source: src/AST/CVQualifiers.hpp@ 4a60488

//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// CVQualifiers.hpp --
//
// Author           : Aaron B. Moss
// Created On       : Mon May 13 15:00:00 2019
// Last Modified By : Aaron B. Moss
// Last Modified On : Mon May 13 15:00:00 2019
// Update Count     : 1
//

#pragma once

#include "Bitfield.hpp"

namespace ast {

namespace CV {

        /// Bitflags for qualifiers
        enum {
                Const    = 1 << 0,
                Restrict = 1 << 1,
                Volatile = 1 << 2,
                Lvalue   = 1 << 3,
                Mutex    = 1 << 4,
                Atomic   = 1 << 5,
                NumQualifiers = 6
        };

        /// Mask for equivalence-preserving qualfiers
        enum { EquivQualifiers = ~(Restrict | Lvalue) };

        /// Underlying data for qualifiers
        struct qualifier_flags {
                union {
                        unsigned int val;
                        struct {
                                bool is_const    : 1;
                                bool is_restrict : 1;
                                bool is_volatile : 1;
                                bool is_lvalue   : 1;
                                bool is_mutex    : 1;
                                bool is_atomic   : 1;
                        };
                };

                constexpr qualifier_flags( unsigned int val = 0 ) : val(val) {}
        };

        /// Type qualifiers
        using Qualifiers = bitfield<qualifier_flags>;

        // `restrict` and `lvalue` are ignored by qualifier equivalence.
        // ordering is a subtype relationship over qualifiers, e.g. `int` => `const int` is free

        inline bool operator== ( Qualifiers a, Qualifiers b ) {
                return (a.val & EquivQualifiers) == (b.val & EquivQualifiers);
        }
        inline bool operator!= ( Qualifiers a, Qualifiers b ) {
                return !(a == b);
        }
        inline bool operator<= ( Qualifiers a, Qualifiers b ) {
                return a.is_const    <= b.is_const    // non-const converts to const for free
                        && a.is_volatile <= b.is_volatile // non-volatile converts to volatile for free
                        && a.is_mutex    >= b.is_mutex    // mutex converts to non-mutex for free
                        && a.is_atomic   == b.is_atomic;  // atomicity must be preserved in free conversion
        }
        inline bool operator<  ( Qualifiers a, Qualifiers b ) { return a != b && a <= b; }
        inline bool operator>= ( Qualifiers a, Qualifiers b ) { return b <= a; }
        inline bool operator>  ( Qualifiers a, Qualifiers b ) { return b < a; }

}

}

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// mode: c++ //
// compile-command: "make install" //
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