From: Husam Senussi <husam@...>
Date: 2009-08-05T08:11:50+09:00
Subject: Re: Loading precompiled code

Thanks  thats clear things up :)

On 4 Aug 2009, at 23:45, Jörg W Mittag wrote:

> Husam Senussi wrote:
>> Does ruby support storing and loading bytecode !!
>
> Short answer: No, it doesn't.
>
> (Slightly) longer answer: No, *Ruby* doesn't support storing and
> loading bytecode, but most Ruby *Implementations* do. IOW: it's not
> part of the Ruby Language Specification, but most Ruby Implementations
> support it anyway. However, each Implementation has its own bytecode,
> its own archive format and its own APIs. And, of course, some
> implementations don't even *have* bytecode, so it's obviously
> impossible for them to support bytecode loading.
>
> (Much too) long answer: There is no portable bytecode specification
> for Ruby, and thus also no standard way to load precompiled bytecode
> archives. However, almost all Ruby implementations use some kind of
> bytecode or intcode format, and several of them can dump and reload
> bytecode archives.
>
> YARV (<http://Ruby-Lang.Org/>) always compiles to bytecode before
> executing the code, however that is usually only done in memory. There
> are ways to dump out the bytecode to disk. At the moment, there is no
> way to read it back *in*
> (<https://GitHub.Com/RubySpec/MatzRuby/blob/trunk/iseq.c#L1427-1429>),
> however. This will change in the future: work is underway on a
> bytecode verifier for YARV, and once that is done, bytecode can safely
> be loaded into the VM, without fear of corruption. Also, the JRuby
> developers have indicated that they are willing to implement a YARV VM
> emulator
> (<https://GitHub.Com/JRuby/JRuby/blob/da23e51968ffc17d750fca340f4b9538e5e2b425/src/org/jruby/ast/executable/YARVMachine.java 
> >)
> inside JRuby, once the YARV bytecode format and verifier are
> stabilized, so that you could load YARV bytecode into JRuby. (Note
> that this version is obsolete
> (<https://GitHub.Com/JRuby/JRuby/commit/2257c8f811fab8d675a942c86ab712922dc46c6f/ 
> >).)
>
> Rubinius (<http://Rubini.us/>) also always compiles to bytecode, and
> it has a format for compiled files
> (<https://GitHub.Com/EvanPhx/Rubinius/blob/master/kernel/compiler/compiled_file.rb 
> >)
> ('.rbc' files, analogous to JVM '.class' files). There is a chance
> that Rubinius might implement a YARV emulator, if deploying apps as
> YARV bytecode ever becomes popular. Also, the JRuby developers have
> indicated that they are willing to implement a Rubinius bytecode
> emulator
> (<https://GitHub.Com/JRuby/JRuby/blob/da23e51968ffc17d750fca340f4b9538e5e2b425/src/org/jruby/ast/executable/RubiniusMachine.java 
> >)
> inside JRuby, if Rubinius bytecode becomes a popular way of deploying
> Ruby apps. (Note that this version is also obsolete
> (<https://GitHub.Com/JRuby/JRuby/commit/2257c8f811fab8d675a942c86ab712922dc46c6f/ 
> >).)
>
> XRuby (<http://XRuby.GoogleCode.Com/>) is a pure compiler, it compiles
> Ruby sourcecode straight to JVM bytecode ('.class' files). You can
> deploy these '.class' files just like any other Java application.
>
> JRuby (<http://JRuby.Org/>) started out as an interpreter, but it has
> both a JIT compiler and an AOT compiler
> (<https://GitHub.Com/JRuby/JRuby/tree/master/src/org/jruby/compiler/>)
> ('jrubyc') that can compile Ruby sourcecode to JVM bytecode ('.class'
> files). Also, work is underway to create a *new*
> (<https://GitHub.Com/JRuby/JRuby/blob/master/tool/compiler2.rb>)
> compiler that can compile (type-annotated) Ruby code to JVM bytecode
> that actually looks like a Java class and can be used from Java code
> without barriers.
>
> Ruby.NET (<http://RubyDotNETCompiler.GoogleCode.Com/>) is a pure
> compiler that compiles Ruby sourcecode to CIL bytecode (PE '.dll' or
> '.exe' files). You can deploy these just like any other CLI
> application.
>
> IronRuby (<http://IronRuby.Net/>) also compiles to CIL bytecode, but
> typically does this in-memory. However, you can pass commandline
> switches
> (<https://GitHub.Com/IronRuby/IronRuby/blob/master/Merlin/Main/Languages/Ruby/Ruby/Hosting/RubyOptionsParser.cs#L275-276 
> >)
> to it, so it dumps the '.dll' and '.exe' files out to disk. Once you
> have those, they can be deployed normally.
>
> BlueRuby
> (<https://SDN.SAP.Com/irj/scn/wiki?path=/display/Research/BlueRuby>)
> automatically pre-parses Ruby sourcecode into BRIL (BlueRuby
> Intermediate Language), which is basically a serialized parsetree.
> (See *Blue Ruby - A Ruby VM in SAP ABAP*
> (<https://SDN.SAP.Com/irj/scn/go/portal/prtroot/docs/library/uuid/408a9a3b-03f9-2b10-b29c-f0a3374b19d8 
> >)
> for details.)
>
> I *think* (but I am definitely not sure) that there is a way to get
> Cardinal (<https://GitHub.Com/Cardinal/Cardinal/>) to dump out Parrot
> (<http://ParrotCode.Org/>) bytecode archives (PBC). (Actually,
> Cardinal only compiles to PAST, and then Parrot takes over, so it
> would be Parrot's job to dump and load bytecode archives.)
>
> MRI doesn't have a bytecode.
>
> HotRuby (<http://HotRuby.Accelart.Jp/>) and Red Sun
> (<https://GitHub.Com/JonathanBranam/RedSun/>) appear to have the same
> bytecode format as YARV, and they appear to be able to load bytecode,
> but I am not familiar with them and can't make a definitive statement.
>
> I am not familiar enough with tinyrb
> (<http://Code.MACournoyer.Com/tinyrb/>) or MagLev
> (<http://MagLev.GemStone.Com/>) to make any statement about them.
>
> jwm
>