In some scenarios, GDB or GDBserver can be spawned with input _not_
connected to a tty, and then tests that rely on stdio fail with
timeouts, because the inferior's stdout and stderr streams end up
fully buffered.
See discussion here:
https://sourceware.org/ml/gdb-patches/2015-02/msg00809.html
We have a hack in place that works around this for Windows testing,
that forces every test program to link with an .o file that does
(lib/set_unbuffered_mode.c):
static int __gdb_set_unbuffered_output (void) __attribute__ ((constructor));
static int
__gdb_set_unbuffered_output (void)
{
setvbuf (stdout, NULL, _IONBF, BUFSIZ);
setvbuf (stderr, NULL, _IONBF, BUFSIZ);
}
That's a bit hacky; it ends up done for _all_ tests.
This patch adds a way to do this unbuffering explicitly from the test
code itself, so it is done only when necessary, and for all
targets/hosts. For starters, it adjusts gdb.base/interrupt.c to use
it.
Tested on x86_64 Fedora 20, native, and against a remote gdbserver
board file that connects to the target with ssh, with and without -t
(create pty).
gdb/testsuite/
2015-02-27 Pedro Alves <palves@redhat.com>
* lib/unbuffer_output.c: New file.
* gdb.base/interrupt.c: Include "../lib/unbuffer_output.c".
(main): Call gdb_unbuffer_output.
