[Vm-dev] Overview of the OpenSmalltalk VM and its build process
Mariano Martinez Peck
marianopeck at gmail.com
Wed Oct 18 11:37:38 UTC 2017
It's a bit outdated and aimed for newbies but you can see my posts about
the VM:
https://marianopeck.wordpress.com/2011/04/28/the-first-part-of-the-journey-is-over/
https://marianopeck.wordpress.com/2011/07/18/the-second-part-of-the-journey-is-over/
Cheers,
On Wed, Oct 18, 2017 at 3:11 AM, <raffaello.giulietti at lifeware.ch> wrote:
>
> Hi Clément and Nicolas,
>
> thanks for the useful hints and background information.
>
>
>
>
> On 17/10/17 19:22, Nicolas Cellier wrote:
> >
> >
> >
> >
> >
> >
> > 2017-10-17 19:03 GMT+02:00 Nicolas Cellier
> > <nicolas.cellier.aka.nice at gmail.com
> > <mailto:nicolas.cellier.aka.nice at gmail.com>>:
> >
> >
> >
> > 2017-10-17 16:00 GMT+02:00 Clément Bera <bera.clement at gmail.com
> > <mailto:bera.clement at gmail.com>>:
> >
> >
> > Hi Raffaello,
> >
> > Answers inlined...
> >
> > On Tue, Oct 17, 2017 at 3:07 PM, Raffaello Giulietti
> > <raffaello.giulietti at lifeware.ch
> > <mailto:raffaello.giulietti at lifeware.ch>> wrote:
> >
> >
> > Hi,
> >
> > I'm interested in understanding the overall OpenSmalltalk VM
> > structure and design and its build process.
> >
> > I read [1] and [2] to get a high level picture of the vm and
> > its interesting strategy to development (Slang, VMMaker,
> etc.)
> >
> > Apart from these, are there other useful
> > documents/sites/tutorials on the vm development process in
> > general and about the underlying ideas in the build process?
> > I'm aware that vm construction is a rather special topic but
> > any useful reference or hint is welcome.
> >
> > I'm already familiar with the interesting [3] and [4]
> > websites and their authors papers, talks and slides, but
> > these do not seem to help much in clarifying the development
> > process itself.
> >
> > In particular, I'm targeting Pharo 64 bit/Win 64 bit
> > (x64-86). I hope to be able someday to actively participate
> > in bringing Cog/Spur/Sista to a more mature status on this
> > platform.
> >
> > The questions I would like to find an answer to are of the
> > following kind:
> > * Where should I start?
> >
> >
> > A good start would be to load the Squeak VMMaker dev image (See
> > here: http://www.mirandabanda.org/cogblog/build-image/
> > <http://www.mirandabanda.org/cogblog/build-image/>) and read the
> > different opened workspaces. In addition, ...
> >
> > *Compilation toolchain*
> >
> > To check you have everything installed to compile, you can go to
> > the one of the build folder (One of the windows build folder if
> > you're on windows, for example build.Win64x64, in most case we
> > don't recommend cross compilation), read the HowToBuild file,
> > then go to one of the inner folder and use the mvm script to
> > compile a VM from pre-generated C sources.
> >
> >
> > See below though, on windows, we target mingw so it's kind of
> > cross-compilation anyway.
> >
> >
> > If it does not work, check on the openSmalltalk-VM repo how the
> > VM is built using Travis CI and set-up your machine similarly to
> > the Travis slaves.
> >
> > *Changes in Slang (GC/Interpreter/JIT/...)*
> >
> > In general when you want to change something in the GC /
> > Interpreter the process is as follow:
> >
> > 1) Make your changes work with the StackVM (interpreter-only)
> > simulator
> > 2) Make your changes work with the compiled StackVM
> > (interpreter-only)
> > 3) Make your changes work with the CogVM simulator
> > 4) Make your changes work with the compiled CogVM
> >
> > In general when you want to change something in the JIT the
> > process is as follow:
> >
> > 1) Make your changes generate correct in-image machine code
> > 2) Make your changes work with the CogVM simulator
> > 3) Make your changes work with the compiled CogVM
> >
> > So a good place to start is to have the simulators working. You
> > could use this to help:
> > https://clementbera.wordpress.com/2016/05/30/simulating-the-
> cog-vm/
> > <https://clementbera.wordpress.com/2016/05/30/
> simulating-the-cog-vm/>
> >
> > Once the simulator works with your changes, you can generate C
> > sources with something like "VMMaker generateConfiguration"
> >
> > *Changes in Platform code*
> > *
> > *
> > Go to the platform folder at the root and change the C files
> > with a text editor
> >
> >
> > * Should I use Squaek or can I use Pharo for vm development
> > purposes?
> >
> >
> > Currently I still use Squeak but I plan to migrate to Pharo. I'd
> > say it's still a bit easier from Squeak due to package
> > compatibility making it hard to commit from Pharo without
> > uncommitting something else, some scripts are also present by
> > default in the Squeak dev image, but everything should work on
> > both environments. No big deal in using one of the other.
> >
> >
> > * What are the restrictions of Slang?
> >
> >
> > ...
> > As long as the VM compiles and run, this is correct Slang code,
> > else it's not.
> > In general you should just think in C and write Smalltalk
> instead.
> > I don't know what to say. This is not dynamic at all. No
> > dictionaries, no look-up, no nothing. Even arrays look like
> > Smalltalk arrays but like C arrays you don't have the actual
> size.
> > Blocks work as long as they're inlined and removed when
> > performing inlining in the Slang to C compiler.
> >
> > * Where does VMMaker live?
> >
> >
> > Half there:
> > https://github.com/OpenSmalltalk/opensmalltalk-vm
> > <https://github.com/OpenSmalltalk/opensmalltalk-vm>
> > Accessible from git
> >
> > Half there:
> > http://source.squeak.org/VMMaker/
> > <http://source.squeak.org/VMMaker/>
> > Accessible from Monticello
> >
> > * Which C toolchain shall I use?
> >
> > * Which release of gcc, ld, make are known to work?
> > * What about clang?
> >
> >
> > Depends on the platform. The mvm script normally chooses for
> you.
> >
> > All VMs are built from Travis CI so you can check how to set up
> > your machine from the Travis set-up.
> >
> > On linux it's gcc by default. All recent gcc versions should
> > work since 4.4
> > On Mac, gcc is not supported anymore, so clang is used. I've
> > used many different versions of clang and they all worked.
> >
> > Specific compiler versions that don't work are mentioned in the
> > HowToBuild file in the platform folders (if any).
> >
> >
> > * Which version of cygwin64 or mingw64 are OK?
> >
> >
> > Arf. Both worked at some point, I don't know what the default
> > script use right now I would start with the version used by the
> > mvm script / the Travis build.
> >
> >
> > gcc is broken for win64 (or at least not satisfying our expectations
> > about stack management)
> > So we have to use clang.
> > For this reason, we prefer to compile thru cygwin which has prebuilt
> > (downlodable) clang modules.
> > It's much more difficult to get a working clang in a mingw
> > environment, so this brand is not maintained anymore.
> >
> >
> > Ah, and there was another grief with mingw...
> > Currently the VM still uses DirectX-9.
> > cygwin provides support for this (maybe it's not very future proof
> now...)
> > mingw status is unclear, and it seems that recent distributions lack
> > this support...
> >
> >
> > But the target is a mingw target, not a cygwin target (we don't want
> > VM to depend on cygwin layer, we want to stay minimal).
> > So we use a cross compiler. See the line
> >
> > TOOLPREFIX:=x86_64-w64-mingw32-
> >
> > in
> > https://github.com/OpenSmalltalk/opensmalltalk-
> vm/blob/Cog/build.win64x64/common/Makefile.tools
> > <https://github.com/OpenSmalltalk/opensmalltalk-
> vm/blob/Cog/build.win64x64/common/Makefile.tools>
> >
> > Using cross-compiler means that we can eventually build a x86_64
> > .exe from a cygwin32.
> > But cygwin32 does not provide a debugger (gdb) for x86_64, that's
> > why we prefer developing from a cygwin64 environment.
> >
> > Eventually, I have a hand-assembled visual studio project for
> > compiling the vm with MSVC (2015 if I remember...)
> > Of course that kind of project should better be generated (as was
> > possible via cmake) rather than hand-assembled...
> > It's absolutely cumbersome to maintain such .vc(x)proj across
> > several versions of MSVC.
> > Anyway, it does not produce working VM yet.
> > I retried with 2017 but encountered a code generation bug.
> >
> > We could try to adapt the gnu makefiles to use MSVC thru command
> > line, but IMO the main interest of MSVC is to perform complementary
> > analysis thru IDE.
> >
> >
> >
> > * etc.
> >
> >
> >
> > Greetings
> > Raffaello
> >
> > ---
> >
> > [1] http://www.vpri.org/pdf/tr1997001_backto.pdf
> > <http://www.vpri.org/pdf/tr1997001_backto.pdf>
> > [2]
> > http://design.cs.iastate.edu/vmil/2011/papers/p03-miranda.
> pdf <http://design.cs.iastate.edu/vmil/2011/papers/p03-miranda.pdf>
> > [3] http://www.mirandabanda.org/cogblog/
> > <http://www.mirandabanda.org/cogblog/>
> > [4] https://clementbera.wordpress.com/
> > <https://clementbera.wordpress.com/>
> >
> >
> >
> >
> > --
> > Clément Béra
> > Pharo consortium engineer
> > https://clementbera.wordpress.com/
> > <https://clementbera.wordpress.com/>
> > Bâtiment B 40, avenue Halley 59650 Villeneuve d'Ascq
> >
> >
> >
>
>
--
Mariano
http://marianopeck.wordpress.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.squeakfoundation.org/pipermail/vm-dev/attachments/20171018/8c829200/attachment-0001.html>
More information about the Vm-dev
mailing list