reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
    1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
//===-- Flags.h -------------------------------------------------*- 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
//
//===----------------------------------------------------------------------===//

#ifndef LLDB_UTILITY_FLAGS_H
#define LLDB_UTILITY_FLAGS_H

#include <cstddef>
#include <cstdint>

namespace lldb_private {

/// \class Flags Flags.h "lldb/Utility/Flags.h"
/// A class to manage flags.
///
/// The Flags class managed flag bits and allows testing and modification of
/// individual or multiple flag bits.
class Flags {
public:
  /// The value type for flags is a 32 bit unsigned integer type.
  typedef uint32_t ValueType;

  /// Construct with initial flag bit values.
  ///
  /// Constructs this object with \a mask as the initial value for all of the
  /// flags.
  ///
  /// \param[in] mask
  ///     The initial value for all flags.
  Flags(ValueType flags = 0) : m_flags(flags) {}

  /// Copy constructor.
  ///
  /// Construct and copy the flags from \a rhs.
  ///
  /// \param[in] rhs
  ///     A const Flags object reference to copy.
  Flags(const Flags &rhs) : m_flags(rhs.m_flags) {}

  /// Destructor.
  ~Flags() {}

  /// Get accessor for all flags.
  ///
  /// \return
  ///     Returns all of the flags as a Flags::ValueType.
  ValueType Get() const { return m_flags; }

  /// Return the number of flags that can be represented in this object.
  ///
  /// \return
  ///     The maximum number bits in this flag object.
  size_t GetBitSize() const { return sizeof(ValueType) * 8; }

  /// Set accessor for all flags.
  ///
  /// \param[in] flags
  ///     The bits with which to replace all of the current flags.
  void Reset(ValueType flags) { m_flags = flags; }

  /// Clear one or more flags.
  ///
  /// \param[in] mask
  ///     A bitfield containing one or more flags.
  ///
  /// \return
  ///     The new flags after clearing all bits from \a mask.
  ValueType Clear(ValueType mask = ~static_cast<ValueType>(0)) {
    m_flags &= ~mask;
    return m_flags;
  }

  /// Set one or more flags by logical OR'ing \a mask with the current flags.
  ///
  /// \param[in] mask
  ///     A bitfield containing one or more flags.
  ///
  /// \return
  ///     The new flags after setting all bits from \a mask.
  ValueType Set(ValueType mask) {
    m_flags |= mask;
    return m_flags;
  }

  /// Test if all bits in \a mask are 1 in the current flags
  ///
  /// \return
  ///     \b true if all flags in \a mask are 1, \b false
  ///     otherwise.
  bool AllSet(ValueType mask) const { return (m_flags & mask) == mask; }

  /// Test one or more flags.
  ///
  /// \return
  ///     \b true if any flags in \a mask are 1, \b false
  ///     otherwise.
  bool AnySet(ValueType mask) const { return (m_flags & mask) != 0; }

  /// Test a single flag bit.
  ///
  /// \return
  ///     \b true if \a bit is set, \b false otherwise.
  bool Test(ValueType bit) const { return (m_flags & bit) != 0; }

  /// Test if all bits in \a mask are clear.
  ///
  /// \return
  ///     \b true if \b all flags in \a mask are clear, \b false
  ///     otherwise.
  bool AllClear(ValueType mask) const { return (m_flags & mask) == 0; }

  bool AnyClear(ValueType mask) const { return (m_flags & mask) != mask; }

  /// Test a single flag bit to see if it is clear (zero).
  ///
  /// \return
  ///     \b true if \a bit is 0, \b false otherwise.
  bool IsClear(ValueType bit) const { return (m_flags & bit) == 0; }

protected:
  ValueType m_flags; ///< The flags.
};

} // namespace lldb_private

#endif // liblldb_Flags_h_