[10] Review Request: 8187442 Xcheck:jni produces various "WARNING in native method" in launcher

[David Holmes]

Hi Sergey,

On 13/09/2017 5:18 AM, Sergey Bylokhov wrote:
> Hello,
> Please review the fix for jdk10/jdk10.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8187442
> Webrev can be found at: http://cr.openjdk.java.net/~serb/8187442/webrev.00

This doesn't look right to me:

               str = (*env)->CallStaticObjectMethod(env, cls,
                       makePlatformStringMID, USE_STDERR, ary);
+             CHECK_EXCEPTION_RETURN_VALUE(0);
               (*env)->DeleteLocalRef(env, ary);
               return str;

If there is an exception pending you fail to delete the local ref. And 
there's no need to clear the exception before calling DeleteLocalRef as 
that is okay to call with a pending exception. But there is no point 
returning zero if an exception occurred because in that case str will 
already be 0/NULL.

The same here:

1596     appClass = (*env)->CallStaticObjectMethod(env, cls, mid);
1597     CHECK_EXCEPTION_RETURN_VALUE(0);
1598     return appClass;

If an exception is pending then appClass will be 0/NULL.

In addition CHECK_EXCEPTION_RETURN_VALUE doesn't clear the pending 
exception so I can't see what warnings this would be clearing up ???

Thanks,
David
-----

> The simple application with empty main method produce some "warnings" 
> when Xcheck:jni is used. Because of that it is hard to cleanup other 
> parts of jdk from such warnings.
> 
> Two additional checks were added, in both cases the new code will return 
> 0 in the same way as NULL_CHECK0 in the same methods.
> 
>