Re: [cocci] mm/slab: prepare for struct page conversion by spatch

[Vlastimil Babka <vbabka@suse.cz>]

On 11/8/21 18:35, Markus Elfring wrote:
>>> - struct page *page;
>>> + struct slab *slab;
>>
>> If you first rename struct page as strict slab and then do
>>
>> struct slab *
>> - page
>> + slab
>>   ;
>>
>> it might work even for the multiple declaration case.
> 
> Will there are need occur to adjust any more variable names?
> (Would different suffixes matter for corresponding identifiers?)

I was suprised that it works, which means the matching is more complex than
I thought. So I was able for example to achieve this:

-       struct page *page, *discard_page = NULL;
+       struct slab *slab, *slab_to_discard = NULL;

by the following rules (with ok_function per Julia's other e-mail):

@@
position p : script:ocaml() { ok_function p };
@@
- struct page@p
+ struct slab

@@
@@
struct slab *
- page
+ slab
;

@@
expression E;
@@
struct slab *
- discard_page
+ slab_to_discard
= E;

Thanks,
Vlastimil