SemaOverload.cpp revision 3e15cc318e9cd577eda56c0294f32535738d8630
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInherit.h" 16#include "clang/Basic/Diagnostic.h" 17#include "clang/Lex/Preprocessor.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/TypeOrdering.h" 22#include "llvm/ADT/SmallPtrSet.h" 23#include "llvm/ADT/STLExtras.h" 24#include "llvm/Support/Compiler.h" 25#include <algorithm> 26 27namespace clang { 28 29/// GetConversionCategory - Retrieve the implicit conversion 30/// category corresponding to the given implicit conversion kind. 31ImplicitConversionCategory 32GetConversionCategory(ImplicitConversionKind Kind) { 33 static const ImplicitConversionCategory 34 Category[(int)ICK_Num_Conversion_Kinds] = { 35 ICC_Identity, 36 ICC_Lvalue_Transformation, 37 ICC_Lvalue_Transformation, 38 ICC_Lvalue_Transformation, 39 ICC_Qualification_Adjustment, 40 ICC_Promotion, 41 ICC_Promotion, 42 ICC_Promotion, 43 ICC_Conversion, 44 ICC_Conversion, 45 ICC_Conversion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion 53 }; 54 return Category[(int)Kind]; 55} 56 57/// GetConversionRank - Retrieve the implicit conversion rank 58/// corresponding to the given implicit conversion kind. 59ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 60 static const ImplicitConversionRank 61 Rank[(int)ICK_Num_Conversion_Kinds] = { 62 ICR_Exact_Match, 63 ICR_Exact_Match, 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Promotion, 68 ICR_Promotion, 69 ICR_Promotion, 70 ICR_Conversion, 71 ICR_Conversion, 72 ICR_Conversion, 73 ICR_Conversion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion 80 }; 81 return Rank[(int)Kind]; 82} 83 84/// GetImplicitConversionName - Return the name of this kind of 85/// implicit conversion. 86const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 87 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 88 "No conversion", 89 "Lvalue-to-rvalue", 90 "Array-to-pointer", 91 "Function-to-pointer", 92 "Qualification", 93 "Integral promotion", 94 "Floating point promotion", 95 "Complex promotion", 96 "Integral conversion", 97 "Floating conversion", 98 "Complex conversion", 99 "Floating-integral conversion", 100 "Complex-real conversion", 101 "Pointer conversion", 102 "Pointer-to-member conversion", 103 "Boolean conversion", 104 "Compatible-types conversion", 105 "Derived-to-base conversion" 106 }; 107 return Name[Kind]; 108} 109 110/// StandardConversionSequence - Set the standard conversion 111/// sequence to the identity conversion. 112void StandardConversionSequence::setAsIdentityConversion() { 113 First = ICK_Identity; 114 Second = ICK_Identity; 115 Third = ICK_Identity; 116 Deprecated = false; 117 ReferenceBinding = false; 118 DirectBinding = false; 119 RRefBinding = false; 120 CopyConstructor = 0; 121} 122 123/// getRank - Retrieve the rank of this standard conversion sequence 124/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 125/// implicit conversions. 126ImplicitConversionRank StandardConversionSequence::getRank() const { 127 ImplicitConversionRank Rank = ICR_Exact_Match; 128 if (GetConversionRank(First) > Rank) 129 Rank = GetConversionRank(First); 130 if (GetConversionRank(Second) > Rank) 131 Rank = GetConversionRank(Second); 132 if (GetConversionRank(Third) > Rank) 133 Rank = GetConversionRank(Third); 134 return Rank; 135} 136 137/// isPointerConversionToBool - Determines whether this conversion is 138/// a conversion of a pointer or pointer-to-member to bool. This is 139/// used as part of the ranking of standard conversion sequences 140/// (C++ 13.3.3.2p4). 141bool StandardConversionSequence::isPointerConversionToBool() const 142{ 143 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 144 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 145 146 // Note that FromType has not necessarily been transformed by the 147 // array-to-pointer or function-to-pointer implicit conversions, so 148 // check for their presence as well as checking whether FromType is 149 // a pointer. 150 if (ToType->isBooleanType() && 151 (FromType->isPointerType() || FromType->isBlockPointerType() || 152 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 153 return true; 154 155 return false; 156} 157 158/// isPointerConversionToVoidPointer - Determines whether this 159/// conversion is a conversion of a pointer to a void pointer. This is 160/// used as part of the ranking of standard conversion sequences (C++ 161/// 13.3.3.2p4). 162bool 163StandardConversionSequence:: 164isPointerConversionToVoidPointer(ASTContext& Context) const 165{ 166 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 167 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion) 176 if (const PointerType* ToPtrType = ToType->getAsPointerType()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 bool PrintedSomething = false; 186 if (First != ICK_Identity) { 187 fprintf(stderr, "%s", GetImplicitConversionName(First)); 188 PrintedSomething = true; 189 } 190 191 if (Second != ICK_Identity) { 192 if (PrintedSomething) { 193 fprintf(stderr, " -> "); 194 } 195 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 196 197 if (CopyConstructor) { 198 fprintf(stderr, " (by copy constructor)"); 199 } else if (DirectBinding) { 200 fprintf(stderr, " (direct reference binding)"); 201 } else if (ReferenceBinding) { 202 fprintf(stderr, " (reference binding)"); 203 } 204 PrintedSomething = true; 205 } 206 207 if (Third != ICK_Identity) { 208 if (PrintedSomething) { 209 fprintf(stderr, " -> "); 210 } 211 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 212 PrintedSomething = true; 213 } 214 215 if (!PrintedSomething) { 216 fprintf(stderr, "No conversions required"); 217 } 218} 219 220/// DebugPrint - Print this user-defined conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void UserDefinedConversionSequence::DebugPrint() const { 223 if (Before.First || Before.Second || Before.Third) { 224 Before.DebugPrint(); 225 fprintf(stderr, " -> "); 226 } 227 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 228 if (After.First || After.Second || After.Third) { 229 fprintf(stderr, " -> "); 230 After.DebugPrint(); 231 } 232} 233 234/// DebugPrint - Print this implicit conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void ImplicitConversionSequence::DebugPrint() const { 237 switch (ConversionKind) { 238 case StandardConversion: 239 fprintf(stderr, "Standard conversion: "); 240 Standard.DebugPrint(); 241 break; 242 case UserDefinedConversion: 243 fprintf(stderr, "User-defined conversion: "); 244 UserDefined.DebugPrint(); 245 break; 246 case EllipsisConversion: 247 fprintf(stderr, "Ellipsis conversion"); 248 break; 249 case BadConversion: 250 fprintf(stderr, "Bad conversion"); 251 break; 252 } 253 254 fprintf(stderr, "\n"); 255} 256 257// IsOverload - Determine whether the given New declaration is an 258// overload of the Old declaration. This routine returns false if New 259// and Old cannot be overloaded, e.g., if they are functions with the 260// same signature (C++ 1.3.10) or if the Old declaration isn't a 261// function (or overload set). When it does return false and Old is an 262// OverloadedFunctionDecl, MatchedDecl will be set to point to the 263// FunctionDecl that New cannot be overloaded with. 264// 265// Example: Given the following input: 266// 267// void f(int, float); // #1 268// void f(int, int); // #2 269// int f(int, int); // #3 270// 271// When we process #1, there is no previous declaration of "f", 272// so IsOverload will not be used. 273// 274// When we process #2, Old is a FunctionDecl for #1. By comparing the 275// parameter types, we see that #1 and #2 are overloaded (since they 276// have different signatures), so this routine returns false; 277// MatchedDecl is unchanged. 278// 279// When we process #3, Old is an OverloadedFunctionDecl containing #1 280// and #2. We compare the signatures of #3 to #1 (they're overloaded, 281// so we do nothing) and then #3 to #2. Since the signatures of #3 and 282// #2 are identical (return types of functions are not part of the 283// signature), IsOverload returns false and MatchedDecl will be set to 284// point to the FunctionDecl for #2. 285bool 286Sema::IsOverload(FunctionDecl *New, Decl* OldD, 287 OverloadedFunctionDecl::function_iterator& MatchedDecl) 288{ 289 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 290 // Is this new function an overload of every function in the 291 // overload set? 292 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 293 FuncEnd = Ovl->function_end(); 294 for (; Func != FuncEnd; ++Func) { 295 if (!IsOverload(New, *Func, MatchedDecl)) { 296 MatchedDecl = Func; 297 return false; 298 } 299 } 300 301 // This function overloads every function in the overload set. 302 return true; 303 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 304 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 305 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 306 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 307 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 308 309 // C++ [temp.fct]p2: 310 // A function template can be overloaded with other function templates 311 // and with normal (non-template) functions. 312 if ((OldTemplate == 0) != (NewTemplate == 0)) 313 return true; 314 315 // Is the function New an overload of the function Old? 316 QualType OldQType = Context.getCanonicalType(Old->getType()); 317 QualType NewQType = Context.getCanonicalType(New->getType()); 318 319 // Compare the signatures (C++ 1.3.10) of the two functions to 320 // determine whether they are overloads. If we find any mismatch 321 // in the signature, they are overloads. 322 323 // If either of these functions is a K&R-style function (no 324 // prototype), then we consider them to have matching signatures. 325 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 326 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 327 return false; 328 329 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 330 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 331 332 // The signature of a function includes the types of its 333 // parameters (C++ 1.3.10), which includes the presence or absence 334 // of the ellipsis; see C++ DR 357). 335 if (OldQType != NewQType && 336 (OldType->getNumArgs() != NewType->getNumArgs() || 337 OldType->isVariadic() != NewType->isVariadic() || 338 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 339 NewType->arg_type_begin()))) 340 return true; 341 342 // C++ [temp.over.link]p4: 343 // The signature of a function template consists of its function 344 // signature, its return type and its template parameter list. The names 345 // of the template parameters are significant only for establishing the 346 // relationship between the template parameters and the rest of the 347 // signature. 348 // 349 // We check the return type and template parameter lists for function 350 // templates first; the remaining checks follow. 351 if (NewTemplate && 352 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 353 OldTemplate->getTemplateParameters(), 354 false, false, SourceLocation()) || 355 OldType->getResultType() != NewType->getResultType())) 356 return true; 357 358 // If the function is a class member, its signature includes the 359 // cv-qualifiers (if any) on the function itself. 360 // 361 // As part of this, also check whether one of the member functions 362 // is static, in which case they are not overloads (C++ 363 // 13.1p2). While not part of the definition of the signature, 364 // this check is important to determine whether these functions 365 // can be overloaded. 366 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 367 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 368 if (OldMethod && NewMethod && 369 !OldMethod->isStatic() && !NewMethod->isStatic() && 370 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 371 return true; 372 373 // The signatures match; this is not an overload. 374 return false; 375 } else { 376 // (C++ 13p1): 377 // Only function declarations can be overloaded; object and type 378 // declarations cannot be overloaded. 379 return false; 380 } 381} 382 383/// TryImplicitConversion - Attempt to perform an implicit conversion 384/// from the given expression (Expr) to the given type (ToType). This 385/// function returns an implicit conversion sequence that can be used 386/// to perform the initialization. Given 387/// 388/// void f(float f); 389/// void g(int i) { f(i); } 390/// 391/// this routine would produce an implicit conversion sequence to 392/// describe the initialization of f from i, which will be a standard 393/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 394/// 4.1) followed by a floating-integral conversion (C++ 4.9). 395// 396/// Note that this routine only determines how the conversion can be 397/// performed; it does not actually perform the conversion. As such, 398/// it will not produce any diagnostics if no conversion is available, 399/// but will instead return an implicit conversion sequence of kind 400/// "BadConversion". 401/// 402/// If @p SuppressUserConversions, then user-defined conversions are 403/// not permitted. 404/// If @p AllowExplicit, then explicit user-defined conversions are 405/// permitted. 406/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 407/// no matter its actual lvalueness. 408ImplicitConversionSequence 409Sema::TryImplicitConversion(Expr* From, QualType ToType, 410 bool SuppressUserConversions, 411 bool AllowExplicit, bool ForceRValue) 412{ 413 ImplicitConversionSequence ICS; 414 if (IsStandardConversion(From, ToType, ICS.Standard)) 415 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 416 else if (getLangOptions().CPlusPlus && 417 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 418 !SuppressUserConversions, AllowExplicit, 419 ForceRValue)) { 420 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 421 // C++ [over.ics.user]p4: 422 // A conversion of an expression of class type to the same class 423 // type is given Exact Match rank, and a conversion of an 424 // expression of class type to a base class of that type is 425 // given Conversion rank, in spite of the fact that a copy 426 // constructor (i.e., a user-defined conversion function) is 427 // called for those cases. 428 if (CXXConstructorDecl *Constructor 429 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 430 QualType FromCanon 431 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 432 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 433 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 434 // Turn this into a "standard" conversion sequence, so that it 435 // gets ranked with standard conversion sequences. 436 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 437 ICS.Standard.setAsIdentityConversion(); 438 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 439 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 440 ICS.Standard.CopyConstructor = Constructor; 441 if (ToCanon != FromCanon) 442 ICS.Standard.Second = ICK_Derived_To_Base; 443 } 444 } 445 446 // C++ [over.best.ics]p4: 447 // However, when considering the argument of a user-defined 448 // conversion function that is a candidate by 13.3.1.3 when 449 // invoked for the copying of the temporary in the second step 450 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 451 // 13.3.1.6 in all cases, only standard conversion sequences and 452 // ellipsis conversion sequences are allowed. 453 if (SuppressUserConversions && 454 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 455 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 456 } else 457 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 458 459 return ICS; 460} 461 462/// IsStandardConversion - Determines whether there is a standard 463/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 464/// expression From to the type ToType. Standard conversion sequences 465/// only consider non-class types; for conversions that involve class 466/// types, use TryImplicitConversion. If a conversion exists, SCS will 467/// contain the standard conversion sequence required to perform this 468/// conversion and this routine will return true. Otherwise, this 469/// routine will return false and the value of SCS is unspecified. 470bool 471Sema::IsStandardConversion(Expr* From, QualType ToType, 472 StandardConversionSequence &SCS) 473{ 474 QualType FromType = From->getType(); 475 476 // Standard conversions (C++ [conv]) 477 SCS.setAsIdentityConversion(); 478 SCS.Deprecated = false; 479 SCS.IncompatibleObjC = false; 480 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 481 SCS.CopyConstructor = 0; 482 483 // There are no standard conversions for class types in C++, so 484 // abort early. When overloading in C, however, we do permit 485 if (FromType->isRecordType() || ToType->isRecordType()) { 486 if (getLangOptions().CPlusPlus) 487 return false; 488 489 // When we're overloading in C, we allow, as standard conversions, 490 } 491 492 // The first conversion can be an lvalue-to-rvalue conversion, 493 // array-to-pointer conversion, or function-to-pointer conversion 494 // (C++ 4p1). 495 496 // Lvalue-to-rvalue conversion (C++ 4.1): 497 // An lvalue (3.10) of a non-function, non-array type T can be 498 // converted to an rvalue. 499 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 500 if (argIsLvalue == Expr::LV_Valid && 501 !FromType->isFunctionType() && !FromType->isArrayType() && 502 Context.getCanonicalType(FromType) != Context.OverloadTy) { 503 SCS.First = ICK_Lvalue_To_Rvalue; 504 505 // If T is a non-class type, the type of the rvalue is the 506 // cv-unqualified version of T. Otherwise, the type of the rvalue 507 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 508 // just strip the qualifiers because they don't matter. 509 510 // FIXME: Doesn't see through to qualifiers behind a typedef! 511 FromType = FromType.getUnqualifiedType(); 512 } 513 // Array-to-pointer conversion (C++ 4.2) 514 else if (FromType->isArrayType()) { 515 SCS.First = ICK_Array_To_Pointer; 516 517 // An lvalue or rvalue of type "array of N T" or "array of unknown 518 // bound of T" can be converted to an rvalue of type "pointer to 519 // T" (C++ 4.2p1). 520 FromType = Context.getArrayDecayedType(FromType); 521 522 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 523 // This conversion is deprecated. (C++ D.4). 524 SCS.Deprecated = true; 525 526 // For the purpose of ranking in overload resolution 527 // (13.3.3.1.1), this conversion is considered an 528 // array-to-pointer conversion followed by a qualification 529 // conversion (4.4). (C++ 4.2p2) 530 SCS.Second = ICK_Identity; 531 SCS.Third = ICK_Qualification; 532 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 533 return true; 534 } 535 } 536 // Function-to-pointer conversion (C++ 4.3). 537 else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 538 SCS.First = ICK_Function_To_Pointer; 539 540 // An lvalue of function type T can be converted to an rvalue of 541 // type "pointer to T." The result is a pointer to the 542 // function. (C++ 4.3p1). 543 FromType = Context.getPointerType(FromType); 544 } 545 // Address of overloaded function (C++ [over.over]). 546 else if (FunctionDecl *Fn 547 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 548 SCS.First = ICK_Function_To_Pointer; 549 550 // We were able to resolve the address of the overloaded function, 551 // so we can convert to the type of that function. 552 FromType = Fn->getType(); 553 if (ToType->isLValueReferenceType()) 554 FromType = Context.getLValueReferenceType(FromType); 555 else if (ToType->isRValueReferenceType()) 556 FromType = Context.getRValueReferenceType(FromType); 557 else if (ToType->isMemberPointerType()) { 558 // Resolve address only succeeds if both sides are member pointers, 559 // but it doesn't have to be the same class. See DR 247. 560 // Note that this means that the type of &Derived::fn can be 561 // Ret (Base::*)(Args) if the fn overload actually found is from the 562 // base class, even if it was brought into the derived class via a 563 // using declaration. The standard isn't clear on this issue at all. 564 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 565 FromType = Context.getMemberPointerType(FromType, 566 Context.getTypeDeclType(M->getParent()).getTypePtr()); 567 } else 568 FromType = Context.getPointerType(FromType); 569 } 570 // We don't require any conversions for the first step. 571 else { 572 SCS.First = ICK_Identity; 573 } 574 575 // The second conversion can be an integral promotion, floating 576 // point promotion, integral conversion, floating point conversion, 577 // floating-integral conversion, pointer conversion, 578 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 579 // For overloading in C, this can also be a "compatible-type" 580 // conversion. 581 bool IncompatibleObjC = false; 582 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 583 // The unqualified versions of the types are the same: there's no 584 // conversion to do. 585 SCS.Second = ICK_Identity; 586 } 587 // Integral promotion (C++ 4.5). 588 else if (IsIntegralPromotion(From, FromType, ToType)) { 589 SCS.Second = ICK_Integral_Promotion; 590 FromType = ToType.getUnqualifiedType(); 591 } 592 // Floating point promotion (C++ 4.6). 593 else if (IsFloatingPointPromotion(FromType, ToType)) { 594 SCS.Second = ICK_Floating_Promotion; 595 FromType = ToType.getUnqualifiedType(); 596 } 597 // Complex promotion (Clang extension) 598 else if (IsComplexPromotion(FromType, ToType)) { 599 SCS.Second = ICK_Complex_Promotion; 600 FromType = ToType.getUnqualifiedType(); 601 } 602 // Integral conversions (C++ 4.7). 603 // FIXME: isIntegralType shouldn't be true for enums in C++. 604 else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 605 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 606 SCS.Second = ICK_Integral_Conversion; 607 FromType = ToType.getUnqualifiedType(); 608 } 609 // Floating point conversions (C++ 4.8). 610 else if (FromType->isFloatingType() && ToType->isFloatingType()) { 611 SCS.Second = ICK_Floating_Conversion; 612 FromType = ToType.getUnqualifiedType(); 613 } 614 // Complex conversions (C99 6.3.1.6) 615 else if (FromType->isComplexType() && ToType->isComplexType()) { 616 SCS.Second = ICK_Complex_Conversion; 617 FromType = ToType.getUnqualifiedType(); 618 } 619 // Floating-integral conversions (C++ 4.9). 620 // FIXME: isIntegralType shouldn't be true for enums in C++. 621 else if ((FromType->isFloatingType() && 622 ToType->isIntegralType() && !ToType->isBooleanType() && 623 !ToType->isEnumeralType()) || 624 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 625 ToType->isFloatingType())) { 626 SCS.Second = ICK_Floating_Integral; 627 FromType = ToType.getUnqualifiedType(); 628 } 629 // Complex-real conversions (C99 6.3.1.7) 630 else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 631 (ToType->isComplexType() && FromType->isArithmeticType())) { 632 SCS.Second = ICK_Complex_Real; 633 FromType = ToType.getUnqualifiedType(); 634 } 635 // Pointer conversions (C++ 4.10). 636 else if (IsPointerConversion(From, FromType, ToType, FromType, 637 IncompatibleObjC)) { 638 SCS.Second = ICK_Pointer_Conversion; 639 SCS.IncompatibleObjC = IncompatibleObjC; 640 } 641 // Pointer to member conversions (4.11). 642 else if (IsMemberPointerConversion(From, FromType, ToType, FromType)) { 643 SCS.Second = ICK_Pointer_Member; 644 } 645 // Boolean conversions (C++ 4.12). 646 else if (ToType->isBooleanType() && 647 (FromType->isArithmeticType() || 648 FromType->isEnumeralType() || 649 FromType->isPointerType() || 650 FromType->isBlockPointerType() || 651 FromType->isMemberPointerType() || 652 FromType->isNullPtrType())) { 653 SCS.Second = ICK_Boolean_Conversion; 654 FromType = Context.BoolTy; 655 } 656 // Compatible conversions (Clang extension for C function overloading) 657 else if (!getLangOptions().CPlusPlus && 658 Context.typesAreCompatible(ToType, FromType)) { 659 SCS.Second = ICK_Compatible_Conversion; 660 } else { 661 // No second conversion required. 662 SCS.Second = ICK_Identity; 663 } 664 665 QualType CanonFrom; 666 QualType CanonTo; 667 // The third conversion can be a qualification conversion (C++ 4p1). 668 if (IsQualificationConversion(FromType, ToType)) { 669 SCS.Third = ICK_Qualification; 670 FromType = ToType; 671 CanonFrom = Context.getCanonicalType(FromType); 672 CanonTo = Context.getCanonicalType(ToType); 673 } else { 674 // No conversion required 675 SCS.Third = ICK_Identity; 676 677 // C++ [over.best.ics]p6: 678 // [...] Any difference in top-level cv-qualification is 679 // subsumed by the initialization itself and does not constitute 680 // a conversion. [...] 681 CanonFrom = Context.getCanonicalType(FromType); 682 CanonTo = Context.getCanonicalType(ToType); 683 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 684 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 685 FromType = ToType; 686 CanonFrom = CanonTo; 687 } 688 } 689 690 // If we have not converted the argument type to the parameter type, 691 // this is a bad conversion sequence. 692 if (CanonFrom != CanonTo) 693 return false; 694 695 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 696 return true; 697} 698 699/// IsIntegralPromotion - Determines whether the conversion from the 700/// expression From (whose potentially-adjusted type is FromType) to 701/// ToType is an integral promotion (C++ 4.5). If so, returns true and 702/// sets PromotedType to the promoted type. 703bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) 704{ 705 const BuiltinType *To = ToType->getAsBuiltinType(); 706 // All integers are built-in. 707 if (!To) { 708 return false; 709 } 710 711 // An rvalue of type char, signed char, unsigned char, short int, or 712 // unsigned short int can be converted to an rvalue of type int if 713 // int can represent all the values of the source type; otherwise, 714 // the source rvalue can be converted to an rvalue of type unsigned 715 // int (C++ 4.5p1). 716 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 717 if (// We can promote any signed, promotable integer type to an int 718 (FromType->isSignedIntegerType() || 719 // We can promote any unsigned integer type whose size is 720 // less than int to an int. 721 (!FromType->isSignedIntegerType() && 722 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 723 return To->getKind() == BuiltinType::Int; 724 } 725 726 return To->getKind() == BuiltinType::UInt; 727 } 728 729 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 730 // can be converted to an rvalue of the first of the following types 731 // that can represent all the values of its underlying type: int, 732 // unsigned int, long, or unsigned long (C++ 4.5p2). 733 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 734 && ToType->isIntegerType()) { 735 // Determine whether the type we're converting from is signed or 736 // unsigned. 737 bool FromIsSigned; 738 uint64_t FromSize = Context.getTypeSize(FromType); 739 if (const EnumType *FromEnumType = FromType->getAsEnumType()) { 740 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 741 FromIsSigned = UnderlyingType->isSignedIntegerType(); 742 } else { 743 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 744 FromIsSigned = true; 745 } 746 747 // The types we'll try to promote to, in the appropriate 748 // order. Try each of these types. 749 QualType PromoteTypes[6] = { 750 Context.IntTy, Context.UnsignedIntTy, 751 Context.LongTy, Context.UnsignedLongTy , 752 Context.LongLongTy, Context.UnsignedLongLongTy 753 }; 754 for (int Idx = 0; Idx < 6; ++Idx) { 755 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 756 if (FromSize < ToSize || 757 (FromSize == ToSize && 758 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 759 // We found the type that we can promote to. If this is the 760 // type we wanted, we have a promotion. Otherwise, no 761 // promotion. 762 return Context.getCanonicalType(ToType).getUnqualifiedType() 763 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 764 } 765 } 766 } 767 768 // An rvalue for an integral bit-field (9.6) can be converted to an 769 // rvalue of type int if int can represent all the values of the 770 // bit-field; otherwise, it can be converted to unsigned int if 771 // unsigned int can represent all the values of the bit-field. If 772 // the bit-field is larger yet, no integral promotion applies to 773 // it. If the bit-field has an enumerated type, it is treated as any 774 // other value of that type for promotion purposes (C++ 4.5p3). 775 // FIXME: We should delay checking of bit-fields until we actually perform the 776 // conversion. 777 using llvm::APSInt; 778 if (From) 779 if (FieldDecl *MemberDecl = From->getBitField()) { 780 APSInt BitWidth; 781 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 782 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 783 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 784 ToSize = Context.getTypeSize(ToType); 785 786 // Are we promoting to an int from a bitfield that fits in an int? 787 if (BitWidth < ToSize || 788 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 789 return To->getKind() == BuiltinType::Int; 790 } 791 792 // Are we promoting to an unsigned int from an unsigned bitfield 793 // that fits into an unsigned int? 794 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 795 return To->getKind() == BuiltinType::UInt; 796 } 797 798 return false; 799 } 800 } 801 802 // An rvalue of type bool can be converted to an rvalue of type int, 803 // with false becoming zero and true becoming one (C++ 4.5p4). 804 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 805 return true; 806 } 807 808 return false; 809} 810 811/// IsFloatingPointPromotion - Determines whether the conversion from 812/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 813/// returns true and sets PromotedType to the promoted type. 814bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) 815{ 816 /// An rvalue of type float can be converted to an rvalue of type 817 /// double. (C++ 4.6p1). 818 if (const BuiltinType *FromBuiltin = FromType->getAsBuiltinType()) 819 if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType()) { 820 if (FromBuiltin->getKind() == BuiltinType::Float && 821 ToBuiltin->getKind() == BuiltinType::Double) 822 return true; 823 824 // C99 6.3.1.5p1: 825 // When a float is promoted to double or long double, or a 826 // double is promoted to long double [...]. 827 if (!getLangOptions().CPlusPlus && 828 (FromBuiltin->getKind() == BuiltinType::Float || 829 FromBuiltin->getKind() == BuiltinType::Double) && 830 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 831 return true; 832 } 833 834 return false; 835} 836 837/// \brief Determine if a conversion is a complex promotion. 838/// 839/// A complex promotion is defined as a complex -> complex conversion 840/// where the conversion between the underlying real types is a 841/// floating-point or integral promotion. 842bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 843 const ComplexType *FromComplex = FromType->getAsComplexType(); 844 if (!FromComplex) 845 return false; 846 847 const ComplexType *ToComplex = ToType->getAsComplexType(); 848 if (!ToComplex) 849 return false; 850 851 return IsFloatingPointPromotion(FromComplex->getElementType(), 852 ToComplex->getElementType()) || 853 IsIntegralPromotion(0, FromComplex->getElementType(), 854 ToComplex->getElementType()); 855} 856 857/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 858/// the pointer type FromPtr to a pointer to type ToPointee, with the 859/// same type qualifiers as FromPtr has on its pointee type. ToType, 860/// if non-empty, will be a pointer to ToType that may or may not have 861/// the right set of qualifiers on its pointee. 862static QualType 863BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 864 QualType ToPointee, QualType ToType, 865 ASTContext &Context) { 866 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 867 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 868 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 869 870 // Exact qualifier match -> return the pointer type we're converting to. 871 if (CanonToPointee.getCVRQualifiers() == Quals) { 872 // ToType is exactly what we need. Return it. 873 if (ToType.getTypePtr()) 874 return ToType; 875 876 // Build a pointer to ToPointee. It has the right qualifiers 877 // already. 878 return Context.getPointerType(ToPointee); 879 } 880 881 // Just build a canonical type that has the right qualifiers. 882 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 883} 884 885/// IsPointerConversion - Determines whether the conversion of the 886/// expression From, which has the (possibly adjusted) type FromType, 887/// can be converted to the type ToType via a pointer conversion (C++ 888/// 4.10). If so, returns true and places the converted type (that 889/// might differ from ToType in its cv-qualifiers at some level) into 890/// ConvertedType. 891/// 892/// This routine also supports conversions to and from block pointers 893/// and conversions with Objective-C's 'id', 'id<protocols...>', and 894/// pointers to interfaces. FIXME: Once we've determined the 895/// appropriate overloading rules for Objective-C, we may want to 896/// split the Objective-C checks into a different routine; however, 897/// GCC seems to consider all of these conversions to be pointer 898/// conversions, so for now they live here. IncompatibleObjC will be 899/// set if the conversion is an allowed Objective-C conversion that 900/// should result in a warning. 901bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 902 QualType& ConvertedType, 903 bool &IncompatibleObjC) 904{ 905 IncompatibleObjC = false; 906 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 907 return true; 908 909 // Conversion from a null pointer constant to any Objective-C pointer type. 910 if (Context.isObjCObjectPointerType(ToType) && 911 From->isNullPointerConstant(Context)) { 912 ConvertedType = ToType; 913 return true; 914 } 915 916 // Blocks: Block pointers can be converted to void*. 917 if (FromType->isBlockPointerType() && ToType->isPointerType() && 918 ToType->getAsPointerType()->getPointeeType()->isVoidType()) { 919 ConvertedType = ToType; 920 return true; 921 } 922 // Blocks: A null pointer constant can be converted to a block 923 // pointer type. 924 if (ToType->isBlockPointerType() && From->isNullPointerConstant(Context)) { 925 ConvertedType = ToType; 926 return true; 927 } 928 929 // If the left-hand-side is nullptr_t, the right side can be a null 930 // pointer constant. 931 if (ToType->isNullPtrType() && From->isNullPointerConstant(Context)) { 932 ConvertedType = ToType; 933 return true; 934 } 935 936 const PointerType* ToTypePtr = ToType->getAsPointerType(); 937 if (!ToTypePtr) 938 return false; 939 940 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 941 if (From->isNullPointerConstant(Context)) { 942 ConvertedType = ToType; 943 return true; 944 } 945 946 // Beyond this point, both types need to be pointers. 947 const PointerType *FromTypePtr = FromType->getAsPointerType(); 948 if (!FromTypePtr) 949 return false; 950 951 QualType FromPointeeType = FromTypePtr->getPointeeType(); 952 QualType ToPointeeType = ToTypePtr->getPointeeType(); 953 954 // An rvalue of type "pointer to cv T," where T is an object type, 955 // can be converted to an rvalue of type "pointer to cv void" (C++ 956 // 4.10p2). 957 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 958 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 959 ToPointeeType, 960 ToType, Context); 961 return true; 962 } 963 964 // When we're overloading in C, we allow a special kind of pointer 965 // conversion for compatible-but-not-identical pointee types. 966 if (!getLangOptions().CPlusPlus && 967 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 968 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 969 ToPointeeType, 970 ToType, Context); 971 return true; 972 } 973 974 // C++ [conv.ptr]p3: 975 // 976 // An rvalue of type "pointer to cv D," where D is a class type, 977 // can be converted to an rvalue of type "pointer to cv B," where 978 // B is a base class (clause 10) of D. If B is an inaccessible 979 // (clause 11) or ambiguous (10.2) base class of D, a program that 980 // necessitates this conversion is ill-formed. The result of the 981 // conversion is a pointer to the base class sub-object of the 982 // derived class object. The null pointer value is converted to 983 // the null pointer value of the destination type. 984 // 985 // Note that we do not check for ambiguity or inaccessibility 986 // here. That is handled by CheckPointerConversion. 987 if (getLangOptions().CPlusPlus && 988 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 989 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 990 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 991 ToPointeeType, 992 ToType, Context); 993 return true; 994 } 995 996 return false; 997} 998 999/// isObjCPointerConversion - Determines whether this is an 1000/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1001/// with the same arguments and return values. 1002bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1003 QualType& ConvertedType, 1004 bool &IncompatibleObjC) { 1005 if (!getLangOptions().ObjC1) 1006 return false; 1007 1008 // Conversions with Objective-C's id<...>. 1009 if ((FromType->isObjCQualifiedIdType() || ToType->isObjCQualifiedIdType()) && 1010 ObjCQualifiedIdTypesAreCompatible(ToType, FromType, /*compare=*/false)) { 1011 ConvertedType = ToType; 1012 return true; 1013 } 1014 1015 // Beyond this point, both types need to be pointers or block pointers. 1016 QualType ToPointeeType; 1017 const PointerType* ToTypePtr = ToType->getAsPointerType(); 1018 if (ToTypePtr) 1019 ToPointeeType = ToTypePtr->getPointeeType(); 1020 else if (const BlockPointerType *ToBlockPtr = ToType->getAsBlockPointerType()) 1021 ToPointeeType = ToBlockPtr->getPointeeType(); 1022 else 1023 return false; 1024 1025 QualType FromPointeeType; 1026 const PointerType *FromTypePtr = FromType->getAsPointerType(); 1027 if (FromTypePtr) 1028 FromPointeeType = FromTypePtr->getPointeeType(); 1029 else if (const BlockPointerType *FromBlockPtr 1030 = FromType->getAsBlockPointerType()) 1031 FromPointeeType = FromBlockPtr->getPointeeType(); 1032 else 1033 return false; 1034 1035 // Objective C++: We're able to convert from a pointer to an 1036 // interface to a pointer to a different interface. 1037 const ObjCInterfaceType* FromIface = FromPointeeType->getAsObjCInterfaceType(); 1038 const ObjCInterfaceType* ToIface = ToPointeeType->getAsObjCInterfaceType(); 1039 if (FromIface && ToIface && 1040 Context.canAssignObjCInterfaces(ToIface, FromIface)) { 1041 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1042 ToPointeeType, 1043 ToType, Context); 1044 return true; 1045 } 1046 1047 if (FromIface && ToIface && 1048 Context.canAssignObjCInterfaces(FromIface, ToIface)) { 1049 // Okay: this is some kind of implicit downcast of Objective-C 1050 // interfaces, which is permitted. However, we're going to 1051 // complain about it. 1052 IncompatibleObjC = true; 1053 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1054 ToPointeeType, 1055 ToType, Context); 1056 return true; 1057 } 1058 1059 // Objective C++: We're able to convert between "id" and a pointer 1060 // to any interface (in both directions). 1061 if ((FromIface && Context.isObjCIdStructType(ToPointeeType)) 1062 || (ToIface && Context.isObjCIdStructType(FromPointeeType))) { 1063 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1064 ToPointeeType, 1065 ToType, Context); 1066 return true; 1067 } 1068 1069 // Objective C++: Allow conversions between the Objective-C "id" and 1070 // "Class", in either direction. 1071 if ((Context.isObjCIdStructType(FromPointeeType) && 1072 Context.isObjCClassStructType(ToPointeeType)) || 1073 (Context.isObjCClassStructType(FromPointeeType) && 1074 Context.isObjCIdStructType(ToPointeeType))) { 1075 ConvertedType = ToType; 1076 return true; 1077 } 1078 1079 // If we have pointers to pointers, recursively check whether this 1080 // is an Objective-C conversion. 1081 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1082 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1083 IncompatibleObjC)) { 1084 // We always complain about this conversion. 1085 IncompatibleObjC = true; 1086 ConvertedType = ToType; 1087 return true; 1088 } 1089 1090 // If we have pointers to functions or blocks, check whether the only 1091 // differences in the argument and result types are in Objective-C 1092 // pointer conversions. If so, we permit the conversion (but 1093 // complain about it). 1094 const FunctionProtoType *FromFunctionType 1095 = FromPointeeType->getAsFunctionProtoType(); 1096 const FunctionProtoType *ToFunctionType 1097 = ToPointeeType->getAsFunctionProtoType(); 1098 if (FromFunctionType && ToFunctionType) { 1099 // If the function types are exactly the same, this isn't an 1100 // Objective-C pointer conversion. 1101 if (Context.getCanonicalType(FromPointeeType) 1102 == Context.getCanonicalType(ToPointeeType)) 1103 return false; 1104 1105 // Perform the quick checks that will tell us whether these 1106 // function types are obviously different. 1107 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1108 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1109 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1110 return false; 1111 1112 bool HasObjCConversion = false; 1113 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1114 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1115 // Okay, the types match exactly. Nothing to do. 1116 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1117 ToFunctionType->getResultType(), 1118 ConvertedType, IncompatibleObjC)) { 1119 // Okay, we have an Objective-C pointer conversion. 1120 HasObjCConversion = true; 1121 } else { 1122 // Function types are too different. Abort. 1123 return false; 1124 } 1125 1126 // Check argument types. 1127 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1128 ArgIdx != NumArgs; ++ArgIdx) { 1129 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1130 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1131 if (Context.getCanonicalType(FromArgType) 1132 == Context.getCanonicalType(ToArgType)) { 1133 // Okay, the types match exactly. Nothing to do. 1134 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1135 ConvertedType, IncompatibleObjC)) { 1136 // Okay, we have an Objective-C pointer conversion. 1137 HasObjCConversion = true; 1138 } else { 1139 // Argument types are too different. Abort. 1140 return false; 1141 } 1142 } 1143 1144 if (HasObjCConversion) { 1145 // We had an Objective-C conversion. Allow this pointer 1146 // conversion, but complain about it. 1147 ConvertedType = ToType; 1148 IncompatibleObjC = true; 1149 return true; 1150 } 1151 } 1152 1153 return false; 1154} 1155 1156/// CheckPointerConversion - Check the pointer conversion from the 1157/// expression From to the type ToType. This routine checks for 1158/// ambiguous (FIXME: or inaccessible) derived-to-base pointer 1159/// conversions for which IsPointerConversion has already returned 1160/// true. It returns true and produces a diagnostic if there was an 1161/// error, or returns false otherwise. 1162bool Sema::CheckPointerConversion(Expr *From, QualType ToType) { 1163 QualType FromType = From->getType(); 1164 1165 if (const PointerType *FromPtrType = FromType->getAsPointerType()) 1166 if (const PointerType *ToPtrType = ToType->getAsPointerType()) { 1167 QualType FromPointeeType = FromPtrType->getPointeeType(), 1168 ToPointeeType = ToPtrType->getPointeeType(); 1169 1170 // Objective-C++ conversions are always okay. 1171 // FIXME: We should have a different class of conversions for the 1172 // Objective-C++ implicit conversions. 1173 if (Context.isObjCIdStructType(FromPointeeType) || 1174 Context.isObjCIdStructType(ToPointeeType) || 1175 Context.isObjCClassStructType(FromPointeeType) || 1176 Context.isObjCClassStructType(ToPointeeType)) 1177 return false; 1178 1179 if (FromPointeeType->isRecordType() && 1180 ToPointeeType->isRecordType()) { 1181 // We must have a derived-to-base conversion. Check an 1182 // ambiguous or inaccessible conversion. 1183 return CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1184 From->getExprLoc(), 1185 From->getSourceRange()); 1186 } 1187 } 1188 1189 return false; 1190} 1191 1192/// IsMemberPointerConversion - Determines whether the conversion of the 1193/// expression From, which has the (possibly adjusted) type FromType, can be 1194/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1195/// If so, returns true and places the converted type (that might differ from 1196/// ToType in its cv-qualifiers at some level) into ConvertedType. 1197bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1198 QualType ToType, QualType &ConvertedType) 1199{ 1200 const MemberPointerType *ToTypePtr = ToType->getAsMemberPointerType(); 1201 if (!ToTypePtr) 1202 return false; 1203 1204 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1205 if (From->isNullPointerConstant(Context)) { 1206 ConvertedType = ToType; 1207 return true; 1208 } 1209 1210 // Otherwise, both types have to be member pointers. 1211 const MemberPointerType *FromTypePtr = FromType->getAsMemberPointerType(); 1212 if (!FromTypePtr) 1213 return false; 1214 1215 // A pointer to member of B can be converted to a pointer to member of D, 1216 // where D is derived from B (C++ 4.11p2). 1217 QualType FromClass(FromTypePtr->getClass(), 0); 1218 QualType ToClass(ToTypePtr->getClass(), 0); 1219 // FIXME: What happens when these are dependent? Is this function even called? 1220 1221 if (IsDerivedFrom(ToClass, FromClass)) { 1222 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1223 ToClass.getTypePtr()); 1224 return true; 1225 } 1226 1227 return false; 1228} 1229 1230/// CheckMemberPointerConversion - Check the member pointer conversion from the 1231/// expression From to the type ToType. This routine checks for ambiguous or 1232/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1233/// for which IsMemberPointerConversion has already returned true. It returns 1234/// true and produces a diagnostic if there was an error, or returns false 1235/// otherwise. 1236bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType) { 1237 QualType FromType = From->getType(); 1238 const MemberPointerType *FromPtrType = FromType->getAsMemberPointerType(); 1239 if (!FromPtrType) 1240 return false; 1241 1242 const MemberPointerType *ToPtrType = ToType->getAsMemberPointerType(); 1243 assert(ToPtrType && "No member pointer cast has a target type " 1244 "that is not a member pointer."); 1245 1246 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1247 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1248 1249 // FIXME: What about dependent types? 1250 assert(FromClass->isRecordType() && "Pointer into non-class."); 1251 assert(ToClass->isRecordType() && "Pointer into non-class."); 1252 1253 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1254 /*DetectVirtual=*/true); 1255 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1256 assert(DerivationOkay && 1257 "Should not have been called if derivation isn't OK."); 1258 (void)DerivationOkay; 1259 1260 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1261 getUnqualifiedType())) { 1262 // Derivation is ambiguous. Redo the check to find the exact paths. 1263 Paths.clear(); 1264 Paths.setRecordingPaths(true); 1265 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1266 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1267 (void)StillOkay; 1268 1269 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1270 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1271 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1272 return true; 1273 } 1274 1275 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1276 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1277 << FromClass << ToClass << QualType(VBase, 0) 1278 << From->getSourceRange(); 1279 return true; 1280 } 1281 1282 return false; 1283} 1284 1285/// IsQualificationConversion - Determines whether the conversion from 1286/// an rvalue of type FromType to ToType is a qualification conversion 1287/// (C++ 4.4). 1288bool 1289Sema::IsQualificationConversion(QualType FromType, QualType ToType) 1290{ 1291 FromType = Context.getCanonicalType(FromType); 1292 ToType = Context.getCanonicalType(ToType); 1293 1294 // If FromType and ToType are the same type, this is not a 1295 // qualification conversion. 1296 if (FromType == ToType) 1297 return false; 1298 1299 // (C++ 4.4p4): 1300 // A conversion can add cv-qualifiers at levels other than the first 1301 // in multi-level pointers, subject to the following rules: [...] 1302 bool PreviousToQualsIncludeConst = true; 1303 bool UnwrappedAnyPointer = false; 1304 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1305 // Within each iteration of the loop, we check the qualifiers to 1306 // determine if this still looks like a qualification 1307 // conversion. Then, if all is well, we unwrap one more level of 1308 // pointers or pointers-to-members and do it all again 1309 // until there are no more pointers or pointers-to-members left to 1310 // unwrap. 1311 UnwrappedAnyPointer = true; 1312 1313 // -- for every j > 0, if const is in cv 1,j then const is in cv 1314 // 2,j, and similarly for volatile. 1315 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1316 return false; 1317 1318 // -- if the cv 1,j and cv 2,j are different, then const is in 1319 // every cv for 0 < k < j. 1320 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1321 && !PreviousToQualsIncludeConst) 1322 return false; 1323 1324 // Keep track of whether all prior cv-qualifiers in the "to" type 1325 // include const. 1326 PreviousToQualsIncludeConst 1327 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1328 } 1329 1330 // We are left with FromType and ToType being the pointee types 1331 // after unwrapping the original FromType and ToType the same number 1332 // of types. If we unwrapped any pointers, and if FromType and 1333 // ToType have the same unqualified type (since we checked 1334 // qualifiers above), then this is a qualification conversion. 1335 return UnwrappedAnyPointer && 1336 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1337} 1338 1339/// Determines whether there is a user-defined conversion sequence 1340/// (C++ [over.ics.user]) that converts expression From to the type 1341/// ToType. If such a conversion exists, User will contain the 1342/// user-defined conversion sequence that performs such a conversion 1343/// and this routine will return true. Otherwise, this routine returns 1344/// false and User is unspecified. 1345/// 1346/// \param AllowConversionFunctions true if the conversion should 1347/// consider conversion functions at all. If false, only constructors 1348/// will be considered. 1349/// 1350/// \param AllowExplicit true if the conversion should consider C++0x 1351/// "explicit" conversion functions as well as non-explicit conversion 1352/// functions (C++0x [class.conv.fct]p2). 1353/// 1354/// \param ForceRValue true if the expression should be treated as an rvalue 1355/// for overload resolution. 1356bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1357 UserDefinedConversionSequence& User, 1358 bool AllowConversionFunctions, 1359 bool AllowExplicit, bool ForceRValue) 1360{ 1361 OverloadCandidateSet CandidateSet; 1362 if (const RecordType *ToRecordType = ToType->getAsRecordType()) { 1363 if (CXXRecordDecl *ToRecordDecl 1364 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1365 // C++ [over.match.ctor]p1: 1366 // When objects of class type are direct-initialized (8.5), or 1367 // copy-initialized from an expression of the same or a 1368 // derived class type (8.5), overload resolution selects the 1369 // constructor. [...] For copy-initialization, the candidate 1370 // functions are all the converting constructors (12.3.1) of 1371 // that class. The argument list is the expression-list within 1372 // the parentheses of the initializer. 1373 DeclarationName ConstructorName 1374 = Context.DeclarationNames.getCXXConstructorName( 1375 Context.getCanonicalType(ToType).getUnqualifiedType()); 1376 DeclContext::lookup_iterator Con, ConEnd; 1377 for (llvm::tie(Con, ConEnd) 1378 = ToRecordDecl->lookup(ConstructorName); 1379 Con != ConEnd; ++Con) { 1380 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 1381 if (Constructor->isConvertingConstructor()) 1382 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1383 /*SuppressUserConversions=*/true, ForceRValue); 1384 } 1385 } 1386 } 1387 1388 if (!AllowConversionFunctions) { 1389 // Don't allow any conversion functions to enter the overload set. 1390 } else if (const RecordType *FromRecordType 1391 = From->getType()->getAsRecordType()) { 1392 if (CXXRecordDecl *FromRecordDecl 1393 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1394 // Add all of the conversion functions as candidates. 1395 // FIXME: Look for conversions in base classes! 1396 OverloadedFunctionDecl *Conversions 1397 = FromRecordDecl->getConversionFunctions(); 1398 for (OverloadedFunctionDecl::function_iterator Func 1399 = Conversions->function_begin(); 1400 Func != Conversions->function_end(); ++Func) { 1401 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 1402 if (AllowExplicit || !Conv->isExplicit()) 1403 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1404 } 1405 } 1406 } 1407 1408 OverloadCandidateSet::iterator Best; 1409 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1410 case OR_Success: 1411 // Record the standard conversion we used and the conversion function. 1412 if (CXXConstructorDecl *Constructor 1413 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1414 // C++ [over.ics.user]p1: 1415 // If the user-defined conversion is specified by a 1416 // constructor (12.3.1), the initial standard conversion 1417 // sequence converts the source type to the type required by 1418 // the argument of the constructor. 1419 // 1420 // FIXME: What about ellipsis conversions? 1421 QualType ThisType = Constructor->getThisType(Context); 1422 User.Before = Best->Conversions[0].Standard; 1423 User.ConversionFunction = Constructor; 1424 User.After.setAsIdentityConversion(); 1425 User.After.FromTypePtr 1426 = ThisType->getAsPointerType()->getPointeeType().getAsOpaquePtr(); 1427 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1428 return true; 1429 } else if (CXXConversionDecl *Conversion 1430 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1431 // C++ [over.ics.user]p1: 1432 // 1433 // [...] If the user-defined conversion is specified by a 1434 // conversion function (12.3.2), the initial standard 1435 // conversion sequence converts the source type to the 1436 // implicit object parameter of the conversion function. 1437 User.Before = Best->Conversions[0].Standard; 1438 User.ConversionFunction = Conversion; 1439 1440 // C++ [over.ics.user]p2: 1441 // The second standard conversion sequence converts the 1442 // result of the user-defined conversion to the target type 1443 // for the sequence. Since an implicit conversion sequence 1444 // is an initialization, the special rules for 1445 // initialization by user-defined conversion apply when 1446 // selecting the best user-defined conversion for a 1447 // user-defined conversion sequence (see 13.3.3 and 1448 // 13.3.3.1). 1449 User.After = Best->FinalConversion; 1450 return true; 1451 } else { 1452 assert(false && "Not a constructor or conversion function?"); 1453 return false; 1454 } 1455 1456 case OR_No_Viable_Function: 1457 case OR_Deleted: 1458 // No conversion here! We're done. 1459 return false; 1460 1461 case OR_Ambiguous: 1462 // FIXME: See C++ [over.best.ics]p10 for the handling of 1463 // ambiguous conversion sequences. 1464 return false; 1465 } 1466 1467 return false; 1468} 1469 1470/// CompareImplicitConversionSequences - Compare two implicit 1471/// conversion sequences to determine whether one is better than the 1472/// other or if they are indistinguishable (C++ 13.3.3.2). 1473ImplicitConversionSequence::CompareKind 1474Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1475 const ImplicitConversionSequence& ICS2) 1476{ 1477 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1478 // conversion sequences (as defined in 13.3.3.1) 1479 // -- a standard conversion sequence (13.3.3.1.1) is a better 1480 // conversion sequence than a user-defined conversion sequence or 1481 // an ellipsis conversion sequence, and 1482 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1483 // conversion sequence than an ellipsis conversion sequence 1484 // (13.3.3.1.3). 1485 // 1486 if (ICS1.ConversionKind < ICS2.ConversionKind) 1487 return ImplicitConversionSequence::Better; 1488 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1489 return ImplicitConversionSequence::Worse; 1490 1491 // Two implicit conversion sequences of the same form are 1492 // indistinguishable conversion sequences unless one of the 1493 // following rules apply: (C++ 13.3.3.2p3): 1494 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1495 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1496 else if (ICS1.ConversionKind == 1497 ImplicitConversionSequence::UserDefinedConversion) { 1498 // User-defined conversion sequence U1 is a better conversion 1499 // sequence than another user-defined conversion sequence U2 if 1500 // they contain the same user-defined conversion function or 1501 // constructor and if the second standard conversion sequence of 1502 // U1 is better than the second standard conversion sequence of 1503 // U2 (C++ 13.3.3.2p3). 1504 if (ICS1.UserDefined.ConversionFunction == 1505 ICS2.UserDefined.ConversionFunction) 1506 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1507 ICS2.UserDefined.After); 1508 } 1509 1510 return ImplicitConversionSequence::Indistinguishable; 1511} 1512 1513/// CompareStandardConversionSequences - Compare two standard 1514/// conversion sequences to determine whether one is better than the 1515/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1516ImplicitConversionSequence::CompareKind 1517Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1518 const StandardConversionSequence& SCS2) 1519{ 1520 // Standard conversion sequence S1 is a better conversion sequence 1521 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1522 1523 // -- S1 is a proper subsequence of S2 (comparing the conversion 1524 // sequences in the canonical form defined by 13.3.3.1.1, 1525 // excluding any Lvalue Transformation; the identity conversion 1526 // sequence is considered to be a subsequence of any 1527 // non-identity conversion sequence) or, if not that, 1528 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1529 // Neither is a proper subsequence of the other. Do nothing. 1530 ; 1531 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1532 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1533 (SCS1.Second == ICK_Identity && 1534 SCS1.Third == ICK_Identity)) 1535 // SCS1 is a proper subsequence of SCS2. 1536 return ImplicitConversionSequence::Better; 1537 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1538 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1539 (SCS2.Second == ICK_Identity && 1540 SCS2.Third == ICK_Identity)) 1541 // SCS2 is a proper subsequence of SCS1. 1542 return ImplicitConversionSequence::Worse; 1543 1544 // -- the rank of S1 is better than the rank of S2 (by the rules 1545 // defined below), or, if not that, 1546 ImplicitConversionRank Rank1 = SCS1.getRank(); 1547 ImplicitConversionRank Rank2 = SCS2.getRank(); 1548 if (Rank1 < Rank2) 1549 return ImplicitConversionSequence::Better; 1550 else if (Rank2 < Rank1) 1551 return ImplicitConversionSequence::Worse; 1552 1553 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1554 // are indistinguishable unless one of the following rules 1555 // applies: 1556 1557 // A conversion that is not a conversion of a pointer, or 1558 // pointer to member, to bool is better than another conversion 1559 // that is such a conversion. 1560 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1561 return SCS2.isPointerConversionToBool() 1562 ? ImplicitConversionSequence::Better 1563 : ImplicitConversionSequence::Worse; 1564 1565 // C++ [over.ics.rank]p4b2: 1566 // 1567 // If class B is derived directly or indirectly from class A, 1568 // conversion of B* to A* is better than conversion of B* to 1569 // void*, and conversion of A* to void* is better than conversion 1570 // of B* to void*. 1571 bool SCS1ConvertsToVoid 1572 = SCS1.isPointerConversionToVoidPointer(Context); 1573 bool SCS2ConvertsToVoid 1574 = SCS2.isPointerConversionToVoidPointer(Context); 1575 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1576 // Exactly one of the conversion sequences is a conversion to 1577 // a void pointer; it's the worse conversion. 1578 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1579 : ImplicitConversionSequence::Worse; 1580 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1581 // Neither conversion sequence converts to a void pointer; compare 1582 // their derived-to-base conversions. 1583 if (ImplicitConversionSequence::CompareKind DerivedCK 1584 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1585 return DerivedCK; 1586 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1587 // Both conversion sequences are conversions to void 1588 // pointers. Compare the source types to determine if there's an 1589 // inheritance relationship in their sources. 1590 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1591 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1592 1593 // Adjust the types we're converting from via the array-to-pointer 1594 // conversion, if we need to. 1595 if (SCS1.First == ICK_Array_To_Pointer) 1596 FromType1 = Context.getArrayDecayedType(FromType1); 1597 if (SCS2.First == ICK_Array_To_Pointer) 1598 FromType2 = Context.getArrayDecayedType(FromType2); 1599 1600 QualType FromPointee1 1601 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1602 QualType FromPointee2 1603 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1604 1605 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1606 return ImplicitConversionSequence::Better; 1607 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1608 return ImplicitConversionSequence::Worse; 1609 1610 // Objective-C++: If one interface is more specific than the 1611 // other, it is the better one. 1612 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1613 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1614 if (FromIface1 && FromIface1) { 1615 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1616 return ImplicitConversionSequence::Better; 1617 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1618 return ImplicitConversionSequence::Worse; 1619 } 1620 } 1621 1622 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1623 // bullet 3). 1624 if (ImplicitConversionSequence::CompareKind QualCK 1625 = CompareQualificationConversions(SCS1, SCS2)) 1626 return QualCK; 1627 1628 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1629 // C++0x [over.ics.rank]p3b4: 1630 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1631 // implicit object parameter of a non-static member function declared 1632 // without a ref-qualifier, and S1 binds an rvalue reference to an 1633 // rvalue and S2 binds an lvalue reference. 1634 // FIXME: We don't know if we're dealing with the implicit object parameter, 1635 // or if the member function in this case has a ref qualifier. 1636 // (Of course, we don't have ref qualifiers yet.) 1637 if (SCS1.RRefBinding != SCS2.RRefBinding) 1638 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1639 : ImplicitConversionSequence::Worse; 1640 1641 // C++ [over.ics.rank]p3b4: 1642 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1643 // which the references refer are the same type except for 1644 // top-level cv-qualifiers, and the type to which the reference 1645 // initialized by S2 refers is more cv-qualified than the type 1646 // to which the reference initialized by S1 refers. 1647 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1648 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1649 T1 = Context.getCanonicalType(T1); 1650 T2 = Context.getCanonicalType(T2); 1651 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1652 if (T2.isMoreQualifiedThan(T1)) 1653 return ImplicitConversionSequence::Better; 1654 else if (T1.isMoreQualifiedThan(T2)) 1655 return ImplicitConversionSequence::Worse; 1656 } 1657 } 1658 1659 return ImplicitConversionSequence::Indistinguishable; 1660} 1661 1662/// CompareQualificationConversions - Compares two standard conversion 1663/// sequences to determine whether they can be ranked based on their 1664/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1665ImplicitConversionSequence::CompareKind 1666Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1667 const StandardConversionSequence& SCS2) 1668{ 1669 // C++ 13.3.3.2p3: 1670 // -- S1 and S2 differ only in their qualification conversion and 1671 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1672 // cv-qualification signature of type T1 is a proper subset of 1673 // the cv-qualification signature of type T2, and S1 is not the 1674 // deprecated string literal array-to-pointer conversion (4.2). 1675 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1676 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1677 return ImplicitConversionSequence::Indistinguishable; 1678 1679 // FIXME: the example in the standard doesn't use a qualification 1680 // conversion (!) 1681 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1682 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1683 T1 = Context.getCanonicalType(T1); 1684 T2 = Context.getCanonicalType(T2); 1685 1686 // If the types are the same, we won't learn anything by unwrapped 1687 // them. 1688 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1689 return ImplicitConversionSequence::Indistinguishable; 1690 1691 ImplicitConversionSequence::CompareKind Result 1692 = ImplicitConversionSequence::Indistinguishable; 1693 while (UnwrapSimilarPointerTypes(T1, T2)) { 1694 // Within each iteration of the loop, we check the qualifiers to 1695 // determine if this still looks like a qualification 1696 // conversion. Then, if all is well, we unwrap one more level of 1697 // pointers or pointers-to-members and do it all again 1698 // until there are no more pointers or pointers-to-members left 1699 // to unwrap. This essentially mimics what 1700 // IsQualificationConversion does, but here we're checking for a 1701 // strict subset of qualifiers. 1702 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1703 // The qualifiers are the same, so this doesn't tell us anything 1704 // about how the sequences rank. 1705 ; 1706 else if (T2.isMoreQualifiedThan(T1)) { 1707 // T1 has fewer qualifiers, so it could be the better sequence. 1708 if (Result == ImplicitConversionSequence::Worse) 1709 // Neither has qualifiers that are a subset of the other's 1710 // qualifiers. 1711 return ImplicitConversionSequence::Indistinguishable; 1712 1713 Result = ImplicitConversionSequence::Better; 1714 } else if (T1.isMoreQualifiedThan(T2)) { 1715 // T2 has fewer qualifiers, so it could be the better sequence. 1716 if (Result == ImplicitConversionSequence::Better) 1717 // Neither has qualifiers that are a subset of the other's 1718 // qualifiers. 1719 return ImplicitConversionSequence::Indistinguishable; 1720 1721 Result = ImplicitConversionSequence::Worse; 1722 } else { 1723 // Qualifiers are disjoint. 1724 return ImplicitConversionSequence::Indistinguishable; 1725 } 1726 1727 // If the types after this point are equivalent, we're done. 1728 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1729 break; 1730 } 1731 1732 // Check that the winning standard conversion sequence isn't using 1733 // the deprecated string literal array to pointer conversion. 1734 switch (Result) { 1735 case ImplicitConversionSequence::Better: 1736 if (SCS1.Deprecated) 1737 Result = ImplicitConversionSequence::Indistinguishable; 1738 break; 1739 1740 case ImplicitConversionSequence::Indistinguishable: 1741 break; 1742 1743 case ImplicitConversionSequence::Worse: 1744 if (SCS2.Deprecated) 1745 Result = ImplicitConversionSequence::Indistinguishable; 1746 break; 1747 } 1748 1749 return Result; 1750} 1751 1752/// CompareDerivedToBaseConversions - Compares two standard conversion 1753/// sequences to determine whether they can be ranked based on their 1754/// various kinds of derived-to-base conversions (C++ 1755/// [over.ics.rank]p4b3). As part of these checks, we also look at 1756/// conversions between Objective-C interface types. 1757ImplicitConversionSequence::CompareKind 1758Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1759 const StandardConversionSequence& SCS2) { 1760 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1761 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1762 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1763 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1764 1765 // Adjust the types we're converting from via the array-to-pointer 1766 // conversion, if we need to. 1767 if (SCS1.First == ICK_Array_To_Pointer) 1768 FromType1 = Context.getArrayDecayedType(FromType1); 1769 if (SCS2.First == ICK_Array_To_Pointer) 1770 FromType2 = Context.getArrayDecayedType(FromType2); 1771 1772 // Canonicalize all of the types. 1773 FromType1 = Context.getCanonicalType(FromType1); 1774 ToType1 = Context.getCanonicalType(ToType1); 1775 FromType2 = Context.getCanonicalType(FromType2); 1776 ToType2 = Context.getCanonicalType(ToType2); 1777 1778 // C++ [over.ics.rank]p4b3: 1779 // 1780 // If class B is derived directly or indirectly from class A and 1781 // class C is derived directly or indirectly from B, 1782 // 1783 // For Objective-C, we let A, B, and C also be Objective-C 1784 // interfaces. 1785 1786 // Compare based on pointer conversions. 1787 if (SCS1.Second == ICK_Pointer_Conversion && 1788 SCS2.Second == ICK_Pointer_Conversion && 1789 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1790 FromType1->isPointerType() && FromType2->isPointerType() && 1791 ToType1->isPointerType() && ToType2->isPointerType()) { 1792 QualType FromPointee1 1793 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1794 QualType ToPointee1 1795 = ToType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1796 QualType FromPointee2 1797 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1798 QualType ToPointee2 1799 = ToType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1800 1801 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1802 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1803 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1804 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1805 1806 // -- conversion of C* to B* is better than conversion of C* to A*, 1807 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1808 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1809 return ImplicitConversionSequence::Better; 1810 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1811 return ImplicitConversionSequence::Worse; 1812 1813 if (ToIface1 && ToIface2) { 1814 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1815 return ImplicitConversionSequence::Better; 1816 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1817 return ImplicitConversionSequence::Worse; 1818 } 1819 } 1820 1821 // -- conversion of B* to A* is better than conversion of C* to A*, 1822 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1823 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1824 return ImplicitConversionSequence::Better; 1825 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1826 return ImplicitConversionSequence::Worse; 1827 1828 if (FromIface1 && FromIface2) { 1829 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1830 return ImplicitConversionSequence::Better; 1831 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1832 return ImplicitConversionSequence::Worse; 1833 } 1834 } 1835 } 1836 1837 // Compare based on reference bindings. 1838 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1839 SCS1.Second == ICK_Derived_To_Base) { 1840 // -- binding of an expression of type C to a reference of type 1841 // B& is better than binding an expression of type C to a 1842 // reference of type A&, 1843 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1844 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1845 if (IsDerivedFrom(ToType1, ToType2)) 1846 return ImplicitConversionSequence::Better; 1847 else if (IsDerivedFrom(ToType2, ToType1)) 1848 return ImplicitConversionSequence::Worse; 1849 } 1850 1851 // -- binding of an expression of type B to a reference of type 1852 // A& is better than binding an expression of type C to a 1853 // reference of type A&, 1854 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1855 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1856 if (IsDerivedFrom(FromType2, FromType1)) 1857 return ImplicitConversionSequence::Better; 1858 else if (IsDerivedFrom(FromType1, FromType2)) 1859 return ImplicitConversionSequence::Worse; 1860 } 1861 } 1862 1863 1864 // FIXME: conversion of A::* to B::* is better than conversion of 1865 // A::* to C::*, 1866 1867 // FIXME: conversion of B::* to C::* is better than conversion of 1868 // A::* to C::*, and 1869 1870 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1871 SCS1.Second == ICK_Derived_To_Base) { 1872 // -- conversion of C to B is better than conversion of C to A, 1873 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1874 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1875 if (IsDerivedFrom(ToType1, ToType2)) 1876 return ImplicitConversionSequence::Better; 1877 else if (IsDerivedFrom(ToType2, ToType1)) 1878 return ImplicitConversionSequence::Worse; 1879 } 1880 1881 // -- conversion of B to A is better than conversion of C to A. 1882 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1883 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1884 if (IsDerivedFrom(FromType2, FromType1)) 1885 return ImplicitConversionSequence::Better; 1886 else if (IsDerivedFrom(FromType1, FromType2)) 1887 return ImplicitConversionSequence::Worse; 1888 } 1889 } 1890 1891 return ImplicitConversionSequence::Indistinguishable; 1892} 1893 1894/// TryCopyInitialization - Try to copy-initialize a value of type 1895/// ToType from the expression From. Return the implicit conversion 1896/// sequence required to pass this argument, which may be a bad 1897/// conversion sequence (meaning that the argument cannot be passed to 1898/// a parameter of this type). If @p SuppressUserConversions, then we 1899/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1900/// then we treat @p From as an rvalue, even if it is an lvalue. 1901ImplicitConversionSequence 1902Sema::TryCopyInitialization(Expr *From, QualType ToType, 1903 bool SuppressUserConversions, bool ForceRValue) { 1904 if (ToType->isReferenceType()) { 1905 ImplicitConversionSequence ICS; 1906 CheckReferenceInit(From, ToType, &ICS, SuppressUserConversions, 1907 /*AllowExplicit=*/false, ForceRValue); 1908 return ICS; 1909 } else { 1910 return TryImplicitConversion(From, ToType, SuppressUserConversions, 1911 ForceRValue); 1912 } 1913} 1914 1915/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1916/// the expression @p From. Returns true (and emits a diagnostic) if there was 1917/// an error, returns false if the initialization succeeded. Elidable should 1918/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1919/// differently in C++0x for this case. 1920bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1921 const char* Flavor, bool Elidable) { 1922 if (!getLangOptions().CPlusPlus) { 1923 // In C, argument passing is the same as performing an assignment. 1924 QualType FromType = From->getType(); 1925 1926 AssignConvertType ConvTy = 1927 CheckSingleAssignmentConstraints(ToType, From); 1928 if (ConvTy != Compatible && 1929 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1930 ConvTy = Compatible; 1931 1932 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1933 FromType, From, Flavor); 1934 } 1935 1936 if (ToType->isReferenceType()) 1937 return CheckReferenceInit(From, ToType); 1938 1939 if (!PerformImplicitConversion(From, ToType, Flavor, 1940 /*AllowExplicit=*/false, Elidable)) 1941 return false; 1942 1943 return Diag(From->getSourceRange().getBegin(), 1944 diag::err_typecheck_convert_incompatible) 1945 << ToType << From->getType() << Flavor << From->getSourceRange(); 1946} 1947 1948/// TryObjectArgumentInitialization - Try to initialize the object 1949/// parameter of the given member function (@c Method) from the 1950/// expression @p From. 1951ImplicitConversionSequence 1952Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1953 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1954 unsigned MethodQuals = Method->getTypeQualifiers(); 1955 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 1956 1957 // Set up the conversion sequence as a "bad" conversion, to allow us 1958 // to exit early. 1959 ImplicitConversionSequence ICS; 1960 ICS.Standard.setAsIdentityConversion(); 1961 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1962 1963 // We need to have an object of class type. 1964 QualType FromType = From->getType(); 1965 if (const PointerType *PT = FromType->getAsPointerType()) 1966 FromType = PT->getPointeeType(); 1967 1968 assert(FromType->isRecordType()); 1969 1970 // The implicit object parmeter is has the type "reference to cv X", 1971 // where X is the class of which the function is a member 1972 // (C++ [over.match.funcs]p4). However, when finding an implicit 1973 // conversion sequence for the argument, we are not allowed to 1974 // create temporaries or perform user-defined conversions 1975 // (C++ [over.match.funcs]p5). We perform a simplified version of 1976 // reference binding here, that allows class rvalues to bind to 1977 // non-constant references. 1978 1979 // First check the qualifiers. We don't care about lvalue-vs-rvalue 1980 // with the implicit object parameter (C++ [over.match.funcs]p5). 1981 QualType FromTypeCanon = Context.getCanonicalType(FromType); 1982 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 1983 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 1984 return ICS; 1985 1986 // Check that we have either the same type or a derived type. It 1987 // affects the conversion rank. 1988 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 1989 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 1990 ICS.Standard.Second = ICK_Identity; 1991 else if (IsDerivedFrom(FromType, ClassType)) 1992 ICS.Standard.Second = ICK_Derived_To_Base; 1993 else 1994 return ICS; 1995 1996 // Success. Mark this as a reference binding. 1997 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 1998 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 1999 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2000 ICS.Standard.ReferenceBinding = true; 2001 ICS.Standard.DirectBinding = true; 2002 ICS.Standard.RRefBinding = false; 2003 return ICS; 2004} 2005 2006/// PerformObjectArgumentInitialization - Perform initialization of 2007/// the implicit object parameter for the given Method with the given 2008/// expression. 2009bool 2010Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2011 QualType FromRecordType, DestType; 2012 QualType ImplicitParamRecordType = 2013 Method->getThisType(Context)->getAsPointerType()->getPointeeType(); 2014 2015 if (const PointerType *PT = From->getType()->getAsPointerType()) { 2016 FromRecordType = PT->getPointeeType(); 2017 DestType = Method->getThisType(Context); 2018 } else { 2019 FromRecordType = From->getType(); 2020 DestType = ImplicitParamRecordType; 2021 } 2022 2023 ImplicitConversionSequence ICS 2024 = TryObjectArgumentInitialization(From, Method); 2025 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2026 return Diag(From->getSourceRange().getBegin(), 2027 diag::err_implicit_object_parameter_init) 2028 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2029 2030 if (ICS.Standard.Second == ICK_Derived_To_Base && 2031 CheckDerivedToBaseConversion(FromRecordType, 2032 ImplicitParamRecordType, 2033 From->getSourceRange().getBegin(), 2034 From->getSourceRange())) 2035 return true; 2036 2037 ImpCastExprToType(From, DestType, /*isLvalue=*/true); 2038 return false; 2039} 2040 2041/// TryContextuallyConvertToBool - Attempt to contextually convert the 2042/// expression From to bool (C++0x [conv]p3). 2043ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2044 return TryImplicitConversion(From, Context.BoolTy, false, true); 2045} 2046 2047/// PerformContextuallyConvertToBool - Perform a contextual conversion 2048/// of the expression From to bool (C++0x [conv]p3). 2049bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2050 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2051 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2052 return false; 2053 2054 return Diag(From->getSourceRange().getBegin(), 2055 diag::err_typecheck_bool_condition) 2056 << From->getType() << From->getSourceRange(); 2057} 2058 2059/// AddOverloadCandidate - Adds the given function to the set of 2060/// candidate functions, using the given function call arguments. If 2061/// @p SuppressUserConversions, then don't allow user-defined 2062/// conversions via constructors or conversion operators. 2063/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2064/// hacky way to implement the overloading rules for elidable copy 2065/// initialization in C++0x (C++0x 12.8p15). 2066void 2067Sema::AddOverloadCandidate(FunctionDecl *Function, 2068 Expr **Args, unsigned NumArgs, 2069 OverloadCandidateSet& CandidateSet, 2070 bool SuppressUserConversions, 2071 bool ForceRValue) 2072{ 2073 const FunctionProtoType* Proto 2074 = dyn_cast<FunctionProtoType>(Function->getType()->getAsFunctionType()); 2075 assert(Proto && "Functions without a prototype cannot be overloaded"); 2076 assert(!isa<CXXConversionDecl>(Function) && 2077 "Use AddConversionCandidate for conversion functions"); 2078 assert(!Function->getDescribedFunctionTemplate() && 2079 "Use AddTemplateOverloadCandidate for function templates"); 2080 2081 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2082 if (!isa<CXXConstructorDecl>(Method)) { 2083 // If we get here, it's because we're calling a member function 2084 // that is named without a member access expression (e.g., 2085 // "this->f") that was either written explicitly or created 2086 // implicitly. This can happen with a qualified call to a member 2087 // function, e.g., X::f(). We use a NULL object as the implied 2088 // object argument (C++ [over.call.func]p3). 2089 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2090 SuppressUserConversions, ForceRValue); 2091 return; 2092 } 2093 // We treat a constructor like a non-member function, since its object 2094 // argument doesn't participate in overload resolution. 2095 } 2096 2097 2098 // Add this candidate 2099 CandidateSet.push_back(OverloadCandidate()); 2100 OverloadCandidate& Candidate = CandidateSet.back(); 2101 Candidate.Function = Function; 2102 Candidate.Viable = true; 2103 Candidate.IsSurrogate = false; 2104 Candidate.IgnoreObjectArgument = false; 2105 2106 unsigned NumArgsInProto = Proto->getNumArgs(); 2107 2108 // (C++ 13.3.2p2): A candidate function having fewer than m 2109 // parameters is viable only if it has an ellipsis in its parameter 2110 // list (8.3.5). 2111 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2112 Candidate.Viable = false; 2113 return; 2114 } 2115 2116 // (C++ 13.3.2p2): A candidate function having more than m parameters 2117 // is viable only if the (m+1)st parameter has a default argument 2118 // (8.3.6). For the purposes of overload resolution, the 2119 // parameter list is truncated on the right, so that there are 2120 // exactly m parameters. 2121 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2122 if (NumArgs < MinRequiredArgs) { 2123 // Not enough arguments. 2124 Candidate.Viable = false; 2125 return; 2126 } 2127 2128 // Determine the implicit conversion sequences for each of the 2129 // arguments. 2130 Candidate.Conversions.resize(NumArgs); 2131 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2132 if (ArgIdx < NumArgsInProto) { 2133 // (C++ 13.3.2p3): for F to be a viable function, there shall 2134 // exist for each argument an implicit conversion sequence 2135 // (13.3.3.1) that converts that argument to the corresponding 2136 // parameter of F. 2137 QualType ParamType = Proto->getArgType(ArgIdx); 2138 Candidate.Conversions[ArgIdx] 2139 = TryCopyInitialization(Args[ArgIdx], ParamType, 2140 SuppressUserConversions, ForceRValue); 2141 if (Candidate.Conversions[ArgIdx].ConversionKind 2142 == ImplicitConversionSequence::BadConversion) { 2143 Candidate.Viable = false; 2144 break; 2145 } 2146 } else { 2147 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2148 // argument for which there is no corresponding parameter is 2149 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2150 Candidate.Conversions[ArgIdx].ConversionKind 2151 = ImplicitConversionSequence::EllipsisConversion; 2152 } 2153 } 2154} 2155 2156/// \brief Add all of the function declarations in the given function set to 2157/// the overload canddiate set. 2158void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2159 Expr **Args, unsigned NumArgs, 2160 OverloadCandidateSet& CandidateSet, 2161 bool SuppressUserConversions) { 2162 for (FunctionSet::const_iterator F = Functions.begin(), 2163 FEnd = Functions.end(); 2164 F != FEnd; ++F) { 2165 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) 2166 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2167 SuppressUserConversions); 2168 else 2169 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*F), 2170 /*FIXME: explicit args */false, 0, 0, 2171 Args, NumArgs, CandidateSet, 2172 SuppressUserConversions); 2173 } 2174} 2175 2176/// AddMethodCandidate - Adds the given C++ member function to the set 2177/// of candidate functions, using the given function call arguments 2178/// and the object argument (@c Object). For example, in a call 2179/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2180/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2181/// allow user-defined conversions via constructors or conversion 2182/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2183/// a slightly hacky way to implement the overloading rules for elidable copy 2184/// initialization in C++0x (C++0x 12.8p15). 2185void 2186Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2187 Expr **Args, unsigned NumArgs, 2188 OverloadCandidateSet& CandidateSet, 2189 bool SuppressUserConversions, bool ForceRValue) 2190{ 2191 const FunctionProtoType* Proto 2192 = dyn_cast<FunctionProtoType>(Method->getType()->getAsFunctionType()); 2193 assert(Proto && "Methods without a prototype cannot be overloaded"); 2194 assert(!isa<CXXConversionDecl>(Method) && 2195 "Use AddConversionCandidate for conversion functions"); 2196 assert(!isa<CXXConstructorDecl>(Method) && 2197 "Use AddOverloadCandidate for constructors"); 2198 2199 // Add this candidate 2200 CandidateSet.push_back(OverloadCandidate()); 2201 OverloadCandidate& Candidate = CandidateSet.back(); 2202 Candidate.Function = Method; 2203 Candidate.IsSurrogate = false; 2204 Candidate.IgnoreObjectArgument = false; 2205 2206 unsigned NumArgsInProto = Proto->getNumArgs(); 2207 2208 // (C++ 13.3.2p2): A candidate function having fewer than m 2209 // parameters is viable only if it has an ellipsis in its parameter 2210 // list (8.3.5). 2211 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2212 Candidate.Viable = false; 2213 return; 2214 } 2215 2216 // (C++ 13.3.2p2): A candidate function having more than m parameters 2217 // is viable only if the (m+1)st parameter has a default argument 2218 // (8.3.6). For the purposes of overload resolution, the 2219 // parameter list is truncated on the right, so that there are 2220 // exactly m parameters. 2221 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2222 if (NumArgs < MinRequiredArgs) { 2223 // Not enough arguments. 2224 Candidate.Viable = false; 2225 return; 2226 } 2227 2228 Candidate.Viable = true; 2229 Candidate.Conversions.resize(NumArgs + 1); 2230 2231 if (Method->isStatic() || !Object) 2232 // The implicit object argument is ignored. 2233 Candidate.IgnoreObjectArgument = true; 2234 else { 2235 // Determine the implicit conversion sequence for the object 2236 // parameter. 2237 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2238 if (Candidate.Conversions[0].ConversionKind 2239 == ImplicitConversionSequence::BadConversion) { 2240 Candidate.Viable = false; 2241 return; 2242 } 2243 } 2244 2245 // Determine the implicit conversion sequences for each of the 2246 // arguments. 2247 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2248 if (ArgIdx < NumArgsInProto) { 2249 // (C++ 13.3.2p3): for F to be a viable function, there shall 2250 // exist for each argument an implicit conversion sequence 2251 // (13.3.3.1) that converts that argument to the corresponding 2252 // parameter of F. 2253 QualType ParamType = Proto->getArgType(ArgIdx); 2254 Candidate.Conversions[ArgIdx + 1] 2255 = TryCopyInitialization(Args[ArgIdx], ParamType, 2256 SuppressUserConversions, ForceRValue); 2257 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2258 == ImplicitConversionSequence::BadConversion) { 2259 Candidate.Viable = false; 2260 break; 2261 } 2262 } else { 2263 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2264 // argument for which there is no corresponding parameter is 2265 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2266 Candidate.Conversions[ArgIdx + 1].ConversionKind 2267 = ImplicitConversionSequence::EllipsisConversion; 2268 } 2269 } 2270} 2271 2272/// \brief Add a C++ function template as a candidate in the candidate set, 2273/// using template argument deduction to produce an appropriate function 2274/// template specialization. 2275void 2276Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2277 bool HasExplicitTemplateArgs, 2278 const TemplateArgument *ExplicitTemplateArgs, 2279 unsigned NumExplicitTemplateArgs, 2280 Expr **Args, unsigned NumArgs, 2281 OverloadCandidateSet& CandidateSet, 2282 bool SuppressUserConversions, 2283 bool ForceRValue) { 2284 // C++ [over.match.funcs]p7: 2285 // In each case where a candidate is a function template, candidate 2286 // function template specializations are generated using template argument 2287 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2288 // candidate functions in the usual way.113) A given name can refer to one 2289 // or more function templates and also to a set of overloaded non-template 2290 // functions. In such a case, the candidate functions generated from each 2291 // function template are combined with the set of non-template candidate 2292 // functions. 2293 TemplateDeductionInfo Info(Context); 2294 FunctionDecl *Specialization = 0; 2295 if (TemplateDeductionResult Result 2296 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2297 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2298 Args, NumArgs, Specialization, Info)) { 2299 // FIXME: Record what happened with template argument deduction, so 2300 // that we can give the user a beautiful diagnostic. 2301 (void)Result; 2302 return; 2303 } 2304 2305 // Add the function template specialization produced by template argument 2306 // deduction as a candidate. 2307 assert(Specialization && "Missing function template specialization?"); 2308 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2309 SuppressUserConversions, ForceRValue); 2310} 2311 2312/// AddConversionCandidate - Add a C++ conversion function as a 2313/// candidate in the candidate set (C++ [over.match.conv], 2314/// C++ [over.match.copy]). From is the expression we're converting from, 2315/// and ToType is the type that we're eventually trying to convert to 2316/// (which may or may not be the same type as the type that the 2317/// conversion function produces). 2318void 2319Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2320 Expr *From, QualType ToType, 2321 OverloadCandidateSet& CandidateSet) { 2322 // Add this candidate 2323 CandidateSet.push_back(OverloadCandidate()); 2324 OverloadCandidate& Candidate = CandidateSet.back(); 2325 Candidate.Function = Conversion; 2326 Candidate.IsSurrogate = false; 2327 Candidate.IgnoreObjectArgument = false; 2328 Candidate.FinalConversion.setAsIdentityConversion(); 2329 Candidate.FinalConversion.FromTypePtr 2330 = Conversion->getConversionType().getAsOpaquePtr(); 2331 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2332 2333 // Determine the implicit conversion sequence for the implicit 2334 // object parameter. 2335 Candidate.Viable = true; 2336 Candidate.Conversions.resize(1); 2337 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2338 2339 if (Candidate.Conversions[0].ConversionKind 2340 == ImplicitConversionSequence::BadConversion) { 2341 Candidate.Viable = false; 2342 return; 2343 } 2344 2345 // To determine what the conversion from the result of calling the 2346 // conversion function to the type we're eventually trying to 2347 // convert to (ToType), we need to synthesize a call to the 2348 // conversion function and attempt copy initialization from it. This 2349 // makes sure that we get the right semantics with respect to 2350 // lvalues/rvalues and the type. Fortunately, we can allocate this 2351 // call on the stack and we don't need its arguments to be 2352 // well-formed. 2353 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2354 SourceLocation()); 2355 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2356 &ConversionRef, false); 2357 2358 // Note that it is safe to allocate CallExpr on the stack here because 2359 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2360 // allocator). 2361 CallExpr Call(Context, &ConversionFn, 0, 0, 2362 Conversion->getConversionType().getNonReferenceType(), 2363 SourceLocation()); 2364 ImplicitConversionSequence ICS = TryCopyInitialization(&Call, ToType, true); 2365 switch (ICS.ConversionKind) { 2366 case ImplicitConversionSequence::StandardConversion: 2367 Candidate.FinalConversion = ICS.Standard; 2368 break; 2369 2370 case ImplicitConversionSequence::BadConversion: 2371 Candidate.Viable = false; 2372 break; 2373 2374 default: 2375 assert(false && 2376 "Can only end up with a standard conversion sequence or failure"); 2377 } 2378} 2379 2380/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2381/// converts the given @c Object to a function pointer via the 2382/// conversion function @c Conversion, and then attempts to call it 2383/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2384/// the type of function that we'll eventually be calling. 2385void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2386 const FunctionProtoType *Proto, 2387 Expr *Object, Expr **Args, unsigned NumArgs, 2388 OverloadCandidateSet& CandidateSet) { 2389 CandidateSet.push_back(OverloadCandidate()); 2390 OverloadCandidate& Candidate = CandidateSet.back(); 2391 Candidate.Function = 0; 2392 Candidate.Surrogate = Conversion; 2393 Candidate.Viable = true; 2394 Candidate.IsSurrogate = true; 2395 Candidate.IgnoreObjectArgument = false; 2396 Candidate.Conversions.resize(NumArgs + 1); 2397 2398 // Determine the implicit conversion sequence for the implicit 2399 // object parameter. 2400 ImplicitConversionSequence ObjectInit 2401 = TryObjectArgumentInitialization(Object, Conversion); 2402 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2403 Candidate.Viable = false; 2404 return; 2405 } 2406 2407 // The first conversion is actually a user-defined conversion whose 2408 // first conversion is ObjectInit's standard conversion (which is 2409 // effectively a reference binding). Record it as such. 2410 Candidate.Conversions[0].ConversionKind 2411 = ImplicitConversionSequence::UserDefinedConversion; 2412 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2413 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2414 Candidate.Conversions[0].UserDefined.After 2415 = Candidate.Conversions[0].UserDefined.Before; 2416 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2417 2418 // Find the 2419 unsigned NumArgsInProto = Proto->getNumArgs(); 2420 2421 // (C++ 13.3.2p2): A candidate function having fewer than m 2422 // parameters is viable only if it has an ellipsis in its parameter 2423 // list (8.3.5). 2424 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2425 Candidate.Viable = false; 2426 return; 2427 } 2428 2429 // Function types don't have any default arguments, so just check if 2430 // we have enough arguments. 2431 if (NumArgs < NumArgsInProto) { 2432 // Not enough arguments. 2433 Candidate.Viable = false; 2434 return; 2435 } 2436 2437 // Determine the implicit conversion sequences for each of the 2438 // arguments. 2439 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2440 if (ArgIdx < NumArgsInProto) { 2441 // (C++ 13.3.2p3): for F to be a viable function, there shall 2442 // exist for each argument an implicit conversion sequence 2443 // (13.3.3.1) that converts that argument to the corresponding 2444 // parameter of F. 2445 QualType ParamType = Proto->getArgType(ArgIdx); 2446 Candidate.Conversions[ArgIdx + 1] 2447 = TryCopyInitialization(Args[ArgIdx], ParamType, 2448 /*SuppressUserConversions=*/false); 2449 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2450 == ImplicitConversionSequence::BadConversion) { 2451 Candidate.Viable = false; 2452 break; 2453 } 2454 } else { 2455 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2456 // argument for which there is no corresponding parameter is 2457 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2458 Candidate.Conversions[ArgIdx + 1].ConversionKind 2459 = ImplicitConversionSequence::EllipsisConversion; 2460 } 2461 } 2462} 2463 2464// FIXME: This will eventually be removed, once we've migrated all of the 2465// operator overloading logic over to the scheme used by binary operators, which 2466// works for template instantiation. 2467void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2468 SourceLocation OpLoc, 2469 Expr **Args, unsigned NumArgs, 2470 OverloadCandidateSet& CandidateSet, 2471 SourceRange OpRange) { 2472 2473 FunctionSet Functions; 2474 2475 QualType T1 = Args[0]->getType(); 2476 QualType T2; 2477 if (NumArgs > 1) 2478 T2 = Args[1]->getType(); 2479 2480 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2481 if (S) 2482 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2483 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2484 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2485 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2486 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2487} 2488 2489/// \brief Add overload candidates for overloaded operators that are 2490/// member functions. 2491/// 2492/// Add the overloaded operator candidates that are member functions 2493/// for the operator Op that was used in an operator expression such 2494/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2495/// CandidateSet will store the added overload candidates. (C++ 2496/// [over.match.oper]). 2497void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2498 SourceLocation OpLoc, 2499 Expr **Args, unsigned NumArgs, 2500 OverloadCandidateSet& CandidateSet, 2501 SourceRange OpRange) { 2502 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2503 2504 // C++ [over.match.oper]p3: 2505 // For a unary operator @ with an operand of a type whose 2506 // cv-unqualified version is T1, and for a binary operator @ with 2507 // a left operand of a type whose cv-unqualified version is T1 and 2508 // a right operand of a type whose cv-unqualified version is T2, 2509 // three sets of candidate functions, designated member 2510 // candidates, non-member candidates and built-in candidates, are 2511 // constructed as follows: 2512 QualType T1 = Args[0]->getType(); 2513 QualType T2; 2514 if (NumArgs > 1) 2515 T2 = Args[1]->getType(); 2516 2517 // -- If T1 is a class type, the set of member candidates is the 2518 // result of the qualified lookup of T1::operator@ 2519 // (13.3.1.1.1); otherwise, the set of member candidates is 2520 // empty. 2521 // FIXME: Lookup in base classes, too! 2522 if (const RecordType *T1Rec = T1->getAsRecordType()) { 2523 DeclContext::lookup_const_iterator Oper, OperEnd; 2524 for (llvm::tie(Oper, OperEnd) = T1Rec->getDecl()->lookup(OpName); 2525 Oper != OperEnd; ++Oper) 2526 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2527 Args+1, NumArgs - 1, CandidateSet, 2528 /*SuppressUserConversions=*/false); 2529 } 2530} 2531 2532/// AddBuiltinCandidate - Add a candidate for a built-in 2533/// operator. ResultTy and ParamTys are the result and parameter types 2534/// of the built-in candidate, respectively. Args and NumArgs are the 2535/// arguments being passed to the candidate. IsAssignmentOperator 2536/// should be true when this built-in candidate is an assignment 2537/// operator. NumContextualBoolArguments is the number of arguments 2538/// (at the beginning of the argument list) that will be contextually 2539/// converted to bool. 2540void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2541 Expr **Args, unsigned NumArgs, 2542 OverloadCandidateSet& CandidateSet, 2543 bool IsAssignmentOperator, 2544 unsigned NumContextualBoolArguments) { 2545 // Add this candidate 2546 CandidateSet.push_back(OverloadCandidate()); 2547 OverloadCandidate& Candidate = CandidateSet.back(); 2548 Candidate.Function = 0; 2549 Candidate.IsSurrogate = false; 2550 Candidate.IgnoreObjectArgument = false; 2551 Candidate.BuiltinTypes.ResultTy = ResultTy; 2552 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2553 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2554 2555 // Determine the implicit conversion sequences for each of the 2556 // arguments. 2557 Candidate.Viable = true; 2558 Candidate.Conversions.resize(NumArgs); 2559 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2560 // C++ [over.match.oper]p4: 2561 // For the built-in assignment operators, conversions of the 2562 // left operand are restricted as follows: 2563 // -- no temporaries are introduced to hold the left operand, and 2564 // -- no user-defined conversions are applied to the left 2565 // operand to achieve a type match with the left-most 2566 // parameter of a built-in candidate. 2567 // 2568 // We block these conversions by turning off user-defined 2569 // conversions, since that is the only way that initialization of 2570 // a reference to a non-class type can occur from something that 2571 // is not of the same type. 2572 if (ArgIdx < NumContextualBoolArguments) { 2573 assert(ParamTys[ArgIdx] == Context.BoolTy && 2574 "Contextual conversion to bool requires bool type"); 2575 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2576 } else { 2577 Candidate.Conversions[ArgIdx] 2578 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2579 ArgIdx == 0 && IsAssignmentOperator); 2580 } 2581 if (Candidate.Conversions[ArgIdx].ConversionKind 2582 == ImplicitConversionSequence::BadConversion) { 2583 Candidate.Viable = false; 2584 break; 2585 } 2586 } 2587} 2588 2589/// BuiltinCandidateTypeSet - A set of types that will be used for the 2590/// candidate operator functions for built-in operators (C++ 2591/// [over.built]). The types are separated into pointer types and 2592/// enumeration types. 2593class BuiltinCandidateTypeSet { 2594 /// TypeSet - A set of types. 2595 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2596 2597 /// PointerTypes - The set of pointer types that will be used in the 2598 /// built-in candidates. 2599 TypeSet PointerTypes; 2600 2601 /// MemberPointerTypes - The set of member pointer types that will be 2602 /// used in the built-in candidates. 2603 TypeSet MemberPointerTypes; 2604 2605 /// EnumerationTypes - The set of enumeration types that will be 2606 /// used in the built-in candidates. 2607 TypeSet EnumerationTypes; 2608 2609 /// Context - The AST context in which we will build the type sets. 2610 ASTContext &Context; 2611 2612 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2613 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2614 2615public: 2616 /// iterator - Iterates through the types that are part of the set. 2617 typedef TypeSet::iterator iterator; 2618 2619 BuiltinCandidateTypeSet(ASTContext &Context) : Context(Context) { } 2620 2621 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2622 bool AllowExplicitConversions); 2623 2624 /// pointer_begin - First pointer type found; 2625 iterator pointer_begin() { return PointerTypes.begin(); } 2626 2627 /// pointer_end - Past the last pointer type found; 2628 iterator pointer_end() { return PointerTypes.end(); } 2629 2630 /// member_pointer_begin - First member pointer type found; 2631 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2632 2633 /// member_pointer_end - Past the last member pointer type found; 2634 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2635 2636 /// enumeration_begin - First enumeration type found; 2637 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2638 2639 /// enumeration_end - Past the last enumeration type found; 2640 iterator enumeration_end() { return EnumerationTypes.end(); } 2641}; 2642 2643/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2644/// the set of pointer types along with any more-qualified variants of 2645/// that type. For example, if @p Ty is "int const *", this routine 2646/// will add "int const *", "int const volatile *", "int const 2647/// restrict *", and "int const volatile restrict *" to the set of 2648/// pointer types. Returns true if the add of @p Ty itself succeeded, 2649/// false otherwise. 2650bool 2651BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2652 // Insert this type. 2653 if (!PointerTypes.insert(Ty)) 2654 return false; 2655 2656 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2657 QualType PointeeTy = PointerTy->getPointeeType(); 2658 // FIXME: Optimize this so that we don't keep trying to add the same types. 2659 2660 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal with all 2661 // pointer conversions that don't cast away constness? 2662 if (!PointeeTy.isConstQualified()) 2663 AddPointerWithMoreQualifiedTypeVariants 2664 (Context.getPointerType(PointeeTy.withConst())); 2665 if (!PointeeTy.isVolatileQualified()) 2666 AddPointerWithMoreQualifiedTypeVariants 2667 (Context.getPointerType(PointeeTy.withVolatile())); 2668 if (!PointeeTy.isRestrictQualified()) 2669 AddPointerWithMoreQualifiedTypeVariants 2670 (Context.getPointerType(PointeeTy.withRestrict())); 2671 } 2672 2673 return true; 2674} 2675 2676/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2677/// to the set of pointer types along with any more-qualified variants of 2678/// that type. For example, if @p Ty is "int const *", this routine 2679/// will add "int const *", "int const volatile *", "int const 2680/// restrict *", and "int const volatile restrict *" to the set of 2681/// pointer types. Returns true if the add of @p Ty itself succeeded, 2682/// false otherwise. 2683bool 2684BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2685 QualType Ty) { 2686 // Insert this type. 2687 if (!MemberPointerTypes.insert(Ty)) 2688 return false; 2689 2690 if (const MemberPointerType *PointerTy = Ty->getAsMemberPointerType()) { 2691 QualType PointeeTy = PointerTy->getPointeeType(); 2692 const Type *ClassTy = PointerTy->getClass(); 2693 // FIXME: Optimize this so that we don't keep trying to add the same types. 2694 2695 if (!PointeeTy.isConstQualified()) 2696 AddMemberPointerWithMoreQualifiedTypeVariants 2697 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2698 if (!PointeeTy.isVolatileQualified()) 2699 AddMemberPointerWithMoreQualifiedTypeVariants 2700 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2701 if (!PointeeTy.isRestrictQualified()) 2702 AddMemberPointerWithMoreQualifiedTypeVariants 2703 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2704 } 2705 2706 return true; 2707} 2708 2709/// AddTypesConvertedFrom - Add each of the types to which the type @p 2710/// Ty can be implicit converted to the given set of @p Types. We're 2711/// primarily interested in pointer types and enumeration types. We also 2712/// take member pointer types, for the conditional operator. 2713/// AllowUserConversions is true if we should look at the conversion 2714/// functions of a class type, and AllowExplicitConversions if we 2715/// should also include the explicit conversion functions of a class 2716/// type. 2717void 2718BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2719 bool AllowUserConversions, 2720 bool AllowExplicitConversions) { 2721 // Only deal with canonical types. 2722 Ty = Context.getCanonicalType(Ty); 2723 2724 // Look through reference types; they aren't part of the type of an 2725 // expression for the purposes of conversions. 2726 if (const ReferenceType *RefTy = Ty->getAsReferenceType()) 2727 Ty = RefTy->getPointeeType(); 2728 2729 // We don't care about qualifiers on the type. 2730 Ty = Ty.getUnqualifiedType(); 2731 2732 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2733 QualType PointeeTy = PointerTy->getPointeeType(); 2734 2735 // Insert our type, and its more-qualified variants, into the set 2736 // of types. 2737 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2738 return; 2739 2740 // Add 'cv void*' to our set of types. 2741 if (!Ty->isVoidType()) { 2742 QualType QualVoid 2743 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2744 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2745 } 2746 2747 // If this is a pointer to a class type, add pointers to its bases 2748 // (with the same level of cv-qualification as the original 2749 // derived class, of course). 2750 if (const RecordType *PointeeRec = PointeeTy->getAsRecordType()) { 2751 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2752 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2753 Base != ClassDecl->bases_end(); ++Base) { 2754 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2755 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2756 2757 // Add the pointer type, recursively, so that we get all of 2758 // the indirect base classes, too. 2759 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2760 } 2761 } 2762 } else if (Ty->isMemberPointerType()) { 2763 // Member pointers are far easier, since the pointee can't be converted. 2764 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2765 return; 2766 } else if (Ty->isEnumeralType()) { 2767 EnumerationTypes.insert(Ty); 2768 } else if (AllowUserConversions) { 2769 if (const RecordType *TyRec = Ty->getAsRecordType()) { 2770 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2771 // FIXME: Visit conversion functions in the base classes, too. 2772 OverloadedFunctionDecl *Conversions 2773 = ClassDecl->getConversionFunctions(); 2774 for (OverloadedFunctionDecl::function_iterator Func 2775 = Conversions->function_begin(); 2776 Func != Conversions->function_end(); ++Func) { 2777 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 2778 if (AllowExplicitConversions || !Conv->isExplicit()) 2779 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2780 } 2781 } 2782 } 2783} 2784 2785/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2786/// operator overloads to the candidate set (C++ [over.built]), based 2787/// on the operator @p Op and the arguments given. For example, if the 2788/// operator is a binary '+', this routine might add "int 2789/// operator+(int, int)" to cover integer addition. 2790void 2791Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2792 Expr **Args, unsigned NumArgs, 2793 OverloadCandidateSet& CandidateSet) { 2794 // The set of "promoted arithmetic types", which are the arithmetic 2795 // types are that preserved by promotion (C++ [over.built]p2). Note 2796 // that the first few of these types are the promoted integral 2797 // types; these types need to be first. 2798 // FIXME: What about complex? 2799 const unsigned FirstIntegralType = 0; 2800 const unsigned LastIntegralType = 13; 2801 const unsigned FirstPromotedIntegralType = 7, 2802 LastPromotedIntegralType = 13; 2803 const unsigned FirstPromotedArithmeticType = 7, 2804 LastPromotedArithmeticType = 16; 2805 const unsigned NumArithmeticTypes = 16; 2806 QualType ArithmeticTypes[NumArithmeticTypes] = { 2807 Context.BoolTy, Context.CharTy, Context.WCharTy, 2808 Context.SignedCharTy, Context.ShortTy, 2809 Context.UnsignedCharTy, Context.UnsignedShortTy, 2810 Context.IntTy, Context.LongTy, Context.LongLongTy, 2811 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 2812 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 2813 }; 2814 2815 // Find all of the types that the arguments can convert to, but only 2816 // if the operator we're looking at has built-in operator candidates 2817 // that make use of these types. 2818 BuiltinCandidateTypeSet CandidateTypes(Context); 2819 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 2820 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 2821 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 2822 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 2823 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 2824 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 2825 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2826 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 2827 true, 2828 (Op == OO_Exclaim || 2829 Op == OO_AmpAmp || 2830 Op == OO_PipePipe)); 2831 } 2832 2833 bool isComparison = false; 2834 switch (Op) { 2835 case OO_None: 2836 case NUM_OVERLOADED_OPERATORS: 2837 assert(false && "Expected an overloaded operator"); 2838 break; 2839 2840 case OO_Star: // '*' is either unary or binary 2841 if (NumArgs == 1) 2842 goto UnaryStar; 2843 else 2844 goto BinaryStar; 2845 break; 2846 2847 case OO_Plus: // '+' is either unary or binary 2848 if (NumArgs == 1) 2849 goto UnaryPlus; 2850 else 2851 goto BinaryPlus; 2852 break; 2853 2854 case OO_Minus: // '-' is either unary or binary 2855 if (NumArgs == 1) 2856 goto UnaryMinus; 2857 else 2858 goto BinaryMinus; 2859 break; 2860 2861 case OO_Amp: // '&' is either unary or binary 2862 if (NumArgs == 1) 2863 goto UnaryAmp; 2864 else 2865 goto BinaryAmp; 2866 2867 case OO_PlusPlus: 2868 case OO_MinusMinus: 2869 // C++ [over.built]p3: 2870 // 2871 // For every pair (T, VQ), where T is an arithmetic type, and VQ 2872 // is either volatile or empty, there exist candidate operator 2873 // functions of the form 2874 // 2875 // VQ T& operator++(VQ T&); 2876 // T operator++(VQ T&, int); 2877 // 2878 // C++ [over.built]p4: 2879 // 2880 // For every pair (T, VQ), where T is an arithmetic type other 2881 // than bool, and VQ is either volatile or empty, there exist 2882 // candidate operator functions of the form 2883 // 2884 // VQ T& operator--(VQ T&); 2885 // T operator--(VQ T&, int); 2886 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 2887 Arith < NumArithmeticTypes; ++Arith) { 2888 QualType ArithTy = ArithmeticTypes[Arith]; 2889 QualType ParamTypes[2] 2890 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 2891 2892 // Non-volatile version. 2893 if (NumArgs == 1) 2894 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2895 else 2896 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2897 2898 // Volatile version 2899 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 2900 if (NumArgs == 1) 2901 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2902 else 2903 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2904 } 2905 2906 // C++ [over.built]p5: 2907 // 2908 // For every pair (T, VQ), where T is a cv-qualified or 2909 // cv-unqualified object type, and VQ is either volatile or 2910 // empty, there exist candidate operator functions of the form 2911 // 2912 // T*VQ& operator++(T*VQ&); 2913 // T*VQ& operator--(T*VQ&); 2914 // T* operator++(T*VQ&, int); 2915 // T* operator--(T*VQ&, int); 2916 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2917 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2918 // Skip pointer types that aren't pointers to object types. 2919 if (!(*Ptr)->getAsPointerType()->getPointeeType()->isObjectType()) 2920 continue; 2921 2922 QualType ParamTypes[2] = { 2923 Context.getLValueReferenceType(*Ptr), Context.IntTy 2924 }; 2925 2926 // Without volatile 2927 if (NumArgs == 1) 2928 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2929 else 2930 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2931 2932 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 2933 // With volatile 2934 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 2935 if (NumArgs == 1) 2936 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2937 else 2938 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2939 } 2940 } 2941 break; 2942 2943 UnaryStar: 2944 // C++ [over.built]p6: 2945 // For every cv-qualified or cv-unqualified object type T, there 2946 // exist candidate operator functions of the form 2947 // 2948 // T& operator*(T*); 2949 // 2950 // C++ [over.built]p7: 2951 // For every function type T, there exist candidate operator 2952 // functions of the form 2953 // T& operator*(T*); 2954 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2955 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2956 QualType ParamTy = *Ptr; 2957 QualType PointeeTy = ParamTy->getAsPointerType()->getPointeeType(); 2958 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 2959 &ParamTy, Args, 1, CandidateSet); 2960 } 2961 break; 2962 2963 UnaryPlus: 2964 // C++ [over.built]p8: 2965 // For every type T, there exist candidate operator functions of 2966 // the form 2967 // 2968 // T* operator+(T*); 2969 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2970 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2971 QualType ParamTy = *Ptr; 2972 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 2973 } 2974 2975 // Fall through 2976 2977 UnaryMinus: 2978 // C++ [over.built]p9: 2979 // For every promoted arithmetic type T, there exist candidate 2980 // operator functions of the form 2981 // 2982 // T operator+(T); 2983 // T operator-(T); 2984 for (unsigned Arith = FirstPromotedArithmeticType; 2985 Arith < LastPromotedArithmeticType; ++Arith) { 2986 QualType ArithTy = ArithmeticTypes[Arith]; 2987 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 2988 } 2989 break; 2990 2991 case OO_Tilde: 2992 // C++ [over.built]p10: 2993 // For every promoted integral type T, there exist candidate 2994 // operator functions of the form 2995 // 2996 // T operator~(T); 2997 for (unsigned Int = FirstPromotedIntegralType; 2998 Int < LastPromotedIntegralType; ++Int) { 2999 QualType IntTy = ArithmeticTypes[Int]; 3000 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3001 } 3002 break; 3003 3004 case OO_New: 3005 case OO_Delete: 3006 case OO_Array_New: 3007 case OO_Array_Delete: 3008 case OO_Call: 3009 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3010 break; 3011 3012 case OO_Comma: 3013 UnaryAmp: 3014 case OO_Arrow: 3015 // C++ [over.match.oper]p3: 3016 // -- For the operator ',', the unary operator '&', or the 3017 // operator '->', the built-in candidates set is empty. 3018 break; 3019 3020 case OO_Less: 3021 case OO_Greater: 3022 case OO_LessEqual: 3023 case OO_GreaterEqual: 3024 case OO_EqualEqual: 3025 case OO_ExclaimEqual: 3026 // C++ [over.built]p15: 3027 // 3028 // For every pointer or enumeration type T, there exist 3029 // candidate operator functions of the form 3030 // 3031 // bool operator<(T, T); 3032 // bool operator>(T, T); 3033 // bool operator<=(T, T); 3034 // bool operator>=(T, T); 3035 // bool operator==(T, T); 3036 // bool operator!=(T, T); 3037 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3038 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3039 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3040 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3041 } 3042 for (BuiltinCandidateTypeSet::iterator Enum 3043 = CandidateTypes.enumeration_begin(); 3044 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3045 QualType ParamTypes[2] = { *Enum, *Enum }; 3046 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3047 } 3048 3049 // Fall through. 3050 isComparison = true; 3051 3052 BinaryPlus: 3053 BinaryMinus: 3054 if (!isComparison) { 3055 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3056 3057 // C++ [over.built]p13: 3058 // 3059 // For every cv-qualified or cv-unqualified object type T 3060 // there exist candidate operator functions of the form 3061 // 3062 // T* operator+(T*, ptrdiff_t); 3063 // T& operator[](T*, ptrdiff_t); [BELOW] 3064 // T* operator-(T*, ptrdiff_t); 3065 // T* operator+(ptrdiff_t, T*); 3066 // T& operator[](ptrdiff_t, T*); [BELOW] 3067 // 3068 // C++ [over.built]p14: 3069 // 3070 // For every T, where T is a pointer to object type, there 3071 // exist candidate operator functions of the form 3072 // 3073 // ptrdiff_t operator-(T, T); 3074 for (BuiltinCandidateTypeSet::iterator Ptr 3075 = CandidateTypes.pointer_begin(); 3076 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3077 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3078 3079 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3080 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3081 3082 if (Op == OO_Plus) { 3083 // T* operator+(ptrdiff_t, T*); 3084 ParamTypes[0] = ParamTypes[1]; 3085 ParamTypes[1] = *Ptr; 3086 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3087 } else { 3088 // ptrdiff_t operator-(T, T); 3089 ParamTypes[1] = *Ptr; 3090 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3091 Args, 2, CandidateSet); 3092 } 3093 } 3094 } 3095 // Fall through 3096 3097 case OO_Slash: 3098 BinaryStar: 3099 Conditional: 3100 // C++ [over.built]p12: 3101 // 3102 // For every pair of promoted arithmetic types L and R, there 3103 // exist candidate operator functions of the form 3104 // 3105 // LR operator*(L, R); 3106 // LR operator/(L, R); 3107 // LR operator+(L, R); 3108 // LR operator-(L, R); 3109 // bool operator<(L, R); 3110 // bool operator>(L, R); 3111 // bool operator<=(L, R); 3112 // bool operator>=(L, R); 3113 // bool operator==(L, R); 3114 // bool operator!=(L, R); 3115 // 3116 // where LR is the result of the usual arithmetic conversions 3117 // between types L and R. 3118 // 3119 // C++ [over.built]p24: 3120 // 3121 // For every pair of promoted arithmetic types L and R, there exist 3122 // candidate operator functions of the form 3123 // 3124 // LR operator?(bool, L, R); 3125 // 3126 // where LR is the result of the usual arithmetic conversions 3127 // between types L and R. 3128 // Our candidates ignore the first parameter. 3129 for (unsigned Left = FirstPromotedArithmeticType; 3130 Left < LastPromotedArithmeticType; ++Left) { 3131 for (unsigned Right = FirstPromotedArithmeticType; 3132 Right < LastPromotedArithmeticType; ++Right) { 3133 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3134 QualType Result 3135 = isComparison? Context.BoolTy 3136 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3137 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3138 } 3139 } 3140 break; 3141 3142 case OO_Percent: 3143 BinaryAmp: 3144 case OO_Caret: 3145 case OO_Pipe: 3146 case OO_LessLess: 3147 case OO_GreaterGreater: 3148 // C++ [over.built]p17: 3149 // 3150 // For every pair of promoted integral types L and R, there 3151 // exist candidate operator functions of the form 3152 // 3153 // LR operator%(L, R); 3154 // LR operator&(L, R); 3155 // LR operator^(L, R); 3156 // LR operator|(L, R); 3157 // L operator<<(L, R); 3158 // L operator>>(L, R); 3159 // 3160 // where LR is the result of the usual arithmetic conversions 3161 // between types L and R. 3162 for (unsigned Left = FirstPromotedIntegralType; 3163 Left < LastPromotedIntegralType; ++Left) { 3164 for (unsigned Right = FirstPromotedIntegralType; 3165 Right < LastPromotedIntegralType; ++Right) { 3166 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3167 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3168 ? LandR[0] 3169 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3170 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3171 } 3172 } 3173 break; 3174 3175 case OO_Equal: 3176 // C++ [over.built]p20: 3177 // 3178 // For every pair (T, VQ), where T is an enumeration or 3179 // (FIXME:) pointer to member type and VQ is either volatile or 3180 // empty, there exist candidate operator functions of the form 3181 // 3182 // VQ T& operator=(VQ T&, T); 3183 for (BuiltinCandidateTypeSet::iterator Enum 3184 = CandidateTypes.enumeration_begin(); 3185 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3186 QualType ParamTypes[2]; 3187 3188 // T& operator=(T&, T) 3189 ParamTypes[0] = Context.getLValueReferenceType(*Enum); 3190 ParamTypes[1] = *Enum; 3191 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3192 /*IsAssignmentOperator=*/false); 3193 3194 if (!Context.getCanonicalType(*Enum).isVolatileQualified()) { 3195 // volatile T& operator=(volatile T&, T) 3196 ParamTypes[0] = Context.getLValueReferenceType((*Enum).withVolatile()); 3197 ParamTypes[1] = *Enum; 3198 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3199 /*IsAssignmentOperator=*/false); 3200 } 3201 } 3202 // Fall through. 3203 3204 case OO_PlusEqual: 3205 case OO_MinusEqual: 3206 // C++ [over.built]p19: 3207 // 3208 // For every pair (T, VQ), where T is any type and VQ is either 3209 // volatile or empty, there exist candidate operator functions 3210 // of the form 3211 // 3212 // T*VQ& operator=(T*VQ&, T*); 3213 // 3214 // C++ [over.built]p21: 3215 // 3216 // For every pair (T, VQ), where T is a cv-qualified or 3217 // cv-unqualified object type and VQ is either volatile or 3218 // empty, there exist candidate operator functions of the form 3219 // 3220 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3221 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3222 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3223 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3224 QualType ParamTypes[2]; 3225 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3226 3227 // non-volatile version 3228 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3229 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3230 /*IsAssigmentOperator=*/Op == OO_Equal); 3231 3232 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3233 // volatile version 3234 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3235 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3236 /*IsAssigmentOperator=*/Op == OO_Equal); 3237 } 3238 } 3239 // Fall through. 3240 3241 case OO_StarEqual: 3242 case OO_SlashEqual: 3243 // C++ [over.built]p18: 3244 // 3245 // For every triple (L, VQ, R), where L is an arithmetic type, 3246 // VQ is either volatile or empty, and R is a promoted 3247 // arithmetic type, there exist candidate operator functions of 3248 // the form 3249 // 3250 // VQ L& operator=(VQ L&, R); 3251 // VQ L& operator*=(VQ L&, R); 3252 // VQ L& operator/=(VQ L&, R); 3253 // VQ L& operator+=(VQ L&, R); 3254 // VQ L& operator-=(VQ L&, R); 3255 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3256 for (unsigned Right = FirstPromotedArithmeticType; 3257 Right < LastPromotedArithmeticType; ++Right) { 3258 QualType ParamTypes[2]; 3259 ParamTypes[1] = ArithmeticTypes[Right]; 3260 3261 // Add this built-in operator as a candidate (VQ is empty). 3262 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3263 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3264 /*IsAssigmentOperator=*/Op == OO_Equal); 3265 3266 // Add this built-in operator as a candidate (VQ is 'volatile'). 3267 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3268 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3269 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3270 /*IsAssigmentOperator=*/Op == OO_Equal); 3271 } 3272 } 3273 break; 3274 3275 case OO_PercentEqual: 3276 case OO_LessLessEqual: 3277 case OO_GreaterGreaterEqual: 3278 case OO_AmpEqual: 3279 case OO_CaretEqual: 3280 case OO_PipeEqual: 3281 // C++ [over.built]p22: 3282 // 3283 // For every triple (L, VQ, R), where L is an integral type, VQ 3284 // is either volatile or empty, and R is a promoted integral 3285 // type, there exist candidate operator functions of the form 3286 // 3287 // VQ L& operator%=(VQ L&, R); 3288 // VQ L& operator<<=(VQ L&, R); 3289 // VQ L& operator>>=(VQ L&, R); 3290 // VQ L& operator&=(VQ L&, R); 3291 // VQ L& operator^=(VQ L&, R); 3292 // VQ L& operator|=(VQ L&, R); 3293 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3294 for (unsigned Right = FirstPromotedIntegralType; 3295 Right < LastPromotedIntegralType; ++Right) { 3296 QualType ParamTypes[2]; 3297 ParamTypes[1] = ArithmeticTypes[Right]; 3298 3299 // Add this built-in operator as a candidate (VQ is empty). 3300 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3301 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3302 3303 // Add this built-in operator as a candidate (VQ is 'volatile'). 3304 ParamTypes[0] = ArithmeticTypes[Left]; 3305 ParamTypes[0].addVolatile(); 3306 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3307 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3308 } 3309 } 3310 break; 3311 3312 case OO_Exclaim: { 3313 // C++ [over.operator]p23: 3314 // 3315 // There also exist candidate operator functions of the form 3316 // 3317 // bool operator!(bool); 3318 // bool operator&&(bool, bool); [BELOW] 3319 // bool operator||(bool, bool); [BELOW] 3320 QualType ParamTy = Context.BoolTy; 3321 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3322 /*IsAssignmentOperator=*/false, 3323 /*NumContextualBoolArguments=*/1); 3324 break; 3325 } 3326 3327 case OO_AmpAmp: 3328 case OO_PipePipe: { 3329 // C++ [over.operator]p23: 3330 // 3331 // There also exist candidate operator functions of the form 3332 // 3333 // bool operator!(bool); [ABOVE] 3334 // bool operator&&(bool, bool); 3335 // bool operator||(bool, bool); 3336 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3337 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3338 /*IsAssignmentOperator=*/false, 3339 /*NumContextualBoolArguments=*/2); 3340 break; 3341 } 3342 3343 case OO_Subscript: 3344 // C++ [over.built]p13: 3345 // 3346 // For every cv-qualified or cv-unqualified object type T there 3347 // exist candidate operator functions of the form 3348 // 3349 // T* operator+(T*, ptrdiff_t); [ABOVE] 3350 // T& operator[](T*, ptrdiff_t); 3351 // T* operator-(T*, ptrdiff_t); [ABOVE] 3352 // T* operator+(ptrdiff_t, T*); [ABOVE] 3353 // T& operator[](ptrdiff_t, T*); 3354 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3355 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3356 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3357 QualType PointeeType = (*Ptr)->getAsPointerType()->getPointeeType(); 3358 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3359 3360 // T& operator[](T*, ptrdiff_t) 3361 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3362 3363 // T& operator[](ptrdiff_t, T*); 3364 ParamTypes[0] = ParamTypes[1]; 3365 ParamTypes[1] = *Ptr; 3366 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3367 } 3368 break; 3369 3370 case OO_ArrowStar: 3371 // FIXME: No support for pointer-to-members yet. 3372 break; 3373 3374 case OO_Conditional: 3375 // Note that we don't consider the first argument, since it has been 3376 // contextually converted to bool long ago. The candidates below are 3377 // therefore added as binary. 3378 // 3379 // C++ [over.built]p24: 3380 // For every type T, where T is a pointer or pointer-to-member type, 3381 // there exist candidate operator functions of the form 3382 // 3383 // T operator?(bool, T, T); 3384 // 3385 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3386 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3387 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3388 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3389 } 3390 for (BuiltinCandidateTypeSet::iterator Ptr = 3391 CandidateTypes.member_pointer_begin(), 3392 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3393 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3394 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3395 } 3396 goto Conditional; 3397 } 3398} 3399 3400/// \brief Add function candidates found via argument-dependent lookup 3401/// to the set of overloading candidates. 3402/// 3403/// This routine performs argument-dependent name lookup based on the 3404/// given function name (which may also be an operator name) and adds 3405/// all of the overload candidates found by ADL to the overload 3406/// candidate set (C++ [basic.lookup.argdep]). 3407void 3408Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3409 Expr **Args, unsigned NumArgs, 3410 OverloadCandidateSet& CandidateSet) { 3411 FunctionSet Functions; 3412 3413 // Record all of the function candidates that we've already 3414 // added to the overload set, so that we don't add those same 3415 // candidates a second time. 3416 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3417 CandEnd = CandidateSet.end(); 3418 Cand != CandEnd; ++Cand) 3419 if (Cand->Function) { 3420 Functions.insert(Cand->Function); 3421 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3422 Functions.insert(FunTmpl); 3423 } 3424 3425 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3426 3427 // Erase all of the candidates we already knew about. 3428 // FIXME: This is suboptimal. Is there a better way? 3429 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3430 CandEnd = CandidateSet.end(); 3431 Cand != CandEnd; ++Cand) 3432 if (Cand->Function) { 3433 Functions.erase(Cand->Function); 3434 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3435 Functions.erase(FunTmpl); 3436 } 3437 3438 // For each of the ADL candidates we found, add it to the overload 3439 // set. 3440 for (FunctionSet::iterator Func = Functions.begin(), 3441 FuncEnd = Functions.end(); 3442 Func != FuncEnd; ++Func) { 3443 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) 3444 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet); 3445 else 3446 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3447 /*FIXME: explicit args */false, 0, 0, 3448 Args, NumArgs, CandidateSet); 3449 } 3450} 3451 3452/// isBetterOverloadCandidate - Determines whether the first overload 3453/// candidate is a better candidate than the second (C++ 13.3.3p1). 3454bool 3455Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3456 const OverloadCandidate& Cand2) 3457{ 3458 // Define viable functions to be better candidates than non-viable 3459 // functions. 3460 if (!Cand2.Viable) 3461 return Cand1.Viable; 3462 else if (!Cand1.Viable) 3463 return false; 3464 3465 // C++ [over.match.best]p1: 3466 // 3467 // -- if F is a static member function, ICS1(F) is defined such 3468 // that ICS1(F) is neither better nor worse than ICS1(G) for 3469 // any function G, and, symmetrically, ICS1(G) is neither 3470 // better nor worse than ICS1(F). 3471 unsigned StartArg = 0; 3472 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3473 StartArg = 1; 3474 3475 // C++ [over.match.best]p1: 3476 // A viable function F1 is defined to be a better function than another 3477 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3478 // conversion sequence than ICSi(F2), and then... 3479 unsigned NumArgs = Cand1.Conversions.size(); 3480 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3481 bool HasBetterConversion = false; 3482 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3483 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3484 Cand2.Conversions[ArgIdx])) { 3485 case ImplicitConversionSequence::Better: 3486 // Cand1 has a better conversion sequence. 3487 HasBetterConversion = true; 3488 break; 3489 3490 case ImplicitConversionSequence::Worse: 3491 // Cand1 can't be better than Cand2. 3492 return false; 3493 3494 case ImplicitConversionSequence::Indistinguishable: 3495 // Do nothing. 3496 break; 3497 } 3498 } 3499 3500 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3501 // ICSj(F2), or, if not that, 3502 if (HasBetterConversion) 3503 return true; 3504 3505 // - F1 is a non-template function and F2 is a function template 3506 // specialization, or, if not that, 3507 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3508 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3509 return true; 3510 3511 // -- F1 and F2 are function template specializations, and the function 3512 // template for F1 is more specialized than the template for F2 3513 // according to the partial ordering rules described in 14.5.5.2, or, 3514 // if not that, 3515 3516 // FIXME: Implement partial ordering of function templates. 3517 3518 // -- the context is an initialization by user-defined conversion 3519 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3520 // from the return type of F1 to the destination type (i.e., 3521 // the type of the entity being initialized) is a better 3522 // conversion sequence than the standard conversion sequence 3523 // from the return type of F2 to the destination type. 3524 if (Cand1.Function && Cand2.Function && 3525 isa<CXXConversionDecl>(Cand1.Function) && 3526 isa<CXXConversionDecl>(Cand2.Function)) { 3527 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3528 Cand2.FinalConversion)) { 3529 case ImplicitConversionSequence::Better: 3530 // Cand1 has a better conversion sequence. 3531 return true; 3532 3533 case ImplicitConversionSequence::Worse: 3534 // Cand1 can't be better than Cand2. 3535 return false; 3536 3537 case ImplicitConversionSequence::Indistinguishable: 3538 // Do nothing 3539 break; 3540 } 3541 } 3542 3543 return false; 3544} 3545 3546/// \brief Computes the best viable function (C++ 13.3.3) 3547/// within an overload candidate set. 3548/// 3549/// \param CandidateSet the set of candidate functions. 3550/// 3551/// \param Loc the location of the function name (or operator symbol) for 3552/// which overload resolution occurs. 3553/// 3554/// \param Best f overload resolution was successful or found a deleted 3555/// function, Best points to the candidate function found. 3556/// 3557/// \returns The result of overload resolution. 3558Sema::OverloadingResult 3559Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3560 SourceLocation Loc, 3561 OverloadCandidateSet::iterator& Best) 3562{ 3563 // Find the best viable function. 3564 Best = CandidateSet.end(); 3565 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3566 Cand != CandidateSet.end(); ++Cand) { 3567 if (Cand->Viable) { 3568 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3569 Best = Cand; 3570 } 3571 } 3572 3573 // If we didn't find any viable functions, abort. 3574 if (Best == CandidateSet.end()) 3575 return OR_No_Viable_Function; 3576 3577 // Make sure that this function is better than every other viable 3578 // function. If not, we have an ambiguity. 3579 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3580 Cand != CandidateSet.end(); ++Cand) { 3581 if (Cand->Viable && 3582 Cand != Best && 3583 !isBetterOverloadCandidate(*Best, *Cand)) { 3584 Best = CandidateSet.end(); 3585 return OR_Ambiguous; 3586 } 3587 } 3588 3589 // Best is the best viable function. 3590 if (Best->Function && 3591 (Best->Function->isDeleted() || 3592 Best->Function->getAttr<UnavailableAttr>())) 3593 return OR_Deleted; 3594 3595 // C++ [basic.def.odr]p2: 3596 // An overloaded function is used if it is selected by overload resolution 3597 // when referred to from a potentially-evaluated expression. [Note: this 3598 // covers calls to named functions (5.2.2), operator overloading 3599 // (clause 13), user-defined conversions (12.3.2), allocation function for 3600 // placement new (5.3.4), as well as non-default initialization (8.5). 3601 if (Best->Function) 3602 MarkDeclarationReferenced(Loc, Best->Function); 3603 return OR_Success; 3604} 3605 3606/// PrintOverloadCandidates - When overload resolution fails, prints 3607/// diagnostic messages containing the candidates in the candidate 3608/// set. If OnlyViable is true, only viable candidates will be printed. 3609void 3610Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3611 bool OnlyViable) 3612{ 3613 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3614 LastCand = CandidateSet.end(); 3615 for (; Cand != LastCand; ++Cand) { 3616 if (Cand->Viable || !OnlyViable) { 3617 if (Cand->Function) { 3618 if (Cand->Function->isDeleted() || 3619 Cand->Function->getAttr<UnavailableAttr>()) { 3620 // Deleted or "unavailable" function. 3621 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3622 << Cand->Function->isDeleted(); 3623 } else { 3624 // Normal function 3625 // FIXME: Give a better reason! 3626 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3627 } 3628 } else if (Cand->IsSurrogate) { 3629 // Desugar the type of the surrogate down to a function type, 3630 // retaining as many typedefs as possible while still showing 3631 // the function type (and, therefore, its parameter types). 3632 QualType FnType = Cand->Surrogate->getConversionType(); 3633 bool isLValueReference = false; 3634 bool isRValueReference = false; 3635 bool isPointer = false; 3636 if (const LValueReferenceType *FnTypeRef = 3637 FnType->getAsLValueReferenceType()) { 3638 FnType = FnTypeRef->getPointeeType(); 3639 isLValueReference = true; 3640 } else if (const RValueReferenceType *FnTypeRef = 3641 FnType->getAsRValueReferenceType()) { 3642 FnType = FnTypeRef->getPointeeType(); 3643 isRValueReference = true; 3644 } 3645 if (const PointerType *FnTypePtr = FnType->getAsPointerType()) { 3646 FnType = FnTypePtr->getPointeeType(); 3647 isPointer = true; 3648 } 3649 // Desugar down to a function type. 3650 FnType = QualType(FnType->getAsFunctionType(), 0); 3651 // Reconstruct the pointer/reference as appropriate. 3652 if (isPointer) FnType = Context.getPointerType(FnType); 3653 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3654 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3655 3656 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3657 << FnType; 3658 } else { 3659 // FIXME: We need to get the identifier in here 3660 // FIXME: Do we want the error message to point at the operator? 3661 // (built-ins won't have a location) 3662 QualType FnType 3663 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3664 Cand->BuiltinTypes.ParamTypes, 3665 Cand->Conversions.size(), 3666 false, 0); 3667 3668 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3669 } 3670 } 3671 } 3672} 3673 3674/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3675/// an overloaded function (C++ [over.over]), where @p From is an 3676/// expression with overloaded function type and @p ToType is the type 3677/// we're trying to resolve to. For example: 3678/// 3679/// @code 3680/// int f(double); 3681/// int f(int); 3682/// 3683/// int (*pfd)(double) = f; // selects f(double) 3684/// @endcode 3685/// 3686/// This routine returns the resulting FunctionDecl if it could be 3687/// resolved, and NULL otherwise. When @p Complain is true, this 3688/// routine will emit diagnostics if there is an error. 3689FunctionDecl * 3690Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3691 bool Complain) { 3692 QualType FunctionType = ToType; 3693 bool IsMember = false; 3694 if (const PointerType *ToTypePtr = ToType->getAsPointerType()) 3695 FunctionType = ToTypePtr->getPointeeType(); 3696 else if (const ReferenceType *ToTypeRef = ToType->getAsReferenceType()) 3697 FunctionType = ToTypeRef->getPointeeType(); 3698 else if (const MemberPointerType *MemTypePtr = 3699 ToType->getAsMemberPointerType()) { 3700 FunctionType = MemTypePtr->getPointeeType(); 3701 IsMember = true; 3702 } 3703 3704 // We only look at pointers or references to functions. 3705 if (!FunctionType->isFunctionType()) 3706 return 0; 3707 3708 // Find the actual overloaded function declaration. 3709 OverloadedFunctionDecl *Ovl = 0; 3710 3711 // C++ [over.over]p1: 3712 // [...] [Note: any redundant set of parentheses surrounding the 3713 // overloaded function name is ignored (5.1). ] 3714 Expr *OvlExpr = From->IgnoreParens(); 3715 3716 // C++ [over.over]p1: 3717 // [...] The overloaded function name can be preceded by the & 3718 // operator. 3719 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3720 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3721 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3722 } 3723 3724 // Try to dig out the overloaded function. 3725 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) 3726 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3727 3728 // If there's no overloaded function declaration, we're done. 3729 if (!Ovl) 3730 return 0; 3731 3732 // Look through all of the overloaded functions, searching for one 3733 // whose type matches exactly. 3734 // FIXME: When templates or using declarations come along, we'll actually 3735 // have to deal with duplicates, partial ordering, etc. For now, we 3736 // can just do a simple search. 3737 FunctionType = Context.getCanonicalType(FunctionType.getUnqualifiedType()); 3738 for (OverloadedFunctionDecl::function_iterator Fun = Ovl->function_begin(); 3739 Fun != Ovl->function_end(); ++Fun) { 3740 // C++ [over.over]p3: 3741 // Non-member functions and static member functions match 3742 // targets of type "pointer-to-function" or "reference-to-function." 3743 // Nonstatic member functions match targets of 3744 // type "pointer-to-member-function." 3745 // Note that according to DR 247, the containing class does not matter. 3746 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 3747 // Skip non-static functions when converting to pointer, and static 3748 // when converting to member pointer. 3749 if (Method->isStatic() == IsMember) 3750 continue; 3751 } else if (IsMember) 3752 continue; 3753 3754 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 3755 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) 3756 return FunDecl; 3757 } else { 3758 unsigned DiagID 3759 = PP.getDiagnostics().getCustomDiagID(Diagnostic::Warning, 3760 "Clang does not yet support templated conversion functions"); 3761 Diag(From->getLocStart(), DiagID); 3762 } 3763 } 3764 3765 return 0; 3766} 3767 3768/// ResolveOverloadedCallFn - Given the call expression that calls Fn 3769/// (which eventually refers to the declaration Func) and the call 3770/// arguments Args/NumArgs, attempt to resolve the function call down 3771/// to a specific function. If overload resolution succeeds, returns 3772/// the function declaration produced by overload 3773/// resolution. Otherwise, emits diagnostics, deletes all of the 3774/// arguments and Fn, and returns NULL. 3775FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 3776 DeclarationName UnqualifiedName, 3777 bool HasExplicitTemplateArgs, 3778 const TemplateArgument *ExplicitTemplateArgs, 3779 unsigned NumExplicitTemplateArgs, 3780 SourceLocation LParenLoc, 3781 Expr **Args, unsigned NumArgs, 3782 SourceLocation *CommaLocs, 3783 SourceLocation RParenLoc, 3784 bool &ArgumentDependentLookup) { 3785 OverloadCandidateSet CandidateSet; 3786 3787 // Add the functions denoted by Callee to the set of candidate 3788 // functions. While we're doing so, track whether argument-dependent 3789 // lookup still applies, per: 3790 // 3791 // C++0x [basic.lookup.argdep]p3: 3792 // Let X be the lookup set produced by unqualified lookup (3.4.1) 3793 // and let Y be the lookup set produced by argument dependent 3794 // lookup (defined as follows). If X contains 3795 // 3796 // -- a declaration of a class member, or 3797 // 3798 // -- a block-scope function declaration that is not a 3799 // using-declaration, or 3800 // 3801 // -- a declaration that is neither a function or a function 3802 // template 3803 // 3804 // then Y is empty. 3805 if (OverloadedFunctionDecl *Ovl 3806 = dyn_cast_or_null<OverloadedFunctionDecl>(Callee)) { 3807 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 3808 FuncEnd = Ovl->function_end(); 3809 Func != FuncEnd; ++Func) { 3810 DeclContext *Ctx = 0; 3811 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Func)) { 3812 if (HasExplicitTemplateArgs) 3813 continue; 3814 3815 AddOverloadCandidate(FunDecl, Args, NumArgs, CandidateSet); 3816 Ctx = FunDecl->getDeclContext(); 3817 } else { 3818 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*Func); 3819 AddTemplateOverloadCandidate(FunTmpl, HasExplicitTemplateArgs, 3820 ExplicitTemplateArgs, 3821 NumExplicitTemplateArgs, 3822 Args, NumArgs, CandidateSet); 3823 Ctx = FunTmpl->getDeclContext(); 3824 } 3825 3826 3827 if (Ctx->isRecord() || Ctx->isFunctionOrMethod()) 3828 ArgumentDependentLookup = false; 3829 } 3830 } else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee)) { 3831 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 3832 AddOverloadCandidate(Func, Args, NumArgs, CandidateSet); 3833 3834 if (Func->getDeclContext()->isRecord() || 3835 Func->getDeclContext()->isFunctionOrMethod()) 3836 ArgumentDependentLookup = false; 3837 } else if (FunctionTemplateDecl *FuncTemplate 3838 = dyn_cast_or_null<FunctionTemplateDecl>(Callee)) { 3839 AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 3840 ExplicitTemplateArgs, 3841 NumExplicitTemplateArgs, 3842 Args, NumArgs, CandidateSet); 3843 3844 if (FuncTemplate->getDeclContext()->isRecord()) 3845 ArgumentDependentLookup = false; 3846 } 3847 3848 if (Callee) 3849 UnqualifiedName = Callee->getDeclName(); 3850 3851 // FIXME: Pass explicit template arguments through for ADL 3852 if (ArgumentDependentLookup) 3853 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 3854 CandidateSet); 3855 3856 OverloadCandidateSet::iterator Best; 3857 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 3858 case OR_Success: 3859 return Best->Function; 3860 3861 case OR_No_Viable_Function: 3862 Diag(Fn->getSourceRange().getBegin(), 3863 diag::err_ovl_no_viable_function_in_call) 3864 << UnqualifiedName << Fn->getSourceRange(); 3865 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3866 break; 3867 3868 case OR_Ambiguous: 3869 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 3870 << UnqualifiedName << Fn->getSourceRange(); 3871 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3872 break; 3873 3874 case OR_Deleted: 3875 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 3876 << Best->Function->isDeleted() 3877 << UnqualifiedName 3878 << Fn->getSourceRange(); 3879 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3880 break; 3881 } 3882 3883 // Overload resolution failed. Destroy all of the subexpressions and 3884 // return NULL. 3885 Fn->Destroy(Context); 3886 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 3887 Args[Arg]->Destroy(Context); 3888 return 0; 3889} 3890 3891/// \brief Create a unary operation that may resolve to an overloaded 3892/// operator. 3893/// 3894/// \param OpLoc The location of the operator itself (e.g., '*'). 3895/// 3896/// \param OpcIn The UnaryOperator::Opcode that describes this 3897/// operator. 3898/// 3899/// \param Functions The set of non-member functions that will be 3900/// considered by overload resolution. The caller needs to build this 3901/// set based on the context using, e.g., 3902/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 3903/// set should not contain any member functions; those will be added 3904/// by CreateOverloadedUnaryOp(). 3905/// 3906/// \param input The input argument. 3907Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 3908 unsigned OpcIn, 3909 FunctionSet &Functions, 3910 ExprArg input) { 3911 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 3912 Expr *Input = (Expr *)input.get(); 3913 3914 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 3915 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 3916 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3917 3918 Expr *Args[2] = { Input, 0 }; 3919 unsigned NumArgs = 1; 3920 3921 // For post-increment and post-decrement, add the implicit '0' as 3922 // the second argument, so that we know this is a post-increment or 3923 // post-decrement. 3924 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 3925 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 3926 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 3927 SourceLocation()); 3928 NumArgs = 2; 3929 } 3930 3931 if (Input->isTypeDependent()) { 3932 OverloadedFunctionDecl *Overloads 3933 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 3934 for (FunctionSet::iterator Func = Functions.begin(), 3935 FuncEnd = Functions.end(); 3936 Func != FuncEnd; ++Func) 3937 Overloads->addOverload(*Func); 3938 3939 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 3940 OpLoc, false, false); 3941 3942 input.release(); 3943 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 3944 &Args[0], NumArgs, 3945 Context.DependentTy, 3946 OpLoc)); 3947 } 3948 3949 // Build an empty overload set. 3950 OverloadCandidateSet CandidateSet; 3951 3952 // Add the candidates from the given function set. 3953 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 3954 3955 // Add operator candidates that are member functions. 3956 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 3957 3958 // Add builtin operator candidates. 3959 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 3960 3961 // Perform overload resolution. 3962 OverloadCandidateSet::iterator Best; 3963 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 3964 case OR_Success: { 3965 // We found a built-in operator or an overloaded operator. 3966 FunctionDecl *FnDecl = Best->Function; 3967 3968 if (FnDecl) { 3969 // We matched an overloaded operator. Build a call to that 3970 // operator. 3971 3972 // Convert the arguments. 3973 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 3974 if (PerformObjectArgumentInitialization(Input, Method)) 3975 return ExprError(); 3976 } else { 3977 // Convert the arguments. 3978 if (PerformCopyInitialization(Input, 3979 FnDecl->getParamDecl(0)->getType(), 3980 "passing")) 3981 return ExprError(); 3982 } 3983 3984 // Determine the result type 3985 QualType ResultTy 3986 = FnDecl->getType()->getAsFunctionType()->getResultType(); 3987 ResultTy = ResultTy.getNonReferenceType(); 3988 3989 // Build the actual expression node. 3990 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 3991 SourceLocation()); 3992 UsualUnaryConversions(FnExpr); 3993 3994 input.release(); 3995 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 3996 &Input, 1, ResultTy, 3997 OpLoc)); 3998 } else { 3999 // We matched a built-in operator. Convert the arguments, then 4000 // break out so that we will build the appropriate built-in 4001 // operator node. 4002 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4003 Best->Conversions[0], "passing")) 4004 return ExprError(); 4005 4006 break; 4007 } 4008 } 4009 4010 case OR_No_Viable_Function: 4011 // No viable function; fall through to handling this as a 4012 // built-in operator, which will produce an error message for us. 4013 break; 4014 4015 case OR_Ambiguous: 4016 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4017 << UnaryOperator::getOpcodeStr(Opc) 4018 << Input->getSourceRange(); 4019 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4020 return ExprError(); 4021 4022 case OR_Deleted: 4023 Diag(OpLoc, diag::err_ovl_deleted_oper) 4024 << Best->Function->isDeleted() 4025 << UnaryOperator::getOpcodeStr(Opc) 4026 << Input->getSourceRange(); 4027 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4028 return ExprError(); 4029 } 4030 4031 // Either we found no viable overloaded operator or we matched a 4032 // built-in operator. In either case, fall through to trying to 4033 // build a built-in operation. 4034 input.release(); 4035 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4036} 4037 4038/// \brief Create a binary operation that may resolve to an overloaded 4039/// operator. 4040/// 4041/// \param OpLoc The location of the operator itself (e.g., '+'). 4042/// 4043/// \param OpcIn The BinaryOperator::Opcode that describes this 4044/// operator. 4045/// 4046/// \param Functions The set of non-member functions that will be 4047/// considered by overload resolution. The caller needs to build this 4048/// set based on the context using, e.g., 4049/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4050/// set should not contain any member functions; those will be added 4051/// by CreateOverloadedBinOp(). 4052/// 4053/// \param LHS Left-hand argument. 4054/// \param RHS Right-hand argument. 4055Sema::OwningExprResult 4056Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4057 unsigned OpcIn, 4058 FunctionSet &Functions, 4059 Expr *LHS, Expr *RHS) { 4060 Expr *Args[2] = { LHS, RHS }; 4061 4062 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4063 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4064 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4065 4066 // If either side is type-dependent, create an appropriate dependent 4067 // expression. 4068 if (LHS->isTypeDependent() || RHS->isTypeDependent()) { 4069 // .* cannot be overloaded. 4070 if (Opc == BinaryOperator::PtrMemD) 4071 return Owned(new (Context) BinaryOperator(LHS, RHS, Opc, 4072 Context.DependentTy, OpLoc)); 4073 4074 OverloadedFunctionDecl *Overloads 4075 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4076 for (FunctionSet::iterator Func = Functions.begin(), 4077 FuncEnd = Functions.end(); 4078 Func != FuncEnd; ++Func) 4079 Overloads->addOverload(*Func); 4080 4081 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4082 OpLoc, false, false); 4083 4084 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4085 Args, 2, 4086 Context.DependentTy, 4087 OpLoc)); 4088 } 4089 4090 // If this is the .* operator, which is not overloadable, just 4091 // create a built-in binary operator. 4092 if (Opc == BinaryOperator::PtrMemD) 4093 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4094 4095 // If this is one of the assignment operators, we only perform 4096 // overload resolution if the left-hand side is a class or 4097 // enumeration type (C++ [expr.ass]p3). 4098 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4099 !LHS->getType()->isOverloadableType()) 4100 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4101 4102 // Build an empty overload set. 4103 OverloadCandidateSet CandidateSet; 4104 4105 // Add the candidates from the given function set. 4106 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4107 4108 // Add operator candidates that are member functions. 4109 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4110 4111 // Add builtin operator candidates. 4112 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4113 4114 // Perform overload resolution. 4115 OverloadCandidateSet::iterator Best; 4116 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4117 case OR_Success: { 4118 // We found a built-in operator or an overloaded operator. 4119 FunctionDecl *FnDecl = Best->Function; 4120 4121 if (FnDecl) { 4122 // We matched an overloaded operator. Build a call to that 4123 // operator. 4124 4125 // Convert the arguments. 4126 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4127 if (PerformObjectArgumentInitialization(LHS, Method) || 4128 PerformCopyInitialization(RHS, FnDecl->getParamDecl(0)->getType(), 4129 "passing")) 4130 return ExprError(); 4131 } else { 4132 // Convert the arguments. 4133 if (PerformCopyInitialization(LHS, FnDecl->getParamDecl(0)->getType(), 4134 "passing") || 4135 PerformCopyInitialization(RHS, FnDecl->getParamDecl(1)->getType(), 4136 "passing")) 4137 return ExprError(); 4138 } 4139 4140 // Determine the result type 4141 QualType ResultTy 4142 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4143 ResultTy = ResultTy.getNonReferenceType(); 4144 4145 // Build the actual expression node. 4146 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4147 SourceLocation()); 4148 UsualUnaryConversions(FnExpr); 4149 4150 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4151 Args, 2, ResultTy, 4152 OpLoc)); 4153 } else { 4154 // We matched a built-in operator. Convert the arguments, then 4155 // break out so that we will build the appropriate built-in 4156 // operator node. 4157 if (PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0], 4158 Best->Conversions[0], "passing") || 4159 PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1], 4160 Best->Conversions[1], "passing")) 4161 return ExprError(); 4162 4163 break; 4164 } 4165 } 4166 4167 case OR_No_Viable_Function: 4168 // For class as left operand for assignment or compound assigment operator 4169 // do not fall through to handling in built-in, but report that no overloaded 4170 // assignment operator found 4171 if (LHS->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4172 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4173 << BinaryOperator::getOpcodeStr(Opc) 4174 << LHS->getSourceRange() << RHS->getSourceRange(); 4175 return ExprError(); 4176 } 4177 // No viable function; fall through to handling this as a 4178 // built-in operator, which will produce an error message for us. 4179 break; 4180 4181 case OR_Ambiguous: 4182 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4183 << BinaryOperator::getOpcodeStr(Opc) 4184 << LHS->getSourceRange() << RHS->getSourceRange(); 4185 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4186 return ExprError(); 4187 4188 case OR_Deleted: 4189 Diag(OpLoc, diag::err_ovl_deleted_oper) 4190 << Best->Function->isDeleted() 4191 << BinaryOperator::getOpcodeStr(Opc) 4192 << LHS->getSourceRange() << RHS->getSourceRange(); 4193 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4194 return ExprError(); 4195 } 4196 4197 // Either we found no viable overloaded operator or we matched a 4198 // built-in operator. In either case, try to build a built-in 4199 // operation. 4200 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4201} 4202 4203/// BuildCallToMemberFunction - Build a call to a member 4204/// function. MemExpr is the expression that refers to the member 4205/// function (and includes the object parameter), Args/NumArgs are the 4206/// arguments to the function call (not including the object 4207/// parameter). The caller needs to validate that the member 4208/// expression refers to a member function or an overloaded member 4209/// function. 4210Sema::ExprResult 4211Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4212 SourceLocation LParenLoc, Expr **Args, 4213 unsigned NumArgs, SourceLocation *CommaLocs, 4214 SourceLocation RParenLoc) { 4215 // Dig out the member expression. This holds both the object 4216 // argument and the member function we're referring to. 4217 MemberExpr *MemExpr = 0; 4218 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4219 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4220 else 4221 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4222 assert(MemExpr && "Building member call without member expression"); 4223 4224 // Extract the object argument. 4225 Expr *ObjectArg = MemExpr->getBase(); 4226 4227 CXXMethodDecl *Method = 0; 4228 if (OverloadedFunctionDecl *Ovl 4229 = dyn_cast<OverloadedFunctionDecl>(MemExpr->getMemberDecl())) { 4230 // Add overload candidates 4231 OverloadCandidateSet CandidateSet; 4232 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4233 FuncEnd = Ovl->function_end(); 4234 Func != FuncEnd; ++Func) { 4235 assert(isa<CXXMethodDecl>(*Func) && "Function is not a method"); 4236 Method = cast<CXXMethodDecl>(*Func); 4237 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4238 /*SuppressUserConversions=*/false); 4239 } 4240 4241 OverloadCandidateSet::iterator Best; 4242 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4243 case OR_Success: 4244 Method = cast<CXXMethodDecl>(Best->Function); 4245 break; 4246 4247 case OR_No_Viable_Function: 4248 Diag(MemExpr->getSourceRange().getBegin(), 4249 diag::err_ovl_no_viable_member_function_in_call) 4250 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4251 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4252 // FIXME: Leaking incoming expressions! 4253 return true; 4254 4255 case OR_Ambiguous: 4256 Diag(MemExpr->getSourceRange().getBegin(), 4257 diag::err_ovl_ambiguous_member_call) 4258 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4259 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4260 // FIXME: Leaking incoming expressions! 4261 return true; 4262 4263 case OR_Deleted: 4264 Diag(MemExpr->getSourceRange().getBegin(), 4265 diag::err_ovl_deleted_member_call) 4266 << Best->Function->isDeleted() 4267 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4268 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4269 // FIXME: Leaking incoming expressions! 4270 return true; 4271 } 4272 4273 FixOverloadedFunctionReference(MemExpr, Method); 4274 } else { 4275 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4276 } 4277 4278 assert(Method && "Member call to something that isn't a method?"); 4279 ExprOwningPtr<CXXMemberCallExpr> 4280 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4281 NumArgs, 4282 Method->getResultType().getNonReferenceType(), 4283 RParenLoc)); 4284 4285 // Convert the object argument (for a non-static member function call). 4286 if (!Method->isStatic() && 4287 PerformObjectArgumentInitialization(ObjectArg, Method)) 4288 return true; 4289 MemExpr->setBase(ObjectArg); 4290 4291 // Convert the rest of the arguments 4292 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4293 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4294 RParenLoc)) 4295 return true; 4296 4297 return CheckFunctionCall(Method, TheCall.take()).release(); 4298} 4299 4300/// BuildCallToObjectOfClassType - Build a call to an object of class 4301/// type (C++ [over.call.object]), which can end up invoking an 4302/// overloaded function call operator (@c operator()) or performing a 4303/// user-defined conversion on the object argument. 4304Sema::ExprResult 4305Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4306 SourceLocation LParenLoc, 4307 Expr **Args, unsigned NumArgs, 4308 SourceLocation *CommaLocs, 4309 SourceLocation RParenLoc) { 4310 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4311 const RecordType *Record = Object->getType()->getAsRecordType(); 4312 4313 // C++ [over.call.object]p1: 4314 // If the primary-expression E in the function call syntax 4315 // evaluates to a class object of type “cv T”, then the set of 4316 // candidate functions includes at least the function call 4317 // operators of T. The function call operators of T are obtained by 4318 // ordinary lookup of the name operator() in the context of 4319 // (E).operator(). 4320 OverloadCandidateSet CandidateSet; 4321 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4322 DeclContext::lookup_const_iterator Oper, OperEnd; 4323 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4324 Oper != OperEnd; ++Oper) 4325 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4326 CandidateSet, /*SuppressUserConversions=*/false); 4327 4328 // C++ [over.call.object]p2: 4329 // In addition, for each conversion function declared in T of the 4330 // form 4331 // 4332 // operator conversion-type-id () cv-qualifier; 4333 // 4334 // where cv-qualifier is the same cv-qualification as, or a 4335 // greater cv-qualification than, cv, and where conversion-type-id 4336 // denotes the type "pointer to function of (P1,...,Pn) returning 4337 // R", or the type "reference to pointer to function of 4338 // (P1,...,Pn) returning R", or the type "reference to function 4339 // of (P1,...,Pn) returning R", a surrogate call function [...] 4340 // is also considered as a candidate function. Similarly, 4341 // surrogate call functions are added to the set of candidate 4342 // functions for each conversion function declared in an 4343 // accessible base class provided the function is not hidden 4344 // within T by another intervening declaration. 4345 // 4346 // FIXME: Look in base classes for more conversion operators! 4347 OverloadedFunctionDecl *Conversions 4348 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4349 for (OverloadedFunctionDecl::function_iterator 4350 Func = Conversions->function_begin(), 4351 FuncEnd = Conversions->function_end(); 4352 Func != FuncEnd; ++Func) { 4353 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 4354 4355 // Strip the reference type (if any) and then the pointer type (if 4356 // any) to get down to what might be a function type. 4357 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4358 if (const PointerType *ConvPtrType = ConvType->getAsPointerType()) 4359 ConvType = ConvPtrType->getPointeeType(); 4360 4361 if (const FunctionProtoType *Proto = ConvType->getAsFunctionProtoType()) 4362 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4363 } 4364 4365 // Perform overload resolution. 4366 OverloadCandidateSet::iterator Best; 4367 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4368 case OR_Success: 4369 // Overload resolution succeeded; we'll build the appropriate call 4370 // below. 4371 break; 4372 4373 case OR_No_Viable_Function: 4374 Diag(Object->getSourceRange().getBegin(), 4375 diag::err_ovl_no_viable_object_call) 4376 << Object->getType() << Object->getSourceRange(); 4377 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4378 break; 4379 4380 case OR_Ambiguous: 4381 Diag(Object->getSourceRange().getBegin(), 4382 diag::err_ovl_ambiguous_object_call) 4383 << Object->getType() << Object->getSourceRange(); 4384 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4385 break; 4386 4387 case OR_Deleted: 4388 Diag(Object->getSourceRange().getBegin(), 4389 diag::err_ovl_deleted_object_call) 4390 << Best->Function->isDeleted() 4391 << Object->getType() << Object->getSourceRange(); 4392 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4393 break; 4394 } 4395 4396 if (Best == CandidateSet.end()) { 4397 // We had an error; delete all of the subexpressions and return 4398 // the error. 4399 Object->Destroy(Context); 4400 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4401 Args[ArgIdx]->Destroy(Context); 4402 return true; 4403 } 4404 4405 if (Best->Function == 0) { 4406 // Since there is no function declaration, this is one of the 4407 // surrogate candidates. Dig out the conversion function. 4408 CXXConversionDecl *Conv 4409 = cast<CXXConversionDecl>( 4410 Best->Conversions[0].UserDefined.ConversionFunction); 4411 4412 // We selected one of the surrogate functions that converts the 4413 // object parameter to a function pointer. Perform the conversion 4414 // on the object argument, then let ActOnCallExpr finish the job. 4415 // FIXME: Represent the user-defined conversion in the AST! 4416 ImpCastExprToType(Object, 4417 Conv->getConversionType().getNonReferenceType(), 4418 Conv->getConversionType()->isLValueReferenceType()); 4419 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4420 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4421 CommaLocs, RParenLoc).release(); 4422 } 4423 4424 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4425 // that calls this method, using Object for the implicit object 4426 // parameter and passing along the remaining arguments. 4427 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4428 const FunctionProtoType *Proto = Method->getType()->getAsFunctionProtoType(); 4429 4430 unsigned NumArgsInProto = Proto->getNumArgs(); 4431 unsigned NumArgsToCheck = NumArgs; 4432 4433 // Build the full argument list for the method call (the 4434 // implicit object parameter is placed at the beginning of the 4435 // list). 4436 Expr **MethodArgs; 4437 if (NumArgs < NumArgsInProto) { 4438 NumArgsToCheck = NumArgsInProto; 4439 MethodArgs = new Expr*[NumArgsInProto + 1]; 4440 } else { 4441 MethodArgs = new Expr*[NumArgs + 1]; 4442 } 4443 MethodArgs[0] = Object; 4444 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4445 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4446 4447 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4448 SourceLocation()); 4449 UsualUnaryConversions(NewFn); 4450 4451 // Once we've built TheCall, all of the expressions are properly 4452 // owned. 4453 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4454 ExprOwningPtr<CXXOperatorCallExpr> 4455 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4456 MethodArgs, NumArgs + 1, 4457 ResultTy, RParenLoc)); 4458 delete [] MethodArgs; 4459 4460 // We may have default arguments. If so, we need to allocate more 4461 // slots in the call for them. 4462 if (NumArgs < NumArgsInProto) 4463 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4464 else if (NumArgs > NumArgsInProto) 4465 NumArgsToCheck = NumArgsInProto; 4466 4467 bool IsError = false; 4468 4469 // Initialize the implicit object parameter. 4470 IsError |= PerformObjectArgumentInitialization(Object, Method); 4471 TheCall->setArg(0, Object); 4472 4473 4474 // Check the argument types. 4475 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4476 Expr *Arg; 4477 if (i < NumArgs) { 4478 Arg = Args[i]; 4479 4480 // Pass the argument. 4481 QualType ProtoArgType = Proto->getArgType(i); 4482 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4483 } else { 4484 Arg = new (Context) CXXDefaultArgExpr(Method->getParamDecl(i)); 4485 } 4486 4487 TheCall->setArg(i + 1, Arg); 4488 } 4489 4490 // If this is a variadic call, handle args passed through "...". 4491 if (Proto->isVariadic()) { 4492 // Promote the arguments (C99 6.5.2.2p7). 4493 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4494 Expr *Arg = Args[i]; 4495 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4496 TheCall->setArg(i + 1, Arg); 4497 } 4498 } 4499 4500 if (IsError) return true; 4501 4502 return CheckFunctionCall(Method, TheCall.take()).release(); 4503} 4504 4505/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4506/// (if one exists), where @c Base is an expression of class type and 4507/// @c Member is the name of the member we're trying to find. 4508Action::ExprResult 4509Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc, 4510 SourceLocation MemberLoc, 4511 IdentifierInfo &Member) { 4512 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4513 4514 // C++ [over.ref]p1: 4515 // 4516 // [...] An expression x->m is interpreted as (x.operator->())->m 4517 // for a class object x of type T if T::operator->() exists and if 4518 // the operator is selected as the best match function by the 4519 // overload resolution mechanism (13.3). 4520 // FIXME: look in base classes. 4521 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4522 OverloadCandidateSet CandidateSet; 4523 const RecordType *BaseRecord = Base->getType()->getAsRecordType(); 4524 4525 DeclContext::lookup_const_iterator Oper, OperEnd; 4526 for (llvm::tie(Oper, OperEnd) 4527 = BaseRecord->getDecl()->lookup(OpName); Oper != OperEnd; ++Oper) 4528 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4529 /*SuppressUserConversions=*/false); 4530 4531 ExprOwningPtr<Expr> BasePtr(this, Base); 4532 4533 // Perform overload resolution. 4534 OverloadCandidateSet::iterator Best; 4535 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4536 case OR_Success: 4537 // Overload resolution succeeded; we'll build the call below. 4538 break; 4539 4540 case OR_No_Viable_Function: 4541 if (CandidateSet.empty()) 4542 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4543 << BasePtr->getType() << BasePtr->getSourceRange(); 4544 else 4545 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4546 << "operator->" << BasePtr->getSourceRange(); 4547 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4548 return true; 4549 4550 case OR_Ambiguous: 4551 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4552 << "operator->" << BasePtr->getSourceRange(); 4553 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4554 return true; 4555 4556 case OR_Deleted: 4557 Diag(OpLoc, diag::err_ovl_deleted_oper) 4558 << Best->Function->isDeleted() 4559 << "operator->" << BasePtr->getSourceRange(); 4560 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4561 return true; 4562 } 4563 4564 // Convert the object parameter. 4565 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4566 if (PerformObjectArgumentInitialization(Base, Method)) 4567 return true; 4568 4569 // No concerns about early exits now. 4570 BasePtr.take(); 4571 4572 // Build the operator call. 4573 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 4574 SourceLocation()); 4575 UsualUnaryConversions(FnExpr); 4576 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 4577 Method->getResultType().getNonReferenceType(), 4578 OpLoc); 4579 return ActOnMemberReferenceExpr(S, ExprArg(*this, Base), OpLoc, tok::arrow, 4580 MemberLoc, Member, DeclPtrTy()).release(); 4581} 4582 4583/// FixOverloadedFunctionReference - E is an expression that refers to 4584/// a C++ overloaded function (possibly with some parentheses and 4585/// perhaps a '&' around it). We have resolved the overloaded function 4586/// to the function declaration Fn, so patch up the expression E to 4587/// refer (possibly indirectly) to Fn. 4588void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 4589 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4590 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 4591 E->setType(PE->getSubExpr()->getType()); 4592 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 4593 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 4594 "Can only take the address of an overloaded function"); 4595 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4596 if (Method->isStatic()) { 4597 // Do nothing: static member functions aren't any different 4598 // from non-member functions. 4599 } 4600 else if (QualifiedDeclRefExpr *DRE 4601 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 4602 // We have taken the address of a pointer to member 4603 // function. Perform the computation here so that we get the 4604 // appropriate pointer to member type. 4605 DRE->setDecl(Fn); 4606 DRE->setType(Fn->getType()); 4607 QualType ClassType 4608 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 4609 E->setType(Context.getMemberPointerType(Fn->getType(), 4610 ClassType.getTypePtr())); 4611 return; 4612 } 4613 } 4614 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 4615 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 4616 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 4617 assert(isa<OverloadedFunctionDecl>(DR->getDecl()) && 4618 "Expected overloaded function"); 4619 DR->setDecl(Fn); 4620 E->setType(Fn->getType()); 4621 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 4622 MemExpr->setMemberDecl(Fn); 4623 E->setType(Fn->getType()); 4624 } else { 4625 assert(false && "Invalid reference to overloaded function"); 4626 } 4627} 4628 4629} // end namespace clang 4630