SemaOverload.cpp revision 071f2aec57467027540ea849b7889c4c263dbb7d
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/Support/Compiler.h" 24#include <algorithm> 25 26namespace clang { 27 28/// GetConversionCategory - Retrieve the implicit conversion 29/// category corresponding to the given implicit conversion kind. 30ImplicitConversionCategory 31GetConversionCategory(ImplicitConversionKind Kind) { 32 static const ImplicitConversionCategory 33 Category[(int)ICK_Num_Conversion_Kinds] = { 34 ICC_Identity, 35 ICC_Lvalue_Transformation, 36 ICC_Lvalue_Transformation, 37 ICC_Lvalue_Transformation, 38 ICC_Qualification_Adjustment, 39 ICC_Promotion, 40 ICC_Promotion, 41 ICC_Conversion, 42 ICC_Conversion, 43 ICC_Conversion, 44 ICC_Conversion, 45 ICC_Conversion, 46 ICC_Conversion, 47 ICC_Conversion 48 }; 49 return Category[(int)Kind]; 50} 51 52/// GetConversionRank - Retrieve the implicit conversion rank 53/// corresponding to the given implicit conversion kind. 54ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 55 static const ImplicitConversionRank 56 Rank[(int)ICK_Num_Conversion_Kinds] = { 57 ICR_Exact_Match, 58 ICR_Exact_Match, 59 ICR_Exact_Match, 60 ICR_Exact_Match, 61 ICR_Exact_Match, 62 ICR_Promotion, 63 ICR_Promotion, 64 ICR_Conversion, 65 ICR_Conversion, 66 ICR_Conversion, 67 ICR_Conversion, 68 ICR_Conversion, 69 ICR_Conversion, 70 ICR_Conversion 71 }; 72 return Rank[(int)Kind]; 73} 74 75/// GetImplicitConversionName - Return the name of this kind of 76/// implicit conversion. 77const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 78 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 79 "No conversion", 80 "Lvalue-to-rvalue", 81 "Array-to-pointer", 82 "Function-to-pointer", 83 "Qualification", 84 "Integral promotion", 85 "Floating point promotion", 86 "Integral conversion", 87 "Floating conversion", 88 "Floating-integral conversion", 89 "Pointer conversion", 90 "Pointer-to-member conversion", 91 "Boolean conversion", 92 "Derived-to-base conversion" 93 }; 94 return Name[Kind]; 95} 96 97/// StandardConversionSequence - Set the standard conversion 98/// sequence to the identity conversion. 99void StandardConversionSequence::setAsIdentityConversion() { 100 First = ICK_Identity; 101 Second = ICK_Identity; 102 Third = ICK_Identity; 103 Deprecated = false; 104 ReferenceBinding = false; 105 DirectBinding = false; 106 CopyConstructor = 0; 107} 108 109/// getRank - Retrieve the rank of this standard conversion sequence 110/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 111/// implicit conversions. 112ImplicitConversionRank StandardConversionSequence::getRank() const { 113 ImplicitConversionRank Rank = ICR_Exact_Match; 114 if (GetConversionRank(First) > Rank) 115 Rank = GetConversionRank(First); 116 if (GetConversionRank(Second) > Rank) 117 Rank = GetConversionRank(Second); 118 if (GetConversionRank(Third) > Rank) 119 Rank = GetConversionRank(Third); 120 return Rank; 121} 122 123/// isPointerConversionToBool - Determines whether this conversion is 124/// a conversion of a pointer or pointer-to-member to bool. This is 125/// used as part of the ranking of standard conversion sequences 126/// (C++ 13.3.3.2p4). 127bool StandardConversionSequence::isPointerConversionToBool() const 128{ 129 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 130 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 131 132 // Note that FromType has not necessarily been transformed by the 133 // array-to-pointer or function-to-pointer implicit conversions, so 134 // check for their presence as well as checking whether FromType is 135 // a pointer. 136 if (ToType->isBooleanType() && 137 (FromType->isPointerType() || 138 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 139 return true; 140 141 return false; 142} 143 144/// isPointerConversionToVoidPointer - Determines whether this 145/// conversion is a conversion of a pointer to a void pointer. This is 146/// used as part of the ranking of standard conversion sequences (C++ 147/// 13.3.3.2p4). 148bool 149StandardConversionSequence:: 150isPointerConversionToVoidPointer(ASTContext& Context) const 151{ 152 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 153 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 154 155 // Note that FromType has not necessarily been transformed by the 156 // array-to-pointer implicit conversion, so check for its presence 157 // and redo the conversion to get a pointer. 158 if (First == ICK_Array_To_Pointer) 159 FromType = Context.getArrayDecayedType(FromType); 160 161 if (Second == ICK_Pointer_Conversion) 162 if (const PointerType* ToPtrType = ToType->getAsPointerType()) 163 return ToPtrType->getPointeeType()->isVoidType(); 164 165 return false; 166} 167 168/// DebugPrint - Print this standard conversion sequence to standard 169/// error. Useful for debugging overloading issues. 170void StandardConversionSequence::DebugPrint() const { 171 bool PrintedSomething = false; 172 if (First != ICK_Identity) { 173 fprintf(stderr, "%s", GetImplicitConversionName(First)); 174 PrintedSomething = true; 175 } 176 177 if (Second != ICK_Identity) { 178 if (PrintedSomething) { 179 fprintf(stderr, " -> "); 180 } 181 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 182 183 if (CopyConstructor) { 184 fprintf(stderr, " (by copy constructor)"); 185 } else if (DirectBinding) { 186 fprintf(stderr, " (direct reference binding)"); 187 } else if (ReferenceBinding) { 188 fprintf(stderr, " (reference binding)"); 189 } 190 PrintedSomething = true; 191 } 192 193 if (Third != ICK_Identity) { 194 if (PrintedSomething) { 195 fprintf(stderr, " -> "); 196 } 197 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 198 PrintedSomething = true; 199 } 200 201 if (!PrintedSomething) { 202 fprintf(stderr, "No conversions required"); 203 } 204} 205 206/// DebugPrint - Print this user-defined conversion sequence to standard 207/// error. Useful for debugging overloading issues. 208void UserDefinedConversionSequence::DebugPrint() const { 209 if (Before.First || Before.Second || Before.Third) { 210 Before.DebugPrint(); 211 fprintf(stderr, " -> "); 212 } 213 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 214 if (After.First || After.Second || After.Third) { 215 fprintf(stderr, " -> "); 216 After.DebugPrint(); 217 } 218} 219 220/// DebugPrint - Print this implicit conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void ImplicitConversionSequence::DebugPrint() const { 223 switch (ConversionKind) { 224 case StandardConversion: 225 fprintf(stderr, "Standard conversion: "); 226 Standard.DebugPrint(); 227 break; 228 case UserDefinedConversion: 229 fprintf(stderr, "User-defined conversion: "); 230 UserDefined.DebugPrint(); 231 break; 232 case EllipsisConversion: 233 fprintf(stderr, "Ellipsis conversion"); 234 break; 235 case BadConversion: 236 fprintf(stderr, "Bad conversion"); 237 break; 238 } 239 240 fprintf(stderr, "\n"); 241} 242 243// IsOverload - Determine whether the given New declaration is an 244// overload of the Old declaration. This routine returns false if New 245// and Old cannot be overloaded, e.g., if they are functions with the 246// same signature (C++ 1.3.10) or if the Old declaration isn't a 247// function (or overload set). When it does return false and Old is an 248// OverloadedFunctionDecl, MatchedDecl will be set to point to the 249// FunctionDecl that New cannot be overloaded with. 250// 251// Example: Given the following input: 252// 253// void f(int, float); // #1 254// void f(int, int); // #2 255// int f(int, int); // #3 256// 257// When we process #1, there is no previous declaration of "f", 258// so IsOverload will not be used. 259// 260// When we process #2, Old is a FunctionDecl for #1. By comparing the 261// parameter types, we see that #1 and #2 are overloaded (since they 262// have different signatures), so this routine returns false; 263// MatchedDecl is unchanged. 264// 265// When we process #3, Old is an OverloadedFunctionDecl containing #1 266// and #2. We compare the signatures of #3 to #1 (they're overloaded, 267// so we do nothing) and then #3 to #2. Since the signatures of #3 and 268// #2 are identical (return types of functions are not part of the 269// signature), IsOverload returns false and MatchedDecl will be set to 270// point to the FunctionDecl for #2. 271bool 272Sema::IsOverload(FunctionDecl *New, Decl* OldD, 273 OverloadedFunctionDecl::function_iterator& MatchedDecl) 274{ 275 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 276 // Is this new function an overload of every function in the 277 // overload set? 278 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 279 FuncEnd = Ovl->function_end(); 280 for (; Func != FuncEnd; ++Func) { 281 if (!IsOverload(New, *Func, MatchedDecl)) { 282 MatchedDecl = Func; 283 return false; 284 } 285 } 286 287 // This function overloads every function in the overload set. 288 return true; 289 } else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 290 // Is the function New an overload of the function Old? 291 QualType OldQType = Context.getCanonicalType(Old->getType()); 292 QualType NewQType = Context.getCanonicalType(New->getType()); 293 294 // Compare the signatures (C++ 1.3.10) of the two functions to 295 // determine whether they are overloads. If we find any mismatch 296 // in the signature, they are overloads. 297 298 // If either of these functions is a K&R-style function (no 299 // prototype), then we consider them to have matching signatures. 300 if (isa<FunctionTypeNoProto>(OldQType.getTypePtr()) || 301 isa<FunctionTypeNoProto>(NewQType.getTypePtr())) 302 return false; 303 304 FunctionTypeProto* OldType = cast<FunctionTypeProto>(OldQType.getTypePtr()); 305 FunctionTypeProto* NewType = cast<FunctionTypeProto>(NewQType.getTypePtr()); 306 307 // The signature of a function includes the types of its 308 // parameters (C++ 1.3.10), which includes the presence or absence 309 // of the ellipsis; see C++ DR 357). 310 if (OldQType != NewQType && 311 (OldType->getNumArgs() != NewType->getNumArgs() || 312 OldType->isVariadic() != NewType->isVariadic() || 313 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 314 NewType->arg_type_begin()))) 315 return true; 316 317 // If the function is a class member, its signature includes the 318 // cv-qualifiers (if any) on the function itself. 319 // 320 // As part of this, also check whether one of the member functions 321 // is static, in which case they are not overloads (C++ 322 // 13.1p2). While not part of the definition of the signature, 323 // this check is important to determine whether these functions 324 // can be overloaded. 325 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 326 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 327 if (OldMethod && NewMethod && 328 !OldMethod->isStatic() && !NewMethod->isStatic() && 329 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 330 return true; 331 332 // The signatures match; this is not an overload. 333 return false; 334 } else { 335 // (C++ 13p1): 336 // Only function declarations can be overloaded; object and type 337 // declarations cannot be overloaded. 338 return false; 339 } 340} 341 342/// TryImplicitConversion - Attempt to perform an implicit conversion 343/// from the given expression (Expr) to the given type (ToType). This 344/// function returns an implicit conversion sequence that can be used 345/// to perform the initialization. Given 346/// 347/// void f(float f); 348/// void g(int i) { f(i); } 349/// 350/// this routine would produce an implicit conversion sequence to 351/// describe the initialization of f from i, which will be a standard 352/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 353/// 4.1) followed by a floating-integral conversion (C++ 4.9). 354// 355/// Note that this routine only determines how the conversion can be 356/// performed; it does not actually perform the conversion. As such, 357/// it will not produce any diagnostics if no conversion is available, 358/// but will instead return an implicit conversion sequence of kind 359/// "BadConversion". 360/// 361/// If @p SuppressUserConversions, then user-defined conversions are 362/// not permitted. 363ImplicitConversionSequence 364Sema::TryImplicitConversion(Expr* From, QualType ToType, 365 bool SuppressUserConversions) 366{ 367 ImplicitConversionSequence ICS; 368 if (IsStandardConversion(From, ToType, ICS.Standard)) 369 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 370 else if (!SuppressUserConversions && 371 IsUserDefinedConversion(From, ToType, ICS.UserDefined)) { 372 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 373 // C++ [over.ics.user]p4: 374 // A conversion of an expression of class type to the same class 375 // type is given Exact Match rank, and a conversion of an 376 // expression of class type to a base class of that type is 377 // given Conversion rank, in spite of the fact that a copy 378 // constructor (i.e., a user-defined conversion function) is 379 // called for those cases. 380 if (CXXConstructorDecl *Constructor 381 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 382 if (Constructor->isCopyConstructor(Context)) { 383 // Turn this into a "standard" conversion sequence, so that it 384 // gets ranked with standard conversion sequences. 385 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 386 ICS.Standard.setAsIdentityConversion(); 387 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 388 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 389 ICS.Standard.CopyConstructor = Constructor; 390 if (IsDerivedFrom(From->getType().getUnqualifiedType(), 391 ToType.getUnqualifiedType())) 392 ICS.Standard.Second = ICK_Derived_To_Base; 393 } 394 } 395 } else 396 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 397 398 return ICS; 399} 400 401/// IsStandardConversion - Determines whether there is a standard 402/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 403/// expression From to the type ToType. Standard conversion sequences 404/// only consider non-class types; for conversions that involve class 405/// types, use TryImplicitConversion. If a conversion exists, SCS will 406/// contain the standard conversion sequence required to perform this 407/// conversion and this routine will return true. Otherwise, this 408/// routine will return false and the value of SCS is unspecified. 409bool 410Sema::IsStandardConversion(Expr* From, QualType ToType, 411 StandardConversionSequence &SCS) 412{ 413 QualType FromType = From->getType(); 414 415 // There are no standard conversions for class types, so abort early. 416 if (FromType->isRecordType() || ToType->isRecordType()) 417 return false; 418 419 // Standard conversions (C++ [conv]) 420 SCS.setAsIdentityConversion(); 421 SCS.Deprecated = false; 422 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 423 SCS.CopyConstructor = 0; 424 425 // The first conversion can be an lvalue-to-rvalue conversion, 426 // array-to-pointer conversion, or function-to-pointer conversion 427 // (C++ 4p1). 428 429 // Lvalue-to-rvalue conversion (C++ 4.1): 430 // An lvalue (3.10) of a non-function, non-array type T can be 431 // converted to an rvalue. 432 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 433 if (argIsLvalue == Expr::LV_Valid && 434 !FromType->isFunctionType() && !FromType->isArrayType() && 435 !FromType->isOverloadType()) { 436 SCS.First = ICK_Lvalue_To_Rvalue; 437 438 // If T is a non-class type, the type of the rvalue is the 439 // cv-unqualified version of T. Otherwise, the type of the rvalue 440 // is T (C++ 4.1p1). 441 FromType = FromType.getUnqualifiedType(); 442 } 443 // Array-to-pointer conversion (C++ 4.2) 444 else if (FromType->isArrayType()) { 445 SCS.First = ICK_Array_To_Pointer; 446 447 // An lvalue or rvalue of type "array of N T" or "array of unknown 448 // bound of T" can be converted to an rvalue of type "pointer to 449 // T" (C++ 4.2p1). 450 FromType = Context.getArrayDecayedType(FromType); 451 452 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 453 // This conversion is deprecated. (C++ D.4). 454 SCS.Deprecated = true; 455 456 // For the purpose of ranking in overload resolution 457 // (13.3.3.1.1), this conversion is considered an 458 // array-to-pointer conversion followed by a qualification 459 // conversion (4.4). (C++ 4.2p2) 460 SCS.Second = ICK_Identity; 461 SCS.Third = ICK_Qualification; 462 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 463 return true; 464 } 465 } 466 // Function-to-pointer conversion (C++ 4.3). 467 else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 468 SCS.First = ICK_Function_To_Pointer; 469 470 // An lvalue of function type T can be converted to an rvalue of 471 // type "pointer to T." The result is a pointer to the 472 // function. (C++ 4.3p1). 473 FromType = Context.getPointerType(FromType); 474 } 475 // Address of overloaded function (C++ [over.over]). 476 else if (FunctionDecl *Fn 477 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 478 SCS.First = ICK_Function_To_Pointer; 479 480 // We were able to resolve the address of the overloaded function, 481 // so we can convert to the type of that function. 482 FromType = Fn->getType(); 483 if (ToType->isReferenceType()) 484 FromType = Context.getReferenceType(FromType); 485 else 486 FromType = Context.getPointerType(FromType); 487 } 488 // We don't require any conversions for the first step. 489 else { 490 SCS.First = ICK_Identity; 491 } 492 493 // The second conversion can be an integral promotion, floating 494 // point promotion, integral conversion, floating point conversion, 495 // floating-integral conversion, pointer conversion, 496 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 497 if (Context.getCanonicalType(FromType).getUnqualifiedType() == 498 Context.getCanonicalType(ToType).getUnqualifiedType()) { 499 // The unqualified versions of the types are the same: there's no 500 // conversion to do. 501 SCS.Second = ICK_Identity; 502 } 503 // Integral promotion (C++ 4.5). 504 else if (IsIntegralPromotion(From, FromType, ToType)) { 505 SCS.Second = ICK_Integral_Promotion; 506 FromType = ToType.getUnqualifiedType(); 507 } 508 // Floating point promotion (C++ 4.6). 509 else if (IsFloatingPointPromotion(FromType, ToType)) { 510 SCS.Second = ICK_Floating_Promotion; 511 FromType = ToType.getUnqualifiedType(); 512 } 513 // Integral conversions (C++ 4.7). 514 // FIXME: isIntegralType shouldn't be true for enums in C++. 515 else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 516 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 517 SCS.Second = ICK_Integral_Conversion; 518 FromType = ToType.getUnqualifiedType(); 519 } 520 // Floating point conversions (C++ 4.8). 521 else if (FromType->isFloatingType() && ToType->isFloatingType()) { 522 SCS.Second = ICK_Floating_Conversion; 523 FromType = ToType.getUnqualifiedType(); 524 } 525 // Floating-integral conversions (C++ 4.9). 526 // FIXME: isIntegralType shouldn't be true for enums in C++. 527 else if ((FromType->isFloatingType() && 528 ToType->isIntegralType() && !ToType->isBooleanType() && 529 !ToType->isEnumeralType()) || 530 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 531 ToType->isFloatingType())) { 532 SCS.Second = ICK_Floating_Integral; 533 FromType = ToType.getUnqualifiedType(); 534 } 535 // Pointer conversions (C++ 4.10). 536 else if (IsPointerConversion(From, FromType, ToType, FromType)) { 537 SCS.Second = ICK_Pointer_Conversion; 538 } 539 // FIXME: Pointer to member conversions (4.11). 540 // Boolean conversions (C++ 4.12). 541 // FIXME: pointer-to-member type 542 else if (ToType->isBooleanType() && 543 (FromType->isArithmeticType() || 544 FromType->isEnumeralType() || 545 FromType->isPointerType())) { 546 SCS.Second = ICK_Boolean_Conversion; 547 FromType = Context.BoolTy; 548 } else { 549 // No second conversion required. 550 SCS.Second = ICK_Identity; 551 } 552 553 QualType CanonFrom; 554 QualType CanonTo; 555 // The third conversion can be a qualification conversion (C++ 4p1). 556 if (IsQualificationConversion(FromType, ToType)) { 557 SCS.Third = ICK_Qualification; 558 FromType = ToType; 559 CanonFrom = Context.getCanonicalType(FromType); 560 CanonTo = Context.getCanonicalType(ToType); 561 } else { 562 // No conversion required 563 SCS.Third = ICK_Identity; 564 565 // C++ [over.best.ics]p6: 566 // [...] Any difference in top-level cv-qualification is 567 // subsumed by the initialization itself and does not constitute 568 // a conversion. [...] 569 CanonFrom = Context.getCanonicalType(FromType); 570 CanonTo = Context.getCanonicalType(ToType); 571 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 572 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 573 FromType = ToType; 574 CanonFrom = CanonTo; 575 } 576 } 577 578 // If we have not converted the argument type to the parameter type, 579 // this is a bad conversion sequence. 580 if (CanonFrom != CanonTo) 581 return false; 582 583 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 584 return true; 585} 586 587/// IsIntegralPromotion - Determines whether the conversion from the 588/// expression From (whose potentially-adjusted type is FromType) to 589/// ToType is an integral promotion (C++ 4.5). If so, returns true and 590/// sets PromotedType to the promoted type. 591bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) 592{ 593 const BuiltinType *To = ToType->getAsBuiltinType(); 594 // All integers are built-in. 595 if (!To) { 596 return false; 597 } 598 599 // An rvalue of type char, signed char, unsigned char, short int, or 600 // unsigned short int can be converted to an rvalue of type int if 601 // int can represent all the values of the source type; otherwise, 602 // the source rvalue can be converted to an rvalue of type unsigned 603 // int (C++ 4.5p1). 604 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 605 if (// We can promote any signed, promotable integer type to an int 606 (FromType->isSignedIntegerType() || 607 // We can promote any unsigned integer type whose size is 608 // less than int to an int. 609 (!FromType->isSignedIntegerType() && 610 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 611 return To->getKind() == BuiltinType::Int; 612 } 613 614 return To->getKind() == BuiltinType::UInt; 615 } 616 617 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 618 // can be converted to an rvalue of the first of the following types 619 // that can represent all the values of its underlying type: int, 620 // unsigned int, long, or unsigned long (C++ 4.5p2). 621 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 622 && ToType->isIntegerType()) { 623 // Determine whether the type we're converting from is signed or 624 // unsigned. 625 bool FromIsSigned; 626 uint64_t FromSize = Context.getTypeSize(FromType); 627 if (const EnumType *FromEnumType = FromType->getAsEnumType()) { 628 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 629 FromIsSigned = UnderlyingType->isSignedIntegerType(); 630 } else { 631 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 632 FromIsSigned = true; 633 } 634 635 // The types we'll try to promote to, in the appropriate 636 // order. Try each of these types. 637 QualType PromoteTypes[4] = { 638 Context.IntTy, Context.UnsignedIntTy, 639 Context.LongTy, Context.UnsignedLongTy 640 }; 641 for (int Idx = 0; Idx < 4; ++Idx) { 642 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 643 if (FromSize < ToSize || 644 (FromSize == ToSize && 645 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 646 // We found the type that we can promote to. If this is the 647 // type we wanted, we have a promotion. Otherwise, no 648 // promotion. 649 return Context.getCanonicalType(ToType).getUnqualifiedType() 650 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 651 } 652 } 653 } 654 655 // An rvalue for an integral bit-field (9.6) can be converted to an 656 // rvalue of type int if int can represent all the values of the 657 // bit-field; otherwise, it can be converted to unsigned int if 658 // unsigned int can represent all the values of the bit-field. If 659 // the bit-field is larger yet, no integral promotion applies to 660 // it. If the bit-field has an enumerated type, it is treated as any 661 // other value of that type for promotion purposes (C++ 4.5p3). 662 if (MemberExpr *MemRef = dyn_cast<MemberExpr>(From)) { 663 using llvm::APSInt; 664 FieldDecl *MemberDecl = MemRef->getMemberDecl(); 665 APSInt BitWidth; 666 if (MemberDecl->isBitField() && 667 FromType->isIntegralType() && !FromType->isEnumeralType() && 668 From->isIntegerConstantExpr(BitWidth, Context)) { 669 APSInt ToSize(Context.getTypeSize(ToType)); 670 671 // Are we promoting to an int from a bitfield that fits in an int? 672 if (BitWidth < ToSize || 673 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 674 return To->getKind() == BuiltinType::Int; 675 } 676 677 // Are we promoting to an unsigned int from an unsigned bitfield 678 // that fits into an unsigned int? 679 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 680 return To->getKind() == BuiltinType::UInt; 681 } 682 683 return false; 684 } 685 } 686 687 // An rvalue of type bool can be converted to an rvalue of type int, 688 // with false becoming zero and true becoming one (C++ 4.5p4). 689 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 690 return true; 691 } 692 693 return false; 694} 695 696/// IsFloatingPointPromotion - Determines whether the conversion from 697/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 698/// returns true and sets PromotedType to the promoted type. 699bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) 700{ 701 /// An rvalue of type float can be converted to an rvalue of type 702 /// double. (C++ 4.6p1). 703 if (const BuiltinType *FromBuiltin = FromType->getAsBuiltinType()) 704 if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType()) 705 if (FromBuiltin->getKind() == BuiltinType::Float && 706 ToBuiltin->getKind() == BuiltinType::Double) 707 return true; 708 709 return false; 710} 711 712/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 713/// the pointer type FromPtr to a pointer to type ToPointee, with the 714/// same type qualifiers as FromPtr has on its pointee type. ToType, 715/// if non-empty, will be a pointer to ToType that may or may not have 716/// the right set of qualifiers on its pointee. 717static QualType 718BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 719 QualType ToPointee, QualType ToType, 720 ASTContext &Context) { 721 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 722 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 723 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 724 725 // Exact qualifier match -> return the pointer type we're converting to. 726 if (CanonToPointee.getCVRQualifiers() == Quals) { 727 // ToType is exactly what we need. Return it. 728 if (ToType.getTypePtr()) 729 return ToType; 730 731 // Build a pointer to ToPointee. It has the right qualifiers 732 // already. 733 return Context.getPointerType(ToPointee); 734 } 735 736 // Just build a canonical type that has the right qualifiers. 737 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 738} 739 740/// IsPointerConversion - Determines whether the conversion of the 741/// expression From, which has the (possibly adjusted) type FromType, 742/// can be converted to the type ToType via a pointer conversion (C++ 743/// 4.10). If so, returns true and places the converted type (that 744/// might differ from ToType in its cv-qualifiers at some level) into 745/// ConvertedType. 746/// 747/// This routine also supports conversions to and from block pointers. 748bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 749 QualType& ConvertedType) 750{ 751 // Blocks: Block pointers can be converted to void*. 752 if (FromType->isBlockPointerType() && ToType->isPointerType() && 753 ToType->getAsPointerType()->getPointeeType()->isVoidType()) { 754 ConvertedType = ToType; 755 return true; 756 } 757 // Blocks: A null pointer constant can be converted to a block 758 // pointer type. 759 if (ToType->isBlockPointerType() && From->isNullPointerConstant(Context)) { 760 ConvertedType = ToType; 761 return true; 762 } 763 764 const PointerType* ToTypePtr = ToType->getAsPointerType(); 765 if (!ToTypePtr) 766 return false; 767 768 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 769 if (From->isNullPointerConstant(Context)) { 770 ConvertedType = ToType; 771 return true; 772 } 773 774 // Beyond this point, both types need to be pointers. 775 const PointerType *FromTypePtr = FromType->getAsPointerType(); 776 if (!FromTypePtr) 777 return false; 778 779 QualType FromPointeeType = FromTypePtr->getPointeeType(); 780 QualType ToPointeeType = ToTypePtr->getPointeeType(); 781 782 // An rvalue of type "pointer to cv T," where T is an object type, 783 // can be converted to an rvalue of type "pointer to cv void" (C++ 784 // 4.10p2). 785 if (FromPointeeType->isIncompleteOrObjectType() && ToPointeeType->isVoidType()) { 786 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, ToPointeeType, 787 ToType, Context); 788 return true; 789 } 790 791 // C++ [conv.ptr]p3: 792 // 793 // An rvalue of type "pointer to cv D," where D is a class type, 794 // can be converted to an rvalue of type "pointer to cv B," where 795 // B is a base class (clause 10) of D. If B is an inaccessible 796 // (clause 11) or ambiguous (10.2) base class of D, a program that 797 // necessitates this conversion is ill-formed. The result of the 798 // conversion is a pointer to the base class sub-object of the 799 // derived class object. The null pointer value is converted to 800 // the null pointer value of the destination type. 801 // 802 // Note that we do not check for ambiguity or inaccessibility 803 // here. That is handled by CheckPointerConversion. 804 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 805 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 806 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, ToPointeeType, 807 ToType, Context); 808 return true; 809 } 810 811 // Objective C++: We're able to convert from a pointer to an 812 // interface to a pointer to a different interface. 813 const ObjCInterfaceType* FromIface = FromPointeeType->getAsObjCInterfaceType(); 814 const ObjCInterfaceType* ToIface = ToPointeeType->getAsObjCInterfaceType(); 815 if (FromIface && ToIface && 816 Context.canAssignObjCInterfaces(ToIface, FromIface)) { 817 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, ToPointeeType, 818 ToType, Context); 819 return true; 820 } 821 822 // Objective C++: We're able to convert between "id" and a pointer 823 // to any interface (in both directions). 824 if ((FromIface && Context.isObjCIdType(ToPointeeType)) 825 || (ToIface && Context.isObjCIdType(FromPointeeType))) { 826 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, ToPointeeType, 827 ToType, Context); 828 return true; 829 } 830 831 return false; 832} 833 834/// CheckPointerConversion - Check the pointer conversion from the 835/// expression From to the type ToType. This routine checks for 836/// ambiguous (FIXME: or inaccessible) derived-to-base pointer 837/// conversions for which IsPointerConversion has already returned 838/// true. It returns true and produces a diagnostic if there was an 839/// error, or returns false otherwise. 840bool Sema::CheckPointerConversion(Expr *From, QualType ToType) { 841 QualType FromType = From->getType(); 842 843 if (const PointerType *FromPtrType = FromType->getAsPointerType()) 844 if (const PointerType *ToPtrType = ToType->getAsPointerType()) { 845 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 846 /*DetectVirtual=*/false); 847 QualType FromPointeeType = FromPtrType->getPointeeType(), 848 ToPointeeType = ToPtrType->getPointeeType(); 849 if (FromPointeeType->isRecordType() && 850 ToPointeeType->isRecordType()) { 851 // We must have a derived-to-base conversion. Check an 852 // ambiguous or inaccessible conversion. 853 return CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 854 From->getExprLoc(), 855 From->getSourceRange()); 856 } 857 } 858 859 return false; 860} 861 862/// IsQualificationConversion - Determines whether the conversion from 863/// an rvalue of type FromType to ToType is a qualification conversion 864/// (C++ 4.4). 865bool 866Sema::IsQualificationConversion(QualType FromType, QualType ToType) 867{ 868 FromType = Context.getCanonicalType(FromType); 869 ToType = Context.getCanonicalType(ToType); 870 871 // If FromType and ToType are the same type, this is not a 872 // qualification conversion. 873 if (FromType == ToType) 874 return false; 875 876 // (C++ 4.4p4): 877 // A conversion can add cv-qualifiers at levels other than the first 878 // in multi-level pointers, subject to the following rules: [...] 879 bool PreviousToQualsIncludeConst = true; 880 bool UnwrappedAnyPointer = false; 881 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 882 // Within each iteration of the loop, we check the qualifiers to 883 // determine if this still looks like a qualification 884 // conversion. Then, if all is well, we unwrap one more level of 885 // pointers or pointers-to-members and do it all again 886 // until there are no more pointers or pointers-to-members left to 887 // unwrap. 888 UnwrappedAnyPointer = true; 889 890 // -- for every j > 0, if const is in cv 1,j then const is in cv 891 // 2,j, and similarly for volatile. 892 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 893 return false; 894 895 // -- if the cv 1,j and cv 2,j are different, then const is in 896 // every cv for 0 < k < j. 897 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 898 && !PreviousToQualsIncludeConst) 899 return false; 900 901 // Keep track of whether all prior cv-qualifiers in the "to" type 902 // include const. 903 PreviousToQualsIncludeConst 904 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 905 } 906 907 // We are left with FromType and ToType being the pointee types 908 // after unwrapping the original FromType and ToType the same number 909 // of types. If we unwrapped any pointers, and if FromType and 910 // ToType have the same unqualified type (since we checked 911 // qualifiers above), then this is a qualification conversion. 912 return UnwrappedAnyPointer && 913 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 914} 915 916/// IsUserDefinedConversion - Determines whether there is a 917/// user-defined conversion sequence (C++ [over.ics.user]) that 918/// converts expression From to the type ToType. If such a conversion 919/// exists, User will contain the user-defined conversion sequence 920/// that performs such a conversion and this routine will return 921/// true. Otherwise, this routine returns false and User is 922/// unspecified. 923bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 924 UserDefinedConversionSequence& User) 925{ 926 OverloadCandidateSet CandidateSet; 927 if (const CXXRecordType *ToRecordType 928 = dyn_cast_or_null<CXXRecordType>(ToType->getAsRecordType())) { 929 // C++ [over.match.ctor]p1: 930 // When objects of class type are direct-initialized (8.5), or 931 // copy-initialized from an expression of the same or a 932 // derived class type (8.5), overload resolution selects the 933 // constructor. [...] For copy-initialization, the candidate 934 // functions are all the converting constructors (12.3.1) of 935 // that class. The argument list is the expression-list within 936 // the parentheses of the initializer. 937 CXXRecordDecl *ToRecordDecl = ToRecordType->getDecl(); 938 const OverloadedFunctionDecl *Constructors = ToRecordDecl->getConstructors(); 939 for (OverloadedFunctionDecl::function_const_iterator func 940 = Constructors->function_begin(); 941 func != Constructors->function_end(); ++func) { 942 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*func); 943 if (Constructor->isConvertingConstructor()) 944 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 945 /*SuppressUserConversions=*/true); 946 } 947 } 948 949 if (const CXXRecordType *FromRecordType 950 = dyn_cast_or_null<CXXRecordType>(From->getType()->getAsRecordType())) { 951 // Add all of the conversion functions as candidates. 952 // FIXME: Look for conversions in base classes! 953 CXXRecordDecl *FromRecordDecl = FromRecordType->getDecl(); 954 OverloadedFunctionDecl *Conversions 955 = FromRecordDecl->getConversionFunctions(); 956 for (OverloadedFunctionDecl::function_iterator Func 957 = Conversions->function_begin(); 958 Func != Conversions->function_end(); ++Func) { 959 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 960 AddConversionCandidate(Conv, From, ToType, CandidateSet); 961 } 962 } 963 964 OverloadCandidateSet::iterator Best; 965 switch (BestViableFunction(CandidateSet, Best)) { 966 case OR_Success: 967 // Record the standard conversion we used and the conversion function. 968 if (CXXConstructorDecl *Constructor 969 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 970 // C++ [over.ics.user]p1: 971 // If the user-defined conversion is specified by a 972 // constructor (12.3.1), the initial standard conversion 973 // sequence converts the source type to the type required by 974 // the argument of the constructor. 975 // 976 // FIXME: What about ellipsis conversions? 977 QualType ThisType = Constructor->getThisType(Context); 978 User.Before = Best->Conversions[0].Standard; 979 User.ConversionFunction = Constructor; 980 User.After.setAsIdentityConversion(); 981 User.After.FromTypePtr 982 = ThisType->getAsPointerType()->getPointeeType().getAsOpaquePtr(); 983 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 984 return true; 985 } else if (CXXConversionDecl *Conversion 986 = dyn_cast<CXXConversionDecl>(Best->Function)) { 987 // C++ [over.ics.user]p1: 988 // 989 // [...] If the user-defined conversion is specified by a 990 // conversion function (12.3.2), the initial standard 991 // conversion sequence converts the source type to the 992 // implicit object parameter of the conversion function. 993 User.Before = Best->Conversions[0].Standard; 994 User.ConversionFunction = Conversion; 995 996 // C++ [over.ics.user]p2: 997 // The second standard conversion sequence converts the 998 // result of the user-defined conversion to the target type 999 // for the sequence. Since an implicit conversion sequence 1000 // is an initialization, the special rules for 1001 // initialization by user-defined conversion apply when 1002 // selecting the best user-defined conversion for a 1003 // user-defined conversion sequence (see 13.3.3 and 1004 // 13.3.3.1). 1005 User.After = Best->FinalConversion; 1006 return true; 1007 } else { 1008 assert(false && "Not a constructor or conversion function?"); 1009 return false; 1010 } 1011 1012 case OR_No_Viable_Function: 1013 // No conversion here! We're done. 1014 return false; 1015 1016 case OR_Ambiguous: 1017 // FIXME: See C++ [over.best.ics]p10 for the handling of 1018 // ambiguous conversion sequences. 1019 return false; 1020 } 1021 1022 return false; 1023} 1024 1025/// CompareImplicitConversionSequences - Compare two implicit 1026/// conversion sequences to determine whether one is better than the 1027/// other or if they are indistinguishable (C++ 13.3.3.2). 1028ImplicitConversionSequence::CompareKind 1029Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1030 const ImplicitConversionSequence& ICS2) 1031{ 1032 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1033 // conversion sequences (as defined in 13.3.3.1) 1034 // -- a standard conversion sequence (13.3.3.1.1) is a better 1035 // conversion sequence than a user-defined conversion sequence or 1036 // an ellipsis conversion sequence, and 1037 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1038 // conversion sequence than an ellipsis conversion sequence 1039 // (13.3.3.1.3). 1040 // 1041 if (ICS1.ConversionKind < ICS2.ConversionKind) 1042 return ImplicitConversionSequence::Better; 1043 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1044 return ImplicitConversionSequence::Worse; 1045 1046 // Two implicit conversion sequences of the same form are 1047 // indistinguishable conversion sequences unless one of the 1048 // following rules apply: (C++ 13.3.3.2p3): 1049 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1050 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1051 else if (ICS1.ConversionKind == 1052 ImplicitConversionSequence::UserDefinedConversion) { 1053 // User-defined conversion sequence U1 is a better conversion 1054 // sequence than another user-defined conversion sequence U2 if 1055 // they contain the same user-defined conversion function or 1056 // constructor and if the second standard conversion sequence of 1057 // U1 is better than the second standard conversion sequence of 1058 // U2 (C++ 13.3.3.2p3). 1059 if (ICS1.UserDefined.ConversionFunction == 1060 ICS2.UserDefined.ConversionFunction) 1061 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1062 ICS2.UserDefined.After); 1063 } 1064 1065 return ImplicitConversionSequence::Indistinguishable; 1066} 1067 1068/// CompareStandardConversionSequences - Compare two standard 1069/// conversion sequences to determine whether one is better than the 1070/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1071ImplicitConversionSequence::CompareKind 1072Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1073 const StandardConversionSequence& SCS2) 1074{ 1075 // Standard conversion sequence S1 is a better conversion sequence 1076 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1077 1078 // -- S1 is a proper subsequence of S2 (comparing the conversion 1079 // sequences in the canonical form defined by 13.3.3.1.1, 1080 // excluding any Lvalue Transformation; the identity conversion 1081 // sequence is considered to be a subsequence of any 1082 // non-identity conversion sequence) or, if not that, 1083 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1084 // Neither is a proper subsequence of the other. Do nothing. 1085 ; 1086 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1087 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1088 (SCS1.Second == ICK_Identity && 1089 SCS1.Third == ICK_Identity)) 1090 // SCS1 is a proper subsequence of SCS2. 1091 return ImplicitConversionSequence::Better; 1092 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1093 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1094 (SCS2.Second == ICK_Identity && 1095 SCS2.Third == ICK_Identity)) 1096 // SCS2 is a proper subsequence of SCS1. 1097 return ImplicitConversionSequence::Worse; 1098 1099 // -- the rank of S1 is better than the rank of S2 (by the rules 1100 // defined below), or, if not that, 1101 ImplicitConversionRank Rank1 = SCS1.getRank(); 1102 ImplicitConversionRank Rank2 = SCS2.getRank(); 1103 if (Rank1 < Rank2) 1104 return ImplicitConversionSequence::Better; 1105 else if (Rank2 < Rank1) 1106 return ImplicitConversionSequence::Worse; 1107 1108 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1109 // are indistinguishable unless one of the following rules 1110 // applies: 1111 1112 // A conversion that is not a conversion of a pointer, or 1113 // pointer to member, to bool is better than another conversion 1114 // that is such a conversion. 1115 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1116 return SCS2.isPointerConversionToBool() 1117 ? ImplicitConversionSequence::Better 1118 : ImplicitConversionSequence::Worse; 1119 1120 // C++ [over.ics.rank]p4b2: 1121 // 1122 // If class B is derived directly or indirectly from class A, 1123 // conversion of B* to A* is better than conversion of B* to 1124 // void*, and conversion of A* to void* is better than conversion 1125 // of B* to void*. 1126 bool SCS1ConvertsToVoid 1127 = SCS1.isPointerConversionToVoidPointer(Context); 1128 bool SCS2ConvertsToVoid 1129 = SCS2.isPointerConversionToVoidPointer(Context); 1130 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1131 // Exactly one of the conversion sequences is a conversion to 1132 // a void pointer; it's the worse conversion. 1133 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1134 : ImplicitConversionSequence::Worse; 1135 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1136 // Neither conversion sequence converts to a void pointer; compare 1137 // their derived-to-base conversions. 1138 if (ImplicitConversionSequence::CompareKind DerivedCK 1139 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1140 return DerivedCK; 1141 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1142 // Both conversion sequences are conversions to void 1143 // pointers. Compare the source types to determine if there's an 1144 // inheritance relationship in their sources. 1145 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1146 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1147 1148 // Adjust the types we're converting from via the array-to-pointer 1149 // conversion, if we need to. 1150 if (SCS1.First == ICK_Array_To_Pointer) 1151 FromType1 = Context.getArrayDecayedType(FromType1); 1152 if (SCS2.First == ICK_Array_To_Pointer) 1153 FromType2 = Context.getArrayDecayedType(FromType2); 1154 1155 QualType FromPointee1 1156 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1157 QualType FromPointee2 1158 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1159 1160 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1161 return ImplicitConversionSequence::Better; 1162 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1163 return ImplicitConversionSequence::Worse; 1164 1165 // Objective-C++: If one interface is more specific than the 1166 // other, it is the better one. 1167 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1168 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1169 if (FromIface1 && FromIface1) { 1170 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1171 return ImplicitConversionSequence::Better; 1172 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1173 return ImplicitConversionSequence::Worse; 1174 } 1175 } 1176 1177 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1178 // bullet 3). 1179 if (ImplicitConversionSequence::CompareKind QualCK 1180 = CompareQualificationConversions(SCS1, SCS2)) 1181 return QualCK; 1182 1183 // C++ [over.ics.rank]p3b4: 1184 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1185 // which the references refer are the same type except for 1186 // top-level cv-qualifiers, and the type to which the reference 1187 // initialized by S2 refers is more cv-qualified than the type 1188 // to which the reference initialized by S1 refers. 1189 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1190 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1191 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1192 T1 = Context.getCanonicalType(T1); 1193 T2 = Context.getCanonicalType(T2); 1194 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1195 if (T2.isMoreQualifiedThan(T1)) 1196 return ImplicitConversionSequence::Better; 1197 else if (T1.isMoreQualifiedThan(T2)) 1198 return ImplicitConversionSequence::Worse; 1199 } 1200 } 1201 1202 return ImplicitConversionSequence::Indistinguishable; 1203} 1204 1205/// CompareQualificationConversions - Compares two standard conversion 1206/// sequences to determine whether they can be ranked based on their 1207/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1208ImplicitConversionSequence::CompareKind 1209Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1210 const StandardConversionSequence& SCS2) 1211{ 1212 // C++ 13.3.3.2p3: 1213 // -- S1 and S2 differ only in their qualification conversion and 1214 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1215 // cv-qualification signature of type T1 is a proper subset of 1216 // the cv-qualification signature of type T2, and S1 is not the 1217 // deprecated string literal array-to-pointer conversion (4.2). 1218 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1219 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1220 return ImplicitConversionSequence::Indistinguishable; 1221 1222 // FIXME: the example in the standard doesn't use a qualification 1223 // conversion (!) 1224 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1225 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1226 T1 = Context.getCanonicalType(T1); 1227 T2 = Context.getCanonicalType(T2); 1228 1229 // If the types are the same, we won't learn anything by unwrapped 1230 // them. 1231 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1232 return ImplicitConversionSequence::Indistinguishable; 1233 1234 ImplicitConversionSequence::CompareKind Result 1235 = ImplicitConversionSequence::Indistinguishable; 1236 while (UnwrapSimilarPointerTypes(T1, T2)) { 1237 // Within each iteration of the loop, we check the qualifiers to 1238 // determine if this still looks like a qualification 1239 // conversion. Then, if all is well, we unwrap one more level of 1240 // pointers or pointers-to-members and do it all again 1241 // until there are no more pointers or pointers-to-members left 1242 // to unwrap. This essentially mimics what 1243 // IsQualificationConversion does, but here we're checking for a 1244 // strict subset of qualifiers. 1245 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1246 // The qualifiers are the same, so this doesn't tell us anything 1247 // about how the sequences rank. 1248 ; 1249 else if (T2.isMoreQualifiedThan(T1)) { 1250 // T1 has fewer qualifiers, so it could be the better sequence. 1251 if (Result == ImplicitConversionSequence::Worse) 1252 // Neither has qualifiers that are a subset of the other's 1253 // qualifiers. 1254 return ImplicitConversionSequence::Indistinguishable; 1255 1256 Result = ImplicitConversionSequence::Better; 1257 } else if (T1.isMoreQualifiedThan(T2)) { 1258 // T2 has fewer qualifiers, so it could be the better sequence. 1259 if (Result == ImplicitConversionSequence::Better) 1260 // Neither has qualifiers that are a subset of the other's 1261 // qualifiers. 1262 return ImplicitConversionSequence::Indistinguishable; 1263 1264 Result = ImplicitConversionSequence::Worse; 1265 } else { 1266 // Qualifiers are disjoint. 1267 return ImplicitConversionSequence::Indistinguishable; 1268 } 1269 1270 // If the types after this point are equivalent, we're done. 1271 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1272 break; 1273 } 1274 1275 // Check that the winning standard conversion sequence isn't using 1276 // the deprecated string literal array to pointer conversion. 1277 switch (Result) { 1278 case ImplicitConversionSequence::Better: 1279 if (SCS1.Deprecated) 1280 Result = ImplicitConversionSequence::Indistinguishable; 1281 break; 1282 1283 case ImplicitConversionSequence::Indistinguishable: 1284 break; 1285 1286 case ImplicitConversionSequence::Worse: 1287 if (SCS2.Deprecated) 1288 Result = ImplicitConversionSequence::Indistinguishable; 1289 break; 1290 } 1291 1292 return Result; 1293} 1294 1295/// CompareDerivedToBaseConversions - Compares two standard conversion 1296/// sequences to determine whether they can be ranked based on their 1297/// various kinds of derived-to-base conversions (C++ 1298/// [over.ics.rank]p4b3). As part of these checks, we also look at 1299/// conversions between Objective-C interface types. 1300ImplicitConversionSequence::CompareKind 1301Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1302 const StandardConversionSequence& SCS2) { 1303 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1304 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1305 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1306 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1307 1308 // Adjust the types we're converting from via the array-to-pointer 1309 // conversion, if we need to. 1310 if (SCS1.First == ICK_Array_To_Pointer) 1311 FromType1 = Context.getArrayDecayedType(FromType1); 1312 if (SCS2.First == ICK_Array_To_Pointer) 1313 FromType2 = Context.getArrayDecayedType(FromType2); 1314 1315 // Canonicalize all of the types. 1316 FromType1 = Context.getCanonicalType(FromType1); 1317 ToType1 = Context.getCanonicalType(ToType1); 1318 FromType2 = Context.getCanonicalType(FromType2); 1319 ToType2 = Context.getCanonicalType(ToType2); 1320 1321 // C++ [over.ics.rank]p4b3: 1322 // 1323 // If class B is derived directly or indirectly from class A and 1324 // class C is derived directly or indirectly from B, 1325 // 1326 // For Objective-C, we let A, B, and C also be Objective-C 1327 // interfaces. 1328 1329 // Compare based on pointer conversions. 1330 if (SCS1.Second == ICK_Pointer_Conversion && 1331 SCS2.Second == ICK_Pointer_Conversion) { 1332 QualType FromPointee1 1333 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1334 QualType ToPointee1 1335 = ToType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1336 QualType FromPointee2 1337 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1338 QualType ToPointee2 1339 = ToType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1340 1341 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1342 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1343 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1344 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1345 1346 // -- conversion of C* to B* is better than conversion of C* to A*, 1347 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1348 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1349 return ImplicitConversionSequence::Better; 1350 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1351 return ImplicitConversionSequence::Worse; 1352 1353 if (ToIface1 && ToIface2) { 1354 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1355 return ImplicitConversionSequence::Better; 1356 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1357 return ImplicitConversionSequence::Worse; 1358 } 1359 } 1360 1361 // -- conversion of B* to A* is better than conversion of C* to A*, 1362 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1363 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1364 return ImplicitConversionSequence::Better; 1365 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1366 return ImplicitConversionSequence::Worse; 1367 1368 if (FromIface1 && FromIface2) { 1369 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1370 return ImplicitConversionSequence::Better; 1371 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1372 return ImplicitConversionSequence::Worse; 1373 } 1374 } 1375 } 1376 1377 // Compare based on reference bindings. 1378 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1379 SCS1.Second == ICK_Derived_To_Base) { 1380 // -- binding of an expression of type C to a reference of type 1381 // B& is better than binding an expression of type C to a 1382 // reference of type A&, 1383 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1384 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1385 if (IsDerivedFrom(ToType1, ToType2)) 1386 return ImplicitConversionSequence::Better; 1387 else if (IsDerivedFrom(ToType2, ToType1)) 1388 return ImplicitConversionSequence::Worse; 1389 } 1390 1391 // -- binding of an expression of type B to a reference of type 1392 // A& is better than binding an expression of type C to a 1393 // reference of type A&, 1394 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1395 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1396 if (IsDerivedFrom(FromType2, FromType1)) 1397 return ImplicitConversionSequence::Better; 1398 else if (IsDerivedFrom(FromType1, FromType2)) 1399 return ImplicitConversionSequence::Worse; 1400 } 1401 } 1402 1403 1404 // FIXME: conversion of A::* to B::* is better than conversion of 1405 // A::* to C::*, 1406 1407 // FIXME: conversion of B::* to C::* is better than conversion of 1408 // A::* to C::*, and 1409 1410 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1411 SCS1.Second == ICK_Derived_To_Base) { 1412 // -- conversion of C to B is better than conversion of C to A, 1413 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1414 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1415 if (IsDerivedFrom(ToType1, ToType2)) 1416 return ImplicitConversionSequence::Better; 1417 else if (IsDerivedFrom(ToType2, ToType1)) 1418 return ImplicitConversionSequence::Worse; 1419 } 1420 1421 // -- conversion of B to A is better than conversion of C to A. 1422 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1423 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1424 if (IsDerivedFrom(FromType2, FromType1)) 1425 return ImplicitConversionSequence::Better; 1426 else if (IsDerivedFrom(FromType1, FromType2)) 1427 return ImplicitConversionSequence::Worse; 1428 } 1429 } 1430 1431 return ImplicitConversionSequence::Indistinguishable; 1432} 1433 1434/// TryCopyInitialization - Try to copy-initialize a value of type 1435/// ToType from the expression From. Return the implicit conversion 1436/// sequence required to pass this argument, which may be a bad 1437/// conversion sequence (meaning that the argument cannot be passed to 1438/// a parameter of this type). If @p SuppressUserConversions, then we 1439/// do not permit any user-defined conversion sequences. 1440ImplicitConversionSequence 1441Sema::TryCopyInitialization(Expr *From, QualType ToType, 1442 bool SuppressUserConversions) { 1443 if (!getLangOptions().CPlusPlus) { 1444 // In C, copy initialization is the same as performing an assignment. 1445 AssignConvertType ConvTy = 1446 CheckSingleAssignmentConstraints(ToType, From); 1447 ImplicitConversionSequence ICS; 1448 if (getLangOptions().NoExtensions? ConvTy != Compatible 1449 : ConvTy == Incompatible) 1450 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1451 else 1452 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 1453 return ICS; 1454 } else if (ToType->isReferenceType()) { 1455 ImplicitConversionSequence ICS; 1456 CheckReferenceInit(From, ToType, &ICS, SuppressUserConversions); 1457 return ICS; 1458 } else { 1459 return TryImplicitConversion(From, ToType, SuppressUserConversions); 1460 } 1461} 1462 1463/// PerformArgumentPassing - Pass the argument Arg into a parameter of 1464/// type ToType. Returns true (and emits a diagnostic) if there was 1465/// an error, returns false if the initialization succeeded. 1466bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1467 const char* Flavor) { 1468 if (!getLangOptions().CPlusPlus) { 1469 // In C, argument passing is the same as performing an assignment. 1470 QualType FromType = From->getType(); 1471 AssignConvertType ConvTy = 1472 CheckSingleAssignmentConstraints(ToType, From); 1473 1474 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1475 FromType, From, Flavor); 1476 } 1477 1478 if (ToType->isReferenceType()) 1479 return CheckReferenceInit(From, ToType); 1480 1481 if (!PerformImplicitConversion(From, ToType)) 1482 return false; 1483 1484 return Diag(From->getSourceRange().getBegin(), 1485 diag::err_typecheck_convert_incompatible) 1486 << ToType << From->getType() << Flavor << From->getSourceRange(); 1487} 1488 1489/// TryObjectArgumentInitialization - Try to initialize the object 1490/// parameter of the given member function (@c Method) from the 1491/// expression @p From. 1492ImplicitConversionSequence 1493Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1494 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1495 unsigned MethodQuals = Method->getTypeQualifiers(); 1496 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 1497 1498 // Set up the conversion sequence as a "bad" conversion, to allow us 1499 // to exit early. 1500 ImplicitConversionSequence ICS; 1501 ICS.Standard.setAsIdentityConversion(); 1502 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1503 1504 // We need to have an object of class type. 1505 QualType FromType = From->getType(); 1506 if (!FromType->isRecordType()) 1507 return ICS; 1508 1509 // The implicit object parmeter is has the type "reference to cv X", 1510 // where X is the class of which the function is a member 1511 // (C++ [over.match.funcs]p4). However, when finding an implicit 1512 // conversion sequence for the argument, we are not allowed to 1513 // create temporaries or perform user-defined conversions 1514 // (C++ [over.match.funcs]p5). We perform a simplified version of 1515 // reference binding here, that allows class rvalues to bind to 1516 // non-constant references. 1517 1518 // First check the qualifiers. We don't care about lvalue-vs-rvalue 1519 // with the implicit object parameter (C++ [over.match.funcs]p5). 1520 QualType FromTypeCanon = Context.getCanonicalType(FromType); 1521 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 1522 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 1523 return ICS; 1524 1525 // Check that we have either the same type or a derived type. It 1526 // affects the conversion rank. 1527 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 1528 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 1529 ICS.Standard.Second = ICK_Identity; 1530 else if (IsDerivedFrom(FromType, ClassType)) 1531 ICS.Standard.Second = ICK_Derived_To_Base; 1532 else 1533 return ICS; 1534 1535 // Success. Mark this as a reference binding. 1536 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 1537 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 1538 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 1539 ICS.Standard.ReferenceBinding = true; 1540 ICS.Standard.DirectBinding = true; 1541 return ICS; 1542} 1543 1544/// PerformObjectArgumentInitialization - Perform initialization of 1545/// the implicit object parameter for the given Method with the given 1546/// expression. 1547bool 1548Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 1549 QualType ImplicitParamType 1550 = Method->getThisType(Context)->getAsPointerType()->getPointeeType(); 1551 ImplicitConversionSequence ICS 1552 = TryObjectArgumentInitialization(From, Method); 1553 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 1554 return Diag(From->getSourceRange().getBegin(), 1555 diag::err_implicit_object_parameter_init) 1556 << ImplicitParamType << From->getType() << From->getSourceRange(); 1557 1558 if (ICS.Standard.Second == ICK_Derived_To_Base && 1559 CheckDerivedToBaseConversion(From->getType(), ImplicitParamType, 1560 From->getSourceRange().getBegin(), 1561 From->getSourceRange())) 1562 return true; 1563 1564 ImpCastExprToType(From, ImplicitParamType, /*isLvalue=*/true); 1565 return false; 1566} 1567 1568/// AddOverloadCandidate - Adds the given function to the set of 1569/// candidate functions, using the given function call arguments. If 1570/// @p SuppressUserConversions, then don't allow user-defined 1571/// conversions via constructors or conversion operators. 1572void 1573Sema::AddOverloadCandidate(FunctionDecl *Function, 1574 Expr **Args, unsigned NumArgs, 1575 OverloadCandidateSet& CandidateSet, 1576 bool SuppressUserConversions) 1577{ 1578 const FunctionTypeProto* Proto 1579 = dyn_cast<FunctionTypeProto>(Function->getType()->getAsFunctionType()); 1580 assert(Proto && "Functions without a prototype cannot be overloaded"); 1581 assert(!isa<CXXConversionDecl>(Function) && 1582 "Use AddConversionCandidate for conversion functions"); 1583 1584 // Add this candidate 1585 CandidateSet.push_back(OverloadCandidate()); 1586 OverloadCandidate& Candidate = CandidateSet.back(); 1587 Candidate.Function = Function; 1588 Candidate.IsSurrogate = false; 1589 1590 unsigned NumArgsInProto = Proto->getNumArgs(); 1591 1592 // (C++ 13.3.2p2): A candidate function having fewer than m 1593 // parameters is viable only if it has an ellipsis in its parameter 1594 // list (8.3.5). 1595 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 1596 Candidate.Viable = false; 1597 return; 1598 } 1599 1600 // (C++ 13.3.2p2): A candidate function having more than m parameters 1601 // is viable only if the (m+1)st parameter has a default argument 1602 // (8.3.6). For the purposes of overload resolution, the 1603 // parameter list is truncated on the right, so that there are 1604 // exactly m parameters. 1605 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 1606 if (NumArgs < MinRequiredArgs) { 1607 // Not enough arguments. 1608 Candidate.Viable = false; 1609 return; 1610 } 1611 1612 // Determine the implicit conversion sequences for each of the 1613 // arguments. 1614 Candidate.Viable = true; 1615 Candidate.Conversions.resize(NumArgs); 1616 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 1617 if (ArgIdx < NumArgsInProto) { 1618 // (C++ 13.3.2p3): for F to be a viable function, there shall 1619 // exist for each argument an implicit conversion sequence 1620 // (13.3.3.1) that converts that argument to the corresponding 1621 // parameter of F. 1622 QualType ParamType = Proto->getArgType(ArgIdx); 1623 Candidate.Conversions[ArgIdx] 1624 = TryCopyInitialization(Args[ArgIdx], ParamType, 1625 SuppressUserConversions); 1626 if (Candidate.Conversions[ArgIdx].ConversionKind 1627 == ImplicitConversionSequence::BadConversion) { 1628 Candidate.Viable = false; 1629 break; 1630 } 1631 } else { 1632 // (C++ 13.3.2p2): For the purposes of overload resolution, any 1633 // argument for which there is no corresponding parameter is 1634 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 1635 Candidate.Conversions[ArgIdx].ConversionKind 1636 = ImplicitConversionSequence::EllipsisConversion; 1637 } 1638 } 1639} 1640 1641/// AddMethodCandidate - Adds the given C++ member function to the set 1642/// of candidate functions, using the given function call arguments 1643/// and the object argument (@c Object). For example, in a call 1644/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 1645/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 1646/// allow user-defined conversions via constructors or conversion 1647/// operators. 1648void 1649Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 1650 Expr **Args, unsigned NumArgs, 1651 OverloadCandidateSet& CandidateSet, 1652 bool SuppressUserConversions) 1653{ 1654 const FunctionTypeProto* Proto 1655 = dyn_cast<FunctionTypeProto>(Method->getType()->getAsFunctionType()); 1656 assert(Proto && "Methods without a prototype cannot be overloaded"); 1657 assert(!isa<CXXConversionDecl>(Method) && 1658 "Use AddConversionCandidate for conversion functions"); 1659 1660 // Add this candidate 1661 CandidateSet.push_back(OverloadCandidate()); 1662 OverloadCandidate& Candidate = CandidateSet.back(); 1663 Candidate.Function = Method; 1664 Candidate.IsSurrogate = false; 1665 1666 unsigned NumArgsInProto = Proto->getNumArgs(); 1667 1668 // (C++ 13.3.2p2): A candidate function having fewer than m 1669 // parameters is viable only if it has an ellipsis in its parameter 1670 // list (8.3.5). 1671 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 1672 Candidate.Viable = false; 1673 return; 1674 } 1675 1676 // (C++ 13.3.2p2): A candidate function having more than m parameters 1677 // is viable only if the (m+1)st parameter has a default argument 1678 // (8.3.6). For the purposes of overload resolution, the 1679 // parameter list is truncated on the right, so that there are 1680 // exactly m parameters. 1681 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 1682 if (NumArgs < MinRequiredArgs) { 1683 // Not enough arguments. 1684 Candidate.Viable = false; 1685 return; 1686 } 1687 1688 Candidate.Viable = true; 1689 Candidate.Conversions.resize(NumArgs + 1); 1690 1691 // Determine the implicit conversion sequence for the object 1692 // parameter. 1693 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 1694 if (Candidate.Conversions[0].ConversionKind 1695 == ImplicitConversionSequence::BadConversion) { 1696 Candidate.Viable = false; 1697 return; 1698 } 1699 1700 // Determine the implicit conversion sequences for each of the 1701 // arguments. 1702 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 1703 if (ArgIdx < NumArgsInProto) { 1704 // (C++ 13.3.2p3): for F to be a viable function, there shall 1705 // exist for each argument an implicit conversion sequence 1706 // (13.3.3.1) that converts that argument to the corresponding 1707 // parameter of F. 1708 QualType ParamType = Proto->getArgType(ArgIdx); 1709 Candidate.Conversions[ArgIdx + 1] 1710 = TryCopyInitialization(Args[ArgIdx], ParamType, 1711 SuppressUserConversions); 1712 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 1713 == ImplicitConversionSequence::BadConversion) { 1714 Candidate.Viable = false; 1715 break; 1716 } 1717 } else { 1718 // (C++ 13.3.2p2): For the purposes of overload resolution, any 1719 // argument for which there is no corresponding parameter is 1720 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 1721 Candidate.Conversions[ArgIdx + 1].ConversionKind 1722 = ImplicitConversionSequence::EllipsisConversion; 1723 } 1724 } 1725} 1726 1727/// AddConversionCandidate - Add a C++ conversion function as a 1728/// candidate in the candidate set (C++ [over.match.conv], 1729/// C++ [over.match.copy]). From is the expression we're converting from, 1730/// and ToType is the type that we're eventually trying to convert to 1731/// (which may or may not be the same type as the type that the 1732/// conversion function produces). 1733void 1734Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 1735 Expr *From, QualType ToType, 1736 OverloadCandidateSet& CandidateSet) { 1737 // Add this candidate 1738 CandidateSet.push_back(OverloadCandidate()); 1739 OverloadCandidate& Candidate = CandidateSet.back(); 1740 Candidate.Function = Conversion; 1741 Candidate.IsSurrogate = false; 1742 Candidate.FinalConversion.setAsIdentityConversion(); 1743 Candidate.FinalConversion.FromTypePtr 1744 = Conversion->getConversionType().getAsOpaquePtr(); 1745 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 1746 1747 // Determine the implicit conversion sequence for the implicit 1748 // object parameter. 1749 Candidate.Viable = true; 1750 Candidate.Conversions.resize(1); 1751 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 1752 1753 if (Candidate.Conversions[0].ConversionKind 1754 == ImplicitConversionSequence::BadConversion) { 1755 Candidate.Viable = false; 1756 return; 1757 } 1758 1759 // To determine what the conversion from the result of calling the 1760 // conversion function to the type we're eventually trying to 1761 // convert to (ToType), we need to synthesize a call to the 1762 // conversion function and attempt copy initialization from it. This 1763 // makes sure that we get the right semantics with respect to 1764 // lvalues/rvalues and the type. Fortunately, we can allocate this 1765 // call on the stack and we don't need its arguments to be 1766 // well-formed. 1767 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 1768 SourceLocation()); 1769 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 1770 &ConversionRef, false); 1771 CallExpr Call(&ConversionFn, 0, 0, 1772 Conversion->getConversionType().getNonReferenceType(), 1773 SourceLocation()); 1774 ImplicitConversionSequence ICS = TryCopyInitialization(&Call, ToType, true); 1775 switch (ICS.ConversionKind) { 1776 case ImplicitConversionSequence::StandardConversion: 1777 Candidate.FinalConversion = ICS.Standard; 1778 break; 1779 1780 case ImplicitConversionSequence::BadConversion: 1781 Candidate.Viable = false; 1782 break; 1783 1784 default: 1785 assert(false && 1786 "Can only end up with a standard conversion sequence or failure"); 1787 } 1788} 1789 1790/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 1791/// converts the given @c Object to a function pointer via the 1792/// conversion function @c Conversion, and then attempts to call it 1793/// with the given arguments (C++ [over.call.object]p2-4). Proto is 1794/// the type of function that we'll eventually be calling. 1795void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 1796 const FunctionTypeProto *Proto, 1797 Expr *Object, Expr **Args, unsigned NumArgs, 1798 OverloadCandidateSet& CandidateSet) { 1799 CandidateSet.push_back(OverloadCandidate()); 1800 OverloadCandidate& Candidate = CandidateSet.back(); 1801 Candidate.Function = 0; 1802 Candidate.Surrogate = Conversion; 1803 Candidate.Viable = true; 1804 Candidate.IsSurrogate = true; 1805 Candidate.Conversions.resize(NumArgs + 1); 1806 1807 // Determine the implicit conversion sequence for the implicit 1808 // object parameter. 1809 ImplicitConversionSequence ObjectInit 1810 = TryObjectArgumentInitialization(Object, Conversion); 1811 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 1812 Candidate.Viable = false; 1813 return; 1814 } 1815 1816 // The first conversion is actually a user-defined conversion whose 1817 // first conversion is ObjectInit's standard conversion (which is 1818 // effectively a reference binding). Record it as such. 1819 Candidate.Conversions[0].ConversionKind 1820 = ImplicitConversionSequence::UserDefinedConversion; 1821 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 1822 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 1823 Candidate.Conversions[0].UserDefined.After 1824 = Candidate.Conversions[0].UserDefined.Before; 1825 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 1826 1827 // Find the 1828 unsigned NumArgsInProto = Proto->getNumArgs(); 1829 1830 // (C++ 13.3.2p2): A candidate function having fewer than m 1831 // parameters is viable only if it has an ellipsis in its parameter 1832 // list (8.3.5). 1833 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 1834 Candidate.Viable = false; 1835 return; 1836 } 1837 1838 // Function types don't have any default arguments, so just check if 1839 // we have enough arguments. 1840 if (NumArgs < NumArgsInProto) { 1841 // Not enough arguments. 1842 Candidate.Viable = false; 1843 return; 1844 } 1845 1846 // Determine the implicit conversion sequences for each of the 1847 // arguments. 1848 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 1849 if (ArgIdx < NumArgsInProto) { 1850 // (C++ 13.3.2p3): for F to be a viable function, there shall 1851 // exist for each argument an implicit conversion sequence 1852 // (13.3.3.1) that converts that argument to the corresponding 1853 // parameter of F. 1854 QualType ParamType = Proto->getArgType(ArgIdx); 1855 Candidate.Conversions[ArgIdx + 1] 1856 = TryCopyInitialization(Args[ArgIdx], ParamType, 1857 /*SuppressUserConversions=*/false); 1858 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 1859 == ImplicitConversionSequence::BadConversion) { 1860 Candidate.Viable = false; 1861 break; 1862 } 1863 } else { 1864 // (C++ 13.3.2p2): For the purposes of overload resolution, any 1865 // argument for which there is no corresponding parameter is 1866 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 1867 Candidate.Conversions[ArgIdx + 1].ConversionKind 1868 = ImplicitConversionSequence::EllipsisConversion; 1869 } 1870 } 1871} 1872 1873/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is 1874/// an acceptable non-member overloaded operator for a call whose 1875/// arguments have types T1 (and, if non-empty, T2). This routine 1876/// implements the check in C++ [over.match.oper]p3b2 concerning 1877/// enumeration types. 1878static bool 1879IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn, 1880 QualType T1, QualType T2, 1881 ASTContext &Context) { 1882 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType())) 1883 return true; 1884 1885 const FunctionTypeProto *Proto = Fn->getType()->getAsFunctionTypeProto(); 1886 if (Proto->getNumArgs() < 1) 1887 return false; 1888 1889 if (T1->isEnumeralType()) { 1890 QualType ArgType = Proto->getArgType(0).getNonReferenceType(); 1891 if (Context.getCanonicalType(T1).getUnqualifiedType() 1892 == Context.getCanonicalType(ArgType).getUnqualifiedType()) 1893 return true; 1894 } 1895 1896 if (Proto->getNumArgs() < 2) 1897 return false; 1898 1899 if (!T2.isNull() && T2->isEnumeralType()) { 1900 QualType ArgType = Proto->getArgType(1).getNonReferenceType(); 1901 if (Context.getCanonicalType(T2).getUnqualifiedType() 1902 == Context.getCanonicalType(ArgType).getUnqualifiedType()) 1903 return true; 1904 } 1905 1906 return false; 1907} 1908 1909/// AddOperatorCandidates - Add the overloaded operator candidates for 1910/// the operator Op that was used in an operator expression such as "x 1911/// Op y". S is the scope in which the expression occurred (used for 1912/// name lookup of the operator), Args/NumArgs provides the operator 1913/// arguments, and CandidateSet will store the added overload 1914/// candidates. (C++ [over.match.oper]). 1915void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 1916 Expr **Args, unsigned NumArgs, 1917 OverloadCandidateSet& CandidateSet) { 1918 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 1919 1920 // C++ [over.match.oper]p3: 1921 // For a unary operator @ with an operand of a type whose 1922 // cv-unqualified version is T1, and for a binary operator @ with 1923 // a left operand of a type whose cv-unqualified version is T1 and 1924 // a right operand of a type whose cv-unqualified version is T2, 1925 // three sets of candidate functions, designated member 1926 // candidates, non-member candidates and built-in candidates, are 1927 // constructed as follows: 1928 QualType T1 = Args[0]->getType(); 1929 QualType T2; 1930 if (NumArgs > 1) 1931 T2 = Args[1]->getType(); 1932 1933 // -- If T1 is a class type, the set of member candidates is the 1934 // result of the qualified lookup of T1::operator@ 1935 // (13.3.1.1.1); otherwise, the set of member candidates is 1936 // empty. 1937 if (const RecordType *T1Rec = T1->getAsRecordType()) { 1938 IdentifierResolver::iterator I 1939 = IdResolver.begin(OpName, cast<CXXRecordType>(T1Rec)->getDecl(), 1940 /*LookInParentCtx=*/false); 1941 NamedDecl *MemberOps = (I == IdResolver.end())? 0 : *I; 1942 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(MemberOps)) 1943 AddMethodCandidate(Method, Args[0], Args+1, NumArgs - 1, CandidateSet, 1944 /*SuppressUserConversions=*/false); 1945 else if (OverloadedFunctionDecl *Ovl 1946 = dyn_cast_or_null<OverloadedFunctionDecl>(MemberOps)) { 1947 for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(), 1948 FEnd = Ovl->function_end(); 1949 F != FEnd; ++F) { 1950 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*F)) 1951 AddMethodCandidate(Method, Args[0], Args+1, NumArgs - 1, CandidateSet, 1952 /*SuppressUserConversions=*/false); 1953 } 1954 } 1955 } 1956 1957 // -- The set of non-member candidates is the result of the 1958 // unqualified lookup of operator@ in the context of the 1959 // expression according to the usual rules for name lookup in 1960 // unqualified function calls (3.4.2) except that all member 1961 // functions are ignored. However, if no operand has a class 1962 // type, only those non-member functions in the lookup set 1963 // that have a first parameter of type T1 or “reference to 1964 // (possibly cv-qualified) T1”, when T1 is an enumeration 1965 // type, or (if there is a right operand) a second parameter 1966 // of type T2 or “reference to (possibly cv-qualified) T2”, 1967 // when T2 is an enumeration type, are candidate functions. 1968 { 1969 NamedDecl *NonMemberOps = 0; 1970 for (IdentifierResolver::iterator I 1971 = IdResolver.begin(OpName, CurContext, true/*LookInParentCtx*/); 1972 I != IdResolver.end(); ++I) { 1973 // We don't need to check the identifier namespace, because 1974 // operator names can only be ordinary identifiers. 1975 1976 // Ignore member functions. 1977 if (ScopedDecl *SD = dyn_cast<ScopedDecl>(*I)) { 1978 if (SD->getDeclContext()->isCXXRecord()) 1979 continue; 1980 } 1981 1982 // We found something with this name. We're done. 1983 NonMemberOps = *I; 1984 break; 1985 } 1986 1987 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(NonMemberOps)) { 1988 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context)) 1989 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 1990 /*SuppressUserConversions=*/false); 1991 } else if (OverloadedFunctionDecl *Ovl 1992 = dyn_cast_or_null<OverloadedFunctionDecl>(NonMemberOps)) { 1993 for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(), 1994 FEnd = Ovl->function_end(); 1995 F != FEnd; ++F) { 1996 if (IsAcceptableNonMemberOperatorCandidate(*F, T1, T2, Context)) 1997 AddOverloadCandidate(*F, Args, NumArgs, CandidateSet, 1998 /*SuppressUserConversions=*/false); 1999 } 2000 } 2001 } 2002 2003 // Add builtin overload candidates (C++ [over.built]). 2004 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2005} 2006 2007/// AddBuiltinCandidate - Add a candidate for a built-in 2008/// operator. ResultTy and ParamTys are the result and parameter types 2009/// of the built-in candidate, respectively. Args and NumArgs are the 2010/// arguments being passed to the candidate. 2011void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2012 Expr **Args, unsigned NumArgs, 2013 OverloadCandidateSet& CandidateSet) { 2014 // Add this candidate 2015 CandidateSet.push_back(OverloadCandidate()); 2016 OverloadCandidate& Candidate = CandidateSet.back(); 2017 Candidate.Function = 0; 2018 Candidate.BuiltinTypes.ResultTy = ResultTy; 2019 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2020 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2021 2022 // Determine the implicit conversion sequences for each of the 2023 // arguments. 2024 Candidate.Viable = true; 2025 Candidate.Conversions.resize(NumArgs); 2026 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2027 Candidate.Conversions[ArgIdx] 2028 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], false); 2029 if (Candidate.Conversions[ArgIdx].ConversionKind 2030 == ImplicitConversionSequence::BadConversion) { 2031 Candidate.Viable = false; 2032 break; 2033 } 2034 } 2035} 2036 2037/// BuiltinCandidateTypeSet - A set of types that will be used for the 2038/// candidate operator functions for built-in operators (C++ 2039/// [over.built]). The types are separated into pointer types and 2040/// enumeration types. 2041class BuiltinCandidateTypeSet { 2042 /// TypeSet - A set of types. 2043 typedef llvm::SmallPtrSet<void*, 8> TypeSet; 2044 2045 /// PointerTypes - The set of pointer types that will be used in the 2046 /// built-in candidates. 2047 TypeSet PointerTypes; 2048 2049 /// EnumerationTypes - The set of enumeration types that will be 2050 /// used in the built-in candidates. 2051 TypeSet EnumerationTypes; 2052 2053 /// Context - The AST context in which we will build the type sets. 2054 ASTContext &Context; 2055 2056 bool AddWithMoreQualifiedTypeVariants(QualType Ty); 2057 2058public: 2059 /// iterator - Iterates through the types that are part of the set. 2060 class iterator { 2061 TypeSet::iterator Base; 2062 2063 public: 2064 typedef QualType value_type; 2065 typedef QualType reference; 2066 typedef QualType pointer; 2067 typedef std::ptrdiff_t difference_type; 2068 typedef std::input_iterator_tag iterator_category; 2069 2070 iterator(TypeSet::iterator B) : Base(B) { } 2071 2072 iterator& operator++() { 2073 ++Base; 2074 return *this; 2075 } 2076 2077 iterator operator++(int) { 2078 iterator tmp(*this); 2079 ++(*this); 2080 return tmp; 2081 } 2082 2083 reference operator*() const { 2084 return QualType::getFromOpaquePtr(*Base); 2085 } 2086 2087 pointer operator->() const { 2088 return **this; 2089 } 2090 2091 friend bool operator==(iterator LHS, iterator RHS) { 2092 return LHS.Base == RHS.Base; 2093 } 2094 2095 friend bool operator!=(iterator LHS, iterator RHS) { 2096 return LHS.Base != RHS.Base; 2097 } 2098 }; 2099 2100 BuiltinCandidateTypeSet(ASTContext &Context) : Context(Context) { } 2101 2102 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions = true); 2103 2104 /// pointer_begin - First pointer type found; 2105 iterator pointer_begin() { return PointerTypes.begin(); } 2106 2107 /// pointer_end - Last pointer type found; 2108 iterator pointer_end() { return PointerTypes.end(); } 2109 2110 /// enumeration_begin - First enumeration type found; 2111 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2112 2113 /// enumeration_end - Last enumeration type found; 2114 iterator enumeration_end() { return EnumerationTypes.end(); } 2115}; 2116 2117/// AddWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2118/// the set of pointer types along with any more-qualified variants of 2119/// that type. For example, if @p Ty is "int const *", this routine 2120/// will add "int const *", "int const volatile *", "int const 2121/// restrict *", and "int const volatile restrict *" to the set of 2122/// pointer types. Returns true if the add of @p Ty itself succeeded, 2123/// false otherwise. 2124bool BuiltinCandidateTypeSet::AddWithMoreQualifiedTypeVariants(QualType Ty) { 2125 // Insert this type. 2126 if (!PointerTypes.insert(Ty.getAsOpaquePtr())) 2127 return false; 2128 2129 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2130 QualType PointeeTy = PointerTy->getPointeeType(); 2131 // FIXME: Optimize this so that we don't keep trying to add the same types. 2132 2133 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal 2134 // with all pointer conversions that don't cast away constness? 2135 if (!PointeeTy.isConstQualified()) 2136 AddWithMoreQualifiedTypeVariants 2137 (Context.getPointerType(PointeeTy.withConst())); 2138 if (!PointeeTy.isVolatileQualified()) 2139 AddWithMoreQualifiedTypeVariants 2140 (Context.getPointerType(PointeeTy.withVolatile())); 2141 if (!PointeeTy.isRestrictQualified()) 2142 AddWithMoreQualifiedTypeVariants 2143 (Context.getPointerType(PointeeTy.withRestrict())); 2144 } 2145 2146 return true; 2147} 2148 2149/// AddTypesConvertedFrom - Add each of the types to which the type @p 2150/// Ty can be implicit converted to the given set of @p Types. We're 2151/// primarily interested in pointer types, enumeration types, 2152void BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2153 bool AllowUserConversions) { 2154 // Only deal with canonical types. 2155 Ty = Context.getCanonicalType(Ty); 2156 2157 // Look through reference types; they aren't part of the type of an 2158 // expression for the purposes of conversions. 2159 if (const ReferenceType *RefTy = Ty->getAsReferenceType()) 2160 Ty = RefTy->getPointeeType(); 2161 2162 // We don't care about qualifiers on the type. 2163 Ty = Ty.getUnqualifiedType(); 2164 2165 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2166 QualType PointeeTy = PointerTy->getPointeeType(); 2167 2168 // Insert our type, and its more-qualified variants, into the set 2169 // of types. 2170 if (!AddWithMoreQualifiedTypeVariants(Ty)) 2171 return; 2172 2173 // Add 'cv void*' to our set of types. 2174 if (!Ty->isVoidType()) { 2175 QualType QualVoid 2176 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2177 AddWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2178 } 2179 2180 // If this is a pointer to a class type, add pointers to its bases 2181 // (with the same level of cv-qualification as the original 2182 // derived class, of course). 2183 if (const RecordType *PointeeRec = PointeeTy->getAsRecordType()) { 2184 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2185 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2186 Base != ClassDecl->bases_end(); ++Base) { 2187 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2188 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2189 2190 // Add the pointer type, recursively, so that we get all of 2191 // the indirect base classes, too. 2192 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false); 2193 } 2194 } 2195 } else if (Ty->isEnumeralType()) { 2196 EnumerationTypes.insert(Ty.getAsOpaquePtr()); 2197 } else if (AllowUserConversions) { 2198 if (const RecordType *TyRec = Ty->getAsRecordType()) { 2199 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2200 // FIXME: Visit conversion functions in the base classes, too. 2201 OverloadedFunctionDecl *Conversions 2202 = ClassDecl->getConversionFunctions(); 2203 for (OverloadedFunctionDecl::function_iterator Func 2204 = Conversions->function_begin(); 2205 Func != Conversions->function_end(); ++Func) { 2206 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 2207 AddTypesConvertedFrom(Conv->getConversionType(), false); 2208 } 2209 } 2210 } 2211} 2212 2213/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2214/// operator overloads to the candidate set (C++ [over.built]), based 2215/// on the operator @p Op and the arguments given. For example, if the 2216/// operator is a binary '+', this routine might add "int 2217/// operator+(int, int)" to cover integer addition. 2218void 2219Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2220 Expr **Args, unsigned NumArgs, 2221 OverloadCandidateSet& CandidateSet) { 2222 // The set of "promoted arithmetic types", which are the arithmetic 2223 // types are that preserved by promotion (C++ [over.built]p2). Note 2224 // that the first few of these types are the promoted integral 2225 // types; these types need to be first. 2226 // FIXME: What about complex? 2227 const unsigned FirstIntegralType = 0; 2228 const unsigned LastIntegralType = 13; 2229 const unsigned FirstPromotedIntegralType = 7, 2230 LastPromotedIntegralType = 13; 2231 const unsigned FirstPromotedArithmeticType = 7, 2232 LastPromotedArithmeticType = 16; 2233 const unsigned NumArithmeticTypes = 16; 2234 QualType ArithmeticTypes[NumArithmeticTypes] = { 2235 Context.BoolTy, Context.CharTy, Context.WCharTy, 2236 Context.SignedCharTy, Context.ShortTy, 2237 Context.UnsignedCharTy, Context.UnsignedShortTy, 2238 Context.IntTy, Context.LongTy, Context.LongLongTy, 2239 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 2240 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 2241 }; 2242 2243 // Find all of the types that the arguments can convert to, but only 2244 // if the operator we're looking at has built-in operator candidates 2245 // that make use of these types. 2246 BuiltinCandidateTypeSet CandidateTypes(Context); 2247 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 2248 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 2249 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 2250 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 2251 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 2252 (Op == OO_Star && NumArgs == 1)) { 2253 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2254 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType()); 2255 } 2256 2257 bool isComparison = false; 2258 switch (Op) { 2259 case OO_None: 2260 case NUM_OVERLOADED_OPERATORS: 2261 assert(false && "Expected an overloaded operator"); 2262 break; 2263 2264 case OO_Star: // '*' is either unary or binary 2265 if (NumArgs == 1) 2266 goto UnaryStar; 2267 else 2268 goto BinaryStar; 2269 break; 2270 2271 case OO_Plus: // '+' is either unary or binary 2272 if (NumArgs == 1) 2273 goto UnaryPlus; 2274 else 2275 goto BinaryPlus; 2276 break; 2277 2278 case OO_Minus: // '-' is either unary or binary 2279 if (NumArgs == 1) 2280 goto UnaryMinus; 2281 else 2282 goto BinaryMinus; 2283 break; 2284 2285 case OO_Amp: // '&' is either unary or binary 2286 if (NumArgs == 1) 2287 goto UnaryAmp; 2288 else 2289 goto BinaryAmp; 2290 2291 case OO_PlusPlus: 2292 case OO_MinusMinus: 2293 // C++ [over.built]p3: 2294 // 2295 // For every pair (T, VQ), where T is an arithmetic type, and VQ 2296 // is either volatile or empty, there exist candidate operator 2297 // functions of the form 2298 // 2299 // VQ T& operator++(VQ T&); 2300 // T operator++(VQ T&, int); 2301 // 2302 // C++ [over.built]p4: 2303 // 2304 // For every pair (T, VQ), where T is an arithmetic type other 2305 // than bool, and VQ is either volatile or empty, there exist 2306 // candidate operator functions of the form 2307 // 2308 // VQ T& operator--(VQ T&); 2309 // T operator--(VQ T&, int); 2310 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 2311 Arith < NumArithmeticTypes; ++Arith) { 2312 QualType ArithTy = ArithmeticTypes[Arith]; 2313 QualType ParamTypes[2] 2314 = { Context.getReferenceType(ArithTy), Context.IntTy }; 2315 2316 // Non-volatile version. 2317 if (NumArgs == 1) 2318 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2319 else 2320 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2321 2322 // Volatile version 2323 ParamTypes[0] = Context.getReferenceType(ArithTy.withVolatile()); 2324 if (NumArgs == 1) 2325 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2326 else 2327 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2328 } 2329 2330 // C++ [over.built]p5: 2331 // 2332 // For every pair (T, VQ), where T is a cv-qualified or 2333 // cv-unqualified object type, and VQ is either volatile or 2334 // empty, there exist candidate operator functions of the form 2335 // 2336 // T*VQ& operator++(T*VQ&); 2337 // T*VQ& operator--(T*VQ&); 2338 // T* operator++(T*VQ&, int); 2339 // T* operator--(T*VQ&, int); 2340 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2341 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2342 // Skip pointer types that aren't pointers to object types. 2343 if (!(*Ptr)->getAsPointerType()->getPointeeType()->isIncompleteOrObjectType()) 2344 continue; 2345 2346 QualType ParamTypes[2] = { 2347 Context.getReferenceType(*Ptr), Context.IntTy 2348 }; 2349 2350 // Without volatile 2351 if (NumArgs == 1) 2352 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2353 else 2354 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2355 2356 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 2357 // With volatile 2358 ParamTypes[0] = Context.getReferenceType((*Ptr).withVolatile()); 2359 if (NumArgs == 1) 2360 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2361 else 2362 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2363 } 2364 } 2365 break; 2366 2367 UnaryStar: 2368 // C++ [over.built]p6: 2369 // For every cv-qualified or cv-unqualified object type T, there 2370 // exist candidate operator functions of the form 2371 // 2372 // T& operator*(T*); 2373 // 2374 // C++ [over.built]p7: 2375 // For every function type T, there exist candidate operator 2376 // functions of the form 2377 // T& operator*(T*); 2378 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2379 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2380 QualType ParamTy = *Ptr; 2381 QualType PointeeTy = ParamTy->getAsPointerType()->getPointeeType(); 2382 AddBuiltinCandidate(Context.getReferenceType(PointeeTy), 2383 &ParamTy, Args, 1, CandidateSet); 2384 } 2385 break; 2386 2387 UnaryPlus: 2388 // C++ [over.built]p8: 2389 // For every type T, there exist candidate operator functions of 2390 // the form 2391 // 2392 // T* operator+(T*); 2393 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2394 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2395 QualType ParamTy = *Ptr; 2396 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 2397 } 2398 2399 // Fall through 2400 2401 UnaryMinus: 2402 // C++ [over.built]p9: 2403 // For every promoted arithmetic type T, there exist candidate 2404 // operator functions of the form 2405 // 2406 // T operator+(T); 2407 // T operator-(T); 2408 for (unsigned Arith = FirstPromotedArithmeticType; 2409 Arith < LastPromotedArithmeticType; ++Arith) { 2410 QualType ArithTy = ArithmeticTypes[Arith]; 2411 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 2412 } 2413 break; 2414 2415 case OO_Tilde: 2416 // C++ [over.built]p10: 2417 // For every promoted integral type T, there exist candidate 2418 // operator functions of the form 2419 // 2420 // T operator~(T); 2421 for (unsigned Int = FirstPromotedIntegralType; 2422 Int < LastPromotedIntegralType; ++Int) { 2423 QualType IntTy = ArithmeticTypes[Int]; 2424 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 2425 } 2426 break; 2427 2428 case OO_New: 2429 case OO_Delete: 2430 case OO_Array_New: 2431 case OO_Array_Delete: 2432 case OO_Call: 2433 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 2434 break; 2435 2436 case OO_Comma: 2437 UnaryAmp: 2438 case OO_Arrow: 2439 // C++ [over.match.oper]p3: 2440 // -- For the operator ',', the unary operator '&', or the 2441 // operator '->', the built-in candidates set is empty. 2442 break; 2443 2444 case OO_Less: 2445 case OO_Greater: 2446 case OO_LessEqual: 2447 case OO_GreaterEqual: 2448 case OO_EqualEqual: 2449 case OO_ExclaimEqual: 2450 // C++ [over.built]p15: 2451 // 2452 // For every pointer or enumeration type T, there exist 2453 // candidate operator functions of the form 2454 // 2455 // bool operator<(T, T); 2456 // bool operator>(T, T); 2457 // bool operator<=(T, T); 2458 // bool operator>=(T, T); 2459 // bool operator==(T, T); 2460 // bool operator!=(T, T); 2461 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2462 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2463 QualType ParamTypes[2] = { *Ptr, *Ptr }; 2464 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 2465 } 2466 for (BuiltinCandidateTypeSet::iterator Enum 2467 = CandidateTypes.enumeration_begin(); 2468 Enum != CandidateTypes.enumeration_end(); ++Enum) { 2469 QualType ParamTypes[2] = { *Enum, *Enum }; 2470 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 2471 } 2472 2473 // Fall through. 2474 isComparison = true; 2475 2476 BinaryPlus: 2477 BinaryMinus: 2478 if (!isComparison) { 2479 // We didn't fall through, so we must have OO_Plus or OO_Minus. 2480 2481 // C++ [over.built]p13: 2482 // 2483 // For every cv-qualified or cv-unqualified object type T 2484 // there exist candidate operator functions of the form 2485 // 2486 // T* operator+(T*, ptrdiff_t); 2487 // T& operator[](T*, ptrdiff_t); [BELOW] 2488 // T* operator-(T*, ptrdiff_t); 2489 // T* operator+(ptrdiff_t, T*); 2490 // T& operator[](ptrdiff_t, T*); [BELOW] 2491 // 2492 // C++ [over.built]p14: 2493 // 2494 // For every T, where T is a pointer to object type, there 2495 // exist candidate operator functions of the form 2496 // 2497 // ptrdiff_t operator-(T, T); 2498 for (BuiltinCandidateTypeSet::iterator Ptr 2499 = CandidateTypes.pointer_begin(); 2500 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2501 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 2502 2503 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 2504 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2505 2506 if (Op == OO_Plus) { 2507 // T* operator+(ptrdiff_t, T*); 2508 ParamTypes[0] = ParamTypes[1]; 2509 ParamTypes[1] = *Ptr; 2510 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2511 } else { 2512 // ptrdiff_t operator-(T, T); 2513 ParamTypes[1] = *Ptr; 2514 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 2515 Args, 2, CandidateSet); 2516 } 2517 } 2518 } 2519 // Fall through 2520 2521 case OO_Slash: 2522 BinaryStar: 2523 // C++ [over.built]p12: 2524 // 2525 // For every pair of promoted arithmetic types L and R, there 2526 // exist candidate operator functions of the form 2527 // 2528 // LR operator*(L, R); 2529 // LR operator/(L, R); 2530 // LR operator+(L, R); 2531 // LR operator-(L, R); 2532 // bool operator<(L, R); 2533 // bool operator>(L, R); 2534 // bool operator<=(L, R); 2535 // bool operator>=(L, R); 2536 // bool operator==(L, R); 2537 // bool operator!=(L, R); 2538 // 2539 // where LR is the result of the usual arithmetic conversions 2540 // between types L and R. 2541 for (unsigned Left = FirstPromotedArithmeticType; 2542 Left < LastPromotedArithmeticType; ++Left) { 2543 for (unsigned Right = FirstPromotedArithmeticType; 2544 Right < LastPromotedArithmeticType; ++Right) { 2545 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 2546 QualType Result 2547 = isComparison? Context.BoolTy 2548 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 2549 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 2550 } 2551 } 2552 break; 2553 2554 case OO_Percent: 2555 BinaryAmp: 2556 case OO_Caret: 2557 case OO_Pipe: 2558 case OO_LessLess: 2559 case OO_GreaterGreater: 2560 // C++ [over.built]p17: 2561 // 2562 // For every pair of promoted integral types L and R, there 2563 // exist candidate operator functions of the form 2564 // 2565 // LR operator%(L, R); 2566 // LR operator&(L, R); 2567 // LR operator^(L, R); 2568 // LR operator|(L, R); 2569 // L operator<<(L, R); 2570 // L operator>>(L, R); 2571 // 2572 // where LR is the result of the usual arithmetic conversions 2573 // between types L and R. 2574 for (unsigned Left = FirstPromotedIntegralType; 2575 Left < LastPromotedIntegralType; ++Left) { 2576 for (unsigned Right = FirstPromotedIntegralType; 2577 Right < LastPromotedIntegralType; ++Right) { 2578 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 2579 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 2580 ? LandR[0] 2581 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 2582 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 2583 } 2584 } 2585 break; 2586 2587 case OO_Equal: 2588 // C++ [over.built]p20: 2589 // 2590 // For every pair (T, VQ), where T is an enumeration or 2591 // (FIXME:) pointer to member type and VQ is either volatile or 2592 // empty, there exist candidate operator functions of the form 2593 // 2594 // VQ T& operator=(VQ T&, T); 2595 for (BuiltinCandidateTypeSet::iterator Enum 2596 = CandidateTypes.enumeration_begin(); 2597 Enum != CandidateTypes.enumeration_end(); ++Enum) { 2598 QualType ParamTypes[2]; 2599 2600 // T& operator=(T&, T) 2601 ParamTypes[0] = Context.getReferenceType(*Enum); 2602 ParamTypes[1] = *Enum; 2603 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2604 2605 if (!Context.getCanonicalType(*Enum).isVolatileQualified()) { 2606 // volatile T& operator=(volatile T&, T) 2607 ParamTypes[0] = Context.getReferenceType((*Enum).withVolatile()); 2608 ParamTypes[1] = *Enum; 2609 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2610 } 2611 } 2612 // Fall through. 2613 2614 case OO_PlusEqual: 2615 case OO_MinusEqual: 2616 // C++ [over.built]p19: 2617 // 2618 // For every pair (T, VQ), where T is any type and VQ is either 2619 // volatile or empty, there exist candidate operator functions 2620 // of the form 2621 // 2622 // T*VQ& operator=(T*VQ&, T*); 2623 // 2624 // C++ [over.built]p21: 2625 // 2626 // For every pair (T, VQ), where T is a cv-qualified or 2627 // cv-unqualified object type and VQ is either volatile or 2628 // empty, there exist candidate operator functions of the form 2629 // 2630 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 2631 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 2632 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2633 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2634 QualType ParamTypes[2]; 2635 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 2636 2637 // non-volatile version 2638 ParamTypes[0] = Context.getReferenceType(*Ptr); 2639 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2640 2641 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 2642 // volatile version 2643 ParamTypes[0] = Context.getReferenceType((*Ptr).withVolatile()); 2644 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2645 } 2646 } 2647 // Fall through. 2648 2649 case OO_StarEqual: 2650 case OO_SlashEqual: 2651 // C++ [over.built]p18: 2652 // 2653 // For every triple (L, VQ, R), where L is an arithmetic type, 2654 // VQ is either volatile or empty, and R is a promoted 2655 // arithmetic type, there exist candidate operator functions of 2656 // the form 2657 // 2658 // VQ L& operator=(VQ L&, R); 2659 // VQ L& operator*=(VQ L&, R); 2660 // VQ L& operator/=(VQ L&, R); 2661 // VQ L& operator+=(VQ L&, R); 2662 // VQ L& operator-=(VQ L&, R); 2663 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 2664 for (unsigned Right = FirstPromotedArithmeticType; 2665 Right < LastPromotedArithmeticType; ++Right) { 2666 QualType ParamTypes[2]; 2667 ParamTypes[1] = ArithmeticTypes[Right]; 2668 2669 // Add this built-in operator as a candidate (VQ is empty). 2670 ParamTypes[0] = Context.getReferenceType(ArithmeticTypes[Left]); 2671 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2672 2673 // Add this built-in operator as a candidate (VQ is 'volatile'). 2674 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 2675 ParamTypes[0] = Context.getReferenceType(ParamTypes[0]); 2676 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2677 } 2678 } 2679 break; 2680 2681 case OO_PercentEqual: 2682 case OO_LessLessEqual: 2683 case OO_GreaterGreaterEqual: 2684 case OO_AmpEqual: 2685 case OO_CaretEqual: 2686 case OO_PipeEqual: 2687 // C++ [over.built]p22: 2688 // 2689 // For every triple (L, VQ, R), where L is an integral type, VQ 2690 // is either volatile or empty, and R is a promoted integral 2691 // type, there exist candidate operator functions of the form 2692 // 2693 // VQ L& operator%=(VQ L&, R); 2694 // VQ L& operator<<=(VQ L&, R); 2695 // VQ L& operator>>=(VQ L&, R); 2696 // VQ L& operator&=(VQ L&, R); 2697 // VQ L& operator^=(VQ L&, R); 2698 // VQ L& operator|=(VQ L&, R); 2699 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 2700 for (unsigned Right = FirstPromotedIntegralType; 2701 Right < LastPromotedIntegralType; ++Right) { 2702 QualType ParamTypes[2]; 2703 ParamTypes[1] = ArithmeticTypes[Right]; 2704 2705 // Add this built-in operator as a candidate (VQ is empty). 2706 // FIXME: We should be caching these declarations somewhere, 2707 // rather than re-building them every time. 2708 ParamTypes[0] = Context.getReferenceType(ArithmeticTypes[Left]); 2709 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2710 2711 // Add this built-in operator as a candidate (VQ is 'volatile'). 2712 ParamTypes[0] = ArithmeticTypes[Left]; 2713 ParamTypes[0].addVolatile(); 2714 ParamTypes[0] = Context.getReferenceType(ParamTypes[0]); 2715 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2716 } 2717 } 2718 break; 2719 2720 case OO_Exclaim: { 2721 // C++ [over.operator]p23: 2722 // 2723 // There also exist candidate operator functions of the form 2724 // 2725 // bool operator!(bool); 2726 // bool operator&&(bool, bool); [BELOW] 2727 // bool operator||(bool, bool); [BELOW] 2728 QualType ParamTy = Context.BoolTy; 2729 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 2730 break; 2731 } 2732 2733 case OO_AmpAmp: 2734 case OO_PipePipe: { 2735 // C++ [over.operator]p23: 2736 // 2737 // There also exist candidate operator functions of the form 2738 // 2739 // bool operator!(bool); [ABOVE] 2740 // bool operator&&(bool, bool); 2741 // bool operator||(bool, bool); 2742 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 2743 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 2744 break; 2745 } 2746 2747 case OO_Subscript: 2748 // C++ [over.built]p13: 2749 // 2750 // For every cv-qualified or cv-unqualified object type T there 2751 // exist candidate operator functions of the form 2752 // 2753 // T* operator+(T*, ptrdiff_t); [ABOVE] 2754 // T& operator[](T*, ptrdiff_t); 2755 // T* operator-(T*, ptrdiff_t); [ABOVE] 2756 // T* operator+(ptrdiff_t, T*); [ABOVE] 2757 // T& operator[](ptrdiff_t, T*); 2758 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2759 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2760 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 2761 QualType PointeeType = (*Ptr)->getAsPointerType()->getPointeeType(); 2762 QualType ResultTy = Context.getReferenceType(PointeeType); 2763 2764 // T& operator[](T*, ptrdiff_t) 2765 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 2766 2767 // T& operator[](ptrdiff_t, T*); 2768 ParamTypes[0] = ParamTypes[1]; 2769 ParamTypes[1] = *Ptr; 2770 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 2771 } 2772 break; 2773 2774 case OO_ArrowStar: 2775 // FIXME: No support for pointer-to-members yet. 2776 break; 2777 } 2778} 2779 2780/// AddOverloadCandidates - Add all of the function overloads in Ovl 2781/// to the candidate set. 2782void 2783Sema::AddOverloadCandidates(const OverloadedFunctionDecl *Ovl, 2784 Expr **Args, unsigned NumArgs, 2785 OverloadCandidateSet& CandidateSet, 2786 bool SuppressUserConversions) 2787{ 2788 for (OverloadedFunctionDecl::function_const_iterator Func 2789 = Ovl->function_begin(); 2790 Func != Ovl->function_end(); ++Func) 2791 AddOverloadCandidate(*Func, Args, NumArgs, CandidateSet, 2792 SuppressUserConversions); 2793} 2794 2795/// isBetterOverloadCandidate - Determines whether the first overload 2796/// candidate is a better candidate than the second (C++ 13.3.3p1). 2797bool 2798Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 2799 const OverloadCandidate& Cand2) 2800{ 2801 // Define viable functions to be better candidates than non-viable 2802 // functions. 2803 if (!Cand2.Viable) 2804 return Cand1.Viable; 2805 else if (!Cand1.Viable) 2806 return false; 2807 2808 // FIXME: Deal with the implicit object parameter for static member 2809 // functions. (C++ 13.3.3p1). 2810 2811 // (C++ 13.3.3p1): a viable function F1 is defined to be a better 2812 // function than another viable function F2 if for all arguments i, 2813 // ICSi(F1) is not a worse conversion sequence than ICSi(F2), and 2814 // then... 2815 unsigned NumArgs = Cand1.Conversions.size(); 2816 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 2817 bool HasBetterConversion = false; 2818 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2819 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 2820 Cand2.Conversions[ArgIdx])) { 2821 case ImplicitConversionSequence::Better: 2822 // Cand1 has a better conversion sequence. 2823 HasBetterConversion = true; 2824 break; 2825 2826 case ImplicitConversionSequence::Worse: 2827 // Cand1 can't be better than Cand2. 2828 return false; 2829 2830 case ImplicitConversionSequence::Indistinguishable: 2831 // Do nothing. 2832 break; 2833 } 2834 } 2835 2836 if (HasBetterConversion) 2837 return true; 2838 2839 // FIXME: Several other bullets in (C++ 13.3.3p1) need to be 2840 // implemented, but they require template support. 2841 2842 // C++ [over.match.best]p1b4: 2843 // 2844 // -- the context is an initialization by user-defined conversion 2845 // (see 8.5, 13.3.1.5) and the standard conversion sequence 2846 // from the return type of F1 to the destination type (i.e., 2847 // the type of the entity being initialized) is a better 2848 // conversion sequence than the standard conversion sequence 2849 // from the return type of F2 to the destination type. 2850 if (Cand1.Function && Cand2.Function && 2851 isa<CXXConversionDecl>(Cand1.Function) && 2852 isa<CXXConversionDecl>(Cand2.Function)) { 2853 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 2854 Cand2.FinalConversion)) { 2855 case ImplicitConversionSequence::Better: 2856 // Cand1 has a better conversion sequence. 2857 return true; 2858 2859 case ImplicitConversionSequence::Worse: 2860 // Cand1 can't be better than Cand2. 2861 return false; 2862 2863 case ImplicitConversionSequence::Indistinguishable: 2864 // Do nothing 2865 break; 2866 } 2867 } 2868 2869 return false; 2870} 2871 2872/// BestViableFunction - Computes the best viable function (C++ 13.3.3) 2873/// within an overload candidate set. If overloading is successful, 2874/// the result will be OR_Success and Best will be set to point to the 2875/// best viable function within the candidate set. Otherwise, one of 2876/// several kinds of errors will be returned; see 2877/// Sema::OverloadingResult. 2878Sema::OverloadingResult 2879Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 2880 OverloadCandidateSet::iterator& Best) 2881{ 2882 // Find the best viable function. 2883 Best = CandidateSet.end(); 2884 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2885 Cand != CandidateSet.end(); ++Cand) { 2886 if (Cand->Viable) { 2887 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 2888 Best = Cand; 2889 } 2890 } 2891 2892 // If we didn't find any viable functions, abort. 2893 if (Best == CandidateSet.end()) 2894 return OR_No_Viable_Function; 2895 2896 // Make sure that this function is better than every other viable 2897 // function. If not, we have an ambiguity. 2898 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2899 Cand != CandidateSet.end(); ++Cand) { 2900 if (Cand->Viable && 2901 Cand != Best && 2902 !isBetterOverloadCandidate(*Best, *Cand)) { 2903 Best = CandidateSet.end(); 2904 return OR_Ambiguous; 2905 } 2906 } 2907 2908 // Best is the best viable function. 2909 return OR_Success; 2910} 2911 2912/// PrintOverloadCandidates - When overload resolution fails, prints 2913/// diagnostic messages containing the candidates in the candidate 2914/// set. If OnlyViable is true, only viable candidates will be printed. 2915void 2916Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 2917 bool OnlyViable) 2918{ 2919 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 2920 LastCand = CandidateSet.end(); 2921 for (; Cand != LastCand; ++Cand) { 2922 if (Cand->Viable || !OnlyViable) { 2923 if (Cand->Function) { 2924 // Normal function 2925 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 2926 } else if (Cand->IsSurrogate) { 2927 // Desugar the type of the surrogate down to a function type, 2928 // retaining as many typedefs as possible while still showing 2929 // the function type (and, therefore, its parameter types). 2930 QualType FnType = Cand->Surrogate->getConversionType(); 2931 bool isReference = false; 2932 bool isPointer = false; 2933 if (const ReferenceType *FnTypeRef = FnType->getAsReferenceType()) { 2934 FnType = FnTypeRef->getPointeeType(); 2935 isReference = true; 2936 } 2937 if (const PointerType *FnTypePtr = FnType->getAsPointerType()) { 2938 FnType = FnTypePtr->getPointeeType(); 2939 isPointer = true; 2940 } 2941 // Desugar down to a function type. 2942 FnType = QualType(FnType->getAsFunctionType(), 0); 2943 // Reconstruct the pointer/reference as appropriate. 2944 if (isPointer) FnType = Context.getPointerType(FnType); 2945 if (isReference) FnType = Context.getReferenceType(FnType); 2946 2947 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 2948 << FnType; 2949 } else { 2950 // FIXME: We need to get the identifier in here 2951 // FIXME: Do we want the error message to point at the 2952 // operator? (built-ins won't have a location) 2953 QualType FnType 2954 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 2955 Cand->BuiltinTypes.ParamTypes, 2956 Cand->Conversions.size(), 2957 false, 0); 2958 2959 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 2960 } 2961 } 2962 } 2963} 2964 2965/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 2966/// an overloaded function (C++ [over.over]), where @p From is an 2967/// expression with overloaded function type and @p ToType is the type 2968/// we're trying to resolve to. For example: 2969/// 2970/// @code 2971/// int f(double); 2972/// int f(int); 2973/// 2974/// int (*pfd)(double) = f; // selects f(double) 2975/// @endcode 2976/// 2977/// This routine returns the resulting FunctionDecl if it could be 2978/// resolved, and NULL otherwise. When @p Complain is true, this 2979/// routine will emit diagnostics if there is an error. 2980FunctionDecl * 2981Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 2982 bool Complain) { 2983 QualType FunctionType = ToType; 2984 if (const PointerLikeType *ToTypePtr = ToType->getAsPointerLikeType()) 2985 FunctionType = ToTypePtr->getPointeeType(); 2986 2987 // We only look at pointers or references to functions. 2988 if (!FunctionType->isFunctionType()) 2989 return 0; 2990 2991 // Find the actual overloaded function declaration. 2992 OverloadedFunctionDecl *Ovl = 0; 2993 2994 // C++ [over.over]p1: 2995 // [...] [Note: any redundant set of parentheses surrounding the 2996 // overloaded function name is ignored (5.1). ] 2997 Expr *OvlExpr = From->IgnoreParens(); 2998 2999 // C++ [over.over]p1: 3000 // [...] The overloaded function name can be preceded by the & 3001 // operator. 3002 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3003 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3004 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3005 } 3006 3007 // Try to dig out the overloaded function. 3008 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) 3009 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3010 3011 // If there's no overloaded function declaration, we're done. 3012 if (!Ovl) 3013 return 0; 3014 3015 // Look through all of the overloaded functions, searching for one 3016 // whose type matches exactly. 3017 // FIXME: When templates or using declarations come along, we'll actually 3018 // have to deal with duplicates, partial ordering, etc. For now, we 3019 // can just do a simple search. 3020 FunctionType = Context.getCanonicalType(FunctionType.getUnqualifiedType()); 3021 for (OverloadedFunctionDecl::function_iterator Fun = Ovl->function_begin(); 3022 Fun != Ovl->function_end(); ++Fun) { 3023 // C++ [over.over]p3: 3024 // Non-member functions and static member functions match 3025 // targets of type “pointer-to-function”or 3026 // “reference-to-function.” 3027 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) 3028 if (!Method->isStatic()) 3029 continue; 3030 3031 if (FunctionType == Context.getCanonicalType((*Fun)->getType())) 3032 return *Fun; 3033 } 3034 3035 return 0; 3036} 3037 3038/// ResolveOverloadedCallFn - Given the call expression that calls Fn 3039/// (which eventually refers to the set of overloaded functions in 3040/// Ovl) and the call arguments Args/NumArgs, attempt to resolve the 3041/// function call down to a specific function. If overload resolution 3042/// succeeds, returns the function declaration produced by overload 3043/// resolution. Otherwise, emits diagnostics, deletes all of the 3044/// arguments and Fn, and returns NULL. 3045FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, OverloadedFunctionDecl *Ovl, 3046 SourceLocation LParenLoc, 3047 Expr **Args, unsigned NumArgs, 3048 SourceLocation *CommaLocs, 3049 SourceLocation RParenLoc) { 3050 OverloadCandidateSet CandidateSet; 3051 AddOverloadCandidates(Ovl, Args, NumArgs, CandidateSet); 3052 OverloadCandidateSet::iterator Best; 3053 switch (BestViableFunction(CandidateSet, Best)) { 3054 case OR_Success: 3055 return Best->Function; 3056 3057 case OR_No_Viable_Function: 3058 Diag(Fn->getSourceRange().getBegin(), 3059 diag::err_ovl_no_viable_function_in_call) 3060 << Ovl->getDeclName() << (unsigned)CandidateSet.size() 3061 << Fn->getSourceRange(); 3062 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3063 break; 3064 3065 case OR_Ambiguous: 3066 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 3067 << Ovl->getDeclName() << Fn->getSourceRange(); 3068 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3069 break; 3070 } 3071 3072 // Overload resolution failed. Destroy all of the subexpressions and 3073 // return NULL. 3074 Fn->Destroy(Context); 3075 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 3076 Args[Arg]->Destroy(Context); 3077 return 0; 3078} 3079 3080/// BuildCallToObjectOfClassType - Build a call to an object of class 3081/// type (C++ [over.call.object]), which can end up invoking an 3082/// overloaded function call operator (@c operator()) or performing a 3083/// user-defined conversion on the object argument. 3084Action::ExprResult 3085Sema::BuildCallToObjectOfClassType(Expr *Object, SourceLocation LParenLoc, 3086 Expr **Args, unsigned NumArgs, 3087 SourceLocation *CommaLocs, 3088 SourceLocation RParenLoc) { 3089 assert(Object->getType()->isRecordType() && "Requires object type argument"); 3090 const RecordType *Record = Object->getType()->getAsRecordType(); 3091 3092 // C++ [over.call.object]p1: 3093 // If the primary-expression E in the function call syntax 3094 // evaluates to a class object of type “cv T”, then the set of 3095 // candidate functions includes at least the function call 3096 // operators of T. The function call operators of T are obtained by 3097 // ordinary lookup of the name operator() in the context of 3098 // (E).operator(). 3099 OverloadCandidateSet CandidateSet; 3100 IdentifierResolver::iterator I 3101 = IdResolver.begin(Context.DeclarationNames.getCXXOperatorName(OO_Call), 3102 cast<CXXRecordType>(Record)->getDecl(), 3103 /*LookInParentCtx=*/false); 3104 NamedDecl *MemberOps = (I == IdResolver.end())? 0 : *I; 3105 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(MemberOps)) 3106 AddMethodCandidate(Method, Object, Args, NumArgs, CandidateSet, 3107 /*SuppressUserConversions=*/false); 3108 else if (OverloadedFunctionDecl *Ovl 3109 = dyn_cast_or_null<OverloadedFunctionDecl>(MemberOps)) { 3110 for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(), 3111 FEnd = Ovl->function_end(); 3112 F != FEnd; ++F) { 3113 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*F)) 3114 AddMethodCandidate(Method, Object, Args, NumArgs, CandidateSet, 3115 /*SuppressUserConversions=*/false); 3116 } 3117 } 3118 3119 // C++ [over.call.object]p2: 3120 // In addition, for each conversion function declared in T of the 3121 // form 3122 // 3123 // operator conversion-type-id () cv-qualifier; 3124 // 3125 // where cv-qualifier is the same cv-qualification as, or a 3126 // greater cv-qualification than, cv, and where conversion-type-id 3127 // denotes the type "pointer to function of (P1,...,Pn) returning 3128 // R", or the type "reference to pointer to function of 3129 // (P1,...,Pn) returning R", or the type "reference to function 3130 // of (P1,...,Pn) returning R", a surrogate call function [...] 3131 // is also considered as a candidate function. Similarly, 3132 // surrogate call functions are added to the set of candidate 3133 // functions for each conversion function declared in an 3134 // accessible base class provided the function is not hidden 3135 // within T by another intervening declaration. 3136 // 3137 // FIXME: Look in base classes for more conversion operators! 3138 OverloadedFunctionDecl *Conversions 3139 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 3140 for (OverloadedFunctionDecl::function_iterator 3141 Func = Conversions->function_begin(), 3142 FuncEnd = Conversions->function_end(); 3143 Func != FuncEnd; ++Func) { 3144 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 3145 3146 // Strip the reference type (if any) and then the pointer type (if 3147 // any) to get down to what might be a function type. 3148 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 3149 if (const PointerType *ConvPtrType = ConvType->getAsPointerType()) 3150 ConvType = ConvPtrType->getPointeeType(); 3151 3152 if (const FunctionTypeProto *Proto = ConvType->getAsFunctionTypeProto()) 3153 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 3154 } 3155 3156 // Perform overload resolution. 3157 OverloadCandidateSet::iterator Best; 3158 switch (BestViableFunction(CandidateSet, Best)) { 3159 case OR_Success: 3160 // Overload resolution succeeded; we'll build the appropriate call 3161 // below. 3162 break; 3163 3164 case OR_No_Viable_Function: 3165 Diag(Object->getSourceRange().getBegin(), 3166 diag::err_ovl_no_viable_object_call) 3167 << Object->getType() << (unsigned)CandidateSet.size() 3168 << Object->getSourceRange(); 3169 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3170 break; 3171 3172 case OR_Ambiguous: 3173 Diag(Object->getSourceRange().getBegin(), 3174 diag::err_ovl_ambiguous_object_call) 3175 << Object->getType() << Object->getSourceRange(); 3176 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3177 break; 3178 } 3179 3180 if (Best == CandidateSet.end()) { 3181 // We had an error; delete all of the subexpressions and return 3182 // the error. 3183 delete Object; 3184 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3185 delete Args[ArgIdx]; 3186 return true; 3187 } 3188 3189 if (Best->Function == 0) { 3190 // Since there is no function declaration, this is one of the 3191 // surrogate candidates. Dig out the conversion function. 3192 CXXConversionDecl *Conv 3193 = cast<CXXConversionDecl>( 3194 Best->Conversions[0].UserDefined.ConversionFunction); 3195 3196 // We selected one of the surrogate functions that converts the 3197 // object parameter to a function pointer. Perform the conversion 3198 // on the object argument, then let ActOnCallExpr finish the job. 3199 // FIXME: Represent the user-defined conversion in the AST! 3200 ImpCastExprToType(Object, 3201 Conv->getConversionType().getNonReferenceType(), 3202 Conv->getConversionType()->isReferenceType()); 3203 return ActOnCallExpr((ExprTy*)Object, LParenLoc, (ExprTy**)Args, NumArgs, 3204 CommaLocs, RParenLoc); 3205 } 3206 3207 // We found an overloaded operator(). Build a CXXOperatorCallExpr 3208 // that calls this method, using Object for the implicit object 3209 // parameter and passing along the remaining arguments. 3210 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 3211 const FunctionTypeProto *Proto = Method->getType()->getAsFunctionTypeProto(); 3212 3213 unsigned NumArgsInProto = Proto->getNumArgs(); 3214 unsigned NumArgsToCheck = NumArgs; 3215 3216 // Build the full argument list for the method call (the 3217 // implicit object parameter is placed at the beginning of the 3218 // list). 3219 Expr **MethodArgs; 3220 if (NumArgs < NumArgsInProto) { 3221 NumArgsToCheck = NumArgsInProto; 3222 MethodArgs = new Expr*[NumArgsInProto + 1]; 3223 } else { 3224 MethodArgs = new Expr*[NumArgs + 1]; 3225 } 3226 MethodArgs[0] = Object; 3227 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3228 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 3229 3230 Expr *NewFn = new DeclRefExpr(Method, Method->getType(), 3231 SourceLocation()); 3232 UsualUnaryConversions(NewFn); 3233 3234 // Once we've built TheCall, all of the expressions are properly 3235 // owned. 3236 QualType ResultTy = Method->getResultType().getNonReferenceType(); 3237 llvm::OwningPtr<CXXOperatorCallExpr> 3238 TheCall(new CXXOperatorCallExpr(NewFn, MethodArgs, NumArgs + 1, 3239 ResultTy, RParenLoc)); 3240 delete [] MethodArgs; 3241 3242 // Initialize the implicit object parameter. 3243 if (!PerformObjectArgumentInitialization(Object, Method)) 3244 return true; 3245 TheCall->setArg(0, Object); 3246 3247 // Check the argument types. 3248 for (unsigned i = 0; i != NumArgsToCheck; i++) { 3249 QualType ProtoArgType = Proto->getArgType(i); 3250 3251 Expr *Arg; 3252 if (i < NumArgs) 3253 Arg = Args[i]; 3254 else 3255 Arg = new CXXDefaultArgExpr(Method->getParamDecl(i)); 3256 QualType ArgType = Arg->getType(); 3257 3258 // Pass the argument. 3259 if (PerformCopyInitialization(Arg, ProtoArgType, "passing")) 3260 return true; 3261 3262 TheCall->setArg(i + 1, Arg); 3263 } 3264 3265 // If this is a variadic call, handle args passed through "...". 3266 if (Proto->isVariadic()) { 3267 // Promote the arguments (C99 6.5.2.2p7). 3268 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 3269 Expr *Arg = Args[i]; 3270 DefaultArgumentPromotion(Arg); 3271 TheCall->setArg(i + 1, Arg); 3272 } 3273 } 3274 3275 return CheckFunctionCall(Method, TheCall.take()); 3276} 3277 3278/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 3279/// (if one exists), where @c Base is an expression of class type and 3280/// @c Member is the name of the member we're trying to find. 3281Action::ExprResult 3282Sema::BuildOverloadedArrowExpr(Expr *Base, SourceLocation OpLoc, 3283 SourceLocation MemberLoc, 3284 IdentifierInfo &Member) { 3285 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 3286 3287 // C++ [over.ref]p1: 3288 // 3289 // [...] An expression x->m is interpreted as (x.operator->())->m 3290 // for a class object x of type T if T::operator->() exists and if 3291 // the operator is selected as the best match function by the 3292 // overload resolution mechanism (13.3). 3293 // FIXME: look in base classes. 3294 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 3295 OverloadCandidateSet CandidateSet; 3296 const RecordType *BaseRecord = Base->getType()->getAsRecordType(); 3297 IdentifierResolver::iterator I 3298 = IdResolver.begin(OpName, cast<CXXRecordType>(BaseRecord)->getDecl(), 3299 /*LookInParentCtx=*/false); 3300 NamedDecl *MemberOps = (I == IdResolver.end())? 0 : *I; 3301 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(MemberOps)) 3302 AddMethodCandidate(Method, Base, 0, 0, CandidateSet, 3303 /*SuppressUserConversions=*/false); 3304 else if (OverloadedFunctionDecl *Ovl 3305 = dyn_cast_or_null<OverloadedFunctionDecl>(MemberOps)) { 3306 for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(), 3307 FEnd = Ovl->function_end(); 3308 F != FEnd; ++F) { 3309 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*F)) 3310 AddMethodCandidate(Method, Base, 0, 0, CandidateSet, 3311 /*SuppressUserConversions=*/false); 3312 } 3313 } 3314 3315 llvm::OwningPtr<Expr> BasePtr(Base); 3316 3317 // Perform overload resolution. 3318 OverloadCandidateSet::iterator Best; 3319 switch (BestViableFunction(CandidateSet, Best)) { 3320 case OR_Success: 3321 // Overload resolution succeeded; we'll build the call below. 3322 break; 3323 3324 case OR_No_Viable_Function: 3325 if (CandidateSet.empty()) 3326 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 3327 << BasePtr->getType() << BasePtr->getSourceRange(); 3328 else 3329 Diag(OpLoc, diag::err_ovl_no_viable_oper) 3330 << "operator->" << (unsigned)CandidateSet.size() 3331 << BasePtr->getSourceRange(); 3332 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3333 return true; 3334 3335 case OR_Ambiguous: 3336 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 3337 << "operator->" << BasePtr->getSourceRange(); 3338 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3339 return true; 3340 } 3341 3342 // Convert the object parameter. 3343 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 3344 if (PerformObjectArgumentInitialization(Base, Method)) 3345 return true; 3346 3347 // No concerns about early exits now. 3348 BasePtr.take(); 3349 3350 // Build the operator call. 3351 Expr *FnExpr = new DeclRefExpr(Method, Method->getType(), SourceLocation()); 3352 UsualUnaryConversions(FnExpr); 3353 Base = new CXXOperatorCallExpr(FnExpr, &Base, 1, 3354 Method->getResultType().getNonReferenceType(), 3355 OpLoc); 3356 return ActOnMemberReferenceExpr(Base, OpLoc, tok::arrow, MemberLoc, Member); 3357} 3358 3359/// FixOverloadedFunctionReference - E is an expression that refers to 3360/// a C++ overloaded function (possibly with some parentheses and 3361/// perhaps a '&' around it). We have resolved the overloaded function 3362/// to the function declaration Fn, so patch up the expression E to 3363/// refer (possibly indirectly) to Fn. 3364void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 3365 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 3366 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 3367 E->setType(PE->getSubExpr()->getType()); 3368 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 3369 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 3370 "Can only take the address of an overloaded function"); 3371 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 3372 E->setType(Context.getPointerType(E->getType())); 3373 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 3374 assert(isa<OverloadedFunctionDecl>(DR->getDecl()) && 3375 "Expected overloaded function"); 3376 DR->setDecl(Fn); 3377 E->setType(Fn->getType()); 3378 } else { 3379 assert(false && "Invalid reference to overloaded function"); 3380 } 3381} 3382 3383} // end namespace clang 3384