Re: [PATCH] trace-cmd: Fix a warning about incompatible pointer type of load_plugin()

[Steven Rostedt]

On Mon, 24 Apr 2017 22:43:31 +0900
Taeung Song <treeze.taeung@xxxxxxxxx> wrote:

> Currently the return type of load_plugin() in plugin_python.c is void type,
> but it is different from the argument type of trace_util_load_plugins().
> So fix it for the below warning.
> 
>   /home/taeung/git/opensource/trace-cmd/plugin_python.c: In function âpevent_plugin_loaderâ:
>   /home/taeung/git/opensource/trace-cmd/plugin_python.c:95:41: warning: passing argument 3 of âtrace_util_load_pluginsâ from incompatible pointer type [-Wincompatible-pointer-types]
>     trace_util_load_plugins(pevent, ".py", load_plugin, globals);
>                                          ^
>   In file included from /home/taeung/git/opensource/trace-cmd/plugin_python.c:3:0:
>   /home/taeung/git/opensource/trace-cmd/trace-cmd.h:300:5: note: expected âint (*)(struct pevent *, const char *, const char *, void *)â but argument is of type âvoid (*)(struct pevent *,   const char *, const char *, void *)â
>    int trace_util_load_plugins(struct pevent *pevent, const char *suffix,
>      ^
> 

Thanks but Federico beat you to it.

 http://lkml.kernel.org/r/20170423102258.21609-2-federico.vaga@xxxxxxxxxx

I'll be updating and pushing out a new trace-cmd this week.

> Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
> ---
>  plugin_python.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/plugin_python.c b/plugin_python.c
> index da07d27..d736f50 100644
> --- a/plugin_python.c
> +++ b/plugin_python.c
> @@ -20,7 +20,7 @@ static const char pyload[] =
>  "finally:\n"
>  "   file.close()\n";
>  
> -static void load_plugin(struct pevent *pevent, const char *path,
> +static int load_plugin(struct pevent *pevent, const char *path,
>  			const char *name, void *data)
>  {
>  	PyObject *globals = data;
> @@ -32,7 +32,7 @@ static void load_plugin(struct pevent *pevent, const char *path,
>  	PyObject *res;
>  
>  	if (!full || !n)
> -		return;
> +		return -ENOMEM;
>  
>  	strcpy(full, path);
>  	strcat(full, "/");
> @@ -43,16 +43,18 @@ static void load_plugin(struct pevent *pevent, const char *path,
>  
>  	asprintf(&load, pyload, full, n);
>  	if (!load)
> -		return;
> +		return -1;
>  
>  	res = PyRun_String(load, Py_file_input, globals, globals);
>  	if (!res) {
>  		fprintf(stderr, "failed loading %s\n", full);
>  		PyErr_Print();
> +		return -1;

Although, Federico's version didn't have this. I may add this under
your patch. Although, it requires freeing load. The better way would be
to set a "ret" variable and return that.

Want to send another patch on top of Federico's?

Thanks!

-- Steve

>  	} else
>  		Py_DECREF(res);
>  
>  	free(load);
> +	return 0;
>  }
>  
>  int PEVENT_PLUGIN_LOADER(struct pevent *pevent)