Commit | Line | Data |
---|---|---|
d20bc122 MF |
1 | # select.m4 serial 12 |
2 | dnl Copyright (C) 2009-2021 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 | AC_DEFUN([gl_FUNC_SELECT], | |
8 | [ | |
9 | AC_REQUIRE([gl_HEADER_SYS_SELECT]) | |
10 | AC_REQUIRE([AC_C_RESTRICT]) | |
11 | AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles | |
12 | AC_REQUIRE([gl_SOCKETS]) | |
13 | if test "$ac_cv_header_winsock2_h" = yes; then | |
14 | REPLACE_SELECT=1 | |
15 | else | |
16 | dnl On Interix 3.5, select(0, NULL, NULL, NULL, timeout) fails with error | |
17 | dnl EFAULT. | |
18 | AC_CHECK_HEADERS_ONCE([sys/select.h]) | |
19 | AC_CACHE_CHECK([whether select supports a 0 argument], | |
20 | [gl_cv_func_select_supports0], | |
21 | [ | |
22 | AC_RUN_IFELSE([AC_LANG_SOURCE([[ | |
23 | #include <sys/types.h> | |
24 | #include <sys/time.h> | |
25 | #if HAVE_SYS_SELECT_H | |
26 | #include <sys/select.h> | |
27 | #endif | |
28 | int main () | |
29 | { | |
30 | struct timeval timeout; | |
31 | timeout.tv_sec = 0; | |
32 | timeout.tv_usec = 5; | |
33 | return select (0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &timeout) < 0; | |
34 | }]])], [gl_cv_func_select_supports0=yes], [gl_cv_func_select_supports0=no], | |
35 | [ | |
36 | changequote(,)dnl | |
37 | case "$host_os" in | |
38 | # Guess no on Interix. | |
39 | interix*) gl_cv_func_select_supports0="guessing no";; | |
40 | # Guess yes otherwise. | |
41 | *) gl_cv_func_select_supports0="guessing yes";; | |
42 | esac | |
43 | changequote([,])dnl | |
44 | ]) | |
45 | ]) | |
46 | case "$gl_cv_func_select_supports0" in | |
47 | *yes) ;; | |
48 | *) REPLACE_SELECT=1 ;; | |
49 | esac | |
50 | ||
51 | dnl On FreeBSD 8.2, select() doesn't always reject bad fds. | |
52 | AC_CACHE_CHECK([whether select detects invalid fds], | |
53 | [gl_cv_func_select_detects_ebadf], | |
54 | [ | |
55 | AC_RUN_IFELSE([AC_LANG_PROGRAM([[ | |
56 | #include <sys/types.h> | |
57 | #include <sys/time.h> | |
58 | #if HAVE_SYS_SELECT_H | |
59 | # include <sys/select.h> | |
60 | #endif | |
61 | #include <unistd.h> | |
62 | #include <errno.h> | |
63 | ]GL_MDA_DEFINES], | |
64 | [[ | |
65 | fd_set set; | |
66 | dup2(0, 16); | |
67 | FD_ZERO(&set); | |
68 | FD_SET(16, &set); | |
69 | close(16); | |
70 | struct timeval timeout; | |
71 | timeout.tv_sec = 0; | |
72 | timeout.tv_usec = 5; | |
73 | return select (17, &set, NULL, NULL, &timeout) != -1 || errno != EBADF; | |
74 | ]])], [gl_cv_func_select_detects_ebadf=yes], | |
75 | [gl_cv_func_select_detects_ebadf=no], | |
76 | [ | |
77 | case "$host_os" in | |
78 | # Guess yes on Linux systems. | |
79 | linux-* | linux) gl_cv_func_select_detects_ebadf="guessing yes" ;; | |
80 | # Guess yes on glibc systems. | |
81 | *-gnu* | gnu*) gl_cv_func_select_detects_ebadf="guessing yes" ;; | |
82 | # If we don't know, obey --enable-cross-guesses. | |
83 | *) gl_cv_func_select_detects_ebadf="$gl_cross_guess_normal" ;; | |
84 | esac | |
85 | ]) | |
86 | ]) | |
87 | case $gl_cv_func_select_detects_ebadf in | |
88 | *yes) ;; | |
89 | *) REPLACE_SELECT=1 ;; | |
90 | esac | |
91 | fi | |
92 | ||
93 | dnl Determine the needed libraries. | |
94 | LIB_SELECT="$LIBSOCKET" | |
95 | if test $REPLACE_SELECT = 1; then | |
96 | case "$host_os" in | |
97 | mingw*) | |
98 | dnl On the MSVC platform, the function MsgWaitForMultipleObjects | |
99 | dnl (used in lib/select.c) requires linking with -luser32. On mingw, | |
100 | dnl it is implicit. | |
101 | AC_LINK_IFELSE( | |
102 | [AC_LANG_SOURCE([[ | |
103 | #define WIN32_LEAN_AND_MEAN | |
104 | #include <windows.h> | |
105 | int | |
106 | main () | |
107 | { | |
108 | MsgWaitForMultipleObjects (0, NULL, 0, 0, 0); | |
109 | return 0; | |
110 | }]])], | |
111 | [], | |
112 | [LIB_SELECT="$LIB_SELECT -luser32"]) | |
113 | ;; | |
114 | esac | |
115 | fi | |
116 | AC_SUBST([LIB_SELECT]) | |
117 | ]) |