Stream: git-wasmtime

Topic: wasmtime / issue #4090 ISLE: Add a flag to not expand int...


view this post on Zulip Wasmtime GitHub notifications bot (Apr 29 2022 at 21:10):

github-actions[bot] commented on issue #4090:

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view this post on Zulip Wasmtime GitHub notifications bot (Apr 29 2022 at 21:58):

cfallin commented on issue #4090:

I think this general approach is sound -- thanks for the early-feedback pass @avanhatt!

One general thought: I have a sense that internal-extractors-as-macro-expansion should not be special-cased, in the long run. In other words, a call to an internal extractor should happen just like a call to an external one, and it should be generated as a separate Rust function. (Just as internal constructors are handled today). The main reason this is not the case today is that we need the inlining in order to put all of the opcode-match cases together in the trie and allow efficient instruction matching. (Otherwise, each "helper" extractor that wraps "get the inst and see if its opcode is Add" will be called, one at a time in a linear sequence.) But this is kind of a special case and really we should have a notion of "this extractor should be inlined"; it shouldn't be the default.

All of this to say: I think a refactor toward my goal, which would simultaneously serve the needs here, would be to (i) create sema::Pattern nodes for internal extractor invocations, just as we do in sema::Expr for internal constructor invocations; (ii) factor the macro-expansion bit out into a separate inlining pass. That's enough to do what you need here (omit the inlining pass invocation when doing analysis). Then the final step for my goal above is to add an inline flag to extractors, and make it non-default.

(Part of my motivation for the above is to allow if-lets in internal extractors too, but that's neither here nor there!)

If you'd be up for that as an alternative approach, I'd be grateful; if not, no worries, we can probably land a shorter-term hack if that's what is needed.

Also, this will merge-conflict with #4091; not sure which will go in first, but I'm happy to help resolve merge conflicts here if needed!

view this post on Zulip Wasmtime GitHub notifications bot (Apr 29 2022 at 21:58):

cfallin edited a comment on issue #4090:

I think this general approach is sound -- thanks for the early-feedback pass @avanhatt!

One general thought: I have a sense that internal-extractors-as-macro-expansion should not be special-cased, in the long run. In other words, a call to an internal extractor should happen just like a call to an external one, and it should be generated as a separate Rust function. (Just as internal constructors are handled today.) The main reason this is not the case today is that we need the inlining in order to put all of the opcode-match cases together in the trie and allow efficient instruction matching. (Otherwise, each "helper" extractor that wraps "get the inst and see if its opcode is Add" will be called, one at a time in a linear sequence.) But this is kind of a special case and really we should have a notion of "this extractor should be inlined"; it shouldn't be the default.

All of this to say: I think a refactor toward my goal, which would simultaneously serve the needs here, would be to (i) create sema::Pattern nodes for internal extractor invocations, just as we do in sema::Expr for internal constructor invocations; (ii) factor the macro-expansion bit out into a separate inlining pass. That's enough to do what you need here (omit the inlining pass invocation when doing analysis). Then the final step for my goal above is to add an inline flag to extractors, and make it non-default.

(Part of my motivation for the above is to allow if-lets in internal extractors too, but that's neither here nor there!)

If you'd be up for that as an alternative approach, I'd be grateful; if not, no worries, we can probably land a shorter-term hack if that's what is needed.

Also, this will merge-conflict with #4091; not sure which will go in first, but I'm happy to help resolve merge conflicts here if needed!

view this post on Zulip Wasmtime GitHub notifications bot (May 02 2022 at 19:19):

avanhatt commented on issue #4090:

Thanks for the feedback, @cfallin!

I agree that adding this as an explicit construct at the sema level would be nicer. I'll take a stab at that refactor and circle back if that ends up being too time consuming for unblocking our verification path.

view this post on Zulip Wasmtime GitHub notifications bot (Sep 01 2022 at 00:01):

jameysharp commented on issue #4090:

Just glancing at older PRs: is this still a direction you're interested in, @avanhatt? Or have you all found a different direction that's meeting your needs?

view this post on Zulip Wasmtime GitHub notifications bot (Sep 01 2022 at 15:37):

avanhatt commented on issue #4090:

@jameysharp I'm still using this code on our fork, but I'll close this PR for now until we are actually at the point of merging back. Thanks!


Last updated: Oct 23 2024 at 20:03 UTC