Re: [PATCH] libgccjit Fix a RTL bug for libgccjit

[Jeff Law <jeffreyalaw@gmail.com>]

On 11/20/23 15:46, David Malcolm wrote:
> On Fri, 2023-11-17 at 14:09 -0700, Jeff Law wrote:
>>
>>
>> On 11/17/23 14:08, Antoni Boucher wrote:
>>> In contrast with the other frontends, libgccjit can be executed
>>> multiple times in a row in the same process.
>> Yup.  I'm aware of that.  Even so calling init_emit_once more than
>> one
>> time still seems wrong.
> 
> There are two approaches we follow when dealing with state stored in
> global variables:
> (a) clean it all up via the various functions called from
> toplev::finalize
> (b) make it effectively constant once initialized, with idempotent
> initialization
> 
> The multiple in-process executions of libgccjit could pass in different
> code-generation options.  Does the RTL-initialization logic depend
> anywhere on flags passed in, because if so, we're probably going to
> need to re-run the initialization.
The INIT_EXPANDERS code would be the most concerning as it's 
implementation is totally hidden and provided by the target. I wouldn't 
be at all surprised if one or more do something evil in there.  That 
probably needs to be evaluated on a target by target basis.

The rest really do look like single init, even in a JIT environment 
kinds of things -- ie all the shared constants in RTL.



Jeff