Re: [PATCH v2 2/3] dtc: Support character literals in cell lists

On Thu, Sep 08, 2011 at 02:20:16PM -0700, Anton Staaf wrote:

On Wed, Sep 7, 2011 at 8:47 PM, David Gibson
[off-list ref] wrote:

quoted

On Wed, Sep 07, 2011 at 04:15:39PM -0700, Anton Staaf wrote:

[snip]

quoted

Hrm, this paragraph is clearly referring to the old-style dts-v0
syntax (hex is not the default, these days) - which may well mean the
whole document is hopelessly out of date.  And I think the char
literals should only be processed in dts-v1 mode.

Fair enough, would it make sense for me to just remove this
modification to manual.txt and leave the changes in place in
dts-format.txt?

I think so.

quoted

quoted

-Strings support common escape sequences from C: "\n", "\t", "\r",
-"\(octal value)", "\x(hex value)".
+Strings and character literals support common escape sequences from C:
+"\n", "\t", "\r", "\(octal value)", "\x(hex value)".


 4.3) Labels and References

diff --git a/dtc-lexer.l b/dtc-lexer.l
index e866ea5..d4f9eaa 100644
--- a/dtc-lexer.l
+++ b/dtc-lexer.l

@@ -29,6 +29,8 @@ PROPNODECHAR        [a-zA-Z0-9,._+*#?@-]

 PATHCHAR     ({PROPNODECHAR}|[/])
 LABEL                [a-zA-Z_][a-zA-Z0-9_]*
 STRING               \"([^\\"]|\\.)*\"
+CHAR_LITERAL '[^\\']'
+CHAR_ESCAPED '\\([^']+|')'

I'd prefer a single regex here, of '[^']+', and then check that it is
indeed a single character when you process it.  An aside as to why...

Done, though I made it a slightly more complex regex that can also match '\''.

Good call, I forgot that case.

[snip]

quoted

So, I'd prefer the error handling to be done here - that is if there's
a bad escape sequence or more than one character, report it here.  For
now, a die() will do, although longer term I'd prefer a not
immediately fatal message (allowing the rest of the file to be checked
for errors) with an error triggered after the parse is complete.

I ended up (as you'll see shortly) doing this in dtc-parser.y and
using the print_error function there so I didn't have to just die out.
 So longer term can be now, instead of...

Superb :)

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson