Avoid const-eval ICEs from invalid CoerceShared impls

[chenyukang]

Fixes #158149

Do not allow malformed coercion MIR to reach CTFE, which may trigger a size-mismatch ICE.

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[aapoalas]

I don't know about the error taint stuff and all that, but from a Reborrow-traits point of view this seems fine.

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[oli-obk]

maybe we can get this automatically everywhere by loading coerce_shared_info when the trait solver looks at an impl of CoerceShared and tainting the infcx there. It is fragile to only do it here.

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[chenyukang]

I moved the check to match_impl, should be a better location.

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[oli-obk]

The new solver needs the same treatment, I think. Make the ice test have a revision for both solvers, too

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[oli-obk]

Doesn't selection already check this language item somewhere? Add the check there

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[chenyukang]

you means coerce_shared_reborrow at https://github.com/chenyukang/rust/blob/9996b9dc57838ea6611c6328933073060159c854/compiler/rustc_hir_typeck/src/coercion.rs#L980 ?

I have found coerce_unsize have similar check
https://github.com/chenyukang/rust/blob/9996b9dc57838ea6611c6328933073060159c854/compiler/rustc_hir_typeck/src/coercion.rs#L808-L817

[chenyukang]

I moved the check into coerce_shared_reborrow

now we can make these tests no ICE:
912df9a

but I find another testcase will be ICE which we can not cover for this fix(also upstream main):

#![feature(reborrow)]
#![allow(dead_code)]
use std::marker::CoerceShared;

struct InvalidMut<'a>(&'a u8);

#[derive(Copy, Clone)]
struct InvalidRef<'a>(&'a ());

fn invalid<'a>(value: InvalidMut<'a>)
where
    InvalidMut<'a>: CoerceShared<InvalidRef<'a>>,
{
    let _: InvalidRef<'a> = value;
    //~^ ERROR mismatched types
}

fn main() {}

the reason is we haven't do enough validation for ImplSource::Param.
cc @aapoalas

[rustbot]

This PR changes a file inside tests/crashes. If a crash was fixed, please move into the corresponding ui subdir and add 'Fixes #' to the PR description to autoclose the issue upon merge.

[rust-bors]

☔ The latest upstream changes (presumably #160586) made this pull request unmergeable. Please resolve the merge conflicts by rebasing.