Re: [PATCH 3/4] tests/unit/test-char: Avoid using g_alloca()

[Pierrick Bouvier]

On 6/5/25 11:09 PM, Philippe Mathieu-Daudé wrote:
> On 5/6/25 22:53, Pierrick Bouvier wrote:
> > On 6/5/25 12:35 PM, Philippe Mathieu-Daudé wrote:
> > > Do not use g_alloca(), simply allocate the CharBackend
> > > structure on the stack.
> > >
> > > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> > > ---
> > >    tests/unit/test-char.c | 3 +--
> > >    1 file changed, 1 insertion(+), 2 deletions(-)
> > >
> > > diff --git a/tests/unit/test-char.c b/tests/unit/test-char.c
> > > index 60a843b79d9..f30a39f61ff 100644
> > > --- a/tests/unit/test-char.c
> > > +++ b/tests/unit/test-char.c
> > > @@ -993,7 +993,7 @@ static void char_udp_test_internal(Chardev
> > > *reuse_chr, int sock)
> > >        struct sockaddr_in other;
> > >        SocketIdleData d = { 0, };
> > >        Chardev *chr;
> > > -    CharBackend *be;
> > > +    CharBackend stack_be, *be = &stack_be;
> > >        socklen_t alen = sizeof(other);
> > >        int ret;
> > >        char buf[10];
> > > @@ -1009,7 +1009,6 @@ static void char_udp_test_internal(Chardev
> > > *reuse_chr, int sock)
> > >            chr = qemu_chr_new("client", tmp, NULL);
> > >            g_assert_nonnull(chr);
> > > -        be = g_alloca(sizeof(CharBackend));
> > >            qemu_chr_fe_init(be, chr, &error_abort);
> > >        }
> >
> > Would that be more simple to declare the variable, and use &be in the
> > function code?
>
> More context (see reuse_chr ladder):
>
> -- >8 --
> @@ -991,45 +991,44 @@ static int make_udp_socket(int *port)
>    static void char_udp_test_internal(Chardev *reuse_chr, int sock)
>    {
>        struct sockaddr_in other;
>        SocketIdleData d = { 0, };
>        Chardev *chr;
> -    CharBackend *be;
> +    CharBackend stack_be, *be = &stack_be;
>        socklen_t alen = sizeof(other);
>        int ret;
>        char buf[10];
>        char *tmp = NULL;
>
>        if (reuse_chr) {
>            chr = reuse_chr;
>            be = chr->be;
>        } else {
>            int port;
>            sock = make_udp_socket(&port);
>            tmp = g_strdup_printf("udp:127.0.0.1:%d", port);
>            chr = qemu_chr_new("client", tmp, NULL);
>            g_assert_nonnull(chr);
>
> -        be = g_alloca(sizeof(CharBackend));
>            qemu_chr_fe_init(be, chr, &error_abort);
>        }
> ---

Ok!