[Bug 158] New: JNI jlong weirdness on ARM

http://sablevm.org/bugs/show_bug.cgi?id=158

           Summary: JNI jlong weirdness on ARM
           Product: SableVM
           Version: unspecified
          Platform: Other
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: default
        AssignedTo: [email protected]
        ReportedBy: [email protected]
         QAContact: [email protected]


jlong types exhibit a weird behaviour when "transferred" to Java code from a JNI
library in ARM, although they are correctly interpreted on the native C code. I
 can't reproduce the bug on an x86 box.

This is SableVM 1.12 running on an ARM920TID (S32410) processor.

Example code follows:

HelloWorld.java:

class HelloWorld {
    public native long displayHelloWorld();

    static {
        System.loadLibrary("hello");
    }

    public static void main(String[] args) {
          long foo = new HelloWorld().bar();
          System.out.println("Java: " + foo);
    }
}

HelloWorld.h:

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

#ifndef _Included_HelloWorld
#define _Included_HelloWorld
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     HelloWorld
 * Method:    displayHelloWorld
 * Signature: ()J
 */
JNIEXPORT jlong JNICALL Java_HelloWorld_bar
  (JNIEnv *, jobject);

#ifdef __cplusplus
}
#endif
#endif

HelloWorldImpl.c:

#include <jni.h>
#include "HelloWorld.h"
#include <stdio.h>

JNIEXPORT long long JNICALL
Java_HelloWorld_bar(JNIEnv *env, jobject obj)
{
  jlong result = 0;
  printf("native: %lld\n", result);
  return result;
}


This code displays:
$ java -Djava.library.path=. HelloWorld
native: 0
Java: 356447925829632

The difference between C value and Java value is 0x1443000000000 (I don't know
if it's relevant)

I can't find the exact portion of code that interprets a native value into a
Java value so I could substract this value to every jlong returned by a JNI call.

This only affects jlong values. jint, jbyteArray et al work as expected.



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