[kaffe] Warning: Unrecognized version number 47/0 in classfile.

Dalibor Topic robilad at yahoo.com
Mon Jun 30 02:56:01 PDT 2003

Ciao Gerlando,

--- Gerlando Falauto <iurly at writeme.com> wrote:
> What I am wondering now is, what's the difference between those versions?
> I mean, is there any chance that the 1.3 class format is /really/
> incompatible with kaffe-1.0.7 and therefore might lead to unexpected
> behaviors (which would inevitably drive me insane)? Why would we have a
> different number (apart from a different *language* specification) if the
> classfiles were 100% compatible? Or are they compatible, but it's just by
> accident?

They are compatible, mostly. The big version change was for assertions, if I
remeber it correctly. The mailing list archive has some discussions on this
issue, but I don't have a link at hand. 

For making jikes 1.18 generate class files that are porperly versioned for
kaffe 1.07, see http://www.kaffe.org/doc/kaffe/FAQ.classlibrary-compile :

What compilers are known to work?

* jikes

The preferred compiler is jikes. The URL for jikes is:


Please note that jikes 1.14 and 1.15 have bugs that result in a
miscompiled Klasses.jar file. If you use jikes 1.18, you need to pass
it the "-source 1.1" option. Jikes 1.18 generates class files for JDK
1.4 by default, and kaffe complains about an unknown version

The recommended version of jikes is 1.18.

> And how (using which tool) was the distribution 1.0.7 Klasses.jar built
> to begin with?

I don't know anymore. You can try to figure it out by building it with jikes
1.13, 1.15, 1.16 and 1.17, as well as with kjc and compare the resulting files.

A patch that would write the compiler used and its options to the MANIFEST.MF
file would be cool. Could you create one?

dalibor topic

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