanonicalType(FromPointeeType) 1067 == Context.getCanonicalType(ToPointeeType)) 1068 return false; 1069 1070 // Perform the quick checks that will tell us whether these 1071 // function types are obviously different. 1072 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1073 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1074 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1075 return false; 1076 1077 bool HasObjCConversion = false; 1078 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1079 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1080 // Okay, the types match exactly. Nothing to do. 1081 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1082 ToFunctionType->getResultType(), 1083 ConvertedType, IncompatibleObjC)) { 1084 // Okay, we have an Objective-C pointer conversion. 1085 HasObjCConversion = true; 1086 } else { 1087 // Function types are too different. Abort. 1088 return false; 1089 } 1090 1091 // Check argument types. 1092 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1093 ArgIdx != NumArgs; ++ArgIdx) { 1094 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1095 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1096 if (Context.getCanonicalType(FromArgType) 1097 == Context.getCanonicalType(ToArgType)) { 1098 // Okay, the types match exactly. Nothing to do. 1099 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1100 ConvertedType, IncompatibleObjC)) { 1101 // Okay, we have an Objective-C pointer conversion. 1102 HasObjCConversion = true; 1103 } else { 1104 // Argument types are too different. Abort. 1105 return false; 1106 } 1107 } 1108 1109 if (HasObjCConversion) { 1110 // We had an Objective-C conversion. Allow this pointer 1111 // conversion, but complain about it. 1112 ConvertedType = ToType; 1113 IncompatibleObjC = true; 1114 return true; 1115 } 1116 } 1117 1118 return false; 1119} 1120 1121/// CheckPointerConversion - Check the pointer conversion from the 1122/// expression From to the type ToType. This routine checks for 1123/// ambiguous or inaccessible derived-to-base pointer 1124/// conversions for which IsPointerConversion has already returned 1125/// true. It returns true and produces a diagnostic if there was an 1126/// error, or returns false otherwise. 1127bool Sema::CheckPointerConversion(Expr *From, QualType ToType) { 1128 QualType FromType = From->getType(); 1129 1130 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1131 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1132 QualType FromPointeeType = FromPtrType->getPointeeType(), 1133 ToPointeeType = ToPtrType->getPointeeType(); 1134 1135 if (FromPointeeType->isRecordType() && 1136 ToPointeeType->isRecordType()) { 1137 // We must have a derived-to-base conversion. Check an 1138 // ambiguous or inaccessible conversion. 1139 return CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1140 From->getExprLoc(), 1141 From->getSourceRange()); 1142 } 1143 } 1144 if (const ObjCObjectPointerType *FromPtrType = 1145 FromType->getAsObjCObjectPointerType()) 1146 if (const ObjCObjectPointerType *ToPtrType = 1147 ToType->getAsObjCObjectPointerType()) { 1148 // Objective-C++ conversions are always okay. 1149 // FIXME: We should have a different class of conversions for the 1150 // Objective-C++ implicit conversions. 1151 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1152 return false; 1153 1154 } 1155 return false; 1156} 1157 1158/// IsMemberPointerConversion - Determines whether the conversion of the 1159/// expression From, which has the (possibly adjusted) type FromType, can be 1160/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1161/// If so, returns true and places the converted type (that might differ from 1162/// ToType in its cv-qualifiers at some level) into ConvertedType. 1163bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1164 QualType ToType, QualType &ConvertedType) 1165{ 1166 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1167 if (!ToTypePtr) 1168 return false; 1169 1170 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1171 if (From->isNullPointerConstant(Context)) { 1172 ConvertedType = ToType; 1173 return true; 1174 } 1175 1176 // Otherwise, both types have to be member pointers. 1177 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1178 if (!FromTypePtr) 1179 return false; 1180 1181 // A pointer to member of B can be converted to a pointer to member of D, 1182 // where D is derived from B (C++ 4.11p2). 1183 QualType FromClass(FromTypePtr->getClass(), 0); 1184 QualType ToClass(ToTypePtr->getClass(), 0); 1185 // FIXME: What happens when these are dependent? Is this function even called? 1186 1187 if (IsDerivedFrom(ToClass, FromClass)) { 1188 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1189 ToClass.getTypePtr()); 1190 return true; 1191 } 1192 1193 return false; 1194} 1195 1196/// CheckMemberPointerConversion - Check the member pointer conversion from the 1197/// expression From to the type ToType. This routine checks for ambiguous or 1198/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1199/// for which IsMemberPointerConversion has already returned true. It returns 1200/// true and produces a diagnostic if there was an error, or returns false 1201/// otherwise. 1202bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType) { 1203 QualType FromType = From->getType(); 1204 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1205 if (!FromPtrType) 1206 return false; 1207 1208 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1209 assert(ToPtrType && "No member pointer cast has a target type " 1210 "that is not a member pointer."); 1211 1212 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1213 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1214 1215 // FIXME: What about dependent types? 1216 assert(FromClass->isRecordType() && "Pointer into non-class."); 1217 assert(ToClass->isRecordType() && "Pointer into non-class."); 1218 1219 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1220 /*DetectVirtual=*/true); 1221 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1222 assert(DerivationOkay && 1223 "Should not have been called if derivation isn't OK."); 1224 (void)DerivationOkay; 1225 1226 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1227 getUnqualifiedType())) { 1228 // Derivation is ambiguous. Redo the check to find the exact paths. 1229 Paths.clear(); 1230 Paths.setRecordingPaths(true); 1231 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1232 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1233 (void)StillOkay; 1234 1235 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1236 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1237 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1238 return true; 1239 } 1240 1241 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1242 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1243 << FromClass << ToClass << QualType(VBase, 0) 1244 << From->getSourceRange(); 1245 return true; 1246 } 1247 1248 return false; 1249} 1250 1251/// IsQualificationConversion - Determines whether the conversion from 1252/// an rvalue of type FromType to ToType is a qualification conversion 1253/// (C++ 4.4). 1254bool 1255Sema::IsQualificationConversion(QualType FromType, QualType ToType) 1256{ 1257 FromType = Context.getCanonicalType(FromType); 1258 ToType = Context.getCanonicalType(ToType); 1259 1260 // If FromType and ToType are the same type, this is not a 1261 // qualification conversion. 1262 if (FromType == ToType) 1263 return false; 1264 1265 // (C++ 4.4p4): 1266 // A conversion can add cv-qualifiers at levels other than the first 1267 // in multi-level pointers, subject to the following rules: [...] 1268 bool PreviousToQualsIncludeConst = true; 1269 bool UnwrappedAnyPointer = false; 1270 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1271 // Within each iteration of the loop, we check the qualifiers to 1272 // determine if this still looks like a qualification 1273 // conversion. Then, if all is well, we unwrap one more level of 1274 // pointers or pointers-to-members and do it all again 1275 // until there are no more pointers or pointers-to-members left to 1276 // unwrap. 1277 UnwrappedAnyPointer = true; 1278 1279 // -- for every j > 0, if const is in cv 1,j then const is in cv 1280 // 2,j, and similarly for volatile. 1281 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1282 return false; 1283 1284 // -- if the cv 1,j and cv 2,j are different, then const is in 1285 // every cv for 0 < k < j. 1286 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1287 && !PreviousToQualsIncludeConst) 1288 return false; 1289 1290 // Keep track of whether all prior cv-qualifiers in the "to" type 1291 // include const. 1292 PreviousToQualsIncludeConst 1293 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1294 } 1295 1296 // We are left with FromType and ToType being the pointee types 1297 // after unwrapping the original FromType and ToType the same number 1298 // of types. If we unwrapped any pointers, and if FromType and 1299 // ToType have the same unqualified type (since we checked 1300 // qualifiers above), then this is a qualification conversion. 1301 return UnwrappedAnyPointer && 1302 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1303} 1304 1305/// Determines whether there is a user-defined conversion sequence 1306/// (C++ [over.ics.user]) that converts expression From to the type 1307/// ToType. If such a conversion exists, User will contain the 1308/// user-defined conversion sequence that performs such a conversion 1309/// and this routine will return true. Otherwise, this routine returns 1310/// false and User is unspecified. 1311/// 1312/// \param AllowConversionFunctions true if the conversion should 1313/// consider conversion functions at all. If false, only constructors 1314/// will be considered. 1315/// 1316/// \param AllowExplicit true if the conversion should consider C++0x 1317/// "explicit" conversion functions as well as non-explicit conversion 1318/// functions (C++0x [class.conv.fct]p2). 1319/// 1320/// \param ForceRValue true if the expression should be treated as an rvalue 1321/// for overload resolution. 1322bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1323 UserDefinedConversionSequence& User, 1324 bool AllowConversionFunctions, 1325 bool AllowExplicit, bool ForceRValue) 1326{ 1327 OverloadCandidateSet CandidateSet; 1328 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1329 if (CXXRecordDecl *ToRecordDecl 1330 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1331 // C++ [over.match.ctor]p1: 1332 // When objects of class type are direct-initialized (8.5), or 1333 // copy-initialized from an expression of the same or a 1334 // derived class type (8.5), overload resolution selects the 1335 // constructor. [...] For copy-initialization, the candidate 1336 // functions are all the converting constructors (12.3.1) of 1337 // that class. The argument list is the expression-list within 1338 // the parentheses of the initializer. 1339 DeclarationName ConstructorName 1340 = Context.DeclarationNames.getCXXConstructorName( 1341 Context.getCanonicalType(ToType).getUnqualifiedType()); 1342 DeclContext::lookup_iterator Con, ConEnd; 1343 for (llvm::tie(Con, ConEnd) 1344 = ToRecordDecl->lookup(ConstructorName); 1345 Con != ConEnd; ++Con) { 1346 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 1347 if (!Constructor->isInvalidDecl() && 1348 Constructor->isConvertingConstructor()) 1349 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1350 /*SuppressUserConversions=*/true, ForceRValue); 1351 } 1352 } 1353 } 1354 1355 if (!AllowConversionFunctions) { 1356 // Don't allow any conversion functions to enter the overload set. 1357 } else if (const RecordType *FromRecordType 1358 = From->getType()->getAs<RecordType>()) { 1359 if (CXXRecordDecl *FromRecordDecl 1360 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1361 // Add all of the conversion functions as candidates. 1362 // FIXME: Look for conversions in base classes! 1363 OverloadedFunctionDecl *Conversions 1364 = FromRecordDecl->getConversionFunctions(); 1365 for (OverloadedFunctionDecl::function_iterator Func 1366 = Conversions->function_begin(); 1367 Func != Conversions->function_end(); ++Func) { 1368 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 1369 if (AllowExplicit || !Conv->isExplicit()) 1370 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1371 } 1372 } 1373 } 1374 1375 OverloadCandidateSet::iterator Best; 1376 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1377 case OR_Success: 1378 // Record the standard conversion we used and the conversion function. 1379 if (CXXConstructorDecl *Constructor 1380 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1381 // C++ [over.ics.user]p1: 1382 // If the user-defined conversion is specified by a 1383 // constructor (12.3.1), the initial standard conversion 1384 // sequence converts the source type to the type required by 1385 // the argument of the constructor. 1386 // 1387 // FIXME: What about ellipsis conversions? 1388 QualType ThisType = Constructor->getThisType(Context); 1389 User.Before = Best->Conversions[0].Standard; 1390 User.ConversionFunction = Constructor; 1391 User.After.setAsIdentityConversion(); 1392 User.After.FromTypePtr 1393 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1394 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1395 return true; 1396 } else if (CXXConversionDecl *Conversion 1397 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1398 // C++ [over.ics.user]p1: 1399 // 1400 // [...] If the user-defined conversion is specified by a 1401 // conversion function (12.3.2), the initial standard 1402 // conversion sequence converts the source type to the 1403 // implicit object parameter of the conversion function. 1404 User.Before = Best->Conversions[0].Standard; 1405 User.ConversionFunction = Conversion; 1406 1407 // C++ [over.ics.user]p2: 1408 // The second standard conversion sequence converts the 1409 // result of the user-defined conversion to the target type 1410 // for the sequence. Since an implicit conversion sequence 1411 // is an initialization, the special rules for 1412 // initialization by user-defined conversion apply when 1413 // selecting the best user-defined conversion for a 1414 // user-defined conversion sequence (see 13.3.3 and 1415 // 13.3.3.1). 1416 User.After = Best->FinalConversion; 1417 return true; 1418 } else { 1419 assert(false && "Not a constructor or conversion function?"); 1420 return false; 1421 } 1422 1423 case OR_No_Viable_Function: 1424 case OR_Deleted: 1425 // No conversion here! We're done. 1426 return false; 1427 1428 case OR_Ambiguous: 1429 // FIXME: See C++ [over.best.ics]p10 for the handling of 1430 // ambiguous conversion sequences. 1431 return false; 1432 } 1433 1434 return false; 1435} 1436 1437/// CompareImplicitConversionSequences - Compare two implicit 1438/// conversion sequences to determine whether one is better than the 1439/// other or if they are indistinguishable (C++ 13.3.3.2). 1440ImplicitConversionSequence::CompareKind 1441Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1442 const ImplicitConversionSequence& ICS2) 1443{ 1444 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1445 // conversion sequences (as defined in 13.3.3.1) 1446 // -- a standard conversion sequence (13.3.3.1.1) is a better 1447 // conversion sequence than a user-defined conversion sequence or 1448 // an ellipsis conversion sequence, and 1449 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1450 // conversion sequence than an ellipsis conversion sequence 1451 // (13.3.3.1.3). 1452 // 1453 if (ICS1.ConversionKind < ICS2.ConversionKind) 1454 return ImplicitConversionSequence::Better; 1455 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1456 return ImplicitConversionSequence::Worse; 1457 1458 // Two implicit conversion sequences of the same form are 1459 // indistinguishable conversion sequences unless one of the 1460 // following rules apply: (C++ 13.3.3.2p3): 1461 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1462 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1463 else if (ICS1.ConversionKind == 1464 ImplicitConversionSequence::UserDefinedConversion) { 1465 // User-defined conversion sequence U1 is a better conversion 1466 // sequence than another user-defined conversion sequence U2 if 1467 // they contain the same user-defined conversion function or 1468 // constructor and if the second standard conversion sequence of 1469 // U1 is better than the second standard conversion sequence of 1470 // U2 (C++ 13.3.3.2p3). 1471 if (ICS1.UserDefined.ConversionFunction == 1472 ICS2.UserDefined.ConversionFunction) 1473 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1474 ICS2.UserDefined.After); 1475 } 1476 1477 return ImplicitConversionSequence::Indistinguishable; 1478} 1479 1480/// CompareStandardConversionSequences - Compare two standard 1481/// conversion sequences to determine whether one is better than the 1482/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1483ImplicitConversionSequence::CompareKind 1484Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1485 const StandardConversionSequence& SCS2) 1486{ 1487 // Standard conversion sequence S1 is a better conversion sequence 1488 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1489 1490 // -- S1 is a proper subsequence of S2 (comparing the conversion 1491 // sequences in the canonical form defined by 13.3.3.1.1, 1492 // excluding any Lvalue Transformation; the identity conversion 1493 // sequence is considered to be a subsequence of any 1494 // non-identity conversion sequence) or, if not that, 1495 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1496 // Neither is a proper subsequence of the other. Do nothing. 1497 ; 1498 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1499 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1500 (SCS1.Second == ICK_Identity && 1501 SCS1.Third == ICK_Identity)) 1502 // SCS1 is a proper subsequence of SCS2. 1503 return ImplicitConversionSequence::Better; 1504 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1505 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1506 (SCS2.Second == ICK_Identity && 1507 SCS2.Third == ICK_Identity)) 1508 // SCS2 is a proper subsequence of SCS1. 1509 return ImplicitConversionSequence::Worse; 1510 1511 // -- the rank of S1 is better than the rank of S2 (by the rules 1512 // defined below), or, if not that, 1513 ImplicitConversionRank Rank1 = SCS1.getRank(); 1514 ImplicitConversionRank Rank2 = SCS2.getRank(); 1515 if (Rank1 < Rank2) 1516 return ImplicitConversionSequence::Better; 1517 else if (Rank2 < Rank1) 1518 return ImplicitConversionSequence::Worse; 1519 1520 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1521 // are indistinguishable unless one of the following rules 1522 // applies: 1523 1524 // A conversion that is not a conversion of a pointer, or 1525 // pointer to member, to bool is better than another conversion 1526 // that is such a conversion. 1527 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1528 return SCS2.isPointerConversionToBool() 1529 ? ImplicitConversionSequence::Better 1530 : ImplicitConversionSequence::Worse; 1531 1532 // C++ [over.ics.rank]p4b2: 1533 // 1534 // If class B is derived directly or indirectly from class A, 1535 // conversion of B* to A* is better than conversion of B* to 1536 // void*, and conversion of A* to void* is better than conversion 1537 // of B* to void*. 1538 bool SCS1ConvertsToVoid 1539 = SCS1.isPointerConversionToVoidPointer(Context); 1540 bool SCS2ConvertsToVoid 1541 = SCS2.isPointerConversionToVoidPointer(Context); 1542 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1543 // Exactly one of the conversion sequences is a conversion to 1544 // a void pointer; it's the worse conversion. 1545 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1546 : ImplicitConversionSequence::Worse; 1547 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1548 // Neither conversion sequence converts to a void pointer; compare 1549 // their derived-to-base conversions. 1550 if (ImplicitConversionSequence::CompareKind DerivedCK 1551 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1552 return DerivedCK; 1553 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1554 // Both conversion sequences are conversions to void 1555 // pointers. Compare the source types to determine if there's an 1556 // inheritance relationship in their sources. 1557 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1558 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1559 1560 // Adjust the types we're converting from via the array-to-pointer 1561 // conversion, if we need to. 1562 if (SCS1.First == ICK_Array_To_Pointer) 1563 FromType1 = Context.getArrayDecayedType(FromType1); 1564 if (SCS2.First == ICK_Array_To_Pointer) 1565 FromType2 = Context.getArrayDecayedType(FromType2); 1566 1567 QualType FromPointee1 1568 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1569 QualType FromPointee2 1570 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1571 1572 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1573 return ImplicitConversionSequence::Better; 1574 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1575 return ImplicitConversionSequence::Worse; 1576 1577 // Objective-C++: If one interface is more specific than the 1578 // other, it is the better one. 1579 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1580 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1581 if (FromIface1 && FromIface1) { 1582 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1583 return ImplicitConversionSequence::Better; 1584 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1585 return ImplicitConversionSequence::Worse; 1586 } 1587 } 1588 1589 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1590 // bullet 3). 1591 if (ImplicitConversionSequence::CompareKind QualCK 1592 = CompareQualificationConversions(SCS1, SCS2)) 1593 return QualCK; 1594 1595 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1596 // C++0x [over.ics.rank]p3b4: 1597 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1598 // implicit object parameter of a non-static member function declared 1599 // without a ref-qualifier, and S1 binds an rvalue reference to an 1600 // rvalue and S2 binds an lvalue reference. 1601 // FIXME: We don't know if we're dealing with the implicit object parameter, 1602 // or if the member function in this case has a ref qualifier. 1603 // (Of course, we don't have ref qualifiers yet.) 1604 if (SCS1.RRefBinding != SCS2.RRefBinding) 1605 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1606 : ImplicitConversionSequence::Worse; 1607 1608 // C++ [over.ics.rank]p3b4: 1609 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1610 // which the references refer are the same type except for 1611 // top-level cv-qualifiers, and the type to which the reference 1612 // initialized by S2 refers is more cv-qualified than the type 1613 // to which the reference initialized by S1 refers. 1614 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1615 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1616 T1 = Context.getCanonicalType(T1); 1617 T2 = Context.getCanonicalType(T2); 1618 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1619 if (T2.isMoreQualifiedThan(T1)) 1620 return ImplicitConversionSequence::Better; 1621 else if (T1.isMoreQualifiedThan(T2)) 1622 return ImplicitConversionSequence::Worse; 1623 } 1624 } 1625 1626 return ImplicitConversionSequence::Indistinguishable; 1627} 1628 1629/// CompareQualificationConversions - Compares two standard conversion 1630/// sequences to determine whether they can be ranked based on their 1631/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1632ImplicitConversionSequence::CompareKind 1633Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1634 const StandardConversionSequence& SCS2) 1635{ 1636 // C++ 13.3.3.2p3: 1637 // -- S1 and S2 differ only in their qualification conversion and 1638 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1639 // cv-qualification signature of type T1 is a proper subset of 1640 // the cv-qualification signature of type T2, and S1 is not the 1641 // deprecated string literal array-to-pointer conversion (4.2). 1642 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1643 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1644 return ImplicitConversionSequence::Indistinguishable; 1645 1646 // FIXME: the example in the standard doesn't use a qualification 1647 // conversion (!) 1648 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1649 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1650 T1 = Context.getCanonicalType(T1); 1651 T2 = Context.getCanonicalType(T2); 1652 1653 // If the types are the same, we won't learn anything by unwrapped 1654 // them. 1655 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1656 return ImplicitConversionSequence::Indistinguishable; 1657 1658 ImplicitConversionSequence::CompareKind Result 1659 = ImplicitConversionSequence::Indistinguishable; 1660 while (UnwrapSimilarPointerTypes(T1, T2)) { 1661 // Within each iteration of the loop, we check the qualifiers to 1662 // determine if this still looks like a qualification 1663 // conversion. Then, if all is well, we unwrap one more level of 1664 // pointers or pointers-to-members and do it all again 1665 // until there are no more pointers or pointers-to-members left 1666 // to unwrap. This essentially mimics what 1667 // IsQualificationConversion does, but here we're checking for a 1668 // strict subset of qualifiers. 1669 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1670 // The qualifiers are the same, so this doesn't tell us anything 1671 // about how the sequences rank. 1672 ; 1673 else if (T2.isMoreQualifiedThan(T1)) { 1674 // T1 has fewer qualifiers, so it could be the better sequence. 1675 if (Result == ImplicitConversionSequence::Worse) 1676 // Neither has qualifiers that are a subset of the other's 1677 // qualifiers. 1678 return ImplicitConversionSequence::Indistinguishable; 1679 1680 Result = ImplicitConversionSequence::Better; 1681 } else if (T1.isMoreQualifiedThan(T2)) { 1682 // T2 has fewer qualifiers, so it could be the better sequence. 1683 if (Result == ImplicitConversionSequence::Better) 1684 // Neither has qualifiers that are a subset of the other's 1685 // qualifiers. 1686 return ImplicitConversionSequence::Indistinguishable; 1687 1688 Result = ImplicitConversionSequence::Worse; 1689 } else { 1690 // Qualifiers are disjoint. 1691 return ImplicitConversionSequence::Indistinguishable; 1692 } 1693 1694 // If the types after this point are equivalent, we're done. 1695 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1696 break; 1697 } 1698 1699 // Check that the winning standard conversion sequence isn't using 1700 // the deprecated string literal array to pointer conversion. 1701 switch (Result) { 1702 case ImplicitConversionSequence::Better: 1703 if (SCS1.Deprecated) 1704 Result = ImplicitConversionSequence::Indistinguishable; 1705 break; 1706 1707 case ImplicitConversionSequence::Indistinguishable: 1708 break; 1709 1710 case ImplicitConversionSequence::Worse: 1711 if (SCS2.Deprecated) 1712 Result = ImplicitConversionSequence::Indistinguishable; 1713 break; 1714 } 1715 1716 return Result; 1717} 1718 1719/// CompareDerivedToBaseConversions - Compares two standard conversion 1720/// sequences to determine whether they can be ranked based on their 1721/// various kinds of derived-to-base conversions (C++ 1722/// [over.ics.rank]p4b3). As part of these checks, we also look at 1723/// conversions between Objective-C interface types. 1724ImplicitConversionSequence::CompareKind 1725Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1726 const StandardConversionSequence& SCS2) { 1727 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1728 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1729 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1730 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1731 1732 // Adjust the types we're converting from via the array-to-pointer 1733 // conversion, if we need to. 1734 if (SCS1.First == ICK_Array_To_Pointer) 1735 FromType1 = Context.getArrayDecayedType(FromType1); 1736 if (SCS2.First == ICK_Array_To_Pointer) 1737 FromType2 = Context.getArrayDecayedType(FromType2); 1738 1739 // Canonicalize all of the types. 1740 FromType1 = Context.getCanonicalType(FromType1); 1741 ToType1 = Context.getCanonicalType(ToType1); 1742 FromType2 = Context.getCanonicalType(FromType2); 1743 ToType2 = Context.getCanonicalType(ToType2); 1744 1745 // C++ [over.ics.rank]p4b3: 1746 // 1747 // If class B is derived directly or indirectly from class A and 1748 // class C is derived directly or indirectly from B, 1749 // 1750 // For Objective-C, we let A, B, and C also be Objective-C 1751 // interfaces. 1752 1753 // Compare based on pointer conversions. 1754 if (SCS1.Second == ICK_Pointer_Conversion && 1755 SCS2.Second == ICK_Pointer_Conversion && 1756 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1757 FromType1->isPointerType() && FromType2->isPointerType() && 1758 ToType1->isPointerType() && ToType2->isPointerType()) { 1759 QualType FromPointee1 1760 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1761 QualType ToPointee1 1762 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1763 QualType FromPointee2 1764 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1765 QualType ToPointee2 1766 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1767 1768 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1769 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1770 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1771 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1772 1773 // -- conversion of C* to B* is better than conversion of C* to A*, 1774 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1775 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1776 return ImplicitConversionSequence::Better; 1777 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1778 return ImplicitConversionSequence::Worse; 1779 1780 if (ToIface1 && ToIface2) { 1781 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1782 return ImplicitConversionSequence::Better; 1783 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1784 return ImplicitConversionSequence::Worse; 1785 } 1786 } 1787 1788 // -- conversion of B* to A* is better than conversion of C* to A*, 1789 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1790 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1791 return ImplicitConversionSequence::Better; 1792 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1793 return ImplicitConversionSequence::Worse; 1794 1795 if (FromIface1 && FromIface2) { 1796 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1797 return ImplicitConversionSequence::Better; 1798 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1799 return ImplicitConversionSequence::Worse; 1800 } 1801 } 1802 } 1803 1804 // Compare based on reference bindings. 1805 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1806 SCS1.Second == ICK_Derived_To_Base) { 1807 // -- binding of an expression of type C to a reference of type 1808 // B& is better than binding an expression of type C to a 1809 // reference of type A&, 1810 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1811 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1812 if (IsDerivedFrom(ToType1, ToType2)) 1813 return ImplicitConversionSequence::Better; 1814 else if (IsDerivedFrom(ToType2, ToType1)) 1815 return ImplicitConversionSequence::Worse; 1816 } 1817 1818 // -- binding of an expression of type B to a reference of type 1819 // A& is better than binding an expression of type C to a 1820 // reference of type A&, 1821 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1822 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1823 if (IsDerivedFrom(FromType2, FromType1)) 1824 return ImplicitConversionSequence::Better; 1825 else if (IsDerivedFrom(FromType1, FromType2)) 1826 return ImplicitConversionSequence::Worse; 1827 } 1828 } 1829 1830 1831 // FIXME: conversion of A::* to B::* is better than conversion of 1832 // A::* to C::*, 1833 1834 // FIXME: conversion of B::* to C::* is better than conversion of 1835 // A::* to C::*, and 1836 1837 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1838 SCS1.Second == ICK_Derived_To_Base) { 1839 // -- conversion of C to B is better than conversion of C to A, 1840 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1841 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1842 if (IsDerivedFrom(ToType1, ToType2)) 1843 return ImplicitConversionSequence::Better; 1844 else if (IsDerivedFrom(ToType2, ToType1)) 1845 return ImplicitConversionSequence::Worse; 1846 } 1847 1848 // -- conversion of B to A is better than conversion of C to A. 1849 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1850 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1851 if (IsDerivedFrom(FromType2, FromType1)) 1852 return ImplicitConversionSequence::Better; 1853 else if (IsDerivedFrom(FromType1, FromType2)) 1854 return ImplicitConversionSequence::Worse; 1855 } 1856 } 1857 1858 return ImplicitConversionSequence::Indistinguishable; 1859} 1860 1861/// TryCopyInitialization - Try to copy-initialize a value of type 1862/// ToType from the expression From. Return the implicit conversion 1863/// sequence required to pass this argument, which may be a bad 1864/// conversion sequence (meaning that the argument cannot be passed to 1865/// a parameter of this type). If @p SuppressUserConversions, then we 1866/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1867/// then we treat @p From as an rvalue, even if it is an lvalue. 1868ImplicitConversionSequence 1869Sema::TryCopyInitialization(Expr *From, QualType ToType, 1870 bool SuppressUserConversions, bool ForceRValue) { 1871 if (ToType->isReferenceType()) { 1872 ImplicitConversionSequence ICS; 1873 CheckReferenceInit(From, ToType, &ICS, SuppressUserConversions, 1874 /*AllowExplicit=*/false, ForceRValue); 1875 return ICS; 1876 } else { 1877 return TryImplicitConversion(From, ToType, SuppressUserConversions, 1878 ForceRValue); 1879 } 1880} 1881 1882/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1883/// the expression @p From. Returns true (and emits a diagnostic) if there was 1884/// an error, returns false if the initialization succeeded. Elidable should 1885/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1886/// differently in C++0x for this case. 1887bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1888 const char* Flavor, bool Elidable) { 1889 if (!getLangOptions().CPlusPlus) { 1890 // In C, argument passing is the same as performing an assignment. 1891 QualType FromType = From->getType(); 1892 1893 AssignConvertType ConvTy = 1894 CheckSingleAssignmentConstraints(ToType, From); 1895 if (ConvTy != Compatible && 1896 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1897 ConvTy = Compatible; 1898 1899 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1900 FromType, From, Flavor); 1901 } 1902 1903 if (ToType->isReferenceType()) 1904 return CheckReferenceInit(From, ToType); 1905 1906 if (!PerformImplicitConversion(From, ToType, Flavor, 1907 /*AllowExplicit=*/false, Elidable)) 1908 return false; 1909 1910 return Diag(From->getSourceRange().getBegin(), 1911 diag::err_typecheck_convert_incompatible) 1912 << ToType << From->getType() << Flavor << From->getSourceRange(); 1913} 1914 1915/// TryObjectArgumentInitialization - Try to initialize the object 1916/// parameter of the given member function (@c Method) from the 1917/// expression @p From. 1918ImplicitConversionSequence 1919Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1920 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1921 unsigned MethodQuals = Method->getTypeQualifiers(); 1922 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 1923 1924 // Set up the conversion sequence as a "bad" conversion, to allow us 1925 // to exit early. 1926 ImplicitConversionSequence ICS; 1927 ICS.Standard.setAsIdentityConversion(); 1928 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1929 1930 // We need to have an object of class type. 1931 QualType FromType = From->getType(); 1932 if (const PointerType *PT = FromType->getAs<PointerType>()) 1933 FromType = PT->getPointeeType(); 1934 1935 assert(FromType->isRecordType()); 1936 1937 // The implicit object parmeter is has the type "reference to cv X", 1938 // where X is the class of which the function is a member 1939 // (C++ [over.match.funcs]p4). However, when finding an implicit 1940 // conversion sequence for the argument, we are not allowed to 1941 // create temporaries or perform user-defined conversions 1942 // (C++ [over.match.funcs]p5). We perform a simplified version of 1943 // reference binding here, that allows class rvalues to bind to 1944 // non-constant references. 1945 1946 // First check the qualifiers. We don't care about lvalue-vs-rvalue 1947 // with the implicit object parameter (C++ [over.match.funcs]p5). 1948 QualType FromTypeCanon = Context.getCanonicalType(FromType); 1949 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 1950 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 1951 return ICS; 1952 1953 // Check that we have either the same type or a derived type. It 1954 // affects the conversion rank. 1955 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 1956 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 1957 ICS.Standard.Second = ICK_Identity; 1958 else if (IsDerivedFrom(FromType, ClassType)) 1959 ICS.Standard.Second = ICK_Derived_To_Base; 1960 else 1961 return ICS; 1962 1963 // Success. Mark this as a reference binding. 1964 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 1965 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 1966 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 1967 ICS.Standard.ReferenceBinding = true; 1968 ICS.Standard.DirectBinding = true; 1969 ICS.Standard.RRefBinding = false; 1970 return ICS; 1971} 1972 1973/// PerformObjectArgumentInitialization - Perform initialization of 1974/// the implicit object parameter for the given Method with the given 1975/// expression. 1976bool 1977Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 1978 QualType FromRecordType, DestType; 1979 QualType ImplicitParamRecordType = 1980 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 1981 1982 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 1983 FromRecordType = PT->getPointeeType(); 1984 DestType = Method->getThisType(Context); 1985 } else { 1986 FromRecordType = From->getType(); 1987 DestType = ImplicitParamRecordType; 1988 } 1989 1990 ImplicitConversionSequence ICS 1991 = TryObjectArgumentInitialization(From, Method); 1992 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 1993 return Diag(From->getSourceRange().getBegin(), 1994 diag::err_implicit_object_parameter_init) 1995 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 1996 1997 if (ICS.Standard.Second == ICK_Derived_To_Base && 1998 CheckDerivedToBaseConversion(FromRecordType, 1999 ImplicitParamRecordType, 2000 From->getSourceRange().getBegin(), 2001 From->getSourceRange())) 2002 return true; 2003 2004 ImpCastExprToType(From, DestType, CastExpr::CK_Unknown, /*isLvalue=*/true); 2005 return false; 2006} 2007 2008/// TryContextuallyConvertToBool - Attempt to contextually convert the 2009/// expression From to bool (C++0x [conv]p3). 2010ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2011 return TryImplicitConversion(From, Context.BoolTy, false, true); 2012} 2013 2014/// PerformContextuallyConvertToBool - Perform a contextual conversion 2015/// of the expression From to bool (C++0x [conv]p3). 2016bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2017 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2018 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2019 return false; 2020 2021 return Diag(From->getSourceRange().getBegin(), 2022 diag::err_typecheck_bool_condition) 2023 << From->getType() << From->getSourceRange(); 2024} 2025 2026/// AddOverloadCandidate - Adds the given function to the set of 2027/// candidate functions, using the given function call arguments. If 2028/// @p SuppressUserConversions, then don't allow user-defined 2029/// conversions via constructors or conversion operators. 2030/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2031/// hacky way to implement the overloading rules for elidable copy 2032/// initialization in C++0x (C++0x 12.8p15). 2033void 2034Sema::AddOverloadCandidate(FunctionDecl *Function, 2035 Expr **Args, unsigned NumArgs, 2036 OverloadCandidateSet& CandidateSet, 2037 bool SuppressUserConversions, 2038 bool ForceRValue) 2039{ 2040 const FunctionProtoType* Proto 2041 = dyn_cast<FunctionProtoType>(Function->getType()->getAsFunctionType()); 2042 assert(Proto && "Functions without a prototype cannot be overloaded"); 2043 assert(!isa<CXXConversionDecl>(Function) && 2044 "Use AddConversionCandidate for conversion functions"); 2045 assert(!Function->getDescribedFunctionTemplate() && 2046 "Use AddTemplateOverloadCandidate for function templates"); 2047 2048 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2049 if (!isa<CXXConstructorDecl>(Method)) { 2050 // If we get here, it's because we're calling a member function 2051 // that is named without a member access expression (e.g., 2052 // "this->f") that was either written explicitly or created 2053 // implicitly. This can happen with a qualified call to a member 2054 // function, e.g., X::f(). We use a NULL object as the implied 2055 // object argument (C++ [over.call.func]p3). 2056 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2057 SuppressUserConversions, ForceRValue); 2058 return; 2059 } 2060 // We treat a constructor like a non-member function, since its object 2061 // argument doesn't participate in overload resolution. 2062 } 2063 2064 2065 // Add this candidate 2066 CandidateSet.push_back(OverloadCandidate()); 2067 OverloadCandidate& Candidate = CandidateSet.back(); 2068 Candidate.Function = Function; 2069 Candidate.Viable = true; 2070 Candidate.IsSurrogate = false; 2071 Candidate.IgnoreObjectArgument = false; 2072 2073 unsigned NumArgsInProto = Proto->getNumArgs(); 2074 2075 // (C++ 13.3.2p2): A candidate function having fewer than m 2076 // parameters is viable only if it has an ellipsis in its parameter 2077 // list (8.3.5). 2078 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2079 Candidate.Viable = false; 2080 return; 2081 } 2082 2083 // (C++ 13.3.2p2): A candidate function having more than m parameters 2084 // is viable only if the (m+1)st parameter has a default argument 2085 // (8.3.6). For the purposes of overload resolution, the 2086 // parameter list is truncated on the right, so that there are 2087 // exactly m parameters. 2088 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2089 if (NumArgs < MinRequiredArgs) { 2090 // Not enough arguments. 2091 Candidate.Viable = false; 2092 return; 2093 } 2094 2095 // Determine the implicit conversion sequences for each of the 2096 // arguments. 2097 Candidate.Conversions.resize(NumArgs); 2098 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2099 if (ArgIdx < NumArgsInProto) { 2100 // (C++ 13.3.2p3): for F to be a viable function, there shall 2101 // exist for each argument an implicit conversion sequence 2102 // (13.3.3.1) that converts that argument to the corresponding 2103 // parameter of F. 2104 QualType ParamType = Proto->getArgType(ArgIdx); 2105 Candidate.Conversions[ArgIdx] 2106 = TryCopyInitialization(Args[ArgIdx], ParamType, 2107 SuppressUserConversions, ForceRValue); 2108 if (Candidate.Conversions[ArgIdx].ConversionKind 2109 == ImplicitConversionSequence::BadConversion) { 2110 Candidate.Viable = false; 2111 break; 2112 } 2113 } else { 2114 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2115 // argument for which there is no corresponding parameter is 2116 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2117 Candidate.Conversions[ArgIdx].ConversionKind 2118 = ImplicitConversionSequence::EllipsisConversion; 2119 } 2120 } 2121} 2122 2123/// \brief Add all of the function declarations in the given function set to 2124/// the overload canddiate set. 2125void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2126 Expr **Args, unsigned NumArgs, 2127 OverloadCandidateSet& CandidateSet, 2128 bool SuppressUserConversions) { 2129 for (FunctionSet::const_iterator F = Functions.begin(), 2130 FEnd = Functions.end(); 2131 F != FEnd; ++F) { 2132 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) 2133 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2134 SuppressUserConversions); 2135 else 2136 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*F), 2137 /*FIXME: explicit args */false, 0, 0, 2138 Args, NumArgs, CandidateSet, 2139 SuppressUserConversions); 2140 } 2141} 2142 2143/// AddMethodCandidate - Adds the given C++ member function to the set 2144/// of candidate functions, using the given function call arguments 2145/// and the object argument (@c Object). For example, in a call 2146/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2147/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2148/// allow user-defined conversions via constructors or conversion 2149/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2150/// a slightly hacky way to implement the overloading rules for elidable copy 2151/// initialization in C++0x (C++0x 12.8p15). 2152void 2153Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2154 Expr **Args, unsigned NumArgs, 2155 OverloadCandidateSet& CandidateSet, 2156 bool SuppressUserConversions, bool ForceRValue) 2157{ 2158 const FunctionProtoType* Proto 2159 = dyn_cast<FunctionProtoType>(Method->getType()->getAsFunctionType()); 2160 assert(Proto && "Methods without a prototype cannot be overloaded"); 2161 assert(!isa<CXXConversionDecl>(Method) && 2162 "Use AddConversionCandidate for conversion functions"); 2163 assert(!isa<CXXConstructorDecl>(Method) && 2164 "Use AddOverloadCandidate for constructors"); 2165 2166 // Add this candidate 2167 CandidateSet.push_back(OverloadCandidate()); 2168 OverloadCandidate& Candidate = CandidateSet.back(); 2169 Candidate.Function = Method; 2170 Candidate.IsSurrogate = false; 2171 Candidate.IgnoreObjectArgument = false; 2172 2173 unsigned NumArgsInProto = Proto->getNumArgs(); 2174 2175 // (C++ 13.3.2p2): A candidate function having fewer than m 2176 // parameters is viable only if it has an ellipsis in its parameter 2177 // list (8.3.5). 2178 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2179 Candidate.Viable = false; 2180 return; 2181 } 2182 2183 // (C++ 13.3.2p2): A candidate function having more than m parameters 2184 // is viable only if the (m+1)st parameter has a default argument 2185 // (8.3.6). For the purposes of overload resolution, the 2186 // parameter list is truncated on the right, so that there are 2187 // exactly m parameters. 2188 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2189 if (NumArgs < MinRequiredArgs) { 2190 // Not enough arguments. 2191 Candidate.Viable = false; 2192 return; 2193 } 2194 2195 Candidate.Viable = true; 2196 Candidate.Conversions.resize(NumArgs + 1); 2197 2198 if (Method->isStatic() || !Object) 2199 // The implicit object argument is ignored. 2200 Candidate.IgnoreObjectArgument = true; 2201 else { 2202 // Determine the implicit conversion sequence for the object 2203 // parameter. 2204 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2205 if (Candidate.Conversions[0].ConversionKind 2206 == ImplicitConversionSequence::BadConversion) { 2207 Candidate.Viable = false; 2208 return; 2209 } 2210 } 2211 2212 // Determine the implicit conversion sequences for each of the 2213 // arguments. 2214 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2215 if (ArgIdx < NumArgsInProto) { 2216 // (C++ 13.3.2p3): for F to be a viable function, there shall 2217 // exist for each argument an implicit conversion sequence 2218 // (13.3.3.1) that converts that argument to the corresponding 2219 // parameter of F. 2220 QualType ParamType = Proto->getArgType(ArgIdx); 2221 Candidate.Conversions[ArgIdx + 1] 2222 = TryCopyInitialization(Args[ArgIdx], ParamType, 2223 SuppressUserConversions, ForceRValue); 2224 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2225 == ImplicitConversionSequence::BadConversion) { 2226 Candidate.Viable = false; 2227 break; 2228 } 2229 } else { 2230 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2231 // argument for which there is no corresponding parameter is 2232 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2233 Candidate.Conversions[ArgIdx + 1].ConversionKind 2234 = ImplicitConversionSequence::EllipsisConversion; 2235 } 2236 } 2237} 2238 2239/// \brief Add a C++ function template as a candidate in the candidate set, 2240/// using template argument deduction to produce an appropriate function 2241/// template specialization. 2242void 2243Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2244 bool HasExplicitTemplateArgs, 2245 const TemplateArgument *ExplicitTemplateArgs, 2246 unsigned NumExplicitTemplateArgs, 2247 Expr **Args, unsigned NumArgs, 2248 OverloadCandidateSet& CandidateSet, 2249 bool SuppressUserConversions, 2250 bool ForceRValue) { 2251 // C++ [over.match.funcs]p7: 2252 // In each case where a candidate is a function template, candidate 2253 // function template specializations are generated using template argument 2254 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2255 // candidate functions in the usual way.113) A given name can refer to one 2256 // or more function templates and also to a set of overloaded non-template 2257 // functions. In such a case, the candidate functions generated from each 2258 // function template are combined with the set of non-template candidate 2259 // functions. 2260 TemplateDeductionInfo Info(Context); 2261 FunctionDecl *Specialization = 0; 2262 if (TemplateDeductionResult Result 2263 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2264 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2265 Args, NumArgs, Specialization, Info)) { 2266 // FIXME: Record what happened with template argument deduction, so 2267 // that we can give the user a beautiful diagnostic. 2268 (void)Result; 2269 return; 2270 } 2271 2272 // Add the function template specialization produced by template argument 2273 // deduction as a candidate. 2274 assert(Specialization && "Missing function template specialization?"); 2275 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2276 SuppressUserConversions, ForceRValue); 2277} 2278 2279/// AddConversionCandidate - Add a C++ conversion function as a 2280/// candidate in the candidate set (C++ [over.match.conv], 2281/// C++ [over.match.copy]). From is the expression we're converting from, 2282/// and ToType is the type that we're eventually trying to convert to 2283/// (which may or may not be the same type as the type that the 2284/// conversion function produces). 2285void 2286Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2287 Expr *From, QualType ToType, 2288 OverloadCandidateSet& CandidateSet) { 2289 // Add this candidate 2290 CandidateSet.push_back(OverloadCandidate()); 2291 OverloadCandidate& Candidate = CandidateSet.back(); 2292 Candidate.Function = Conversion; 2293 Candidate.IsSurrogate = false; 2294 Candidate.IgnoreObjectArgument = false; 2295 Candidate.FinalConversion.setAsIdentityConversion(); 2296 Candidate.FinalConversion.FromTypePtr 2297 = Conversion->getConversionType().getAsOpaquePtr(); 2298 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2299 2300 // Determine the implicit conversion sequence for the implicit 2301 // object parameter. 2302 Candidate.Viable = true; 2303 Candidate.Conversions.resize(1); 2304 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2305 2306 if (Candidate.Conversions[0].ConversionKind 2307 == ImplicitConversionSequence::BadConversion) { 2308 Candidate.Viable = false; 2309 return; 2310 } 2311 2312 // To determine what the conversion from the result of calling the 2313 // conversion function to the type we're eventually trying to 2314 // convert to (ToType), we need to synthesize a call to the 2315 // conversion function and attempt copy initialization from it. This 2316 // makes sure that we get the right semantics with respect to 2317 // lvalues/rvalues and the type. Fortunately, we can allocate this 2318 // call on the stack and we don't need its arguments to be 2319 // well-formed. 2320 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2321 SourceLocation()); 2322 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2323 CastExpr::CK_Unknown, 2324 &ConversionRef, false); 2325 2326 // Note that it is safe to allocate CallExpr on the stack here because 2327 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2328 // allocator). 2329 CallExpr Call(Context, &ConversionFn, 0, 0, 2330 Conversion->getConversionType().getNonReferenceType(), 2331 SourceLocation()); 2332 ImplicitConversionSequence ICS = TryCopyInitialization(&Call, ToType, true); 2333 switch (ICS.ConversionKind) { 2334 case ImplicitConversionSequence::StandardConversion: 2335 Candidate.FinalConversion = ICS.Standard; 2336 break; 2337 2338 case ImplicitConversionSequence::BadConversion: 2339 Candidate.Viable = false; 2340 break; 2341 2342 default: 2343 assert(false && 2344 "Can only end up with a standard conversion sequence or failure"); 2345 } 2346} 2347 2348/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2349/// converts the given @c Object to a function pointer via the 2350/// conversion function @c Conversion, and then attempts to call it 2351/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2352/// the type of function that we'll eventually be calling. 2353void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2354 const FunctionProtoType *Proto, 2355 Expr *Object, Expr **Args, unsigned NumArgs, 2356 OverloadCandidateSet& CandidateSet) { 2357 CandidateSet.push_back(OverloadCandidate()); 2358 OverloadCandidate& Candidate = CandidateSet.back(); 2359 Candidate.Function = 0; 2360 Candidate.Surrogate = Conversion; 2361 Candidate.Viable = true; 2362 Candidate.IsSurrogate = true; 2363 Candidate.IgnoreObjectArgument = false; 2364 Candidate.Conversions.resize(NumArgs + 1); 2365 2366 // Determine the implicit conversion sequence for the implicit 2367 // object parameter. 2368 ImplicitConversionSequence ObjectInit 2369 = TryObjectArgumentInitialization(Object, Conversion); 2370 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2371 Candidate.Viable = false; 2372 return; 2373 } 2374 2375 // The first conversion is actually a user-defined conversion whose 2376 // first conversion is ObjectInit's standard conversion (which is 2377 // effectively a reference binding). Record it as such. 2378 Candidate.Conversions[0].ConversionKind 2379 = ImplicitConversionSequence::UserDefinedConversion; 2380 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2381 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2382 Candidate.Conversions[0].UserDefined.After 2383 = Candidate.Conversions[0].UserDefined.Before; 2384 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2385 2386 // Find the 2387 unsigned NumArgsInProto = Proto->getNumArgs(); 2388 2389 // (C++ 13.3.2p2): A candidate function having fewer than m 2390 // parameters is viable only if it has an ellipsis in its parameter 2391 // list (8.3.5). 2392 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2393 Candidate.Viable = false; 2394 return; 2395 } 2396 2397 // Function types don't have any default arguments, so just check if 2398 // we have enough arguments. 2399 if (NumArgs < NumArgsInProto) { 2400 // Not enough arguments. 2401 Candidate.Viable = false; 2402 return; 2403 } 2404 2405 // Determine the implicit conversion sequences for each of the 2406 // arguments. 2407 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2408 if (ArgIdx < NumArgsInProto) { 2409 // (C++ 13.3.2p3): for F to be a viable function, there shall 2410 // exist for each argument an implicit conversion sequence 2411 // (13.3.3.1) that converts that argument to the corresponding 2412 // parameter of F. 2413 QualType ParamType = Proto->getArgType(ArgIdx); 2414 Candidate.Conversions[ArgIdx + 1] 2415 = TryCopyInitialization(Args[ArgIdx], ParamType, 2416 /*SuppressUserConversions=*/false); 2417 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2418 == ImplicitConversionSequence::BadConversion) { 2419 Candidate.Viable = false; 2420 break; 2421 } 2422 } else { 2423 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2424 // argument for which there is no corresponding parameter is 2425 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2426 Candidate.Conversions[ArgIdx + 1].ConversionKind 2427 = ImplicitConversionSequence::EllipsisConversion; 2428 } 2429 } 2430} 2431 2432// FIXME: This will eventually be removed, once we've migrated all of the 2433// operator overloading logic over to the scheme used by binary operators, which 2434// works for template instantiation. 2435void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2436 SourceLocation OpLoc, 2437 Expr **Args, unsigned NumArgs, 2438 OverloadCandidateSet& CandidateSet, 2439 SourceRange OpRange) { 2440 2441 FunctionSet Functions; 2442 2443 QualType T1 = Args[0]->getType(); 2444 QualType T2; 2445 if (NumArgs > 1) 2446 T2 = Args[1]->getType(); 2447 2448 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2449 if (S) 2450 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2451 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2452 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2453 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2454 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2455} 2456 2457/// \brief Add overload candidates for overloaded operators that are 2458/// member functions. 2459/// 2460/// Add the overloaded operator candidates that are member functions 2461/// for the operator Op that was used in an operator expression such 2462/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2463/// CandidateSet will store the added overload candidates. (C++ 2464/// [over.match.oper]). 2465void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2466 SourceLocation OpLoc, 2467 Expr **Args, unsigned NumArgs, 2468 OverloadCandidateSet& CandidateSet, 2469 SourceRange OpRange) { 2470 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2471 2472 // C++ [over.match.oper]p3: 2473 // For a unary operator @ with an operand of a type whose 2474 // cv-unqualified version is T1, and for a binary operator @ with 2475 // a left operand of a type whose cv-unqualified version is T1 and 2476 // a right operand of a type whose cv-unqualified version is T2, 2477 // three sets of candidate functions, designated member 2478 // candidates, non-member candidates and built-in candidates, are 2479 // constructed as follows: 2480 QualType T1 = Args[0]->getType(); 2481 QualType T2; 2482 if (NumArgs > 1) 2483 T2 = Args[1]->getType(); 2484 2485 // -- If T1 is a class type, the set of member candidates is the 2486 // result of the qualified lookup of T1::operator@ 2487 // (13.3.1.1.1); otherwise, the set of member candidates is 2488 // empty. 2489 // FIXME: Lookup in base classes, too! 2490 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2491 DeclContext::lookup_const_iterator Oper, OperEnd; 2492 for (llvm::tie(Oper, OperEnd) = T1Rec->getDecl()->lookup(OpName); 2493 Oper != OperEnd; ++Oper) 2494 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2495 Args+1, NumArgs - 1, CandidateSet, 2496 /*SuppressUserConversions=*/false); 2497 } 2498} 2499 2500/// AddBuiltinCandidate - Add a candidate for a built-in 2501/// operator. ResultTy and ParamTys are the result and parameter types 2502/// of the built-in candidate, respectively. Args and NumArgs are the 2503/// arguments being passed to the candidate. IsAssignmentOperator 2504/// should be true when this built-in candidate is an assignment 2505/// operator. NumContextualBoolArguments is the number of arguments 2506/// (at the beginning of the argument list) that will be contextually 2507/// converted to bool. 2508void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2509 Expr **Args, unsigned NumArgs, 2510 OverloadCandidateSet& CandidateSet, 2511 bool IsAssignmentOperator, 2512 unsigned NumContextualBoolArguments) { 2513 // Add this candidate 2514 CandidateSet.push_back(OverloadCandidate()); 2515 OverloadCandidate& Candidate = CandidateSet.back(); 2516 Candidate.Function = 0; 2517 Candidate.IsSurrogate = false; 2518 Candidate.IgnoreObjectArgument = false; 2519 Candidate.BuiltinTypes.ResultTy = ResultTy; 2520 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2521 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2522 2523 // Determine the implicit conversion sequences for each of the 2524 // arguments. 2525 Candidate.Viable = true; 2526 Candidate.Conversions.resize(NumArgs); 2527 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2528 // C++ [over.match.oper]p4: 2529 // For the built-in assignment operators, conversions of the 2530 // left operand are restricted as follows: 2531 // -- no temporaries are introduced to hold the left operand, and 2532 // -- no user-defined conversions are applied to the left 2533 // operand to achieve a type match with the left-most 2534 // parameter of a built-in candidate. 2535 // 2536 // We block these conversions by turning off user-defined 2537 // conversions, since that is the only way that initialization of 2538 // a reference to a non-class type can occur from something that 2539 // is not of the same type. 2540 if (ArgIdx < NumContextualBoolArguments) { 2541 assert(ParamTys[ArgIdx] == Context.BoolTy && 2542 "Contextual conversion to bool requires bool type"); 2543 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2544 } else { 2545 Candidate.Conversions[ArgIdx] 2546 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2547 ArgIdx == 0 && IsAssignmentOperator); 2548 } 2549 if (Candidate.Conversions[ArgIdx].ConversionKind 2550 == ImplicitConversionSequence::BadConversion) { 2551 Candidate.Viable = false; 2552 break; 2553 } 2554 } 2555} 2556 2557/// BuiltinCandidateTypeSet - A set of types that will be used for the 2558/// candidate operator functions for built-in operators (C++ 2559/// [over.built]). The types are separated into pointer types and 2560/// enumeration types. 2561class BuiltinCandidateTypeSet { 2562 /// TypeSet - A set of types. 2563 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2564 2565 /// PointerTypes - The set of pointer types that will be used in the 2566 /// built-in candidates. 2567 TypeSet PointerTypes; 2568 2569 /// MemberPointerTypes - The set of member pointer types that will be 2570 /// used in the built-in candidates. 2571 TypeSet MemberPointerTypes; 2572 2573 /// EnumerationTypes - The set of enumeration types that will be 2574 /// used in the built-in candidates. 2575 TypeSet EnumerationTypes; 2576 2577 /// Context - The AST context in which we will build the type sets. 2578 ASTContext &Context; 2579 2580 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2581 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2582 2583public: 2584 /// iterator - Iterates through the types that are part of the set. 2585 typedef TypeSet::iterator iterator; 2586 2587 BuiltinCandidateTypeSet(ASTContext &Context) : Context(Context) { } 2588 2589 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2590 bool AllowExplicitConversions); 2591 2592 /// pointer_begin - First pointer type found; 2593 iterator pointer_begin() { return PointerTypes.begin(); } 2594 2595 /// pointer_end - Past the last pointer type found; 2596 iterator pointer_end() { return PointerTypes.end(); } 2597 2598 /// member_pointer_begin - First member pointer type found; 2599 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2600 2601 /// member_pointer_end - Past the last member pointer type found; 2602 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2603 2604 /// enumeration_begin - First enumeration type found; 2605 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2606 2607 /// enumeration_end - Past the last enumeration type found; 2608 iterator enumeration_end() { return EnumerationTypes.end(); } 2609}; 2610 2611/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2612/// the set of pointer types along with any more-qualified variants of 2613/// that type. For example, if @p Ty is "int const *", this routine 2614/// will add "int const *", "int const volatile *", "int const 2615/// restrict *", and "int const volatile restrict *" to the set of 2616/// pointer types. Returns true if the add of @p Ty itself succeeded, 2617/// false otherwise. 2618bool 2619BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2620 // Insert this type. 2621 if (!PointerTypes.insert(Ty)) 2622 return false; 2623 2624 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2625 QualType PointeeTy = PointerTy->getPointeeType(); 2626 // FIXME: Optimize this so that we don't keep trying to add the same types. 2627 2628 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal with all 2629 // pointer conversions that don't cast away constness? 2630 if (!PointeeTy.isConstQualified()) 2631 AddPointerWithMoreQualifiedTypeVariants 2632 (Context.getPointerType(PointeeTy.withConst())); 2633 if (!PointeeTy.isVolatileQualified()) 2634 AddPointerWithMoreQualifiedTypeVariants 2635 (Context.getPointerType(PointeeTy.withVolatile())); 2636 if (!PointeeTy.isRestrictQualified()) 2637 AddPointerWithMoreQualifiedTypeVariants 2638 (Context.getPointerType(PointeeTy.withRestrict())); 2639 } 2640 2641 return true; 2642} 2643 2644/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2645/// to the set of pointer types along with any more-qualified variants of 2646/// that type. For example, if @p Ty is "int const *", this routine 2647/// will add "int const *", "int const volatile *", "int const 2648/// restrict *", and "int const volatile restrict *" to the set of 2649/// pointer types. Returns true if the add of @p Ty itself succeeded, 2650/// false otherwise. 2651bool 2652BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2653 QualType Ty) { 2654 // Insert this type. 2655 if (!MemberPointerTypes.insert(Ty)) 2656 return false; 2657 2658 if (const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>()) { 2659 QualType PointeeTy = PointerTy->getPointeeType(); 2660 const Type *ClassTy = PointerTy->getClass(); 2661 // FIXME: Optimize this so that we don't keep trying to add the same types. 2662 2663 if (!PointeeTy.isConstQualified()) 2664 AddMemberPointerWithMoreQualifiedTypeVariants 2665 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2666 if (!PointeeTy.isVolatileQualified()) 2667 AddMemberPointerWithMoreQualifiedTypeVariants 2668 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2669 if (!PointeeTy.isRestrictQualified()) 2670 AddMemberPointerWithMoreQualifiedTypeVariants 2671 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2672 } 2673 2674 return true; 2675} 2676 2677/// AddTypesConvertedFrom - Add each of the types to which the type @p 2678/// Ty can be implicit converted to the given set of @p Types. We're 2679/// primarily interested in pointer types and enumeration types. We also 2680/// take member pointer types, for the conditional operator. 2681/// AllowUserConversions is true if we should look at the conversion 2682/// functions of a class type, and AllowExplicitConversions if we 2683/// should also include the explicit conversion functions of a class 2684/// type. 2685void 2686BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2687 bool AllowUserConversions, 2688 bool AllowExplicitConversions) { 2689 // Only deal with canonical types. 2690 Ty = Context.getCanonicalType(Ty); 2691 2692 // Look through reference types; they aren't part of the type of an 2693 // expression for the purposes of conversions. 2694 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 2695 Ty = RefTy->getPointeeType(); 2696 2697 // We don't care about qualifiers on the type. 2698 Ty = Ty.getUnqualifiedType(); 2699 2700 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2701 QualType PointeeTy = PointerTy->getPointeeType(); 2702 2703 // Insert our type, and its more-qualified variants, into the set 2704 // of types. 2705 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2706 return; 2707 2708 // Add 'cv void*' to our set of types. 2709 if (!Ty->isVoidType()) { 2710 QualType QualVoid 2711 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2712 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2713 } 2714 2715 // If this is a pointer to a class type, add pointers to its bases 2716 // (with the same level of cv-qualification as the original 2717 // derived class, of course). 2718 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 2719 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2720 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2721 Base != ClassDecl->bases_end(); ++Base) { 2722 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2723 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2724 2725 // Add the pointer type, recursively, so that we get all of 2726 // the indirect base classes, too. 2727 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2728 } 2729 } 2730 } else if (Ty->isMemberPointerType()) { 2731 // Member pointers are far easier, since the pointee can't be converted. 2732 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2733 return; 2734 } else if (Ty->isEnumeralType()) { 2735 EnumerationTypes.insert(Ty); 2736 } else if (AllowUserConversions) { 2737 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 2738 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2739 // FIXME: Visit conversion functions in the base classes, too. 2740 OverloadedFunctionDecl *Conversions 2741 = ClassDecl->getConversionFunctions(); 2742 for (OverloadedFunctionDecl::function_iterator Func 2743 = Conversions->function_begin(); 2744 Func != Conversions->function_end(); ++Func) { 2745 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 2746 if (AllowExplicitConversions || !Conv->isExplicit()) 2747 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2748 } 2749 } 2750 } 2751} 2752 2753/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2754/// operator overloads to the candidate set (C++ [over.built]), based 2755/// on the operator @p Op and the arguments given. For example, if the 2756/// operator is a binary '+', this routine might add "int 2757/// operator+(int, int)" to cover integer addition. 2758void 2759Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2760 Expr **Args, unsigned NumArgs, 2761 OverloadCandidateSet& CandidateSet) { 2762 // The set of "promoted arithmetic types", which are the arithmetic 2763 // types are that preserved by promotion (C++ [over.built]p2). Note 2764 // that the first few of these types are the promoted integral 2765 // types; these types need to be first. 2766 // FIXME: What about complex? 2767 const unsigned FirstIntegralType = 0; 2768 const unsigned LastIntegralType = 13; 2769 const unsigned FirstPromotedIntegralType = 7, 2770 LastPromotedIntegralType = 13; 2771 const unsigned FirstPromotedArithmeticType = 7, 2772 LastPromotedArithmeticType = 16; 2773 const unsigned NumArithmeticTypes = 16; 2774 QualType ArithmeticTypes[NumArithmeticTypes] = { 2775 Context.BoolTy, Context.CharTy, Context.WCharTy, 2776// Context.Char16Ty, Context.Char32Ty, 2777 Context.SignedCharTy, Context.ShortTy, 2778 Context.UnsignedCharTy, Context.UnsignedShortTy, 2779 Context.IntTy, Context.LongTy, Context.LongLongTy, 2780 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 2781 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 2782 }; 2783 2784 // Find all of the types that the arguments can convert to, but only 2785 // if the operator we're looking at has built-in operator candidates 2786 // that make use of these types. 2787 BuiltinCandidateTypeSet CandidateTypes(Context); 2788 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 2789 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 2790 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 2791 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 2792 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 2793 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 2794 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2795 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 2796 true, 2797 (Op == OO_Exclaim || 2798 Op == OO_AmpAmp || 2799 Op == OO_PipePipe)); 2800 } 2801 2802 bool isComparison = false; 2803 switch (Op) { 2804 case OO_None: 2805 case NUM_OVERLOADED_OPERATORS: 2806 assert(false && "Expected an overloaded operator"); 2807 break; 2808 2809 case OO_Star: // '*' is either unary or binary 2810 if (NumArgs == 1) 2811 goto UnaryStar; 2812 else 2813 goto BinaryStar; 2814 break; 2815 2816 case OO_Plus: // '+' is either unary or binary 2817 if (NumArgs == 1) 2818 goto UnaryPlus; 2819 else 2820 goto BinaryPlus; 2821 break; 2822 2823 case OO_Minus: // '-' is either unary or binary 2824 if (NumArgs == 1) 2825 goto UnaryMinus; 2826 else 2827 goto BinaryMinus; 2828 break; 2829 2830 case OO_Amp: // '&' is either unary or binary 2831 if (NumArgs == 1) 2832 goto UnaryAmp; 2833 else 2834 goto BinaryAmp; 2835 2836 case OO_PlusPlus: 2837 case OO_MinusMinus: 2838 // C++ [over.built]p3: 2839 // 2840 // For every pair (T, VQ), where T is an arithmetic type, and VQ 2841 // is either volatile or empty, there exist candidate operator 2842 // functions of the form 2843 // 2844 // VQ T& operator++(VQ T&); 2845 // T operator++(VQ T&, int); 2846 // 2847 // C++ [over.built]p4: 2848 // 2849 // For every pair (T, VQ), where T is an arithmetic type other 2850 // than bool, and VQ is either volatile or empty, there exist 2851 // candidate operator functions of the form 2852 // 2853 // VQ T& operator--(VQ T&); 2854 // T operator--(VQ T&, int); 2855 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 2856 Arith < NumArithmeticTypes; ++Arith) { 2857 QualType ArithTy = ArithmeticTypes[Arith]; 2858 QualType ParamTypes[2] 2859 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 2860 2861 // Non-volatile version. 2862 if (NumArgs == 1) 2863 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2864 else 2865 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2866 2867 // Volatile version 2868 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 2869 if (NumArgs == 1) 2870 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2871 else 2872 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2873 } 2874 2875 // C++ [over.built]p5: 2876 // 2877 // For every pair (T, VQ), where T is a cv-qualified or 2878 // cv-unqualified object type, and VQ is either volatile or 2879 // empty, there exist candidate operator functions of the form 2880 // 2881 // T*VQ& operator++(T*VQ&); 2882 // T*VQ& operator--(T*VQ&); 2883 // T* operator++(T*VQ&, int); 2884 // T* operator--(T*VQ&, int); 2885 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2886 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2887 // Skip pointer types that aren't pointers to object types. 2888 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 2889 continue; 2890 2891 QualType ParamTypes[2] = { 2892 Context.getLValueReferenceType(*Ptr), Context.IntTy 2893 }; 2894 2895 // Without volatile 2896 if (NumArgs == 1) 2897 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2898 else 2899 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2900 2901 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 2902 // With volatile 2903 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 2904 if (NumArgs == 1) 2905 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2906 else 2907 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2908 } 2909 } 2910 break; 2911 2912 UnaryStar: 2913 // C++ [over.built]p6: 2914 // For every cv-qualified or cv-unqualified object type T, there 2915 // exist candidate operator functions of the form 2916 // 2917 // T& operator*(T*); 2918 // 2919 // C++ [over.built]p7: 2920 // For every function type T, there exist candidate operator 2921 // functions of the form 2922 // T& operator*(T*); 2923 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2924 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2925 QualType ParamTy = *Ptr; 2926 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 2927 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 2928 &ParamTy, Args, 1, CandidateSet); 2929 } 2930 break; 2931 2932 UnaryPlus: 2933 // C++ [over.built]p8: 2934 // For every type T, there exist candidate operator functions of 2935 // the form 2936 // 2937 // T* operator+(T*); 2938 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2939 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2940 QualType ParamTy = *Ptr; 2941 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 2942 } 2943 2944 // Fall through 2945 2946 UnaryMinus: 2947 // C++ [over.built]p9: 2948 // For every promoted arithmetic type T, there exist candidate 2949 // operator functions of the form 2950 // 2951 // T operator+(T); 2952 // T operator-(T); 2953 for (unsigned Arith = FirstPromotedArithmeticType; 2954 Arith < LastPromotedArithmeticType; ++Arith) { 2955 QualType ArithTy = ArithmeticTypes[Arith]; 2956 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 2957 } 2958 break; 2959 2960 case OO_Tilde: 2961 // C++ [over.built]p10: 2962 // For every promoted integral type T, there exist candidate 2963 // operator functions of the form 2964 // 2965 // T operator~(T); 2966 for (unsigned Int = FirstPromotedIntegralType; 2967 Int < LastPromotedIntegralType; ++Int) { 2968 QualType IntTy = ArithmeticTypes[Int]; 2969 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 2970 } 2971 break; 2972 2973 case OO_New: 2974 case OO_Delete: 2975 case OO_Array_New: 2976 case OO_Array_Delete: 2977 case OO_Call: 2978 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 2979 break; 2980 2981 case OO_Comma: 2982 UnaryAmp: 2983 case OO_Arrow: 2984 // C++ [over.match.oper]p3: 2985 // -- For the operator ',', the unary operator '&', or the 2986 // operator '->', the built-in candidates set is empty. 2987 break; 2988 2989 case OO_Less: 2990 case OO_Greater: 2991 case OO_LessEqual: 2992 case OO_GreaterEqual: 2993 case OO_EqualEqual: 2994 case OO_ExclaimEqual: 2995 // C++ [over.built]p15: 2996 // 2997 // For every pointer or enumeration type T, there exist 2998 // candidate operator functions of the form 2999 // 3000 // bool operator<(T, T); 3001 // bool operator>(T, T); 3002 // bool operator<=(T, T); 3003 // bool operator>=(T, T); 3004 // bool operator==(T, T); 3005 // bool operator!=(T, T); 3006 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3007 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3008 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3009 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3010 } 3011 for (BuiltinCandidateTypeSet::iterator Enum 3012 = CandidateTypes.enumeration_begin(); 3013 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3014 QualType ParamTypes[2] = { *Enum, *Enum }; 3015 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3016 } 3017 3018 // Fall through. 3019 isComparison = true; 3020 3021 BinaryPlus: 3022 BinaryMinus: 3023 if (!isComparison) { 3024 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3025 3026 // C++ [over.built]p13: 3027 // 3028 // For every cv-qualified or cv-unqualified object type T 3029 // there exist candidate operator functions of the form 3030 // 3031 // T* operator+(T*, ptrdiff_t); 3032 // T& operator[](T*, ptrdiff_t); [BELOW] 3033 // T* operator-(T*, ptrdiff_t); 3034 // T* operator+(ptrdiff_t, T*); 3035 // T& operator[](ptrdiff_t, T*); [BELOW] 3036 // 3037 // C++ [over.built]p14: 3038 // 3039 // For every T, where T is a pointer to object type, there 3040 // exist candidate operator functions of the form 3041 // 3042 // ptrdiff_t operator-(T, T); 3043 for (BuiltinCandidateTypeSet::iterator Ptr 3044 = CandidateTypes.pointer_begin(); 3045 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3046 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3047 3048 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3049 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3050 3051 if (Op == OO_Plus) { 3052 // T* operator+(ptrdiff_t, T*); 3053 ParamTypes[0] = ParamTypes[1]; 3054 ParamTypes[1] = *Ptr; 3055 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3056 } else { 3057 // ptrdiff_t operator-(T, T); 3058 ParamTypes[1] = *Ptr; 3059 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3060 Args, 2, CandidateSet); 3061 } 3062 } 3063 } 3064 // Fall through 3065 3066 case OO_Slash: 3067 BinaryStar: 3068 Conditional: 3069 // C++ [over.built]p12: 3070 // 3071 // For every pair of promoted arithmetic types L and R, there 3072 // exist candidate operator functions of the form 3073 // 3074 // LR operator*(L, R); 3075 // LR operator/(L, R); 3076 // LR operator+(L, R); 3077 // LR operator-(L, R); 3078 // bool operator<(L, R); 3079 // bool operator>(L, R); 3080 // bool operator<=(L, R); 3081 // bool operator>=(L, R); 3082 // bool operator==(L, R); 3083 // bool operator!=(L, R); 3084 // 3085 // where LR is the result of the usual arithmetic conversions 3086 // between types L and R. 3087 // 3088 // C++ [over.built]p24: 3089 // 3090 // For every pair of promoted arithmetic types L and R, there exist 3091 // candidate operator functions of the form 3092 // 3093 // LR operator?(bool, L, R); 3094 // 3095 // where LR is the result of the usual arithmetic conversions 3096 // between types L and R. 3097 // Our candidates ignore the first parameter. 3098 for (unsigned Left = FirstPromotedArithmeticType; 3099 Left < LastPromotedArithmeticType; ++Left) { 3100 for (unsigned Right = FirstPromotedArithmeticType; 3101 Right < LastPromotedArithmeticType; ++Right) { 3102 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3103 QualType Result 3104 = isComparison? Context.BoolTy 3105 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3106 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3107 } 3108 } 3109 break; 3110 3111 case OO_Percent: 3112 BinaryAmp: 3113 case OO_Caret: 3114 case OO_Pipe: 3115 case OO_LessLess: 3116 case OO_GreaterGreater: 3117 // C++ [over.built]p17: 3118 // 3119 // For every pair of promoted integral types L and R, there 3120 // exist candidate operator functions of the form 3121 // 3122 // LR operator%(L, R); 3123 // LR operator&(L, R); 3124 // LR operator^(L, R); 3125 // LR operator|(L, R); 3126 // L operator<<(L, R); 3127 // L operator>>(L, R); 3128 // 3129 // where LR is the result of the usual arithmetic conversions 3130 // between types L and R. 3131 for (unsigned Left = FirstPromotedIntegralType; 3132 Left < LastPromotedIntegralType; ++Left) { 3133 for (unsigned Right = FirstPromotedIntegralType; 3134 Right < LastPromotedIntegralType; ++Right) { 3135 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3136 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3137 ? LandR[0] 3138 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3139 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3140 } 3141 } 3142 break; 3143 3144 case OO_Equal: 3145 // C++ [over.built]p20: 3146 // 3147 // For every pair (T, VQ), where T is an enumeration or 3148 // (FIXME:) pointer to member type and VQ is either volatile or 3149 // empty, there exist candidate operator functions of the form 3150 // 3151 // VQ T& operator=(VQ T&, T); 3152 for (BuiltinCandidateTypeSet::iterator Enum 3153 = CandidateTypes.enumeration_begin(); 3154 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3155 QualType ParamTypes[2]; 3156 3157 // T& operator=(T&, T) 3158 ParamTypes[0] = Context.getLValueReferenceType(*Enum); 3159 ParamTypes[1] = *Enum; 3160 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3161 /*IsAssignmentOperator=*/false); 3162 3163 if (!Context.getCanonicalType(*Enum).isVolatileQualified()) { 3164 // volatile T& operator=(volatile T&, T) 3165 ParamTypes[0] = Context.getLValueReferenceType((*Enum).withVolatile()); 3166 ParamTypes[1] = *Enum; 3167 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3168 /*IsAssignmentOperator=*/false); 3169 } 3170 } 3171 // Fall through. 3172 3173 case OO_PlusEqual: 3174 case OO_MinusEqual: 3175 // C++ [over.built]p19: 3176 // 3177 // For every pair (T, VQ), where T is any type and VQ is either 3178 // volatile or empty, there exist candidate operator functions 3179 // of the form 3180 // 3181 // T*VQ& operator=(T*VQ&, T*); 3182 // 3183 // C++ [over.built]p21: 3184 // 3185 // For every pair (T, VQ), where T is a cv-qualified or 3186 // cv-unqualified object type and VQ is either volatile or 3187 // empty, there exist candidate operator functions of the form 3188 // 3189 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3190 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3191 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3192 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3193 QualType ParamTypes[2]; 3194 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3195 3196 // non-volatile version 3197 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3198 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3199 /*IsAssigmentOperator=*/Op == OO_Equal); 3200 3201 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3202 // volatile version 3203 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3204 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3205 /*IsAssigmentOperator=*/Op == OO_Equal); 3206 } 3207 } 3208 // Fall through. 3209 3210 case OO_StarEqual: 3211 case OO_SlashEqual: 3212 // C++ [over.built]p18: 3213 // 3214 // For every triple (L, VQ, R), where L is an arithmetic type, 3215 // VQ is either volatile or empty, and R is a promoted 3216 // arithmetic type, there exist candidate operator functions of 3217 // the form 3218 // 3219 // VQ L& operator=(VQ L&, R); 3220 // VQ L& operator*=(VQ L&, R); 3221 // VQ L& operator/=(VQ L&, R); 3222 // VQ L& operator+=(VQ L&, R); 3223 // VQ L& operator-=(VQ L&, R); 3224 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3225 for (unsigned Right = FirstPromotedArithmeticType; 3226 Right < LastPromotedArithmeticType; ++Right) { 3227 QualType ParamTypes[2]; 3228 ParamTypes[1] = ArithmeticTypes[Right]; 3229 3230 // Add this built-in operator as a candidate (VQ is empty). 3231 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3232 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3233 /*IsAssigmentOperator=*/Op == OO_Equal); 3234 3235 // Add this built-in operator as a candidate (VQ is 'volatile'). 3236 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3237 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3238 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3239 /*IsAssigmentOperator=*/Op == OO_Equal); 3240 } 3241 } 3242 break; 3243 3244 case OO_PercentEqual: 3245 case OO_LessLessEqual: 3246 case OO_GreaterGreaterEqual: 3247 case OO_AmpEqual: 3248 case OO_CaretEqual: 3249 case OO_PipeEqual: 3250 // C++ [over.built]p22: 3251 // 3252 // For every triple (L, VQ, R), where L is an integral type, VQ 3253 // is either volatile or empty, and R is a promoted integral 3254 // type, there exist candidate operator functions of the form 3255 // 3256 // VQ L& operator%=(VQ L&, R); 3257 // VQ L& operator<<=(VQ L&, R); 3258 // VQ L& operator>>=(VQ L&, R); 3259 // VQ L& operator&=(VQ L&, R); 3260 // VQ L& operator^=(VQ L&, R); 3261 // VQ L& operator|=(VQ L&, R); 3262 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3263 for (unsigned Right = FirstPromotedIntegralType; 3264 Right < LastPromotedIntegralType; ++Right) { 3265 QualType ParamTypes[2]; 3266 ParamTypes[1] = ArithmeticTypes[Right]; 3267 3268 // Add this built-in operator as a candidate (VQ is empty). 3269 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3270 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3271 3272 // Add this built-in operator as a candidate (VQ is 'volatile'). 3273 ParamTypes[0] = ArithmeticTypes[Left]; 3274 ParamTypes[0].addVolatile(); 3275 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3276 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3277 } 3278 } 3279 break; 3280 3281 case OO_Exclaim: { 3282 // C++ [over.operator]p23: 3283 // 3284 // There also exist candidate operator functions of the form 3285 // 3286 // bool operator!(bool); 3287 // bool operator&&(bool, bool); [BELOW] 3288 // bool operator||(bool, bool); [BELOW] 3289 QualType ParamTy = Context.BoolTy; 3290 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3291 /*IsAssignmentOperator=*/false, 3292 /*NumContextualBoolArguments=*/1); 3293 break; 3294 } 3295 3296 case OO_AmpAmp: 3297 case OO_PipePipe: { 3298 // C++ [over.operator]p23: 3299 // 3300 // There also exist candidate operator functions of the form 3301 // 3302 // bool operator!(bool); [ABOVE] 3303 // bool operator&&(bool, bool); 3304 // bool operator||(bool, bool); 3305 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3306 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3307 /*IsAssignmentOperator=*/false, 3308 /*NumContextualBoolArguments=*/2); 3309 break; 3310 } 3311 3312 case OO_Subscript: 3313 // C++ [over.built]p13: 3314 // 3315 // For every cv-qualified or cv-unqualified object type T there 3316 // exist candidate operator functions of the form 3317 // 3318 // T* operator+(T*, ptrdiff_t); [ABOVE] 3319 // T& operator[](T*, ptrdiff_t); 3320 // T* operator-(T*, ptrdiff_t); [ABOVE] 3321 // T* operator+(ptrdiff_t, T*); [ABOVE] 3322 // T& operator[](ptrdiff_t, T*); 3323 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3324 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3325 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3326 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3327 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3328 3329 // T& operator[](T*, ptrdiff_t) 3330 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3331 3332 // T& operator[](ptrdiff_t, T*); 3333 ParamTypes[0] = ParamTypes[1]; 3334 ParamTypes[1] = *Ptr; 3335 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3336 } 3337 break; 3338 3339 case OO_ArrowStar: 3340 // FIXME: No support for pointer-to-members yet. 3341 break; 3342 3343 case OO_Conditional: 3344 // Note that we don't consider the first argument, since it has been 3345 // contextually converted to bool long ago. The candidates below are 3346 // therefore added as binary. 3347 // 3348 // C++ [over.built]p24: 3349 // For every type T, where T is a pointer or pointer-to-member type, 3350 // there exist candidate operator functions of the form 3351 // 3352 // T operator?(bool, T, T); 3353 // 3354 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3355 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3356 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3357 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3358 } 3359 for (BuiltinCandidateTypeSet::iterator Ptr = 3360 CandidateTypes.member_pointer_begin(), 3361 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3362 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3363 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3364 } 3365 goto Conditional; 3366 } 3367} 3368 3369/// \brief Add function candidates found via argument-dependent lookup 3370/// to the set of overloading candidates. 3371/// 3372/// This routine performs argument-dependent name lookup based on the 3373/// given function name (which may also be an operator name) and adds 3374/// all of the overload candidates found by ADL to the overload 3375/// candidate set (C++ [basic.lookup.argdep]). 3376void 3377Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3378 Expr **Args, unsigned NumArgs, 3379 OverloadCandidateSet& CandidateSet) { 3380 FunctionSet Functions; 3381 3382 // Record all of the function candidates that we've already 3383 // added to the overload set, so that we don't add those same 3384 // candidates a second time. 3385 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3386 CandEnd = CandidateSet.end(); 3387 Cand != CandEnd; ++Cand) 3388 if (Cand->Function) { 3389 Functions.insert(Cand->Function); 3390 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3391 Functions.insert(FunTmpl); 3392 } 3393 3394 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3395 3396 // Erase all of the candidates we already knew about. 3397 // FIXME: This is suboptimal. Is there a better way? 3398 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3399 CandEnd = CandidateSet.end(); 3400 Cand != CandEnd; ++Cand) 3401 if (Cand->Function) { 3402 Functions.erase(Cand->Function); 3403 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3404 Functions.erase(FunTmpl); 3405 } 3406 3407 // For each of the ADL candidates we found, add it to the overload 3408 // set. 3409 for (FunctionSet::iterator Func = Functions.begin(), 3410 FuncEnd = Functions.end(); 3411 Func != FuncEnd; ++Func) { 3412 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) 3413 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet); 3414 else 3415 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3416 /*FIXME: explicit args */false, 0, 0, 3417 Args, NumArgs, CandidateSet); 3418 } 3419} 3420 3421/// isBetterOverloadCandidate - Determines whether the first overload 3422/// candidate is a better candidate than the second (C++ 13.3.3p1). 3423bool 3424Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3425 const OverloadCandidate& Cand2) 3426{ 3427 // Define viable functions to be better candidates than non-viable 3428 // functions. 3429 if (!Cand2.Viable) 3430 return Cand1.Viable; 3431 else if (!Cand1.Viable) 3432 return false; 3433 3434 // C++ [over.match.best]p1: 3435 // 3436 // -- if F is a static member function, ICS1(F) is defined such 3437 // that ICS1(F) is neither better nor worse than ICS1(G) for 3438 // any function G, and, symmetrically, ICS1(G) is neither 3439 // better nor worse than ICS1(F). 3440 unsigned StartArg = 0; 3441 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3442 StartArg = 1; 3443 3444 // C++ [over.match.best]p1: 3445 // A viable function F1 is defined to be a better function than another 3446 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3447 // conversion sequence than ICSi(F2), and then... 3448 unsigned NumArgs = Cand1.Conversions.size(); 3449 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3450 bool HasBetterConversion = false; 3451 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3452 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3453 Cand2.Conversions[ArgIdx])) { 3454 case ImplicitConversionSequence::Better: 3455 // Cand1 has a better conversion sequence. 3456 HasBetterConversion = true; 3457 break; 3458 3459 case ImplicitConversionSequence::Worse: 3460 // Cand1 can't be better than Cand2. 3461 return false; 3462 3463 case ImplicitConversionSequence::Indistinguishable: 3464 // Do nothing. 3465 break; 3466 } 3467 } 3468 3469 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3470 // ICSj(F2), or, if not that, 3471 if (HasBetterConversion) 3472 return true; 3473 3474 // - F1 is a non-template function and F2 is a function template 3475 // specialization, or, if not that, 3476 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3477 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3478 return true; 3479 3480 // -- F1 and F2 are function template specializations, and the function 3481 // template for F1 is more specialized than the template for F2 3482 // according to the partial ordering rules described in 14.5.5.2, or, 3483 // if not that, 3484 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3485 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3486 // FIXME: Implement partial ordering of function templates. 3487 Diag(SourceLocation(), diag::unsup_function_template_partial_ordering); 3488 3489 // -- the context is an initialization by user-defined conversion 3490 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3491 // from the return type of F1 to the destination type (i.e., 3492 // the type of the entity being initialized) is a better 3493 // conversion sequence than the standard conversion sequence 3494 // from the return type of F2 to the destination type. 3495 if (Cand1.Function && Cand2.Function && 3496 isa<CXXConversionDecl>(Cand1.Function) && 3497 isa<CXXConversionDecl>(Cand2.Function)) { 3498 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3499 Cand2.FinalConversion)) { 3500 case ImplicitConversionSequence::Better: 3501 // Cand1 has a better conversion sequence. 3502 return true; 3503 3504 case ImplicitConversionSequence::Worse: 3505 // Cand1 can't be better than Cand2. 3506 return false; 3507 3508 case ImplicitConversionSequence::Indistinguishable: 3509 // Do nothing 3510 break; 3511 } 3512 } 3513 3514 return false; 3515} 3516 3517/// \brief Computes the best viable function (C++ 13.3.3) 3518/// within an overload candidate set. 3519/// 3520/// \param CandidateSet the set of candidate functions. 3521/// 3522/// \param Loc the location of the function name (or operator symbol) for 3523/// which overload resolution occurs. 3524/// 3525/// \param Best f overload resolution was successful or found a deleted 3526/// function, Best points to the candidate function found. 3527/// 3528/// \returns The result of overload resolution. 3529Sema::OverloadingResult 3530Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3531 SourceLocation Loc, 3532 OverloadCandidateSet::iterator& Best) 3533{ 3534 // Find the best viable function. 3535 Best = CandidateSet.end(); 3536 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3537 Cand != CandidateSet.end(); ++Cand) { 3538 if (Cand->Viable) { 3539 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3540 Best = Cand; 3541 } 3542 } 3543 3544 // If we didn't find any viable functions, abort. 3545 if (Best == CandidateSet.end()) 3546 return OR_No_Viable_Function; 3547 3548 // Make sure that this function is better than every other viable 3549 // function. If not, we have an ambiguity. 3550 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3551 Cand != CandidateSet.end(); ++Cand) { 3552 if (Cand->Viable && 3553 Cand != Best && 3554 !isBetterOverloadCandidate(*Best, *Cand)) { 3555 Best = CandidateSet.end(); 3556 return OR_Ambiguous; 3557 } 3558 } 3559 3560 // Best is the best viable function. 3561 if (Best->Function && 3562 (Best->Function->isDeleted() || 3563 Best->Function->getAttr<UnavailableAttr>())) 3564 return OR_Deleted; 3565 3566 // C++ [basic.def.odr]p2: 3567 // An overloaded function is used if it is selected by overload resolution 3568 // when referred to from a potentially-evaluated expression. [Note: this 3569 // covers calls to named functions (5.2.2), operator overloading 3570 // (clause 13), user-defined conversions (12.3.2), allocation function for 3571 // placement new (5.3.4), as well as non-default initialization (8.5). 3572 if (Best->Function) 3573 MarkDeclarationReferenced(Loc, Best->Function); 3574 return OR_Success; 3575} 3576 3577/// PrintOverloadCandidates - When overload resolution fails, prints 3578/// diagnostic messages containing the candidates in the candidate 3579/// set. If OnlyViable is true, only viable candidates will be printed. 3580void 3581Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3582 bool OnlyViable) 3583{ 3584 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3585 LastCand = CandidateSet.end(); 3586 for (; Cand != LastCand; ++Cand) { 3587 if (Cand->Viable || !OnlyViable) { 3588 if (Cand->Function) { 3589 if (Cand->Function->isDeleted() || 3590 Cand->Function->getAttr<UnavailableAttr>()) { 3591 // Deleted or "unavailable" function. 3592 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3593 << Cand->Function->isDeleted(); 3594 } else { 3595 // Normal function 3596 // FIXME: Give a better reason! 3597 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3598 } 3599 } else if (Cand->IsSurrogate) { 3600 // Desugar the type of the surrogate down to a function type, 3601 // retaining as many typedefs as possible while still showing 3602 // the function type (and, therefore, its parameter types). 3603 QualType FnType = Cand->Surrogate->getConversionType(); 3604 bool isLValueReference = false; 3605 bool isRValueReference = false; 3606 bool isPointer = false; 3607 if (const LValueReferenceType *FnTypeRef = 3608 FnType->getAs<LValueReferenceType>()) { 3609 FnType = FnTypeRef->getPointeeType(); 3610 isLValueReference = true; 3611 } else if (const RValueReferenceType *FnTypeRef = 3612 FnType->getAs<RValueReferenceType>()) { 3613 FnType = FnTypeRef->getPointeeType(); 3614 isRValueReference = true; 3615 } 3616 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 3617 FnType = FnTypePtr->getPointeeType(); 3618 isPointer = true; 3619 } 3620 // Desugar down to a function type. 3621 FnType = QualType(FnType->getAsFunctionType(), 0); 3622 // Reconstruct the pointer/reference as appropriate. 3623 if (isPointer) FnType = Context.getPointerType(FnType); 3624 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3625 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3626 3627 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3628 << FnType; 3629 } else { 3630 // FIXME: We need to get the identifier in here 3631 // FIXME: Do we want the error message to point at the operator? 3632 // (built-ins won't have a location) 3633 QualType FnType 3634 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3635 Cand->BuiltinTypes.ParamTypes, 3636 Cand->Conversions.size(), 3637 false, 0); 3638 3639 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3640 } 3641 } 3642 } 3643} 3644 3645/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3646/// an overloaded function (C++ [over.over]), where @p From is an 3647/// expression with overloaded function type and @p ToType is the type 3648/// we're trying to resolve to. For example: 3649/// 3650/// @code 3651/// int f(double); 3652/// int f(int); 3653/// 3654/// int (*pfd)(double) = f; // selects f(double) 3655/// @endcode 3656/// 3657/// This routine returns the resulting FunctionDecl if it could be 3658/// resolved, and NULL otherwise. When @p Complain is true, this 3659/// routine will emit diagnostics if there is an error. 3660FunctionDecl * 3661Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3662 bool Complain) { 3663 QualType FunctionType = ToType; 3664 bool IsMember = false; 3665 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 3666 FunctionType = ToTypePtr->getPointeeType(); 3667 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 3668 FunctionType = ToTypeRef->getPointeeType(); 3669 else if (const MemberPointerType *MemTypePtr = 3670 ToType->getAs<MemberPointerType>()) { 3671 FunctionType = MemTypePtr->getPointeeType(); 3672 IsMember = true; 3673 } 3674 3675 // We only look at pointers or references to functions. 3676 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 3677 if (!FunctionType->isFunctionType()) 3678 return 0; 3679 3680 // Find the actual overloaded function declaration. 3681 OverloadedFunctionDecl *Ovl = 0; 3682 3683 // C++ [over.over]p1: 3684 // [...] [Note: any redundant set of parentheses surrounding the 3685 // overloaded function name is ignored (5.1). ] 3686 Expr *OvlExpr = From->IgnoreParens(); 3687 3688 // C++ [over.over]p1: 3689 // [...] The overloaded function name can be preceded by the & 3690 // operator. 3691 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3692 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3693 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3694 } 3695 3696 // Try to dig out the overloaded function. 3697 FunctionTemplateDecl *FunctionTemplate = 0; 3698 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 3699 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3700 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 3701 } 3702 3703 // If there's no overloaded function declaration or function template, 3704 // we're done. 3705 if (!Ovl && !FunctionTemplate) 3706 return 0; 3707 3708 OverloadIterator Fun; 3709 if (Ovl) 3710 Fun = Ovl; 3711 else 3712 Fun = FunctionTemplate; 3713 3714 // Look through all of the overloaded functions, searching for one 3715 // whose type matches exactly. 3716 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 3717 3718 bool FoundNonTemplateFunction = false; 3719 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 3720 // C++ [over.over]p3: 3721 // Non-member functions and static member functions match 3722 // targets of type "pointer-to-function" or "reference-to-function." 3723 // Nonstatic member functions match targets of 3724 // type "pointer-to-member-function." 3725 // Note that according to DR 247, the containing class does not matter. 3726 3727 if (FunctionTemplateDecl *FunctionTemplate 3728 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 3729 if (CXXMethodDecl *Method 3730 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 3731 // Skip non-static function templates when converting to pointer, and 3732 // static when converting to member pointer. 3733 if (Method->isStatic() == IsMember) 3734 continue; 3735 } else if (IsMember) 3736 continue; 3737 3738 // C++ [over.over]p2: 3739 // If the name is a function template, template argument deduction is 3740 // done (14.8.2.2), and if the argument deduction succeeds, the 3741 // resulting template argument list is used to generate a single 3742 // function template specialization, which is added to the set of 3743 // overloaded functions considered. 3744 FunctionDecl *Specialization = 0; 3745 TemplateDeductionInfo Info(Context); 3746 if (TemplateDeductionResult Result 3747 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 3748 /*FIXME:*/0, /*FIXME:*/0, 3749 FunctionType, Specialization, Info)) { 3750 // FIXME: make a note of the failed deduction for diagnostics. 3751 (void)Result; 3752 } else { 3753 assert(FunctionType 3754 == Context.getCanonicalType(Specialization->getType())); 3755 Matches.insert( 3756 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 3757 } 3758 } 3759 3760 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 3761 // Skip non-static functions when converting to pointer, and static 3762 // when converting to member pointer. 3763 if (Method->isStatic() == IsMember) 3764 continue; 3765 } else if (IsMember) 3766 continue; 3767 3768 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 3769 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 3770 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 3771 FoundNonTemplateFunction = true; 3772 } 3773 } 3774 } 3775 3776 // If there were 0 or 1 matches, we're done. 3777 if (Matches.empty()) 3778 return 0; 3779 else if (Matches.size() == 1) 3780 return *Matches.begin(); 3781 3782 // C++ [over.over]p4: 3783 // If more than one function is selected, [...] 3784 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 3785 if (FoundNonTemplateFunction) { 3786 // [...] any function template specializations in the set are eliminated 3787 // if the set also contains a non-template function, [...] 3788 for (llvm::SmallPtrSet<FunctionDecl *, 4>::iterator M = Matches.begin(), 3789 MEnd = Matches.end(); 3790 M != MEnd; ++M) 3791 if ((*M)->getPrimaryTemplate() == 0) 3792 RemainingMatches.push_back(*M); 3793 } else { 3794 // [...] and any given function template specialization F1 is eliminated 3795 // if the set contains a second function template specialization whose 3796 // function template is more specialized than the function template of F1 3797 // according to the partial ordering rules of 14.5.5.2. 3798 // FIXME: Implement this! 3799 RemainingMatches.append(Matches.begin(), Matches.end()); 3800 } 3801 3802 // [...] After such eliminations, if any, there shall remain exactly one 3803 // selected function. 3804 if (RemainingMatches.size() == 1) 3805 return RemainingMatches.front(); 3806 3807 // FIXME: We should probably return the same thing that BestViableFunction 3808 // returns (even if we issue the diagnostics here). 3809 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 3810 << RemainingMatches[0]->getDeclName(); 3811 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 3812 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 3813 return 0; 3814} 3815 3816/// ResolveOverloadedCallFn - Given the call expression that calls Fn 3817/// (which eventually refers to the declaration Func) and the call 3818/// arguments Args/NumArgs, attempt to resolve the function call down 3819/// to a specific function. If overload resolution succeeds, returns 3820/// the function declaration produced by overload 3821/// resolution. Otherwise, emits diagnostics, deletes all of the 3822/// arguments and Fn, and returns NULL. 3823FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 3824 DeclarationName UnqualifiedName, 3825 bool HasExplicitTemplateArgs, 3826 const TemplateArgument *ExplicitTemplateArgs, 3827 unsigned NumExplicitTemplateArgs, 3828 SourceLocation LParenLoc, 3829 Expr **Args, unsigned NumArgs, 3830 SourceLocation *CommaLocs, 3831 SourceLocation RParenLoc, 3832 bool &ArgumentDependentLookup) { 3833 OverloadCandidateSet CandidateSet; 3834 3835 // Add the functions denoted by Callee to the set of candidate 3836 // functions. While we're doing so, track whether argument-dependent 3837 // lookup still applies, per: 3838 // 3839 // C++0x [basic.lookup.argdep]p3: 3840 // Let X be the lookup set produced by unqualified lookup (3.4.1) 3841 // and let Y be the lookup set produced by argument dependent 3842 // lookup (defined as follows). If X contains 3843 // 3844 // -- a declaration of a class member, or 3845 // 3846 // -- a block-scope function declaration that is not a 3847 // using-declaration, or 3848 // 3849 // -- a declaration that is neither a function or a function 3850 // template 3851 // 3852 // then Y is empty. 3853 if (OverloadedFunctionDecl *Ovl 3854 = dyn_cast_or_null<OverloadedFunctionDecl>(Callee)) { 3855 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 3856 FuncEnd = Ovl->function_end(); 3857 Func != FuncEnd; ++Func) { 3858 DeclContext *Ctx = 0; 3859 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Func)) { 3860 if (HasExplicitTemplateArgs) 3861 continue; 3862 3863 AddOverloadCandidate(FunDecl, Args, NumArgs, CandidateSet); 3864 Ctx = FunDecl->getDeclContext(); 3865 } else { 3866 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*Func); 3867 AddTemplateOverloadCandidate(FunTmpl, HasExplicitTemplateArgs, 3868 ExplicitTemplateArgs, 3869 NumExplicitTemplateArgs, 3870 Args, NumArgs, CandidateSet); 3871 Ctx = FunTmpl->getDeclContext(); 3872 } 3873 3874 3875 if (Ctx->isRecord() || Ctx->isFunctionOrMethod()) 3876 ArgumentDependentLookup = false; 3877 } 3878 } else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee)) { 3879 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 3880 AddOverloadCandidate(Func, Args, NumArgs, CandidateSet); 3881 3882 if (Func->getDeclContext()->isRecord() || 3883 Func->getDeclContext()->isFunctionOrMethod()) 3884 ArgumentDependentLookup = false; 3885 } else if (FunctionTemplateDecl *FuncTemplate 3886 = dyn_cast_or_null<FunctionTemplateDecl>(Callee)) { 3887 AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 3888 ExplicitTemplateArgs, 3889 NumExplicitTemplateArgs, 3890 Args, NumArgs, CandidateSet); 3891 3892 if (FuncTemplate->getDeclContext()->isRecord()) 3893 ArgumentDependentLookup = false; 3894 } 3895 3896 if (Callee) 3897 UnqualifiedName = Callee->getDeclName(); 3898 3899 // FIXME: Pass explicit template arguments through for ADL 3900 if (ArgumentDependentLookup) 3901 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 3902 CandidateSet); 3903 3904 OverloadCandidateSet::iterator Best; 3905 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 3906 case OR_Success: 3907 return Best->Function; 3908 3909 case OR_No_Viable_Function: 3910 Diag(Fn->getSourceRange().getBegin(), 3911 diag::err_ovl_no_viable_function_in_call) 3912 << UnqualifiedName << Fn->getSourceRange(); 3913 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3914 break; 3915 3916 case OR_Ambiguous: 3917 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 3918 << UnqualifiedName << Fn->getSourceRange(); 3919 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3920 break; 3921 3922 case OR_Deleted: 3923 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 3924 << Best->Function->isDeleted() 3925 << UnqualifiedName 3926 << Fn->getSourceRange(); 3927 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3928 break; 3929 } 3930 3931 // Overload resolution failed. Destroy all of the subexpressions and 3932 // return NULL. 3933 Fn->Destroy(Context); 3934 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 3935 Args[Arg]->Destroy(Context); 3936 return 0; 3937} 3938 3939/// \brief Create a unary operation that may resolve to an overloaded 3940/// operator. 3941/// 3942/// \param OpLoc The location of the operator itself (e.g., '*'). 3943/// 3944/// \param OpcIn The UnaryOperator::Opcode that describes this 3945/// operator. 3946/// 3947/// \param Functions The set of non-member functions that will be 3948/// considered by overload resolution. The caller needs to build this 3949/// set based on the context using, e.g., 3950/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 3951/// set should not contain any member functions; those will be added 3952/// by CreateOverloadedUnaryOp(). 3953/// 3954/// \param input The input argument. 3955Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 3956 unsigned OpcIn, 3957 FunctionSet &Functions, 3958 ExprArg input) { 3959 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 3960 Expr *Input = (Expr *)input.get(); 3961 3962 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 3963 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 3964 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3965 3966 Expr *Args[2] = { Input, 0 }; 3967 unsigned NumArgs = 1; 3968 3969 // For post-increment and post-decrement, add the implicit '0' as 3970 // the second argument, so that we know this is a post-increment or 3971 // post-decrement. 3972 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 3973 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 3974 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 3975 SourceLocation()); 3976 NumArgs = 2; 3977 } 3978 3979 if (Input->isTypeDependent()) { 3980 OverloadedFunctionDecl *Overloads 3981 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 3982 for (FunctionSet::iterator Func = Functions.begin(), 3983 FuncEnd = Functions.end(); 3984 Func != FuncEnd; ++Func) 3985 Overloads->addOverload(*Func); 3986 3987 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 3988 OpLoc, false, false); 3989 3990 input.release(); 3991 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 3992 &Args[0], NumArgs, 3993 Context.DependentTy, 3994 OpLoc)); 3995 } 3996 3997 // Build an empty overload set. 3998 OverloadCandidateSet CandidateSet; 3999 4000 // Add the candidates from the given function set. 4001 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4002 4003 // Add operator candidates that are member functions. 4004 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4005 4006 // Add builtin operator candidates. 4007 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4008 4009 // Perform overload resolution. 4010 OverloadCandidateSet::iterator Best; 4011 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4012 case OR_Success: { 4013 // We found a built-in operator or an overloaded operator. 4014 FunctionDecl *FnDecl = Best->Function; 4015 4016 if (FnDecl) { 4017 // We matched an overloaded operator. Build a call to that 4018 // operator. 4019 4020 // Convert the arguments. 4021 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4022 if (PerformObjectArgumentInitialization(Input, Method)) 4023 return ExprError(); 4024 } else { 4025 // Convert the arguments. 4026 if (PerformCopyInitialization(Input, 4027 FnDecl->getParamDecl(0)->getType(), 4028 "passing")) 4029 return ExprError(); 4030 } 4031 4032 // Determine the result type 4033 QualType ResultTy 4034 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4035 ResultTy = ResultTy.getNonReferenceType(); 4036 4037 // Build the actual expression node. 4038 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4039 SourceLocation()); 4040 UsualUnaryConversions(FnExpr); 4041 4042 input.release(); 4043 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4044 &Input, 1, ResultTy, 4045 OpLoc)); 4046 } else { 4047 // We matched a built-in operator. Convert the arguments, then 4048 // break out so that we will build the appropriate built-in 4049 // operator node. 4050 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4051 Best->Conversions[0], "passing")) 4052 return ExprError(); 4053 4054 break; 4055 } 4056 } 4057 4058 case OR_No_Viable_Function: 4059 // No viable function; fall through to handling this as a 4060 // built-in operator, which will produce an error message for us. 4061 break; 4062 4063 case OR_Ambiguous: 4064 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4065 << UnaryOperator::getOpcodeStr(Opc) 4066 << Input->getSourceRange(); 4067 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4068 return ExprError(); 4069 4070 case OR_Deleted: 4071 Diag(OpLoc, diag::err_ovl_deleted_oper) 4072 << Best->Function->isDeleted() 4073 << UnaryOperator::getOpcodeStr(Opc) 4074 << Input->getSourceRange(); 4075 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4076 return ExprError(); 4077 } 4078 4079 // Either we found no viable overloaded operator or we matched a 4080 // built-in operator. In either case, fall through to trying to 4081 // build a built-in operation. 4082 input.release(); 4083 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4084} 4085 4086/// \brief Create a binary operation that may resolve to an overloaded 4087/// operator. 4088/// 4089/// \param OpLoc The location of the operator itself (e.g., '+'). 4090/// 4091/// \param OpcIn The BinaryOperator::Opcode that describes this 4092/// operator. 4093/// 4094/// \param Functions The set of non-member functions that will be 4095/// considered by overload resolution. The caller needs to build this 4096/// set based on the context using, e.g., 4097/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4098/// set should not contain any member functions; those will be added 4099/// by CreateOverloadedBinOp(). 4100/// 4101/// \param LHS Left-hand argument. 4102/// \param RHS Right-hand argument. 4103Sema::OwningExprResult 4104Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4105 unsigned OpcIn, 4106 FunctionSet &Functions, 4107 Expr *LHS, Expr *RHS) { 4108 Expr *Args[2] = { LHS, RHS }; 4109 4110 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4111 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4112 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4113 4114 // If either side is type-dependent, create an appropriate dependent 4115 // expression. 4116 if (LHS->isTypeDependent() || RHS->isTypeDependent()) { 4117 // .* cannot be overloaded. 4118 if (Opc == BinaryOperator::PtrMemD) 4119 return Owned(new (Context) BinaryOperator(LHS, RHS, Opc, 4120 Context.DependentTy, OpLoc)); 4121 4122 OverloadedFunctionDecl *Overloads 4123 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4124 for (FunctionSet::iterator Func = Functions.begin(), 4125 FuncEnd = Functions.end(); 4126 Func != FuncEnd; ++Func) 4127 Overloads->addOverload(*Func); 4128 4129 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4130 OpLoc, false, false); 4131 4132 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4133 Args, 2, 4134 Context.DependentTy, 4135 OpLoc)); 4136 } 4137 4138 // If this is the .* operator, which is not overloadable, just 4139 // create a built-in binary operator. 4140 if (Opc == BinaryOperator::PtrMemD) 4141 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4142 4143 // If this is one of the assignment operators, we only perform 4144 // overload resolution if the left-hand side is a class or 4145 // enumeration type (C++ [expr.ass]p3). 4146 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4147 !LHS->getType()->isOverloadableType()) 4148 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4149 4150 // Build an empty overload set. 4151 OverloadCandidateSet CandidateSet; 4152 4153 // Add the candidates from the given function set. 4154 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4155 4156 // Add operator candidates that are member functions. 4157 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4158 4159 // Add builtin operator candidates. 4160 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4161 4162 // Perform overload resolution. 4163 OverloadCandidateSet::iterator Best; 4164 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4165 case OR_Success: { 4166 // We found a built-in operator or an overloaded operator. 4167 FunctionDecl *FnDecl = Best->Function; 4168 4169 if (FnDecl) { 4170 // We matched an overloaded operator. Build a call to that 4171 // operator. 4172 4173 // Convert the arguments. 4174 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4175 if (PerformObjectArgumentInitialization(LHS, Method) || 4176 PerformCopyInitialization(RHS, FnDecl->getParamDecl(0)->getType(), 4177 "passing")) 4178 return ExprError(); 4179 } else { 4180 // Convert the arguments. 4181 if (PerformCopyInitialization(LHS, FnDecl->getParamDecl(0)->getType(), 4182 "passing") || 4183 PerformCopyInitialization(RHS, FnDecl->getParamDecl(1)->getType(), 4184 "passing")) 4185 return ExprError(); 4186 } 4187 4188 // Determine the result type 4189 QualType ResultTy 4190 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4191 ResultTy = ResultTy.getNonReferenceType(); 4192 4193 // Build the actual expression node. 4194 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4195 OpLoc); 4196 UsualUnaryConversions(FnExpr); 4197 4198 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4199 Args, 2, ResultTy, 4200 OpLoc)); 4201 } else { 4202 // We matched a built-in operator. Convert the arguments, then 4203 // break out so that we will build the appropriate built-in 4204 // operator node. 4205 if (PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0], 4206 Best->Conversions[0], "passing") || 4207 PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1], 4208 Best->Conversions[1], "passing")) 4209 return ExprError(); 4210 4211 break; 4212 } 4213 } 4214 4215 case OR_No_Viable_Function: 4216 // For class as left operand for assignment or compound assigment operator 4217 // do not fall through to handling in built-in, but report that no overloaded 4218 // assignment operator found 4219 if (LHS->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4220 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4221 << BinaryOperator::getOpcodeStr(Opc) 4222 << LHS->getSourceRange() << RHS->getSourceRange(); 4223 return ExprError(); 4224 } 4225 // No viable function; fall through to handling this as a 4226 // built-in operator, which will produce an error message for us. 4227 break; 4228 4229 case OR_Ambiguous: 4230 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4231 << BinaryOperator::getOpcodeStr(Opc) 4232 << LHS->getSourceRange() << RHS->getSourceRange(); 4233 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4234 return ExprError(); 4235 4236 case OR_Deleted: 4237 Diag(OpLoc, diag::err_ovl_deleted_oper) 4238 << Best->Function->isDeleted() 4239 << BinaryOperator::getOpcodeStr(Opc) 4240 << LHS->getSourceRange() << RHS->getSourceRange(); 4241 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4242 return ExprError(); 4243 } 4244 4245 // Either we found no viable overloaded operator or we matched a 4246 // built-in operator. In either case, try to build a built-in 4247 // operation. 4248 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4249} 4250 4251/// BuildCallToMemberFunction - Build a call to a member 4252/// function. MemExpr is the expression that refers to the member 4253/// function (and includes the object parameter), Args/NumArgs are the 4254/// arguments to the function call (not including the object 4255/// parameter). The caller needs to validate that the member 4256/// expression refers to a member function or an overloaded member 4257/// function. 4258Sema::ExprResult 4259Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4260 SourceLocation LParenLoc, Expr **Args, 4261 unsigned NumArgs, SourceLocation *CommaLocs, 4262 SourceLocation RParenLoc) { 4263 // Dig out the member expression. This holds both the object 4264 // argument and the member function we're referring to. 4265 MemberExpr *MemExpr = 0; 4266 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4267 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4268 else 4269 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4270 assert(MemExpr && "Building member call without member expression"); 4271 4272 // Extract the object argument. 4273 Expr *ObjectArg = MemExpr->getBase(); 4274 4275 CXXMethodDecl *Method = 0; 4276 if (OverloadedFunctionDecl *Ovl 4277 = dyn_cast<OverloadedFunctionDecl>(MemExpr->getMemberDecl())) { 4278 // Add overload candidates 4279 OverloadCandidateSet CandidateSet; 4280 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4281 FuncEnd = Ovl->function_end(); 4282 Func != FuncEnd; ++Func) { 4283 assert(isa<CXXMethodDecl>(*Func) && "Function is not a method"); 4284 Method = cast<CXXMethodDecl>(*Func); 4285 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4286 /*SuppressUserConversions=*/false); 4287 } 4288 4289 OverloadCandidateSet::iterator Best; 4290 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4291 case OR_Success: 4292 Method = cast<CXXMethodDecl>(Best->Function); 4293 break; 4294 4295 case OR_No_Viable_Function: 4296 Diag(MemExpr->getSourceRange().getBegin(), 4297 diag::err_ovl_no_viable_member_function_in_call) 4298 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4299 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4300 // FIXME: Leaking incoming expressions! 4301 return true; 4302 4303 case OR_Ambiguous: 4304 Diag(MemExpr->getSourceRange().getBegin(), 4305 diag::err_ovl_ambiguous_member_call) 4306 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4307 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4308 // FIXME: Leaking incoming expressions! 4309 return true; 4310 4311 case OR_Deleted: 4312 Diag(MemExpr->getSourceRange().getBegin(), 4313 diag::err_ovl_deleted_member_call) 4314 << Best->Function->isDeleted() 4315 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4316 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4317 // FIXME: Leaking incoming expressions! 4318 return true; 4319 } 4320 4321 FixOverloadedFunctionReference(MemExpr, Method); 4322 } else { 4323 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4324 } 4325 4326 assert(Method && "Member call to something that isn't a method?"); 4327 ExprOwningPtr<CXXMemberCallExpr> 4328 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4329 NumArgs, 4330 Method->getResultType().getNonReferenceType(), 4331 RParenLoc)); 4332 4333 // Convert the object argument (for a non-static member function call). 4334 if (!Method->isStatic() && 4335 PerformObjectArgumentInitialization(ObjectArg, Method)) 4336 return true; 4337 MemExpr->setBase(ObjectArg); 4338 4339 // Convert the rest of the arguments 4340 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4341 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4342 RParenLoc)) 4343 return true; 4344 4345 return CheckFunctionCall(Method, TheCall.take()).release(); 4346} 4347 4348/// BuildCallToObjectOfClassType - Build a call to an object of class 4349/// type (C++ [over.call.object]), which can end up invoking an 4350/// overloaded function call operator (@c operator()) or performing a 4351/// user-defined conversion on the object argument. 4352Sema::ExprResult 4353Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4354 SourceLocation LParenLoc, 4355 Expr **Args, unsigned NumArgs, 4356 SourceLocation *CommaLocs, 4357 SourceLocation RParenLoc) { 4358 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4359 const RecordType *Record = Object->getType()->getAs<RecordType>(); 4360 4361 // C++ [over.call.object]p1: 4362 // If the primary-expression E in the function call syntax 4363 // evaluates to a class object of type "cv T", then the set of 4364 // candidate functions includes at least the function call 4365 // operators of T. The function call operators of T are obtained by 4366 // ordinary lookup of the name operator() in the context of 4367 // (E).operator(). 4368 OverloadCandidateSet CandidateSet; 4369 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4370 DeclContext::lookup_const_iterator Oper, OperEnd; 4371 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4372 Oper != OperEnd; ++Oper) 4373 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4374 CandidateSet, /*SuppressUserConversions=*/false); 4375 4376 // C++ [over.call.object]p2: 4377 // In addition, for each conversion function declared in T of the 4378 // form 4379 // 4380 // operator conversion-type-id () cv-qualifier; 4381 // 4382 // where cv-qualifier is the same cv-qualification as, or a 4383 // greater cv-qualification than, cv, and where conversion-type-id 4384 // denotes the type "pointer to function of (P1,...,Pn) returning 4385 // R", or the type "reference to pointer to function of 4386 // (P1,...,Pn) returning R", or the type "reference to function 4387 // of (P1,...,Pn) returning R", a surrogate call function [...] 4388 // is also considered as a candidate function. Similarly, 4389 // surrogate call functions are added to the set of candidate 4390 // functions for each conversion function declared in an 4391 // accessible base class provided the function is not hidden 4392 // within T by another intervening declaration. 4393 // 4394 // FIXME: Look in base classes for more conversion operators! 4395 OverloadedFunctionDecl *Conversions 4396 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4397 for (OverloadedFunctionDecl::function_iterator 4398 Func = Conversions->function_begin(), 4399 FuncEnd = Conversions->function_end(); 4400 Func != FuncEnd; ++Func) { 4401 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 4402 4403 // Strip the reference type (if any) and then the pointer type (if 4404 // any) to get down to what might be a function type. 4405 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4406 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4407 ConvType = ConvPtrType->getPointeeType(); 4408 4409 if (const FunctionProtoType *Proto = ConvType->getAsFunctionProtoType()) 4410 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4411 } 4412 4413 // Perform overload resolution. 4414 OverloadCandidateSet::iterator Best; 4415 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4416 case OR_Success: 4417 // Overload resolution succeeded; we'll build the appropriate call 4418 // below. 4419 break; 4420 4421 case OR_No_Viable_Function: 4422 Diag(Object->getSourceRange().getBegin(), 4423 diag::err_ovl_no_viable_object_call) 4424 << Object->getType() << Object->getSourceRange(); 4425 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4426 break; 4427 4428 case OR_Ambiguous: 4429 Diag(Object->getSourceRange().getBegin(), 4430 diag::err_ovl_ambiguous_object_call) 4431 << Object->getType() << Object->getSourceRange(); 4432 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4433 break; 4434 4435 case OR_Deleted: 4436 Diag(Object->getSourceRange().getBegin(), 4437 diag::err_ovl_deleted_object_call) 4438 << Best->Function->isDeleted() 4439 << Object->getType() << Object->getSourceRange(); 4440 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4441 break; 4442 } 4443 4444 if (Best == CandidateSet.end()) { 4445 // We had an error; delete all of the subexpressions and return 4446 // the error. 4447 Object->Destroy(Context); 4448 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4449 Args[ArgIdx]->Destroy(Context); 4450 return true; 4451 } 4452 4453 if (Best->Function == 0) { 4454 // Since there is no function declaration, this is one of the 4455 // surrogate candidates. Dig out the conversion function. 4456 CXXConversionDecl *Conv 4457 = cast<CXXConversionDecl>( 4458 Best->Conversions[0].UserDefined.ConversionFunction); 4459 4460 // We selected one of the surrogate functions that converts the 4461 // object parameter to a function pointer. Perform the conversion 4462 // on the object argument, then let ActOnCallExpr finish the job. 4463 // FIXME: Represent the user-defined conversion in the AST! 4464 ImpCastExprToType(Object, 4465 Conv->getConversionType().getNonReferenceType(), 4466 CastExpr::CK_Unknown, 4467 Conv->getConversionType()->isLValueReferenceType()); 4468 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4469 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4470 CommaLocs, RParenLoc).release(); 4471 } 4472 4473 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4474 // that calls this method, using Object for the implicit object 4475 // parameter and passing along the remaining arguments. 4476 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4477 const FunctionProtoType *Proto = Method->getType()->getAsFunctionProtoType(); 4478 4479 unsigned NumArgsInProto = Proto->getNumArgs(); 4480 unsigned NumArgsToCheck = NumArgs; 4481 4482 // Build the full argument list for the method call (the 4483 // implicit object parameter is placed at the beginning of the 4484 // list). 4485 Expr **MethodArgs; 4486 if (NumArgs < NumArgsInProto) { 4487 NumArgsToCheck = NumArgsInProto; 4488 MethodArgs = new Expr*[NumArgsInProto + 1]; 4489 } else { 4490 MethodArgs = new Expr*[NumArgs + 1]; 4491 } 4492 MethodArgs[0] = Object; 4493 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4494 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4495 4496 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4497 SourceLocation()); 4498 UsualUnaryConversions(NewFn); 4499 4500 // Once we've built TheCall, all of the expressions are properly 4501 // owned. 4502 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4503 ExprOwningPtr<CXXOperatorCallExpr> 4504 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4505 MethodArgs, NumArgs + 1, 4506 ResultTy, RParenLoc)); 4507 delete [] MethodArgs; 4508 4509 // We may have default arguments. If so, we need to allocate more 4510 // slots in the call for them. 4511 if (NumArgs < NumArgsInProto) 4512 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4513 else if (NumArgs > NumArgsInProto) 4514 NumArgsToCheck = NumArgsInProto; 4515 4516 bool IsError = false; 4517 4518 // Initialize the implicit object parameter. 4519 IsError |= PerformObjectArgumentInitialization(Object, Method); 4520 TheCall->setArg(0, Object); 4521 4522 4523 // Check the argument types. 4524 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4525 Expr *Arg; 4526 if (i < NumArgs) { 4527 Arg = Args[i]; 4528 4529 // Pass the argument. 4530 QualType ProtoArgType = Proto->getArgType(i); 4531 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4532 } else { 4533 Arg = new (Context) CXXDefaultArgExpr(Method->getParamDecl(i)); 4534 } 4535 4536 TheCall->setArg(i + 1, Arg); 4537 } 4538 4539 // If this is a variadic call, handle args passed through "...". 4540 if (Proto->isVariadic()) { 4541 // Promote the arguments (C99 6.5.2.2p7). 4542 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4543 Expr *Arg = Args[i]; 4544 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4545 TheCall->setArg(i + 1, Arg); 4546 } 4547 } 4548 4549 if (IsError) return true; 4550 4551 return CheckFunctionCall(Method, TheCall.take()).release(); 4552} 4553 4554/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4555/// (if one exists), where @c Base is an expression of class type and 4556/// @c Member is the name of the member we're trying to find. 4557Sema::OwningExprResult 4558Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 4559 Expr *Base = static_cast<Expr *>(BaseIn.get()); 4560 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4561 4562 // C++ [over.ref]p1: 4563 // 4564 // [...] An expression x->m is interpreted as (x.operator->())->m 4565 // for a class object x of type T if T::operator->() exists and if 4566 // the operator is selected as the best match function by the 4567 // overload resolution mechanism (13.3). 4568 // FIXME: look in base classes. 4569 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4570 OverloadCandidateSet CandidateSet; 4571 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 4572 4573 DeclContext::lookup_const_iterator Oper, OperEnd; 4574 for (llvm::tie(Oper, OperEnd) 4575 = BaseRecord->getDecl()->lookup(OpName); Oper != OperEnd; ++Oper) 4576 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4577 /*SuppressUserConversions=*/false); 4578 4579 // Perform overload resolution. 4580 OverloadCandidateSet::iterator Best; 4581 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4582 case OR_Success: 4583 // Overload resolution succeeded; we'll build the call below. 4584 break; 4585 4586 case OR_No_Viable_Function: 4587 if (CandidateSet.empty()) 4588 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4589 << Base->getType() << Base->getSourceRange(); 4590 else 4591 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4592 << "operator->" << Base->getSourceRange(); 4593 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4594 return ExprError(); 4595 4596 case OR_Ambiguous: 4597 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4598 << "operator->" << Base->getSourceRange(); 4599 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4600 return ExprError(); 4601 4602 case OR_Deleted: 4603 Diag(OpLoc, diag::err_ovl_deleted_oper) 4604 << Best->Function->isDeleted() 4605 << "operator->" << Base->getSourceRange(); 4606 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4607 return ExprError(); 4608 } 4609 4610 // Convert the object parameter. 4611 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4612 if (PerformObjectArgumentInitialization(Base, Method)) 4613 return ExprError(); 4614 4615 // No concerns about early exits now. 4616 BaseIn.release(); 4617 4618 // Build the operator call. 4619 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 4620 SourceLocation()); 4621 UsualUnaryConversions(FnExpr); 4622 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 4623 Method->getResultType().getNonReferenceType(), 4624 OpLoc); 4625 return Owned(Base); 4626} 4627 4628/// FixOverloadedFunctionReference - E is an expression that refers to 4629/// a C++ overloaded function (possibly with some parentheses and 4630/// perhaps a '&' around it). We have resolved the overloaded function 4631/// to the function declaration Fn, so patch up the expression E to 4632/// refer (possibly indirectly) to Fn. 4633void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 4634 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4635 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 4636 E->setType(PE->getSubExpr()->getType()); 4637 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 4638 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 4639 "Can only take the address of an overloaded function"); 4640 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4641 if (Method->isStatic()) { 4642 // Do nothing: static member functions aren't any different 4643 // from non-member functions. 4644 } else if (QualifiedDeclRefExpr *DRE 4645 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 4646 // We have taken the address of a pointer to member 4647 // function. Perform the computation here so that we get the 4648 // appropriate pointer to member type. 4649 DRE->setDecl(Fn); 4650 DRE->setType(Fn->getType()); 4651 QualType ClassType 4652 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 4653 E->setType(Context.getMemberPointerType(Fn->getType(), 4654 ClassType.getTypePtr())); 4655 return; 4656 } 4657 } 4658 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 4659 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 4660 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 4661 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 4662 isa<FunctionTemplateDecl>(DR->getDecl())) && 4663 "Expected overloaded function or function template"); 4664 DR->setDecl(Fn); 4665 E->setType(Fn->getType()); 4666 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 4667 MemExpr->setMemberDecl(Fn); 4668 E->setType(Fn->getType()); 4669 } else { 4670 assert(false && "Invalid reference to overloaded function"); 4671 } 4672} 4673 4674} // end namespace clang 4675