[CMake] Add pre-existing object file to linker line?

[Trevor Kellaway]

Bill,

> >> You want to create your own rules for CMAKE_(LANG)_COMPILE_OBJECT:
> It should be like this:
> "command ..."
> "command2 .."
> "command3 .."

Thanks, as you say you can have multiple commands. Alas, I've fallen
down another hole which rules this solution out.

For any lurkers there are a few caveats:

1) The command invoked must have native style slashes, under Windows
forward slashes in the command caused it to be ignored.

2) Any variable arguments can't be lists, as they cause a line split,
which is then interpreted as another command. The solution is to undo
the list:

  FOREACH (_arg ${MY_LIST})
	SET (MY_ARGS "${MY_ARGS} ${_arg}")
  ENDFOREACH (_arg ${MY_LIST})
 
  "command ${_arg} <SOURCE>"

3) Be aware that the command's current directory will be in the binary
tree.


Because of (3) I can't use this solution, as I need to run the command
in the source directory.

The ADD_CUSTOM_COMMAND solution is still the best (I can also the have
source file specific args which CMAKE_(LANG)_COMPILE_OBJECT won't
support), if only I could determine the object file directory. 

I notice that GET_SOURCE_FILE_PROPERTIES has a LOCATION property that
returns the source file location. How hard would it be to add the same
for an object file based on cmGetSourceFilePropertyCommand?

Your assistance is much appreciated.

 - TrevK