AST/HIR: Introduce `ExprKind::Err` for better error recovery in the front-end
This way we can avoid aborting compilation if expansion produces errors and generate `ExprKind::Err`s instead.
- Point at opening mismatched formatting brace
- Account for differences between raw and regular strings
- Account for differences between the code snippet and `InternedString`
- Add more tests
make non_camel_case_types an early lint
This allows us to catch these kinds of style violations much earlier, as evidenced by the large number of tests that had to be updated for this change.
enum type instead of variant suggestion unification
Fixes#56028.
Weirdly, we were deciding between a help note and a structured suggestion based on whether the import candidate span was a dummy—but we weren't using that span in any case! The dummy-ness of the span (which appears to be a matter of this-crate vs. other-crate definition) isn't the right criterion by which we should decide whether it's germane to mention that "there is an enum variant"; instead, let's use the someness of `def` (which is used as the `has_unexpected_resolution` argument to `error_code`).
Since `import_candidate_to_paths` has no other callers, we are free to stop returning the span and rename the function. By using `span_suggestions_`, we leverage the max-suggestions output limit already built in to the emitter, thus resolving #56028.
In the matter of message wording, "you can" is redundant (and perhaps too informal); prefer the imperative.
In a second commit, we do some unprincipled special-casing to correct and beautify suggestions for `Option` and `Result` (where the existing code was being confused by their being reexported in the prelude).
r? @davidtwco
Weirdly, we were deciding between a help note and a structured
suggestion based on whether the import candidate span was a dummy—but
we weren't using that span in any case! The dummy-ness of the span
(which appears to be a matter of this-crate vs. other-crate
definition) isn't the right criterion by which we should decide
whether it's germane to mention that "there is an enum variant";
instead, let's use the someness of `def` (which is used as the
`has_unexpected_resolution` argument to `error_code`).
Since `import_candidate_to_paths` has no other callers, we are free to
stop returning the span and rename the function. By using
`span_suggestions_`, we leverage the max-suggestions output limit
already built in to the emitter, thus resolving #56028.
In the matter of message wording, "you can" is redundant (and perhaps
too informal); prefer the imperative.
Update migrate warning wording.
This PR modifies the wording of the warning for backwards-incompatible changes in migrate mode. The warning messages are changed to be lowercase and not include line-breaks in order to be consistent with other compiler diagnostics.
static eval: Do not ICE on layout size overflow
Layout size overflow and typeck eval errors are reported. Trigger a bug
only when the eval error is strictly labeled as TooGeneric.
Fixes: #56762
This commit modifies the wording of the warning for
backwards-incompatible changes in migrate mode. The warning messages are
changed to be lowercase and not include line-breaks in order to be
consistent with other compiler diagnostics.
Fix various aspects around `let` bindings inside const functions
* forbid `let` bindings in const contexts that use short circuiting operators
* harden analysis code against derefs of mutable references
Initially this PR was about stabilizing `let` bindings, but too many flaws were exposed that need some more testing on nightly
add coherence future-compat warnings for marker-only trait objects
The future-compat warnings break code that assumes that `dyn Send + Sync !=
dyn Sync + Send`, and are the first step in making them equal. cc #33140.
Note: this lint should be made to default-warn before we merge. It is deny only for the crater run.
r? @nikomatsakis / @scalexm . cc @Centril & @alexreg.
The future-compat warnings break code that assumes that `dyn Send + Sync !=
dyn Sync + Send`, and are the first step in making them equal. cc #33140.
It should be possible to revert this commit when we're done with the
warnings.
Ever since we added a Cargo-based build system for the compiler the
standard library has always been a little special, it's never been able
to depend on crates.io crates for runtime dependencies. This has been a
result of various limitations, namely that Cargo doesn't understand that
crates from crates.io depend on libcore, so Cargo tries to build crates
before libcore is finished.
I had an idea this afternoon, however, which lifts the strategy
from #52919 to directly depend on crates.io crates from the standard
library. After all is said and done this removes a whopping three
submodules that we need to manage!
The basic idea here is that for any crate `std` depends on it adds an
*optional* dependency on an empty crate on crates.io, in this case named
`rustc-std-workspace-core`. This crate is overridden via `[patch]` in
this repository to point to a local crate we write, and *that* has a
`path` dependency on libcore.
Note that all `no_std` crates also depend on `compiler_builtins`, but if
we're not using submodules we can publish `compiler_builtins` to
crates.io and all crates can depend on it anyway! The basic strategy
then looks like:
* The standard library (or some transitive dep) decides to depend on a
crate `foo`.
* The standard library adds
```toml
[dependencies]
foo = { version = "0.1", features = ['rustc-dep-of-std'] }
```
* The crate `foo` has an optional dependency on `rustc-std-workspace-core`
* The crate `foo` has an optional dependency on `compiler_builtins`
* The crate `foo` has a feature `rustc-dep-of-std` which activates these
crates and any other necessary infrastructure in the crate.
A sample commit for `dlmalloc` [turns out to be quite simple][commit].
After that all `no_std` crates should largely build "as is" and still be
publishable on crates.io! Notably they should be able to continue to use
stable Rust if necessary, since the `rename-dependency` feature of Cargo
is soon stabilizing.
As a proof of concept, this commit removes the `dlmalloc`,
`libcompiler_builtins`, and `libc` submodules from this repository. Long
thorns in our side these are now gone for good and we can directly
depend on crates.io! It's hoped that in the long term we can bring in
other crates as necessary, but for now this is largely intended to
simply make it easier to manage these crates and remove submodules.
This should be a transparent non-breaking change for all users, but one
possible stickler is that this almost for sure breaks out-of-tree
`std`-building tools like `xargo` and `cargo-xbuild`. I think it should
be relatively easy to get them working, however, as all that's needed is
an entry in the `[patch]` section used to build the standard library.
Hopefully we can work with these tools to solve this problem!
[commit]: 28ee12db81
Consider references and unions potentially inhabited during privacy-respecting inhabitedness checks
It isn't settled exactly how references to uninhabited types and unions of uninhabited types should act, but we should be more conservative here, as it's likely it will be permitted to soundly have values of such types.
This will also be more important in light of the changes at https://github.com/rust-lang/rust/pull/54125.
cc @RalfJung
