diff options
Diffstat (limited to 'gl/m4/dup2.m4')
| -rw-r--r-- | gl/m4/dup2.m4 | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/gl/m4/dup2.m4 b/gl/m4/dup2.m4 new file mode 100644 index 00000000..998d66f8 --- /dev/null +++ b/gl/m4/dup2.m4 @@ -0,0 +1,58 @@ +#serial 10 +dnl Copyright (C) 2002, 2005, 2007, 2009-2010 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +AC_DEFUN([gl_FUNC_DUP2], +[ + AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_CHECK_FUNCS_ONCE([dup2]) + if test $ac_cv_func_dup2 = no; then + HAVE_DUP2=0 + AC_LIBOBJ([dup2]) + else + AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works], + [AC_RUN_IFELSE([ + AC_LANG_PROGRAM([[#include <unistd.h> +#include <errno.h>]], + [if (dup2 (1, 1) == 0) + return 1; + close (0); + if (dup2 (0, 0) != -1) + return 2; + /* Many gnulib modules require POSIX conformance of EBADF. */ + if (dup2 (1, 1000000) == -1 && errno != EBADF) + return 3; + return 0; + ]) + ], + [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no], + [case "$host_os" in + mingw*) # on this platform, dup2 always returns 0 for success + gl_cv_func_dup2_works=no;; + cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0 + gl_cv_func_dup2_works=no;; + linux*) # On linux between 2008-07-27 and 2009-05-11, dup2 of a + # closed fd may yield -EBADF instead of -1 / errno=EBADF. + gl_cv_func_dup2_works=no;; + freebsd*) # on FreeBSD 6.1, dup2(1,1000000) gives EMFILE, not EBADF. + gl_cv_func_dup2_works=no;; + *) gl_cv_func_dup2_works=yes;; + esac]) + ]) + if test "$gl_cv_func_dup2_works" = no; then + gl_REPLACE_DUP2 + fi + fi +]) + +AC_DEFUN([gl_REPLACE_DUP2], +[ + AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) + if test $ac_cv_func_dup2 = yes; then + REPLACE_DUP2=1 + fi + AC_LIBOBJ([dup2]) +]) |