/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2025 The NASM Authors - All Rights Reserved
 *   See the file AUTHORS included with the NASM distribution for
 *   the specific copyright holders.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following
 *   conditions are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *
 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * ----------------------------------------------------------------------- */

#include "compiler.h"
#include "nasm.h"
#include "asmutil.h"
#include "stdscan.h"
#include "eval.h"

/*
 * 1. An expression (true if nonzero 0)
 * 2. The keywords true, on, yes for true
 * 3. The keywords false, off, no for false
 * 4. An empty line, for true
 *
 * This is equivalent to pp_get_boolean_option() outside of the
 * preprocessor.
 *
 * On error, return defval (usually the previous value)
 *
 * If str is NULL, return NULL without changing *val.
 */
char *get_boolean_option(const char *str, bool *val)
{
    static const char * const noyes[] = {
        "no", "yes",
        "false", "true",
        "off", "on"
    };
    struct tokenval tokval;
    expr *evalresult;
    char *p;
    int tt;

    if (!str)
        return NULL;

    str = nasm_skip_spaces(str);
    p = nasm_strdup(str);

    tokval.t_type  = TOKEN_INVALID;
    tokval.t_start = str;
    stdscan_reset(p);

    tt = stdscan(NULL, &tokval);
    if (tt == TOKEN_EOS || tt == ']' || tt == ',') {
        *val = true;
        goto done;
    }

    if (tt == TOKEN_ID) {
        size_t i;
        for (i = 0; i < ARRAY_SIZE(noyes); i++)
            if (!nasm_stricmp(tokval.t_charptr, noyes[i])) {
                *val = i & 1;
                goto done;
            }
    }

    evalresult = evaluate(stdscan, NULL, &tokval, NULL, true, NULL);

    if (!evalresult)
        goto done;

    if (!is_really_simple(evalresult)) {
        nasm_nonfatal("boolean flag expression must be a constant");
        goto done;
    }

    *val = reloc_value(evalresult) != 0;

done:
    str += nasm_skip_spaces(tokval.t_start) - p;
    nasm_free(p);
    return (char *)str;
}