Using my own prebuilt shared library in an Android NDK project

Question

I came across this post that is almost what I need:

How to compile a static library using the Android NDK?

Basically, there are certain parts in my project that are never updated, so I am trying to avoid having them built every single time I update the Android.mk file to add something.

The above answer shows how to get some of the code built into a separate static lib, but when I try to pre-build the above code in a separate Android.mk file, It won't build by itself. This seems a little redundant... If I have to build them both at the same time, then what's the point of making a separate static lib anyways?

And if I change Android.mk in the separate project to read:

include $(BUILD_SHARED_LIBRARY)

and include it like this in the main project:

LOCAL_SHARED_LIBRARIES := libMyaccessories.so

then I get unresolved reference to(function name), probably because it can't find the shared lib(which is in the calling path)

Can anyone help me out with this?

Solution

In the documentation of Android.mk, check the PREBUILT_SHARED_LIBRARY script description. Put the .so file in lib (not libs) directory and write an Android.mk file next to it that looks something like:

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE := Myaccessories
LOCAL_SRC_FILES := libMyaccessories.so
LOCAL_C_INCLUDES := $(LOCAL_PATH)/../jni/include

include $(PREBUILT_SHARED_LIBRARY)

Comments

[CuriousGeorge]

thanks. I used the other post to make ndk build the static libs, foudn the static libs and moved them into the local dir, then swapped out the build_static_lib for the part above, and everything is peachy =)

[ESV]

After you download the Android NDK, the Android.mk documentation is in docs/ANDROID-MK.html. See developer.android.com/sdk/ndk/overview.html#docs

[Jeegar Patel]

@ESV i have did the same but still its not working see stackoverflow.com/questions/10106965/…

[Sreekanth Karumanaghat]

there is no lib in my file hierarchy...can you help me with respect to this?