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Diffstat (limited to 'm4/fcntl-o.m4')
-rw-r--r-- | m4/fcntl-o.m4 | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/m4/fcntl-o.m4 b/m4/fcntl-o.m4 new file mode 100644 index 000000000..43c93124e --- /dev/null +++ b/m4/fcntl-o.m4 | |||
@@ -0,0 +1,134 @@ | |||
1 | # fcntl-o.m4 serial 4 | ||
2 | dnl Copyright (C) 2006, 2009-2014 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 | dnl AC_USE_SYSTEM_EXTENSIONS was introduced in autoconf 2.60 and obsoletes | ||
16 | dnl AC_GNU_SOURCE. | ||
17 | m4_ifdef([AC_USE_SYSTEM_EXTENSIONS], | ||
18 | [AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])], | ||
19 | [AC_REQUIRE([AC_GNU_SOURCE])]) | ||
20 | |||
21 | AC_CHECK_HEADERS_ONCE([unistd.h]) | ||
22 | AC_CHECK_FUNCS_ONCE([symlink]) | ||
23 | AC_CACHE_CHECK([for working fcntl.h], [gl_cv_header_working_fcntl_h], | ||
24 | [AC_RUN_IFELSE( | ||
25 | [AC_LANG_PROGRAM( | ||
26 | [[#include <sys/types.h> | ||
27 | #include <sys/stat.h> | ||
28 | #if HAVE_UNISTD_H | ||
29 | # include <unistd.h> | ||
30 | #else /* on Windows with MSVC */ | ||
31 | # include <io.h> | ||
32 | # include <stdlib.h> | ||
33 | # defined sleep(n) _sleep ((n) * 1000) | ||
34 | #endif | ||
35 | #include <fcntl.h> | ||
36 | #ifndef O_NOATIME | ||
37 | #define O_NOATIME 0 | ||
38 | #endif | ||
39 | #ifndef O_NOFOLLOW | ||
40 | #define O_NOFOLLOW 0 | ||
41 | #endif | ||
42 | static int const constants[] = | ||
43 | { | ||
44 | O_CREAT, O_EXCL, O_NOCTTY, O_TRUNC, O_APPEND, | ||
45 | O_NONBLOCK, O_SYNC, O_ACCMODE, O_RDONLY, O_RDWR, O_WRONLY | ||
46 | }; | ||
47 | ]], | ||
48 | [[ | ||
49 | int result = !constants; | ||
50 | #if HAVE_SYMLINK | ||
51 | { | ||
52 | static char const sym[] = "conftest.sym"; | ||
53 | if (symlink ("/dev/null", sym) != 0) | ||
54 | result |= 2; | ||
55 | else | ||
56 | { | ||
57 | int fd = open (sym, O_WRONLY | O_NOFOLLOW | O_CREAT, 0); | ||
58 | if (fd >= 0) | ||
59 | { | ||
60 | close (fd); | ||
61 | result |= 4; | ||
62 | } | ||
63 | } | ||
64 | if (unlink (sym) != 0 || symlink (".", sym) != 0) | ||
65 | result |= 2; | ||
66 | else | ||
67 | { | ||
68 | int fd = open (sym, O_RDONLY | O_NOFOLLOW); | ||
69 | if (fd >= 0) | ||
70 | { | ||
71 | close (fd); | ||
72 | result |= 4; | ||
73 | } | ||
74 | } | ||
75 | unlink (sym); | ||
76 | } | ||
77 | #endif | ||
78 | { | ||
79 | static char const file[] = "confdefs.h"; | ||
80 | int fd = open (file, O_RDONLY | O_NOATIME); | ||
81 | if (fd < 0) | ||
82 | result |= 8; | ||
83 | else | ||
84 | { | ||
85 | struct stat st0; | ||
86 | if (fstat (fd, &st0) != 0) | ||
87 | result |= 16; | ||
88 | else | ||
89 | { | ||
90 | char c; | ||
91 | sleep (1); | ||
92 | if (read (fd, &c, 1) != 1) | ||
93 | result |= 24; | ||
94 | else | ||
95 | { | ||
96 | if (close (fd) != 0) | ||
97 | result |= 32; | ||
98 | else | ||
99 | { | ||
100 | struct stat st1; | ||
101 | if (stat (file, &st1) != 0) | ||
102 | result |= 40; | ||
103 | else | ||
104 | if (st0.st_atime != st1.st_atime) | ||
105 | result |= 64; | ||
106 | } | ||
107 | } | ||
108 | } | ||
109 | } | ||
110 | } | ||
111 | return result;]])], | ||
112 | [gl_cv_header_working_fcntl_h=yes], | ||
113 | [case $? in #( | ||
114 | 4) gl_cv_header_working_fcntl_h='no (bad O_NOFOLLOW)';; #( | ||
115 | 64) gl_cv_header_working_fcntl_h='no (bad O_NOATIME)';; #( | ||
116 | 68) gl_cv_header_working_fcntl_h='no (bad O_NOATIME, O_NOFOLLOW)';; #( | ||
117 | *) gl_cv_header_working_fcntl_h='no';; | ||
118 | esac], | ||
119 | [gl_cv_header_working_fcntl_h=cross-compiling])]) | ||
120 | |||
121 | case $gl_cv_header_working_fcntl_h in #( | ||
122 | *O_NOATIME* | no | cross-compiling) ac_val=0;; #( | ||
123 | *) ac_val=1;; | ||
124 | esac | ||
125 | AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOATIME], [$ac_val], | ||
126 | [Define to 1 if O_NOATIME works.]) | ||
127 | |||
128 | case $gl_cv_header_working_fcntl_h in #( | ||
129 | *O_NOFOLLOW* | no | cross-compiling) ac_val=0;; #( | ||
130 | *) ac_val=1;; | ||
131 | esac | ||
132 | AC_DEFINE_UNQUOTED([HAVE_WORKING_O_NOFOLLOW], [$ac_val], | ||
133 | [Define to 1 if O_NOFOLLOW works.]) | ||
134 | ]) | ||