Update Android build instr. for ARMv8, PIE, etc.
* Include information on how to do a 64-bit ARMv8 build with the latest
NDK
* Suggest -fPIE and -pie as default CFLAGS (required for android-16 and
later.
* Remove -fstrict-aliasing flag (-Wall already includes it)
diff --git a/BUILDING.md b/BUILDING.md
index 94ee140..9075c18 100644
--- a/BUILDING.md
+++ b/BUILDING.md
@@ -414,18 +414,25 @@
# Set these variables to suit your needs
NDK_PATH={full path to the "ndk" directory-- for example, /opt/android/ndk}
BUILD_PLATFORM={the platform name for the NDK package you installed--
- for example, "windows-x86" or "linux-x86_64"}
- TOOLCHAIN_VERSION={"4.6", "4.8", etc. This corresponds to a toolchain
- directory under ${NDK_PATH}/toolchains/.}
+ for example, "windows-x86" or "linux-x86_64" or "darwin-x86_64"}
+ TOOLCHAIN_VERSION={"4.8", "4.9", "clang3.5", etc. This corresponds to a
+ toolchain directory under ${NDK_PATH}/toolchains/.}
ANDROID_VERSION={The minimum version of Android to support-- for example,
- "9", "19", etc.}
+ "16", "19", etc. "21" or later is required for a 64-bit build.}
+ # 32-bit ARMv7 build
HOST=arm-linux-androideabi
- TOOLCHAIN=${NDK_PATH}/toolchains/${HOST}-${TOOLCHAIN_VERSION}/prebuilt/${BUILD_PLATFORM}
SYSROOT=${NDK_PATH}/platforms/android-${ANDROID_VERSION}/arch-arm
- ANDROID_INCLUDES="-I${SYSROOT}/usr/include -I${TOOLCHAIN}/include"
ANDROID_CFLAGS="-march=armv7-a -mfloat-abi=softfp -fprefetch-loop-arrays \
- -fstrict-aliasing --sysroot=${SYSROOT}"
+ --sysroot=${SYSROOT}"
+
+ # 64-bit ARMv8 build
+ HOST=aarch64-linux-android
+ SYSROOT=${NDK_PATH}/platforms/android-${ANDROID_VERSION}/arch-arm64
+ ANDROID_CFLAGS="--sysroot=${SYSROOT}"
+
+ TOOLCHAIN=${NDK_PATH}/toolchains/${HOST}-${TOOLCHAIN_VERSION}/prebuilt/${BUILD_PLATFORM}
+ ANDROID_INCLUDES="-I${SYSROOT}/usr/include -I${TOOLCHAIN}/include"
export CPP=${TOOLCHAIN}/bin/${HOST}-cpp
export AR=${TOOLCHAIN}/bin/${HOST}-ar
export AS=${TOOLCHAIN}/bin/${HOST}-as
@@ -437,11 +444,14 @@
export STRIP=${TOOLCHAIN}/bin/${HOST}-strip
cd {build_directory}
sh {source_directory}/configure --host=${HOST} \
- CFLAGS="${ANDROID_INCLUDES} ${ANDROID_CFLAGS} -O3" \
+ CFLAGS="${ANDROID_INCLUDES} ${ANDROID_CFLAGS} -O3 -fPIE" \
CPPFLAGS="${ANDROID_INCLUDES} ${ANDROID_CFLAGS}" \
- LDFLAGS="${ANDROID_CFLAGS}" --with-simd ${1+"$@"}
+ LDFLAGS="${ANDROID_CFLAGS} -pie" --with-simd ${1+"$@"}
make
+If building for Android 4.0.x (API level < 16) or earlier, remove `-fPIE` from
+`CFLAGS` and `-pie` from `LDFLAGS`.
+
Building on Windows (Visual C++ or MinGW)
=========================================
