check if a memory region overlaps a str

crux-00011: $SRC/str/str_overlaps.c

#include "str/str.h"
#include "utils/ar.h"
#include "utils/panic.h"

int
str_overlaps (struct str * s, int l, char * c)
{
  if (l < 0) panic ("sub-0 length overlap check");
  if (l == 0) return 0;
  if (s->l == 0) return 0;
  if (c < s->s) return 0;
  if (c >= (s->s + s->z)) return 0;
  if (c >= (s->s + s->l)) panic ("known invalid character pointer to overlaps");
  if (c + l >= (s->s + s->l)) panic ("known invalid length to overlaps");
  return 1;
}

/*

    This file is part of Crux.

    Crux 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.

    Crux 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 Crux.  If not, see <http://www.gnu.org/licenses/>.

*/