Re: [PATCH 2/2] libtracefs: Silence sometimes-uninitialized warning

[Steven Rostedt <rostedt@goodmis.org>]

On Tue,  3 Aug 2021 17:41:09 -0700
Ian Rogers <irogers@google.com> wrote:

> Warning generated by clang:
> 
> src/tracefs-events.c:1046:6: error: variable 'ret' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
>         if (!systems)
>             ^~~~~~~~
> src/tracefs-events.c:1101:9: note: uninitialized use occurs here
>         return ret;
>                ^~~
> src/tracefs-events.c:1046:2: note: remove the 'if' if its condition is always false
>         if (!systems)
>         ^~~~~~~~~~~~~
> src/tracefs-events.c:1038:9: note: initialize the variable 'ret' to silence this warning
>         int ret;
>                ^
>                 = 0

That's a legitimate path to have ret returned without being initialized.

I'll add both patches to my next push.

Thanks!

-- Steve


> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  src/tracefs-events.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/tracefs-events.c b/src/tracefs-events.c
> index 8d84838..4679926 100644
> --- a/src/tracefs-events.c
> +++ b/src/tracefs-events.c
> @@ -1035,7 +1035,7 @@ static int event_enable_disable(struct tracefs_instance *instance,
>  	regex_t system_re, event_re;
>  	char **systems;
>  	char **events = NULL;
> -	int ret;
> +	int ret = -1;
>  	int s, e;
>  
>  	/* Handle all events first */