SemaOverload.cpp revision e53060fa78ad7e98352049f72787bdb7543e2a48
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->getAsPointerType()) 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 } 513 // Array-to-pointer conversion (C++ 4.2) 514 else if (FromType->isArrayType()) { 515 SCS.First = ICK_Array_To_Pointer; 516 517 // An lvalue or rvalue of type "array of N T" or "array of unknown 518 // bound of T" can be converted to an rvalue of type "pointer to 519 // T" (C++ 4.2p1). 520 FromType = Context.getArrayDecayedType(FromType); 521 522 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 523 // This conversion is deprecated. (C++ D.4). 524 SCS.Deprecated = true; 525 526 // For the purpose of ranking in overload resolution 527 // (13.3.3.1.1), this conversion is considered an 528 // array-to-pointer conversion followed by a qualification 529 // conversion (4.4). (C++ 4.2p2) 530 SCS.Second = ICK_Identity; 531 SCS.Third = ICK_Qualification; 532 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 533 return true; 534 } 535 } 536 // Function-to-pointer conversion (C++ 4.3). 537 else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 538 SCS.First = ICK_Function_To_Pointer; 539 540 // An lvalue of function type T can be converted to an rvalue of 541 // type "pointer to T." The result is a pointer to the 542 // function. (C++ 4.3p1). 543 FromType = Context.getPointerType(FromType); 544 } 545 // Address of overloaded function (C++ [over.over]). 546 else if (FunctionDecl *Fn 547 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 548 SCS.First = ICK_Function_To_Pointer; 549 550 // We were able to resolve the address of the overloaded function, 551 // so we can convert to the type of that function. 552 FromType = Fn->getType(); 553 if (ToType->isLValueReferenceType()) 554 FromType = Context.getLValueReferenceType(FromType); 555 else if (ToType->isRValueReferenceType()) 556 FromType = Context.getRValueReferenceType(FromType); 557 else if (ToType->isMemberPointerType()) { 558 // Resolve address only succeeds if both sides are member pointers, 559 // but it doesn't have to be the same class. See DR 247. 560 // Note that this means that the type of &Derived::fn can be 561 // Ret (Base::*)(Args) if the fn overload actually found is from the 562 // base class, even if it was brought into the derived class via a 563 // using declaration. The standard isn't clear on this issue at all. 564 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 565 FromType = Context.getMemberPointerType(FromType, 566 Context.getTypeDeclType(M->getParent()).getTypePtr()); 567 } else 568 FromType = Context.getPointerType(FromType); 569 } 570 // We don't require any conversions for the first step. 571 else { 572 SCS.First = ICK_Identity; 573 } 574 575 // The second conversion can be an integral promotion, floating 576 // point promotion, integral conversion, floating point conversion, 577 // floating-integral conversion, pointer conversion, 578 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 579 // For overloading in C, this can also be a "compatible-type" 580 // conversion. 581 bool IncompatibleObjC = false; 582 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 583 // The unqualified versions of the types are the same: there's no 584 // conversion to do. 585 SCS.Second = ICK_Identity; 586 } 587 // Integral promotion (C++ 4.5). 588 else if (IsIntegralPromotion(From, FromType, ToType)) { 589 SCS.Second = ICK_Integral_Promotion; 590 FromType = ToType.getUnqualifiedType(); 591 } 592 // Floating point promotion (C++ 4.6). 593 else if (IsFloatingPointPromotion(FromType, ToType)) { 594 SCS.Second = ICK_Floating_Promotion; 595 FromType = ToType.getUnqualifiedType(); 596 } 597 // Complex promotion (Clang extension) 598 else if (IsComplexPromotion(FromType, ToType)) { 599 SCS.Second = ICK_Complex_Promotion; 600 FromType = ToType.getUnqualifiedType(); 601 } 602 // Integral conversions (C++ 4.7). 603 // FIXME: isIntegralType shouldn't be true for enums in C++. 604 else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 605 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 606 SCS.Second = ICK_Integral_Conversion; 607 FromType = ToType.getUnqualifiedType(); 608 } 609 // Floating point conversions (C++ 4.8). 610 else if (FromType->isFloatingType() && ToType->isFloatingType()) { 611 SCS.Second = ICK_Floating_Conversion; 612 FromType = ToType.getUnqualifiedType(); 613 } 614 // Complex conversions (C99 6.3.1.6) 615 else if (FromType->isComplexType() && ToType->isComplexType()) { 616 SCS.Second = ICK_Complex_Conversion; 617 FromType = ToType.getUnqualifiedType(); 618 } 619 // Floating-integral conversions (C++ 4.9). 620 // FIXME: isIntegralType shouldn't be true for enums in C++. 621 else if ((FromType->isFloatingType() && 622 ToType->isIntegralType() && !ToType->isBooleanType() && 623 !ToType->isEnumeralType()) || 624 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 625 ToType->isFloatingType())) { 626 SCS.Second = ICK_Floating_Integral; 627 FromType = ToType.getUnqualifiedType(); 628 } 629 // Complex-real conversions (C99 6.3.1.7) 630 else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 631 (ToType->isComplexType() && FromType->isArithmeticType())) { 632 SCS.Second = ICK_Complex_Real; 633 FromType = ToType.getUnqualifiedType(); 634 } 635 // Pointer conversions (C++ 4.10). 636 else if (IsPointerConversion(From, FromType, ToType, FromType, 637 IncompatibleObjC)) { 638 SCS.Second = ICK_Pointer_Conversion; 639 SCS.IncompatibleObjC = IncompatibleObjC; 640 } 641 // Pointer to member conversions (4.11). 642 else if (IsMemberPointerConversion(From, FromType, ToType, FromType)) { 643 SCS.Second = ICK_Pointer_Member; 644 } 645 // Boolean conversions (C++ 4.12). 646 else if (ToType->isBooleanType() && 647 (FromType->isArithmeticType() || 648 FromType->isEnumeralType() || 649 FromType->isPointerType() || 650 FromType->isBlockPointerType() || 651 FromType->isMemberPointerType() || 652 FromType->isNullPtrType())) { 653 SCS.Second = ICK_Boolean_Conversion; 654 FromType = Context.BoolTy; 655 } 656 // Compatible conversions (Clang extension for C function overloading) 657 else if (!getLangOptions().CPlusPlus && 658 Context.typesAreCompatible(ToType, FromType)) { 659 SCS.Second = ICK_Compatible_Conversion; 660 } else { 661 // No second conversion required. 662 SCS.Second = ICK_Identity; 663 } 664 665 QualType CanonFrom; 666 QualType CanonTo; 667 // The third conversion can be a qualification conversion (C++ 4p1). 668 if (IsQualificationConversion(FromType, ToType)) { 669 SCS.Third = ICK_Qualification; 670 FromType = ToType; 671 CanonFrom = Context.getCanonicalType(FromType); 672 CanonTo = Context.getCanonicalType(ToType); 673 } else { 674 // No conversion required 675 SCS.Third = ICK_Identity; 676 677 // C++ [over.best.ics]p6: 678 // [...] Any difference in top-level cv-qualification is 679 // subsumed by the initialization itself and does not constitute 680 // a conversion. [...] 681 CanonFrom = Context.getCanonicalType(FromType); 682 CanonTo = Context.getCanonicalType(ToType); 683 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 684 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 685 FromType = ToType; 686 CanonFrom = CanonTo; 687 } 688 } 689 690 // If we have not converted the argument type to the parameter type, 691 // this is a bad conversion sequence. 692 if (CanonFrom != CanonTo) 693 return false; 694 695 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 696 return true; 697} 698 699/// IsIntegralPromotion - Determines whether the conversion from the 700/// expression From (whose potentially-adjusted type is FromType) to 701/// ToType is an integral promotion (C++ 4.5). If so, returns true and 702/// sets PromotedType to the promoted type. 703bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) 704{ 705 const BuiltinType *To = ToType->getAsBuiltinType(); 706 // All integers are built-in. 707 if (!To) { 708 return false; 709 } 710 711 // An rvalue of type char, signed char, unsigned char, short int, or 712 // unsigned short int can be converted to an rvalue of type int if 713 // int can represent all the values of the source type; otherwise, 714 // the source rvalue can be converted to an rvalue of type unsigned 715 // int (C++ 4.5p1). 716 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 717 if (// We can promote any signed, promotable integer type to an int 718 (FromType->isSignedIntegerType() || 719 // We can promote any unsigned integer type whose size is 720 // less than int to an int. 721 (!FromType->isSignedIntegerType() && 722 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 723 return To->getKind() == BuiltinType::Int; 724 } 725 726 return To->getKind() == BuiltinType::UInt; 727 } 728 729 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 730 // can be converted to an rvalue of the first of the following types 731 // that can represent all the values of its underlying type: int, 732 // unsigned int, long, or unsigned long (C++ 4.5p2). 733 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 734 && ToType->isIntegerType()) { 735 // Determine whether the type we're converting from is signed or 736 // unsigned. 737 bool FromIsSigned; 738 uint64_t FromSize = Context.getTypeSize(FromType); 739 if (const EnumType *FromEnumType = FromType->getAsEnumType()) { 740 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 741 FromIsSigned = UnderlyingType->isSignedIntegerType(); 742 } else { 743 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 744 FromIsSigned = true; 745 } 746 747 // The types we'll try to promote to, in the appropriate 748 // order. Try each of these types. 749 QualType PromoteTypes[6] = { 750 Context.IntTy, Context.UnsignedIntTy, 751 Context.LongTy, Context.UnsignedLongTy , 752 Context.LongLongTy, Context.UnsignedLongLongTy 753 }; 754 for (int Idx = 0; Idx < 6; ++Idx) { 755 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 756 if (FromSize < ToSize || 757 (FromSize == ToSize && 758 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 759 // We found the type that we can promote to. If this is the 760 // type we wanted, we have a promotion. Otherwise, no 761 // promotion. 762 return Context.getCanonicalType(ToType).getUnqualifiedType() 763 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 764 } 765 } 766 } 767 768 // An rvalue for an integral bit-field (9.6) can be converted to an 769 // rvalue of type int if int can represent all the values of the 770 // bit-field; otherwise, it can be converted to unsigned int if 771 // unsigned int can represent all the values of the bit-field. If 772 // the bit-field is larger yet, no integral promotion applies to 773 // it. If the bit-field has an enumerated type, it is treated as any 774 // other value of that type for promotion purposes (C++ 4.5p3). 775 // FIXME: We should delay checking of bit-fields until we actually perform the 776 // conversion. 777 using llvm::APSInt; 778 if (From) 779 if (FieldDecl *MemberDecl = From->getBitField()) { 780 APSInt BitWidth; 781 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 782 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 783 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 784 ToSize = Context.getTypeSize(ToType); 785 786 // Are we promoting to an int from a bitfield that fits in an int? 787 if (BitWidth < ToSize || 788 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 789 return To->getKind() == BuiltinType::Int; 790 } 791 792 // Are we promoting to an unsigned int from an unsigned bitfield 793 // that fits into an unsigned int? 794 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 795 return To->getKind() == BuiltinType::UInt; 796 } 797 798 return false; 799 } 800 } 801 802 // An rvalue of type bool can be converted to an rvalue of type int, 803 // with false becoming zero and true becoming one (C++ 4.5p4). 804 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 805 return true; 806 } 807 808 return false; 809} 810 811/// IsFloatingPointPromotion - Determines whether the conversion from 812/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 813/// returns true and sets PromotedType to the promoted type. 814bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) 815{ 816 /// An rvalue of type float can be converted to an rvalue of type 817 /// double. (C++ 4.6p1). 818 if (const BuiltinType *FromBuiltin = FromType->getAsBuiltinType()) 819 if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType()) { 820 if (FromBuiltin->getKind() == BuiltinType::Float && 821 ToBuiltin->getKind() == BuiltinType::Double) 822 return true; 823 824 // C99 6.3.1.5p1: 825 // When a float is promoted to double or long double, or a 826 // double is promoted to long double [...]. 827 if (!getLangOptions().CPlusPlus && 828 (FromBuiltin->getKind() == BuiltinType::Float || 829 FromBuiltin->getKind() == BuiltinType::Double) && 830 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 831 return true; 832 } 833 834 return false; 835} 836 837/// \brief Determine if a conversion is a complex promotion. 838/// 839/// A complex promotion is defined as a complex -> complex conversion 840/// where the conversion between the underlying real types is a 841/// floating-point or integral promotion. 842bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 843 const ComplexType *FromComplex = FromType->getAsComplexType(); 844 if (!FromComplex) 845 return false; 846 847 const ComplexType *ToComplex = ToType->getAsComplexType(); 848 if (!ToComplex) 849 return false; 850 851 return IsFloatingPointPromotion(FromComplex->getElementType(), 852 ToComplex->getElementType()) || 853 IsIntegralPromotion(0, FromComplex->getElementType(), 854 ToComplex->getElementType()); 855} 856 857/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 858/// the pointer type FromPtr to a pointer to type ToPointee, with the 859/// same type qualifiers as FromPtr has on its pointee type. ToType, 860/// if non-empty, will be a pointer to ToType that may or may not have 861/// the right set of qualifiers on its pointee. 862static QualType 863BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 864 QualType ToPointee, QualType ToType, 865 ASTContext &Context) { 866 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 867 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 868 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 869 870 // Exact qualifier match -> return the pointer type we're converting to. 871 if (CanonToPointee.getCVRQualifiers() == Quals) { 872 // ToType is exactly what we need. Return it. 873 if (ToType.getTypePtr()) 874 return ToType; 875 876 // Build a pointer to ToPointee. It has the right qualifiers 877 // already. 878 return Context.getPointerType(ToPointee); 879 } 880 881 // Just build a canonical type that has the right qualifiers. 882 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 883} 884 885/// IsPointerConversion - Determines whether the conversion of the 886/// expression From, which has the (possibly adjusted) type FromType, 887/// can be converted to the type ToType via a pointer conversion (C++ 888/// 4.10). If so, returns true and places the converted type (that 889/// might differ from ToType in its cv-qualifiers at some level) into 890/// ConvertedType. 891/// 892/// This routine also supports conversions to and from block pointers 893/// and conversions with Objective-C's 'id', 'id<protocols...>', and 894/// pointers to interfaces. FIXME: Once we've determined the 895/// appropriate overloading rules for Objective-C, we may want to 896/// split the Objective-C checks into a different routine; however, 897/// GCC seems to consider all of these conversions to be pointer 898/// conversions, so for now they live here. IncompatibleObjC will be 899/// set if the conversion is an allowed Objective-C conversion that 900/// should result in a warning. 901bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 902 QualType& ConvertedType, 903 bool &IncompatibleObjC) 904{ 905 IncompatibleObjC = false; 906 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 907 return true; 908 909 // Conversion from a null pointer constant to any Objective-C pointer type. 910 if (Context.isObjCObjectPointerType(ToType) && 911 From->isNullPointerConstant(Context)) { 912 ConvertedType = ToType; 913 return true; 914 } 915 916 // Blocks: Block pointers can be converted to void*. 917 if (FromType->isBlockPointerType() && ToType->isPointerType() && 918 ToType->getAsPointerType()->getPointeeType()->isVoidType()) { 919 ConvertedType = ToType; 920 return true; 921 } 922 // Blocks: A null pointer constant can be converted to a block 923 // pointer type. 924 if (ToType->isBlockPointerType() && From->isNullPointerConstant(Context)) { 925 ConvertedType = ToType; 926 return true; 927 } 928 929 // If the left-hand-side is nullptr_t, the right side can be a null 930 // pointer constant. 931 if (ToType->isNullPtrType() && From->isNullPointerConstant(Context)) { 932 ConvertedType = ToType; 933 return true; 934 } 935 936 const PointerType* ToTypePtr = ToType->getAsPointerType(); 937 if (!ToTypePtr) 938 return false; 939 940 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 941 if (From->isNullPointerConstant(Context)) { 942 ConvertedType = ToType; 943 return true; 944 } 945 946 // Beyond this point, both types need to be pointers. 947 const PointerType *FromTypePtr = FromType->getAsPointerType(); 948 if (!FromTypePtr) 949 return false; 950 951 QualType FromPointeeType = FromTypePtr->getPointeeType(); 952 QualType ToPointeeType = ToTypePtr->getPointeeType(); 953 954 // An rvalue of type "pointer to cv T," where T is an object type, 955 // can be converted to an rvalue of type "pointer to cv void" (C++ 956 // 4.10p2). 957 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 958 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 959 ToPointeeType, 960 ToType, Context); 961 return true; 962 } 963 964 // When we're overloading in C, we allow a special kind of pointer 965 // conversion for compatible-but-not-identical pointee types. 966 if (!getLangOptions().CPlusPlus && 967 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 968 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 969 ToPointeeType, 970 ToType, Context); 971 return true; 972 } 973 974 // C++ [conv.ptr]p3: 975 // 976 // An rvalue of type "pointer to cv D," where D is a class type, 977 // can be converted to an rvalue of type "pointer to cv B," where 978 // B is a base class (clause 10) of D. If B is an inaccessible 979 // (clause 11) or ambiguous (10.2) base class of D, a program that 980 // necessitates this conversion is ill-formed. The result of the 981 // conversion is a pointer to the base class sub-object of the 982 // derived class object. The null pointer value is converted to 983 // the null pointer value of the destination type. 984 // 985 // Note that we do not check for ambiguity or inaccessibility 986 // here. That is handled by CheckPointerConversion. 987 if (getLangOptions().CPlusPlus && 988 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 989 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 990 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 991 ToPointeeType, 992 ToType, Context); 993 return true; 994 } 995 996 return false; 997} 998 999/// isObjCPointerConversion - Determines whether this is an 1000/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1001/// with the same arguments and return values. 1002bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1003 QualType& ConvertedType, 1004 bool &IncompatibleObjC) { 1005 if (!getLangOptions().ObjC1) 1006 return false; 1007 1008 // Conversions with Objective-C's id<...>. 1009 if ((FromType->isObjCQualifiedIdType() || ToType->isObjCQualifiedIdType()) && 1010 ObjCQualifiedIdTypesAreCompatible(ToType, FromType, /*compare=*/false)) { 1011 ConvertedType = ToType; 1012 return true; 1013 } 1014 1015 // Beyond this point, both types need to be pointers or block pointers. 1016 QualType ToPointeeType; 1017 const PointerType* ToTypePtr = ToType->getAsPointerType(); 1018 if (ToTypePtr) 1019 ToPointeeType = ToTypePtr->getPointeeType(); 1020 else if (const BlockPointerType *ToBlockPtr = ToType->getAsBlockPointerType()) 1021 ToPointeeType = ToBlockPtr->getPointeeType(); 1022 else 1023 return false; 1024 1025 QualType FromPointeeType; 1026 const PointerType *FromTypePtr = FromType->getAsPointerType(); 1027 if (FromTypePtr) 1028 FromPointeeType = FromTypePtr->getPointeeType(); 1029 else if (const BlockPointerType *FromBlockPtr 1030 = FromType->getAsBlockPointerType()) 1031 FromPointeeType = FromBlockPtr->getPointeeType(); 1032 else 1033 return false; 1034 1035 // Objective C++: We're able to convert from a pointer to an 1036 // interface to a pointer to a different interface. 1037 const ObjCInterfaceType* FromIface = FromPointeeType->getAsObjCInterfaceType(); 1038 const ObjCInterfaceType* ToIface = ToPointeeType->getAsObjCInterfaceType(); 1039 if (FromIface && ToIface && 1040 Context.canAssignObjCInterfaces(ToIface, FromIface)) { 1041 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1042 ToPointeeType, 1043 ToType, Context); 1044 return true; 1045 } 1046 1047 if (FromIface && ToIface && 1048 Context.canAssignObjCInterfaces(FromIface, ToIface)) { 1049 // Okay: this is some kind of implicit downcast of Objective-C 1050 // interfaces, which is permitted. However, we're going to 1051 // complain about it. 1052 IncompatibleObjC = true; 1053 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1054 ToPointeeType, 1055 ToType, Context); 1056 return true; 1057 } 1058 1059 // Objective C++: We're able to convert between "id" and a pointer 1060 // to any interface (in both directions). 1061 if ((FromIface && Context.isObjCIdStructType(ToPointeeType)) 1062 || (ToIface && Context.isObjCIdStructType(FromPointeeType))) { 1063 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1064 ToPointeeType, 1065 ToType, Context); 1066 return true; 1067 } 1068 1069 // Objective C++: Allow conversions between the Objective-C "id" and 1070 // "Class", in either direction. 1071 if ((Context.isObjCIdStructType(FromPointeeType) && 1072 Context.isObjCClassStructType(ToPointeeType)) || 1073 (Context.isObjCClassStructType(FromPointeeType) && 1074 Context.isObjCIdStructType(ToPointeeType))) { 1075 ConvertedType = ToType; 1076 return true; 1077 } 1078 1079 // If we have pointers to pointers, recursively check whether this 1080 // is an Objective-C conversion. 1081 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1082 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1083 IncompatibleObjC)) { 1084 // We always complain about this conversion. 1085 IncompatibleObjC = true; 1086 ConvertedType = ToType; 1087 return true; 1088 } 1089 1090 // If we have pointers to functions or blocks, check whether the only 1091 // differences in the argument and result types are in Objective-C 1092 // pointer conversions. If so, we permit the conversion (but 1093 // complain about it). 1094 const FunctionProtoType *FromFunctionType 1095 = FromPointeeType->getAsFunctionProtoType(); 1096 const FunctionProtoType *ToFunctionType 1097 = ToPointeeType->getAsFunctionProtoType(); 1098 if (FromFunctionType && ToFunctionType) { 1099 // If the function types are exactly the same, this isn't an 1100 // Objective-C pointer conversion. 1101 if (Context.getCanonicalType(FromPointeeType) 1102 == Context.getCanonicalType(ToPointeeType)) 1103 return false; 1104 1105 // Perform the quick checks that will tell us whether these 1106 // function types are obviously different. 1107 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1108 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1109 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1110 return false; 1111 1112 bool HasObjCConversion = false; 1113 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1114 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1115 // Okay, the types match exactly. Nothing to do. 1116 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1117 ToFunctionType->getResultType(), 1118 ConvertedType, IncompatibleObjC)) { 1119 // Okay, we have an Objective-C pointer conversion. 1120 HasObjCConversion = true; 1121 } else { 1122 // Function types are too different. Abort. 1123 return false; 1124 } 1125 1126 // Check argument types. 1127 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1128 ArgIdx != NumArgs; ++ArgIdx) { 1129 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1130 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1131 if (Context.getCanonicalType(FromArgType) 1132 == Context.getCanonicalType(ToArgType)) { 1133 // Okay, the types match exactly. Nothing to do. 1134 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1135 ConvertedType, IncompatibleObjC)) { 1136 // Okay, we have an Objective-C pointer conversion. 1137 HasObjCConversion = true; 1138 } else { 1139 // Argument types are too different. Abort. 1140 return false; 1141 } 1142 } 1143 1144 if (HasObjCConversion) { 1145 // We had an Objective-C conversion. Allow this pointer 1146 // conversion, but complain about it. 1147 ConvertedType = ToType; 1148 IncompatibleObjC = true; 1149 return true; 1150 } 1151 } 1152 1153 return false; 1154} 1155 1156/// CheckPointerConversion - Check the pointer conversion from the 1157/// expression From to the type ToType. This routine checks for 1158/// ambiguous (FIXME: or inaccessible) derived-to-base pointer 1159/// conversions for which IsPointerConversion has already returned 1160/// true. It returns true and produces a diagnostic if there was an 1161/// error, or returns false otherwise. 1162bool Sema::CheckPointerConversion(Expr *From, QualType ToType) { 1163 QualType FromType = From->getType(); 1164 1165 if (const PointerType *FromPtrType = FromType->getAsPointerType()) 1166 if (const PointerType *ToPtrType = ToType->getAsPointerType()) { 1167 QualType FromPointeeType = FromPtrType->getPointeeType(), 1168 ToPointeeType = ToPtrType->getPointeeType(); 1169 1170 // Objective-C++ conversions are always okay. 1171 // FIXME: We should have a different class of conversions for the 1172 // Objective-C++ implicit conversions. 1173 if (Context.isObjCIdStructType(FromPointeeType) || 1174 Context.isObjCIdStructType(ToPointeeType) || 1175 Context.isObjCClassStructType(FromPointeeType) || 1176 Context.isObjCClassStructType(ToPointeeType)) 1177 return false; 1178 1179 if (FromPointeeType->isRecordType() && 1180 ToPointeeType->isRecordType()) { 1181 // We must have a derived-to-base conversion. Check an 1182 // ambiguous or inaccessible conversion. 1183 return CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1184 From->getExprLoc(), 1185 From->getSourceRange()); 1186 } 1187 } 1188 1189 return false; 1190} 1191 1192/// IsMemberPointerConversion - Determines whether the conversion of the 1193/// expression From, which has the (possibly adjusted) type FromType, can be 1194/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1195/// If so, returns true and places the converted type (that might differ from 1196/// ToType in its cv-qualifiers at some level) into ConvertedType. 1197bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1198 QualType ToType, QualType &ConvertedType) 1199{ 1200 const MemberPointerType *ToTypePtr = ToType->getAsMemberPointerType(); 1201 if (!ToTypePtr) 1202 return false; 1203 1204 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1205 if (From->isNullPointerConstant(Context)) { 1206 ConvertedType = ToType; 1207 return true; 1208 } 1209 1210 // Otherwise, both types have to be member pointers. 1211 const MemberPointerType *FromTypePtr = FromType->getAsMemberPointerType(); 1212 if (!FromTypePtr) 1213 return false; 1214 1215 // A pointer to member of B can be converted to a pointer to member of D, 1216 // where D is derived from B (C++ 4.11p2). 1217 QualType FromClass(FromTypePtr->getClass(), 0); 1218 QualType ToClass(ToTypePtr->getClass(), 0); 1219 // FIXME: What happens when these are dependent? Is this function even called? 1220 1221 if (IsDerivedFrom(ToClass, FromClass)) { 1222 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1223 ToClass.getTypePtr()); 1224 return true; 1225 } 1226 1227 return false; 1228} 1229 1230/// CheckMemberPointerConversion - Check the member pointer conversion from the 1231/// expression From to the type ToType. This routine checks for ambiguous or 1232/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1233/// for which IsMemberPointerConversion has already returned true. It returns 1234/// true and produces a diagnostic if there was an error, or returns false 1235/// otherwise. 1236bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType) { 1237 QualType FromType = From->getType(); 1238 const MemberPointerType *FromPtrType = FromType->getAsMemberPointerType(); 1239 if (!FromPtrType) 1240 return false; 1241 1242 const MemberPointerType *ToPtrType = ToType->getAsMemberPointerType(); 1243 assert(ToPtrType && "No member pointer cast has a target type " 1244 "that is not a member pointer."); 1245 1246 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1247 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1248 1249 // FIXME: What about dependent types? 1250 assert(FromClass->isRecordType() && "Pointer into non-class."); 1251 assert(ToClass->isRecordType() && "Pointer into non-class."); 1252 1253 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1254 /*DetectVirtual=*/true); 1255 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1256 assert(DerivationOkay && 1257 "Should not have been called if derivation isn't OK."); 1258 (void)DerivationOkay; 1259 1260 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1261 getUnqualifiedType())) { 1262 // Derivation is ambiguous. Redo the check to find the exact paths. 1263 Paths.clear(); 1264 Paths.setRecordingPaths(true); 1265 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1266 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1267 (void)StillOkay; 1268 1269 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1270 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1271 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1272 return true; 1273 } 1274 1275 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1276 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1277 << FromClass << ToClass << QualType(VBase, 0) 1278 << From->getSourceRange(); 1279 return true; 1280 } 1281 1282 return false; 1283} 1284 1285/// IsQualificationConversion - Determines whether the conversion from 1286/// an rvalue of type FromType to ToType is a qualification conversion 1287/// (C++ 4.4). 1288bool 1289Sema::IsQualificationConversion(QualType FromType, QualType ToType) 1290{ 1291 FromType = Context.getCanonicalType(FromType); 1292 ToType = Context.getCanonicalType(ToType); 1293 1294 // If FromType and ToType are the same type, this is not a 1295 // qualification conversion. 1296 if (FromType == ToType) 1297 return false; 1298 1299 // (C++ 4.4p4): 1300 // A conversion can add cv-qualifiers at levels other than the first 1301 // in multi-level pointers, subject to the following rules: [...] 1302 bool PreviousToQualsIncludeConst = true; 1303 bool UnwrappedAnyPointer = false; 1304 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1305 // Within each iteration of the loop, we check the qualifiers to 1306 // determine if this still looks like a qualification 1307 // conversion. Then, if all is well, we unwrap one more level of 1308 // pointers or pointers-to-members and do it all again 1309 // until there are no more pointers or pointers-to-members left to 1310 // unwrap. 1311 UnwrappedAnyPointer = true; 1312 1313 // -- for every j > 0, if const is in cv 1,j then const is in cv 1314 // 2,j, and similarly for volatile. 1315 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1316 return false; 1317 1318 // -- if the cv 1,j and cv 2,j are different, then const is in 1319 // every cv for 0 < k < j. 1320 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1321 && !PreviousToQualsIncludeConst) 1322 return false; 1323 1324 // Keep track of whether all prior cv-qualifiers in the "to" type 1325 // include const. 1326 PreviousToQualsIncludeConst 1327 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1328 } 1329 1330 // We are left with FromType and ToType being the pointee types 1331 // after unwrapping the original FromType and ToType the same number 1332 // of types. If we unwrapped any pointers, and if FromType and 1333 // ToType have the same unqualified type (since we checked 1334 // qualifiers above), then this is a qualification conversion. 1335 return UnwrappedAnyPointer && 1336 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1337} 1338 1339/// Determines whether there is a user-defined conversion sequence 1340/// (C++ [over.ics.user]) that converts expression From to the type 1341/// ToType. If such a conversion exists, User will contain the 1342/// user-defined conversion sequence that performs such a conversion 1343/// and this routine will return true. Otherwise, this routine returns 1344/// false and User is unspecified. 1345/// 1346/// \param AllowConversionFunctions true if the conversion should 1347/// consider conversion functions at all. If false, only constructors 1348/// will be considered. 1349/// 1350/// \param AllowExplicit true if the conversion should consider C++0x 1351/// "explicit" conversion functions as well as non-explicit conversion 1352/// functions (C++0x [class.conv.fct]p2). 1353/// 1354/// \param ForceRValue true if the expression should be treated as an rvalue 1355/// for overload resolution. 1356bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1357 UserDefinedConversionSequence& User, 1358 bool AllowConversionFunctions, 1359 bool AllowExplicit, bool ForceRValue) 1360{ 1361 OverloadCandidateSet CandidateSet; 1362 if (const RecordType *ToRecordType = ToType->getAsRecordType()) { 1363 if (CXXRecordDecl *ToRecordDecl 1364 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1365 // C++ [over.match.ctor]p1: 1366 // When objects of class type are direct-initialized (8.5), or 1367 // copy-initialized from an expression of the same or a 1368 // derived class type (8.5), overload resolution selects the 1369 // constructor. [...] For copy-initialization, the candidate 1370 // functions are all the converting constructors (12.3.1) of 1371 // that class. The argument list is the expression-list within 1372 // the parentheses of the initializer. 1373 DeclarationName ConstructorName 1374 = Context.DeclarationNames.getCXXConstructorName( 1375 Context.getCanonicalType(ToType).getUnqualifiedType()); 1376 DeclContext::lookup_iterator Con, ConEnd; 1377 for (llvm::tie(Con, ConEnd) 1378 = ToRecordDecl->lookup(Context, ConstructorName); 1379 Con != ConEnd; ++Con) { 1380 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 1381 if (Constructor->isConvertingConstructor()) 1382 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1383 /*SuppressUserConversions=*/true, ForceRValue); 1384 } 1385 } 1386 } 1387 1388 if (!AllowConversionFunctions) { 1389 // Don't allow any conversion functions to enter the overload set. 1390 } else if (const RecordType *FromRecordType 1391 = From->getType()->getAsRecordType()) { 1392 if (CXXRecordDecl *FromRecordDecl 1393 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1394 // Add all of the conversion functions as candidates. 1395 // FIXME: Look for conversions in base classes! 1396 OverloadedFunctionDecl *Conversions 1397 = FromRecordDecl->getConversionFunctions(); 1398 for (OverloadedFunctionDecl::function_iterator Func 1399 = Conversions->function_begin(); 1400 Func != Conversions->function_end(); ++Func) { 1401 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 1402 if (AllowExplicit || !Conv->isExplicit()) 1403 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1404 } 1405 } 1406 } 1407 1408 OverloadCandidateSet::iterator Best; 1409 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1410 case OR_Success: 1411 // Record the standard conversion we used and the conversion function. 1412 if (CXXConstructorDecl *Constructor 1413 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1414 // C++ [over.ics.user]p1: 1415 // If the user-defined conversion is specified by a 1416 // constructor (12.3.1), the initial standard conversion 1417 // sequence converts the source type to the type required by 1418 // the argument of the constructor. 1419 // 1420 // FIXME: What about ellipsis conversions? 1421 QualType ThisType = Constructor->getThisType(Context); 1422 User.Before = Best->Conversions[0].Standard; 1423 User.ConversionFunction = Constructor; 1424 User.After.setAsIdentityConversion(); 1425 User.After.FromTypePtr 1426 = ThisType->getAsPointerType()->getPointeeType().getAsOpaquePtr(); 1427 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1428 return true; 1429 } else if (CXXConversionDecl *Conversion 1430 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1431 // C++ [over.ics.user]p1: 1432 // 1433 // [...] If the user-defined conversion is specified by a 1434 // conversion function (12.3.2), the initial standard 1435 // conversion sequence converts the source type to the 1436 // implicit object parameter of the conversion function. 1437 User.Before = Best->Conversions[0].Standard; 1438 User.ConversionFunction = Conversion; 1439 1440 // C++ [over.ics.user]p2: 1441 // The second standard conversion sequence converts the 1442 // result of the user-defined conversion to the target type 1443 // for the sequence. Since an implicit conversion sequence 1444 // is an initialization, the special rules for 1445 // initialization by user-defined conversion apply when 1446 // selecting the best user-defined conversion for a 1447 // user-defined conversion sequence (see 13.3.3 and 1448 // 13.3.3.1). 1449 User.After = Best->FinalConversion; 1450 return true; 1451 } else { 1452 assert(false && "Not a constructor or conversion function?"); 1453 return false; 1454 } 1455 1456 case OR_No_Viable_Function: 1457 case OR_Deleted: 1458 // No conversion here! We're done. 1459 return false; 1460 1461 case OR_Ambiguous: 1462 // FIXME: See C++ [over.best.ics]p10 for the handling of 1463 // ambiguous conversion sequences. 1464 return false; 1465 } 1466 1467 return false; 1468} 1469 1470/// CompareImplicitConversionSequences - Compare two implicit 1471/// conversion sequences to determine whether one is better than the 1472/// other or if they are indistinguishable (C++ 13.3.3.2). 1473ImplicitConversionSequence::CompareKind 1474Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1475 const ImplicitConversionSequence& ICS2) 1476{ 1477 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1478 // conversion sequences (as defined in 13.3.3.1) 1479 // -- a standard conversion sequence (13.3.3.1.1) is a better 1480 // conversion sequence than a user-defined conversion sequence or 1481 // an ellipsis conversion sequence, and 1482 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1483 // conversion sequence than an ellipsis conversion sequence 1484 // (13.3.3.1.3). 1485 // 1486 if (ICS1.ConversionKind < ICS2.ConversionKind) 1487 return ImplicitConversionSequence::Better; 1488 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1489 return ImplicitConversionSequence::Worse; 1490 1491 // Two implicit conversion sequences of the same form are 1492 // indistinguishable conversion sequences unless one of the 1493 // following rules apply: (C++ 13.3.3.2p3): 1494 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1495 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1496 else if (ICS1.ConversionKind == 1497 ImplicitConversionSequence::UserDefinedConversion) { 1498 // User-defined conversion sequence U1 is a better conversion 1499 // sequence than another user-defined conversion sequence U2 if 1500 // they contain the same user-defined conversion function or 1501 // constructor and if the second standard conversion sequence of 1502 // U1 is better than the second standard conversion sequence of 1503 // U2 (C++ 13.3.3.2p3). 1504 if (ICS1.UserDefined.ConversionFunction == 1505 ICS2.UserDefined.ConversionFunction) 1506 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1507 ICS2.UserDefined.After); 1508 } 1509 1510 return ImplicitConversionSequence::Indistinguishable; 1511} 1512 1513/// CompareStandardConversionSequences - Compare two standard 1514/// conversion sequences to determine whether one is better than the 1515/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1516ImplicitConversionSequence::CompareKind 1517Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1518 const StandardConversionSequence& SCS2) 1519{ 1520 // Standard conversion sequence S1 is a better conversion sequence 1521 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1522 1523 // -- S1 is a proper subsequence of S2 (comparing the conversion 1524 // sequences in the canonical form defined by 13.3.3.1.1, 1525 // excluding any Lvalue Transformation; the identity conversion 1526 // sequence is considered to be a subsequence of any 1527 // non-identity conversion sequence) or, if not that, 1528 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1529 // Neither is a proper subsequence of the other. Do nothing. 1530 ; 1531 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1532 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1533 (SCS1.Second == ICK_Identity && 1534 SCS1.Third == ICK_Identity)) 1535 // SCS1 is a proper subsequence of SCS2. 1536 return ImplicitConversionSequence::Better; 1537 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1538 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1539 (SCS2.Second == ICK_Identity && 1540 SCS2.Third == ICK_Identity)) 1541 // SCS2 is a proper subsequence of SCS1. 1542 return ImplicitConversionSequence::Worse; 1543 1544 // -- the rank of S1 is better than the rank of S2 (by the rules 1545 // defined below), or, if not that, 1546 ImplicitConversionRank Rank1 = SCS1.getRank(); 1547 ImplicitConversionRank Rank2 = SCS2.getRank(); 1548 if (Rank1 < Rank2) 1549 return ImplicitConversionSequence::Better; 1550 else if (Rank2 < Rank1) 1551 return ImplicitConversionSequence::Worse; 1552 1553 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1554 // are indistinguishable unless one of the following rules 1555 // applies: 1556 1557 // A conversion that is not a conversion of a pointer, or 1558 // pointer to member, to bool is better than another conversion 1559 // that is such a conversion. 1560 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1561 return SCS2.isPointerConversionToBool() 1562 ? ImplicitConversionSequence::Better 1563 : ImplicitConversionSequence::Worse; 1564 1565 // C++ [over.ics.rank]p4b2: 1566 // 1567 // If class B is derived directly or indirectly from class A, 1568 // conversion of B* to A* is better than conversion of B* to 1569 // void*, and conversion of A* to void* is better than conversion 1570 // of B* to void*. 1571 bool SCS1ConvertsToVoid 1572 = SCS1.isPointerConversionToVoidPointer(Context); 1573 bool SCS2ConvertsToVoid 1574 = SCS2.isPointerConversionToVoidPointer(Context); 1575 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1576 // Exactly one of the conversion sequences is a conversion to 1577 // a void pointer; it's the worse conversion. 1578 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1579 : ImplicitConversionSequence::Worse; 1580 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1581 // Neither conversion sequence converts to a void pointer; compare 1582 // their derived-to-base conversions. 1583 if (ImplicitConversionSequence::CompareKind DerivedCK 1584 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1585 return DerivedCK; 1586 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1587 // Both conversion sequences are conversions to void 1588 // pointers. Compare the source types to determine if there's an 1589 // inheritance relationship in their sources. 1590 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1591 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1592 1593 // Adjust the types we're converting from via the array-to-pointer 1594 // conversion, if we need to. 1595 if (SCS1.First == ICK_Array_To_Pointer) 1596 FromType1 = Context.getArrayDecayedType(FromType1); 1597 if (SCS2.First == ICK_Array_To_Pointer) 1598 FromType2 = Context.getArrayDecayedType(FromType2); 1599 1600 QualType FromPointee1 1601 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1602 QualType FromPointee2 1603 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1604 1605 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1606 return ImplicitConversionSequence::Better; 1607 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1608 return ImplicitConversionSequence::Worse; 1609 1610 // Objective-C++: If one interface is more specific than the 1611 // other, it is the better one. 1612 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1613 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1614 if (FromIface1 && FromIface1) { 1615 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1616 return ImplicitConversionSequence::Better; 1617 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1618 return ImplicitConversionSequence::Worse; 1619 } 1620 } 1621 1622 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1623 // bullet 3). 1624 if (ImplicitConversionSequence::CompareKind QualCK 1625 = CompareQualificationConversions(SCS1, SCS2)) 1626 return QualCK; 1627 1628 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1629 // C++0x [over.ics.rank]p3b4: 1630 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1631 // implicit object parameter of a non-static member function declared 1632 // without a ref-qualifier, and S1 binds an rvalue reference to an 1633 // rvalue and S2 binds an lvalue reference. 1634 // FIXME: We don't know if we're dealing with the implicit object parameter, 1635 // or if the member function in this case has a ref qualifier. 1636 // (Of course, we don't have ref qualifiers yet.) 1637 if (SCS1.RRefBinding != SCS2.RRefBinding) 1638 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1639 : ImplicitConversionSequence::Worse; 1640 1641 // C++ [over.ics.rank]p3b4: 1642 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1643 // which the references refer are the same type except for 1644 // top-level cv-qualifiers, and the type to which the reference 1645 // initialized by S2 refers is more cv-qualified than the type 1646 // to which the reference initialized by S1 refers. 1647 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1648 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1649 T1 = Context.getCanonicalType(T1); 1650 T2 = Context.getCanonicalType(T2); 1651 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1652 if (T2.isMoreQualifiedThan(T1)) 1653 return ImplicitConversionSequence::Better; 1654 else if (T1.isMoreQualifiedThan(T2)) 1655 return ImplicitConversionSequence::Worse; 1656 } 1657 } 1658 1659 return ImplicitConversionSequence::Indistinguishable; 1660} 1661 1662/// CompareQualificationConversions - Compares two standard conversion 1663/// sequences to determine whether they can be ranked based on their 1664/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1665ImplicitConversionSequence::CompareKind 1666Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1667 const StandardConversionSequence& SCS2) 1668{ 1669 // C++ 13.3.3.2p3: 1670 // -- S1 and S2 differ only in their qualification conversion and 1671 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1672 // cv-qualification signature of type T1 is a proper subset of 1673 // the cv-qualification signature of type T2, and S1 is not the 1674 // deprecated string literal array-to-pointer conversion (4.2). 1675 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1676 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1677 return ImplicitConversionSequence::Indistinguishable; 1678 1679 // FIXME: the example in the standard doesn't use a qualification 1680 // conversion (!) 1681 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1682 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1683 T1 = Context.getCanonicalType(T1); 1684 T2 = Context.getCanonicalType(T2); 1685 1686 // If the types are the same, we won't learn anything by unwrapped 1687 // them. 1688 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1689 return ImplicitConversionSequence::Indistinguishable; 1690 1691 ImplicitConversionSequence::CompareKind Result 1692 = ImplicitConversionSequence::Indistinguishable; 1693 while (UnwrapSimilarPointerTypes(T1, T2)) { 1694 // Within each iteration of the loop, we check the qualifiers to 1695 // determine if this still looks like a qualification 1696 // conversion. Then, if all is well, we unwrap one more level of 1697 // pointers or pointers-to-members and do it all again 1698 // until there are no more pointers or pointers-to-members left 1699 // to unwrap. This essentially mimics what 1700 // IsQualificationConversion does, but here we're checking for a 1701 // strict subset of qualifiers. 1702 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1703 // The qualifiers are the same, so this doesn't tell us anything 1704 // about how the sequences rank. 1705 ; 1706 else if (T2.isMoreQualifiedThan(T1)) { 1707 // T1 has fewer qualifiers, so it could be the better sequence. 1708 if (Result == ImplicitConversionSequence::Worse) 1709 // Neither has qualifiers that are a subset of the other's 1710 // qualifiers. 1711 return ImplicitConversionSequence::Indistinguishable; 1712 1713 Result = ImplicitConversionSequence::Better; 1714 } else if (T1.isMoreQualifiedThan(T2)) { 1715 // T2 has fewer qualifiers, so it could be the better sequence. 1716 if (Result == ImplicitConversionSequence::Better) 1717 // Neither has qualifiers that are a subset of the other's 1718 // qualifiers. 1719 return ImplicitConversionSequence::Indistinguishable; 1720 1721 Result = ImplicitConversionSequence::Worse; 1722 } else { 1723 // Qualifiers are disjoint. 1724 return ImplicitConversionSequence::Indistinguishable; 1725 } 1726 1727 // If the types after this point are equivalent, we're done. 1728 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1729 break; 1730 } 1731 1732 // Check that the winning standard conversion sequence isn't using 1733 // the deprecated string literal array to pointer conversion. 1734 switch (Result) { 1735 case ImplicitConversionSequence::Better: 1736 if (SCS1.Deprecated) 1737 Result = ImplicitConversionSequence::Indistinguishable; 1738 break; 1739 1740 case ImplicitConversionSequence::Indistinguishable: 1741 break; 1742 1743 case ImplicitConversionSequence::Worse: 1744 if (SCS2.Deprecated) 1745 Result = ImplicitConversionSequence::Indistinguishable; 1746 break; 1747 } 1748 1749 return Result; 1750} 1751 1752/// CompareDerivedToBaseConversions - Compares two standard conversion 1753/// sequences to determine whether they can be ranked based on their 1754/// various kinds of derived-to-base conversions (C++ 1755/// [over.ics.rank]p4b3). As part of these checks, we also look at 1756/// conversions between Objective-C interface types. 1757ImplicitConversionSequence::CompareKind 1758Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1759 const StandardConversionSequence& SCS2) { 1760 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1761 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1762 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1763 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1764 1765 // Adjust the types we're converting from via the array-to-pointer 1766 // conversion, if we need to. 1767 if (SCS1.First == ICK_Array_To_Pointer) 1768 FromType1 = Context.getArrayDecayedType(FromType1); 1769 if (SCS2.First == ICK_Array_To_Pointer) 1770 FromType2 = Context.getArrayDecayedType(FromType2); 1771 1772 // Canonicalize all of the types. 1773 FromType1 = Context.getCanonicalType(FromType1); 1774 ToType1 = Context.getCanonicalType(ToType1); 1775 FromType2 = Context.getCanonicalType(FromType2); 1776 ToType2 = Context.getCanonicalType(ToType2); 1777 1778 // C++ [over.ics.rank]p4b3: 1779 // 1780 // If class B is derived directly or indirectly from class A and 1781 // class C is derived directly or indirectly from B, 1782 // 1783 // For Objective-C, we let A, B, and C also be Objective-C 1784 // interfaces. 1785 1786 // Compare based on pointer conversions. 1787 if (SCS1.Second == ICK_Pointer_Conversion && 1788 SCS2.Second == ICK_Pointer_Conversion && 1789 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1790 FromType1->isPointerType() && FromType2->isPointerType() && 1791 ToType1->isPointerType() && ToType2->isPointerType()) { 1792 QualType FromPointee1 1793 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1794 QualType ToPointee1 1795 = ToType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1796 QualType FromPointee2 1797 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1798 QualType ToPointee2 1799 = ToType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1800 1801 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1802 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1803 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1804 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1805 1806 // -- conversion of C* to B* is better than conversion of C* to A*, 1807 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1808 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1809 return ImplicitConversionSequence::Better; 1810 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1811 return ImplicitConversionSequence::Worse; 1812 1813 if (ToIface1 && ToIface2) { 1814 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1815 return ImplicitConversionSequence::Better; 1816 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1817 return ImplicitConversionSequence::Worse; 1818 } 1819 } 1820 1821 // -- conversion of B* to A* is better than conversion of C* to A*, 1822 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1823 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1824 return ImplicitConversionSequence::Better; 1825 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1826 return ImplicitConversionSequence::Worse; 1827 1828 if (FromIface1 && FromIface2) { 1829 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1830 return ImplicitConversionSequence::Better; 1831 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1832 return ImplicitConversionSequence::Worse; 1833 } 1834 } 1835 } 1836 1837 // Compare based on reference bindings. 1838 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1839 SCS1.Second == ICK_Derived_To_Base) { 1840 // -- binding of an expression of type C to a reference of type 1841 // B& is better than binding an expression of type C to a 1842 // reference of type A&, 1843 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1844 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1845 if (IsDerivedFrom(ToType1, ToType2)) 1846 return ImplicitConversionSequence::Better; 1847 else if (IsDerivedFrom(ToType2, ToType1)) 1848 return ImplicitConversionSequence::Worse; 1849 } 1850 1851 // -- binding of an expression of type B to a reference of type 1852 // A& is better than binding an expression of type C to a 1853 // reference of type A&, 1854 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1855 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1856 if (IsDerivedFrom(FromType2, FromType1)) 1857 return ImplicitConversionSequence::Better; 1858 else if (IsDerivedFrom(FromType1, FromType2)) 1859 return ImplicitConversionSequence::Worse; 1860 } 1861 } 1862 1863 1864 // FIXME: conversion of A::* to B::* is better than conversion of 1865 // A::* to C::*, 1866 1867 // FIXME: conversion of B::* to C::* is better than conversion of 1868 // A::* to C::*, and 1869 1870 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1871 SCS1.Second == ICK_Derived_To_Base) { 1872 // -- conversion of C to B is better than conversion of C to A, 1873 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1874 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1875 if (IsDerivedFrom(ToType1, ToType2)) 1876 return ImplicitConversionSequence::Better; 1877 else if (IsDerivedFrom(ToType2, ToType1)) 1878 return ImplicitConversionSequence::Worse; 1879 } 1880 1881 // -- conversion of B to A is better than conversion of C to A. 1882 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1883 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1884 if (IsDerivedFrom(FromType2, FromType1)) 1885 return ImplicitConversionSequence::Better; 1886 else if (IsDerivedFrom(FromType1, FromType2)) 1887 return ImplicitConversionSequence::Worse; 1888 } 1889 } 1890 1891 return ImplicitConversionSequence::Indistinguishable; 1892} 1893 1894/// TryCopyInitialization - Try to copy-initialize a value of type 1895/// ToType from the expression From. Return the implicit conversion 1896/// sequence required to pass this argument, which may be a bad 1897/// conversion sequence (meaning that the argument cannot be passed to 1898/// a parameter of this type). If @p SuppressUserConversions, then we 1899/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1900/// then we treat @p From as an rvalue, even if it is an lvalue. 1901ImplicitConversionSequence 1902Sema::TryCopyInitialization(Expr *From, QualType ToType, 1903 bool SuppressUserConversions, bool ForceRValue) { 1904 if (ToType->isReferenceType()) { 1905 ImplicitConversionSequence ICS; 1906 CheckReferenceInit(From, ToType, &ICS, SuppressUserConversions, 1907 /*AllowExplicit=*/false, ForceRValue); 1908 return ICS; 1909 } else { 1910 return TryImplicitConversion(From, ToType, SuppressUserConversions, 1911 ForceRValue); 1912 } 1913} 1914 1915/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1916/// the expression @p From. Returns true (and emits a diagnostic) if there was 1917/// an error, returns false if the initialization succeeded. Elidable should 1918/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1919/// differently in C++0x for this case. 1920bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1921 const char* Flavor, bool Elidable) { 1922 if (!getLangOptions().CPlusPlus) { 1923 // In C, argument passing is the same as performing an assignment. 1924 QualType FromType = From->getType(); 1925 1926 AssignConvertType ConvTy = 1927 CheckSingleAssignmentConstraints(ToType, From); 1928 if (ConvTy != Compatible && 1929 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1930 ConvTy = Compatible; 1931 1932 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1933 FromType, From, Flavor); 1934 } 1935 1936 if (ToType->isReferenceType()) 1937 return CheckReferenceInit(From, ToType); 1938 1939 if (!PerformImplicitConversion(From, ToType, Flavor, 1940 /*AllowExplicit=*/false, Elidable)) 1941 return false; 1942 1943 return Diag(From->getSourceRange().getBegin(), 1944 diag::err_typecheck_convert_incompatible) 1945 << ToType << From->getType() << Flavor << From->getSourceRange(); 1946} 1947 1948/// TryObjectArgumentInitialization - Try to initialize the object 1949/// parameter of the given member function (@c Method) from the 1950/// expression @p From. 1951ImplicitConversionSequence 1952Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1953 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1954 unsigned MethodQuals = Method->getTypeQualifiers(); 1955 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 1956 1957 // Set up the conversion sequence as a "bad" conversion, to allow us 1958 // to exit early. 1959 ImplicitConversionSequence ICS; 1960 ICS.Standard.setAsIdentityConversion(); 1961 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1962 1963 // We need to have an object of class type. 1964 QualType FromType = From->getType(); 1965 if (const PointerType *PT = FromType->getAsPointerType()) 1966 FromType = PT->getPointeeType(); 1967 1968 assert(FromType->isRecordType()); 1969 1970 // The implicit object parmeter is has the type "reference to cv X", 1971 // where X is the class of which the function is a member 1972 // (C++ [over.match.funcs]p4). However, when finding an implicit 1973 // conversion sequence for the argument, we are not allowed to 1974 // create temporaries or perform user-defined conversions 1975 // (C++ [over.match.funcs]p5). We perform a simplified version of 1976 // reference binding here, that allows class rvalues to bind to 1977 // non-constant references. 1978 1979 // First check the qualifiers. We don't care about lvalue-vs-rvalue 1980 // with the implicit object parameter (C++ [over.match.funcs]p5). 1981 QualType FromTypeCanon = Context.getCanonicalType(FromType); 1982 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 1983 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 1984 return ICS; 1985 1986 // Check that we have either the same type or a derived type. It 1987 // affects the conversion rank. 1988 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 1989 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 1990 ICS.Standard.Second = ICK_Identity; 1991 else if (IsDerivedFrom(FromType, ClassType)) 1992 ICS.Standard.Second = ICK_Derived_To_Base; 1993 else 1994 return ICS; 1995 1996 // Success. Mark this as a reference binding. 1997 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 1998 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 1999 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2000 ICS.Standard.ReferenceBinding = true; 2001 ICS.Standard.DirectBinding = true; 2002 ICS.Standard.RRefBinding = false; 2003 return ICS; 2004} 2005 2006/// PerformObjectArgumentInitialization - Perform initialization of 2007/// the implicit object parameter for the given Method with the given 2008/// expression. 2009bool 2010Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2011 QualType FromRecordType, DestType; 2012 QualType ImplicitParamRecordType = 2013 Method->getThisType(Context)->getAsPointerType()->getPointeeType(); 2014 2015 if (const PointerType *PT = From->getType()->getAsPointerType()) { 2016 FromRecordType = PT->getPointeeType(); 2017 DestType = Method->getThisType(Context); 2018 } else { 2019 FromRecordType = From->getType(); 2020 DestType = ImplicitParamRecordType; 2021 } 2022 2023 ImplicitConversionSequence ICS 2024 = TryObjectArgumentInitialization(From, Method); 2025 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2026 return Diag(From->getSourceRange().getBegin(), 2027 diag::err_implicit_object_parameter_init) 2028 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2029 2030 if (ICS.Standard.Second == ICK_Derived_To_Base && 2031 CheckDerivedToBaseConversion(FromRecordType, 2032 ImplicitParamRecordType, 2033 From->getSourceRange().getBegin(), 2034 From->getSourceRange())) 2035 return true; 2036 2037 ImpCastExprToType(From, DestType, /*isLvalue=*/true); 2038 return false; 2039} 2040 2041/// TryContextuallyConvertToBool - Attempt to contextually convert the 2042/// expression From to bool (C++0x [conv]p3). 2043ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2044 return TryImplicitConversion(From, Context.BoolTy, false, true); 2045} 2046 2047/// PerformContextuallyConvertToBool - Perform a contextual conversion 2048/// of the expression From to bool (C++0x [conv]p3). 2049bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2050 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2051 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2052 return false; 2053 2054 return Diag(From->getSourceRange().getBegin(), 2055 diag::err_typecheck_bool_condition) 2056 << From->getType() << From->getSourceRange(); 2057} 2058 2059/// AddOverloadCandidate - Adds the given function to the set of 2060/// candidate functions, using the given function call arguments. If 2061/// @p SuppressUserConversions, then don't allow user-defined 2062/// conversions via constructors or conversion operators. 2063/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2064/// hacky way to implement the overloading rules for elidable copy 2065/// initialization in C++0x (C++0x 12.8p15). 2066void 2067Sema::AddOverloadCandidate(FunctionDecl *Function, 2068 Expr **Args, unsigned NumArgs, 2069 OverloadCandidateSet& CandidateSet, 2070 bool SuppressUserConversions, 2071 bool ForceRValue) 2072{ 2073 const FunctionProtoType* Proto 2074 = dyn_cast<FunctionProtoType>(Function->getType()->getAsFunctionType()); 2075 assert(Proto && "Functions without a prototype cannot be overloaded"); 2076 assert(!isa<CXXConversionDecl>(Function) && 2077 "Use AddConversionCandidate for conversion functions"); 2078 assert(!Function->getDescribedFunctionTemplate() && 2079 "Use AddTemplateOverloadCandidate for function templates"); 2080 2081 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2082 if (!isa<CXXConstructorDecl>(Method)) { 2083 // If we get here, it's because we're calling a member function 2084 // that is named without a member access expression (e.g., 2085 // "this->f") that was either written explicitly or created 2086 // implicitly. This can happen with a qualified call to a member 2087 // function, e.g., X::f(). We use a NULL object as the implied 2088 // object argument (C++ [over.call.func]p3). 2089 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2090 SuppressUserConversions, ForceRValue); 2091 return; 2092 } 2093 // We treat a constructor like a non-member function, since its object 2094 // argument doesn't participate in overload resolution. 2095 } 2096 2097 2098 // Add this candidate 2099 CandidateSet.push_back(OverloadCandidate()); 2100 OverloadCandidate& Candidate = CandidateSet.back(); 2101 Candidate.Function = Function; 2102 Candidate.Viable = true; 2103 Candidate.IsSurrogate = false; 2104 Candidate.IgnoreObjectArgument = false; 2105 2106 unsigned NumArgsInProto = Proto->getNumArgs(); 2107 2108 // (C++ 13.3.2p2): A candidate function having fewer than m 2109 // parameters is viable only if it has an ellipsis in its parameter 2110 // list (8.3.5). 2111 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2112 Candidate.Viable = false; 2113 return; 2114 } 2115 2116 // (C++ 13.3.2p2): A candidate function having more than m parameters 2117 // is viable only if the (m+1)st parameter has a default argument 2118 // (8.3.6). For the purposes of overload resolution, the 2119 // parameter list is truncated on the right, so that there are 2120 // exactly m parameters. 2121 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2122 if (NumArgs < MinRequiredArgs) { 2123 // Not enough arguments. 2124 Candidate.Viable = false; 2125 return; 2126 } 2127 2128 // Determine the implicit conversion sequences for each of the 2129 // arguments. 2130 Candidate.Conversions.resize(NumArgs); 2131 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2132 if (ArgIdx < NumArgsInProto) { 2133 // (C++ 13.3.2p3): for F to be a viable function, there shall 2134 // exist for each argument an implicit conversion sequence 2135 // (13.3.3.1) that converts that argument to the corresponding 2136 // parameter of F. 2137 QualType ParamType = Proto->getArgType(ArgIdx); 2138 Candidate.Conversions[ArgIdx] 2139 = TryCopyInitialization(Args[ArgIdx], ParamType, 2140 SuppressUserConversions, ForceRValue); 2141 if (Candidate.Conversions[ArgIdx].ConversionKind 2142 == ImplicitConversionSequence::BadConversion) { 2143 Candidate.Viable = false; 2144 break; 2145 } 2146 } else { 2147 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2148 // argument for which there is no corresponding parameter is 2149 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2150 Candidate.Conversions[ArgIdx].ConversionKind 2151 = ImplicitConversionSequence::EllipsisConversion; 2152 } 2153 } 2154} 2155 2156/// \brief Add all of the function declarations in the given function set to 2157/// the overload canddiate set. 2158void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2159 Expr **Args, unsigned NumArgs, 2160 OverloadCandidateSet& CandidateSet, 2161 bool SuppressUserConversions) { 2162 for (FunctionSet::const_iterator F = Functions.begin(), 2163 FEnd = Functions.end(); 2164 F != FEnd; ++F) 2165 AddOverloadCandidate(*F, Args, NumArgs, CandidateSet, 2166 SuppressUserConversions); 2167} 2168 2169/// AddMethodCandidate - Adds the given C++ member function to the set 2170/// of candidate functions, using the given function call arguments 2171/// and the object argument (@c Object). For example, in a call 2172/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2173/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2174/// allow user-defined conversions via constructors or conversion 2175/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2176/// a slightly hacky way to implement the overloading rules for elidable copy 2177/// initialization in C++0x (C++0x 12.8p15). 2178void 2179Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2180 Expr **Args, unsigned NumArgs, 2181 OverloadCandidateSet& CandidateSet, 2182 bool SuppressUserConversions, bool ForceRValue) 2183{ 2184 const FunctionProtoType* Proto 2185 = dyn_cast<FunctionProtoType>(Method->getType()->getAsFunctionType()); 2186 assert(Proto && "Methods without a prototype cannot be overloaded"); 2187 assert(!isa<CXXConversionDecl>(Method) && 2188 "Use AddConversionCandidate for conversion functions"); 2189 assert(!isa<CXXConstructorDecl>(Method) && 2190 "Use AddOverloadCandidate for constructors"); 2191 2192 // Add this candidate 2193 CandidateSet.push_back(OverloadCandidate()); 2194 OverloadCandidate& Candidate = CandidateSet.back(); 2195 Candidate.Function = Method; 2196 Candidate.IsSurrogate = false; 2197 Candidate.IgnoreObjectArgument = false; 2198 2199 unsigned NumArgsInProto = Proto->getNumArgs(); 2200 2201 // (C++ 13.3.2p2): A candidate function having fewer than m 2202 // parameters is viable only if it has an ellipsis in its parameter 2203 // list (8.3.5). 2204 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2205 Candidate.Viable = false; 2206 return; 2207 } 2208 2209 // (C++ 13.3.2p2): A candidate function having more than m parameters 2210 // is viable only if the (m+1)st parameter has a default argument 2211 // (8.3.6). For the purposes of overload resolution, the 2212 // parameter list is truncated on the right, so that there are 2213 // exactly m parameters. 2214 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2215 if (NumArgs < MinRequiredArgs) { 2216 // Not enough arguments. 2217 Candidate.Viable = false; 2218 return; 2219 } 2220 2221 Candidate.Viable = true; 2222 Candidate.Conversions.resize(NumArgs + 1); 2223 2224 if (Method->isStatic() || !Object) 2225 // The implicit object argument is ignored. 2226 Candidate.IgnoreObjectArgument = true; 2227 else { 2228 // Determine the implicit conversion sequence for the object 2229 // parameter. 2230 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2231 if (Candidate.Conversions[0].ConversionKind 2232 == ImplicitConversionSequence::BadConversion) { 2233 Candidate.Viable = false; 2234 return; 2235 } 2236 } 2237 2238 // Determine the implicit conversion sequences for each of the 2239 // arguments. 2240 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2241 if (ArgIdx < NumArgsInProto) { 2242 // (C++ 13.3.2p3): for F to be a viable function, there shall 2243 // exist for each argument an implicit conversion sequence 2244 // (13.3.3.1) that converts that argument to the corresponding 2245 // parameter of F. 2246 QualType ParamType = Proto->getArgType(ArgIdx); 2247 Candidate.Conversions[ArgIdx + 1] 2248 = TryCopyInitialization(Args[ArgIdx], ParamType, 2249 SuppressUserConversions, ForceRValue); 2250 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2251 == ImplicitConversionSequence::BadConversion) { 2252 Candidate.Viable = false; 2253 break; 2254 } 2255 } else { 2256 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2257 // argument for which there is no corresponding parameter is 2258 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2259 Candidate.Conversions[ArgIdx + 1].ConversionKind 2260 = ImplicitConversionSequence::EllipsisConversion; 2261 } 2262 } 2263} 2264 2265/// \brief Add a C++ function template as a candidate in the candidate set, 2266/// using template argument deduction to produce an appropriate function 2267/// template specialization. 2268void 2269Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2270 Expr **Args, unsigned NumArgs, 2271 OverloadCandidateSet& CandidateSet, 2272 bool SuppressUserConversions, 2273 bool ForceRValue) { 2274 // C++ [over.match.funcs]p7: 2275 // In each case where a candidate is a function template, candidate 2276 // function template specializations are generated using template argument 2277 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2278 // candidate functions in the usual way.113) A given name can refer to one 2279 // or more function templates and also to a set of overloaded non-template 2280 // functions. In such a case, the candidate functions generated from each 2281 // function template are combined with the set of non-template candidate 2282 // functions. 2283 TemplateDeductionInfo Info(Context); 2284 FunctionDecl *Specialization = 0; 2285 if (TemplateDeductionResult Result 2286 = DeduceTemplateArguments(FunctionTemplate, Args, NumArgs, 2287 Specialization, Info)) { 2288 // FIXME: Record what happened with template argument deduction, so 2289 // that we can give the user a beautiful diagnostic. 2290 (void)Result; 2291 return; 2292 } 2293 2294 // Add the function template specialization produced by template argument 2295 // deduction as a candidate. 2296 assert(Specialization && "Missing function template specialization?"); 2297 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2298 SuppressUserConversions, ForceRValue); 2299} 2300 2301/// AddConversionCandidate - Add a C++ conversion function as a 2302/// candidate in the candidate set (C++ [over.match.conv], 2303/// C++ [over.match.copy]). From is the expression we're converting from, 2304/// and ToType is the type that we're eventually trying to convert to 2305/// (which may or may not be the same type as the type that the 2306/// conversion function produces). 2307void 2308Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2309 Expr *From, QualType ToType, 2310 OverloadCandidateSet& CandidateSet) { 2311 // Add this candidate 2312 CandidateSet.push_back(OverloadCandidate()); 2313 OverloadCandidate& Candidate = CandidateSet.back(); 2314 Candidate.Function = Conversion; 2315 Candidate.IsSurrogate = false; 2316 Candidate.IgnoreObjectArgument = false; 2317 Candidate.FinalConversion.setAsIdentityConversion(); 2318 Candidate.FinalConversion.FromTypePtr 2319 = Conversion->getConversionType().getAsOpaquePtr(); 2320 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2321 2322 // Determine the implicit conversion sequence for the implicit 2323 // object parameter. 2324 Candidate.Viable = true; 2325 Candidate.Conversions.resize(1); 2326 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2327 2328 if (Candidate.Conversions[0].ConversionKind 2329 == ImplicitConversionSequence::BadConversion) { 2330 Candidate.Viable = false; 2331 return; 2332 } 2333 2334 // To determine what the conversion from the result of calling the 2335 // conversion function to the type we're eventually trying to 2336 // convert to (ToType), we need to synthesize a call to the 2337 // conversion function and attempt copy initialization from it. This 2338 // makes sure that we get the right semantics with respect to 2339 // lvalues/rvalues and the type. Fortunately, we can allocate this 2340 // call on the stack and we don't need its arguments to be 2341 // well-formed. 2342 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2343 SourceLocation()); 2344 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2345 &ConversionRef, false); 2346 2347 // Note that it is safe to allocate CallExpr on the stack here because 2348 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2349 // allocator). 2350 CallExpr Call(Context, &ConversionFn, 0, 0, 2351 Conversion->getConversionType().getNonReferenceType(), 2352 SourceLocation()); 2353 ImplicitConversionSequence ICS = TryCopyInitialization(&Call, ToType, true); 2354 switch (ICS.ConversionKind) { 2355 case ImplicitConversionSequence::StandardConversion: 2356 Candidate.FinalConversion = ICS.Standard; 2357 break; 2358 2359 case ImplicitConversionSequence::BadConversion: 2360 Candidate.Viable = false; 2361 break; 2362 2363 default: 2364 assert(false && 2365 "Can only end up with a standard conversion sequence or failure"); 2366 } 2367} 2368 2369/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2370/// converts the given @c Object to a function pointer via the 2371/// conversion function @c Conversion, and then attempts to call it 2372/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2373/// the type of function that we'll eventually be calling. 2374void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2375 const FunctionProtoType *Proto, 2376 Expr *Object, Expr **Args, unsigned NumArgs, 2377 OverloadCandidateSet& CandidateSet) { 2378 CandidateSet.push_back(OverloadCandidate()); 2379 OverloadCandidate& Candidate = CandidateSet.back(); 2380 Candidate.Function = 0; 2381 Candidate.Surrogate = Conversion; 2382 Candidate.Viable = true; 2383 Candidate.IsSurrogate = true; 2384 Candidate.IgnoreObjectArgument = false; 2385 Candidate.Conversions.resize(NumArgs + 1); 2386 2387 // Determine the implicit conversion sequence for the implicit 2388 // object parameter. 2389 ImplicitConversionSequence ObjectInit 2390 = TryObjectArgumentInitialization(Object, Conversion); 2391 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2392 Candidate.Viable = false; 2393 return; 2394 } 2395 2396 // The first conversion is actually a user-defined conversion whose 2397 // first conversion is ObjectInit's standard conversion (which is 2398 // effectively a reference binding). Record it as such. 2399 Candidate.Conversions[0].ConversionKind 2400 = ImplicitConversionSequence::UserDefinedConversion; 2401 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2402 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2403 Candidate.Conversions[0].UserDefined.After 2404 = Candidate.Conversions[0].UserDefined.Before; 2405 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2406 2407 // Find the 2408 unsigned NumArgsInProto = Proto->getNumArgs(); 2409 2410 // (C++ 13.3.2p2): A candidate function having fewer than m 2411 // parameters is viable only if it has an ellipsis in its parameter 2412 // list (8.3.5). 2413 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2414 Candidate.Viable = false; 2415 return; 2416 } 2417 2418 // Function types don't have any default arguments, so just check if 2419 // we have enough arguments. 2420 if (NumArgs < NumArgsInProto) { 2421 // Not enough arguments. 2422 Candidate.Viable = false; 2423 return; 2424 } 2425 2426 // Determine the implicit conversion sequences for each of the 2427 // arguments. 2428 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2429 if (ArgIdx < NumArgsInProto) { 2430 // (C++ 13.3.2p3): for F to be a viable function, there shall 2431 // exist for each argument an implicit conversion sequence 2432 // (13.3.3.1) that converts that argument to the corresponding 2433 // parameter of F. 2434 QualType ParamType = Proto->getArgType(ArgIdx); 2435 Candidate.Conversions[ArgIdx + 1] 2436 = TryCopyInitialization(Args[ArgIdx], ParamType, 2437 /*SuppressUserConversions=*/false); 2438 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2439 == ImplicitConversionSequence::BadConversion) { 2440 Candidate.Viable = false; 2441 break; 2442 } 2443 } else { 2444 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2445 // argument for which there is no corresponding parameter is 2446 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2447 Candidate.Conversions[ArgIdx + 1].ConversionKind 2448 = ImplicitConversionSequence::EllipsisConversion; 2449 } 2450 } 2451} 2452 2453// FIXME: This will eventually be removed, once we've migrated all of the 2454// operator overloading logic over to the scheme used by binary operators, which 2455// works for template instantiation. 2456void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2457 SourceLocation OpLoc, 2458 Expr **Args, unsigned NumArgs, 2459 OverloadCandidateSet& CandidateSet, 2460 SourceRange OpRange) { 2461 2462 FunctionSet Functions; 2463 2464 QualType T1 = Args[0]->getType(); 2465 QualType T2; 2466 if (NumArgs > 1) 2467 T2 = Args[1]->getType(); 2468 2469 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2470 if (S) 2471 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2472 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2473 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2474 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2475 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2476} 2477 2478/// \brief Add overload candidates for overloaded operators that are 2479/// member functions. 2480/// 2481/// Add the overloaded operator candidates that are member functions 2482/// for the operator Op that was used in an operator expression such 2483/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2484/// CandidateSet will store the added overload candidates. (C++ 2485/// [over.match.oper]). 2486void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2487 SourceLocation OpLoc, 2488 Expr **Args, unsigned NumArgs, 2489 OverloadCandidateSet& CandidateSet, 2490 SourceRange OpRange) { 2491 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2492 2493 // C++ [over.match.oper]p3: 2494 // For a unary operator @ with an operand of a type whose 2495 // cv-unqualified version is T1, and for a binary operator @ with 2496 // a left operand of a type whose cv-unqualified version is T1 and 2497 // a right operand of a type whose cv-unqualified version is T2, 2498 // three sets of candidate functions, designated member 2499 // candidates, non-member candidates and built-in candidates, are 2500 // constructed as follows: 2501 QualType T1 = Args[0]->getType(); 2502 QualType T2; 2503 if (NumArgs > 1) 2504 T2 = Args[1]->getType(); 2505 2506 // -- If T1 is a class type, the set of member candidates is the 2507 // result of the qualified lookup of T1::operator@ 2508 // (13.3.1.1.1); otherwise, the set of member candidates is 2509 // empty. 2510 // FIXME: Lookup in base classes, too! 2511 if (const RecordType *T1Rec = T1->getAsRecordType()) { 2512 DeclContext::lookup_const_iterator Oper, OperEnd; 2513 for (llvm::tie(Oper, OperEnd) = T1Rec->getDecl()->lookup(Context, OpName); 2514 Oper != OperEnd; ++Oper) 2515 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2516 Args+1, NumArgs - 1, CandidateSet, 2517 /*SuppressUserConversions=*/false); 2518 } 2519} 2520 2521/// AddBuiltinCandidate - Add a candidate for a built-in 2522/// operator. ResultTy and ParamTys are the result and parameter types 2523/// of the built-in candidate, respectively. Args and NumArgs are the 2524/// arguments being passed to the candidate. IsAssignmentOperator 2525/// should be true when this built-in candidate is an assignment 2526/// operator. NumContextualBoolArguments is the number of arguments 2527/// (at the beginning of the argument list) that will be contextually 2528/// converted to bool. 2529void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2530 Expr **Args, unsigned NumArgs, 2531 OverloadCandidateSet& CandidateSet, 2532 bool IsAssignmentOperator, 2533 unsigned NumContextualBoolArguments) { 2534 // Add this candidate 2535 CandidateSet.push_back(OverloadCandidate()); 2536 OverloadCandidate& Candidate = CandidateSet.back(); 2537 Candidate.Function = 0; 2538 Candidate.IsSurrogate = false; 2539 Candidate.IgnoreObjectArgument = false; 2540 Candidate.BuiltinTypes.ResultTy = ResultTy; 2541 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2542 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2543 2544 // Determine the implicit conversion sequences for each of the 2545 // arguments. 2546 Candidate.Viable = true; 2547 Candidate.Conversions.resize(NumArgs); 2548 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2549 // C++ [over.match.oper]p4: 2550 // For the built-in assignment operators, conversions of the 2551 // left operand are restricted as follows: 2552 // -- no temporaries are introduced to hold the left operand, and 2553 // -- no user-defined conversions are applied to the left 2554 // operand to achieve a type match with the left-most 2555 // parameter of a built-in candidate. 2556 // 2557 // We block these conversions by turning off user-defined 2558 // conversions, since that is the only way that initialization of 2559 // a reference to a non-class type can occur from something that 2560 // is not of the same type. 2561 if (ArgIdx < NumContextualBoolArguments) { 2562 assert(ParamTys[ArgIdx] == Context.BoolTy && 2563 "Contextual conversion to bool requires bool type"); 2564 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2565 } else { 2566 Candidate.Conversions[ArgIdx] 2567 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2568 ArgIdx == 0 && IsAssignmentOperator); 2569 } 2570 if (Candidate.Conversions[ArgIdx].ConversionKind 2571 == ImplicitConversionSequence::BadConversion) { 2572 Candidate.Viable = false; 2573 break; 2574 } 2575 } 2576} 2577 2578/// BuiltinCandidateTypeSet - A set of types that will be used for the 2579/// candidate operator functions for built-in operators (C++ 2580/// [over.built]). The types are separated into pointer types and 2581/// enumeration types. 2582class BuiltinCandidateTypeSet { 2583 /// TypeSet - A set of types. 2584 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2585 2586 /// PointerTypes - The set of pointer types that will be used in the 2587 /// built-in candidates. 2588 TypeSet PointerTypes; 2589 2590 /// MemberPointerTypes - The set of member pointer types that will be 2591 /// used in the built-in candidates. 2592 TypeSet MemberPointerTypes; 2593 2594 /// EnumerationTypes - The set of enumeration types that will be 2595 /// used in the built-in candidates. 2596 TypeSet EnumerationTypes; 2597 2598 /// Context - The AST context in which we will build the type sets. 2599 ASTContext &Context; 2600 2601 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2602 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2603 2604public: 2605 /// iterator - Iterates through the types that are part of the set. 2606 typedef TypeSet::iterator iterator; 2607 2608 BuiltinCandidateTypeSet(ASTContext &Context) : Context(Context) { } 2609 2610 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2611 bool AllowExplicitConversions); 2612 2613 /// pointer_begin - First pointer type found; 2614 iterator pointer_begin() { return PointerTypes.begin(); } 2615 2616 /// pointer_end - Past the last pointer type found; 2617 iterator pointer_end() { return PointerTypes.end(); } 2618 2619 /// member_pointer_begin - First member pointer type found; 2620 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2621 2622 /// member_pointer_end - Past the last member pointer type found; 2623 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2624 2625 /// enumeration_begin - First enumeration type found; 2626 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2627 2628 /// enumeration_end - Past the last enumeration type found; 2629 iterator enumeration_end() { return EnumerationTypes.end(); } 2630}; 2631 2632/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2633/// the set of pointer types along with any more-qualified variants of 2634/// that type. For example, if @p Ty is "int const *", this routine 2635/// will add "int const *", "int const volatile *", "int const 2636/// restrict *", and "int const volatile restrict *" to the set of 2637/// pointer types. Returns true if the add of @p Ty itself succeeded, 2638/// false otherwise. 2639bool 2640BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2641 // Insert this type. 2642 if (!PointerTypes.insert(Ty)) 2643 return false; 2644 2645 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2646 QualType PointeeTy = PointerTy->getPointeeType(); 2647 // FIXME: Optimize this so that we don't keep trying to add the same types. 2648 2649 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal with all 2650 // pointer conversions that don't cast away constness? 2651 if (!PointeeTy.isConstQualified()) 2652 AddPointerWithMoreQualifiedTypeVariants 2653 (Context.getPointerType(PointeeTy.withConst())); 2654 if (!PointeeTy.isVolatileQualified()) 2655 AddPointerWithMoreQualifiedTypeVariants 2656 (Context.getPointerType(PointeeTy.withVolatile())); 2657 if (!PointeeTy.isRestrictQualified()) 2658 AddPointerWithMoreQualifiedTypeVariants 2659 (Context.getPointerType(PointeeTy.withRestrict())); 2660 } 2661 2662 return true; 2663} 2664 2665/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2666/// to the set of pointer types along with any more-qualified variants of 2667/// that type. For example, if @p Ty is "int const *", this routine 2668/// will add "int const *", "int const volatile *", "int const 2669/// restrict *", and "int const volatile restrict *" to the set of 2670/// pointer types. Returns true if the add of @p Ty itself succeeded, 2671/// false otherwise. 2672bool 2673BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2674 QualType Ty) { 2675 // Insert this type. 2676 if (!MemberPointerTypes.insert(Ty)) 2677 return false; 2678 2679 if (const MemberPointerType *PointerTy = Ty->getAsMemberPointerType()) { 2680 QualType PointeeTy = PointerTy->getPointeeType(); 2681 const Type *ClassTy = PointerTy->getClass(); 2682 // FIXME: Optimize this so that we don't keep trying to add the same types. 2683 2684 if (!PointeeTy.isConstQualified()) 2685 AddMemberPointerWithMoreQualifiedTypeVariants 2686 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2687 if (!PointeeTy.isVolatileQualified()) 2688 AddMemberPointerWithMoreQualifiedTypeVariants 2689 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2690 if (!PointeeTy.isRestrictQualified()) 2691 AddMemberPointerWithMoreQualifiedTypeVariants 2692 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2693 } 2694 2695 return true; 2696} 2697 2698/// AddTypesConvertedFrom - Add each of the types to which the type @p 2699/// Ty can be implicit converted to the given set of @p Types. We're 2700/// primarily interested in pointer types and enumeration types. We also 2701/// take member pointer types, for the conditional operator. 2702/// AllowUserConversions is true if we should look at the conversion 2703/// functions of a class type, and AllowExplicitConversions if we 2704/// should also include the explicit conversion functions of a class 2705/// type. 2706void 2707BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2708 bool AllowUserConversions, 2709 bool AllowExplicitConversions) { 2710 // Only deal with canonical types. 2711 Ty = Context.getCanonicalType(Ty); 2712 2713 // Look through reference types; they aren't part of the type of an 2714 // expression for the purposes of conversions. 2715 if (const ReferenceType *RefTy = Ty->getAsReferenceType()) 2716 Ty = RefTy->getPointeeType(); 2717 2718 // We don't care about qualifiers on the type. 2719 Ty = Ty.getUnqualifiedType(); 2720 2721 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2722 QualType PointeeTy = PointerTy->getPointeeType(); 2723 2724 // Insert our type, and its more-qualified variants, into the set 2725 // of types. 2726 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2727 return; 2728 2729 // Add 'cv void*' to our set of types. 2730 if (!Ty->isVoidType()) { 2731 QualType QualVoid 2732 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2733 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2734 } 2735 2736 // If this is a pointer to a class type, add pointers to its bases 2737 // (with the same level of cv-qualification as the original 2738 // derived class, of course). 2739 if (const RecordType *PointeeRec = PointeeTy->getAsRecordType()) { 2740 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2741 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2742 Base != ClassDecl->bases_end(); ++Base) { 2743 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2744 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2745 2746 // Add the pointer type, recursively, so that we get all of 2747 // the indirect base classes, too. 2748 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2749 } 2750 } 2751 } else if (Ty->isMemberPointerType()) { 2752 // Member pointers are far easier, since the pointee can't be converted. 2753 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2754 return; 2755 } else if (Ty->isEnumeralType()) { 2756 EnumerationTypes.insert(Ty); 2757 } else if (AllowUserConversions) { 2758 if (const RecordType *TyRec = Ty->getAsRecordType()) { 2759 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2760 // FIXME: Visit conversion functions in the base classes, too. 2761 OverloadedFunctionDecl *Conversions 2762 = ClassDecl->getConversionFunctions(); 2763 for (OverloadedFunctionDecl::function_iterator Func 2764 = Conversions->function_begin(); 2765 Func != Conversions->function_end(); ++Func) { 2766 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 2767 if (AllowExplicitConversions || !Conv->isExplicit()) 2768 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2769 } 2770 } 2771 } 2772} 2773 2774/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2775/// operator overloads to the candidate set (C++ [over.built]), based 2776/// on the operator @p Op and the arguments given. For example, if the 2777/// operator is a binary '+', this routine might add "int 2778/// operator+(int, int)" to cover integer addition. 2779void 2780Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2781 Expr **Args, unsigned NumArgs, 2782 OverloadCandidateSet& CandidateSet) { 2783 // The set of "promoted arithmetic types", which are the arithmetic 2784 // types are that preserved by promotion (C++ [over.built]p2). Note 2785 // that the first few of these types are the promoted integral 2786 // types; these types need to be first. 2787 // FIXME: What about complex? 2788 const unsigned FirstIntegralType = 0; 2789 const unsigned LastIntegralType = 13; 2790 const unsigned FirstPromotedIntegralType = 7, 2791 LastPromotedIntegralType = 13; 2792 const unsigned FirstPromotedArithmeticType = 7, 2793 LastPromotedArithmeticType = 16; 2794 const unsigned NumArithmeticTypes = 16; 2795 QualType ArithmeticTypes[NumArithmeticTypes] = { 2796 Context.BoolTy, Context.CharTy, Context.WCharTy, 2797 Context.SignedCharTy, Context.ShortTy, 2798 Context.UnsignedCharTy, Context.UnsignedShortTy, 2799 Context.IntTy, Context.LongTy, Context.LongLongTy, 2800 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 2801 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 2802 }; 2803 2804 // Find all of the types that the arguments can convert to, but only 2805 // if the operator we're looking at has built-in operator candidates 2806 // that make use of these types. 2807 BuiltinCandidateTypeSet CandidateTypes(Context); 2808 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 2809 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 2810 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 2811 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 2812 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 2813 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 2814 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2815 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 2816 true, 2817 (Op == OO_Exclaim || 2818 Op == OO_AmpAmp || 2819 Op == OO_PipePipe)); 2820 } 2821 2822 bool isComparison = false; 2823 switch (Op) { 2824 case OO_None: 2825 case NUM_OVERLOADED_OPERATORS: 2826 assert(false && "Expected an overloaded operator"); 2827 break; 2828 2829 case OO_Star: // '*' is either unary or binary 2830 if (NumArgs == 1) 2831 goto UnaryStar; 2832 else 2833 goto BinaryStar; 2834 break; 2835 2836 case OO_Plus: // '+' is either unary or binary 2837 if (NumArgs == 1) 2838 goto UnaryPlus; 2839 else 2840 goto BinaryPlus; 2841 break; 2842 2843 case OO_Minus: // '-' is either unary or binary 2844 if (NumArgs == 1) 2845 goto UnaryMinus; 2846 else 2847 goto BinaryMinus; 2848 break; 2849 2850 case OO_Amp: // '&' is either unary or binary 2851 if (NumArgs == 1) 2852 goto UnaryAmp; 2853 else 2854 goto BinaryAmp; 2855 2856 case OO_PlusPlus: 2857 case OO_MinusMinus: 2858 // C++ [over.built]p3: 2859 // 2860 // For every pair (T, VQ), where T is an arithmetic type, and VQ 2861 // is either volatile or empty, there exist candidate operator 2862 // functions of the form 2863 // 2864 // VQ T& operator++(VQ T&); 2865 // T operator++(VQ T&, int); 2866 // 2867 // C++ [over.built]p4: 2868 // 2869 // For every pair (T, VQ), where T is an arithmetic type other 2870 // than bool, and VQ is either volatile or empty, there exist 2871 // candidate operator functions of the form 2872 // 2873 // VQ T& operator--(VQ T&); 2874 // T operator--(VQ T&, int); 2875 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 2876 Arith < NumArithmeticTypes; ++Arith) { 2877 QualType ArithTy = ArithmeticTypes[Arith]; 2878 QualType ParamTypes[2] 2879 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 2880 2881 // Non-volatile version. 2882 if (NumArgs == 1) 2883 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2884 else 2885 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2886 2887 // Volatile version 2888 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 2889 if (NumArgs == 1) 2890 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2891 else 2892 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2893 } 2894 2895 // C++ [over.built]p5: 2896 // 2897 // For every pair (T, VQ), where T is a cv-qualified or 2898 // cv-unqualified object type, and VQ is either volatile or 2899 // empty, there exist candidate operator functions of the form 2900 // 2901 // T*VQ& operator++(T*VQ&); 2902 // T*VQ& operator--(T*VQ&); 2903 // T* operator++(T*VQ&, int); 2904 // T* operator--(T*VQ&, int); 2905 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2906 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2907 // Skip pointer types that aren't pointers to object types. 2908 if (!(*Ptr)->getAsPointerType()->getPointeeType()->isObjectType()) 2909 continue; 2910 2911 QualType ParamTypes[2] = { 2912 Context.getLValueReferenceType(*Ptr), Context.IntTy 2913 }; 2914 2915 // Without volatile 2916 if (NumArgs == 1) 2917 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2918 else 2919 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2920 2921 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 2922 // With volatile 2923 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 2924 if (NumArgs == 1) 2925 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2926 else 2927 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2928 } 2929 } 2930 break; 2931 2932 UnaryStar: 2933 // C++ [over.built]p6: 2934 // For every cv-qualified or cv-unqualified object type T, there 2935 // exist candidate operator functions of the form 2936 // 2937 // T& operator*(T*); 2938 // 2939 // C++ [over.built]p7: 2940 // For every function type T, there exist candidate operator 2941 // functions of the form 2942 // T& operator*(T*); 2943 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2944 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2945 QualType ParamTy = *Ptr; 2946 QualType PointeeTy = ParamTy->getAsPointerType()->getPointeeType(); 2947 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 2948 &ParamTy, Args, 1, CandidateSet); 2949 } 2950 break; 2951 2952 UnaryPlus: 2953 // C++ [over.built]p8: 2954 // For every type T, there exist candidate operator functions of 2955 // the form 2956 // 2957 // T* operator+(T*); 2958 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2959 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2960 QualType ParamTy = *Ptr; 2961 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 2962 } 2963 2964 // Fall through 2965 2966 UnaryMinus: 2967 // C++ [over.built]p9: 2968 // For every promoted arithmetic type T, there exist candidate 2969 // operator functions of the form 2970 // 2971 // T operator+(T); 2972 // T operator-(T); 2973 for (unsigned Arith = FirstPromotedArithmeticType; 2974 Arith < LastPromotedArithmeticType; ++Arith) { 2975 QualType ArithTy = ArithmeticTypes[Arith]; 2976 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 2977 } 2978 break; 2979 2980 case OO_Tilde: 2981 // C++ [over.built]p10: 2982 // For every promoted integral type T, there exist candidate 2983 // operator functions of the form 2984 // 2985 // T operator~(T); 2986 for (unsigned Int = FirstPromotedIntegralType; 2987 Int < LastPromotedIntegralType; ++Int) { 2988 QualType IntTy = ArithmeticTypes[Int]; 2989 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 2990 } 2991 break; 2992 2993 case OO_New: 2994 case OO_Delete: 2995 case OO_Array_New: 2996 case OO_Array_Delete: 2997 case OO_Call: 2998 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 2999 break; 3000 3001 case OO_Comma: 3002 UnaryAmp: 3003 case OO_Arrow: 3004 // C++ [over.match.oper]p3: 3005 // -- For the operator ',', the unary operator '&', or the 3006 // operator '->', the built-in candidates set is empty. 3007 break; 3008 3009 case OO_Less: 3010 case OO_Greater: 3011 case OO_LessEqual: 3012 case OO_GreaterEqual: 3013 case OO_EqualEqual: 3014 case OO_ExclaimEqual: 3015 // C++ [over.built]p15: 3016 // 3017 // For every pointer or enumeration type T, there exist 3018 // candidate operator functions of the form 3019 // 3020 // bool operator<(T, T); 3021 // bool operator>(T, T); 3022 // bool operator<=(T, T); 3023 // bool operator>=(T, T); 3024 // bool operator==(T, T); 3025 // bool operator!=(T, T); 3026 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3027 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3028 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3029 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3030 } 3031 for (BuiltinCandidateTypeSet::iterator Enum 3032 = CandidateTypes.enumeration_begin(); 3033 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3034 QualType ParamTypes[2] = { *Enum, *Enum }; 3035 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3036 } 3037 3038 // Fall through. 3039 isComparison = true; 3040 3041 BinaryPlus: 3042 BinaryMinus: 3043 if (!isComparison) { 3044 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3045 3046 // C++ [over.built]p13: 3047 // 3048 // For every cv-qualified or cv-unqualified object type T 3049 // there exist candidate operator functions of the form 3050 // 3051 // T* operator+(T*, ptrdiff_t); 3052 // T& operator[](T*, ptrdiff_t); [BELOW] 3053 // T* operator-(T*, ptrdiff_t); 3054 // T* operator+(ptrdiff_t, T*); 3055 // T& operator[](ptrdiff_t, T*); [BELOW] 3056 // 3057 // C++ [over.built]p14: 3058 // 3059 // For every T, where T is a pointer to object type, there 3060 // exist candidate operator functions of the form 3061 // 3062 // ptrdiff_t operator-(T, T); 3063 for (BuiltinCandidateTypeSet::iterator Ptr 3064 = CandidateTypes.pointer_begin(); 3065 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3066 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3067 3068 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3069 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3070 3071 if (Op == OO_Plus) { 3072 // T* operator+(ptrdiff_t, T*); 3073 ParamTypes[0] = ParamTypes[1]; 3074 ParamTypes[1] = *Ptr; 3075 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3076 } else { 3077 // ptrdiff_t operator-(T, T); 3078 ParamTypes[1] = *Ptr; 3079 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3080 Args, 2, CandidateSet); 3081 } 3082 } 3083 } 3084 // Fall through 3085 3086 case OO_Slash: 3087 BinaryStar: 3088 Conditional: 3089 // C++ [over.built]p12: 3090 // 3091 // For every pair of promoted arithmetic types L and R, there 3092 // exist candidate operator functions of the form 3093 // 3094 // LR operator*(L, R); 3095 // LR operator/(L, R); 3096 // LR operator+(L, R); 3097 // LR operator-(L, R); 3098 // bool operator<(L, R); 3099 // bool operator>(L, R); 3100 // bool operator<=(L, R); 3101 // bool operator>=(L, R); 3102 // bool operator==(L, R); 3103 // bool operator!=(L, R); 3104 // 3105 // where LR is the result of the usual arithmetic conversions 3106 // between types L and R. 3107 // 3108 // C++ [over.built]p24: 3109 // 3110 // For every pair of promoted arithmetic types L and R, there exist 3111 // candidate operator functions of the form 3112 // 3113 // LR operator?(bool, L, R); 3114 // 3115 // where LR is the result of the usual arithmetic conversions 3116 // between types L and R. 3117 // Our candidates ignore the first parameter. 3118 for (unsigned Left = FirstPromotedArithmeticType; 3119 Left < LastPromotedArithmeticType; ++Left) { 3120 for (unsigned Right = FirstPromotedArithmeticType; 3121 Right < LastPromotedArithmeticType; ++Right) { 3122 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3123 QualType Result 3124 = isComparison? Context.BoolTy 3125 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3126 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3127 } 3128 } 3129 break; 3130 3131 case OO_Percent: 3132 BinaryAmp: 3133 case OO_Caret: 3134 case OO_Pipe: 3135 case OO_LessLess: 3136 case OO_GreaterGreater: 3137 // C++ [over.built]p17: 3138 // 3139 // For every pair of promoted integral types L and R, there 3140 // exist candidate operator functions of the form 3141 // 3142 // LR operator%(L, R); 3143 // LR operator&(L, R); 3144 // LR operator^(L, R); 3145 // LR operator|(L, R); 3146 // L operator<<(L, R); 3147 // L operator>>(L, R); 3148 // 3149 // where LR is the result of the usual arithmetic conversions 3150 // between types L and R. 3151 for (unsigned Left = FirstPromotedIntegralType; 3152 Left < LastPromotedIntegralType; ++Left) { 3153 for (unsigned Right = FirstPromotedIntegralType; 3154 Right < LastPromotedIntegralType; ++Right) { 3155 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3156 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3157 ? LandR[0] 3158 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3159 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3160 } 3161 } 3162 break; 3163 3164 case OO_Equal: 3165 // C++ [over.built]p20: 3166 // 3167 // For every pair (T, VQ), where T is an enumeration or 3168 // (FIXME:) pointer to member type and VQ is either volatile or 3169 // empty, there exist candidate operator functions of the form 3170 // 3171 // VQ T& operator=(VQ T&, T); 3172 for (BuiltinCandidateTypeSet::iterator Enum 3173 = CandidateTypes.enumeration_begin(); 3174 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3175 QualType ParamTypes[2]; 3176 3177 // T& operator=(T&, T) 3178 ParamTypes[0] = Context.getLValueReferenceType(*Enum); 3179 ParamTypes[1] = *Enum; 3180 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3181 /*IsAssignmentOperator=*/false); 3182 3183 if (!Context.getCanonicalType(*Enum).isVolatileQualified()) { 3184 // volatile T& operator=(volatile T&, T) 3185 ParamTypes[0] = Context.getLValueReferenceType((*Enum).withVolatile()); 3186 ParamTypes[1] = *Enum; 3187 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3188 /*IsAssignmentOperator=*/false); 3189 } 3190 } 3191 // Fall through. 3192 3193 case OO_PlusEqual: 3194 case OO_MinusEqual: 3195 // C++ [over.built]p19: 3196 // 3197 // For every pair (T, VQ), where T is any type and VQ is either 3198 // volatile or empty, there exist candidate operator functions 3199 // of the form 3200 // 3201 // T*VQ& operator=(T*VQ&, T*); 3202 // 3203 // C++ [over.built]p21: 3204 // 3205 // For every pair (T, VQ), where T is a cv-qualified or 3206 // cv-unqualified object type and VQ is either volatile or 3207 // empty, there exist candidate operator functions of the form 3208 // 3209 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3210 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3211 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3212 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3213 QualType ParamTypes[2]; 3214 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3215 3216 // non-volatile version 3217 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3218 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3219 /*IsAssigmentOperator=*/Op == OO_Equal); 3220 3221 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3222 // volatile version 3223 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3224 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3225 /*IsAssigmentOperator=*/Op == OO_Equal); 3226 } 3227 } 3228 // Fall through. 3229 3230 case OO_StarEqual: 3231 case OO_SlashEqual: 3232 // C++ [over.built]p18: 3233 // 3234 // For every triple (L, VQ, R), where L is an arithmetic type, 3235 // VQ is either volatile or empty, and R is a promoted 3236 // arithmetic type, there exist candidate operator functions of 3237 // the form 3238 // 3239 // VQ L& operator=(VQ L&, R); 3240 // VQ L& operator*=(VQ L&, R); 3241 // VQ L& operator/=(VQ L&, R); 3242 // VQ L& operator+=(VQ L&, R); 3243 // VQ L& operator-=(VQ L&, R); 3244 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3245 for (unsigned Right = FirstPromotedArithmeticType; 3246 Right < LastPromotedArithmeticType; ++Right) { 3247 QualType ParamTypes[2]; 3248 ParamTypes[1] = ArithmeticTypes[Right]; 3249 3250 // Add this built-in operator as a candidate (VQ is empty). 3251 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3252 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3253 /*IsAssigmentOperator=*/Op == OO_Equal); 3254 3255 // Add this built-in operator as a candidate (VQ is 'volatile'). 3256 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3257 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3258 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3259 /*IsAssigmentOperator=*/Op == OO_Equal); 3260 } 3261 } 3262 break; 3263 3264 case OO_PercentEqual: 3265 case OO_LessLessEqual: 3266 case OO_GreaterGreaterEqual: 3267 case OO_AmpEqual: 3268 case OO_CaretEqual: 3269 case OO_PipeEqual: 3270 // C++ [over.built]p22: 3271 // 3272 // For every triple (L, VQ, R), where L is an integral type, VQ 3273 // is either volatile or empty, and R is a promoted integral 3274 // type, there exist candidate operator functions of the form 3275 // 3276 // VQ L& operator%=(VQ L&, R); 3277 // VQ L& operator<<=(VQ L&, R); 3278 // VQ L& operator>>=(VQ L&, R); 3279 // VQ L& operator&=(VQ L&, R); 3280 // VQ L& operator^=(VQ L&, R); 3281 // VQ L& operator|=(VQ L&, R); 3282 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3283 for (unsigned Right = FirstPromotedIntegralType; 3284 Right < LastPromotedIntegralType; ++Right) { 3285 QualType ParamTypes[2]; 3286 ParamTypes[1] = ArithmeticTypes[Right]; 3287 3288 // Add this built-in operator as a candidate (VQ is empty). 3289 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3290 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3291 3292 // Add this built-in operator as a candidate (VQ is 'volatile'). 3293 ParamTypes[0] = ArithmeticTypes[Left]; 3294 ParamTypes[0].addVolatile(); 3295 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3296 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3297 } 3298 } 3299 break; 3300 3301 case OO_Exclaim: { 3302 // C++ [over.operator]p23: 3303 // 3304 // There also exist candidate operator functions of the form 3305 // 3306 // bool operator!(bool); 3307 // bool operator&&(bool, bool); [BELOW] 3308 // bool operator||(bool, bool); [BELOW] 3309 QualType ParamTy = Context.BoolTy; 3310 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3311 /*IsAssignmentOperator=*/false, 3312 /*NumContextualBoolArguments=*/1); 3313 break; 3314 } 3315 3316 case OO_AmpAmp: 3317 case OO_PipePipe: { 3318 // C++ [over.operator]p23: 3319 // 3320 // There also exist candidate operator functions of the form 3321 // 3322 // bool operator!(bool); [ABOVE] 3323 // bool operator&&(bool, bool); 3324 // bool operator||(bool, bool); 3325 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3326 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3327 /*IsAssignmentOperator=*/false, 3328 /*NumContextualBoolArguments=*/2); 3329 break; 3330 } 3331 3332 case OO_Subscript: 3333 // C++ [over.built]p13: 3334 // 3335 // For every cv-qualified or cv-unqualified object type T there 3336 // exist candidate operator functions of the form 3337 // 3338 // T* operator+(T*, ptrdiff_t); [ABOVE] 3339 // T& operator[](T*, ptrdiff_t); 3340 // T* operator-(T*, ptrdiff_t); [ABOVE] 3341 // T* operator+(ptrdiff_t, T*); [ABOVE] 3342 // T& operator[](ptrdiff_t, T*); 3343 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3344 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3345 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3346 QualType PointeeType = (*Ptr)->getAsPointerType()->getPointeeType(); 3347 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3348 3349 // T& operator[](T*, ptrdiff_t) 3350 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3351 3352 // T& operator[](ptrdiff_t, T*); 3353 ParamTypes[0] = ParamTypes[1]; 3354 ParamTypes[1] = *Ptr; 3355 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3356 } 3357 break; 3358 3359 case OO_ArrowStar: 3360 // FIXME: No support for pointer-to-members yet. 3361 break; 3362 3363 case OO_Conditional: 3364 // Note that we don't consider the first argument, since it has been 3365 // contextually converted to bool long ago. The candidates below are 3366 // therefore added as binary. 3367 // 3368 // C++ [over.built]p24: 3369 // For every type T, where T is a pointer or pointer-to-member type, 3370 // there exist candidate operator functions of the form 3371 // 3372 // T operator?(bool, T, T); 3373 // 3374 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3375 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3376 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3377 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3378 } 3379 for (BuiltinCandidateTypeSet::iterator Ptr = 3380 CandidateTypes.member_pointer_begin(), 3381 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3382 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3383 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3384 } 3385 goto Conditional; 3386 } 3387} 3388 3389/// \brief Add function candidates found via argument-dependent lookup 3390/// to the set of overloading candidates. 3391/// 3392/// This routine performs argument-dependent name lookup based on the 3393/// given function name (which may also be an operator name) and adds 3394/// all of the overload candidates found by ADL to the overload 3395/// candidate set (C++ [basic.lookup.argdep]). 3396void 3397Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3398 Expr **Args, unsigned NumArgs, 3399 OverloadCandidateSet& CandidateSet) { 3400 FunctionSet Functions; 3401 3402 // Record all of the function candidates that we've already 3403 // added to the overload set, so that we don't add those same 3404 // candidates a second time. 3405 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3406 CandEnd = CandidateSet.end(); 3407 Cand != CandEnd; ++Cand) 3408 if (Cand->Function) 3409 Functions.insert(Cand->Function); 3410 3411 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3412 3413 // Erase all of the candidates we already knew about. 3414 // FIXME: This is suboptimal. Is there a better way? 3415 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3416 CandEnd = CandidateSet.end(); 3417 Cand != CandEnd; ++Cand) 3418 if (Cand->Function) 3419 Functions.erase(Cand->Function); 3420 3421 // For each of the ADL candidates we found, add it to the overload 3422 // set. 3423 for (FunctionSet::iterator Func = Functions.begin(), 3424 FuncEnd = Functions.end(); 3425 Func != FuncEnd; ++Func) 3426 AddOverloadCandidate(*Func, Args, NumArgs, CandidateSet); 3427} 3428 3429/// isBetterOverloadCandidate - Determines whether the first overload 3430/// candidate is a better candidate than the second (C++ 13.3.3p1). 3431bool 3432Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3433 const OverloadCandidate& Cand2) 3434{ 3435 // Define viable functions to be better candidates than non-viable 3436 // functions. 3437 if (!Cand2.Viable) 3438 return Cand1.Viable; 3439 else if (!Cand1.Viable) 3440 return false; 3441 3442 // C++ [over.match.best]p1: 3443 // 3444 // -- if F is a static member function, ICS1(F) is defined such 3445 // that ICS1(F) is neither better nor worse than ICS1(G) for 3446 // any function G, and, symmetrically, ICS1(G) is neither 3447 // better nor worse than ICS1(F). 3448 unsigned StartArg = 0; 3449 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3450 StartArg = 1; 3451 3452 // (C++ 13.3.3p1): a viable function F1 is defined to be a better 3453 // function than another viable function F2 if for all arguments i, 3454 // ICSi(F1) is not a worse conversion sequence than ICSi(F2), and 3455 // then... 3456 unsigned NumArgs = Cand1.Conversions.size(); 3457 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3458 bool HasBetterConversion = false; 3459 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3460 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3461 Cand2.Conversions[ArgIdx])) { 3462 case ImplicitConversionSequence::Better: 3463 // Cand1 has a better conversion sequence. 3464 HasBetterConversion = true; 3465 break; 3466 3467 case ImplicitConversionSequence::Worse: 3468 // Cand1 can't be better than Cand2. 3469 return false; 3470 3471 case ImplicitConversionSequence::Indistinguishable: 3472 // Do nothing. 3473 break; 3474 } 3475 } 3476 3477 if (HasBetterConversion) 3478 return true; 3479 3480 // FIXME: Several other bullets in (C++ 13.3.3p1) need to be 3481 // implemented, but they require template support. 3482 3483 // C++ [over.match.best]p1b4: 3484 // 3485 // -- the context is an initialization by user-defined conversion 3486 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3487 // from the return type of F1 to the destination type (i.e., 3488 // the type of the entity being initialized) is a better 3489 // conversion sequence than the standard conversion sequence 3490 // from the return type of F2 to the destination type. 3491 if (Cand1.Function && Cand2.Function && 3492 isa<CXXConversionDecl>(Cand1.Function) && 3493 isa<CXXConversionDecl>(Cand2.Function)) { 3494 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3495 Cand2.FinalConversion)) { 3496 case ImplicitConversionSequence::Better: 3497 // Cand1 has a better conversion sequence. 3498 return true; 3499 3500 case ImplicitConversionSequence::Worse: 3501 // Cand1 can't be better than Cand2. 3502 return false; 3503 3504 case ImplicitConversionSequence::Indistinguishable: 3505 // Do nothing 3506 break; 3507 } 3508 } 3509 3510 return false; 3511} 3512 3513/// \brief Computes the best viable function (C++ 13.3.3) 3514/// within an overload candidate set. 3515/// 3516/// \param CandidateSet the set of candidate functions. 3517/// 3518/// \param Loc the location of the function name (or operator symbol) for 3519/// which overload resolution occurs. 3520/// 3521/// \param Best f overload resolution was successful or found a deleted 3522/// function, Best points to the candidate function found. 3523/// 3524/// \returns The result of overload resolution. 3525Sema::OverloadingResult 3526Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3527 SourceLocation Loc, 3528 OverloadCandidateSet::iterator& Best) 3529{ 3530 // Find the best viable function. 3531 Best = CandidateSet.end(); 3532 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3533 Cand != CandidateSet.end(); ++Cand) { 3534 if (Cand->Viable) { 3535 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3536 Best = Cand; 3537 } 3538 } 3539 3540 // If we didn't find any viable functions, abort. 3541 if (Best == CandidateSet.end()) 3542 return OR_No_Viable_Function; 3543 3544 // Make sure that this function is better than every other viable 3545 // function. If not, we have an ambiguity. 3546 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3547 Cand != CandidateSet.end(); ++Cand) { 3548 if (Cand->Viable && 3549 Cand != Best && 3550 !isBetterOverloadCandidate(*Best, *Cand)) { 3551 Best = CandidateSet.end(); 3552 return OR_Ambiguous; 3553 } 3554 } 3555 3556 // Best is the best viable function. 3557 if (Best->Function && 3558 (Best->Function->isDeleted() || 3559 Best->Function->getAttr<UnavailableAttr>(Context))) 3560 return OR_Deleted; 3561 3562 // C++ [basic.def.odr]p2: 3563 // An overloaded function is used if it is selected by overload resolution 3564 // when referred to from a potentially-evaluated expression. [Note: this 3565 // covers calls to named functions (5.2.2), operator overloading 3566 // (clause 13), user-defined conversions (12.3.2), allocation function for 3567 // placement new (5.3.4), as well as non-default initialization (8.5). 3568 if (Best->Function) 3569 MarkDeclarationReferenced(Loc, Best->Function); 3570 return OR_Success; 3571} 3572 3573/// PrintOverloadCandidates - When overload resolution fails, prints 3574/// diagnostic messages containing the candidates in the candidate 3575/// set. If OnlyViable is true, only viable candidates will be printed. 3576void 3577Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3578 bool OnlyViable) 3579{ 3580 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3581 LastCand = CandidateSet.end(); 3582 for (; Cand != LastCand; ++Cand) { 3583 if (Cand->Viable || !OnlyViable) { 3584 if (Cand->Function) { 3585 if (Cand->Function->isDeleted() || 3586 Cand->Function->getAttr<UnavailableAttr>(Context)) { 3587 // Deleted or "unavailable" function. 3588 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3589 << Cand->Function->isDeleted(); 3590 } else { 3591 // Normal function 3592 // FIXME: Give a better reason! 3593 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3594 } 3595 } else if (Cand->IsSurrogate) { 3596 // Desugar the type of the surrogate down to a function type, 3597 // retaining as many typedefs as possible while still showing 3598 // the function type (and, therefore, its parameter types). 3599 QualType FnType = Cand->Surrogate->getConversionType(); 3600 bool isLValueReference = false; 3601 bool isRValueReference = false; 3602 bool isPointer = false; 3603 if (const LValueReferenceType *FnTypeRef = 3604 FnType->getAsLValueReferenceType()) { 3605 FnType = FnTypeRef->getPointeeType(); 3606 isLValueReference = true; 3607 } else if (const RValueReferenceType *FnTypeRef = 3608 FnType->getAsRValueReferenceType()) { 3609 FnType = FnTypeRef->getPointeeType(); 3610 isRValueReference = true; 3611 } 3612 if (const PointerType *FnTypePtr = FnType->getAsPointerType()) { 3613 FnType = FnTypePtr->getPointeeType(); 3614 isPointer = true; 3615 } 3616 // Desugar down to a function type. 3617 FnType = QualType(FnType->getAsFunctionType(), 0); 3618 // Reconstruct the pointer/reference as appropriate. 3619 if (isPointer) FnType = Context.getPointerType(FnType); 3620 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3621 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3622 3623 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3624 << FnType; 3625 } else { 3626 // FIXME: We need to get the identifier in here 3627 // FIXME: Do we want the error message to point at the operator? 3628 // (built-ins won't have a location) 3629 QualType FnType 3630 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3631 Cand->BuiltinTypes.ParamTypes, 3632 Cand->Conversions.size(), 3633 false, 0); 3634 3635 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3636 } 3637 } 3638 } 3639} 3640 3641/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3642/// an overloaded function (C++ [over.over]), where @p From is an 3643/// expression with overloaded function type and @p ToType is the type 3644/// we're trying to resolve to. For example: 3645/// 3646/// @code 3647/// int f(double); 3648/// int f(int); 3649/// 3650/// int (*pfd)(double) = f; // selects f(double) 3651/// @endcode 3652/// 3653/// This routine returns the resulting FunctionDecl if it could be 3654/// resolved, and NULL otherwise. When @p Complain is true, this 3655/// routine will emit diagnostics if there is an error. 3656FunctionDecl * 3657Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3658 bool Complain) { 3659 QualType FunctionType = ToType; 3660 bool IsMember = false; 3661 if (const PointerType *ToTypePtr = ToType->getAsPointerType()) 3662 FunctionType = ToTypePtr->getPointeeType(); 3663 else if (const ReferenceType *ToTypeRef = ToType->getAsReferenceType()) 3664 FunctionType = ToTypeRef->getPointeeType(); 3665 else if (const MemberPointerType *MemTypePtr = 3666 ToType->getAsMemberPointerType()) { 3667 FunctionType = MemTypePtr->getPointeeType(); 3668 IsMember = true; 3669 } 3670 3671 // We only look at pointers or references to functions. 3672 if (!FunctionType->isFunctionType()) 3673 return 0; 3674 3675 // Find the actual overloaded function declaration. 3676 OverloadedFunctionDecl *Ovl = 0; 3677 3678 // C++ [over.over]p1: 3679 // [...] [Note: any redundant set of parentheses surrounding the 3680 // overloaded function name is ignored (5.1). ] 3681 Expr *OvlExpr = From->IgnoreParens(); 3682 3683 // C++ [over.over]p1: 3684 // [...] The overloaded function name can be preceded by the & 3685 // operator. 3686 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3687 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3688 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3689 } 3690 3691 // Try to dig out the overloaded function. 3692 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) 3693 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3694 3695 // If there's no overloaded function declaration, we're done. 3696 if (!Ovl) 3697 return 0; 3698 3699 // Look through all of the overloaded functions, searching for one 3700 // whose type matches exactly. 3701 // FIXME: When templates or using declarations come along, we'll actually 3702 // have to deal with duplicates, partial ordering, etc. For now, we 3703 // can just do a simple search. 3704 FunctionType = Context.getCanonicalType(FunctionType.getUnqualifiedType()); 3705 for (OverloadedFunctionDecl::function_iterator Fun = Ovl->function_begin(); 3706 Fun != Ovl->function_end(); ++Fun) { 3707 // C++ [over.over]p3: 3708 // Non-member functions and static member functions match 3709 // targets of type "pointer-to-function" or "reference-to-function." 3710 // Nonstatic member functions match targets of 3711 // type "pointer-to-member-function." 3712 // Note that according to DR 247, the containing class does not matter. 3713 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 3714 // Skip non-static functions when converting to pointer, and static 3715 // when converting to member pointer. 3716 if (Method->isStatic() == IsMember) 3717 continue; 3718 } else if (IsMember) 3719 continue; 3720 3721 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 3722 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) 3723 return FunDecl; 3724 } else { 3725 unsigned DiagID 3726 = PP.getDiagnostics().getCustomDiagID(Diagnostic::Warning, 3727 "Clang does not yet support templated conversion functions"); 3728 Diag(From->getLocStart(), DiagID); 3729 } 3730 } 3731 3732 return 0; 3733} 3734 3735/// ResolveOverloadedCallFn - Given the call expression that calls Fn 3736/// (which eventually refers to the declaration Func) and the call 3737/// arguments Args/NumArgs, attempt to resolve the function call down 3738/// to a specific function. If overload resolution succeeds, returns 3739/// the function declaration produced by overload 3740/// resolution. Otherwise, emits diagnostics, deletes all of the 3741/// arguments and Fn, and returns NULL. 3742FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 3743 DeclarationName UnqualifiedName, 3744 SourceLocation LParenLoc, 3745 Expr **Args, unsigned NumArgs, 3746 SourceLocation *CommaLocs, 3747 SourceLocation RParenLoc, 3748 bool &ArgumentDependentLookup) { 3749 OverloadCandidateSet CandidateSet; 3750 3751 // Add the functions denoted by Callee to the set of candidate 3752 // functions. While we're doing so, track whether argument-dependent 3753 // lookup still applies, per: 3754 // 3755 // C++0x [basic.lookup.argdep]p3: 3756 // Let X be the lookup set produced by unqualified lookup (3.4.1) 3757 // and let Y be the lookup set produced by argument dependent 3758 // lookup (defined as follows). If X contains 3759 // 3760 // -- a declaration of a class member, or 3761 // 3762 // -- a block-scope function declaration that is not a 3763 // using-declaration, or 3764 // 3765 // -- a declaration that is neither a function or a function 3766 // template 3767 // 3768 // then Y is empty. 3769 if (OverloadedFunctionDecl *Ovl 3770 = dyn_cast_or_null<OverloadedFunctionDecl>(Callee)) { 3771 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 3772 FuncEnd = Ovl->function_end(); 3773 Func != FuncEnd; ++Func) { 3774 DeclContext *Ctx = 0; 3775 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Func)) { 3776 AddOverloadCandidate(FunDecl, Args, NumArgs, CandidateSet); 3777 Ctx = FunDecl->getDeclContext(); 3778 } else { 3779 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*Func); 3780 AddTemplateOverloadCandidate(FunTmpl, Args, NumArgs, CandidateSet); 3781 Ctx = FunTmpl->getDeclContext(); 3782 } 3783 3784 3785 if (Ctx->isRecord() || Ctx->isFunctionOrMethod()) 3786 ArgumentDependentLookup = false; 3787 } 3788 } else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee)) { 3789 AddOverloadCandidate(Func, Args, NumArgs, CandidateSet); 3790 3791 if (Func->getDeclContext()->isRecord() || 3792 Func->getDeclContext()->isFunctionOrMethod()) 3793 ArgumentDependentLookup = false; 3794 } else if (FunctionTemplateDecl *FuncTemplate 3795 = dyn_cast_or_null<FunctionTemplateDecl>(Callee)) { 3796 AddTemplateOverloadCandidate(FuncTemplate, Args, NumArgs, CandidateSet); 3797 3798 if (FuncTemplate->getDeclContext()->isRecord()) 3799 ArgumentDependentLookup = false; 3800 } 3801 3802 if (Callee) 3803 UnqualifiedName = Callee->getDeclName(); 3804 3805 if (ArgumentDependentLookup) 3806 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 3807 CandidateSet); 3808 3809 OverloadCandidateSet::iterator Best; 3810 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 3811 case OR_Success: 3812 return Best->Function; 3813 3814 case OR_No_Viable_Function: 3815 Diag(Fn->getSourceRange().getBegin(), 3816 diag::err_ovl_no_viable_function_in_call) 3817 << UnqualifiedName << Fn->getSourceRange(); 3818 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3819 break; 3820 3821 case OR_Ambiguous: 3822 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 3823 << UnqualifiedName << Fn->getSourceRange(); 3824 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3825 break; 3826 3827 case OR_Deleted: 3828 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 3829 << Best->Function->isDeleted() 3830 << UnqualifiedName 3831 << Fn->getSourceRange(); 3832 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3833 break; 3834 } 3835 3836 // Overload resolution failed. Destroy all of the subexpressions and 3837 // return NULL. 3838 Fn->Destroy(Context); 3839 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 3840 Args[Arg]->Destroy(Context); 3841 return 0; 3842} 3843 3844/// \brief Create a unary operation that may resolve to an overloaded 3845/// operator. 3846/// 3847/// \param OpLoc The location of the operator itself (e.g., '*'). 3848/// 3849/// \param OpcIn The UnaryOperator::Opcode that describes this 3850/// operator. 3851/// 3852/// \param Functions The set of non-member functions that will be 3853/// considered by overload resolution. The caller needs to build this 3854/// set based on the context using, e.g., 3855/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 3856/// set should not contain any member functions; those will be added 3857/// by CreateOverloadedUnaryOp(). 3858/// 3859/// \param input The input argument. 3860Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 3861 unsigned OpcIn, 3862 FunctionSet &Functions, 3863 ExprArg input) { 3864 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 3865 Expr *Input = (Expr *)input.get(); 3866 3867 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 3868 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 3869 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3870 3871 Expr *Args[2] = { Input, 0 }; 3872 unsigned NumArgs = 1; 3873 3874 // For post-increment and post-decrement, add the implicit '0' as 3875 // the second argument, so that we know this is a post-increment or 3876 // post-decrement. 3877 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 3878 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 3879 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 3880 SourceLocation()); 3881 NumArgs = 2; 3882 } 3883 3884 if (Input->isTypeDependent()) { 3885 OverloadedFunctionDecl *Overloads 3886 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 3887 for (FunctionSet::iterator Func = Functions.begin(), 3888 FuncEnd = Functions.end(); 3889 Func != FuncEnd; ++Func) 3890 Overloads->addOverload(*Func); 3891 3892 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 3893 OpLoc, false, false); 3894 3895 input.release(); 3896 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 3897 &Args[0], NumArgs, 3898 Context.DependentTy, 3899 OpLoc)); 3900 } 3901 3902 // Build an empty overload set. 3903 OverloadCandidateSet CandidateSet; 3904 3905 // Add the candidates from the given function set. 3906 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 3907 3908 // Add operator candidates that are member functions. 3909 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 3910 3911 // Add builtin operator candidates. 3912 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 3913 3914 // Perform overload resolution. 3915 OverloadCandidateSet::iterator Best; 3916 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 3917 case OR_Success: { 3918 // We found a built-in operator or an overloaded operator. 3919 FunctionDecl *FnDecl = Best->Function; 3920 3921 if (FnDecl) { 3922 // We matched an overloaded operator. Build a call to that 3923 // operator. 3924 3925 // Convert the arguments. 3926 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 3927 if (PerformObjectArgumentInitialization(Input, Method)) 3928 return ExprError(); 3929 } else { 3930 // Convert the arguments. 3931 if (PerformCopyInitialization(Input, 3932 FnDecl->getParamDecl(0)->getType(), 3933 "passing")) 3934 return ExprError(); 3935 } 3936 3937 // Determine the result type 3938 QualType ResultTy 3939 = FnDecl->getType()->getAsFunctionType()->getResultType(); 3940 ResultTy = ResultTy.getNonReferenceType(); 3941 3942 // Build the actual expression node. 3943 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 3944 SourceLocation()); 3945 UsualUnaryConversions(FnExpr); 3946 3947 input.release(); 3948 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 3949 &Input, 1, ResultTy, 3950 OpLoc)); 3951 } else { 3952 // We matched a built-in operator. Convert the arguments, then 3953 // break out so that we will build the appropriate built-in 3954 // operator node. 3955 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 3956 Best->Conversions[0], "passing")) 3957 return ExprError(); 3958 3959 break; 3960 } 3961 } 3962 3963 case OR_No_Viable_Function: 3964 // No viable function; fall through to handling this as a 3965 // built-in operator, which will produce an error message for us. 3966 break; 3967 3968 case OR_Ambiguous: 3969 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 3970 << UnaryOperator::getOpcodeStr(Opc) 3971 << Input->getSourceRange(); 3972 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3973 return ExprError(); 3974 3975 case OR_Deleted: 3976 Diag(OpLoc, diag::err_ovl_deleted_oper) 3977 << Best->Function->isDeleted() 3978 << UnaryOperator::getOpcodeStr(Opc) 3979 << Input->getSourceRange(); 3980 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3981 return ExprError(); 3982 } 3983 3984 // Either we found no viable overloaded operator or we matched a 3985 // built-in operator. In either case, fall through to trying to 3986 // build a built-in operation. 3987 input.release(); 3988 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 3989} 3990 3991/// \brief Create a binary operation that may resolve to an overloaded 3992/// operator. 3993/// 3994/// \param OpLoc The location of the operator itself (e.g., '+'). 3995/// 3996/// \param OpcIn The BinaryOperator::Opcode that describes this 3997/// operator. 3998/// 3999/// \param Functions The set of non-member functions that will be 4000/// considered by overload resolution. The caller needs to build this 4001/// set based on the context using, e.g., 4002/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4003/// set should not contain any member functions; those will be added 4004/// by CreateOverloadedBinOp(). 4005/// 4006/// \param LHS Left-hand argument. 4007/// \param RHS Right-hand argument. 4008Sema::OwningExprResult 4009Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4010 unsigned OpcIn, 4011 FunctionSet &Functions, 4012 Expr *LHS, Expr *RHS) { 4013 Expr *Args[2] = { LHS, RHS }; 4014 4015 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4016 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4017 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4018 4019 // If either side is type-dependent, create an appropriate dependent 4020 // expression. 4021 if (LHS->isTypeDependent() || RHS->isTypeDependent()) { 4022 // .* cannot be overloaded. 4023 if (Opc == BinaryOperator::PtrMemD) 4024 return Owned(new (Context) BinaryOperator(LHS, RHS, Opc, 4025 Context.DependentTy, OpLoc)); 4026 4027 OverloadedFunctionDecl *Overloads 4028 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4029 for (FunctionSet::iterator Func = Functions.begin(), 4030 FuncEnd = Functions.end(); 4031 Func != FuncEnd; ++Func) 4032 Overloads->addOverload(*Func); 4033 4034 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4035 OpLoc, false, false); 4036 4037 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4038 Args, 2, 4039 Context.DependentTy, 4040 OpLoc)); 4041 } 4042 4043 // If this is the .* operator, which is not overloadable, just 4044 // create a built-in binary operator. 4045 if (Opc == BinaryOperator::PtrMemD) 4046 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4047 4048 // If this is one of the assignment operators, we only perform 4049 // overload resolution if the left-hand side is a class or 4050 // enumeration type (C++ [expr.ass]p3). 4051 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4052 !LHS->getType()->isOverloadableType()) 4053 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4054 4055 // Build an empty overload set. 4056 OverloadCandidateSet CandidateSet; 4057 4058 // Add the candidates from the given function set. 4059 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4060 4061 // Add operator candidates that are member functions. 4062 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4063 4064 // Add builtin operator candidates. 4065 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4066 4067 // Perform overload resolution. 4068 OverloadCandidateSet::iterator Best; 4069 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4070 case OR_Success: { 4071 // We found a built-in operator or an overloaded operator. 4072 FunctionDecl *FnDecl = Best->Function; 4073 4074 if (FnDecl) { 4075 // We matched an overloaded operator. Build a call to that 4076 // operator. 4077 4078 // Convert the arguments. 4079 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4080 if (PerformObjectArgumentInitialization(LHS, Method) || 4081 PerformCopyInitialization(RHS, FnDecl->getParamDecl(0)->getType(), 4082 "passing")) 4083 return ExprError(); 4084 } else { 4085 // Convert the arguments. 4086 if (PerformCopyInitialization(LHS, FnDecl->getParamDecl(0)->getType(), 4087 "passing") || 4088 PerformCopyInitialization(RHS, FnDecl->getParamDecl(1)->getType(), 4089 "passing")) 4090 return ExprError(); 4091 } 4092 4093 // Determine the result type 4094 QualType ResultTy 4095 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4096 ResultTy = ResultTy.getNonReferenceType(); 4097 4098 // Build the actual expression node. 4099 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4100 SourceLocation()); 4101 UsualUnaryConversions(FnExpr); 4102 4103 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4104 Args, 2, ResultTy, 4105 OpLoc)); 4106 } else { 4107 // We matched a built-in operator. Convert the arguments, then 4108 // break out so that we will build the appropriate built-in 4109 // operator node. 4110 if (PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0], 4111 Best->Conversions[0], "passing") || 4112 PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1], 4113 Best->Conversions[1], "passing")) 4114 return ExprError(); 4115 4116 break; 4117 } 4118 } 4119 4120 case OR_No_Viable_Function: 4121 // For class as left operand for assignment or compound assigment operator 4122 // do not fall through to handling in built-in, but report that no overloaded 4123 // assignment operator found 4124 if (LHS->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4125 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4126 << BinaryOperator::getOpcodeStr(Opc) 4127 << LHS->getSourceRange() << RHS->getSourceRange(); 4128 return ExprError(); 4129 } 4130 // No viable function; fall through to handling this as a 4131 // built-in operator, which will produce an error message for us. 4132 break; 4133 4134 case OR_Ambiguous: 4135 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4136 << BinaryOperator::getOpcodeStr(Opc) 4137 << LHS->getSourceRange() << RHS->getSourceRange(); 4138 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4139 return ExprError(); 4140 4141 case OR_Deleted: 4142 Diag(OpLoc, diag::err_ovl_deleted_oper) 4143 << Best->Function->isDeleted() 4144 << BinaryOperator::getOpcodeStr(Opc) 4145 << LHS->getSourceRange() << RHS->getSourceRange(); 4146 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4147 return ExprError(); 4148 } 4149 4150 // Either we found no viable overloaded operator or we matched a 4151 // built-in operator. In either case, try to build a built-in 4152 // operation. 4153 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4154} 4155 4156/// BuildCallToMemberFunction - Build a call to a member 4157/// function. MemExpr is the expression that refers to the member 4158/// function (and includes the object parameter), Args/NumArgs are the 4159/// arguments to the function call (not including the object 4160/// parameter). The caller needs to validate that the member 4161/// expression refers to a member function or an overloaded member 4162/// function. 4163Sema::ExprResult 4164Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4165 SourceLocation LParenLoc, Expr **Args, 4166 unsigned NumArgs, SourceLocation *CommaLocs, 4167 SourceLocation RParenLoc) { 4168 // Dig out the member expression. This holds both the object 4169 // argument and the member function we're referring to. 4170 MemberExpr *MemExpr = 0; 4171 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4172 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4173 else 4174 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4175 assert(MemExpr && "Building member call without member expression"); 4176 4177 // Extract the object argument. 4178 Expr *ObjectArg = MemExpr->getBase(); 4179 4180 CXXMethodDecl *Method = 0; 4181 if (OverloadedFunctionDecl *Ovl 4182 = dyn_cast<OverloadedFunctionDecl>(MemExpr->getMemberDecl())) { 4183 // Add overload candidates 4184 OverloadCandidateSet CandidateSet; 4185 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4186 FuncEnd = Ovl->function_end(); 4187 Func != FuncEnd; ++Func) { 4188 assert(isa<CXXMethodDecl>(*Func) && "Function is not a method"); 4189 Method = cast<CXXMethodDecl>(*Func); 4190 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4191 /*SuppressUserConversions=*/false); 4192 } 4193 4194 OverloadCandidateSet::iterator Best; 4195 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4196 case OR_Success: 4197 Method = cast<CXXMethodDecl>(Best->Function); 4198 break; 4199 4200 case OR_No_Viable_Function: 4201 Diag(MemExpr->getSourceRange().getBegin(), 4202 diag::err_ovl_no_viable_member_function_in_call) 4203 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4204 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4205 // FIXME: Leaking incoming expressions! 4206 return true; 4207 4208 case OR_Ambiguous: 4209 Diag(MemExpr->getSourceRange().getBegin(), 4210 diag::err_ovl_ambiguous_member_call) 4211 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4212 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4213 // FIXME: Leaking incoming expressions! 4214 return true; 4215 4216 case OR_Deleted: 4217 Diag(MemExpr->getSourceRange().getBegin(), 4218 diag::err_ovl_deleted_member_call) 4219 << Best->Function->isDeleted() 4220 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4221 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4222 // FIXME: Leaking incoming expressions! 4223 return true; 4224 } 4225 4226 FixOverloadedFunctionReference(MemExpr, Method); 4227 } else { 4228 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4229 } 4230 4231 assert(Method && "Member call to something that isn't a method?"); 4232 ExprOwningPtr<CXXMemberCallExpr> 4233 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4234 NumArgs, 4235 Method->getResultType().getNonReferenceType(), 4236 RParenLoc)); 4237 4238 // Convert the object argument (for a non-static member function call). 4239 if (!Method->isStatic() && 4240 PerformObjectArgumentInitialization(ObjectArg, Method)) 4241 return true; 4242 MemExpr->setBase(ObjectArg); 4243 4244 // Convert the rest of the arguments 4245 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4246 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4247 RParenLoc)) 4248 return true; 4249 4250 return CheckFunctionCall(Method, TheCall.take()).release(); 4251} 4252 4253/// BuildCallToObjectOfClassType - Build a call to an object of class 4254/// type (C++ [over.call.object]), which can end up invoking an 4255/// overloaded function call operator (@c operator()) or performing a 4256/// user-defined conversion on the object argument. 4257Sema::ExprResult 4258Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4259 SourceLocation LParenLoc, 4260 Expr **Args, unsigned NumArgs, 4261 SourceLocation *CommaLocs, 4262 SourceLocation RParenLoc) { 4263 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4264 const RecordType *Record = Object->getType()->getAsRecordType(); 4265 4266 // C++ [over.call.object]p1: 4267 // If the primary-expression E in the function call syntax 4268 // evaluates to a class object of type “cv T”, then the set of 4269 // candidate functions includes at least the function call 4270 // operators of T. The function call operators of T are obtained by 4271 // ordinary lookup of the name operator() in the context of 4272 // (E).operator(). 4273 OverloadCandidateSet CandidateSet; 4274 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4275 DeclContext::lookup_const_iterator Oper, OperEnd; 4276 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(Context, OpName); 4277 Oper != OperEnd; ++Oper) 4278 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4279 CandidateSet, /*SuppressUserConversions=*/false); 4280 4281 // C++ [over.call.object]p2: 4282 // In addition, for each conversion function declared in T of the 4283 // form 4284 // 4285 // operator conversion-type-id () cv-qualifier; 4286 // 4287 // where cv-qualifier is the same cv-qualification as, or a 4288 // greater cv-qualification than, cv, and where conversion-type-id 4289 // denotes the type "pointer to function of (P1,...,Pn) returning 4290 // R", or the type "reference to pointer to function of 4291 // (P1,...,Pn) returning R", or the type "reference to function 4292 // of (P1,...,Pn) returning R", a surrogate call function [...] 4293 // is also considered as a candidate function. Similarly, 4294 // surrogate call functions are added to the set of candidate 4295 // functions for each conversion function declared in an 4296 // accessible base class provided the function is not hidden 4297 // within T by another intervening declaration. 4298 // 4299 // FIXME: Look in base classes for more conversion operators! 4300 OverloadedFunctionDecl *Conversions 4301 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4302 for (OverloadedFunctionDecl::function_iterator 4303 Func = Conversions->function_begin(), 4304 FuncEnd = Conversions->function_end(); 4305 Func != FuncEnd; ++Func) { 4306 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 4307 4308 // Strip the reference type (if any) and then the pointer type (if 4309 // any) to get down to what might be a function type. 4310 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4311 if (const PointerType *ConvPtrType = ConvType->getAsPointerType()) 4312 ConvType = ConvPtrType->getPointeeType(); 4313 4314 if (const FunctionProtoType *Proto = ConvType->getAsFunctionProtoType()) 4315 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4316 } 4317 4318 // Perform overload resolution. 4319 OverloadCandidateSet::iterator Best; 4320 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4321 case OR_Success: 4322 // Overload resolution succeeded; we'll build the appropriate call 4323 // below. 4324 break; 4325 4326 case OR_No_Viable_Function: 4327 Diag(Object->getSourceRange().getBegin(), 4328 diag::err_ovl_no_viable_object_call) 4329 << Object->getType() << Object->getSourceRange(); 4330 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4331 break; 4332 4333 case OR_Ambiguous: 4334 Diag(Object->getSourceRange().getBegin(), 4335 diag::err_ovl_ambiguous_object_call) 4336 << Object->getType() << Object->getSourceRange(); 4337 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4338 break; 4339 4340 case OR_Deleted: 4341 Diag(Object->getSourceRange().getBegin(), 4342 diag::err_ovl_deleted_object_call) 4343 << Best->Function->isDeleted() 4344 << Object->getType() << Object->getSourceRange(); 4345 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4346 break; 4347 } 4348 4349 if (Best == CandidateSet.end()) { 4350 // We had an error; delete all of the subexpressions and return 4351 // the error. 4352 Object->Destroy(Context); 4353 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4354 Args[ArgIdx]->Destroy(Context); 4355 return true; 4356 } 4357 4358 if (Best->Function == 0) { 4359 // Since there is no function declaration, this is one of the 4360 // surrogate candidates. Dig out the conversion function. 4361 CXXConversionDecl *Conv 4362 = cast<CXXConversionDecl>( 4363 Best->Conversions[0].UserDefined.ConversionFunction); 4364 4365 // We selected one of the surrogate functions that converts the 4366 // object parameter to a function pointer. Perform the conversion 4367 // on the object argument, then let ActOnCallExpr finish the job. 4368 // FIXME: Represent the user-defined conversion in the AST! 4369 ImpCastExprToType(Object, 4370 Conv->getConversionType().getNonReferenceType(), 4371 Conv->getConversionType()->isLValueReferenceType()); 4372 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4373 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4374 CommaLocs, RParenLoc).release(); 4375 } 4376 4377 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4378 // that calls this method, using Object for the implicit object 4379 // parameter and passing along the remaining arguments. 4380 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4381 const FunctionProtoType *Proto = Method->getType()->getAsFunctionProtoType(); 4382 4383 unsigned NumArgsInProto = Proto->getNumArgs(); 4384 unsigned NumArgsToCheck = NumArgs; 4385 4386 // Build the full argument list for the method call (the 4387 // implicit object parameter is placed at the beginning of the 4388 // list). 4389 Expr **MethodArgs; 4390 if (NumArgs < NumArgsInProto) { 4391 NumArgsToCheck = NumArgsInProto; 4392 MethodArgs = new Expr*[NumArgsInProto + 1]; 4393 } else { 4394 MethodArgs = new Expr*[NumArgs + 1]; 4395 } 4396 MethodArgs[0] = Object; 4397 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4398 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4399 4400 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4401 SourceLocation()); 4402 UsualUnaryConversions(NewFn); 4403 4404 // Once we've built TheCall, all of the expressions are properly 4405 // owned. 4406 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4407 ExprOwningPtr<CXXOperatorCallExpr> 4408 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4409 MethodArgs, NumArgs + 1, 4410 ResultTy, RParenLoc)); 4411 delete [] MethodArgs; 4412 4413 // We may have default arguments. If so, we need to allocate more 4414 // slots in the call for them. 4415 if (NumArgs < NumArgsInProto) 4416 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4417 else if (NumArgs > NumArgsInProto) 4418 NumArgsToCheck = NumArgsInProto; 4419 4420 bool IsError = false; 4421 4422 // Initialize the implicit object parameter. 4423 IsError |= PerformObjectArgumentInitialization(Object, Method); 4424 TheCall->setArg(0, Object); 4425 4426 4427 // Check the argument types. 4428 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4429 Expr *Arg; 4430 if (i < NumArgs) { 4431 Arg = Args[i]; 4432 4433 // Pass the argument. 4434 QualType ProtoArgType = Proto->getArgType(i); 4435 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4436 } else { 4437 Arg = new (Context) CXXDefaultArgExpr(Method->getParamDecl(i)); 4438 } 4439 4440 TheCall->setArg(i + 1, Arg); 4441 } 4442 4443 // If this is a variadic call, handle args passed through "...". 4444 if (Proto->isVariadic()) { 4445 // Promote the arguments (C99 6.5.2.2p7). 4446 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4447 Expr *Arg = Args[i]; 4448 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4449 TheCall->setArg(i + 1, Arg); 4450 } 4451 } 4452 4453 if (IsError) return true; 4454 4455 return CheckFunctionCall(Method, TheCall.take()).release(); 4456} 4457 4458/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4459/// (if one exists), where @c Base is an expression of class type and 4460/// @c Member is the name of the member we're trying to find. 4461Action::ExprResult 4462Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc, 4463 SourceLocation MemberLoc, 4464 IdentifierInfo &Member) { 4465 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4466 4467 // C++ [over.ref]p1: 4468 // 4469 // [...] An expression x->m is interpreted as (x.operator->())->m 4470 // for a class object x of type T if T::operator->() exists and if 4471 // the operator is selected as the best match function by the 4472 // overload resolution mechanism (13.3). 4473 // FIXME: look in base classes. 4474 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4475 OverloadCandidateSet CandidateSet; 4476 const RecordType *BaseRecord = Base->getType()->getAsRecordType(); 4477 4478 DeclContext::lookup_const_iterator Oper, OperEnd; 4479 for (llvm::tie(Oper, OperEnd) 4480 = BaseRecord->getDecl()->lookup(Context, OpName); 4481 Oper != OperEnd; ++Oper) 4482 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4483 /*SuppressUserConversions=*/false); 4484 4485 ExprOwningPtr<Expr> BasePtr(this, Base); 4486 4487 // Perform overload resolution. 4488 OverloadCandidateSet::iterator Best; 4489 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4490 case OR_Success: 4491 // Overload resolution succeeded; we'll build the call below. 4492 break; 4493 4494 case OR_No_Viable_Function: 4495 if (CandidateSet.empty()) 4496 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4497 << BasePtr->getType() << BasePtr->getSourceRange(); 4498 else 4499 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4500 << "operator->" << BasePtr->getSourceRange(); 4501 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4502 return true; 4503 4504 case OR_Ambiguous: 4505 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4506 << "operator->" << BasePtr->getSourceRange(); 4507 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4508 return true; 4509 4510 case OR_Deleted: 4511 Diag(OpLoc, diag::err_ovl_deleted_oper) 4512 << Best->Function->isDeleted() 4513 << "operator->" << BasePtr->getSourceRange(); 4514 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4515 return true; 4516 } 4517 4518 // Convert the object parameter. 4519 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4520 if (PerformObjectArgumentInitialization(Base, Method)) 4521 return true; 4522 4523 // No concerns about early exits now. 4524 BasePtr.take(); 4525 4526 // Build the operator call. 4527 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 4528 SourceLocation()); 4529 UsualUnaryConversions(FnExpr); 4530 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 4531 Method->getResultType().getNonReferenceType(), 4532 OpLoc); 4533 return ActOnMemberReferenceExpr(S, ExprArg(*this, Base), OpLoc, tok::arrow, 4534 MemberLoc, Member, DeclPtrTy()).release(); 4535} 4536 4537/// FixOverloadedFunctionReference - E is an expression that refers to 4538/// a C++ overloaded function (possibly with some parentheses and 4539/// perhaps a '&' around it). We have resolved the overloaded function 4540/// to the function declaration Fn, so patch up the expression E to 4541/// refer (possibly indirectly) to Fn. 4542void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 4543 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4544 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 4545 E->setType(PE->getSubExpr()->getType()); 4546 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 4547 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 4548 "Can only take the address of an overloaded function"); 4549 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4550 if (Method->isStatic()) { 4551 // Do nothing: static member functions aren't any different 4552 // from non-member functions. 4553 } 4554 else if (QualifiedDeclRefExpr *DRE 4555 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 4556 // We have taken the address of a pointer to member 4557 // function. Perform the computation here so that we get the 4558 // appropriate pointer to member type. 4559 DRE->setDecl(Fn); 4560 DRE->setType(Fn->getType()); 4561 QualType ClassType 4562 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 4563 E->setType(Context.getMemberPointerType(Fn->getType(), 4564 ClassType.getTypePtr())); 4565 return; 4566 } 4567 } 4568 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 4569 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 4570 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 4571 assert(isa<OverloadedFunctionDecl>(DR->getDecl()) && 4572 "Expected overloaded function"); 4573 DR->setDecl(Fn); 4574 E->setType(Fn->getType()); 4575 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 4576 MemExpr->setMemberDecl(Fn); 4577 E->setType(Fn->getType()); 4578 } else { 4579 assert(false && "Invalid reference to overloaded function"); 4580 } 4581} 4582 4583} // end namespace clang 4584