From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e35.co.us.ibm.com (e35.co.us.ibm.com [32.97.110.153]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e35.co.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 70521DDDF7 for ; Thu, 6 Dec 2007 09:37:15 +1100 (EST) Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e35.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id lB5Mb7Zl001936 for ; Wed, 5 Dec 2007 17:37:07 -0500 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id lB5MaxZM059900 for ; Wed, 5 Dec 2007 15:37:01 -0700 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id lB5MawNK006819 for ; Wed, 5 Dec 2007 15:36:58 -0700 Date: Wed, 5 Dec 2007 16:34:09 -0600 From: Josh Boyer To: David Gibson Subject: Re: dtc: RFC: Fix some lexical problems with references Message-ID: <20071205163409.77fba42b@zod.rchland.ibm.com> In-Reply-To: <20071122061007.GA22888@localhost.localdomain> References: <20071122061007.GA22888@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 22 Nov 2007 17:10:07 +1100 David Gibson wrote: > The recent change to the lexer to only recognize property and node > names in the appropriate context removed a number of lexical warts in > our language that would have gotten ugly as we add expression support > and so forth. > > But there's one nasty one remaining: references can contain a full > path, including the various problematic node name characters (',', '+' > and '-', for example). This would cause trouble with expressions, and > it also causes trouble with the patch I'm working on to allow > expanding references to paths rather than phandles. This patch > therefore reworks the lexer to mitigate these problems. > > - References to labels cause no problems. These are now > recognized separately from references to full paths. No syntax change > here. > > - References to full paths, including problematic characters > are allowed by "quoting" the path with braces > e.g. &{/pci@10000/somedevice@3,8000}. The braces protect any internal > problematic characters from being confused with operators or whatever. > > - For compatibility with existing dts files, in v0 dts files > we allow bare references to paths as before &/foo/bar/whatever - but > *only* if the path contains no troublesome characters. Specifically > only [a-zA-Z0-9_@/] are allowed. > > This is an incompatible change to the dts-v1 format, but since AFAIK > no-one has yet switched to dts-v1 files, I think we can get away with > it. Better to make the transition when people to convert to v1, and > get rid of the problematic old syntax. > > Strictly speaking, it's also an incompatible change to the v0 format, > since some path references that were allowed before are no longer > allowed. I suspect no-one has been using the no-longer-supported > forms (certainly none of the kernel dts files will cause trouble). We > might need to think about this harder, though. > > Signed-off-by: David Gibson So this breaks some of the in-kernel DTS files. Example, bamboo.dts on line 19 produces: bamboo.dts: 19 syntax error FATAL ERROR: Couldn't read input tree I tried quoting the path with {} but that didn't seem to work. josh