There is much sense in this mail, I like it. The unicorn GPL shouldn���t be an issue in this usage scenario.

Well done,

Norbert

Am 05.08.2019 um 11:48 schrieb Guillermo Polito <guillermopolito@gmail.com>:


El 3 ago 2019, a las 13:59, Norbert Hartl <norbert@hartl.name> escribi��:

That is pretty awesome. Couldn���t be an constraint umbrella for VMMaker. This way it would be possible to write tests that check for resulting code. Or writing tests for the JIT (does sista has something like this). Could be one step closer to a deterministic code generation, no?

Just to be fair, there are in Cog machine code simulation capabilities by using Bochs for intel and gdb 7.10 for arm32.
And there is also a starting point for testing the JIT.

However, we have seen that for this the opensmalltalk-vm contains a copy of bochs and gdb source code 

And with Pablo we have thought this was a suboptimal (both regarding building and licencing���), so we started to look at alternatives.
That���s why we took a look at unicorn and llvm. Unicorn is ultimately based on qemu, which is fairly mature from our point of view.
There is not much to say about llvm :).

What is nice is that with a single set of bindings we can cover lots of platforms. E.g., no need for new bindings for arm64.

Aaand, with some little adjustments here and there, we have ~85% of 114 existing tests passing for arm32, x86 and x86-64.
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Of course there are not many tests, and they are only testing the basic compiler (just instructions) and not the Jitting of methods.
But it���s a good start.

Now, also we were a bit picky about licensing:
 - The llvm disassembler bindings are MIT.
 - We have licensed the unicorn bindings as LGPL because Unicorn is GPL, and this would allow people to use the bindings without any requirements on licensing. However, any modifications to the bindings or unicorn itself should be further published as LGPL or GPL.

Guille


Norbert

Am 02.08.2019 um 18:09 schrieb Guillermo Polito <guillermopolito@gmail.com>:

Hi everybody,

I���ve been playing around with machine code simulation this last week and I���ve made bindings for the unicorn library and the llvm disassembler:


Funny thing: both support lots of platforms (x86 and arm both 32 and 64 bits and more���). So out of the box we can simulate and disassemble lots of platforms.

And in one afternoon I���ve played with them to do a native debugger with Spec2 just for fun.
Hope this evolves a bit more soon, and that it helps somebody.

Guille

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