[CMake] Multiple source directory scenario and cdt generator

[Dan Kegel]

In http://www.cmake.org/pipermail/cmake/2011-November/047250.html
I wrote

"I can't reorganize the source tree on the developers,
so I'm making do by putting the enclosing CMakeLists.txt next to all
the projects:
   toplevel/trunk/CMakeLists.txt
which is checked out to
   toplevel/CMakeLists.txt
It does
   add_subdirectory(../libfoo libfoo)
   add_subdirectory(../libbar libbar)
   add_subdirectory(../baz baz)
This has the possible advantage that one can have multiple
"top levels" (say, one for server code, and one for client).
I don't know how many shops suffer from this svn layout, but I'll probably
add an example covering it anyway for completeness once I'm sure
it doesn't explode in practice."

Right, well, I found out where it explodes in practice.  Here's an example:
http://code.google.com/p/winezeug/source/browse/trunk/cmake_examples/ex7/

The problem comes when using the cdt generator.  We can't use
-DECLIPSE_CDT4_GENERATE_SOURCE_PROJECT=TRUE
since there are more than one source project, but the
source project that generates is really trivial, so I generate
one for each source directory myself with a bit of shell:

for dir in demo libsrc
do
    sed "s/PROJNAME/_$dir/" < ../skeleton.project > ../$dir/.project
done

before or after running cmake.

It all works great, the source projects all show up, the project builds...
BUT when you edit a source file and tell eclipse to rebuild, it just
sits there.  It doesn't know that the source projects are related to
the build project.

It looks like adding a link does the trick:

--- .project.old	2011-11-11 22:51:56.797674441 +0000
+++ .project	2011-11-11 22:52:25.380913484 +0000
@@ -113,5 +113,11 @@
 			<type>2</type>
 			<location>/home/dank/winezeug/cmake_examples/ex7/demo</location>
 		</link>
+		<link>
+			<name>[Source directory 2]</name>
+			<type>2</type>
+			<location>/home/dank/winezeug/cmake_examples/ex7/libsrc</location>
+		</link>
+
 	</linkedResources>
 </projectDescription>

After I add those lines to the .project, saved changes in libsrc do seem
to cause a rebuild the next time you click "build project".

So, I guess to support this style of project, the cdt generator
should call cmExtraEclipseCDT4Generator::AppendLinkedResource()
once for each call in my outer CMakeLists.txt like
add_subdirectory(../libsrc libsrc).

I have no idea how to make that happen inside the cdt generator.  I could kludge
it in the shell script that runs cmake, but then it would break whenever
the project was updated and cmake rebuilt the project automatically.

Was http://public.kitware.com/Bug/view.php?id=9978 /
https://github.com/rpavlik/CMake/commit/10aece0d8199409fbb695478eab2c60545fcf310
related at all?
- Dan