Henryk's experimental Coccinelle tests

Here are my experimental C flow tests using Coccinelle tool.

Tested environment:

Installed packages:

sudo apt-get install coccinelle graphviz gv

Future environment:

List of projects:

lock-ex1/ - simple locking example without preprocessor macros. Any call of acquire_lock() must be followed with release_lock() just before return. This example works properly.
lock-ex2 - example with macros - problem is when modified statements are part of macro (it will fail) - in our case the problem is caused when we need to modify return statement.
lock-ex3 - using just functions without macro definition. There is problem that Coccinelle does not known that my_return(x) that looks like function is actually macro ending with return(x); which affects execution flow significantly. Thus legit code may throw error:
```
ret_wo_release: node 24: return ...[1,2,10] in ok_with_branch \
  reachable by inconsistent control-flow paths
```

hpaluch-pil/coccinelle-sandbox