[Cmake] Generating header files and dependencies

[Bradley Lowekamp]

	I am needed to use a script to generate some source and header files 
in my project. I was able to get the generation of the source code to 
work well and all of the dependencies to be correct with the  
SET_SOURCE_FILES_PROPERTIES and the GENERATED option.
	However with generated header files I can not seem to get the 
dependencies to work correctly. The  SET_SOURCE_FILES_PROPERTIES with 
the GENERATED option appears to have no affect. When CMake tries to 
make the dependencies for the source files, the header files do not 
exist and so they are not implicitly added as dependent for anything, 
so they will not get generated. I had to resort to adding them as a 
dependency  to all source files, which results in an unacceptable 
amount of building needing to be done when any generated header file is 
modified, but it does work. (I have what I am doing at the end of this 
e-mail.) So how can I get the dependencies to work correctly for the 
header files?
	I just had a thought as I was righting up this e-mail. If I could add 
a dependency to the make_depends or what ever target it is, I could 
some how make the make depends target dependent on the generated header 
files or something? Any suggestions about how to get this to work would 
be good and very much appreciated I am actually not sure what versions 
of CMake I have tried these things with.

Thanks!
Brad


FOREACH(file ${GENERATED_PLAWARE_LIB_HEADER})
   ADD_CUSTOM_COMMAND( OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/include/${file}
     COMMAND ${TCL_TCLSH}
     ARGS ${PLAWARE_SOURCE_DIR}/varexpand.tcl 
${CMAKE_CURRENT_SOURCE_DIR}/include/${file}.in ${CMAKE_CUR
RENT_BINARY_DIR}/include/${file}
     MAIN_DEPENDENCY ${CMAKE_CURRENT_SOURCE_DIR}/include/${file}.in
     DEPENDS ${PLAWARE_SOURCE_DIR}/varexpand.tcl 
${CMAKE_CURRENT_SOURCE_DIR}/include/${file}.in )
   SET(GENERATED_HEADER_FILES  ${GENERATED_HEADER_FILES} 
${CMAKE_CURRENT_BINARY_DIR}/include/${file} )
ENDFOREACH(file)

SET_SOURCE_FILES_PROPERTIES(${PLAWARE_LIB_SRC} PROPERTIES 
OBJECT_DEPENDS "${GENERATED_HEADER_FILES}" )


========================================================
Bradley Lowekamp
Management Systems Designers Contractor for
Office of High Performance Computing and Communications
National Library of Medicine
'blowekamp at mail.nih.gov