Re: Fix %error-verbose for conflicts resolved by %nonassoc.

[Akim Demaille]

Le 25 août 09 à 09:10, Joel E. Denny a écrit :

Hi Joel,

Nice and deep work!

> Verbose syntax error messages used to include error action tokens in  
> the
> expected token list.  There was a FIXME in conflicts.at about this.   
> To
> fix it, I pushed the following patches to master and similar ones to
> branch-2.5.  I feel this area is a bit too subtle to include this  
> change
> in branch-2.4.2.

I agree.

> I'm not proud of propagating more preprocessor macros to yacc.c.   
> Maybe
> this is a good place for some more functions like the ones Akim has
> discussed recently.  Also, we could probably find better names than  
> NINF.
> For example, error_action or default_action.

Sounds good to me.

> diff --git a/tests/conflicts.at b/tests/conflicts.at
> index 98b7d41..f2f7861 100644
> --- a/tests/conflicts.at
> +++ b/tests/conflicts.at
> @@ -99,20 +99,17 @@ AT_BISON_CHECK([-o input.c input.y])
> AT_COMPILE([input])
>
> AT_PARSER_CHECK([./input '0<0'])
> -# FIXME: This is an actual bug, but a new one, in the sense that
> -# no one has ever spotted it!  The messages are *wrong*: there should
> -# be nothing there, it should be expected eof.
> AT_PARSER_CHECK([./input '0<0<0'], [1], [],
> -         [syntax error, unexpected '<', expecting '<' or '>'
> +         [syntax error, unexpected '<'
> ])
>
> AT_PARSER_CHECK([./input '0>0'])
> AT_PARSER_CHECK([./input '0>0>0'], [1], [],
> -         [syntax error, unexpected '>', expecting '<' or '>'
> +         [syntax error, unexpected '>'
> ])
>
> AT_PARSER_CHECK([./input '0<0>0'], [1], [],
> -         [syntax error, unexpected '>', expecting '<' or '>'
> +         [syntax error, unexpected '>'
> ])

I don't understand why it does not refer to eof, as was noted in the  
comment.  I have not followed accurately everything you wrote about  
the NINF vs. 0 issue, but is it possible that the special case of end- 
of-file, which number is 0, be a reason about it?  Maybe that would  
also explain my incorrect messages in the nearby thread about semantic  
error messages.