/* String descriptors, with out-of-memory checking.
   Copyright (C) 2023-2025 Free Software Foundation, Inc.

   This file is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published
   by the Free Software Foundation, either version 3 of the License,
   or (at your option) any later version.

   This file is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

#define GL_XSTRING_DESC_INLINE _GL_EXTERN_INLINE
#include "xstring-desc.h"

#include "ialloc.h"

rw_string_desc_t
xsd_concat (idx_t n, /* [rw_]string_desc_t string1, */ ...)
{
  if (n <= 0)
    /* Invalid argument.  */
    abort ();

  idx_t total = 0;
  {
    va_list strings;
    va_start (strings, n);
    string_desc_t string1 = va_arg (strings, string_desc_t);
    total += string1._nbytes;
    if (n > 1)
      {
        idx_t i;

        for (i = n - 1; i > 0; i--)
          {
            string_desc_t arg = va_arg (strings, string_desc_t);
            total += arg._nbytes;
          }
      }
    va_end (strings);
  }

  char *combined = (char *) imalloc (total);
  if (combined == NULL)
    xalloc_die ();
  idx_t pos = 0;
  {
    va_list strings;
    va_start (strings, n);
    string_desc_t string1 = va_arg (strings, string_desc_t);
    memcpy (combined, string1._data, string1._nbytes);
    pos += string1._nbytes;
    if (n > 1)
      {
        idx_t i;

        for (i = n - 1; i > 0; i--)
          {
            string_desc_t arg = va_arg (strings, string_desc_t);
            if (arg._nbytes > 0)
              memcpy (combined + pos, arg._data, arg._nbytes);
            pos += arg._nbytes;
          }
      }
    va_end (strings);
  }

  rw_string_desc_t result;
  result._nbytes = total;
  result._data = combined;

  return result;
}
