0. Make sure you have built\installed gcov\lcov\genhtml on your linux machine
1. Put -g -O0 -fprofile-arcs -ftest-coverage to your CXXFLAG in your makefile. (--coverage doesn't work for me)
2. Put -lgcov to LFLAGS
3. gmake your project and run your binaries
4. In case your intermediate output folder is different with your src folder, copy *.gcda\*.gcno\*.o(*.o?) files to the same folder of src with the same names
5. lcov --capture -directory ../../EACH_DIR --output-file YOUR_PRJ_NAME.info, at your binary path.
6. If needed, converge all your .cov files into one: lcov -a 1.cov -a 2.cov... -o n.gov
7. genhtml n.cov --output-directory WEB_PATH
Important note: geninfo in lcov 1.9- has a hanging bug. Please make sure you use 1.10+.