snprintf_s.c

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/* August 2017, Reini Urban
 *
 * Copyright (c) 2017 by Reini Urban
 * All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *------------------------------------------------------------------
 */

/* Need restrict */
#include "config.h"
#include "safe_str_lib.h"
#include "safe_str_constraint.h"
#include <stdarg.h>

/* TODO: error when fmt contains %n, or encoding errors occur.
 */

int snprintf_s(char * restrict dest, rsize_t dmax, const char * restrict fmt, ...)
{
    va_list ap;
    int ret = -1;
    if (dmax > RSIZE_MAX_STR) {
        invoke_safe_str_constraint_handler("snprintf_s: dmax exceeds max",
                   NULL, ESLEMAX);
        return RCNEGATE(ESLEMAX);
    }

    if (dest == NULL) {
        invoke_safe_str_constraint_handler("snprintf_s: dest is null",
                   NULL, ESNULLP);
        return RCNEGATE(ESNULLP);
    }

    if (fmt == NULL) {
        invoke_safe_str_constraint_handler("snprintf_s: fmt is null",
                   NULL, ESNULLP);
        return RCNEGATE(ESNULLP);
    }

    if (dmax == 0) {
        invoke_safe_str_constraint_handler("snprintf_s: dmax is 0",
                   NULL, ESZEROL);
        return RCNEGATE(ESZEROL);
    }

    va_start(ap, fmt);

    ret = vsnprintf(dest, (size_t)dmax, fmt, ap);

    /*if (ret >= (int)dmax) {
        invoke_safe_str_constraint_handler("snprintf_s: len exceeds dmax",
                   NULL, ESNOSPC);
        *dest = 0;
        ret = RCNEGATE(ESNOSPC);
    }*/

    va_end(ap);

    return ret;
}