error-code docs improvements (No. 2)
- Added empty error-code docs for `E0208`, `E0640` and `E0717` with the "internal" header as discussed on Discord.
- Wrote docs and UI test for `E0711`, again with the header.
- `tidy` changes are common-sense and make everything pass, `style.rs` hack is annoying though.
r? ```@GuillaumeGomez```
Use FxIndexSet when updating obligation causes in `adjust_fulfillment_errors_for_expr_obligation`
I have no idea how to test this reliably, but I've **manually** verified it fixes the instability in #106417 that isn't due to dtolnay/trybuild#212.
Fixes#106417
Simplify some canonical type alias names
* delete the `Canonicalized<'tcx>` type alias in favor for `Canonical<'tcx>`
* `CanonicalizedQueryResponse` -> `CanonicalQueryResponse`
I don't particularly care about the latter, but it should be consistent. We could alternatively delete the first alias and rename the struct to `Canonicalized`, and then keep the name of `CanonicalizedQueryResponse` untouched.
Move `check_region_obligations_and_report_errors` to `TypeErrCtxt`
Makes sense for this function to live with its sibling `resolve_regions_and_report_errors`, around which it's basically just a wrapper.
Enable Shadow Call Stack for Fuchsia on AArch64
Fuchsia already uses SCS by default for C/C++ code on ARM hardware. This patch allows SCS to be used for Rust code as well.
Remove invalid case for mutable borrow suggestion
If we have a call such as `foo(&mut buf)` and after reference
collapsing the type is inferred as `&T` where-as the required type is
`&mut T`, don't suggest `foo(&mut mut buf)`. This is wrong syntactically
and the issue lies elsewhere, not in the borrow.
Fixes#105645
Change a commit_if_ok call to probe
Removes an over-eager `commit_if_ok` which makes inference worse.
I'm not entirely sure whether it's ok to remove the check that types are the same, because casting seems to cause equality checks with incorrect types?
Fixes#105037
r? ```@BoxyUwU```
Always permit ConstProp to exploit arithmetic identities
Fixes https://github.com/rust-lang/rust/issues/72751
Initially, I thought I would need to enable operand propagation then do something else, but actually https://github.com/rust-lang/rust/pull/74491 already has the fix for the issue in question! It looks like this optimization was put under MIR opt level 3 due to possible soundness/stability implications, then demoted further to MIR opt level 4 when MIR opt level 2 became associated with `--release`.
Perhaps in the past we were doing CTFE on optimized MIR? We aren't anymore, so this optimization has no stability implications.
r? `@oli-obk`
Simplify match statement
Add multiple tests
- 1 test for checking `N + 1 + 1` does not unify with `N+1`
- 2 tests for checking that a function that uses two parameters only returns the parameter that
is actually used.
- Check exact repeat predicates
Instead of just switching to a probe, check for different matches, and see how many there are.
If one, unify it, otherwise return true and let it be unified later.
