/* Implement string-related runtime actions for CHILL.
   Copyright (C) 1992,1993 Free Software Foundation, Inc.
   Author: Bill Cox

This file is part of GNU CC.

GNU CC 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 2, or (at your option)
any later version.

GNU CC 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

#define MIN(a, b)  ((a) < (b) ? (a) : (b))

extern void cause_exception (char *exname, char *file, int lineno);

/*
 * function __concatstring 
 *
 * parameters:
 *     OUT  - pointer to output string
 *     S1   - pointer to left string
 *     LEN1 - length of left string
 *     S2   - pointer to right string
 *     LEN2 - length of right string
 *
 * returns:
 *     pointer to OUT string
 *
 * exceptions:
 *     none
 *
 * abstract:
 *     concatenates two character strings into the output string
 *
 */

char *
__concatstring (out, s1, len1, s2, len2)
     char *out, *s1;
     int   len1;
     char *s2;
     int   len2;
{
  if (out)
    {
      if (s2 /* Check for overlap between s2 and out. */
	  && ((s2 >= out && s2 < (out + len1 + len2))
	      || (s2 + len2 > out && s2 <= out + len1)))
	{
	  char *tmp = alloca (len2);
	  memcpy (tmp, s2, len2);
	  s2 = tmp;
	}
      if (s1)
	memmove (out, s1, len1);
      if (s2)
	memcpy (&out[len1], s2, len2);
    }
  return out;
}