SemaOverload.cpp revision bf40818928d2a7f76a4ba9abee469a7d02225ab2
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, 787 ToPointeeType, 788 ToType, Context); 789 return true; 790 } 791 792 // C++ [conv.ptr]p3: 793 // 794 // An rvalue of type "pointer to cv D," where D is a class type, 795 // can be converted to an rvalue of type "pointer to cv B," where 796 // B is a base class (clause 10) of D. If B is an inaccessible 797 // (clause 11) or ambiguous (10.2) base class of D, a program that 798 // necessitates this conversion is ill-formed. The result of the 799 // conversion is a pointer to the base class sub-object of the 800 // derived class object. The null pointer value is converted to 801 // the null pointer value of the destination type. 802 // 803 // Note that we do not check for ambiguity or inaccessibility 804 // here. That is handled by CheckPointerConversion. 805 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 806 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 807 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 808 ToPointeeType, 809 ToType, Context); 810 return true; 811 } 812 813 // Objective C++: We're able to convert from a pointer to an 814 // interface to a pointer to a different interface. 815 const ObjCInterfaceType* FromIface = FromPointeeType->getAsObjCInterfaceType(); 816 const ObjCInterfaceType* ToIface = ToPointeeType->getAsObjCInterfaceType(); 817 if (FromIface && ToIface && 818 Context.canAssignObjCInterfaces(ToIface, FromIface)) { 819 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 820 ToPointeeType, 821 ToType, Context); 822 return true; 823 } 824 825 // Objective C++: We're able to convert between "id" and a pointer 826 // to any interface (in both directions). 827 if ((FromIface && Context.isObjCIdType(ToPointeeType)) 828 || (ToIface && Context.isObjCIdType(FromPointeeType))) { 829 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 830 ToPointeeType, 831 ToType, Context); 832 return true; 833 } 834 835 return false; 836} 837 838/// CheckPointerConversion - Check the pointer conversion from the 839/// expression From to the type ToType. This routine checks for 840/// ambiguous (FIXME: or inaccessible) derived-to-base pointer 841/// conversions for which IsPointerConversion has already returned 842/// true. It returns true and produces a diagnostic if there was an 843/// error, or returns false otherwise. 844bool Sema::CheckPointerConversion(Expr *From, QualType ToType) { 845 QualType FromType = From->getType(); 846 847 if (const PointerType *FromPtrType = FromType->getAsPointerType()) 848 if (const PointerType *ToPtrType = ToType->getAsPointerType()) { 849 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 850 /*DetectVirtual=*/false); 851 QualType FromPointeeType = FromPtrType->getPointeeType(), 852 ToPointeeType = ToPtrType->getPointeeType(); 853 if (FromPointeeType->isRecordType() && 854 ToPointeeType->isRecordType()) { 855 // We must have a derived-to-base conversion. Check an 856 // ambiguous or inaccessible conversion. 857 return CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 858 From->getExprLoc(), 859 From->getSourceRange()); 860 } 861 } 862 863 return false; 864} 865 866/// IsQualificationConversion - Determines whether the conversion from 867/// an rvalue of type FromType to ToType is a qualification conversion 868/// (C++ 4.4). 869bool 870Sema::IsQualificationConversion(QualType FromType, QualType ToType) 871{ 872 FromType = Context.getCanonicalType(FromType); 873 ToType = Context.getCanonicalType(ToType); 874 875 // If FromType and ToType are the same type, this is not a 876 // qualification conversion. 877 if (FromType == ToType) 878 return false; 879 880 // (C++ 4.4p4): 881 // A conversion can add cv-qualifiers at levels other than the first 882 // in multi-level pointers, subject to the following rules: [...] 883 bool PreviousToQualsIncludeConst = true; 884 bool UnwrappedAnyPointer = false; 885 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 886 // Within each iteration of the loop, we check the qualifiers to 887 // determine if this still looks like a qualification 888 // conversion. Then, if all is well, we unwrap one more level of 889 // pointers or pointers-to-members and do it all again 890 // until there are no more pointers or pointers-to-members left to 891 // unwrap. 892 UnwrappedAnyPointer = true; 893 894 // -- for every j > 0, if const is in cv 1,j then const is in cv 895 // 2,j, and similarly for volatile. 896 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 897 return false; 898 899 // -- if the cv 1,j and cv 2,j are different, then const is in 900 // every cv for 0 < k < j. 901 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 902 && !PreviousToQualsIncludeConst) 903 return false; 904 905 // Keep track of whether all prior cv-qualifiers in the "to" type 906 // include const. 907 PreviousToQualsIncludeConst 908 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 909 } 910 911 // We are left with FromType and ToType being the pointee types 912 // after unwrapping the original FromType and ToType the same number 913 // of types. If we unwrapped any pointers, and if FromType and 914 // ToType have the same unqualified type (since we checked 915 // qualifiers above), then this is a qualification conversion. 916 return UnwrappedAnyPointer && 917 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 918} 919 920/// IsUserDefinedConversion - Determines whether there is a 921/// user-defined conversion sequence (C++ [over.ics.user]) that 922/// converts expression From to the type ToType. If such a conversion 923/// exists, User will contain the user-defined conversion sequence 924/// that performs such a conversion and this routine will return 925/// true. Otherwise, this routine returns false and User is 926/// unspecified. 927bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 928 UserDefinedConversionSequence& User) 929{ 930 OverloadCandidateSet CandidateSet; 931 if (const CXXRecordType *ToRecordType 932 = dyn_cast_or_null<CXXRecordType>(ToType->getAsRecordType())) { 933 // C++ [over.match.ctor]p1: 934 // When objects of class type are direct-initialized (8.5), or 935 // copy-initialized from an expression of the same or a 936 // derived class type (8.5), overload resolution selects the 937 // constructor. [...] For copy-initialization, the candidate 938 // functions are all the converting constructors (12.3.1) of 939 // that class. The argument list is the expression-list within 940 // the parentheses of the initializer. 941 CXXRecordDecl *ToRecordDecl = ToRecordType->getDecl(); 942 const OverloadedFunctionDecl *Constructors = ToRecordDecl->getConstructors(); 943 for (OverloadedFunctionDecl::function_const_iterator func 944 = Constructors->function_begin(); 945 func != Constructors->function_end(); ++func) { 946 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*func); 947 if (Constructor->isConvertingConstructor()) 948 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 949 /*SuppressUserConversions=*/true); 950 } 951 } 952 953 if (const CXXRecordType *FromRecordType 954 = dyn_cast_or_null<CXXRecordType>(From->getType()->getAsRecordType())) { 955 // Add all of the conversion functions as candidates. 956 // FIXME: Look for conversions in base classes! 957 CXXRecordDecl *FromRecordDecl = FromRecordType->getDecl(); 958 OverloadedFunctionDecl *Conversions 959 = FromRecordDecl->getConversionFunctions(); 960 for (OverloadedFunctionDecl::function_iterator Func 961 = Conversions->function_begin(); 962 Func != Conversions->function_end(); ++Func) { 963 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 964 AddConversionCandidate(Conv, From, ToType, CandidateSet); 965 } 966 } 967 968 OverloadCandidateSet::iterator Best; 969 switch (BestViableFunction(CandidateSet, Best)) { 970 case OR_Success: 971 // Record the standard conversion we used and the conversion function. 972 if (CXXConstructorDecl *Constructor 973 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 974 // C++ [over.ics.user]p1: 975 // If the user-defined conversion is specified by a 976 // constructor (12.3.1), the initial standard conversion 977 // sequence converts the source type to the type required by 978 // the argument of the constructor. 979 // 980 // FIXME: What about ellipsis conversions? 981 QualType ThisType = Constructor->getThisType(Context); 982 User.Before = Best->Conversions[0].Standard; 983 User.ConversionFunction = Constructor; 984 User.After.setAsIdentityConversion(); 985 User.After.FromTypePtr 986 = ThisType->getAsPointerType()->getPointeeType().getAsOpaquePtr(); 987 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 988 return true; 989 } else if (CXXConversionDecl *Conversion 990 = dyn_cast<CXXConversionDecl>(Best->Function)) { 991 // C++ [over.ics.user]p1: 992 // 993 // [...] If the user-defined conversion is specified by a 994 // conversion function (12.3.2), the initial standard 995 // conversion sequence converts the source type to the 996 // implicit object parameter of the conversion function. 997 User.Before = Best->Conversions[0].Standard; 998 User.ConversionFunction = Conversion; 999 1000 // C++ [over.ics.user]p2: 1001 // The second standard conversion sequence converts the 1002 // result of the user-defined conversion to the target type 1003 // for the sequence. Since an implicit conversion sequence 1004 // is an initialization, the special rules for 1005 // initialization by user-defined conversion apply when 1006 // selecting the best user-defined conversion for a 1007 // user-defined conversion sequence (see 13.3.3 and 1008 // 13.3.3.1). 1009 User.After = Best->FinalConversion; 1010 return true; 1011 } else { 1012 assert(false && "Not a constructor or conversion function?"); 1013 return false; 1014 } 1015 1016 case OR_No_Viable_Function: 1017 // No conversion here! We're done. 1018 return false; 1019 1020 case OR_Ambiguous: 1021 // FIXME: See C++ [over.best.ics]p10 for the handling of 1022 // ambiguous conversion sequences. 1023 return false; 1024 } 1025 1026 return false; 1027} 1028 1029/// CompareImplicitConversionSequences - Compare two implicit 1030/// conversion sequences to determine whether one is better than the 1031/// other or if they are indistinguishable (C++ 13.3.3.2). 1032ImplicitConversionSequence::CompareKind 1033Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1034 const ImplicitConversionSequence& ICS2) 1035{ 1036 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1037 // conversion sequences (as defined in 13.3.3.1) 1038 // -- a standard conversion sequence (13.3.3.1.1) is a better 1039 // conversion sequence than a user-defined conversion sequence or 1040 // an ellipsis conversion sequence, and 1041 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1042 // conversion sequence than an ellipsis conversion sequence 1043 // (13.3.3.1.3). 1044 // 1045 if (ICS1.ConversionKind < ICS2.ConversionKind) 1046 return ImplicitConversionSequence::Better; 1047 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1048 return ImplicitConversionSequence::Worse; 1049 1050 // Two implicit conversion sequences of the same form are 1051 // indistinguishable conversion sequences unless one of the 1052 // following rules apply: (C++ 13.3.3.2p3): 1053 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1054 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1055 else if (ICS1.ConversionKind == 1056 ImplicitConversionSequence::UserDefinedConversion) { 1057 // User-defined conversion sequence U1 is a better conversion 1058 // sequence than another user-defined conversion sequence U2 if 1059 // they contain the same user-defined conversion function or 1060 // constructor and if the second standard conversion sequence of 1061 // U1 is better than the second standard conversion sequence of 1062 // U2 (C++ 13.3.3.2p3). 1063 if (ICS1.UserDefined.ConversionFunction == 1064 ICS2.UserDefined.ConversionFunction) 1065 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1066 ICS2.UserDefined.After); 1067 } 1068 1069 return ImplicitConversionSequence::Indistinguishable; 1070} 1071 1072/// CompareStandardConversionSequences - Compare two standard 1073/// conversion sequences to determine whether one is better than the 1074/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1075ImplicitConversionSequence::CompareKind 1076Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1077 const StandardConversionSequence& SCS2) 1078{ 1079 // Standard conversion sequence S1 is a better conversion sequence 1080 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1081 1082 // -- S1 is a proper subsequence of S2 (comparing the conversion 1083 // sequences in the canonical form defined by 13.3.3.1.1, 1084 // excluding any Lvalue Transformation; the identity conversion 1085 // sequence is considered to be a subsequence of any 1086 // non-identity conversion sequence) or, if not that, 1087 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1088 // Neither is a proper subsequence of the other. Do nothing. 1089 ; 1090 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1091 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1092 (SCS1.Second == ICK_Identity && 1093 SCS1.Third == ICK_Identity)) 1094 // SCS1 is a proper subsequence of SCS2. 1095 return ImplicitConversionSequence::Better; 1096 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1097 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1098 (SCS2.Second == ICK_Identity && 1099 SCS2.Third == ICK_Identity)) 1100 // SCS2 is a proper subsequence of SCS1. 1101 return ImplicitConversionSequence::Worse; 1102 1103 // -- the rank of S1 is better than the rank of S2 (by the rules 1104 // defined below), or, if not that, 1105 ImplicitConversionRank Rank1 = SCS1.getRank(); 1106 ImplicitConversionRank Rank2 = SCS2.getRank(); 1107 if (Rank1 < Rank2) 1108 return ImplicitConversionSequence::Better; 1109 else if (Rank2 < Rank1) 1110 return ImplicitConversionSequence::Worse; 1111 1112 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1113 // are indistinguishable unless one of the following rules 1114 // applies: 1115 1116 // A conversion that is not a conversion of a pointer, or 1117 // pointer to member, to bool is better than another conversion 1118 // that is such a conversion. 1119 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1120 return SCS2.isPointerConversionToBool() 1121 ? ImplicitConversionSequence::Better 1122 : ImplicitConversionSequence::Worse; 1123 1124 // C++ [over.ics.rank]p4b2: 1125 // 1126 // If class B is derived directly or indirectly from class A, 1127 // conversion of B* to A* is better than conversion of B* to 1128 // void*, and conversion of A* to void* is better than conversion 1129 // of B* to void*. 1130 bool SCS1ConvertsToVoid 1131 = SCS1.isPointerConversionToVoidPointer(Context); 1132 bool SCS2ConvertsToVoid 1133 = SCS2.isPointerConversionToVoidPointer(Context); 1134 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1135 // Exactly one of the conversion sequences is a conversion to 1136 // a void pointer; it's the worse conversion. 1137 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1138 : ImplicitConversionSequence::Worse; 1139 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1140 // Neither conversion sequence converts to a void pointer; compare 1141 // their derived-to-base conversions. 1142 if (ImplicitConversionSequence::CompareKind DerivedCK 1143 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1144 return DerivedCK; 1145 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1146 // Both conversion sequences are conversions to void 1147 // pointers. Compare the source types to determine if there's an 1148 // inheritance relationship in their sources. 1149 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1150 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1151 1152 // Adjust the types we're converting from via the array-to-pointer 1153 // conversion, if we need to. 1154 if (SCS1.First == ICK_Array_To_Pointer) 1155 FromType1 = Context.getArrayDecayedType(FromType1); 1156 if (SCS2.First == ICK_Array_To_Pointer) 1157 FromType2 = Context.getArrayDecayedType(FromType2); 1158 1159 QualType FromPointee1 1160 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1161 QualType FromPointee2 1162 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1163 1164 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1165 return ImplicitConversionSequence::Better; 1166 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1167 return ImplicitConversionSequence::Worse; 1168 1169 // Objective-C++: If one interface is more specific than the 1170 // other, it is the better one. 1171 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1172 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1173 if (FromIface1 && FromIface1) { 1174 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1175 return ImplicitConversionSequence::Better; 1176 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1177 return ImplicitConversionSequence::Worse; 1178 } 1179 } 1180 1181 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1182 // bullet 3). 1183 if (ImplicitConversionSequence::CompareKind QualCK 1184 = CompareQualificationConversions(SCS1, SCS2)) 1185 return QualCK; 1186 1187 // C++ [over.ics.rank]p3b4: 1188 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1189 // which the references refer are the same type except for 1190 // top-level cv-qualifiers, and the type to which the reference 1191 // initialized by S2 refers is more cv-qualified than the type 1192 // to which the reference initialized by S1 refers. 1193 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1194 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1195 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1196 T1 = Context.getCanonicalType(T1); 1197 T2 = Context.getCanonicalType(T2); 1198 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1199 if (T2.isMoreQualifiedThan(T1)) 1200 return ImplicitConversionSequence::Better; 1201 else if (T1.isMoreQualifiedThan(T2)) 1202 return ImplicitConversionSequence::Worse; 1203 } 1204 } 1205 1206 return ImplicitConversionSequence::Indistinguishable; 1207} 1208 1209/// CompareQualificationConversions - Compares two standard conversion 1210/// sequences to determine whether they can be ranked based on their 1211/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1212ImplicitConversionSequence::CompareKind 1213Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1214 const StandardConversionSequence& SCS2) 1215{ 1216 // C++ 13.3.3.2p3: 1217 // -- S1 and S2 differ only in their qualification conversion and 1218 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1219 // cv-qualification signature of type T1 is a proper subset of 1220 // the cv-qualification signature of type T2, and S1 is not the 1221 // deprecated string literal array-to-pointer conversion (4.2). 1222 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1223 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1224 return ImplicitConversionSequence::Indistinguishable; 1225 1226 // FIXME: the example in the standard doesn't use a qualification 1227 // conversion (!) 1228 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1229 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1230 T1 = Context.getCanonicalType(T1); 1231 T2 = Context.getCanonicalType(T2); 1232 1233 // If the types are the same, we won't learn anything by unwrapped 1234 // them. 1235 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1236 return ImplicitConversionSequence::Indistinguishable; 1237 1238 ImplicitConversionSequence::CompareKind Result 1239 = ImplicitConversionSequence::Indistinguishable; 1240 while (UnwrapSimilarPointerTypes(T1, T2)) { 1241 // Within each iteration of the loop, we check the qualifiers to 1242 // determine if this still looks like a qualification 1243 // conversion. Then, if all is well, we unwrap one more level of 1244 // pointers or pointers-to-members and do it all again 1245 // until there are no more pointers or pointers-to-members left 1246 // to unwrap. This essentially mimics what 1247 // IsQualificationConversion does, but here we're checking for a 1248 // strict subset of qualifiers. 1249 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1250 // The qualifiers are the same, so this doesn't tell us anything 1251 // about how the sequences rank. 1252 ; 1253 else if (T2.isMoreQualifiedThan(T1)) { 1254 // T1 has fewer qualifiers, so it could be the better sequence. 1255 if (Result == ImplicitConversionSequence::Worse) 1256 // Neither has qualifiers that are a subset of the other's 1257 // qualifiers. 1258 return ImplicitConversionSequence::Indistinguishable; 1259 1260 Result = ImplicitConversionSequence::Better; 1261 } else if (T1.isMoreQualifiedThan(T2)) { 1262 // T2 has fewer qualifiers, so it could be the better sequence. 1263 if (Result == ImplicitConversionSequence::Better) 1264 // Neither has qualifiers that are a subset of the other's 1265 // qualifiers. 1266 return ImplicitConversionSequence::Indistinguishable; 1267 1268 Result = ImplicitConversionSequence::Worse; 1269 } else { 1270 // Qualifiers are disjoint. 1271 return ImplicitConversionSequence::Indistinguishable; 1272 } 1273 1274 // If the types after this point are equivalent, we're done. 1275 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1276 break; 1277 } 1278 1279 // Check that the winning standard conversion sequence isn't using 1280 // the deprecated string literal array to pointer conversion. 1281 switch (Result) { 1282 case ImplicitConversionSequence::Better: 1283 if (SCS1.Deprecated) 1284 Result = ImplicitConversionSequence::Indistinguishable; 1285 break; 1286 1287 case ImplicitConversionSequence::Indistinguishable: 1288 break; 1289 1290 case ImplicitConversionSequence::Worse: 1291 if (SCS2.Deprecated) 1292 Result = ImplicitConversionSequence::Indistinguishable; 1293 break; 1294 } 1295 1296 return Result; 1297} 1298 1299/// CompareDerivedToBaseConversions - Compares two standard conversion 1300/// sequences to determine whether they can be ranked based on their 1301/// various kinds of derived-to-base conversions (C++ 1302/// [over.ics.rank]p4b3). As part of these checks, we also look at 1303/// conversions between Objective-C interface types. 1304ImplicitConversionSequence::CompareKind 1305Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1306 const StandardConversionSequence& SCS2) { 1307 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1308 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1309 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1310 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1311 1312 // Adjust the types we're converting from via the array-to-pointer 1313 // conversion, if we need to. 1314 if (SCS1.First == ICK_Array_To_Pointer) 1315 FromType1 = Context.getArrayDecayedType(FromType1); 1316 if (SCS2.First == ICK_Array_To_Pointer) 1317 FromType2 = Context.getArrayDecayedType(FromType2); 1318 1319 // Canonicalize all of the types. 1320 FromType1 = Context.getCanonicalType(FromType1); 1321 ToType1 = Context.getCanonicalType(ToType1); 1322 FromType2 = Context.getCanonicalType(FromType2); 1323 ToType2 = Context.getCanonicalType(ToType2); 1324 1325 // C++ [over.ics.rank]p4b3: 1326 // 1327 // If class B is derived directly or indirectly from class A and 1328 // class C is derived directly or indirectly from B, 1329 // 1330 // For Objective-C, we let A, B, and C also be Objective-C 1331 // interfaces. 1332 1333 // Compare based on pointer conversions. 1334 if (SCS1.Second == ICK_Pointer_Conversion && 1335 SCS2.Second == ICK_Pointer_Conversion) { 1336 QualType FromPointee1 1337 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1338 QualType ToPointee1 1339 = ToType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1340 QualType FromPointee2 1341 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1342 QualType ToPointee2 1343 = ToType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1344 1345 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1346 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1347 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1348 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1349 1350 // -- conversion of C* to B* is better than conversion of C* to A*, 1351 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1352 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1353 return ImplicitConversionSequence::Better; 1354 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1355 return ImplicitConversionSequence::Worse; 1356 1357 if (ToIface1 && ToIface2) { 1358 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1359 return ImplicitConversionSequence::Better; 1360 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1361 return ImplicitConversionSequence::Worse; 1362 } 1363 } 1364 1365 // -- conversion of B* to A* is better than conversion of C* to A*, 1366 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1367 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1368 return ImplicitConversionSequence::Better; 1369 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1370 return ImplicitConversionSequence::Worse; 1371 1372 if (FromIface1 && FromIface2) { 1373 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1374 return ImplicitConversionSequence::Better; 1375 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1376 return ImplicitConversionSequence::Worse; 1377 } 1378 } 1379 } 1380 1381 // Compare based on reference bindings. 1382 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1383 SCS1.Second == ICK_Derived_To_Base) { 1384 // -- binding of an expression of type C to a reference of type 1385 // B& is better than binding an expression of type C to a 1386 // reference of type A&, 1387 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1388 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1389 if (IsDerivedFrom(ToType1, ToType2)) 1390 return ImplicitConversionSequence::Better; 1391 else if (IsDerivedFrom(ToType2, ToType1)) 1392 return ImplicitConversionSequence::Worse; 1393 } 1394 1395 // -- binding of an expression of type B to a reference of type 1396 // A& is better than binding an expression of type C to a 1397 // reference of type A&, 1398 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1399 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1400 if (IsDerivedFrom(FromType2, FromType1)) 1401 return ImplicitConversionSequence::Better; 1402 else if (IsDerivedFrom(FromType1, FromType2)) 1403 return ImplicitConversionSequence::Worse; 1404 } 1405 } 1406 1407 1408 // FIXME: conversion of A::* to B::* is better than conversion of 1409 // A::* to C::*, 1410 1411 // FIXME: conversion of B::* to C::* is better than conversion of 1412 // A::* to C::*, and 1413 1414 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1415 SCS1.Second == ICK_Derived_To_Base) { 1416 // -- conversion of C to B is better than conversion of C to A, 1417 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1418 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1419 if (IsDerivedFrom(ToType1, ToType2)) 1420 return ImplicitConversionSequence::Better; 1421 else if (IsDerivedFrom(ToType2, ToType1)) 1422 return ImplicitConversionSequence::Worse; 1423 } 1424 1425 // -- conversion of B to A is better than conversion of C to A. 1426 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1427 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1428 if (IsDerivedFrom(FromType2, FromType1)) 1429 return ImplicitConversionSequence::Better; 1430 else if (IsDerivedFrom(FromType1, FromType2)) 1431 return ImplicitConversionSequence::Worse; 1432 } 1433 } 1434 1435 return ImplicitConversionSequence::Indistinguishable; 1436} 1437 1438/// TryCopyInitialization - Try to copy-initialize a value of type 1439/// ToType from the expression From. Return the implicit conversion 1440/// sequence required to pass this argument, which may be a bad 1441/// conversion sequence (meaning that the argument cannot be passed to 1442/// a parameter of this type). If @p SuppressUserConversions, then we 1443/// do not permit any user-defined conversion sequences. 1444ImplicitConversionSequence 1445Sema::TryCopyInitialization(Expr *From, QualType ToType, 1446 bool SuppressUserConversions) { 1447 if (!getLangOptions().CPlusPlus) { 1448 // In C, copy initialization is the same as performing an assignment. 1449 AssignConvertType ConvTy = 1450 CheckSingleAssignmentConstraints(ToType, From); 1451 ImplicitConversionSequence ICS; 1452 if (getLangOptions().NoExtensions? ConvTy != Compatible 1453 : ConvTy == Incompatible) 1454 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1455 else 1456 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 1457 return ICS; 1458 } else if (ToType->isReferenceType()) { 1459 ImplicitConversionSequence ICS; 1460 CheckReferenceInit(From, ToType, &ICS, SuppressUserConversions); 1461 return ICS; 1462 } else { 1463 return TryImplicitConversion(From, ToType, SuppressUserConversions); 1464 } 1465} 1466 1467/// PerformArgumentPassing - Pass the argument Arg into a parameter of 1468/// type ToType. Returns true (and emits a diagnostic) if there was 1469/// an error, returns false if the initialization succeeded. 1470bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1471 const char* Flavor) { 1472 if (!getLangOptions().CPlusPlus) { 1473 // In C, argument passing is the same as performing an assignment. 1474 QualType FromType = From->getType(); 1475 AssignConvertType ConvTy = 1476 CheckSingleAssignmentConstraints(ToType, From); 1477 1478 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1479 FromType, From, Flavor); 1480 } 1481 1482 if (ToType->isReferenceType()) 1483 return CheckReferenceInit(From, ToType); 1484 1485 if (!PerformImplicitConversion(From, ToType)) 1486 return false; 1487 1488 return Diag(From->getSourceRange().getBegin(), 1489 diag::err_typecheck_convert_incompatible) 1490 << ToType << From->getType() << Flavor << From->getSourceRange(); 1491} 1492 1493/// TryObjectArgumentInitialization - Try to initialize the object 1494/// parameter of the given member function (@c Method) from the 1495/// expression @p From. 1496ImplicitConversionSequence 1497Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1498 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1499 unsigned MethodQuals = Method->getTypeQualifiers(); 1500 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 1501 1502 // Set up the conversion sequence as a "bad" conversion, to allow us 1503 // to exit early. 1504 ImplicitConversionSequence ICS; 1505 ICS.Standard.setAsIdentityConversion(); 1506 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1507 1508 // We need to have an object of class type. 1509 QualType FromType = From->getType(); 1510 if (!FromType->isRecordType()) 1511 return ICS; 1512 1513 // The implicit object parmeter is has the type "reference to cv X", 1514 // where X is the class of which the function is a member 1515 // (C++ [over.match.funcs]p4). However, when finding an implicit 1516 // conversion sequence for the argument, we are not allowed to 1517 // create temporaries or perform user-defined conversions 1518 // (C++ [over.match.funcs]p5). We perform a simplified version of 1519 // reference binding here, that allows class rvalues to bind to 1520 // non-constant references. 1521 1522 // First check the qualifiers. We don't care about lvalue-vs-rvalue 1523 // with the implicit object parameter (C++ [over.match.funcs]p5). 1524 QualType FromTypeCanon = Context.getCanonicalType(FromType); 1525 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 1526 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 1527 return ICS; 1528 1529 // Check that we have either the same type or a derived type. It 1530 // affects the conversion rank. 1531 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 1532 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 1533 ICS.Standard.Second = ICK_Identity; 1534 else if (IsDerivedFrom(FromType, ClassType)) 1535 ICS.Standard.Second = ICK_Derived_To_Base; 1536 else 1537 return ICS; 1538 1539 // Success. Mark this as a reference binding. 1540 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 1541 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 1542 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 1543 ICS.Standard.ReferenceBinding = true; 1544 ICS.Standard.DirectBinding = true; 1545 return ICS; 1546} 1547 1548/// PerformObjectArgumentInitialization - Perform initialization of 1549/// the implicit object parameter for the given Method with the given 1550/// expression. 1551bool 1552Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 1553 QualType ImplicitParamType 1554 = Method->getThisType(Context)->getAsPointerType()->getPointeeType(); 1555 ImplicitConversionSequence ICS 1556 = TryObjectArgumentInitialization(From, Method); 1557 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 1558 return Diag(From->getSourceRange().getBegin(), 1559 diag::err_implicit_object_parameter_init) 1560 << ImplicitParamType << From->getType() << From->getSourceRange(); 1561 1562 if (ICS.Standard.Second == ICK_Derived_To_Base && 1563 CheckDerivedToBaseConversion(From->getType(), ImplicitParamType, 1564 From->getSourceRange().getBegin(), 1565 From->getSourceRange())) 1566 return true; 1567 1568 ImpCastExprToType(From, ImplicitParamType, /*isLvalue=*/true); 1569 return false; 1570} 1571 1572/// AddOverloadCandidate - Adds the given function to the set of 1573/// candidate functions, using the given function call arguments. If 1574/// @p SuppressUserConversions, then don't allow user-defined 1575/// conversions via constructors or conversion operators. 1576void 1577Sema::AddOverloadCandidate(FunctionDecl *Function, 1578 Expr **Args, unsigned NumArgs, 1579 OverloadCandidateSet& CandidateSet, 1580 bool SuppressUserConversions) 1581{ 1582 const FunctionTypeProto* Proto 1583 = dyn_cast<FunctionTypeProto>(Function->getType()->getAsFunctionType()); 1584 assert(Proto && "Functions without a prototype cannot be overloaded"); 1585 assert(!isa<CXXConversionDecl>(Function) && 1586 "Use AddConversionCandidate for conversion functions"); 1587 1588 // Add this candidate 1589 CandidateSet.push_back(OverloadCandidate()); 1590 OverloadCandidate& Candidate = CandidateSet.back(); 1591 Candidate.Function = Function; 1592 Candidate.IsSurrogate = false; 1593 1594 unsigned NumArgsInProto = Proto->getNumArgs(); 1595 1596 // (C++ 13.3.2p2): A candidate function having fewer than m 1597 // parameters is viable only if it has an ellipsis in its parameter 1598 // list (8.3.5). 1599 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 1600 Candidate.Viable = false; 1601 return; 1602 } 1603 1604 // (C++ 13.3.2p2): A candidate function having more than m parameters 1605 // is viable only if the (m+1)st parameter has a default argument 1606 // (8.3.6). For the purposes of overload resolution, the 1607 // parameter list is truncated on the right, so that there are 1608 // exactly m parameters. 1609 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 1610 if (NumArgs < MinRequiredArgs) { 1611 // Not enough arguments. 1612 Candidate.Viable = false; 1613 return; 1614 } 1615 1616 // Determine the implicit conversion sequences for each of the 1617 // arguments. 1618 Candidate.Viable = true; 1619 Candidate.Conversions.resize(NumArgs); 1620 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 1621 if (ArgIdx < NumArgsInProto) { 1622 // (C++ 13.3.2p3): for F to be a viable function, there shall 1623 // exist for each argument an implicit conversion sequence 1624 // (13.3.3.1) that converts that argument to the corresponding 1625 // parameter of F. 1626 QualType ParamType = Proto->getArgType(ArgIdx); 1627 Candidate.Conversions[ArgIdx] 1628 = TryCopyInitialization(Args[ArgIdx], ParamType, 1629 SuppressUserConversions); 1630 if (Candidate.Conversions[ArgIdx].ConversionKind 1631 == ImplicitConversionSequence::BadConversion) { 1632 Candidate.Viable = false; 1633 break; 1634 } 1635 } else { 1636 // (C++ 13.3.2p2): For the purposes of overload resolution, any 1637 // argument for which there is no corresponding parameter is 1638 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 1639 Candidate.Conversions[ArgIdx].ConversionKind 1640 = ImplicitConversionSequence::EllipsisConversion; 1641 } 1642 } 1643} 1644 1645/// AddMethodCandidate - Adds the given C++ member function to the set 1646/// of candidate functions, using the given function call arguments 1647/// and the object argument (@c Object). For example, in a call 1648/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 1649/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 1650/// allow user-defined conversions via constructors or conversion 1651/// operators. 1652void 1653Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 1654 Expr **Args, unsigned NumArgs, 1655 OverloadCandidateSet& CandidateSet, 1656 bool SuppressUserConversions) 1657{ 1658 const FunctionTypeProto* Proto 1659 = dyn_cast<FunctionTypeProto>(Method->getType()->getAsFunctionType()); 1660 assert(Proto && "Methods without a prototype cannot be overloaded"); 1661 assert(!isa<CXXConversionDecl>(Method) && 1662 "Use AddConversionCandidate for conversion functions"); 1663 1664 // Add this candidate 1665 CandidateSet.push_back(OverloadCandidate()); 1666 OverloadCandidate& Candidate = CandidateSet.back(); 1667 Candidate.Function = Method; 1668 Candidate.IsSurrogate = false; 1669 1670 unsigned NumArgsInProto = Proto->getNumArgs(); 1671 1672 // (C++ 13.3.2p2): A candidate function having fewer than m 1673 // parameters is viable only if it has an ellipsis in its parameter 1674 // list (8.3.5). 1675 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 1676 Candidate.Viable = false; 1677 return; 1678 } 1679 1680 // (C++ 13.3.2p2): A candidate function having more than m parameters 1681 // is viable only if the (m+1)st parameter has a default argument 1682 // (8.3.6). For the purposes of overload resolution, the 1683 // parameter list is truncated on the right, so that there are 1684 // exactly m parameters. 1685 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 1686 if (NumArgs < MinRequiredArgs) { 1687 // Not enough arguments. 1688 Candidate.Viable = false; 1689 return; 1690 } 1691 1692 Candidate.Viable = true; 1693 Candidate.Conversions.resize(NumArgs + 1); 1694 1695 // Determine the implicit conversion sequence for the object 1696 // parameter. 1697 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 1698 if (Candidate.Conversions[0].ConversionKind 1699 == ImplicitConversionSequence::BadConversion) { 1700 Candidate.Viable = false; 1701 return; 1702 } 1703 1704 // Determine the implicit conversion sequences for each of the 1705 // arguments. 1706 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 1707 if (ArgIdx < NumArgsInProto) { 1708 // (C++ 13.3.2p3): for F to be a viable function, there shall 1709 // exist for each argument an implicit conversion sequence 1710 // (13.3.3.1) that converts that argument to the corresponding 1711 // parameter of F. 1712 QualType ParamType = Proto->getArgType(ArgIdx); 1713 Candidate.Conversions[ArgIdx + 1] 1714 = TryCopyInitialization(Args[ArgIdx], ParamType, 1715 SuppressUserConversions); 1716 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 1717 == ImplicitConversionSequence::BadConversion) { 1718 Candidate.Viable = false; 1719 break; 1720 } 1721 } else { 1722 // (C++ 13.3.2p2): For the purposes of overload resolution, any 1723 // argument for which there is no corresponding parameter is 1724 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 1725 Candidate.Conversions[ArgIdx + 1].ConversionKind 1726 = ImplicitConversionSequence::EllipsisConversion; 1727 } 1728 } 1729} 1730 1731/// AddConversionCandidate - Add a C++ conversion function as a 1732/// candidate in the candidate set (C++ [over.match.conv], 1733/// C++ [over.match.copy]). From is the expression we're converting from, 1734/// and ToType is the type that we're eventually trying to convert to 1735/// (which may or may not be the same type as the type that the 1736/// conversion function produces). 1737void 1738Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 1739 Expr *From, QualType ToType, 1740 OverloadCandidateSet& CandidateSet) { 1741 // Add this candidate 1742 CandidateSet.push_back(OverloadCandidate()); 1743 OverloadCandidate& Candidate = CandidateSet.back(); 1744 Candidate.Function = Conversion; 1745 Candidate.IsSurrogate = false; 1746 Candidate.FinalConversion.setAsIdentityConversion(); 1747 Candidate.FinalConversion.FromTypePtr 1748 = Conversion->getConversionType().getAsOpaquePtr(); 1749 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 1750 1751 // Determine the implicit conversion sequence for the implicit 1752 // object parameter. 1753 Candidate.Viable = true; 1754 Candidate.Conversions.resize(1); 1755 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 1756 1757 if (Candidate.Conversions[0].ConversionKind 1758 == ImplicitConversionSequence::BadConversion) { 1759 Candidate.Viable = false; 1760 return; 1761 } 1762 1763 // To determine what the conversion from the result of calling the 1764 // conversion function to the type we're eventually trying to 1765 // convert to (ToType), we need to synthesize a call to the 1766 // conversion function and attempt copy initialization from it. This 1767 // makes sure that we get the right semantics with respect to 1768 // lvalues/rvalues and the type. Fortunately, we can allocate this 1769 // call on the stack and we don't need its arguments to be 1770 // well-formed. 1771 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 1772 SourceLocation()); 1773 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 1774 &ConversionRef, false); 1775 CallExpr Call(&ConversionFn, 0, 0, 1776 Conversion->getConversionType().getNonReferenceType(), 1777 SourceLocation()); 1778 ImplicitConversionSequence ICS = TryCopyInitialization(&Call, ToType, true); 1779 switch (ICS.ConversionKind) { 1780 case ImplicitConversionSequence::StandardConversion: 1781 Candidate.FinalConversion = ICS.Standard; 1782 break; 1783 1784 case ImplicitConversionSequence::BadConversion: 1785 Candidate.Viable = false; 1786 break; 1787 1788 default: 1789 assert(false && 1790 "Can only end up with a standard conversion sequence or failure"); 1791 } 1792} 1793 1794/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 1795/// converts the given @c Object to a function pointer via the 1796/// conversion function @c Conversion, and then attempts to call it 1797/// with the given arguments (C++ [over.call.object]p2-4). Proto is 1798/// the type of function that we'll eventually be calling. 1799void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 1800 const FunctionTypeProto *Proto, 1801 Expr *Object, Expr **Args, unsigned NumArgs, 1802 OverloadCandidateSet& CandidateSet) { 1803 CandidateSet.push_back(OverloadCandidate()); 1804 OverloadCandidate& Candidate = CandidateSet.back(); 1805 Candidate.Function = 0; 1806 Candidate.Surrogate = Conversion; 1807 Candidate.Viable = true; 1808 Candidate.IsSurrogate = true; 1809 Candidate.Conversions.resize(NumArgs + 1); 1810 1811 // Determine the implicit conversion sequence for the implicit 1812 // object parameter. 1813 ImplicitConversionSequence ObjectInit 1814 = TryObjectArgumentInitialization(Object, Conversion); 1815 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 1816 Candidate.Viable = false; 1817 return; 1818 } 1819 1820 // The first conversion is actually a user-defined conversion whose 1821 // first conversion is ObjectInit's standard conversion (which is 1822 // effectively a reference binding). Record it as such. 1823 Candidate.Conversions[0].ConversionKind 1824 = ImplicitConversionSequence::UserDefinedConversion; 1825 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 1826 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 1827 Candidate.Conversions[0].UserDefined.After 1828 = Candidate.Conversions[0].UserDefined.Before; 1829 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 1830 1831 // Find the 1832 unsigned NumArgsInProto = Proto->getNumArgs(); 1833 1834 // (C++ 13.3.2p2): A candidate function having fewer than m 1835 // parameters is viable only if it has an ellipsis in its parameter 1836 // list (8.3.5). 1837 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 1838 Candidate.Viable = false; 1839 return; 1840 } 1841 1842 // Function types don't have any default arguments, so just check if 1843 // we have enough arguments. 1844 if (NumArgs < NumArgsInProto) { 1845 // Not enough arguments. 1846 Candidate.Viable = false; 1847 return; 1848 } 1849 1850 // Determine the implicit conversion sequences for each of the 1851 // arguments. 1852 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 1853 if (ArgIdx < NumArgsInProto) { 1854 // (C++ 13.3.2p3): for F to be a viable function, there shall 1855 // exist for each argument an implicit conversion sequence 1856 // (13.3.3.1) that converts that argument to the corresponding 1857 // parameter of F. 1858 QualType ParamType = Proto->getArgType(ArgIdx); 1859 Candidate.Conversions[ArgIdx + 1] 1860 = TryCopyInitialization(Args[ArgIdx], ParamType, 1861 /*SuppressUserConversions=*/false); 1862 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 1863 == ImplicitConversionSequence::BadConversion) { 1864 Candidate.Viable = false; 1865 break; 1866 } 1867 } else { 1868 // (C++ 13.3.2p2): For the purposes of overload resolution, any 1869 // argument for which there is no corresponding parameter is 1870 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 1871 Candidate.Conversions[ArgIdx + 1].ConversionKind 1872 = ImplicitConversionSequence::EllipsisConversion; 1873 } 1874 } 1875} 1876 1877/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is 1878/// an acceptable non-member overloaded operator for a call whose 1879/// arguments have types T1 (and, if non-empty, T2). This routine 1880/// implements the check in C++ [over.match.oper]p3b2 concerning 1881/// enumeration types. 1882static bool 1883IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn, 1884 QualType T1, QualType T2, 1885 ASTContext &Context) { 1886 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType())) 1887 return true; 1888 1889 const FunctionTypeProto *Proto = Fn->getType()->getAsFunctionTypeProto(); 1890 if (Proto->getNumArgs() < 1) 1891 return false; 1892 1893 if (T1->isEnumeralType()) { 1894 QualType ArgType = Proto->getArgType(0).getNonReferenceType(); 1895 if (Context.getCanonicalType(T1).getUnqualifiedType() 1896 == Context.getCanonicalType(ArgType).getUnqualifiedType()) 1897 return true; 1898 } 1899 1900 if (Proto->getNumArgs() < 2) 1901 return false; 1902 1903 if (!T2.isNull() && T2->isEnumeralType()) { 1904 QualType ArgType = Proto->getArgType(1).getNonReferenceType(); 1905 if (Context.getCanonicalType(T2).getUnqualifiedType() 1906 == Context.getCanonicalType(ArgType).getUnqualifiedType()) 1907 return true; 1908 } 1909 1910 return false; 1911} 1912 1913/// AddOperatorCandidates - Add the overloaded operator candidates for 1914/// the operator Op that was used in an operator expression such as "x 1915/// Op y". S is the scope in which the expression occurred (used for 1916/// name lookup of the operator), Args/NumArgs provides the operator 1917/// arguments, and CandidateSet will store the added overload 1918/// candidates. (C++ [over.match.oper]). 1919void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 1920 Expr **Args, unsigned NumArgs, 1921 OverloadCandidateSet& CandidateSet) { 1922 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 1923 1924 // C++ [over.match.oper]p3: 1925 // For a unary operator @ with an operand of a type whose 1926 // cv-unqualified version is T1, and for a binary operator @ with 1927 // a left operand of a type whose cv-unqualified version is T1 and 1928 // a right operand of a type whose cv-unqualified version is T2, 1929 // three sets of candidate functions, designated member 1930 // candidates, non-member candidates and built-in candidates, are 1931 // constructed as follows: 1932 QualType T1 = Args[0]->getType(); 1933 QualType T2; 1934 if (NumArgs > 1) 1935 T2 = Args[1]->getType(); 1936 1937 // -- If T1 is a class type, the set of member candidates is the 1938 // result of the qualified lookup of T1::operator@ 1939 // (13.3.1.1.1); otherwise, the set of member candidates is 1940 // empty. 1941 if (const RecordType *T1Rec = T1->getAsRecordType()) { 1942 IdentifierResolver::iterator I 1943 = IdResolver.begin(OpName, cast<CXXRecordType>(T1Rec)->getDecl(), 1944 /*LookInParentCtx=*/false); 1945 NamedDecl *MemberOps = (I == IdResolver.end())? 0 : *I; 1946 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(MemberOps)) 1947 AddMethodCandidate(Method, Args[0], Args+1, NumArgs - 1, CandidateSet, 1948 /*SuppressUserConversions=*/false); 1949 else if (OverloadedFunctionDecl *Ovl 1950 = dyn_cast_or_null<OverloadedFunctionDecl>(MemberOps)) { 1951 for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(), 1952 FEnd = Ovl->function_end(); 1953 F != FEnd; ++F) { 1954 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*F)) 1955 AddMethodCandidate(Method, Args[0], Args+1, NumArgs - 1, CandidateSet, 1956 /*SuppressUserConversions=*/false); 1957 } 1958 } 1959 } 1960 1961 // -- The set of non-member candidates is the result of the 1962 // unqualified lookup of operator@ in the context of the 1963 // expression according to the usual rules for name lookup in 1964 // unqualified function calls (3.4.2) except that all member 1965 // functions are ignored. However, if no operand has a class 1966 // type, only those non-member functions in the lookup set 1967 // that have a first parameter of type T1 or “reference to 1968 // (possibly cv-qualified) T1”, when T1 is an enumeration 1969 // type, or (if there is a right operand) a second parameter 1970 // of type T2 or “reference to (possibly cv-qualified) T2”, 1971 // when T2 is an enumeration type, are candidate functions. 1972 { 1973 NamedDecl *NonMemberOps = 0; 1974 for (IdentifierResolver::iterator I 1975 = IdResolver.begin(OpName, CurContext, true/*LookInParentCtx*/); 1976 I != IdResolver.end(); ++I) { 1977 // We don't need to check the identifier namespace, because 1978 // operator names can only be ordinary identifiers. 1979 1980 // Ignore member functions. 1981 if (ScopedDecl *SD = dyn_cast<ScopedDecl>(*I)) { 1982 if (SD->getDeclContext()->isCXXRecord()) 1983 continue; 1984 } 1985 1986 // We found something with this name. We're done. 1987 NonMemberOps = *I; 1988 break; 1989 } 1990 1991 if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(NonMemberOps)) { 1992 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context)) 1993 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 1994 /*SuppressUserConversions=*/false); 1995 } else if (OverloadedFunctionDecl *Ovl 1996 = dyn_cast_or_null<OverloadedFunctionDecl>(NonMemberOps)) { 1997 for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(), 1998 FEnd = Ovl->function_end(); 1999 F != FEnd; ++F) { 2000 if (IsAcceptableNonMemberOperatorCandidate(*F, T1, T2, Context)) 2001 AddOverloadCandidate(*F, Args, NumArgs, CandidateSet, 2002 /*SuppressUserConversions=*/false); 2003 } 2004 } 2005 } 2006 2007 // Add builtin overload candidates (C++ [over.built]). 2008 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2009} 2010 2011/// AddBuiltinCandidate - Add a candidate for a built-in 2012/// operator. ResultTy and ParamTys are the result and parameter types 2013/// of the built-in candidate, respectively. Args and NumArgs are the 2014/// arguments being passed to the candidate. 2015void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2016 Expr **Args, unsigned NumArgs, 2017 OverloadCandidateSet& CandidateSet) { 2018 // Add this candidate 2019 CandidateSet.push_back(OverloadCandidate()); 2020 OverloadCandidate& Candidate = CandidateSet.back(); 2021 Candidate.Function = 0; 2022 Candidate.BuiltinTypes.ResultTy = ResultTy; 2023 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2024 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2025 2026 // Determine the implicit conversion sequences for each of the 2027 // arguments. 2028 Candidate.Viable = true; 2029 Candidate.Conversions.resize(NumArgs); 2030 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2031 Candidate.Conversions[ArgIdx] 2032 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], false); 2033 if (Candidate.Conversions[ArgIdx].ConversionKind 2034 == ImplicitConversionSequence::BadConversion) { 2035 Candidate.Viable = false; 2036 break; 2037 } 2038 } 2039} 2040 2041/// BuiltinCandidateTypeSet - A set of types that will be used for the 2042/// candidate operator functions for built-in operators (C++ 2043/// [over.built]). The types are separated into pointer types and 2044/// enumeration types. 2045class BuiltinCandidateTypeSet { 2046 /// TypeSet - A set of types. 2047 typedef llvm::SmallPtrSet<void*, 8> TypeSet; 2048 2049 /// PointerTypes - The set of pointer types that will be used in the 2050 /// built-in candidates. 2051 TypeSet PointerTypes; 2052 2053 /// EnumerationTypes - The set of enumeration types that will be 2054 /// used in the built-in candidates. 2055 TypeSet EnumerationTypes; 2056 2057 /// Context - The AST context in which we will build the type sets. 2058 ASTContext &Context; 2059 2060 bool AddWithMoreQualifiedTypeVariants(QualType Ty); 2061 2062public: 2063 /// iterator - Iterates through the types that are part of the set. 2064 class iterator { 2065 TypeSet::iterator Base; 2066 2067 public: 2068 typedef QualType value_type; 2069 typedef QualType reference; 2070 typedef QualType pointer; 2071 typedef std::ptrdiff_t difference_type; 2072 typedef std::input_iterator_tag iterator_category; 2073 2074 iterator(TypeSet::iterator B) : Base(B) { } 2075 2076 iterator& operator++() { 2077 ++Base; 2078 return *this; 2079 } 2080 2081 iterator operator++(int) { 2082 iterator tmp(*this); 2083 ++(*this); 2084 return tmp; 2085 } 2086 2087 reference operator*() const { 2088 return QualType::getFromOpaquePtr(*Base); 2089 } 2090 2091 pointer operator->() const { 2092 return **this; 2093 } 2094 2095 friend bool operator==(iterator LHS, iterator RHS) { 2096 return LHS.Base == RHS.Base; 2097 } 2098 2099 friend bool operator!=(iterator LHS, iterator RHS) { 2100 return LHS.Base != RHS.Base; 2101 } 2102 }; 2103 2104 BuiltinCandidateTypeSet(ASTContext &Context) : Context(Context) { } 2105 2106 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions = true); 2107 2108 /// pointer_begin - First pointer type found; 2109 iterator pointer_begin() { return PointerTypes.begin(); } 2110 2111 /// pointer_end - Last pointer type found; 2112 iterator pointer_end() { return PointerTypes.end(); } 2113 2114 /// enumeration_begin - First enumeration type found; 2115 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2116 2117 /// enumeration_end - Last enumeration type found; 2118 iterator enumeration_end() { return EnumerationTypes.end(); } 2119}; 2120 2121/// AddWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2122/// the set of pointer types along with any more-qualified variants of 2123/// that type. For example, if @p Ty is "int const *", this routine 2124/// will add "int const *", "int const volatile *", "int const 2125/// restrict *", and "int const volatile restrict *" to the set of 2126/// pointer types. Returns true if the add of @p Ty itself succeeded, 2127/// false otherwise. 2128bool BuiltinCandidateTypeSet::AddWithMoreQualifiedTypeVariants(QualType Ty) { 2129 // Insert this type. 2130 if (!PointerTypes.insert(Ty.getAsOpaquePtr())) 2131 return false; 2132 2133 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2134 QualType PointeeTy = PointerTy->getPointeeType(); 2135 // FIXME: Optimize this so that we don't keep trying to add the same types. 2136 2137 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal 2138 // with all pointer conversions that don't cast away constness? 2139 if (!PointeeTy.isConstQualified()) 2140 AddWithMoreQualifiedTypeVariants 2141 (Context.getPointerType(PointeeTy.withConst())); 2142 if (!PointeeTy.isVolatileQualified()) 2143 AddWithMoreQualifiedTypeVariants 2144 (Context.getPointerType(PointeeTy.withVolatile())); 2145 if (!PointeeTy.isRestrictQualified()) 2146 AddWithMoreQualifiedTypeVariants 2147 (Context.getPointerType(PointeeTy.withRestrict())); 2148 } 2149 2150 return true; 2151} 2152 2153/// AddTypesConvertedFrom - Add each of the types to which the type @p 2154/// Ty can be implicit converted to the given set of @p Types. We're 2155/// primarily interested in pointer types, enumeration types, 2156void BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2157 bool AllowUserConversions) { 2158 // Only deal with canonical types. 2159 Ty = Context.getCanonicalType(Ty); 2160 2161 // Look through reference types; they aren't part of the type of an 2162 // expression for the purposes of conversions. 2163 if (const ReferenceType *RefTy = Ty->getAsReferenceType()) 2164 Ty = RefTy->getPointeeType(); 2165 2166 // We don't care about qualifiers on the type. 2167 Ty = Ty.getUnqualifiedType(); 2168 2169 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2170 QualType PointeeTy = PointerTy->getPointeeType(); 2171 2172 // Insert our type, and its more-qualified variants, into the set 2173 // of types. 2174 if (!AddWithMoreQualifiedTypeVariants(Ty)) 2175 return; 2176 2177 // Add 'cv void*' to our set of types. 2178 if (!Ty->isVoidType()) { 2179 QualType QualVoid 2180 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2181 AddWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2182 } 2183 2184 // If this is a pointer to a class type, add pointers to its bases 2185 // (with the same level of cv-qualification as the original 2186 // derived class, of course). 2187 if (const RecordType *PointeeRec = PointeeTy->getAsRecordType()) { 2188 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2189 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2190 Base != ClassDecl->bases_end(); ++Base) { 2191 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2192 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2193 2194 // Add the pointer type, recursively, so that we get all of 2195 // the indirect base classes, too. 2196 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false); 2197 } 2198 } 2199 } else if (Ty->isEnumeralType()) { 2200 EnumerationTypes.insert(Ty.getAsOpaquePtr()); 2201 } else if (AllowUserConversions) { 2202 if (const RecordType *TyRec = Ty->getAsRecordType()) { 2203 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2204 // FIXME: Visit conversion functions in the base classes, too. 2205 OverloadedFunctionDecl *Conversions 2206 = ClassDecl->getConversionFunctions(); 2207 for (OverloadedFunctionDecl::function_iterator Func 2208 = Conversions->function_begin(); 2209 Func != Conversions->function_end(); ++Func) { 2210 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 2211 AddTypesConvertedFrom(Conv->getConversionType(), false); 2212 } 2213 } 2214 } 2215} 2216 2217/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2218/// operator overloads to the candidate set (C++ [over.built]), based 2219/// on the operator @p Op and the arguments given. For example, if the 2220/// operator is a binary '+', this routine might add "int 2221/// operator+(int, int)" to cover integer addition. 2222void 2223Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2224 Expr **Args, unsigned NumArgs, 2225 OverloadCandidateSet& CandidateSet) { 2226 // The set of "promoted arithmetic types", which are the arithmetic 2227 // types are that preserved by promotion (C++ [over.built]p2). Note 2228 // that the first few of these types are the promoted integral 2229 // types; these types need to be first. 2230 // FIXME: What about complex? 2231 const unsigned FirstIntegralType = 0; 2232 const unsigned LastIntegralType = 13; 2233 const unsigned FirstPromotedIntegralType = 7, 2234 LastPromotedIntegralType = 13; 2235 const unsigned FirstPromotedArithmeticType = 7, 2236 LastPromotedArithmeticType = 16; 2237 const unsigned NumArithmeticTypes = 16; 2238 QualType ArithmeticTypes[NumArithmeticTypes] = { 2239 Context.BoolTy, Context.CharTy, Context.WCharTy, 2240 Context.SignedCharTy, Context.ShortTy, 2241 Context.UnsignedCharTy, Context.UnsignedShortTy, 2242 Context.IntTy, Context.LongTy, Context.LongLongTy, 2243 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 2244 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 2245 }; 2246 2247 // Find all of the types that the arguments can convert to, but only 2248 // if the operator we're looking at has built-in operator candidates 2249 // that make use of these types. 2250 BuiltinCandidateTypeSet CandidateTypes(Context); 2251 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 2252 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 2253 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 2254 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 2255 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 2256 (Op == OO_Star && NumArgs == 1)) { 2257 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2258 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType()); 2259 } 2260 2261 bool isComparison = false; 2262 switch (Op) { 2263 case OO_None: 2264 case NUM_OVERLOADED_OPERATORS: 2265 assert(false && "Expected an overloaded operator"); 2266 break; 2267 2268 case OO_Star: // '*' is either unary or binary 2269 if (NumArgs == 1) 2270 goto UnaryStar; 2271 else 2272 goto BinaryStar; 2273 break; 2274 2275 case OO_Plus: // '+' is either unary or binary 2276 if (NumArgs == 1) 2277 goto UnaryPlus; 2278 else 2279 goto BinaryPlus; 2280 break; 2281 2282 case OO_Minus: // '-' is either unary or binary 2283 if (NumArgs == 1) 2284 goto UnaryMinus; 2285 else 2286 goto BinaryMinus; 2287 break; 2288 2289 case OO_Amp: // '&' is either unary or binary 2290 if (NumArgs == 1) 2291 goto UnaryAmp; 2292 else 2293 goto BinaryAmp; 2294 2295 case OO_PlusPlus: 2296 case OO_MinusMinus: 2297 // C++ [over.built]p3: 2298 // 2299 // For every pair (T, VQ), where T is an arithmetic type, and VQ 2300 // is either volatile or empty, there exist candidate operator 2301 // functions of the form 2302 // 2303 // VQ T& operator++(VQ T&); 2304 // T operator++(VQ T&, int); 2305 // 2306 // C++ [over.built]p4: 2307 // 2308 // For every pair (T, VQ), where T is an arithmetic type other 2309 // than bool, and VQ is either volatile or empty, there exist 2310 // candidate operator functions of the form 2311 // 2312 // VQ T& operator--(VQ T&); 2313 // T operator--(VQ T&, int); 2314 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 2315 Arith < NumArithmeticTypes; ++Arith) { 2316 QualType ArithTy = ArithmeticTypes[Arith]; 2317 QualType ParamTypes[2] 2318 = { Context.getReferenceType(ArithTy), Context.IntTy }; 2319 2320 // Non-volatile version. 2321 if (NumArgs == 1) 2322 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2323 else 2324 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2325 2326 // Volatile version 2327 ParamTypes[0] = Context.getReferenceType(ArithTy.withVolatile()); 2328 if (NumArgs == 1) 2329 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2330 else 2331 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2332 } 2333 2334 // C++ [over.built]p5: 2335 // 2336 // For every pair (T, VQ), where T is a cv-qualified or 2337 // cv-unqualified object type, and VQ is either volatile or 2338 // empty, there exist candidate operator functions of the form 2339 // 2340 // T*VQ& operator++(T*VQ&); 2341 // T*VQ& operator--(T*VQ&); 2342 // T* operator++(T*VQ&, int); 2343 // T* operator--(T*VQ&, int); 2344 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2345 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2346 // Skip pointer types that aren't pointers to object types. 2347 if (!(*Ptr)->getAsPointerType()->getPointeeType()->isIncompleteOrObjectType()) 2348 continue; 2349 2350 QualType ParamTypes[2] = { 2351 Context.getReferenceType(*Ptr), Context.IntTy 2352 }; 2353 2354 // Without volatile 2355 if (NumArgs == 1) 2356 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2357 else 2358 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2359 2360 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 2361 // With volatile 2362 ParamTypes[0] = Context.getReferenceType((*Ptr).withVolatile()); 2363 if (NumArgs == 1) 2364 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2365 else 2366 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2367 } 2368 } 2369 break; 2370 2371 UnaryStar: 2372 // C++ [over.built]p6: 2373 // For every cv-qualified or cv-unqualified object type T, there 2374 // exist candidate operator functions of the form 2375 // 2376 // T& operator*(T*); 2377 // 2378 // C++ [over.built]p7: 2379 // For every function type T, there exist candidate operator 2380 // functions of the form 2381 // T& operator*(T*); 2382 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2383 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2384 QualType ParamTy = *Ptr; 2385 QualType PointeeTy = ParamTy->getAsPointerType()->getPointeeType(); 2386 AddBuiltinCandidate(Context.getReferenceType(PointeeTy), 2387 &ParamTy, Args, 1, CandidateSet); 2388 } 2389 break; 2390 2391 UnaryPlus: 2392 // C++ [over.built]p8: 2393 // For every type T, there exist candidate operator functions of 2394 // the form 2395 // 2396 // T* operator+(T*); 2397 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2398 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2399 QualType ParamTy = *Ptr; 2400 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 2401 } 2402 2403 // Fall through 2404 2405 UnaryMinus: 2406 // C++ [over.built]p9: 2407 // For every promoted arithmetic type T, there exist candidate 2408 // operator functions of the form 2409 // 2410 // T operator+(T); 2411 // T operator-(T); 2412 for (unsigned Arith = FirstPromotedArithmeticType; 2413 Arith < LastPromotedArithmeticType; ++Arith) { 2414 QualType ArithTy = ArithmeticTypes[Arith]; 2415 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 2416 } 2417 break; 2418 2419 case OO_Tilde: 2420 // C++ [over.built]p10: 2421 // For every promoted integral type T, there exist candidate 2422 // operator functions of the form 2423 // 2424 // T operator~(T); 2425 for (unsigned Int = FirstPromotedIntegralType; 2426 Int < LastPromotedIntegralType; ++Int) { 2427 QualType IntTy = ArithmeticTypes[Int]; 2428 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 2429 } 2430 break; 2431 2432 case OO_New: 2433 case OO_Delete: 2434 case OO_Array_New: 2435 case OO_Array_Delete: 2436 case OO_Call: 2437 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 2438 break; 2439 2440 case OO_Comma: 2441 UnaryAmp: 2442 case OO_Arrow: 2443 // C++ [over.match.oper]p3: 2444 // -- For the operator ',', the unary operator '&', or the 2445 // operator '->', the built-in candidates set is empty. 2446 break; 2447 2448 case OO_Less: 2449 case OO_Greater: 2450 case OO_LessEqual: 2451 case OO_GreaterEqual: 2452 case OO_EqualEqual: 2453 case OO_ExclaimEqual: 2454 // C++ [over.built]p15: 2455 // 2456 // For every pointer or enumeration type T, there exist 2457 // candidate operator functions of the form 2458 // 2459 // bool operator<(T, T); 2460 // bool operator>(T, T); 2461 // bool operator<=(T, T); 2462 // bool operator>=(T, T); 2463 // bool operator==(T, T); 2464 // bool operator!=(T, T); 2465 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2466 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2467 QualType ParamTypes[2] = { *Ptr, *Ptr }; 2468 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 2469 } 2470 for (BuiltinCandidateTypeSet::iterator Enum 2471 = CandidateTypes.enumeration_begin(); 2472 Enum != CandidateTypes.enumeration_end(); ++Enum) { 2473 QualType ParamTypes[2] = { *Enum, *Enum }; 2474 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 2475 } 2476 2477 // Fall through. 2478 isComparison = true; 2479 2480 BinaryPlus: 2481 BinaryMinus: 2482 if (!isComparison) { 2483 // We didn't fall through, so we must have OO_Plus or OO_Minus. 2484 2485 // C++ [over.built]p13: 2486 // 2487 // For every cv-qualified or cv-unqualified object type T 2488 // there exist candidate operator functions of the form 2489 // 2490 // T* operator+(T*, ptrdiff_t); 2491 // T& operator[](T*, ptrdiff_t); [BELOW] 2492 // T* operator-(T*, ptrdiff_t); 2493 // T* operator+(ptrdiff_t, T*); 2494 // T& operator[](ptrdiff_t, T*); [BELOW] 2495 // 2496 // C++ [over.built]p14: 2497 // 2498 // For every T, where T is a pointer to object type, there 2499 // exist candidate operator functions of the form 2500 // 2501 // ptrdiff_t operator-(T, T); 2502 for (BuiltinCandidateTypeSet::iterator Ptr 2503 = CandidateTypes.pointer_begin(); 2504 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2505 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 2506 2507 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 2508 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2509 2510 if (Op == OO_Plus) { 2511 // T* operator+(ptrdiff_t, T*); 2512 ParamTypes[0] = ParamTypes[1]; 2513 ParamTypes[1] = *Ptr; 2514 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2515 } else { 2516 // ptrdiff_t operator-(T, T); 2517 ParamTypes[1] = *Ptr; 2518 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 2519 Args, 2, CandidateSet); 2520 } 2521 } 2522 } 2523 // Fall through 2524 2525 case OO_Slash: 2526 BinaryStar: 2527 // C++ [over.built]p12: 2528 // 2529 // For every pair of promoted arithmetic types L and R, there 2530 // exist candidate operator functions of the form 2531 // 2532 // LR operator*(L, R); 2533 // LR operator/(L, R); 2534 // LR operator+(L, R); 2535 // LR operator-(L, R); 2536 // bool operator<(L, R); 2537 // bool operator>(L, R); 2538 // bool operator<=(L, R); 2539 // bool operator>=(L, R); 2540 // bool operator==(L, R); 2541 // bool operator!=(L, R); 2542 // 2543 // where LR is the result of the usual arithmetic conversions 2544 // between types L and R. 2545 for (unsigned Left = FirstPromotedArithmeticType; 2546 Left < LastPromotedArithmeticType; ++Left) { 2547 for (unsigned Right = FirstPromotedArithmeticType; 2548 Right < LastPromotedArithmeticType; ++Right) { 2549 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 2550 QualType Result 2551 = isComparison? Context.BoolTy 2552 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 2553 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 2554 } 2555 } 2556 break; 2557 2558 case OO_Percent: 2559 BinaryAmp: 2560 case OO_Caret: 2561 case OO_Pipe: 2562 case OO_LessLess: 2563 case OO_GreaterGreater: 2564 // C++ [over.built]p17: 2565 // 2566 // For every pair of promoted integral types L and R, there 2567 // exist candidate operator functions of the form 2568 // 2569 // LR operator%(L, R); 2570 // LR operator&(L, R); 2571 // LR operator^(L, R); 2572 // LR operator|(L, R); 2573 // L operator<<(L, R); 2574 // L operator>>(L, R); 2575 // 2576 // where LR is the result of the usual arithmetic conversions 2577 // between types L and R. 2578 for (unsigned Left = FirstPromotedIntegralType; 2579 Left < LastPromotedIntegralType; ++Left) { 2580 for (unsigned Right = FirstPromotedIntegralType; 2581 Right < LastPromotedIntegralType; ++Right) { 2582 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 2583 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 2584 ? LandR[0] 2585 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 2586 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 2587 } 2588 } 2589 break; 2590 2591 case OO_Equal: 2592 // C++ [over.built]p20: 2593 // 2594 // For every pair (T, VQ), where T is an enumeration or 2595 // (FIXME:) pointer to member type and VQ is either volatile or 2596 // empty, there exist candidate operator functions of the form 2597 // 2598 // VQ T& operator=(VQ T&, T); 2599 for (BuiltinCandidateTypeSet::iterator Enum 2600 = CandidateTypes.enumeration_begin(); 2601 Enum != CandidateTypes.enumeration_end(); ++Enum) { 2602 QualType ParamTypes[2]; 2603 2604 // T& operator=(T&, T) 2605 ParamTypes[0] = Context.getReferenceType(*Enum); 2606 ParamTypes[1] = *Enum; 2607 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2608 2609 if (!Context.getCanonicalType(*Enum).isVolatileQualified()) { 2610 // volatile T& operator=(volatile T&, T) 2611 ParamTypes[0] = Context.getReferenceType((*Enum).withVolatile()); 2612 ParamTypes[1] = *Enum; 2613 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2614 } 2615 } 2616 // Fall through. 2617 2618 case OO_PlusEqual: 2619 case OO_MinusEqual: 2620 // C++ [over.built]p19: 2621 // 2622 // For every pair (T, VQ), where T is any type and VQ is either 2623 // volatile or empty, there exist candidate operator functions 2624 // of the form 2625 // 2626 // T*VQ& operator=(T*VQ&, T*); 2627 // 2628 // C++ [over.built]p21: 2629 // 2630 // For every pair (T, VQ), where T is a cv-qualified or 2631 // cv-unqualified object type and VQ is either volatile or 2632 // empty, there exist candidate operator functions of the form 2633 // 2634 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 2635 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 2636 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2637 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2638 QualType ParamTypes[2]; 2639 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 2640 2641 // non-volatile version 2642 ParamTypes[0] = Context.getReferenceType(*Ptr); 2643 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2644 2645 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 2646 // volatile version 2647 ParamTypes[0] = Context.getReferenceType((*Ptr).withVolatile()); 2648 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2649 } 2650 } 2651 // Fall through. 2652 2653 case OO_StarEqual: 2654 case OO_SlashEqual: 2655 // C++ [over.built]p18: 2656 // 2657 // For every triple (L, VQ, R), where L is an arithmetic type, 2658 // VQ is either volatile or empty, and R is a promoted 2659 // arithmetic type, there exist candidate operator functions of 2660 // the form 2661 // 2662 // VQ L& operator=(VQ L&, R); 2663 // VQ L& operator*=(VQ L&, R); 2664 // VQ L& operator/=(VQ L&, R); 2665 // VQ L& operator+=(VQ L&, R); 2666 // VQ L& operator-=(VQ L&, R); 2667 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 2668 for (unsigned Right = FirstPromotedArithmeticType; 2669 Right < LastPromotedArithmeticType; ++Right) { 2670 QualType ParamTypes[2]; 2671 ParamTypes[1] = ArithmeticTypes[Right]; 2672 2673 // Add this built-in operator as a candidate (VQ is empty). 2674 ParamTypes[0] = Context.getReferenceType(ArithmeticTypes[Left]); 2675 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2676 2677 // Add this built-in operator as a candidate (VQ is 'volatile'). 2678 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 2679 ParamTypes[0] = Context.getReferenceType(ParamTypes[0]); 2680 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2681 } 2682 } 2683 break; 2684 2685 case OO_PercentEqual: 2686 case OO_LessLessEqual: 2687 case OO_GreaterGreaterEqual: 2688 case OO_AmpEqual: 2689 case OO_CaretEqual: 2690 case OO_PipeEqual: 2691 // C++ [over.built]p22: 2692 // 2693 // For every triple (L, VQ, R), where L is an integral type, VQ 2694 // is either volatile or empty, and R is a promoted integral 2695 // type, there exist candidate operator functions of the form 2696 // 2697 // VQ L& operator%=(VQ L&, R); 2698 // VQ L& operator<<=(VQ L&, R); 2699 // VQ L& operator>>=(VQ L&, R); 2700 // VQ L& operator&=(VQ L&, R); 2701 // VQ L& operator^=(VQ L&, R); 2702 // VQ L& operator|=(VQ L&, R); 2703 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 2704 for (unsigned Right = FirstPromotedIntegralType; 2705 Right < LastPromotedIntegralType; ++Right) { 2706 QualType ParamTypes[2]; 2707 ParamTypes[1] = ArithmeticTypes[Right]; 2708 2709 // Add this built-in operator as a candidate (VQ is empty). 2710 // FIXME: We should be caching these declarations somewhere, 2711 // rather than re-building them every time. 2712 ParamTypes[0] = Context.getReferenceType(ArithmeticTypes[Left]); 2713 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2714 2715 // Add this built-in operator as a candidate (VQ is 'volatile'). 2716 ParamTypes[0] = ArithmeticTypes[Left]; 2717 ParamTypes[0].addVolatile(); 2718 ParamTypes[0] = Context.getReferenceType(ParamTypes[0]); 2719 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 2720 } 2721 } 2722 break; 2723 2724 case OO_Exclaim: { 2725 // C++ [over.operator]p23: 2726 // 2727 // There also exist candidate operator functions of the form 2728 // 2729 // bool operator!(bool); 2730 // bool operator&&(bool, bool); [BELOW] 2731 // bool operator||(bool, bool); [BELOW] 2732 QualType ParamTy = Context.BoolTy; 2733 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 2734 break; 2735 } 2736 2737 case OO_AmpAmp: 2738 case OO_PipePipe: { 2739 // C++ [over.operator]p23: 2740 // 2741 // There also exist candidate operator functions of the form 2742 // 2743 // bool operator!(bool); [ABOVE] 2744 // bool operator&&(bool, bool); 2745 // bool operator||(bool, bool); 2746 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 2747 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 2748 break; 2749 } 2750 2751 case OO_Subscript: 2752 // C++ [over.built]p13: 2753 // 2754 // For every cv-qualified or cv-unqualified object type T there 2755 // exist candidate operator functions of the form 2756 // 2757 // T* operator+(T*, ptrdiff_t); [ABOVE] 2758 // T& operator[](T*, ptrdiff_t); 2759 // T* operator-(T*, ptrdiff_t); [ABOVE] 2760 // T* operator+(ptrdiff_t, T*); [ABOVE] 2761 // T& operator[](ptrdiff_t, T*); 2762 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2763 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2764 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 2765 QualType PointeeType = (*Ptr)->getAsPointerType()->getPointeeType(); 2766 QualType ResultTy = Context.getReferenceType(PointeeType); 2767 2768 // T& operator[](T*, ptrdiff_t) 2769 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 2770 2771 // T& operator[](ptrdiff_t, T*); 2772 ParamTypes[0] = ParamTypes[1]; 2773 ParamTypes[1] = *Ptr; 2774 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 2775 } 2776 break; 2777 2778 case OO_ArrowStar: 2779 // FIXME: No support for pointer-to-members yet. 2780 break; 2781 } 2782} 2783 2784/// AddOverloadCandidates - Add all of the function overloads in Ovl 2785/// to the candidate set. 2786void 2787Sema::AddOverloadCandidates(const OverloadedFunctionDecl *Ovl, 2788 Expr **Args, unsigned NumArgs, 2789 OverloadCandidateSet& CandidateSet, 2790 bool SuppressUserConversions) 2791{ 2792 for (OverloadedFunctionDecl::function_const_iterator Func 2793 = Ovl->function_begin(); 2794 Func != Ovl->function_end(); ++Func) 2795 AddOverloadCandidate(*Func, Args, NumArgs, CandidateSet, 2796 SuppressUserConversions); 2797} 2798 2799/// isBetterOverloadCandidate - Determines whether the first overload 2800/// candidate is a better candidate than the second (C++ 13.3.3p1). 2801bool 2802Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 2803 const OverloadCandidate& Cand2) 2804{ 2805 // Define viable functions to be better candidates than non-viable 2806 // functions. 2807 if (!Cand2.Viable) 2808 return Cand1.Viable; 2809 else if (!Cand1.Viable) 2810 return false; 2811 2812 // FIXME: Deal with the implicit object parameter for static member 2813 // functions. (C++ 13.3.3p1). 2814 2815 // (C++ 13.3.3p1): a viable function F1 is defined to be a better 2816 // function than another viable function F2 if for all arguments i, 2817 // ICSi(F1) is not a worse conversion sequence than ICSi(F2), and 2818 // then... 2819 unsigned NumArgs = Cand1.Conversions.size(); 2820 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 2821 bool HasBetterConversion = false; 2822 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2823 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 2824 Cand2.Conversions[ArgIdx])) { 2825 case ImplicitConversionSequence::Better: 2826 // Cand1 has a better conversion sequence. 2827 HasBetterConversion = true; 2828 break; 2829 2830 case ImplicitConversionSequence::Worse: 2831 // Cand1 can't be better than Cand2. 2832 return false; 2833 2834 case ImplicitConversionSequence::Indistinguishable: 2835 // Do nothing. 2836 break; 2837 } 2838 } 2839 2840 if (HasBetterConversion) 2841 return true; 2842 2843 // FIXME: Several other bullets in (C++ 13.3.3p1) need to be 2844 // implemented, but they require template support. 2845 2846 // C++ [over.match.best]p1b4: 2847 // 2848 // -- the context is an initialization by user-defined conversion 2849 // (see 8.5, 13.3.1.5) and the standard conversion sequence 2850 // from the return type of F1 to the destination type (i.e., 2851 // the type of the entity being initialized) is a better 2852 // conversion sequence than the standard conversion sequence 2853 // from the return type of F2 to the destination type. 2854 if (Cand1.Function && Cand2.Function && 2855 isa<CXXConversionDecl>(Cand1.Function) && 2856 isa<CXXConversionDecl>(Cand2.Function)) { 2857 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 2858 Cand2.FinalConversion)) { 2859 case ImplicitConversionSequence::Better: 2860 // Cand1 has a better conversion sequence. 2861 return true; 2862 2863 case ImplicitConversionSequence::Worse: 2864 // Cand1 can't be better than Cand2. 2865 return false; 2866 2867 case ImplicitConversionSequence::Indistinguishable: 2868 // Do nothing 2869 break; 2870 } 2871 } 2872 2873 return false; 2874} 2875 2876/// BestViableFunction - Computes the best viable function (C++ 13.3.3) 2877/// within an overload candidate set. If overloading is successful, 2878/// the result will be OR_Success and Best will be set to point to the 2879/// best viable function within the candidate set. Otherwise, one of 2880/// several kinds of errors will be returned; see 2881/// Sema::OverloadingResult. 2882Sema::OverloadingResult 2883Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 2884 OverloadCandidateSet::iterator& Best) 2885{ 2886 // Find the best viable function. 2887 Best = CandidateSet.end(); 2888 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2889 Cand != CandidateSet.end(); ++Cand) { 2890 if (Cand->Viable) { 2891 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 2892 Best = Cand; 2893 } 2894 } 2895 2896 // If we didn't find any viable functions, abort. 2897 if (Best == CandidateSet.end()) 2898 return OR_No_Viable_Function; 2899 2900 // Make sure that this function is better than every other viable 2901 // function. If not, we have an ambiguity. 2902 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2903 Cand != CandidateSet.end(); ++Cand) { 2904 if (Cand->Viable && 2905 Cand != Best && 2906 !isBetterOverloadCandidate(*Best, *Cand)) { 2907 Best = CandidateSet.end(); 2908 return OR_Ambiguous; 2909 } 2910 } 2911 2912 // Best is the best viable function. 2913 return OR_Success; 2914} 2915 2916/// PrintOverloadCandidates - When overload resolution fails, prints 2917/// diagnostic messages containing the candidates in the candidate 2918/// set. If OnlyViable is true, only viable candidates will be printed. 2919void 2920Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 2921 bool OnlyViable) 2922{ 2923 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 2924 LastCand = CandidateSet.end(); 2925 for (; Cand != LastCand; ++Cand) { 2926 if (Cand->Viable || !OnlyViable) { 2927 if (Cand->Function) { 2928 // Normal function 2929 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 2930 } else if (Cand->IsSurrogate) { 2931 // Desugar the type of the surrogate down to a function type, 2932 // retaining as many typedefs as possible while still showing 2933 // the function type (and, therefore, its parameter types). 2934 QualType FnType = Cand->Surrogate->getConversionType(); 2935 bool isReference = false; 2936 bool isPointer = false; 2937 if (const ReferenceType *FnTypeRef = FnType->getAsReferenceType()) { 2938 FnType = FnTypeRef->getPointeeType(); 2939 isReference = true; 2940 } 2941 if (const PointerType *FnTypePtr = FnType->getAsPointerType()) { 2942 FnType = FnTypePtr->getPointeeType(); 2943 isPointer = true; 2944 } 2945 // Desugar down to a function type. 2946 FnType = QualType(FnType->getAsFunctionType(), 0); 2947 // Reconstruct the pointer/reference as appropriate. 2948 if (isPointer) FnType = Context.getPointerType(FnType); 2949 if (isReference) FnType = Context.getReferenceType(FnType); 2950 2951 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 2952 << FnType; 2953 } else { 2954 // FIXME: We need to get the identifier in here 2955 // FIXME: Do we want the error message to point at the 2956 // operator? (built-ins won't have a location) 2957 QualType FnType 2958 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 2959 Cand->BuiltinTypes.ParamTypes, 2960 Cand->Conversions.size(), 2961 false, 0); 2962 2963 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 2964 } 2965 } 2966 } 2967} 2968 2969/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 2970/// an overloaded function (C++ [over.over]), where @p From is an 2971/// expression with overloaded function type and @p ToType is the type 2972/// we're trying to resolve to. For example: 2973/// 2974/// @code 2975/// int f(double); 2976/// int f(int); 2977/// 2978/// int (*pfd)(double) = f; // selects f(double) 2979/// @endcode 2980/// 2981/// This routine returns the resulting FunctionDecl if it could be 2982/// resolved, and NULL otherwise. When @p Complain is true, this 2983/// routine will emit diagnostics if there is an error. 2984FunctionDecl * 2985Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 2986 bool Complain) { 2987 QualType FunctionType = ToType; 2988 if (const PointerLikeType *ToTypePtr = ToType->getAsPointerLikeType()) 2989 FunctionType = ToTypePtr->getPointeeType(); 2990 2991 // We only look at pointers or references to functions. 2992 if (!FunctionType->isFunctionType()) 2993 return 0; 2994 2995 // Find the actual overloaded function declaration. 2996 OverloadedFunctionDecl *Ovl = 0; 2997 2998 // C++ [over.over]p1: 2999 // [...] [Note: any redundant set of parentheses surrounding the 3000 // overloaded function name is ignored (5.1). ] 3001 Expr *OvlExpr = From->IgnoreParens(); 3002 3003 // C++ [over.over]p1: 3004 // [...] The overloaded function name can be preceded by the & 3005 // operator. 3006 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3007 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3008 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3009 } 3010 3011 // Try to dig out the overloaded function. 3012 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) 3013 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3014 3015 // If there's no overloaded function declaration, we're done. 3016 if (!Ovl) 3017 return 0; 3018 3019 // Look through all of the overloaded functions, searching for one 3020 // whose type matches exactly. 3021 // FIXME: When templates or using declarations come along, we'll actually 3022 // have to deal with duplicates, partial ordering, etc. For now, we 3023 // can just do a simple search. 3024 FunctionType = Context.getCanonicalType(FunctionType.getUnqualifiedType()); 3025 for (OverloadedFunctionDecl::function_iterator Fun = Ovl->function_begin(); 3026 Fun != Ovl->function_end(); ++Fun) { 3027 // C++ [over.over]p3: 3028 // Non-member functions and static member functions match 3029 // targets of type “pointer-to-function”or 3030 // “reference-to-function.” 3031 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) 3032 if (!Method->isStatic()) 3033 continue; 3034 3035 if (FunctionType == Context.getCanonicalType((*Fun)->getType())) 3036 return *Fun; 3037 } 3038 3039 return 0; 3040} 3041 3042/// ResolveOverloadedCallFn - Given the call expression that calls Fn 3043/// (which eventually refers to the set of overloaded functions in 3044/// Ovl) and the call arguments Args/NumArgs, attempt to resolve the 3045/// function call down to a specific function. If overload resolution 3046/// succeeds, returns the function declaration produced by overload 3047/// resolution. Otherwise, emits diagnostics, deletes all of the 3048/// arguments and Fn, and returns NULL. 3049FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, OverloadedFunctionDecl *Ovl, 3050 SourceLocation LParenLoc, 3051 Expr **Args, unsigned NumArgs, 3052 SourceLocation *CommaLocs, 3053 SourceLocation RParenLoc) { 3054 OverloadCandidateSet CandidateSet; 3055 AddOverloadCandidates(Ovl, Args, NumArgs, CandidateSet); 3056 OverloadCandidateSet::iterator Best; 3057 switch (BestViableFunction(CandidateSet, Best)) { 3058 case OR_Success: 3059 return Best->Function; 3060 3061 case OR_No_Viable_Function: 3062 Diag(Fn->getSourceRange().getBegin(), 3063 diag::err_ovl_no_viable_function_in_call) 3064 << Ovl->getDeclName() << (unsigned)CandidateSet.size() 3065 << Fn->getSourceRange(); 3066 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3067 break; 3068 3069 case OR_Ambiguous: 3070 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 3071 << Ovl->getDeclName() << Fn->getSourceRange(); 3072 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3073 break; 3074 } 3075 3076 // Overload resolution failed. Destroy all of the subexpressions and 3077 // return NULL. 3078 Fn->Destroy(Context); 3079 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 3080 Args[Arg]->Destroy(Context); 3081 return 0; 3082} 3083 3084/// BuildCallToObjectOfClassType - Build a call to an object of class 3085/// type (C++ [over.call.object]), which can end up invoking an 3086/// overloaded function call operator (@c operator()) or performing a 3087/// user-defined conversion on the object argument. 3088Action::ExprResult 3089Sema::BuildCallToObjectOfClassType(Expr *Object, SourceLocation LParenLoc, 3090 Expr **Args, unsigned NumArgs, 3091 SourceLocation *CommaLocs, 3092 SourceLocation RParenLoc) { 3093 assert(Object->getType()->isRecordType() && "Requires object type argument"); 3094 const RecordType *Record = Object->getType()->getAsRecordType(); 3095 3096 // C++ [over.call.object]p1: 3097 // If the primary-expression E in the function call syntax 3098 // evaluates to a class object of type “cv T”, then the set of 3099 // candidate functions includes at least the function call 3100 // operators of T. The function call operators of T are obtained by 3101 // ordinary lookup of the name operator() in the context of 3102 // (E).operator(). 3103 OverloadCandidateSet CandidateSet; 3104 IdentifierResolver::iterator I 3105 = IdResolver.begin(Context.DeclarationNames.getCXXOperatorName(OO_Call), 3106 cast<CXXRecordType>(Record)->getDecl(), 3107 /*LookInParentCtx=*/false); 3108 NamedDecl *MemberOps = (I == IdResolver.end())? 0 : *I; 3109 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(MemberOps)) 3110 AddMethodCandidate(Method, Object, Args, NumArgs, CandidateSet, 3111 /*SuppressUserConversions=*/false); 3112 else if (OverloadedFunctionDecl *Ovl 3113 = dyn_cast_or_null<OverloadedFunctionDecl>(MemberOps)) { 3114 for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(), 3115 FEnd = Ovl->function_end(); 3116 F != FEnd; ++F) { 3117 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*F)) 3118 AddMethodCandidate(Method, Object, Args, NumArgs, CandidateSet, 3119 /*SuppressUserConversions=*/false); 3120 } 3121 } 3122 3123 // C++ [over.call.object]p2: 3124 // In addition, for each conversion function declared in T of the 3125 // form 3126 // 3127 // operator conversion-type-id () cv-qualifier; 3128 // 3129 // where cv-qualifier is the same cv-qualification as, or a 3130 // greater cv-qualification than, cv, and where conversion-type-id 3131 // denotes the type "pointer to function of (P1,...,Pn) returning 3132 // R", or the type "reference to pointer to function of 3133 // (P1,...,Pn) returning R", or the type "reference to function 3134 // of (P1,...,Pn) returning R", a surrogate call function [...] 3135 // is also considered as a candidate function. Similarly, 3136 // surrogate call functions are added to the set of candidate 3137 // functions for each conversion function declared in an 3138 // accessible base class provided the function is not hidden 3139 // within T by another intervening declaration. 3140 // 3141 // FIXME: Look in base classes for more conversion operators! 3142 OverloadedFunctionDecl *Conversions 3143 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 3144 for (OverloadedFunctionDecl::function_iterator 3145 Func = Conversions->function_begin(), 3146 FuncEnd = Conversions->function_end(); 3147 Func != FuncEnd; ++Func) { 3148 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 3149 3150 // Strip the reference type (if any) and then the pointer type (if 3151 // any) to get down to what might be a function type. 3152 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 3153 if (const PointerType *ConvPtrType = ConvType->getAsPointerType()) 3154 ConvType = ConvPtrType->getPointeeType(); 3155 3156 if (const FunctionTypeProto *Proto = ConvType->getAsFunctionTypeProto()) 3157 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 3158 } 3159 3160 // Perform overload resolution. 3161 OverloadCandidateSet::iterator Best; 3162 switch (BestViableFunction(CandidateSet, Best)) { 3163 case OR_Success: 3164 // Overload resolution succeeded; we'll build the appropriate call 3165 // below. 3166 break; 3167 3168 case OR_No_Viable_Function: 3169 Diag(Object->getSourceRange().getBegin(), 3170 diag::err_ovl_no_viable_object_call) 3171 << Object->getType() << (unsigned)CandidateSet.size() 3172 << Object->getSourceRange(); 3173 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3174 break; 3175 3176 case OR_Ambiguous: 3177 Diag(Object->getSourceRange().getBegin(), 3178 diag::err_ovl_ambiguous_object_call) 3179 << Object->getType() << Object->getSourceRange(); 3180 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3181 break; 3182 } 3183 3184 if (Best == CandidateSet.end()) { 3185 // We had an error; delete all of the subexpressions and return 3186 // the error. 3187 delete Object; 3188 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3189 delete Args[ArgIdx]; 3190 return true; 3191 } 3192 3193 if (Best->Function == 0) { 3194 // Since there is no function declaration, this is one of the 3195 // surrogate candidates. Dig out the conversion function. 3196 CXXConversionDecl *Conv 3197 = cast<CXXConversionDecl>( 3198 Best->Conversions[0].UserDefined.ConversionFunction); 3199 3200 // We selected one of the surrogate functions that converts the 3201 // object parameter to a function pointer. Perform the conversion 3202 // on the object argument, then let ActOnCallExpr finish the job. 3203 // FIXME: Represent the user-defined conversion in the AST! 3204 ImpCastExprToType(Object, 3205 Conv->getConversionType().getNonReferenceType(), 3206 Conv->getConversionType()->isReferenceType()); 3207 return ActOnCallExpr((ExprTy*)Object, LParenLoc, (ExprTy**)Args, NumArgs, 3208 CommaLocs, RParenLoc); 3209 } 3210 3211 // We found an overloaded operator(). Build a CXXOperatorCallExpr 3212 // that calls this method, using Object for the implicit object 3213 // parameter and passing along the remaining arguments. 3214 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 3215 const FunctionTypeProto *Proto = Method->getType()->getAsFunctionTypeProto(); 3216 3217 unsigned NumArgsInProto = Proto->getNumArgs(); 3218 unsigned NumArgsToCheck = NumArgs; 3219 3220 // Build the full argument list for the method call (the 3221 // implicit object parameter is placed at the beginning of the 3222 // list). 3223 Expr **MethodArgs; 3224 if (NumArgs < NumArgsInProto) { 3225 NumArgsToCheck = NumArgsInProto; 3226 MethodArgs = new Expr*[NumArgsInProto + 1]; 3227 } else { 3228 MethodArgs = new Expr*[NumArgs + 1]; 3229 } 3230 MethodArgs[0] = Object; 3231 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3232 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 3233 3234 Expr *NewFn = new DeclRefExpr(Method, Method->getType(), 3235 SourceLocation()); 3236 UsualUnaryConversions(NewFn); 3237 3238 // Once we've built TheCall, all of the expressions are properly 3239 // owned. 3240 QualType ResultTy = Method->getResultType().getNonReferenceType(); 3241 llvm::OwningPtr<CXXOperatorCallExpr> 3242 TheCall(new CXXOperatorCallExpr(NewFn, MethodArgs, NumArgs + 1, 3243 ResultTy, RParenLoc)); 3244 delete [] MethodArgs; 3245 3246 // Initialize the implicit object parameter. 3247 if (!PerformObjectArgumentInitialization(Object, Method)) 3248 return true; 3249 TheCall->setArg(0, Object); 3250 3251 // Check the argument types. 3252 for (unsigned i = 0; i != NumArgsToCheck; i++) { 3253 QualType ProtoArgType = Proto->getArgType(i); 3254 3255 Expr *Arg; 3256 if (i < NumArgs) 3257 Arg = Args[i]; 3258 else 3259 Arg = new CXXDefaultArgExpr(Method->getParamDecl(i)); 3260 QualType ArgType = Arg->getType(); 3261 3262 // Pass the argument. 3263 if (PerformCopyInitialization(Arg, ProtoArgType, "passing")) 3264 return true; 3265 3266 TheCall->setArg(i + 1, Arg); 3267 } 3268 3269 // If this is a variadic call, handle args passed through "...". 3270 if (Proto->isVariadic()) { 3271 // Promote the arguments (C99 6.5.2.2p7). 3272 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 3273 Expr *Arg = Args[i]; 3274 DefaultArgumentPromotion(Arg); 3275 TheCall->setArg(i + 1, Arg); 3276 } 3277 } 3278 3279 return CheckFunctionCall(Method, TheCall.take()); 3280} 3281 3282/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 3283/// (if one exists), where @c Base is an expression of class type and 3284/// @c Member is the name of the member we're trying to find. 3285Action::ExprResult 3286Sema::BuildOverloadedArrowExpr(Expr *Base, SourceLocation OpLoc, 3287 SourceLocation MemberLoc, 3288 IdentifierInfo &Member) { 3289 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 3290 3291 // C++ [over.ref]p1: 3292 // 3293 // [...] An expression x->m is interpreted as (x.operator->())->m 3294 // for a class object x of type T if T::operator->() exists and if 3295 // the operator is selected as the best match function by the 3296 // overload resolution mechanism (13.3). 3297 // FIXME: look in base classes. 3298 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 3299 OverloadCandidateSet CandidateSet; 3300 const RecordType *BaseRecord = Base->getType()->getAsRecordType(); 3301 IdentifierResolver::iterator I 3302 = IdResolver.begin(OpName, cast<CXXRecordType>(BaseRecord)->getDecl(), 3303 /*LookInParentCtx=*/false); 3304 NamedDecl *MemberOps = (I == IdResolver.end())? 0 : *I; 3305 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(MemberOps)) 3306 AddMethodCandidate(Method, Base, 0, 0, CandidateSet, 3307 /*SuppressUserConversions=*/false); 3308 else if (OverloadedFunctionDecl *Ovl 3309 = dyn_cast_or_null<OverloadedFunctionDecl>(MemberOps)) { 3310 for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(), 3311 FEnd = Ovl->function_end(); 3312 F != FEnd; ++F) { 3313 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*F)) 3314 AddMethodCandidate(Method, Base, 0, 0, CandidateSet, 3315 /*SuppressUserConversions=*/false); 3316 } 3317 } 3318 3319 llvm::OwningPtr<Expr> BasePtr(Base); 3320 3321 // Perform overload resolution. 3322 OverloadCandidateSet::iterator Best; 3323 switch (BestViableFunction(CandidateSet, Best)) { 3324 case OR_Success: 3325 // Overload resolution succeeded; we'll build the call below. 3326 break; 3327 3328 case OR_No_Viable_Function: 3329 if (CandidateSet.empty()) 3330 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 3331 << BasePtr->getType() << BasePtr->getSourceRange(); 3332 else 3333 Diag(OpLoc, diag::err_ovl_no_viable_oper) 3334 << "operator->" << (unsigned)CandidateSet.size() 3335 << BasePtr->getSourceRange(); 3336 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3337 return true; 3338 3339 case OR_Ambiguous: 3340 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 3341 << "operator->" << BasePtr->getSourceRange(); 3342 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3343 return true; 3344 } 3345 3346 // Convert the object parameter. 3347 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 3348 if (PerformObjectArgumentInitialization(Base, Method)) 3349 return true; 3350 3351 // No concerns about early exits now. 3352 BasePtr.take(); 3353 3354 // Build the operator call. 3355 Expr *FnExpr = new DeclRefExpr(Method, Method->getType(), SourceLocation()); 3356 UsualUnaryConversions(FnExpr); 3357 Base = new CXXOperatorCallExpr(FnExpr, &Base, 1, 3358 Method->getResultType().getNonReferenceType(), 3359 OpLoc); 3360 return ActOnMemberReferenceExpr(Base, OpLoc, tok::arrow, MemberLoc, Member); 3361} 3362 3363/// FixOverloadedFunctionReference - E is an expression that refers to 3364/// a C++ overloaded function (possibly with some parentheses and 3365/// perhaps a '&' around it). We have resolved the overloaded function 3366/// to the function declaration Fn, so patch up the expression E to 3367/// refer (possibly indirectly) to Fn. 3368void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 3369 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 3370 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 3371 E->setType(PE->getSubExpr()->getType()); 3372 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 3373 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 3374 "Can only take the address of an overloaded function"); 3375 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 3376 E->setType(Context.getPointerType(E->getType())); 3377 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 3378 assert(isa<OverloadedFunctionDecl>(DR->getDecl()) && 3379 "Expected overloaded function"); 3380 DR->setDecl(Fn); 3381 E->setType(Fn->getType()); 3382 } else { 3383 assert(false && "Invalid reference to overloaded function"); 3384 } 3385} 3386 3387} // end namespace clang 3388