I am new to using gcov and gcovr and I wanted to get the statement coverage of a given function. It is coded in C, compiled with minGW and called from Matlab (which I use to later process the coverage information given by gcov).
I am executing the code in two different ways: for the first one I am using Simulink, in which the function inputs are given by the outputs of other functions that encompass the dynamic process I modelled on Simulink. For the second one, I am using the editor on Matlab and defining directly the inputs to the function.
Because the Simulink - executed code depends on secondary functions whose output I cannot control (contrary to the second way), I expected the statement coverage of the first execution to be worse than the second but to have the same number of statement lines (since it is exactly the same code). However, I found that:
- For some function callers inside the function, the second method counts the few lines of the caller (like the first line and the following lines when the input and output variables are too long to fit in a single line), adding up statements that in reality don't exist.
- The first method doesn't take into account some variable definitions at the beginning of the code, not counting them as line statements (for instance, setting input variables to 0).
Has anybody also encountered this discrepancy when getting the statement coverage of the same function? Do you know why this may be?
Thank you very much in advance!
