[CMake] Request for a reopen of bug 3812

[Chris Piker]

I'm in the process of evaluating cmake to replace our current
build system which is based solely on gnu make with custom
makefiles for each operating system we deal with.  If the
functionality described in Bug 3812 @

http://www.cmake.org/Bug/view.php?id=3812

were implemented cmake would be able to meet my needs and
work in a similar manner to our current system.

Specifically I'm attempting to do the following in my
CMakeLists.txt, which of course doesn't work:

if(DEFINED ENV{N_ARCH})
   set(proj_N_ARCH $ENV{N_ARCH})
else()
   set(proj_N_ARCH ${CMAKE_SYSTEM_NAME}.${CMAKE_SYSTEM_PROCESSOR})
endif()

set(proj_BUILD_DIR build.${proj_N_ARCH})
message(Build Directory is ${proj_BUILD_DIR})

set(CMAKE_BINARY_DIR ${proj_BUILD_DIR})

and then continue on with the build.

If I could put this kind of information in an "InSource.cmake"
file at the root directory of the source directory (as described
in bug 3812) it would be very useful since we have a large
network filesystem shared by handful of different operating
systems.

If I can help in getting this feature implemented please let
me know.
--
Chris