OT: Apache POI Native Library using GCJ

OT: Apache POI Native Library using GCJ

[TJ Mather]

This is marked as offtopic, since it doesn't involve the RHUG project,
however I thought it may interest anyone who wanted to compile Apache
POI with GCJ...

I was able to get Apache POI to compile down to a shared library by
compiling *.java -> *.class using Ant with Sun JDK, then running
gcj -shared -o poi.so `cat classlist.txt` where the classlist contained 
the core HSSF files (not the ones that used Swing, etc)[1].  I had to 
compile FormulaParser.java, POIFSViewEngine.java, and HexRead.java to 
*.class using GCJ, because I got a "bad pc in exception_table" if I tried 
to compile the JDK *.class to *.so using GCJ.  Also note that *.java -> 
*.class using GCJ doesn't work for some *.java files.

For more details on to build and use the Apache POI GCJ shared library
see http://tjmather.com/poifilter/

-TJ

Re: OT: Apache POI Native Library using GCJ

[Tom Tromey]

>>>>> "TJ" == TJ Mather <tjmather@maxmind.com> writes:

TJ> I had to compile FormulaParser.java, POIFSViewEngine.java, and
TJ> HexRead.java to *.class using GCJ, because I got a "bad pc in
TJ> exception_table" if I tried to compile the JDK *.class to *.so
TJ> using GCJ.

I believe Andrew fixed this bug in the trunk gcj.

TJ> Also note that *.java -> *.class using GCJ doesn't work for some
TJ> *.java files.

Please submit gcj PRs for this.  Especially good would be a small test
case that shows the problem.

Tom

Re: OT: Apache POI Native Library using GCJ

[TJ Mather]

On 16 Nov 2002, Tom Tromey wrote:

> Please submit gcj PRs for this.  Especially good would be a small test
> case that shows the problem.

I'm planning to do this, I first wanted to test them against the latest 
GCJ CVS to make sure they haven't already been fixed.

Regards,
TJ

Re: OT: Apache POI Native Library using GCJ

[Tom Tromey]

>>>>> "TJ" == TJ Mather <tjmather@maxmind.com> writes:

TJ> I'm planning to do this, I first wanted to test them against the latest 
TJ> GCJ CVS to make sure they haven't already been fixed.

Even better!  Thanks.

Tom

Re: OT: Apache POI Native Library using GCJ

[TJ Mather]

On 16 Nov 2002, Tom Tromey wrote:

> TJ> I had to compile FormulaParser.java, POIFSViewEngine.java, and
> TJ> HexRead.java to *.class using GCJ, because I got a "bad pc in
> TJ> exception_table" if I tried to compile the JDK *.class to *.so
> TJ> using GCJ.
> 
> I believe Andrew fixed this bug in the trunk gcj.

Yep, the bad pc in exception_table seems to be fixed in GCJ CVS.

> TJ> Also note that *.java -> *.class using GCJ doesn't work for some
> TJ> *.java files.
> 
> Please submit gcj PRs for this.  Especially good would be a small test
> case that shows the problem.

There are two issues with GCJ 3.2, #8457 (submitted by Martin Aliger),
and the "bad pc in exception_table" which has since been fixed.  I tried 
running against GCJ 3.3 20021120, and #8457 was still a problem, and there 
seems to be a problem with CNI Invocation of Java code from C++ see PR 
#8685.  So the example on the web site seems to be broken on 3.3 20021120:
http://gcc.gnu.org/onlinedocs/gcj/Invocation.html

-TJ