Re: [PATCH v3] tools/lib/traceevent, perf tools: Handle %pU format correctly

[Steven Rostedt]

On Mon, 21 Oct 2019 17:47:30 +0800
Qu Wenruo <wqu@xxxxxxxx> wrote:

> +static void print_uuid_arg(struct trace_seq *s, void *data, int size,
> +			   struct tep_event *event, struct tep_print_arg *arg)
> +{
> +	unsigned char *buf;
> +	int i;
> +
> +	if (arg->type != TEP_PRINT_FIELD) {
> +		trace_seq_printf(s, "ARG TYPE NOT FIELID but %d", arg->type);
> +		return;
> +	}
> +
> +	if (!arg->field.field) {
> +		arg->field.field = tep_find_any_field(event, arg->field.name);
> +		if (!arg->field.field) {
> +			do_warning("%s: field %s not found",
> +				   __func__, arg->field.name);
> +			return;
> +		}
> +	}
> +	if (arg->field.field->size < 16) {
> +		trace_seq_printf(s, "INVALID UUID: size have %u expect 16",
> +				arg->field.field->size);
> +		return;
> +	}
> +	buf = data + arg->field.field->offset;
> +
> +	for (i = 0; i < 8; i++) {
> +		trace_seq_printf(s, "%02x", buf[2 * i]);
> +		trace_seq_printf(s, "%02x", buf[2 * i + 1]);
> +		if (1 <= i && i <= 4)

I'm fine with this patch except for one nit. The above is hard to read
(in my opinion), and I absolutely hate the "constant" compare to
"variable" notation. Please change the above to:

		if (i >= 1 && i <= 4)

Thanks,

-- Steve

> +			trace_seq_putc(s, '-');
> +	}
> +}
> +