Re: [PATCH v3 8/8] tests/plugin/syscall.c: fix compiler warnings

[Richard Henderson]

On 11/29/21 3:09 PM, Alex Bennée wrote:
> From: Juro Bystricky <juro.bystricky@intel.com>
>
> Fix compiler warnings. The warnings can result in a broken build.
> This patch fixes warnings such as:
>
> In file included from /usr/include/glib-2.0/glib.h:111,
>                   from ../tests/plugin/syscall.c:13:
> ../tests/plugin/syscall.c: In function ‘print_entry’:
> /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: ‘out’ may be
>         used uninitialized in this function [-Werror=maybe-uninitialized]
>     g_free (*pp);
>     ^~~~~~~~~~~~
> ../tests/plugin/syscall.c:82:23: note: ‘out’ was declared here
>       g_autofree gchar *out;
>                         ^~~
> In file included from /usr/include/glib-2.0/glib.h:111,
>                   from ../tests/plugin/syscall.c:13:
> ../tests/plugin/syscall.c: In function ‘vcpu_syscall_ret’:
> /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: ‘out’ may be
>          used uninitialized in this function [-Werror=maybe-uninitialized]
>     g_free (*pp);
>     ^~~~~~~~~~~~
> ../tests/plugin/syscall.c:73:27: note: ‘out’ was declared here
>           g_autofree gchar *out;
>                             ^~~
> cc1: all warnings being treated as errors
>
> Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Message-Id: <20211128011551.2115468-1-juro.bystricky@intel.com>
> ---
>   tests/plugin/syscall.c | 8 +++-----
>   1 file changed, 3 insertions(+), 5 deletions(-)


Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~


> diff --git a/tests/plugin/syscall.c b/tests/plugin/syscall.c
> index 484b48de49..96040c578f 100644
> --- a/tests/plugin/syscall.c
> +++ b/tests/plugin/syscall.c
> @@ -70,19 +70,17 @@ static void vcpu_syscall_ret(qemu_plugin_id_t id, unsigned 
> int vcpu_idx,
>           }
>           g_mutex_unlock(&lock);
>       } else {
> -        g_autofree gchar *out;
> -        out = g_strdup_printf("syscall #%" PRIi64 " returned -> %" PRIi64 "\n",
> -                num, ret);
> +        g_autofree gchar *out = g_strdup_printf(
> +             "syscall #%" PRIi64 " returned -> %" PRIi64 "\n", num, ret);
>           qemu_plugin_outs(out);
>       }
>   }
>   
>   static void print_entry(gpointer val, gpointer user_data)
>   {
> -    g_autofree gchar *out;
>       SyscallStats *entry = (SyscallStats *) val;
>       int64_t syscall_num = entry->num;
> -    out = g_strdup_printf(
> +    g_autofree gchar *out = g_strdup_printf(
>           "%-13" PRIi64 "%-6" PRIi64 " %" PRIi64 "\n",
>           syscall_num, entry->calls, entry->errors);
>       qemu_plugin_outs(out);