Short version:
I suspect a few files within V8 source code have Sun's JVM as their origin.
Lil' longer version:
Let me introduce our guests...
...V8 is the high-performance javascript engine Google developed for their web browser Chrome. One of the reasons why V8 seems to outperform other engines is it compiles javascript to native machine code (currently just for x86 and ARM) instead of interpreting it. V8 is written in C++ and is distributed under BSD license.
...Sun's Java Virtual Machine, codenamed hotspot, which was released some time ago as part of OpenJDK, among other things, provides a Just-in-Time (JIT) java bytecode compiler which on the fly "translates" bytecode fragments into machine code. Hotspot is written in C++ and is distributed under GPL license.
A couple of days ago I was tinkering with V8's code, concretely with the x86 machine code generation stuff, and I came across a surprising copyright note in file assembler-ia32.h:
// Copyright (c) 1994-2006 Sun Microsystems Inc.
// All Rights Reserved.
Yes, it is Sun's copyright note! And it can be also found in other files: assembler-ia32.cc, assembler.cc, assembler.h, assembler-arm.h, etc.
After that copyright note, you can find the BSD license, and after, this comment:
// The original source code covered by the above license above has been
// modified significantly by Google Inc.
// Copyright 2006-2008 the V8 project authors. All rights reserved.
I immediately googled around to find out something more on that, and I found someone who already noticed it, although he didn't go any further from the discovery thing.
Intrigued for it, I searched which piece of software from Sun Google took the original files from, and I reached to OpenJDK: if you carefully examine files assembler-ia32.h from V8 and assembler_x86_32.hpp from OpenJDK you'll notice how similar they are.
But I found it strange that V8's supposedly derived code, released under BSD license, had been initially taken from Sun's JVM which is distributed under GPL, as Google would be violating the license. Also, hotspot lacks ARM support while V8's ARM assembler files do have Sun's copyright note.
After taking some history lessons I found the actual nexus between V8 and Sun: Lars Bak, V8 tech leader, is a former employee of Sun where he worked in StrongTalk, Self, Hotspot and in...
...Monty VM which powers CLDC, (Sun's high performance Java ME implementation) and supports x86 and ARM architectures. It was open sourced as part of phoneMe under GPL license.
BINGO!
Although I still have no answer for the licensing thing (perhaps Sun licensed some parts of MontyVM to Google under BSD?), I think the origin of V8 Sun-copyrighted files is MontyVM JIT compiler.
Maybe I am right, maybe not, who cares, but this "investigation" has granted me interesting background on where the concepts implemented in V8 come from and hopefully will help me understand V8's design decissions as I digg deeper and deeper in its code :-)
UPDATE:
I found a more feasible origin for Sun's copyrighted stuff: StrongTalk VM (open sourced by Sun, now hosted at google code); I think this is the actual origin because:
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