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

[Pierrick Bouvier <pierrick.bouvier@linaro.org>]

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!