Framework for building and managing third-party libraries

Question

I am working on a cross-platform project which uses a large number of third party libraries (currently 22 and counting, and I expect this number to increase significantly). My project is CMake-based, and keeps the ThirdParty/ directory organized like so:

ThirdParty/$libname/include/
ThirdParty/$libname/lib/$platform/$buildtype/

My CMakeLists.txt has logic to determine the appropriate values for $platform (mac-i386, mac-ia64, win32-i386, and so on) and $buildtype (debug/release).

The difficulty arises in keeping these libraries up-to-date for each platform. Currently I am doing this manually - when I update one library, I go and rebuild it for each platform. But this is a nightmare, and adding a new platform is a two day affair.

This would be easy to automate if the third party libraries were themselves CMake-based, but they use everything from CMake to autoconf to custom solutions to hand-rolled Makefiles. There is no consistency between them, and all require various hoops to be jumped through with regards to build platform (especially with regards to 32- vs. 64-bit builds).

Are there any tools (or CMake extensions) which would make this easier to manage? Is there even any reasonable common ground that can be reached between CMake and autoconf, for example?

The ideal solution would give me a single command to build everything that needs rebuilding for a given platform (cross-compilation is not necessary, as I have access to all necessary platforms), but anything that incrementally makes my life easier would be appreciated.

Answer 1

You can probably use ExternalProject for this.

Create custom targets to build projects in external trees. The 'ExternalProject_Add' function creates a custom target to drive download, update/patch, configure, build, install and test steps of an external project.

If you already have the source in your project's file hierarchy, then you can use something like this (for zlib):

include(ExternalProject)
ExternalProject_Add(zlib URL ${CMAKE_CURRENT_SOURCE_DIR}/zlib-1.2.4/
    CONFIGURE_COMMAND cd <SOURCE_DIR> && ./configure --prefix=${CMAKE_CURRENT_BINARY_DIR}/zlib-build
    BUILD_IN_SOURCE 1
    BUILD_COMMAND make)

That will copy the zlib source code from your source tree into the build tree, run the configure step (after cd'ing into the copied directory), then run make on the configured directory. Finally the built version of zlib is installed into the current build directory, in a sub-directory called zlib-build.

You can tweak the setup, configure, and build steps however you like - zlib 1.2.4 for example doesn't like to have "configure" run out-of-source.

For a custom setup, you can skip the CONFIGURE step and just run the build command (for example). This requires a recent version of CMake to work (2.8+).