SemaOverload.cpp revision 4084c306635b70f37029dca938444e6013f08684
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInherit.h" 16#include "clang/Basic/Diagnostic.h" 17#include "clang/Lex/Preprocessor.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/TypeOrdering.h" 22#include "llvm/ADT/SmallPtrSet.h" 23#include "llvm/ADT/STLExtras.h" 24#include "llvm/Support/Compiler.h" 25#include <algorithm> 26 27namespace clang { 28 29/// GetConversionCategory - Retrieve the implicit conversion 30/// category corresponding to the given implicit conversion kind. 31ImplicitConversionCategory 32GetConversionCategory(ImplicitConversionKind Kind) { 33 static const ImplicitConversionCategory 34 Category[(int)ICK_Num_Conversion_Kinds] = { 35 ICC_Identity, 36 ICC_Lvalue_Transformation, 37 ICC_Lvalue_Transformation, 38 ICC_Lvalue_Transformation, 39 ICC_Qualification_Adjustment, 40 ICC_Promotion, 41 ICC_Promotion, 42 ICC_Promotion, 43 ICC_Conversion, 44 ICC_Conversion, 45 ICC_Conversion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion 53 }; 54 return Category[(int)Kind]; 55} 56 57/// GetConversionRank - Retrieve the implicit conversion rank 58/// corresponding to the given implicit conversion kind. 59ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 60 static const ImplicitConversionRank 61 Rank[(int)ICK_Num_Conversion_Kinds] = { 62 ICR_Exact_Match, 63 ICR_Exact_Match, 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Promotion, 68 ICR_Promotion, 69 ICR_Promotion, 70 ICR_Conversion, 71 ICR_Conversion, 72 ICR_Conversion, 73 ICR_Conversion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion 80 }; 81 return Rank[(int)Kind]; 82} 83 84/// GetImplicitConversionName - Return the name of this kind of 85/// implicit conversion. 86const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 87 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 88 "No conversion", 89 "Lvalue-to-rvalue", 90 "Array-to-pointer", 91 "Function-to-pointer", 92 "Qualification", 93 "Integral promotion", 94 "Floating point promotion", 95 "Complex promotion", 96 "Integral conversion", 97 "Floating conversion", 98 "Complex conversion", 99 "Floating-integral conversion", 100 "Complex-real conversion", 101 "Pointer conversion", 102 "Pointer-to-member conversion", 103 "Boolean conversion", 104 "Compatible-types conversion", 105 "Derived-to-base conversion" 106 }; 107 return Name[Kind]; 108} 109 110/// StandardConversionSequence - Set the standard conversion 111/// sequence to the identity conversion. 112void StandardConversionSequence::setAsIdentityConversion() { 113 First = ICK_Identity; 114 Second = ICK_Identity; 115 Third = ICK_Identity; 116 Deprecated = false; 117 ReferenceBinding = false; 118 DirectBinding = false; 119 RRefBinding = false; 120 CopyConstructor = 0; 121} 122 123/// getRank - Retrieve the rank of this standard conversion sequence 124/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 125/// implicit conversions. 126ImplicitConversionRank StandardConversionSequence::getRank() const { 127 ImplicitConversionRank Rank = ICR_Exact_Match; 128 if (GetConversionRank(First) > Rank) 129 Rank = GetConversionRank(First); 130 if (GetConversionRank(Second) > Rank) 131 Rank = GetConversionRank(Second); 132 if (GetConversionRank(Third) > Rank) 133 Rank = GetConversionRank(Third); 134 return Rank; 135} 136 137/// isPointerConversionToBool - Determines whether this conversion is 138/// a conversion of a pointer or pointer-to-member to bool. This is 139/// used as part of the ranking of standard conversion sequences 140/// (C++ 13.3.3.2p4). 141bool StandardConversionSequence::isPointerConversionToBool() const 142{ 143 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 144 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 145 146 // Note that FromType has not necessarily been transformed by the 147 // array-to-pointer or function-to-pointer implicit conversions, so 148 // check for their presence as well as checking whether FromType is 149 // a pointer. 150 if (ToType->isBooleanType() && 151 (FromType->isPointerType() || FromType->isBlockPointerType() || 152 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 153 return true; 154 155 return false; 156} 157 158/// isPointerConversionToVoidPointer - Determines whether this 159/// conversion is a conversion of a pointer to a void pointer. This is 160/// used as part of the ranking of standard conversion sequences (C++ 161/// 13.3.3.2p4). 162bool 163StandardConversionSequence:: 164isPointerConversionToVoidPointer(ASTContext& Context) const 165{ 166 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 167 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion) 176 if (const PointerType* ToPtrType = ToType->getAsPointerType()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 bool PrintedSomething = false; 186 if (First != ICK_Identity) { 187 fprintf(stderr, "%s", GetImplicitConversionName(First)); 188 PrintedSomething = true; 189 } 190 191 if (Second != ICK_Identity) { 192 if (PrintedSomething) { 193 fprintf(stderr, " -> "); 194 } 195 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 196 197 if (CopyConstructor) { 198 fprintf(stderr, " (by copy constructor)"); 199 } else if (DirectBinding) { 200 fprintf(stderr, " (direct reference binding)"); 201 } else if (ReferenceBinding) { 202 fprintf(stderr, " (reference binding)"); 203 } 204 PrintedSomething = true; 205 } 206 207 if (Third != ICK_Identity) { 208 if (PrintedSomething) { 209 fprintf(stderr, " -> "); 210 } 211 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 212 PrintedSomething = true; 213 } 214 215 if (!PrintedSomething) { 216 fprintf(stderr, "No conversions required"); 217 } 218} 219 220/// DebugPrint - Print this user-defined conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void UserDefinedConversionSequence::DebugPrint() const { 223 if (Before.First || Before.Second || Before.Third) { 224 Before.DebugPrint(); 225 fprintf(stderr, " -> "); 226 } 227 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 228 if (After.First || After.Second || After.Third) { 229 fprintf(stderr, " -> "); 230 After.DebugPrint(); 231 } 232} 233 234/// DebugPrint - Print this implicit conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void ImplicitConversionSequence::DebugPrint() const { 237 switch (ConversionKind) { 238 case StandardConversion: 239 fprintf(stderr, "Standard conversion: "); 240 Standard.DebugPrint(); 241 break; 242 case UserDefinedConversion: 243 fprintf(stderr, "User-defined conversion: "); 244 UserDefined.DebugPrint(); 245 break; 246 case EllipsisConversion: 247 fprintf(stderr, "Ellipsis conversion"); 248 break; 249 case BadConversion: 250 fprintf(stderr, "Bad conversion"); 251 break; 252 } 253 254 fprintf(stderr, "\n"); 255} 256 257// IsOverload - Determine whether the given New declaration is an 258// overload of the Old declaration. This routine returns false if New 259// and Old cannot be overloaded, e.g., if they are functions with the 260// same signature (C++ 1.3.10) or if the Old declaration isn't a 261// function (or overload set). When it does return false and Old is an 262// OverloadedFunctionDecl, MatchedDecl will be set to point to the 263// FunctionDecl that New cannot be overloaded with. 264// 265// Example: Given the following input: 266// 267// void f(int, float); // #1 268// void f(int, int); // #2 269// int f(int, int); // #3 270// 271// When we process #1, there is no previous declaration of "f", 272// so IsOverload will not be used. 273// 274// When we process #2, Old is a FunctionDecl for #1. By comparing the 275// parameter types, we see that #1 and #2 are overloaded (since they 276// have different signatures), so this routine returns false; 277// MatchedDecl is unchanged. 278// 279// When we process #3, Old is an OverloadedFunctionDecl containing #1 280// and #2. We compare the signatures of #3 to #1 (they're overloaded, 281// so we do nothing) and then #3 to #2. Since the signatures of #3 and 282// #2 are identical (return types of functions are not part of the 283// signature), IsOverload returns false and MatchedDecl will be set to 284// point to the FunctionDecl for #2. 285bool 286Sema::IsOverload(FunctionDecl *New, Decl* OldD, 287 OverloadedFunctionDecl::function_iterator& MatchedDecl) 288{ 289 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 290 // Is this new function an overload of every function in the 291 // overload set? 292 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 293 FuncEnd = Ovl->function_end(); 294 for (; Func != FuncEnd; ++Func) { 295 if (!IsOverload(New, *Func, MatchedDecl)) { 296 MatchedDecl = Func; 297 return false; 298 } 299 } 300 301 // This function overloads every function in the overload set. 302 return true; 303 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 304 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 305 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 306 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 307 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 308 309 // C++ [temp.fct]p2: 310 // A function template can be overloaded with other function templates 311 // and with normal (non-template) functions. 312 if ((OldTemplate == 0) != (NewTemplate == 0)) 313 return true; 314 315 // Is the function New an overload of the function Old? 316 QualType OldQType = Context.getCanonicalType(Old->getType()); 317 QualType NewQType = Context.getCanonicalType(New->getType()); 318 319 // Compare the signatures (C++ 1.3.10) of the two functions to 320 // determine whether they are overloads. If we find any mismatch 321 // in the signature, they are overloads. 322 323 // If either of these functions is a K&R-style function (no 324 // prototype), then we consider them to have matching signatures. 325 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 326 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 327 return false; 328 329 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 330 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 331 332 // The signature of a function includes the types of its 333 // parameters (C++ 1.3.10), which includes the presence or absence 334 // of the ellipsis; see C++ DR 357). 335 if (OldQType != NewQType && 336 (OldType->getNumArgs() != NewType->getNumArgs() || 337 OldType->isVariadic() != NewType->isVariadic() || 338 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 339 NewType->arg_type_begin()))) 340 return true; 341 342 // C++ [temp.over.link]p4: 343 // The signature of a function template consists of its function 344 // signature, its return type and its template parameter list. The names 345 // of the template parameters are significant only for establishing the 346 // relationship between the template parameters and the rest of the 347 // signature. 348 // 349 // We check the return type and template parameter lists for function 350 // templates first; the remaining checks follow. 351 if (NewTemplate && 352 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 353 OldTemplate->getTemplateParameters(), 354 false, false, SourceLocation()) || 355 OldType->getResultType() != NewType->getResultType())) 356 return true; 357 358 // If the function is a class member, its signature includes the 359 // cv-qualifiers (if any) on the function itself. 360 // 361 // As part of this, also check whether one of the member functions 362 // is static, in which case they are not overloads (C++ 363 // 13.1p2). While not part of the definition of the signature, 364 // this check is important to determine whether these functions 365 // can be overloaded. 366 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 367 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 368 if (OldMethod && NewMethod && 369 !OldMethod->isStatic() && !NewMethod->isStatic() && 370 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 371 return true; 372 373 // The signatures match; this is not an overload. 374 return false; 375 } else { 376 // (C++ 13p1): 377 // Only function declarations can be overloaded; object and type 378 // declarations cannot be overloaded. 379 return false; 380 } 381} 382 383/// TryImplicitConversion - Attempt to perform an implicit conversion 384/// from the given expression (Expr) to the given type (ToType). This 385/// function returns an implicit conversion sequence that can be used 386/// to perform the initialization. Given 387/// 388/// void f(float f); 389/// void g(int i) { f(i); } 390/// 391/// this routine would produce an implicit conversion sequence to 392/// describe the initialization of f from i, which will be a standard 393/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 394/// 4.1) followed by a floating-integral conversion (C++ 4.9). 395// 396/// Note that this routine only determines how the conversion can be 397/// performed; it does not actually perform the conversion. As such, 398/// it will not produce any diagnostics if no conversion is available, 399/// but will instead return an implicit conversion sequence of kind 400/// "BadConversion". 401/// 402/// If @p SuppressUserConversions, then user-defined conversions are 403/// not permitted. 404/// If @p AllowExplicit, then explicit user-defined conversions are 405/// permitted. 406/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 407/// no matter its actual lvalueness. 408ImplicitConversionSequence 409Sema::TryImplicitConversion(Expr* From, QualType ToType, 410 bool SuppressUserConversions, 411 bool AllowExplicit, bool ForceRValue) 412{ 413 ImplicitConversionSequence ICS; 414 if (IsStandardConversion(From, ToType, ICS.Standard)) 415 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 416 else if (getLangOptions().CPlusPlus && 417 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 418 !SuppressUserConversions, AllowExplicit, 419 ForceRValue)) { 420 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 421 // C++ [over.ics.user]p4: 422 // A conversion of an expression of class type to the same class 423 // type is given Exact Match rank, and a conversion of an 424 // expression of class type to a base class of that type is 425 // given Conversion rank, in spite of the fact that a copy 426 // constructor (i.e., a user-defined conversion function) is 427 // called for those cases. 428 if (CXXConstructorDecl *Constructor 429 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 430 QualType FromCanon 431 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 432 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 433 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 434 // Turn this into a "standard" conversion sequence, so that it 435 // gets ranked with standard conversion sequences. 436 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 437 ICS.Standard.setAsIdentityConversion(); 438 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 439 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 440 ICS.Standard.CopyConstructor = Constructor; 441 if (ToCanon != FromCanon) 442 ICS.Standard.Second = ICK_Derived_To_Base; 443 } 444 } 445 446 // C++ [over.best.ics]p4: 447 // However, when considering the argument of a user-defined 448 // conversion function that is a candidate by 13.3.1.3 when 449 // invoked for the copying of the temporary in the second step 450 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 451 // 13.3.1.6 in all cases, only standard conversion sequences and 452 // ellipsis conversion sequences are allowed. 453 if (SuppressUserConversions && 454 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 455 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 456 } else 457 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 458 459 return ICS; 460} 461 462/// IsStandardConversion - Determines whether there is a standard 463/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 464/// expression From to the type ToType. Standard conversion sequences 465/// only consider non-class types; for conversions that involve class 466/// types, use TryImplicitConversion. If a conversion exists, SCS will 467/// contain the standard conversion sequence required to perform this 468/// conversion and this routine will return true. Otherwise, this 469/// routine will return false and the value of SCS is unspecified. 470bool 471Sema::IsStandardConversion(Expr* From, QualType ToType, 472 StandardConversionSequence &SCS) 473{ 474 QualType FromType = From->getType(); 475 476 // Standard conversions (C++ [conv]) 477 SCS.setAsIdentityConversion(); 478 SCS.Deprecated = false; 479 SCS.IncompatibleObjC = false; 480 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 481 SCS.CopyConstructor = 0; 482 483 // There are no standard conversions for class types in C++, so 484 // abort early. When overloading in C, however, we do permit 485 if (FromType->isRecordType() || ToType->isRecordType()) { 486 if (getLangOptions().CPlusPlus) 487 return false; 488 489 // When we're overloading in C, we allow, as standard conversions, 490 } 491 492 // The first conversion can be an lvalue-to-rvalue conversion, 493 // array-to-pointer conversion, or function-to-pointer conversion 494 // (C++ 4p1). 495 496 // Lvalue-to-rvalue conversion (C++ 4.1): 497 // An lvalue (3.10) of a non-function, non-array type T can be 498 // converted to an rvalue. 499 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 500 if (argIsLvalue == Expr::LV_Valid && 501 !FromType->isFunctionType() && !FromType->isArrayType() && 502 Context.getCanonicalType(FromType) != Context.OverloadTy) { 503 SCS.First = ICK_Lvalue_To_Rvalue; 504 505 // If T is a non-class type, the type of the rvalue is the 506 // cv-unqualified version of T. Otherwise, the type of the rvalue 507 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 508 // just strip the qualifiers because they don't matter. 509 510 // FIXME: Doesn't see through to qualifiers behind a typedef! 511 FromType = FromType.getUnqualifiedType(); 512 } 513 // Array-to-pointer conversion (C++ 4.2) 514 else if (FromType->isArrayType()) { 515 SCS.First = ICK_Array_To_Pointer; 516 517 // An lvalue or rvalue of type "array of N T" or "array of unknown 518 // bound of T" can be converted to an rvalue of type "pointer to 519 // T" (C++ 4.2p1). 520 FromType = Context.getArrayDecayedType(FromType); 521 522 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 523 // This conversion is deprecated. (C++ D.4). 524 SCS.Deprecated = true; 525 526 // For the purpose of ranking in overload resolution 527 // (13.3.3.1.1), this conversion is considered an 528 // array-to-pointer conversion followed by a qualification 529 // conversion (4.4). (C++ 4.2p2) 530 SCS.Second = ICK_Identity; 531 SCS.Third = ICK_Qualification; 532 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 533 return true; 534 } 535 } 536 // Function-to-pointer conversion (C++ 4.3). 537 else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 538 SCS.First = ICK_Function_To_Pointer; 539 540 // An lvalue of function type T can be converted to an rvalue of 541 // type "pointer to T." The result is a pointer to the 542 // function. (C++ 4.3p1). 543 FromType = Context.getPointerType(FromType); 544 } 545 // Address of overloaded function (C++ [over.over]). 546 else if (FunctionDecl *Fn 547 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 548 SCS.First = ICK_Function_To_Pointer; 549 550 // We were able to resolve the address of the overloaded function, 551 // so we can convert to the type of that function. 552 FromType = Fn->getType(); 553 if (ToType->isLValueReferenceType()) 554 FromType = Context.getLValueReferenceType(FromType); 555 else if (ToType->isRValueReferenceType()) 556 FromType = Context.getRValueReferenceType(FromType); 557 else if (ToType->isMemberPointerType()) { 558 // Resolve address only succeeds if both sides are member pointers, 559 // but it doesn't have to be the same class. See DR 247. 560 // Note that this means that the type of &Derived::fn can be 561 // Ret (Base::*)(Args) if the fn overload actually found is from the 562 // base class, even if it was brought into the derived class via a 563 // using declaration. The standard isn't clear on this issue at all. 564 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 565 FromType = Context.getMemberPointerType(FromType, 566 Context.getTypeDeclType(M->getParent()).getTypePtr()); 567 } else 568 FromType = Context.getPointerType(FromType); 569 } 570 // We don't require any conversions for the first step. 571 else { 572 SCS.First = ICK_Identity; 573 } 574 575 // The second conversion can be an integral promotion, floating 576 // point promotion, integral conversion, floating point conversion, 577 // floating-integral conversion, pointer conversion, 578 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 579 // For overloading in C, this can also be a "compatible-type" 580 // conversion. 581 bool IncompatibleObjC = false; 582 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 583 // The unqualified versions of the types are the same: there's no 584 // conversion to do. 585 SCS.Second = ICK_Identity; 586 } 587 // Integral promotion (C++ 4.5). 588 else if (IsIntegralPromotion(From, FromType, ToType)) { 589 SCS.Second = ICK_Integral_Promotion; 590 FromType = ToType.getUnqualifiedType(); 591 } 592 // Floating point promotion (C++ 4.6). 593 else if (IsFloatingPointPromotion(FromType, ToType)) { 594 SCS.Second = ICK_Floating_Promotion; 595 FromType = ToType.getUnqualifiedType(); 596 } 597 // Complex promotion (Clang extension) 598 else if (IsComplexPromotion(FromType, ToType)) { 599 SCS.Second = ICK_Complex_Promotion; 600 FromType = ToType.getUnqualifiedType(); 601 } 602 // Integral conversions (C++ 4.7). 603 // FIXME: isIntegralType shouldn't be true for enums in C++. 604 else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 605 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 606 SCS.Second = ICK_Integral_Conversion; 607 FromType = ToType.getUnqualifiedType(); 608 } 609 // Floating point conversions (C++ 4.8). 610 else if (FromType->isFloatingType() && ToType->isFloatingType()) { 611 SCS.Second = ICK_Floating_Conversion; 612 FromType = ToType.getUnqualifiedType(); 613 } 614 // Complex conversions (C99 6.3.1.6) 615 else if (FromType->isComplexType() && ToType->isComplexType()) { 616 SCS.Second = ICK_Complex_Conversion; 617 FromType = ToType.getUnqualifiedType(); 618 } 619 // Floating-integral conversions (C++ 4.9). 620 // FIXME: isIntegralType shouldn't be true for enums in C++. 621 else if ((FromType->isFloatingType() && 622 ToType->isIntegralType() && !ToType->isBooleanType() && 623 !ToType->isEnumeralType()) || 624 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 625 ToType->isFloatingType())) { 626 SCS.Second = ICK_Floating_Integral; 627 FromType = ToType.getUnqualifiedType(); 628 } 629 // Complex-real conversions (C99 6.3.1.7) 630 else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 631 (ToType->isComplexType() && FromType->isArithmeticType())) { 632 SCS.Second = ICK_Complex_Real; 633 FromType = ToType.getUnqualifiedType(); 634 } 635 // Pointer conversions (C++ 4.10). 636 else if (IsPointerConversion(From, FromType, ToType, FromType, 637 IncompatibleObjC)) { 638 SCS.Second = ICK_Pointer_Conversion; 639 SCS.IncompatibleObjC = IncompatibleObjC; 640 } 641 // Pointer to member conversions (4.11). 642 else if (IsMemberPointerConversion(From, FromType, ToType, FromType)) { 643 SCS.Second = ICK_Pointer_Member; 644 } 645 // Boolean conversions (C++ 4.12). 646 else if (ToType->isBooleanType() && 647 (FromType->isArithmeticType() || 648 FromType->isEnumeralType() || 649 FromType->isPointerType() || 650 FromType->isBlockPointerType() || 651 FromType->isMemberPointerType() || 652 FromType->isNullPtrType())) { 653 SCS.Second = ICK_Boolean_Conversion; 654 FromType = Context.BoolTy; 655 } 656 // Compatible conversions (Clang extension for C function overloading) 657 else if (!getLangOptions().CPlusPlus && 658 Context.typesAreCompatible(ToType, FromType)) { 659 SCS.Second = ICK_Compatible_Conversion; 660 } else { 661 // No second conversion required. 662 SCS.Second = ICK_Identity; 663 } 664 665 QualType CanonFrom; 666 QualType CanonTo; 667 // The third conversion can be a qualification conversion (C++ 4p1). 668 if (IsQualificationConversion(FromType, ToType)) { 669 SCS.Third = ICK_Qualification; 670 FromType = ToType; 671 CanonFrom = Context.getCanonicalType(FromType); 672 CanonTo = Context.getCanonicalType(ToType); 673 } else { 674 // No conversion required 675 SCS.Third = ICK_Identity; 676 677 // C++ [over.best.ics]p6: 678 // [...] Any difference in top-level cv-qualification is 679 // subsumed by the initialization itself and does not constitute 680 // a conversion. [...] 681 CanonFrom = Context.getCanonicalType(FromType); 682 CanonTo = Context.getCanonicalType(ToType); 683 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 684 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 685 FromType = ToType; 686 CanonFrom = CanonTo; 687 } 688 } 689 690 // If we have not converted the argument type to the parameter type, 691 // this is a bad conversion sequence. 692 if (CanonFrom != CanonTo) 693 return false; 694 695 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 696 return true; 697} 698 699/// IsIntegralPromotion - Determines whether the conversion from the 700/// expression From (whose potentially-adjusted type is FromType) to 701/// ToType is an integral promotion (C++ 4.5). If so, returns true and 702/// sets PromotedType to the promoted type. 703bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) 704{ 705 const BuiltinType *To = ToType->getAsBuiltinType(); 706 // All integers are built-in. 707 if (!To) { 708 return false; 709 } 710 711 // An rvalue of type char, signed char, unsigned char, short int, or 712 // unsigned short int can be converted to an rvalue of type int if 713 // int can represent all the values of the source type; otherwise, 714 // the source rvalue can be converted to an rvalue of type unsigned 715 // int (C++ 4.5p1). 716 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 717 if (// We can promote any signed, promotable integer type to an int 718 (FromType->isSignedIntegerType() || 719 // We can promote any unsigned integer type whose size is 720 // less than int to an int. 721 (!FromType->isSignedIntegerType() && 722 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 723 return To->getKind() == BuiltinType::Int; 724 } 725 726 return To->getKind() == BuiltinType::UInt; 727 } 728 729 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 730 // can be converted to an rvalue of the first of the following types 731 // that can represent all the values of its underlying type: int, 732 // unsigned int, long, or unsigned long (C++ 4.5p2). 733 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 734 && ToType->isIntegerType()) { 735 // Determine whether the type we're converting from is signed or 736 // unsigned. 737 bool FromIsSigned; 738 uint64_t FromSize = Context.getTypeSize(FromType); 739 if (const EnumType *FromEnumType = FromType->getAsEnumType()) { 740 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 741 FromIsSigned = UnderlyingType->isSignedIntegerType(); 742 } else { 743 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 744 FromIsSigned = true; 745 } 746 747 // The types we'll try to promote to, in the appropriate 748 // order. Try each of these types. 749 QualType PromoteTypes[6] = { 750 Context.IntTy, Context.UnsignedIntTy, 751 Context.LongTy, Context.UnsignedLongTy , 752 Context.LongLongTy, Context.UnsignedLongLongTy 753 }; 754 for (int Idx = 0; Idx < 6; ++Idx) { 755 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 756 if (FromSize < ToSize || 757 (FromSize == ToSize && 758 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 759 // We found the type that we can promote to. If this is the 760 // type we wanted, we have a promotion. Otherwise, no 761 // promotion. 762 return Context.getCanonicalType(ToType).getUnqualifiedType() 763 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 764 } 765 } 766 } 767 768 // An rvalue for an integral bit-field (9.6) can be converted to an 769 // rvalue of type int if int can represent all the values of the 770 // bit-field; otherwise, it can be converted to unsigned int if 771 // unsigned int can represent all the values of the bit-field. If 772 // the bit-field is larger yet, no integral promotion applies to 773 // it. If the bit-field has an enumerated type, it is treated as any 774 // other value of that type for promotion purposes (C++ 4.5p3). 775 // FIXME: We should delay checking of bit-fields until we actually perform the 776 // conversion. 777 using llvm::APSInt; 778 if (From) 779 if (FieldDecl *MemberDecl = From->getBitField()) { 780 APSInt BitWidth; 781 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 782 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 783 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 784 ToSize = Context.getTypeSize(ToType); 785 786 // Are we promoting to an int from a bitfield that fits in an int? 787 if (BitWidth < ToSize || 788 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 789 return To->getKind() == BuiltinType::Int; 790 } 791 792 // Are we promoting to an unsigned int from an unsigned bitfield 793 // that fits into an unsigned int? 794 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 795 return To->getKind() == BuiltinType::UInt; 796 } 797 798 return false; 799 } 800 } 801 802 // An rvalue of type bool can be converted to an rvalue of type int, 803 // with false becoming zero and true becoming one (C++ 4.5p4). 804 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 805 return true; 806 } 807 808 return false; 809} 810 811/// IsFloatingPointPromotion - Determines whether the conversion from 812/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 813/// returns true and sets PromotedType to the promoted type. 814bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) 815{ 816 /// An rvalue of type float can be converted to an rvalue of type 817 /// double. (C++ 4.6p1). 818 if (const BuiltinType *FromBuiltin = FromType->getAsBuiltinType()) 819 if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType()) { 820 if (FromBuiltin->getKind() == BuiltinType::Float && 821 ToBuiltin->getKind() == BuiltinType::Double) 822 return true; 823 824 // C99 6.3.1.5p1: 825 // When a float is promoted to double or long double, or a 826 // double is promoted to long double [...]. 827 if (!getLangOptions().CPlusPlus && 828 (FromBuiltin->getKind() == BuiltinType::Float || 829 FromBuiltin->getKind() == BuiltinType::Double) && 830 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 831 return true; 832 } 833 834 return false; 835} 836 837/// \brief Determine if a conversion is a complex promotion. 838/// 839/// A complex promotion is defined as a complex -> complex conversion 840/// where the conversion between the underlying real types is a 841/// floating-point or integral promotion. 842bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 843 const ComplexType *FromComplex = FromType->getAsComplexType(); 844 if (!FromComplex) 845 return false; 846 847 const ComplexType *ToComplex = ToType->getAsComplexType(); 848 if (!ToComplex) 849 return false; 850 851 return IsFloatingPointPromotion(FromComplex->getElementType(), 852 ToComplex->getElementType()) || 853 IsIntegralPromotion(0, FromComplex->getElementType(), 854 ToComplex->getElementType()); 855} 856 857/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 858/// the pointer type FromPtr to a pointer to type ToPointee, with the 859/// same type qualifiers as FromPtr has on its pointee type. ToType, 860/// if non-empty, will be a pointer to ToType that may or may not have 861/// the right set of qualifiers on its pointee. 862static QualType 863BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 864 QualType ToPointee, QualType ToType, 865 ASTContext &Context) { 866 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 867 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 868 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 869 870 // Exact qualifier match -> return the pointer type we're converting to. 871 if (CanonToPointee.getCVRQualifiers() == Quals) { 872 // ToType is exactly what we need. Return it. 873 if (ToType.getTypePtr()) 874 return ToType; 875 876 // Build a pointer to ToPointee. It has the right qualifiers 877 // already. 878 return Context.getPointerType(ToPointee); 879 } 880 881 // Just build a canonical type that has the right qualifiers. 882 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 883} 884 885/// IsPointerConversion - Determines whether the conversion of the 886/// expression From, which has the (possibly adjusted) type FromType, 887/// can be converted to the type ToType via a pointer conversion (C++ 888/// 4.10). If so, returns true and places the converted type (that 889/// might differ from ToType in its cv-qualifiers at some level) into 890/// ConvertedType. 891/// 892/// This routine also supports conversions to and from block pointers 893/// and conversions with Objective-C's 'id', 'id<protocols...>', and 894/// pointers to interfaces. FIXME: Once we've determined the 895/// appropriate overloading rules for Objective-C, we may want to 896/// split the Objective-C checks into a different routine; however, 897/// GCC seems to consider all of these conversions to be pointer 898/// conversions, so for now they live here. IncompatibleObjC will be 899/// set if the conversion is an allowed Objective-C conversion that 900/// should result in a warning. 901bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 902 QualType& ConvertedType, 903 bool &IncompatibleObjC) 904{ 905 IncompatibleObjC = false; 906 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 907 return true; 908 909 // Conversion from a null pointer constant to any Objective-C pointer type. 910 if (ToType->isObjCObjectPointerType() && 911 From->isNullPointerConstant(Context)) { 912 ConvertedType = ToType; 913 return true; 914 } 915 916 // Blocks: Block pointers can be converted to void*. 917 if (FromType->isBlockPointerType() && ToType->isPointerType() && 918 ToType->getAsPointerType()->getPointeeType()->isVoidType()) { 919 ConvertedType = ToType; 920 return true; 921 } 922 // Blocks: A null pointer constant can be converted to a block 923 // pointer type. 924 if (ToType->isBlockPointerType() && From->isNullPointerConstant(Context)) { 925 ConvertedType = ToType; 926 return true; 927 } 928 929 // If the left-hand-side is nullptr_t, the right side can be a null 930 // pointer constant. 931 if (ToType->isNullPtrType() && From->isNullPointerConstant(Context)) { 932 ConvertedType = ToType; 933 return true; 934 } 935 936 const PointerType* ToTypePtr = ToType->getAsPointerType(); 937 if (!ToTypePtr) 938 return false; 939 940 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 941 if (From->isNullPointerConstant(Context)) { 942 ConvertedType = ToType; 943 return true; 944 } 945 946 // Beyond this point, both types need to be pointers. 947 const PointerType *FromTypePtr = FromType->getAsPointerType(); 948 if (!FromTypePtr) 949 return false; 950 951 QualType FromPointeeType = FromTypePtr->getPointeeType(); 952 QualType ToPointeeType = ToTypePtr->getPointeeType(); 953 954 // An rvalue of type "pointer to cv T," where T is an object type, 955 // can be converted to an rvalue of type "pointer to cv void" (C++ 956 // 4.10p2). 957 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 958 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 959 ToPointeeType, 960 ToType, Context); 961 return true; 962 } 963 964 // When we're overloading in C, we allow a special kind of pointer 965 // conversion for compatible-but-not-identical pointee types. 966 if (!getLangOptions().CPlusPlus && 967 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 968 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 969 ToPointeeType, 970 ToType, Context); 971 return true; 972 } 973 974 // C++ [conv.ptr]p3: 975 // 976 // An rvalue of type "pointer to cv D," where D is a class type, 977 // can be converted to an rvalue of type "pointer to cv B," where 978 // B is a base class (clause 10) of D. If B is an inaccessible 979 // (clause 11) or ambiguous (10.2) base class of D, a program that 980 // necessitates this conversion is ill-formed. The result of the 981 // conversion is a pointer to the base class sub-object of the 982 // derived class object. The null pointer value is converted to 983 // the null pointer value of the destination type. 984 // 985 // Note that we do not check for ambiguity or inaccessibility 986 // here. That is handled by CheckPointerConversion. 987 if (getLangOptions().CPlusPlus && 988 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 989 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 990 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 991 ToPointeeType, 992 ToType, Context); 993 return true; 994 } 995 996 return false; 997} 998 999/// isObjCPointerConversion - Determines whether this is an 1000/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1001/// with the same arguments and return values. 1002bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1003 QualType& ConvertedType, 1004 bool &IncompatibleObjC) { 1005 if (!getLangOptions().ObjC1) 1006 return false; 1007 1008 // First, we handle all conversions on ObjC object pointer types. 1009 const ObjCObjectPointerType* ToObjCPtr = ToType->getAsObjCObjectPointerType(); 1010 const ObjCObjectPointerType *FromObjCPtr = 1011 FromType->getAsObjCObjectPointerType(); 1012 1013 if (ToObjCPtr && FromObjCPtr) { 1014 // Objective C++: We're able to convert between "id" or "Class" and a 1015 // pointer to any interface (in both directions). 1016 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1017 ConvertedType = ToType; 1018 return true; 1019 } 1020 // Conversions with Objective-C's id<...>. 1021 if ((FromObjCPtr->isObjCQualifiedIdType() || 1022 ToObjCPtr->isObjCQualifiedIdType()) && 1023 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1024 /*compare=*/false)) { 1025 ConvertedType = ToType; 1026 return true; 1027 } 1028 // Objective C++: We're able to convert from a pointer to an 1029 // interface to a pointer to a different interface. 1030 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1031 ConvertedType = ToType; 1032 return true; 1033 } 1034 1035 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1036 // Okay: this is some kind of implicit downcast of Objective-C 1037 // interfaces, which is permitted. However, we're going to 1038 // complain about it. 1039 IncompatibleObjC = true; 1040 ConvertedType = FromType; 1041 return true; 1042 } 1043 } 1044 // Beyond this point, both types need to be C pointers or block pointers. 1045 QualType ToPointeeType; 1046 if (const PointerType *ToCPtr = ToType->getAsPointerType()) 1047 ToPointeeType = ToCPtr->getPointeeType(); 1048 else if (const BlockPointerType *ToBlockPtr = ToType->getAsBlockPointerType()) 1049 ToPointeeType = ToBlockPtr->getPointeeType(); 1050 else 1051 return false; 1052 1053 QualType FromPointeeType; 1054 if (const PointerType *FromCPtr = FromType->getAsPointerType()) 1055 FromPointeeType = FromCPtr->getPointeeType(); 1056 else if (const BlockPointerType *FromBlockPtr = FromType->getAsBlockPointerType()) 1057 FromPointeeType = FromBlockPtr->getPointeeType(); 1058 else 1059 return false; 1060 1061 // If we have pointers to pointers, recursively check whether this 1062 // is an Objective-C conversion. 1063 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1064 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1065 IncompatibleObjC)) { 1066 // We always complain about this conversion. 1067 IncompatibleObjC = true; 1068 ConvertedType = ToType; 1069 return true; 1070 } 1071 // If we have pointers to functions or blocks, check whether the only 1072 // differences in the argument and result types are in Objective-C 1073 // pointer conversions. If so, we permit the conversion (but 1074 // complain about it). 1075 const FunctionProtoType *FromFunctionType 1076 = FromPointeeType->getAsFunctionProtoType(); 1077 const FunctionProtoType *ToFunctionType 1078 = ToPointeeType->getAsFunctionProtoType(); 1079 if (FromFunctionType && ToFunctionType) { 1080 // If the function types are exactly the same, this isn't an 1081 // Objective-C pointer conversion. 1082 if (Context.getCanonicalType(FromPointeeType) 1083 == Context.getCanonicalType(ToPointeeType)) 1084 return false; 1085 1086 // Perform the quick checks that will tell us whether these 1087 // function types are obviously different. 1088 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1089 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1090 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1091 return false; 1092 1093 bool HasObjCConversion = false; 1094 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1095 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1096 // Okay, the types match exactly. Nothing to do. 1097 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1098 ToFunctionType->getResultType(), 1099 ConvertedType, IncompatibleObjC)) { 1100 // Okay, we have an Objective-C pointer conversion. 1101 HasObjCConversion = true; 1102 } else { 1103 // Function types are too different. Abort. 1104 return false; 1105 } 1106 1107 // Check argument types. 1108 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1109 ArgIdx != NumArgs; ++ArgIdx) { 1110 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1111 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1112 if (Context.getCanonicalType(FromArgType) 1113 == Context.getCanonicalType(ToArgType)) { 1114 // Okay, the types match exactly. Nothing to do. 1115 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1116 ConvertedType, IncompatibleObjC)) { 1117 // Okay, we have an Objective-C pointer conversion. 1118 HasObjCConversion = true; 1119 } else { 1120 // Argument types are too different. Abort. 1121 return false; 1122 } 1123 } 1124 1125 if (HasObjCConversion) { 1126 // We had an Objective-C conversion. Allow this pointer 1127 // conversion, but complain about it. 1128 ConvertedType = ToType; 1129 IncompatibleObjC = true; 1130 return true; 1131 } 1132 } 1133 1134 return false; 1135} 1136 1137/// CheckPointerConversion - Check the pointer conversion from the 1138/// expression From to the type ToType. This routine checks for 1139/// ambiguous (FIXME: or inaccessible) derived-to-base pointer 1140/// conversions for which IsPointerConversion has already returned 1141/// true. It returns true and produces a diagnostic if there was an 1142/// error, or returns false otherwise. 1143bool Sema::CheckPointerConversion(Expr *From, QualType ToType) { 1144 QualType FromType = From->getType(); 1145 1146 if (const PointerType *FromPtrType = FromType->getAsPointerType()) 1147 if (const PointerType *ToPtrType = ToType->getAsPointerType()) { 1148 QualType FromPointeeType = FromPtrType->getPointeeType(), 1149 ToPointeeType = ToPtrType->getPointeeType(); 1150 1151 if (FromPointeeType->isRecordType() && 1152 ToPointeeType->isRecordType()) { 1153 // We must have a derived-to-base conversion. Check an 1154 // ambiguous or inaccessible conversion. 1155 return CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1156 From->getExprLoc(), 1157 From->getSourceRange()); 1158 } 1159 } 1160 if (const ObjCObjectPointerType *FromPtrType = 1161 FromType->getAsObjCObjectPointerType()) 1162 if (const ObjCObjectPointerType *ToPtrType = 1163 ToType->getAsObjCObjectPointerType()) { 1164 // Objective-C++ conversions are always okay. 1165 // FIXME: We should have a different class of conversions for the 1166 // Objective-C++ implicit conversions. 1167 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1168 return false; 1169 1170 } 1171 return false; 1172} 1173 1174/// IsMemberPointerConversion - Determines whether the conversion of the 1175/// expression From, which has the (possibly adjusted) type FromType, can be 1176/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1177/// If so, returns true and places the converted type (that might differ from 1178/// ToType in its cv-qualifiers at some level) into ConvertedType. 1179bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1180 QualType ToType, QualType &ConvertedType) 1181{ 1182 const MemberPointerType *ToTypePtr = ToType->getAsMemberPointerType(); 1183 if (!ToTypePtr) 1184 return false; 1185 1186 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1187 if (From->isNullPointerConstant(Context)) { 1188 ConvertedType = ToType; 1189 return true; 1190 } 1191 1192 // Otherwise, both types have to be member pointers. 1193 const MemberPointerType *FromTypePtr = FromType->getAsMemberPointerType(); 1194 if (!FromTypePtr) 1195 return false; 1196 1197 // A pointer to member of B can be converted to a pointer to member of D, 1198 // where D is derived from B (C++ 4.11p2). 1199 QualType FromClass(FromTypePtr->getClass(), 0); 1200 QualType ToClass(ToTypePtr->getClass(), 0); 1201 // FIXME: What happens when these are dependent? Is this function even called? 1202 1203 if (IsDerivedFrom(ToClass, FromClass)) { 1204 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1205 ToClass.getTypePtr()); 1206 return true; 1207 } 1208 1209 return false; 1210} 1211 1212/// CheckMemberPointerConversion - Check the member pointer conversion from the 1213/// expression From to the type ToType. This routine checks for ambiguous or 1214/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1215/// for which IsMemberPointerConversion has already returned true. It returns 1216/// true and produces a diagnostic if there was an error, or returns false 1217/// otherwise. 1218bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType) { 1219 QualType FromType = From->getType(); 1220 const MemberPointerType *FromPtrType = FromType->getAsMemberPointerType(); 1221 if (!FromPtrType) 1222 return false; 1223 1224 const MemberPointerType *ToPtrType = ToType->getAsMemberPointerType(); 1225 assert(ToPtrType && "No member pointer cast has a target type " 1226 "that is not a member pointer."); 1227 1228 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1229 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1230 1231 // FIXME: What about dependent types? 1232 assert(FromClass->isRecordType() && "Pointer into non-class."); 1233 assert(ToClass->isRecordType() && "Pointer into non-class."); 1234 1235 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1236 /*DetectVirtual=*/true); 1237 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1238 assert(DerivationOkay && 1239 "Should not have been called if derivation isn't OK."); 1240 (void)DerivationOkay; 1241 1242 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1243 getUnqualifiedType())) { 1244 // Derivation is ambiguous. Redo the check to find the exact paths. 1245 Paths.clear(); 1246 Paths.setRecordingPaths(true); 1247 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1248 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1249 (void)StillOkay; 1250 1251 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1252 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1253 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1254 return true; 1255 } 1256 1257 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1258 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1259 << FromClass << ToClass << QualType(VBase, 0) 1260 << From->getSourceRange(); 1261 return true; 1262 } 1263 1264 return false; 1265} 1266 1267/// IsQualificationConversion - Determines whether the conversion from 1268/// an rvalue of type FromType to ToType is a qualification conversion 1269/// (C++ 4.4). 1270bool 1271Sema::IsQualificationConversion(QualType FromType, QualType ToType) 1272{ 1273 FromType = Context.getCanonicalType(FromType); 1274 ToType = Context.getCanonicalType(ToType); 1275 1276 // If FromType and ToType are the same type, this is not a 1277 // qualification conversion. 1278 if (FromType == ToType) 1279 return false; 1280 1281 // (C++ 4.4p4): 1282 // A conversion can add cv-qualifiers at levels other than the first 1283 // in multi-level pointers, subject to the following rules: [...] 1284 bool PreviousToQualsIncludeConst = true; 1285 bool UnwrappedAnyPointer = false; 1286 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1287 // Within each iteration of the loop, we check the qualifiers to 1288 // determine if this still looks like a qualification 1289 // conversion. Then, if all is well, we unwrap one more level of 1290 // pointers or pointers-to-members and do it all again 1291 // until there are no more pointers or pointers-to-members left to 1292 // unwrap. 1293 UnwrappedAnyPointer = true; 1294 1295 // -- for every j > 0, if const is in cv 1,j then const is in cv 1296 // 2,j, and similarly for volatile. 1297 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1298 return false; 1299 1300 // -- if the cv 1,j and cv 2,j are different, then const is in 1301 // every cv for 0 < k < j. 1302 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1303 && !PreviousToQualsIncludeConst) 1304 return false; 1305 1306 // Keep track of whether all prior cv-qualifiers in the "to" type 1307 // include const. 1308 PreviousToQualsIncludeConst 1309 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1310 } 1311 1312 // We are left with FromType and ToType being the pointee types 1313 // after unwrapping the original FromType and ToType the same number 1314 // of types. If we unwrapped any pointers, and if FromType and 1315 // ToType have the same unqualified type (since we checked 1316 // qualifiers above), then this is a qualification conversion. 1317 return UnwrappedAnyPointer && 1318 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1319} 1320 1321/// Determines whether there is a user-defined conversion sequence 1322/// (C++ [over.ics.user]) that converts expression From to the type 1323/// ToType. If such a conversion exists, User will contain the 1324/// user-defined conversion sequence that performs such a conversion 1325/// and this routine will return true. Otherwise, this routine returns 1326/// false and User is unspecified. 1327/// 1328/// \param AllowConversionFunctions true if the conversion should 1329/// consider conversion functions at all. If false, only constructors 1330/// will be considered. 1331/// 1332/// \param AllowExplicit true if the conversion should consider C++0x 1333/// "explicit" conversion functions as well as non-explicit conversion 1334/// functions (C++0x [class.conv.fct]p2). 1335/// 1336/// \param ForceRValue true if the expression should be treated as an rvalue 1337/// for overload resolution. 1338bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1339 UserDefinedConversionSequence& User, 1340 bool AllowConversionFunctions, 1341 bool AllowExplicit, bool ForceRValue) 1342{ 1343 OverloadCandidateSet CandidateSet; 1344 if (const RecordType *ToRecordType = ToType->getAsRecordType()) { 1345 if (CXXRecordDecl *ToRecordDecl 1346 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1347 // C++ [over.match.ctor]p1: 1348 // When objects of class type are direct-initialized (8.5), or 1349 // copy-initialized from an expression of the same or a 1350 // derived class type (8.5), overload resolution selects the 1351 // constructor. [...] For copy-initialization, the candidate 1352 // functions are all the converting constructors (12.3.1) of 1353 // that class. The argument list is the expression-list within 1354 // the parentheses of the initializer. 1355 DeclarationName ConstructorName 1356 = Context.DeclarationNames.getCXXConstructorName( 1357 Context.getCanonicalType(ToType).getUnqualifiedType()); 1358 DeclContext::lookup_iterator Con, ConEnd; 1359 for (llvm::tie(Con, ConEnd) 1360 = ToRecordDecl->lookup(ConstructorName); 1361 Con != ConEnd; ++Con) { 1362 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 1363 if (Constructor->isConvertingConstructor()) 1364 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1365 /*SuppressUserConversions=*/true, ForceRValue); 1366 } 1367 } 1368 } 1369 1370 if (!AllowConversionFunctions) { 1371 // Don't allow any conversion functions to enter the overload set. 1372 } else if (const RecordType *FromRecordType 1373 = From->getType()->getAsRecordType()) { 1374 if (CXXRecordDecl *FromRecordDecl 1375 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1376 // Add all of the conversion functions as candidates. 1377 // FIXME: Look for conversions in base classes! 1378 OverloadedFunctionDecl *Conversions 1379 = FromRecordDecl->getConversionFunctions(); 1380 for (OverloadedFunctionDecl::function_iterator Func 1381 = Conversions->function_begin(); 1382 Func != Conversions->function_end(); ++Func) { 1383 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 1384 if (AllowExplicit || !Conv->isExplicit()) 1385 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1386 } 1387 } 1388 } 1389 1390 OverloadCandidateSet::iterator Best; 1391 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1392 case OR_Success: 1393 // Record the standard conversion we used and the conversion function. 1394 if (CXXConstructorDecl *Constructor 1395 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1396 // C++ [over.ics.user]p1: 1397 // If the user-defined conversion is specified by a 1398 // constructor (12.3.1), the initial standard conversion 1399 // sequence converts the source type to the type required by 1400 // the argument of the constructor. 1401 // 1402 // FIXME: What about ellipsis conversions? 1403 QualType ThisType = Constructor->getThisType(Context); 1404 User.Before = Best->Conversions[0].Standard; 1405 User.ConversionFunction = Constructor; 1406 User.After.setAsIdentityConversion(); 1407 User.After.FromTypePtr 1408 = ThisType->getAsPointerType()->getPointeeType().getAsOpaquePtr(); 1409 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1410 return true; 1411 } else if (CXXConversionDecl *Conversion 1412 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1413 // C++ [over.ics.user]p1: 1414 // 1415 // [...] If the user-defined conversion is specified by a 1416 // conversion function (12.3.2), the initial standard 1417 // conversion sequence converts the source type to the 1418 // implicit object parameter of the conversion function. 1419 User.Before = Best->Conversions[0].Standard; 1420 User.ConversionFunction = Conversion; 1421 1422 // C++ [over.ics.user]p2: 1423 // The second standard conversion sequence converts the 1424 // result of the user-defined conversion to the target type 1425 // for the sequence. Since an implicit conversion sequence 1426 // is an initialization, the special rules for 1427 // initialization by user-defined conversion apply when 1428 // selecting the best user-defined conversion for a 1429 // user-defined conversion sequence (see 13.3.3 and 1430 // 13.3.3.1). 1431 User.After = Best->FinalConversion; 1432 return true; 1433 } else { 1434 assert(false && "Not a constructor or conversion function?"); 1435 return false; 1436 } 1437 1438 case OR_No_Viable_Function: 1439 case OR_Deleted: 1440 // No conversion here! We're done. 1441 return false; 1442 1443 case OR_Ambiguous: 1444 // FIXME: See C++ [over.best.ics]p10 for the handling of 1445 // ambiguous conversion sequences. 1446 return false; 1447 } 1448 1449 return false; 1450} 1451 1452/// CompareImplicitConversionSequences - Compare two implicit 1453/// conversion sequences to determine whether one is better than the 1454/// other or if they are indistinguishable (C++ 13.3.3.2). 1455ImplicitConversionSequence::CompareKind 1456Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1457 const ImplicitConversionSequence& ICS2) 1458{ 1459 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1460 // conversion sequences (as defined in 13.3.3.1) 1461 // -- a standard conversion sequence (13.3.3.1.1) is a better 1462 // conversion sequence than a user-defined conversion sequence or 1463 // an ellipsis conversion sequence, and 1464 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1465 // conversion sequence than an ellipsis conversion sequence 1466 // (13.3.3.1.3). 1467 // 1468 if (ICS1.ConversionKind < ICS2.ConversionKind) 1469 return ImplicitConversionSequence::Better; 1470 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1471 return ImplicitConversionSequence::Worse; 1472 1473 // Two implicit conversion sequences of the same form are 1474 // indistinguishable conversion sequences unless one of the 1475 // following rules apply: (C++ 13.3.3.2p3): 1476 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1477 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1478 else if (ICS1.ConversionKind == 1479 ImplicitConversionSequence::UserDefinedConversion) { 1480 // User-defined conversion sequence U1 is a better conversion 1481 // sequence than another user-defined conversion sequence U2 if 1482 // they contain the same user-defined conversion function or 1483 // constructor and if the second standard conversion sequence of 1484 // U1 is better than the second standard conversion sequence of 1485 // U2 (C++ 13.3.3.2p3). 1486 if (ICS1.UserDefined.ConversionFunction == 1487 ICS2.UserDefined.ConversionFunction) 1488 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1489 ICS2.UserDefined.After); 1490 } 1491 1492 return ImplicitConversionSequence::Indistinguishable; 1493} 1494 1495/// CompareStandardConversionSequences - Compare two standard 1496/// conversion sequences to determine whether one is better than the 1497/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1498ImplicitConversionSequence::CompareKind 1499Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1500 const StandardConversionSequence& SCS2) 1501{ 1502 // Standard conversion sequence S1 is a better conversion sequence 1503 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1504 1505 // -- S1 is a proper subsequence of S2 (comparing the conversion 1506 // sequences in the canonical form defined by 13.3.3.1.1, 1507 // excluding any Lvalue Transformation; the identity conversion 1508 // sequence is considered to be a subsequence of any 1509 // non-identity conversion sequence) or, if not that, 1510 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1511 // Neither is a proper subsequence of the other. Do nothing. 1512 ; 1513 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1514 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1515 (SCS1.Second == ICK_Identity && 1516 SCS1.Third == ICK_Identity)) 1517 // SCS1 is a proper subsequence of SCS2. 1518 return ImplicitConversionSequence::Better; 1519 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1520 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1521 (SCS2.Second == ICK_Identity && 1522 SCS2.Third == ICK_Identity)) 1523 // SCS2 is a proper subsequence of SCS1. 1524 return ImplicitConversionSequence::Worse; 1525 1526 // -- the rank of S1 is better than the rank of S2 (by the rules 1527 // defined below), or, if not that, 1528 ImplicitConversionRank Rank1 = SCS1.getRank(); 1529 ImplicitConversionRank Rank2 = SCS2.getRank(); 1530 if (Rank1 < Rank2) 1531 return ImplicitConversionSequence::Better; 1532 else if (Rank2 < Rank1) 1533 return ImplicitConversionSequence::Worse; 1534 1535 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1536 // are indistinguishable unless one of the following rules 1537 // applies: 1538 1539 // A conversion that is not a conversion of a pointer, or 1540 // pointer to member, to bool is better than another conversion 1541 // that is such a conversion. 1542 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1543 return SCS2.isPointerConversionToBool() 1544 ? ImplicitConversionSequence::Better 1545 : ImplicitConversionSequence::Worse; 1546 1547 // C++ [over.ics.rank]p4b2: 1548 // 1549 // If class B is derived directly or indirectly from class A, 1550 // conversion of B* to A* is better than conversion of B* to 1551 // void*, and conversion of A* to void* is better than conversion 1552 // of B* to void*. 1553 bool SCS1ConvertsToVoid 1554 = SCS1.isPointerConversionToVoidPointer(Context); 1555 bool SCS2ConvertsToVoid 1556 = SCS2.isPointerConversionToVoidPointer(Context); 1557 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1558 // Exactly one of the conversion sequences is a conversion to 1559 // a void pointer; it's the worse conversion. 1560 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1561 : ImplicitConversionSequence::Worse; 1562 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1563 // Neither conversion sequence converts to a void pointer; compare 1564 // their derived-to-base conversions. 1565 if (ImplicitConversionSequence::CompareKind DerivedCK 1566 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1567 return DerivedCK; 1568 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1569 // Both conversion sequences are conversions to void 1570 // pointers. Compare the source types to determine if there's an 1571 // inheritance relationship in their sources. 1572 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1573 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1574 1575 // Adjust the types we're converting from via the array-to-pointer 1576 // conversion, if we need to. 1577 if (SCS1.First == ICK_Array_To_Pointer) 1578 FromType1 = Context.getArrayDecayedType(FromType1); 1579 if (SCS2.First == ICK_Array_To_Pointer) 1580 FromType2 = Context.getArrayDecayedType(FromType2); 1581 1582 QualType FromPointee1 1583 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1584 QualType FromPointee2 1585 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1586 1587 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1588 return ImplicitConversionSequence::Better; 1589 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1590 return ImplicitConversionSequence::Worse; 1591 1592 // Objective-C++: If one interface is more specific than the 1593 // other, it is the better one. 1594 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1595 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1596 if (FromIface1 && FromIface1) { 1597 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1598 return ImplicitConversionSequence::Better; 1599 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1600 return ImplicitConversionSequence::Worse; 1601 } 1602 } 1603 1604 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1605 // bullet 3). 1606 if (ImplicitConversionSequence::CompareKind QualCK 1607 = CompareQualificationConversions(SCS1, SCS2)) 1608 return QualCK; 1609 1610 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1611 // C++0x [over.ics.rank]p3b4: 1612 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1613 // implicit object parameter of a non-static member function declared 1614 // without a ref-qualifier, and S1 binds an rvalue reference to an 1615 // rvalue and S2 binds an lvalue reference. 1616 // FIXME: We don't know if we're dealing with the implicit object parameter, 1617 // or if the member function in this case has a ref qualifier. 1618 // (Of course, we don't have ref qualifiers yet.) 1619 if (SCS1.RRefBinding != SCS2.RRefBinding) 1620 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1621 : ImplicitConversionSequence::Worse; 1622 1623 // C++ [over.ics.rank]p3b4: 1624 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1625 // which the references refer are the same type except for 1626 // top-level cv-qualifiers, and the type to which the reference 1627 // initialized by S2 refers is more cv-qualified than the type 1628 // to which the reference initialized by S1 refers. 1629 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1630 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1631 T1 = Context.getCanonicalType(T1); 1632 T2 = Context.getCanonicalType(T2); 1633 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1634 if (T2.isMoreQualifiedThan(T1)) 1635 return ImplicitConversionSequence::Better; 1636 else if (T1.isMoreQualifiedThan(T2)) 1637 return ImplicitConversionSequence::Worse; 1638 } 1639 } 1640 1641 return ImplicitConversionSequence::Indistinguishable; 1642} 1643 1644/// CompareQualificationConversions - Compares two standard conversion 1645/// sequences to determine whether they can be ranked based on their 1646/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1647ImplicitConversionSequence::CompareKind 1648Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1649 const StandardConversionSequence& SCS2) 1650{ 1651 // C++ 13.3.3.2p3: 1652 // -- S1 and S2 differ only in their qualification conversion and 1653 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1654 // cv-qualification signature of type T1 is a proper subset of 1655 // the cv-qualification signature of type T2, and S1 is not the 1656 // deprecated string literal array-to-pointer conversion (4.2). 1657 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1658 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1659 return ImplicitConversionSequence::Indistinguishable; 1660 1661 // FIXME: the example in the standard doesn't use a qualification 1662 // conversion (!) 1663 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1664 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1665 T1 = Context.getCanonicalType(T1); 1666 T2 = Context.getCanonicalType(T2); 1667 1668 // If the types are the same, we won't learn anything by unwrapped 1669 // them. 1670 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1671 return ImplicitConversionSequence::Indistinguishable; 1672 1673 ImplicitConversionSequence::CompareKind Result 1674 = ImplicitConversionSequence::Indistinguishable; 1675 while (UnwrapSimilarPointerTypes(T1, T2)) { 1676 // Within each iteration of the loop, we check the qualifiers to 1677 // determine if this still looks like a qualification 1678 // conversion. Then, if all is well, we unwrap one more level of 1679 // pointers or pointers-to-members and do it all again 1680 // until there are no more pointers or pointers-to-members left 1681 // to unwrap. This essentially mimics what 1682 // IsQualificationConversion does, but here we're checking for a 1683 // strict subset of qualifiers. 1684 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1685 // The qualifiers are the same, so this doesn't tell us anything 1686 // about how the sequences rank. 1687 ; 1688 else if (T2.isMoreQualifiedThan(T1)) { 1689 // T1 has fewer qualifiers, so it could be the better sequence. 1690 if (Result == ImplicitConversionSequence::Worse) 1691 // Neither has qualifiers that are a subset of the other's 1692 // qualifiers. 1693 return ImplicitConversionSequence::Indistinguishable; 1694 1695 Result = ImplicitConversionSequence::Better; 1696 } else if (T1.isMoreQualifiedThan(T2)) { 1697 // T2 has fewer qualifiers, so it could be the better sequence. 1698 if (Result == ImplicitConversionSequence::Better) 1699 // Neither has qualifiers that are a subset of the other's 1700 // qualifiers. 1701 return ImplicitConversionSequence::Indistinguishable; 1702 1703 Result = ImplicitConversionSequence::Worse; 1704 } else { 1705 // Qualifiers are disjoint. 1706 return ImplicitConversionSequence::Indistinguishable; 1707 } 1708 1709 // If the types after this point are equivalent, we're done. 1710 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1711 break; 1712 } 1713 1714 // Check that the winning standard conversion sequence isn't using 1715 // the deprecated string literal array to pointer conversion. 1716 switch (Result) { 1717 case ImplicitConversionSequence::Better: 1718 if (SCS1.Deprecated) 1719 Result = ImplicitConversionSequence::Indistinguishable; 1720 break; 1721 1722 case ImplicitConversionSequence::Indistinguishable: 1723 break; 1724 1725 case ImplicitConversionSequence::Worse: 1726 if (SCS2.Deprecated) 1727 Result = ImplicitConversionSequence::Indistinguishable; 1728 break; 1729 } 1730 1731 return Result; 1732} 1733 1734/// CompareDerivedToBaseConversions - Compares two standard conversion 1735/// sequences to determine whether they can be ranked based on their 1736/// various kinds of derived-to-base conversions (C++ 1737/// [over.ics.rank]p4b3). As part of these checks, we also look at 1738/// conversions between Objective-C interface types. 1739ImplicitConversionSequence::CompareKind 1740Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1741 const StandardConversionSequence& SCS2) { 1742 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1743 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1744 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1745 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1746 1747 // Adjust the types we're converting from via the array-to-pointer 1748 // conversion, if we need to. 1749 if (SCS1.First == ICK_Array_To_Pointer) 1750 FromType1 = Context.getArrayDecayedType(FromType1); 1751 if (SCS2.First == ICK_Array_To_Pointer) 1752 FromType2 = Context.getArrayDecayedType(FromType2); 1753 1754 // Canonicalize all of the types. 1755 FromType1 = Context.getCanonicalType(FromType1); 1756 ToType1 = Context.getCanonicalType(ToType1); 1757 FromType2 = Context.getCanonicalType(FromType2); 1758 ToType2 = Context.getCanonicalType(ToType2); 1759 1760 // C++ [over.ics.rank]p4b3: 1761 // 1762 // If class B is derived directly or indirectly from class A and 1763 // class C is derived directly or indirectly from B, 1764 // 1765 // For Objective-C, we let A, B, and C also be Objective-C 1766 // interfaces. 1767 1768 // Compare based on pointer conversions. 1769 if (SCS1.Second == ICK_Pointer_Conversion && 1770 SCS2.Second == ICK_Pointer_Conversion && 1771 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1772 FromType1->isPointerType() && FromType2->isPointerType() && 1773 ToType1->isPointerType() && ToType2->isPointerType()) { 1774 QualType FromPointee1 1775 = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1776 QualType ToPointee1 1777 = ToType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1778 QualType FromPointee2 1779 = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1780 QualType ToPointee2 1781 = ToType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); 1782 1783 const ObjCInterfaceType* FromIface1 = FromPointee1->getAsObjCInterfaceType(); 1784 const ObjCInterfaceType* FromIface2 = FromPointee2->getAsObjCInterfaceType(); 1785 const ObjCInterfaceType* ToIface1 = ToPointee1->getAsObjCInterfaceType(); 1786 const ObjCInterfaceType* ToIface2 = ToPointee2->getAsObjCInterfaceType(); 1787 1788 // -- conversion of C* to B* is better than conversion of C* to A*, 1789 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1790 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1791 return ImplicitConversionSequence::Better; 1792 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1793 return ImplicitConversionSequence::Worse; 1794 1795 if (ToIface1 && ToIface2) { 1796 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1797 return ImplicitConversionSequence::Better; 1798 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1799 return ImplicitConversionSequence::Worse; 1800 } 1801 } 1802 1803 // -- conversion of B* to A* is better than conversion of C* to A*, 1804 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1805 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1806 return ImplicitConversionSequence::Better; 1807 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1808 return ImplicitConversionSequence::Worse; 1809 1810 if (FromIface1 && FromIface2) { 1811 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1812 return ImplicitConversionSequence::Better; 1813 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1814 return ImplicitConversionSequence::Worse; 1815 } 1816 } 1817 } 1818 1819 // Compare based on reference bindings. 1820 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1821 SCS1.Second == ICK_Derived_To_Base) { 1822 // -- binding of an expression of type C to a reference of type 1823 // B& is better than binding an expression of type C to a 1824 // reference of type A&, 1825 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1826 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1827 if (IsDerivedFrom(ToType1, ToType2)) 1828 return ImplicitConversionSequence::Better; 1829 else if (IsDerivedFrom(ToType2, ToType1)) 1830 return ImplicitConversionSequence::Worse; 1831 } 1832 1833 // -- binding of an expression of type B to a reference of type 1834 // A& is better than binding an expression of type C to a 1835 // reference of type A&, 1836 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1837 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1838 if (IsDerivedFrom(FromType2, FromType1)) 1839 return ImplicitConversionSequence::Better; 1840 else if (IsDerivedFrom(FromType1, FromType2)) 1841 return ImplicitConversionSequence::Worse; 1842 } 1843 } 1844 1845 1846 // FIXME: conversion of A::* to B::* is better than conversion of 1847 // A::* to C::*, 1848 1849 // FIXME: conversion of B::* to C::* is better than conversion of 1850 // A::* to C::*, and 1851 1852 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1853 SCS1.Second == ICK_Derived_To_Base) { 1854 // -- conversion of C to B is better than conversion of C to A, 1855 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1856 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1857 if (IsDerivedFrom(ToType1, ToType2)) 1858 return ImplicitConversionSequence::Better; 1859 else if (IsDerivedFrom(ToType2, ToType1)) 1860 return ImplicitConversionSequence::Worse; 1861 } 1862 1863 // -- conversion of B to A is better than conversion of C to A. 1864 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1865 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1866 if (IsDerivedFrom(FromType2, FromType1)) 1867 return ImplicitConversionSequence::Better; 1868 else if (IsDerivedFrom(FromType1, FromType2)) 1869 return ImplicitConversionSequence::Worse; 1870 } 1871 } 1872 1873 return ImplicitConversionSequence::Indistinguishable; 1874} 1875 1876/// TryCopyInitialization - Try to copy-initialize a value of type 1877/// ToType from the expression From. Return the implicit conversion 1878/// sequence required to pass this argument, which may be a bad 1879/// conversion sequence (meaning that the argument cannot be passed to 1880/// a parameter of this type). If @p SuppressUserConversions, then we 1881/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1882/// then we treat @p From as an rvalue, even if it is an lvalue. 1883ImplicitConversionSequence 1884Sema::TryCopyInitialization(Expr *From, QualType ToType, 1885 bool SuppressUserConversions, bool ForceRValue) { 1886 if (ToType->isReferenceType()) { 1887 ImplicitConversionSequence ICS; 1888 CheckReferenceInit(From, ToType, &ICS, SuppressUserConversions, 1889 /*AllowExplicit=*/false, ForceRValue); 1890 return ICS; 1891 } else { 1892 return TryImplicitConversion(From, ToType, SuppressUserConversions, 1893 ForceRValue); 1894 } 1895} 1896 1897/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1898/// the expression @p From. Returns true (and emits a diagnostic) if there was 1899/// an error, returns false if the initialization succeeded. Elidable should 1900/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1901/// differently in C++0x for this case. 1902bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1903 const char* Flavor, bool Elidable) { 1904 if (!getLangOptions().CPlusPlus) { 1905 // In C, argument passing is the same as performing an assignment. 1906 QualType FromType = From->getType(); 1907 1908 AssignConvertType ConvTy = 1909 CheckSingleAssignmentConstraints(ToType, From); 1910 if (ConvTy != Compatible && 1911 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1912 ConvTy = Compatible; 1913 1914 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1915 FromType, From, Flavor); 1916 } 1917 1918 if (ToType->isReferenceType()) 1919 return CheckReferenceInit(From, ToType); 1920 1921 if (!PerformImplicitConversion(From, ToType, Flavor, 1922 /*AllowExplicit=*/false, Elidable)) 1923 return false; 1924 1925 return Diag(From->getSourceRange().getBegin(), 1926 diag::err_typecheck_convert_incompatible) 1927 << ToType << From->getType() << Flavor << From->getSourceRange(); 1928} 1929 1930/// TryObjectArgumentInitialization - Try to initialize the object 1931/// parameter of the given member function (@c Method) from the 1932/// expression @p From. 1933ImplicitConversionSequence 1934Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 1935 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 1936 unsigned MethodQuals = Method->getTypeQualifiers(); 1937 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 1938 1939 // Set up the conversion sequence as a "bad" conversion, to allow us 1940 // to exit early. 1941 ImplicitConversionSequence ICS; 1942 ICS.Standard.setAsIdentityConversion(); 1943 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1944 1945 // We need to have an object of class type. 1946 QualType FromType = From->getType(); 1947 if (const PointerType *PT = FromType->getAsPointerType()) 1948 FromType = PT->getPointeeType(); 1949 1950 assert(FromType->isRecordType()); 1951 1952 // The implicit object parmeter is has the type "reference to cv X", 1953 // where X is the class of which the function is a member 1954 // (C++ [over.match.funcs]p4). However, when finding an implicit 1955 // conversion sequence for the argument, we are not allowed to 1956 // create temporaries or perform user-defined conversions 1957 // (C++ [over.match.funcs]p5). We perform a simplified version of 1958 // reference binding here, that allows class rvalues to bind to 1959 // non-constant references. 1960 1961 // First check the qualifiers. We don't care about lvalue-vs-rvalue 1962 // with the implicit object parameter (C++ [over.match.funcs]p5). 1963 QualType FromTypeCanon = Context.getCanonicalType(FromType); 1964 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 1965 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 1966 return ICS; 1967 1968 // Check that we have either the same type or a derived type. It 1969 // affects the conversion rank. 1970 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 1971 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 1972 ICS.Standard.Second = ICK_Identity; 1973 else if (IsDerivedFrom(FromType, ClassType)) 1974 ICS.Standard.Second = ICK_Derived_To_Base; 1975 else 1976 return ICS; 1977 1978 // Success. Mark this as a reference binding. 1979 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 1980 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 1981 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 1982 ICS.Standard.ReferenceBinding = true; 1983 ICS.Standard.DirectBinding = true; 1984 ICS.Standard.RRefBinding = false; 1985 return ICS; 1986} 1987 1988/// PerformObjectArgumentInitialization - Perform initialization of 1989/// the implicit object parameter for the given Method with the given 1990/// expression. 1991bool 1992Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 1993 QualType FromRecordType, DestType; 1994 QualType ImplicitParamRecordType = 1995 Method->getThisType(Context)->getAsPointerType()->getPointeeType(); 1996 1997 if (const PointerType *PT = From->getType()->getAsPointerType()) { 1998 FromRecordType = PT->getPointeeType(); 1999 DestType = Method->getThisType(Context); 2000 } else { 2001 FromRecordType = From->getType(); 2002 DestType = ImplicitParamRecordType; 2003 } 2004 2005 ImplicitConversionSequence ICS 2006 = TryObjectArgumentInitialization(From, Method); 2007 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2008 return Diag(From->getSourceRange().getBegin(), 2009 diag::err_implicit_object_parameter_init) 2010 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2011 2012 if (ICS.Standard.Second == ICK_Derived_To_Base && 2013 CheckDerivedToBaseConversion(FromRecordType, 2014 ImplicitParamRecordType, 2015 From->getSourceRange().getBegin(), 2016 From->getSourceRange())) 2017 return true; 2018 2019 ImpCastExprToType(From, DestType, /*isLvalue=*/true); 2020 return false; 2021} 2022 2023/// TryContextuallyConvertToBool - Attempt to contextually convert the 2024/// expression From to bool (C++0x [conv]p3). 2025ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2026 return TryImplicitConversion(From, Context.BoolTy, false, true); 2027} 2028 2029/// PerformContextuallyConvertToBool - Perform a contextual conversion 2030/// of the expression From to bool (C++0x [conv]p3). 2031bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2032 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2033 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2034 return false; 2035 2036 return Diag(From->getSourceRange().getBegin(), 2037 diag::err_typecheck_bool_condition) 2038 << From->getType() << From->getSourceRange(); 2039} 2040 2041/// AddOverloadCandidate - Adds the given function to the set of 2042/// candidate functions, using the given function call arguments. If 2043/// @p SuppressUserConversions, then don't allow user-defined 2044/// conversions via constructors or conversion operators. 2045/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2046/// hacky way to implement the overloading rules for elidable copy 2047/// initialization in C++0x (C++0x 12.8p15). 2048void 2049Sema::AddOverloadCandidate(FunctionDecl *Function, 2050 Expr **Args, unsigned NumArgs, 2051 OverloadCandidateSet& CandidateSet, 2052 bool SuppressUserConversions, 2053 bool ForceRValue) 2054{ 2055 const FunctionProtoType* Proto 2056 = dyn_cast<FunctionProtoType>(Function->getType()->getAsFunctionType()); 2057 assert(Proto && "Functions without a prototype cannot be overloaded"); 2058 assert(!isa<CXXConversionDecl>(Function) && 2059 "Use AddConversionCandidate for conversion functions"); 2060 assert(!Function->getDescribedFunctionTemplate() && 2061 "Use AddTemplateOverloadCandidate for function templates"); 2062 2063 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2064 if (!isa<CXXConstructorDecl>(Method)) { 2065 // If we get here, it's because we're calling a member function 2066 // that is named without a member access expression (e.g., 2067 // "this->f") that was either written explicitly or created 2068 // implicitly. This can happen with a qualified call to a member 2069 // function, e.g., X::f(). We use a NULL object as the implied 2070 // object argument (C++ [over.call.func]p3). 2071 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2072 SuppressUserConversions, ForceRValue); 2073 return; 2074 } 2075 // We treat a constructor like a non-member function, since its object 2076 // argument doesn't participate in overload resolution. 2077 } 2078 2079 2080 // Add this candidate 2081 CandidateSet.push_back(OverloadCandidate()); 2082 OverloadCandidate& Candidate = CandidateSet.back(); 2083 Candidate.Function = Function; 2084 Candidate.Viable = true; 2085 Candidate.IsSurrogate = false; 2086 Candidate.IgnoreObjectArgument = false; 2087 2088 unsigned NumArgsInProto = Proto->getNumArgs(); 2089 2090 // (C++ 13.3.2p2): A candidate function having fewer than m 2091 // parameters is viable only if it has an ellipsis in its parameter 2092 // list (8.3.5). 2093 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2094 Candidate.Viable = false; 2095 return; 2096 } 2097 2098 // (C++ 13.3.2p2): A candidate function having more than m parameters 2099 // is viable only if the (m+1)st parameter has a default argument 2100 // (8.3.6). For the purposes of overload resolution, the 2101 // parameter list is truncated on the right, so that there are 2102 // exactly m parameters. 2103 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2104 if (NumArgs < MinRequiredArgs) { 2105 // Not enough arguments. 2106 Candidate.Viable = false; 2107 return; 2108 } 2109 2110 // Determine the implicit conversion sequences for each of the 2111 // arguments. 2112 Candidate.Conversions.resize(NumArgs); 2113 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2114 if (ArgIdx < NumArgsInProto) { 2115 // (C++ 13.3.2p3): for F to be a viable function, there shall 2116 // exist for each argument an implicit conversion sequence 2117 // (13.3.3.1) that converts that argument to the corresponding 2118 // parameter of F. 2119 QualType ParamType = Proto->getArgType(ArgIdx); 2120 Candidate.Conversions[ArgIdx] 2121 = TryCopyInitialization(Args[ArgIdx], ParamType, 2122 SuppressUserConversions, ForceRValue); 2123 if (Candidate.Conversions[ArgIdx].ConversionKind 2124 == ImplicitConversionSequence::BadConversion) { 2125 Candidate.Viable = false; 2126 break; 2127 } 2128 } else { 2129 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2130 // argument for which there is no corresponding parameter is 2131 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2132 Candidate.Conversions[ArgIdx].ConversionKind 2133 = ImplicitConversionSequence::EllipsisConversion; 2134 } 2135 } 2136} 2137 2138/// \brief Add all of the function declarations in the given function set to 2139/// the overload canddiate set. 2140void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2141 Expr **Args, unsigned NumArgs, 2142 OverloadCandidateSet& CandidateSet, 2143 bool SuppressUserConversions) { 2144 for (FunctionSet::const_iterator F = Functions.begin(), 2145 FEnd = Functions.end(); 2146 F != FEnd; ++F) { 2147 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) 2148 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2149 SuppressUserConversions); 2150 else 2151 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*F), 2152 /*FIXME: explicit args */false, 0, 0, 2153 Args, NumArgs, CandidateSet, 2154 SuppressUserConversions); 2155 } 2156} 2157 2158/// AddMethodCandidate - Adds the given C++ member function to the set 2159/// of candidate functions, using the given function call arguments 2160/// and the object argument (@c Object). For example, in a call 2161/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2162/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2163/// allow user-defined conversions via constructors or conversion 2164/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2165/// a slightly hacky way to implement the overloading rules for elidable copy 2166/// initialization in C++0x (C++0x 12.8p15). 2167void 2168Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2169 Expr **Args, unsigned NumArgs, 2170 OverloadCandidateSet& CandidateSet, 2171 bool SuppressUserConversions, bool ForceRValue) 2172{ 2173 const FunctionProtoType* Proto 2174 = dyn_cast<FunctionProtoType>(Method->getType()->getAsFunctionType()); 2175 assert(Proto && "Methods without a prototype cannot be overloaded"); 2176 assert(!isa<CXXConversionDecl>(Method) && 2177 "Use AddConversionCandidate for conversion functions"); 2178 assert(!isa<CXXConstructorDecl>(Method) && 2179 "Use AddOverloadCandidate for constructors"); 2180 2181 // Add this candidate 2182 CandidateSet.push_back(OverloadCandidate()); 2183 OverloadCandidate& Candidate = CandidateSet.back(); 2184 Candidate.Function = Method; 2185 Candidate.IsSurrogate = false; 2186 Candidate.IgnoreObjectArgument = false; 2187 2188 unsigned NumArgsInProto = Proto->getNumArgs(); 2189 2190 // (C++ 13.3.2p2): A candidate function having fewer than m 2191 // parameters is viable only if it has an ellipsis in its parameter 2192 // list (8.3.5). 2193 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2194 Candidate.Viable = false; 2195 return; 2196 } 2197 2198 // (C++ 13.3.2p2): A candidate function having more than m parameters 2199 // is viable only if the (m+1)st parameter has a default argument 2200 // (8.3.6). For the purposes of overload resolution, the 2201 // parameter list is truncated on the right, so that there are 2202 // exactly m parameters. 2203 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2204 if (NumArgs < MinRequiredArgs) { 2205 // Not enough arguments. 2206 Candidate.Viable = false; 2207 return; 2208 } 2209 2210 Candidate.Viable = true; 2211 Candidate.Conversions.resize(NumArgs + 1); 2212 2213 if (Method->isStatic() || !Object) 2214 // The implicit object argument is ignored. 2215 Candidate.IgnoreObjectArgument = true; 2216 else { 2217 // Determine the implicit conversion sequence for the object 2218 // parameter. 2219 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2220 if (Candidate.Conversions[0].ConversionKind 2221 == ImplicitConversionSequence::BadConversion) { 2222 Candidate.Viable = false; 2223 return; 2224 } 2225 } 2226 2227 // Determine the implicit conversion sequences for each of the 2228 // arguments. 2229 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2230 if (ArgIdx < NumArgsInProto) { 2231 // (C++ 13.3.2p3): for F to be a viable function, there shall 2232 // exist for each argument an implicit conversion sequence 2233 // (13.3.3.1) that converts that argument to the corresponding 2234 // parameter of F. 2235 QualType ParamType = Proto->getArgType(ArgIdx); 2236 Candidate.Conversions[ArgIdx + 1] 2237 = TryCopyInitialization(Args[ArgIdx], ParamType, 2238 SuppressUserConversions, ForceRValue); 2239 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2240 == ImplicitConversionSequence::BadConversion) { 2241 Candidate.Viable = false; 2242 break; 2243 } 2244 } else { 2245 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2246 // argument for which there is no corresponding parameter is 2247 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2248 Candidate.Conversions[ArgIdx + 1].ConversionKind 2249 = ImplicitConversionSequence::EllipsisConversion; 2250 } 2251 } 2252} 2253 2254/// \brief Add a C++ function template as a candidate in the candidate set, 2255/// using template argument deduction to produce an appropriate function 2256/// template specialization. 2257void 2258Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2259 bool HasExplicitTemplateArgs, 2260 const TemplateArgument *ExplicitTemplateArgs, 2261 unsigned NumExplicitTemplateArgs, 2262 Expr **Args, unsigned NumArgs, 2263 OverloadCandidateSet& CandidateSet, 2264 bool SuppressUserConversions, 2265 bool ForceRValue) { 2266 // C++ [over.match.funcs]p7: 2267 // In each case where a candidate is a function template, candidate 2268 // function template specializations are generated using template argument 2269 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2270 // candidate functions in the usual way.113) A given name can refer to one 2271 // or more function templates and also to a set of overloaded non-template 2272 // functions. In such a case, the candidate functions generated from each 2273 // function template are combined with the set of non-template candidate 2274 // functions. 2275 TemplateDeductionInfo Info(Context); 2276 FunctionDecl *Specialization = 0; 2277 if (TemplateDeductionResult Result 2278 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2279 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2280 Args, NumArgs, Specialization, Info)) { 2281 // FIXME: Record what happened with template argument deduction, so 2282 // that we can give the user a beautiful diagnostic. 2283 (void)Result; 2284 return; 2285 } 2286 2287 // Add the function template specialization produced by template argument 2288 // deduction as a candidate. 2289 assert(Specialization && "Missing function template specialization?"); 2290 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2291 SuppressUserConversions, ForceRValue); 2292} 2293 2294/// AddConversionCandidate - Add a C++ conversion function as a 2295/// candidate in the candidate set (C++ [over.match.conv], 2296/// C++ [over.match.copy]). From is the expression we're converting from, 2297/// and ToType is the type that we're eventually trying to convert to 2298/// (which may or may not be the same type as the type that the 2299/// conversion function produces). 2300void 2301Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2302 Expr *From, QualType ToType, 2303 OverloadCandidateSet& CandidateSet) { 2304 // Add this candidate 2305 CandidateSet.push_back(OverloadCandidate()); 2306 OverloadCandidate& Candidate = CandidateSet.back(); 2307 Candidate.Function = Conversion; 2308 Candidate.IsSurrogate = false; 2309 Candidate.IgnoreObjectArgument = false; 2310 Candidate.FinalConversion.setAsIdentityConversion(); 2311 Candidate.FinalConversion.FromTypePtr 2312 = Conversion->getConversionType().getAsOpaquePtr(); 2313 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2314 2315 // Determine the implicit conversion sequence for the implicit 2316 // object parameter. 2317 Candidate.Viable = true; 2318 Candidate.Conversions.resize(1); 2319 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2320 2321 if (Candidate.Conversions[0].ConversionKind 2322 == ImplicitConversionSequence::BadConversion) { 2323 Candidate.Viable = false; 2324 return; 2325 } 2326 2327 // To determine what the conversion from the result of calling the 2328 // conversion function to the type we're eventually trying to 2329 // convert to (ToType), we need to synthesize a call to the 2330 // conversion function and attempt copy initialization from it. This 2331 // makes sure that we get the right semantics with respect to 2332 // lvalues/rvalues and the type. Fortunately, we can allocate this 2333 // call on the stack and we don't need its arguments to be 2334 // well-formed. 2335 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2336 SourceLocation()); 2337 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2338 &ConversionRef, false); 2339 2340 // Note that it is safe to allocate CallExpr on the stack here because 2341 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2342 // allocator). 2343 CallExpr Call(Context, &ConversionFn, 0, 0, 2344 Conversion->getConversionType().getNonReferenceType(), 2345 SourceLocation()); 2346 ImplicitConversionSequence ICS = TryCopyInitialization(&Call, ToType, true); 2347 switch (ICS.ConversionKind) { 2348 case ImplicitConversionSequence::StandardConversion: 2349 Candidate.FinalConversion = ICS.Standard; 2350 break; 2351 2352 case ImplicitConversionSequence::BadConversion: 2353 Candidate.Viable = false; 2354 break; 2355 2356 default: 2357 assert(false && 2358 "Can only end up with a standard conversion sequence or failure"); 2359 } 2360} 2361 2362/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2363/// converts the given @c Object to a function pointer via the 2364/// conversion function @c Conversion, and then attempts to call it 2365/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2366/// the type of function that we'll eventually be calling. 2367void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2368 const FunctionProtoType *Proto, 2369 Expr *Object, Expr **Args, unsigned NumArgs, 2370 OverloadCandidateSet& CandidateSet) { 2371 CandidateSet.push_back(OverloadCandidate()); 2372 OverloadCandidate& Candidate = CandidateSet.back(); 2373 Candidate.Function = 0; 2374 Candidate.Surrogate = Conversion; 2375 Candidate.Viable = true; 2376 Candidate.IsSurrogate = true; 2377 Candidate.IgnoreObjectArgument = false; 2378 Candidate.Conversions.resize(NumArgs + 1); 2379 2380 // Determine the implicit conversion sequence for the implicit 2381 // object parameter. 2382 ImplicitConversionSequence ObjectInit 2383 = TryObjectArgumentInitialization(Object, Conversion); 2384 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2385 Candidate.Viable = false; 2386 return; 2387 } 2388 2389 // The first conversion is actually a user-defined conversion whose 2390 // first conversion is ObjectInit's standard conversion (which is 2391 // effectively a reference binding). Record it as such. 2392 Candidate.Conversions[0].ConversionKind 2393 = ImplicitConversionSequence::UserDefinedConversion; 2394 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2395 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2396 Candidate.Conversions[0].UserDefined.After 2397 = Candidate.Conversions[0].UserDefined.Before; 2398 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2399 2400 // Find the 2401 unsigned NumArgsInProto = Proto->getNumArgs(); 2402 2403 // (C++ 13.3.2p2): A candidate function having fewer than m 2404 // parameters is viable only if it has an ellipsis in its parameter 2405 // list (8.3.5). 2406 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2407 Candidate.Viable = false; 2408 return; 2409 } 2410 2411 // Function types don't have any default arguments, so just check if 2412 // we have enough arguments. 2413 if (NumArgs < NumArgsInProto) { 2414 // Not enough arguments. 2415 Candidate.Viable = false; 2416 return; 2417 } 2418 2419 // Determine the implicit conversion sequences for each of the 2420 // arguments. 2421 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2422 if (ArgIdx < NumArgsInProto) { 2423 // (C++ 13.3.2p3): for F to be a viable function, there shall 2424 // exist for each argument an implicit conversion sequence 2425 // (13.3.3.1) that converts that argument to the corresponding 2426 // parameter of F. 2427 QualType ParamType = Proto->getArgType(ArgIdx); 2428 Candidate.Conversions[ArgIdx + 1] 2429 = TryCopyInitialization(Args[ArgIdx], ParamType, 2430 /*SuppressUserConversions=*/false); 2431 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2432 == ImplicitConversionSequence::BadConversion) { 2433 Candidate.Viable = false; 2434 break; 2435 } 2436 } else { 2437 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2438 // argument for which there is no corresponding parameter is 2439 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2440 Candidate.Conversions[ArgIdx + 1].ConversionKind 2441 = ImplicitConversionSequence::EllipsisConversion; 2442 } 2443 } 2444} 2445 2446// FIXME: This will eventually be removed, once we've migrated all of the 2447// operator overloading logic over to the scheme used by binary operators, which 2448// works for template instantiation. 2449void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2450 SourceLocation OpLoc, 2451 Expr **Args, unsigned NumArgs, 2452 OverloadCandidateSet& CandidateSet, 2453 SourceRange OpRange) { 2454 2455 FunctionSet Functions; 2456 2457 QualType T1 = Args[0]->getType(); 2458 QualType T2; 2459 if (NumArgs > 1) 2460 T2 = Args[1]->getType(); 2461 2462 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2463 if (S) 2464 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2465 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2466 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2467 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2468 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2469} 2470 2471/// \brief Add overload candidates for overloaded operators that are 2472/// member functions. 2473/// 2474/// Add the overloaded operator candidates that are member functions 2475/// for the operator Op that was used in an operator expression such 2476/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2477/// CandidateSet will store the added overload candidates. (C++ 2478/// [over.match.oper]). 2479void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2480 SourceLocation OpLoc, 2481 Expr **Args, unsigned NumArgs, 2482 OverloadCandidateSet& CandidateSet, 2483 SourceRange OpRange) { 2484 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2485 2486 // C++ [over.match.oper]p3: 2487 // For a unary operator @ with an operand of a type whose 2488 // cv-unqualified version is T1, and for a binary operator @ with 2489 // a left operand of a type whose cv-unqualified version is T1 and 2490 // a right operand of a type whose cv-unqualified version is T2, 2491 // three sets of candidate functions, designated member 2492 // candidates, non-member candidates and built-in candidates, are 2493 // constructed as follows: 2494 QualType T1 = Args[0]->getType(); 2495 QualType T2; 2496 if (NumArgs > 1) 2497 T2 = Args[1]->getType(); 2498 2499 // -- If T1 is a class type, the set of member candidates is the 2500 // result of the qualified lookup of T1::operator@ 2501 // (13.3.1.1.1); otherwise, the set of member candidates is 2502 // empty. 2503 // FIXME: Lookup in base classes, too! 2504 if (const RecordType *T1Rec = T1->getAsRecordType()) { 2505 DeclContext::lookup_const_iterator Oper, OperEnd; 2506 for (llvm::tie(Oper, OperEnd) = T1Rec->getDecl()->lookup(OpName); 2507 Oper != OperEnd; ++Oper) 2508 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2509 Args+1, NumArgs - 1, CandidateSet, 2510 /*SuppressUserConversions=*/false); 2511 } 2512} 2513 2514/// AddBuiltinCandidate - Add a candidate for a built-in 2515/// operator. ResultTy and ParamTys are the result and parameter types 2516/// of the built-in candidate, respectively. Args and NumArgs are the 2517/// arguments being passed to the candidate. IsAssignmentOperator 2518/// should be true when this built-in candidate is an assignment 2519/// operator. NumContextualBoolArguments is the number of arguments 2520/// (at the beginning of the argument list) that will be contextually 2521/// converted to bool. 2522void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2523 Expr **Args, unsigned NumArgs, 2524 OverloadCandidateSet& CandidateSet, 2525 bool IsAssignmentOperator, 2526 unsigned NumContextualBoolArguments) { 2527 // Add this candidate 2528 CandidateSet.push_back(OverloadCandidate()); 2529 OverloadCandidate& Candidate = CandidateSet.back(); 2530 Candidate.Function = 0; 2531 Candidate.IsSurrogate = false; 2532 Candidate.IgnoreObjectArgument = false; 2533 Candidate.BuiltinTypes.ResultTy = ResultTy; 2534 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2535 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2536 2537 // Determine the implicit conversion sequences for each of the 2538 // arguments. 2539 Candidate.Viable = true; 2540 Candidate.Conversions.resize(NumArgs); 2541 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2542 // C++ [over.match.oper]p4: 2543 // For the built-in assignment operators, conversions of the 2544 // left operand are restricted as follows: 2545 // -- no temporaries are introduced to hold the left operand, and 2546 // -- no user-defined conversions are applied to the left 2547 // operand to achieve a type match with the left-most 2548 // parameter of a built-in candidate. 2549 // 2550 // We block these conversions by turning off user-defined 2551 // conversions, since that is the only way that initialization of 2552 // a reference to a non-class type can occur from something that 2553 // is not of the same type. 2554 if (ArgIdx < NumContextualBoolArguments) { 2555 assert(ParamTys[ArgIdx] == Context.BoolTy && 2556 "Contextual conversion to bool requires bool type"); 2557 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2558 } else { 2559 Candidate.Conversions[ArgIdx] 2560 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2561 ArgIdx == 0 && IsAssignmentOperator); 2562 } 2563 if (Candidate.Conversions[ArgIdx].ConversionKind 2564 == ImplicitConversionSequence::BadConversion) { 2565 Candidate.Viable = false; 2566 break; 2567 } 2568 } 2569} 2570 2571/// BuiltinCandidateTypeSet - A set of types that will be used for the 2572/// candidate operator functions for built-in operators (C++ 2573/// [over.built]). The types are separated into pointer types and 2574/// enumeration types. 2575class BuiltinCandidateTypeSet { 2576 /// TypeSet - A set of types. 2577 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2578 2579 /// PointerTypes - The set of pointer types that will be used in the 2580 /// built-in candidates. 2581 TypeSet PointerTypes; 2582 2583 /// MemberPointerTypes - The set of member pointer types that will be 2584 /// used in the built-in candidates. 2585 TypeSet MemberPointerTypes; 2586 2587 /// EnumerationTypes - The set of enumeration types that will be 2588 /// used in the built-in candidates. 2589 TypeSet EnumerationTypes; 2590 2591 /// Context - The AST context in which we will build the type sets. 2592 ASTContext &Context; 2593 2594 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2595 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2596 2597public: 2598 /// iterator - Iterates through the types that are part of the set. 2599 typedef TypeSet::iterator iterator; 2600 2601 BuiltinCandidateTypeSet(ASTContext &Context) : Context(Context) { } 2602 2603 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2604 bool AllowExplicitConversions); 2605 2606 /// pointer_begin - First pointer type found; 2607 iterator pointer_begin() { return PointerTypes.begin(); } 2608 2609 /// pointer_end - Past the last pointer type found; 2610 iterator pointer_end() { return PointerTypes.end(); } 2611 2612 /// member_pointer_begin - First member pointer type found; 2613 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2614 2615 /// member_pointer_end - Past the last member pointer type found; 2616 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2617 2618 /// enumeration_begin - First enumeration type found; 2619 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2620 2621 /// enumeration_end - Past the last enumeration type found; 2622 iterator enumeration_end() { return EnumerationTypes.end(); } 2623}; 2624 2625/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2626/// the set of pointer types along with any more-qualified variants of 2627/// that type. For example, if @p Ty is "int const *", this routine 2628/// will add "int const *", "int const volatile *", "int const 2629/// restrict *", and "int const volatile restrict *" to the set of 2630/// pointer types. Returns true if the add of @p Ty itself succeeded, 2631/// false otherwise. 2632bool 2633BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2634 // Insert this type. 2635 if (!PointerTypes.insert(Ty)) 2636 return false; 2637 2638 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2639 QualType PointeeTy = PointerTy->getPointeeType(); 2640 // FIXME: Optimize this so that we don't keep trying to add the same types. 2641 2642 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal with all 2643 // pointer conversions that don't cast away constness? 2644 if (!PointeeTy.isConstQualified()) 2645 AddPointerWithMoreQualifiedTypeVariants 2646 (Context.getPointerType(PointeeTy.withConst())); 2647 if (!PointeeTy.isVolatileQualified()) 2648 AddPointerWithMoreQualifiedTypeVariants 2649 (Context.getPointerType(PointeeTy.withVolatile())); 2650 if (!PointeeTy.isRestrictQualified()) 2651 AddPointerWithMoreQualifiedTypeVariants 2652 (Context.getPointerType(PointeeTy.withRestrict())); 2653 } 2654 2655 return true; 2656} 2657 2658/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2659/// to the set of pointer types along with any more-qualified variants of 2660/// that type. For example, if @p Ty is "int const *", this routine 2661/// will add "int const *", "int const volatile *", "int const 2662/// restrict *", and "int const volatile restrict *" to the set of 2663/// pointer types. Returns true if the add of @p Ty itself succeeded, 2664/// false otherwise. 2665bool 2666BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2667 QualType Ty) { 2668 // Insert this type. 2669 if (!MemberPointerTypes.insert(Ty)) 2670 return false; 2671 2672 if (const MemberPointerType *PointerTy = Ty->getAsMemberPointerType()) { 2673 QualType PointeeTy = PointerTy->getPointeeType(); 2674 const Type *ClassTy = PointerTy->getClass(); 2675 // FIXME: Optimize this so that we don't keep trying to add the same types. 2676 2677 if (!PointeeTy.isConstQualified()) 2678 AddMemberPointerWithMoreQualifiedTypeVariants 2679 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2680 if (!PointeeTy.isVolatileQualified()) 2681 AddMemberPointerWithMoreQualifiedTypeVariants 2682 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2683 if (!PointeeTy.isRestrictQualified()) 2684 AddMemberPointerWithMoreQualifiedTypeVariants 2685 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2686 } 2687 2688 return true; 2689} 2690 2691/// AddTypesConvertedFrom - Add each of the types to which the type @p 2692/// Ty can be implicit converted to the given set of @p Types. We're 2693/// primarily interested in pointer types and enumeration types. We also 2694/// take member pointer types, for the conditional operator. 2695/// AllowUserConversions is true if we should look at the conversion 2696/// functions of a class type, and AllowExplicitConversions if we 2697/// should also include the explicit conversion functions of a class 2698/// type. 2699void 2700BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2701 bool AllowUserConversions, 2702 bool AllowExplicitConversions) { 2703 // Only deal with canonical types. 2704 Ty = Context.getCanonicalType(Ty); 2705 2706 // Look through reference types; they aren't part of the type of an 2707 // expression for the purposes of conversions. 2708 if (const ReferenceType *RefTy = Ty->getAsReferenceType()) 2709 Ty = RefTy->getPointeeType(); 2710 2711 // We don't care about qualifiers on the type. 2712 Ty = Ty.getUnqualifiedType(); 2713 2714 if (const PointerType *PointerTy = Ty->getAsPointerType()) { 2715 QualType PointeeTy = PointerTy->getPointeeType(); 2716 2717 // Insert our type, and its more-qualified variants, into the set 2718 // of types. 2719 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2720 return; 2721 2722 // Add 'cv void*' to our set of types. 2723 if (!Ty->isVoidType()) { 2724 QualType QualVoid 2725 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2726 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2727 } 2728 2729 // If this is a pointer to a class type, add pointers to its bases 2730 // (with the same level of cv-qualification as the original 2731 // derived class, of course). 2732 if (const RecordType *PointeeRec = PointeeTy->getAsRecordType()) { 2733 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2734 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2735 Base != ClassDecl->bases_end(); ++Base) { 2736 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2737 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2738 2739 // Add the pointer type, recursively, so that we get all of 2740 // the indirect base classes, too. 2741 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2742 } 2743 } 2744 } else if (Ty->isMemberPointerType()) { 2745 // Member pointers are far easier, since the pointee can't be converted. 2746 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2747 return; 2748 } else if (Ty->isEnumeralType()) { 2749 EnumerationTypes.insert(Ty); 2750 } else if (AllowUserConversions) { 2751 if (const RecordType *TyRec = Ty->getAsRecordType()) { 2752 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2753 // FIXME: Visit conversion functions in the base classes, too. 2754 OverloadedFunctionDecl *Conversions 2755 = ClassDecl->getConversionFunctions(); 2756 for (OverloadedFunctionDecl::function_iterator Func 2757 = Conversions->function_begin(); 2758 Func != Conversions->function_end(); ++Func) { 2759 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 2760 if (AllowExplicitConversions || !Conv->isExplicit()) 2761 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2762 } 2763 } 2764 } 2765} 2766 2767/// AddBuiltinOperatorCandidates - Add the appropriate built-in 2768/// operator overloads to the candidate set (C++ [over.built]), based 2769/// on the operator @p Op and the arguments given. For example, if the 2770/// operator is a binary '+', this routine might add "int 2771/// operator+(int, int)" to cover integer addition. 2772void 2773Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 2774 Expr **Args, unsigned NumArgs, 2775 OverloadCandidateSet& CandidateSet) { 2776 // The set of "promoted arithmetic types", which are the arithmetic 2777 // types are that preserved by promotion (C++ [over.built]p2). Note 2778 // that the first few of these types are the promoted integral 2779 // types; these types need to be first. 2780 // FIXME: What about complex? 2781 const unsigned FirstIntegralType = 0; 2782 const unsigned LastIntegralType = 13; 2783 const unsigned FirstPromotedIntegralType = 7, 2784 LastPromotedIntegralType = 13; 2785 const unsigned FirstPromotedArithmeticType = 7, 2786 LastPromotedArithmeticType = 16; 2787 const unsigned NumArithmeticTypes = 16; 2788 QualType ArithmeticTypes[NumArithmeticTypes] = { 2789 Context.BoolTy, Context.CharTy, Context.WCharTy, 2790// Context.Char16Ty, Context.Char32Ty, 2791 Context.SignedCharTy, Context.ShortTy, 2792 Context.UnsignedCharTy, Context.UnsignedShortTy, 2793 Context.IntTy, Context.LongTy, Context.LongLongTy, 2794 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 2795 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 2796 }; 2797 2798 // Find all of the types that the arguments can convert to, but only 2799 // if the operator we're looking at has built-in operator candidates 2800 // that make use of these types. 2801 BuiltinCandidateTypeSet CandidateTypes(Context); 2802 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 2803 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 2804 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 2805 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 2806 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 2807 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 2808 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2809 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 2810 true, 2811 (Op == OO_Exclaim || 2812 Op == OO_AmpAmp || 2813 Op == OO_PipePipe)); 2814 } 2815 2816 bool isComparison = false; 2817 switch (Op) { 2818 case OO_None: 2819 case NUM_OVERLOADED_OPERATORS: 2820 assert(false && "Expected an overloaded operator"); 2821 break; 2822 2823 case OO_Star: // '*' is either unary or binary 2824 if (NumArgs == 1) 2825 goto UnaryStar; 2826 else 2827 goto BinaryStar; 2828 break; 2829 2830 case OO_Plus: // '+' is either unary or binary 2831 if (NumArgs == 1) 2832 goto UnaryPlus; 2833 else 2834 goto BinaryPlus; 2835 break; 2836 2837 case OO_Minus: // '-' is either unary or binary 2838 if (NumArgs == 1) 2839 goto UnaryMinus; 2840 else 2841 goto BinaryMinus; 2842 break; 2843 2844 case OO_Amp: // '&' is either unary or binary 2845 if (NumArgs == 1) 2846 goto UnaryAmp; 2847 else 2848 goto BinaryAmp; 2849 2850 case OO_PlusPlus: 2851 case OO_MinusMinus: 2852 // C++ [over.built]p3: 2853 // 2854 // For every pair (T, VQ), where T is an arithmetic type, and VQ 2855 // is either volatile or empty, there exist candidate operator 2856 // functions of the form 2857 // 2858 // VQ T& operator++(VQ T&); 2859 // T operator++(VQ T&, int); 2860 // 2861 // C++ [over.built]p4: 2862 // 2863 // For every pair (T, VQ), where T is an arithmetic type other 2864 // than bool, and VQ is either volatile or empty, there exist 2865 // candidate operator functions of the form 2866 // 2867 // VQ T& operator--(VQ T&); 2868 // T operator--(VQ T&, int); 2869 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 2870 Arith < NumArithmeticTypes; ++Arith) { 2871 QualType ArithTy = ArithmeticTypes[Arith]; 2872 QualType ParamTypes[2] 2873 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 2874 2875 // Non-volatile version. 2876 if (NumArgs == 1) 2877 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2878 else 2879 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2880 2881 // Volatile version 2882 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 2883 if (NumArgs == 1) 2884 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2885 else 2886 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 2887 } 2888 2889 // C++ [over.built]p5: 2890 // 2891 // For every pair (T, VQ), where T is a cv-qualified or 2892 // cv-unqualified object type, and VQ is either volatile or 2893 // empty, there exist candidate operator functions of the form 2894 // 2895 // T*VQ& operator++(T*VQ&); 2896 // T*VQ& operator--(T*VQ&); 2897 // T* operator++(T*VQ&, int); 2898 // T* operator--(T*VQ&, int); 2899 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2900 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2901 // Skip pointer types that aren't pointers to object types. 2902 if (!(*Ptr)->getAsPointerType()->getPointeeType()->isObjectType()) 2903 continue; 2904 2905 QualType ParamTypes[2] = { 2906 Context.getLValueReferenceType(*Ptr), Context.IntTy 2907 }; 2908 2909 // Without volatile 2910 if (NumArgs == 1) 2911 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2912 else 2913 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2914 2915 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 2916 // With volatile 2917 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 2918 if (NumArgs == 1) 2919 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 2920 else 2921 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 2922 } 2923 } 2924 break; 2925 2926 UnaryStar: 2927 // C++ [over.built]p6: 2928 // For every cv-qualified or cv-unqualified object type T, there 2929 // exist candidate operator functions of the form 2930 // 2931 // T& operator*(T*); 2932 // 2933 // C++ [over.built]p7: 2934 // For every function type T, there exist candidate operator 2935 // functions of the form 2936 // T& operator*(T*); 2937 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2938 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2939 QualType ParamTy = *Ptr; 2940 QualType PointeeTy = ParamTy->getAsPointerType()->getPointeeType(); 2941 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 2942 &ParamTy, Args, 1, CandidateSet); 2943 } 2944 break; 2945 2946 UnaryPlus: 2947 // C++ [over.built]p8: 2948 // For every type T, there exist candidate operator functions of 2949 // the form 2950 // 2951 // T* operator+(T*); 2952 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 2953 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 2954 QualType ParamTy = *Ptr; 2955 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 2956 } 2957 2958 // Fall through 2959 2960 UnaryMinus: 2961 // C++ [over.built]p9: 2962 // For every promoted arithmetic type T, there exist candidate 2963 // operator functions of the form 2964 // 2965 // T operator+(T); 2966 // T operator-(T); 2967 for (unsigned Arith = FirstPromotedArithmeticType; 2968 Arith < LastPromotedArithmeticType; ++Arith) { 2969 QualType ArithTy = ArithmeticTypes[Arith]; 2970 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 2971 } 2972 break; 2973 2974 case OO_Tilde: 2975 // C++ [over.built]p10: 2976 // For every promoted integral type T, there exist candidate 2977 // operator functions of the form 2978 // 2979 // T operator~(T); 2980 for (unsigned Int = FirstPromotedIntegralType; 2981 Int < LastPromotedIntegralType; ++Int) { 2982 QualType IntTy = ArithmeticTypes[Int]; 2983 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 2984 } 2985 break; 2986 2987 case OO_New: 2988 case OO_Delete: 2989 case OO_Array_New: 2990 case OO_Array_Delete: 2991 case OO_Call: 2992 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 2993 break; 2994 2995 case OO_Comma: 2996 UnaryAmp: 2997 case OO_Arrow: 2998 // C++ [over.match.oper]p3: 2999 // -- For the operator ',', the unary operator '&', or the 3000 // operator '->', the built-in candidates set is empty. 3001 break; 3002 3003 case OO_Less: 3004 case OO_Greater: 3005 case OO_LessEqual: 3006 case OO_GreaterEqual: 3007 case OO_EqualEqual: 3008 case OO_ExclaimEqual: 3009 // C++ [over.built]p15: 3010 // 3011 // For every pointer or enumeration type T, there exist 3012 // candidate operator functions of the form 3013 // 3014 // bool operator<(T, T); 3015 // bool operator>(T, T); 3016 // bool operator<=(T, T); 3017 // bool operator>=(T, T); 3018 // bool operator==(T, T); 3019 // bool operator!=(T, T); 3020 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3021 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3022 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3023 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3024 } 3025 for (BuiltinCandidateTypeSet::iterator Enum 3026 = CandidateTypes.enumeration_begin(); 3027 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3028 QualType ParamTypes[2] = { *Enum, *Enum }; 3029 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3030 } 3031 3032 // Fall through. 3033 isComparison = true; 3034 3035 BinaryPlus: 3036 BinaryMinus: 3037 if (!isComparison) { 3038 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3039 3040 // C++ [over.built]p13: 3041 // 3042 // For every cv-qualified or cv-unqualified object type T 3043 // there exist candidate operator functions of the form 3044 // 3045 // T* operator+(T*, ptrdiff_t); 3046 // T& operator[](T*, ptrdiff_t); [BELOW] 3047 // T* operator-(T*, ptrdiff_t); 3048 // T* operator+(ptrdiff_t, T*); 3049 // T& operator[](ptrdiff_t, T*); [BELOW] 3050 // 3051 // C++ [over.built]p14: 3052 // 3053 // For every T, where T is a pointer to object type, there 3054 // exist candidate operator functions of the form 3055 // 3056 // ptrdiff_t operator-(T, T); 3057 for (BuiltinCandidateTypeSet::iterator Ptr 3058 = CandidateTypes.pointer_begin(); 3059 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3060 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3061 3062 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3063 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3064 3065 if (Op == OO_Plus) { 3066 // T* operator+(ptrdiff_t, T*); 3067 ParamTypes[0] = ParamTypes[1]; 3068 ParamTypes[1] = *Ptr; 3069 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3070 } else { 3071 // ptrdiff_t operator-(T, T); 3072 ParamTypes[1] = *Ptr; 3073 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3074 Args, 2, CandidateSet); 3075 } 3076 } 3077 } 3078 // Fall through 3079 3080 case OO_Slash: 3081 BinaryStar: 3082 Conditional: 3083 // C++ [over.built]p12: 3084 // 3085 // For every pair of promoted arithmetic types L and R, there 3086 // exist candidate operator functions of the form 3087 // 3088 // LR operator*(L, R); 3089 // LR operator/(L, R); 3090 // LR operator+(L, R); 3091 // LR operator-(L, R); 3092 // bool operator<(L, R); 3093 // bool operator>(L, R); 3094 // bool operator<=(L, R); 3095 // bool operator>=(L, R); 3096 // bool operator==(L, R); 3097 // bool operator!=(L, R); 3098 // 3099 // where LR is the result of the usual arithmetic conversions 3100 // between types L and R. 3101 // 3102 // C++ [over.built]p24: 3103 // 3104 // For every pair of promoted arithmetic types L and R, there exist 3105 // candidate operator functions of the form 3106 // 3107 // LR operator?(bool, L, R); 3108 // 3109 // where LR is the result of the usual arithmetic conversions 3110 // between types L and R. 3111 // Our candidates ignore the first parameter. 3112 for (unsigned Left = FirstPromotedArithmeticType; 3113 Left < LastPromotedArithmeticType; ++Left) { 3114 for (unsigned Right = FirstPromotedArithmeticType; 3115 Right < LastPromotedArithmeticType; ++Right) { 3116 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3117 QualType Result 3118 = isComparison? Context.BoolTy 3119 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3120 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3121 } 3122 } 3123 break; 3124 3125 case OO_Percent: 3126 BinaryAmp: 3127 case OO_Caret: 3128 case OO_Pipe: 3129 case OO_LessLess: 3130 case OO_GreaterGreater: 3131 // C++ [over.built]p17: 3132 // 3133 // For every pair of promoted integral types L and R, there 3134 // exist candidate operator functions of the form 3135 // 3136 // LR operator%(L, R); 3137 // LR operator&(L, R); 3138 // LR operator^(L, R); 3139 // LR operator|(L, R); 3140 // L operator<<(L, R); 3141 // L operator>>(L, R); 3142 // 3143 // where LR is the result of the usual arithmetic conversions 3144 // between types L and R. 3145 for (unsigned Left = FirstPromotedIntegralType; 3146 Left < LastPromotedIntegralType; ++Left) { 3147 for (unsigned Right = FirstPromotedIntegralType; 3148 Right < LastPromotedIntegralType; ++Right) { 3149 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3150 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3151 ? LandR[0] 3152 : UsualArithmeticConversionsType(LandR[0], LandR[1]); 3153 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3154 } 3155 } 3156 break; 3157 3158 case OO_Equal: 3159 // C++ [over.built]p20: 3160 // 3161 // For every pair (T, VQ), where T is an enumeration or 3162 // (FIXME:) pointer to member type and VQ is either volatile or 3163 // empty, there exist candidate operator functions of the form 3164 // 3165 // VQ T& operator=(VQ T&, T); 3166 for (BuiltinCandidateTypeSet::iterator Enum 3167 = CandidateTypes.enumeration_begin(); 3168 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3169 QualType ParamTypes[2]; 3170 3171 // T& operator=(T&, T) 3172 ParamTypes[0] = Context.getLValueReferenceType(*Enum); 3173 ParamTypes[1] = *Enum; 3174 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3175 /*IsAssignmentOperator=*/false); 3176 3177 if (!Context.getCanonicalType(*Enum).isVolatileQualified()) { 3178 // volatile T& operator=(volatile T&, T) 3179 ParamTypes[0] = Context.getLValueReferenceType((*Enum).withVolatile()); 3180 ParamTypes[1] = *Enum; 3181 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3182 /*IsAssignmentOperator=*/false); 3183 } 3184 } 3185 // Fall through. 3186 3187 case OO_PlusEqual: 3188 case OO_MinusEqual: 3189 // C++ [over.built]p19: 3190 // 3191 // For every pair (T, VQ), where T is any type and VQ is either 3192 // volatile or empty, there exist candidate operator functions 3193 // of the form 3194 // 3195 // T*VQ& operator=(T*VQ&, T*); 3196 // 3197 // C++ [over.built]p21: 3198 // 3199 // For every pair (T, VQ), where T is a cv-qualified or 3200 // cv-unqualified object type and VQ is either volatile or 3201 // empty, there exist candidate operator functions of the form 3202 // 3203 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3204 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3205 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3206 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3207 QualType ParamTypes[2]; 3208 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3209 3210 // non-volatile version 3211 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3212 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3213 /*IsAssigmentOperator=*/Op == OO_Equal); 3214 3215 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3216 // volatile version 3217 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3218 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3219 /*IsAssigmentOperator=*/Op == OO_Equal); 3220 } 3221 } 3222 // Fall through. 3223 3224 case OO_StarEqual: 3225 case OO_SlashEqual: 3226 // C++ [over.built]p18: 3227 // 3228 // For every triple (L, VQ, R), where L is an arithmetic type, 3229 // VQ is either volatile or empty, and R is a promoted 3230 // arithmetic type, there exist candidate operator functions of 3231 // the form 3232 // 3233 // VQ L& operator=(VQ L&, R); 3234 // VQ L& operator*=(VQ L&, R); 3235 // VQ L& operator/=(VQ L&, R); 3236 // VQ L& operator+=(VQ L&, R); 3237 // VQ L& operator-=(VQ L&, R); 3238 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3239 for (unsigned Right = FirstPromotedArithmeticType; 3240 Right < LastPromotedArithmeticType; ++Right) { 3241 QualType ParamTypes[2]; 3242 ParamTypes[1] = ArithmeticTypes[Right]; 3243 3244 // Add this built-in operator as a candidate (VQ is empty). 3245 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3246 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3247 /*IsAssigmentOperator=*/Op == OO_Equal); 3248 3249 // Add this built-in operator as a candidate (VQ is 'volatile'). 3250 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3251 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3252 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3253 /*IsAssigmentOperator=*/Op == OO_Equal); 3254 } 3255 } 3256 break; 3257 3258 case OO_PercentEqual: 3259 case OO_LessLessEqual: 3260 case OO_GreaterGreaterEqual: 3261 case OO_AmpEqual: 3262 case OO_CaretEqual: 3263 case OO_PipeEqual: 3264 // C++ [over.built]p22: 3265 // 3266 // For every triple (L, VQ, R), where L is an integral type, VQ 3267 // is either volatile or empty, and R is a promoted integral 3268 // type, there exist candidate operator functions of the form 3269 // 3270 // VQ L& operator%=(VQ L&, R); 3271 // VQ L& operator<<=(VQ L&, R); 3272 // VQ L& operator>>=(VQ L&, R); 3273 // VQ L& operator&=(VQ L&, R); 3274 // VQ L& operator^=(VQ L&, R); 3275 // VQ L& operator|=(VQ L&, R); 3276 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3277 for (unsigned Right = FirstPromotedIntegralType; 3278 Right < LastPromotedIntegralType; ++Right) { 3279 QualType ParamTypes[2]; 3280 ParamTypes[1] = ArithmeticTypes[Right]; 3281 3282 // Add this built-in operator as a candidate (VQ is empty). 3283 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3284 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3285 3286 // Add this built-in operator as a candidate (VQ is 'volatile'). 3287 ParamTypes[0] = ArithmeticTypes[Left]; 3288 ParamTypes[0].addVolatile(); 3289 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3290 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3291 } 3292 } 3293 break; 3294 3295 case OO_Exclaim: { 3296 // C++ [over.operator]p23: 3297 // 3298 // There also exist candidate operator functions of the form 3299 // 3300 // bool operator!(bool); 3301 // bool operator&&(bool, bool); [BELOW] 3302 // bool operator||(bool, bool); [BELOW] 3303 QualType ParamTy = Context.BoolTy; 3304 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3305 /*IsAssignmentOperator=*/false, 3306 /*NumContextualBoolArguments=*/1); 3307 break; 3308 } 3309 3310 case OO_AmpAmp: 3311 case OO_PipePipe: { 3312 // C++ [over.operator]p23: 3313 // 3314 // There also exist candidate operator functions of the form 3315 // 3316 // bool operator!(bool); [ABOVE] 3317 // bool operator&&(bool, bool); 3318 // bool operator||(bool, bool); 3319 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3320 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3321 /*IsAssignmentOperator=*/false, 3322 /*NumContextualBoolArguments=*/2); 3323 break; 3324 } 3325 3326 case OO_Subscript: 3327 // C++ [over.built]p13: 3328 // 3329 // For every cv-qualified or cv-unqualified object type T there 3330 // exist candidate operator functions of the form 3331 // 3332 // T* operator+(T*, ptrdiff_t); [ABOVE] 3333 // T& operator[](T*, ptrdiff_t); 3334 // T* operator-(T*, ptrdiff_t); [ABOVE] 3335 // T* operator+(ptrdiff_t, T*); [ABOVE] 3336 // T& operator[](ptrdiff_t, T*); 3337 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3338 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3339 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3340 QualType PointeeType = (*Ptr)->getAsPointerType()->getPointeeType(); 3341 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3342 3343 // T& operator[](T*, ptrdiff_t) 3344 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3345 3346 // T& operator[](ptrdiff_t, T*); 3347 ParamTypes[0] = ParamTypes[1]; 3348 ParamTypes[1] = *Ptr; 3349 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3350 } 3351 break; 3352 3353 case OO_ArrowStar: 3354 // FIXME: No support for pointer-to-members yet. 3355 break; 3356 3357 case OO_Conditional: 3358 // Note that we don't consider the first argument, since it has been 3359 // contextually converted to bool long ago. The candidates below are 3360 // therefore added as binary. 3361 // 3362 // C++ [over.built]p24: 3363 // For every type T, where T is a pointer or pointer-to-member type, 3364 // there exist candidate operator functions of the form 3365 // 3366 // T operator?(bool, T, T); 3367 // 3368 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3369 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3370 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3371 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3372 } 3373 for (BuiltinCandidateTypeSet::iterator Ptr = 3374 CandidateTypes.member_pointer_begin(), 3375 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3376 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3377 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3378 } 3379 goto Conditional; 3380 } 3381} 3382 3383/// \brief Add function candidates found via argument-dependent lookup 3384/// to the set of overloading candidates. 3385/// 3386/// This routine performs argument-dependent name lookup based on the 3387/// given function name (which may also be an operator name) and adds 3388/// all of the overload candidates found by ADL to the overload 3389/// candidate set (C++ [basic.lookup.argdep]). 3390void 3391Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3392 Expr **Args, unsigned NumArgs, 3393 OverloadCandidateSet& CandidateSet) { 3394 FunctionSet Functions; 3395 3396 // Record all of the function candidates that we've already 3397 // added to the overload set, so that we don't add those same 3398 // candidates a second time. 3399 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3400 CandEnd = CandidateSet.end(); 3401 Cand != CandEnd; ++Cand) 3402 if (Cand->Function) { 3403 Functions.insert(Cand->Function); 3404 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3405 Functions.insert(FunTmpl); 3406 } 3407 3408 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3409 3410 // Erase all of the candidates we already knew about. 3411 // FIXME: This is suboptimal. Is there a better way? 3412 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3413 CandEnd = CandidateSet.end(); 3414 Cand != CandEnd; ++Cand) 3415 if (Cand->Function) { 3416 Functions.erase(Cand->Function); 3417 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3418 Functions.erase(FunTmpl); 3419 } 3420 3421 // For each of the ADL candidates we found, add it to the overload 3422 // set. 3423 for (FunctionSet::iterator Func = Functions.begin(), 3424 FuncEnd = Functions.end(); 3425 Func != FuncEnd; ++Func) { 3426 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) 3427 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet); 3428 else 3429 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3430 /*FIXME: explicit args */false, 0, 0, 3431 Args, NumArgs, CandidateSet); 3432 } 3433} 3434 3435/// isBetterOverloadCandidate - Determines whether the first overload 3436/// candidate is a better candidate than the second (C++ 13.3.3p1). 3437bool 3438Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3439 const OverloadCandidate& Cand2) 3440{ 3441 // Define viable functions to be better candidates than non-viable 3442 // functions. 3443 if (!Cand2.Viable) 3444 return Cand1.Viable; 3445 else if (!Cand1.Viable) 3446 return false; 3447 3448 // C++ [over.match.best]p1: 3449 // 3450 // -- if F is a static member function, ICS1(F) is defined such 3451 // that ICS1(F) is neither better nor worse than ICS1(G) for 3452 // any function G, and, symmetrically, ICS1(G) is neither 3453 // better nor worse than ICS1(F). 3454 unsigned StartArg = 0; 3455 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3456 StartArg = 1; 3457 3458 // C++ [over.match.best]p1: 3459 // A viable function F1 is defined to be a better function than another 3460 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3461 // conversion sequence than ICSi(F2), and then... 3462 unsigned NumArgs = Cand1.Conversions.size(); 3463 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3464 bool HasBetterConversion = false; 3465 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3466 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3467 Cand2.Conversions[ArgIdx])) { 3468 case ImplicitConversionSequence::Better: 3469 // Cand1 has a better conversion sequence. 3470 HasBetterConversion = true; 3471 break; 3472 3473 case ImplicitConversionSequence::Worse: 3474 // Cand1 can't be better than Cand2. 3475 return false; 3476 3477 case ImplicitConversionSequence::Indistinguishable: 3478 // Do nothing. 3479 break; 3480 } 3481 } 3482 3483 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3484 // ICSj(F2), or, if not that, 3485 if (HasBetterConversion) 3486 return true; 3487 3488 // - F1 is a non-template function and F2 is a function template 3489 // specialization, or, if not that, 3490 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3491 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3492 return true; 3493 3494 // -- F1 and F2 are function template specializations, and the function 3495 // template for F1 is more specialized than the template for F2 3496 // according to the partial ordering rules described in 14.5.5.2, or, 3497 // if not that, 3498 3499 // FIXME: Implement partial ordering of function templates. 3500 3501 // -- the context is an initialization by user-defined conversion 3502 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3503 // from the return type of F1 to the destination type (i.e., 3504 // the type of the entity being initialized) is a better 3505 // conversion sequence than the standard conversion sequence 3506 // from the return type of F2 to the destination type. 3507 if (Cand1.Function && Cand2.Function && 3508 isa<CXXConversionDecl>(Cand1.Function) && 3509 isa<CXXConversionDecl>(Cand2.Function)) { 3510 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3511 Cand2.FinalConversion)) { 3512 case ImplicitConversionSequence::Better: 3513 // Cand1 has a better conversion sequence. 3514 return true; 3515 3516 case ImplicitConversionSequence::Worse: 3517 // Cand1 can't be better than Cand2. 3518 return false; 3519 3520 case ImplicitConversionSequence::Indistinguishable: 3521 // Do nothing 3522 break; 3523 } 3524 } 3525 3526 return false; 3527} 3528 3529/// \brief Computes the best viable function (C++ 13.3.3) 3530/// within an overload candidate set. 3531/// 3532/// \param CandidateSet the set of candidate functions. 3533/// 3534/// \param Loc the location of the function name (or operator symbol) for 3535/// which overload resolution occurs. 3536/// 3537/// \param Best f overload resolution was successful or found a deleted 3538/// function, Best points to the candidate function found. 3539/// 3540/// \returns The result of overload resolution. 3541Sema::OverloadingResult 3542Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3543 SourceLocation Loc, 3544 OverloadCandidateSet::iterator& Best) 3545{ 3546 // Find the best viable function. 3547 Best = CandidateSet.end(); 3548 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3549 Cand != CandidateSet.end(); ++Cand) { 3550 if (Cand->Viable) { 3551 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3552 Best = Cand; 3553 } 3554 } 3555 3556 // If we didn't find any viable functions, abort. 3557 if (Best == CandidateSet.end()) 3558 return OR_No_Viable_Function; 3559 3560 // Make sure that this function is better than every other viable 3561 // function. If not, we have an ambiguity. 3562 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3563 Cand != CandidateSet.end(); ++Cand) { 3564 if (Cand->Viable && 3565 Cand != Best && 3566 !isBetterOverloadCandidate(*Best, *Cand)) { 3567 Best = CandidateSet.end(); 3568 return OR_Ambiguous; 3569 } 3570 } 3571 3572 // Best is the best viable function. 3573 if (Best->Function && 3574 (Best->Function->isDeleted() || 3575 Best->Function->getAttr<UnavailableAttr>())) 3576 return OR_Deleted; 3577 3578 // C++ [basic.def.odr]p2: 3579 // An overloaded function is used if it is selected by overload resolution 3580 // when referred to from a potentially-evaluated expression. [Note: this 3581 // covers calls to named functions (5.2.2), operator overloading 3582 // (clause 13), user-defined conversions (12.3.2), allocation function for 3583 // placement new (5.3.4), as well as non-default initialization (8.5). 3584 if (Best->Function) 3585 MarkDeclarationReferenced(Loc, Best->Function); 3586 return OR_Success; 3587} 3588 3589/// PrintOverloadCandidates - When overload resolution fails, prints 3590/// diagnostic messages containing the candidates in the candidate 3591/// set. If OnlyViable is true, only viable candidates will be printed. 3592void 3593Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3594 bool OnlyViable) 3595{ 3596 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3597 LastCand = CandidateSet.end(); 3598 for (; Cand != LastCand; ++Cand) { 3599 if (Cand->Viable || !OnlyViable) { 3600 if (Cand->Function) { 3601 if (Cand->Function->isDeleted() || 3602 Cand->Function->getAttr<UnavailableAttr>()) { 3603 // Deleted or "unavailable" function. 3604 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3605 << Cand->Function->isDeleted(); 3606 } else { 3607 // Normal function 3608 // FIXME: Give a better reason! 3609 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3610 } 3611 } else if (Cand->IsSurrogate) { 3612 // Desugar the type of the surrogate down to a function type, 3613 // retaining as many typedefs as possible while still showing 3614 // the function type (and, therefore, its parameter types). 3615 QualType FnType = Cand->Surrogate->getConversionType(); 3616 bool isLValueReference = false; 3617 bool isRValueReference = false; 3618 bool isPointer = false; 3619 if (const LValueReferenceType *FnTypeRef = 3620 FnType->getAsLValueReferenceType()) { 3621 FnType = FnTypeRef->getPointeeType(); 3622 isLValueReference = true; 3623 } else if (const RValueReferenceType *FnTypeRef = 3624 FnType->getAsRValueReferenceType()) { 3625 FnType = FnTypeRef->getPointeeType(); 3626 isRValueReference = true; 3627 } 3628 if (const PointerType *FnTypePtr = FnType->getAsPointerType()) { 3629 FnType = FnTypePtr->getPointeeType(); 3630 isPointer = true; 3631 } 3632 // Desugar down to a function type. 3633 FnType = QualType(FnType->getAsFunctionType(), 0); 3634 // Reconstruct the pointer/reference as appropriate. 3635 if (isPointer) FnType = Context.getPointerType(FnType); 3636 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3637 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3638 3639 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3640 << FnType; 3641 } else { 3642 // FIXME: We need to get the identifier in here 3643 // FIXME: Do we want the error message to point at the operator? 3644 // (built-ins won't have a location) 3645 QualType FnType 3646 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3647 Cand->BuiltinTypes.ParamTypes, 3648 Cand->Conversions.size(), 3649 false, 0); 3650 3651 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3652 } 3653 } 3654 } 3655} 3656 3657/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3658/// an overloaded function (C++ [over.over]), where @p From is an 3659/// expression with overloaded function type and @p ToType is the type 3660/// we're trying to resolve to. For example: 3661/// 3662/// @code 3663/// int f(double); 3664/// int f(int); 3665/// 3666/// int (*pfd)(double) = f; // selects f(double) 3667/// @endcode 3668/// 3669/// This routine returns the resulting FunctionDecl if it could be 3670/// resolved, and NULL otherwise. When @p Complain is true, this 3671/// routine will emit diagnostics if there is an error. 3672FunctionDecl * 3673Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3674 bool Complain) { 3675 QualType FunctionType = ToType; 3676 bool IsMember = false; 3677 if (const PointerType *ToTypePtr = ToType->getAsPointerType()) 3678 FunctionType = ToTypePtr->getPointeeType(); 3679 else if (const ReferenceType *ToTypeRef = ToType->getAsReferenceType()) 3680 FunctionType = ToTypeRef->getPointeeType(); 3681 else if (const MemberPointerType *MemTypePtr = 3682 ToType->getAsMemberPointerType()) { 3683 FunctionType = MemTypePtr->getPointeeType(); 3684 IsMember = true; 3685 } 3686 3687 // We only look at pointers or references to functions. 3688 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 3689 if (!FunctionType->isFunctionType()) 3690 return 0; 3691 3692 // Find the actual overloaded function declaration. 3693 OverloadedFunctionDecl *Ovl = 0; 3694 3695 // C++ [over.over]p1: 3696 // [...] [Note: any redundant set of parentheses surrounding the 3697 // overloaded function name is ignored (5.1). ] 3698 Expr *OvlExpr = From->IgnoreParens(); 3699 3700 // C++ [over.over]p1: 3701 // [...] The overloaded function name can be preceded by the & 3702 // operator. 3703 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3704 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3705 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3706 } 3707 3708 // Try to dig out the overloaded function. 3709 FunctionTemplateDecl *FunctionTemplate = 0; 3710 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 3711 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 3712 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 3713 } 3714 3715 // If there's no overloaded function declaration or function template, 3716 // we're done. 3717 if (!Ovl && !FunctionTemplate) 3718 return 0; 3719 3720 OverloadIterator Fun; 3721 if (Ovl) 3722 Fun = Ovl; 3723 else 3724 Fun = FunctionTemplate; 3725 3726 // Look through all of the overloaded functions, searching for one 3727 // whose type matches exactly. 3728 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 3729 3730 bool FoundNonTemplateFunction = false; 3731 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 3732 // C++ [over.over]p3: 3733 // Non-member functions and static member functions match 3734 // targets of type "pointer-to-function" or "reference-to-function." 3735 // Nonstatic member functions match targets of 3736 // type "pointer-to-member-function." 3737 // Note that according to DR 247, the containing class does not matter. 3738 3739 if (FunctionTemplateDecl *FunctionTemplate 3740 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 3741 if (CXXMethodDecl *Method 3742 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 3743 // Skip non-static function templates when converting to pointer, and 3744 // static when converting to member pointer. 3745 if (Method->isStatic() == IsMember) 3746 continue; 3747 } else if (IsMember) 3748 continue; 3749 3750 // C++ [over.over]p2: 3751 // If the name is a function template, template argument deduction is 3752 // done (14.8.2.2), and if the argument deduction succeeds, the 3753 // resulting template argument list is used to generate a single 3754 // function template specialization, which is added to the set of 3755 // overloaded functions considered. 3756 FunctionDecl *Specialization = 0; 3757 TemplateDeductionInfo Info(Context); 3758 if (TemplateDeductionResult Result 3759 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 3760 /*FIXME:*/0, /*FIXME:*/0, 3761 FunctionType, Specialization, Info)) { 3762 // FIXME: make a note of the failed deduction for diagnostics. 3763 (void)Result; 3764 } else { 3765 assert(FunctionType 3766 == Context.getCanonicalType(Specialization->getType())); 3767 Matches.insert( 3768 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 3769 } 3770 } 3771 3772 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 3773 // Skip non-static functions when converting to pointer, and static 3774 // when converting to member pointer. 3775 if (Method->isStatic() == IsMember) 3776 continue; 3777 } else if (IsMember) 3778 continue; 3779 3780 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 3781 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 3782 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 3783 FoundNonTemplateFunction = true; 3784 } 3785 } 3786 } 3787 3788 // If there were 0 or 1 matches, we're done. 3789 if (Matches.empty()) 3790 return 0; 3791 else if (Matches.size() == 1) 3792 return *Matches.begin(); 3793 3794 // C++ [over.over]p4: 3795 // If more than one function is selected, [...] 3796 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 3797 if (FoundNonTemplateFunction) { 3798 // [...] any function template specializations in the set are eliminated 3799 // if the set also contains a non-template function, [...] 3800 for (llvm::SmallPtrSet<FunctionDecl *, 4>::iterator M = Matches.begin(), 3801 MEnd = Matches.end(); 3802 M != MEnd; ++M) 3803 if ((*M)->getPrimaryTemplate() == 0) 3804 RemainingMatches.push_back(*M); 3805 } else { 3806 // [...] and any given function template specialization F1 is eliminated 3807 // if the set contains a second function template specialization whose 3808 // function template is more specialized than the function template of F1 3809 // according to the partial ordering rules of 14.5.5.2. 3810 // FIXME: Implement this! 3811 RemainingMatches.append(Matches.begin(), Matches.end()); 3812 } 3813 3814 // [...] After such eliminations, if any, there shall remain exactly one 3815 // selected function. 3816 if (RemainingMatches.size() == 1) 3817 return RemainingMatches.front(); 3818 3819 // FIXME: We should probably return the same thing that BestViableFunction 3820 // returns (even if we issue the diagnostics here). 3821 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 3822 << RemainingMatches[0]->getDeclName(); 3823 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 3824 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 3825 return 0; 3826} 3827 3828/// ResolveOverloadedCallFn - Given the call expression that calls Fn 3829/// (which eventually refers to the declaration Func) and the call 3830/// arguments Args/NumArgs, attempt to resolve the function call down 3831/// to a specific function. If overload resolution succeeds, returns 3832/// the function declaration produced by overload 3833/// resolution. Otherwise, emits diagnostics, deletes all of the 3834/// arguments and Fn, and returns NULL. 3835FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 3836 DeclarationName UnqualifiedName, 3837 bool HasExplicitTemplateArgs, 3838 const TemplateArgument *ExplicitTemplateArgs, 3839 unsigned NumExplicitTemplateArgs, 3840 SourceLocation LParenLoc, 3841 Expr **Args, unsigned NumArgs, 3842 SourceLocation *CommaLocs, 3843 SourceLocation RParenLoc, 3844 bool &ArgumentDependentLookup) { 3845 OverloadCandidateSet CandidateSet; 3846 3847 // Add the functions denoted by Callee to the set of candidate 3848 // functions. While we're doing so, track whether argument-dependent 3849 // lookup still applies, per: 3850 // 3851 // C++0x [basic.lookup.argdep]p3: 3852 // Let X be the lookup set produced by unqualified lookup (3.4.1) 3853 // and let Y be the lookup set produced by argument dependent 3854 // lookup (defined as follows). If X contains 3855 // 3856 // -- a declaration of a class member, or 3857 // 3858 // -- a block-scope function declaration that is not a 3859 // using-declaration, or 3860 // 3861 // -- a declaration that is neither a function or a function 3862 // template 3863 // 3864 // then Y is empty. 3865 if (OverloadedFunctionDecl *Ovl 3866 = dyn_cast_or_null<OverloadedFunctionDecl>(Callee)) { 3867 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 3868 FuncEnd = Ovl->function_end(); 3869 Func != FuncEnd; ++Func) { 3870 DeclContext *Ctx = 0; 3871 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Func)) { 3872 if (HasExplicitTemplateArgs) 3873 continue; 3874 3875 AddOverloadCandidate(FunDecl, Args, NumArgs, CandidateSet); 3876 Ctx = FunDecl->getDeclContext(); 3877 } else { 3878 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*Func); 3879 AddTemplateOverloadCandidate(FunTmpl, HasExplicitTemplateArgs, 3880 ExplicitTemplateArgs, 3881 NumExplicitTemplateArgs, 3882 Args, NumArgs, CandidateSet); 3883 Ctx = FunTmpl->getDeclContext(); 3884 } 3885 3886 3887 if (Ctx->isRecord() || Ctx->isFunctionOrMethod()) 3888 ArgumentDependentLookup = false; 3889 } 3890 } else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee)) { 3891 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 3892 AddOverloadCandidate(Func, Args, NumArgs, CandidateSet); 3893 3894 if (Func->getDeclContext()->isRecord() || 3895 Func->getDeclContext()->isFunctionOrMethod()) 3896 ArgumentDependentLookup = false; 3897 } else if (FunctionTemplateDecl *FuncTemplate 3898 = dyn_cast_or_null<FunctionTemplateDecl>(Callee)) { 3899 AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 3900 ExplicitTemplateArgs, 3901 NumExplicitTemplateArgs, 3902 Args, NumArgs, CandidateSet); 3903 3904 if (FuncTemplate->getDeclContext()->isRecord()) 3905 ArgumentDependentLookup = false; 3906 } 3907 3908 if (Callee) 3909 UnqualifiedName = Callee->getDeclName(); 3910 3911 // FIXME: Pass explicit template arguments through for ADL 3912 if (ArgumentDependentLookup) 3913 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 3914 CandidateSet); 3915 3916 OverloadCandidateSet::iterator Best; 3917 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 3918 case OR_Success: 3919 return Best->Function; 3920 3921 case OR_No_Viable_Function: 3922 Diag(Fn->getSourceRange().getBegin(), 3923 diag::err_ovl_no_viable_function_in_call) 3924 << UnqualifiedName << Fn->getSourceRange(); 3925 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 3926 break; 3927 3928 case OR_Ambiguous: 3929 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 3930 << UnqualifiedName << Fn->getSourceRange(); 3931 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3932 break; 3933 3934 case OR_Deleted: 3935 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 3936 << Best->Function->isDeleted() 3937 << UnqualifiedName 3938 << Fn->getSourceRange(); 3939 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 3940 break; 3941 } 3942 3943 // Overload resolution failed. Destroy all of the subexpressions and 3944 // return NULL. 3945 Fn->Destroy(Context); 3946 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 3947 Args[Arg]->Destroy(Context); 3948 return 0; 3949} 3950 3951/// \brief Create a unary operation that may resolve to an overloaded 3952/// operator. 3953/// 3954/// \param OpLoc The location of the operator itself (e.g., '*'). 3955/// 3956/// \param OpcIn The UnaryOperator::Opcode that describes this 3957/// operator. 3958/// 3959/// \param Functions The set of non-member functions that will be 3960/// considered by overload resolution. The caller needs to build this 3961/// set based on the context using, e.g., 3962/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 3963/// set should not contain any member functions; those will be added 3964/// by CreateOverloadedUnaryOp(). 3965/// 3966/// \param input The input argument. 3967Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 3968 unsigned OpcIn, 3969 FunctionSet &Functions, 3970 ExprArg input) { 3971 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 3972 Expr *Input = (Expr *)input.get(); 3973 3974 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 3975 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 3976 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3977 3978 Expr *Args[2] = { Input, 0 }; 3979 unsigned NumArgs = 1; 3980 3981 // For post-increment and post-decrement, add the implicit '0' as 3982 // the second argument, so that we know this is a post-increment or 3983 // post-decrement. 3984 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 3985 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 3986 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 3987 SourceLocation()); 3988 NumArgs = 2; 3989 } 3990 3991 if (Input->isTypeDependent()) { 3992 OverloadedFunctionDecl *Overloads 3993 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 3994 for (FunctionSet::iterator Func = Functions.begin(), 3995 FuncEnd = Functions.end(); 3996 Func != FuncEnd; ++Func) 3997 Overloads->addOverload(*Func); 3998 3999 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4000 OpLoc, false, false); 4001 4002 input.release(); 4003 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4004 &Args[0], NumArgs, 4005 Context.DependentTy, 4006 OpLoc)); 4007 } 4008 4009 // Build an empty overload set. 4010 OverloadCandidateSet CandidateSet; 4011 4012 // Add the candidates from the given function set. 4013 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4014 4015 // Add operator candidates that are member functions. 4016 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4017 4018 // Add builtin operator candidates. 4019 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4020 4021 // Perform overload resolution. 4022 OverloadCandidateSet::iterator Best; 4023 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4024 case OR_Success: { 4025 // We found a built-in operator or an overloaded operator. 4026 FunctionDecl *FnDecl = Best->Function; 4027 4028 if (FnDecl) { 4029 // We matched an overloaded operator. Build a call to that 4030 // operator. 4031 4032 // Convert the arguments. 4033 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4034 if (PerformObjectArgumentInitialization(Input, Method)) 4035 return ExprError(); 4036 } else { 4037 // Convert the arguments. 4038 if (PerformCopyInitialization(Input, 4039 FnDecl->getParamDecl(0)->getType(), 4040 "passing")) 4041 return ExprError(); 4042 } 4043 4044 // Determine the result type 4045 QualType ResultTy 4046 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4047 ResultTy = ResultTy.getNonReferenceType(); 4048 4049 // Build the actual expression node. 4050 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4051 SourceLocation()); 4052 UsualUnaryConversions(FnExpr); 4053 4054 input.release(); 4055 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4056 &Input, 1, ResultTy, 4057 OpLoc)); 4058 } else { 4059 // We matched a built-in operator. Convert the arguments, then 4060 // break out so that we will build the appropriate built-in 4061 // operator node. 4062 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4063 Best->Conversions[0], "passing")) 4064 return ExprError(); 4065 4066 break; 4067 } 4068 } 4069 4070 case OR_No_Viable_Function: 4071 // No viable function; fall through to handling this as a 4072 // built-in operator, which will produce an error message for us. 4073 break; 4074 4075 case OR_Ambiguous: 4076 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4077 << UnaryOperator::getOpcodeStr(Opc) 4078 << Input->getSourceRange(); 4079 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4080 return ExprError(); 4081 4082 case OR_Deleted: 4083 Diag(OpLoc, diag::err_ovl_deleted_oper) 4084 << Best->Function->isDeleted() 4085 << UnaryOperator::getOpcodeStr(Opc) 4086 << Input->getSourceRange(); 4087 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4088 return ExprError(); 4089 } 4090 4091 // Either we found no viable overloaded operator or we matched a 4092 // built-in operator. In either case, fall through to trying to 4093 // build a built-in operation. 4094 input.release(); 4095 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4096} 4097 4098/// \brief Create a binary operation that may resolve to an overloaded 4099/// operator. 4100/// 4101/// \param OpLoc The location of the operator itself (e.g., '+'). 4102/// 4103/// \param OpcIn The BinaryOperator::Opcode that describes this 4104/// operator. 4105/// 4106/// \param Functions The set of non-member functions that will be 4107/// considered by overload resolution. The caller needs to build this 4108/// set based on the context using, e.g., 4109/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4110/// set should not contain any member functions; those will be added 4111/// by CreateOverloadedBinOp(). 4112/// 4113/// \param LHS Left-hand argument. 4114/// \param RHS Right-hand argument. 4115Sema::OwningExprResult 4116Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4117 unsigned OpcIn, 4118 FunctionSet &Functions, 4119 Expr *LHS, Expr *RHS) { 4120 Expr *Args[2] = { LHS, RHS }; 4121 4122 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4123 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4124 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4125 4126 // If either side is type-dependent, create an appropriate dependent 4127 // expression. 4128 if (LHS->isTypeDependent() || RHS->isTypeDependent()) { 4129 // .* cannot be overloaded. 4130 if (Opc == BinaryOperator::PtrMemD) 4131 return Owned(new (Context) BinaryOperator(LHS, RHS, Opc, 4132 Context.DependentTy, OpLoc)); 4133 4134 OverloadedFunctionDecl *Overloads 4135 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4136 for (FunctionSet::iterator Func = Functions.begin(), 4137 FuncEnd = Functions.end(); 4138 Func != FuncEnd; ++Func) 4139 Overloads->addOverload(*Func); 4140 4141 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4142 OpLoc, false, false); 4143 4144 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4145 Args, 2, 4146 Context.DependentTy, 4147 OpLoc)); 4148 } 4149 4150 // If this is the .* operator, which is not overloadable, just 4151 // create a built-in binary operator. 4152 if (Opc == BinaryOperator::PtrMemD) 4153 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4154 4155 // If this is one of the assignment operators, we only perform 4156 // overload resolution if the left-hand side is a class or 4157 // enumeration type (C++ [expr.ass]p3). 4158 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4159 !LHS->getType()->isOverloadableType()) 4160 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4161 4162 // Build an empty overload set. 4163 OverloadCandidateSet CandidateSet; 4164 4165 // Add the candidates from the given function set. 4166 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4167 4168 // Add operator candidates that are member functions. 4169 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4170 4171 // Add builtin operator candidates. 4172 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4173 4174 // Perform overload resolution. 4175 OverloadCandidateSet::iterator Best; 4176 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4177 case OR_Success: { 4178 // We found a built-in operator or an overloaded operator. 4179 FunctionDecl *FnDecl = Best->Function; 4180 4181 if (FnDecl) { 4182 // We matched an overloaded operator. Build a call to that 4183 // operator. 4184 4185 // Convert the arguments. 4186 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4187 if (PerformObjectArgumentInitialization(LHS, Method) || 4188 PerformCopyInitialization(RHS, FnDecl->getParamDecl(0)->getType(), 4189 "passing")) 4190 return ExprError(); 4191 } else { 4192 // Convert the arguments. 4193 if (PerformCopyInitialization(LHS, FnDecl->getParamDecl(0)->getType(), 4194 "passing") || 4195 PerformCopyInitialization(RHS, FnDecl->getParamDecl(1)->getType(), 4196 "passing")) 4197 return ExprError(); 4198 } 4199 4200 // Determine the result type 4201 QualType ResultTy 4202 = FnDecl->getType()->getAsFunctionType()->getResultType(); 4203 ResultTy = ResultTy.getNonReferenceType(); 4204 4205 // Build the actual expression node. 4206 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4207 OpLoc); 4208 UsualUnaryConversions(FnExpr); 4209 4210 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4211 Args, 2, ResultTy, 4212 OpLoc)); 4213 } else { 4214 // We matched a built-in operator. Convert the arguments, then 4215 // break out so that we will build the appropriate built-in 4216 // operator node. 4217 if (PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0], 4218 Best->Conversions[0], "passing") || 4219 PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1], 4220 Best->Conversions[1], "passing")) 4221 return ExprError(); 4222 4223 break; 4224 } 4225 } 4226 4227 case OR_No_Viable_Function: 4228 // For class as left operand for assignment or compound assigment operator 4229 // do not fall through to handling in built-in, but report that no overloaded 4230 // assignment operator found 4231 if (LHS->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4232 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4233 << BinaryOperator::getOpcodeStr(Opc) 4234 << LHS->getSourceRange() << RHS->getSourceRange(); 4235 return ExprError(); 4236 } 4237 // No viable function; fall through to handling this as a 4238 // built-in operator, which will produce an error message for us. 4239 break; 4240 4241 case OR_Ambiguous: 4242 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4243 << BinaryOperator::getOpcodeStr(Opc) 4244 << LHS->getSourceRange() << RHS->getSourceRange(); 4245 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4246 return ExprError(); 4247 4248 case OR_Deleted: 4249 Diag(OpLoc, diag::err_ovl_deleted_oper) 4250 << Best->Function->isDeleted() 4251 << BinaryOperator::getOpcodeStr(Opc) 4252 << LHS->getSourceRange() << RHS->getSourceRange(); 4253 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4254 return ExprError(); 4255 } 4256 4257 // Either we found no viable overloaded operator or we matched a 4258 // built-in operator. In either case, try to build a built-in 4259 // operation. 4260 return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS); 4261} 4262 4263/// BuildCallToMemberFunction - Build a call to a member 4264/// function. MemExpr is the expression that refers to the member 4265/// function (and includes the object parameter), Args/NumArgs are the 4266/// arguments to the function call (not including the object 4267/// parameter). The caller needs to validate that the member 4268/// expression refers to a member function or an overloaded member 4269/// function. 4270Sema::ExprResult 4271Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4272 SourceLocation LParenLoc, Expr **Args, 4273 unsigned NumArgs, SourceLocation *CommaLocs, 4274 SourceLocation RParenLoc) { 4275 // Dig out the member expression. This holds both the object 4276 // argument and the member function we're referring to. 4277 MemberExpr *MemExpr = 0; 4278 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4279 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4280 else 4281 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4282 assert(MemExpr && "Building member call without member expression"); 4283 4284 // Extract the object argument. 4285 Expr *ObjectArg = MemExpr->getBase(); 4286 4287 CXXMethodDecl *Method = 0; 4288 if (OverloadedFunctionDecl *Ovl 4289 = dyn_cast<OverloadedFunctionDecl>(MemExpr->getMemberDecl())) { 4290 // Add overload candidates 4291 OverloadCandidateSet CandidateSet; 4292 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4293 FuncEnd = Ovl->function_end(); 4294 Func != FuncEnd; ++Func) { 4295 assert(isa<CXXMethodDecl>(*Func) && "Function is not a method"); 4296 Method = cast<CXXMethodDecl>(*Func); 4297 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4298 /*SuppressUserConversions=*/false); 4299 } 4300 4301 OverloadCandidateSet::iterator Best; 4302 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4303 case OR_Success: 4304 Method = cast<CXXMethodDecl>(Best->Function); 4305 break; 4306 4307 case OR_No_Viable_Function: 4308 Diag(MemExpr->getSourceRange().getBegin(), 4309 diag::err_ovl_no_viable_member_function_in_call) 4310 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4311 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4312 // FIXME: Leaking incoming expressions! 4313 return true; 4314 4315 case OR_Ambiguous: 4316 Diag(MemExpr->getSourceRange().getBegin(), 4317 diag::err_ovl_ambiguous_member_call) 4318 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4319 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4320 // FIXME: Leaking incoming expressions! 4321 return true; 4322 4323 case OR_Deleted: 4324 Diag(MemExpr->getSourceRange().getBegin(), 4325 diag::err_ovl_deleted_member_call) 4326 << Best->Function->isDeleted() 4327 << Ovl->getDeclName() << MemExprE->getSourceRange(); 4328 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4329 // FIXME: Leaking incoming expressions! 4330 return true; 4331 } 4332 4333 FixOverloadedFunctionReference(MemExpr, Method); 4334 } else { 4335 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4336 } 4337 4338 assert(Method && "Member call to something that isn't a method?"); 4339 ExprOwningPtr<CXXMemberCallExpr> 4340 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4341 NumArgs, 4342 Method->getResultType().getNonReferenceType(), 4343 RParenLoc)); 4344 4345 // Convert the object argument (for a non-static member function call). 4346 if (!Method->isStatic() && 4347 PerformObjectArgumentInitialization(ObjectArg, Method)) 4348 return true; 4349 MemExpr->setBase(ObjectArg); 4350 4351 // Convert the rest of the arguments 4352 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4353 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4354 RParenLoc)) 4355 return true; 4356 4357 return CheckFunctionCall(Method, TheCall.take()).release(); 4358} 4359 4360/// BuildCallToObjectOfClassType - Build a call to an object of class 4361/// type (C++ [over.call.object]), which can end up invoking an 4362/// overloaded function call operator (@c operator()) or performing a 4363/// user-defined conversion on the object argument. 4364Sema::ExprResult 4365Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4366 SourceLocation LParenLoc, 4367 Expr **Args, unsigned NumArgs, 4368 SourceLocation *CommaLocs, 4369 SourceLocation RParenLoc) { 4370 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4371 const RecordType *Record = Object->getType()->getAsRecordType(); 4372 4373 // C++ [over.call.object]p1: 4374 // If the primary-expression E in the function call syntax 4375 // evaluates to a class object of type “cv T”, then the set of 4376 // candidate functions includes at least the function call 4377 // operators of T. The function call operators of T are obtained by 4378 // ordinary lookup of the name operator() in the context of 4379 // (E).operator(). 4380 OverloadCandidateSet CandidateSet; 4381 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4382 DeclContext::lookup_const_iterator Oper, OperEnd; 4383 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4384 Oper != OperEnd; ++Oper) 4385 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4386 CandidateSet, /*SuppressUserConversions=*/false); 4387 4388 // C++ [over.call.object]p2: 4389 // In addition, for each conversion function declared in T of the 4390 // form 4391 // 4392 // operator conversion-type-id () cv-qualifier; 4393 // 4394 // where cv-qualifier is the same cv-qualification as, or a 4395 // greater cv-qualification than, cv, and where conversion-type-id 4396 // denotes the type "pointer to function of (P1,...,Pn) returning 4397 // R", or the type "reference to pointer to function of 4398 // (P1,...,Pn) returning R", or the type "reference to function 4399 // of (P1,...,Pn) returning R", a surrogate call function [...] 4400 // is also considered as a candidate function. Similarly, 4401 // surrogate call functions are added to the set of candidate 4402 // functions for each conversion function declared in an 4403 // accessible base class provided the function is not hidden 4404 // within T by another intervening declaration. 4405 // 4406 // FIXME: Look in base classes for more conversion operators! 4407 OverloadedFunctionDecl *Conversions 4408 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4409 for (OverloadedFunctionDecl::function_iterator 4410 Func = Conversions->function_begin(), 4411 FuncEnd = Conversions->function_end(); 4412 Func != FuncEnd; ++Func) { 4413 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); 4414 4415 // Strip the reference type (if any) and then the pointer type (if 4416 // any) to get down to what might be a function type. 4417 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4418 if (const PointerType *ConvPtrType = ConvType->getAsPointerType()) 4419 ConvType = ConvPtrType->getPointeeType(); 4420 4421 if (const FunctionProtoType *Proto = ConvType->getAsFunctionProtoType()) 4422 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4423 } 4424 4425 // Perform overload resolution. 4426 OverloadCandidateSet::iterator Best; 4427 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4428 case OR_Success: 4429 // Overload resolution succeeded; we'll build the appropriate call 4430 // below. 4431 break; 4432 4433 case OR_No_Viable_Function: 4434 Diag(Object->getSourceRange().getBegin(), 4435 diag::err_ovl_no_viable_object_call) 4436 << Object->getType() << Object->getSourceRange(); 4437 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4438 break; 4439 4440 case OR_Ambiguous: 4441 Diag(Object->getSourceRange().getBegin(), 4442 diag::err_ovl_ambiguous_object_call) 4443 << Object->getType() << Object->getSourceRange(); 4444 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4445 break; 4446 4447 case OR_Deleted: 4448 Diag(Object->getSourceRange().getBegin(), 4449 diag::err_ovl_deleted_object_call) 4450 << Best->Function->isDeleted() 4451 << Object->getType() << Object->getSourceRange(); 4452 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4453 break; 4454 } 4455 4456 if (Best == CandidateSet.end()) { 4457 // We had an error; delete all of the subexpressions and return 4458 // the error. 4459 Object->Destroy(Context); 4460 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4461 Args[ArgIdx]->Destroy(Context); 4462 return true; 4463 } 4464 4465 if (Best->Function == 0) { 4466 // Since there is no function declaration, this is one of the 4467 // surrogate candidates. Dig out the conversion function. 4468 CXXConversionDecl *Conv 4469 = cast<CXXConversionDecl>( 4470 Best->Conversions[0].UserDefined.ConversionFunction); 4471 4472 // We selected one of the surrogate functions that converts the 4473 // object parameter to a function pointer. Perform the conversion 4474 // on the object argument, then let ActOnCallExpr finish the job. 4475 // FIXME: Represent the user-defined conversion in the AST! 4476 ImpCastExprToType(Object, 4477 Conv->getConversionType().getNonReferenceType(), 4478 Conv->getConversionType()->isLValueReferenceType()); 4479 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4480 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4481 CommaLocs, RParenLoc).release(); 4482 } 4483 4484 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4485 // that calls this method, using Object for the implicit object 4486 // parameter and passing along the remaining arguments. 4487 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4488 const FunctionProtoType *Proto = Method->getType()->getAsFunctionProtoType(); 4489 4490 unsigned NumArgsInProto = Proto->getNumArgs(); 4491 unsigned NumArgsToCheck = NumArgs; 4492 4493 // Build the full argument list for the method call (the 4494 // implicit object parameter is placed at the beginning of the 4495 // list). 4496 Expr **MethodArgs; 4497 if (NumArgs < NumArgsInProto) { 4498 NumArgsToCheck = NumArgsInProto; 4499 MethodArgs = new Expr*[NumArgsInProto + 1]; 4500 } else { 4501 MethodArgs = new Expr*[NumArgs + 1]; 4502 } 4503 MethodArgs[0] = Object; 4504 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4505 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4506 4507 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4508 SourceLocation()); 4509 UsualUnaryConversions(NewFn); 4510 4511 // Once we've built TheCall, all of the expressions are properly 4512 // owned. 4513 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4514 ExprOwningPtr<CXXOperatorCallExpr> 4515 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4516 MethodArgs, NumArgs + 1, 4517 ResultTy, RParenLoc)); 4518 delete [] MethodArgs; 4519 4520 // We may have default arguments. If so, we need to allocate more 4521 // slots in the call for them. 4522 if (NumArgs < NumArgsInProto) 4523 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4524 else if (NumArgs > NumArgsInProto) 4525 NumArgsToCheck = NumArgsInProto; 4526 4527 bool IsError = false; 4528 4529 // Initialize the implicit object parameter. 4530 IsError |= PerformObjectArgumentInitialization(Object, Method); 4531 TheCall->setArg(0, Object); 4532 4533 4534 // Check the argument types. 4535 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4536 Expr *Arg; 4537 if (i < NumArgs) { 4538 Arg = Args[i]; 4539 4540 // Pass the argument. 4541 QualType ProtoArgType = Proto->getArgType(i); 4542 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4543 } else { 4544 Arg = new (Context) CXXDefaultArgExpr(Method->getParamDecl(i)); 4545 } 4546 4547 TheCall->setArg(i + 1, Arg); 4548 } 4549 4550 // If this is a variadic call, handle args passed through "...". 4551 if (Proto->isVariadic()) { 4552 // Promote the arguments (C99 6.5.2.2p7). 4553 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4554 Expr *Arg = Args[i]; 4555 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4556 TheCall->setArg(i + 1, Arg); 4557 } 4558 } 4559 4560 if (IsError) return true; 4561 4562 return CheckFunctionCall(Method, TheCall.take()).release(); 4563} 4564 4565/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4566/// (if one exists), where @c Base is an expression of class type and 4567/// @c Member is the name of the member we're trying to find. 4568Action::ExprResult 4569Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc, 4570 SourceLocation MemberLoc, 4571 IdentifierInfo &Member) { 4572 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4573 4574 // C++ [over.ref]p1: 4575 // 4576 // [...] An expression x->m is interpreted as (x.operator->())->m 4577 // for a class object x of type T if T::operator->() exists and if 4578 // the operator is selected as the best match function by the 4579 // overload resolution mechanism (13.3). 4580 // FIXME: look in base classes. 4581 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4582 OverloadCandidateSet CandidateSet; 4583 const RecordType *BaseRecord = Base->getType()->getAsRecordType(); 4584 4585 DeclContext::lookup_const_iterator Oper, OperEnd; 4586 for (llvm::tie(Oper, OperEnd) 4587 = BaseRecord->getDecl()->lookup(OpName); Oper != OperEnd; ++Oper) 4588 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4589 /*SuppressUserConversions=*/false); 4590 4591 ExprOwningPtr<Expr> BasePtr(this, Base); 4592 4593 // Perform overload resolution. 4594 OverloadCandidateSet::iterator Best; 4595 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4596 case OR_Success: 4597 // Overload resolution succeeded; we'll build the call below. 4598 break; 4599 4600 case OR_No_Viable_Function: 4601 if (CandidateSet.empty()) 4602 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4603 << BasePtr->getType() << BasePtr->getSourceRange(); 4604 else 4605 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4606 << "operator->" << BasePtr->getSourceRange(); 4607 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4608 return true; 4609 4610 case OR_Ambiguous: 4611 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4612 << "operator->" << BasePtr->getSourceRange(); 4613 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4614 return true; 4615 4616 case OR_Deleted: 4617 Diag(OpLoc, diag::err_ovl_deleted_oper) 4618 << Best->Function->isDeleted() 4619 << "operator->" << BasePtr->getSourceRange(); 4620 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4621 return true; 4622 } 4623 4624 // Convert the object parameter. 4625 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4626 if (PerformObjectArgumentInitialization(Base, Method)) 4627 return true; 4628 4629 // No concerns about early exits now. 4630 BasePtr.take(); 4631 4632 // Build the operator call. 4633 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 4634 SourceLocation()); 4635 UsualUnaryConversions(FnExpr); 4636 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 4637 Method->getResultType().getNonReferenceType(), 4638 OpLoc); 4639 return ActOnMemberReferenceExpr(S, ExprArg(*this, Base), OpLoc, tok::arrow, 4640 MemberLoc, Member, DeclPtrTy()).release(); 4641} 4642 4643/// FixOverloadedFunctionReference - E is an expression that refers to 4644/// a C++ overloaded function (possibly with some parentheses and 4645/// perhaps a '&' around it). We have resolved the overloaded function 4646/// to the function declaration Fn, so patch up the expression E to 4647/// refer (possibly indirectly) to Fn. 4648void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 4649 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4650 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 4651 E->setType(PE->getSubExpr()->getType()); 4652 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 4653 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 4654 "Can only take the address of an overloaded function"); 4655 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4656 if (Method->isStatic()) { 4657 // Do nothing: static member functions aren't any different 4658 // from non-member functions. 4659 } 4660 else if (QualifiedDeclRefExpr *DRE 4661 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 4662 // We have taken the address of a pointer to member 4663 // function. Perform the computation here so that we get the 4664 // appropriate pointer to member type. 4665 DRE->setDecl(Fn); 4666 DRE->setType(Fn->getType()); 4667 QualType ClassType 4668 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 4669 E->setType(Context.getMemberPointerType(Fn->getType(), 4670 ClassType.getTypePtr())); 4671 return; 4672 } 4673 } 4674 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 4675 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 4676 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 4677 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 4678 isa<FunctionTemplateDecl>(DR->getDecl())) && 4679 "Expected overloaded function or function template"); 4680 DR->setDecl(Fn); 4681 E->setType(Fn->getType()); 4682 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 4683 MemExpr->setMemberDecl(Fn); 4684 E->setType(Fn->getType()); 4685 } else { 4686 assert(false && "Invalid reference to overloaded function"); 4687 } 4688} 4689 4690} // end namespace clang 4691