Dlib: android neon compile failure

[jackweiwang]

i use latest version and compile android and edit dlib/config.h add # define DLIB_HAVE_NEON

my Android.mk
include $(CLEAR_VARS)
LOCAL_MODULE := dlib
LOCAL_C_INCLUDES := $(LOCAL_PATH)/../dlib
LOCAL_SRC_FILES += ../$(LOCAL_PATH)/../dlib/dlib/all/source.cpp
ifeq ($(TARGET_ARCH_ABI), armeabi-v7a)
LOCAL_ARM_MODE := arm
LOCAL_ARM_NEON := true

LOCAL_CFLAGS += -O3 -march=armv7-a -mfpu=neon -fprofile-use -mfloat-abi=softfp

$(info "support neon")
endif
compile libdlib.a on my ubuntu16.04:
Partial output：
In file included from jni/../dlib/dlib/dnn.h:13:
In file included from jni/../dlib/dlib/dnn/input.h:10:
In file included from jni/../dlib/dlib/dnn/../image_processing.h:11:
In file included from jni/../dlib/dlib/image_processing/scan_image.h:13:
In file included from jni/../dlib/dlib/array2d/../geometry/../image_processing/../image_transforms/spatial_filtering.h:13:
In file included from jni/../dlib/dlib/array2d/../geometry/../image_processing/../image_transforms/../simd.h:6:
In file included from jni/../dlib/dlib/simd/simd4f.h:6:
In file included from jni/../dlib/dlib/simd/simd_check.h:108:
/home/ww/download/android-ndk-r17/toolchains/llvm/prebuilt/linux-x86_64/lib64/clang/6.0.2/include/arm_neon.h:28:2: error:
"NEON support not enabled"

error "NEON support not enabled"

^
/home/ww/download/android-ndk-r17/toolchains/llvm/prebuilt/linux-x86_64/lib64/clang/6.0.2/include/arm_neon.h:48:24: error:
'neon_vector_type' attribute is not supported for this target
typedef __attribute__((neon_vector_type(8))) int8_t int8x8_t;
^
/home/ww/download/android-ndk-r17/toolchains/llvm/prebuilt/linux-x86_64/lib64/clang/6.0.2/include/arm_neon.h:49:24: error:
'neon_vector_type' attribute is not supported for this target
typedef __attribute__((neon_vector_type(16))) int8_t int8x16_t;

I don't know why it's going to be a problem. android-ndk-r16b same problem
what should i do?

thank you

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[jackweiwang]

sorry，i solved it

[maksimgusarovsc]

@jackweiwang how did you solve it? I'm having the same issue now.

[jackweiwang]

@maksimgusarovsc
My directory structure is 'android.mk directory1 directory2 ...'.
An error occurred when I added the following to android.mk.
However, when I added it to the android.mk in the subdirectory(directory/Android.mk), the problem disappeared.

ifeq ($(TARGET_ARCH_ABI), armeabi-v7a)
LOCAL_ARM_MODE := arm
LOCAL_ARM_NEON := true
LOCAL_CFLAGS += -O3 -march=armv7-a -mfpu=neon -mfloat-abi=softfp

I hope it will be helpful to you.