Does not build on Android ARM

[sdroege]

It unconditionally uses NEON it seems. Not all Android devices have NEON so we need to compile it in conditionally and detect at runtime.

libtool: compile: arm-linux-androideabi-gcc -fuse-ld=gold -DHAVE_CONFIG_H -I. -DGRAPHENE_COMPILATION=1 -DG_LOG_DOMAIN="Graphene" -I../src -I../src -DGRAPHENE_ENABLE_DEBUG --sysroot=/home/jenkins/workspace/cerbero-android/workdir/android-ndk-r9d/platforms/android-9/arch-arm -I/home/jenkins/workspace/cerbero-android/workdir/android-ndk-r9d/platforms/android-9/arch-arm/usr/include -DANDROID -DPIC -D__ARM_ARCH_5__ -D__ARM_ARCH_5T__ -D__ARM_ARCH_5E__ -D__ARM_ARCH_5TE__ -O3 -ffast-math -fstrict-aliasing -I/home/jenkins/workspace/cerbero-android/workdir/dist/android_arm/include/glib-2.0 -I/home/jenkins/workspace/cerbero-android/workdir/dist/android_arm/lib/glib-2.0/include -fvisibility=hidden -I/home/jenkins/workspace/cerbero-android/workdir/dist/android_arm/include/glib-2.0 -I/home/jenkins/workspace/cerbero-android/workdir/dist/android_arm/lib/glib-2.0/include -Wall -Wshadow -Wstrict-aliasing=2 -Wno-uninitialized -Wcast-align -Wstrict-prototypes -Werror=logical-op -Werror=pointer-arith -Werror=missing-declarations -Werror=redundant-decls -Werror=implicit-function-declaration -Werror=format=2 -Werror=missing-include-dirs -Werror=init-self -Werror=empty-body -Werror=declaration-after-statement -mfpu=neon -Wall -g -Os --sysroot=/home/jenkins/workspace/cerbero-android/workdir/android-ndk-r9d/platforms/android-9/arch-arm -I/home/jenkins/workspace/cerbero-android/workdir/android-ndk-r9d/platforms/android-9/arch-arm/usr/include -ffunction-sections -funwind-tables -fstack-protector -no-canonical-prefixes -fPIC -mthumb -fomit-frame-pointer -fno-strict-aliasing -finline-limit=64 -march=armv5te -mtune=xscale -msoft-float -DANDROID -DPIC -D__ARM_ARCH_5__ -D__ARM_ARCH_5T__ -D__ARM_ARCH_5E__ -D__ARM_ARCH_5TE__ -Wa,--noexecstack -g -MT libgraphene_1_0_la-graphene-point.lo -MD -MP -MF .deps/libgraphene_1_0_la-graphene-point.Tpo -c graphene-point.c -fPIC -DPIC -o .libs/libgraphene_1_0_la-graphene-point.o
graphene-alloc.c: In function 'graphene_alloc':
In file included from graphene-config.h:38:0,
from graphene-types.h:32,
from graphene-matrix.h:27,
from graphene-matrix.c:35:
/home/jenkins/workspace/cerbero-android/workdir/android-ndk-r9d/toolchains/arm-linux-androideabi-4.8/prebuilt/linux-x86_64/lib/gcc/arm-linux-androideabi/4.8/include/arm_neon.h:32:2: error: #error You must enable NEON instructions (e.g. -mfloat-abi=softfp -mfpu=neon) to use arm_neon.h
#error You must enable NEON instructions (e.g. -mfloat-abi=softfp -mfpu=neon) to use arm_neon.h

[ebassi]

I only tested ARM builds by cross-compiling with the GNU EABI toolchain.

I don't have an Android environment, and setting one up is going to probably take me more time than I am able to devote to such a task. a patch to enable NEON flags on Android would be very welcome.

[ebassi]

just to check, you can use the NEON_CFLAGS variable to specify -mfloat-abi=softfp -mfpu=neon when configuring, and see if that fixes it.

I can push a patch that blindly adds -mfloat-abi=softfp to the fallback NEON_CFLAGS in case the canonical host is Android as well.

[ebassi]

there's also the option of reworking the configure.ac check to use intrinsics instead of the NEON assembly, so that we can rely on the check doing the right thing.

[ebassi]

merged the issues/12 branch; let's see what happens.

[sdroege]

Works now, thanks 😄