feat(HIS): add CALLS his metric

[AfonsoSantos96]

This PR introduces the feature of checking the number of function calls inside a function.
Each function must only call a maximum of other 7 functions during its execution flow.
The cflow tool is used to check this metric.

Checklist:

• The changes generate no new warnings when building the project. If so, I have justified above.
• I have run the CI checkers before submitting the PR to avoid unnecessary runs of the workflow.

[danielRep]

While testing this inside the partitioner, I'm getting this log output:

== Checking McCabe Cyclomatic Complexity metric ==
At src/core/main.c(4): complex_function has a complexity of 12. The maximum is 10
"/home/daniel/workspace/osyxtech/bao-partitioner/src/arch/armv8/inc/sysregs.h", line 83: expected pretty much anything after closing paren of function, but got EOF

== Check done with 1 error(s) ==

== Checking the number of called functions ==
At /core/main.c (81): calling_function calls 8 functions.The maximum are 7 calls
cflow:/home/daniel/workspace/osyxtech/bao-partitioner/src/core/console.c:37: chars_writen redefined
cflow:/home/daniel/workspace/osyxtech/bao-partitioner/src/core/console.c:33: this is the place of previous definition
== Check done with 1 error(s) ==

make: *** [ci/ci.mk:299: his-check] Error 255

The first report seems correct, since I introduce those +7 function calls.
The next two reports regarding console.c seem that the tool is checking other properties outside the scope of the his metric introduced in this PR. Despite not being triggered as an error, I would avoid those out-scope log information.

[AfonsoSantos96]

While testing this inside the partitioner, I'm getting this log output:

== Checking McCabe Cyclomatic Complexity metric ==
At src/core/main.c(4): complex_function has a complexity of 12. The maximum is 10
"/home/daniel/workspace/osyxtech/bao-partitioner/src/arch/armv8/inc/sysregs.h", line 83: expected pretty much anything after closing paren of function, but got EOF

== Check done with 1 error(s) ==

== Checking the number of called functions ==
At /core/main.c (81): calling_function calls 8 functions.The maximum are 7 calls
cflow:/home/daniel/workspace/osyxtech/bao-partitioner/src/core/console.c:37: chars_writen redefined
cflow:/home/daniel/workspace/osyxtech/bao-partitioner/src/core/console.c:33: this is the place of previous definition
== Check done with 1 error(s) ==

make: *** [ci/ci.mk:299: his-check] Error 255

The first report seems correct, since I introduce those +7 function calls. The next two reports regarding console.c seem that the tool is checking other properties outside the scope of the his metric introduced in this PR. Despite not being triggered as an error, I would avoid those out-scope log information.

Nicely spotted! During my tests that stderr didn't appear to me. Now that I re-ran your setup, I can see the error message.
To fix this, I redirected all stderr messages of all tools to /dev/null

[danielRep]

Small change. Tested it and LGTM.

[danielRep]

I had the change substantially how this metric has been done. Previously the cflow was cap to a depth of 2 which lead to some calls not being capture. To verify this just run cflow -l --depth=2 src/calls/calls.c vs cflow -l src/calls/calls.cusing the bao-his-tests.
With the newer changes we construct a tree from cflow output to handle data. Each node represents a function call and through a traversal process we identify functions with a greater number of functions calls than the permitted limit/threshold.