我如何使用pre_built库

Question

let say I have this piece of code:

print.cpp

int print ()
{
  return 10;
}

print.h

#ifndef PRINT_H
#define PRINT_H
int print(); // function prototype for add.h
#endif

I compiled into a library call libTest.a

now let say i have this android.mk file

include $(CLEAR_VARS)
LOCAL_MODULE    := libtest
LOCAL_SRC_FILES := ../issmlib/libTest.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/../include
include $(PREBUILT_STATIC_LIBRARY)

of course there is others thing like shared, but assumed they all work fine!!! I put libTest.a in a folder called issmlib and it is in my project same level as jni folder I then put print.h into a folder called include.

now this is my main:

#include "com_lan_factorial_FacLib.h"
#include "fac.h"

    //extern long fac(long n);

    JNIEXPORT jlong JNICALL Java_com_lan_factorial_FacLib_fac(JNIEnv *env, jclass clazz, jlong n)
    {
        fac *f = new fac();
        jlong result = (jlong) (f->factorial(n));
        delete(f);
        return result + print();
    }

so what it does it compute the result and add 10 to it. I do not know how to use that pre-built library, do i have to state #include "print.h" I did put it in but it complains that no implementation of the method. When I take it out, it complains that no print() have been declared.

This is much of a C++ question, but hopefully you can help.

I believe my pathing for Android.mk is fine, but if you spot something wierd, please let me know. Thanks alot.

Answer 1

Make sure that you have V=1 parameter on the ndk-build command line. This way, you will see the actual compilation commands as the are prepared by ndk-build. This often gives a clue as to what is wrong with the path definitions in Android.mk .

If you need help interpreting this log, leave a comment here and edit the question to include the full build log and the full Android.mk , including the part that invokes BUILD_SHARED_LIBRARY