Building a toolchain with cmake to cross-compile for android

Question

gcc (GCC) 4.8.1 
android-ndk-r9 

Hello,

My host machine is Fedora 19 and I want to create a tool-chain for compiling programs

Answer 1

I managed to solve the problem by first going to this website:

http://developer.android.com/tools/sdk/ndk/index.html

There is an example of using the standalone toolchain that comes with NDK.

make-standalone-toolchain.sh --toolchain=arm-linux-androideabi-4.8

Extracted the into my /opt directory.

And using this sample toolchain cmake file

# Target system
set(CMAKE_SYSTEM_NAME  Android)

set(CMAKE_SYSTEM_VERSION 1)

# Compiler to build for the target
set(CMAKE_C_COMPILER /opt/arm-linux-androideabi-4.8/bin/arm-linux-androideabi-gcc)
set(CMAKE_CXX_COMPILER /opt/arm-linux-androideabi-4.8/bin/arm-linux-androideabi-g++)

Everything just worked after that. However, I couldn't get my previous problem working. Maybe I have set some environmental variables incorrectly to the wrong paths.

Hope this helps someone else.

Answer 2

For original problem from ant2009, please have a try to add following lines in .cmake:

SET (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} --sysroot=/opt/ndk/platforms/android-23/arch-arm" CACHE STRING "" FORCE)

SET (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} --sysroot=/opt/ndk/platforms/android-23/arch-arm" CACHE STRING "" FORCE)

Answer 3

Why you don't try this android-cmake. I still use this script and it works fairly well. If that approach does not fit your needs, you could use it as an inspiration anyway :-) .

Answer 4

In 2020 the make-standalone-toolchain.sh approach is deprecated.

This is an updated CMakeList.txt:

set(CMAKE_SYSTEM_NAME Android)
set(CMAKE_SYSTEM_VERSION 24)
set(CMAKE_ANDROID_ARCH_ABI arm64-v8a)

PROJECT(mylib C)
CMAKE_MINIMUM_REQUIRED(VERSION 3.18.0)

SET( ${PROJECT_NAME}_CURRENT 1 )
SET( ${PROJECT_NAME}_REVISION 0 )
SET( ${PROJECT_NAME}_AGE 0 )
SET(VERSION "${${PROJECT_NAME}_CURRENT}.${${PROJECT_NAME}_REVISION}.${${PROJECT_NAME}_AGE}")


SET(SOURCES foobar.c)
ADD_LIBRARY(mylib SHARED ${SOURCES})

NOTE: For the ABI arm64-v8a CMake 3.18 is needed to detect the NDK toolchain correctly, 3.10 which is the version in Ubuntu 18.04, does not find the toolchain.