SemaOverload.cpp revision cca21b8ae5bb22ca9625ce96bdc858853bd57123
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 // First, we handle all conversions on ObjC object pointer types. 1009 const ObjCObjectPointerType* ToObjCPtr = ToType->getAsObjCObjectPointerType(); 1010 const ObjCObjectPointerType *FromObjCPtr = 1011 FromType->getAsObjCObjectPointerType(); 1012 1013 if (ToObjCPtr && FromObjCPtr) { 1014 // Objective C++: We're able to convert between "id" and a pointer 1015 // to any interface (in both directions). 1016 if (ToObjCPtr->isObjCIdType() && FromObjCPtr->isObjCIdType()) { 1017 ConvertedType = ToType; 1018 return true; 1019 } 1020 // Objective C++: Allow conversions between the Objective-C "Class" and a 1021 // pointer to any interface (in both directions). 1022 if (ToObjCPtr->isObjCClassType() || FromObjCPtr->isObjCClassType()) { 1023 ConvertedType = ToType; 1024 return true; 1025 } 1026 // Conversions with Objective-C's id<...>. 1027 if ((FromObjCPtr->isObjCQualifiedIdType() || 1028 ToObjCPtr->isObjCQualifiedIdType()) && 1029 ObjCQualifiedIdTypesAreCompatible(ToType, FromType, /*compare=*/false)) { 1030 ConvertedType = ToType; 1031 return true; 1032 } 1033 // Objective C++: We're able to convert from a pointer to an 1034 // interface to a pointer to a different interface. 1035 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1036 ConvertedType = ToType; 1037 return true; 1038 } 1039 1040 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1041 // Okay: this is some kind of implicit downcast of Objective-C 1042 // interfaces, which is permitted. However, we're going to 1043 // complain about it. 1044 IncompatibleObjC = true; 1045 ConvertedType = FromType; 1046 return true; 1047 } 1048 } 1049 // Beyond this point, both types need to be C pointers or block pointers. 1050 QualType ToPointeeType; 1051 if (const PointerType *ToCPtr = ToType->getAsPointerType()) 1052 ToPointeeType = ToCPtr->getPointeeType(); 1053 else if (const BlockPointerType *ToBlockPtr = ToType->getAsBlockPointerType()) 1054 ToPointeeType = ToBlockPtr->getPointeeType(); 1055 else 1056 return false; 1057 1058 QualType FromPointeeType; 1059 if (const PointerType *FromCPtr = FromType->getAsPointerType()) 1060 FromPointeeType = FromCPtr->getPointeeType(); 1061 else if (const BlockPointerType *FromBlockPtr = FromType->getAsBlockPointerType()) 1062 FromPointeeType = FromBlockPtr->getPointeeType(); 1063 else 1064 return false; 1065 1066 // If we have pointers to pointers, recursively check whether this 1067 // is an Objective-C conversion. 1068 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1069 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1070 IncompatibleObjC)) { 1071 // We always complain about this conversion. 1072 IncompatibleObjC = true; 1073 ConvertedType = ToType; 1074 return true; 1075 } 1076 // If we have pointers to functions or blocks, check whether the only 1077 // differences in the argument and result types are in Objective-C 1078 // pointer conversions. If so, we permit the conversion (but 1079 // complain about it). 1080 const FunctionProtoType *FromFunctionType 1081 = FromPointeeType->getAsFunctionProtoType(); 1082 const FunctionProtoType *ToFunctionType 1083 = ToPointeeType->getAsFunctionProtoType(); 1084 if (FromFunctionType && ToFunctionType) { 1085 // If the function types are exactly the same, this isn't an 1086 // Objective-C pointer conversion. 1087 if (Context.getCanonicalType(FromPointeeType) 1088 == Context.getCanonicalType(ToPointeeType)) 1089 return false; 1090 1091 // Perform the quick checks that will tell us whether these 1092 // function types are obviously different. 1093 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1094 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1095 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1096 return false; 1097 1098 bool HasObjCConversion = false; 1099 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1100 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1101 // Okay, the types match exactly. Nothing to do. 1102 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1103 ToFunctionType->getResultType(), 1104 ConvertedType, IncompatibleObjC)) { 1105 // Okay, we have an Objective-C pointer conversion. 1106 HasObjCConversion = true; 1107 } else { 1108 // Function types are too different. Abort. 1109 return false; 1110 } 1111 1112 // Check argument types. 1113 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1114 ArgIdx != NumArgs; ++ArgIdx) { 1115 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1116 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1117 if (Context.getCanonicalType(FromArgType) 1118 == Context.getCanonicalType(ToArgType)) { 1119 // Okay, the types match exactly. Nothing to do. 1120 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1121 ConvertedType, IncompatibleObjC)) { 1122 // Okay, we have an Objective-C pointer conversion. 1123 HasObjCConversion = true; 1124 } else { 1125 // Argument types are too different. Abort. 1126 return false; 1127 } 1128 } 1129 1130 if (HasObjCConversion) { 1131 // We had an Objective-C conversion. Allow this pointer 1132 // conversion, but complain about it. 1133 ConvertedType = ToType; 1134 IncompatibleObjC = true; 1135 return true; 1136 } 1137 } 1138 1139 return false; 1140} 1141 1142/// CheckPointerConversion - Check the pointer conversion from the 1143/// expression From to the type ToType. This routine checks for 1144/// ambiguous (FIXME: or inaccessible) derived-to-base pointer 1145/// conversions for which IsPointerConversion has already returned 1146/// true. It returns true and produces a diagnostic if there was an 1147/// error, or returns false otherwise. 1148bool Sema::CheckPointerConversion(Expr *From, QualType ToType) { 1149 QualType FromType = From->getType(); 1150 1151 if (const PointerType *FromPtrType = FromType->getAsPointerType()) 1152 if (const PointerType *ToPtrType = ToType->getAsPointerType()) { 1153 QualType FromPointeeType = FromPtrType->getPointeeType(), 1154 ToPointeeType = ToPtrType->getPointeeType(); 1155 1156 if (FromPointeeType->isRecordType() && 1157 ToPointeeType->isRecordType()) { 1158 // We must have a derived-to-base conversion. Check an 1159 // ambiguous or inaccessible conversion. 1160 return CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1161 From->getExprLoc(), 1162 From->getSourceRange()); 1163 } 1164 } 1165 if (const ObjCObjectPointerType *FromPtrType = 1166 FromType->getAsObjCObjectPointerType()) 1167 if (const ObjCObjectPointerType *ToPtrType = 1168 ToType->getAsObjCObjectPointerType()) { 1169 // Objective-C++ conversions are always okay. 1170 // FIXME: We should have a different class of conversions for the 1171 // Objective-C++ implicit conversions. 1172 if (FromPtrType->isObjCIdType() || ToPtrType->isObjCIdType() || 1173 FromPtrType->isObjCClassType() || ToPtrType->isObjCClassType()) 1174 return false; 1175 1176 } 1177 return false; 1178} 1179 1180/// IsMemberPointerConversion - Determines whether the conversion of the 1181/// expression From, which has the (possibly adjusted) type FromType, can be 1182/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1183/// If so, returns true and places the converted type (that might differ from 1184/// ToType in its cv-qualifiers at some level) into ConvertedType. 1185bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1186 QualType ToType, QualType &ConvertedType) 1187{ 1188 const MemberPointerType *ToTypePtr = ToType->getAsMemberPointerType(); 1189 if (!ToTypePtr) 1190 return false; 1191 1192 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1193 if (From->isNullPointerConstant(Context)) { 1194 ConvertedType = ToType; 1195 return true; 1196 } 1197 1198 // Otherwise, both types have to be member pointers. 1199 const MemberPointerType *FromTypePtr = FromType->getAsMemberPointerType(); 1200 if (!FromTypePtr) 1201 return false; 1202 1203 // A pointer to member of B can be converted to a pointer to member of D, 1204 // where D is derived from B (C++ 4.11p2). 1205 QualType FromClass(FromTypePtr->getClass(), 0); 1206 QualType ToClass(ToTypePtr->getClass(), 0); 1207 // FIXME: What happens when these are dependent? Is this function even called? 1208 1209 if (IsDerivedFrom(ToClass, FromClass)) { 1210 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1211 ToClass.getTypePtr()); 1212 return true; 1213 } 1214 1215 return false; 1216} 1217 1218/// CheckMemberPointerConversion - Check the member pointer conversion from the 1219/// expression From to the type ToType. This routine checks for ambiguous or 1220/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1221/// for which IsMemberPointerConversion has already returned true. It returns 1222/// true and produces a diagnostic if there was an error, or returns false 1223/// otherwise. 1224bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType) { 1225 QualType FromType = From->getType(); 1226 const MemberPointerType *FromPtrType = FromType->getAsMemberPointerType(); 1227 if (!FromPtrType) 1228 return false; 1229 1230 const MemberPointerType *ToPtrType = ToType->getAsMemberPointerType(); 1231 assert(ToPtrType && "No member pointer cast has a target type " 1232 "that is not a member pointer."); 1233 1234 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1235 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1236 1237 // FIXME: What about dependent types? 1238 assert(FromClass->isRecordType() && "Pointer into non-class."); 1239 assert(ToClass->isRecordType() && "Pointer into non-class."); 1240 1241 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1242 /*DetectVirtual=*/true); 1243 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1244 assert(DerivationOkay && 1245 "Should not have been called if derivation isn't OK."); 1246 (void)DerivationOkay; 1247 1248 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1249 getUnqualifiedType())) { 1250 // Derivation is ambiguous. Redo the check to find the exact paths. 1251 Paths.clear(); 1252 Paths.setRecordingPaths(true); 1253 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1254 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1255 (void)StillOkay; 1256 1257 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1258 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1259 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1260 return true; 1261 } 1262 1263 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1264 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1265 << FromClass << ToClass << QualType(VBase, 0) 1266 << From->getSourceRange(); 1267 return true; 1268 } 1269 1270 return false; 1271} 1272 1273/// IsQualificationConversion - Determines whether the conversion from 1274/// an rvalue of type FromType to ToType is a qualification conversion 1275/// (C++ 4.4). 1276bool 1277Sema::IsQualificationConversion(QualType FromType, QualType ToType) 1278{ 1279 FromType = Context.getCanonicalType(FromType); 1280 ToType = Context.getCanonicalType(ToType); 1281 1282 // If FromType and ToType are the same type, this is not a 1283 // qualification conversion. 1284 if (FromType == ToType) 1285 return false; 1286 1287 // (C++ 4.4p4): 1288 // A conversion can add cv-qualifiers at levels other than the first 1289 // in multi-level pointers, subject to the following rules: [...] 1290 bool PreviousToQualsIncludeConst = true; 1291 bool UnwrappedAnyPointer = false; 1292 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1293 // Within each iteration of the loop, we check the qualifiers to 1294 // determine if this still looks like a qualification 1295 // conversion. Then, if all is well, we unwrap one more level of 1296 // pointers or pointers-to-members and do it all again 1297 // until there are no more pointers or pointers-to-members left to 1298 // unwrap. 1299 UnwrappedAnyPointer = true; 1300 1301 // -- for every j > 0, if const is in cv 1,j then const is in cv 1302 // 2,j, and similarly for volatile. 1303 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1304 return false; 1305 1306 // -- if the cv 1,j and cv 2,j are different, then const is in 1307 // every cv for 0 < k < j. 1308 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1309 && !PreviousToQualsIncludeConst) 1310 return false; 1311 1312 // Keep track of whether all prior cv-qualifiers in the "to" type 1313 // include const. 1314 PreviousToQualsIncludeConst 1315 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1316 } 1317 1318 // We are left with FromType and ToType being the pointee types 1319 // after unwrapping the original FromType and ToType the same number 1320 // of types. If we unwrapped any pointers, and if FromType and 1321 // ToType have the same unqualified type (since we checked 1322 // qualifiers above), then this is a qualification conversion. 1323 return UnwrappedAnyPointer && 1324 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1325} 1326 1327/// Determines whether there is a user-defined conversion sequence 1328/// (C++ [over.ics.user]) that converts expression From to the type 1329/// ToType. If such a conversion exists, User will contain the 1330/// user-defined conversion sequence that performs such a conversion 1331/// and this routine will return true. Otherwise, this routine returns 1332/// false and User is unspecified. 1333/// 1334/// \param AllowConversionFunctions true if the conversion should 1335/// consider conversion functions at all. If false, only constructors 1336/// will be considered. 1337/// 1338/// \param AllowExplicit true if the conversion should consider C++0x 1339/// "explicit" conversion functions as well as non-explicit conversion 1340/// functions (C++0x [class.conv.fct]p2). 1341/// 1342/// \param ForceRValue true if the expression should be treated as an rvalue 1343/// for overload resolution. 1344bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1345 UserDefinedConversionSequence& User, 1346 bool AllowConversionFunctions, 1347 bool AllowExplicit, bool ForceRValue) 1348{ 1349 OverloadCandidateSet CandidateSet; 1350 if (const RecordType *ToRecordType = ToType->getAsRecordType()) { 1351 if (CXXRecordDecl *ToRecordDecl 1352 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1353 // C++ [over.match.ctor]p1: 1354 // When objects of class type are direct-initialized (8.5), or 1355 // copy-initialized from an expression of the same or a 1356 // derived class type (8.5), overload resolution selects the 1357 // constructor. [...] For copy-initialization, the candidate 1358 // functions are all the converting constructors (12.3.1) of 1359 // that class. The argument list is the expression-list within 1360 // the parentheses of the initializer. 1361 DeclarationName ConstructorName 1362 = Context.DeclarationNames.getCXXConstructorName( 1363 Context.getCanonicalType(ToType).getUnqualifiedType()); 1364 DeclContext::lookup_iterator Con, ConEnd; 1365 for (llvm::tie(Con, ConEnd) 1366 = ToRecordDecl->lookup(ConstructorName); 1367 Con != ConEnd; ++Con) { 1368 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 1369 if (Constructor->isConvertingConstructor()) 1370 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1371 /*SuppressUserConversions=*/true, ForceRValue); 1372 } 1373 } 1374 } 1375 1376 if (!AllowConversionFunctions) { 1377 // Don't allow any conversion functions to enter the overload set. 1378 } else if (const RecordType *FromRecordType 1379 = From->getType()->getAsRecordType()) { 1380 if (CXXRecordDecl *FromRecordDecl 1381 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1382 // Add all of the conversion functions as candidates. 1383 // FIXME: Look for conversions in base classes! 1384 OverloadedFunctionDecl *Conversions 1385 = FromRecordDecl->getConversionFunctions(); 1386 for (OverloadedFunctionDecl::function_iterator Func 1387 = Conversions->function_begin(); 1388 Func != Conversions->function_end(); ++Func) { 1389 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 1390 if (AllowExplicit || !Conv->isExplicit()) 1391 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1392 } 1393 } 1394 } 1395 1396 OverloadCandidateSet::iterator Best; 1397 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1398 case OR_Success: 1399 // Record the standard conversion we used and the conversion function. 1400 if (CXXConstructorDecl *Constructor 1401 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1402 // C++ [over.ics.user]p1: 1403 // If the user-defined conversion is specified by a 1404 // constructor (12.3.1), the initial standard conversion 1405 // sequence converts the source type to the type required by 1406 // the argument of the constructor. 1407 // 1408 // FIXME: What about ellipsis conversions? 1409 QualType ThisType = Constructor->getThisType(Context); 1410 User.Before = Best->Conversions[0].Standard; 1411 User.ConversionFunction = Constructor; 1412 User.After.setAsIdentityConversion(); 1413 User.After.FromTypePtr 1414 = ThisType->getAsPointerType()->getPointeeType().getAsOpaquePtr(); 1415 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1416 return true; 1417 } else if (CXXConversionDecl *Conversion 1418 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1419 // C++ [over.ics.user]p1: 1420 // 1421 // [...] If the user-defined conversion is specified by a 1422 // conversion function (12.3.2), the initial standard 1423 // conversion sequence converts the source type to the 1424 // implicit object parameter of the conversion function. 1425 User.Before = Best->Conversions[0].Standard; 1426 User.ConversionFunction = Conversion; 1427 1428 // C++ [over.ics.user]p2: 1429 // The second standard conversion sequence converts the 1430 // result of the user-defined conversion to the target type 1431 // for the sequence. Since an implicit conversion sequence 1432 // is an initialization, the special rules for 1433 // initialization by user-defined conversion apply when 1434 // selecting the best user-defined conversion for a 1435 // user-defined conversion sequence (see 13.3.3 and 1436 // 13.3.3.1). 1437 User.After = Best->FinalConversion; 1438 return true; 1439 } else { 1440 assert(false && "Not a constructor or conversion function?"); 1441 return false; 1442 } 1443 1444 case OR_No_Viable_Function: 1445 case OR_Deleted: 1446 // No conversion here! We're done. 1447 return false; 1448 1449 case OR_Ambiguous: 1450 // FIXME: See C++ [over.best.ics]p10 for the handling of 1451 // ambiguous conversion sequences. 1452 return false; 1453 } 1454 1455 return false; 1456} 1457 1458/// CompareImplicitConversionSequences - Compare two implicit 1459/// conversion sequences to determine whether one is better than the 1460/// other or if they are indistinguishable (C++ 13.3.3.2). 1461ImplicitConversionSequence::CompareKind 1462Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1463 const ImplicitConversionSequence& ICS2) 1464{ 1465 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1466 // conversion sequences (as defined in 13.3.3.1) 1467 // -- a standard conversion sequence (13.3.3.1.1) is a better 1468 // conversion sequence than a user-defined conversion sequence or 1469 // an ellipsis conversion sequence, and 1470 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1471 // conversion sequence than an ellipsis conversion sequence 1472 // (13.3.3.1.3). 1473 // 1474 if (ICS1.ConversionKind < ICS2.ConversionKind) 1475 return ImplicitConversionSequence::Better; 1476 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1477 return ImplicitConversionSequence::Worse; 1478 1479 // Two implicit conversion sequences of the same form are 1480 // indistinguishable conversion sequences unless one of the 1481 // following rules apply: (C++ 13.3.3.2p3): 1482 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1483 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1484 else if (ICS1.ConversionKind == 1485 ImplicitConversionSequence::UserDefinedConversion) { 1486 // User-defined conversion sequence U1 is a better conversion 1487 // sequence than another user-defined conversion sequence U2 if 1488 // they contain the same user-defined conversion function or 1489 // constructor and if the second standard conversion sequence of 1490 // U1 is better than the second standard conversion sequence of 1491 // U2 (C++ 13.3.3.2p3). 1492 if (ICS1.UserDefined.ConversionFunction == 1493 ICS2.UserDefined.ConversionFunction) 1494 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1495 ICS2.UserDefined.After); 1496 } 1497 1498 return ImplicitConversionSequence::Indistinguishable; 1499} 1500 1501/// CompareStandardConversionSequences - Compare two standard 1502/// conversion sequences to determine whether one is better than the 1503/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1504ImplicitConversionSequence::CompareKind 1505Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1506 const StandardConversionSequence& SCS2) 1507{ 1508 // Standard conversion sequence S1 is a better conversion sequence 1509 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1510 1511 // -- S1 is a proper subsequence of S2 (comparing the conversion 1512 // sequences in the canonical form defined by 13.3.3.1.1, 1513 // excluding any Lvalue Transformation; the identity conversion 1514 // sequence is considered to be a subsequence of any 1515 // non-identity conversion sequence) or, if not that, 1516 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1517 // Neither is a proper subsequence of the other. Do nothing. 1518 ; 1519 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1520 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1521 (SCS1.Second == ICK_Identity && 1522 SCS1.Third == ICK_Identity)) 1523 // SCS1 is a proper subsequence of SCS2. 1524 return ImplicitConversionSequence::Better; 1525 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1526 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1527 (SCS2.Second == ICK_Identity && 1528 SCS2.Third == ICK_Identity)) 1529 // SCS2 is a proper subsequence of SCS1. 1530 return ImplicitConversionSequence::Worse; 1531 1532 // -- the rank of S1 is better than the rank of S2 (by the rules 1533 // defined below), or, if not that, 1534 ImplicitConversionRank Rank1 = SCS1.getRank(); 1535 ImplicitConversionRank Rank2 = SCS2.getRank(); 1536 if (Rank1 < Rank2) 1537 return ImplicitConversionSequence::Better; 1538 else if (Rank2 < Rank1) 1539 return ImplicitConversionSequence::Worse; 1540 1541 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1542 // are indistinguishable unless one of the following rules 1543 // applies: 1544 1545 // A conversion that is not a conversion of a pointer, or 1546 // pointer to member, to bool is better than another conversion 1547 // that is such a conversion. 1548 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1549 return SCS2.isPointerConversionToBool() 1550 ? ImplicitConversionSequence::Better 1551 : ImplicitConversionSequence::Worse; 1552 1553 // C++ [over.ics.rank]p4b2: 1554 // 1555 // If class B is derived directly or indirectly from class A, 1556 // conversion of B* to A* is better than conversion of B* to 1557 // void*, and conversion of A* to void* is better than conversion 1558 // of B* to void*. 1559 bool SCS1ConvertsToVoid 1560 = SCS1.isPointerConversionToVoidPointer(Context); 1561 bool SCS2ConvertsToVoid 1562 = SCS2.isPointerConversionToVoidPointer(Context); 1563 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1564 // Exactly one of the conversion sequences is a conversion to 1565 // a void pointer; it's the worse conversion. 1566 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1567 : ImplicitConversionSequence::Worse; 1568 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1569 // Neither conversion sequence converts to a void pointer; compare 1570 // their derived-to-base conversions. 1571 if (ImplicitConversionSequence::CompareKind DerivedCK 1572 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1573 return DerivedCK; 1574 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1575 // Both conversion sequences are conversions to void 1576 // pointers. Compare the source types to determine if there's an 1577 // inheritance relationship in their sources. 1578 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1579 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1580 1581 // Adjust the types we're converting from via the array-to-pointer 1582 // conversion, if we need to. 1583 if (SCS1.First == ICK_Array_To_Pointer) 1584 FromType1 = Context.getArrayDecayedType(FromType1); 1585 if (SCS2.First == ICK_Array_To_Pointer) 1586 FromType2 = Context.getArrayDecayedType(FromType2); 1587 1588 QualType FromPointee1 1589 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1590 QualType FromPointee2 1591 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1592 1593 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1594 return ImplicitConversionSequence::Better; 1595 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1596 return ImplicitConversionSequence::Worse; 1597 1598 // Objective-C++: If one interface is more specific than the 1599 // other, it is the better one. 1600 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1601 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1602 if (FromIface1 && FromIface1) { 1603 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1604 return ImplicitConversionSequence::Better; 1605 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1606 return ImplicitConversionSequence::Worse; 1607 } 1608 } 1609 1610 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1611 // bullet 3). 1612 if (ImplicitConversionSequence::CompareKind QualCK 1613 = CompareQualificationConversions(SCS1, SCS2)) 1614 return QualCK; 1615 1616 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1617 // C++0x [over.ics.rank]p3b4: 1618 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1619 // implicit object parameter of a non-static member function declared 1620 // without a ref-qualifier, and S1 binds an rvalue reference to an 1621 // rvalue and S2 binds an lvalue reference. 1622 // FIXME: We don't know if we're dealing with the implicit object parameter, 1623 // or if the member function in this case has a ref qualifier. 1624 // (Of course, we don't have ref qualifiers yet.) 1625 if (SCS1.RRefBinding != SCS2.RRefBinding) 1626 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1627 : ImplicitConversionSequence::Worse; 1628 1629 // C++ [over.ics.rank]p3b4: 1630 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1631 // which the references refer are the same type except for 1632 // top-level cv-qualifiers, and the type to which the reference 1633 // initialized by S2 refers is more cv-qualified than the type 1634 // to which the reference initialized by S1 refers. 1635 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1636 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1637 T1 = Context.getCanonicalType(T1); 1638 T2 = Context.getCanonicalType(T2); 1639 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1640 if (T2.isMoreQualifiedThan(T1)) 1641 return ImplicitConversionSequence::Better; 1642 else if (T1.isMoreQualifiedThan(T2)) 1643 return ImplicitConversionSequence::Worse; 1644 } 1645 } 1646 1647 return ImplicitConversionSequence::Indistinguishable; 1648} 1649 1650/// CompareQualificationConversions - Compares two standard conversion 1651/// sequences to determine whether they can be ranked based on their 1652/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1653ImplicitConversionSequence::CompareKind 1654Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1655 const StandardConversionSequence& SCS2) 1656{ 1657 // C++ 13.3.3.2p3: 1658 // -- S1 and S2 differ only in their qualification conversion and 1659 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1660 // cv-qualification signature of type T1 is a proper subset of 1661 // the cv-qualification signature of type T2, and S1 is not the 1662 // deprecated string literal array-to-pointer conversion (4.2). 1663 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1664 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1665 return ImplicitConversionSequence::Indistinguishable; 1666 1667 // FIXME: the example in the standard doesn't use a qualification 1668 // conversion (!) 1669 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1670 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1671 T1 = Context.getCanonicalType(T1); 1672 T2 = Context.getCanonicalType(T2); 1673 1674 // If the types are the same, we won't learn anything by unwrapped 1675 // them. 1676 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1677 return ImplicitConversionSequence::Indistinguishable; 1678 1679 ImplicitConversionSequence::CompareKind Result 1680 = ImplicitConversionSequence::Indistinguishable; 1681 while (UnwrapSimilarPointerTypes(T1, T2)) { 1682 // Within each iteration of the loop, we check the qualifiers to 1683 // determine if this still looks like a qualification 1684 // conversion. Then, if all is well, we unwrap one more level of 1685 // pointers or pointers-to-members and do it all again 1686 // until there are no more pointers or pointers-to-members left 1687 // to unwrap. This essentially mimics what 1688 // IsQualificationConversion does, but here we're checking for a 1689 // strict subset of qualifiers. 1690 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1691 // The qualifiers are the same, so this doesn't tell us anything 1692 // about how the sequences rank. 1693 ; 1694 else if (T2.isMoreQualifiedThan(T1)) { 1695 // T1 has fewer qualifiers, so it could be the better sequence. 1696 if (Result == ImplicitConversionSequence::Worse) 1697 // Neither has qualifiers that are a subset of the other's 1698 // qualifiers. 1699 return ImplicitConversionSequence::Indistinguishable; 1700 1701 Result = ImplicitConversionSequence::Better; 1702 } else if (T1.isMoreQualifiedThan(T2)) { 1703 // T2 has fewer qualifiers, so it could be the better sequence. 1704 if (Result == ImplicitConversionSequence::Better) 1705 // Neither has qualifiers that are a subset of the other's 1706 // qualifiers. 1707 return ImplicitConversionSequence::Indistinguishable; 1708 1709 Result = ImplicitConversionSequence::Worse; 1710 } else { 1711 // Qualifiers are disjoint. 1712 return ImplicitConversionSequence::Indistinguishable; 1713 } 1714 1715 // If the types after this point are equivalent, we're done. 1716 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1717 break; 1718 } 1719 1720 // Check that the winning standard conversion sequence isn't using 1721 // the deprecated string literal array to pointer conversion. 1722 switch (Result) { 1723 case ImplicitConversionSequence::Better: 1724 if (SCS1.Deprecated) 1725 Result = ImplicitConversionSequence::Indistinguishable; 1726 break; 1727 1728 case ImplicitConversionSequence::Indistinguishable: 1729 break; 1730 1731 case ImplicitConversionSequence::Worse: 1732 if (SCS2.Deprecated) 1733 Result = ImplicitConversionSequence::Indistinguishable; 1734 break; 1735 } 1736 1737 return Result; 1738} 1739 1740/// CompareDerivedToBaseConversions - Compares two standard conversion 1741/// sequences to determine whether they can be ranked based on their 1742/// various kinds of derived-to-base conversions (C++ 1743/// [over.ics.rank]p4b3). As part of these checks, we also look at 1744/// conversions between Objective-C interface types. 1745ImplicitConversionSequence::CompareKind 1746Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1747 const StandardConversionSequence& SCS2) { 1748 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1749 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1750 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1751 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1752 1753 // Adjust the types we're converting from via the array-to-pointer 1754 // conversion, if we need to. 1755 if (SCS1.First == ICK_Array_To_Pointer) 1756 FromType1 = Context.getArrayDecayedType(FromType1); 1757 if (SCS2.First == ICK_Array_To_Pointer) 1758 FromType2 = Context.getArrayDecayedType(FromType2); 1759 1760 // Canonicalize all of the types. 1761 FromType1 = Context.getCanonicalType(FromType1); 1762 ToType1 = Context.getCanonicalType(ToType1); 1763 FromType2 = Context.getCanonicalType(FromType2); 1764 ToType2 = Context.getCanonicalType(ToType2); 1765 1766 // C++ [over.ics.rank]p4b3: 1767 // 1768 // If class B is derived directly or indirectly from class A and 1769 // class C is derived directly or indirectly from B, 1770 // 1771 // For Objective-C, we let A, B, and C also be Objective-C 1772 // interfaces. 1773 1774 // Compare based on pointer conversions. 1775 if (SCS1.Second == ICK_Pointer_Conversion && 1776 SCS2.Second == ICK_Pointer_Conversion && 1777 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1778 FromType1->isPointerType() && FromType2->isPointerType() && 1779 ToType1->isPointerType() && ToType2->isPointerType()) { 1780 QualType FromPointee1 1781 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1782 QualType ToPointee1 1783 = ToType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1784 QualType FromPointee2 1785 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1786 QualType ToPointee2 1787 = ToType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1788 1789 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1790 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1791 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1792 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1793 1794 // -- conversion of C* to B* is better than conversion of C* to A*, 1795 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1796 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1797 return ImplicitConversionSequence::Better; 1798 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1799 return ImplicitConversionSequence::Worse; 1800 1801 if (ToIface1 && ToIface2) { 1802 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1803 return ImplicitConversionSequence::Better; 1804 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1805 return ImplicitConversionSequence::Worse; 1806 } 1807 } 1808 1809 // -- conversion of B* to A* is better than conversion of C* to A*, 1810 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1811 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1812 return ImplicitConversionSequence::Better; 1813 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1814 return ImplicitConversionSequence::Worse; 1815 1816 if (FromIface1 && FromIface2) { 1817 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1818 return ImplicitConversionSequence::Better; 1819 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1820 return ImplicitConversionSequence::Worse; 1821 } 1822 } 1823 } 1824 1825 // Compare based on reference bindings. 1826 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1827 SCS1.Second == ICK_Derived_To_Base) { 1828 // -- binding of an expression of type C to a reference of type 1829 // B& is better than binding an expression of type C to a 1830 // reference of type A&, 1831 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1832 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1833 if (IsDerivedFrom(ToType1, ToType2)) 1834 return ImplicitConversionSequence::Better; 1835 else if (IsDerivedFrom(ToType2, ToType1)) 1836 return ImplicitConversionSequence::Worse; 1837 } 1838 1839 // -- binding of an expression of type B to a reference of type 1840 // A& is better than binding an expression of type C to a 1841 // reference of type A&, 1842 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1843 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1844 if (IsDerivedFrom(FromType2, FromType1)) 1845 return ImplicitConversionSequence::Better; 1846 else if (IsDerivedFrom(FromType1, FromType2)) 1847 return ImplicitConversionSequence::Worse; 1848 } 1849 } 1850 1851 1852 // FIXME: conversion of A::* to B::* is better than conversion of 1853 // A::* to C::*, 1854 1855 // FIXME: conversion of B::* to C::* is better than conversion of 1856 // A::* to C::*, and 1857 1858 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1859 SCS1.Second == ICK_Derived_To_Base) { 1860 // -- conversion of C to B is better than conversion of C to A, 1861 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1862 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1863 if (IsDerivedFrom(ToType1, ToType2)) 1864 return ImplicitConversionSequence::Better; 1865 else if (IsDerivedFrom(ToType2, ToType1)) 1866 return ImplicitConversionSequence::Worse; 1867 } 1868 1869 // -- conversion of B to A is better than conversion of C to A. 1870 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1871 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1872 if (IsDerivedFrom(FromType2, FromType1)) 1873 return ImplicitConversionSequence::Better; 1874 else if (IsDerivedFrom(FromType1, FromType2)) 1875 return ImplicitConversionSequence::Worse; 1876 } 1877 } 1878 1879 return ImplicitConversionSequence::Indistinguishable; 1880} 1881 1882/// TryCopyInitialization - Try to copy-initialize a value of type 1883/// ToType from the expression From. Return the implicit conversion 1884/// sequence required to pass this argument, which may be a bad 1885/// conversion sequence (meaning that the argument cannot be passed to 1886/// a parameter of this type). If @p SuppressUserConversions, then we 1887/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1888/// then we treat @p From as an rvalue, even if it is an lvalue. 1889ImplicitConversionSequence 1890Sema::TryCopyInitialization(Expr *From, QualType ToType, 1891 bool SuppressUserConversions, bool ForceRValue) { 1892 if (ToType->isReferenceType()) { 1893 ImplicitConversionSequence ICS; 1894 CheckReferenceInit(From, ToType, &ICS, SuppressUserConversions, 1895 /*AllowExplicit=*/false, ForceRValue); 1896 return ICS; 1897 } else { 1898 return TryImplicitConversion(From, ToType, SuppressUserConversions, 1899 ForceRValue); 1900 } 1901} 1902 1903/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1904/// the expression @p From. Returns true (and emits a diagnostic) if there was 1905/// an error, returns false if the initialization succeeded. Elidable should 1906/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1907/// differently in C++0x for this case. 1908bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1909 const char* Flavor, bool Elidable) { 1910 if (!getLangOptions().CPlusPlus) { 1911 // In C, argument passing is the same as performing an assignment. 1912 QualType FromType = From->getType(); 1913 1914 AssignConvertType ConvTy = 1915 CheckSingleAssignmentConstraints(ToType, From); 1916 if (ConvTy != Compatible && 1917 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1918 ConvTy = Compatible; 1919 1920 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1921 FromType, From, Flavor); 1922 } 1923 1924 if (ToType->isReferenceType()) 1925 return CheckReferenceInit(From, ToType); 1926 1927 if (!PerformImplicitConversion(From, ToType, Flavor, 1928 /*AllowExplicit=*/false, Elidable)) 1929 return false; 1930 1931 return Diag(From->getSourceRange().getBegin(), 1932 diag::err_typecheck_convert_incompatible) 1933 << ToType << From->getType() << Flavor << From->getSourceRange(); 1934} 1935 1936/// TryObjectArgumentInitialization - Try to initialize the object 1937/// parameter of the given member function (@c Method) from the 1938/// expression @p From. 1939ImplicitConversionSequence 1940Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1941 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1942 unsigned MethodQuals = Method->getTypeQualifiers(); 1943 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 1944 1945 // Set up the conversion sequence as a "bad" conversion, to allow us 1946 // to exit early. 1947 ImplicitConversionSequence ICS; 1948 ICS.Standard.setAsIdentityConversion(); 1949 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1950 1951 // We need to have an object of class type. 1952 QualType FromType = From->getType(); 1953 if (const PointerType *PT = FromType->getAsPointerType()) 1954 FromType = PT->getPointeeType(); 1955 1956 assert(FromType->isRecordType()); 1957 1958 // The implicit object parmeter is has the type "reference to cv X", 1959 // where X is the class of which the function is a member 1960 // (C++ [over.match.funcs]p4). However, when finding an implicit 1961 // conversion sequence for the argument, we are not allowed to 1962 // create temporaries or perform user-defined conversions 1963 // (C++ [over.match.funcs]p5). We perform a simplified version of 1964 // reference binding here, that allows class rvalues to bind to 1965 // non-constant references. 1966 1967 // First check the qualifiers. We don't care about lvalue-vs-rvalue 1968 // with the implicit object parameter (C++ [over.match.funcs]p5). 1969 QualType FromTypeCanon = Context.getCanonicalType(FromType); 1970 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 1971 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 1972 return ICS; 1973 1974 // Check that we have either the same type or a derived type. It 1975 // affects the conversion rank. 1976 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 1977 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 1978 ICS.Standard.Second = ICK_Identity; 1979 else if (IsDerivedFrom(FromType, ClassType)) 1980 ICS.Standard.Second = ICK_Derived_To_Base; 1981 else 1982 return ICS; 1983 1984 // Success. Mark this as a reference binding. 1985 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 1986 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 1987 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 1988 ICS.Standard.ReferenceBinding = true; 1989 ICS.Standard.DirectBinding = true; 1990 ICS.Standard.RRefBinding = false; 1991 return ICS; 1992} 1993 1994/// PerformObjectArgumentInitialization - Perform initialization of 1995/// the implicit object parameter for the given Method with the given 1996/// expression. 1997bool 1998Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 1999 QualType FromRecordType, DestType; 2000 QualType ImplicitParamRecordType = 2001 Method->getThisType(Context)->getAsPointerType()->getPointeeType(); 2002 2003 if (const PointerType *PT = From->getType()->getAsPointerType()) { 2004 FromRecordType = PT->getPointeeType(); 2005 DestType = Method->getThisType(Context); 2006 } else { 2007 FromRecordType = From->getType(); 2008 DestType = ImplicitParamRecordType; 2009 } 2010 2011 ImplicitConversionSequence ICS 2012 = TryObjectArgumentInitialization(From, Method); 2013 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2014 return Diag(From->getSourceRange().getBegin(), 2015 diag::err_implicit_object_parameter_init) 2016 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2017 2018 if (ICS.Standard.Second == ICK_Derived_To_Base && 2019 CheckDerivedToBaseConversion(FromRecordType, 2020 ImplicitParamRecordType, 2021 From->getSourceRange().getBegin(), 2022 From->getSourceRange())) 2023 return true; 2024 2025 ImpCastExprToType(From, DestType, /*isLvalue=*/true); 2026 return false; 2027} 2028 2029/// TryContextuallyConvertToBool - Attempt to contextually convert the 2030/// expression From to bool (C++0x [conv]p3). 2031ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2032 return TryImplicitConversion(From, Context.BoolTy, false, true); 2033} 2034 2035/// PerformContextuallyConvertToBool - Perform a contextual conversion 2036/// of the expression From to bool (C++0x [conv]p3). 2037bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2038 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2039 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2040 return false; 2041 2042 return Diag(From->getSourceRange().getBegin(), 2043 diag::err_typecheck_bool_condition) 2044 << From->getType() << From->getSourceRange(); 2045} 2046 2047/// AddOverloadCandidate - Adds the given function to the set of 2048/// candidate functions, using the given function call arguments. If 2049/// @p SuppressUserConversions, then don't allow user-defined 2050/// conversions via constructors or conversion operators. 2051/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2052/// hacky way to implement the overloading rules for elidable copy 2053/// initialization in C++0x (C++0x 12.8p15). 2054void 2055Sema::AddOverloadCandidate(FunctionDecl *Function, 2056 Expr **Args, unsigned NumArgs, 2057 OverloadCandidateSet& CandidateSet, 2058 bool SuppressUserConversions, 2059 bool ForceRValue) 2060{ 2061 const FunctionProtoType* Proto 2062 = dyn_cast<FunctionProtoType>(Function->getType()->getAsFunctionType()); 2063 assert(Proto && "Functions without a prototype cannot be overloaded"); 2064 assert(!isa<CXXConversionDecl>(Function) && 2065 "Use AddConversionCandidate for conversion functions"); 2066 assert(!Function->getDescribedFunctionTemplate() && 2067 "Use AddTemplateOverloadCandidate for function templates"); 2068 2069 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2070 if (!isa<CXXConstructorDecl>(Method)) { 2071 // If we get here, it's because we're calling a member function 2072 // that is named without a member access expression (e.g., 2073 // "this->f") that was either written explicitly or created 2074 // implicitly. This can happen with a qualified call to a member 2075 // function, e.g., X::f(). We use a NULL object as the implied 2076 // object argument (C++ [over.call.func]p3). 2077 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2078 SuppressUserConversions, ForceRValue); 2079 return; 2080 } 2081 // We treat a constructor like a non-member function, since its object 2082 // argument doesn't participate in overload resolution. 2083 } 2084 2085 2086 // Add this candidate 2087 CandidateSet.push_back(OverloadCandidate()); 2088 OverloadCandidate& Candidate = CandidateSet.back(); 2089 Candidate.Function = Function; 2090 Candidate.Viable = true; 2091 Candidate.IsSurrogate = false; 2092 Candidate.IgnoreObjectArgument = false; 2093 2094 unsigned NumArgsInProto = Proto->getNumArgs(); 2095 2096 // (C++ 13.3.2p2): A candidate function having fewer than m 2097 // parameters is viable only if it has an ellipsis in its parameter 2098 // list (8.3.5). 2099 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2100 Candidate.Viable = false; 2101 return; 2102 } 2103 2104 // (C++ 13.3.2p2): A candidate function having more than m parameters 2105 // is viable only if the (m+1)st parameter has a default argument 2106 // (8.3.6). For the purposes of overload resolution, the 2107 // parameter list is truncated on the right, so that there are 2108 // exactly m parameters. 2109 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2110 if (NumArgs < MinRequiredArgs) { 2111 // Not enough arguments. 2112 Candidate.Viable = false; 2113 return; 2114 } 2115 2116 // Determine the implicit conversion sequences for each of the 2117 // arguments. 2118 Candidate.Conversions.resize(NumArgs); 2119 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2120 if (ArgIdx < NumArgsInProto) { 2121 // (C++ 13.3.2p3): for F to be a viable function, there shall 2122 // exist for each argument an implicit conversion sequence 2123 // (13.3.3.1) that converts that argument to the corresponding 2124 // parameter of F. 2125 QualType ParamType = Proto->getArgType(ArgIdx); 2126 Candidate.Conversions[ArgIdx] 2127 = TryCopyInitialization(Args[ArgIdx], ParamType, 2128 SuppressUserConversions, ForceRValue); 2129 if (Candidate.Conversions[ArgIdx].ConversionKind 2130 == ImplicitConversionSequence::BadConversion) { 2131 Candidate.Viable = false; 2132 break; 2133 } 2134 } else { 2135 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2136 // argument for which there is no corresponding parameter is 2137 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2138 Candidate.Conversions[ArgIdx].ConversionKind 2139 = ImplicitConversionSequence::EllipsisConversion; 2140 } 2141 } 2142} 2143 2144/// \brief Add all of the function declarations in the given function set to 2145/// the overload canddiate set. 2146void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2147 Expr **Args, unsigned NumArgs, 2148 OverloadCandidateSet& CandidateSet, 2149 bool SuppressUserConversions) { 2150 for (FunctionSet::const_iterator F = Functions.begin(), 2151 FEnd = Functions.end(); 2152 F != FEnd; ++F) { 2153 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) 2154 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2155 SuppressUserConversions); 2156 else 2157 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*F), 2158 /*FIXME: explicit args */false, 0, 0, 2159 Args, NumArgs, CandidateSet, 2160 SuppressUserConversions); 2161 } 2162} 2163 2164/// AddMethodCandidate - Adds the given C++ member function to the set 2165/// of candidate functions, using the given function call arguments 2166/// and the object argument (@c Object). For example, in a call 2167/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2168/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2169/// allow user-defined conversions via constructors or conversion 2170/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2171/// a slightly hacky way to implement the overloading rules for elidable copy 2172/// initialization in C++0x (C++0x 12.8p15). 2173void 2174Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2175 Expr **Args, unsigned NumArgs, 2176 OverloadCandidateSet& CandidateSet, 2177 bool SuppressUserConversions, bool ForceRValue) 2178{ 2179 const FunctionProtoType* Proto 2180 = dyn_cast<FunctionProtoType>(Method->getType()->getAsFunctionType()); 2181 assert(Proto && "Methods without a prototype cannot be overloaded"); 2182 assert(!isa<CXXConversionDecl>(Method) && 2183 "Use AddConversionCandidate for conversion functions"); 2184 assert(!isa<CXXConstructorDecl>(Method) && 2185 "Use AddOverloadCandidate for constructors"); 2186 2187 // Add this candidate 2188 CandidateSet.push_back(OverloadCandidate()); 2189 OverloadCandidate& Candidate = CandidateSet.back(); 2190 Candidate.Function = Method; 2191 Candidate.IsSurrogate = false; 2192 Candidate.IgnoreObjectArgument = false; 2193 2194 unsigned NumArgsInProto = Proto->getNumArgs(); 2195 2196 // (C++ 13.3.2p2): A candidate function having fewer than m 2197 // parameters is viable only if it has an ellipsis in its parameter 2198 // list (8.3.5). 2199 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2200 Candidate.Viable = false; 2201 return; 2202 } 2203 2204 // (C++ 13.3.2p2): A candidate function having more than m parameters 2205 // is viable only if the (m+1)st parameter has a default argument 2206 // (8.3.6). For the purposes of overload resolution, the 2207 // parameter list is truncated on the right, so that there are 2208 // exactly m parameters. 2209 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2210 if (NumArgs < MinRequiredArgs) { 2211 // Not enough arguments. 2212 Candidate.Viable = false; 2213 return; 2214 } 2215 2216 Candidate.Viable = true; 2217 Candidate.Conversions.resize(NumArgs + 1); 2218 2219 if (Method->isStatic() || !Object) 2220 // The implicit object argument is ignored. 2221 Candidate.IgnoreObjectArgument = true; 2222 else { 2223 // Determine the implicit conversion sequence for the object 2224 // parameter. 2225 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2226 if (Candidate.Conversions[0].ConversionKind 2227 == ImplicitConversionSequence::BadConversion) { 2228 Candidate.Viable = false; 2229 return; 2230 } 2231 } 2232 2233 // Determine the implicit conversion sequences for each of the 2234 // arguments. 2235 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2236 if (ArgIdx < NumArgsInProto) { 2237 // (C++ 13.3.2p3): for F to be a viable function, there shall 2238 // exist for each argument an implicit conversion sequence 2239 // (13.3.3.1) that converts that argument to the corresponding 2240 // parameter of F. 2241 QualType ParamType = Proto->getArgType(ArgIdx); 2242 Candidate.Conversions[ArgIdx + 1] 2243 = TryCopyInitialization(Args[ArgIdx], ParamType, 2244 SuppressUserConversions, ForceRValue); 2245 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2246 == ImplicitConversionSequence::BadConversion) { 2247 Candidate.Viable = false; 2248 break; 2249 } 2250 } else { 2251 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2252 // argument for which there is no corresponding parameter is 2253 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2254 Candidate.Conversions[ArgIdx + 1].ConversionKind 2255 = ImplicitConversionSequence::EllipsisConversion; 2256 } 2257 } 2258} 2259 2260/// \brief Add a C++ function template as a candidate in the candidate set, 2261/// using template argument deduction to produce an appropriate function 2262/// template specialization. 2263void 2264Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2265 bool HasExplicitTemplateArgs, 2266 const TemplateArgument *ExplicitTemplateArgs, 2267 unsigned NumExplicitTemplateArgs, 2268 Expr **Args, unsigned NumArgs, 2269 OverloadCandidateSet& CandidateSet, 2270 bool SuppressUserConversions, 2271 bool ForceRValue) { 2272 // C++ [over.match.funcs]p7: 2273 // In each case where a candidate is a function template, candidate 2274 // function template specializations are generated using template argument 2275 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2276 // candidate functions in the usual way.113) A given name can refer to one 2277 // or more function templates and also to a set of overloaded non-template 2278 // functions. In such a case, the candidate functions generated from each 2279 // function template are combined with the set of non-template candidate 2280 // functions. 2281 TemplateDeductionInfo Info(Context); 2282 FunctionDecl *Specialization = 0; 2283 if (TemplateDeductionResult Result 2284 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2285 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2286 Args, NumArgs, Specialization, Info)) { 2287 // FIXME: Record what happened with template argument deduction, so 2288 // that we can give the user a beautiful diagnostic. 2289 (void)Result; 2290 return; 2291 } 2292 2293 // Add the function template specialization produced by template argument 2294 // deduction as a candidate. 2295 assert(Specialization && "Missing function template specialization?"); 2296 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2297 SuppressUserConversions, ForceRValue); 2298} 2299 2300/// AddConversionCandidate - Add a C++ conversion function as a 2301/// candidate in the candidate set (C++ [over.match.conv], 2302/// C++ [over.match.copy]). From is the expression we're converting from, 2303/// and ToType is the type that we're eventually trying to convert to 2304/// (which may or may not be the same type as the type that the 2305/// conversion function produces). 2306void 2307Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2308 Expr *From, QualType ToType, 2309 OverloadCandidateSet& CandidateSet) { 2310 // Add this candidate 2311 CandidateSet.push_back(OverloadCandidate()); 2312 OverloadCandidate& Candidate = CandidateSet.back(); 2313 Candidate.Function = Conversion; 2314 Candidate.IsSurrogate = false; 2315 Candidate.IgnoreObjectArgument = false; 2316 Candidate.FinalConversion.setAsIdentityConversion(); 2317 Candidate.FinalConversion.FromTypePtr 2318 = Conversion->getConversionType().getAsOpaquePtr(); 2319 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2320 2321 // Determine the implicit conversion sequence for the implicit 2322 // object parameter. 2323 Candidate.Viable = true; 2324 Candidate.Conversions.resize(1); 2325 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2326 2327 if (Candidate.Conversions[0].ConversionKind 2328 == ImplicitConversionSequence::BadConversion) { 2329 Candidate.Viable = false; 2330 return; 2331 } 2332 2333 // To determine what the conversion from the result of calling the 2334 // conversion function to the type we're eventually trying to 2335 // convert to (ToType), we need to synthesize a call to the 2336 // conversion function and attempt copy initialization from it. This 2337 // makes sure that we get the right semantics with respect to 2338 // lvalues/rvalues and the type. Fortunately, we can allocate this 2339 // call on the stack and we don't need its arguments to be 2340 // well-formed. 2341 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2342 SourceLocation()); 2343 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2344 &ConversionRef, false); 2345 2346 // Note that it is safe to allocate CallExpr on the stack here because 2347 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2348 // allocator). 2349 CallExpr Call(Context, &ConversionFn, 0, 0, 2350 Conversion->getConversionType().getNonReferenceType(), 2351 SourceLocation()); 2352 ImplicitConversionSequence ICS = TryCopyInitialization(&Call, ToType, true); 2353 switch (ICS.ConversionKind) { 2354 case ImplicitConversionSequence::StandardConversion: 2355 Candidate.FinalConversion = ICS.Standard; 2356 break; 2357 2358 case ImplicitConversionSequence::BadConversion: 2359 Candidate.Viable = false; 2360 break; 2361 2362 default: 2363 assert(false && 2364 "Can only end up with a standard conversion sequence or failure"); 2365 } 2366} 2367 2368/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2369/// converts the given @c Object to a function pointer via the 2370/// conversion function @c Conversion, and then attempts to call it 2371/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2372/// the type of function that we'll eventually be calling. 2373void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2374 const FunctionProtoType *Proto, 2375 Expr *Object, Expr **Args, unsigned NumArgs, 2376 OverloadCandidateSet& CandidateSet) { 2377 CandidateSet.push_back(OverloadCandidate()); 2378 OverloadCandidate& Candidate = CandidateSet.back(); 2379 Candidate.Function = 0; 2380 Candidate.Surrogate = Conversion; 2381 Candidate.Viable = true; 2382 Candidate.IsSurrogate = true; 2383 Candidate.IgnoreObjectArgument = false; 2384 Candidate.Conversions.resize(NumArgs + 1); 2385 2386 // Determine the implicit conversion sequence for the implicit 2387 // object parameter. 2388 ImplicitConversionSequence ObjectInit 2389 = TryObjectArgumentInitialization(Object, Conversion); 2390 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2391 Candidate.Viable = false; 2392 return; 2393 } 2394 2395 // The first conversion is actually a user-defined conversion whose 2396 // first conversion is ObjectInit's standard conversion (which is 2397 // effectively a reference binding). Record it as such. 2398 Candidate.Conversions[0].ConversionKind 2399 = ImplicitConversionSequence::UserDefinedConversion; 2400 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2401 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2402 Candidate.Conversions[0].UserDefined.After 2403 = Candidate.Conversions[0].UserDefined.Before; 2404 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2405 2406 // Find the 2407 unsigned NumArgsInProto = Proto->getNumArgs(); 2408 2409 // (C++ 13.3.2p2): A candidate function having fewer than m 2410 // parameters is viable only if it has an ellipsis in its parameter 2411 // list (8.3.5). 2412 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2413 Candidate.Viable = false; 2414 return; 2415 } 2416 2417 // Function types don't have any default arguments, so just check if 2418 // we have enough arguments. 2419 if (NumArgs < NumArgsInProto) { 2420 // Not enough arguments. 2421 Candidate.Viable = false; 2422 return; 2423 } 2424 2425 // Determine the implicit conversion sequences for each of the 2426 // arguments. 2427 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2428 if (ArgIdx < NumArgsInProto) { 2429 // (C++ 13.3.2p3): for F to be a viable function, there shall 2430 // exist for each argument an implicit conversion sequence 2431 // (13.3.3.1) that converts that argument to the corresponding 2432 // parameter of F. 2433 QualType ParamType = Proto->getArgType(ArgIdx); 2434 Candidate.Conversions[ArgIdx + 1] 2435 = TryCopyInitialization(Args[ArgIdx], ParamType, 2436 /*SuppressUserConversions=*/false); 2437 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2438 == ImplicitConversionSequence::BadConversion) { 2439 Candidate.Viable = false; 2440 break; 2441 } 2442 } else { 2443 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2444 // argument for which there is no corresponding parameter is 2445 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2446 Candidate.Conversions[ArgIdx + 1].ConversionKind 2447 = ImplicitConversionSequence::EllipsisConversion; 2448 } 2449 } 2450} 2451 2452// FIXME: This will eventually be removed, once we've migrated all of the 2453// operator overloading logic over to the scheme used by binary operators, which 2454// works for template instantiation. 2455void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2456 SourceLocation OpLoc, 2457 Expr **Args, unsigned NumArgs, 2458 OverloadCandidateSet& CandidateSet, 2459 SourceRange OpRange) { 2460 2461 FunctionSet Functions; 2462 2463 QualType T1 = Args[0]->getType(); 2464 QualType T2; 2465 if (NumArgs > 1) 2466 T2 = Args[1]->getType(); 2467 2468 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2469 if (S) 2470 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2471 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2472 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2473 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2474 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2475} 2476 2477/// \brief Add overload candidates for overloaded operators that are 2478/// member functions. 2479/// 2480/// Add the overloaded operator candidates that are member functions 2481/// for the operator Op that was used in an operator expression such 2482/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2483/// CandidateSet will store the added overload candidates. (C++ 2484/// [over.match.oper]). 2485void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2486 SourceLocation OpLoc, 2487 Expr **Args, unsigned NumArgs, 2488 OverloadCandidateSet& CandidateSet, 2489 SourceRange OpRange) { 2490 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2491 2492 // C++ [over.match.oper]p3: 2493 // For a unary operator @ with an operand of a type whose 2494 // cv-unqualified version is T1, and for a binary operator @ with 2495 // a left operand of a type whose cv-unqualified version is T1 and 2496 // a right operand of a type whose cv-unqualified version is T2, 2497 // three sets of candidate functions, designated member 2498 // candidates, non-member candidates and built-in candidates, are 2499 // constructed as follows: 2500 QualType T1 = Args[0]->getType(); 2501 QualType T2; 2502 if (NumArgs > 1) 2503 T2 = Args[1]->getType(); 2504 2505 // -- If T1 is a class type, the set of member candidates is the 2506 // result of the qualified lookup of T1::operator@ 2507 // (13.3.1.1.1); otherwise, the set of member candidates is 2508 // empty. 2509 // FIXME: Lookup in base classes, too! 2510 if (const RecordType *T1Rec = T1->getAsRecordType()) { 2511 DeclContext::lookup_const_iterator Oper, OperEnd; 2512 for (llvm::tie(Oper, OperEnd) = T1Rec->getDecl()->lookup(OpName); 2513 Oper != OperEnd; ++Oper) 2514 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2515 Args+1, NumArgs - 1, CandidateSet, 2516 /*SuppressUserConversions=*/false); 2517 } 2518} 2519 2520/// AddBuiltinCandidate - Add a candidate for a built-in 2521/// operator. ResultTy and ParamTys are the result and parameter types 2522/// of the built-in candidate, respectively. Args and NumArgs are the 2523/// arguments being passed to the candidate. IsAssignmentOperator 2524/// should be true when this built-in candidate is an assignment 2525/// operator. NumContextualBoolArguments is the number of arguments 2526/// (at the beginning of the argument list) that will be contextually 2527/// converted to bool. 2528void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2529 Expr **Args, unsigned NumArgs, 2530 OverloadCandidateSet& CandidateSet, 2531 bool IsAssignmentOperator, 2532 unsigned NumContextualBoolArguments) { 2533 // Add this candidate 2534 CandidateSet.push_back(OverloadCandidate()); 2535 OverloadCandidate& Candidate = CandidateSet.back(); 2536 Candidate.Function = 0; 2537 Candidate.IsSurrogate = false; 2538 Candidate.IgnoreObjectArgument = false; 2539 Candidate.BuiltinTypes.ResultTy = ResultTy; 2540 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2541 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2542 2543 // Determine the implicit conversion sequences for each of the 2544 // arguments. 2545 Candidate.Viable = true; 2546 Candidate.Conversions.resize(NumArgs); 2547 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2548 // C++ [over.match.oper]p4: 2549 // For the built-in assignment operators, conversions of the 2550 // left operand are restricted as follows: 2551 // -- no temporaries are introduced to hold the left operand, and 2552 // -- no user-defined conversions are applied to the left 2553 // operand to achieve a type match with the left-most 2554 // parameter of a built-in candidate. 2555 // 2556 // We block these conversions by turning off user-defined 2557 // conversions, since that is the only way that initialization of 2558 // a reference to a non-class type can occur from something that 2559 // is not of the same type. 2560 if (ArgIdx < NumContextualBoolArguments) { 2561 assert(ParamTys[ArgIdx] == Context.BoolTy && 2562 "Contextual conversion to bool requires bool type"); 2563 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2564 } else { 2565 Candidate.Conversions[ArgIdx] 2566 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2567 ArgIdx == 0 && IsAssignmentOperator); 2568 } 2569 if (Candidate.Conversions[ArgIdx].ConversionKind 2570 == ImplicitConversionSequence::BadConversion) { 2571 Candidate.Viable = false; 2572 break; 2573 } 2574 } 2575} 2576 2577/// BuiltinCandidateTypeSet - A set of types that will be used for the 2578/// candidate operator functions for built-in operators (C++ 2579/// [over.built]). The types are separated into pointer types and 2580/// enumeration types. 2581class BuiltinCandidateTypeSet { 2582 /// TypeSet - A set of types. 2583 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2584 2585 /// PointerTypes - The set of pointer types that will be used in the 2586 /// built-in candidates. 2587 TypeSet PointerTypes; 2588 2589 /// MemberPointerTypes - The set of member pointer types that will be 2590 /// used in the built-in candidates. 2591 TypeSet MemberPointerTypes; 2592 2593 /// EnumerationTypes - The set of enumeration types that will be 2594 /// used in the built-in candidates. 2595 TypeSet EnumerationTypes; 2596 2597 /// Context - The AST context in which we will build the type sets. 2598 ASTContext &Context; 2599 2600 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2601 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2602 2603public: 2604 /// iterator - Iterates through the types that are part of the set. 2605 typedef TypeSet::iterator iterator; 2606 2607 BuiltinCandidateTypeSet(ASTContext &Context) : Context(Context) { } 2608 2609 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2610 bool AllowExplicitConversions); 2611 2612 /// pointer_begin - First pointer type found; 2613 iterator pointer_begin() { return PointerTypes.begin(); } 2614 2615 /// pointer_end - Past the last pointer type found; 2616 iterator pointer_end() { return PointerTypes.end(); } 2617 2618 /// member_pointer_begin - First member pointer type found; 2619 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2620 2621 /// member_pointer_end - Past the last member pointer type found; 2622 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2623 2624 /// enumeration_begin - First enumeration type found; 2625 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2626 2627 /// enumeration_end - Past the last enumeration type found; 2628 iterator enumeration_end() { return EnumerationTypes.end(); } 2629}; 2630 2631/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2632/// the set of pointer types along with any more-qualified variants of 2633/// that type. For example, if @p Ty is "int const *", this routine 2634/// will add "int const *", "int const volatile *", "int const 2635/// restrict *", and "int const volatile restrict *" to the set of 2636/// pointer types. Returns true if the add of @p Ty itself succeeded, 2637/// false otherwise. 2638bool 2639BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2640 // Insert this type. 2641 if (!PointerTypes.insert(Ty)) 2642 return false; 2643 2644 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2645 QualType PointeeTy = PointerTy->getPointeeType(); 2646 // FIXME: Optimize this so that we don't keep trying to add the same types. 2647 2648 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal with all 2649 // pointer conversions that don't cast away constness? 2650 if (!PointeeTy.isConstQualified()) 2651 AddPointerWithMoreQualifiedTypeVariants 2652 (Context.getPointerType(PointeeTy.withConst())); 2653 if (!PointeeTy.isVolatileQualified()) 2654 AddPointerWithMoreQualifiedTypeVariants 2655 (Context.getPointerType(PointeeTy.withVolatile())); 2656 if (!PointeeTy.isRestrictQualified()) 2657 AddPointerWithMoreQualifiedTypeVariants 2658 (Context.getPointerType(PointeeTy.withRestrict())); 2659 } 2660 2661 return true; 2662} 2663 2664/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2665/// to the set of pointer types along with any more-qualified variants of 2666/// that type. For example, if @p Ty is "int const *", this routine 2667/// will add "int const *", "int const volatile *", "int const 2668/// restrict *", and "int const volatile restrict *" to the set of 2669/// pointer types. Returns true if the add of @p Ty itself succeeded, 2670/// false otherwise. 2671bool 2672BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2673 QualType Ty) { 2674 // Insert this type. 2675 if (!MemberPointerTypes.insert(Ty)) 2676 return false; 2677 2678 if (const MemberPointerType *PointerTy = Ty->getAsMemberPointerType()) { 2679 QualType PointeeTy = PointerTy->getPointeeType(); 2680 const Type *ClassTy = PointerTy->getClass(); 2681 // FIXME: Optimize this so that we don't keep trying to add the same types. 2682 2683 if (!PointeeTy.isConstQualified()) 2684 AddMemberPointerWithMoreQualifiedTypeVariants 2685 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2686 if (!PointeeTy.isVolatileQualified()) 2687 AddMemberPointerWithMoreQualifiedTypeVariants 2688 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2689 if (!PointeeTy.isRestrictQualified()) 2690 AddMemberPointerWithMoreQualifiedTypeVariants 2691 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2692 } 2693 2694 return true; 2695} 2696 2697/// AddTypesConvertedFrom - Add each of the types to which the type @p 2698/// Ty can be implicit converted to the given set of @p Types. We're 2699/// primarily interested in pointer types and enumeration types. We also 2700/// take member pointer types, for the conditional operator. 2701/// AllowUserConversions is true if we should look at the conversion 2702/// functions of a class type, and AllowExplicitConversions if we 2703/// should also include the explicit conversion functions of a class 2704/// type. 2705void 2706BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2707 bool AllowUserConversions, 2708 bool AllowExplicitConversions) { 2709 // Only deal with canonical types. 2710 Ty = Context.getCanonicalType(Ty); 2711 2712 // Look through reference types; they aren't part of the type of an 2713 // expression for the purposes of conversions. 2714 if (const ReferenceType *RefTy = Ty->getAsReferenceType()) 2715 Ty = RefTy->getPointeeType(); 2716 2717 // We don't care about qualifiers on the type. 2718 Ty = Ty.getUnqualifiedType(); 2719 2720 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2721 QualType PointeeTy = PointerTy->getPointeeType(); 2722 2723 // Insert our type, and its more-qualified variants, into the set 2724 // of types. 2725 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2726 return; 2727 2728 // Add 'cv void*' to our set of types. 2729 if (!Ty->isVoidType()) { 2730 QualType QualVoid 2731 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2732 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2733 } 2734 2735 // If this is a pointer to a class type, add pointers to its bases 2736 // (with the same level of cv-qualification as the original 2737 // derived class, of course). 2738 if (const RecordType *PointeeRec = PointeeTy->getAsRecordType()) { 2739 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2740 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2741 Base != ClassDecl->bases_end(); ++Base) { 2742 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2743 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2744 2745 // Add the pointer type, recursively, so that we get all of 2746 // the indirect base classes, too. 2747 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2748 } 2749 } 2750 } else if (Ty->isMemberPointerType()) { 2751 // Member pointers are far easier, since the pointee can't be converted. 2752 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2753 return; 2754 } else if (Ty->isEnumeralType()) { 2755 EnumerationTypes.insert(Ty); 2756 } else if (AllowUserConversions) { 2757 if (const RecordType *TyRec = Ty->getAsRecordType()) { 2758 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2759 // FIXME: Visit conversion functions in the base classes, too. 2760 OverloadedFunctionDecl *Conversions 2761 = ClassDecl->getConversionFunctions(); 2762 for (OverloadedFunctionDecl::function_iterator Func 2763 = Conversions->function_begin(); 2764 Func != Conversions->function_end(); ++Func) { 2765 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 2766 if (AllowExplicitConversions || !Conv->isExplicit()) 2767 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2768 } 2769 } 2770 } 2771} 2772 2773/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2774/// operator overloads to the candidate set (C++ [over.built]), based 2775/// on the operator @p Op and the arguments given. For example, if the 2776/// operator is a binary '+', this routine might add "int 2777/// operator+(int, int)" to cover integer addition. 2778void 2779Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2780 Expr **Args, unsigned NumArgs, 2781 OverloadCandidateSet& CandidateSet) { 2782 // The set of "promoted arithmetic types", which are the arithmetic 2783 // types are that preserved by promotion (C++ [over.built]p2). Note 2784 // that the first few of these types are the promoted integral 2785 // types; these types need to be first. 2786 // FIXME: What about complex? 2787 const unsigned FirstIntegralType = 0; 2788 const unsigned LastIntegralType = 13; 2789 const unsigned FirstPromotedIntegralType = 7, 2790 LastPromotedIntegralType = 13; 2791 const unsigned FirstPromotedArithmeticType = 7, 2792 LastPromotedArithmeticType = 16; 2793 const unsigned NumArithmeticTypes = 16; 2794 QualType ArithmeticTypes[NumArithmeticTypes] = { 2795 Context.BoolTy, Context.CharTy, Context.WCharTy, 2796 Context.SignedCharTy, Context.ShortTy, 2797 Context.UnsignedCharTy, Context.UnsignedShortTy, 2798 Context.IntTy, Context.LongTy, Context.LongLongTy, 2799 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 2800 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 2801 }; 2802 2803 // Find all of the types that the arguments can convert to, but only 2804 // if the operator we're looking at has built-in operator candidates 2805 // that make use of these types. 2806 BuiltinCandidateTypeSet CandidateTypes(Context); 2807 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 2808 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 2809 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 2810 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 2811 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 2812 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 2813 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2814 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 2815 true, 2816 (Op == OO_Exclaim || 2817 Op == OO_AmpAmp || 2818 Op == OO_PipePipe)); 2819 } 2820 2821 bool isComparison = false; 2822 switch (Op) { 2823 case OO_None: 2824 case NUM_OVERLOADED_OPERATORS: 2825 assert(false && "Expected an overloaded operator"); 2826 break; 2827 2828 case OO_Star: // '*' is either unary or binary 2829 if (NumArgs == 1) 2830 goto UnaryStar; 2831 else 2832 goto BinaryStar; 2833 break; 2834 2835 case OO_Plus: // '+' is either unary or binary 2836 if (NumArgs == 1) 2837 goto UnaryPlus; 2838 else 2839 goto BinaryPlus; 2840 break; 2841 2842 case OO_Minus: // '-' is either unary or binary 2843 if (NumArgs == 1) 2844 goto UnaryMinus; 2845 else 2846 goto BinaryMinus; 2847 break; 2848 2849 case OO_Amp: // '&' is either unary or binary 2850 if (NumArgs == 1) 2851 goto UnaryAmp; 2852 else 2853 goto BinaryAmp; 2854 2855 case OO_PlusPlus: 2856 case OO_MinusMinus: 2857 // C++ [over.built]p3: 2858 // 2859 // For every pair (T, VQ), where T is an arithmetic type, and VQ 2860 // is either volatile or empty, there exist candidate operator 2861 // functions of the form 2862 // 2863 // VQ T& operator++(VQ T&); 2864 // T operator++(VQ T&, int); 2865 // 2866 // C++ [over.built]p4: 2867 // 2868 // For every pair (T, VQ), where T is an arithmetic type other 2869 // than bool, and VQ is either volatile or empty, there exist 2870 // candidate operator functions of the form 2871 // 2872 // VQ T& operator--(VQ T&); 2873 // T operator--(VQ T&, int); 2874 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 2875 Arith < NumArithmeticTypes; ++Arith) { 2876 QualType ArithTy = ArithmeticTypes[Arith]; 2877 QualType ParamTypes[2] 2878 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 2879 2880 // Non-volatile version. 2881 if (NumArgs == 1) 2882 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2883 else 2884 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2885 2886 // Volatile version 2887 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 2888 if (NumArgs == 1) 2889 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2890 else 2891 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2892 } 2893 2894 // C++ [over.built]p5: 2895 // 2896 // For every pair (T, VQ), where T is a cv-qualified or 2897 // cv-unqualified object type, and VQ is either volatile or 2898 // empty, there exist candidate operator functions of the form 2899 // 2900 // T*VQ& operator++(T*VQ&); 2901 // T*VQ& operator--(T*VQ&); 2902 // T* operator++(T*VQ&, int); 2903 // T* operator--(T*VQ&, int); 2904 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2905 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2906 // Skip pointer types that aren't pointers to object types. 2907 if (!(*Ptr)->getAsPointerType()->getPointeeType()->isObjectType()) 2908 continue; 2909 2910 QualType ParamTypes[2] = { 2911 Context.getLValueReferenceType(*Ptr), Context.IntTy 2912 }; 2913 2914 // Without volatile 2915 if (NumArgs == 1) 2916 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2917 else 2918 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2919 2920 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 2921 // With volatile 2922 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 2923 if (NumArgs == 1) 2924 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2925 else 2926 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2927 } 2928 } 2929 break; 2930 2931 UnaryStar: 2932 // C++ [over.built]p6: 2933 // For every cv-qualified or cv-unqualified object type T, there 2934 // exist candidate operator functions of the form 2935 // 2936 // T& operator*(T*); 2937 // 2938 // C++ [over.built]p7: 2939 // For every function type T, there exist candidate operator 2940 // functions of the form 2941 // T& operator*(T*); 2942 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2943 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2944 QualType ParamTy = *Ptr; 2945 QualType PointeeTy = ParamTy->getAsPointerType()->getPointeeType(); 2946 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 2947 &ParamTy, Args, 1, CandidateSet); 2948 } 2949 break; 2950 2951 UnaryPlus: 2952 // C++ [over.built]p8: 2953 // For every type T, there exist candidate operator functions of 2954 // the form 2955 // 2956 // T* operator+(T*); 2957 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2958 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2959 QualType ParamTy = *Ptr; 2960 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 2961 } 2962 2963 // Fall through 2964 2965 UnaryMinus: 2966 // C++ [over.built]p9: 2967 // For every promoted arithmetic type T, there exist candidate 2968 // operator functions of the form 2969 // 2970 // T operator+(T); 2971 // T operator-(T); 2972 for (unsigned Arith = FirstPromotedArithmeticType; 2973 Arith < LastPromotedArithmeticType; ++Arith) { 2974 QualType ArithTy = ArithmeticTypes[Arith]; 2975 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 2976 } 2977 break; 2978 2979 case OO_Tilde: 2980 // C++ [over.built]p10: 2981 // For every promoted integral type T, there exist candidate 2982 // operator functions of the form 2983 // 2984 // T operator~(T); 2985 for (unsigned Int = FirstPromotedIntegralType; 2986 Int < LastPromotedIntegralType; ++Int) { 2987 QualType IntTy = ArithmeticTypes[Int]; 2988 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 2989 } 2990 break; 2991 2992 case OO_New: 2993 case OO_Delete: 2994 case OO_Array_New: 2995 case OO_Array_Delete: 2996 case OO_Call: 2997 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 2998 break; 2999 3000 case OO_Comma: 3001 UnaryAmp: 3002 case OO_Arrow: 3003 // C++ [over.match.oper]p3: 3004 // -- For the operator ',', the unary operator '&', or the 3005 // operator '->', the built-in candidates set is empty. 3006 break; 3007 3008 case OO_Less: 3009 case OO_Greater: 3010 case OO_LessEqual: 3011 case OO_GreaterEqual: 3012 case OO_EqualEqual: 3013 case OO_ExclaimEqual: 3014 // C++ [over.built]p15: 3015 // 3016 // For every pointer or enumeration type T, there exist 3017 // candidate operator functions of the form 3018 // 3019 // bool operator<(T, T); 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 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3026 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3027 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3028 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3029 } 3030 for (BuiltinCandidateTypeSet::iterator Enum 3031 = CandidateTypes.enumeration_begin(); 3032 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3033 QualType ParamTypes[2] = { *Enum, *Enum }; 3034 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3035 } 3036 3037 // Fall through. 3038 isComparison = true; 3039 3040 BinaryPlus: 3041 BinaryMinus: 3042 if (!isComparison) { 3043 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3044 3045 // C++ [over.built]p13: 3046 // 3047 // For every cv-qualified or cv-unqualified object type T 3048 // there exist candidate operator functions of the form 3049 // 3050 // T* operator+(T*, ptrdiff_t); 3051 // T& operator[](T*, ptrdiff_t); [BELOW] 3052 // T* operator-(T*, ptrdiff_t); 3053 // T* operator+(ptrdiff_t, T*); 3054 // T& operator[](ptrdiff_t, T*); [BELOW] 3055 // 3056 // C++ [over.built]p14: 3057 // 3058 // For every T, where T is a pointer to object type, there 3059 // exist candidate operator functions of the form 3060 // 3061 // ptrdiff_t operator-(T, T); 3062 for (BuiltinCandidateTypeSet::iterator Ptr 3063 = CandidateTypes.pointer_begin(); 3064 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3065 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3066 3067 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3068 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3069 3070 if (Op == OO_Plus) { 3071 // T* operator+(ptrdiff_t, T*); 3072 ParamTypes[0] = ParamTypes[1]; 3073 ParamTypes[1] = *Ptr; 3074 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3075 } else { 3076 // ptrdiff_t operator-(T, T); 3077 ParamTypes[1] = *Ptr; 3078 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3079 Args, 2, CandidateSet); 3080 } 3081 } 3082 } 3083 // Fall through 3084 3085 case OO_Slash: 3086 BinaryStar: 3087 Conditional: 3088 // C++ [over.built]p12: 3089 // 3090 // For every pair of promoted arithmetic types L and R, there 3091 // exist candidate operator functions of the form 3092 // 3093 // LR operator*(L, R); 3094 // LR operator/(L, R); 3095 // LR operator+(L, R); 3096 // LR operator-(L, R); 3097 // bool 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 // 3104 // where LR is the result of the usual arithmetic conversions 3105 // between types L and R. 3106 // 3107 // C++ [over.built]p24: 3108 // 3109 // For every pair of promoted arithmetic types L and R, there exist 3110 // candidate operator functions of the form 3111 // 3112 // LR operator?(bool, L, R); 3113 // 3114 // where LR is the result of the usual arithmetic conversions 3115 // between types L and R. 3116 // Our candidates ignore the first parameter. 3117 for (unsigned Left = FirstPromotedArithmeticType; 3118 Left < LastPromotedArithmeticType; ++Left) { 3119 for (unsigned Right = FirstPromotedArithmeticType; 3120 Right < LastPromotedArithmeticType; ++Right) { 3121 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3122 QualType Result 3123 = isComparison? Context.BoolTy 3124 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3125 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3126 } 3127 } 3128 break; 3129 3130 case OO_Percent: 3131 BinaryAmp: 3132 case OO_Caret: 3133 case OO_Pipe: 3134 case OO_LessLess: 3135 case OO_GreaterGreater: 3136 // C++ [over.built]p17: 3137 // 3138 // For every pair of promoted integral types L and R, there 3139 // exist candidate operator functions of the form 3140 // 3141 // LR operator%(L, R); 3142 // LR operator&(L, R); 3143 // LR operator^(L, R); 3144 // LR operator|(L, R); 3145 // L operator<<(L, R); 3146 // L operator>>(L, R); 3147 // 3148 // where LR is the result of the usual arithmetic conversions 3149 // between types L and R. 3150 for (unsigned Left = FirstPromotedIntegralType; 3151 Left < LastPromotedIntegralType; ++Left) { 3152 for (unsigned Right = FirstPromotedIntegralType; 3153 Right < LastPromotedIntegralType; ++Right) { 3154 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3155 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3156 ? LandR[0] 3157 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3158 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3159 } 3160 } 3161 break; 3162 3163 case OO_Equal: 3164 // C++ [over.built]p20: 3165 // 3166 // For every pair (T, VQ), where T is an enumeration or 3167 // (FIXME:) pointer to member type and VQ is either volatile or 3168 // empty, there exist candidate operator functions of the form 3169 // 3170 // VQ T& operator=(VQ T&, T); 3171 for (BuiltinCandidateTypeSet::iterator Enum 3172 = CandidateTypes.enumeration_begin(); 3173 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3174 QualType ParamTypes[2]; 3175 3176 // T& operator=(T&, T) 3177 ParamTypes[0] = Context.getLValueReferenceType(*Enum); 3178 ParamTypes[1] = *Enum; 3179 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3180 /*IsAssignmentOperator=*/false); 3181 3182 if (!Context.getCanonicalType(*Enum).isVolatileQualified()) { 3183 // volatile T& operator=(volatile T&, T) 3184 ParamTypes[0] = Context.getLValueReferenceType((*Enum).withVolatile()); 3185 ParamTypes[1] = *Enum; 3186 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3187 /*IsAssignmentOperator=*/false); 3188 } 3189 } 3190 // Fall through. 3191 3192 case OO_PlusEqual: 3193 case OO_MinusEqual: 3194 // C++ [over.built]p19: 3195 // 3196 // For every pair (T, VQ), where T is any type and VQ is either 3197 // volatile or empty, there exist candidate operator functions 3198 // of the form 3199 // 3200 // T*VQ& operator=(T*VQ&, T*); 3201 // 3202 // C++ [over.built]p21: 3203 // 3204 // For every pair (T, VQ), where T is a cv-qualified or 3205 // cv-unqualified object type and VQ is either volatile or 3206 // empty, there exist candidate operator functions of the form 3207 // 3208 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3209 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3210 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3211 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3212 QualType ParamTypes[2]; 3213 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3214 3215 // non-volatile version 3216 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3217 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3218 /*IsAssigmentOperator=*/Op == OO_Equal); 3219 3220 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3221 // volatile version 3222 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3223 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3224 /*IsAssigmentOperator=*/Op == OO_Equal); 3225 } 3226 } 3227 // Fall through. 3228 3229 case OO_StarEqual: 3230 case OO_SlashEqual: 3231 // C++ [over.built]p18: 3232 // 3233 // For every triple (L, VQ, R), where L is an arithmetic type, 3234 // VQ is either volatile or empty, and R is a promoted 3235 // arithmetic type, there exist candidate operator functions of 3236 // the form 3237 // 3238 // VQ L& operator=(VQ L&, R); 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 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3244 for (unsigned Right = FirstPromotedArithmeticType; 3245 Right < LastPromotedArithmeticType; ++Right) { 3246 QualType ParamTypes[2]; 3247 ParamTypes[1] = ArithmeticTypes[Right]; 3248 3249 // Add this built-in operator as a candidate (VQ is empty). 3250 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3251 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3252 /*IsAssigmentOperator=*/Op == OO_Equal); 3253 3254 // Add this built-in operator as a candidate (VQ is 'volatile'). 3255 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3256 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3257 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3258 /*IsAssigmentOperator=*/Op == OO_Equal); 3259 } 3260 } 3261 break; 3262 3263 case OO_PercentEqual: 3264 case OO_LessLessEqual: 3265 case OO_GreaterGreaterEqual: 3266 case OO_AmpEqual: 3267 case OO_CaretEqual: 3268 case OO_PipeEqual: 3269 // C++ [over.built]p22: 3270 // 3271 // For every triple (L, VQ, R), where L is an integral type, VQ 3272 // is either volatile or empty, and R is a promoted integral 3273 // type, there exist candidate operator functions of the form 3274 // 3275 // VQ L& operator%=(VQ L&, R); 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 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3282 for (unsigned Right = FirstPromotedIntegralType; 3283 Right < LastPromotedIntegralType; ++Right) { 3284 QualType ParamTypes[2]; 3285 ParamTypes[1] = ArithmeticTypes[Right]; 3286 3287 // Add this built-in operator as a candidate (VQ is empty). 3288 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3289 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3290 3291 // Add this built-in operator as a candidate (VQ is 'volatile'). 3292 ParamTypes[0] = ArithmeticTypes[Left]; 3293 ParamTypes[0].addVolatile(); 3294 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3295 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3296 } 3297 } 3298 break; 3299 3300 case OO_Exclaim: { 3301 // C++ [over.operator]p23: 3302 // 3303 // There also exist candidate operator functions of the form 3304 // 3305 // bool operator!(bool); 3306 // bool operator&&(bool, bool); [BELOW] 3307 // bool operator||(bool, bool); [BELOW] 3308 QualType ParamTy = Context.BoolTy; 3309 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3310 /*IsAssignmentOperator=*/false, 3311 /*NumContextualBoolArguments=*/1); 3312 break; 3313 } 3314 3315 case OO_AmpAmp: 3316 case OO_PipePipe: { 3317 // C++ [over.operator]p23: 3318 // 3319 // There also exist candidate operator functions of the form 3320 // 3321 // bool operator!(bool); [ABOVE] 3322 // bool operator&&(bool, bool); 3323 // bool operator||(bool, bool); 3324 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3325 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3326 /*IsAssignmentOperator=*/false, 3327 /*NumContextualBoolArguments=*/2); 3328 break; 3329 } 3330 3331 case OO_Subscript: 3332 // C++ [over.built]p13: 3333 // 3334 // For every cv-qualified or cv-unqualified object type T there 3335 // exist candidate operator functions of the form 3336 // 3337 // T* operator+(T*, ptrdiff_t); [ABOVE] 3338 // T& operator[](T*, ptrdiff_t); 3339 // T* operator-(T*, ptrdiff_t); [ABOVE] 3340 // T* operator+(ptrdiff_t, T*); [ABOVE] 3341 // T& operator[](ptrdiff_t, T*); 3342 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3343 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3344 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3345 QualType PointeeType = (*Ptr)->getAsPointerType()->getPointeeType(); 3346 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3347 3348 // T& operator[](T*, ptrdiff_t) 3349 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3350 3351 // T& operator[](ptrdiff_t, T*); 3352 ParamTypes[0] = ParamTypes[1]; 3353 ParamTypes[1] = *Ptr; 3354 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3355 } 3356 break; 3357 3358 case OO_ArrowStar: 3359 // FIXME: No support for pointer-to-members yet. 3360 break; 3361 3362 case OO_Conditional: 3363 // Note that we don't consider the first argument, since it has been 3364 // contextually converted to bool long ago. The candidates below are 3365 // therefore added as binary. 3366 // 3367 // C++ [over.built]p24: 3368 // For every type T, where T is a pointer or pointer-to-member type, 3369 // there exist candidate operator functions of the form 3370 // 3371 // T operator?(bool, T, T); 3372 // 3373 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3374 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3375 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3376 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3377 } 3378 for (BuiltinCandidateTypeSet::iterator Ptr = 3379 CandidateTypes.member_pointer_begin(), 3380 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3381 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3382 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3383 } 3384 goto Conditional; 3385 } 3386} 3387 3388/// \brief Add function candidates found via argument-dependent lookup 3389/// to the set of overloading candidates. 3390/// 3391/// This routine performs argument-dependent name lookup based on the 3392/// given function name (which may also be an operator name) and adds 3393/// all of the overload candidates found by ADL to the overload 3394/// candidate set (C++ [basic.lookup.argdep]). 3395void 3396Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3397 Expr **Args, unsigned NumArgs, 3398 OverloadCandidateSet& CandidateSet) { 3399 FunctionSet Functions; 3400 3401 // Record all of the function candidates that we've already 3402 // added to the overload set, so that we don't add those same 3403 // candidates a second time. 3404 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3405 CandEnd = CandidateSet.end(); 3406 Cand != CandEnd; ++Cand) 3407 if (Cand->Function) { 3408 Functions.insert(Cand->Function); 3409 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3410 Functions.insert(FunTmpl); 3411 } 3412 3413 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3414 3415 // Erase all of the candidates we already knew about. 3416 // FIXME: This is suboptimal. Is there a better way? 3417 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3418 CandEnd = CandidateSet.end(); 3419 Cand != CandEnd; ++Cand) 3420 if (Cand->Function) { 3421 Functions.erase(Cand->Function); 3422 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3423 Functions.erase(FunTmpl); 3424 } 3425 3426 // For each of the ADL candidates we found, add it to the overload 3427 // set. 3428 for (FunctionSet::iterator Func = Functions.begin(), 3429 FuncEnd = Functions.end(); 3430 Func != FuncEnd; ++Func) { 3431 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) 3432 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet); 3433 else 3434 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3435 /*FIXME: explicit args */false, 0, 0, 3436 Args, NumArgs, CandidateSet); 3437 } 3438} 3439 3440/// isBetterOverloadCandidate - Determines whether the first overload 3441/// candidate is a better candidate than the second (C++ 13.3.3p1). 3442bool 3443Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3444 const OverloadCandidate& Cand2) 3445{ 3446 // Define viable functions to be better candidates than non-viable 3447 // functions. 3448 if (!Cand2.Viable) 3449 return Cand1.Viable; 3450 else if (!Cand1.Viable) 3451 return false; 3452 3453 // C++ [over.match.best]p1: 3454 // 3455 // -- if F is a static member function, ICS1(F) is defined such 3456 // that ICS1(F) is neither better nor worse than ICS1(G) for 3457 // any function G, and, symmetrically, ICS1(G) is neither 3458 // better nor worse than ICS1(F). 3459 unsigned StartArg = 0; 3460 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3461 StartArg = 1; 3462 3463 // C++ [over.match.best]p1: 3464 // A viable function F1 is defined to be a better function than another 3465 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3466 // conversion sequence than ICSi(F2), and then... 3467 unsigned NumArgs = Cand1.Conversions.size(); 3468 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3469 bool HasBetterConversion = false; 3470 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3471 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3472 Cand2.Conversions[ArgIdx])) { 3473 case ImplicitConversionSequence::Better: 3474 // Cand1 has a better conversion sequence. 3475 HasBetterConversion = true; 3476 break; 3477 3478 case ImplicitConversionSequence::Worse: 3479 // Cand1 can't be better than Cand2. 3480 return false; 3481 3482 case ImplicitConversionSequence::Indistinguishable: 3483 // Do nothing. 3484 break; 3485 } 3486 } 3487 3488 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3489 // ICSj(F2), or, if not that, 3490 if (HasBetterConversion) 3491 return true; 3492 3493 // - F1 is a non-template function and F2 is a function template 3494 // specialization, or, if not that, 3495 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3496 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3497 return true; 3498 3499 // -- F1 and F2 are function template specializations, and the function 3500 // template for F1 is more specialized than the template for F2 3501 // according to the partial ordering rules described in 14.5.5.2, or, 3502 // if not that, 3503 3504 // FIXME: Implement partial ordering of function templates. 3505 3506 // -- the context is an initialization by user-defined conversion 3507 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3508 // from the return type of F1 to the destination type (i.e., 3509 // the type of the entity being initialized) is a better 3510 // conversion sequence than the standard conversion sequence 3511 // from the return type of F2 to the destination type. 3512 if (Cand1.Function && Cand2.Function && 3513 isa<CXXConversionDecl>(Cand1.Function) && 3514 isa<CXXConversionDecl>(Cand2.Function)) { 3515 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3516 Cand2.FinalConversion)) { 3517 case ImplicitConversionSequence::Better: 3518 // Cand1 has a better conversion sequence. 3519 return true; 3520 3521 case ImplicitConversionSequence::Worse: 3522 // Cand1 can't be better than Cand2. 3523 return false; 3524 3525 case ImplicitConversionSequence::Indistinguishable: 3526 // Do nothing 3527 break; 3528 } 3529 } 3530 3531 return false; 3532} 3533 3534/// \brief Computes the best viable function (C++ 13.3.3) 3535/// within an overload candidate set. 3536/// 3537/// \param CandidateSet the set of candidate functions. 3538/// 3539/// \param Loc the location of the function name (or operator symbol) for 3540/// which overload resolution occurs. 3541/// 3542/// \param Best f overload resolution was successful or found a deleted 3543/// function, Best points to the candidate function found. 3544/// 3545/// \returns The result of overload resolution. 3546Sema::OverloadingResult 3547Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3548 SourceLocation Loc, 3549 OverloadCandidateSet::iterator& Best) 3550{ 3551 // Find the best viable function. 3552 Best = CandidateSet.end(); 3553 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3554 Cand != CandidateSet.end(); ++Cand) { 3555 if (Cand->Viable) { 3556 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3557 Best = Cand; 3558 } 3559 } 3560 3561 // If we didn't find any viable functions, abort. 3562 if (Best == CandidateSet.end()) 3563 return OR_No_Viable_Function; 3564 3565 // Make sure that this function is better than every other viable 3566 // function. If not, we have an ambiguity. 3567 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3568 Cand != CandidateSet.end(); ++Cand) { 3569 if (Cand->Viable && 3570 Cand != Best && 3571 !isBetterOverloadCandidate(*Best, *Cand)) { 3572 Best = CandidateSet.end(); 3573 return OR_Ambiguous; 3574 } 3575 } 3576 3577 // Best is the best viable function. 3578 if (Best->Function && 3579 (Best->Function->isDeleted() || 3580 Best->Function->getAttr<UnavailableAttr>())) 3581 return OR_Deleted; 3582 3583 // C++ [basic.def.odr]p2: 3584 // An overloaded function is used if it is selected by overload resolution 3585 // when referred to from a potentially-evaluated expression. [Note: this 3586 // covers calls to named functions (5.2.2), operator overloading 3587 // (clause 13), user-defined conversions (12.3.2), allocation function for 3588 // placement new (5.3.4), as well as non-default initialization (8.5). 3589 if (Best->Function) 3590 MarkDeclarationReferenced(Loc, Best->Function); 3591 return OR_Success; 3592} 3593 3594/// PrintOverloadCandidates - When overload resolution fails, prints 3595/// diagnostic messages containing the candidates in the candidate 3596/// set. If OnlyViable is true, only viable candidates will be printed. 3597void 3598Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3599 bool OnlyViable) 3600{ 3601 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3602 LastCand = CandidateSet.end(); 3603 for (; Cand != LastCand; ++Cand) { 3604 if (Cand->Viable || !OnlyViable) { 3605 if (Cand->Function) { 3606 if (Cand->Function->isDeleted() || 3607 Cand->Function->getAttr<UnavailableAttr>()) { 3608 // Deleted or "unavailable" function. 3609 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3610 << Cand->Function->isDeleted(); 3611 } else { 3612 // Normal function 3613 // FIXME: Give a better reason! 3614 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3615 } 3616 } else if (Cand->IsSurrogate) { 3617 // Desugar the type of the surrogate down to a function type, 3618 // retaining as many typedefs as possible while still showing 3619 // the function type (and, therefore, its parameter types). 3620 QualType FnType = Cand->Surrogate->getConversionType(); 3621 bool isLValueReference = false; 3622 bool isRValueReference = false; 3623 bool isPointer = false; 3624 if (const LValueReferenceType *FnTypeRef = 3625 FnType->getAsLValueReferenceType()) { 3626 FnType = FnTypeRef->getPointeeType(); 3627 isLValueReference = true; 3628 } else if (const RValueReferenceType *FnTypeRef = 3629 FnType->getAsRValueReferenceType()) { 3630 FnType = FnTypeRef->getPointeeType(); 3631 isRValueReference = true; 3632 } 3633 if (const PointerType *FnTypePtr = FnType->getAsPointerType()) { 3634 FnType = FnTypePtr->getPointeeType(); 3635 isPointer = true; 3636 } 3637 // Desugar down to a function type. 3638 FnType = QualType(FnType->getAsFunctionType(), 0); 3639 // Reconstruct the pointer/reference as appropriate. 3640 if (isPointer) FnType = Context.getPointerType(FnType); 3641 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3642 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3643 3644 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3645 << FnType; 3646 } else { 3647 // FIXME: We need to get the identifier in here 3648 // FIXME: Do we want the error message to point at the operator? 3649 // (built-ins won't have a location) 3650 QualType FnType 3651 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3652 Cand->BuiltinTypes.ParamTypes, 3653 Cand->Conversions.size(), 3654 false, 0); 3655 3656 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3657 } 3658 } 3659 } 3660} 3661 3662/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3663/// an overloaded function (C++ [over.over]), where @p From is an 3664/// expression with overloaded function type and @p ToType is the type 3665/// we're trying to resolve to. For example: 3666/// 3667/// @code 3668/// int f(double); 3669/// int f(int); 3670/// 3671/// int (*pfd)(double) = f; // selects f(double) 3672/// @endcode 3673/// 3674/// This routine returns the resulting FunctionDecl if it could be 3675/// resolved, and NULL otherwise. When @p Complain is true, this 3676/// routine will emit diagnostics if there is an error. 3677FunctionDecl * 3678Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3679 bool Complain) { 3680 QualType FunctionType = ToType; 3681 bool IsMember = false; 3682 if (const PointerType *ToTypePtr = ToType->getAsPointerType()) 3683 FunctionType = ToTypePtr->getPointeeType(); 3684 else if (const ReferenceType *ToTypeRef = ToType->getAsReferenceType()) 3685 FunctionType = ToTypeRef->getPointeeType(); 3686 else if (const MemberPointerType *MemTypePtr = 3687 ToType->getAsMemberPointerType()) { 3688 FunctionType = MemTypePtr->getPointeeType(); 3689 IsMember = true; 3690 } 3691 3692 // We only look at pointers or references to functions. 3693 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 3694 if (!FunctionType->isFunctionType()) 3695 return 0; 3696 3697 // Find the actual overloaded function declaration. 3698 OverloadedFunctionDecl *Ovl = 0; 3699 3700 // C++ [over.over]p1: 3701 // [...] [Note: any redundant set of parentheses surrounding the 3702 // overloaded function name is ignored (5.1). ] 3703 Expr *OvlExpr = From->IgnoreParens(); 3704 3705 // C++ [over.over]p1: 3706 // [...] The overloaded function name can be preceded by the & 3707 // operator. 3708 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3709 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3710 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3711 } 3712 3713 // Try to dig out the overloaded function. 3714 FunctionTemplateDecl *FunctionTemplate = 0; 3715 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 3716 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3717 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 3718 } 3719 3720 // If there's no overloaded function declaration or function template, 3721 // we're done. 3722 if (!Ovl && !FunctionTemplate) 3723 return 0; 3724 3725 OverloadIterator Fun; 3726 if (Ovl) 3727 Fun = Ovl; 3728 else 3729 Fun = FunctionTemplate; 3730 3731 // Look through all of the overloaded functions, searching for one 3732 // whose type matches exactly. 3733 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 3734 3735 bool FoundNonTemplateFunction = false; 3736 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 3737 // C++ [over.over]p3: 3738 // Non-member functions and static member functions match 3739 // targets of type "pointer-to-function" or "reference-to-function." 3740 // Nonstatic member functions match targets of 3741 // type "pointer-to-member-function." 3742 // Note that according to DR 247, the containing class does not matter. 3743 3744 if (FunctionTemplateDecl *FunctionTemplate 3745 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 3746 if (CXXMethodDecl *Method 3747 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 3748 // Skip non-static function templates when converting to pointer, and 3749 // static when converting to member pointer. 3750 if (Method->isStatic() == IsMember) 3751 continue; 3752 } else if (IsMember) 3753 continue; 3754 3755 // C++ [over.over]p2: 3756 // If the name is a function template, template argument deduction is 3757 // done (14.8.2.2), and if the argument deduction succeeds, the 3758 // resulting template argument list is used to generate a single 3759 // function template specialization, which is added to the set of 3760 // overloaded functions considered. 3761 FunctionDecl *Specialization = 0; 3762 TemplateDeductionInfo Info(Context); 3763 if (TemplateDeductionResult Result 3764 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 3765 /*FIXME:*/0, /*FIXME:*/0, 3766 FunctionType, Specialization, Info)) { 3767 // FIXME: make a note of the failed deduction for diagnostics. 3768 (void)Result; 3769 } else { 3770 assert(FunctionType 3771 == Context.getCanonicalType(Specialization->getType())); 3772 Matches.insert( 3773 cast<FunctionDecl>(Context.getCanonicalDecl(Specialization))); 3774 } 3775 } 3776 3777 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 3778 // Skip non-static functions when converting to pointer, and static 3779 // when converting to member pointer. 3780 if (Method->isStatic() == IsMember) 3781 continue; 3782 } else if (IsMember) 3783 continue; 3784 3785 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 3786 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 3787 Matches.insert(cast<FunctionDecl>(Context.getCanonicalDecl(*Fun))); 3788 FoundNonTemplateFunction = true; 3789 } 3790 } 3791 } 3792 3793 // If there were 0 or 1 matches, we're done. 3794 if (Matches.empty()) 3795 return 0; 3796 else if (Matches.size() == 1) 3797 return *Matches.begin(); 3798 3799 // C++ [over.over]p4: 3800 // If more than one function is selected, [...] 3801 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 3802 if (FoundNonTemplateFunction) { 3803 // [...] any function template specializations in the set are eliminated 3804 // if the set also contains a non-template function, [...] 3805 for (llvm::SmallPtrSet<FunctionDecl *, 4>::iterator M = Matches.begin(), 3806 MEnd = Matches.end(); 3807 M != MEnd; ++M) 3808 if ((*M)->getPrimaryTemplate() == 0) 3809 RemainingMatches.push_back(*M); 3810 } else { 3811 // [...] and any given function template specialization F1 is eliminated 3812 // if the set contains a second function template specialization whose 3813 // function template is more specialized than the function template of F1 3814 // according to the partial ordering rules of 14.5.5.2. 3815 // FIXME: Implement this! 3816 RemainingMatches.append(Matches.begin(), Matches.end()); 3817 } 3818 3819 // [...] After such eliminations, if any, there shall remain exactly one 3820 // selected function. 3821 if (RemainingMatches.size() == 1) 3822 return RemainingMatches.front(); 3823 3824 // FIXME: We should probably return the same thing that BestViableFunction 3825 // returns (even if we issue the diagnostics here). 3826 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 3827 << RemainingMatches[0]->getDeclName(); 3828 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 3829 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 3830 return 0; 3831} 3832 3833/// ResolveOverloadedCallFn - Given the call expression that calls Fn 3834/// (which eventually refers to the declaration Func) and the call 3835/// arguments Args/NumArgs, attempt to resolve the function call down 3836/// to a specific function. If overload resolution succeeds, returns 3837/// the function declaration produced by overload 3838/// resolution. Otherwise, emits diagnostics, deletes all of the 3839/// arguments and Fn, and returns NULL. 3840FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 3841 DeclarationName UnqualifiedName, 3842 bool HasExplicitTemplateArgs, 3843 const TemplateArgument *ExplicitTemplateArgs, 3844 unsigned NumExplicitTemplateArgs, 3845 SourceLocation LParenLoc, 3846 Expr **Args, unsigned NumArgs, 3847 SourceLocation *CommaLocs, 3848 SourceLocation RParenLoc, 3849 bool &ArgumentDependentLookup) { 3850 OverloadCandidateSet CandidateSet; 3851 3852 // Add the functions denoted by Callee to the set of candidate 3853 // functions. While we're doing so, track whether argument-dependent 3854 // lookup still applies, per: 3855 // 3856 // C++0x [basic.lookup.argdep]p3: 3857 // Let X be the lookup set produced by unqualified lookup (3.4.1) 3858 // and let Y be the lookup set produced by argument dependent 3859 // lookup (defined as follows). If X contains 3860 // 3861 // -- a declaration of a class member, or 3862 // 3863 // -- a block-scope function declaration that is not a 3864 // using-declaration, or 3865 // 3866 // -- a declaration that is neither a function or a function 3867 // template 3868 // 3869 // then Y is empty. 3870 if (OverloadedFunctionDecl *Ovl 3871 = dyn_cast_or_null<OverloadedFunctionDecl>(Callee)) { 3872 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 3873 FuncEnd = Ovl->function_end(); 3874 Func != FuncEnd; ++Func) { 3875 DeclContext *Ctx = 0; 3876 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Func)) { 3877 if (HasExplicitTemplateArgs) 3878 continue; 3879 3880 AddOverloadCandidate(FunDecl, Args, NumArgs, CandidateSet); 3881 Ctx = FunDecl->getDeclContext(); 3882 } else { 3883 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*Func); 3884 AddTemplateOverloadCandidate(FunTmpl, HasExplicitTemplateArgs, 3885 ExplicitTemplateArgs, 3886 NumExplicitTemplateArgs, 3887 Args, NumArgs, CandidateSet); 3888 Ctx = FunTmpl->getDeclContext(); 3889 } 3890 3891 3892 if (Ctx->isRecord() || Ctx->isFunctionOrMethod()) 3893 ArgumentDependentLookup = false; 3894 } 3895 } else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee)) { 3896 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 3897 AddOverloadCandidate(Func, Args, NumArgs, CandidateSet); 3898 3899 if (Func->getDeclContext()->isRecord() || 3900 Func->getDeclContext()->isFunctionOrMethod()) 3901 ArgumentDependentLookup = false; 3902 } else if (FunctionTemplateDecl *FuncTemplate 3903 = dyn_cast_or_null<FunctionTemplateDecl>(Callee)) { 3904 AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 3905 ExplicitTemplateArgs, 3906 NumExplicitTemplateArgs, 3907 Args, NumArgs, CandidateSet); 3908 3909 if (FuncTemplate->getDeclContext()->isRecord()) 3910 ArgumentDependentLookup = false; 3911 } 3912 3913 if (Callee) 3914 UnqualifiedName = Callee->getDeclName(); 3915 3916 // FIXME: Pass explicit template arguments through for ADL 3917 if (ArgumentDependentLookup) 3918 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 3919 CandidateSet); 3920 3921 OverloadCandidateSet::iterator Best; 3922 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 3923 case OR_Success: 3924 return Best->Function; 3925 3926 case OR_No_Viable_Function: 3927 Diag(Fn->getSourceRange().getBegin(), 3928 diag::err_ovl_no_viable_function_in_call) 3929 << UnqualifiedName << Fn->getSourceRange(); 3930 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3931 break; 3932 3933 case OR_Ambiguous: 3934 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 3935 << UnqualifiedName << Fn->getSourceRange(); 3936 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3937 break; 3938 3939 case OR_Deleted: 3940 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 3941 << Best->Function->isDeleted() 3942 << UnqualifiedName 3943 << Fn->getSourceRange(); 3944 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3945 break; 3946 } 3947 3948 // Overload resolution failed. Destroy all of the subexpressions and 3949 // return NULL. 3950 Fn->Destroy(Context); 3951 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 3952 Args[Arg]->Destroy(Context); 3953 return 0; 3954} 3955 3956/// \brief Create a unary operation that may resolve to an overloaded 3957/// operator. 3958/// 3959/// \param OpLoc The location of the operator itself (e.g., '*'). 3960/// 3961/// \param OpcIn The UnaryOperator::Opcode that describes this 3962/// operator. 3963/// 3964/// \param Functions The set of non-member functions that will be 3965/// considered by overload resolution. The caller needs to build this 3966/// set based on the context using, e.g., 3967/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 3968/// set should not contain any member functions; those will be added 3969/// by CreateOverloadedUnaryOp(). 3970/// 3971/// \param input The input argument. 3972Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 3973 unsigned OpcIn, 3974 FunctionSet &Functions, 3975 ExprArg input) { 3976 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 3977 Expr *Input = (Expr *)input.get(); 3978 3979 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 3980 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 3981 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3982 3983 Expr *Args[2] = { Input, 0 }; 3984 unsigned NumArgs = 1; 3985 3986 // For post-increment and post-decrement, add the implicit '0' as 3987 // the second argument, so that we know this is a post-increment or 3988 // post-decrement. 3989 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 3990 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 3991 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 3992 SourceLocation()); 3993 NumArgs = 2; 3994 } 3995 3996 if (Input->isTypeDependent()) { 3997 OverloadedFunctionDecl *Overloads 3998 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 3999 for (FunctionSet::iterator Func = Functions.begin(), 4000 FuncEnd = Functions.end(); 4001 Func != FuncEnd; ++Func) 4002 Overloads->addOverload(*Func); 4003 4004 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4005 OpLoc, false, false); 4006 4007 input.release(); 4008 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4009 &Args[0], NumArgs, 4010 Context.DependentTy, 4011 OpLoc)); 4012 } 4013 4014 // Build an empty overload set. 4015 OverloadCandidateSet CandidateSet; 4016 4017 // Add the candidates from the given function set. 4018 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4019 4020 // Add operator candidates that are member functions. 4021 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4022 4023 // Add builtin operator candidates. 4024 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4025 4026 // Perform overload resolution. 4027 OverloadCandidateSet::iterator Best; 4028 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4029 case OR_Success: { 4030 // We found a built-in operator or an overloaded operator. 4031 FunctionDecl *FnDecl = Best->Function; 4032 4033 if (FnDecl) { 4034 // We matched an overloaded operator. Build a call to that 4035 // operator. 4036 4037 // Convert the arguments. 4038 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4039 if (PerformObjectArgumentInitialization(Input, Method)) 4040 return ExprError(); 4041 } else { 4042 // Convert the arguments. 4043 if (PerformCopyInitialization(Input, 4044 FnDecl->getParamDecl(0)->getType(), 4045 "passing")) 4046 return ExprError(); 4047 } 4048 4049 // Determine the result type 4050 QualType ResultTy 4051 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4052 ResultTy = ResultTy.getNonReferenceType(); 4053 4054 // Build the actual expression node. 4055 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4056 SourceLocation()); 4057 UsualUnaryConversions(FnExpr); 4058 4059 input.release(); 4060 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4061 &Input, 1, ResultTy, 4062 OpLoc)); 4063 } else { 4064 // We matched a built-in operator. Convert the arguments, then 4065 // break out so that we will build the appropriate built-in 4066 // operator node. 4067 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4068 Best->Conversions[0], "passing")) 4069 return ExprError(); 4070 4071 break; 4072 } 4073 } 4074 4075 case OR_No_Viable_Function: 4076 // No viable function; fall through to handling this as a 4077 // built-in operator, which will produce an error message for us. 4078 break; 4079 4080 case OR_Ambiguous: 4081 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4082 << UnaryOperator::getOpcodeStr(Opc) 4083 << Input->getSourceRange(); 4084 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4085 return ExprError(); 4086 4087 case OR_Deleted: 4088 Diag(OpLoc, diag::err_ovl_deleted_oper) 4089 << Best->Function->isDeleted() 4090 << UnaryOperator::getOpcodeStr(Opc) 4091 << Input->getSourceRange(); 4092 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4093 return ExprError(); 4094 } 4095 4096 // Either we found no viable overloaded operator or we matched a 4097 // built-in operator. In either case, fall through to trying to 4098 // build a built-in operation. 4099 input.release(); 4100 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4101} 4102 4103/// \brief Create a binary operation that may resolve to an overloaded 4104/// operator. 4105/// 4106/// \param OpLoc The location of the operator itself (e.g., '+'). 4107/// 4108/// \param OpcIn The BinaryOperator::Opcode that describes this 4109/// operator. 4110/// 4111/// \param Functions The set of non-member functions that will be 4112/// considered by overload resolution. The caller needs to build this 4113/// set based on the context using, e.g., 4114/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4115/// set should not contain any member functions; those will be added 4116/// by CreateOverloadedBinOp(). 4117/// 4118/// \param LHS Left-hand argument. 4119/// \param RHS Right-hand argument. 4120Sema::OwningExprResult 4121Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4122 unsigned OpcIn, 4123 FunctionSet &Functions, 4124 Expr *LHS, Expr *RHS) { 4125 Expr *Args[2] = { LHS, RHS }; 4126 4127 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4128 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4129 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4130 4131 // If either side is type-dependent, create an appropriate dependent 4132 // expression. 4133 if (LHS->isTypeDependent() || RHS->isTypeDependent()) { 4134 // .* cannot be overloaded. 4135 if (Opc == BinaryOperator::PtrMemD) 4136 return Owned(new (Context) BinaryOperator(LHS, RHS, Opc, 4137 Context.DependentTy, OpLoc)); 4138 4139 OverloadedFunctionDecl *Overloads 4140 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4141 for (FunctionSet::iterator Func = Functions.begin(), 4142 FuncEnd = Functions.end(); 4143 Func != FuncEnd; ++Func) 4144 Overloads->addOverload(*Func); 4145 4146 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4147 OpLoc, false, false); 4148 4149 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4150 Args, 2, 4151 Context.DependentTy, 4152 OpLoc)); 4153 } 4154 4155 // If this is the .* operator, which is not overloadable, just 4156 // create a built-in binary operator. 4157 if (Opc == BinaryOperator::PtrMemD) 4158 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4159 4160 // If this is one of the assignment operators, we only perform 4161 // overload resolution if the left-hand side is a class or 4162 // enumeration type (C++ [expr.ass]p3). 4163 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4164 !LHS->getType()->isOverloadableType()) 4165 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4166 4167 // Build an empty overload set. 4168 OverloadCandidateSet CandidateSet; 4169 4170 // Add the candidates from the given function set. 4171 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4172 4173 // Add operator candidates that are member functions. 4174 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4175 4176 // Add builtin operator candidates. 4177 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4178 4179 // Perform overload resolution. 4180 OverloadCandidateSet::iterator Best; 4181 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4182 case OR_Success: { 4183 // We found a built-in operator or an overloaded operator. 4184 FunctionDecl *FnDecl = Best->Function; 4185 4186 if (FnDecl) { 4187 // We matched an overloaded operator. Build a call to that 4188 // operator. 4189 4190 // Convert the arguments. 4191 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4192 if (PerformObjectArgumentInitialization(LHS, Method) || 4193 PerformCopyInitialization(RHS, FnDecl->getParamDecl(0)->getType(), 4194 "passing")) 4195 return ExprError(); 4196 } else { 4197 // Convert the arguments. 4198 if (PerformCopyInitialization(LHS, FnDecl->getParamDecl(0)->getType(), 4199 "passing") || 4200 PerformCopyInitialization(RHS, FnDecl->getParamDecl(1)->getType(), 4201 "passing")) 4202 return ExprError(); 4203 } 4204 4205 // Determine the result type 4206 QualType ResultTy 4207 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4208 ResultTy = ResultTy.getNonReferenceType(); 4209 4210 // Build the actual expression node. 4211 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4212 OpLoc); 4213 UsualUnaryConversions(FnExpr); 4214 4215 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4216 Args, 2, ResultTy, 4217 OpLoc)); 4218 } else { 4219 // We matched a built-in operator. Convert the arguments, then 4220 // break out so that we will build the appropriate built-in 4221 // operator node. 4222 if (PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0], 4223 Best->Conversions[0], "passing") || 4224 PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1], 4225 Best->Conversions[1], "passing")) 4226 return ExprError(); 4227 4228 break; 4229 } 4230 } 4231 4232 case OR_No_Viable_Function: 4233 // For class as left operand for assignment or compound assigment operator 4234 // do not fall through to handling in built-in, but report that no overloaded 4235 // assignment operator found 4236 if (LHS->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4237 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4238 << BinaryOperator::getOpcodeStr(Opc) 4239 << LHS->getSourceRange() << RHS->getSourceRange(); 4240 return ExprError(); 4241 } 4242 // No viable function; fall through to handling this as a 4243 // built-in operator, which will produce an error message for us. 4244 break; 4245 4246 case OR_Ambiguous: 4247 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4248 << BinaryOperator::getOpcodeStr(Opc) 4249 << LHS->getSourceRange() << RHS->getSourceRange(); 4250 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4251 return ExprError(); 4252 4253 case OR_Deleted: 4254 Diag(OpLoc, diag::err_ovl_deleted_oper) 4255 << Best->Function->isDeleted() 4256 << BinaryOperator::getOpcodeStr(Opc) 4257 << LHS->getSourceRange() << RHS->getSourceRange(); 4258 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4259 return ExprError(); 4260 } 4261 4262 // Either we found no viable overloaded operator or we matched a 4263 // built-in operator. In either case, try to build a built-in 4264 // operation. 4265 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4266} 4267 4268/// BuildCallToMemberFunction - Build a call to a member 4269/// function. MemExpr is the expression that refers to the member 4270/// function (and includes the object parameter), Args/NumArgs are the 4271/// arguments to the function call (not including the object 4272/// parameter). The caller needs to validate that the member 4273/// expression refers to a member function or an overloaded member 4274/// function. 4275Sema::ExprResult 4276Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4277 SourceLocation LParenLoc, Expr **Args, 4278 unsigned NumArgs, SourceLocation *CommaLocs, 4279 SourceLocation RParenLoc) { 4280 // Dig out the member expression. This holds both the object 4281 // argument and the member function we're referring to. 4282 MemberExpr *MemExpr = 0; 4283 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4284 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4285 else 4286 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4287 assert(MemExpr && "Building member call without member expression"); 4288 4289 // Extract the object argument. 4290 Expr *ObjectArg = MemExpr->getBase(); 4291 4292 CXXMethodDecl *Method = 0; 4293 if (OverloadedFunctionDecl *Ovl 4294 = dyn_cast<OverloadedFunctionDecl>(MemExpr->getMemberDecl())) { 4295 // Add overload candidates 4296 OverloadCandidateSet CandidateSet; 4297 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4298 FuncEnd = Ovl->function_end(); 4299 Func != FuncEnd; ++Func) { 4300 assert(isa<CXXMethodDecl>(*Func) && "Function is not a method"); 4301 Method = cast<CXXMethodDecl>(*Func); 4302 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4303 /*SuppressUserConversions=*/false); 4304 } 4305 4306 OverloadCandidateSet::iterator Best; 4307 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4308 case OR_Success: 4309 Method = cast<CXXMethodDecl>(Best->Function); 4310 break; 4311 4312 case OR_No_Viable_Function: 4313 Diag(MemExpr->getSourceRange().getBegin(), 4314 diag::err_ovl_no_viable_member_function_in_call) 4315 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4316 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4317 // FIXME: Leaking incoming expressions! 4318 return true; 4319 4320 case OR_Ambiguous: 4321 Diag(MemExpr->getSourceRange().getBegin(), 4322 diag::err_ovl_ambiguous_member_call) 4323 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4324 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4325 // FIXME: Leaking incoming expressions! 4326 return true; 4327 4328 case OR_Deleted: 4329 Diag(MemExpr->getSourceRange().getBegin(), 4330 diag::err_ovl_deleted_member_call) 4331 << Best->Function->isDeleted() 4332 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4333 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4334 // FIXME: Leaking incoming expressions! 4335 return true; 4336 } 4337 4338 FixOverloadedFunctionReference(MemExpr, Method); 4339 } else { 4340 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4341 } 4342 4343 assert(Method && "Member call to something that isn't a method?"); 4344 ExprOwningPtr<CXXMemberCallExpr> 4345 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4346 NumArgs, 4347 Method->getResultType().getNonReferenceType(), 4348 RParenLoc)); 4349 4350 // Convert the object argument (for a non-static member function call). 4351 if (!Method->isStatic() && 4352 PerformObjectArgumentInitialization(ObjectArg, Method)) 4353 return true; 4354 MemExpr->setBase(ObjectArg); 4355 4356 // Convert the rest of the arguments 4357 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4358 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4359 RParenLoc)) 4360 return true; 4361 4362 return CheckFunctionCall(Method, TheCall.take()).release(); 4363} 4364 4365/// BuildCallToObjectOfClassType - Build a call to an object of class 4366/// type (C++ [over.call.object]), which can end up invoking an 4367/// overloaded function call operator (@c operator()) or performing a 4368/// user-defined conversion on the object argument. 4369Sema::ExprResult 4370Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4371 SourceLocation LParenLoc, 4372 Expr **Args, unsigned NumArgs, 4373 SourceLocation *CommaLocs, 4374 SourceLocation RParenLoc) { 4375 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4376 const RecordType *Record = Object->getType()->getAsRecordType(); 4377 4378 // C++ [over.call.object]p1: 4379 // If the primary-expression E in the function call syntax 4380 // evaluates to a class object of type “cv T”, then the set of 4381 // candidate functions includes at least the function call 4382 // operators of T. The function call operators of T are obtained by 4383 // ordinary lookup of the name operator() in the context of 4384 // (E).operator(). 4385 OverloadCandidateSet CandidateSet; 4386 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4387 DeclContext::lookup_const_iterator Oper, OperEnd; 4388 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4389 Oper != OperEnd; ++Oper) 4390 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4391 CandidateSet, /*SuppressUserConversions=*/false); 4392 4393 // C++ [over.call.object]p2: 4394 // In addition, for each conversion function declared in T of the 4395 // form 4396 // 4397 // operator conversion-type-id () cv-qualifier; 4398 // 4399 // where cv-qualifier is the same cv-qualification as, or a 4400 // greater cv-qualification than, cv, and where conversion-type-id 4401 // denotes the type "pointer to function of (P1,...,Pn) returning 4402 // R", or the type "reference to pointer to function of 4403 // (P1,...,Pn) returning R", or the type "reference to function 4404 // of (P1,...,Pn) returning R", a surrogate call function [...] 4405 // is also considered as a candidate function. Similarly, 4406 // surrogate call functions are added to the set of candidate 4407 // functions for each conversion function declared in an 4408 // accessible base class provided the function is not hidden 4409 // within T by another intervening declaration. 4410 // 4411 // FIXME: Look in base classes for more conversion operators! 4412 OverloadedFunctionDecl *Conversions 4413 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4414 for (OverloadedFunctionDecl::function_iterator 4415 Func = Conversions->function_begin(), 4416 FuncEnd = Conversions->function_end(); 4417 Func != FuncEnd; ++Func) { 4418 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 4419 4420 // Strip the reference type (if any) and then the pointer type (if 4421 // any) to get down to what might be a function type. 4422 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4423 if (const PointerType *ConvPtrType = ConvType->getAsPointerType()) 4424 ConvType = ConvPtrType->getPointeeType(); 4425 4426 if (const FunctionProtoType *Proto = ConvType->getAsFunctionProtoType()) 4427 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4428 } 4429 4430 // Perform overload resolution. 4431 OverloadCandidateSet::iterator Best; 4432 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4433 case OR_Success: 4434 // Overload resolution succeeded; we'll build the appropriate call 4435 // below. 4436 break; 4437 4438 case OR_No_Viable_Function: 4439 Diag(Object->getSourceRange().getBegin(), 4440 diag::err_ovl_no_viable_object_call) 4441 << Object->getType() << Object->getSourceRange(); 4442 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4443 break; 4444 4445 case OR_Ambiguous: 4446 Diag(Object->getSourceRange().getBegin(), 4447 diag::err_ovl_ambiguous_object_call) 4448 << Object->getType() << Object->getSourceRange(); 4449 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4450 break; 4451 4452 case OR_Deleted: 4453 Diag(Object->getSourceRange().getBegin(), 4454 diag::err_ovl_deleted_object_call) 4455 << Best->Function->isDeleted() 4456 << Object->getType() << Object->getSourceRange(); 4457 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4458 break; 4459 } 4460 4461 if (Best == CandidateSet.end()) { 4462 // We had an error; delete all of the subexpressions and return 4463 // the error. 4464 Object->Destroy(Context); 4465 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4466 Args[ArgIdx]->Destroy(Context); 4467 return true; 4468 } 4469 4470 if (Best->Function == 0) { 4471 // Since there is no function declaration, this is one of the 4472 // surrogate candidates. Dig out the conversion function. 4473 CXXConversionDecl *Conv 4474 = cast<CXXConversionDecl>( 4475 Best->Conversions[0].UserDefined.ConversionFunction); 4476 4477 // We selected one of the surrogate functions that converts the 4478 // object parameter to a function pointer. Perform the conversion 4479 // on the object argument, then let ActOnCallExpr finish the job. 4480 // FIXME: Represent the user-defined conversion in the AST! 4481 ImpCastExprToType(Object, 4482 Conv->getConversionType().getNonReferenceType(), 4483 Conv->getConversionType()->isLValueReferenceType()); 4484 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4485 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4486 CommaLocs, RParenLoc).release(); 4487 } 4488 4489 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4490 // that calls this method, using Object for the implicit object 4491 // parameter and passing along the remaining arguments. 4492 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4493 const FunctionProtoType *Proto = Method->getType()->getAsFunctionProtoType(); 4494 4495 unsigned NumArgsInProto = Proto->getNumArgs(); 4496 unsigned NumArgsToCheck = NumArgs; 4497 4498 // Build the full argument list for the method call (the 4499 // implicit object parameter is placed at the beginning of the 4500 // list). 4501 Expr **MethodArgs; 4502 if (NumArgs < NumArgsInProto) { 4503 NumArgsToCheck = NumArgsInProto; 4504 MethodArgs = new Expr*[NumArgsInProto + 1]; 4505 } else { 4506 MethodArgs = new Expr*[NumArgs + 1]; 4507 } 4508 MethodArgs[0] = Object; 4509 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4510 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4511 4512 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4513 SourceLocation()); 4514 UsualUnaryConversions(NewFn); 4515 4516 // Once we've built TheCall, all of the expressions are properly 4517 // owned. 4518 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4519 ExprOwningPtr<CXXOperatorCallExpr> 4520 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4521 MethodArgs, NumArgs + 1, 4522 ResultTy, RParenLoc)); 4523 delete [] MethodArgs; 4524 4525 // We may have default arguments. If so, we need to allocate more 4526 // slots in the call for them. 4527 if (NumArgs < NumArgsInProto) 4528 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4529 else if (NumArgs > NumArgsInProto) 4530 NumArgsToCheck = NumArgsInProto; 4531 4532 bool IsError = false; 4533 4534 // Initialize the implicit object parameter. 4535 IsError |= PerformObjectArgumentInitialization(Object, Method); 4536 TheCall->setArg(0, Object); 4537 4538 4539 // Check the argument types. 4540 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4541 Expr *Arg; 4542 if (i < NumArgs) { 4543 Arg = Args[i]; 4544 4545 // Pass the argument. 4546 QualType ProtoArgType = Proto->getArgType(i); 4547 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4548 } else { 4549 Arg = new (Context) CXXDefaultArgExpr(Method->getParamDecl(i)); 4550 } 4551 4552 TheCall->setArg(i + 1, Arg); 4553 } 4554 4555 // If this is a variadic call, handle args passed through "...". 4556 if (Proto->isVariadic()) { 4557 // Promote the arguments (C99 6.5.2.2p7). 4558 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4559 Expr *Arg = Args[i]; 4560 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4561 TheCall->setArg(i + 1, Arg); 4562 } 4563 } 4564 4565 if (IsError) return true; 4566 4567 return CheckFunctionCall(Method, TheCall.take()).release(); 4568} 4569 4570/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4571/// (if one exists), where @c Base is an expression of class type and 4572/// @c Member is the name of the member we're trying to find. 4573Action::ExprResult 4574Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc, 4575 SourceLocation MemberLoc, 4576 IdentifierInfo &Member) { 4577 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4578 4579 // C++ [over.ref]p1: 4580 // 4581 // [...] An expression x->m is interpreted as (x.operator->())->m 4582 // for a class object x of type T if T::operator->() exists and if 4583 // the operator is selected as the best match function by the 4584 // overload resolution mechanism (13.3). 4585 // FIXME: look in base classes. 4586 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4587 OverloadCandidateSet CandidateSet; 4588 const RecordType *BaseRecord = Base->getType()->getAsRecordType(); 4589 4590 DeclContext::lookup_const_iterator Oper, OperEnd; 4591 for (llvm::tie(Oper, OperEnd) 4592 = BaseRecord->getDecl()->lookup(OpName); Oper != OperEnd; ++Oper) 4593 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4594 /*SuppressUserConversions=*/false); 4595 4596 ExprOwningPtr<Expr> BasePtr(this, Base); 4597 4598 // Perform overload resolution. 4599 OverloadCandidateSet::iterator Best; 4600 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4601 case OR_Success: 4602 // Overload resolution succeeded; we'll build the call below. 4603 break; 4604 4605 case OR_No_Viable_Function: 4606 if (CandidateSet.empty()) 4607 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4608 << BasePtr->getType() << BasePtr->getSourceRange(); 4609 else 4610 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4611 << "operator->" << BasePtr->getSourceRange(); 4612 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4613 return true; 4614 4615 case OR_Ambiguous: 4616 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4617 << "operator->" << BasePtr->getSourceRange(); 4618 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4619 return true; 4620 4621 case OR_Deleted: 4622 Diag(OpLoc, diag::err_ovl_deleted_oper) 4623 << Best->Function->isDeleted() 4624 << "operator->" << BasePtr->getSourceRange(); 4625 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4626 return true; 4627 } 4628 4629 // Convert the object parameter. 4630 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4631 if (PerformObjectArgumentInitialization(Base, Method)) 4632 return true; 4633 4634 // No concerns about early exits now. 4635 BasePtr.take(); 4636 4637 // Build the operator call. 4638 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 4639 SourceLocation()); 4640 UsualUnaryConversions(FnExpr); 4641 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 4642 Method->getResultType().getNonReferenceType(), 4643 OpLoc); 4644 return ActOnMemberReferenceExpr(S, ExprArg(*this, Base), OpLoc, tok::arrow, 4645 MemberLoc, Member, DeclPtrTy()).release(); 4646} 4647 4648/// FixOverloadedFunctionReference - E is an expression that refers to 4649/// a C++ overloaded function (possibly with some parentheses and 4650/// perhaps a '&' around it). We have resolved the overloaded function 4651/// to the function declaration Fn, so patch up the expression E to 4652/// refer (possibly indirectly) to Fn. 4653void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 4654 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4655 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 4656 E->setType(PE->getSubExpr()->getType()); 4657 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 4658 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 4659 "Can only take the address of an overloaded function"); 4660 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4661 if (Method->isStatic()) { 4662 // Do nothing: static member functions aren't any different 4663 // from non-member functions. 4664 } 4665 else if (QualifiedDeclRefExpr *DRE 4666 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 4667 // We have taken the address of a pointer to member 4668 // function. Perform the computation here so that we get the 4669 // appropriate pointer to member type. 4670 DRE->setDecl(Fn); 4671 DRE->setType(Fn->getType()); 4672 QualType ClassType 4673 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 4674 E->setType(Context.getMemberPointerType(Fn->getType(), 4675 ClassType.getTypePtr())); 4676 return; 4677 } 4678 } 4679 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 4680 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 4681 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 4682 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 4683 isa<FunctionTemplateDecl>(DR->getDecl())) && 4684 "Expected overloaded function or function template"); 4685 DR->setDecl(Fn); 4686 E->setType(Fn->getType()); 4687 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 4688 MemExpr->setMemberDecl(Fn); 4689 E->setType(Fn->getType()); 4690 } else { 4691 assert(false && "Invalid reference to overloaded function"); 4692 } 4693} 4694 4695} // end namespace clang 4696