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

[Philippe Mathieu-Daudé]

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 <phi...@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);
     }
---