Re: [RFC 3/4] ref-filter: change parsing function error handling
2018-03-13 22:18 GMT+03:00 Martin Ågren :
> On 13 March 2018 at 11:16, Olga Telezhnaya 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
>> ---
>> 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
Re: [RFC 3/4] ref-filter: change parsing function error handling
On 13 March 2018 at 11:16, Olga Telezhnaya 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?
>
> Signed-off-by: Olga Telezhnaia
> ---
> 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?
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
[RFC 3/4] ref-filter: change parsing function error handling
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.
Signed-off-by: Olga Telezhnaia
---
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;
+ }
}
/*
@@ -432,8 +437,10 @@ static int parse_ref_filter_atom(const struct ref_format
*format,
break;
}
- if (ARRAY_SIZE(valid_atom) <= i)
- die(_("unknown field name: %.*s"), (int)(ep-atom), atom);
+ if (ARRAY_SIZE(valid_atom) <= i) {
+ strbuf_addf(err, _("unknown field name: %.*s"), (int)(ep-atom),
atom);
+ return -1;
+ }
/* Add it in, including the deref prefix */
at = used_atom_cnt;
@@ -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;
}
static void quote_formatting(struct strbuf *s, const char *str, int
quote_style)
@@ -725,17 +733,20 @@ int verify_ref_format(struct ref_format *format)
format->need_color_reset_at_eol = 0;
for (cp = format->format; *cp && (sp = find_next(cp)); ) {
+ struct strbuf err = STRBUF_INIT;
const char *color, *ep = strchr(sp, ')');
int at;
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);
cp = ep + 1;
if (skip_prefix(used_atom[at].name, "color:", &color))
format->need_color_reset_at_eol = !!strcmp(color,
"reset");
+ strbuf_release(&err);
}
if (format->need_color_reset_at_eol && !want_color(format->use_color))
format->need_color_reset_at_eol = 0;
@@ -2154,15 +2165,18 @@ int format_ref_array_item(struct ref_array_item *info,
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);
}
if (*cp) {
sp = cp + strlen(cp);
@@ -2215,7 +2229,12 @@ static int parse_sorting_atom(const char *atom)
*/
struct ref_format dummy = REF_FORMAT_INIT;
const char *end = atom + strlen(atom);
- return parse_ref_filter_atom(&dummy, atom, end);
+ struct strbuf err = STRBUF_INIT;
+ int res;
+ if (parse_ref_filter_atom(&d
