In CTest, why is the variable argument to my function not set?

Question

I have a CTestList.cmake file containing this function definition and call:

function(add_test_r testname )
  add_test(
    ${testname} python executeRegressionTestCase.py ${testname}
  )
endfunction(add_test_r)

add_test_r(Test01)

I need to support testing through CMake directly, cmake ..; make test, and through CTest without running CMake first. When CMake builds the test target and I run make test, the function above executes fine. However, when I run the same file with CTest, ${testname} is empty. Are function variables not supported in CTestList when running with CTest or is there something I'm missing?

Answer 1

I don't have a definitive answer, but after some testing it looks like CMake does a preprocessing step for the input files. Specifically, it reads in CTestList.cmake, evaluates the variables and functions, and generates an "expanded" CTestTestfile.cmake. Running CTest with a steering script does not run the preprocessing step so the variables and functions are not expanded. A few people on the internet have suggested that the CTestTestfile.cmake used in the steering script should be generated by CMake in the first place. Unfortunately, thats not the use case I'm looking for, but it may help someone else with running into this problem.