Issue 1414 - Document how to build libadblockplus for Android

README.md

 libadblockplus
 ==============
 
 A C++ library offering the core functionality of Adblock Plus.
 
 Getting/updating the dependencies
 ---------------------------------
 
 libadblockplus has dependencies that aren't part of this repository. They are
 retrieved and updated during the build process, but you can also manually update
 them by running the following:
 
     ./ensure_dependencies.py
 
 Building
 --------
 
+### Supported target platforms and prerequisites
+
+You need a C++11 compatible compiler to build libadblockplus.
+
+Win32:
+* Microsoft Visual Studio 2010, 2012
+
+Linux:
+* g++ 5.2
+
+Mac:
+* clang 3.6 for OS X
+
+Android:
+* The host system should be Linux or OS X
+* android-ndk-r9, android-ndk-r10c. You can download the latter for [OS X](http://dl.google.com/android/ndk/android-ndk-r10c-darwin-x86_64.bin), [Linux 32](http://dl.google.com/android/ndk/android-ndk-r10c-linux-x86.bin), [Linux 64](http://dl.google.com/android/ndk/android-ndk-r10c-linux-x86_64.bin).
+* g++ multilib
+
+If you have a compilation issue with another compiler please [create an issue](https://issues.adblockplus.org/).
+
 ### Unix
 
 All you need is Python 2.7 and Make:
 
     make
 
 The default target architecture is x64. On a 32 bit system, run:
 
     make ARCH=ia32
 
@@ skipping 16 matching lines @@
 
 * Execute `createsolution.bat` to generate project files, this will create
 `build\ia32\libadblockplus.sln` (solution for the 32 bit build) and
 `build\x64\libadblockplus.sln` (solution for the 64 bit build). Unfortunately,
 V8 doesn't support creating both from the same project files.
 * Open `build\ia32\libadblockplus.sln` or `build\x64\libadblockplus.sln` in
 Visual Studio and build the solution there. Alternatively you can use the
 `msbuild` command line tool, e.g. run `msbuild /m build\ia32\libadblockplus.sln`
 from the Visual Studio Developer Command Prompt to create a 32 bit debug build.
 
-### Supported compilers
+### Building for Android
 
-You need a C++11 compatible compiler to build libadblockplus.
+First set ANDROID_NDK_ROOT environment variable to your Android NDK directory.
 
-The compilation was tested with the following compilers:
-* g++ 4.8
-* Microsoft Visual Studio 2010, 2012
-* clang 3.4 for Android (from android-ndk-r9)
-* clang 3.6 for OS X
+To build for *x86* arch run:
 
-If you have a question about another compiler please [create an issue](https://issues.adblockplus.org/).
+    make android_x86
+
+To build for *arm* arch run:
+
+    make android_arm
 
 Usage
 -----
 
 You can use libadblockplus to build an ad blocker. Or, strictly speaking, a web
 content filter. Just like Adblock Plus, it can detect resources that should be
 blocked based on their URL and context information, and generate CSS selectors
 to hide DOM elements.
 
 The basic usage is explained below, see the
@@ skipping 134 matching lines @@
 
 ### Unix
 
 The shell is automatically built by `make`, you can run it as follows:
 
     build/out/abpshell
 
 ### Windows
 
 Just run the project *abpshell*.