MATLAB: Do I get “Not computed” values for Code Complexity Metrics: Program Stack Usage using Polyspace Code Prover Access R2020a

Question

In Polyspace code prover, I would like to determine the Code Complexity Metrics "Program Maximum Stack Usage" and "Program Minimum Stack Usage".

I have used the '-code-metrics' option and also activated the checkers PROG_MAX_STACK and PROG_MIN_STACK, but still I am not able to see the corresponding metrics in my Access dashboard.

(In the result list I can find stack usage values for functions but I get "Not computed" at project level.)

The code project has no 'open' run-time red checks, so I don't understand why the value is not calculated.

I had one red check related to infinite loop, but I've justified it as it is an intended loop used to manage background task.

Answer 1

If the stack size usage is *"Not computed" *there are 3 common reasons:

• Please, check whether the function or its callee contains a red check (definite run-time error). If yes, the error has to be fixed. If your program contains a red check, you do not see this metric. The reason is that code following a red check is not analyzed. If that code contains function calls, any metric value shown would be inaccurate.
• Even if there are any intentional infinite loops like while(1) { } or a red loop that was justified, these would prevent this metrics from being calculated as well.
• You also do not see this metric if your code has calls to recursive functions. Please, check whether the function or its callee contains a call to a recursive function. Please, also be aware that this is the case, if there is a potential recursion (if the recursion could be avoided with certain conditions)

In order to spot places where recursion is used, you might turn on the following MISRA checker "MISRA C:2012 Rule 17.2" and check the results for Coding Rule Violations.

Please refer the below link for more documentation:

https://www.mathworks.com/help/releases/R2020a/bugfinder/ref/misrac2012rule17.2.html