CMake - copying/merging files with dependencies a change-checking - cmake

Question

I have a big project with one executable, some plugins and web interface with some generated JSONs.
Therefore, after I compile executables and .so plugins, I'm doing following:
Merge all .js files into one big
Compile "generators" (set of macros and printfs to describe some structures in C++ code)
Run generators and generate JSON files (with some sed and jshon) processing
In install phase, and copy all of this and some other files to their destination directories (which should be created if doesn't exists).
But I don't know, how to use CMake to make correct dependencies and date-time checking. Actually, first step is made with:
FILE(GLOB WEB_INPUT_JS *.js)
FILE(WRITE scripts.js.tmp "")
FOREACH(SCRIPTFILE ${WEB_INPUT_JS})
FILE(READ ${SCRIPTFILE} CONTENTS)
FILE(APPEND scripts.js.tmp "${CONTENTS}")
ENDFOREACH()
CONFIGURE_FILE(scripts.js.tmp ${WEB_BUILD_PATH}/scripts.js COPYONLY)
But this doesn't create dependency in makefiles. I want to re-run this piece of "code", when some of ${WEB_INPUT_JS} files has been changed or ${WEB_BUILD_PATH}/scripts.js has been deleted.
Third step is made with series of
add_custom_command(TARGET gen_somedata POST_BUILD COMMAND gen_somedata | sed ${JSON_SED} | jshon > ${JSON_BUILD_PATH}/somedata.json)
install (FILES ${JSON_BUILD_PATH}/somedata.json ......nextfiles.... DESTINATION ${JSON_OUTPUT_PATH})
How is this done? Thanks much for your answers!

Answer 1

So I've finally found out, how to do some of this things.
Merging files is pretty tricky.
First, cmake "script" doing merging is needed (I will explain some lines later). I will name it "concat.cmake":
FUNCTION(CONCAT_FILES OUTPUT FILELIST)
FILE(WRITE ${OUTPUT} "")
FOREACH(SCRIPTFILE ${FILELIST})
FILE(READ ${SCRIPTFILE} CONTENTS)
FILE(APPEND ${OUTPUT} "${CONTENTS}")
ENDFOREACH()
ENDFUNCTION(CONCAT_FILES)
STRING(REPLACE "," ";" FILELIST ${FILELIST})
CONCAT_FILES(${OUTPUT} "${FILELIST}")
Then, when merging script is used as follows (write it into CMakeLists.txt):
1) First, make an file list (using globbing or by writing file list by hand).
FILE(GLOB INPUT_FILES_LIST *.js) # get list of JS files
2) The only way, how to pass a cmake list to other cmake script is creating file list separated by comma, then passing comma-separated list to external script. I've done this following way:
SET(FILELIST "")
FOREACH(ITEM ${INPUT_FILES_LIST})
SET(FILELIST "${FILELIST},${ITEM}") # append list item by ','
ENDFOREACH()
STRING(SUBSTRING ${JSFILES} 1 -1 JSFILES) # remove first ','
3) Now it's not problem to call merging script..
add_custom_command(OUTPUT some_output_file.ext
COMMAND ${CMAKE_COMMAND} -DFILELIST=${FILELIST} -DOUTPUT=some_output_frile.ext -P ${CMAKE_CURRENT_SOURCE_DIR}/concat.cmake
DEPENDS ${INPUT_FILES_LIST} VERBATIM )
The precedent code will correctly track changes in input files and output file will be generated when missing or input changes. Installation is just easy as
INSTALL (FILES "output.ext" DESTINATION /usr/share/...)