Eclipse, Android ndk, source files, and library project dependencies

Question

In Microsoft Visual Studio 2010, it is possible to create a Solution with multiple projects and set dependencies between projects. I'm trying to figure out if the same thing can be done using Eclipse via the NDK. More specifically, I want to know if it is possible to create C source files in an ordinary Android project that can reference C header files in an Android library project.

For example:

Android library project: Sockets
Ordinary Android project: Socket_Server 

Sockets contains all the C header/source files that are needed to do socket I/O.
Socket_Server contains test code that makes calls to the functions that are defined in Sockets library project.  This test code requires a header file that contains the function declaration of all API calls.

I already set the library dependencies between the projects via:

Properties > Android > Library > Add

In Socket_Server, there's a file called SocketTestServer.cpp. It contains test code, but makes API calls to the library project, Sockets, and does so by #include "Nv_Socket.h", which is not part of Socket_Server:

jni/SocketTestServer.cpp:1:23: fatal error: Nv_Socket.h: No such file or directory
compilation terminated.

Answer 1

See http://www.kandroid.org/ndk/docs/IMPORT-MODULE.html and http://www.kandroid.org/ndk/docs/PREBUILTS.html. The trick is not to have to copy the binary from one project to another! Also, using LOCAL_EXPORT_C_INCLUDES you can guarantee that the up-to-date version is used with

#include "Nv_Socket.h"

Answer 2

I think I solved it. If you make a .so file, put it in your /jni folder and then reference it in your .mk file, you should have no problems compiling.

.mk file:

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

# Turn on C++ Exception handling
LOCAL_CPP_FEATURES += exceptions
LOCAL_CPPFLAGS += -fexceptions

# Load LogCat utility
LOCAL_LDLIBS := -llog

# C flags
LOCAL_CFLAGS    += -Wno-psabi -fpermissive

# Module name                  
LOCAL_MODULE    := ServerSockets

# C Header includes
LOCAL_C_INCLUDES := $(LOCAL_PATH)

# Source files
LOCAL_SRC_FILES := libSockets.so 

include $(PREBUILT_SHARED_LIBRARY)