xref: /netbsd-src/external/gpl3/gdb/dist/gdbsupport/scoped_mmap.cc (revision 32d1c65c71fbdb65a012e8392a62a757dd6853e9)
1 /* scoped_mmap, automatically unmap files
2 
3    Copyright (C) 2018-2024 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 "scoped_mmap.h"
21 #include "scoped_fd.h"
22 #include "gdbsupport/filestuff.h"
23 
24 #ifdef HAVE_SYS_MMAN_H
25 
26 scoped_mmap
27 mmap_file (const char *filename)
28 {
29   scoped_fd fd = gdb_open_cloexec (filename, O_RDONLY, 0);
30   if (fd.get () < 0)
31     perror_with_name (("open"));
32 
33   off_t size = lseek (fd.get (), 0, SEEK_END);
34   if (size < 0)
35     perror_with_name (("lseek"));
36 
37   /* We can't map an empty file.  */
38   if (size == 0)
39     error (_("file to mmap is empty"));
40 
41   scoped_mmap mmapped_file (nullptr, size, PROT_READ, MAP_PRIVATE, fd.get (), 0);
42   if (mmapped_file.get () == MAP_FAILED)
43     perror_with_name (("mmap"));
44 
45   return mmapped_file;
46 }
47 
48 #endif /* HAVE_SYS_MMAN_H */
49