Commit | Line | Data |
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3dac6181 | 1 | # select.m4 serial 7 |
5e69ceb7 | 2 | dnl Copyright (C) 2009-2014 Free Software Foundation, Inc. |
3dac6181 AW |
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 | AC_DEFUN([gl_FUNC_SELECT], | |
8 | [ | |
9 | AC_REQUIRE([gl_HEADER_SYS_SELECT]) | |
10 | AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles | |
11 | AC_REQUIRE([gl_SOCKETS]) | |
12 | if test "$ac_cv_header_winsock2_h" = yes; then | |
13 | REPLACE_SELECT=1 | |
14 | else | |
15 | dnl On Interix 3.5, select(0, NULL, NULL, NULL, timeout) fails with error | |
16 | dnl EFAULT. | |
17 | AC_CHECK_HEADERS_ONCE([sys/select.h]) | |
18 | AC_CACHE_CHECK([whether select supports a 0 argument], | |
19 | [gl_cv_func_select_supports0], | |
20 | [ | |
21 | AC_RUN_IFELSE([AC_LANG_SOURCE([[ | |
22 | #include <sys/types.h> | |
23 | #include <sys/time.h> | |
24 | #if HAVE_SYS_SELECT_H | |
25 | #include <sys/select.h> | |
26 | #endif | |
27 | int main () | |
28 | { | |
29 | struct timeval timeout; | |
30 | timeout.tv_sec = 0; | |
31 | timeout.tv_usec = 5; | |
32 | return select (0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &timeout) < 0; | |
33 | }]])], [gl_cv_func_select_supports0=yes], [gl_cv_func_select_supports0=no], | |
34 | [ | |
35 | changequote(,)dnl | |
36 | case "$host_os" in | |
37 | # Guess no on Interix. | |
38 | interix*) gl_cv_func_select_supports0="guessing no";; | |
39 | # Guess yes otherwise. | |
40 | *) gl_cv_func_select_supports0="guessing yes";; | |
41 | esac | |
42 | changequote([,])dnl | |
43 | ]) | |
44 | ]) | |
45 | case "$gl_cv_func_select_supports0" in | |
46 | *yes) ;; | |
47 | *) REPLACE_SELECT=1 ;; | |
48 | esac | |
49 | ||
50 | dnl On FreeBSD 8.2, select() doesn't always reject bad fds. | |
51 | AC_CACHE_CHECK([whether select detects invalid fds], | |
52 | [gl_cv_func_select_detects_ebadf], | |
53 | [ | |
54 | AC_RUN_IFELSE([AC_LANG_PROGRAM([[ | |
55 | #include <sys/types.h> | |
56 | #include <sys/time.h> | |
57 | #if HAVE_SYS_SELECT_H | |
58 | # include <sys/select.h> | |
59 | #endif | |
60 | #include <unistd.h> | |
61 | #include <errno.h> | |
62 | ]],[[ | |
63 | fd_set set; | |
64 | dup2(0, 16); | |
65 | FD_ZERO(&set); | |
66 | FD_SET(16, &set); | |
67 | close(16); | |
68 | struct timeval timeout; | |
69 | timeout.tv_sec = 0; | |
70 | timeout.tv_usec = 5; | |
71 | return select (17, &set, NULL, NULL, &timeout) != -1 || errno != EBADF; | |
72 | ]])], [gl_cv_func_select_detects_ebadf=yes], | |
73 | [gl_cv_func_select_detects_ebadf=no], | |
74 | [ | |
75 | case "$host_os" in | |
76 | # Guess yes on glibc systems. | |
77 | *-gnu*) gl_cv_func_select_detects_ebadf="guessing yes" ;; | |
78 | # If we don't know, assume the worst. | |
79 | *) gl_cv_func_select_detects_ebadf="guessing no" ;; | |
80 | esac | |
81 | ]) | |
82 | ]) | |
83 | case $gl_cv_func_select_detects_ebadf in | |
84 | *yes) ;; | |
85 | *) REPLACE_SELECT=1 ;; | |
86 | esac | |
87 | fi | |
88 | ||
89 | dnl Determine the needed libraries. | |
90 | LIB_SELECT="$LIBSOCKET" | |
91 | if test $REPLACE_SELECT = 1; then | |
92 | case "$host_os" in | |
93 | mingw*) | |
94 | dnl On the MSVC platform, the function MsgWaitForMultipleObjects | |
95 | dnl (used in lib/select.c) requires linking with -luser32. On mingw, | |
96 | dnl it is implicit. | |
97 | AC_LINK_IFELSE( | |
98 | [AC_LANG_SOURCE([[ | |
99 | #define WIN32_LEAN_AND_MEAN | |
100 | #include <windows.h> | |
101 | int | |
102 | main () | |
103 | { | |
104 | MsgWaitForMultipleObjects (0, NULL, 0, 0, 0); | |
105 | return 0; | |
106 | }]])], | |
107 | [], | |
108 | [LIB_SELECT="$LIB_SELECT -luser32"]) | |
109 | ;; | |
110 | esac | |
111 | fi | |
112 | AC_SUBST([LIB_SELECT]) | |
113 | ]) |