[CMake] Mixing non-CMake ExternalProjects using Visual Studio

[Braden McDaniel]

On Apr 1, 2013, at 3:10 PM, Micha Hergarden <micha.hergarden at gmail.com> wrote:

> On 01-04-13 20:02, Braden McDaniel wrote:
>> When mixing a CMake Visual Studio build that has ExternalProjects (that is, via ExternalProject_Add) that use non-CMake makefile builds, how does one resolve the mismatch between the *_<config> variables (CMAKE_CXX_FLAGS_RELEASE, etc.)?
>> 
>> Specifically, how do I propagate the build flags in the *_<config> variables down to the ExternalProject?  I can't seem to find a way in CMake that will let me pick which variable to propagate (that is, CMAKE_CXX_FLAGS_DEBUG when I'm building the Debug configuration, CMAKE_CXX_FLAGS_RELEASE when building the Release configuration, etc.).
>> 
>> One option seems to be just to build the makefile-based ExternalProject four times--one for each configuration CMake generates in its project files.  But that, too, has a problem: what if the makefile-based ExternalProject has a dependency on another ExternalProject with a CMake build?
>> 
>> Are there any good solutions to these sorts of problems?
>> 
> 
> In my project I've added wrappers for each stage:
> 
> PATCH_COMMAND "${CMAKE_CURRENT_BINARY_DIR}/patchwrapper"
> CONFIGURE_COMMAND "${CMAKE_CURRENT_BINARY_DIR}/configurationwrapper"
> BUILD_COMMAND "${CMAKE_CURRENT_BINARY_DIR}/buildwrapper"
> INSTALL_COMMAND "${CMAKE_CURRENT_BINARY_DIR}/installwrapper"
> 
> These wrappers include a defaults file that I create from a defaults.in, using configure_file command. That way I can set flags and all kinds of build related variables. Although officially it's not recommended to use it in generic cmake based projects, it works quite well for me as I don't distribute my project. I just use the external projects to precompile some third party tooling.


Thanks... I've made quite a bit of progress with this approach.

I'm attempting to use cmake -P for the wrapper script and I've been mostly successful; though I've hit a bit of a speedbump that I'll outline in another posting.

-- 
Braden McDaniel
braden at endoframe.com