gdbsupport/scoped_mmap.cc

   1 /* scoped_mmap, automatically unmap files
   2
   3    Copyright (C) 2018-2020 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "common-defs.h"
  21 #include "scoped_mmap.h"
  22 #include "scoped_fd.h"
  23 #include "gdbsupport/filestuff.h"
  24
  25 #ifdef HAVE_SYS_MMAN_H
  26
  27 scoped_mmap
  28 mmap_file (const char *filename)
  29 {
  30   scoped_fd fd (gdb_open_cloexec (filename, O_RDONLY, 0));
  31   if (fd.get () < 0)
  32     perror_with_name (("open"));
  33
  34   off_t size = lseek (fd.get (), 0, SEEK_END);
  35   if (size < 0)
  36     perror_with_name (("lseek"));
  37
  38   /* We can't map an empty file.  */
  39   if (size == 0)
  40     error (_("file to mmap is empty"));
  41
  42   scoped_mmap mmapped_file (nullptr, size, PROT_READ, MAP_PRIVATE, fd.get (), 0);
  43   if (mmapped_file.get () == MAP_FAILED)
  44     perror_with_name (("mmap"));
  45
  46   return mmapped_file;
  47 }
  48
  49 #endif /* HAVE_SYS_MMAN_H */