cosmopolitan/libc/runtime/describemapping.c

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/runtime/memtrack.internal.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/prot.h"

noasan char *DescribeMapping(int prot, int flags, char p[hasatleast 8]) {
  /* asan runtime depends on this function */
  p[0] = (prot & PROT_READ) ? 'r' : '-';
  p[1] = (prot & PROT_WRITE) ? 'w' : '-';
  p[2] = (prot & PROT_EXEC) ? 'x' : '-';
  if (flags & MAP_PRIVATE) {
    p[3] = 'p';
  } else if (flags & MAP_SHARED) {
    p[3] = 's';
  } else {
    p[3] = '?';
  }
  p[4] = (flags & MAP_ANONYMOUS) ? 'a' : 'f';
  p[5] = (flags & MAP_GROWSDOWN) ? 'S' : '-';
  p[6] = (flags & MAP_FIXED) ? 'F' : '-';
  p[7] = 0;
  return p;
}