[Bug c++/33607] New: -O2 optimisation causes null pointer exception at runtime when calling g++ from java using jni

[mattias dot ellert at tsl dot uu dot se]

I have experienced a null pointer exception when calling g++ from java (using
swig generated bindings).

I have made a reduced test case that exhibits the same behaviour which
is attached to this report. If I run this on Fedora Core 6 I get:

[ellert@ellert ~]$ tar -z -x -f java-test.tar.gz 
[ellert@ellert ~]$ cd java-test
[ellert@ellert java-test]$ ./test.sh 
Exception in thread "main" java.lang.NullPointerException
   at test.mytest.Status.getKind(Status.java:45)
   at test.main(test.java:9)

Running on RHEL 4 works:

[ellert@bestla ~]$ tar -z -x -f java-test.tar.gz 
[ellert@bestla ~]$ cd java-test
[ellert@bestla java-test]$ ./test.sh 
OK

If I remove the -O2 optimisation flag from the compilation of the C++
code generated by swig as part of the Java binding it works also on FC6:

[ellert@ellert java-test]$ OPT=no ./test.sh 
OK

My RHEL 4 installation has g++ 3.4.6-8, my FC6 installation has g++
4.1.2-13.

The same behaviour has been seen using Debian/Etch g++ 4.1.1-21.

Since removing the -O2 flag makes the code work I suspect this to be an
optimisation problem in g++. Since it works with the -O2 flag with the older
g++ in RHEL4 this would be a regression.


-- 
           Summary: -O2 optimisation causes null pointer exception at
                    runtime when calling g++ from java using jni
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mattias dot ellert at tsl dot uu dot se


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33607