C++ Test Coverage

I've been working on additional functional tests this week for my current project. Dan was working with me this morning when he asked about C++ test coverage tools. I have never used one for C++, so we did the obvious thing and googled for it.

Turns out that gcc comes with gcov.

1) Add the following option to the environment.

    export CPPFLAGS="-fprofile-arcs -ftest-coverage"

2) Compile as normal
3) Run your tests.
4) gcov -l -c FileName.cpp
5) vi FileName.cpp.gcov and search for "######"

"######" indicate lines that were never executed.

It is simple and easy to use.

Here is an example of the output of gcov:

                    11:    9:  for (i = 0; i < 10; i++)
                    10:   10:    total += i;
                     -:   11:
                     1:   12:  if (total != 45)
                 #####:   13:    printf ("Failure\n");
                     -:   14:  else
                     1:   15:    printf ("Success\n");

Line #13 above was never executed. Line #9 was executed 11 times. You can also have it output percentages.