Mercurial > hg > octave-lojdl > gnulib-hg
changeset 14255:dfb3316e7c70
dup2: work around Haiku bug
dup2(n,n) must be a no-op, but on Haiku, it resets FD_CLOEXEC.
However, we must keep the Linux workaround for dup2(n,n)
returning (unsigned int)-EBADF.
* m4/dup2.m4 (gl_FUNC_DUP2): Test for bug.
* lib/dup2.c (rpl_dup2) [!WIN32]: Add workaround.
* doc/posix-functions/dup2.texi (dup2): Document the bug.
* tests/test-dup2.c (main): Enhance test.
Signed-off-by: Eric Blake <eblake@redhat.com>
| author | Eric Blake <eblake@redhat.com> |
|---|---|
| date | Mon, 31 Jan 2011 20:14:37 -0700 |
| parents | 53a5188cc58f |
| children | 16723ac102a6 |
| files | ChangeLog doc/posix-functions/dup2.texi lib/dup2.c m4/dup2.m4 tests/test-dup2.c |
| diffstat | 5 files changed, 39 insertions(+), 6 deletions(-) [+] |
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--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2011-01-31 Eric Blake <eblake@redhat.com> + + dup2: work around Haiku bug + * m4/dup2.m4 (gl_FUNC_DUP2): Test for bug. + * lib/dup2.c (rpl_dup2) [!WIN32]: Add workaround. + * doc/posix-functions/dup2.texi (dup2): Document the bug. + * tests/test-dup2.c (main): Enhance test. + 2011-01-31 Simon Josefsson <simon@josefsson.org> doc: off_t is not available in eglibc 2.11.2 stdio.h.
--- a/doc/posix-functions/dup2.texi +++ b/doc/posix-functions/dup2.texi @@ -17,6 +17,11 @@ mingw. @item +This function resets the @code{FD_CLOEXEC} flag when duplicating an fd +to itself on some platforms: +Haiku. + +@item This function returns 0 for @code{dup2 (1, 1)} on some platforms: Cygwin 1.5.x.
--- a/lib/dup2.c +++ b/lib/dup2.c @@ -59,6 +59,10 @@ errno = EBADF; return -1; } +# elif !defined __linux__ + /* On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC. */ + if (fd == desired_fd) + return fcntl (fd, F_GETFL) == -1 ? -1 : fd; # endif result = dup2 (fd, desired_fd); # ifdef __linux__
--- a/m4/dup2.m4 +++ b/m4/dup2.m4 @@ -1,4 +1,4 @@ -#serial 11 +#serial 12 dnl Copyright (C) 2002, 2005, 2007, 2009-2011 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -8,7 +8,7 @@ [ AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) AC_REQUIRE([AC_CANONICAL_HOST]) - AC_CHECK_FUNCS_ONCE([dup2]) + AC_CHECK_FUNCS_ONCE([dup2 fcntl]) if test $ac_cv_func_dup2 = no; then HAVE_DUP2=0 AC_LIBOBJ([dup2]) @@ -16,16 +16,25 @@ AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works], [AC_RUN_IFELSE([ AC_LANG_PROGRAM([[#include <unistd.h> +#include <fcntl.h> #include <errno.h>]], [int result = 0; +#if HAVE_FCNTL + if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1) + result |= 1; +#endif HAVE_FCNTL if (dup2 (1, 1) == 0) - result |= 1; + result |= 2; +#if HAVE_FCNTL + if (fcntl (1, F_GETFD) != FD_CLOEXEC) + result |= 4; +#endif close (0); if (dup2 (0, 0) != -1) - result |= 2; + result |= 8; /* Many gnulib modules require POSIX conformance of EBADF. */ - if (dup2 (1, 1000000) == -1 && errno != EBADF) - result |= 4; + if (dup2 (2, 1000000) == -1 && errno != EBADF) + result |= 16; return result; ]) ], @@ -40,6 +49,8 @@ gl_cv_func_dup2_works=no;; freebsd*) # on FreeBSD 6.1, dup2(1,1000000) gives EMFILE, not EBADF. gl_cv_func_dup2_works=no;; + haiku*) # on Haiku alpha 2, dup2(1, 1) resets FD_CLOEXEC. + gl_cv_func_dup2_works=no;; *) gl_cv_func_dup2_works=yes;; esac]) ])
--- a/tests/test-dup2.c +++ b/tests/test-dup2.c @@ -169,7 +169,12 @@ ASSERT (dup2 (fd + 1, fd + 1) == fd + 1); ASSERT (!is_inheritable (fd + 1)); ASSERT (dup2 (fd + 1, fd + 2) == fd + 2); + ASSERT (!is_inheritable (fd + 1)); ASSERT (is_inheritable (fd + 2)); + errno = 0; + ASSERT (dup2 (fd + 1, -1) == -1); + ASSERT (errno == EBADF); + ASSERT (!is_inheritable (fd + 1)); #endif /* On systems that distinguish between text and binary mode, dup2