[llvm-commits] [PATCH] unit tests for MCJIT

[Jim Grosbach]

On Sep 24, 2012, at 2:20 PM, "Du Toit, Stefanus" <stefanus.du.toit at intel.com> wrote:

>> -----Original Message-----
>> From: llvm-commits-bounces at cs.uiuc.edu [mailto:llvm-commits-
>> bounces at cs.uiuc.edu] On Behalf Of Jim Grosbach
>> Sent: Monday, September 24, 2012 1:38 PM
>> To: Malea, Daniel
>> Cc: llvm-commits at cs.uiuc.edu
>> Subject: Re: [llvm-commits] [PATCH] unit tests for MCJIT
>> 
>> The most substantive comment is that we shouldn't move the memory
>> manager out of lli.cpp. That's very much not a general purpose memory
>> manager, but rather is intended as a (trivial) example of what a client
>> application may need to implement in order to utilize the MCJIT. It's not
>> part of a general LLVM library, but rather part of the lli tool.
> 
> What's the downside of moving the memory manager out of lli? If it's sufficient for a simple client (like lli's) needs, why not have it be reusable?

> My understanding is that the tests do need *some* memory manager implementation. If it's not moved here, wouldn't it need to be included from inside of the lli sources (awkward) or duplicated somewhere in the test sources (even more awkward)?

It's a division of responsibility and layering thing. The MCJIT library defines the interface to the memory manager, but that's it. The client is responsible for supplying an implementation. We want the implementation to make this distinction very starkly at least for now, and moving the memory manager into the library rather than part of lli obfuscates that purpose. It's possible we'll create another library later that supplies, for example, a simple default hosted JIT environment complete with simple memory manager and refactor lli to reference that. That's an interesting thing and I'm open to it as a design direction, but it's orthogonal to getting unit tests for other parts of the MCJIT and I'd prefer it be dealt with separately.

-Jim

> 
> Thanks,
> 
> Stefanus
> 
> --
> Stefanus Du Toit stefanus.du.toit at intel.com
>  Intel Dynamic Mobility and Parallelism
>  Intel Waterloo
>  phone: +1 519 772 2576
>