[CMake] cmake side effects: possible bug

[William A. Hoffman]

At 05:13 PM 8/27/2006, Alan W. Irwin wrote:
>On 2006-08-27 16:30-0400 William A. Hoffman wrote:
>
>>At 12:00 PM 8/27/2006, Steve Johns wrote:
>>>Michael Bell wrote:
>>>>>ADD_CUSTOM_TARGET(makeExecutable ALL)
>>>>>FOREACH(file ${SCRIPTS})
>>>>>  CONFIGURE_FILE(${CMAKE_CURRENT_SOURCE_DIR}/${file}
>>>>>      ${EXECUTABLE_OUTPUT_PATH}/../${file}
>>>>>      @ONLY)
>>>>>  ADD_CUSTOM_COMMAND(
>>>>>      TARGET makeExecutable
>>>>>      POST_BUILD
>>>>>      COMMAND chmod
>>>>>      ARGS +x ${EXECUTABLE_OUTPUT_PATH}/../${file}
>>>>>      )
>>>>>ENDFOREACH(file)
>
>>[...] So, in the above example, the foreach and configure_file will run
>>when cmake is run on the project, and not when make is run.  The custom
>>target will run when make is run but not the foreach and configure_file.
>
>
>Bill, just to make sure I am understanding your explanation, does that mean
>the above ADD_CUSTOM_COMMAND in the foreach loop creates a large number of
>different rules (one for each of the files in the SCRIPTS list) at cmake
>time, all of which are executed at make time?

Yes, that is what it is doing, basically, it is creating a makefile like this:
makeExecutable:
    chmod a+x file1
    chmod a+x file2
    chmod a+x file3 
....

But any time one of the input files changes, cmake is re-run,
and it is rerun on the whole project.

Something like this:
runCmake:  CMakeLists.txt [any input to a configure_file command] 
   cmake /path/to/binary/for/project

Since variables can be shared from parent and sibling CMakeLists.txt files,
cmake has to read the whole project before creating any single Makefile.

-Bill