[CMake] custom target not working on windows

[Tyler Roscoe]

On Fri, Jul 31, 2009 at 08:42:10AM -0400, Marc Schafer wrote:
> add_custom_target ( generated_messages ALL
>   COMMAND
>   ${ANT_EXECUTABLE} -f ${PROJECT_SOURCE_DIR}/java/MessageGenerator/build.xml
> run
>   COMMAND
>   ${CMAKE_COMMAND} -E copy_if_different ${DICTIONARY_DIR}/c/messages.h
> ${PROJECT_BINARY_DIR}/include/messages.h
> )
> 
> This works fine on Linux and Mac with the make generator but does not work
> on Windows XP with the Visual studio 2008 generator.  From the build log
> file, I can see that a batch file is getting generated with two commands:
> one to run ant and the other to do the copy.  When the batch file is run,
> the ant command works fine, but the copy never seems to happen.  My library
> fails to build because it can't find messages.h even though it does exist in
> ${DICTIONARY_DIR}/c/messages.h

I have run into this. Here's a note from our (internal) wiki:

"If invoking a DOS batch file you must precede the command with the call
keyword. Also, it must not have quotes surrounding the call and the
command."

Your ant "executable" is probably a batch file. For reasons I don't
remember, VS gets confused and likes to exit immediately after running a
batch file as a custom build step.

tyler