Re: [Qemu-devel] [PATCH] qtest: Add assertion that required environment variable is set

[John Snow <jsnow@redhat.com>]

On 04/01/2015 02:00 PM, Ed Maste wrote:
> Signed-off-by: Ed Maste <emaste@freebsd.org>
> ---
>   tests/libqtest.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/tests/libqtest.c b/tests/libqtest.c
> index 12d65bd..54550a8 100644
> --- a/tests/libqtest.c
> +++ b/tests/libqtest.c
> @@ -453,6 +453,7 @@ void qtest_qmp_discard_response(QTestState *s, const char *fmt, ...)
>   const char *qtest_get_arch(void)
>   {
>       const char *qemu = getenv("QTEST_QEMU_BINARY");
> +    g_assert(qemu != NULL);
>       const char *end = strrchr(qemu, '/');
>
>       return end + strlen("/qemu-system-");
>

This one has annoyed me in the past, too.

I wonder if it would be even nicer to add an fprintf to give the user a 
nice message explaining exactly what went wrong, though -- since this 
particular error is only going to happen when a user is invoking the 
test manually.

Maybe:

if (qemu == NULL) {
   fprintf(stderr, "...");
   g_assert_not_reached();
}

Though that does read a little strangely. ("Here's a nice error message 
for something we are asserting will never happen.")



Well, either way, it's better than segfaulting, so:

Reviewed-by: John Snow <jsnow@redhat.com>