HCoop / bpt / emacs.git / blame
| Commit | Line | Data |
|---|---|---|
| caf8a9b2 PE |
1 | #serial 18 |
| 2 | dnl Copyright (C) 2002, 2005, 2007, 2009-2012 Free Software Foundation, Inc. | |
| 7a7ef429 PE |
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_DUP2], | |
| 8 | [ | |
| 9 | AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) | |
| 10 | AC_REQUIRE([AC_CANONICAL_HOST]) | |
| 11 | m4_ifdef([gl_FUNC_DUP2_OBSOLETE], [ | |
| 12 | AC_CHECK_FUNCS_ONCE([dup2]) | |
| 13 | if test $ac_cv_func_dup2 = no; then | |
| 14 | HAVE_DUP2=0 | |
| 7a7ef429 PE |
15 | fi |
| 16 | ], [ | |
| 17 | AC_DEFINE([HAVE_DUP2], [1], [Define to 1 if you have the 'dup2' function.]) | |
| 18 | ]) | |
| 19 | if test $HAVE_DUP2 = 1; then | |
| 20 | AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works], | |
| 21 | [AC_RUN_IFELSE([ | |
| 22 | AC_LANG_PROGRAM([[#include <unistd.h> | |
| 23 | #include <fcntl.h> | |
| 24 | #include <errno.h>]], | |
| 25 | [int result = 0; | |
| 26 | #ifdef FD_CLOEXEC | |
| 27 | if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1) | |
| 28 | result |= 1; | |
| 29 | #endif | |
| 30 | if (dup2 (1, 1) == 0) | |
| 31 | result |= 2; | |
| 32 | #ifdef FD_CLOEXEC | |
| 33 | if (fcntl (1, F_GETFD) != FD_CLOEXEC) | |
| 34 | result |= 4; | |
| 35 | #endif | |
| 36 | close (0); | |
| 37 | if (dup2 (0, 0) != -1) | |
| 38 | result |= 8; | |
| 39 | /* Many gnulib modules require POSIX conformance of EBADF. */ | |
| 40 | if (dup2 (2, 1000000) == -1 && errno != EBADF) | |
| 41 | result |= 16; | |
| 42 | return result; | |
| 43 | ]) | |
| 44 | ], | |
| 45 | [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no], | |
| 46 | [case "$host_os" in | |
| 47 | mingw*) # on this platform, dup2 always returns 0 for success | |
| caf8a9b2 | 48 | gl_cv_func_dup2_works="guessing no" ;; |
| 7a7ef429 | 49 | cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0 |
| caf8a9b2 | 50 | gl_cv_func_dup2_works="guessing no" ;; |
| 7a7ef429 PE |
51 | linux*) # On linux between 2008-07-27 and 2009-05-11, dup2 of a |
| 52 | # closed fd may yield -EBADF instead of -1 / errno=EBADF. | |
| caf8a9b2 | 53 | gl_cv_func_dup2_works="guessing no" ;; |
| 7a7ef429 | 54 | freebsd*) # on FreeBSD 6.1, dup2(1,1000000) gives EMFILE, not EBADF. |
| caf8a9b2 | 55 | gl_cv_func_dup2_works="guessing no" ;; |
| 7a7ef429 | 56 | haiku*) # on Haiku alpha 2, dup2(1, 1) resets FD_CLOEXEC. |
| caf8a9b2 PE |
57 | gl_cv_func_dup2_works="guessing no" ;; |
| 58 | *) gl_cv_func_dup2_works="guessing yes" ;; | |
| 7a7ef429 PE |
59 | esac]) |
| 60 | ]) | |
| caf8a9b2 PE |
61 | case "$gl_cv_func_dup2_works" in |
| 62 | *yes) ;; | |
| 63 | *) | |
| 64 | REPLACE_DUP2=1 | |
| 65 | ;; | |
| 66 | esac | |
| 7a7ef429 | 67 | fi |
| 54020294 PE |
68 | dnl Replace dup2() for supporting the gnulib-defined fchdir() function, |
| 69 | dnl to keep fchdir's bookkeeping up-to-date. | |
| 70 | m4_ifdef([gl_FUNC_FCHDIR], [ | |
| 71 | gl_TEST_FCHDIR | |
| 72 | if test $HAVE_FCHDIR = 0; then | |
| caf8a9b2 PE |
73 | if test $HAVE_DUP2 = 1; then |
| 74 | REPLACE_DUP2=1 | |
| 75 | fi | |
| 54020294 PE |
76 | fi |
| 77 | ]) | |
| 7a7ef429 | 78 | ]) |
| 316f8af0 PE |
79 | |
| 80 | # Prerequisites of lib/dup2.c. | |
| 81 | AC_DEFUN([gl_PREREQ_DUP2], []) |