Introduce a no-op `PlaceMention` statement for `let _ =`.
Fixes https://github.com/rust-lang/rust/issues/54003
Fixes https://github.com/rust-lang/rust/issues/80059
Split from https://github.com/rust-lang/rust/pull/101500
This PR introduces a new `PlaceMention` statement dedicated to matches that neither introduce bindings nor ascribe types. Without this, all traces of the match would vanish from MIR, making it impossible to diagnose unsafety or use in #101500.
This allows to mark `let _ = <unsafe union access or dereference>` as requiring an unsafe block.
Nominating for lang team, as this introduces an extra error.
Rollup of 8 pull requests
Successful merges:
- #106915 (Only load one CSS theme by default)
- #108294 (Place binder correctly for arbitrary trait bound suggestion)
- #108778 (x fmt: Don't print all modified files if there's more than 10)
- #108854 (feat/refactor: improve errors in case of ident with number at start)
- #108870 (Fix invalid inlining of reexport of reexport of private item)
- #108917 (Consider target_family as pal)
- #108922 (Add auto notification for changes to stable mir)
- #108929 (Fix typo in span_map.rs)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add auto notification for changes to stable mir
Adds a new entry to the triagebot configuration file to notify subscribers about changes to the stable MIR. I added myself and `@oli-obk` for now.
r?oli-obk
Consider target_family as pal
Currently, tidy does not consider code in target_family as platform-specific. This is erroneous and should be fixed.
r? `@workingjubilee`
Fix invalid inlining of reexport of reexport of private item
Fixes https://github.com/rust-lang/rust/issues/108679.
The problem is that a reexport is always resolving to the end type, so if the end type is private, the reexport inlines. Except that if you reexport a public reexport (which reexports the private item), then it should not be inlined again.
r? `@notriddle`
feat/refactor: improve errors in case of ident with number at start
Improve parser code when we parse a integer (or float) literal but expect an identifier. We emit an error message saying that identifiers can't begin with numbers. This PR just improves that code and expands it to all identifiers. Note that I haven't implemented error recovery (this didn't exist before anyway), I might do that in a follow up PR.
Rollup of 8 pull requests
Successful merges:
- #108754 (Retry `pred_known_to_hold_modulo_regions` with fulfillment if ambiguous)
- #108759 (1.41.1 supported 32-bit Apple targets)
- #108839 (Canonicalize root var when making response from new solver)
- #108856 (Remove DropAndReplace terminator)
- #108882 (Tweak E0740)
- #108898 (Set `LIBC_CHECK_CFG=1` when building Rust code in bootstrap)
- #108911 (Improve rustdoc-gui/tester.js code a bit)
- #108916 (Remove an unused return value in `rustc_hir_typeck`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Do not consider `&mut *x` as mutating `x` in `CopyProp`
This PR removes an unfortunate overly cautious case from the current implementation.
Found by https://github.com/rust-lang/rust/pull/105274 cc `@saethlin`
Set `LIBC_CHECK_CFG=1` when building Rust code in bootstrap
Downstream forks of the Rust compiler might want to use a custom `libc` to add support for targets that are not yet available upstream. Adding a patch to replace `libc` with a custom one would cause compilation errors though, because Cargo would interpret the custom `libc` as part of the workspace, and apply the check-cfg lints on it.
Since https://github.com/rust-lang/libc/pull/3037, the `libc` build script emits check-cfg flags only when the `LIBC_CHECK_CFG` environment variable is set, so this PR allows the use of custom `libc`s.
Canonicalize root var when making response from new solver
During trait solving, if we equate two inference variables `?0` and `?1` but don't equate them with any rigid types, then `InferCtxt::probe_ty_var` will return `Err` for both of these. The canonicalizer code will then canonicalize the variables independently(!), and the response will not reflect the fact that these two variables have been made equal.
This hinders inference and I also don't think it's sound? I haven't thought too much about it past that, so let's talk about it.
r? ``@lcnr``
Retry `pred_known_to_hold_modulo_regions` with fulfillment if ambiguous
Fixes#108721
The problem here is that when we're checking `is_sized_raw` during codegen on some type that has a lot of opaques in it, something emits several nested obligations that are individually ambiguous, but when processed together in a loop then apply modulo regions. Since the `evaluate_predicates_recursively` inner loop doesn't process predicates until they stop changing, we return `EvaluatedToAmbig`, which makes the sized check return false incorrectly. See:
f15f0ea739/compiler/rustc_trait_selection/src/traits/select/mod.rs (L596-L606)
... Compared to the analogous loop in the new solver:
f15f0ea739/compiler/rustc_trait_selection/src/solve/mod.rs (L481-L512)
To fix this, if we get ambiguous during `pred_known_to_hold_modulo_regions`, just retry the obligation in a fulfillment context.
--
Unfortunately... I don't have a test for this. I've only tested this locally. Pending minimization :/
r? types
Rename `MapInPlace` as `FlatMapInPlace`.
After removing the `map_in_place` method, which isn't much use because modifying every element in a collection such as a `Vec` can be done trivially with iteration.
r? ``@lqd``
Suppress copy impl error when post-normalized type references errors
Suppress spurious errors from the `Copy` impl validity check when fields have bad types *post*-normalization, instead of just pre-normalization.
----
The const-generics test regressed recently due to #107965, cc `````@BoxyUwU.`````
* I think it's because `[_; 0u32]: Copy` now fails to hold because a nested obligation `ConstArgHasType(0u32, usize)` fails.
* It's interesting that `[const_error]` shows up in the type only after normalization, though, but I'm pretty sure that it's due to the evaluate call that happens when normalizing unevaluated consts.
StableMIR: Proof-of-concept implementation + test
This PR is part of the [project Stable MIR](https://github.com/rust-lang/project-stable-mir). The PR deletes old re-exports from rustc_smir and introduces a proof-of-concept implementation for APIs to retrieve crate information.
The implementation follows the [design described here](https://hackmd.io/XhnYHKKuR6-LChhobvlT-g?view), but instead of using separate crates for the implementation, it uses separate modules inside `rustc_smir`.
The API introduced at this point should be seen just as an example on how we are planning to structure the communication between tools and the compiler.
I have not explored yet what should be the right granularity, the best starting point for users, neither the best way to implement it.
r? ``````@oli-obk``````
