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From: Segher Boessenkool <segher@kernel.crashing.org>
To: Jon Loeliger <jdl@jdl.com>
Cc: linuxppc-dev@ozlabs.org, David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [PATCH] DTC: Remove the need for the GLR Parser.
Date: Tue, 23 Oct 2007 16:41:51 +0200	[thread overview]
Message-ID: <cace68e0fe3e4e257b7c63d18c805f18@kernel.crashing.org> (raw)
In-Reply-To: <E1IkKge-00060g-2l@jdl.com>

>>> Flip a right-recursive stack-abusing rule into a left-recursive
>>> stack-friendly rule and clear up three messes in one shot: No more
>>> conflicts, no need for the GLR parser, and friendlier stackness.
>>
>> Ouch.  I'm feeling a bit stupid now,
>
> Absolutely no need for that.

If you haven't had "exp := aexp | exp aexp" beaten into you with
a big stick, maybe you should be happy about that ("'s got a nail
in it!") :-)

>> And even without glr-parser, I'm still uncomfortable with the
>> lexer<->parser execution ordering issues with the current
>> /dts-version/ proposal.  It may now be true that the order is
>> guaranteed to be correct, but it's still not exactly obvious.

If you require /dts-version/ (and similar global dtc-control stmts)
to be at the start of the file, can't you avoid this ordering problem
by starting to parse the file with a simple (hand-written) parser
(which would handle these statements) and only when you cannot parse
any more switch to the "normal" parser (which won't handle them)?
Or is this a stupid suggestion :-)


Segher

  reply	other threads:[~2007-10-23 14:42 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-22 21:13 [PATCH] DTC: Remove the need for the GLR Parser Jon Loeliger
2007-10-23  2:54 ` David Gibson
2007-10-23 14:24   ` Jon Loeliger
2007-10-23 14:41     ` Segher Boessenkool [this message]
2007-10-23 14:49       ` Jon Loeliger
2007-10-23 23:41         ` David Gibson
2007-10-23 23:37       ` David Gibson
2007-10-23 16:07     ` Jon Loeliger
2007-10-23 23:44       ` David Gibson
2007-10-24  1:11     ` David Gibson

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