2018-03-13 22:18 GMT+03:00 Martin Ågren <martin.agren@xxxxxxxxx>:
> On 13 March 2018 at 11:16, Olga Telezhnaya <olyatelezhnaya@xxxxxxxxx> wrote:
>> Continue removing any printing from ref-filter formatting logic,
>> so that it could be more general.
>>
>> Change the signature of parse_ref_filter_atom() by changing return value,
>> adding previous return value to function parameter and also adding
>> strbuf parameter for error message.
>
> I think the current return value is always non-negative. Maybe it would
> be easier to leave the return value as-is, except return negative on
> error? Unless I am missing something?
That's interesting. I like your idea, but let's see what other people think.
If others agree with us, I am ready to implement your solution.
>
>>
>> Signed-off-by: Olga Telezhnaia <olyatelezhnaya@xxxxxxxxx>
>> ---
>> ref-filter.c | 45 ++++++++++++++++++++++++++++++++-------------
>> 1 file changed, 32 insertions(+), 13 deletions(-)
>>
>> diff --git a/ref-filter.c b/ref-filter.c
>> index 07bedc636398c..e146215bf1e64 100644
>> --- a/ref-filter.c
>> +++ b/ref-filter.c
>> @@ -397,7 +397,8 @@ struct atom_value {
>> * Used to parse format string and sort specifiers
>> */
>> static int parse_ref_filter_atom(const struct ref_format *format,
>> - const char *atom, const char *ep)
>> + const char *atom, const char *ep, int *res,
>> + struct strbuf *err)
>> {
>> const char *sp;
>> const char *arg;
>> @@ -406,14 +407,18 @@ static int parse_ref_filter_atom(const struct ref_format *format,
>> sp = atom;
>> if (*sp == '*' && sp < ep)
>> sp++; /* deref */
>> - if (ep <= sp)
>> - die(_("malformed field name: %.*s"), (int)(ep-atom), atom);
>> + if (ep <= sp) {
>> + strbuf_addf(err, _("malformed field name: %.*s"), (int)(ep-atom), atom);
>> + return -1;
>> + }
>>
>> /* Do we have the atom already used elsewhere? */
>> for (i = 0; i < used_atom_cnt; i++) {
>> int len = strlen(used_atom[i].name);
>> - if (len == ep - atom && !memcmp(used_atom[i].name, atom, len))
>> - return i;
>> + if (len == ep - atom && !memcmp(used_atom[i].name, atom, len)) {
>> + *res = i;
>> + return 0;
>> + }
>> }
>
> If you did so, this hunk above would not need to be changed ...
>
>> @@ -458,7 +465,8 @@ static int parse_ref_filter_atom(const struct ref_format *format,
>> need_tagged = 1;
>> if (!strcmp(valid_atom[i].name, "symref"))
>> need_symref = 1;
>> - return at;
>> + *res = at;
>> + return 0;
>> }
>
> ... nor this one above ...
>
>> if (!ep)
>> return error(_("malformed format string %s"), sp);
>> /* sp points at "%(" and ep points at the closing ")" */
>> - at = parse_ref_filter_atom(format, sp + 2, ep);
>> + if (parse_ref_filter_atom(format, sp + 2, ep, &at, &err))
>> + die("%s", err.buf);
>
> And this would be more like "if (at < 0) die(...)".
>
>> for (cp = format->format; *cp && (sp = find_next(cp)); cp = ep + 1) {
>> struct atom_value *atomv;
>> + struct strbuf err = STRBUF_INIT;
>> + int pos;
>>
>> ep = strchr(sp, ')');
>> if (cp < sp)
>> append_literal(cp, sp, &state);
>> - get_ref_atom_value(info,
>> - parse_ref_filter_atom(format, sp + 2, ep),
>> - &atomv);
>> + if (parse_ref_filter_atom(format, sp + 2, ep, &pos, &err))
>> + return -1;
>> + get_ref_atom_value(info, pos, &atomv);
>> if (atomv->handler(atomv, &state, error_buf))
>> return -1;
>> + strbuf_release(&err);
>
> This looks leaky: if we get an error, we've got something in the buffer
> but we do not release it because we return early. Stepping back a bit, I
> wonder why we do not do anything at all with "err". Stepping back a bit
> more :-) I wonder if you could get rid of "err" and pass "error_buf" to
> parse_ref_filter_atom() instead. Our caller would like to have access to
> the error string?
Fully agree, I don't know why I decided to create one more buffer. Fixed.
>
> This ties back to my comment on the first patch -- "return negative if
> and only if you add some error string to the buffer" might be a useful
> rule?
>
> Martin
