[CMake] EXTERNAL_OBJECT

[Yevgen Muntyan]

Hello,

How to make cmake rebuild a program when give file changes, if there isn't
a corresponding C or C++ file? I am trying to compile a windows resource file
in, it works, but I just can't make it rebuild the executable when the
resource file
changes. I have the following code:

SET(GGAP_SOURCES main.cpp)
ADD_CUSTOM_COMMAND(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/ggap.res
      COMMAND ${CMAKE_WINDRES} -i ${CMAKE_CURRENT_BINARY_DIR}/ggap.rc
--input-format=rc -o ${CMAKE_CURRENT_BINARY_DIR}/ggap.res -O coff
      DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/ggap.rc
    )
LIST(APPEND GGAP_SOURCES "${CMAKE_CURRENT_BINARY_DIR}/ggap.res")
SET_SOURCE_FILES_PROPERTIES("${CMAKE_CURRENT_BINARY_DIR}/ggap.res"
                                PROPERTIES EXTERNAL_OBJECT 1 GENERATED 1)

ADD_EXECUTABLE(ggap WIN32 ${GGAP_SOURCES})

SET_TARGET_PROPERTIES(ggap PROPERTIES LINK_FLAGS -Wl,ggap.res)

It does recreate ggap.res file whenever I change ggap.rc, but it won't
rebuild the
executable ggap.exe when that happens. Sometimes it actually will,
it's something
I can't understand at all (I suspect it happens because I change
CMakeLists.txt though,
not because of changed ggap.res).

Note, this is cross-comilation with mingw on linux, where simply
putting teh rc file into
sources doesn't work.

Thanks!
Yevgen