Because it was a mess.
Previously, pretty much you had to handle all path diagnostics manually: remember to check for them and handle them. Now, we wrap the resolver in `TyLoweringContext` and ensure proper error reporting.
This means that you don't have to worry about them: most of the things are handled automatically, and things that cannot will create a compile-time error (forcing you top `drop(ty_lowering_context);`) if forgotten, instead of silently dropping the diagnostics.
The real place for error reporting is in the hir-def resolver, because there are other things resolving, both in hir-ty and in hir-def, and they all need to ensure proper diagnostics. But this is a good start, and future compatible.
This commit also ensures proper path diagnostics for value/pattern paths, which is why it's marked "feat".
Begin to implement type system layer of unsafe binders
Mostly TODOs, but there's a lot of match arms that are basically just noops so I wanted to split these out before I put up the MIR lowering/projection part of this logic.
r? oli-obk
Tracking:
- https://github.com/rust-lang/rust/issues/130516
For Windows, this removes the need to add a breakpoint and modify a value to exit the debugger wait loop.
As a ridealong, this adds a 100ms sleep for all platforms such that waiting for the debugger doesn't hog the CPU thread.
Generate shell completions for x as well
It would be nice to be have shell completions for both `./x` and `x` (installed with `cargo install --path src/tools/x`) instead of just `x.py`. This pr generates the corresponding completions for each shell in a similar way to `x.py` but under `x.<shell>` instead.
Rollup of 5 pull requests
Successful merges:
- #134363 (Use `#[derive(Default)]` instead of manual `impl` when possible)
- #134517 (Add tests for coverage attribute on trait functions)
- #134528 (opt-dist: propagate channel info to bootstrap)
- #134669 (Document the `--dev` flag for `src/ci/docker/run.sh`)
- #134680 (Clean up a few rmake tests )
r? `@ghost`
`@rustbot` modify labels: rollup
Clean up a few rmake tests
Now I'm aware it's a bit late to start participating in the Advent of Tests, but here are a few cleanups in the rmake tests to put under the 🎄 anyways. A handful of unused imports, some warnings, and a couple typos.
r? `@jieyouxu` 🎅
Document the `--dev` flag for `src/ci/docker/run.sh`
This flag is very helpful for debugging CI issues locally, but it's not documented anywhere and I wasn't aware of it until `@jieyouxu` pointed it out. Add a note to the CI Docker readme to make this more discoverable
opt-dist: propagate channel info to bootstrap
Fixes#133503.
Previously, `tests/ui/bootstrap/rustc_bootstap.rs` [sic] failed during [beta bump](https://github.com/rust-lang/rust/pull/133447#issuecomment-2501298794) in opt-dist tests. This is because:
- `opt-dist` tried to run `./x test` against beta-channel dist `rustc` through `bootstrap`.
- The dist build produced during the beta bump produces a `rustc` which correctly thinks that it is a beta compiler based on `src/ci/channel` info.
- `opt-dist` tries to run `./x test` on the beta `rustc` from the dist build, but without specifying channel through a synthetic `config.toml`, so `bootstrap` tells `compiletest` that we're on the `nightly` channel (by default).
- Now there's a channel mismatch: `compiletest` believes the `rustc` under test is a *nightly* rustc, but the `rustc` under test actually considers itself a *beta* rustc. This means that `//@ only-nightly` will be satisfied yet the test will fail as the *beta* rustc is not a *nightly* rustc.
This PR:
- Fixes the test failure during beta bump (i.e. #133503) by having `opt-dist` faithfully report the channel of the dist `rustc` being tested (i.e. "beta" in a beta bump PR). This will properly make the test be ignored during beta bump as the `rustc` under test is not a *nightly* rustc.
- Fixes the test name `rustc_bootstap.rs` -> `rustc_bootstrap.rs`. No more stapping.
- Slightly adjusts the doc comment in the test to make it more clear.
I ran a try-job against the beta branch (explicitly running the opt-dist tests by modifying the job definition) with these changes in #134131, and it appears that the try-job was [successful](https://github.com/rust-lang/rust/pull/134131#issuecomment-2555492215). The two commits in this PR are cherry-picked from #134131, with the test commit slightly modified (to also adjust the test comments).
r? `@Kobzol` (or compiler or bootstrap or infra I guess?)
Use `#[derive(Default)]` instead of manual `impl` when possible
While working on #134175 I noticed a few manual `Default` `impl`s that could be `derive`d instead. These likely predate the existence of the `#[default]` attribute for `enum`s.
Revert stabilization of the `#[coverage(..)]` attribute
Due to a process mixup, the PR to stabilize the `#[coverage(..)]` attribute (#130766) was merged while there are still outstanding concerns. The default action in that situation is to revert, and the feature is not sufficiently urgent or uncontroversial to justify special treatment, so this PR reverts that stabilization.
---
- A key point that came up in offline discussions is that unlike most user-facing features, this one never had a proper RFC, so parts of the normal stabilization process that implicitly rely on an RFC break down in this case.
- As the implementor and de-facto owner of the feature in its current form, I would like to think that I made good choices in designing and implementing it, but I don't feel comfortable proceeding to stabilization without further scrutiny.
- There hasn't been a clear opportunity for T-compiler to weigh in or express concerns prior to stabilization.
- The stabilization PR cites a T-lang FCP that occurred in the tracking issue, but due to the messy design and implementation history (and lack of a clear RFC), it's unclear what that FCP approval actually represents in this case.
- At the very least, we should not proceed without a clear statement from T-lang or the relevant members about the team's stance on this feature, especially in light of the other concerns listed here.
- The existing user-facing documentation doesn't clearly reflect which parts of the feature are stable commitments, and which parts are subject to change. And there doesn't appear to be a clear consensus anywhere about where that line is actually drawn, or whether the chosen boundary is acceptable to the relevant teams and individuals.
- For example, the [stabilization report comment](https://github.com/rust-lang/rust/issues/84605#issuecomment-2166514660) mentions that some aspects are subject to change, but that text isn't consistent with my earlier comments, and there doesn't appear to have been any explicit discussion or approval process.
- [The current reference text](https://github.com/rust-lang/reference/blob/4dfaa4f/src/attributes/coverage-instrumentation.md) doesn't mention this distinction at all, and instead simply describes the current implementation behaviour.
- When the implementation was changed to its current form, the associated user-facing error messages were not updated, so they still refer to the attribute only being allowed on functions and closures.
- On its own, this might have been reasonable to fix-forward in the absence of other concerns, but the fact that it never came up earlier highlights the breakdown in process that has occurred here.
---
Apologies to everyone who was excited for this stabilization to land, but unfortunately it simply isn't ready yet.
cleanup `TypeVerifier`
We should merge it with the `TypeChecker` as we no longer bail in cases where it encounters an error since #111863.
It's quite inconsistent whether a check lives in the verifier or the `TypeChecker`, so this feels like a quite impactful cleanup. I expect that for this we may want to change the `TypeChecker` to also be a MIR visitor 🤔 this is non-trivial so I didn't fully do it in this PR.
Best reviewed commit by commit.
r? `@compiler-errors` feel free to reassign however
Asserts the maximum value that can be returned from `Vec::len`
Currently, casting `Vec<i32>` to `Vec<u32>` takes O(1) time:
```rust
// See <https://godbolt.org/z/hxq3hnYKG> for assembly output.
pub fn cast(vec: Vec<i32>) -> Vec<u32> {
vec.into_iter().map(|e| e as _).collect()
}
```
But the generated assembly is not the same as the identity function, which prevents us from casting `Vec<Vec<i32>>` to `Vec<Vec<u32>>` within O(1) time:
```rust
// See <https://godbolt.org/z/7n48bxd9f> for assembly output.
pub fn cast(vec: Vec<Vec<i32>>) -> Vec<Vec<u32>> {
vec.into_iter()
.map(|e| e.into_iter().map(|e| e as _).collect())
.collect()
}
```
This change tries to fix the problem. You can see the comparison here: <https://godbolt.org/z/jdManrKvx>.
Use `PtrMetadata` instead of `Len` in slice drop shims
I tried to do a bigger change in #134297 which didn't work, so here's the part I really wanted: Removing another use of `Len`, in favour of `PtrMetadata`.
Split into two commits where the first just adds a test, so you can look at the second commit to see how the drop shim for an array changes with this PR.
Reusing the same reviewer from the last one:
r? BoxyUwU
