SemaOverload.cpp revision 981892622a7fbb6d0e7eb7759ed7e8039e46bef9
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 FromType->isNullPtrType())) { 626 SCS.Second = ICK_Boolean_Conversion; 627 FromType = Context.BoolTy; 628 } 629 // Compatible conversions (Clang extension for C function overloading) 630 else if (!getLangOptions().CPlusPlus && 631 Context.typesAreCompatible(ToType, FromType)) { 632 SCS.Second = ICK_Compatible_Conversion; 633 } else { 634 // No second conversion required. 635 SCS.Second = ICK_Identity; 636 } 637 638 QualType CanonFrom; 639 QualType CanonTo; 640 // The third conversion can be a qualification conversion (C++ 4p1). 641 if (IsQualificationConversion(FromType, ToType)) { 642 SCS.Third = ICK_Qualification; 643 FromType = ToType; 644 CanonFrom = Context.getCanonicalType(FromType); 645 CanonTo = Context.getCanonicalType(ToType); 646 } else { 647 // No conversion required 648 SCS.Third = ICK_Identity; 649 650 // C++ [over.best.ics]p6: 651 // [...] Any difference in top-level cv-qualification is 652 // subsumed by the initialization itself and does not constitute 653 // a conversion. [...] 654 CanonFrom = Context.getCanonicalType(FromType); 655 CanonTo = Context.getCanonicalType(ToType); 656 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 657 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 658 FromType = ToType; 659 CanonFrom = CanonTo; 660 } 661 } 662 663 // If we have not converted the argument type to the parameter type, 664 // this is a bad conversion sequence. 665 if (CanonFrom != CanonTo) 666 return false; 667 668 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 669 return true; 670} 671 672/// IsIntegralPromotion - Determines whether the conversion from the 673/// expression From (whose potentially-adjusted type is FromType) to 674/// ToType is an integral promotion (C++ 4.5). If so, returns true and 675/// sets PromotedType to the promoted type. 676bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) 677{ 678 const BuiltinType *To = ToType->getAsBuiltinType(); 679 // All integers are built-in. 680 if (!To) { 681 return false; 682 } 683 684 // An rvalue of type char, signed char, unsigned char, short int, or 685 // unsigned short int can be converted to an rvalue of type int if 686 // int can represent all the values of the source type; otherwise, 687 // the source rvalue can be converted to an rvalue of type unsigned 688 // int (C++ 4.5p1). 689 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 690 if (// We can promote any signed, promotable integer type to an int 691 (FromType->isSignedIntegerType() || 692 // We can promote any unsigned integer type whose size is 693 // less than int to an int. 694 (!FromType->isSignedIntegerType() && 695 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 696 return To->getKind() == BuiltinType::Int; 697 } 698 699 return To->getKind() == BuiltinType::UInt; 700 } 701 702 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 703 // can be converted to an rvalue of the first of the following types 704 // that can represent all the values of its underlying type: int, 705 // unsigned int, long, or unsigned long (C++ 4.5p2). 706 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 707 && ToType->isIntegerType()) { 708 // Determine whether the type we're converting from is signed or 709 // unsigned. 710 bool FromIsSigned; 711 uint64_t FromSize = Context.getTypeSize(FromType); 712 if (const EnumType *FromEnumType = FromType->getAsEnumType()) { 713 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 714 FromIsSigned = UnderlyingType->isSignedIntegerType(); 715 } else { 716 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 717 FromIsSigned = true; 718 } 719 720 // The types we'll try to promote to, in the appropriate 721 // order. Try each of these types. 722 QualType PromoteTypes[6] = { 723 Context.IntTy, Context.UnsignedIntTy, 724 Context.LongTy, Context.UnsignedLongTy , 725 Context.LongLongTy, Context.UnsignedLongLongTy 726 }; 727 for (int Idx = 0; Idx < 6; ++Idx) { 728 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 729 if (FromSize < ToSize || 730 (FromSize == ToSize && 731 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 732 // We found the type that we can promote to. If this is the 733 // type we wanted, we have a promotion. Otherwise, no 734 // promotion. 735 return Context.getCanonicalType(ToType).getUnqualifiedType() 736 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 737 } 738 } 739 } 740 741 // An rvalue for an integral bit-field (9.6) can be converted to an 742 // rvalue of type int if int can represent all the values of the 743 // bit-field; otherwise, it can be converted to unsigned int if 744 // unsigned int can represent all the values of the bit-field. If 745 // the bit-field is larger yet, no integral promotion applies to 746 // it. If the bit-field has an enumerated type, it is treated as any 747 // other value of that type for promotion purposes (C++ 4.5p3). 748 // FIXME: We should delay checking of bit-fields until we actually perform the 749 // conversion. 750 using llvm::APSInt; 751 if (From) 752 if (FieldDecl *MemberDecl = From->getBitField()) { 753 APSInt BitWidth; 754 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 755 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 756 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 757 ToSize = Context.getTypeSize(ToType); 758 759 // Are we promoting to an int from a bitfield that fits in an int? 760 if (BitWidth < ToSize || 761 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 762 return To->getKind() == BuiltinType::Int; 763 } 764 765 // Are we promoting to an unsigned int from an unsigned bitfield 766 // that fits into an unsigned int? 767 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 768 return To->getKind() == BuiltinType::UInt; 769 } 770 771 return false; 772 } 773 } 774 775 // An rvalue of type bool can be converted to an rvalue of type int, 776 // with false becoming zero and true becoming one (C++ 4.5p4). 777 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 778 return true; 779 } 780 781 return false; 782} 783 784/// IsFloatingPointPromotion - Determines whether the conversion from 785/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 786/// returns true and sets PromotedType to the promoted type. 787bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) 788{ 789 /// An rvalue of type float can be converted to an rvalue of type 790 /// double. (C++ 4.6p1). 791 if (const BuiltinType *FromBuiltin = FromType->getAsBuiltinType()) 792 if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType()) { 793 if (FromBuiltin->getKind() == BuiltinType::Float && 794 ToBuiltin->getKind() == BuiltinType::Double) 795 return true; 796 797 // C99 6.3.1.5p1: 798 // When a float is promoted to double or long double, or a 799 // double is promoted to long double [...]. 800 if (!getLangOptions().CPlusPlus && 801 (FromBuiltin->getKind() == BuiltinType::Float || 802 FromBuiltin->getKind() == BuiltinType::Double) && 803 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 804 return true; 805 } 806 807 return false; 808} 809 810/// \brief Determine if a conversion is a complex promotion. 811/// 812/// A complex promotion is defined as a complex -> complex conversion 813/// where the conversion between the underlying real types is a 814/// floating-point or integral promotion. 815bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 816 const ComplexType *FromComplex = FromType->getAsComplexType(); 817 if (!FromComplex) 818 return false; 819 820 const ComplexType *ToComplex = ToType->getAsComplexType(); 821 if (!ToComplex) 822 return false; 823 824 return IsFloatingPointPromotion(FromComplex->getElementType(), 825 ToComplex->getElementType()) || 826 IsIntegralPromotion(0, FromComplex->getElementType(), 827 ToComplex->getElementType()); 828} 829 830/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 831/// the pointer type FromPtr to a pointer to type ToPointee, with the 832/// same type qualifiers as FromPtr has on its pointee type. ToType, 833/// if non-empty, will be a pointer to ToType that may or may not have 834/// the right set of qualifiers on its pointee. 835static QualType 836BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 837 QualType ToPointee, QualType ToType, 838 ASTContext &Context) { 839 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 840 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 841 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 842 843 // Exact qualifier match -> return the pointer type we're converting to. 844 if (CanonToPointee.getCVRQualifiers() == Quals) { 845 // ToType is exactly what we need. Return it. 846 if (ToType.getTypePtr()) 847 return ToType; 848 849 // Build a pointer to ToPointee. It has the right qualifiers 850 // already. 851 return Context.getPointerType(ToPointee); 852 } 853 854 // Just build a canonical type that has the right qualifiers. 855 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 856} 857 858/// IsPointerConversion - Determines whether the conversion of the 859/// expression From, which has the (possibly adjusted) type FromType, 860/// can be converted to the type ToType via a pointer conversion (C++ 861/// 4.10). If so, returns true and places the converted type (that 862/// might differ from ToType in its cv-qualifiers at some level) into 863/// ConvertedType. 864/// 865/// This routine also supports conversions to and from block pointers 866/// and conversions with Objective-C's 'id', 'id<protocols...>', and 867/// pointers to interfaces. FIXME: Once we've determined the 868/// appropriate overloading rules for Objective-C, we may want to 869/// split the Objective-C checks into a different routine; however, 870/// GCC seems to consider all of these conversions to be pointer 871/// conversions, so for now they live here. IncompatibleObjC will be 872/// set if the conversion is an allowed Objective-C conversion that 873/// should result in a warning. 874bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 875 QualType& ConvertedType, 876 bool &IncompatibleObjC) 877{ 878 IncompatibleObjC = false; 879 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 880 return true; 881 882 // Conversion from a null pointer constant to any Objective-C pointer type. 883 if (Context.isObjCObjectPointerType(ToType) && 884 From->isNullPointerConstant(Context)) { 885 ConvertedType = ToType; 886 return true; 887 } 888 889 // Blocks: Block pointers can be converted to void*. 890 if (FromType->isBlockPointerType() && ToType->isPointerType() && 891 ToType->getAsPointerType()->getPointeeType()->isVoidType()) { 892 ConvertedType = ToType; 893 return true; 894 } 895 // Blocks: A null pointer constant can be converted to a block 896 // pointer type. 897 if (ToType->isBlockPointerType() && From->isNullPointerConstant(Context)) { 898 ConvertedType = ToType; 899 return true; 900 } 901 902 // If the left-hand-side is nullptr_t, the right side can be a null 903 // pointer constant. 904 if (ToType->isNullPtrType() && From->isNullPointerConstant(Context)) { 905 ConvertedType = ToType; 906 return true; 907 } 908 909 const PointerType* ToTypePtr = ToType->getAsPointerType(); 910 if (!ToTypePtr) 911 return false; 912 913 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 914 if (From->isNullPointerConstant(Context)) { 915 ConvertedType = ToType; 916 return true; 917 } 918 919 // Beyond this point, both types need to be pointers. 920 const PointerType *FromTypePtr = FromType->getAsPointerType(); 921 if (!FromTypePtr) 922 return false; 923 924 QualType FromPointeeType = FromTypePtr->getPointeeType(); 925 QualType ToPointeeType = ToTypePtr->getPointeeType(); 926 927 // An rvalue of type "pointer to cv T," where T is an object type, 928 // can be converted to an rvalue of type "pointer to cv void" (C++ 929 // 4.10p2). 930 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 931 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 932 ToPointeeType, 933 ToType, Context); 934 return true; 935 } 936 937 // When we're overloading in C, we allow a special kind of pointer 938 // conversion for compatible-but-not-identical pointee types. 939 if (!getLangOptions().CPlusPlus && 940 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 941 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 942 ToPointeeType, 943 ToType, Context); 944 return true; 945 } 946 947 // C++ [conv.ptr]p3: 948 // 949 // An rvalue of type "pointer to cv D," where D is a class type, 950 // can be converted to an rvalue of type "pointer to cv B," where 951 // B is a base class (clause 10) of D. If B is an inaccessible 952 // (clause 11) or ambiguous (10.2) base class of D, a program that 953 // necessitates this conversion is ill-formed. The result of the 954 // conversion is a pointer to the base class sub-object of the 955 // derived class object. The null pointer value is converted to 956 // the null pointer value of the destination type. 957 // 958 // Note that we do not check for ambiguity or inaccessibility 959 // here. That is handled by CheckPointerConversion. 960 if (getLangOptions().CPlusPlus && 961 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 962 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 963 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 964 ToPointeeType, 965 ToType, Context); 966 return true; 967 } 968 969 return false; 970} 971 972/// isObjCPointerConversion - Determines whether this is an 973/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 974/// with the same arguments and return values. 975bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 976 QualType& ConvertedType, 977 bool &IncompatibleObjC) { 978 if (!getLangOptions().ObjC1) 979 return false; 980 981 // Conversions with Objective-C's id<...>. 982 if ((FromType->isObjCQualifiedIdType() || ToType->isObjCQualifiedIdType()) && 983 ObjCQualifiedIdTypesAreCompatible(ToType, FromType, /*compare=*/false)) { 984 ConvertedType = ToType; 985 return true; 986 } 987 988 // Beyond this point, both types need to be pointers or block pointers. 989 QualType ToPointeeType; 990 const PointerType* ToTypePtr = ToType->getAsPointerType(); 991 if (ToTypePtr) 992 ToPointeeType = ToTypePtr->getPointeeType(); 993 else if (const BlockPointerType *ToBlockPtr = ToType->getAsBlockPointerType()) 994 ToPointeeType = ToBlockPtr->getPointeeType(); 995 else 996 return false; 997 998 QualType FromPointeeType; 999 const PointerType *FromTypePtr = FromType->getAsPointerType(); 1000 if (FromTypePtr) 1001 FromPointeeType = FromTypePtr->getPointeeType(); 1002 else if (const BlockPointerType *FromBlockPtr 1003 = FromType->getAsBlockPointerType()) 1004 FromPointeeType = FromBlockPtr->getPointeeType(); 1005 else 1006 return false; 1007 1008 // Objective C++: We're able to convert from a pointer to an 1009 // interface to a pointer to a different interface. 1010 const ObjCInterfaceType* FromIface = FromPointeeType->getAsObjCInterfaceType(); 1011 const ObjCInterfaceType* ToIface = ToPointeeType->getAsObjCInterfaceType(); 1012 if (FromIface && ToIface && 1013 Context.canAssignObjCInterfaces(ToIface, FromIface)) { 1014 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1015 ToPointeeType, 1016 ToType, Context); 1017 return true; 1018 } 1019 1020 if (FromIface && ToIface && 1021 Context.canAssignObjCInterfaces(FromIface, ToIface)) { 1022 // Okay: this is some kind of implicit downcast of Objective-C 1023 // interfaces, which is permitted. However, we're going to 1024 // complain about it. 1025 IncompatibleObjC = true; 1026 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1027 ToPointeeType, 1028 ToType, Context); 1029 return true; 1030 } 1031 1032 // Objective C++: We're able to convert between "id" and a pointer 1033 // to any interface (in both directions). 1034 if ((FromIface && Context.isObjCIdStructType(ToPointeeType)) 1035 || (ToIface && Context.isObjCIdStructType(FromPointeeType))) { 1036 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1037 ToPointeeType, 1038 ToType, Context); 1039 return true; 1040 } 1041 1042 // Objective C++: Allow conversions between the Objective-C "id" and 1043 // "Class", in either direction. 1044 if ((Context.isObjCIdStructType(FromPointeeType) && 1045 Context.isObjCClassStructType(ToPointeeType)) || 1046 (Context.isObjCClassStructType(FromPointeeType) && 1047 Context.isObjCIdStructType(ToPointeeType))) { 1048 ConvertedType = ToType; 1049 return true; 1050 } 1051 1052 // If we have pointers to pointers, recursively check whether this 1053 // is an Objective-C conversion. 1054 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1055 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1056 IncompatibleObjC)) { 1057 // We always complain about this conversion. 1058 IncompatibleObjC = true; 1059 ConvertedType = ToType; 1060 return true; 1061 } 1062 1063 // If we have pointers to functions or blocks, check whether the only 1064 // differences in the argument and result types are in Objective-C 1065 // pointer conversions. If so, we permit the conversion (but 1066 // complain about it). 1067 const FunctionProtoType *FromFunctionType 1068 = FromPointeeType->getAsFunctionProtoType(); 1069 const FunctionProtoType *ToFunctionType 1070 = ToPointeeType->getAsFunctionProtoType(); 1071 if (FromFunctionType && ToFunctionType) { 1072 // If the function types are exactly the same, this isn't an 1073 // Objective-C pointer conversion. 1074 if (Context.getCanonicalType(FromPointeeType) 1075 == Context.getCanonicalType(ToPointeeType)) 1076 return false; 1077 1078 // Perform the quick checks that will tell us whether these 1079 // function types are obviously different. 1080 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1081 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1082 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1083 return false; 1084 1085 bool HasObjCConversion = false; 1086 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1087 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1088 // Okay, the types match exactly. Nothing to do. 1089 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1090 ToFunctionType->getResultType(), 1091 ConvertedType, IncompatibleObjC)) { 1092 // Okay, we have an Objective-C pointer conversion. 1093 HasObjCConversion = true; 1094 } else { 1095 // Function types are too different. Abort. 1096 return false; 1097 } 1098 1099 // Check argument types. 1100 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1101 ArgIdx != NumArgs; ++ArgIdx) { 1102 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1103 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1104 if (Context.getCanonicalType(FromArgType) 1105 == Context.getCanonicalType(ToArgType)) { 1106 // Okay, the types match exactly. Nothing to do. 1107 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1108 ConvertedType, IncompatibleObjC)) { 1109 // Okay, we have an Objective-C pointer conversion. 1110 HasObjCConversion = true; 1111 } else { 1112 // Argument types are too different. Abort. 1113 return false; 1114 } 1115 } 1116 1117 if (HasObjCConversion) { 1118 // We had an Objective-C conversion. Allow this pointer 1119 // conversion, but complain about it. 1120 ConvertedType = ToType; 1121 IncompatibleObjC = true; 1122 return true; 1123 } 1124 } 1125 1126 return false; 1127} 1128 1129/// CheckPointerConversion - Check the pointer conversion from the 1130/// expression From to the type ToType. This routine checks for 1131/// ambiguous (FIXME: or inaccessible) derived-to-base pointer 1132/// conversions for which IsPointerConversion has already returned 1133/// true. It returns true and produces a diagnostic if there was an 1134/// error, or returns false otherwise. 1135bool Sema::CheckPointerConversion(Expr *From, QualType ToType) { 1136 QualType FromType = From->getType(); 1137 1138 if (const PointerType *FromPtrType = FromType->getAsPointerType()) 1139 if (const PointerType *ToPtrType = ToType->getAsPointerType()) { 1140 QualType FromPointeeType = FromPtrType->getPointeeType(), 1141 ToPointeeType = ToPtrType->getPointeeType(); 1142 1143 // Objective-C++ conversions are always okay. 1144 // FIXME: We should have a different class of conversions for the 1145 // Objective-C++ implicit conversions. 1146 if (Context.isObjCIdStructType(FromPointeeType) || 1147 Context.isObjCIdStructType(ToPointeeType) || 1148 Context.isObjCClassStructType(FromPointeeType) || 1149 Context.isObjCClassStructType(ToPointeeType)) 1150 return false; 1151 1152 if (FromPointeeType->isRecordType() && 1153 ToPointeeType->isRecordType()) { 1154 // We must have a derived-to-base conversion. Check an 1155 // ambiguous or inaccessible conversion. 1156 return CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1157 From->getExprLoc(), 1158 From->getSourceRange()); 1159 } 1160 } 1161 1162 return false; 1163} 1164 1165/// IsMemberPointerConversion - Determines whether the conversion of the 1166/// expression From, which has the (possibly adjusted) type FromType, can be 1167/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1168/// If so, returns true and places the converted type (that might differ from 1169/// ToType in its cv-qualifiers at some level) into ConvertedType. 1170bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1171 QualType ToType, QualType &ConvertedType) 1172{ 1173 const MemberPointerType *ToTypePtr = ToType->getAsMemberPointerType(); 1174 if (!ToTypePtr) 1175 return false; 1176 1177 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1178 if (From->isNullPointerConstant(Context)) { 1179 ConvertedType = ToType; 1180 return true; 1181 } 1182 1183 // Otherwise, both types have to be member pointers. 1184 const MemberPointerType *FromTypePtr = FromType->getAsMemberPointerType(); 1185 if (!FromTypePtr) 1186 return false; 1187 1188 // A pointer to member of B can be converted to a pointer to member of D, 1189 // where D is derived from B (C++ 4.11p2). 1190 QualType FromClass(FromTypePtr->getClass(), 0); 1191 QualType ToClass(ToTypePtr->getClass(), 0); 1192 // FIXME: What happens when these are dependent? Is this function even called? 1193 1194 if (IsDerivedFrom(ToClass, FromClass)) { 1195 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1196 ToClass.getTypePtr()); 1197 return true; 1198 } 1199 1200 return false; 1201} 1202 1203/// CheckMemberPointerConversion - Check the member pointer conversion from the 1204/// expression From to the type ToType. This routine checks for ambiguous or 1205/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1206/// for which IsMemberPointerConversion has already returned true. It returns 1207/// true and produces a diagnostic if there was an error, or returns false 1208/// otherwise. 1209bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType) { 1210 QualType FromType = From->getType(); 1211 const MemberPointerType *FromPtrType = FromType->getAsMemberPointerType(); 1212 if (!FromPtrType) 1213 return false; 1214 1215 const MemberPointerType *ToPtrType = ToType->getAsMemberPointerType(); 1216 assert(ToPtrType && "No member pointer cast has a target type " 1217 "that is not a member pointer."); 1218 1219 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1220 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1221 1222 // FIXME: What about dependent types? 1223 assert(FromClass->isRecordType() && "Pointer into non-class."); 1224 assert(ToClass->isRecordType() && "Pointer into non-class."); 1225 1226 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1227 /*DetectVirtual=*/true); 1228 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1229 assert(DerivationOkay && 1230 "Should not have been called if derivation isn't OK."); 1231 (void)DerivationOkay; 1232 1233 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1234 getUnqualifiedType())) { 1235 // Derivation is ambiguous. Redo the check to find the exact paths. 1236 Paths.clear(); 1237 Paths.setRecordingPaths(true); 1238 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1239 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1240 (void)StillOkay; 1241 1242 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1243 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1244 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1245 return true; 1246 } 1247 1248 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1249 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1250 << FromClass << ToClass << QualType(VBase, 0) 1251 << From->getSourceRange(); 1252 return true; 1253 } 1254 1255 return false; 1256} 1257 1258/// IsQualificationConversion - Determines whether the conversion from 1259/// an rvalue of type FromType to ToType is a qualification conversion 1260/// (C++ 4.4). 1261bool 1262Sema::IsQualificationConversion(QualType FromType, QualType ToType) 1263{ 1264 FromType = Context.getCanonicalType(FromType); 1265 ToType = Context.getCanonicalType(ToType); 1266 1267 // If FromType and ToType are the same type, this is not a 1268 // qualification conversion. 1269 if (FromType == ToType) 1270 return false; 1271 1272 // (C++ 4.4p4): 1273 // A conversion can add cv-qualifiers at levels other than the first 1274 // in multi-level pointers, subject to the following rules: [...] 1275 bool PreviousToQualsIncludeConst = true; 1276 bool UnwrappedAnyPointer = false; 1277 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1278 // Within each iteration of the loop, we check the qualifiers to 1279 // determine if this still looks like a qualification 1280 // conversion. Then, if all is well, we unwrap one more level of 1281 // pointers or pointers-to-members and do it all again 1282 // until there are no more pointers or pointers-to-members left to 1283 // unwrap. 1284 UnwrappedAnyPointer = true; 1285 1286 // -- for every j > 0, if const is in cv 1,j then const is in cv 1287 // 2,j, and similarly for volatile. 1288 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1289 return false; 1290 1291 // -- if the cv 1,j and cv 2,j are different, then const is in 1292 // every cv for 0 < k < j. 1293 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1294 && !PreviousToQualsIncludeConst) 1295 return false; 1296 1297 // Keep track of whether all prior cv-qualifiers in the "to" type 1298 // include const. 1299 PreviousToQualsIncludeConst 1300 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1301 } 1302 1303 // We are left with FromType and ToType being the pointee types 1304 // after unwrapping the original FromType and ToType the same number 1305 // of types. If we unwrapped any pointers, and if FromType and 1306 // ToType have the same unqualified type (since we checked 1307 // qualifiers above), then this is a qualification conversion. 1308 return UnwrappedAnyPointer && 1309 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1310} 1311 1312/// Determines whether there is a user-defined conversion sequence 1313/// (C++ [over.ics.user]) that converts expression From to the type 1314/// ToType. If such a conversion exists, User will contain the 1315/// user-defined conversion sequence that performs such a conversion 1316/// and this routine will return true. Otherwise, this routine returns 1317/// false and User is unspecified. 1318/// 1319/// \param AllowConversionFunctions true if the conversion should 1320/// consider conversion functions at all. If false, only constructors 1321/// will be considered. 1322/// 1323/// \param AllowExplicit true if the conversion should consider C++0x 1324/// "explicit" conversion functions as well as non-explicit conversion 1325/// functions (C++0x [class.conv.fct]p2). 1326/// 1327/// \param ForceRValue true if the expression should be treated as an rvalue 1328/// for overload resolution. 1329bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1330 UserDefinedConversionSequence& User, 1331 bool AllowConversionFunctions, 1332 bool AllowExplicit, bool ForceRValue) 1333{ 1334 OverloadCandidateSet CandidateSet; 1335 if (const RecordType *ToRecordType = ToType->getAsRecordType()) { 1336 if (CXXRecordDecl *ToRecordDecl 1337 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1338 // C++ [over.match.ctor]p1: 1339 // When objects of class type are direct-initialized (8.5), or 1340 // copy-initialized from an expression of the same or a 1341 // derived class type (8.5), overload resolution selects the 1342 // constructor. [...] For copy-initialization, the candidate 1343 // functions are all the converting constructors (12.3.1) of 1344 // that class. The argument list is the expression-list within 1345 // the parentheses of the initializer. 1346 DeclarationName ConstructorName 1347 = Context.DeclarationNames.getCXXConstructorName( 1348 Context.getCanonicalType(ToType).getUnqualifiedType()); 1349 DeclContext::lookup_iterator Con, ConEnd; 1350 for (llvm::tie(Con, ConEnd) 1351 = ToRecordDecl->lookup(Context, ConstructorName); 1352 Con != ConEnd; ++Con) { 1353 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 1354 if (Constructor->isConvertingConstructor()) 1355 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1356 /*SuppressUserConversions=*/true, ForceRValue); 1357 } 1358 } 1359 } 1360 1361 if (!AllowConversionFunctions) { 1362 // Don't allow any conversion functions to enter the overload set. 1363 } else if (const RecordType *FromRecordType 1364 = From->getType()->getAsRecordType()) { 1365 if (CXXRecordDecl *FromRecordDecl 1366 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1367 // Add all of the conversion functions as candidates. 1368 // FIXME: Look for conversions in base classes! 1369 OverloadedFunctionDecl *Conversions 1370 = FromRecordDecl->getConversionFunctions(); 1371 for (OverloadedFunctionDecl::function_iterator Func 1372 = Conversions->function_begin(); 1373 Func != Conversions->function_end(); ++Func) { 1374 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 1375 if (AllowExplicit || !Conv->isExplicit()) 1376 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1377 } 1378 } 1379 } 1380 1381 OverloadCandidateSet::iterator Best; 1382 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1383 case OR_Success: 1384 // Record the standard conversion we used and the conversion function. 1385 if (CXXConstructorDecl *Constructor 1386 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1387 // C++ [over.ics.user]p1: 1388 // If the user-defined conversion is specified by a 1389 // constructor (12.3.1), the initial standard conversion 1390 // sequence converts the source type to the type required by 1391 // the argument of the constructor. 1392 // 1393 // FIXME: What about ellipsis conversions? 1394 QualType ThisType = Constructor->getThisType(Context); 1395 User.Before = Best->Conversions[0].Standard; 1396 User.ConversionFunction = Constructor; 1397 User.After.setAsIdentityConversion(); 1398 User.After.FromTypePtr 1399 = ThisType->getAsPointerType()->getPointeeType().getAsOpaquePtr(); 1400 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1401 return true; 1402 } else if (CXXConversionDecl *Conversion 1403 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1404 // C++ [over.ics.user]p1: 1405 // 1406 // [...] If the user-defined conversion is specified by a 1407 // conversion function (12.3.2), the initial standard 1408 // conversion sequence converts the source type to the 1409 // implicit object parameter of the conversion function. 1410 User.Before = Best->Conversions[0].Standard; 1411 User.ConversionFunction = Conversion; 1412 1413 // C++ [over.ics.user]p2: 1414 // The second standard conversion sequence converts the 1415 // result of the user-defined conversion to the target type 1416 // for the sequence. Since an implicit conversion sequence 1417 // is an initialization, the special rules for 1418 // initialization by user-defined conversion apply when 1419 // selecting the best user-defined conversion for a 1420 // user-defined conversion sequence (see 13.3.3 and 1421 // 13.3.3.1). 1422 User.After = Best->FinalConversion; 1423 return true; 1424 } else { 1425 assert(false && "Not a constructor or conversion function?"); 1426 return false; 1427 } 1428 1429 case OR_No_Viable_Function: 1430 case OR_Deleted: 1431 // No conversion here! We're done. 1432 return false; 1433 1434 case OR_Ambiguous: 1435 // FIXME: See C++ [over.best.ics]p10 for the handling of 1436 // ambiguous conversion sequences. 1437 return false; 1438 } 1439 1440 return false; 1441} 1442 1443/// CompareImplicitConversionSequences - Compare two implicit 1444/// conversion sequences to determine whether one is better than the 1445/// other or if they are indistinguishable (C++ 13.3.3.2). 1446ImplicitConversionSequence::CompareKind 1447Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1448 const ImplicitConversionSequence& ICS2) 1449{ 1450 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1451 // conversion sequences (as defined in 13.3.3.1) 1452 // -- a standard conversion sequence (13.3.3.1.1) is a better 1453 // conversion sequence than a user-defined conversion sequence or 1454 // an ellipsis conversion sequence, and 1455 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1456 // conversion sequence than an ellipsis conversion sequence 1457 // (13.3.3.1.3). 1458 // 1459 if (ICS1.ConversionKind < ICS2.ConversionKind) 1460 return ImplicitConversionSequence::Better; 1461 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1462 return ImplicitConversionSequence::Worse; 1463 1464 // Two implicit conversion sequences of the same form are 1465 // indistinguishable conversion sequences unless one of the 1466 // following rules apply: (C++ 13.3.3.2p3): 1467 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1468 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1469 else if (ICS1.ConversionKind == 1470 ImplicitConversionSequence::UserDefinedConversion) { 1471 // User-defined conversion sequence U1 is a better conversion 1472 // sequence than another user-defined conversion sequence U2 if 1473 // they contain the same user-defined conversion function or 1474 // constructor and if the second standard conversion sequence of 1475 // U1 is better than the second standard conversion sequence of 1476 // U2 (C++ 13.3.3.2p3). 1477 if (ICS1.UserDefined.ConversionFunction == 1478 ICS2.UserDefined.ConversionFunction) 1479 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1480 ICS2.UserDefined.After); 1481 } 1482 1483 return ImplicitConversionSequence::Indistinguishable; 1484} 1485 1486/// CompareStandardConversionSequences - Compare two standard 1487/// conversion sequences to determine whether one is better than the 1488/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1489ImplicitConversionSequence::CompareKind 1490Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1491 const StandardConversionSequence& SCS2) 1492{ 1493 // Standard conversion sequence S1 is a better conversion sequence 1494 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1495 1496 // -- S1 is a proper subsequence of S2 (comparing the conversion 1497 // sequences in the canonical form defined by 13.3.3.1.1, 1498 // excluding any Lvalue Transformation; the identity conversion 1499 // sequence is considered to be a subsequence of any 1500 // non-identity conversion sequence) or, if not that, 1501 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1502 // Neither is a proper subsequence of the other. Do nothing. 1503 ; 1504 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1505 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1506 (SCS1.Second == ICK_Identity && 1507 SCS1.Third == ICK_Identity)) 1508 // SCS1 is a proper subsequence of SCS2. 1509 return ImplicitConversionSequence::Better; 1510 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1511 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1512 (SCS2.Second == ICK_Identity && 1513 SCS2.Third == ICK_Identity)) 1514 // SCS2 is a proper subsequence of SCS1. 1515 return ImplicitConversionSequence::Worse; 1516 1517 // -- the rank of S1 is better than the rank of S2 (by the rules 1518 // defined below), or, if not that, 1519 ImplicitConversionRank Rank1 = SCS1.getRank(); 1520 ImplicitConversionRank Rank2 = SCS2.getRank(); 1521 if (Rank1 < Rank2) 1522 return ImplicitConversionSequence::Better; 1523 else if (Rank2 < Rank1) 1524 return ImplicitConversionSequence::Worse; 1525 1526 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1527 // are indistinguishable unless one of the following rules 1528 // applies: 1529 1530 // A conversion that is not a conversion of a pointer, or 1531 // pointer to member, to bool is better than another conversion 1532 // that is such a conversion. 1533 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1534 return SCS2.isPointerConversionToBool() 1535 ? ImplicitConversionSequence::Better 1536 : ImplicitConversionSequence::Worse; 1537 1538 // C++ [over.ics.rank]p4b2: 1539 // 1540 // If class B is derived directly or indirectly from class A, 1541 // conversion of B* to A* is better than conversion of B* to 1542 // void*, and conversion of A* to void* is better than conversion 1543 // of B* to void*. 1544 bool SCS1ConvertsToVoid 1545 = SCS1.isPointerConversionToVoidPointer(Context); 1546 bool SCS2ConvertsToVoid 1547 = SCS2.isPointerConversionToVoidPointer(Context); 1548 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1549 // Exactly one of the conversion sequences is a conversion to 1550 // a void pointer; it's the worse conversion. 1551 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1552 : ImplicitConversionSequence::Worse; 1553 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1554 // Neither conversion sequence converts to a void pointer; compare 1555 // their derived-to-base conversions. 1556 if (ImplicitConversionSequence::CompareKind DerivedCK 1557 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1558 return DerivedCK; 1559 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1560 // Both conversion sequences are conversions to void 1561 // pointers. Compare the source types to determine if there's an 1562 // inheritance relationship in their sources. 1563 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1564 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1565 1566 // Adjust the types we're converting from via the array-to-pointer 1567 // conversion, if we need to. 1568 if (SCS1.First == ICK_Array_To_Pointer) 1569 FromType1 = Context.getArrayDecayedType(FromType1); 1570 if (SCS2.First == ICK_Array_To_Pointer) 1571 FromType2 = Context.getArrayDecayedType(FromType2); 1572 1573 QualType FromPointee1 1574 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1575 QualType FromPointee2 1576 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1577 1578 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1579 return ImplicitConversionSequence::Better; 1580 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1581 return ImplicitConversionSequence::Worse; 1582 1583 // Objective-C++: If one interface is more specific than the 1584 // other, it is the better one. 1585 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1586 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1587 if (FromIface1 && FromIface1) { 1588 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1589 return ImplicitConversionSequence::Better; 1590 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1591 return ImplicitConversionSequence::Worse; 1592 } 1593 } 1594 1595 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1596 // bullet 3). 1597 if (ImplicitConversionSequence::CompareKind QualCK 1598 = CompareQualificationConversions(SCS1, SCS2)) 1599 return QualCK; 1600 1601 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1602 // C++0x [over.ics.rank]p3b4: 1603 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1604 // implicit object parameter of a non-static member function declared 1605 // without a ref-qualifier, and S1 binds an rvalue reference to an 1606 // rvalue and S2 binds an lvalue reference. 1607 // FIXME: We don't know if we're dealing with the implicit object parameter, 1608 // or if the member function in this case has a ref qualifier. 1609 // (Of course, we don't have ref qualifiers yet.) 1610 if (SCS1.RRefBinding != SCS2.RRefBinding) 1611 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1612 : ImplicitConversionSequence::Worse; 1613 1614 // C++ [over.ics.rank]p3b4: 1615 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1616 // which the references refer are the same type except for 1617 // top-level cv-qualifiers, and the type to which the reference 1618 // initialized by S2 refers is more cv-qualified than the type 1619 // to which the reference initialized by S1 refers. 1620 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1621 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1622 T1 = Context.getCanonicalType(T1); 1623 T2 = Context.getCanonicalType(T2); 1624 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1625 if (T2.isMoreQualifiedThan(T1)) 1626 return ImplicitConversionSequence::Better; 1627 else if (T1.isMoreQualifiedThan(T2)) 1628 return ImplicitConversionSequence::Worse; 1629 } 1630 } 1631 1632 return ImplicitConversionSequence::Indistinguishable; 1633} 1634 1635/// CompareQualificationConversions - Compares two standard conversion 1636/// sequences to determine whether they can be ranked based on their 1637/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1638ImplicitConversionSequence::CompareKind 1639Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1640 const StandardConversionSequence& SCS2) 1641{ 1642 // C++ 13.3.3.2p3: 1643 // -- S1 and S2 differ only in their qualification conversion and 1644 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1645 // cv-qualification signature of type T1 is a proper subset of 1646 // the cv-qualification signature of type T2, and S1 is not the 1647 // deprecated string literal array-to-pointer conversion (4.2). 1648 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1649 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1650 return ImplicitConversionSequence::Indistinguishable; 1651 1652 // FIXME: the example in the standard doesn't use a qualification 1653 // conversion (!) 1654 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1655 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1656 T1 = Context.getCanonicalType(T1); 1657 T2 = Context.getCanonicalType(T2); 1658 1659 // If the types are the same, we won't learn anything by unwrapped 1660 // them. 1661 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1662 return ImplicitConversionSequence::Indistinguishable; 1663 1664 ImplicitConversionSequence::CompareKind Result 1665 = ImplicitConversionSequence::Indistinguishable; 1666 while (UnwrapSimilarPointerTypes(T1, T2)) { 1667 // Within each iteration of the loop, we check the qualifiers to 1668 // determine if this still looks like a qualification 1669 // conversion. Then, if all is well, we unwrap one more level of 1670 // pointers or pointers-to-members and do it all again 1671 // until there are no more pointers or pointers-to-members left 1672 // to unwrap. This essentially mimics what 1673 // IsQualificationConversion does, but here we're checking for a 1674 // strict subset of qualifiers. 1675 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1676 // The qualifiers are the same, so this doesn't tell us anything 1677 // about how the sequences rank. 1678 ; 1679 else if (T2.isMoreQualifiedThan(T1)) { 1680 // T1 has fewer qualifiers, so it could be the better sequence. 1681 if (Result == ImplicitConversionSequence::Worse) 1682 // Neither has qualifiers that are a subset of the other's 1683 // qualifiers. 1684 return ImplicitConversionSequence::Indistinguishable; 1685 1686 Result = ImplicitConversionSequence::Better; 1687 } else if (T1.isMoreQualifiedThan(T2)) { 1688 // T2 has fewer qualifiers, so it could be the better sequence. 1689 if (Result == ImplicitConversionSequence::Better) 1690 // Neither has qualifiers that are a subset of the other's 1691 // qualifiers. 1692 return ImplicitConversionSequence::Indistinguishable; 1693 1694 Result = ImplicitConversionSequence::Worse; 1695 } else { 1696 // Qualifiers are disjoint. 1697 return ImplicitConversionSequence::Indistinguishable; 1698 } 1699 1700 // If the types after this point are equivalent, we're done. 1701 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1702 break; 1703 } 1704 1705 // Check that the winning standard conversion sequence isn't using 1706 // the deprecated string literal array to pointer conversion. 1707 switch (Result) { 1708 case ImplicitConversionSequence::Better: 1709 if (SCS1.Deprecated) 1710 Result = ImplicitConversionSequence::Indistinguishable; 1711 break; 1712 1713 case ImplicitConversionSequence::Indistinguishable: 1714 break; 1715 1716 case ImplicitConversionSequence::Worse: 1717 if (SCS2.Deprecated) 1718 Result = ImplicitConversionSequence::Indistinguishable; 1719 break; 1720 } 1721 1722 return Result; 1723} 1724 1725/// CompareDerivedToBaseConversions - Compares two standard conversion 1726/// sequences to determine whether they can be ranked based on their 1727/// various kinds of derived-to-base conversions (C++ 1728/// [over.ics.rank]p4b3). As part of these checks, we also look at 1729/// conversions between Objective-C interface types. 1730ImplicitConversionSequence::CompareKind 1731Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1732 const StandardConversionSequence& SCS2) { 1733 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1734 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1735 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1736 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1737 1738 // Adjust the types we're converting from via the array-to-pointer 1739 // conversion, if we need to. 1740 if (SCS1.First == ICK_Array_To_Pointer) 1741 FromType1 = Context.getArrayDecayedType(FromType1); 1742 if (SCS2.First == ICK_Array_To_Pointer) 1743 FromType2 = Context.getArrayDecayedType(FromType2); 1744 1745 // Canonicalize all of the types. 1746 FromType1 = Context.getCanonicalType(FromType1); 1747 ToType1 = Context.getCanonicalType(ToType1); 1748 FromType2 = Context.getCanonicalType(FromType2); 1749 ToType2 = Context.getCanonicalType(ToType2); 1750 1751 // C++ [over.ics.rank]p4b3: 1752 // 1753 // If class B is derived directly or indirectly from class A and 1754 // class C is derived directly or indirectly from B, 1755 // 1756 // For Objective-C, we let A, B, and C also be Objective-C 1757 // interfaces. 1758 1759 // Compare based on pointer conversions. 1760 if (SCS1.Second == ICK_Pointer_Conversion && 1761 SCS2.Second == ICK_Pointer_Conversion && 1762 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1763 FromType1->isPointerType() && FromType2->isPointerType() && 1764 ToType1->isPointerType() && ToType2->isPointerType()) { 1765 QualType FromPointee1 1766 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1767 QualType ToPointee1 1768 = ToType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1769 QualType FromPointee2 1770 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1771 QualType ToPointee2 1772 = ToType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1773 1774 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1775 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1776 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1777 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1778 1779 // -- conversion of C* to B* is better than conversion of C* to A*, 1780 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1781 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1782 return ImplicitConversionSequence::Better; 1783 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1784 return ImplicitConversionSequence::Worse; 1785 1786 if (ToIface1 && ToIface2) { 1787 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1788 return ImplicitConversionSequence::Better; 1789 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1790 return ImplicitConversionSequence::Worse; 1791 } 1792 } 1793 1794 // -- conversion of B* to A* is better than conversion of C* to A*, 1795 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1796 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1797 return ImplicitConversionSequence::Better; 1798 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1799 return ImplicitConversionSequence::Worse; 1800 1801 if (FromIface1 && FromIface2) { 1802 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1803 return ImplicitConversionSequence::Better; 1804 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1805 return ImplicitConversionSequence::Worse; 1806 } 1807 } 1808 } 1809 1810 // Compare based on reference bindings. 1811 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1812 SCS1.Second == ICK_Derived_To_Base) { 1813 // -- binding of an expression of type C to a reference of type 1814 // B& is better than binding an expression of type C to a 1815 // reference of type A&, 1816 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1817 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1818 if (IsDerivedFrom(ToType1, ToType2)) 1819 return ImplicitConversionSequence::Better; 1820 else if (IsDerivedFrom(ToType2, ToType1)) 1821 return ImplicitConversionSequence::Worse; 1822 } 1823 1824 // -- binding of an expression of type B to a reference of type 1825 // A& is better than binding an expression of type C to a 1826 // reference of type A&, 1827 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1828 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1829 if (IsDerivedFrom(FromType2, FromType1)) 1830 return ImplicitConversionSequence::Better; 1831 else if (IsDerivedFrom(FromType1, FromType2)) 1832 return ImplicitConversionSequence::Worse; 1833 } 1834 } 1835 1836 1837 // FIXME: conversion of A::* to B::* is better than conversion of 1838 // A::* to C::*, 1839 1840 // FIXME: conversion of B::* to C::* is better than conversion of 1841 // A::* to C::*, and 1842 1843 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1844 SCS1.Second == ICK_Derived_To_Base) { 1845 // -- conversion of C to B is better than conversion of C to A, 1846 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1847 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1848 if (IsDerivedFrom(ToType1, ToType2)) 1849 return ImplicitConversionSequence::Better; 1850 else if (IsDerivedFrom(ToType2, ToType1)) 1851 return ImplicitConversionSequence::Worse; 1852 } 1853 1854 // -- conversion of B to A is better than conversion of C to A. 1855 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1856 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1857 if (IsDerivedFrom(FromType2, FromType1)) 1858 return ImplicitConversionSequence::Better; 1859 else if (IsDerivedFrom(FromType1, FromType2)) 1860 return ImplicitConversionSequence::Worse; 1861 } 1862 } 1863 1864 return ImplicitConversionSequence::Indistinguishable; 1865} 1866 1867/// TryCopyInitialization - Try to copy-initialize a value of type 1868/// ToType from the expression From. Return the implicit conversion 1869/// sequence required to pass this argument, which may be a bad 1870/// conversion sequence (meaning that the argument cannot be passed to 1871/// a parameter of this type). If @p SuppressUserConversions, then we 1872/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1873/// then we treat @p From as an rvalue, even if it is an lvalue. 1874ImplicitConversionSequence 1875Sema::TryCopyInitialization(Expr *From, QualType ToType, 1876 bool SuppressUserConversions, bool ForceRValue) { 1877 if (ToType->isReferenceType()) { 1878 ImplicitConversionSequence ICS; 1879 CheckReferenceInit(From, ToType, &ICS, SuppressUserConversions, 1880 /*AllowExplicit=*/false, ForceRValue); 1881 return ICS; 1882 } else { 1883 return TryImplicitConversion(From, ToType, SuppressUserConversions, 1884 ForceRValue); 1885 } 1886} 1887 1888/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1889/// the expression @p From. Returns true (and emits a diagnostic) if there was 1890/// an error, returns false if the initialization succeeded. Elidable should 1891/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1892/// differently in C++0x for this case. 1893bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1894 const char* Flavor, bool Elidable) { 1895 if (!getLangOptions().CPlusPlus) { 1896 // In C, argument passing is the same as performing an assignment. 1897 QualType FromType = From->getType(); 1898 1899 AssignConvertType ConvTy = 1900 CheckSingleAssignmentConstraints(ToType, From); 1901 if (ConvTy != Compatible && 1902 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1903 ConvTy = Compatible; 1904 1905 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1906 FromType, From, Flavor); 1907 } 1908 1909 if (ToType->isReferenceType()) 1910 return CheckReferenceInit(From, ToType); 1911 1912 if (!PerformImplicitConversion(From, ToType, Flavor, 1913 /*AllowExplicit=*/false, Elidable)) 1914 return false; 1915 1916 return Diag(From->getSourceRange().getBegin(), 1917 diag::err_typecheck_convert_incompatible) 1918 << ToType << From->getType() << Flavor << From->getSourceRange(); 1919} 1920 1921/// TryObjectArgumentInitialization - Try to initialize the object 1922/// parameter of the given member function (@c Method) from the 1923/// expression @p From. 1924ImplicitConversionSequence 1925Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1926 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1927 unsigned MethodQuals = Method->getTypeQualifiers(); 1928 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 1929 1930 // Set up the conversion sequence as a "bad" conversion, to allow us 1931 // to exit early. 1932 ImplicitConversionSequence ICS; 1933 ICS.Standard.setAsIdentityConversion(); 1934 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1935 1936 // We need to have an object of class type. 1937 QualType FromType = From->getType(); 1938 if (const PointerType *PT = FromType->getAsPointerType()) 1939 FromType = PT->getPointeeType(); 1940 1941 assert(FromType->isRecordType()); 1942 1943 // The implicit object parmeter is has the type "reference to cv X", 1944 // where X is the class of which the function is a member 1945 // (C++ [over.match.funcs]p4). However, when finding an implicit 1946 // conversion sequence for the argument, we are not allowed to 1947 // create temporaries or perform user-defined conversions 1948 // (C++ [over.match.funcs]p5). We perform a simplified version of 1949 // reference binding here, that allows class rvalues to bind to 1950 // non-constant references. 1951 1952 // First check the qualifiers. We don't care about lvalue-vs-rvalue 1953 // with the implicit object parameter (C++ [over.match.funcs]p5). 1954 QualType FromTypeCanon = Context.getCanonicalType(FromType); 1955 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 1956 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 1957 return ICS; 1958 1959 // Check that we have either the same type or a derived type. It 1960 // affects the conversion rank. 1961 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 1962 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 1963 ICS.Standard.Second = ICK_Identity; 1964 else if (IsDerivedFrom(FromType, ClassType)) 1965 ICS.Standard.Second = ICK_Derived_To_Base; 1966 else 1967 return ICS; 1968 1969 // Success. Mark this as a reference binding. 1970 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 1971 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 1972 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 1973 ICS.Standard.ReferenceBinding = true; 1974 ICS.Standard.DirectBinding = true; 1975 ICS.Standard.RRefBinding = false; 1976 return ICS; 1977} 1978 1979/// PerformObjectArgumentInitialization - Perform initialization of 1980/// the implicit object parameter for the given Method with the given 1981/// expression. 1982bool 1983Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 1984 QualType FromRecordType, DestType; 1985 QualType ImplicitParamRecordType = 1986 Method->getThisType(Context)->getAsPointerType()->getPointeeType(); 1987 1988 if (const PointerType *PT = From->getType()->getAsPointerType()) { 1989 FromRecordType = PT->getPointeeType(); 1990 DestType = Method->getThisType(Context); 1991 } else { 1992 FromRecordType = From->getType(); 1993 DestType = ImplicitParamRecordType; 1994 } 1995 1996 ImplicitConversionSequence ICS 1997 = TryObjectArgumentInitialization(From, Method); 1998 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 1999 return Diag(From->getSourceRange().getBegin(), 2000 diag::err_implicit_object_parameter_init) 2001 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2002 2003 if (ICS.Standard.Second == ICK_Derived_To_Base && 2004 CheckDerivedToBaseConversion(FromRecordType, 2005 ImplicitParamRecordType, 2006 From->getSourceRange().getBegin(), 2007 From->getSourceRange())) 2008 return true; 2009 2010 ImpCastExprToType(From, DestType, /*isLvalue=*/true); 2011 return false; 2012} 2013 2014/// TryContextuallyConvertToBool - Attempt to contextually convert the 2015/// expression From to bool (C++0x [conv]p3). 2016ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2017 return TryImplicitConversion(From, Context.BoolTy, false, true); 2018} 2019 2020/// PerformContextuallyConvertToBool - Perform a contextual conversion 2021/// of the expression From to bool (C++0x [conv]p3). 2022bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2023 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2024 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2025 return false; 2026 2027 return Diag(From->getSourceRange().getBegin(), 2028 diag::err_typecheck_bool_condition) 2029 << From->getType() << From->getSourceRange(); 2030} 2031 2032/// AddOverloadCandidate - Adds the given function to the set of 2033/// candidate functions, using the given function call arguments. If 2034/// @p SuppressUserConversions, then don't allow user-defined 2035/// conversions via constructors or conversion operators. 2036/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2037/// hacky way to implement the overloading rules for elidable copy 2038/// initialization in C++0x (C++0x 12.8p15). 2039void 2040Sema::AddOverloadCandidate(FunctionDecl *Function, 2041 Expr **Args, unsigned NumArgs, 2042 OverloadCandidateSet& CandidateSet, 2043 bool SuppressUserConversions, 2044 bool ForceRValue) 2045{ 2046 const FunctionProtoType* Proto 2047 = dyn_cast<FunctionProtoType>(Function->getType()->getAsFunctionType()); 2048 assert(Proto && "Functions without a prototype cannot be overloaded"); 2049 assert(!isa<CXXConversionDecl>(Function) && 2050 "Use AddConversionCandidate for conversion functions"); 2051 2052 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2053 if (!isa<CXXConstructorDecl>(Method)) { 2054 // If we get here, it's because we're calling a member function 2055 // that is named without a member access expression (e.g., 2056 // "this->f") that was either written explicitly or created 2057 // implicitly. This can happen with a qualified call to a member 2058 // function, e.g., X::f(). We use a NULL object as the implied 2059 // object argument (C++ [over.call.func]p3). 2060 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2061 SuppressUserConversions, ForceRValue); 2062 return; 2063 } 2064 // We treat a constructor like a non-member function, since its object 2065 // argument doesn't participate in overload resolution. 2066 } 2067 2068 2069 // Add this candidate 2070 CandidateSet.push_back(OverloadCandidate()); 2071 OverloadCandidate& Candidate = CandidateSet.back(); 2072 Candidate.Function = Function; 2073 Candidate.Viable = true; 2074 Candidate.IsSurrogate = false; 2075 Candidate.IgnoreObjectArgument = false; 2076 2077 unsigned NumArgsInProto = Proto->getNumArgs(); 2078 2079 // (C++ 13.3.2p2): A candidate function having fewer than m 2080 // parameters is viable only if it has an ellipsis in its parameter 2081 // list (8.3.5). 2082 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2083 Candidate.Viable = false; 2084 return; 2085 } 2086 2087 // (C++ 13.3.2p2): A candidate function having more than m parameters 2088 // is viable only if the (m+1)st parameter has a default argument 2089 // (8.3.6). For the purposes of overload resolution, the 2090 // parameter list is truncated on the right, so that there are 2091 // exactly m parameters. 2092 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2093 if (NumArgs < MinRequiredArgs) { 2094 // Not enough arguments. 2095 Candidate.Viable = false; 2096 return; 2097 } 2098 2099 // Determine the implicit conversion sequences for each of the 2100 // arguments. 2101 Candidate.Conversions.resize(NumArgs); 2102 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2103 if (ArgIdx < NumArgsInProto) { 2104 // (C++ 13.3.2p3): for F to be a viable function, there shall 2105 // exist for each argument an implicit conversion sequence 2106 // (13.3.3.1) that converts that argument to the corresponding 2107 // parameter of F. 2108 QualType ParamType = Proto->getArgType(ArgIdx); 2109 Candidate.Conversions[ArgIdx] 2110 = TryCopyInitialization(Args[ArgIdx], ParamType, 2111 SuppressUserConversions, ForceRValue); 2112 if (Candidate.Conversions[ArgIdx].ConversionKind 2113 == ImplicitConversionSequence::BadConversion) { 2114 Candidate.Viable = false; 2115 break; 2116 } 2117 } else { 2118 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2119 // argument for which there is no corresponding parameter is 2120 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2121 Candidate.Conversions[ArgIdx].ConversionKind 2122 = ImplicitConversionSequence::EllipsisConversion; 2123 } 2124 } 2125} 2126 2127/// \brief Add all of the function declarations in the given function set to 2128/// the overload canddiate set. 2129void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2130 Expr **Args, unsigned NumArgs, 2131 OverloadCandidateSet& CandidateSet, 2132 bool SuppressUserConversions) { 2133 for (FunctionSet::const_iterator F = Functions.begin(), 2134 FEnd = Functions.end(); 2135 F != FEnd; ++F) 2136 AddOverloadCandidate(*F, Args, NumArgs, CandidateSet, 2137 SuppressUserConversions); 2138} 2139 2140/// AddMethodCandidate - Adds the given C++ member function to the set 2141/// of candidate functions, using the given function call arguments 2142/// and the object argument (@c Object). For example, in a call 2143/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2144/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2145/// allow user-defined conversions via constructors or conversion 2146/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2147/// a slightly hacky way to implement the overloading rules for elidable copy 2148/// initialization in C++0x (C++0x 12.8p15). 2149void 2150Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2151 Expr **Args, unsigned NumArgs, 2152 OverloadCandidateSet& CandidateSet, 2153 bool SuppressUserConversions, bool ForceRValue) 2154{ 2155 const FunctionProtoType* Proto 2156 = dyn_cast<FunctionProtoType>(Method->getType()->getAsFunctionType()); 2157 assert(Proto && "Methods without a prototype cannot be overloaded"); 2158 assert(!isa<CXXConversionDecl>(Method) && 2159 "Use AddConversionCandidate for conversion functions"); 2160 assert(!isa<CXXConstructorDecl>(Method) && 2161 "Use AddOverloadCandidate for constructors"); 2162 2163 // Add this candidate 2164 CandidateSet.push_back(OverloadCandidate()); 2165 OverloadCandidate& Candidate = CandidateSet.back(); 2166 Candidate.Function = Method; 2167 Candidate.IsSurrogate = false; 2168 Candidate.IgnoreObjectArgument = false; 2169 2170 unsigned NumArgsInProto = Proto->getNumArgs(); 2171 2172 // (C++ 13.3.2p2): A candidate function having fewer than m 2173 // parameters is viable only if it has an ellipsis in its parameter 2174 // list (8.3.5). 2175 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2176 Candidate.Viable = false; 2177 return; 2178 } 2179 2180 // (C++ 13.3.2p2): A candidate function having more than m parameters 2181 // is viable only if the (m+1)st parameter has a default argument 2182 // (8.3.6). For the purposes of overload resolution, the 2183 // parameter list is truncated on the right, so that there are 2184 // exactly m parameters. 2185 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2186 if (NumArgs < MinRequiredArgs) { 2187 // Not enough arguments. 2188 Candidate.Viable = false; 2189 return; 2190 } 2191 2192 Candidate.Viable = true; 2193 Candidate.Conversions.resize(NumArgs + 1); 2194 2195 if (Method->isStatic() || !Object) 2196 // The implicit object argument is ignored. 2197 Candidate.IgnoreObjectArgument = true; 2198 else { 2199 // Determine the implicit conversion sequence for the object 2200 // parameter. 2201 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2202 if (Candidate.Conversions[0].ConversionKind 2203 == ImplicitConversionSequence::BadConversion) { 2204 Candidate.Viable = false; 2205 return; 2206 } 2207 } 2208 2209 // Determine the implicit conversion sequences for each of the 2210 // arguments. 2211 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2212 if (ArgIdx < NumArgsInProto) { 2213 // (C++ 13.3.2p3): for F to be a viable function, there shall 2214 // exist for each argument an implicit conversion sequence 2215 // (13.3.3.1) that converts that argument to the corresponding 2216 // parameter of F. 2217 QualType ParamType = Proto->getArgType(ArgIdx); 2218 Candidate.Conversions[ArgIdx + 1] 2219 = TryCopyInitialization(Args[ArgIdx], ParamType, 2220 SuppressUserConversions, ForceRValue); 2221 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2222 == ImplicitConversionSequence::BadConversion) { 2223 Candidate.Viable = false; 2224 break; 2225 } 2226 } else { 2227 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2228 // argument for which there is no corresponding parameter is 2229 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2230 Candidate.Conversions[ArgIdx + 1].ConversionKind 2231 = ImplicitConversionSequence::EllipsisConversion; 2232 } 2233 } 2234} 2235 2236/// AddConversionCandidate - Add a C++ conversion function as a 2237/// candidate in the candidate set (C++ [over.match.conv], 2238/// C++ [over.match.copy]). From is the expression we're converting from, 2239/// and ToType is the type that we're eventually trying to convert to 2240/// (which may or may not be the same type as the type that the 2241/// conversion function produces). 2242void 2243Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2244 Expr *From, QualType ToType, 2245 OverloadCandidateSet& CandidateSet) { 2246 // Add this candidate 2247 CandidateSet.push_back(OverloadCandidate()); 2248 OverloadCandidate& Candidate = CandidateSet.back(); 2249 Candidate.Function = Conversion; 2250 Candidate.IsSurrogate = false; 2251 Candidate.IgnoreObjectArgument = false; 2252 Candidate.FinalConversion.setAsIdentityConversion(); 2253 Candidate.FinalConversion.FromTypePtr 2254 = Conversion->getConversionType().getAsOpaquePtr(); 2255 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2256 2257 // Determine the implicit conversion sequence for the implicit 2258 // object parameter. 2259 Candidate.Viable = true; 2260 Candidate.Conversions.resize(1); 2261 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2262 2263 if (Candidate.Conversions[0].ConversionKind 2264 == ImplicitConversionSequence::BadConversion) { 2265 Candidate.Viable = false; 2266 return; 2267 } 2268 2269 // To determine what the conversion from the result of calling the 2270 // conversion function to the type we're eventually trying to 2271 // convert to (ToType), we need to synthesize a call to the 2272 // conversion function and attempt copy initialization from it. This 2273 // makes sure that we get the right semantics with respect to 2274 // lvalues/rvalues and the type. Fortunately, we can allocate this 2275 // call on the stack and we don't need its arguments to be 2276 // well-formed. 2277 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2278 SourceLocation()); 2279 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2280 &ConversionRef, false); 2281 2282 // Note that it is safe to allocate CallExpr on the stack here because 2283 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2284 // allocator). 2285 CallExpr Call(Context, &ConversionFn, 0, 0, 2286 Conversion->getConversionType().getNonReferenceType(), 2287 SourceLocation()); 2288 ImplicitConversionSequence ICS = TryCopyInitialization(&Call, ToType, true); 2289 switch (ICS.ConversionKind) { 2290 case ImplicitConversionSequence::StandardConversion: 2291 Candidate.FinalConversion = ICS.Standard; 2292 break; 2293 2294 case ImplicitConversionSequence::BadConversion: 2295 Candidate.Viable = false; 2296 break; 2297 2298 default: 2299 assert(false && 2300 "Can only end up with a standard conversion sequence or failure"); 2301 } 2302} 2303 2304/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2305/// converts the given @c Object to a function pointer via the 2306/// conversion function @c Conversion, and then attempts to call it 2307/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2308/// the type of function that we'll eventually be calling. 2309void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2310 const FunctionProtoType *Proto, 2311 Expr *Object, Expr **Args, unsigned NumArgs, 2312 OverloadCandidateSet& CandidateSet) { 2313 CandidateSet.push_back(OverloadCandidate()); 2314 OverloadCandidate& Candidate = CandidateSet.back(); 2315 Candidate.Function = 0; 2316 Candidate.Surrogate = Conversion; 2317 Candidate.Viable = true; 2318 Candidate.IsSurrogate = true; 2319 Candidate.IgnoreObjectArgument = false; 2320 Candidate.Conversions.resize(NumArgs + 1); 2321 2322 // Determine the implicit conversion sequence for the implicit 2323 // object parameter. 2324 ImplicitConversionSequence ObjectInit 2325 = TryObjectArgumentInitialization(Object, Conversion); 2326 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2327 Candidate.Viable = false; 2328 return; 2329 } 2330 2331 // The first conversion is actually a user-defined conversion whose 2332 // first conversion is ObjectInit's standard conversion (which is 2333 // effectively a reference binding). Record it as such. 2334 Candidate.Conversions[0].ConversionKind 2335 = ImplicitConversionSequence::UserDefinedConversion; 2336 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2337 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2338 Candidate.Conversions[0].UserDefined.After 2339 = Candidate.Conversions[0].UserDefined.Before; 2340 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2341 2342 // Find the 2343 unsigned NumArgsInProto = Proto->getNumArgs(); 2344 2345 // (C++ 13.3.2p2): A candidate function having fewer than m 2346 // parameters is viable only if it has an ellipsis in its parameter 2347 // list (8.3.5). 2348 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2349 Candidate.Viable = false; 2350 return; 2351 } 2352 2353 // Function types don't have any default arguments, so just check if 2354 // we have enough arguments. 2355 if (NumArgs < NumArgsInProto) { 2356 // Not enough arguments. 2357 Candidate.Viable = false; 2358 return; 2359 } 2360 2361 // Determine the implicit conversion sequences for each of the 2362 // arguments. 2363 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2364 if (ArgIdx < NumArgsInProto) { 2365 // (C++ 13.3.2p3): for F to be a viable function, there shall 2366 // exist for each argument an implicit conversion sequence 2367 // (13.3.3.1) that converts that argument to the corresponding 2368 // parameter of F. 2369 QualType ParamType = Proto->getArgType(ArgIdx); 2370 Candidate.Conversions[ArgIdx + 1] 2371 = TryCopyInitialization(Args[ArgIdx], ParamType, 2372 /*SuppressUserConversions=*/false); 2373 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2374 == ImplicitConversionSequence::BadConversion) { 2375 Candidate.Viable = false; 2376 break; 2377 } 2378 } else { 2379 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2380 // argument for which there is no corresponding parameter is 2381 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2382 Candidate.Conversions[ArgIdx + 1].ConversionKind 2383 = ImplicitConversionSequence::EllipsisConversion; 2384 } 2385 } 2386} 2387 2388// FIXME: This will eventually be removed, once we've migrated all of the 2389// operator overloading logic over to the scheme used by binary operators, which 2390// works for template instantiation. 2391void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2392 SourceLocation OpLoc, 2393 Expr **Args, unsigned NumArgs, 2394 OverloadCandidateSet& CandidateSet, 2395 SourceRange OpRange) { 2396 2397 FunctionSet Functions; 2398 2399 QualType T1 = Args[0]->getType(); 2400 QualType T2; 2401 if (NumArgs > 1) 2402 T2 = Args[1]->getType(); 2403 2404 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2405 if (S) 2406 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2407 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2408 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2409 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2410 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2411} 2412 2413/// \brief Add overload candidates for overloaded operators that are 2414/// member functions. 2415/// 2416/// Add the overloaded operator candidates that are member functions 2417/// for the operator Op that was used in an operator expression such 2418/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2419/// CandidateSet will store the added overload candidates. (C++ 2420/// [over.match.oper]). 2421void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2422 SourceLocation OpLoc, 2423 Expr **Args, unsigned NumArgs, 2424 OverloadCandidateSet& CandidateSet, 2425 SourceRange OpRange) { 2426 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2427 2428 // C++ [over.match.oper]p3: 2429 // For a unary operator @ with an operand of a type whose 2430 // cv-unqualified version is T1, and for a binary operator @ with 2431 // a left operand of a type whose cv-unqualified version is T1 and 2432 // a right operand of a type whose cv-unqualified version is T2, 2433 // three sets of candidate functions, designated member 2434 // candidates, non-member candidates and built-in candidates, are 2435 // constructed as follows: 2436 QualType T1 = Args[0]->getType(); 2437 QualType T2; 2438 if (NumArgs > 1) 2439 T2 = Args[1]->getType(); 2440 2441 // -- If T1 is a class type, the set of member candidates is the 2442 // result of the qualified lookup of T1::operator@ 2443 // (13.3.1.1.1); otherwise, the set of member candidates is 2444 // empty. 2445 // FIXME: Lookup in base classes, too! 2446 if (const RecordType *T1Rec = T1->getAsRecordType()) { 2447 DeclContext::lookup_const_iterator Oper, OperEnd; 2448 for (llvm::tie(Oper, OperEnd) = T1Rec->getDecl()->lookup(Context, OpName); 2449 Oper != OperEnd; ++Oper) 2450 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2451 Args+1, NumArgs - 1, CandidateSet, 2452 /*SuppressUserConversions=*/false); 2453 } 2454} 2455 2456/// AddBuiltinCandidate - Add a candidate for a built-in 2457/// operator. ResultTy and ParamTys are the result and parameter types 2458/// of the built-in candidate, respectively. Args and NumArgs are the 2459/// arguments being passed to the candidate. IsAssignmentOperator 2460/// should be true when this built-in candidate is an assignment 2461/// operator. NumContextualBoolArguments is the number of arguments 2462/// (at the beginning of the argument list) that will be contextually 2463/// converted to bool. 2464void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2465 Expr **Args, unsigned NumArgs, 2466 OverloadCandidateSet& CandidateSet, 2467 bool IsAssignmentOperator, 2468 unsigned NumContextualBoolArguments) { 2469 // Add this candidate 2470 CandidateSet.push_back(OverloadCandidate()); 2471 OverloadCandidate& Candidate = CandidateSet.back(); 2472 Candidate.Function = 0; 2473 Candidate.IsSurrogate = false; 2474 Candidate.IgnoreObjectArgument = false; 2475 Candidate.BuiltinTypes.ResultTy = ResultTy; 2476 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2477 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2478 2479 // Determine the implicit conversion sequences for each of the 2480 // arguments. 2481 Candidate.Viable = true; 2482 Candidate.Conversions.resize(NumArgs); 2483 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2484 // C++ [over.match.oper]p4: 2485 // For the built-in assignment operators, conversions of the 2486 // left operand are restricted as follows: 2487 // -- no temporaries are introduced to hold the left operand, and 2488 // -- no user-defined conversions are applied to the left 2489 // operand to achieve a type match with the left-most 2490 // parameter of a built-in candidate. 2491 // 2492 // We block these conversions by turning off user-defined 2493 // conversions, since that is the only way that initialization of 2494 // a reference to a non-class type can occur from something that 2495 // is not of the same type. 2496 if (ArgIdx < NumContextualBoolArguments) { 2497 assert(ParamTys[ArgIdx] == Context.BoolTy && 2498 "Contextual conversion to bool requires bool type"); 2499 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2500 } else { 2501 Candidate.Conversions[ArgIdx] 2502 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2503 ArgIdx == 0 && IsAssignmentOperator); 2504 } 2505 if (Candidate.Conversions[ArgIdx].ConversionKind 2506 == ImplicitConversionSequence::BadConversion) { 2507 Candidate.Viable = false; 2508 break; 2509 } 2510 } 2511} 2512 2513/// BuiltinCandidateTypeSet - A set of types that will be used for the 2514/// candidate operator functions for built-in operators (C++ 2515/// [over.built]). The types are separated into pointer types and 2516/// enumeration types. 2517class BuiltinCandidateTypeSet { 2518 /// TypeSet - A set of types. 2519 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2520 2521 /// PointerTypes - The set of pointer types that will be used in the 2522 /// built-in candidates. 2523 TypeSet PointerTypes; 2524 2525 /// MemberPointerTypes - The set of member pointer types that will be 2526 /// used in the built-in candidates. 2527 TypeSet MemberPointerTypes; 2528 2529 /// EnumerationTypes - The set of enumeration types that will be 2530 /// used in the built-in candidates. 2531 TypeSet EnumerationTypes; 2532 2533 /// Context - The AST context in which we will build the type sets. 2534 ASTContext &Context; 2535 2536 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2537 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2538 2539public: 2540 /// iterator - Iterates through the types that are part of the set. 2541 typedef TypeSet::iterator iterator; 2542 2543 BuiltinCandidateTypeSet(ASTContext &Context) : Context(Context) { } 2544 2545 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2546 bool AllowExplicitConversions); 2547 2548 /// pointer_begin - First pointer type found; 2549 iterator pointer_begin() { return PointerTypes.begin(); } 2550 2551 /// pointer_end - Past the last pointer type found; 2552 iterator pointer_end() { return PointerTypes.end(); } 2553 2554 /// member_pointer_begin - First member pointer type found; 2555 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2556 2557 /// member_pointer_end - Past the last member pointer type found; 2558 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2559 2560 /// enumeration_begin - First enumeration type found; 2561 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2562 2563 /// enumeration_end - Past the last enumeration type found; 2564 iterator enumeration_end() { return EnumerationTypes.end(); } 2565}; 2566 2567/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2568/// the set of pointer types along with any more-qualified variants of 2569/// that type. For example, if @p Ty is "int const *", this routine 2570/// will add "int const *", "int const volatile *", "int const 2571/// restrict *", and "int const volatile restrict *" to the set of 2572/// pointer types. Returns true if the add of @p Ty itself succeeded, 2573/// false otherwise. 2574bool 2575BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2576 // Insert this type. 2577 if (!PointerTypes.insert(Ty)) 2578 return false; 2579 2580 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2581 QualType PointeeTy = PointerTy->getPointeeType(); 2582 // FIXME: Optimize this so that we don't keep trying to add the same types. 2583 2584 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal with all 2585 // pointer conversions that don't cast away constness? 2586 if (!PointeeTy.isConstQualified()) 2587 AddPointerWithMoreQualifiedTypeVariants 2588 (Context.getPointerType(PointeeTy.withConst())); 2589 if (!PointeeTy.isVolatileQualified()) 2590 AddPointerWithMoreQualifiedTypeVariants 2591 (Context.getPointerType(PointeeTy.withVolatile())); 2592 if (!PointeeTy.isRestrictQualified()) 2593 AddPointerWithMoreQualifiedTypeVariants 2594 (Context.getPointerType(PointeeTy.withRestrict())); 2595 } 2596 2597 return true; 2598} 2599 2600/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2601/// to the set of pointer types along with any more-qualified variants of 2602/// that type. For example, if @p Ty is "int const *", this routine 2603/// will add "int const *", "int const volatile *", "int const 2604/// restrict *", and "int const volatile restrict *" to the set of 2605/// pointer types. Returns true if the add of @p Ty itself succeeded, 2606/// false otherwise. 2607bool 2608BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2609 QualType Ty) { 2610 // Insert this type. 2611 if (!MemberPointerTypes.insert(Ty)) 2612 return false; 2613 2614 if (const MemberPointerType *PointerTy = Ty->getAsMemberPointerType()) { 2615 QualType PointeeTy = PointerTy->getPointeeType(); 2616 const Type *ClassTy = PointerTy->getClass(); 2617 // FIXME: Optimize this so that we don't keep trying to add the same types. 2618 2619 if (!PointeeTy.isConstQualified()) 2620 AddMemberPointerWithMoreQualifiedTypeVariants 2621 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2622 if (!PointeeTy.isVolatileQualified()) 2623 AddMemberPointerWithMoreQualifiedTypeVariants 2624 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2625 if (!PointeeTy.isRestrictQualified()) 2626 AddMemberPointerWithMoreQualifiedTypeVariants 2627 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2628 } 2629 2630 return true; 2631} 2632 2633/// AddTypesConvertedFrom - Add each of the types to which the type @p 2634/// Ty can be implicit converted to the given set of @p Types. We're 2635/// primarily interested in pointer types and enumeration types. We also 2636/// take member pointer types, for the conditional operator. 2637/// AllowUserConversions is true if we should look at the conversion 2638/// functions of a class type, and AllowExplicitConversions if we 2639/// should also include the explicit conversion functions of a class 2640/// type. 2641void 2642BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2643 bool AllowUserConversions, 2644 bool AllowExplicitConversions) { 2645 // Only deal with canonical types. 2646 Ty = Context.getCanonicalType(Ty); 2647 2648 // Look through reference types; they aren't part of the type of an 2649 // expression for the purposes of conversions. 2650 if (const ReferenceType *RefTy = Ty->getAsReferenceType()) 2651 Ty = RefTy->getPointeeType(); 2652 2653 // We don't care about qualifiers on the type. 2654 Ty = Ty.getUnqualifiedType(); 2655 2656 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2657 QualType PointeeTy = PointerTy->getPointeeType(); 2658 2659 // Insert our type, and its more-qualified variants, into the set 2660 // of types. 2661 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2662 return; 2663 2664 // Add 'cv void*' to our set of types. 2665 if (!Ty->isVoidType()) { 2666 QualType QualVoid 2667 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2668 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2669 } 2670 2671 // If this is a pointer to a class type, add pointers to its bases 2672 // (with the same level of cv-qualification as the original 2673 // derived class, of course). 2674 if (const RecordType *PointeeRec = PointeeTy->getAsRecordType()) { 2675 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2676 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2677 Base != ClassDecl->bases_end(); ++Base) { 2678 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2679 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2680 2681 // Add the pointer type, recursively, so that we get all of 2682 // the indirect base classes, too. 2683 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2684 } 2685 } 2686 } else if (Ty->isMemberPointerType()) { 2687 // Member pointers are far easier, since the pointee can't be converted. 2688 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2689 return; 2690 } else if (Ty->isEnumeralType()) { 2691 EnumerationTypes.insert(Ty); 2692 } else if (AllowUserConversions) { 2693 if (const RecordType *TyRec = Ty->getAsRecordType()) { 2694 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2695 // FIXME: Visit conversion functions in the base classes, too. 2696 OverloadedFunctionDecl *Conversions 2697 = ClassDecl->getConversionFunctions(); 2698 for (OverloadedFunctionDecl::function_iterator Func 2699 = Conversions->function_begin(); 2700 Func != Conversions->function_end(); ++Func) { 2701 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 2702 if (AllowExplicitConversions || !Conv->isExplicit()) 2703 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2704 } 2705 } 2706 } 2707} 2708 2709/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2710/// operator overloads to the candidate set (C++ [over.built]), based 2711/// on the operator @p Op and the arguments given. For example, if the 2712/// operator is a binary '+', this routine might add "int 2713/// operator+(int, int)" to cover integer addition. 2714void 2715Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2716 Expr **Args, unsigned NumArgs, 2717 OverloadCandidateSet& CandidateSet) { 2718 // The set of "promoted arithmetic types", which are the arithmetic 2719 // types are that preserved by promotion (C++ [over.built]p2). Note 2720 // that the first few of these types are the promoted integral 2721 // types; these types need to be first. 2722 // FIXME: What about complex? 2723 const unsigned FirstIntegralType = 0; 2724 const unsigned LastIntegralType = 13; 2725 const unsigned FirstPromotedIntegralType = 7, 2726 LastPromotedIntegralType = 13; 2727 const unsigned FirstPromotedArithmeticType = 7, 2728 LastPromotedArithmeticType = 16; 2729 const unsigned NumArithmeticTypes = 16; 2730 QualType ArithmeticTypes[NumArithmeticTypes] = { 2731 Context.BoolTy, Context.CharTy, Context.WCharTy, 2732 Context.SignedCharTy, Context.ShortTy, 2733 Context.UnsignedCharTy, Context.UnsignedShortTy, 2734 Context.IntTy, Context.LongTy, Context.LongLongTy, 2735 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 2736 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 2737 }; 2738 2739 // Find all of the types that the arguments can convert to, but only 2740 // if the operator we're looking at has built-in operator candidates 2741 // that make use of these types. 2742 BuiltinCandidateTypeSet CandidateTypes(Context); 2743 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 2744 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 2745 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 2746 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 2747 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 2748 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 2749 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2750 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 2751 true, 2752 (Op == OO_Exclaim || 2753 Op == OO_AmpAmp || 2754 Op == OO_PipePipe)); 2755 } 2756 2757 bool isComparison = false; 2758 switch (Op) { 2759 case OO_None: 2760 case NUM_OVERLOADED_OPERATORS: 2761 assert(false && "Expected an overloaded operator"); 2762 break; 2763 2764 case OO_Star: // '*' is either unary or binary 2765 if (NumArgs == 1) 2766 goto UnaryStar; 2767 else 2768 goto BinaryStar; 2769 break; 2770 2771 case OO_Plus: // '+' is either unary or binary 2772 if (NumArgs == 1) 2773 goto UnaryPlus; 2774 else 2775 goto BinaryPlus; 2776 break; 2777 2778 case OO_Minus: // '-' is either unary or binary 2779 if (NumArgs == 1) 2780 goto UnaryMinus; 2781 else 2782 goto BinaryMinus; 2783 break; 2784 2785 case OO_Amp: // '&' is either unary or binary 2786 if (NumArgs == 1) 2787 goto UnaryAmp; 2788 else 2789 goto BinaryAmp; 2790 2791 case OO_PlusPlus: 2792 case OO_MinusMinus: 2793 // C++ [over.built]p3: 2794 // 2795 // For every pair (T, VQ), where T is an arithmetic type, and VQ 2796 // is either volatile or empty, there exist candidate operator 2797 // functions of the form 2798 // 2799 // VQ T& operator++(VQ T&); 2800 // T operator++(VQ T&, int); 2801 // 2802 // C++ [over.built]p4: 2803 // 2804 // For every pair (T, VQ), where T is an arithmetic type other 2805 // than bool, and VQ is either volatile or empty, there exist 2806 // candidate operator functions of the form 2807 // 2808 // VQ T& operator--(VQ T&); 2809 // T operator--(VQ T&, int); 2810 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 2811 Arith < NumArithmeticTypes; ++Arith) { 2812 QualType ArithTy = ArithmeticTypes[Arith]; 2813 QualType ParamTypes[2] 2814 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 2815 2816 // Non-volatile version. 2817 if (NumArgs == 1) 2818 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2819 else 2820 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2821 2822 // Volatile version 2823 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 2824 if (NumArgs == 1) 2825 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2826 else 2827 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2828 } 2829 2830 // C++ [over.built]p5: 2831 // 2832 // For every pair (T, VQ), where T is a cv-qualified or 2833 // cv-unqualified object type, and VQ is either volatile or 2834 // empty, there exist candidate operator functions of the form 2835 // 2836 // T*VQ& operator++(T*VQ&); 2837 // T*VQ& operator--(T*VQ&); 2838 // T* operator++(T*VQ&, int); 2839 // T* operator--(T*VQ&, int); 2840 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2841 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2842 // Skip pointer types that aren't pointers to object types. 2843 if (!(*Ptr)->getAsPointerType()->getPointeeType()->isObjectType()) 2844 continue; 2845 2846 QualType ParamTypes[2] = { 2847 Context.getLValueReferenceType(*Ptr), Context.IntTy 2848 }; 2849 2850 // Without volatile 2851 if (NumArgs == 1) 2852 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2853 else 2854 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2855 2856 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 2857 // With volatile 2858 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 2859 if (NumArgs == 1) 2860 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2861 else 2862 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2863 } 2864 } 2865 break; 2866 2867 UnaryStar: 2868 // C++ [over.built]p6: 2869 // For every cv-qualified or cv-unqualified object type T, there 2870 // exist candidate operator functions of the form 2871 // 2872 // T& operator*(T*); 2873 // 2874 // C++ [over.built]p7: 2875 // For every function type T, there exist candidate operator 2876 // functions of the form 2877 // T& operator*(T*); 2878 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2879 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2880 QualType ParamTy = *Ptr; 2881 QualType PointeeTy = ParamTy->getAsPointerType()->getPointeeType(); 2882 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 2883 &ParamTy, Args, 1, CandidateSet); 2884 } 2885 break; 2886 2887 UnaryPlus: 2888 // C++ [over.built]p8: 2889 // For every type T, there exist candidate operator functions of 2890 // the form 2891 // 2892 // T* operator+(T*); 2893 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2894 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2895 QualType ParamTy = *Ptr; 2896 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 2897 } 2898 2899 // Fall through 2900 2901 UnaryMinus: 2902 // C++ [over.built]p9: 2903 // For every promoted arithmetic type T, there exist candidate 2904 // operator functions of the form 2905 // 2906 // T operator+(T); 2907 // T operator-(T); 2908 for (unsigned Arith = FirstPromotedArithmeticType; 2909 Arith < LastPromotedArithmeticType; ++Arith) { 2910 QualType ArithTy = ArithmeticTypes[Arith]; 2911 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 2912 } 2913 break; 2914 2915 case OO_Tilde: 2916 // C++ [over.built]p10: 2917 // For every promoted integral type T, there exist candidate 2918 // operator functions of the form 2919 // 2920 // T operator~(T); 2921 for (unsigned Int = FirstPromotedIntegralType; 2922 Int < LastPromotedIntegralType; ++Int) { 2923 QualType IntTy = ArithmeticTypes[Int]; 2924 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 2925 } 2926 break; 2927 2928 case OO_New: 2929 case OO_Delete: 2930 case OO_Array_New: 2931 case OO_Array_Delete: 2932 case OO_Call: 2933 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 2934 break; 2935 2936 case OO_Comma: 2937 UnaryAmp: 2938 case OO_Arrow: 2939 // C++ [over.match.oper]p3: 2940 // -- For the operator ',', the unary operator '&', or the 2941 // operator '->', the built-in candidates set is empty. 2942 break; 2943 2944 case OO_Less: 2945 case OO_Greater: 2946 case OO_LessEqual: 2947 case OO_GreaterEqual: 2948 case OO_EqualEqual: 2949 case OO_ExclaimEqual: 2950 // C++ [over.built]p15: 2951 // 2952 // For every pointer or enumeration type T, there exist 2953 // candidate operator functions of the form 2954 // 2955 // bool operator<(T, T); 2956 // bool operator>(T, T); 2957 // bool operator<=(T, T); 2958 // bool operator>=(T, T); 2959 // bool operator==(T, T); 2960 // bool operator!=(T, T); 2961 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2962 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2963 QualType ParamTypes[2] = { *Ptr, *Ptr }; 2964 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 2965 } 2966 for (BuiltinCandidateTypeSet::iterator Enum 2967 = CandidateTypes.enumeration_begin(); 2968 Enum != CandidateTypes.enumeration_end(); ++Enum) { 2969 QualType ParamTypes[2] = { *Enum, *Enum }; 2970 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 2971 } 2972 2973 // Fall through. 2974 isComparison = true; 2975 2976 BinaryPlus: 2977 BinaryMinus: 2978 if (!isComparison) { 2979 // We didn't fall through, so we must have OO_Plus or OO_Minus. 2980 2981 // C++ [over.built]p13: 2982 // 2983 // For every cv-qualified or cv-unqualified object type T 2984 // there exist candidate operator functions of the form 2985 // 2986 // T* operator+(T*, ptrdiff_t); 2987 // T& operator[](T*, ptrdiff_t); [BELOW] 2988 // T* operator-(T*, ptrdiff_t); 2989 // T* operator+(ptrdiff_t, T*); 2990 // T& operator[](ptrdiff_t, T*); [BELOW] 2991 // 2992 // C++ [over.built]p14: 2993 // 2994 // For every T, where T is a pointer to object type, there 2995 // exist candidate operator functions of the form 2996 // 2997 // ptrdiff_t operator-(T, T); 2998 for (BuiltinCandidateTypeSet::iterator Ptr 2999 = CandidateTypes.pointer_begin(); 3000 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3001 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3002 3003 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3004 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3005 3006 if (Op == OO_Plus) { 3007 // T* operator+(ptrdiff_t, T*); 3008 ParamTypes[0] = ParamTypes[1]; 3009 ParamTypes[1] = *Ptr; 3010 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3011 } else { 3012 // ptrdiff_t operator-(T, T); 3013 ParamTypes[1] = *Ptr; 3014 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3015 Args, 2, CandidateSet); 3016 } 3017 } 3018 } 3019 // Fall through 3020 3021 case OO_Slash: 3022 BinaryStar: 3023 Conditional: 3024 // C++ [over.built]p12: 3025 // 3026 // For every pair of promoted arithmetic types L and R, there 3027 // exist candidate operator functions of the form 3028 // 3029 // LR operator*(L, R); 3030 // LR operator/(L, R); 3031 // LR operator+(L, R); 3032 // LR operator-(L, R); 3033 // bool operator<(L, R); 3034 // bool operator>(L, R); 3035 // bool operator<=(L, R); 3036 // bool operator>=(L, R); 3037 // bool operator==(L, R); 3038 // bool operator!=(L, R); 3039 // 3040 // where LR is the result of the usual arithmetic conversions 3041 // between types L and R. 3042 // 3043 // C++ [over.built]p24: 3044 // 3045 // For every pair of promoted arithmetic types L and R, there exist 3046 // candidate operator functions of the form 3047 // 3048 // LR operator?(bool, L, R); 3049 // 3050 // where LR is the result of the usual arithmetic conversions 3051 // between types L and R. 3052 // Our candidates ignore the first parameter. 3053 for (unsigned Left = FirstPromotedArithmeticType; 3054 Left < LastPromotedArithmeticType; ++Left) { 3055 for (unsigned Right = FirstPromotedArithmeticType; 3056 Right < LastPromotedArithmeticType; ++Right) { 3057 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3058 QualType Result 3059 = isComparison? Context.BoolTy 3060 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3061 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3062 } 3063 } 3064 break; 3065 3066 case OO_Percent: 3067 BinaryAmp: 3068 case OO_Caret: 3069 case OO_Pipe: 3070 case OO_LessLess: 3071 case OO_GreaterGreater: 3072 // C++ [over.built]p17: 3073 // 3074 // For every pair of promoted integral types L and R, there 3075 // exist candidate operator functions of the form 3076 // 3077 // LR operator%(L, R); 3078 // LR operator&(L, R); 3079 // LR operator^(L, R); 3080 // LR operator|(L, R); 3081 // L operator<<(L, R); 3082 // L operator>>(L, R); 3083 // 3084 // where LR is the result of the usual arithmetic conversions 3085 // between types L and R. 3086 for (unsigned Left = FirstPromotedIntegralType; 3087 Left < LastPromotedIntegralType; ++Left) { 3088 for (unsigned Right = FirstPromotedIntegralType; 3089 Right < LastPromotedIntegralType; ++Right) { 3090 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3091 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3092 ? LandR[0] 3093 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3094 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3095 } 3096 } 3097 break; 3098 3099 case OO_Equal: 3100 // C++ [over.built]p20: 3101 // 3102 // For every pair (T, VQ), where T is an enumeration or 3103 // (FIXME:) pointer to member type and VQ is either volatile or 3104 // empty, there exist candidate operator functions of the form 3105 // 3106 // VQ T& operator=(VQ T&, T); 3107 for (BuiltinCandidateTypeSet::iterator Enum 3108 = CandidateTypes.enumeration_begin(); 3109 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3110 QualType ParamTypes[2]; 3111 3112 // T& operator=(T&, T) 3113 ParamTypes[0] = Context.getLValueReferenceType(*Enum); 3114 ParamTypes[1] = *Enum; 3115 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3116 /*IsAssignmentOperator=*/false); 3117 3118 if (!Context.getCanonicalType(*Enum).isVolatileQualified()) { 3119 // volatile T& operator=(volatile T&, T) 3120 ParamTypes[0] = Context.getLValueReferenceType((*Enum).withVolatile()); 3121 ParamTypes[1] = *Enum; 3122 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3123 /*IsAssignmentOperator=*/false); 3124 } 3125 } 3126 // Fall through. 3127 3128 case OO_PlusEqual: 3129 case OO_MinusEqual: 3130 // C++ [over.built]p19: 3131 // 3132 // For every pair (T, VQ), where T is any type and VQ is either 3133 // volatile or empty, there exist candidate operator functions 3134 // of the form 3135 // 3136 // T*VQ& operator=(T*VQ&, T*); 3137 // 3138 // C++ [over.built]p21: 3139 // 3140 // For every pair (T, VQ), where T is a cv-qualified or 3141 // cv-unqualified object type and VQ is either volatile or 3142 // empty, there exist candidate operator functions of the form 3143 // 3144 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3145 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3146 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3147 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3148 QualType ParamTypes[2]; 3149 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3150 3151 // non-volatile version 3152 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3153 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3154 /*IsAssigmentOperator=*/Op == OO_Equal); 3155 3156 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3157 // volatile version 3158 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3159 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3160 /*IsAssigmentOperator=*/Op == OO_Equal); 3161 } 3162 } 3163 // Fall through. 3164 3165 case OO_StarEqual: 3166 case OO_SlashEqual: 3167 // C++ [over.built]p18: 3168 // 3169 // For every triple (L, VQ, R), where L is an arithmetic type, 3170 // VQ is either volatile or empty, and R is a promoted 3171 // arithmetic type, there exist candidate operator functions of 3172 // the form 3173 // 3174 // VQ L& operator=(VQ L&, R); 3175 // VQ L& operator*=(VQ L&, R); 3176 // VQ L& operator/=(VQ L&, R); 3177 // VQ L& operator+=(VQ L&, R); 3178 // VQ L& operator-=(VQ L&, R); 3179 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3180 for (unsigned Right = FirstPromotedArithmeticType; 3181 Right < LastPromotedArithmeticType; ++Right) { 3182 QualType ParamTypes[2]; 3183 ParamTypes[1] = ArithmeticTypes[Right]; 3184 3185 // Add this built-in operator as a candidate (VQ is empty). 3186 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3187 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3188 /*IsAssigmentOperator=*/Op == OO_Equal); 3189 3190 // Add this built-in operator as a candidate (VQ is 'volatile'). 3191 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3192 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3193 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3194 /*IsAssigmentOperator=*/Op == OO_Equal); 3195 } 3196 } 3197 break; 3198 3199 case OO_PercentEqual: 3200 case OO_LessLessEqual: 3201 case OO_GreaterGreaterEqual: 3202 case OO_AmpEqual: 3203 case OO_CaretEqual: 3204 case OO_PipeEqual: 3205 // C++ [over.built]p22: 3206 // 3207 // For every triple (L, VQ, R), where L is an integral type, VQ 3208 // is either volatile or empty, and R is a promoted integral 3209 // type, there exist candidate operator functions of the form 3210 // 3211 // VQ L& operator%=(VQ L&, R); 3212 // VQ L& operator<<=(VQ L&, R); 3213 // VQ L& operator>>=(VQ L&, R); 3214 // VQ L& operator&=(VQ L&, R); 3215 // VQ L& operator^=(VQ L&, R); 3216 // VQ L& operator|=(VQ L&, R); 3217 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3218 for (unsigned Right = FirstPromotedIntegralType; 3219 Right < LastPromotedIntegralType; ++Right) { 3220 QualType ParamTypes[2]; 3221 ParamTypes[1] = ArithmeticTypes[Right]; 3222 3223 // Add this built-in operator as a candidate (VQ is empty). 3224 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3225 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3226 3227 // Add this built-in operator as a candidate (VQ is 'volatile'). 3228 ParamTypes[0] = ArithmeticTypes[Left]; 3229 ParamTypes[0].addVolatile(); 3230 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3231 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3232 } 3233 } 3234 break; 3235 3236 case OO_Exclaim: { 3237 // C++ [over.operator]p23: 3238 // 3239 // There also exist candidate operator functions of the form 3240 // 3241 // bool operator!(bool); 3242 // bool operator&&(bool, bool); [BELOW] 3243 // bool operator||(bool, bool); [BELOW] 3244 QualType ParamTy = Context.BoolTy; 3245 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3246 /*IsAssignmentOperator=*/false, 3247 /*NumContextualBoolArguments=*/1); 3248 break; 3249 } 3250 3251 case OO_AmpAmp: 3252 case OO_PipePipe: { 3253 // C++ [over.operator]p23: 3254 // 3255 // There also exist candidate operator functions of the form 3256 // 3257 // bool operator!(bool); [ABOVE] 3258 // bool operator&&(bool, bool); 3259 // bool operator||(bool, bool); 3260 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3261 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3262 /*IsAssignmentOperator=*/false, 3263 /*NumContextualBoolArguments=*/2); 3264 break; 3265 } 3266 3267 case OO_Subscript: 3268 // C++ [over.built]p13: 3269 // 3270 // For every cv-qualified or cv-unqualified object type T there 3271 // exist candidate operator functions of the form 3272 // 3273 // T* operator+(T*, ptrdiff_t); [ABOVE] 3274 // T& operator[](T*, ptrdiff_t); 3275 // T* operator-(T*, ptrdiff_t); [ABOVE] 3276 // T* operator+(ptrdiff_t, T*); [ABOVE] 3277 // T& operator[](ptrdiff_t, T*); 3278 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3279 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3280 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3281 QualType PointeeType = (*Ptr)->getAsPointerType()->getPointeeType(); 3282 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3283 3284 // T& operator[](T*, ptrdiff_t) 3285 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3286 3287 // T& operator[](ptrdiff_t, T*); 3288 ParamTypes[0] = ParamTypes[1]; 3289 ParamTypes[1] = *Ptr; 3290 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3291 } 3292 break; 3293 3294 case OO_ArrowStar: 3295 // FIXME: No support for pointer-to-members yet. 3296 break; 3297 3298 case OO_Conditional: 3299 // Note that we don't consider the first argument, since it has been 3300 // contextually converted to bool long ago. The candidates below are 3301 // therefore added as binary. 3302 // 3303 // C++ [over.built]p24: 3304 // For every type T, where T is a pointer or pointer-to-member type, 3305 // there exist candidate operator functions of the form 3306 // 3307 // T operator?(bool, T, T); 3308 // 3309 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3310 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3311 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3312 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3313 } 3314 for (BuiltinCandidateTypeSet::iterator Ptr = 3315 CandidateTypes.member_pointer_begin(), 3316 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3317 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3318 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3319 } 3320 goto Conditional; 3321 } 3322} 3323 3324/// \brief Add function candidates found via argument-dependent lookup 3325/// to the set of overloading candidates. 3326/// 3327/// This routine performs argument-dependent name lookup based on the 3328/// given function name (which may also be an operator name) and adds 3329/// all of the overload candidates found by ADL to the overload 3330/// candidate set (C++ [basic.lookup.argdep]). 3331void 3332Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3333 Expr **Args, unsigned NumArgs, 3334 OverloadCandidateSet& CandidateSet) { 3335 FunctionSet Functions; 3336 3337 // Record all of the function candidates that we've already 3338 // added to the overload set, so that we don't add those same 3339 // candidates a second time. 3340 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3341 CandEnd = CandidateSet.end(); 3342 Cand != CandEnd; ++Cand) 3343 if (Cand->Function) 3344 Functions.insert(Cand->Function); 3345 3346 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3347 3348 // Erase all of the candidates we already knew about. 3349 // FIXME: This is suboptimal. Is there a better way? 3350 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3351 CandEnd = CandidateSet.end(); 3352 Cand != CandEnd; ++Cand) 3353 if (Cand->Function) 3354 Functions.erase(Cand->Function); 3355 3356 // For each of the ADL candidates we found, add it to the overload 3357 // set. 3358 for (FunctionSet::iterator Func = Functions.begin(), 3359 FuncEnd = Functions.end(); 3360 Func != FuncEnd; ++Func) 3361 AddOverloadCandidate(*Func, Args, NumArgs, CandidateSet); 3362} 3363 3364/// isBetterOverloadCandidate - Determines whether the first overload 3365/// candidate is a better candidate than the second (C++ 13.3.3p1). 3366bool 3367Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3368 const OverloadCandidate& Cand2) 3369{ 3370 // Define viable functions to be better candidates than non-viable 3371 // functions. 3372 if (!Cand2.Viable) 3373 return Cand1.Viable; 3374 else if (!Cand1.Viable) 3375 return false; 3376 3377 // C++ [over.match.best]p1: 3378 // 3379 // -- if F is a static member function, ICS1(F) is defined such 3380 // that ICS1(F) is neither better nor worse than ICS1(G) for 3381 // any function G, and, symmetrically, ICS1(G) is neither 3382 // better nor worse than ICS1(F). 3383 unsigned StartArg = 0; 3384 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3385 StartArg = 1; 3386 3387 // (C++ 13.3.3p1): a viable function F1 is defined to be a better 3388 // function than another viable function F2 if for all arguments i, 3389 // ICSi(F1) is not a worse conversion sequence than ICSi(F2), and 3390 // then... 3391 unsigned NumArgs = Cand1.Conversions.size(); 3392 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3393 bool HasBetterConversion = false; 3394 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3395 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3396 Cand2.Conversions[ArgIdx])) { 3397 case ImplicitConversionSequence::Better: 3398 // Cand1 has a better conversion sequence. 3399 HasBetterConversion = true; 3400 break; 3401 3402 case ImplicitConversionSequence::Worse: 3403 // Cand1 can't be better than Cand2. 3404 return false; 3405 3406 case ImplicitConversionSequence::Indistinguishable: 3407 // Do nothing. 3408 break; 3409 } 3410 } 3411 3412 if (HasBetterConversion) 3413 return true; 3414 3415 // FIXME: Several other bullets in (C++ 13.3.3p1) need to be 3416 // implemented, but they require template support. 3417 3418 // C++ [over.match.best]p1b4: 3419 // 3420 // -- the context is an initialization by user-defined conversion 3421 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3422 // from the return type of F1 to the destination type (i.e., 3423 // the type of the entity being initialized) is a better 3424 // conversion sequence than the standard conversion sequence 3425 // from the return type of F2 to the destination type. 3426 if (Cand1.Function && Cand2.Function && 3427 isa<CXXConversionDecl>(Cand1.Function) && 3428 isa<CXXConversionDecl>(Cand2.Function)) { 3429 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3430 Cand2.FinalConversion)) { 3431 case ImplicitConversionSequence::Better: 3432 // Cand1 has a better conversion sequence. 3433 return true; 3434 3435 case ImplicitConversionSequence::Worse: 3436 // Cand1 can't be better than Cand2. 3437 return false; 3438 3439 case ImplicitConversionSequence::Indistinguishable: 3440 // Do nothing 3441 break; 3442 } 3443 } 3444 3445 return false; 3446} 3447 3448/// \brief Computes the best viable function (C++ 13.3.3) 3449/// within an overload candidate set. 3450/// 3451/// \param CandidateSet the set of candidate functions. 3452/// 3453/// \param Loc the location of the function name (or operator symbol) for 3454/// which overload resolution occurs. 3455/// 3456/// \param Best f overload resolution was successful or found a deleted 3457/// function, Best points to the candidate function found. 3458/// 3459/// \returns The result of overload resolution. 3460Sema::OverloadingResult 3461Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3462 SourceLocation Loc, 3463 OverloadCandidateSet::iterator& Best) 3464{ 3465 // Find the best viable function. 3466 Best = CandidateSet.end(); 3467 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3468 Cand != CandidateSet.end(); ++Cand) { 3469 if (Cand->Viable) { 3470 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3471 Best = Cand; 3472 } 3473 } 3474 3475 // If we didn't find any viable functions, abort. 3476 if (Best == CandidateSet.end()) 3477 return OR_No_Viable_Function; 3478 3479 // Make sure that this function is better than every other viable 3480 // function. If not, we have an ambiguity. 3481 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3482 Cand != CandidateSet.end(); ++Cand) { 3483 if (Cand->Viable && 3484 Cand != Best && 3485 !isBetterOverloadCandidate(*Best, *Cand)) { 3486 Best = CandidateSet.end(); 3487 return OR_Ambiguous; 3488 } 3489 } 3490 3491 // Best is the best viable function. 3492 if (Best->Function && 3493 (Best->Function->isDeleted() || 3494 Best->Function->getAttr<UnavailableAttr>(Context))) 3495 return OR_Deleted; 3496 3497 // C++ [basic.def.odr]p2: 3498 // An overloaded function is used if it is selected by overload resolution 3499 // when referred to from a potentially-evaluated expression. [Note: this 3500 // covers calls to named functions (5.2.2), operator overloading 3501 // (clause 13), user-defined conversions (12.3.2), allocation function for 3502 // placement new (5.3.4), as well as non-default initialization (8.5). 3503 if (Best->Function) 3504 MarkDeclarationReferenced(Loc, Best->Function); 3505 return OR_Success; 3506} 3507 3508/// PrintOverloadCandidates - When overload resolution fails, prints 3509/// diagnostic messages containing the candidates in the candidate 3510/// set. If OnlyViable is true, only viable candidates will be printed. 3511void 3512Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3513 bool OnlyViable) 3514{ 3515 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3516 LastCand = CandidateSet.end(); 3517 for (; Cand != LastCand; ++Cand) { 3518 if (Cand->Viable || !OnlyViable) { 3519 if (Cand->Function) { 3520 if (Cand->Function->isDeleted() || 3521 Cand->Function->getAttr<UnavailableAttr>(Context)) { 3522 // Deleted or "unavailable" function. 3523 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3524 << Cand->Function->isDeleted(); 3525 } else { 3526 // Normal function 3527 // FIXME: Give a better reason! 3528 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3529 } 3530 } else if (Cand->IsSurrogate) { 3531 // Desugar the type of the surrogate down to a function type, 3532 // retaining as many typedefs as possible while still showing 3533 // the function type (and, therefore, its parameter types). 3534 QualType FnType = Cand->Surrogate->getConversionType(); 3535 bool isLValueReference = false; 3536 bool isRValueReference = false; 3537 bool isPointer = false; 3538 if (const LValueReferenceType *FnTypeRef = 3539 FnType->getAsLValueReferenceType()) { 3540 FnType = FnTypeRef->getPointeeType(); 3541 isLValueReference = true; 3542 } else if (const RValueReferenceType *FnTypeRef = 3543 FnType->getAsRValueReferenceType()) { 3544 FnType = FnTypeRef->getPointeeType(); 3545 isRValueReference = true; 3546 } 3547 if (const PointerType *FnTypePtr = FnType->getAsPointerType()) { 3548 FnType = FnTypePtr->getPointeeType(); 3549 isPointer = true; 3550 } 3551 // Desugar down to a function type. 3552 FnType = QualType(FnType->getAsFunctionType(), 0); 3553 // Reconstruct the pointer/reference as appropriate. 3554 if (isPointer) FnType = Context.getPointerType(FnType); 3555 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3556 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3557 3558 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3559 << FnType; 3560 } else { 3561 // FIXME: We need to get the identifier in here 3562 // FIXME: Do we want the error message to point at the operator? 3563 // (built-ins won't have a location) 3564 QualType FnType 3565 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3566 Cand->BuiltinTypes.ParamTypes, 3567 Cand->Conversions.size(), 3568 false, 0); 3569 3570 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3571 } 3572 } 3573 } 3574} 3575 3576/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3577/// an overloaded function (C++ [over.over]), where @p From is an 3578/// expression with overloaded function type and @p ToType is the type 3579/// we're trying to resolve to. For example: 3580/// 3581/// @code 3582/// int f(double); 3583/// int f(int); 3584/// 3585/// int (*pfd)(double) = f; // selects f(double) 3586/// @endcode 3587/// 3588/// This routine returns the resulting FunctionDecl if it could be 3589/// resolved, and NULL otherwise. When @p Complain is true, this 3590/// routine will emit diagnostics if there is an error. 3591FunctionDecl * 3592Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3593 bool Complain) { 3594 QualType FunctionType = ToType; 3595 bool IsMember = false; 3596 if (const PointerType *ToTypePtr = ToType->getAsPointerType()) 3597 FunctionType = ToTypePtr->getPointeeType(); 3598 else if (const ReferenceType *ToTypeRef = ToType->getAsReferenceType()) 3599 FunctionType = ToTypeRef->getPointeeType(); 3600 else if (const MemberPointerType *MemTypePtr = 3601 ToType->getAsMemberPointerType()) { 3602 FunctionType = MemTypePtr->getPointeeType(); 3603 IsMember = true; 3604 } 3605 3606 // We only look at pointers or references to functions. 3607 if (!FunctionType->isFunctionType()) 3608 return 0; 3609 3610 // Find the actual overloaded function declaration. 3611 OverloadedFunctionDecl *Ovl = 0; 3612 3613 // C++ [over.over]p1: 3614 // [...] [Note: any redundant set of parentheses surrounding the 3615 // overloaded function name is ignored (5.1). ] 3616 Expr *OvlExpr = From->IgnoreParens(); 3617 3618 // C++ [over.over]p1: 3619 // [...] The overloaded function name can be preceded by the & 3620 // operator. 3621 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3622 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3623 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3624 } 3625 3626 // Try to dig out the overloaded function. 3627 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) 3628 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3629 3630 // If there's no overloaded function declaration, we're done. 3631 if (!Ovl) 3632 return 0; 3633 3634 // Look through all of the overloaded functions, searching for one 3635 // whose type matches exactly. 3636 // FIXME: When templates or using declarations come along, we'll actually 3637 // have to deal with duplicates, partial ordering, etc. For now, we 3638 // can just do a simple search. 3639 FunctionType = Context.getCanonicalType(FunctionType.getUnqualifiedType()); 3640 for (OverloadedFunctionDecl::function_iterator Fun = Ovl->function_begin(); 3641 Fun != Ovl->function_end(); ++Fun) { 3642 // C++ [over.over]p3: 3643 // Non-member functions and static member functions match 3644 // targets of type "pointer-to-function" or "reference-to-function." 3645 // Nonstatic member functions match targets of 3646 // type "pointer-to-member-function." 3647 // Note that according to DR 247, the containing class does not matter. 3648 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 3649 // Skip non-static functions when converting to pointer, and static 3650 // when converting to member pointer. 3651 if (Method->isStatic() == IsMember) 3652 continue; 3653 } else if (IsMember) 3654 continue; 3655 3656 if (FunctionType == Context.getCanonicalType((*Fun)->getType())) 3657 return *Fun; 3658 } 3659 3660 return 0; 3661} 3662 3663/// ResolveOverloadedCallFn - Given the call expression that calls Fn 3664/// (which eventually refers to the declaration Func) and the call 3665/// arguments Args/NumArgs, attempt to resolve the function call down 3666/// to a specific function. If overload resolution succeeds, returns 3667/// the function declaration produced by overload 3668/// resolution. Otherwise, emits diagnostics, deletes all of the 3669/// arguments and Fn, and returns NULL. 3670FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 3671 DeclarationName UnqualifiedName, 3672 SourceLocation LParenLoc, 3673 Expr **Args, unsigned NumArgs, 3674 SourceLocation *CommaLocs, 3675 SourceLocation RParenLoc, 3676 bool &ArgumentDependentLookup) { 3677 OverloadCandidateSet CandidateSet; 3678 3679 // Add the functions denoted by Callee to the set of candidate 3680 // functions. While we're doing so, track whether argument-dependent 3681 // lookup still applies, per: 3682 // 3683 // C++0x [basic.lookup.argdep]p3: 3684 // Let X be the lookup set produced by unqualified lookup (3.4.1) 3685 // and let Y be the lookup set produced by argument dependent 3686 // lookup (defined as follows). If X contains 3687 // 3688 // -- a declaration of a class member, or 3689 // 3690 // -- a block-scope function declaration that is not a 3691 // using-declaration, or 3692 // 3693 // -- a declaration that is neither a function or a function 3694 // template 3695 // 3696 // then Y is empty. 3697 if (OverloadedFunctionDecl *Ovl 3698 = dyn_cast_or_null<OverloadedFunctionDecl>(Callee)) { 3699 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 3700 FuncEnd = Ovl->function_end(); 3701 Func != FuncEnd; ++Func) { 3702 AddOverloadCandidate(*Func, Args, NumArgs, CandidateSet); 3703 3704 if ((*Func)->getDeclContext()->isRecord() || 3705 (*Func)->getDeclContext()->isFunctionOrMethod()) 3706 ArgumentDependentLookup = false; 3707 } 3708 } else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee)) { 3709 AddOverloadCandidate(Func, Args, NumArgs, CandidateSet); 3710 3711 if (Func->getDeclContext()->isRecord() || 3712 Func->getDeclContext()->isFunctionOrMethod()) 3713 ArgumentDependentLookup = false; 3714 } 3715 3716 if (Callee) 3717 UnqualifiedName = Callee->getDeclName(); 3718 3719 if (ArgumentDependentLookup) 3720 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 3721 CandidateSet); 3722 3723 OverloadCandidateSet::iterator Best; 3724 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 3725 case OR_Success: 3726 return Best->Function; 3727 3728 case OR_No_Viable_Function: 3729 Diag(Fn->getSourceRange().getBegin(), 3730 diag::err_ovl_no_viable_function_in_call) 3731 << UnqualifiedName << Fn->getSourceRange(); 3732 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3733 break; 3734 3735 case OR_Ambiguous: 3736 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 3737 << UnqualifiedName << Fn->getSourceRange(); 3738 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3739 break; 3740 3741 case OR_Deleted: 3742 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 3743 << Best->Function->isDeleted() 3744 << UnqualifiedName 3745 << Fn->getSourceRange(); 3746 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3747 break; 3748 } 3749 3750 // Overload resolution failed. Destroy all of the subexpressions and 3751 // return NULL. 3752 Fn->Destroy(Context); 3753 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 3754 Args[Arg]->Destroy(Context); 3755 return 0; 3756} 3757 3758/// \brief Create a unary operation that may resolve to an overloaded 3759/// operator. 3760/// 3761/// \param OpLoc The location of the operator itself (e.g., '*'). 3762/// 3763/// \param OpcIn The UnaryOperator::Opcode that describes this 3764/// operator. 3765/// 3766/// \param Functions The set of non-member functions that will be 3767/// considered by overload resolution. The caller needs to build this 3768/// set based on the context using, e.g., 3769/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 3770/// set should not contain any member functions; those will be added 3771/// by CreateOverloadedUnaryOp(). 3772/// 3773/// \param input The input argument. 3774Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 3775 unsigned OpcIn, 3776 FunctionSet &Functions, 3777 ExprArg input) { 3778 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 3779 Expr *Input = (Expr *)input.get(); 3780 3781 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 3782 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 3783 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3784 3785 Expr *Args[2] = { Input, 0 }; 3786 unsigned NumArgs = 1; 3787 3788 // For post-increment and post-decrement, add the implicit '0' as 3789 // the second argument, so that we know this is a post-increment or 3790 // post-decrement. 3791 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 3792 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 3793 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 3794 SourceLocation()); 3795 NumArgs = 2; 3796 } 3797 3798 if (Input->isTypeDependent()) { 3799 OverloadedFunctionDecl *Overloads 3800 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 3801 for (FunctionSet::iterator Func = Functions.begin(), 3802 FuncEnd = Functions.end(); 3803 Func != FuncEnd; ++Func) 3804 Overloads->addOverload(*Func); 3805 3806 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 3807 OpLoc, false, false); 3808 3809 input.release(); 3810 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 3811 &Args[0], NumArgs, 3812 Context.DependentTy, 3813 OpLoc)); 3814 } 3815 3816 // Build an empty overload set. 3817 OverloadCandidateSet CandidateSet; 3818 3819 // Add the candidates from the given function set. 3820 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 3821 3822 // Add operator candidates that are member functions. 3823 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 3824 3825 // Add builtin operator candidates. 3826 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 3827 3828 // Perform overload resolution. 3829 OverloadCandidateSet::iterator Best; 3830 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 3831 case OR_Success: { 3832 // We found a built-in operator or an overloaded operator. 3833 FunctionDecl *FnDecl = Best->Function; 3834 3835 if (FnDecl) { 3836 // We matched an overloaded operator. Build a call to that 3837 // operator. 3838 3839 // Convert the arguments. 3840 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 3841 if (PerformObjectArgumentInitialization(Input, Method)) 3842 return ExprError(); 3843 } else { 3844 // Convert the arguments. 3845 if (PerformCopyInitialization(Input, 3846 FnDecl->getParamDecl(0)->getType(), 3847 "passing")) 3848 return ExprError(); 3849 } 3850 3851 // Determine the result type 3852 QualType ResultTy 3853 = FnDecl->getType()->getAsFunctionType()->getResultType(); 3854 ResultTy = ResultTy.getNonReferenceType(); 3855 3856 // Build the actual expression node. 3857 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 3858 SourceLocation()); 3859 UsualUnaryConversions(FnExpr); 3860 3861 input.release(); 3862 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 3863 &Input, 1, ResultTy, 3864 OpLoc)); 3865 } else { 3866 // We matched a built-in operator. Convert the arguments, then 3867 // break out so that we will build the appropriate built-in 3868 // operator node. 3869 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 3870 Best->Conversions[0], "passing")) 3871 return ExprError(); 3872 3873 break; 3874 } 3875 } 3876 3877 case OR_No_Viable_Function: 3878 // No viable function; fall through to handling this as a 3879 // built-in operator, which will produce an error message for us. 3880 break; 3881 3882 case OR_Ambiguous: 3883 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 3884 << UnaryOperator::getOpcodeStr(Opc) 3885 << Input->getSourceRange(); 3886 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3887 return ExprError(); 3888 3889 case OR_Deleted: 3890 Diag(OpLoc, diag::err_ovl_deleted_oper) 3891 << Best->Function->isDeleted() 3892 << UnaryOperator::getOpcodeStr(Opc) 3893 << Input->getSourceRange(); 3894 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3895 return ExprError(); 3896 } 3897 3898 // Either we found no viable overloaded operator or we matched a 3899 // built-in operator. In either case, fall through to trying to 3900 // build a built-in operation. 3901 input.release(); 3902 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 3903} 3904 3905/// \brief Create a binary operation that may resolve to an overloaded 3906/// operator. 3907/// 3908/// \param OpLoc The location of the operator itself (e.g., '+'). 3909/// 3910/// \param OpcIn The BinaryOperator::Opcode that describes this 3911/// operator. 3912/// 3913/// \param Functions The set of non-member functions that will be 3914/// considered by overload resolution. The caller needs to build this 3915/// set based on the context using, e.g., 3916/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 3917/// set should not contain any member functions; those will be added 3918/// by CreateOverloadedBinOp(). 3919/// 3920/// \param LHS Left-hand argument. 3921/// \param RHS Right-hand argument. 3922Sema::OwningExprResult 3923Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 3924 unsigned OpcIn, 3925 FunctionSet &Functions, 3926 Expr *LHS, Expr *RHS) { 3927 Expr *Args[2] = { LHS, RHS }; 3928 3929 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 3930 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 3931 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3932 3933 // If either side is type-dependent, create an appropriate dependent 3934 // expression. 3935 if (LHS->isTypeDependent() || RHS->isTypeDependent()) { 3936 // .* cannot be overloaded. 3937 if (Opc == BinaryOperator::PtrMemD) 3938 return Owned(new (Context) BinaryOperator(LHS, RHS, Opc, 3939 Context.DependentTy, OpLoc)); 3940 3941 OverloadedFunctionDecl *Overloads 3942 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 3943 for (FunctionSet::iterator Func = Functions.begin(), 3944 FuncEnd = Functions.end(); 3945 Func != FuncEnd; ++Func) 3946 Overloads->addOverload(*Func); 3947 3948 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 3949 OpLoc, false, false); 3950 3951 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 3952 Args, 2, 3953 Context.DependentTy, 3954 OpLoc)); 3955 } 3956 3957 // If this is the .* operator, which is not overloadable, just 3958 // create a built-in binary operator. 3959 if (Opc == BinaryOperator::PtrMemD) 3960 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 3961 3962 // If this is one of the assignment operators, we only perform 3963 // overload resolution if the left-hand side is a class or 3964 // enumeration type (C++ [expr.ass]p3). 3965 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 3966 !LHS->getType()->isOverloadableType()) 3967 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 3968 3969 // Build an empty overload set. 3970 OverloadCandidateSet CandidateSet; 3971 3972 // Add the candidates from the given function set. 3973 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 3974 3975 // Add operator candidates that are member functions. 3976 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 3977 3978 // Add builtin operator candidates. 3979 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 3980 3981 // Perform overload resolution. 3982 OverloadCandidateSet::iterator Best; 3983 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 3984 case OR_Success: { 3985 // We found a built-in operator or an overloaded operator. 3986 FunctionDecl *FnDecl = Best->Function; 3987 3988 if (FnDecl) { 3989 // We matched an overloaded operator. Build a call to that 3990 // operator. 3991 3992 // Convert the arguments. 3993 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 3994 if (PerformObjectArgumentInitialization(LHS, Method) || 3995 PerformCopyInitialization(RHS, FnDecl->getParamDecl(0)->getType(), 3996 "passing")) 3997 return ExprError(); 3998 } else { 3999 // Convert the arguments. 4000 if (PerformCopyInitialization(LHS, FnDecl->getParamDecl(0)->getType(), 4001 "passing") || 4002 PerformCopyInitialization(RHS, FnDecl->getParamDecl(1)->getType(), 4003 "passing")) 4004 return ExprError(); 4005 } 4006 4007 // Determine the result type 4008 QualType ResultTy 4009 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4010 ResultTy = ResultTy.getNonReferenceType(); 4011 4012 // Build the actual expression node. 4013 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4014 SourceLocation()); 4015 UsualUnaryConversions(FnExpr); 4016 4017 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4018 Args, 2, ResultTy, 4019 OpLoc)); 4020 } else { 4021 // We matched a built-in operator. Convert the arguments, then 4022 // break out so that we will build the appropriate built-in 4023 // operator node. 4024 if (PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0], 4025 Best->Conversions[0], "passing") || 4026 PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1], 4027 Best->Conversions[1], "passing")) 4028 return ExprError(); 4029 4030 break; 4031 } 4032 } 4033 4034 case OR_No_Viable_Function: 4035 // For class as left operand for assignment or compound assigment operator 4036 // do not fall through to handling in built-in, but report that no overloaded 4037 // assignment operator found 4038 if (LHS->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4039 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4040 << BinaryOperator::getOpcodeStr(Opc) 4041 << LHS->getSourceRange() << RHS->getSourceRange(); 4042 return ExprError(); 4043 } 4044 // No viable function; fall through to handling this as a 4045 // built-in operator, which will produce an error message for us. 4046 break; 4047 4048 case OR_Ambiguous: 4049 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4050 << BinaryOperator::getOpcodeStr(Opc) 4051 << LHS->getSourceRange() << RHS->getSourceRange(); 4052 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4053 return ExprError(); 4054 4055 case OR_Deleted: 4056 Diag(OpLoc, diag::err_ovl_deleted_oper) 4057 << Best->Function->isDeleted() 4058 << BinaryOperator::getOpcodeStr(Opc) 4059 << LHS->getSourceRange() << RHS->getSourceRange(); 4060 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4061 return ExprError(); 4062 } 4063 4064 // Either we found no viable overloaded operator or we matched a 4065 // built-in operator. In either case, try to build a built-in 4066 // operation. 4067 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4068} 4069 4070/// BuildCallToMemberFunction - Build a call to a member 4071/// function. MemExpr is the expression that refers to the member 4072/// function (and includes the object parameter), Args/NumArgs are the 4073/// arguments to the function call (not including the object 4074/// parameter). The caller needs to validate that the member 4075/// expression refers to a member function or an overloaded member 4076/// function. 4077Sema::ExprResult 4078Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4079 SourceLocation LParenLoc, Expr **Args, 4080 unsigned NumArgs, SourceLocation *CommaLocs, 4081 SourceLocation RParenLoc) { 4082 // Dig out the member expression. This holds both the object 4083 // argument and the member function we're referring to. 4084 MemberExpr *MemExpr = 0; 4085 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4086 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4087 else 4088 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4089 assert(MemExpr && "Building member call without member expression"); 4090 4091 // Extract the object argument. 4092 Expr *ObjectArg = MemExpr->getBase(); 4093 4094 CXXMethodDecl *Method = 0; 4095 if (OverloadedFunctionDecl *Ovl 4096 = dyn_cast<OverloadedFunctionDecl>(MemExpr->getMemberDecl())) { 4097 // Add overload candidates 4098 OverloadCandidateSet CandidateSet; 4099 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4100 FuncEnd = Ovl->function_end(); 4101 Func != FuncEnd; ++Func) { 4102 assert(isa<CXXMethodDecl>(*Func) && "Function is not a method"); 4103 Method = cast<CXXMethodDecl>(*Func); 4104 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4105 /*SuppressUserConversions=*/false); 4106 } 4107 4108 OverloadCandidateSet::iterator Best; 4109 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4110 case OR_Success: 4111 Method = cast<CXXMethodDecl>(Best->Function); 4112 break; 4113 4114 case OR_No_Viable_Function: 4115 Diag(MemExpr->getSourceRange().getBegin(), 4116 diag::err_ovl_no_viable_member_function_in_call) 4117 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4118 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4119 // FIXME: Leaking incoming expressions! 4120 return true; 4121 4122 case OR_Ambiguous: 4123 Diag(MemExpr->getSourceRange().getBegin(), 4124 diag::err_ovl_ambiguous_member_call) 4125 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4126 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4127 // FIXME: Leaking incoming expressions! 4128 return true; 4129 4130 case OR_Deleted: 4131 Diag(MemExpr->getSourceRange().getBegin(), 4132 diag::err_ovl_deleted_member_call) 4133 << Best->Function->isDeleted() 4134 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4135 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4136 // FIXME: Leaking incoming expressions! 4137 return true; 4138 } 4139 4140 FixOverloadedFunctionReference(MemExpr, Method); 4141 } else { 4142 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4143 } 4144 4145 assert(Method && "Member call to something that isn't a method?"); 4146 ExprOwningPtr<CXXMemberCallExpr> 4147 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4148 NumArgs, 4149 Method->getResultType().getNonReferenceType(), 4150 RParenLoc)); 4151 4152 // Convert the object argument (for a non-static member function call). 4153 if (!Method->isStatic() && 4154 PerformObjectArgumentInitialization(ObjectArg, Method)) 4155 return true; 4156 MemExpr->setBase(ObjectArg); 4157 4158 // Convert the rest of the arguments 4159 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4160 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4161 RParenLoc)) 4162 return true; 4163 4164 return CheckFunctionCall(Method, TheCall.take()).release(); 4165} 4166 4167/// BuildCallToObjectOfClassType - Build a call to an object of class 4168/// type (C++ [over.call.object]), which can end up invoking an 4169/// overloaded function call operator (@c operator()) or performing a 4170/// user-defined conversion on the object argument. 4171Sema::ExprResult 4172Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4173 SourceLocation LParenLoc, 4174 Expr **Args, unsigned NumArgs, 4175 SourceLocation *CommaLocs, 4176 SourceLocation RParenLoc) { 4177 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4178 const RecordType *Record = Object->getType()->getAsRecordType(); 4179 4180 // C++ [over.call.object]p1: 4181 // If the primary-expression E in the function call syntax 4182 // evaluates to a class object of type “cv T”, then the set of 4183 // candidate functions includes at least the function call 4184 // operators of T. The function call operators of T are obtained by 4185 // ordinary lookup of the name operator() in the context of 4186 // (E).operator(). 4187 OverloadCandidateSet CandidateSet; 4188 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4189 DeclContext::lookup_const_iterator Oper, OperEnd; 4190 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(Context, OpName); 4191 Oper != OperEnd; ++Oper) 4192 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4193 CandidateSet, /*SuppressUserConversions=*/false); 4194 4195 // C++ [over.call.object]p2: 4196 // In addition, for each conversion function declared in T of the 4197 // form 4198 // 4199 // operator conversion-type-id () cv-qualifier; 4200 // 4201 // where cv-qualifier is the same cv-qualification as, or a 4202 // greater cv-qualification than, cv, and where conversion-type-id 4203 // denotes the type "pointer to function of (P1,...,Pn) returning 4204 // R", or the type "reference to pointer to function of 4205 // (P1,...,Pn) returning R", or the type "reference to function 4206 // of (P1,...,Pn) returning R", a surrogate call function [...] 4207 // is also considered as a candidate function. Similarly, 4208 // surrogate call functions are added to the set of candidate 4209 // functions for each conversion function declared in an 4210 // accessible base class provided the function is not hidden 4211 // within T by another intervening declaration. 4212 // 4213 // FIXME: Look in base classes for more conversion operators! 4214 OverloadedFunctionDecl *Conversions 4215 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4216 for (OverloadedFunctionDecl::function_iterator 4217 Func = Conversions->function_begin(), 4218 FuncEnd = Conversions->function_end(); 4219 Func != FuncEnd; ++Func) { 4220 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 4221 4222 // Strip the reference type (if any) and then the pointer type (if 4223 // any) to get down to what might be a function type. 4224 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4225 if (const PointerType *ConvPtrType = ConvType->getAsPointerType()) 4226 ConvType = ConvPtrType->getPointeeType(); 4227 4228 if (const FunctionProtoType *Proto = ConvType->getAsFunctionProtoType()) 4229 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4230 } 4231 4232 // Perform overload resolution. 4233 OverloadCandidateSet::iterator Best; 4234 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4235 case OR_Success: 4236 // Overload resolution succeeded; we'll build the appropriate call 4237 // below. 4238 break; 4239 4240 case OR_No_Viable_Function: 4241 Diag(Object->getSourceRange().getBegin(), 4242 diag::err_ovl_no_viable_object_call) 4243 << Object->getType() << Object->getSourceRange(); 4244 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4245 break; 4246 4247 case OR_Ambiguous: 4248 Diag(Object->getSourceRange().getBegin(), 4249 diag::err_ovl_ambiguous_object_call) 4250 << Object->getType() << Object->getSourceRange(); 4251 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4252 break; 4253 4254 case OR_Deleted: 4255 Diag(Object->getSourceRange().getBegin(), 4256 diag::err_ovl_deleted_object_call) 4257 << Best->Function->isDeleted() 4258 << Object->getType() << Object->getSourceRange(); 4259 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4260 break; 4261 } 4262 4263 if (Best == CandidateSet.end()) { 4264 // We had an error; delete all of the subexpressions and return 4265 // the error. 4266 Object->Destroy(Context); 4267 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4268 Args[ArgIdx]->Destroy(Context); 4269 return true; 4270 } 4271 4272 if (Best->Function == 0) { 4273 // Since there is no function declaration, this is one of the 4274 // surrogate candidates. Dig out the conversion function. 4275 CXXConversionDecl *Conv 4276 = cast<CXXConversionDecl>( 4277 Best->Conversions[0].UserDefined.ConversionFunction); 4278 4279 // We selected one of the surrogate functions that converts the 4280 // object parameter to a function pointer. Perform the conversion 4281 // on the object argument, then let ActOnCallExpr finish the job. 4282 // FIXME: Represent the user-defined conversion in the AST! 4283 ImpCastExprToType(Object, 4284 Conv->getConversionType().getNonReferenceType(), 4285 Conv->getConversionType()->isLValueReferenceType()); 4286 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4287 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4288 CommaLocs, RParenLoc).release(); 4289 } 4290 4291 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4292 // that calls this method, using Object for the implicit object 4293 // parameter and passing along the remaining arguments. 4294 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4295 const FunctionProtoType *Proto = Method->getType()->getAsFunctionProtoType(); 4296 4297 unsigned NumArgsInProto = Proto->getNumArgs(); 4298 unsigned NumArgsToCheck = NumArgs; 4299 4300 // Build the full argument list for the method call (the 4301 // implicit object parameter is placed at the beginning of the 4302 // list). 4303 Expr **MethodArgs; 4304 if (NumArgs < NumArgsInProto) { 4305 NumArgsToCheck = NumArgsInProto; 4306 MethodArgs = new Expr*[NumArgsInProto + 1]; 4307 } else { 4308 MethodArgs = new Expr*[NumArgs + 1]; 4309 } 4310 MethodArgs[0] = Object; 4311 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4312 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4313 4314 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4315 SourceLocation()); 4316 UsualUnaryConversions(NewFn); 4317 4318 // Once we've built TheCall, all of the expressions are properly 4319 // owned. 4320 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4321 ExprOwningPtr<CXXOperatorCallExpr> 4322 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4323 MethodArgs, NumArgs + 1, 4324 ResultTy, RParenLoc)); 4325 delete [] MethodArgs; 4326 4327 // We may have default arguments. If so, we need to allocate more 4328 // slots in the call for them. 4329 if (NumArgs < NumArgsInProto) 4330 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4331 else if (NumArgs > NumArgsInProto) 4332 NumArgsToCheck = NumArgsInProto; 4333 4334 bool IsError = false; 4335 4336 // Initialize the implicit object parameter. 4337 IsError |= PerformObjectArgumentInitialization(Object, Method); 4338 TheCall->setArg(0, Object); 4339 4340 4341 // Check the argument types. 4342 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4343 Expr *Arg; 4344 if (i < NumArgs) { 4345 Arg = Args[i]; 4346 4347 // Pass the argument. 4348 QualType ProtoArgType = Proto->getArgType(i); 4349 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4350 } else { 4351 Arg = new (Context) CXXDefaultArgExpr(Method->getParamDecl(i)); 4352 } 4353 4354 TheCall->setArg(i + 1, Arg); 4355 } 4356 4357 // If this is a variadic call, handle args passed through "...". 4358 if (Proto->isVariadic()) { 4359 // Promote the arguments (C99 6.5.2.2p7). 4360 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4361 Expr *Arg = Args[i]; 4362 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4363 TheCall->setArg(i + 1, Arg); 4364 } 4365 } 4366 4367 if (IsError) return true; 4368 4369 return CheckFunctionCall(Method, TheCall.take()).release(); 4370} 4371 4372/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4373/// (if one exists), where @c Base is an expression of class type and 4374/// @c Member is the name of the member we're trying to find. 4375Action::ExprResult 4376Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc, 4377 SourceLocation MemberLoc, 4378 IdentifierInfo &Member) { 4379 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4380 4381 // C++ [over.ref]p1: 4382 // 4383 // [...] An expression x->m is interpreted as (x.operator->())->m 4384 // for a class object x of type T if T::operator->() exists and if 4385 // the operator is selected as the best match function by the 4386 // overload resolution mechanism (13.3). 4387 // FIXME: look in base classes. 4388 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4389 OverloadCandidateSet CandidateSet; 4390 const RecordType *BaseRecord = Base->getType()->getAsRecordType(); 4391 4392 DeclContext::lookup_const_iterator Oper, OperEnd; 4393 for (llvm::tie(Oper, OperEnd) 4394 = BaseRecord->getDecl()->lookup(Context, OpName); 4395 Oper != OperEnd; ++Oper) 4396 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4397 /*SuppressUserConversions=*/false); 4398 4399 ExprOwningPtr<Expr> BasePtr(this, Base); 4400 4401 // Perform overload resolution. 4402 OverloadCandidateSet::iterator Best; 4403 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4404 case OR_Success: 4405 // Overload resolution succeeded; we'll build the call below. 4406 break; 4407 4408 case OR_No_Viable_Function: 4409 if (CandidateSet.empty()) 4410 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4411 << BasePtr->getType() << BasePtr->getSourceRange(); 4412 else 4413 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4414 << "operator->" << BasePtr->getSourceRange(); 4415 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4416 return true; 4417 4418 case OR_Ambiguous: 4419 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4420 << "operator->" << BasePtr->getSourceRange(); 4421 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4422 return true; 4423 4424 case OR_Deleted: 4425 Diag(OpLoc, diag::err_ovl_deleted_oper) 4426 << Best->Function->isDeleted() 4427 << "operator->" << BasePtr->getSourceRange(); 4428 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4429 return true; 4430 } 4431 4432 // Convert the object parameter. 4433 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4434 if (PerformObjectArgumentInitialization(Base, Method)) 4435 return true; 4436 4437 // No concerns about early exits now. 4438 BasePtr.take(); 4439 4440 // Build the operator call. 4441 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 4442 SourceLocation()); 4443 UsualUnaryConversions(FnExpr); 4444 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 4445 Method->getResultType().getNonReferenceType(), 4446 OpLoc); 4447 return ActOnMemberReferenceExpr(S, ExprArg(*this, Base), OpLoc, tok::arrow, 4448 MemberLoc, Member, DeclPtrTy()).release(); 4449} 4450 4451/// FixOverloadedFunctionReference - E is an expression that refers to 4452/// a C++ overloaded function (possibly with some parentheses and 4453/// perhaps a '&' around it). We have resolved the overloaded function 4454/// to the function declaration Fn, so patch up the expression E to 4455/// refer (possibly indirectly) to Fn. 4456void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 4457 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4458 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 4459 E->setType(PE->getSubExpr()->getType()); 4460 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 4461 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 4462 "Can only take the address of an overloaded function"); 4463 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4464 if (Method->isStatic()) { 4465 // Do nothing: static member functions aren't any different 4466 // from non-member functions. 4467 } 4468 else if (QualifiedDeclRefExpr *DRE 4469 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 4470 // We have taken the address of a pointer to member 4471 // function. Perform the computation here so that we get the 4472 // appropriate pointer to member type. 4473 DRE->setDecl(Fn); 4474 DRE->setType(Fn->getType()); 4475 QualType ClassType 4476 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 4477 E->setType(Context.getMemberPointerType(Fn->getType(), 4478 ClassType.getTypePtr())); 4479 return; 4480 } 4481 } 4482 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 4483 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 4484 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 4485 assert(isa<OverloadedFunctionDecl>(DR->getDecl()) && 4486 "Expected overloaded function"); 4487 DR->setDecl(Fn); 4488 E->setType(Fn->getType()); 4489 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 4490 MemExpr->setMemberDecl(Fn); 4491 E->setType(Fn->getType()); 4492 } else { 4493 assert(false && "Invalid reference to overloaded function"); 4494 } 4495} 4496 4497} // end namespace clang 4498