Remove const eval loop detector #70087
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@bors try |
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⌛ Trying commit 044dc6e with merge f88e9a4452e792c29632101b348a1df9876d45cd... |
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☀️ Try build successful - checks-azure |
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@Centril well looks like I still need your help to start a crater run, sorry. |
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Weird... cc @pietroalbini @craterbot check |
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| LL | n = if n % 2 == 0 { n/2 } else { 3*n + 1 }; | ||
| | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | ||
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| = note: see issue #49146 <https://github.com/rust-lang/rust/issues/49146> for more information | ||
| = help: add `#![feature(const_if_match)]` to the crate attributes to enable | ||
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| warning: Constant evaluating a complex constant, this might take some time |
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You mean at like 1% or 10% of the step limit? Not sure how to choose a good number for that, but anything above 10% of the step limit seems useless since you're hitting the step limit soon, and anything below 30s will likely be annoying more often than not. It's very hard to silence this warning (it may be getting emitted in a different crate from the one currently being evaluated).
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Anecdotally, the default step limit only takes a few seconds to trigger, so I don't think preserving the warning is helpful.
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…op-detector, r=RalfJung Remove const eval loop detector Now that there is a configurable instruction limit for CTFE (see rust-lang#67260), we can replace the loop detector with something much simpler. See rust-lang#66946 for more discussion about this. Although the instruction limit is nightly-only, the only practical way to reach the default limit uses nightly-only features as well (although CTFE will still execute code using such features inside an array initializer on stable). This will at the very least require a crater run, since it will result in an error wherever the "long running const eval" warning appeared before. We may need to increase the default for `const_eval_limit` to work around this. Resolves rust-lang#54384 cc rust-lang#49980 r? @oli-obk cc @RalfJung
Rollup of 11 pull requests Successful merges: - rust-lang#67761 (Move the dep_graph construction to a dedicated crate.) - rust-lang#69740 (Replace some desc logic in librustc_lint with article_and_desc) - rust-lang#69981 (Evaluate repeat expression lengths as late as possible) - rust-lang#70087 (Remove const eval loop detector) - rust-lang#70242 (Improve E0308 error message wording) - rust-lang#70264 (Fix invalid suggestion on `&mut` iterators yielding `&` references) - rust-lang#70267 (get rid of ConstPropUnsupported; use ZST marker structs instead) - rust-lang#70277 (Remove `ReClosureBound`) - rust-lang#70283 (Add regression test for rust-lang#70155.) - rust-lang#70294 (Account for bad placeholder types in where clauses) - rust-lang#70309 (Clean up E0452 explanation) Failed merges: r? @ghost
…RalfJung Remove outdated reference to interpreter snapshotting This should have been a part of rust-lang#70087. r? @RalfJung
…RalfJung Remove outdated reference to interpreter snapshotting This should have been a part of rust-lang#70087. r? @RalfJung
Now that there is a configurable instruction limit for CTFE (see #67260), we can replace the loop detector with something much simpler. See #66946 for more discussion about this. Although the instruction limit is nightly-only, the only practical way to reach the default limit uses nightly-only features as well (although CTFE will still execute code using such features inside an array initializer on stable).
This will at the very least require a crater run, since it will result in an error wherever the "long running const eval" warning appeared before. We may need to increase the default for
const_eval_limitto work around this.Resolves #54384 cc #49980
r? @oli-obk cc @RalfJung