[PATCH libxkbcommon 0/2] Use flex and bison features

[Ran Benita]

On Fri, Feb 24, 2012 at 06:56:28PM -0500, Gaetan Nadon wrote:
> On 12-02-24 02:25 PM, Ran Benita wrote:
> > On Fri, Feb 24, 2012 at 10:16:39AM -0500, Gaetan Nadon wrote:
> >> On 12-02-23 07:58 PM, Ran Benita wrote:
> >>> - I couldn't figure out the coding style (there seems to be use of
> >>>   *all* of them...), so I just tried to match the surroundings.
> >>> - I've been using libxkbcommon for some time and I have some more
> >>>   patches laying around. I can send them too if all is well.
> >>>
> >> These look perfect to me. I build them on Linux with bison 2.4.1 and
> >> flex 2.5.35.
> >> I don't know if there could be differences on other platforms such as
> >> Solaris, *BSD MAC, it does not look like there would be any bison/flex
> >> specific features being used.
> >>
> >> The title of the e-mail makes it sound like you are using features that
> >> are specific to flex & bison as opposed to lex & yacc. You are also
> >> saying you are breaking compatibility with lex & yacc, I am confused. I
> >> suppose you are aware that this library builds on multiple platforms
> >> with a variety of scanner/lexer. We document the tools requirements in
> >> http://www.x.org/wiki/ModularDevelopersGuide#Required_Tools, but it is
> >> not very clear in this case.
> > Thanks for the link. I wasn't previously aware of byacc; I tried it now.
> > The first patch works fine, but the second does rely on a bison-only
> > feature (the YYLTYPE location stuff). But does the link mean that I
> > should refactor the code to work with byacc as well (probably possible
> > with some #ifdef's)? I would imagine that if flex is required for a
> > given platform (as per the link), than bison should be available as
> > well. I can also add some configure checks if necessary.
> I have updated the wiki to reflect what I perceived to be the reality at
> the moment based on the discussion in this thread.
> 
>     *yacc*   The original AT&T parser generator or an upward compatible
>     version such as *bison* or *byacc* whitout using its specific features
> 
>     *lex*   The original AT&T lexical analyser generator or an upward
>     compatible version such as *flex* whitout using its specific features

OK, I guess these patches are dropped than; I'll rebase my other
patches. I must say that AT&T lex and yacc is rather limiting this day
and age, for a library at least. It means that the parser cannot be made
to work reliably in a threaded application and other scenarios.