* lib/strerror_r.c: Include <stdarg.h>.
(strerror_r): Provide error messages for errno values 100...140.
* doc/posix-functions/strerror_r.texi: Mention the MSVC 14 problem.
On OpenBSD, strerror_r(1000,buf,19) gives "Unknown error: " rather
than "Unknown error: 100" while failing with ERANGE. Admittedly,
this behavior is nice, since a truncated integer is misleading,
but all other platforms use maximal strings on ERANGE and we are
already replacing strerror_r for other reasons, so it is easier
to work around this behavior than to adjust the testsuite (how
do you quickly decide if the only reason that the ERANGE string
was shorter than maximal was because the implementation avoided
truncating an integer?).
This patch intentionally avoids dragging in the strnlen module.
* lib/strerror_r.c (strerror_r): Always use maximal string.
* doc/posix-functions/strerror_r.texi (strerror_r): Document it.
Signed-off-by: Eric Blake <eblake@redhat.com>
MacOS X 10.5 strerror(0) is "Unknown error: 0", which is not distinguished
from "Unknown error: -1" for out-of-range. Worse, strerror_r(0,,)
is "Undefined error: 0", although strerror_r for all other out-of-range
values matches strerror.
* m4/strerror.m4 (gl_FUNC_STRERROR): Flush out MacOS bug.
* m4/strerror_r.m4 (gl_FUNC_STRERROR_R_WORKS): Likewise, and fix
logic bug.
* lib/strerror_r.c (strerror_r): Fix the bug.
* lib/strerror.c (strerror): Likewise.
* doc/posix-functions/strerror_r.texi (strerror_r): Document the
problem.
* doc/posix-functions/strerror.texi (strerror): Likewise.
* doc/posix-functions/perror.texi (perror): Likewise.
* tests/test-strerror.c (main): Enhance test.
* tests/test-strerror_r.c (main): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Cygwin __xpg_strerror_r clobbers strerror, until cygwin 1.7.10; in
this case, we must replace strerror, but there was nothing in
strerror.m4 finding fault with cygwin's native strerror. Solve
this by splitting strerror_r.m4 into two parts, one for probing
for the strerror_r bug, and one for replacing strerror_r based
on the presence of bugs unrelated to signature issues; that way,
the 'strerror' module in isolation will not replace strerror, but
if strerror_r is in use for any other reason, then the two use
separate buffers.
Note that cygwin's strerror is thread-safe while the gnulib
replacement is not; but this is no worse than any other
platform where strerror is not thread-safe; in a single-threaded
program, the difference is not observable, and in a multi-threaded
program, you really shouldn't be using strerror in the first place.
Also note that this ends up replacing glibc 2.13 strerror as it
deems __xpg_strerror_r broken on that platform, which isn't
technically necessary for strerror, but doesn't hurt too much.
Meanwhile, glibc 2.14 fixed __xpg_strerror_r, and strerror is not
replaced in that scenario.
* m4/strerror_r.m4 (gl_FUNC_STRERROR_R): Split...
(gl_FUNC_STRERROR_R_WORKS): ...into new macro, to detect Cygwin
bug without replacing strerror_r.
* m4/strerror.m4 (gl_FUNC_STRERROR): Replace strerror if
strerror_r is buggy, but without requiring strerror_r compilation.
* doc/posix-functions/strerror_r.texi (strerror_r): Fix docs.
Signed-off-by: Eric Blake <eblake@redhat.com>
Solaris 10 populates buf on EINVAL, but not on ERANGE.
* lib/strerror_r.c (strerror_r): Partially populate buf on ERANGE
failures.
* doc/posix-functions/strerror_r.texi (strerror_r): Document this.
Signed-off-by: Eric Blake <eblake@redhat.com>
POSIX recommends (but does not require) that strerror_r populate
buf even on error. But since we guarantee this behavior for
strerror, we might as well also guarantee it for strerror_r.
* lib/strerror_r.c (safe_copy): New helper method.
(strerror_r): Guarantee a non-empty string.
* tests/test-strerror_r.c (main): Enhance tests to incorporate
recent POSIX rulings and to match our strerror guarantees.
* doc/posix-functions/strerror_r.texi (strerror_r): Document this.
Signed-off-by: Eric Blake <eblake@redhat.com>
Avoid cygwin strerror_r, since it clobbers strerror buffer through
cygwin 1.7.9. __xpg_strerror_r is okay, but if a program is
compiled on cygwin 1.7.8 or earlier, it is not available.
* lib/strerror_r.c (strerror_r): Don't use cygwin's strerror_r;
fall back instead to sys_errlist.
* modules/strerror (configure.ac): Add witness.
* tests/test-strerror_r.c (main): Enhance test.
* doc/posix-functions/strerror_r.texi (strerror_r): Document it.
* tests/test-perror2.c (main): Free memory before exit.
Signed-off-by: Eric Blake <eblake@redhat.com>
On Solaris, a non-zero return was also reflected into errno.
Leaving errno unchanged is a useful feature worth guaranteeing.
* m4/strerror_r.m4 (gl_FUNC_STRERROR_R): Check for Solaris behavior.
* doc/posix-functions/strerror_r.texi (strerror_r): Document it.
Signed-off-by: Eric Blake <eblake@redhat.com>
* lib/string.in.h (strerror_r): New declaration.
* lib/strerror_r.c: New file.
* m4/strerror_r.m4: New file.
* m4/string_h.m4 (gl_HEADER_STRING_H_BODY): Check for the declaration
of strerror_r.
(gl_HEADER_STRING_H_DEFAULTS): Initialize GNULIB_STRERROR_R,
HAVE_DECL_STRERROR_R, REPLACE_STRERROR_R.
* modules/strerror_r-posix: New file.
* modules/string (Makefile.am): Substitute GNULIB_STRERROR_R,
HAVE_DECL_STRERROR_R, REPLACE_STRERROR_R.
* doc/posix-functions/strerror_r.texi: Mention the new module and the
portability problems.
