Re: [PATCH v2] trace-cmd: Remove all die()s from trace-cmd library

[Steven Rostedt <rostedt@goodmis.org>]

On Wed, 24 Mar 2021 15:51:43 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:

> @@ -366,36 +366,32 @@ void __noreturn __vdie(const char *fmt, va_list ap)
>  	vfprintf(stderr, fmt, ap);
>  
>  	fprintf(stderr, "\n");
> -	exit(ret);
> +	return ret;
>  }
>  
> -void __noreturn __die(const char *fmt, ...)
> +#ifdef LIB_DIE

I wonder if it would be more useful not to have it as a compile time
define, but instead a global variable:

static bool lib_die;

void tracecmd_die_on_error(void)
{
	lib_die = true;
}

Make the "die()" functions into static variables here.

void __hidden _lib_fatal(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	if (lib_die)
		__vdie(fmt, ap);
	else
		__vwarning(fmt, ap);
	va_end(ap);
}

That way if we run trace-cmd with the --debug option, it could then call
the tracecmd_die_on_error() function, and it will crash on any "fatal"
places.

-- Steve


> +
> +void __noreturn _lib_fatal(const char *fmt, ...)
>  {
>  	va_list ap;
> +	int ret;
>  
>  	va_start(ap, fmt);
> -	__vdie(fmt, ap);
> +	ret = __vlib_fatal(fmt, ap);
>  	va_end(ap);
> +	exit(ret);
>  }
>  
> -void __weak __noreturn die(const char *fmt, ...)
> +#else
> +void _lib_fatal(const char *fmt, ...)
>  {
>  	va_list ap;
>  
>  	va_start(ap, fmt);
> -	__vdie(fmt, ap);
> +	__vlib_fatal(fmt, ap);
>  	va_end(ap);
>  }
> -
> -void __weak *malloc_or_die(unsigned int size)
> -{
> -	void *data;
> -
> -	data = malloc(size);
> -	if (!data)
> -		die("malloc");
> -	return data;
> -}
> +#endif
>