[CMake] cannot get moc to run on win32 in subdirectories

[Brad King]

Patrick Noffke wrote:
> I'm using cmake 2.4.2 on windows, with Visual Studio 2005 Express Edition.
> 
> I have a Qt class in a subdirectory from my top-level project.  I don't want to build the class as a library, but rather include the source code in the top-level project.  But I can't get moc to run on the file in the subdirectory.
> 
> A snippet of my CMakeLists.txt looks like this:
> 
> SET(FIXED_ASPECT_IMAGE_DIR ${my_project_SOURCE_DIR}/src/fixed_aspect_image_win32)
> 
> GET_FILENAME_COMPONENT(infile ${FIXED_ASPECT_IMAGE_DIR}/FixedAspectImage.h ABSOLUTE)
> MESSAGE(STATUS "infile = ${infile}")
> 
> MESSAGE(STATUS "moc = ${QT_MOC_EXECUTABLE}")
> 
> IF (EXISTS ${infile})
>     MESSAGE(STATUS "infile exists")
> ENDIF (EXISTS ${infile})
> 
> ADD_CUSTOM_COMMAND(OUTPUT ${FIXED_ASPECT_IMAGE_DIR}/FixedAspectImage.moc
>    COMMAND ${QT_MOC_EXECUTABLE}
>    ARGS ${moc_includes} -o ${FIXED_ASPECT_IMAGE_DIR}/FixedAspectImage.moc ${infile}
>    DEPENDS ${infile})
> ADD_FILE_DEPENDENCIES(${infile} ${FIXED_ASPECT_IMAGE_DIR}/FixedAspectImage.moc)
> 
> 
> 
> 
> The project is "my_project", and the above CMakeLists.txt is in the src subdirectory.  The FixedAspectImage class is in the fixed_aspect_image_win32 directory (below the src directory).  I've tried QT4_AUTOMOC, but this puts the moc file in the src subdirectory, not in fixed_aspect_image_win32 (this causes the #include "FixedAspectImage.moc" line to not find the .moc file).
> 
> I tried QT4_GENERATE_MOC, but no rule to generate the moc file was getting created.  So I copied the ADD_CUSTOM_COMMAND from QT4_GENERATE_MOC, and this still doesn't generate the rule.  I'm getting the "infile exists" status message, and the moc executable is pointing to the right place.  I can run the moc command from the command line just fine.
> 
> Other source files in the src directory are getting moc rules (using QT4_AUTOMOC for those), and moc is in fact run for them.
> 
> Why can't I get the moc to run on a file in a subdirectory?  Or how can I get the QT4_AUTOMOC to output the file in the same place as the header file?
> 
> Incidentally, I'm not able to build Qt applications out of the source tree, and it's the same sort of problem.  The moc files are generated in the build directory, causing the #include "foo.moc" lines to not find the .moc files.
> 
> In addition, I can get this to work on Linux just fine with the QT4_GENERATE_MOC command.

Custom command outputs created by ADD_CUSTOM_COMMAND may be referenced 
only in the directory containing the command but not subdirectories.

You should use the INCLUDE_DIRECTORIES command to add the location of 
the moc file to your include path.  Alternatively set the 
CMAKE_INCLUDE_CURRENT_DIR variable to 1.

-Brad