Re: [PATCH] scanner: reintroduce unput for missing end tokens

[Akim Demaille]

Le 14 déc. 2012 à 10:26, Théophile Ranquet <address@hidden> a écrit :

> I am going for the following, does this satisfy you?
> 
> commit a860ad081d025db0629120d030fbf7fd8218949f
> Author: Theophile Ranquet <address@hidden>
> Date:   Thu Nov 15 17:10:35 2012 +0000
> 
>    scanner: reintroduce unput for missing end tokens
> 
>    Unput was no longer used since a POSIX-compatiblity issue with Flex 2.5.31,
>    which has been adressed in newer versions of Flex.  See this discussion:
>    <http://lists.gnu.org/archive/html/bug-bison/2003-04/msg00029.html>
> 
>    This partially reverts commit aa4180418fff518198e1b0f2c43fec6432210dc7.
> 
>    * src/scan-gram.l (unexpected_end): Here.
>    * tests/input.at: Adjust for new order of error reports.

OK.

> 
>> 
>>> index 5e5b1e8..70ad41b 100644
>>> --- a/tests/input.at
>>> +++ b/tests/input.at
>>> @@ -1480,10 +1480,10 @@ AT_CHECK([[$PERL -e "print 'start: \'';" >> empty.y 
>>> || exit 77]])
>>> 
>>> AT_BISON_CHECK([empty.y], [1], [],
>>> [[empty.y:2.8-9: warning: empty character literal [-Wother]
>>> -empty.y:3.8-4.0: warning: empty character literal [-Wother]
>>> empty.y:3.8-4.0: error: missing "'" at end of line
>>> -empty.y:4.8: warning: empty character literal [-Wother]
>>> +empty.y:3.8-4.0: warning: empty character literal [-Wother]
>>> empty.y:4.8: error: missing "'" at end of file
>>> +empty.y:4.8: warning: empty character literal [-Wother]
>>> ]])
>> 
>> I'd like to see -fcaret used here, to see how "cute" the location is.
> 
> Sure. This revealed a bug in our carets, when the input is not
> terminated by a line feed. The following trivial patch fixes this, so
> it will be installed as another commit.
> 
> diff --git a/src/location.c b/src/location.c
> index d48a0a1..c4e0a76 100644
> --- a/src/location.c
> +++ b/src/location.c
> @@ -197,6 +197,8 @@ location_caret (FILE *out, location loc)
> 
>         /* Quote the file, indent by a single column.  */
>         fputc (' ', out);
> +        if (buf[len - 1] != '\n')
> +          buf[len++] = '\n';

How do you know the buffer is large enough???

>         fwrite (buf, 1, len, out);

I would prefer that you just add the \n afterwards.  And really, I'm
having second thoughts on using getline here, as a simple while loop
on getc and putc would perfectly suffice.

> 
>         /* Print the caret, with the same indent as above.  */