New Miscompilation Into Bytecode Error

Thu Jul 1 07:49:00 GMT 2004

Hi,
 Today we have a miscompilation into bytecode
error which essentially causes the Jacks testsuite to
hang because the GCJ interpreter hangs on a testcase.
This is the 8.1.2-runtime-1 testcase from Jacks ("Stress
test of accessing a final local variable through two
layers of nested local/anonymous classes"):
---------------------------- 8< ----------------------------
class Hello
{
 public static void main(String[] args) {
 new Hello().foo(1);
 }
 void foo(final int i) {
 class Local {
 Local() {}
 Local(int i) { this(); }
 int foo() {
 return new Local(0) {
 int j = i;
 }.j;
 }
 }
 System.out.println(new Local().foo());
 }
}
---------------------------- 8< ----------------------------
The expected output of this testcase is "1".
However, a *compiled binary* produces the output "-1073758376"
(and is therefore XFAIL-ed as of now).
The bytecode causes the GCJ interpreter to hang!
With Sun's JDK 1.4.2_03 on Linux/x86, I get:
---------------------------- 8< ----------------------------
~/src/test/tmp > java Hello
Exception in thread "main" java.lang.VerifyError: (class: Hello1ドル$Local, method: <init> signature: (LHello;II)V) Expecting to find integer on stack
 at Hello.foo(Hello.java:16)
 at Hello.main(Hello.java:4)
---------------------------- 8< ----------------------------
Here's the disassembled output (via "javap -c") of
"Hello1ドル$Local.class":
---------------------------- 8< ----------------------------
~/src/test/tmp > javap -c Hello\1ドル\$Local
Compiled from "Hello.java"
class Hello1ドル$Local extends java.lang.Object{
static Hello access0ドル(Hello1ドル$Local);
 Code:
 0: aload_0
 1: getfield #14; //Field this0ドル:LHello;
 4: areturn
Hello1ドル$Local(Hello,int);
 Code:
 0: aload_0
 1: aload_1
 2: putfield #14; //Field this0ドル:LHello;
 5: aload_0
 6: invokespecial #24; //Method java/lang/Object."<init>":()V
 9: aload_0
 10: iload_2
 11: invokespecial #26; //Method finit$:(I)V
 14: return
Hello1ドル$Local(Hello,int,int);
 Code:
 0: aload_0
 1: aload_1
 2: putfield #14; //Field this0ドル:LHello;
 5: aload_0
 6: aload_1
 7: invokespecial #29; //Method "<init>":(LHello;I)V
 10: return
int foo();
 Code:
 0: new #33; //class Hello$Local2ドル
 3: dup
 4: aload_0
 5: iconst_0
 6: invokespecial #36; //Method Hello$Local2ドル."<init>":(LHello1ドル$Local;I)V
 9: getfield #39; //Field Hello$Local2ドル.j:I
 12: ireturn
}
---------------------------- 8< ----------------------------
Any ideas?
Ranjit.
-- 
Ranjit Mathew Email: rmathew AT gmail DOT com
Bangalore, INDIA. Web: http://ranjitmathew.tripod.com/