Re: [PATCH 1/5] checkpatch: fix false errors due to macro concatenation

[Andy Whitcroft <apw@canonical.com>]

On Mon, Sep 21, 2009 at 07:14:47PM -0700, Daniel Walker wrote:
> The macro concatenation (##) sequence can cause false errors when checking
> macro's. Checkpatch doesn't currently know about the operator.
> 
> For example this line,
> 
> + 	entry = (struct ftrace_raw_##call *)raw_data;                   \
> 
> is correct but it produces the following error,
> 
> ERROR: need consistent spacing around '*' (ctx:WxB)
> +       entry = (struct ftrace_raw_##call *)raw_data;\
>                                           ^
> 
> The line above doesn't have any spacing problems, and if you remove the
> macro concatenation sequence checkpatch doesn't give any errors. This change
> resolves this by just always removing "##" in every line checked.

Ok, just removing these characters in the conversion changes the
relative length of the converted form and breaks position reporting for
other checks, for instance if I stupidly convert the ## to # so its
still invalid we then get this:

+	entry = (struct ftrace_raw_##call *)raw_data; \

It is probabally more correct to include this <ident> ## <ident> form in
the definition of an identifier.  I've respun this patch to do just that
and it looks like its working as we would hope.

I will get this tested properly and add it to my next batch.

Perhaps you could test the version at the url below and see if it works
better:

  http://www.kernel.org/pub/linux/kernel/people/apw/checkpatch/checkpatch.pl-testing

NOTE: you want at least version 0.29-5-* which is in the process of
mirroring out.

-apw