Wrong coverage data for unit tests of a library - c++

Question

I want to test a complex shared library (cxsc) with the help of cmake. After a lot of trial and error i managed to create a html coverage report but the lines I test, with the boost testing framework, are still red.
This is the script I use to create the coverage report:
rm -fr build_coverage
mkdir build_coverage
cd build_coverage
cmake \
-DCMAKE_BUILD_TYPE=Coverage \
..
make
cd ../tests
make clean
make
cd ../build_coverage
make cxsc_coverage
The cmake part where the coverage report gets created:
# Cleanup lcov
COMMAND ${LCOV_PATH} --zerocounters --directory ${CMAKE_CURRENT_SOURCE_DIR}/build_coverage/CMakeFiles/cxsc.dir/src
COMMAND ${LCOV_PATH} --capture --initial --no-external --directory ${CMAKE_CURRENT_SOURCE_DIR}/build_coverage/CMakeFiles/cxsc.dir/src --output-file ${_outputname}.before
# Run tests
COMMAND LD_LIBRARY_PATH=${CMAKE_CURRENT_SOURCE_DIR}/build_coverage ${_testrunner} ${ARGV3}
# Capturing lcov counters and generating report
COMMAND ${LCOV_PATH} --capture --no-checksum --no-external --directory ${CMAKE_CURRENT_SOURCE_DIR}/build_coverage/CMakeFiles/cxsc.dir/src --output-file ${_outputname}.after
COMMAND ${LCOV_PATH} --add-tracefile ${_outputname}.before --add-tracefile ${_outputname}.after --output-file ${_outputname}.info
COMMAND ${GENHTML_PATH} -o ${_outputname} ${_outputname}.info
Makefile of the test binary (I think this is where the error is):
g++ \
-o test_runner \
main.cpp \
test_interval.cpp \
-I./../src \
-I./../src/rts \
-I./../src/asm \
-I./../src/fi_lib \
-I./../build_coverage \
-L./../build_coverage \
-lcxsc \
-Wall -Winline \
-lboost_unit_test_framework
This is what happens:
cmake -DCMAKE_BUILD_TYPE=Coverage .. build_coverage directory is created with a target.dir directory and *.gcno files in it
cd tests && make Test executable is created and linked against the shared library in the build_coverage directory (Maybe here is my mistake)
make coverage Coverage data is collected and tests are executed
Edit:
To clarify my problem, there are some lines covered but only global consts or one helper function which is used pretty often. But not the functions/methods I call in my tests.
Files in build_coverage/CMakeFiles/cxsc.dir/src/:
After cmake -DC...: A few *.cmake and *.make files
After make in build_coverage dir: *.gcno files
After lcov -c -i ...: Still *.gcno files
After running tests: *.gcda and *.gcno files
After lcov -c ...: A lot of movement in the directory but still the same filenames

Answer 1

I don't see any gcov flags in your makefile. Try this one for test_runner :
g++ \
-Wall -Winline -fprofile-arcs -ftest-coverage \
main.cpp \
test_interval.cpp \
-I./../src \
-I./../src/rts \
-I./../src/asm \
-I./../src/fi_lib \
-I./../build_coverage \
-L./../build_coverage \
-lcxsc \
-lboost_unit_test_framework \
-lgcov \
-o test_runner
Your shared library need those flags too :
SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fprofile-arcs -ftest-coverage")
SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -lgcov")
See this post with a similar problem.
NB : "--coverage" can substitute "-fprofile-arcs -ftest-coverage" and "-lgcov"