SemaOverload.cpp revision 33bbbc5ec8269bc2cde5b84f970fa49319a30267
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 (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 304 // Is the function New an overload of the function Old? 305 QualType OldQType = Context.getCanonicalType(Old->getType()); 306 QualType NewQType = Context.getCanonicalType(New->getType()); 307 308 // Compare the signatures (C++ 1.3.10) of the two functions to 309 // determine whether they are overloads. If we find any mismatch 310 // in the signature, they are overloads. 311 312 // If either of these functions is a K&R-style function (no 313 // prototype), then we consider them to have matching signatures. 314 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 315 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 316 return false; 317 318 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType.getTypePtr()); 319 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType.getTypePtr()); 320 321 // The signature of a function includes the types of its 322 // parameters (C++ 1.3.10), which includes the presence or absence 323 // of the ellipsis; see C++ DR 357). 324 if (OldQType != NewQType && 325 (OldType->getNumArgs() != NewType->getNumArgs() || 326 OldType->isVariadic() != NewType->isVariadic() || 327 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 328 NewType->arg_type_begin()))) 329 return true; 330 331 // If the function is a class member, its signature includes the 332 // cv-qualifiers (if any) on the function itself. 333 // 334 // As part of this, also check whether one of the member functions 335 // is static, in which case they are not overloads (C++ 336 // 13.1p2). While not part of the definition of the signature, 337 // this check is important to determine whether these functions 338 // can be overloaded. 339 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 340 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 341 if (OldMethod && NewMethod && 342 !OldMethod->isStatic() && !NewMethod->isStatic() && 343 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 344 return true; 345 346 // The signatures match; this is not an overload. 347 return false; 348 } else { 349 // (C++ 13p1): 350 // Only function declarations can be overloaded; object and type 351 // declarations cannot be overloaded. 352 return false; 353 } 354} 355 356/// TryImplicitConversion - Attempt to perform an implicit conversion 357/// from the given expression (Expr) to the given type (ToType). This 358/// function returns an implicit conversion sequence that can be used 359/// to perform the initialization. Given 360/// 361/// void f(float f); 362/// void g(int i) { f(i); } 363/// 364/// this routine would produce an implicit conversion sequence to 365/// describe the initialization of f from i, which will be a standard 366/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 367/// 4.1) followed by a floating-integral conversion (C++ 4.9). 368// 369/// Note that this routine only determines how the conversion can be 370/// performed; it does not actually perform the conversion. As such, 371/// it will not produce any diagnostics if no conversion is available, 372/// but will instead return an implicit conversion sequence of kind 373/// "BadConversion". 374/// 375/// If @p SuppressUserConversions, then user-defined conversions are 376/// not permitted. 377/// If @p AllowExplicit, then explicit user-defined conversions are 378/// permitted. 379/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 380/// no matter its actual lvalueness. 381ImplicitConversionSequence 382Sema::TryImplicitConversion(Expr* From, QualType ToType, 383 bool SuppressUserConversions, 384 bool AllowExplicit, bool ForceRValue) 385{ 386 ImplicitConversionSequence ICS; 387 if (IsStandardConversion(From, ToType, ICS.Standard)) 388 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 389 else if (getLangOptions().CPlusPlus && 390 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 391 !SuppressUserConversions, AllowExplicit, 392 ForceRValue)) { 393 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 394 // C++ [over.ics.user]p4: 395 // A conversion of an expression of class type to the same class 396 // type is given Exact Match rank, and a conversion of an 397 // expression of class type to a base class of that type is 398 // given Conversion rank, in spite of the fact that a copy 399 // constructor (i.e., a user-defined conversion function) is 400 // called for those cases. 401 if (CXXConstructorDecl *Constructor 402 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 403 QualType FromCanon 404 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 405 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 406 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 407 // Turn this into a "standard" conversion sequence, so that it 408 // gets ranked with standard conversion sequences. 409 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 410 ICS.Standard.setAsIdentityConversion(); 411 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 412 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 413 ICS.Standard.CopyConstructor = Constructor; 414 if (ToCanon != FromCanon) 415 ICS.Standard.Second = ICK_Derived_To_Base; 416 } 417 } 418 419 // C++ [over.best.ics]p4: 420 // However, when considering the argument of a user-defined 421 // conversion function that is a candidate by 13.3.1.3 when 422 // invoked for the copying of the temporary in the second step 423 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 424 // 13.3.1.6 in all cases, only standard conversion sequences and 425 // ellipsis conversion sequences are allowed. 426 if (SuppressUserConversions && 427 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 428 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 429 } else 430 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 431 432 return ICS; 433} 434 435/// IsStandardConversion - Determines whether there is a standard 436/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 437/// expression From to the type ToType. Standard conversion sequences 438/// only consider non-class types; for conversions that involve class 439/// types, use TryImplicitConversion. If a conversion exists, SCS will 440/// contain the standard conversion sequence required to perform this 441/// conversion and this routine will return true. Otherwise, this 442/// routine will return false and the value of SCS is unspecified. 443bool 444Sema::IsStandardConversion(Expr* From, QualType ToType, 445 StandardConversionSequence &SCS) 446{ 447 QualType FromType = From->getType(); 448 449 // Standard conversions (C++ [conv]) 450 SCS.setAsIdentityConversion(); 451 SCS.Deprecated = false; 452 SCS.IncompatibleObjC = false; 453 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 454 SCS.CopyConstructor = 0; 455 456 // There are no standard conversions for class types in C++, so 457 // abort early. When overloading in C, however, we do permit 458 if (FromType->isRecordType() || ToType->isRecordType()) { 459 if (getLangOptions().CPlusPlus) 460 return false; 461 462 // When we're overloading in C, we allow, as standard conversions, 463 } 464 465 // The first conversion can be an lvalue-to-rvalue conversion, 466 // array-to-pointer conversion, or function-to-pointer conversion 467 // (C++ 4p1). 468 469 // Lvalue-to-rvalue conversion (C++ 4.1): 470 // An lvalue (3.10) of a non-function, non-array type T can be 471 // converted to an rvalue. 472 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 473 if (argIsLvalue == Expr::LV_Valid && 474 !FromType->isFunctionType() && !FromType->isArrayType() && 475 Context.getCanonicalType(FromType) != Context.OverloadTy) { 476 SCS.First = ICK_Lvalue_To_Rvalue; 477 478 // If T is a non-class type, the type of the rvalue is the 479 // cv-unqualified version of T. Otherwise, the type of the rvalue 480 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 481 // just strip the qualifiers because they don't matter. 482 483 // FIXME: Doesn't see through to qualifiers behind a typedef! 484 FromType = FromType.getUnqualifiedType(); 485 } 486 // Array-to-pointer conversion (C++ 4.2) 487 else if (FromType->isArrayType()) { 488 SCS.First = ICK_Array_To_Pointer; 489 490 // An lvalue or rvalue of type "array of N T" or "array of unknown 491 // bound of T" can be converted to an rvalue of type "pointer to 492 // T" (C++ 4.2p1). 493 FromType = Context.getArrayDecayedType(FromType); 494 495 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 496 // This conversion is deprecated. (C++ D.4). 497 SCS.Deprecated = true; 498 499 // For the purpose of ranking in overload resolution 500 // (13.3.3.1.1), this conversion is considered an 501 // array-to-pointer conversion followed by a qualification 502 // conversion (4.4). (C++ 4.2p2) 503 SCS.Second = ICK_Identity; 504 SCS.Third = ICK_Qualification; 505 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 506 return true; 507 } 508 } 509 // Function-to-pointer conversion (C++ 4.3). 510 else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 511 SCS.First = ICK_Function_To_Pointer; 512 513 // An lvalue of function type T can be converted to an rvalue of 514 // type "pointer to T." The result is a pointer to the 515 // function. (C++ 4.3p1). 516 FromType = Context.getPointerType(FromType); 517 } 518 // Address of overloaded function (C++ [over.over]). 519 else if (FunctionDecl *Fn 520 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 521 SCS.First = ICK_Function_To_Pointer; 522 523 // We were able to resolve the address of the overloaded function, 524 // so we can convert to the type of that function. 525 FromType = Fn->getType(); 526 if (ToType->isLValueReferenceType()) 527 FromType = Context.getLValueReferenceType(FromType); 528 else if (ToType->isRValueReferenceType()) 529 FromType = Context.getRValueReferenceType(FromType); 530 else if (ToType->isMemberPointerType()) { 531 // Resolve address only succeeds if both sides are member pointers, 532 // but it doesn't have to be the same class. See DR 247. 533 // Note that this means that the type of &Derived::fn can be 534 // Ret (Base::*)(Args) if the fn overload actually found is from the 535 // base class, even if it was brought into the derived class via a 536 // using declaration. The standard isn't clear on this issue at all. 537 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 538 FromType = Context.getMemberPointerType(FromType, 539 Context.getTypeDeclType(M->getParent()).getTypePtr()); 540 } else 541 FromType = Context.getPointerType(FromType); 542 } 543 // We don't require any conversions for the first step. 544 else { 545 SCS.First = ICK_Identity; 546 } 547 548 // The second conversion can be an integral promotion, floating 549 // point promotion, integral conversion, floating point conversion, 550 // floating-integral conversion, pointer conversion, 551 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 552 // For overloading in C, this can also be a "compatible-type" 553 // conversion. 554 bool IncompatibleObjC = false; 555 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 556 // The unqualified versions of the types are the same: there's no 557 // conversion to do. 558 SCS.Second = ICK_Identity; 559 } 560 // Integral promotion (C++ 4.5). 561 else if (IsIntegralPromotion(From, FromType, ToType)) { 562 SCS.Second = ICK_Integral_Promotion; 563 FromType = ToType.getUnqualifiedType(); 564 } 565 // Floating point promotion (C++ 4.6). 566 else if (IsFloatingPointPromotion(FromType, ToType)) { 567 SCS.Second = ICK_Floating_Promotion; 568 FromType = ToType.getUnqualifiedType(); 569 } 570 // Complex promotion (Clang extension) 571 else if (IsComplexPromotion(FromType, ToType)) { 572 SCS.Second = ICK_Complex_Promotion; 573 FromType = ToType.getUnqualifiedType(); 574 } 575 // Integral conversions (C++ 4.7). 576 // FIXME: isIntegralType shouldn't be true for enums in C++. 577 else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 578 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 579 SCS.Second = ICK_Integral_Conversion; 580 FromType = ToType.getUnqualifiedType(); 581 } 582 // Floating point conversions (C++ 4.8). 583 else if (FromType->isFloatingType() && ToType->isFloatingType()) { 584 SCS.Second = ICK_Floating_Conversion; 585 FromType = ToType.getUnqualifiedType(); 586 } 587 // Complex conversions (C99 6.3.1.6) 588 else if (FromType->isComplexType() && ToType->isComplexType()) { 589 SCS.Second = ICK_Complex_Conversion; 590 FromType = ToType.getUnqualifiedType(); 591 } 592 // Floating-integral conversions (C++ 4.9). 593 // FIXME: isIntegralType shouldn't be true for enums in C++. 594 else if ((FromType->isFloatingType() && 595 ToType->isIntegralType() && !ToType->isBooleanType() && 596 !ToType->isEnumeralType()) || 597 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 598 ToType->isFloatingType())) { 599 SCS.Second = ICK_Floating_Integral; 600 FromType = ToType.getUnqualifiedType(); 601 } 602 // Complex-real conversions (C99 6.3.1.7) 603 else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 604 (ToType->isComplexType() && FromType->isArithmeticType())) { 605 SCS.Second = ICK_Complex_Real; 606 FromType = ToType.getUnqualifiedType(); 607 } 608 // Pointer conversions (C++ 4.10). 609 else if (IsPointerConversion(From, FromType, ToType, FromType, 610 IncompatibleObjC)) { 611 SCS.Second = ICK_Pointer_Conversion; 612 SCS.IncompatibleObjC = IncompatibleObjC; 613 } 614 // Pointer to member conversions (4.11). 615 else if (IsMemberPointerConversion(From, FromType, ToType, FromType)) { 616 SCS.Second = ICK_Pointer_Member; 617 } 618 // Boolean conversions (C++ 4.12). 619 else if (ToType->isBooleanType() && 620 (FromType->isArithmeticType() || 621 FromType->isEnumeralType() || 622 FromType->isPointerType() || 623 FromType->isBlockPointerType() || 624 FromType->isMemberPointerType())) { 625 SCS.Second = ICK_Boolean_Conversion; 626 FromType = Context.BoolTy; 627 } 628 // Compatible conversions (Clang extension for C function overloading) 629 else if (!getLangOptions().CPlusPlus && 630 Context.typesAreCompatible(ToType, FromType)) { 631 SCS.Second = ICK_Compatible_Conversion; 632 } else { 633 // No second conversion required. 634 SCS.Second = ICK_Identity; 635 } 636 637 QualType CanonFrom; 638 QualType CanonTo; 639 // The third conversion can be a qualification conversion (C++ 4p1). 640 if (IsQualificationConversion(FromType, ToType)) { 641 SCS.Third = ICK_Qualification; 642 FromType = ToType; 643 CanonFrom = Context.getCanonicalType(FromType); 644 CanonTo = Context.getCanonicalType(ToType); 645 } else { 646 // No conversion required 647 SCS.Third = ICK_Identity; 648 649 // C++ [over.best.ics]p6: 650 // [...] Any difference in top-level cv-qualification is 651 // subsumed by the initialization itself and does not constitute 652 // a conversion. [...] 653 CanonFrom = Context.getCanonicalType(FromType); 654 CanonTo = Context.getCanonicalType(ToType); 655 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 656 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 657 FromType = ToType; 658 CanonFrom = CanonTo; 659 } 660 } 661 662 // If we have not converted the argument type to the parameter type, 663 // this is a bad conversion sequence. 664 if (CanonFrom != CanonTo) 665 return false; 666 667 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 668 return true; 669} 670 671/// IsIntegralPromotion - Determines whether the conversion from the 672/// expression From (whose potentially-adjusted type is FromType) to 673/// ToType is an integral promotion (C++ 4.5). If so, returns true and 674/// sets PromotedType to the promoted type. 675bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) 676{ 677 const BuiltinType *To = ToType->getAsBuiltinType(); 678 // All integers are built-in. 679 if (!To) { 680 return false; 681 } 682 683 // An rvalue of type char, signed char, unsigned char, short int, or 684 // unsigned short int can be converted to an rvalue of type int if 685 // int can represent all the values of the source type; otherwise, 686 // the source rvalue can be converted to an rvalue of type unsigned 687 // int (C++ 4.5p1). 688 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 689 if (// We can promote any signed, promotable integer type to an int 690 (FromType->isSignedIntegerType() || 691 // We can promote any unsigned integer type whose size is 692 // less than int to an int. 693 (!FromType->isSignedIntegerType() && 694 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 695 return To->getKind() == BuiltinType::Int; 696 } 697 698 return To->getKind() == BuiltinType::UInt; 699 } 700 701 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 702 // can be converted to an rvalue of the first of the following types 703 // that can represent all the values of its underlying type: int, 704 // unsigned int, long, or unsigned long (C++ 4.5p2). 705 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 706 && ToType->isIntegerType()) { 707 // Determine whether the type we're converting from is signed or 708 // unsigned. 709 bool FromIsSigned; 710 uint64_t FromSize = Context.getTypeSize(FromType); 711 if (const EnumType *FromEnumType = FromType->getAsEnumType()) { 712 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 713 FromIsSigned = UnderlyingType->isSignedIntegerType(); 714 } else { 715 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 716 FromIsSigned = true; 717 } 718 719 // The types we'll try to promote to, in the appropriate 720 // order. Try each of these types. 721 QualType PromoteTypes[6] = { 722 Context.IntTy, Context.UnsignedIntTy, 723 Context.LongTy, Context.UnsignedLongTy , 724 Context.LongLongTy, Context.UnsignedLongLongTy 725 }; 726 for (int Idx = 0; Idx < 6; ++Idx) { 727 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 728 if (FromSize < ToSize || 729 (FromSize == ToSize && 730 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 731 // We found the type that we can promote to. If this is the 732 // type we wanted, we have a promotion. Otherwise, no 733 // promotion. 734 return Context.getCanonicalType(ToType).getUnqualifiedType() 735 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 736 } 737 } 738 } 739 740 // An rvalue for an integral bit-field (9.6) can be converted to an 741 // rvalue of type int if int can represent all the values of the 742 // bit-field; otherwise, it can be converted to unsigned int if 743 // unsigned int can represent all the values of the bit-field. If 744 // the bit-field is larger yet, no integral promotion applies to 745 // it. If the bit-field has an enumerated type, it is treated as any 746 // other value of that type for promotion purposes (C++ 4.5p3). 747 // FIXME: We should delay checking of bit-fields until we actually 748 // perform the conversion. 749 using llvm::APSInt; 750 if (From) 751 if (FieldDecl *MemberDecl = From->getBitField()) { 752 APSInt BitWidth; 753 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 754 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 755 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 756 ToSize = Context.getTypeSize(ToType); 757 758 // Are we promoting to an int from a bitfield that fits in an int? 759 if (BitWidth < ToSize || 760 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 761 return To->getKind() == BuiltinType::Int; 762 } 763 764 // Are we promoting to an unsigned int from an unsigned bitfield 765 // that fits into an unsigned int? 766 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 767 return To->getKind() == BuiltinType::UInt; 768 } 769 770 return false; 771 } 772 } 773 774 // An rvalue of type bool can be converted to an rvalue of type int, 775 // with false becoming zero and true becoming one (C++ 4.5p4). 776 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 777 return true; 778 } 779 780 return false; 781} 782 783/// IsFloatingPointPromotion - Determines whether the conversion from 784/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 785/// returns true and sets PromotedType to the promoted type. 786bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) 787{ 788 /// An rvalue of type float can be converted to an rvalue of type 789 /// double. (C++ 4.6p1). 790 if (const BuiltinType *FromBuiltin = FromType->getAsBuiltinType()) 791 if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType()) { 792 if (FromBuiltin->getKind() == BuiltinType::Float && 793 ToBuiltin->getKind() == BuiltinType::Double) 794 return true; 795 796 // C99 6.3.1.5p1: 797 // When a float is promoted to double or long double, or a 798 // double is promoted to long double [...]. 799 if (!getLangOptions().CPlusPlus && 800 (FromBuiltin->getKind() == BuiltinType::Float || 801 FromBuiltin->getKind() == BuiltinType::Double) && 802 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 803 return true; 804 } 805 806 return false; 807} 808 809/// \brief Determine if a conversion is a complex promotion. 810/// 811/// A complex promotion is defined as a complex -> complex conversion 812/// where the conversion between the underlying real types is a 813/// floating-point or integral promotion. 814bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 815 const ComplexType *FromComplex = FromType->getAsComplexType(); 816 if (!FromComplex) 817 return false; 818 819 const ComplexType *ToComplex = ToType->getAsComplexType(); 820 if (!ToComplex) 821 return false; 822 823 return IsFloatingPointPromotion(FromComplex->getElementType(), 824 ToComplex->getElementType()) || 825 IsIntegralPromotion(0, FromComplex->getElementType(), 826 ToComplex->getElementType()); 827} 828 829/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 830/// the pointer type FromPtr to a pointer to type ToPointee, with the 831/// same type qualifiers as FromPtr has on its pointee type. ToType, 832/// if non-empty, will be a pointer to ToType that may or may not have 833/// the right set of qualifiers on its pointee. 834static QualType 835BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 836 QualType ToPointee, QualType ToType, 837 ASTContext &Context) { 838 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 839 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 840 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 841 842 // Exact qualifier match -> return the pointer type we're converting to. 843 if (CanonToPointee.getCVRQualifiers() == Quals) { 844 // ToType is exactly what we need. Return it. 845 if (ToType.getTypePtr()) 846 return ToType; 847 848 // Build a pointer to ToPointee. It has the right qualifiers 849 // already. 850 return Context.getPointerType(ToPointee); 851 } 852 853 // Just build a canonical type that has the right qualifiers. 854 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 855} 856 857/// IsPointerConversion - Determines whether the conversion of the 858/// expression From, which has the (possibly adjusted) type FromType, 859/// can be converted to the type ToType via a pointer conversion (C++ 860/// 4.10). If so, returns true and places the converted type (that 861/// might differ from ToType in its cv-qualifiers at some level) into 862/// ConvertedType. 863/// 864/// This routine also supports conversions to and from block pointers 865/// and conversions with Objective-C's 'id', 'id<protocols...>', and 866/// pointers to interfaces. FIXME: Once we've determined the 867/// appropriate overloading rules for Objective-C, we may want to 868/// split the Objective-C checks into a different routine; however, 869/// GCC seems to consider all of these conversions to be pointer 870/// conversions, so for now they live here. IncompatibleObjC will be 871/// set if the conversion is an allowed Objective-C conversion that 872/// should result in a warning. 873bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 874 QualType& ConvertedType, 875 bool &IncompatibleObjC) 876{ 877 IncompatibleObjC = false; 878 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 879 return true; 880 881 // Conversion from a null pointer constant to any Objective-C pointer type. 882 if (Context.isObjCObjectPointerType(ToType) && 883 From->isNullPointerConstant(Context)) { 884 ConvertedType = ToType; 885 return true; 886 } 887 888 // Blocks: Block pointers can be converted to void*. 889 if (FromType->isBlockPointerType() && ToType->isPointerType() && 890 ToType->getAsPointerType()->getPointeeType()->isVoidType()) { 891 ConvertedType = ToType; 892 return true; 893 } 894 // Blocks: A null pointer constant can be converted to a block 895 // pointer type. 896 if (ToType->isBlockPointerType() && From->isNullPointerConstant(Context)) { 897 ConvertedType = ToType; 898 return true; 899 } 900 901 const PointerType* ToTypePtr = ToType->getAsPointerType(); 902 if (!ToTypePtr) 903 return false; 904 905 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 906 if (From->isNullPointerConstant(Context)) { 907 ConvertedType = ToType; 908 return true; 909 } 910 911 // Beyond this point, both types need to be pointers. 912 const PointerType *FromTypePtr = FromType->getAsPointerType(); 913 if (!FromTypePtr) 914 return false; 915 916 QualType FromPointeeType = FromTypePtr->getPointeeType(); 917 QualType ToPointeeType = ToTypePtr->getPointeeType(); 918 919 // An rvalue of type "pointer to cv T," where T is an object type, 920 // can be converted to an rvalue of type "pointer to cv void" (C++ 921 // 4.10p2). 922 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 923 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 924 ToPointeeType, 925 ToType, Context); 926 return true; 927 } 928 929 // When we're overloading in C, we allow a special kind of pointer 930 // conversion for compatible-but-not-identical pointee types. 931 if (!getLangOptions().CPlusPlus && 932 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 933 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 934 ToPointeeType, 935 ToType, Context); 936 return true; 937 } 938 939 // C++ [conv.ptr]p3: 940 // 941 // An rvalue of type "pointer to cv D," where D is a class type, 942 // can be converted to an rvalue of type "pointer to cv B," where 943 // B is a base class (clause 10) of D. If B is an inaccessible 944 // (clause 11) or ambiguous (10.2) base class of D, a program that 945 // necessitates this conversion is ill-formed. The result of the 946 // conversion is a pointer to the base class sub-object of the 947 // derived class object. The null pointer value is converted to 948 // the null pointer value of the destination type. 949 // 950 // Note that we do not check for ambiguity or inaccessibility 951 // here. That is handled by CheckPointerConversion. 952 if (getLangOptions().CPlusPlus && 953 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 954 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 955 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 956 ToPointeeType, 957 ToType, Context); 958 return true; 959 } 960 961 return false; 962} 963 964/// isObjCPointerConversion - Determines whether this is an 965/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 966/// with the same arguments and return values. 967bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 968 QualType& ConvertedType, 969 bool &IncompatibleObjC) { 970 if (!getLangOptions().ObjC1) 971 return false; 972 973 // Conversions with Objective-C's id<...>. 974 if ((FromType->isObjCQualifiedIdType() || ToType->isObjCQualifiedIdType()) && 975 ObjCQualifiedIdTypesAreCompatible(ToType, FromType, /*compare=*/false)) { 976 ConvertedType = ToType; 977 return true; 978 } 979 980 // Beyond this point, both types need to be pointers or block pointers. 981 QualType ToPointeeType; 982 const PointerType* ToTypePtr = ToType->getAsPointerType(); 983 if (ToTypePtr) 984 ToPointeeType = ToTypePtr->getPointeeType(); 985 else if (const BlockPointerType *ToBlockPtr = ToType->getAsBlockPointerType()) 986 ToPointeeType = ToBlockPtr->getPointeeType(); 987 else 988 return false; 989 990 QualType FromPointeeType; 991 const PointerType *FromTypePtr = FromType->getAsPointerType(); 992 if (FromTypePtr) 993 FromPointeeType = FromTypePtr->getPointeeType(); 994 else if (const BlockPointerType *FromBlockPtr 995 = FromType->getAsBlockPointerType()) 996 FromPointeeType = FromBlockPtr->getPointeeType(); 997 else 998 return false; 999 1000 // Objective C++: We're able to convert from a pointer to an 1001 // interface to a pointer to a different interface. 1002 const ObjCInterfaceType* FromIface = FromPointeeType->getAsObjCInterfaceType(); 1003 const ObjCInterfaceType* ToIface = ToPointeeType->getAsObjCInterfaceType(); 1004 if (FromIface && ToIface && 1005 Context.canAssignObjCInterfaces(ToIface, FromIface)) { 1006 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1007 ToPointeeType, 1008 ToType, Context); 1009 return true; 1010 } 1011 1012 if (FromIface && ToIface && 1013 Context.canAssignObjCInterfaces(FromIface, ToIface)) { 1014 // Okay: this is some kind of implicit downcast of Objective-C 1015 // interfaces, which is permitted. However, we're going to 1016 // complain about it. 1017 IncompatibleObjC = true; 1018 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1019 ToPointeeType, 1020 ToType, Context); 1021 return true; 1022 } 1023 1024 // Objective C++: We're able to convert between "id" and a pointer 1025 // to any interface (in both directions). 1026 if ((FromIface && Context.isObjCIdStructType(ToPointeeType)) 1027 || (ToIface && Context.isObjCIdStructType(FromPointeeType))) { 1028 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1029 ToPointeeType, 1030 ToType, Context); 1031 return true; 1032 } 1033 1034 // Objective C++: Allow conversions between the Objective-C "id" and 1035 // "Class", in either direction. 1036 if ((Context.isObjCIdStructType(FromPointeeType) && 1037 Context.isObjCClassStructType(ToPointeeType)) || 1038 (Context.isObjCClassStructType(FromPointeeType) && 1039 Context.isObjCIdStructType(ToPointeeType))) { 1040 ConvertedType = ToType; 1041 return true; 1042 } 1043 1044 // If we have pointers to pointers, recursively check whether this 1045 // is an Objective-C conversion. 1046 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1047 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1048 IncompatibleObjC)) { 1049 // We always complain about this conversion. 1050 IncompatibleObjC = true; 1051 ConvertedType = ToType; 1052 return true; 1053 } 1054 1055 // If we have pointers to functions or blocks, check whether the only 1056 // differences in the argument and result types are in Objective-C 1057 // pointer conversions. If so, we permit the conversion (but 1058 // complain about it). 1059 const FunctionProtoType *FromFunctionType 1060 = FromPointeeType->getAsFunctionProtoType(); 1061 const FunctionProtoType *ToFunctionType 1062 = ToPointeeType->getAsFunctionProtoType(); 1063 if (FromFunctionType && ToFunctionType) { 1064 // If the function types are exactly the same, this isn't an 1065 // Objective-C pointer conversion. 1066 if (Context.getCanonicalType(FromPointeeType) 1067 == Context.getCanonicalType(ToPointeeType)) 1068 return false; 1069 1070 // Perform the quick checks that will tell us whether these 1071 // function types are obviously different. 1072 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1073 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1074 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1075 return false; 1076 1077 bool HasObjCConversion = false; 1078 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1079 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1080 // Okay, the types match exactly. Nothing to do. 1081 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1082 ToFunctionType->getResultType(), 1083 ConvertedType, IncompatibleObjC)) { 1084 // Okay, we have an Objective-C pointer conversion. 1085 HasObjCConversion = true; 1086 } else { 1087 // Function types are too different. Abort. 1088 return false; 1089 } 1090 1091 // Check argument types. 1092 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1093 ArgIdx != NumArgs; ++ArgIdx) { 1094 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1095 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1096 if (Context.getCanonicalType(FromArgType) 1097 == Context.getCanonicalType(ToArgType)) { 1098 // Okay, the types match exactly. Nothing to do. 1099 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1100 ConvertedType, IncompatibleObjC)) { 1101 // Okay, we have an Objective-C pointer conversion. 1102 HasObjCConversion = true; 1103 } else { 1104 // Argument types are too different. Abort. 1105 return false; 1106 } 1107 } 1108 1109 if (HasObjCConversion) { 1110 // We had an Objective-C conversion. Allow this pointer 1111 // conversion, but complain about it. 1112 ConvertedType = ToType; 1113 IncompatibleObjC = true; 1114 return true; 1115 } 1116 } 1117 1118 return false; 1119} 1120 1121/// CheckPointerConversion - Check the pointer conversion from the 1122/// expression From to the type ToType. This routine checks for 1123/// ambiguous (FIXME: or inaccessible) derived-to-base pointer 1124/// conversions for which IsPointerConversion has already returned 1125/// true. It returns true and produces a diagnostic if there was an 1126/// error, or returns false otherwise. 1127bool Sema::CheckPointerConversion(Expr *From, QualType ToType) { 1128 QualType FromType = From->getType(); 1129 1130 if (const PointerType *FromPtrType = FromType->getAsPointerType()) 1131 if (const PointerType *ToPtrType = ToType->getAsPointerType()) { 1132 QualType FromPointeeType = FromPtrType->getPointeeType(), 1133 ToPointeeType = ToPtrType->getPointeeType(); 1134 1135 // Objective-C++ conversions are always okay. 1136 // FIXME: We should have a different class of conversions for 1137 // the Objective-C++ implicit conversions. 1138 if (Context.isObjCIdStructType(FromPointeeType) || 1139 Context.isObjCIdStructType(ToPointeeType) || 1140 Context.isObjCClassStructType(FromPointeeType) || 1141 Context.isObjCClassStructType(ToPointeeType)) 1142 return false; 1143 1144 if (FromPointeeType->isRecordType() && 1145 ToPointeeType->isRecordType()) { 1146 // We must have a derived-to-base conversion. Check an 1147 // ambiguous or inaccessible conversion. 1148 return CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1149 From->getExprLoc(), 1150 From->getSourceRange()); 1151 } 1152 } 1153 1154 return false; 1155} 1156 1157/// IsMemberPointerConversion - Determines whether the conversion of the 1158/// expression From, which has the (possibly adjusted) type FromType, can be 1159/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1160/// If so, returns true and places the converted type (that might differ from 1161/// ToType in its cv-qualifiers at some level) into ConvertedType. 1162bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1163 QualType ToType, QualType &ConvertedType) 1164{ 1165 const MemberPointerType *ToTypePtr = ToType->getAsMemberPointerType(); 1166 if (!ToTypePtr) 1167 return false; 1168 1169 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1170 if (From->isNullPointerConstant(Context)) { 1171 ConvertedType = ToType; 1172 return true; 1173 } 1174 1175 // Otherwise, both types have to be member pointers. 1176 const MemberPointerType *FromTypePtr = FromType->getAsMemberPointerType(); 1177 if (!FromTypePtr) 1178 return false; 1179 1180 // A pointer to member of B can be converted to a pointer to member of D, 1181 // where D is derived from B (C++ 4.11p2). 1182 QualType FromClass(FromTypePtr->getClass(), 0); 1183 QualType ToClass(ToTypePtr->getClass(), 0); 1184 // FIXME: What happens when these are dependent? Is this function even called? 1185 1186 if (IsDerivedFrom(ToClass, FromClass)) { 1187 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1188 ToClass.getTypePtr()); 1189 return true; 1190 } 1191 1192 return false; 1193} 1194 1195/// CheckMemberPointerConversion - Check the member pointer conversion from the 1196/// expression From to the type ToType. This routine checks for ambiguous or 1197/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1198/// for which IsMemberPointerConversion has already returned true. It returns 1199/// true and produces a diagnostic if there was an error, or returns false 1200/// otherwise. 1201bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType) { 1202 QualType FromType = From->getType(); 1203 const MemberPointerType *FromPtrType = FromType->getAsMemberPointerType(); 1204 if (!FromPtrType) 1205 return false; 1206 1207 const MemberPointerType *ToPtrType = ToType->getAsMemberPointerType(); 1208 assert(ToPtrType && "No member pointer cast has a target type " 1209 "that is not a member pointer."); 1210 1211 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1212 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1213 1214 // FIXME: What about dependent types? 1215 assert(FromClass->isRecordType() && "Pointer into non-class."); 1216 assert(ToClass->isRecordType() && "Pointer into non-class."); 1217 1218 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1219 /*DetectVirtual=*/true); 1220 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1221 assert(DerivationOkay && 1222 "Should not have been called if derivation isn't OK."); 1223 (void)DerivationOkay; 1224 1225 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1226 getUnqualifiedType())) { 1227 // Derivation is ambiguous. Redo the check to find the exact paths. 1228 Paths.clear(); 1229 Paths.setRecordingPaths(true); 1230 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1231 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1232 (void)StillOkay; 1233 1234 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1235 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1236 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1237 return true; 1238 } 1239 1240 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1241 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1242 << FromClass << ToClass << QualType(VBase, 0) 1243 << From->getSourceRange(); 1244 return true; 1245 } 1246 1247 return false; 1248} 1249 1250/// IsQualificationConversion - Determines whether the conversion from 1251/// an rvalue of type FromType to ToType is a qualification conversion 1252/// (C++ 4.4). 1253bool 1254Sema::IsQualificationConversion(QualType FromType, QualType ToType) 1255{ 1256 FromType = Context.getCanonicalType(FromType); 1257 ToType = Context.getCanonicalType(ToType); 1258 1259 // If FromType and ToType are the same type, this is not a 1260 // qualification conversion. 1261 if (FromType == ToType) 1262 return false; 1263 1264 // (C++ 4.4p4): 1265 // A conversion can add cv-qualifiers at levels other than the first 1266 // in multi-level pointers, subject to the following rules: [...] 1267 bool PreviousToQualsIncludeConst = true; 1268 bool UnwrappedAnyPointer = false; 1269 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1270 // Within each iteration of the loop, we check the qualifiers to 1271 // determine if this still looks like a qualification 1272 // conversion. Then, if all is well, we unwrap one more level of 1273 // pointers or pointers-to-members and do it all again 1274 // until there are no more pointers or pointers-to-members left to 1275 // unwrap. 1276 UnwrappedAnyPointer = true; 1277 1278 // -- for every j > 0, if const is in cv 1,j then const is in cv 1279 // 2,j, and similarly for volatile. 1280 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1281 return false; 1282 1283 // -- if the cv 1,j and cv 2,j are different, then const is in 1284 // every cv for 0 < k < j. 1285 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1286 && !PreviousToQualsIncludeConst) 1287 return false; 1288 1289 // Keep track of whether all prior cv-qualifiers in the "to" type 1290 // include const. 1291 PreviousToQualsIncludeConst 1292 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1293 } 1294 1295 // We are left with FromType and ToType being the pointee types 1296 // after unwrapping the original FromType and ToType the same number 1297 // of types. If we unwrapped any pointers, and if FromType and 1298 // ToType have the same unqualified type (since we checked 1299 // qualifiers above), then this is a qualification conversion. 1300 return UnwrappedAnyPointer && 1301 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1302} 1303 1304/// Determines whether there is a user-defined conversion sequence 1305/// (C++ [over.ics.user]) that converts expression From to the type 1306/// ToType. If such a conversion exists, User will contain the 1307/// user-defined conversion sequence that performs such a conversion 1308/// and this routine will return true. Otherwise, this routine returns 1309/// false and User is unspecified. 1310/// 1311/// \param AllowConversionFunctions true if the conversion should 1312/// consider conversion functions at all. If false, only constructors 1313/// will be considered. 1314/// 1315/// \param AllowExplicit true if the conversion should consider C++0x 1316/// "explicit" conversion functions as well as non-explicit conversion 1317/// functions (C++0x [class.conv.fct]p2). 1318/// 1319/// \param ForceRValue true if the expression should be treated as an rvalue 1320/// for overload resolution. 1321bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1322 UserDefinedConversionSequence& User, 1323 bool AllowConversionFunctions, 1324 bool AllowExplicit, bool ForceRValue) 1325{ 1326 OverloadCandidateSet CandidateSet; 1327 if (const RecordType *ToRecordType = ToType->getAsRecordType()) { 1328 if (CXXRecordDecl *ToRecordDecl 1329 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1330 // C++ [over.match.ctor]p1: 1331 // When objects of class type are direct-initialized (8.5), or 1332 // copy-initialized from an expression of the same or a 1333 // derived class type (8.5), overload resolution selects the 1334 // constructor. [...] For copy-initialization, the candidate 1335 // functions are all the converting constructors (12.3.1) of 1336 // that class. The argument list is the expression-list within 1337 // the parentheses of the initializer. 1338 DeclarationName ConstructorName 1339 = Context.DeclarationNames.getCXXConstructorName( 1340 Context.getCanonicalType(ToType).getUnqualifiedType()); 1341 DeclContext::lookup_iterator Con, ConEnd; 1342 for (llvm::tie(Con, ConEnd) 1343 = ToRecordDecl->lookup(Context, ConstructorName); 1344 Con != ConEnd; ++Con) { 1345 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 1346 if (Constructor->isConvertingConstructor()) 1347 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1348 /*SuppressUserConversions=*/true, ForceRValue); 1349 } 1350 } 1351 } 1352 1353 if (!AllowConversionFunctions) { 1354 // Don't allow any conversion functions to enter the overload set. 1355 } else if (const RecordType *FromRecordType 1356 = From->getType()->getAsRecordType()) { 1357 if (CXXRecordDecl *FromRecordDecl 1358 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1359 // Add all of the conversion functions as candidates. 1360 // FIXME: Look for conversions in base classes! 1361 OverloadedFunctionDecl *Conversions 1362 = FromRecordDecl->getConversionFunctions(); 1363 for (OverloadedFunctionDecl::function_iterator Func 1364 = Conversions->function_begin(); 1365 Func != Conversions->function_end(); ++Func) { 1366 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 1367 if (AllowExplicit || !Conv->isExplicit()) 1368 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1369 } 1370 } 1371 } 1372 1373 OverloadCandidateSet::iterator Best; 1374 switch (BestViableFunction(CandidateSet, Best)) { 1375 case OR_Success: 1376 // Record the standard conversion we used and the conversion function. 1377 if (CXXConstructorDecl *Constructor 1378 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1379 // C++ [over.ics.user]p1: 1380 // If the user-defined conversion is specified by a 1381 // constructor (12.3.1), the initial standard conversion 1382 // sequence converts the source type to the type required by 1383 // the argument of the constructor. 1384 // 1385 // FIXME: What about ellipsis conversions? 1386 QualType ThisType = Constructor->getThisType(Context); 1387 User.Before = Best->Conversions[0].Standard; 1388 User.ConversionFunction = Constructor; 1389 User.After.setAsIdentityConversion(); 1390 User.After.FromTypePtr 1391 = ThisType->getAsPointerType()->getPointeeType().getAsOpaquePtr(); 1392 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1393 return true; 1394 } else if (CXXConversionDecl *Conversion 1395 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1396 // C++ [over.ics.user]p1: 1397 // 1398 // [...] If the user-defined conversion is specified by a 1399 // conversion function (12.3.2), the initial standard 1400 // conversion sequence converts the source type to the 1401 // implicit object parameter of the conversion function. 1402 User.Before = Best->Conversions[0].Standard; 1403 User.ConversionFunction = Conversion; 1404 1405 // C++ [over.ics.user]p2: 1406 // The second standard conversion sequence converts the 1407 // result of the user-defined conversion to the target type 1408 // for the sequence. Since an implicit conversion sequence 1409 // is an initialization, the special rules for 1410 // initialization by user-defined conversion apply when 1411 // selecting the best user-defined conversion for a 1412 // user-defined conversion sequence (see 13.3.3 and 1413 // 13.3.3.1). 1414 User.After = Best->FinalConversion; 1415 return true; 1416 } else { 1417 assert(false && "Not a constructor or conversion function?"); 1418 return false; 1419 } 1420 1421 case OR_No_Viable_Function: 1422 case OR_Deleted: 1423 // No conversion here! We're done. 1424 return false; 1425 1426 case OR_Ambiguous: 1427 // FIXME: See C++ [over.best.ics]p10 for the handling of 1428 // ambiguous conversion sequences. 1429 return false; 1430 } 1431 1432 return false; 1433} 1434 1435/// CompareImplicitConversionSequences - Compare two implicit 1436/// conversion sequences to determine whether one is better than the 1437/// other or if they are indistinguishable (C++ 13.3.3.2). 1438ImplicitConversionSequence::CompareKind 1439Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1440 const ImplicitConversionSequence& ICS2) 1441{ 1442 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1443 // conversion sequences (as defined in 13.3.3.1) 1444 // -- a standard conversion sequence (13.3.3.1.1) is a better 1445 // conversion sequence than a user-defined conversion sequence or 1446 // an ellipsis conversion sequence, and 1447 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1448 // conversion sequence than an ellipsis conversion sequence 1449 // (13.3.3.1.3). 1450 // 1451 if (ICS1.ConversionKind < ICS2.ConversionKind) 1452 return ImplicitConversionSequence::Better; 1453 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1454 return ImplicitConversionSequence::Worse; 1455 1456 // Two implicit conversion sequences of the same form are 1457 // indistinguishable conversion sequences unless one of the 1458 // following rules apply: (C++ 13.3.3.2p3): 1459 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1460 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1461 else if (ICS1.ConversionKind == 1462 ImplicitConversionSequence::UserDefinedConversion) { 1463 // User-defined conversion sequence U1 is a better conversion 1464 // sequence than another user-defined conversion sequence U2 if 1465 // they contain the same user-defined conversion function or 1466 // constructor and if the second standard conversion sequence of 1467 // U1 is better than the second standard conversion sequence of 1468 // U2 (C++ 13.3.3.2p3). 1469 if (ICS1.UserDefined.ConversionFunction == 1470 ICS2.UserDefined.ConversionFunction) 1471 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1472 ICS2.UserDefined.After); 1473 } 1474 1475 return ImplicitConversionSequence::Indistinguishable; 1476} 1477 1478/// CompareStandardConversionSequences - Compare two standard 1479/// conversion sequences to determine whether one is better than the 1480/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1481ImplicitConversionSequence::CompareKind 1482Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1483 const StandardConversionSequence& SCS2) 1484{ 1485 // Standard conversion sequence S1 is a better conversion sequence 1486 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1487 1488 // -- S1 is a proper subsequence of S2 (comparing the conversion 1489 // sequences in the canonical form defined by 13.3.3.1.1, 1490 // excluding any Lvalue Transformation; the identity conversion 1491 // sequence is considered to be a subsequence of any 1492 // non-identity conversion sequence) or, if not that, 1493 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1494 // Neither is a proper subsequence of the other. Do nothing. 1495 ; 1496 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1497 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1498 (SCS1.Second == ICK_Identity && 1499 SCS1.Third == ICK_Identity)) 1500 // SCS1 is a proper subsequence of SCS2. 1501 return ImplicitConversionSequence::Better; 1502 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1503 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1504 (SCS2.Second == ICK_Identity && 1505 SCS2.Third == ICK_Identity)) 1506 // SCS2 is a proper subsequence of SCS1. 1507 return ImplicitConversionSequence::Worse; 1508 1509 // -- the rank of S1 is better than the rank of S2 (by the rules 1510 // defined below), or, if not that, 1511 ImplicitConversionRank Rank1 = SCS1.getRank(); 1512 ImplicitConversionRank Rank2 = SCS2.getRank(); 1513 if (Rank1 < Rank2) 1514 return ImplicitConversionSequence::Better; 1515 else if (Rank2 < Rank1) 1516 return ImplicitConversionSequence::Worse; 1517 1518 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1519 // are indistinguishable unless one of the following rules 1520 // applies: 1521 1522 // A conversion that is not a conversion of a pointer, or 1523 // pointer to member, to bool is better than another conversion 1524 // that is such a conversion. 1525 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1526 return SCS2.isPointerConversionToBool() 1527 ? ImplicitConversionSequence::Better 1528 : ImplicitConversionSequence::Worse; 1529 1530 // C++ [over.ics.rank]p4b2: 1531 // 1532 // If class B is derived directly or indirectly from class A, 1533 // conversion of B* to A* is better than conversion of B* to 1534 // void*, and conversion of A* to void* is better than conversion 1535 // of B* to void*. 1536 bool SCS1ConvertsToVoid 1537 = SCS1.isPointerConversionToVoidPointer(Context); 1538 bool SCS2ConvertsToVoid 1539 = SCS2.isPointerConversionToVoidPointer(Context); 1540 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1541 // Exactly one of the conversion sequences is a conversion to 1542 // a void pointer; it's the worse conversion. 1543 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1544 : ImplicitConversionSequence::Worse; 1545 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1546 // Neither conversion sequence converts to a void pointer; compare 1547 // their derived-to-base conversions. 1548 if (ImplicitConversionSequence::CompareKind DerivedCK 1549 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1550 return DerivedCK; 1551 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1552 // Both conversion sequences are conversions to void 1553 // pointers. Compare the source types to determine if there's an 1554 // inheritance relationship in their sources. 1555 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1556 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1557 1558 // Adjust the types we're converting from via the array-to-pointer 1559 // conversion, if we need to. 1560 if (SCS1.First == ICK_Array_To_Pointer) 1561 FromType1 = Context.getArrayDecayedType(FromType1); 1562 if (SCS2.First == ICK_Array_To_Pointer) 1563 FromType2 = Context.getArrayDecayedType(FromType2); 1564 1565 QualType FromPointee1 1566 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1567 QualType FromPointee2 1568 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1569 1570 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1571 return ImplicitConversionSequence::Better; 1572 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1573 return ImplicitConversionSequence::Worse; 1574 1575 // Objective-C++: If one interface is more specific than the 1576 // other, it is the better one. 1577 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1578 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1579 if (FromIface1 && FromIface1) { 1580 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1581 return ImplicitConversionSequence::Better; 1582 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1583 return ImplicitConversionSequence::Worse; 1584 } 1585 } 1586 1587 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1588 // bullet 3). 1589 if (ImplicitConversionSequence::CompareKind QualCK 1590 = CompareQualificationConversions(SCS1, SCS2)) 1591 return QualCK; 1592 1593 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1594 // C++0x [over.ics.rank]p3b4: 1595 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1596 // implicit object parameter of a non-static member function declared 1597 // without a ref-qualifier, and S1 binds an rvalue reference to an 1598 // rvalue and S2 binds an lvalue reference. 1599 // FIXME: We don't know if we're dealing with the implicit object parameter, 1600 // or if the member function in this case has a ref qualifier. 1601 // (Of course, we don't have ref qualifiers yet.) 1602 if (SCS1.RRefBinding != SCS2.RRefBinding) 1603 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1604 : ImplicitConversionSequence::Worse; 1605 1606 // C++ [over.ics.rank]p3b4: 1607 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1608 // which the references refer are the same type except for 1609 // top-level cv-qualifiers, and the type to which the reference 1610 // initialized by S2 refers is more cv-qualified than the type 1611 // to which the reference initialized by S1 refers. 1612 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1613 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1614 T1 = Context.getCanonicalType(T1); 1615 T2 = Context.getCanonicalType(T2); 1616 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1617 if (T2.isMoreQualifiedThan(T1)) 1618 return ImplicitConversionSequence::Better; 1619 else if (T1.isMoreQualifiedThan(T2)) 1620 return ImplicitConversionSequence::Worse; 1621 } 1622 } 1623 1624 return ImplicitConversionSequence::Indistinguishable; 1625} 1626 1627/// CompareQualificationConversions - Compares two standard conversion 1628/// sequences to determine whether they can be ranked based on their 1629/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1630ImplicitConversionSequence::CompareKind 1631Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1632 const StandardConversionSequence& SCS2) 1633{ 1634 // C++ 13.3.3.2p3: 1635 // -- S1 and S2 differ only in their qualification conversion and 1636 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1637 // cv-qualification signature of type T1 is a proper subset of 1638 // the cv-qualification signature of type T2, and S1 is not the 1639 // deprecated string literal array-to-pointer conversion (4.2). 1640 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1641 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1642 return ImplicitConversionSequence::Indistinguishable; 1643 1644 // FIXME: the example in the standard doesn't use a qualification 1645 // conversion (!) 1646 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1647 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1648 T1 = Context.getCanonicalType(T1); 1649 T2 = Context.getCanonicalType(T2); 1650 1651 // If the types are the same, we won't learn anything by unwrapped 1652 // them. 1653 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1654 return ImplicitConversionSequence::Indistinguishable; 1655 1656 ImplicitConversionSequence::CompareKind Result 1657 = ImplicitConversionSequence::Indistinguishable; 1658 while (UnwrapSimilarPointerTypes(T1, T2)) { 1659 // Within each iteration of the loop, we check the qualifiers to 1660 // determine if this still looks like a qualification 1661 // conversion. Then, if all is well, we unwrap one more level of 1662 // pointers or pointers-to-members and do it all again 1663 // until there are no more pointers or pointers-to-members left 1664 // to unwrap. This essentially mimics what 1665 // IsQualificationConversion does, but here we're checking for a 1666 // strict subset of qualifiers. 1667 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1668 // The qualifiers are the same, so this doesn't tell us anything 1669 // about how the sequences rank. 1670 ; 1671 else if (T2.isMoreQualifiedThan(T1)) { 1672 // T1 has fewer qualifiers, so it could be the better sequence. 1673 if (Result == ImplicitConversionSequence::Worse) 1674 // Neither has qualifiers that are a subset of the other's 1675 // qualifiers. 1676 return ImplicitConversionSequence::Indistinguishable; 1677 1678 Result = ImplicitConversionSequence::Better; 1679 } else if (T1.isMoreQualifiedThan(T2)) { 1680 // T2 has fewer qualifiers, so it could be the better sequence. 1681 if (Result == ImplicitConversionSequence::Better) 1682 // Neither has qualifiers that are a subset of the other's 1683 // qualifiers. 1684 return ImplicitConversionSequence::Indistinguishable; 1685 1686 Result = ImplicitConversionSequence::Worse; 1687 } else { 1688 // Qualifiers are disjoint. 1689 return ImplicitConversionSequence::Indistinguishable; 1690 } 1691 1692 // If the types after this point are equivalent, we're done. 1693 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1694 break; 1695 } 1696 1697 // Check that the winning standard conversion sequence isn't using 1698 // the deprecated string literal array to pointer conversion. 1699 switch (Result) { 1700 case ImplicitConversionSequence::Better: 1701 if (SCS1.Deprecated) 1702 Result = ImplicitConversionSequence::Indistinguishable; 1703 break; 1704 1705 case ImplicitConversionSequence::Indistinguishable: 1706 break; 1707 1708 case ImplicitConversionSequence::Worse: 1709 if (SCS2.Deprecated) 1710 Result = ImplicitConversionSequence::Indistinguishable; 1711 break; 1712 } 1713 1714 return Result; 1715} 1716 1717/// CompareDerivedToBaseConversions - Compares two standard conversion 1718/// sequences to determine whether they can be ranked based on their 1719/// various kinds of derived-to-base conversions (C++ 1720/// [over.ics.rank]p4b3). As part of these checks, we also look at 1721/// conversions between Objective-C interface types. 1722ImplicitConversionSequence::CompareKind 1723Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1724 const StandardConversionSequence& SCS2) { 1725 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1726 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1727 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1728 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1729 1730 // Adjust the types we're converting from via the array-to-pointer 1731 // conversion, if we need to. 1732 if (SCS1.First == ICK_Array_To_Pointer) 1733 FromType1 = Context.getArrayDecayedType(FromType1); 1734 if (SCS2.First == ICK_Array_To_Pointer) 1735 FromType2 = Context.getArrayDecayedType(FromType2); 1736 1737 // Canonicalize all of the types. 1738 FromType1 = Context.getCanonicalType(FromType1); 1739 ToType1 = Context.getCanonicalType(ToType1); 1740 FromType2 = Context.getCanonicalType(FromType2); 1741 ToType2 = Context.getCanonicalType(ToType2); 1742 1743 // C++ [over.ics.rank]p4b3: 1744 // 1745 // If class B is derived directly or indirectly from class A and 1746 // class C is derived directly or indirectly from B, 1747 // 1748 // For Objective-C, we let A, B, and C also be Objective-C 1749 // interfaces. 1750 1751 // Compare based on pointer conversions. 1752 if (SCS1.Second == ICK_Pointer_Conversion && 1753 SCS2.Second == ICK_Pointer_Conversion && 1754 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1755 FromType1->isPointerType() && FromType2->isPointerType() && 1756 ToType1->isPointerType() && ToType2->isPointerType()) { 1757 QualType FromPointee1 1758 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1759 QualType ToPointee1 1760 = ToType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1761 QualType FromPointee2 1762 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1763 QualType ToPointee2 1764 = ToType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1765 1766 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1767 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1768 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1769 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1770 1771 // -- conversion of C* to B* is better than conversion of C* to A*, 1772 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1773 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1774 return ImplicitConversionSequence::Better; 1775 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1776 return ImplicitConversionSequence::Worse; 1777 1778 if (ToIface1 && ToIface2) { 1779 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1780 return ImplicitConversionSequence::Better; 1781 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1782 return ImplicitConversionSequence::Worse; 1783 } 1784 } 1785 1786 // -- conversion of B* to A* is better than conversion of C* to A*, 1787 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1788 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1789 return ImplicitConversionSequence::Better; 1790 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1791 return ImplicitConversionSequence::Worse; 1792 1793 if (FromIface1 && FromIface2) { 1794 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1795 return ImplicitConversionSequence::Better; 1796 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1797 return ImplicitConversionSequence::Worse; 1798 } 1799 } 1800 } 1801 1802 // Compare based on reference bindings. 1803 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1804 SCS1.Second == ICK_Derived_To_Base) { 1805 // -- binding of an expression of type C to a reference of type 1806 // B& is better than binding an expression of type C to a 1807 // reference of type A&, 1808 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1809 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1810 if (IsDerivedFrom(ToType1, ToType2)) 1811 return ImplicitConversionSequence::Better; 1812 else if (IsDerivedFrom(ToType2, ToType1)) 1813 return ImplicitConversionSequence::Worse; 1814 } 1815 1816 // -- binding of an expression of type B to a reference of type 1817 // A& is better than binding an expression of type C to a 1818 // reference of type A&, 1819 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1820 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1821 if (IsDerivedFrom(FromType2, FromType1)) 1822 return ImplicitConversionSequence::Better; 1823 else if (IsDerivedFrom(FromType1, FromType2)) 1824 return ImplicitConversionSequence::Worse; 1825 } 1826 } 1827 1828 1829 // FIXME: conversion of A::* to B::* is better than conversion of 1830 // A::* to C::*, 1831 1832 // FIXME: conversion of B::* to C::* is better than conversion of 1833 // A::* to C::*, and 1834 1835 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1836 SCS1.Second == ICK_Derived_To_Base) { 1837 // -- conversion of C to B is better than conversion of C to A, 1838 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1839 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1840 if (IsDerivedFrom(ToType1, ToType2)) 1841 return ImplicitConversionSequence::Better; 1842 else if (IsDerivedFrom(ToType2, ToType1)) 1843 return ImplicitConversionSequence::Worse; 1844 } 1845 1846 // -- conversion of B to A is better than conversion of C to A. 1847 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1848 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1849 if (IsDerivedFrom(FromType2, FromType1)) 1850 return ImplicitConversionSequence::Better; 1851 else if (IsDerivedFrom(FromType1, FromType2)) 1852 return ImplicitConversionSequence::Worse; 1853 } 1854 } 1855 1856 return ImplicitConversionSequence::Indistinguishable; 1857} 1858 1859/// TryCopyInitialization - Try to copy-initialize a value of type 1860/// ToType from the expression From. Return the implicit conversion 1861/// sequence required to pass this argument, which may be a bad 1862/// conversion sequence (meaning that the argument cannot be passed to 1863/// a parameter of this type). If @p SuppressUserConversions, then we 1864/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1865/// then we treat @p From as an rvalue, even if it is an lvalue. 1866ImplicitConversionSequence 1867Sema::TryCopyInitialization(Expr *From, QualType ToType, 1868 bool SuppressUserConversions, bool ForceRValue) { 1869 if (ToType->isReferenceType()) { 1870 ImplicitConversionSequence ICS; 1871 CheckReferenceInit(From, ToType, &ICS, SuppressUserConversions, 1872 /*AllowExplicit=*/false, ForceRValue); 1873 return ICS; 1874 } else { 1875 return TryImplicitConversion(From, ToType, SuppressUserConversions, 1876 ForceRValue); 1877 } 1878} 1879 1880/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1881/// the expression @p From. Returns true (and emits a diagnostic) if there was 1882/// an error, returns false if the initialization succeeded. Elidable should 1883/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1884/// differently in C++0x for this case. 1885bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1886 const char* Flavor, bool Elidable) { 1887 if (!getLangOptions().CPlusPlus) { 1888 // In C, argument passing is the same as performing an assignment. 1889 QualType FromType = From->getType(); 1890 1891 AssignConvertType ConvTy = 1892 CheckSingleAssignmentConstraints(ToType, From); 1893 if (ConvTy != Compatible && 1894 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1895 ConvTy = Compatible; 1896 1897 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1898 FromType, From, Flavor); 1899 } 1900 1901 if (ToType->isReferenceType()) 1902 return CheckReferenceInit(From, ToType); 1903 1904 if (!PerformImplicitConversion(From, ToType, Flavor, 1905 /*AllowExplicit=*/false, Elidable)) 1906 return false; 1907 1908 return Diag(From->getSourceRange().getBegin(), 1909 diag::err_typecheck_convert_incompatible) 1910 << ToType << From->getType() << Flavor << From->getSourceRange(); 1911} 1912 1913/// TryObjectArgumentInitialization - Try to initialize the object 1914/// parameter of the given member function (@c Method) from the 1915/// expression @p From. 1916ImplicitConversionSequence 1917Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1918 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1919 unsigned MethodQuals = Method->getTypeQualifiers(); 1920 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 1921 1922 // Set up the conversion sequence as a "bad" conversion, to allow us 1923 // to exit early. 1924 ImplicitConversionSequence ICS; 1925 ICS.Standard.setAsIdentityConversion(); 1926 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1927 1928 // We need to have an object of class type. 1929 QualType FromType = From->getType(); 1930 if (const PointerType *PT = FromType->getAsPointerType()) 1931 FromType = PT->getPointeeType(); 1932 1933 assert(FromType->isRecordType()); 1934 1935 // The implicit object parmeter is has the type "reference to cv X", 1936 // where X is the class of which the function is a member 1937 // (C++ [over.match.funcs]p4). However, when finding an implicit 1938 // conversion sequence for the argument, we are not allowed to 1939 // create temporaries or perform user-defined conversions 1940 // (C++ [over.match.funcs]p5). We perform a simplified version of 1941 // reference binding here, that allows class rvalues to bind to 1942 // non-constant references. 1943 1944 // First check the qualifiers. We don't care about lvalue-vs-rvalue 1945 // with the implicit object parameter (C++ [over.match.funcs]p5). 1946 QualType FromTypeCanon = Context.getCanonicalType(FromType); 1947 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 1948 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 1949 return ICS; 1950 1951 // Check that we have either the same type or a derived type. It 1952 // affects the conversion rank. 1953 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 1954 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 1955 ICS.Standard.Second = ICK_Identity; 1956 else if (IsDerivedFrom(FromType, ClassType)) 1957 ICS.Standard.Second = ICK_Derived_To_Base; 1958 else 1959 return ICS; 1960 1961 // Success. Mark this as a reference binding. 1962 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 1963 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 1964 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 1965 ICS.Standard.ReferenceBinding = true; 1966 ICS.Standard.DirectBinding = true; 1967 ICS.Standard.RRefBinding = false; 1968 return ICS; 1969} 1970 1971/// PerformObjectArgumentInitialization - Perform initialization of 1972/// the implicit object parameter for the given Method with the given 1973/// expression. 1974bool 1975Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 1976 QualType FromRecordType, DestType; 1977 QualType ImplicitParamRecordType = 1978 Method->getThisType(Context)->getAsPointerType()->getPointeeType(); 1979 1980 if (const PointerType *PT = From->getType()->getAsPointerType()) { 1981 FromRecordType = PT->getPointeeType(); 1982 DestType = Method->getThisType(Context); 1983 } else { 1984 FromRecordType = From->getType(); 1985 DestType = ImplicitParamRecordType; 1986 } 1987 1988 ImplicitConversionSequence ICS 1989 = TryObjectArgumentInitialization(From, Method); 1990 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 1991 return Diag(From->getSourceRange().getBegin(), 1992 diag::err_implicit_object_parameter_init) 1993 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 1994 1995 if (ICS.Standard.Second == ICK_Derived_To_Base && 1996 CheckDerivedToBaseConversion(FromRecordType, 1997 ImplicitParamRecordType, 1998 From->getSourceRange().getBegin(), 1999 From->getSourceRange())) 2000 return true; 2001 2002 ImpCastExprToType(From, DestType, /*isLvalue=*/true); 2003 return false; 2004} 2005 2006/// TryContextuallyConvertToBool - Attempt to contextually convert the 2007/// expression From to bool (C++0x [conv]p3). 2008ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2009 return TryImplicitConversion(From, Context.BoolTy, false, true); 2010} 2011 2012/// PerformContextuallyConvertToBool - Perform a contextual conversion 2013/// of the expression From to bool (C++0x [conv]p3). 2014bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2015 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2016 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2017 return false; 2018 2019 return Diag(From->getSourceRange().getBegin(), 2020 diag::err_typecheck_bool_condition) 2021 << From->getType() << From->getSourceRange(); 2022} 2023 2024/// AddOverloadCandidate - Adds the given function to the set of 2025/// candidate functions, using the given function call arguments. If 2026/// @p SuppressUserConversions, then don't allow user-defined 2027/// conversions via constructors or conversion operators. 2028/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2029/// hacky way to implement the overloading rules for elidable copy 2030/// initialization in C++0x (C++0x 12.8p15). 2031void 2032Sema::AddOverloadCandidate(FunctionDecl *Function, 2033 Expr **Args, unsigned NumArgs, 2034 OverloadCandidateSet& CandidateSet, 2035 bool SuppressUserConversions, 2036 bool ForceRValue) 2037{ 2038 const FunctionProtoType* Proto 2039 = dyn_cast<FunctionProtoType>(Function->getType()->getAsFunctionType()); 2040 assert(Proto && "Functions without a prototype cannot be overloaded"); 2041 assert(!isa<CXXConversionDecl>(Function) && 2042 "Use AddConversionCandidate for conversion functions"); 2043 2044 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2045 if (!isa<CXXConstructorDecl>(Method)) { 2046 // If we get here, it's because we're calling a member function 2047 // that is named without a member access expression (e.g., 2048 // "this->f") that was either written explicitly or created 2049 // implicitly. This can happen with a qualified call to a member 2050 // function, e.g., X::f(). We use a NULL object as the implied 2051 // object argument (C++ [over.call.func]p3). 2052 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2053 SuppressUserConversions, ForceRValue); 2054 return; 2055 } 2056 // We treat a constructor like a non-member function, since its object 2057 // argument doesn't participate in overload resolution. 2058 } 2059 2060 2061 // Add this candidate 2062 CandidateSet.push_back(OverloadCandidate()); 2063 OverloadCandidate& Candidate = CandidateSet.back(); 2064 Candidate.Function = Function; 2065 Candidate.Viable = true; 2066 Candidate.IsSurrogate = false; 2067 Candidate.IgnoreObjectArgument = false; 2068 2069 unsigned NumArgsInProto = Proto->getNumArgs(); 2070 2071 // (C++ 13.3.2p2): A candidate function having fewer than m 2072 // parameters is viable only if it has an ellipsis in its parameter 2073 // list (8.3.5). 2074 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2075 Candidate.Viable = false; 2076 return; 2077 } 2078 2079 // (C++ 13.3.2p2): A candidate function having more than m parameters 2080 // is viable only if the (m+1)st parameter has a default argument 2081 // (8.3.6). For the purposes of overload resolution, the 2082 // parameter list is truncated on the right, so that there are 2083 // exactly m parameters. 2084 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2085 if (NumArgs < MinRequiredArgs) { 2086 // Not enough arguments. 2087 Candidate.Viable = false; 2088 return; 2089 } 2090 2091 // Determine the implicit conversion sequences for each of the 2092 // arguments. 2093 Candidate.Conversions.resize(NumArgs); 2094 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2095 if (ArgIdx < NumArgsInProto) { 2096 // (C++ 13.3.2p3): for F to be a viable function, there shall 2097 // exist for each argument an implicit conversion sequence 2098 // (13.3.3.1) that converts that argument to the corresponding 2099 // parameter of F. 2100 QualType ParamType = Proto->getArgType(ArgIdx); 2101 Candidate.Conversions[ArgIdx] 2102 = TryCopyInitialization(Args[ArgIdx], ParamType, 2103 SuppressUserConversions, ForceRValue); 2104 if (Candidate.Conversions[ArgIdx].ConversionKind 2105 == ImplicitConversionSequence::BadConversion) { 2106 Candidate.Viable = false; 2107 break; 2108 } 2109 } else { 2110 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2111 // argument for which there is no corresponding parameter is 2112 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2113 Candidate.Conversions[ArgIdx].ConversionKind 2114 = ImplicitConversionSequence::EllipsisConversion; 2115 } 2116 } 2117} 2118 2119/// \brief Add all of the function declarations in the given function set to 2120/// the overload canddiate set. 2121void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2122 Expr **Args, unsigned NumArgs, 2123 OverloadCandidateSet& CandidateSet, 2124 bool SuppressUserConversions) { 2125 for (FunctionSet::const_iterator F = Functions.begin(), 2126 FEnd = Functions.end(); 2127 F != FEnd; ++F) 2128 AddOverloadCandidate(*F, Args, NumArgs, CandidateSet, 2129 SuppressUserConversions); 2130} 2131 2132/// AddMethodCandidate - Adds the given C++ member function to the set 2133/// of candidate functions, using the given function call arguments 2134/// and the object argument (@c Object). For example, in a call 2135/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2136/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2137/// allow user-defined conversions via constructors or conversion 2138/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2139/// a slightly hacky way to implement the overloading rules for elidable copy 2140/// initialization in C++0x (C++0x 12.8p15). 2141void 2142Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2143 Expr **Args, unsigned NumArgs, 2144 OverloadCandidateSet& CandidateSet, 2145 bool SuppressUserConversions, bool ForceRValue) 2146{ 2147 const FunctionProtoType* Proto 2148 = dyn_cast<FunctionProtoType>(Method->getType()->getAsFunctionType()); 2149 assert(Proto && "Methods without a prototype cannot be overloaded"); 2150 assert(!isa<CXXConversionDecl>(Method) && 2151 "Use AddConversionCandidate for conversion functions"); 2152 assert(!isa<CXXConstructorDecl>(Method) && 2153 "Use AddOverloadCandidate for constructors"); 2154 2155 // Add this candidate 2156 CandidateSet.push_back(OverloadCandidate()); 2157 OverloadCandidate& Candidate = CandidateSet.back(); 2158 Candidate.Function = Method; 2159 Candidate.IsSurrogate = false; 2160 Candidate.IgnoreObjectArgument = false; 2161 2162 unsigned NumArgsInProto = Proto->getNumArgs(); 2163 2164 // (C++ 13.3.2p2): A candidate function having fewer than m 2165 // parameters is viable only if it has an ellipsis in its parameter 2166 // list (8.3.5). 2167 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2168 Candidate.Viable = false; 2169 return; 2170 } 2171 2172 // (C++ 13.3.2p2): A candidate function having more than m parameters 2173 // is viable only if the (m+1)st parameter has a default argument 2174 // (8.3.6). For the purposes of overload resolution, the 2175 // parameter list is truncated on the right, so that there are 2176 // exactly m parameters. 2177 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2178 if (NumArgs < MinRequiredArgs) { 2179 // Not enough arguments. 2180 Candidate.Viable = false; 2181 return; 2182 } 2183 2184 Candidate.Viable = true; 2185 Candidate.Conversions.resize(NumArgs + 1); 2186 2187 if (Method->isStatic() || !Object) 2188 // The implicit object argument is ignored. 2189 Candidate.IgnoreObjectArgument = true; 2190 else { 2191 // Determine the implicit conversion sequence for the object 2192 // parameter. 2193 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2194 if (Candidate.Conversions[0].ConversionKind 2195 == ImplicitConversionSequence::BadConversion) { 2196 Candidate.Viable = false; 2197 return; 2198 } 2199 } 2200 2201 // Determine the implicit conversion sequences for each of the 2202 // arguments. 2203 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2204 if (ArgIdx < NumArgsInProto) { 2205 // (C++ 13.3.2p3): for F to be a viable function, there shall 2206 // exist for each argument an implicit conversion sequence 2207 // (13.3.3.1) that converts that argument to the corresponding 2208 // parameter of F. 2209 QualType ParamType = Proto->getArgType(ArgIdx); 2210 Candidate.Conversions[ArgIdx + 1] 2211 = TryCopyInitialization(Args[ArgIdx], ParamType, 2212 SuppressUserConversions, ForceRValue); 2213 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2214 == ImplicitConversionSequence::BadConversion) { 2215 Candidate.Viable = false; 2216 break; 2217 } 2218 } else { 2219 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2220 // argument for which there is no corresponding parameter is 2221 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2222 Candidate.Conversions[ArgIdx + 1].ConversionKind 2223 = ImplicitConversionSequence::EllipsisConversion; 2224 } 2225 } 2226} 2227 2228/// AddConversionCandidate - Add a C++ conversion function as a 2229/// candidate in the candidate set (C++ [over.match.conv], 2230/// C++ [over.match.copy]). From is the expression we're converting from, 2231/// and ToType is the type that we're eventually trying to convert to 2232/// (which may or may not be the same type as the type that the 2233/// conversion function produces). 2234void 2235Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2236 Expr *From, QualType ToType, 2237 OverloadCandidateSet& CandidateSet) { 2238 // Add this candidate 2239 CandidateSet.push_back(OverloadCandidate()); 2240 OverloadCandidate& Candidate = CandidateSet.back(); 2241 Candidate.Function = Conversion; 2242 Candidate.IsSurrogate = false; 2243 Candidate.IgnoreObjectArgument = false; 2244 Candidate.FinalConversion.setAsIdentityConversion(); 2245 Candidate.FinalConversion.FromTypePtr 2246 = Conversion->getConversionType().getAsOpaquePtr(); 2247 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2248 2249 // Determine the implicit conversion sequence for the implicit 2250 // object parameter. 2251 Candidate.Viable = true; 2252 Candidate.Conversions.resize(1); 2253 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2254 2255 if (Candidate.Conversions[0].ConversionKind 2256 == ImplicitConversionSequence::BadConversion) { 2257 Candidate.Viable = false; 2258 return; 2259 } 2260 2261 // To determine what the conversion from the result of calling the 2262 // conversion function to the type we're eventually trying to 2263 // convert to (ToType), we need to synthesize a call to the 2264 // conversion function and attempt copy initialization from it. This 2265 // makes sure that we get the right semantics with respect to 2266 // lvalues/rvalues and the type. Fortunately, we can allocate this 2267 // call on the stack and we don't need its arguments to be 2268 // well-formed. 2269 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2270 SourceLocation()); 2271 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2272 &ConversionRef, false); 2273 2274 // Note that it is safe to allocate CallExpr on the stack here because 2275 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2276 // allocator). 2277 CallExpr Call(Context, &ConversionFn, 0, 0, 2278 Conversion->getConversionType().getNonReferenceType(), 2279 SourceLocation()); 2280 ImplicitConversionSequence ICS = TryCopyInitialization(&Call, ToType, true); 2281 switch (ICS.ConversionKind) { 2282 case ImplicitConversionSequence::StandardConversion: 2283 Candidate.FinalConversion = ICS.Standard; 2284 break; 2285 2286 case ImplicitConversionSequence::BadConversion: 2287 Candidate.Viable = false; 2288 break; 2289 2290 default: 2291 assert(false && 2292 "Can only end up with a standard conversion sequence or failure"); 2293 } 2294} 2295 2296/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2297/// converts the given @c Object to a function pointer via the 2298/// conversion function @c Conversion, and then attempts to call it 2299/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2300/// the type of function that we'll eventually be calling. 2301void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2302 const FunctionProtoType *Proto, 2303 Expr *Object, Expr **Args, unsigned NumArgs, 2304 OverloadCandidateSet& CandidateSet) { 2305 CandidateSet.push_back(OverloadCandidate()); 2306 OverloadCandidate& Candidate = CandidateSet.back(); 2307 Candidate.Function = 0; 2308 Candidate.Surrogate = Conversion; 2309 Candidate.Viable = true; 2310 Candidate.IsSurrogate = true; 2311 Candidate.IgnoreObjectArgument = false; 2312 Candidate.Conversions.resize(NumArgs + 1); 2313 2314 // Determine the implicit conversion sequence for the implicit 2315 // object parameter. 2316 ImplicitConversionSequence ObjectInit 2317 = TryObjectArgumentInitialization(Object, Conversion); 2318 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2319 Candidate.Viable = false; 2320 return; 2321 } 2322 2323 // The first conversion is actually a user-defined conversion whose 2324 // first conversion is ObjectInit's standard conversion (which is 2325 // effectively a reference binding). Record it as such. 2326 Candidate.Conversions[0].ConversionKind 2327 = ImplicitConversionSequence::UserDefinedConversion; 2328 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2329 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2330 Candidate.Conversions[0].UserDefined.After 2331 = Candidate.Conversions[0].UserDefined.Before; 2332 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2333 2334 // Find the 2335 unsigned NumArgsInProto = Proto->getNumArgs(); 2336 2337 // (C++ 13.3.2p2): A candidate function having fewer than m 2338 // parameters is viable only if it has an ellipsis in its parameter 2339 // list (8.3.5). 2340 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2341 Candidate.Viable = false; 2342 return; 2343 } 2344 2345 // Function types don't have any default arguments, so just check if 2346 // we have enough arguments. 2347 if (NumArgs < NumArgsInProto) { 2348 // Not enough arguments. 2349 Candidate.Viable = false; 2350 return; 2351 } 2352 2353 // Determine the implicit conversion sequences for each of the 2354 // arguments. 2355 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2356 if (ArgIdx < NumArgsInProto) { 2357 // (C++ 13.3.2p3): for F to be a viable function, there shall 2358 // exist for each argument an implicit conversion sequence 2359 // (13.3.3.1) that converts that argument to the corresponding 2360 // parameter of F. 2361 QualType ParamType = Proto->getArgType(ArgIdx); 2362 Candidate.Conversions[ArgIdx + 1] 2363 = TryCopyInitialization(Args[ArgIdx], ParamType, 2364 /*SuppressUserConversions=*/false); 2365 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2366 == ImplicitConversionSequence::BadConversion) { 2367 Candidate.Viable = false; 2368 break; 2369 } 2370 } else { 2371 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2372 // argument for which there is no corresponding parameter is 2373 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2374 Candidate.Conversions[ArgIdx + 1].ConversionKind 2375 = ImplicitConversionSequence::EllipsisConversion; 2376 } 2377 } 2378} 2379 2380// FIXME: This will eventually be removed, once we've migrated all of 2381// the operator overloading logic over to the scheme used by binary 2382// operators, which works for template instantiation. 2383void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2384 SourceLocation OpLoc, 2385 Expr **Args, unsigned NumArgs, 2386 OverloadCandidateSet& CandidateSet, 2387 SourceRange OpRange) { 2388 2389 FunctionSet Functions; 2390 2391 QualType T1 = Args[0]->getType(); 2392 QualType T2; 2393 if (NumArgs > 1) 2394 T2 = Args[1]->getType(); 2395 2396 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2397 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2398 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2399 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2400 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2401 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2402} 2403 2404/// \brief Add overload candidates for overloaded operators that are 2405/// member functions. 2406/// 2407/// Add the overloaded operator candidates that are member functions 2408/// for the operator Op that was used in an operator expression such 2409/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2410/// CandidateSet will store the added overload candidates. (C++ 2411/// [over.match.oper]). 2412void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2413 SourceLocation OpLoc, 2414 Expr **Args, unsigned NumArgs, 2415 OverloadCandidateSet& CandidateSet, 2416 SourceRange OpRange) { 2417 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2418 2419 // C++ [over.match.oper]p3: 2420 // For a unary operator @ with an operand of a type whose 2421 // cv-unqualified version is T1, and for a binary operator @ with 2422 // a left operand of a type whose cv-unqualified version is T1 and 2423 // a right operand of a type whose cv-unqualified version is T2, 2424 // three sets of candidate functions, designated member 2425 // candidates, non-member candidates and built-in candidates, are 2426 // constructed as follows: 2427 QualType T1 = Args[0]->getType(); 2428 QualType T2; 2429 if (NumArgs > 1) 2430 T2 = Args[1]->getType(); 2431 2432 // -- If T1 is a class type, the set of member candidates is the 2433 // result of the qualified lookup of T1::operator@ 2434 // (13.3.1.1.1); otherwise, the set of member candidates is 2435 // empty. 2436 // FIXME: Lookup in base classes, too! 2437 if (const RecordType *T1Rec = T1->getAsRecordType()) { 2438 DeclContext::lookup_const_iterator Oper, OperEnd; 2439 for (llvm::tie(Oper, OperEnd) = T1Rec->getDecl()->lookup(Context, OpName); 2440 Oper != OperEnd; ++Oper) 2441 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2442 Args+1, NumArgs - 1, CandidateSet, 2443 /*SuppressUserConversions=*/false); 2444 } 2445} 2446 2447/// AddBuiltinCandidate - Add a candidate for a built-in 2448/// operator. ResultTy and ParamTys are the result and parameter types 2449/// of the built-in candidate, respectively. Args and NumArgs are the 2450/// arguments being passed to the candidate. IsAssignmentOperator 2451/// should be true when this built-in candidate is an assignment 2452/// operator. NumContextualBoolArguments is the number of arguments 2453/// (at the beginning of the argument list) that will be contextually 2454/// converted to bool. 2455void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2456 Expr **Args, unsigned NumArgs, 2457 OverloadCandidateSet& CandidateSet, 2458 bool IsAssignmentOperator, 2459 unsigned NumContextualBoolArguments) { 2460 // Add this candidate 2461 CandidateSet.push_back(OverloadCandidate()); 2462 OverloadCandidate& Candidate = CandidateSet.back(); 2463 Candidate.Function = 0; 2464 Candidate.IsSurrogate = false; 2465 Candidate.IgnoreObjectArgument = false; 2466 Candidate.BuiltinTypes.ResultTy = ResultTy; 2467 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2468 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2469 2470 // Determine the implicit conversion sequences for each of the 2471 // arguments. 2472 Candidate.Viable = true; 2473 Candidate.Conversions.resize(NumArgs); 2474 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2475 // C++ [over.match.oper]p4: 2476 // For the built-in assignment operators, conversions of the 2477 // left operand are restricted as follows: 2478 // -- no temporaries are introduced to hold the left operand, and 2479 // -- no user-defined conversions are applied to the left 2480 // operand to achieve a type match with the left-most 2481 // parameter of a built-in candidate. 2482 // 2483 // We block these conversions by turning off user-defined 2484 // conversions, since that is the only way that initialization of 2485 // a reference to a non-class type can occur from something that 2486 // is not of the same type. 2487 if (ArgIdx < NumContextualBoolArguments) { 2488 assert(ParamTys[ArgIdx] == Context.BoolTy && 2489 "Contextual conversion to bool requires bool type"); 2490 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2491 } else { 2492 Candidate.Conversions[ArgIdx] 2493 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2494 ArgIdx == 0 && IsAssignmentOperator); 2495 } 2496 if (Candidate.Conversions[ArgIdx].ConversionKind 2497 == ImplicitConversionSequence::BadConversion) { 2498 Candidate.Viable = false; 2499 break; 2500 } 2501 } 2502} 2503 2504/// BuiltinCandidateTypeSet - A set of types that will be used for the 2505/// candidate operator functions for built-in operators (C++ 2506/// [over.built]). The types are separated into pointer types and 2507/// enumeration types. 2508class BuiltinCandidateTypeSet { 2509 /// TypeSet - A set of types. 2510 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2511 2512 /// PointerTypes - The set of pointer types that will be used in the 2513 /// built-in candidates. 2514 TypeSet PointerTypes; 2515 2516 /// MemberPointerTypes - The set of member pointer types that will be 2517 /// used in the built-in candidates. 2518 TypeSet MemberPointerTypes; 2519 2520 /// EnumerationTypes - The set of enumeration types that will be 2521 /// used in the built-in candidates. 2522 TypeSet EnumerationTypes; 2523 2524 /// Context - The AST context in which we will build the type sets. 2525 ASTContext &Context; 2526 2527 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2528 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2529 2530public: 2531 /// iterator - Iterates through the types that are part of the set. 2532 typedef TypeSet::iterator iterator; 2533 2534 BuiltinCandidateTypeSet(ASTContext &Context) : Context(Context) { } 2535 2536 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2537 bool AllowExplicitConversions); 2538 2539 /// pointer_begin - First pointer type found; 2540 iterator pointer_begin() { return PointerTypes.begin(); } 2541 2542 /// pointer_end - Past the last pointer type found; 2543 iterator pointer_end() { return PointerTypes.end(); } 2544 2545 /// member_pointer_begin - First member pointer type found; 2546 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2547 2548 /// member_pointer_end - Past the last member pointer type found; 2549 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2550 2551 /// enumeration_begin - First enumeration type found; 2552 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2553 2554 /// enumeration_end - Past the last enumeration type found; 2555 iterator enumeration_end() { return EnumerationTypes.end(); } 2556}; 2557 2558/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2559/// the set of pointer types along with any more-qualified variants of 2560/// that type. For example, if @p Ty is "int const *", this routine 2561/// will add "int const *", "int const volatile *", "int const 2562/// restrict *", and "int const volatile restrict *" to the set of 2563/// pointer types. Returns true if the add of @p Ty itself succeeded, 2564/// false otherwise. 2565bool 2566BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2567 // Insert this type. 2568 if (!PointerTypes.insert(Ty)) 2569 return false; 2570 2571 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2572 QualType PointeeTy = PointerTy->getPointeeType(); 2573 // FIXME: Optimize this so that we don't keep trying to add the same types. 2574 2575 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal 2576 // with all pointer conversions that don't cast away constness? 2577 if (!PointeeTy.isConstQualified()) 2578 AddPointerWithMoreQualifiedTypeVariants 2579 (Context.getPointerType(PointeeTy.withConst())); 2580 if (!PointeeTy.isVolatileQualified()) 2581 AddPointerWithMoreQualifiedTypeVariants 2582 (Context.getPointerType(PointeeTy.withVolatile())); 2583 if (!PointeeTy.isRestrictQualified()) 2584 AddPointerWithMoreQualifiedTypeVariants 2585 (Context.getPointerType(PointeeTy.withRestrict())); 2586 } 2587 2588 return true; 2589} 2590 2591/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2592/// to the set of pointer types along with any more-qualified variants of 2593/// that type. For example, if @p Ty is "int const *", this routine 2594/// will add "int const *", "int const volatile *", "int const 2595/// restrict *", and "int const volatile restrict *" to the set of 2596/// pointer types. Returns true if the add of @p Ty itself succeeded, 2597/// false otherwise. 2598bool 2599BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2600 QualType Ty) { 2601 // Insert this type. 2602 if (!MemberPointerTypes.insert(Ty)) 2603 return false; 2604 2605 if (const MemberPointerType *PointerTy = Ty->getAsMemberPointerType()) { 2606 QualType PointeeTy = PointerTy->getPointeeType(); 2607 const Type *ClassTy = PointerTy->getClass(); 2608 // FIXME: Optimize this so that we don't keep trying to add the same types. 2609 2610 if (!PointeeTy.isConstQualified()) 2611 AddMemberPointerWithMoreQualifiedTypeVariants 2612 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2613 if (!PointeeTy.isVolatileQualified()) 2614 AddMemberPointerWithMoreQualifiedTypeVariants 2615 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2616 if (!PointeeTy.isRestrictQualified()) 2617 AddMemberPointerWithMoreQualifiedTypeVariants 2618 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2619 } 2620 2621 return true; 2622} 2623 2624/// AddTypesConvertedFrom - Add each of the types to which the type @p 2625/// Ty can be implicit converted to the given set of @p Types. We're 2626/// primarily interested in pointer types and enumeration types. We also 2627/// take member pointer types, for the conditional operator. 2628/// AllowUserConversions is true if we should look at the conversion 2629/// functions of a class type, and AllowExplicitConversions if we 2630/// should also include the explicit conversion functions of a class 2631/// type. 2632void 2633BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2634 bool AllowUserConversions, 2635 bool AllowExplicitConversions) { 2636 // Only deal with canonical types. 2637 Ty = Context.getCanonicalType(Ty); 2638 2639 // Look through reference types; they aren't part of the type of an 2640 // expression for the purposes of conversions. 2641 if (const ReferenceType *RefTy = Ty->getAsReferenceType()) 2642 Ty = RefTy->getPointeeType(); 2643 2644 // We don't care about qualifiers on the type. 2645 Ty = Ty.getUnqualifiedType(); 2646 2647 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2648 QualType PointeeTy = PointerTy->getPointeeType(); 2649 2650 // Insert our type, and its more-qualified variants, into the set 2651 // of types. 2652 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2653 return; 2654 2655 // Add 'cv void*' to our set of types. 2656 if (!Ty->isVoidType()) { 2657 QualType QualVoid 2658 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2659 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2660 } 2661 2662 // If this is a pointer to a class type, add pointers to its bases 2663 // (with the same level of cv-qualification as the original 2664 // derived class, of course). 2665 if (const RecordType *PointeeRec = PointeeTy->getAsRecordType()) { 2666 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2667 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2668 Base != ClassDecl->bases_end(); ++Base) { 2669 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2670 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2671 2672 // Add the pointer type, recursively, so that we get all of 2673 // the indirect base classes, too. 2674 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2675 } 2676 } 2677 } else if (Ty->isMemberPointerType()) { 2678 // Member pointers are far easier, since the pointee can't be converted. 2679 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2680 return; 2681 } else if (Ty->isEnumeralType()) { 2682 EnumerationTypes.insert(Ty); 2683 } else if (AllowUserConversions) { 2684 if (const RecordType *TyRec = Ty->getAsRecordType()) { 2685 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2686 // FIXME: Visit conversion functions in the base classes, too. 2687 OverloadedFunctionDecl *Conversions 2688 = ClassDecl->getConversionFunctions(); 2689 for (OverloadedFunctionDecl::function_iterator Func 2690 = Conversions->function_begin(); 2691 Func != Conversions->function_end(); ++Func) { 2692 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 2693 if (AllowExplicitConversions || !Conv->isExplicit()) 2694 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2695 } 2696 } 2697 } 2698} 2699 2700/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2701/// operator overloads to the candidate set (C++ [over.built]), based 2702/// on the operator @p Op and the arguments given. For example, if the 2703/// operator is a binary '+', this routine might add "int 2704/// operator+(int, int)" to cover integer addition. 2705void 2706Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2707 Expr **Args, unsigned NumArgs, 2708 OverloadCandidateSet& CandidateSet) { 2709 // The set of "promoted arithmetic types", which are the arithmetic 2710 // types are that preserved by promotion (C++ [over.built]p2). Note 2711 // that the first few of these types are the promoted integral 2712 // types; these types need to be first. 2713 // FIXME: What about complex? 2714 const unsigned FirstIntegralType = 0; 2715 const unsigned LastIntegralType = 13; 2716 const unsigned FirstPromotedIntegralType = 7, 2717 LastPromotedIntegralType = 13; 2718 const unsigned FirstPromotedArithmeticType = 7, 2719 LastPromotedArithmeticType = 16; 2720 const unsigned NumArithmeticTypes = 16; 2721 QualType ArithmeticTypes[NumArithmeticTypes] = { 2722 Context.BoolTy, Context.CharTy, Context.WCharTy, 2723 Context.SignedCharTy, Context.ShortTy, 2724 Context.UnsignedCharTy, Context.UnsignedShortTy, 2725 Context.IntTy, Context.LongTy, Context.LongLongTy, 2726 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 2727 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 2728 }; 2729 2730 // Find all of the types that the arguments can convert to, but only 2731 // if the operator we're looking at has built-in operator candidates 2732 // that make use of these types. 2733 BuiltinCandidateTypeSet CandidateTypes(Context); 2734 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 2735 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 2736 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 2737 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 2738 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 2739 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 2740 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2741 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 2742 true, 2743 (Op == OO_Exclaim || 2744 Op == OO_AmpAmp || 2745 Op == OO_PipePipe)); 2746 } 2747 2748 bool isComparison = false; 2749 switch (Op) { 2750 case OO_None: 2751 case NUM_OVERLOADED_OPERATORS: 2752 assert(false && "Expected an overloaded operator"); 2753 break; 2754 2755 case OO_Star: // '*' is either unary or binary 2756 if (NumArgs == 1) 2757 goto UnaryStar; 2758 else 2759 goto BinaryStar; 2760 break; 2761 2762 case OO_Plus: // '+' is either unary or binary 2763 if (NumArgs == 1) 2764 goto UnaryPlus; 2765 else 2766 goto BinaryPlus; 2767 break; 2768 2769 case OO_Minus: // '-' is either unary or binary 2770 if (NumArgs == 1) 2771 goto UnaryMinus; 2772 else 2773 goto BinaryMinus; 2774 break; 2775 2776 case OO_Amp: // '&' is either unary or binary 2777 if (NumArgs == 1) 2778 goto UnaryAmp; 2779 else 2780 goto BinaryAmp; 2781 2782 case OO_PlusPlus: 2783 case OO_MinusMinus: 2784 // C++ [over.built]p3: 2785 // 2786 // For every pair (T, VQ), where T is an arithmetic type, and VQ 2787 // is either volatile or empty, there exist candidate operator 2788 // functions of the form 2789 // 2790 // VQ T& operator++(VQ T&); 2791 // T operator++(VQ T&, int); 2792 // 2793 // C++ [over.built]p4: 2794 // 2795 // For every pair (T, VQ), where T is an arithmetic type other 2796 // than bool, and VQ is either volatile or empty, there exist 2797 // candidate operator functions of the form 2798 // 2799 // VQ T& operator--(VQ T&); 2800 // T operator--(VQ T&, int); 2801 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 2802 Arith < NumArithmeticTypes; ++Arith) { 2803 QualType ArithTy = ArithmeticTypes[Arith]; 2804 QualType ParamTypes[2] 2805 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 2806 2807 // Non-volatile version. 2808 if (NumArgs == 1) 2809 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2810 else 2811 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2812 2813 // Volatile version 2814 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 2815 if (NumArgs == 1) 2816 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2817 else 2818 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2819 } 2820 2821 // C++ [over.built]p5: 2822 // 2823 // For every pair (T, VQ), where T is a cv-qualified or 2824 // cv-unqualified object type, and VQ is either volatile or 2825 // empty, there exist candidate operator functions of the form 2826 // 2827 // T*VQ& operator++(T*VQ&); 2828 // T*VQ& operator--(T*VQ&); 2829 // T* operator++(T*VQ&, int); 2830 // T* operator--(T*VQ&, int); 2831 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2832 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2833 // Skip pointer types that aren't pointers to object types. 2834 if (!(*Ptr)->getAsPointerType()->getPointeeType()->isObjectType()) 2835 continue; 2836 2837 QualType ParamTypes[2] = { 2838 Context.getLValueReferenceType(*Ptr), Context.IntTy 2839 }; 2840 2841 // Without volatile 2842 if (NumArgs == 1) 2843 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2844 else 2845 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2846 2847 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 2848 // With volatile 2849 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 2850 if (NumArgs == 1) 2851 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2852 else 2853 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2854 } 2855 } 2856 break; 2857 2858 UnaryStar: 2859 // C++ [over.built]p6: 2860 // For every cv-qualified or cv-unqualified object type T, there 2861 // exist candidate operator functions of the form 2862 // 2863 // T& operator*(T*); 2864 // 2865 // C++ [over.built]p7: 2866 // For every function type T, there exist candidate operator 2867 // functions of the form 2868 // T& operator*(T*); 2869 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2870 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2871 QualType ParamTy = *Ptr; 2872 QualType PointeeTy = ParamTy->getAsPointerType()->getPointeeType(); 2873 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 2874 &ParamTy, Args, 1, CandidateSet); 2875 } 2876 break; 2877 2878 UnaryPlus: 2879 // C++ [over.built]p8: 2880 // For every type T, there exist candidate operator functions of 2881 // the form 2882 // 2883 // T* operator+(T*); 2884 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2885 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2886 QualType ParamTy = *Ptr; 2887 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 2888 } 2889 2890 // Fall through 2891 2892 UnaryMinus: 2893 // C++ [over.built]p9: 2894 // For every promoted arithmetic type T, there exist candidate 2895 // operator functions of the form 2896 // 2897 // T operator+(T); 2898 // T operator-(T); 2899 for (unsigned Arith = FirstPromotedArithmeticType; 2900 Arith < LastPromotedArithmeticType; ++Arith) { 2901 QualType ArithTy = ArithmeticTypes[Arith]; 2902 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 2903 } 2904 break; 2905 2906 case OO_Tilde: 2907 // C++ [over.built]p10: 2908 // For every promoted integral type T, there exist candidate 2909 // operator functions of the form 2910 // 2911 // T operator~(T); 2912 for (unsigned Int = FirstPromotedIntegralType; 2913 Int < LastPromotedIntegralType; ++Int) { 2914 QualType IntTy = ArithmeticTypes[Int]; 2915 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 2916 } 2917 break; 2918 2919 case OO_New: 2920 case OO_Delete: 2921 case OO_Array_New: 2922 case OO_Array_Delete: 2923 case OO_Call: 2924 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 2925 break; 2926 2927 case OO_Comma: 2928 UnaryAmp: 2929 case OO_Arrow: 2930 // C++ [over.match.oper]p3: 2931 // -- For the operator ',', the unary operator '&', or the 2932 // operator '->', the built-in candidates set is empty. 2933 break; 2934 2935 case OO_Less: 2936 case OO_Greater: 2937 case OO_LessEqual: 2938 case OO_GreaterEqual: 2939 case OO_EqualEqual: 2940 case OO_ExclaimEqual: 2941 // C++ [over.built]p15: 2942 // 2943 // For every pointer or enumeration type T, there exist 2944 // candidate operator functions of the form 2945 // 2946 // bool operator<(T, T); 2947 // bool operator>(T, T); 2948 // bool operator<=(T, T); 2949 // bool operator>=(T, T); 2950 // bool operator==(T, T); 2951 // bool operator!=(T, T); 2952 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2953 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2954 QualType ParamTypes[2] = { *Ptr, *Ptr }; 2955 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 2956 } 2957 for (BuiltinCandidateTypeSet::iterator Enum 2958 = CandidateTypes.enumeration_begin(); 2959 Enum != CandidateTypes.enumeration_end(); ++Enum) { 2960 QualType ParamTypes[2] = { *Enum, *Enum }; 2961 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 2962 } 2963 2964 // Fall through. 2965 isComparison = true; 2966 2967 BinaryPlus: 2968 BinaryMinus: 2969 if (!isComparison) { 2970 // We didn't fall through, so we must have OO_Plus or OO_Minus. 2971 2972 // C++ [over.built]p13: 2973 // 2974 // For every cv-qualified or cv-unqualified object type T 2975 // there exist candidate operator functions of the form 2976 // 2977 // T* operator+(T*, ptrdiff_t); 2978 // T& operator[](T*, ptrdiff_t); [BELOW] 2979 // T* operator-(T*, ptrdiff_t); 2980 // T* operator+(ptrdiff_t, T*); 2981 // T& operator[](ptrdiff_t, T*); [BELOW] 2982 // 2983 // C++ [over.built]p14: 2984 // 2985 // For every T, where T is a pointer to object type, there 2986 // exist candidate operator functions of the form 2987 // 2988 // ptrdiff_t operator-(T, T); 2989 for (BuiltinCandidateTypeSet::iterator Ptr 2990 = CandidateTypes.pointer_begin(); 2991 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2992 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 2993 2994 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 2995 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2996 2997 if (Op == OO_Plus) { 2998 // T* operator+(ptrdiff_t, T*); 2999 ParamTypes[0] = ParamTypes[1]; 3000 ParamTypes[1] = *Ptr; 3001 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3002 } else { 3003 // ptrdiff_t operator-(T, T); 3004 ParamTypes[1] = *Ptr; 3005 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3006 Args, 2, CandidateSet); 3007 } 3008 } 3009 } 3010 // Fall through 3011 3012 case OO_Slash: 3013 BinaryStar: 3014 Conditional: 3015 // C++ [over.built]p12: 3016 // 3017 // For every pair of promoted arithmetic types L and R, there 3018 // exist candidate operator functions of the form 3019 // 3020 // LR operator*(L, R); 3021 // LR operator/(L, R); 3022 // LR operator+(L, R); 3023 // LR operator-(L, R); 3024 // bool operator<(L, R); 3025 // bool operator>(L, R); 3026 // bool operator<=(L, R); 3027 // bool operator>=(L, R); 3028 // bool operator==(L, R); 3029 // bool operator!=(L, R); 3030 // 3031 // where LR is the result of the usual arithmetic conversions 3032 // between types L and R. 3033 // 3034 // C++ [over.built]p24: 3035 // 3036 // For every pair of promoted arithmetic types L and R, there exist 3037 // candidate operator functions of the form 3038 // 3039 // LR operator?(bool, L, R); 3040 // 3041 // where LR is the result of the usual arithmetic conversions 3042 // between types L and R. 3043 // Our candidates ignore the first parameter. 3044 for (unsigned Left = FirstPromotedArithmeticType; 3045 Left < LastPromotedArithmeticType; ++Left) { 3046 for (unsigned Right = FirstPromotedArithmeticType; 3047 Right < LastPromotedArithmeticType; ++Right) { 3048 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3049 QualType Result 3050 = isComparison? Context.BoolTy 3051 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3052 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3053 } 3054 } 3055 break; 3056 3057 case OO_Percent: 3058 BinaryAmp: 3059 case OO_Caret: 3060 case OO_Pipe: 3061 case OO_LessLess: 3062 case OO_GreaterGreater: 3063 // C++ [over.built]p17: 3064 // 3065 // For every pair of promoted integral types L and R, there 3066 // exist candidate operator functions of the form 3067 // 3068 // LR operator%(L, R); 3069 // LR operator&(L, R); 3070 // LR operator^(L, R); 3071 // LR operator|(L, R); 3072 // L operator<<(L, R); 3073 // L operator>>(L, R); 3074 // 3075 // where LR is the result of the usual arithmetic conversions 3076 // between types L and R. 3077 for (unsigned Left = FirstPromotedIntegralType; 3078 Left < LastPromotedIntegralType; ++Left) { 3079 for (unsigned Right = FirstPromotedIntegralType; 3080 Right < LastPromotedIntegralType; ++Right) { 3081 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3082 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3083 ? LandR[0] 3084 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3085 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3086 } 3087 } 3088 break; 3089 3090 case OO_Equal: 3091 // C++ [over.built]p20: 3092 // 3093 // For every pair (T, VQ), where T is an enumeration or 3094 // (FIXME:) pointer to member type and VQ is either volatile or 3095 // empty, there exist candidate operator functions of the form 3096 // 3097 // VQ T& operator=(VQ T&, T); 3098 for (BuiltinCandidateTypeSet::iterator Enum 3099 = CandidateTypes.enumeration_begin(); 3100 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3101 QualType ParamTypes[2]; 3102 3103 // T& operator=(T&, T) 3104 ParamTypes[0] = Context.getLValueReferenceType(*Enum); 3105 ParamTypes[1] = *Enum; 3106 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3107 /*IsAssignmentOperator=*/false); 3108 3109 if (!Context.getCanonicalType(*Enum).isVolatileQualified()) { 3110 // volatile T& operator=(volatile T&, T) 3111 ParamTypes[0] = Context.getLValueReferenceType((*Enum).withVolatile()); 3112 ParamTypes[1] = *Enum; 3113 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3114 /*IsAssignmentOperator=*/false); 3115 } 3116 } 3117 // Fall through. 3118 3119 case OO_PlusEqual: 3120 case OO_MinusEqual: 3121 // C++ [over.built]p19: 3122 // 3123 // For every pair (T, VQ), where T is any type and VQ is either 3124 // volatile or empty, there exist candidate operator functions 3125 // of the form 3126 // 3127 // T*VQ& operator=(T*VQ&, T*); 3128 // 3129 // C++ [over.built]p21: 3130 // 3131 // For every pair (T, VQ), where T is a cv-qualified or 3132 // cv-unqualified object type and VQ is either volatile or 3133 // empty, there exist candidate operator functions of the form 3134 // 3135 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3136 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3137 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3138 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3139 QualType ParamTypes[2]; 3140 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3141 3142 // non-volatile version 3143 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3144 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3145 /*IsAssigmentOperator=*/Op == OO_Equal); 3146 3147 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3148 // volatile version 3149 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3150 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3151 /*IsAssigmentOperator=*/Op == OO_Equal); 3152 } 3153 } 3154 // Fall through. 3155 3156 case OO_StarEqual: 3157 case OO_SlashEqual: 3158 // C++ [over.built]p18: 3159 // 3160 // For every triple (L, VQ, R), where L is an arithmetic type, 3161 // VQ is either volatile or empty, and R is a promoted 3162 // arithmetic type, there exist candidate operator functions of 3163 // the form 3164 // 3165 // VQ L& operator=(VQ L&, R); 3166 // VQ L& operator*=(VQ L&, R); 3167 // VQ L& operator/=(VQ L&, R); 3168 // VQ L& operator+=(VQ L&, R); 3169 // VQ L& operator-=(VQ L&, R); 3170 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3171 for (unsigned Right = FirstPromotedArithmeticType; 3172 Right < LastPromotedArithmeticType; ++Right) { 3173 QualType ParamTypes[2]; 3174 ParamTypes[1] = ArithmeticTypes[Right]; 3175 3176 // Add this built-in operator as a candidate (VQ is empty). 3177 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3178 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3179 /*IsAssigmentOperator=*/Op == OO_Equal); 3180 3181 // Add this built-in operator as a candidate (VQ is 'volatile'). 3182 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3183 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3184 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3185 /*IsAssigmentOperator=*/Op == OO_Equal); 3186 } 3187 } 3188 break; 3189 3190 case OO_PercentEqual: 3191 case OO_LessLessEqual: 3192 case OO_GreaterGreaterEqual: 3193 case OO_AmpEqual: 3194 case OO_CaretEqual: 3195 case OO_PipeEqual: 3196 // C++ [over.built]p22: 3197 // 3198 // For every triple (L, VQ, R), where L is an integral type, VQ 3199 // is either volatile or empty, and R is a promoted integral 3200 // type, there exist candidate operator functions of the form 3201 // 3202 // VQ L& operator%=(VQ L&, R); 3203 // VQ L& operator<<=(VQ L&, R); 3204 // VQ L& operator>>=(VQ L&, R); 3205 // VQ L& operator&=(VQ L&, R); 3206 // VQ L& operator^=(VQ L&, R); 3207 // VQ L& operator|=(VQ L&, R); 3208 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3209 for (unsigned Right = FirstPromotedIntegralType; 3210 Right < LastPromotedIntegralType; ++Right) { 3211 QualType ParamTypes[2]; 3212 ParamTypes[1] = ArithmeticTypes[Right]; 3213 3214 // Add this built-in operator as a candidate (VQ is empty). 3215 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3216 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3217 3218 // Add this built-in operator as a candidate (VQ is 'volatile'). 3219 ParamTypes[0] = ArithmeticTypes[Left]; 3220 ParamTypes[0].addVolatile(); 3221 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3222 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3223 } 3224 } 3225 break; 3226 3227 case OO_Exclaim: { 3228 // C++ [over.operator]p23: 3229 // 3230 // There also exist candidate operator functions of the form 3231 // 3232 // bool operator!(bool); 3233 // bool operator&&(bool, bool); [BELOW] 3234 // bool operator||(bool, bool); [BELOW] 3235 QualType ParamTy = Context.BoolTy; 3236 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3237 /*IsAssignmentOperator=*/false, 3238 /*NumContextualBoolArguments=*/1); 3239 break; 3240 } 3241 3242 case OO_AmpAmp: 3243 case OO_PipePipe: { 3244 // C++ [over.operator]p23: 3245 // 3246 // There also exist candidate operator functions of the form 3247 // 3248 // bool operator!(bool); [ABOVE] 3249 // bool operator&&(bool, bool); 3250 // bool operator||(bool, bool); 3251 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3252 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3253 /*IsAssignmentOperator=*/false, 3254 /*NumContextualBoolArguments=*/2); 3255 break; 3256 } 3257 3258 case OO_Subscript: 3259 // C++ [over.built]p13: 3260 // 3261 // For every cv-qualified or cv-unqualified object type T there 3262 // exist candidate operator functions of the form 3263 // 3264 // T* operator+(T*, ptrdiff_t); [ABOVE] 3265 // T& operator[](T*, ptrdiff_t); 3266 // T* operator-(T*, ptrdiff_t); [ABOVE] 3267 // T* operator+(ptrdiff_t, T*); [ABOVE] 3268 // T& operator[](ptrdiff_t, T*); 3269 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3270 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3271 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3272 QualType PointeeType = (*Ptr)->getAsPointerType()->getPointeeType(); 3273 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3274 3275 // T& operator[](T*, ptrdiff_t) 3276 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3277 3278 // T& operator[](ptrdiff_t, T*); 3279 ParamTypes[0] = ParamTypes[1]; 3280 ParamTypes[1] = *Ptr; 3281 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3282 } 3283 break; 3284 3285 case OO_ArrowStar: 3286 // FIXME: No support for pointer-to-members yet. 3287 break; 3288 3289 case OO_Conditional: 3290 // Note that we don't consider the first argument, since it has been 3291 // contextually converted to bool long ago. The candidates below are 3292 // therefore added as binary. 3293 // 3294 // C++ [over.built]p24: 3295 // For every type T, where T is a pointer or pointer-to-member type, 3296 // there exist candidate operator functions of the form 3297 // 3298 // T operator?(bool, T, T); 3299 // 3300 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3301 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3302 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3303 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3304 } 3305 for (BuiltinCandidateTypeSet::iterator Ptr = 3306 CandidateTypes.member_pointer_begin(), 3307 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3308 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3309 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3310 } 3311 goto Conditional; 3312 } 3313} 3314 3315/// \brief Add function candidates found via argument-dependent lookup 3316/// to the set of overloading candidates. 3317/// 3318/// This routine performs argument-dependent name lookup based on the 3319/// given function name (which may also be an operator name) and adds 3320/// all of the overload candidates found by ADL to the overload 3321/// candidate set (C++ [basic.lookup.argdep]). 3322void 3323Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3324 Expr **Args, unsigned NumArgs, 3325 OverloadCandidateSet& CandidateSet) { 3326 FunctionSet Functions; 3327 3328 // Record all of the function candidates that we've already 3329 // added to the overload set, so that we don't add those same 3330 // candidates a second time. 3331 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3332 CandEnd = CandidateSet.end(); 3333 Cand != CandEnd; ++Cand) 3334 if (Cand->Function) 3335 Functions.insert(Cand->Function); 3336 3337 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3338 3339 // Erase all of the candidates we already knew about. 3340 // FIXME: This is suboptimal. Is there a better way? 3341 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3342 CandEnd = CandidateSet.end(); 3343 Cand != CandEnd; ++Cand) 3344 if (Cand->Function) 3345 Functions.erase(Cand->Function); 3346 3347 // For each of the ADL candidates we found, add it to the overload 3348 // set. 3349 for (FunctionSet::iterator Func = Functions.begin(), 3350 FuncEnd = Functions.end(); 3351 Func != FuncEnd; ++Func) 3352 AddOverloadCandidate(*Func, Args, NumArgs, CandidateSet); 3353} 3354 3355/// isBetterOverloadCandidate - Determines whether the first overload 3356/// candidate is a better candidate than the second (C++ 13.3.3p1). 3357bool 3358Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3359 const OverloadCandidate& Cand2) 3360{ 3361 // Define viable functions to be better candidates than non-viable 3362 // functions. 3363 if (!Cand2.Viable) 3364 return Cand1.Viable; 3365 else if (!Cand1.Viable) 3366 return false; 3367 3368 // C++ [over.match.best]p1: 3369 // 3370 // -- if F is a static member function, ICS1(F) is defined such 3371 // that ICS1(F) is neither better nor worse than ICS1(G) for 3372 // any function G, and, symmetrically, ICS1(G) is neither 3373 // better nor worse than ICS1(F). 3374 unsigned StartArg = 0; 3375 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3376 StartArg = 1; 3377 3378 // (C++ 13.3.3p1): a viable function F1 is defined to be a better 3379 // function than another viable function F2 if for all arguments i, 3380 // ICSi(F1) is not a worse conversion sequence than ICSi(F2), and 3381 // then... 3382 unsigned NumArgs = Cand1.Conversions.size(); 3383 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3384 bool HasBetterConversion = false; 3385 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3386 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3387 Cand2.Conversions[ArgIdx])) { 3388 case ImplicitConversionSequence::Better: 3389 // Cand1 has a better conversion sequence. 3390 HasBetterConversion = true; 3391 break; 3392 3393 case ImplicitConversionSequence::Worse: 3394 // Cand1 can't be better than Cand2. 3395 return false; 3396 3397 case ImplicitConversionSequence::Indistinguishable: 3398 // Do nothing. 3399 break; 3400 } 3401 } 3402 3403 if (HasBetterConversion) 3404 return true; 3405 3406 // FIXME: Several other bullets in (C++ 13.3.3p1) need to be 3407 // implemented, but they require template support. 3408 3409 // C++ [over.match.best]p1b4: 3410 // 3411 // -- the context is an initialization by user-defined conversion 3412 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3413 // from the return type of F1 to the destination type (i.e., 3414 // the type of the entity being initialized) is a better 3415 // conversion sequence than the standard conversion sequence 3416 // from the return type of F2 to the destination type. 3417 if (Cand1.Function && Cand2.Function && 3418 isa<CXXConversionDecl>(Cand1.Function) && 3419 isa<CXXConversionDecl>(Cand2.Function)) { 3420 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3421 Cand2.FinalConversion)) { 3422 case ImplicitConversionSequence::Better: 3423 // Cand1 has a better conversion sequence. 3424 return true; 3425 3426 case ImplicitConversionSequence::Worse: 3427 // Cand1 can't be better than Cand2. 3428 return false; 3429 3430 case ImplicitConversionSequence::Indistinguishable: 3431 // Do nothing 3432 break; 3433 } 3434 } 3435 3436 return false; 3437} 3438 3439/// BestViableFunction - Computes the best viable function (C++ 13.3.3) 3440/// within an overload candidate set. If overloading is successful, 3441/// the result will be OR_Success and Best will be set to point to the 3442/// best viable function within the candidate set. Otherwise, one of 3443/// several kinds of errors will be returned; see 3444/// Sema::OverloadingResult. 3445Sema::OverloadingResult 3446Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3447 OverloadCandidateSet::iterator& Best) 3448{ 3449 // Find the best viable function. 3450 Best = CandidateSet.end(); 3451 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3452 Cand != CandidateSet.end(); ++Cand) { 3453 if (Cand->Viable) { 3454 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3455 Best = Cand; 3456 } 3457 } 3458 3459 // If we didn't find any viable functions, abort. 3460 if (Best == CandidateSet.end()) 3461 return OR_No_Viable_Function; 3462 3463 // Make sure that this function is better than every other viable 3464 // function. If not, we have an ambiguity. 3465 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3466 Cand != CandidateSet.end(); ++Cand) { 3467 if (Cand->Viable && 3468 Cand != Best && 3469 !isBetterOverloadCandidate(*Best, *Cand)) { 3470 Best = CandidateSet.end(); 3471 return OR_Ambiguous; 3472 } 3473 } 3474 3475 // Best is the best viable function. 3476 if (Best->Function && 3477 (Best->Function->isDeleted() || 3478 Best->Function->getAttr<UnavailableAttr>())) 3479 return OR_Deleted; 3480 3481 // If Best refers to a function that is either deleted (C++0x) or 3482 // unavailable (Clang extension) report an error. 3483 3484 return OR_Success; 3485} 3486 3487/// PrintOverloadCandidates - When overload resolution fails, prints 3488/// diagnostic messages containing the candidates in the candidate 3489/// set. If OnlyViable is true, only viable candidates will be printed. 3490void 3491Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3492 bool OnlyViable) 3493{ 3494 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3495 LastCand = CandidateSet.end(); 3496 for (; Cand != LastCand; ++Cand) { 3497 if (Cand->Viable || !OnlyViable) { 3498 if (Cand->Function) { 3499 if (Cand->Function->isDeleted() || 3500 Cand->Function->getAttr<UnavailableAttr>()) { 3501 // Deleted or "unavailable" function. 3502 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3503 << Cand->Function->isDeleted(); 3504 } else { 3505 // Normal function 3506 // FIXME: Give a better reason! 3507 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3508 } 3509 } else if (Cand->IsSurrogate) { 3510 // Desugar the type of the surrogate down to a function type, 3511 // retaining as many typedefs as possible while still showing 3512 // the function type (and, therefore, its parameter types). 3513 QualType FnType = Cand->Surrogate->getConversionType(); 3514 bool isLValueReference = false; 3515 bool isRValueReference = false; 3516 bool isPointer = false; 3517 if (const LValueReferenceType *FnTypeRef = 3518 FnType->getAsLValueReferenceType()) { 3519 FnType = FnTypeRef->getPointeeType(); 3520 isLValueReference = true; 3521 } else if (const RValueReferenceType *FnTypeRef = 3522 FnType->getAsRValueReferenceType()) { 3523 FnType = FnTypeRef->getPointeeType(); 3524 isRValueReference = true; 3525 } 3526 if (const PointerType *FnTypePtr = FnType->getAsPointerType()) { 3527 FnType = FnTypePtr->getPointeeType(); 3528 isPointer = true; 3529 } 3530 // Desugar down to a function type. 3531 FnType = QualType(FnType->getAsFunctionType(), 0); 3532 // Reconstruct the pointer/reference as appropriate. 3533 if (isPointer) FnType = Context.getPointerType(FnType); 3534 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3535 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3536 3537 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3538 << FnType; 3539 } else { 3540 // FIXME: We need to get the identifier in here 3541 // FIXME: Do we want the error message to point at the 3542 // operator? (built-ins won't have a location) 3543 QualType FnType 3544 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3545 Cand->BuiltinTypes.ParamTypes, 3546 Cand->Conversions.size(), 3547 false, 0); 3548 3549 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3550 } 3551 } 3552 } 3553} 3554 3555/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3556/// an overloaded function (C++ [over.over]), where @p From is an 3557/// expression with overloaded function type and @p ToType is the type 3558/// we're trying to resolve to. For example: 3559/// 3560/// @code 3561/// int f(double); 3562/// int f(int); 3563/// 3564/// int (*pfd)(double) = f; // selects f(double) 3565/// @endcode 3566/// 3567/// This routine returns the resulting FunctionDecl if it could be 3568/// resolved, and NULL otherwise. When @p Complain is true, this 3569/// routine will emit diagnostics if there is an error. 3570FunctionDecl * 3571Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3572 bool Complain) { 3573 QualType FunctionType = ToType; 3574 bool IsMember = false; 3575 if (const PointerType *ToTypePtr = ToType->getAsPointerType()) 3576 FunctionType = ToTypePtr->getPointeeType(); 3577 else if (const ReferenceType *ToTypeRef = ToType->getAsReferenceType()) 3578 FunctionType = ToTypeRef->getPointeeType(); 3579 else if (const MemberPointerType *MemTypePtr = 3580 ToType->getAsMemberPointerType()) { 3581 FunctionType = MemTypePtr->getPointeeType(); 3582 IsMember = true; 3583 } 3584 3585 // We only look at pointers or references to functions. 3586 if (!FunctionType->isFunctionType()) 3587 return 0; 3588 3589 // Find the actual overloaded function declaration. 3590 OverloadedFunctionDecl *Ovl = 0; 3591 3592 // C++ [over.over]p1: 3593 // [...] [Note: any redundant set of parentheses surrounding the 3594 // overloaded function name is ignored (5.1). ] 3595 Expr *OvlExpr = From->IgnoreParens(); 3596 3597 // C++ [over.over]p1: 3598 // [...] The overloaded function name can be preceded by the & 3599 // operator. 3600 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3601 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3602 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3603 } 3604 3605 // Try to dig out the overloaded function. 3606 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) 3607 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3608 3609 // If there's no overloaded function declaration, we're done. 3610 if (!Ovl) 3611 return 0; 3612 3613 // Look through all of the overloaded functions, searching for one 3614 // whose type matches exactly. 3615 // FIXME: When templates or using declarations come along, we'll actually 3616 // have to deal with duplicates, partial ordering, etc. For now, we 3617 // can just do a simple search. 3618 FunctionType = Context.getCanonicalType(FunctionType.getUnqualifiedType()); 3619 for (OverloadedFunctionDecl::function_iterator Fun = Ovl->function_begin(); 3620 Fun != Ovl->function_end(); ++Fun) { 3621 // C++ [over.over]p3: 3622 // Non-member functions and static member functions match 3623 // targets of type "pointer-to-function" or "reference-to-function." 3624 // Nonstatic member functions match targets of 3625 // type "pointer-to-member-function." 3626 // Note that according to DR 247, the containing class does not matter. 3627 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 3628 // Skip non-static functions when converting to pointer, and static 3629 // when converting to member pointer. 3630 if (Method->isStatic() == IsMember) 3631 continue; 3632 } else if (IsMember) 3633 continue; 3634 3635 if (FunctionType == Context.getCanonicalType((*Fun)->getType())) 3636 return *Fun; 3637 } 3638 3639 return 0; 3640} 3641 3642/// ResolveOverloadedCallFn - Given the call expression that calls Fn 3643/// (which eventually refers to the declaration Func) and the call 3644/// arguments Args/NumArgs, attempt to resolve the function call down 3645/// to a specific function. If overload resolution succeeds, returns 3646/// the function declaration produced by overload 3647/// resolution. Otherwise, emits diagnostics, deletes all of the 3648/// arguments and Fn, and returns NULL. 3649FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 3650 DeclarationName UnqualifiedName, 3651 SourceLocation LParenLoc, 3652 Expr **Args, unsigned NumArgs, 3653 SourceLocation *CommaLocs, 3654 SourceLocation RParenLoc, 3655 bool &ArgumentDependentLookup) { 3656 OverloadCandidateSet CandidateSet; 3657 3658 // Add the functions denoted by Callee to the set of candidate 3659 // functions. While we're doing so, track whether argument-dependent 3660 // lookup still applies, per: 3661 // 3662 // C++0x [basic.lookup.argdep]p3: 3663 // Let X be the lookup set produced by unqualified lookup (3.4.1) 3664 // and let Y be the lookup set produced by argument dependent 3665 // lookup (defined as follows). If X contains 3666 // 3667 // -- a declaration of a class member, or 3668 // 3669 // -- a block-scope function declaration that is not a 3670 // using-declaration, or 3671 // 3672 // -- a declaration that is neither a function or a function 3673 // template 3674 // 3675 // then Y is empty. 3676 if (OverloadedFunctionDecl *Ovl 3677 = dyn_cast_or_null<OverloadedFunctionDecl>(Callee)) { 3678 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 3679 FuncEnd = Ovl->function_end(); 3680 Func != FuncEnd; ++Func) { 3681 AddOverloadCandidate(*Func, Args, NumArgs, CandidateSet); 3682 3683 if ((*Func)->getDeclContext()->isRecord() || 3684 (*Func)->getDeclContext()->isFunctionOrMethod()) 3685 ArgumentDependentLookup = false; 3686 } 3687 } else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee)) { 3688 AddOverloadCandidate(Func, Args, NumArgs, CandidateSet); 3689 3690 if (Func->getDeclContext()->isRecord() || 3691 Func->getDeclContext()->isFunctionOrMethod()) 3692 ArgumentDependentLookup = false; 3693 } 3694 3695 if (Callee) 3696 UnqualifiedName = Callee->getDeclName(); 3697 3698 if (ArgumentDependentLookup) 3699 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 3700 CandidateSet); 3701 3702 OverloadCandidateSet::iterator Best; 3703 switch (BestViableFunction(CandidateSet, Best)) { 3704 case OR_Success: 3705 return Best->Function; 3706 3707 case OR_No_Viable_Function: 3708 Diag(Fn->getSourceRange().getBegin(), 3709 diag::err_ovl_no_viable_function_in_call) 3710 << UnqualifiedName << Fn->getSourceRange(); 3711 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3712 break; 3713 3714 case OR_Ambiguous: 3715 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 3716 << UnqualifiedName << Fn->getSourceRange(); 3717 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3718 break; 3719 3720 case OR_Deleted: 3721 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 3722 << Best->Function->isDeleted() 3723 << UnqualifiedName 3724 << Fn->getSourceRange(); 3725 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3726 break; 3727 } 3728 3729 // Overload resolution failed. Destroy all of the subexpressions and 3730 // return NULL. 3731 Fn->Destroy(Context); 3732 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 3733 Args[Arg]->Destroy(Context); 3734 return 0; 3735} 3736 3737/// \brief Create a unary operation that may resolve to an overloaded 3738/// operator. 3739/// 3740/// \param OpLoc The location of the operator itself (e.g., '*'). 3741/// 3742/// \param OpcIn The UnaryOperator::Opcode that describes this 3743/// operator. 3744/// 3745/// \param Functions The set of non-member functions that will be 3746/// considered by overload resolution. The caller needs to build this 3747/// set based on the context using, e.g., 3748/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 3749/// set should not contain any member functions; those will be added 3750/// by CreateOverloadedUnaryOp(). 3751/// 3752/// \param input The input argument. 3753Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 3754 unsigned OpcIn, 3755 FunctionSet &Functions, 3756 ExprArg input) { 3757 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 3758 Expr *Input = (Expr *)input.get(); 3759 3760 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 3761 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 3762 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3763 3764 Expr *Args[2] = { Input, 0 }; 3765 unsigned NumArgs = 1; 3766 3767 // For post-increment and post-decrement, add the implicit '0' as 3768 // the second argument, so that we know this is a post-increment or 3769 // post-decrement. 3770 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 3771 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 3772 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 3773 SourceLocation()); 3774 NumArgs = 2; 3775 } 3776 3777 if (Input->isTypeDependent()) { 3778 OverloadedFunctionDecl *Overloads 3779 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 3780 for (FunctionSet::iterator Func = Functions.begin(), 3781 FuncEnd = Functions.end(); 3782 Func != FuncEnd; ++Func) 3783 Overloads->addOverload(*Func); 3784 3785 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 3786 OpLoc, false, false); 3787 3788 input.release(); 3789 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 3790 &Args[0], NumArgs, 3791 Context.DependentTy, 3792 OpLoc)); 3793 } 3794 3795 // Build an empty overload set. 3796 OverloadCandidateSet CandidateSet; 3797 3798 // Add the candidates from the given function set. 3799 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 3800 3801 // Add operator candidates that are member functions. 3802 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 3803 3804 // Add builtin operator candidates. 3805 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 3806 3807 // Perform overload resolution. 3808 OverloadCandidateSet::iterator Best; 3809 switch (BestViableFunction(CandidateSet, Best)) { 3810 case OR_Success: { 3811 // We found a built-in operator or an overloaded operator. 3812 FunctionDecl *FnDecl = Best->Function; 3813 3814 if (FnDecl) { 3815 // We matched an overloaded operator. Build a call to that 3816 // operator. 3817 3818 // Convert the arguments. 3819 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 3820 if (PerformObjectArgumentInitialization(Input, Method)) 3821 return ExprError(); 3822 } else { 3823 // Convert the arguments. 3824 if (PerformCopyInitialization(Input, 3825 FnDecl->getParamDecl(0)->getType(), 3826 "passing")) 3827 return ExprError(); 3828 } 3829 3830 // Determine the result type 3831 QualType ResultTy 3832 = FnDecl->getType()->getAsFunctionType()->getResultType(); 3833 ResultTy = ResultTy.getNonReferenceType(); 3834 3835 // Build the actual expression node. 3836 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 3837 SourceLocation()); 3838 UsualUnaryConversions(FnExpr); 3839 3840 input.release(); 3841 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 3842 &Input, 1, ResultTy, 3843 OpLoc)); 3844 } else { 3845 // We matched a built-in operator. Convert the arguments, then 3846 // break out so that we will build the appropriate built-in 3847 // operator node. 3848 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 3849 Best->Conversions[0], "passing")) 3850 return ExprError(); 3851 3852 break; 3853 } 3854 } 3855 3856 case OR_No_Viable_Function: 3857 // No viable function; fall through to handling this as a 3858 // built-in operator, which will produce an error message for us. 3859 break; 3860 3861 case OR_Ambiguous: 3862 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 3863 << UnaryOperator::getOpcodeStr(Opc) 3864 << Input->getSourceRange(); 3865 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3866 return ExprError(); 3867 3868 case OR_Deleted: 3869 Diag(OpLoc, diag::err_ovl_deleted_oper) 3870 << Best->Function->isDeleted() 3871 << UnaryOperator::getOpcodeStr(Opc) 3872 << Input->getSourceRange(); 3873 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3874 return ExprError(); 3875 } 3876 3877 // Either we found no viable overloaded operator or we matched a 3878 // built-in operator. In either case, fall through to trying to 3879 // build a built-in operation. 3880 input.release(); 3881 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 3882} 3883 3884/// \brief Create a binary operation that may resolve to an overloaded 3885/// operator. 3886/// 3887/// \param OpLoc The location of the operator itself (e.g., '+'). 3888/// 3889/// \param OpcIn The BinaryOperator::Opcode that describes this 3890/// operator. 3891/// 3892/// \param Functions The set of non-member functions that will be 3893/// considered by overload resolution. The caller needs to build this 3894/// set based on the context using, e.g., 3895/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 3896/// set should not contain any member functions; those will be added 3897/// by CreateOverloadedBinOp(). 3898/// 3899/// \param LHS Left-hand argument. 3900/// \param RHS Right-hand argument. 3901Sema::OwningExprResult 3902Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 3903 unsigned OpcIn, 3904 FunctionSet &Functions, 3905 Expr *LHS, Expr *RHS) { 3906 Expr *Args[2] = { LHS, RHS }; 3907 3908 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 3909 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 3910 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3911 3912 // If either side is type-dependent, create an appropriate dependent 3913 // expression. 3914 if (LHS->isTypeDependent() || RHS->isTypeDependent()) { 3915 // .* cannot be overloaded. 3916 if (Opc == BinaryOperator::PtrMemD) 3917 return Owned(new (Context) BinaryOperator(LHS, RHS, Opc, 3918 Context.DependentTy, OpLoc)); 3919 3920 OverloadedFunctionDecl *Overloads 3921 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 3922 for (FunctionSet::iterator Func = Functions.begin(), 3923 FuncEnd = Functions.end(); 3924 Func != FuncEnd; ++Func) 3925 Overloads->addOverload(*Func); 3926 3927 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 3928 OpLoc, false, false); 3929 3930 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 3931 Args, 2, 3932 Context.DependentTy, 3933 OpLoc)); 3934 } 3935 3936 // If this is the .* operator, which is not overloadable, just 3937 // create a built-in binary operator. 3938 if (Opc == BinaryOperator::PtrMemD) 3939 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 3940 3941 // If this is one of the assignment operators, we only perform 3942 // overload resolution if the left-hand side is a class or 3943 // enumeration type (C++ [expr.ass]p3). 3944 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 3945 !LHS->getType()->isOverloadableType()) 3946 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 3947 3948 // Build an empty overload set. 3949 OverloadCandidateSet CandidateSet; 3950 3951 // Add the candidates from the given function set. 3952 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 3953 3954 // Add operator candidates that are member functions. 3955 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 3956 3957 // Add builtin operator candidates. 3958 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 3959 3960 // Perform overload resolution. 3961 OverloadCandidateSet::iterator Best; 3962 switch (BestViableFunction(CandidateSet, Best)) { 3963 case OR_Success: { 3964 // We found a built-in operator or an overloaded operator. 3965 FunctionDecl *FnDecl = Best->Function; 3966 3967 if (FnDecl) { 3968 // We matched an overloaded operator. Build a call to that 3969 // operator. 3970 3971 // Convert the arguments. 3972 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 3973 if (PerformObjectArgumentInitialization(LHS, Method) || 3974 PerformCopyInitialization(RHS, FnDecl->getParamDecl(0)->getType(), 3975 "passing")) 3976 return ExprError(); 3977 } else { 3978 // Convert the arguments. 3979 if (PerformCopyInitialization(LHS, FnDecl->getParamDecl(0)->getType(), 3980 "passing") || 3981 PerformCopyInitialization(RHS, FnDecl->getParamDecl(1)->getType(), 3982 "passing")) 3983 return ExprError(); 3984 } 3985 3986 // Determine the result type 3987 QualType ResultTy 3988 = FnDecl->getType()->getAsFunctionType()->getResultType(); 3989 ResultTy = ResultTy.getNonReferenceType(); 3990 3991 // Build the actual expression node. 3992 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 3993 SourceLocation()); 3994 UsualUnaryConversions(FnExpr); 3995 3996 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 3997 Args, 2, ResultTy, 3998 OpLoc)); 3999 } else { 4000 // We matched a built-in operator. Convert the arguments, then 4001 // break out so that we will build the appropriate built-in 4002 // operator node. 4003 if (PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0], 4004 Best->Conversions[0], "passing") || 4005 PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1], 4006 Best->Conversions[1], "passing")) 4007 return ExprError(); 4008 4009 break; 4010 } 4011 } 4012 4013 case OR_No_Viable_Function: 4014 // No viable function; fall through to handling this as a 4015 // built-in operator, which will produce an error message for us. 4016 break; 4017 4018 case OR_Ambiguous: 4019 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4020 << BinaryOperator::getOpcodeStr(Opc) 4021 << LHS->getSourceRange() << RHS->getSourceRange(); 4022 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4023 return ExprError(); 4024 4025 case OR_Deleted: 4026 Diag(OpLoc, diag::err_ovl_deleted_oper) 4027 << Best->Function->isDeleted() 4028 << BinaryOperator::getOpcodeStr(Opc) 4029 << LHS->getSourceRange() << RHS->getSourceRange(); 4030 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4031 return ExprError(); 4032 } 4033 4034 // Either we found no viable overloaded operator or we matched a 4035 // built-in operator. In either case, try to build a built-in 4036 // operation. 4037 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4038} 4039 4040/// BuildCallToMemberFunction - Build a call to a member 4041/// function. MemExpr is the expression that refers to the member 4042/// function (and includes the object parameter), Args/NumArgs are the 4043/// arguments to the function call (not including the object 4044/// parameter). The caller needs to validate that the member 4045/// expression refers to a member function or an overloaded member 4046/// function. 4047Sema::ExprResult 4048Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4049 SourceLocation LParenLoc, Expr **Args, 4050 unsigned NumArgs, SourceLocation *CommaLocs, 4051 SourceLocation RParenLoc) { 4052 // Dig out the member expression. This holds both the object 4053 // argument and the member function we're referring to. 4054 MemberExpr *MemExpr = 0; 4055 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4056 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4057 else 4058 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4059 assert(MemExpr && "Building member call without member expression"); 4060 4061 // Extract the object argument. 4062 Expr *ObjectArg = MemExpr->getBase(); 4063 4064 CXXMethodDecl *Method = 0; 4065 if (OverloadedFunctionDecl *Ovl 4066 = dyn_cast<OverloadedFunctionDecl>(MemExpr->getMemberDecl())) { 4067 // Add overload candidates 4068 OverloadCandidateSet CandidateSet; 4069 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4070 FuncEnd = Ovl->function_end(); 4071 Func != FuncEnd; ++Func) { 4072 assert(isa<CXXMethodDecl>(*Func) && "Function is not a method"); 4073 Method = cast<CXXMethodDecl>(*Func); 4074 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4075 /*SuppressUserConversions=*/false); 4076 } 4077 4078 OverloadCandidateSet::iterator Best; 4079 switch (BestViableFunction(CandidateSet, Best)) { 4080 case OR_Success: 4081 Method = cast<CXXMethodDecl>(Best->Function); 4082 break; 4083 4084 case OR_No_Viable_Function: 4085 Diag(MemExpr->getSourceRange().getBegin(), 4086 diag::err_ovl_no_viable_member_function_in_call) 4087 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4088 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4089 // FIXME: Leaking incoming expressions! 4090 return true; 4091 4092 case OR_Ambiguous: 4093 Diag(MemExpr->getSourceRange().getBegin(), 4094 diag::err_ovl_ambiguous_member_call) 4095 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4096 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4097 // FIXME: Leaking incoming expressions! 4098 return true; 4099 4100 case OR_Deleted: 4101 Diag(MemExpr->getSourceRange().getBegin(), 4102 diag::err_ovl_deleted_member_call) 4103 << Best->Function->isDeleted() 4104 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4105 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4106 // FIXME: Leaking incoming expressions! 4107 return true; 4108 } 4109 4110 FixOverloadedFunctionReference(MemExpr, Method); 4111 } else { 4112 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4113 } 4114 4115 assert(Method && "Member call to something that isn't a method?"); 4116 ExprOwningPtr<CXXMemberCallExpr> 4117 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4118 NumArgs, 4119 Method->getResultType().getNonReferenceType(), 4120 RParenLoc)); 4121 4122 // Convert the object argument (for a non-static member function call). 4123 if (!Method->isStatic() && 4124 PerformObjectArgumentInitialization(ObjectArg, Method)) 4125 return true; 4126 MemExpr->setBase(ObjectArg); 4127 4128 // Convert the rest of the arguments 4129 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4130 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4131 RParenLoc)) 4132 return true; 4133 4134 return CheckFunctionCall(Method, TheCall.take()).release(); 4135} 4136 4137/// BuildCallToObjectOfClassType - Build a call to an object of class 4138/// type (C++ [over.call.object]), which can end up invoking an 4139/// overloaded function call operator (@c operator()) or performing a 4140/// user-defined conversion on the object argument. 4141Sema::ExprResult 4142Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4143 SourceLocation LParenLoc, 4144 Expr **Args, unsigned NumArgs, 4145 SourceLocation *CommaLocs, 4146 SourceLocation RParenLoc) { 4147 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4148 const RecordType *Record = Object->getType()->getAsRecordType(); 4149 4150 // C++ [over.call.object]p1: 4151 // If the primary-expression E in the function call syntax 4152 // evaluates to a class object of type “cv T”, then the set of 4153 // candidate functions includes at least the function call 4154 // operators of T. The function call operators of T are obtained by 4155 // ordinary lookup of the name operator() in the context of 4156 // (E).operator(). 4157 OverloadCandidateSet CandidateSet; 4158 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4159 DeclContext::lookup_const_iterator Oper, OperEnd; 4160 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(Context, OpName); 4161 Oper != OperEnd; ++Oper) 4162 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4163 CandidateSet, /*SuppressUserConversions=*/false); 4164 4165 // C++ [over.call.object]p2: 4166 // In addition, for each conversion function declared in T of the 4167 // form 4168 // 4169 // operator conversion-type-id () cv-qualifier; 4170 // 4171 // where cv-qualifier is the same cv-qualification as, or a 4172 // greater cv-qualification than, cv, and where conversion-type-id 4173 // denotes the type "pointer to function of (P1,...,Pn) returning 4174 // R", or the type "reference to pointer to function of 4175 // (P1,...,Pn) returning R", or the type "reference to function 4176 // of (P1,...,Pn) returning R", a surrogate call function [...] 4177 // is also considered as a candidate function. Similarly, 4178 // surrogate call functions are added to the set of candidate 4179 // functions for each conversion function declared in an 4180 // accessible base class provided the function is not hidden 4181 // within T by another intervening declaration. 4182 // 4183 // FIXME: Look in base classes for more conversion operators! 4184 OverloadedFunctionDecl *Conversions 4185 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4186 for (OverloadedFunctionDecl::function_iterator 4187 Func = Conversions->function_begin(), 4188 FuncEnd = Conversions->function_end(); 4189 Func != FuncEnd; ++Func) { 4190 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 4191 4192 // Strip the reference type (if any) and then the pointer type (if 4193 // any) to get down to what might be a function type. 4194 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4195 if (const PointerType *ConvPtrType = ConvType->getAsPointerType()) 4196 ConvType = ConvPtrType->getPointeeType(); 4197 4198 if (const FunctionProtoType *Proto = ConvType->getAsFunctionProtoType()) 4199 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4200 } 4201 4202 // Perform overload resolution. 4203 OverloadCandidateSet::iterator Best; 4204 switch (BestViableFunction(CandidateSet, Best)) { 4205 case OR_Success: 4206 // Overload resolution succeeded; we'll build the appropriate call 4207 // below. 4208 break; 4209 4210 case OR_No_Viable_Function: 4211 Diag(Object->getSourceRange().getBegin(), 4212 diag::err_ovl_no_viable_object_call) 4213 << Object->getType() << Object->getSourceRange(); 4214 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4215 break; 4216 4217 case OR_Ambiguous: 4218 Diag(Object->getSourceRange().getBegin(), 4219 diag::err_ovl_ambiguous_object_call) 4220 << Object->getType() << Object->getSourceRange(); 4221 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4222 break; 4223 4224 case OR_Deleted: 4225 Diag(Object->getSourceRange().getBegin(), 4226 diag::err_ovl_deleted_object_call) 4227 << Best->Function->isDeleted() 4228 << Object->getType() << Object->getSourceRange(); 4229 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4230 break; 4231 } 4232 4233 if (Best == CandidateSet.end()) { 4234 // We had an error; delete all of the subexpressions and return 4235 // the error. 4236 Object->Destroy(Context); 4237 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4238 Args[ArgIdx]->Destroy(Context); 4239 return true; 4240 } 4241 4242 if (Best->Function == 0) { 4243 // Since there is no function declaration, this is one of the 4244 // surrogate candidates. Dig out the conversion function. 4245 CXXConversionDecl *Conv 4246 = cast<CXXConversionDecl>( 4247 Best->Conversions[0].UserDefined.ConversionFunction); 4248 4249 // We selected one of the surrogate functions that converts the 4250 // object parameter to a function pointer. Perform the conversion 4251 // on the object argument, then let ActOnCallExpr finish the job. 4252 // FIXME: Represent the user-defined conversion in the AST! 4253 ImpCastExprToType(Object, 4254 Conv->getConversionType().getNonReferenceType(), 4255 Conv->getConversionType()->isLValueReferenceType()); 4256 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4257 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4258 CommaLocs, RParenLoc).release(); 4259 } 4260 4261 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4262 // that calls this method, using Object for the implicit object 4263 // parameter and passing along the remaining arguments. 4264 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4265 const FunctionProtoType *Proto = Method->getType()->getAsFunctionProtoType(); 4266 4267 unsigned NumArgsInProto = Proto->getNumArgs(); 4268 unsigned NumArgsToCheck = NumArgs; 4269 4270 // Build the full argument list for the method call (the 4271 // implicit object parameter is placed at the beginning of the 4272 // list). 4273 Expr **MethodArgs; 4274 if (NumArgs < NumArgsInProto) { 4275 NumArgsToCheck = NumArgsInProto; 4276 MethodArgs = new Expr*[NumArgsInProto + 1]; 4277 } else { 4278 MethodArgs = new Expr*[NumArgs + 1]; 4279 } 4280 MethodArgs[0] = Object; 4281 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4282 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4283 4284 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4285 SourceLocation()); 4286 UsualUnaryConversions(NewFn); 4287 4288 // Once we've built TheCall, all of the expressions are properly 4289 // owned. 4290 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4291 ExprOwningPtr<CXXOperatorCallExpr> 4292 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4293 MethodArgs, NumArgs + 1, 4294 ResultTy, RParenLoc)); 4295 delete [] MethodArgs; 4296 4297 // We may have default arguments. If so, we need to allocate more 4298 // slots in the call for them. 4299 if (NumArgs < NumArgsInProto) 4300 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4301 else if (NumArgs > NumArgsInProto) 4302 NumArgsToCheck = NumArgsInProto; 4303 4304 bool IsError = false; 4305 4306 // Initialize the implicit object parameter. 4307 IsError |= PerformObjectArgumentInitialization(Object, Method); 4308 TheCall->setArg(0, Object); 4309 4310 4311 // Check the argument types. 4312 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4313 Expr *Arg; 4314 if (i < NumArgs) { 4315 Arg = Args[i]; 4316 4317 // Pass the argument. 4318 QualType ProtoArgType = Proto->getArgType(i); 4319 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4320 } else { 4321 Arg = new (Context) CXXDefaultArgExpr(Method->getParamDecl(i)); 4322 } 4323 4324 TheCall->setArg(i + 1, Arg); 4325 } 4326 4327 // If this is a variadic call, handle args passed through "...". 4328 if (Proto->isVariadic()) { 4329 // Promote the arguments (C99 6.5.2.2p7). 4330 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4331 Expr *Arg = Args[i]; 4332 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4333 TheCall->setArg(i + 1, Arg); 4334 } 4335 } 4336 4337 if (IsError) return true; 4338 4339 return CheckFunctionCall(Method, TheCall.take()).release(); 4340} 4341 4342/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4343/// (if one exists), where @c Base is an expression of class type and 4344/// @c Member is the name of the member we're trying to find. 4345Action::ExprResult 4346Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc, 4347 SourceLocation MemberLoc, 4348 IdentifierInfo &Member) { 4349 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4350 4351 // C++ [over.ref]p1: 4352 // 4353 // [...] An expression x->m is interpreted as (x.operator->())->m 4354 // for a class object x of type T if T::operator->() exists and if 4355 // the operator is selected as the best match function by the 4356 // overload resolution mechanism (13.3). 4357 // FIXME: look in base classes. 4358 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4359 OverloadCandidateSet CandidateSet; 4360 const RecordType *BaseRecord = Base->getType()->getAsRecordType(); 4361 4362 DeclContext::lookup_const_iterator Oper, OperEnd; 4363 for (llvm::tie(Oper, OperEnd) 4364 = BaseRecord->getDecl()->lookup(Context, OpName); 4365 Oper != OperEnd; ++Oper) 4366 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4367 /*SuppressUserConversions=*/false); 4368 4369 ExprOwningPtr<Expr> BasePtr(this, Base); 4370 4371 // Perform overload resolution. 4372 OverloadCandidateSet::iterator Best; 4373 switch (BestViableFunction(CandidateSet, Best)) { 4374 case OR_Success: 4375 // Overload resolution succeeded; we'll build the call below. 4376 break; 4377 4378 case OR_No_Viable_Function: 4379 if (CandidateSet.empty()) 4380 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4381 << BasePtr->getType() << BasePtr->getSourceRange(); 4382 else 4383 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4384 << "operator->" << BasePtr->getSourceRange(); 4385 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4386 return true; 4387 4388 case OR_Ambiguous: 4389 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4390 << "operator->" << BasePtr->getSourceRange(); 4391 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4392 return true; 4393 4394 case OR_Deleted: 4395 Diag(OpLoc, diag::err_ovl_deleted_oper) 4396 << Best->Function->isDeleted() 4397 << "operator->" << BasePtr->getSourceRange(); 4398 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4399 return true; 4400 } 4401 4402 // Convert the object parameter. 4403 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4404 if (PerformObjectArgumentInitialization(Base, Method)) 4405 return true; 4406 4407 // No concerns about early exits now. 4408 BasePtr.take(); 4409 4410 // Build the operator call. 4411 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 4412 SourceLocation()); 4413 UsualUnaryConversions(FnExpr); 4414 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 4415 Method->getResultType().getNonReferenceType(), 4416 OpLoc); 4417 return ActOnMemberReferenceExpr(S, ExprArg(*this, Base), OpLoc, tok::arrow, 4418 MemberLoc, Member, DeclPtrTy()).release(); 4419} 4420 4421/// FixOverloadedFunctionReference - E is an expression that refers to 4422/// a C++ overloaded function (possibly with some parentheses and 4423/// perhaps a '&' around it). We have resolved the overloaded function 4424/// to the function declaration Fn, so patch up the expression E to 4425/// refer (possibly indirectly) to Fn. 4426void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 4427 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4428 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 4429 E->setType(PE->getSubExpr()->getType()); 4430 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 4431 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 4432 "Can only take the address of an overloaded function"); 4433 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4434 if (Method->isStatic()) { 4435 // Do nothing: static member functions aren't any different 4436 // from non-member functions. 4437 } 4438 else if (QualifiedDeclRefExpr *DRE 4439 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 4440 // We have taken the address of a pointer to member 4441 // function. Perform the computation here so that we get the 4442 // appropriate pointer to member type. 4443 DRE->setDecl(Fn); 4444 DRE->setType(Fn->getType()); 4445 QualType ClassType 4446 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 4447 E->setType(Context.getMemberPointerType(Fn->getType(), 4448 ClassType.getTypePtr())); 4449 return; 4450 } 4451 } 4452 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 4453 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 4454 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 4455 assert(isa<OverloadedFunctionDecl>(DR->getDecl()) && 4456 "Expected overloaded function"); 4457 DR->setDecl(Fn); 4458 E->setType(Fn->getType()); 4459 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 4460 MemExpr->setMemberDecl(Fn); 4461 E->setType(Fn->getType()); 4462 } else { 4463 assert(false && "Invalid reference to overloaded function"); 4464 } 4465} 4466 4467} // end namespace clang 4468