[1915] in java-interest
PreBeta1 bytecode file format change
daemon@ATHENA.MIT.EDU (Randy Neff)
Tue Sep 19 21:42:09 1995
Date: Tue, 19 Sep 1995 15:42:48 -0700
From: rneff@Teknowledge.COM (Randy Neff)
To: java-interest@java.sun.com
I am writing a Java bytecode Analyzer for my own nefarious purposes, but
hit a minor setback today.
The internal byte code format has changed in the PreBeta1 release.
The version number for the alpha versions was 45.2
The new version number for the prebeta1 is 45.3
The changes that I painfully discovered were:
in the Code Attribute structure:
max_stack was u1 (byte) is now u2 (short)
max_locals was u1 (byte) is now u2 (short)
code_length was u2 (short) is now u4 (int)
I am quite disappointed that this change was not documented in any of the
release information; decoding hex dumps of byte code files was only
fun the first time ( since the Virtual Machine Spec of March 15, 1995
is such a mess).
Question: Does anyone know how to get the alpha2 javac to output
the "Local Variable Table Attribute"? The -g flag generates them
on the PreBeta1 compiler, but not on the earlier compiler.
Randall Neff
-
Note to Sun employees: this is an EXTERNAL mailing list!
Info: send 'help' to java-interest-request@java.sun.com
