JNI bug?

[Marco Trudel]

Andrew Haley wrote:
> 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.
> 
> zorro:~ $ ~/gcc/trunk/install/bin/gcj NativeBooleanTest.java --main=NativeBooleanTest -fjni -O2
> zorro:~ $ ~/gcc/trunk/install/bin/gcc -fpic -shared -o libnativeBoolean.so  nativeBoolean.c  
> zorro:~ $ LD_LIBRARY_PATH=.:~/gcc/trunk/install/lib64 ./a.out 
> nativePrintBoolean: 0
> nativePrintBooleanAsInt: 0
> zorro:~ $ ~/gcc/trunk/install/bin/gcj NativeBooleanTest.java --main=NativeBooleanTest -fjni -O3
> zorro:~ $ LD_LIBRARY_PATH=.:~/gcc/trunk/install/lib64 ./a.out 
> nativePrintBoolean: 0
> nativePrintBooleanAsInt: 0
> zorro:~ $ ~/gcc/trunk/install/bin/gcc -fpic -shared -o libnativeBoolean.so  nativeBoolean.c  -O2
> zorro:~ $ LD_LIBRARY_PATH=.:~/gcc/trunk/install/lib64 ./a.out 
> nativePrintBoolean: 0
> nativePrintBooleanAsInt: 0

Interesting...

win32> gcj NativeBooleanTest.java --main=NativeBooleanTest -fjni -O2
win32> gcc -shared -o nativeBoolean.dll NativeBooleanTest.c
win32> a
nativePrintBoolean: 0
nativePrintBooleanAsInt: 16498688

So then a win32 JNI bug?


thanks
Marco