diff options
Diffstat (limited to 'm4/fcntl-o.m4')
-rw-r--r-- | m4/fcntl-o.m4 | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/m4/fcntl-o.m4 b/m4/fcntl-o.m4 new file mode 100644 index 00000000..d416a61c --- /dev/null +++ b/m4/fcntl-o.m4 | |||
@@ -0,0 +1,81 @@ | |||
1 | # fcntl-o.m4 serial 1 | ||
2 | dnl Copyright (C) 2006, 2009-2010 Free Software Foundation, Inc. | ||
3 | dnl This file is free software; the Free Software Foundation | ||
4 | dnl gives unlimited permission to copy and/or distribute it, | ||
5 | dnl with or without modifications, as long as this notice is preserved. | ||
6 | |||
7 | dnl Written by Paul Eggert. | ||
8 | |||
9 | # Test whether the flags O_NOATIME and O_NOFOLLOW actually work. | ||
10 | # Define HAVE_WORKING_O_NOATIME to 1 if O_NOATIME works, or to 0 otherwise. | ||
11 | # Define HAVE_WORKING_O_NOFOLLOW to 1 if O_NOFOLLOW works, or to 0 otherwise. | ||
12 | AC_DEFUN([gl_FCNTL_O_FLAGS], | ||
13 | [ | ||
14 | dnl Persuade glibc <fcntl.h> to define O_NOATIME and O_NOFOLLOW. | ||
15 | AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) | ||
16 | AC_CACHE_CHECK([for working fcntl.h], [gl_cv_header_working_fcntl_h], | ||
17 | [AC_RUN_IFELSE( | ||
18 | [AC_LANG_PROGRAM( | ||
19 | [[#include <sys/types.h> | ||
20 | #include <sys/stat.h> | ||
21 | #include <unistd.h> | ||
22 | #include <fcntl.h> | ||
23 | #ifndef O_NOATIME | ||
24 | #define O_NOATIME 0 | ||
25 | #endif | ||
26 | #ifndef O_NOFOLLOW | ||
27 | #define O_NOFOLLOW 0 | ||
28 | #endif | ||
29 | static int const constants[] = | ||
30 | { | ||
31 | O_CREAT, O_EXCL, O_NOCTTY, O_TRUNC, O_APPEND, | ||
32 | O_NONBLOCK, O_SYNC, O_ACCMODE, O_RDONLY, O_RDWR, O_WRONLY | ||
33 | }; | ||
34 | ]], | ||
35 | [[ | ||
36 | int status = !constants; | ||
37 | { | ||
38 | static char const sym[] = "conftest.sym"; | ||
39 | if (symlink (".", sym) != 0 | ||
40 | || close (open (sym, O_RDONLY | O_NOFOLLOW)) == 0) | ||
41 | status |= 32; | ||
42 | unlink (sym); | ||
43 | } | ||
44 | { | ||
45 | static char const file[] = "confdefs.h"; | ||
46 | int fd = open (file, O_RDONLY | O_NOATIME); | ||
47 | char c; | ||
48 | struct stat st0, st1; | ||
49 | if (fd < 0 | ||
50 | || fstat (fd, &st0) != 0 | ||
51 | || sleep (1) != 0 | ||
52 | || read (fd, &c, 1) != 1 | ||
53 | || close (fd) != 0 | ||
54 | || stat (file, &st1) != 0 | ||
55 | || st0.st_atime != st1.st_atime) | ||
56 | status |= 64; | ||
57 | } | ||
58 | return status;]])], | ||
59 | [gl_cv_header_working_fcntl_h=yes], | ||
60 | [case $? in #( | ||
61 | 32) gl_cv_header_working_fcntl_h='no (bad O_NOFOLLOW)';; #( | ||
62 | 64) gl_cv_header_working_fcntl_h='no (bad O_NOATIME)';; #( | ||
63 | 96) gl_cv_header_working_fcntl_h='no (bad O_NOATIME, O_NOFOLLOW)';; #( | ||
64 | *) gl_cv_header_working_fcntl_h='no';; | ||
65 | esac], | ||
66 | [gl_cv_header_working_fcntl_h=cross-compiling])]) | ||
67 | |||
68 | case $gl_cv_header_working_fcntl_h in #( | ||
69 | *O_NOATIME* | no | cross-compiling) ac_val=0;; #( | ||
70 | *) ac_val=1;; | ||
71 | esac | ||
72 | AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOATIME], [$ac_val], | ||
73 | [Define to 1 if O_NOATIME works.]) | ||
74 | |||
75 | case $gl_cv_header_working_fcntl_h in #( | ||
76 | *O_NOFOLLOW* | no | cross-compiling) ac_val=0;; #( | ||
77 | *) ac_val=1;; | ||
78 | esac | ||
79 | AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOFOLLOW], [$ac_val], | ||
80 | [Define to 1 if O_NOFOLLOW works.]) | ||
81 | ]) | ||