RE: [Jxcl-devel] RE: So what's the status of JXCL

[Jim D. <jd...@di...>]

On Tue, 2 Mar 2004, King Dale wrote:

> I've been studying the code and think I have a grasp. I think we can fix the
> try-finally problems. It appears one problem is that the Eclipse compiler
> generates something entirely different than the Sun compiler. I think what
> javac generates has also changed from one version to another. Looking at
> this old article from 1997 it describes the code that Eclipse generates:
>
> http://www.javaworld.com/javaworld/jw-02-1997/jw-02-hood.html

More to read over coffee.  However, at a glance it's an inaccurate
description of how the compiler generates code.

> So something has changed in javac land. What I see from javac duplicates the
> code from the finally clause in multiple places if it is small and uses a
> subroutine if it is longer.

Got an example?  I test this using samples where the finally clause is one
statement.  It always uses the subroutine.

>                        Eclipse seems to always use the subroutine. When
> javac uses the jsr, it duplicates the jsr in all paths that exit the try
> block gracefully then does a goto to the code after the try. Eclipse moves
> the jsr to the end and has all those paths do a goto to the jsr which then
> falls through to the code after the try.

That's different from what I see.

> I'll try to do a bug search in the bug database to see if I can learn more.
> I'm guessing that they did this to make life easier for HotSpot to figure
> things out, which makes like more complicated for those trying to figure out
> control flow with the output of other compilers.

--
Jim Dixon  jd...@di...   tel +44 117 982 0786  mobile +44 797 373 7881
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