Cmake custom target command does not work on all inputs

Question

I am building a number of sources and then running gcovr with JSON output:

foreach(COMPONENT IN LISTS BLAHDIBLAH)
   ...
   add_custom_command(TARGET ${COMPONENT}_coverage
               COMMAND gcovr --exclude-unreachable-branches -k -r ${CMAKE_CURRENT_SOURCE_DIR} --json -o ${COMPONENT}_coverage_lines.json ${CMAKE_BINARY_DIR}/CMakeFiles/${COMPONENT}_test.dir/${UNIT_PATH_${COMPONENT}}
               COMMAND gcovr --exclude-unreachable-branches -k -r ${CMAKE_CURRENT_SOURCE_DIR} --json -b -o ${COMPONENT}_coverage_branches.json ${CMAKE_BINARY_DIR}/CMakeFiles/${COMPONENT}_test.dir/${UNIT_PATH_${COMPONENT}}
   )

   list(APPEND COV_DEPS ${COMPONENT}_coverage)
   ...
endforeach()

Later on, I add a coverage target to combine the gcovr output:

    add_custom_target(coverage
            COMMAND gcovr --exclude-unreachable-branches -k -r .. --add-tracefile coverage/*.json --html-details coverage/coverage.html
            WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
            )

If I run make coverage, only the first source file is picked up by gcovr, but if I run the command manually:

gcovr --exclude-unreachable-branches -k -r .. --add-tracefile coverage/*.json --html-details coverage/coverage.html

... then all the sources are picked up.

Why does that command work in the terminal, but not in CMake?

Answer 1

The answer is in the custom target. The argument to --add-tracefile needs to be enclosed in speech-marks, which themselves need to be escaped:

COMMAND gcovr --exclude-unreachable-branches -k -r .. --add-tracefile coverage/*.json --html-details coverage/coverage.html

COMMAND gcovr --exclude-unreachable-branches -k -r .. --add-tracefile \"coverage/*.json\" --html-details coverage/coverage.html