Returning Const char* from EDK method using JNI

Question

I am trying to return a String from .java file to my game, but All I am getting is some SIG error. The method is declared in s4e as follows -

const char* s3eExtentionGetRegisterationID() run_on_os_thread

I modified s3eExtension_platform.cpp to edit the JNI method like this -

const char* s3eExtensionGetRegisterationID_platform()

{
    JNIEnv* env = s3eEdkJNIGetEnv();
    JavaString res((jstring)env->CallObjectMethod(g_Obj, g_s3eExtensionGetRegisterationID);
    return getCString((jstring)res);
}

Is there anything else I'd need to do, in order to get the string. The error I am getting is -

09-30 20:45:28.183: A/libc(2662): Fatal signal 11 (SIGSEGV) at 0xf400001d (code=1), thread 2678 (Thread-787)
09-30 20:45:28.293: I/DEBUG(1976): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
09-30 20:45:28.293: I/DEBUG(1976): Build fingerprint: 'SEMC/LT22i_1261-7821/LT22i:4.1.2/6.2.A.1.100/m_v_zg:user/release-keys'
09-30 20:45:28.293: I/DEBUG(1976): pid: 2662, tid: 2678, name: Thread-787  >>> com.creator.test <<<
09-30 20:45:28.293: I/DEBUG(1976): signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr f400001d
09-30 20:45:28.393: I/DEBUG(1976):     r0 0bffffe2  r1 00000000  r2 00000000  r3 f400001d
09-30 20:45:28.393: I/DEBUG(1976):     r4 59c01590  r5 59c01590  r6 00000000  r7 f400001d
09-30 20:45:28.393: I/DEBUG(1976):     r8 5a04ff94  r9 00000004  sl 59c01594  fp 00000000
09-30 20:45:28.393: I/DEBUG(1976):     ip 00000000  sp 5a04fda8  lr 5c423564  pc 5c4566ec  cpsr 60000010
09-30 20:45:28.393: I/DEBUG(1976):     d0  0000000000000000  d1  0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d2  0000000000000000  d3  0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d4  0066007200750053  d5  0054006500630061
09-30 20:45:28.393: I/DEBUG(1976):     d6  0075007400780065  d7  0000000000650072
09-30 20:45:28.393: I/DEBUG(1976):     d8  0000000000000000  d9  0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d10 0000000000000000  d11 0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d12 0000000000000000  d13 0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d14 0000000000000000  d15 0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d16 0000000000000000  d17 0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d18 0000000000000000  d19 0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d20 0000000000000000  d21 3ff0000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d22 8000000000000000  d23 0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d24 0000000000000000  d25 8000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d26 3ff0000000000000  d27 0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d28 0000000000000005  d29 0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     d30 0000000000000000  d31 0000000000000000
09-30 20:45:28.393: I/DEBUG(1976):     scr 20000010
09-30 20:45:28.393: I/DEBUG(1976): backtrace:
09-30 20:45:28.393: I/DEBUG(1976):     #00  pc 000346ec  <unknown>
09-30 20:45:28.393: I/DEBUG(1976):     #01  pc 00001560  <unknown>
09-30 20:45:28.393: I/DEBUG(1976): stack:
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd68  59c01314  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd6c  5c458aa4  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd70  59c01314  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd74  00000052  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd78  59c00fc0  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd7c  5c455f00  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd80  5a04fd98  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd84  5d2356e7  /data/data/com.creator.test/lib/libtest.so
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd88  5a04fd98  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd8c  5d23340b  /data/data/com.creator.test/lib/libtest.so
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd90  5a04fd98  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd94  5d232aa8  /data/data/com.creator.test/lib/libtest.so
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd98  59c014f8  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fd9c  5a04ff00  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fda0  df0027ad  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fda4  00000000  
09-30 20:45:28.393: I/DEBUG(1976):     #00  5a04fda8  00000001  
09-30 20:45:28.393: I/DEBUG(1976):          ........  ........
09-30 20:45:28.393: I/DEBUG(1976):     #01  5a04fda8  00000001  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdac  5a04ff00  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdb0  5a04fe00  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdb4  5a04ff80  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdb8  5a04ff94  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdbc  00000000  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdc0  00000000  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdc4  5c4237fc  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdc8  00000000  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdcc  5c423058  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdd0  00000000  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdd4  00000001  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fdd8  5a04ff00  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fddc  5a04fe00  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fde0  5a04ff80  
09-30 20:45:28.393: I/DEBUG(1976):          5a04fde4  5a04ff94  
09-30 20:45:28.393: I/DEBUG(1976): memory near r0:
09-30 20:45:28.393: I/DEBUG(1976):     0bffffc0 ffffffff ffffffff ffffffff ffffffff  ................
09-30 20:45:28.393: I/DEBUG(1976):     0bffffd0 ffffffff ffffffff ffffffff ffffffff  ................
09-30 20:45:28.393: I/DEBUG(1976):     0bffffe0 ffffffff ffffffff ffffffff ffffffff  ................
09-30 20:45:28.393: I/DEBUG(1976):     0bfffff0 ffffffff ffffffff ffffffff ffffffff  ................
09-30 20:45:28.393: I/DEBUG(1976):     0c000000 ffffffff ffffffff ffffffff ffffffff  ................
09-30 20:45:28.393: I/DEBUG(1976): memory near r4:
09-30 20:45:28.393: I/DEBUG(1976):     59c01570 59c018a8 59c018e0 5f149ff8 5f149ff8  ...Y...Y..._..._
09-30 20:45:28.393: I/DEBUG(1976):     59c01580 5f14a000 00000020 5f14a128 59c01590  ..._ ...(.._...Y
09-30 20:45:28.393: I/DEBUG(1976):     59c01590 5c46105c 5c461070 00001008 00000000  \.F\p.F\........
09-30 20:45:28.393: I/DEBUG(1976):     59c015a0 00000000 00000000 00000000 00000006  ................
09-30 20:45:28.393: I/DEBUG(1976):     59c015b0 00000000 59c01890 00000000 00000000  .......Y........
09-30 20:45:28.393: I/DEBUG(1976): memory near r5:
09-30 20:45:28.393: I/DEBUG(1976):     59c01570 59c018a8 59c018e0 5f149ff8 5f149ff8  ...Y...Y..._..._
09-30 20:45:28.393: I/DEBUG(1976):     59c01580 5f14a000 00000020 5f14a128 59c01590  ..._ ...(.._...Y
09-30 20:45:28.393: I/DEBUG(1976):     59c01590 5c46105c 5c461070 00001008 00000000  \.F\p.F\........
09-30 20:45:28.393: I/DEBUG(1976):     59c015a0 00000000 00000000 00000000 00000006  ................
09-30 20:45:28.393: I/DEBUG(1976):     59c015b0 00000000 59c01890 00000000 00000000  .......Y........
09-30 20:45:28.393: I/DEBUG(1976): memory near r8:
09-30 20:45:28.393: I/DEBUG(1976):     5a04ff74 5c44c0fc 00000005 00000009 76677261  ..D\........argv
09-30 20:45:28.393: I/DEBUG(1976):     5a04ff84 005d315b 00000000 5c4536b4 42494000  [1]......6E\.@IB
09-30 20:45:28.393: I/DEBUG(1976):     5a04ff94 5e0119a8 5e011968 5d26d630 00000000  ...^h..^0.&]....
09-30 20:45:28.393: I/DEBUG(1976):     5a04ffa4 00000000 00000000 5c422048 5e0119a8  ........H B\...^
09-30 20:45:28.393: I/DEBUG(1976):     5a04ffb4 00000000 5e0119a8 5d2335e9 5d26d630  .......^.5#]0.&]
09-30 20:45:28.393: I/DEBUG(1976): memory near sl:
09-30 20:45:28.393: I/DEBUG(1976):     59c01574 59c018e0 5f149ff8 5f149ff8 5f14a000  ...Y..._..._..._
09-30 20:45:28.393: I/DEBUG(1976):     59c01584 00000020 5f14a128 59c01590 5c46105c   ...(.._...Y\.F\
09-30 20:45:28.393: I/DEBUG(1976):     59c01594 5c461070 00001008 00000000 00000000  p.F\............
09-30 20:45:28.393: I/DEBUG(1976):     59c015a4 00000000 00000000 00000006 00000000  ................
09-30 20:45:28.393: I/DEBUG(1976):     59c015b4 59c01890 00000000 00000000 00000000  ...Y............
09-30 20:45:28.393: I/DEBUG(1976): memory near sp:
09-30 20:45:28.393: I/DEBUG(1976):     5a04fd88 5a04fd98 5d23340b 5a04fd98 5d232aa8  ...Z.4#]...Z.*#]
09-30 20:45:28.393: I/DEBUG(1976):     5a04fd98 59c014f8 5a04ff00 df0027ad 00000000  ...Y...Z.'......
09-30 20:45:28.393: I/DEBUG(1976):     5a04fda8 00000001 5a04ff00 5a04fe00 5a04ff80  .......Z...Z...Z
09-30 20:45:28.393: I/DEBUG(1976):     5a04fdb8 5a04ff94 00000000 00000000 5c4237fc  ...Z.........7B\
09-30 20:45:28.393: I/DEBUG(1976):     5a04fdc8 00000000 5c423058 00000000 00000001  ....X0B\........
09-30 20:45:28.393: I/DEBUG(1976): code around pc:
09-30 20:45:28.393: I/DEBUG(1976):     5c4566cc 11a01006 11a02005 1bfffa7d e1a00004  ..... ..}.......
09-30 20:45:28.393: I/DEBUG(1976):     5c4566dc e8bd4070 e12fff1e e1a03000 e1e00000  p@..../..0......
09-30 20:45:28.393: I/DEBUG(1976):     5c4566ec e4d32001 e3520000 1afffffc e0800003  . ....R.........
09-30 20:45:28.393: I/DEBUG(1976):     5c4566fc e12fff1e e92d0030 e1a03000 ea000000  ../.0.-..0......
09-30 20:45:28.403: I/DEBUG(1976):     5c45670c e2833001 e5d3c000 e35c0000 1afffffb  .0........\.....
09-30 20:45:28.403: I/DEBUG(1976): code around lr:
09-30 20:45:28.403: I/DEBUG(1976):     5c423544 e513900c e085a009 e59a1008 e1a0300a  .............0..
09-30 20:45:28.403: I/DEBUG(1976):     5c423554 e3510000 1a000029 e1a00007 eb00cc5f  ..Q.)......._...
09-30 20:45:28.403: I/DEBUG(1976):     5c423564 e59a801c e1500008 e1a06000 aa00003b  ......P..`..;...
09-30 20:45:28.403: I/DEBUG(1976):     5c423574 e0588000 0a000039 e59a2004 e59a0058  ..X.9.... ..X...
09-30 20:45:28.403: I/DEBUG(1976):     5c423584 e202c007 e35c0001 0a000060 e5902000  ......\.`.... ..
09-30 20:45:28.403: I/DEBUG(1976): memory map around fault addr f400001d:
09-30 20:45:28.403: I/DEBUG(1976):     bec60000-bec81000 [stack]
09-30 20:45:28.403: I/DEBUG(1976):     (no map for address)
09-30 20:45:28.403: I/DEBUG(1976):     ffff0000-ffff1000 [vectors]
09-30 20:45:28.534: I/BootReceiver(2474): Copying /data/tombstones/tombstone_05 to DropBox (SYSTEM_TOMBSTONE)
09-30 20:45:28.564: I/WindowState(2474): WIN DEATH: Window{420feed8 SurfaceView paused=false}
09-30 20:45:28.574: I/ActivityManager(2474): Process com.creator.test (pid 2662) has died.
09-30 20:45:28.574: W/ActivityManager(2474): Force removing ActivityRecord{42067fb8 com.creator.test/.Main}: app died, no saved state

Answer 1

I forgot that I need to declare these methods too. I thought they are inbuilt in JNI. Just need to add the following lines of code -

static char* g_RetStr;
static int g_RetStrLen = 16384;

struct JavaString
{
    jstring _Ref;

    JavaString ( const char *Buffer )
    {
        JNIEnv *env = s3eEdkJNIGetEnv();
        _Ref = env->NewStringUTF ( Buffer );
    }

    JavaString ( jstring Ref )
    {
        _Ref = Ref;
    }

    ~JavaString()
    {
        JNIEnv *env = s3eEdkJNIGetEnv();
        env->DeleteLocalRef ( _Ref );
    }

    operator jstring()
    {
        return _Ref;
    }
};

const char* getCString(jstring str)
{
    JNIEnv* env = s3eEdkJNIGetEnv();
    if (!str)
        return NULL;

    jboolean free;
    const char* res = env->GetStringUTFChars(str, &free);
    g_RetStrLen = strlen(res) + 1;
    g_RetStr = (char *)s3eEdkReallocOS(g_RetStr, g_RetStrLen);
    strcpy(g_RetStr, res);
    env->ReleaseStringUTFChars(str, res);
    return g_RetStr;
}

//In Init
g_RetStr = (char*)s3eEdkMallocOS(g_RetStrLen);