Replicant » Upstreaming patches

h1. GuixBuildSystem

h2. Use cases

Guix can be used for faster testing:

* It can build software that uses autotools and Android.mk Makefiles

* We might be able to use it to iterate over different Android versions, to test libsamsung-ril changes for various RIL API way faster (without even having to use it in a specific Replicant version, use repo, etc).

* It's more self contained than the whole Replicant source code

TODO:

* Import the compilation flags for various Replicant versions like -Werror -Wnounused to make sure that everything is usable in all Replicant versions.

* Finish packaging libsamsung-ril

* Add more automatic testing either in libsamsung-ipc / libsamsung-ril and or in the unofficial Guix packages.

h2. Implementation

Guix currently uses "android-make-stub":https://github.com/daym/android-make-stub.git to build Android software using Android.mk.

There are some comments in Guix source code that cross compilation isn't supported for the android-ndk build system.

Practically speaking it means that Guix won't be able to build any BUILD_SHARED_LIBRARY, BUILD_SHARED_LIBRARY or BUILD_STATIC_EXECUTABLE, however building the HOST_* counterpart works fine.

To workaround that they simply do replace them in the Android.mk during the build procedude:

* BUILD_SHARED_LIBRARY becomes BUILD_HOST_SHARED_LIBRARY

* BUILD_SHARED_LIBRARY becomes BUILD_HOST_STATIC_LIBRARY

* BUILD_STATIC_EXECUTABLE becomes BUILD_HOST_STATIC_EXECUTABLE

For instance we have:

<pre>

   (arguments

    `(#:phases

      (modify-phases %standard-phases

		     (delete 'bootstrap)

		     (add-before 'build 'patch-host

				 (lambda _

				   ;; TODO: Cross-compile.

				   (substitute* "Android.mk"

						(("BUILD_SHARED_LIBRARY") "BUILD_HOST_SHARED_LIBRARY")

						;; (("BUILD_STATIC_LIBRARY") "BUILD_HOST_STATIC_LIBRARY")

						;; (("BUILD_STATIC_EXECUTABLE") "BUILD_HOST_STATIC_EXECUTABLE")

						)

				   #t))

		     )))

</pre>

Here the (delete 'bootstrap) is because the build is done in several phases, and here the bootstrap phase wasn't overriden by the android-ndk build system yet. As a result it tried to run autogen.sh. That might be because in libsamsung-ipc there is both an android build system and an autotools based one.

h2. Example

* There is some work in progress to package libsamsung-ril for faster testing: https://git.replicant.us/contrib/GNUtoo/guix/tree/gnu/packages/replicant.scm?h=libsamsung-ril

h2. Additional work

There is some work in progress by Julien Lepiller / roptat to package more Android components (including build systems like blueprint / soong) in this  "android-build.scm":https://framagit.org/tyreunom/guix-android/-/blob/master/android/packages/android-build.scm .