add note android build

Author: uvguy

runtime/Cpp/CMakeLists.txt

@@ -102,6 +102,10 @@ if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU" OR "${CMAKE_CXX_COMPILER_ID}" MATCH
     if (NOT (GCC_VERSION VERSION_GREATER 5.0 OR GCC_VERSION VERSION_EQUAL 5.0))
         message(FATAL_ERROR "${PROJECT_NAME} requires g++ 5.0 or greater.")
     endif ()
+elseif ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" AND ANDROID) 
+	# Need -Os cflag and cxxflags here to work with exception handling on armeabi.
+	# see  https://github.com/android-ndk/ndk/issues/573
+	# and without -stdlib=libc++ cxxflags
 elseif ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" AND APPLE)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
 elseif ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" AND CMAKE_SYSTEM_NAME MATCHES "Linux")

runtime/Cpp/README.md

@@ -25,7 +25,7 @@ The C++ target has been the work of the following people:
 
 ## Project Status
 
-* Building on OS X, Windows, and Linux
+* Building on OS X, Windows, Android and Linux
 * No errors and warnings
 * Library linking
 * Some unit tests in the OSX project, for important base classes with almost 100% code coverage.
@@ -47,6 +47,9 @@ Simply open the VS solution (VS 2013+) and build it.
 #### Compiling on OSX
 Either open the included XCode project and build that or use the cmake compilation as described for linux.
 
+#### Compiling on Android
+Try run cmake -DCMAKE_ANDROID_NDK=/folder/of/android_ndkr17_and_above -DCMAKE_SYSTEM_NAME=Android -DCMAKE_ANDROID_API=14 -DCMAKE_ANDROID_ARCH_ABI=x86 -DCMAKE_ANDROID_STL_TYPE=c++_shared -DCMAKE_ANDROID_NDK_TOOLCHAIN_VERSION=clang -DCMAKE_BUILD_TYPE=Release /folder/antlr4_src_dir -G Ninja.
+
 #### Compiling on Linux
 - cd <antlr4-dir>/runtime/Cpp (this is where this readme is located)
 - mkdir build && mkdir run && cd build