llvm/clang/include/clang/Sema/Overload.h

//===- Overload.h - C++ Overloading -----------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the data structures and types used in C++
// overload resolution.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_SEMA_OVERLOAD_H
#define LLVM_CLANG_SEMA_OVERLOAD_H

#include "clang/AST/Decl.h"
#include "clang/AST/DeclAccessPair.h"
#include "clang/AST/DeclBase.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/Expr.h"
#include "clang/AST/Type.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Sema/SemaFixItUtils.h"
#include "clang/Sema/TemplateDeduction.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/AlignOf.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <utility>

namespace clang {

class APValue;
class ASTContext;
class Sema;

  /// OverloadingResult - Capture the result of performing overload
  /// resolution.
  enum OverloadingResult { … };

  enum OverloadCandidateDisplayKind { … };

  /// The parameter ordering that will be used for the candidate. This is
  /// used to represent C++20 binary operator rewrites that reverse the order
  /// of the arguments. If the parameter ordering is Reversed, the Args list is
  /// reversed (but obviously the ParamDecls for the function are not).
  ///
  /// After forming an OverloadCandidate with reversed parameters, the list
  /// of conversions will (as always) be indexed by argument, so will be
  /// in reverse parameter order.
  enum class OverloadCandidateParamOrder : char { … };

  /// The kinds of rewrite we perform on overload candidates. Note that the
  /// values here are chosen to serve as both bitflags and as a rank (lower
  /// values are preferred by overload resolution).
  enum OverloadCandidateRewriteKind : unsigned { … };

  /// ImplicitConversionKind - The kind of implicit conversion used to
  /// convert an argument to a parameter's type. The enumerator values
  /// match with the table titled 'Conversions' in [over.ics.scs] and are listed
  /// such that better conversion kinds have smaller values.
  enum ImplicitConversionKind { … };

  /// ImplicitConversionRank - The rank of an implicit conversion
  /// kind. The enumerator values match with Table 9 of (C++
  /// 13.3.3.1.1) and are listed such that better conversion ranks
  /// have smaller values.
  enum ImplicitConversionRank { … };

  ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind);

  ImplicitConversionRank
  GetDimensionConversionRank(ImplicitConversionRank Base,
                             ImplicitConversionKind Dimension);

  /// NarrowingKind - The kind of narrowing conversion being performed by a
  /// standard conversion sequence according to C++11 [dcl.init.list]p7.
  enum NarrowingKind { … };

  /// StandardConversionSequence - represents a standard conversion
  /// sequence (C++ 13.3.3.1.1). A standard conversion sequence
  /// contains between zero and three conversions. If a particular
  /// conversion is not needed, it will be set to the identity conversion
  /// (ICK_Identity).
  class StandardConversionSequence { … };

  /// UserDefinedConversionSequence - Represents a user-defined
  /// conversion sequence (C++ 13.3.3.1.2).
  struct UserDefinedConversionSequence { … };

  /// Represents an ambiguous user-defined conversion sequence.
  struct AmbiguousConversionSequence { … };

  /// BadConversionSequence - Records information about an invalid
  /// conversion sequence.
  struct BadConversionSequence { … };

  /// ImplicitConversionSequence - Represents an implicit conversion
  /// sequence, which may be a standard conversion sequence
  /// (C++ 13.3.3.1.1), user-defined conversion sequence (C++ 13.3.3.1.2),
  /// or an ellipsis conversion sequence (C++ 13.3.3.1.3).
  class ImplicitConversionSequence { … };

  enum OverloadFailureKind { … };

  /// A list of implicit conversion sequences for the arguments of an
  /// OverloadCandidate.
  ConversionSequenceList;

  /// OverloadCandidate - A single candidate in an overload set (C++ 13.3).
  struct OverloadCandidate { … };

  /// OverloadCandidateSet - A set of overload candidates, used in C++
  /// overload resolution (C++ 13.3).
  class OverloadCandidateSet { … };

  bool isBetterOverloadCandidate(Sema &S,
                                 const OverloadCandidate &Cand1,
                                 const OverloadCandidate &Cand2,
                                 SourceLocation Loc,
                                 OverloadCandidateSet::CandidateSetKind Kind);

  struct ConstructorInfo { … };

  // FIXME: Add an AddOverloadCandidate / AddTemplateOverloadCandidate overload
  // that takes one of these.
  inline ConstructorInfo getConstructorInfo(NamedDecl *ND) { … }

  // Returns false if signature help is relevant despite number of arguments
  // exceeding parameters. Specifically, it returns false when
  // PartialOverloading is true and one of the following:
  // * Function is variadic
  // * Function is template variadic
  // * Function is an instantiation of template variadic function
  // The last case may seem strange. The idea is that if we added one more
  // argument, we'd end up with a function similar to Function. Since, in the
  // context of signature help and/or code completion, we do not know what the
  // type of the next argument (that the user is typing) will be, this is as
  // good candidate as we can get, despite the fact that it takes one less
  // parameter.
  bool shouldEnforceArgLimit(bool PartialOverloading, FunctionDecl *Function);

} // namespace clang

#endif // LLVM_CLANG_SEMA_OVERLOAD_H