[cocci] Iterator macros

[Peter Senna Tschudin <peter.senna@linux.intel.com>]

Dear List, 

I am trying to make changes to a macro iterator from igt-gpu-tools*, and I am failing to use Coccinelle. My current attempt only captures about 1/2 of call sites, and I am not really sure how to ask Coccinelle to make the changes I want. Here is the pattern I am trying to change: 


From: 

const struct intel_execution_engine2 *e2; 
... 
for_each_ctx_engine(i915, ctx, e2) { 
    execbuf.flags = e2->flags; 
    gem_execbuf(i915, &execbuf); 
} 


To: 

struct intel_engine_data ied;
... 
for_each_ctx_engine(i915, ctx, ied) { 
    execbuf.flags = ied.current_engine->flags; 
    gem_execbuf(i915, &execbuf); 
} 

Changes I want: 
1. From `const struct intel_execution_engine2 *e2` to `struct intel_engine_data ied`. 
2. Replace the last argument of for_each_ctx_engine() following the change on previous step. 
3. Change references from `e2` to `ied.current_engine` inside the iterator statement. 

Here is my starting point that finds about half of the call sites: 

@r1@ 
iterator I =~ "for_each_ctx_engine"; 
statement S; 
@@ 
* I(...) 
S 

I assume that I should create other rules and import I from r1 as the core of the changes I want. Can you point me to an example to help me here?

Thank you,

Peter

* - https://gitlab.freedesktop.org/drm/igt-gpu-tools