Cmake adds gcov code coverage test support

Add gcov to cmakeCodeCoverage test support

(Jinqing's column)

Add the enable_gcov option to root cmakelist.txt:

Option (enable_gcov "enable gcov (debug, Linux builds only)" Off)

If (enable_gcov and not Win32 and not Apple)
Set (cmake_cxx_flags_debug "$ {cmake_cxx_flags_debug}-fprofile-arcs-ftest-coverage ")
Set (cmake_c_flags_debug "$ {cmake_c_flags_debug}-fprofile-arcs-ftest-coverage ")
Set (cmake_exe_linker_flags_debug "$ {cmake_exe_linker_flags_debug}-fprofile-arcs-ftest-coverage-lgcov ")
Endif ()

Use the code above to upload the cmakelists.txt of mysql.

Run cmake as follows:

Cmake src_dir-dcmake_build_type = debug-denable_gcov = 1

After compilation, you can see the graph file *. gcno.

After running, you can see that the data file *. gcda is generated.

Run gcov main. cpp. gcno to generate the main. cpp. gcov test result.