On Mon, 21 Oct 2019 22:03:21 +0800
Qu Wenruo <quwenruo.btrfs@xxxxxxx> wrote:
> On 2019/10/21 下午9:56, Steven Rostedt wrote:
> > 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)
>
> Isn't this ( 1 <= i && i <= 4 ) easier to find out the lower and upper
> boundary? only two numbers, both at the end of the expression.
I don't read it like that.
>
> I feel that ( i >= 1 && i <= 4 ) easier to write, but takes me extra
> half second to read, thus I changed to the current one.
How do you read it in English?
"If one is less than or equal to i and i is less than or equal to
four."
Or
"If i is greater than or equal to one and i is less than or equal to
four."
?
I read it the second way, and I believe most English speakers read it
that way too.
It took me a minute or two to understand the original method, because
my mind likes to take a variable and keep it on the same side of the
comparison, and the variable should always be first.
-- Steve
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