JNI bug?

[Marco Trudel]

Andrew Haley wrote:
> Andrew Haley writes:
>  > Marco Trudel writes:
>  >  > Hey all
>  >  > 
>  >  > Here's an interesting one where GCJ sometimes isn't doing the same as a 
>  >  > Sun JDK (no no Andrew, don't stop reading ;-)). Check out this little 
>  >  > Java class:
>  >  > 
>  >  > public class NativeBooleanTest
>  >  > {
>  >  > 	public static void main(String[] args)
>  >  > 	{
>  >  > 		System.loadLibrary("nativeBoolean");
>  >  > 		nativePrintBoolean(false);
>  >  > 		nativePrintBooleanAsInt(false);
>  >  > 	}
>  >  > 	
>  >  > 	private static native void nativePrintBoolean(boolean b);
>  >  > 	private static native void nativePrintBooleanAsInt(boolean b);
>  >  > }
>  >  > 
>  >  > Now this c code:
>  >  > 
>  >  > #include <jni.h>
>  >  > 
>  >  > JNIEXPORT void JNICALL Java_NativeBooleanTest_nativePrintBoolean
>  >  > 	(JNIEnv *env, jclass c, jboolean b)
>  >  > {
>  >  > 	printf("nativePrintBoolean: %d\n", b);
>  >  > }
>  >  > 
>  >  > JNIEXPORT void JNICALL Java_NativeBooleanTest_nativePrintBooleanAsInt
>  >  > 	(JNIEnv *env, jclass c, jint b)
>  >  > {
>  >  > 	printf("nativePrintBooleanAsInt: %d\n", b);
>  >  > }
>  >  > 
>  >  > 
>  >  > On a sun JVM, the output will be:
>  >  > nativePrintBoolean: 0
>  >  > nativePrintBooleanAsInt: 0
>  >  > 
>  >  > On GCJ, in this minimalistic sample, it will always be:
>  >  > nativePrintBoolean: 0
>  >  > nativePrintBooleanAsInt: 10084864
>  >  > 
>  >  > In a huge library I debugged for this, GCJ 4.3 gives twice 0 if 
>  >  > optimization is disabled and also "10084864" as soon as optimization is 
>  >  > enabled. GCJ 4.2 gives twice 0 in -O3 mode, GCJ 4.3 no longer.
>  >  > 
>  >  > 
>  >  > So,what do others think? What is the problem? Should there be an 
>  >  > implicit cast? Is the code wrong? If yes, should it be attended so that 
>  >  > the Sun RE is met?
>  >  > Unfortunately, this seems to go into the same unpleasant RE topic as my 
>  >  > Arrays patch... But it also might be a GCJ bug. I don't know for sure.
> 
> Err, *why* are you doing this weird thing, anyway?  Why not pass the correct type?

The same old story: I use a library which does it wrong... Someone has 
to test all these libraries out there ;-)
The other reason that I always run into problems is that I develop with 
a Sun JDK and deploy with GCJ...

Marco