review request (L): 6981777 implement JSR 292 EG adjustments from summer 2010

[Christian Thalinger]

On Wed, 2010-09-15 at 01:22 -0700, John Rose wrote:
> On Sep 14, 2010, at 7:55 PM, John Rose wrote:
> 
> > Here's the update:
> > 
> > http://cr.openjdk.java.net/~jrose/6984311/webrev.01/
> > 
> > Note:  I may ask for review of an alternative form of this change set, which uses N-ary instead of binary nodes in the constant pool.  The EG is discussing both options.
> 
> I did the variation which supports N-ary MethodApply nodes.  It is somewhat less natural than the binary MethodApply nodes, because constant pools contain mostly binary nodes, but it matches the meaning of the constants better to allow them to be N-ary.  And the extra data structure is pretty simple.  See what you think.
> 
> http://cr.openjdk.java.net/~jrose/6984311/webrev.01.nary
> 
> (These are only the diffs from the binary to the N-ary version.)

src/share/vm/classfile/classFileParser.cpp:

+          cfs->guarantee_more(3, CHECK);  // operand_count, ..., tag/access_flags
+          u2 op_count = cfs->get_u2_fast();
+          cfs->guarantee_more(2*op_count + 1, CHECK);

I think the additional +1 is wrong as you check for 3 in the first
guarantee_more.

Otherwise it looks good.

-- Christian