bug#59435: 29.0.50; tree-sitter fails to fontify or indent simple function

[Po Lu]

Yuan Fu <casouri@gmail.com> writes:

>> On Nov 20, 2022, at 10:09 PM, Po Lu via Bug reports for GNU Emacs, the Swiss 
>> army knife of text editors <bug-gnu-emacs@gnu.org> wrote:
>> 
>> 
>> c-ts-mode cannot fontify the following code:
>> 
>> ifsubmitbufl (tp)
>> {
>>  register    *kb1 = tp;
>>  extern       tbase, i_len;
>>  register     l = len;
>> 
>> again:
>> 
>>  highprio (); /* tbase is used by protoureg */
>>  iomap (&UBR, tbase += UBR_SIZ);
>>  UBR->addr_l = kb1;
>>  UBR->addr_m = kb1 >> 010;
>>  UBR->mode_l = 07777 &~ UBR_INST;
>>  UBR->mode_m = 0;
>>  UBR->long_l = l;
>>  UBR->long_m = l >> 010;
>> 
>>  iounmap ();
>>  tally_iostat (tbase);
>>  iospoke (UBR, P_LOCK);
>>  resetprio ();
>> 
>>  SWITCH (S_WAIT|S_HIGH|S_IMMED, 0700, again); /* this returns to
>>                                                BR->senv[0], except
>>                                                if CL_HI */
>> }
>> 
>> here, ifsubmitbufl, tbase, l and again are fontified as types.  They are
>> fontified correctly by CC Mode, as three identifiers and one label.
>
> Thanks, I fixe the label’s face.

Thanks.

> As for ifsubmitbufl, tbase, and l, I don’t really understand the
> syntax here, and I think neither does tree-sitter . In general
> tree-sitter struggles with nonstandard (in its book anyway) syntax.

Well, that code is 100% valid C.  "*kb1, tbase, i_len, l" are implicitly
int (which on that machine is 16 bits wide), and so is the value of
"ifsubmitbufl" and "tp".

> And there aren’t much we can do (except for maybe improve
> tree-sitter-c’s parser).

Would someone try that?

> Seems to work fine here. I don’t see anything I changed recently that
> could affect this, either.

Sorry, I think I meant "before".  Place point after "l = len;", then
press RET.