Java JNI symbol lookup error

Question

First of all, I am new to JNI. I have a java class that imports native function, here's Java code:

public static native byte[] sha512(byte[] message);
static {
    System.loadLibrary("sha512");
}

And when I try to call the function in java I got following error:

java: symbol lookup error: /home/kgb/IdeaProjects/JavaCiphersLib/out/production/JavaCiphersLib/libsha512.so: undefined symbol: _Znam

Here's C++ header file which is generated using javah :

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class my_SHA512 */

#ifndef _Included_my_SHA512
#define _Included_my_SHA512
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     my_SHA512
 * Method:    sha512
 * Signature: ([B)[B
 */
JNIEXPORT jbyteArray JNICALL Java_my_SHA512_sha512
  (JNIEnv *, jclass, jbyteArray);

#ifdef __cplusplus
}
#endif
#endif

Here's implementation:

#include <jni.h>
#include "my_SHA512.h"
#include <stdio.h>
#include <stdlib.h>

#ifdef __cplusplus
extern "C" {
#endif

JNIEXPORT jbyteArray JNICALL Java_my_SHA512_sha512(JNIEnv* env, jclass _class, jbyteArray message)
{
    unsigned char* msg = new unsigned char[5];
    delete msg;

    printf("Test Test Test\n");
    return message;
}

#ifdef __cplusplus
}
#endif

Now, if I remove unsigned char* msg = new unsigned char[5]; line the error's gone. Here's what c++filt says:

kgb@KGB-PC:~$ c++filt -n _Znam
operator new[](unsigned long)

Here's how I compiled the c++ code:

gcc -I$JAVA_INC_PATH -I$JAVA_INC_PATH./linux -fPIC -c my_SHA512Impl.cpp
gcc -shared -Wl,-soname,libsha512.so.2 -o libsha512.so.2.0 my_SHA512Impl.o

So how I get rid of the error? And it'd be great if you give some explanation of how all that c++ magic works and how to avoid such errors in the future.
Thanks in advance.

UPD Don't know it's useful, but here's ldd libsha512.so output:

linux-vdso.so.1 =>  (0x00007ffd29171000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f0e1cd86000)
/lib64/ld-linux-x86-64.so.2 (0x00007f0e1d34d000)

Answer 1

有时候使用g ++代替gcc有时会有所帮助，因为默认情况下它会添加C ++运行时库。