Experimental feature postfix match
This has a basic experimental implementation for the RFC postfix match (rust-lang/rfcs#3295, #121618). [Liaison is](https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/Postfix.20Match.20Liaison/near/423301844) ```@scottmcm``` with the lang team's [experimental feature gate process](https://github.com/rust-lang/lang-team/blob/master/src/how_to/experiment.md).
This feature has had an RFC for a while, and there has been discussion on it for a while. It would probably be valuable to see it out in the field rather than continue discussing it. This feature also allows to see how popular postfix expressions like this are for the postfix macros RFC, as those will take more time to implement.
It is entirely implemented in the parser, so it should be relatively easy to remove if needed.
This PR is split in to 5 commits to ease review.
1. The implementation of the feature & gating.
2. Add a MatchKind field, fix uses, fix pretty.
3. Basic rustfmt impl, as rustfmt crashes upon seeing this syntax without a fix.
4. Add new MatchSource to HIR for Clippy & other HIR consumers
Provide structured suggestion for `#![feature(foo)]`
```
error: `S2<'_>` is forbidden as the type of a const generic parameter
--> $DIR/lifetime-in-const-param.rs:5:23
|
LL | struct S<'a, const N: S2>(&'a ());
| ^^
|
= note: the only supported types are integers, `bool` and `char`
help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types
|
LL + #![feature(adt_const_params)]
|
```
Fix#55941.
```
error: `S2<'_>` is forbidden as the type of a const generic parameter
--> $DIR/lifetime-in-const-param.rs:5:23
|
LL | struct S<'a, const N: S2>(&'a ());
| ^^
|
= note: the only supported types are integers, `bool` and `char`
help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types
|
LL + #![feature(adt_const_params)]
|
```
Fix#55941.
Move check-cfg diagnostic logic into a separate file
as well as adding some triagebot mentions (for me) for check-cfg related files.
``@rustbot`` label +F-check-cfg
Split refining_impl_trait lint into _reachable, _internal variants
As discussed in https://github.com/rust-lang/rust/issues/119535#issuecomment-1909352040:
> We discussed this today in triage and developed a consensus to:
>
> * Add a separate lint against impls that refine a return type defined with RPITIT even when the trait is not crate public.
> * Place that in a lint group along with the analogous crate public lint.
> * Create an issue to solicit feedback on these lints (or perhaps two separate ones).
> * Have the warnings displayed with each lint reference this issue in a similar manner to how we do that today with the required `Self: '0'` bound on GATs.
> * Make a note to review this feedback on 2-3 release cycles.
This points users to https://github.com/rust-lang/rust/issues/121718 to leave feedback.
`f16` and `f128` step 3: compiler support & feature gate
Continuation of https://github.com/rust-lang/rust/pull/121841, another portion of https://github.com/rust-lang/rust/pull/114607
This PR exposes the new types to the world and adds a feature gate. Marking this as a draft because I need some feedback on where I did the feature gate check. It also does not yet catch type via suffixed literals (so the feature gate test will fail, probably some others too because I haven't belssed).
If there is a better place to check all types after resolution, I can do that. If not, I figure maybe I can add a second gate location in AST when it checks numeric suffixes.
Unfortunately I still don't think there is much testing to be done for correctness (codegen tests or parsed value checks) until we have basic library support. I think that will be the next step.
Tracking issue: https://github.com/rust-lang/rust/issues/116909
r? `@compiler-errors`
cc `@Nilstrieb`
`@rustbot` label +F-f16_and_f128
Create some minimal HIR for associated opaque types
`LocalDefId`s for opaque types in traits and impls are created after AST -> HIR lowering, so they don't have corresponding HIR and return their various properties through fed queries.
In this PR I also feed some core HIR-related queries for these `LocalDefId`s (which happen to be HIR owners).
As a result all `LocalDefId`s now have corresponding `HirId`s and HIR nodes, and "optional" methods like `opt_local_def_id_to_hir_id` and `opt_hir_node_by_def_id` can be removed.
Follow up to https://github.com/rust-lang/rust/pull/120206.
- Replace some nested if-let with let-chains
- Tweak a match pattern to allow shorthand struct syntax
- Fuse an `is_empty` check with getting the last element
- Merge some common code that emits `MalformedAttribute` and continues
- Format `"{tool}::{name}"` in a way that's consistent with other match arms
- Replace if-let-else-panic with let-else
- Use early-exit to flatten a method body
The internal diagnostic lint currently only allows one, because that was
all that occurred in practice. But rust-lang/rust-clippy/pull/12453
wants to introduce functions with more than one, and this limitation is
getting in the way.
Add a tidy check that checks whether the fluent slugs only appear once
As ``````@Nilstrieb`````` said in https://github.com/rust-lang/rust/pull/121828#issuecomment-1972622855:
> Might make sense to have a tidy check that checks whether the fluent slugs only appear once in the source code and lint for that
there's a tidy check already for sorting
We can get the tidy check error:
```
tidy check
tidy error: /path/to/rust/compiler/rustc_const_eval/messages.ftl: message `const_eval_invalid_align` is not used
tidy error: /path/to/rust/compiler/rustc_lint/messages.ftl: message `lint_trivial_untranslatable_diag` is not used
tidy error: /path/to/rust/compiler/rustc_parse/messages.ftl: message `parse_invalid_literal_suffix` is not used
tidy error: /path/to/rust/compiler/rustc_infer/messages.ftl: message `infer_need_type_info_in_coroutine` is not used
tidy error: /path/to/rust/compiler/rustc_passes/messages.ftl: message `passes_expr_not_allowed_in_context` is not used
tidy error: /path/to/rust/compiler/rustc_passes/messages.ftl: message `passes_layout` is not used
tidy error: /path/to/rust/compiler/rustc_parse/messages.ftl: message `parse_not_supported` is not used
```
r? ``````@Nilstrieb``````
Misc improvements to non local defs lint implementation
This PR is a collection of small improvements I found when I [needlessly tried](https://www.github.com/rust-lang/rust/pull/120393#issuecomment-1971787475) to fix a "perf-regression" in the lint implementation.
I recommend looking at each commit individually.
Use `ControlFlow` in visitors.
Follow up to #121256
This does have a few small behaviour changes in some diagnostic output where the visitor will now find the first match rather than the last match. The change in `find_anon_types.rs` has the only affected test. I don't see this being an issue as the last occurrence isn't any better of a choice than the first.
Rollup of 9 pull requests
Successful merges:
- #121958 (Fix redundant import errors for preload extern crate)
- #121976 (Add an option to have an external download/bootstrap cache)
- #122022 (loongarch: add frecipe and relax target feature)
- #122026 (Do not try to format removed files)
- #122027 (Uplift some feeding out of `associated_type_for_impl_trait_in_impl` and into queries)
- #122063 (Make the lowering of `thir::ExprKind::If` easier to follow)
- #122074 (Add missing PartialOrd trait implementation doc for array)
- #122082 (remove outdated fixme comment)
- #122091 (Note why we're using a new thread in `test_get_os_named_thread`)
r? `@ghost`
`@rustbot` modify labels: rollup
Rework `untranslatable_diagnostic` lint
Currently it only checks calls to functions marked with `#[rustc_lint_diagnostics]`. This PR changes it to check calls to any function with an `impl Into<{D,Subd}iagnosticMessage>` parameter. This greatly improves its coverage and doesn't rely on people remembering to add `#[rustc_lint_diagnostics]`. It also lets us add `#[rustc_lint_diagnostics]` to a number of functions that don't have an `impl Into<{D,Subd}iagnosticMessage>`, such as `Diag::span`.
r? ``@davidtwco``
Currently it only checks calls to functions marked with
`#[rustc_lint_diagnostics]`. This commit changes it to check calls to
any function with an `impl Into<{D,Subd}iagMessage>` parameter. This
greatly improves its coverage and doesn't rely on people remembering to
add `#[rustc_lint_diagnostics]`.
The commit also adds `#[allow(rustc::untranslatable_diagnostic)`]
attributes to places that need it that are caught by the improved lint.
These places that might be easy to convert to translatable diagnostics.
Finally, it also:
- Expands and corrects some comments.
- Does some minor formatting improvements.
- Adds missing `DecorateLint` cases to
`tests/ui-fulldeps/internal-lints/diagnostics.rs`.
Rollup of 8 pull requests
Successful merges:
- #121202 (Limit the number of names and values in check-cfg diagnostics)
- #121301 (errors: share `SilentEmitter` between rustc and rustfmt)
- #121658 (Hint user to update nightly on ICEs produced from outdated nightly)
- #121846 (only compare ambiguity item that have hard error)
- #121961 (add test for #78894#71450)
- #121975 (hir_analysis: enums return `None` in `find_field`)
- #121978 (Fix duplicated path in the "not found dylib" error)
- #121991 (Merge impl_trait_in_assoc_types_defined_by query back into `opaque_types_defined_by`)
r? `@ghost`
`@rustbot` modify labels: rollup
Add a scheme for moving away from `extern "rust-intrinsic"` entirely
All `rust-intrinsic`s can become free functions now, either with a fallback body, or with a dummy body and an attribute, requiring backends to actually implement the intrinsic.
This PR demonstrates the dummy-body scheme with the `vtable_size` intrinsic.
cc https://github.com/rust-lang/rust/issues/63585
follow-up to #120500
MCP at https://github.com/rust-lang/compiler-team/issues/720
Existing names for values of this type are `sess`, `parse_sess`,
`parse_session`, and `ps`. `sess` is particularly annoying because
that's also used for `Session` values, which are often co-located, and
it can be difficult to know which type a value named `sess` refers to.
(That annoyance is the main motivation for this change.) `psess` is nice
and short, which is good for a name used this much.
The commit also renames some `parse_sess_created` values as
`psess_created`.
make unused_imports less assertive in test modules
closes#121502
This is a fairly small change and I used the fix suggested in the example expected error message.
Not sure if I should've rather used the alternatives but this one seems the most descriptive.
Some alternatives:
- if this is meant to be a test module, add `#[cfg(test)]` to the containing module
- try adding #[cfg(test)] to this test module
- consider adding #[allow(unused_imports)] if you want to silent the lint on the unused import
- consider removing the unused import
Add stubs in IR and ABI for `f16` and `f128`
This is the very first step toward the changes in https://github.com/rust-lang/rust/pull/114607 and the [`f16` and `f128` RFC](https://rust-lang.github.io/rfcs/3453-f16-and-f128.html). It adds the types to `rustc_type_ir::FloatTy` and `rustc_abi::Primitive`, and just propagates those out as `unimplemented!` stubs where necessary.
These types do not parse yet so there is no feature gate, and it should be okay to use `unimplemented!`.
The next steps will probably be AST support with parsing and the feature gate.
r? `@compiler-errors`
cc `@Nilstrieb` suggested breaking the PR up in https://github.com/rust-lang/rust/pull/120645#issuecomment-1925900572
Detect empty leading where clauses on type aliases
1. commit: refactor the AST of type alias where clauses
* I could no longer bear the look of `.0.1` and `.1.0`
* Arguably moving `split` out of `TyAlias` into a substruct might not make that much sense from a semantic standpoint since it reprs an index into `TyAlias.predicates` but it's alright and it cleans up the usage sites of `TyAlias`
2. commit: fix an oversight: An empty leading where clause is still a leading where clause
* semantically reject empty leading where clauses on lazy type aliases
* e.g., on `#![feature(lazy_type_alias)] type X where = ();`
* make empty leading where clauses on assoc types trigger lint `deprecated_where_clause_location`
* e.g., `impl Trait for () { type X where = (); }`
Diagnostic renaming
Renaming various diagnostic types from `Diagnostic*` to `Diag*`. Part of https://github.com/rust-lang/compiler-team/issues/722. There are more to do but this is enough for one PR.
r? `@davidtwco`
It's a specialized form of the `UntranslatableDiagnostic` lint that is
deny-by-default.
Now that `UntranslatableDiagnostic` has been changed from
allow-by-default to deny-by-default, the trivial variant is no longer
needed.
Split Diagnostics for Uncommon Codepoints: Add Individual Identifier Types
This pull request further modifies the `uncommon_codepoints` lint, adding the individual identifier types of `Technical`, `Not_NFKC`, `Exclusion` and `Limited_Use` to the diagnostic message.
Example rendered diagnostic:
```
error: identifier contains a Unicode codepoint that is not used in normalized strings: 'ij'
--> $DIR/lint-uncommon-codepoints.rs:6:4
|
LL | fn dijkstra() {}
| ^^^^^^^
= note: this character is included in the Not_NFKC Unicode general security profile
```
Second step of #120228.
Add newtypes for bool fields/params/return types
Fixed all the cases of this found with some simple searches for `*/ bool` and `bool /*`; probably many more
When encountering `<&T as Clone>::clone(x)` because `T: Clone`, suggest `#[derive(Clone)]`
CC #40699.
```
warning: call to `.clone()` on a reference in this situation does nothing
--> $DIR/noop-method-call.rs:23:71
|
LL | let non_clone_type_ref_clone: &PlainType<u32> = non_clone_type_ref.clone();
| ^^^^^^^^
|
= note: the type `PlainType<u32>` does not implement `Clone`, so calling `clone` on `&PlainType<u32>` copies the reference, which does not do anything and can be removed
help: remove this redundant call
|
LL - let non_clone_type_ref_clone: &PlainType<u32> = non_clone_type_ref.clone();
LL + let non_clone_type_ref_clone: &PlainType<u32> = non_clone_type_ref;
|
help: if you meant to clone `PlainType<u32>`, implement `Clone` for it
|
LL + #[derive(Clone)]
LL | struct PlainType<T>(T);
|
```
Downgrade ambiguous_wide_pointer_comparisons suggestions to MaybeIncorrect
In certain cases like #121330, it is possible to have more than one suggestion from the `ambiguous_wide_pointer_comparisons` lint (which before this PR are `MachineApplicable`). When this gets passed to rustfix, rustfix makes *multiple* changes according to the suggestions which result in incorrect code.
This is a temporary workaround. The real long term solution to problems like these is to address <https://github.com/rust-lang/rust/issues/53934>.
This PR also includes a drive-by edit to the panic message emitted by compiletest because "ui" test suite now uses `//`@`` directives.
Fixes#121330.
It is possible to have more than one valid suggestion, which when
applied together via rustfix causes the code to no longer compile.
This is a temporary workaround; the real long term solution to these
issues is to solve <https://github.com/rust-lang/rust/issues/53934>.
Trigger `unsafe_code` lint on invocations of `global_asm`
`unsafe_code` already warns about things that don't involve the `unsafe` keyword, e.g. `#[no_mangle]`. This makes it warn on `core::arch::global_asm` too.
Fixes#103078
Overhaul `Diagnostic` and `DiagnosticBuilder`
Implements the first part of https://github.com/rust-lang/compiler-team/issues/722, which moves functionality and use away from `Diagnostic`, onto `DiagnosticBuilder`.
Likely follow-ups:
- Move things around, because this PR was written to minimize diff size, so some things end up in sub-optimal places. E.g. `DiagnosticBuilder` has impls in both `diagnostic.rs` and `diagnostic_builder.rs`.
- Rename `Diagnostic` as `DiagInner` and `DiagnosticBuilder` as `Diag`.
r? `@davidtwco`
Always evaluate free constants and statics, even if previous errors occurred
work towards https://github.com/rust-lang/rust/issues/79738
We will need to evaluate static items before the `definitions.freeze()` below, as we will start creating new `DefId`s (for nested allocations) within the `eval_static_initializer` query.
But even without that motivation, this is a good change. Hard errors should always be reported and not silenced if other errors happened earlier.
Currently many diagnostic modifier methods are available on both
`Diagnostic` and `DiagnosticBuilder`. This commit removes most of them
from `Diagnostic`. To minimize the diff size, it keeps them within
`diagnostic.rs` but changes the surrounding `impl Diagnostic` block to
`impl DiagnosticBuilder`. (I intend to move things around later, to give
a more sensible code layout.)
`Diagnostic` keeps a few methods that it still needs, like `sub`,
`arg`, and `replace_args`.
The `forward!` macro, which defined two additional methods per call
(e.g. `note` and `with_note`), is replaced by the `with_fn!` macro,
which defines one additional method per call (e.g. `with_note`). It's
now also only used when necessary -- not all modifier methods currently
need a `with_*` form. (New ones can be easily added as necessary.)
All this also requires changing `trait AddToDiagnostic` so its methods
take `DiagnosticBuilder` instead of `Diagnostic`, which leads to many
mechanical changes. `SubdiagnosticMessageOp` gains a type parameter `G`.
There are three subdiagnostics -- `DelayedAtWithoutNewline`,
`DelayedAtWithNewline`, and `InvalidFlushedDelayedDiagnosticLevel` --
that are created within the diagnostics machinery and appended to
external diagnostics. These are handled at the `Diagnostic` level, which
means it's now hard to construct them via `derive(Diagnostic)`, so
instead we construct them by hand. This has no effect on what they look
like when printed.
There are lots of new `allow` markers for `untranslatable_diagnostics`
and `diagnostics_outside_of_impl`. This is because
`#[rustc_lint_diagnostics]` annotations were present on the `Diagnostic`
modifier methods, but missing from the `DiagnosticBuilder` modifier
methods. They're now present.
errors: only eagerly translate subdiagnostics
Subdiagnostics don't need to be lazily translated, they can always be eagerly translated. Eager translation is slightly more complex as we need to have a `DiagCtxt` available to perform the translation, which involves slightly more threading of that context.
This slight increase in complexity should enable later simplifications - like passing `DiagCtxt` into `AddToDiagnostic` and moving Fluent messages into the diagnostic structs rather than having them in separate files (working on that was what led to this change).
r? ```@nnethercote```
Implement intrinsics with fallback bodies
fixes#93145 (though we can port many more intrinsics)
cc #63585
The way this works is that the backend logic for generating custom code for intrinsics has been made fallible. The only failure path is "this intrinsic is unknown". The `Instance` (that was `InstanceDef::Intrinsic`) then gets converted to `InstanceDef::Item`, which represents the fallback body. A regular function call to that body is then codegenned. This is currently implemented for
* codegen_ssa (so llvm and gcc)
* codegen_cranelift
other backends will need to adjust, but they can just keep doing what they were doing if they prefer (though adding new intrinsics to the compiler will then require them to implement them, instead of getting the fallback body).
cc `@scottmcm` `@WaffleLapkin`
### todo
* [ ] miri support
* [x] default intrinsic name to name of function instead of requiring it to be specified in attribute
* [x] make sure that the bodies are always available (must be collected for metadata)
Subdiagnostics don't need to be lazily translated, they can always be
eagerly translated. Eager translation is slightly more complex as we need
to have a `DiagCtxt` available to perform the translation, which involves
slightly more threading of that context.
This slight increase in complexity should enable later simplifications -
like passing `DiagCtxt` into `AddToDiagnostic` and moving Fluent messages
into the diagnostic structs rather than having them in separate files
(working on that was what led to this change).
Signed-off-by: David Wood <david@davidtw.co>
For some cases where it's clear that an error has already occurred,
e.g.:
- there's a comment stating exactly that, or
- things like HIR lowering, where we are lowering an error kind
The commit also tweaks some comments around delayed bug sites.
Remove unnecessary `#![feature(min_specialization)]`
As of #119963 and #120676, we can now rely on `newtype_index!` having `#[allow_internal_unstable(min_specialization)]`, so there are a few compiler crates that no longer need to include min-spec in their own crate features.
---
Some of the expansions of `newtype_index!` still appear to require min-spec in the crate features. I think this is because `#[orderable]` causes the expansion to include an implementation of `TrustedStep`, which is flagged with `#[rustc_specialization_trait]`, and for whatever reason that isn't permitted by allow-internal-unstable. So this PR only touches the crates where that isn't the case.
Avoid a collection and iteration on empty passes
Just some mini optimization I saw in the wild. This way, we avoid a `collect` and `map` on an empty `passes`. Honestly, I don't even think this is big enough of a change to make a benchmark, but I'd still like to see results.
Based on [this book](https://nnethercote.github.io/perf-book/iterators.html#collect-and-extend)
Invert diagnostic lints.
That is, change `diagnostic_outside_of_impl` and `untranslatable_diagnostic` from `allow` to `deny`, because more than half of the compiler has been converted to use translated diagnostics.
This commit removes more `deny` attributes than it adds `allow` attributes, which proves that this change is warranted.
r? ````@davidtwco````
Introduce `enter_forall` to supercede `instantiate_binder_with_placeholders`
r? `@lcnr`
Long term we'd like to experiment with decrementing the universe count after "exiting" binders so that we do not end up creating infer vars in non-root universes even when they logically reside in the root universe. The fact that we dont do this currently results in a number of issues in the new trait solver where we consider goals to be ambiguous because otherwise it would require lowering the universe of an infer var. i.e. the goal `?x.0 eq <T as Trait<?y.1>>::Assoc` where the alias is rigid would not be able to instantiate `?x` with the alias as there would be a universe error.
This PR is the first-ish sort of step towards being able to implement this as eventually we would want to decrement the universe in `enter_forall`. Unfortunately its Difficult to actually implement decrementing universes nicely so this is a separate step which moves us closer to the long term goal ✨
update indirect structural match lints to match RFC and to show up for dependencies
This is a large step towards implementing https://github.com/rust-lang/rfcs/pull/3535.
We currently have five lints related to "the structural match situation":
- nontrivial_structural_match
- indirect_structural_match
- pointer_structural_match
- const_patterns_without_partial_eq
- illegal_floating_point_literal_pattern
This PR concerns the first 3 of them. (The 4th already is set up to show for dependencies, and the 5th is removed by https://github.com/rust-lang/rust/pull/116284.) nontrivial_structural_match is being removed as per the RFC; the other two are enabled to show up in dependencies.
Fixes https://github.com/rust-lang/rust/issues/73448 by removing the affected analysis.
That is, change `diagnostic_outside_of_impl` and
`untranslatable_diagnostic` from `allow` to `deny`, because more than
half of the compiler has be converted to use translated diagnostics.
This commit removes more `deny` attributes than it adds `allow`
attributes, which proves that this change is warranted.
make matching on NaN a hard error, and remove the rest of illegal_floating_point_literal_pattern
These arms would never be hit anyway, so the pattern makes little sense. We have had a future-compat lint against float matches in general for a *long* time, so I hope we can get away with immediately making this a hard error.
This is part of implementing https://github.com/rust-lang/rfcs/pull/3535.
Closes https://github.com/rust-lang/rust/issues/41620 by removing the lint.
https://github.com/rust-lang/reference/pull/1456 updates the reference to match.
Error codes are integers, but `String` is used everywhere to represent
them. Gross!
This commit introduces `ErrCode`, an integral newtype for error codes,
replacing `String`. It also introduces a constant for every error code,
e.g. `E0123`, and removes the `error_code!` macro. The constants are
imported wherever used with `use rustc_errors::codes::*`.
With the old code, we have three different ways to specify an error code
at a use point:
```
error_code!(E0123) // macro call
struct_span_code_err!(dcx, span, E0123, "msg"); // bare ident arg to macro call
\#[diag(name, code = "E0123")] // string
struct Diag;
```
With the new code, they all use the `E0123` constant.
```
E0123 // constant
struct_span_code_err!(dcx, span, E0123, "msg"); // constant
\#[diag(name, code = E0123)] // constant
struct Diag;
```
The commit also changes the structure of the error code definitions:
- `rustc_error_codes` now just defines a higher-order macro listing the
used error codes and nothing else.
- Because that's now the only thing in the `rustc_error_codes` crate, I
moved it into the `lib.rs` file and removed the `error_codes.rs` file.
- `rustc_errors` uses that macro to define everything, e.g. the error
code constants and the `DIAGNOSTIC_TABLES`. This is in its new
`codes.rs` file.
Don't fire `OPAQUE_HIDDEN_INFERRED_BOUND` on sized return of AFIT
Conceptually, we should probably not fire `OPAQUE_HIDDEN_INFERRED_BOUND` for methods like:
```
trait Foo { async fn bar() -> Self; }
```
Even though we technically cannot prove that `Self: Sized`, which is one of the item bounds of the `Output` type in the `-> impl Future<Output = Sized>` from the async desugaring.
This is somewhat justifiable along the same lines as how we allow regular methods to return `-> Self` even though `Self` isn't sized.
Fixes#113538
(side-note: some days i wonder if we should just remove the `OPAQUE_HIDDEN_INFERRED_BOUND` lint... it does make me sad that we have non-well-formed types in signatures, though.)
Revert stabilization of trait_upcasting feature
Reverts #118133
This reverts commit 6d2b84b3ed, reversing changes made to 73bc12199e.
The feature has a soundness bug:
* #120222
It is unclear to me whether we'll actually want to destabilize, but I thought it was still prudent to open the PR for easy destabilization once we get there.
Pack u128 in the compiler to mitigate new alignment
This is based on #116672, adding a new `#[repr(packed(8))]` wrapper on `u128` to avoid changing any of the compiler's size assertions. This is needed in two places:
* `SwitchTargets`, otherwise its `SmallVec<[u128; 1]>` gets padded up to 32 bytes.
* `LitKind::Int`, so that entire `enum` can stay 24 bytes.
* This change definitely has far-reaching effects though, since it's public.
Add way to express that no values are expected with check-cfg
This PR adds way to express no-values (no values expected) with `--check-cfg` by making empty `values()` no longer mean `values(none())` (internal: `&[None]`) and now be an empty list (internal: `&[]`).
### Context
Currently `--check-cfg` has a way to express that _any value is expected_ with `values(any())`, but has no way to do the inverse and say that _no value is expected_.
This would be particularly useful for build systems that control a config name and it's values as they could always declare a config name as expected and if in the current state they have values pass them and if not pass an empty list.
To give a more concrete example, Cargo `--check-cfg` currently needs to generate:
- `--check-cfg=cfg(feature, values(...))` for the case with declared features
- and `--check-cfg=cfg()` for the case without any features declared
This means that when there are no features declared, users will get an `unexpected config name` but from the point of view of Cargo the config name `feature` is expected, it's just that for now there aren't any values for it.
See [Cargo `check_cfg_args` function](92395d9010/src/cargo/core/compiler/mod.rs (L1263-L1281)) for more details.
### De-specializing *empty* `values()`
To solve this issue I propose that we "de-specialize" empty `values()` to no longer mean `values(none())` but to actually mean empty set/list. This is one of the last source of confusion for my-self and others with the `--check-cfg` syntax.
> The confusing part here is that an empty `values()` currently means the same as `values(none())`, i.e. an expected list of values with the _none_ variant (as in `#[cfg(name)]` where the value is none) instead of meaning an empty set.
Before the new `cfg()` syntax, defining the _none_ variant was only possible under certain circumstances, so in https://github.com/rust-lang/rust/pull/111068 I decided to make `values()` to mean the _none_ variant, but it is no longer necessary since https://github.com/rust-lang/rust/pull/119473 which introduced the `none()` syntax.
A simplified representation of the proposed "de-specialization" would be:
| Syntax | List/set of expected values |
|-----------------------------------------|-----------------------------|
| `cfg(name)`/`cfg(name, values(none()))` | `&[None]` |
| `cfg(name, values())` | `&[]` |
Note that I have my-self made the mistake of using an empty `values()` as meaning empty set, see https://github.com/rust-lang/cargo/pull/13011.
`@rustbot` label +F-check-cfg
r? `@petrochenkov`
cc `@epage`
Fix unused_parens issue when cast is followed LT
Fixes#117142
The original check only checks `a as (i32) < 0`, this fix extends it to handle `b + a as (i32) < 0`.
A better way is maybe we suggest `(a as i32) < 0` instead of suppressing the warning, maybe following PR could improve it.
Replace a number of FxHashMaps/Sets with stable-iteration-order alternatives
This PR replaces almost all of the remaining `FxHashMap`s in query results with either `FxIndexMap` or `UnordMap`. The only case that is missing is the `EffectiveVisibilities` struct which turned out to not be straightforward to transform. Once that is done too, we can remove the `HashStable` implementation from `HashMap`.
The first commit adds the `StableCompare` trait which is a companion trait to `StableOrd`. Some types like `Symbol` can be compared in a cross-session stable way, but their `Ord` implementation is not stable. In such cases, a `StableCompare` implementation can be provided to offer a lightweight way for stable sorting. The more heavyweight option is to sort via `ToStableHashKey`, but then sorting needs to have access to a stable hashing context and `ToStableHashKey` can also be expensive as in the case of `Symbol` where it has to allocate a `String`.
The rest of the commits are rather mechanical and don't overlap, so they are best reviewed individually.
Part of [MCP 533](https://github.com/rust-lang/compiler-team/issues/533).
Make named_asm_labels lint not trigger on unicode and trigger on format args
Someone showed me some cursed code that used format args to create named labels, and rustc wasn't linting on that. Additionally while fixing that, I noticed that Unicode alphabetic characters were being used as part of labels, when they are not actually permitted in labels.
r? ```@Amanieu```
`Diagnostic` has 40 methods that return `&mut Self` and could be
considered setters. Four of them have a `set_` prefix. This doesn't seem
necessary for a type that implements the builder pattern. This commit
removes the `set_` prefixes on those four methods.
Stop allowing `rustc::potential_query_instability` on all of
`rustc_lint` and instead allow it on a case-by-case basis if it is safe
to do so. In this particular crate, all lints were safe to allow.
Fix invalid check-cfg Cargo feature diagnostic help
#118213 added specialized diagnostic for Cargo `feature` cfg. However when providing an empty `#[cfg(feature)]` condition the suggestion would suggest adding `feature` as a feature in `Cargo.toml` (wtf!).
This PR removes the invalid logic, which even brings a nice improvement.
```diff
--> $DIR/cargo-feature.rs:18:7
|
LL | #[cfg(feature)]
- | ^^^^^^^
+ | ^^^^^^^- help: specify a config value: `= "bitcode"`
|
= note: expected values for `feature` are: `bitcode`
- = help: consider defining `feature` as feature in `Cargo.toml`
```
The first commit add a test showing the bug and the second commit fixes the bug.
`@rustbot` label +F-check-cfg
Prevent multiple 'ignored unless specified at crate level' lints. The
multiplication happens because we run the same lint three times:
* In BuiltinCombinedEarlyLintPass
* In BuiltinCombinedPreExpansionLintPass
* In shallow_lint_levels_on
Only run the lint one time by checking the `lint_added_lints` bool.
Add more suggestions to unexpected cfg names and values
This pull request adds more suggestion to unexpected cfg names and values diagnostics:
- it first adds a links to the [rustc unstable book](https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html) or the [Cargo reference](https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg), depending if rustc is invoked by Cargo
- it secondly adds a suggestion on how to expect the cfg name or value:
*excluding well known names and values*
- for Cargo: it suggest using a feature or `cargo:rust-check-cfg` in build script
- for rustc: it suggest using `--check-cfg` (with the correct invocation)
Those diagnostics improvements are directed towards enabling users to fix the issue if the previous suggestions weren't good enough.
r? `@petrochenkov`
Renamings:
- find -> opt_hir_node
- get -> hir_node
- find_by_def_id -> opt_hir_node_by_def_id
- get_by_def_id -> hir_node_by_def_id
Fix rebase changes using removed methods
Use `tcx.hir_node_by_def_id()` whenever possible in compiler
Fix clippy errors
Fix compiler
Apply suggestions from code review
Co-authored-by: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>
Add FIXME for `tcx.hir()` returned type about its removal
Simplify with with `tcx.hir_node_by_def_id`
Add lint against ambiguous wide pointer comparisons
This PR is the resolution of https://github.com/rust-lang/rust/issues/106447 decided in https://github.com/rust-lang/rust/issues/117717 by T-lang.
## `ambiguous_wide_pointer_comparisons`
*warn-by-default*
The `ambiguous_wide_pointer_comparisons` lint checks comparison of `*const/*mut ?Sized` as the operands.
### Example
```rust
let ab = (A, B);
let a = &ab.0 as *const dyn T;
let b = &ab.1 as *const dyn T;
let _ = a == b;
```
### Explanation
The comparison includes metadata which may not be expected.
-------
This PR also drops `clippy::vtable_address_comparisons` which is superseded by this one.
~~One thing: is the current naming right? `invalid` seems a bit too much.~~
Fixes https://github.com/rust-lang/rust/issues/117717
This is an extension of the previous commit. It means the output of
something like this:
```
stringify!(let a: Vec<u32> = vec![];)
```
goes from this:
```
let a: Vec<u32> = vec![] ;
```
With this PR, it now produces this string:
```
let a: Vec<u32> = vec![];
```
remove redundant imports
detects redundant imports that can be eliminated.
for #117772 :
In order to facilitate review and modification, split the checking code and removing redundant imports code into two PR.
r? `@petrochenkov`
detects redundant imports that can be eliminated.
for #117772 :
In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.
Introduce support for `async gen` blocks
I'm delighted to demonstrate that `async gen` block are not very difficult to support. They're simply coroutines that yield `Poll<Option<T>>` and return `()`.
**This PR is WIP and in draft mode for now** -- I'm mostly putting it up to show folks that it's possible. This PR needs a lang-team experiment associated with it or possible an RFC, since I don't think it falls under the jurisdiction of the `gen` RFC that was recently authored by oli (https://github.com/rust-lang/rfcs/pull/3513, https://github.com/rust-lang/rust/issues/117078).
### Technical note on the pre-generator-transform yield type:
The reason that the underlying coroutines yield `Poll<Option<T>>` and not `Poll<T>` (which would make more sense, IMO, for the pre-transformed coroutine), is because the `TransformVisitor` that is used to turn coroutines into built-in state machine functions would have to destructure and reconstruct the latter into the former, which requires at least inserting a new basic block (for a `switchInt` terminator, to match on the `Poll` discriminant).
This does mean that the desugaring (at the `rustc_ast_lowering` level) of `async gen` blocks is a bit more involved. However, since we already need to intercept both `.await` and `yield` operators, I don't consider it much of a technical burden.
r? `@ghost`
never_patterns: Parse match arms with no body
Never patterns are meant to signal unreachable cases, and thus don't take bodies:
```rust
let ptr: *const Option<!> = ...;
match *ptr {
None => { foo(); }
Some(!),
}
```
This PR makes rustc accept the above, and enforces that an arm has a body xor is a never pattern. This affects parsing of match arms even with the feature off, so this is delicate. (Plus this is my first non-trivial change to the parser).
~~The last commit is optional; it introduces a bit of churn to allow the new suggestions to be machine-applicable. There may be a better solution? I'm not sure.~~ EDIT: I removed that commit
r? `@compiler-errors`
Enforce `must_use` on associated types and RPITITs that have a must-use trait in bounds
Warn when an RPITIT or (un-normalized) associated type with a `#[must_use]` trait in its bounds is unused.
This is pending T-lang approval, since it changes the semantics of the `#[must_use]` attribute slightly, but I think it strictly catches more strange errors.
I could also limit this to just RPITITs, but that seems less useful.
Fixes#118444
Remove `#[rustc_host]`, use internal desugaring
Also removed a way for users to explicitly specify the host param since that isn't particularly useful. This should eliminate any pain with encoding attributes across crates and etc.
r? `@compiler-errors`
Add `never_patterns` feature gate
This PR adds the feature gate and most basic parsing for the experimental `never_patterns` feature. See the tracking issue (https://github.com/rust-lang/rust/issues/118155) for details on the experiment.
`@scottmcm` has agreed to be my lang-team liaison for this experiment.
Currently we always do this:
```
use rustc_fluent_macro::fluent_messages;
...
fluent_messages! { "./example.ftl" }
```
But there is no need, we can just do this everywhere:
```
rustc_fluent_macro::fluent_messages! { "./example.ftl" }
```
which is shorter.
The `fluent_messages!` macro produces uses of
`crate::{D,Subd}iagnosticMessage`, which means that every crate using
the macro must have this import:
```
use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
```
This commit changes the macro to instead use
`rustc_errors::{D,Subd}iagnosticMessage`, which avoids the need for the
imports.
Add allow-by-default lint for unit bindings
### Example
```rust
#![warn(unit_bindings)]
macro_rules! owo {
() => {
let whats_this = ();
}
}
fn main() {
// No warning if user explicitly wrote `()` on either side.
let expr = ();
let () = expr;
let _ = ();
let _ = expr; //~ WARN binding has unit type
let pat = expr; //~ WARN binding has unit type
let _pat = expr; //~ WARN binding has unit type
// No warning for let bindings with unit type in macro expansions.
owo!();
// No warning if user explicitly annotates the unit type on the binding.
let pat: () = expr;
}
```
outputs
```
warning: binding has unit type `()`
--> $DIR/unit-bindings.rs:17:5
|
LL | let _ = expr;
| ^^^^-^^^^^^^^
| |
| this pattern is inferred to be the unit type `()`
|
note: the lint level is defined here
--> $DIR/unit-bindings.rs:3:9
|
LL | #![warn(unit_bindings)]
| ^^^^^^^^^^^^^
warning: binding has unit type `()`
--> $DIR/unit-bindings.rs:18:5
|
LL | let pat = expr;
| ^^^^---^^^^^^^^
| |
| this pattern is inferred to be the unit type `()`
warning: binding has unit type `()`
--> $DIR/unit-bindings.rs:19:5
|
LL | let _pat = expr;
| ^^^^----^^^^^^^^
| |
| this pattern is inferred to be the unit type `()`
warning: 3 warnings emitted
```
This lint is not triggered if any of the following conditions are met:
- The user explicitly annotates the binding with the `()` type.
- The binding is from a macro expansion.
- The user explicitly wrote `let () = init;`
- The user explicitly wrote `let pat = ();`. This is allowed for local lifetimes.
### Known Issue
It is known that this lint can trigger on some proc-macro generated code whose span returns false for `Span::from_expansion` because e.g. the proc-macro simply forwards user code spans, and otherwise don't have distinguishing syntax context compared to non-macro-generated code. For those kind of proc-macros, I believe the correct way to fix them is to instead emit identifers with span like `Span::mixed_site().located_at(user_span)`.
Closes#71432.
Make some `newtype_index!` derived impls opt-in instead of opt-out
Opt-in is the standard Rust way of doing things, and avoids some unnecessary dependencies on the `rustc_serialize` crate.
r? `@lcnr`
By default, `newtype_index!` types get a default `Encodable`/`Decodable`
impl. You can opt out of this with `custom_encodable`. Opting out is the
opposite to how Rust normally works with autogenerated (derived) impls.
This commit inverts the behaviour, replacing `custom_encodable` with
`encodable` which opts into the default `Encodable`/`Decodable` impl.
Only 23 of the 59 `newtype_index!` occurrences need `encodable`.
Even better, there were eight crates with a dependency on
`rustc_serialize` just from unused default `Encodable`/`Decodable`
impls. This commit removes that dependency from those eight crates.
Remove `feature` from the list of well known check-cfg name
This PR removes `feature` from the list of well known check-cfg.
This is done for multiple reasons:
- Cargo is the source of truth, rustc shouldn't have any knowledge of it
- It creates a conflict between Cargo and rustc when there are no features defined.
In this case Cargo won't pass any `--check-cfg` for `feature` since no feature will ever be passed, but rustc by having in it's list adds a implicit `cfg(feature, values(any()))` which is completely wrong. Having any cfg `feature` is unexpected not allow any `feature` value.
While doing this, I took the opportunity to specialise the diagnostic a bit for the case above.
r? `@petrochenkov`
Remove `--check-cfg` checking of command line `--cfg` args
Back in https://github.com/rust-lang/rust/pull/100574 we added to the `unexpected_cfgs` lint the checking of `--cfg` CLI arguments and emitted unexpected names and values for them.
The implementation works as expected, but it's usability in particular when using it in combination with Cargo+`RUSTFLAGS` as people who set `RUSTFLAGS=--cfg=tokio_unstable` (or whatever) have `unexpected_cfgs` warnings on all of their crates is debatable. ~~To fix this issue this PR proposes that we split the CLI argument checking into it's own separate allow-by-default lint: `unexpected_cli_cfgs`.~~
~~This has the advantage of letting people who want CLI warnings have them (although not by default anymore), while still linting on every unexpected cfg name and values in the code.~~
After some discussion with the Cargo team ([Zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/246057-t-cargo/topic/check-cfg.20and.20RUSTFLAGS.20interaction)) and member of the compiler team (see below), I propose that we follow the suggestion from `@epage:` never check `--cfg` arguments, but still reserve us the possibility to do it later.
We would still lint on unexpected cfgs found in the source code no matter the `--cfg` args passed. This mean reverting https://github.com/rust-lang/rust/pull/100574 but NOT https://github.com/rust-lang/rust/pull/99519.
r? `@petrochenkov`
This lint is not triggered if any of the following conditions are met:
- The user explicitly annotates the binding with the `()` type.
- The binding is from a macro expansion.
- The user explicitly wrote `let () = init;`
- The user explicitly wrote `let pat = ();`. This is allowed for local
lifetimes.
This was made possible by the removal of plugin support, which
simplified lint store creation.
This simplifies the places in rustc and rustdoc that call
`describe_lints`, which are early on. The lint store is now built before
those places, so they don't have to create their own lint store for
temporary use, they can just use the main one.
finish `RegionKind` renaming
second step of https://github.com/rust-lang/types-team/issues/95
continues the work from #117876. While working on this and I encountered a bunch of further cleanup which I'll either open a tracking issue for or will do in a separate PR:
- rewrite the `RegionKind` docs, they still talk about `ReEmpty` and are generally out of date
- rename `DescriptionCtx` to `DescriptionCtxt`
- what is `CheckRegions::Bound`?
- `collect_late_bound_regions` et al
- `erase_late_bound_regions` -> `instantiate_bound_regions_with_erased`?
- `EraseEarlyRegions` visitor should be removed, feels duplicate
r? `@BoxyUwU`
They've been deprecated for four years.
This commit includes the following changes.
- It eliminates the `rustc_plugin_impl` crate.
- It changes the language used for lints in
`compiler/rustc_driver_impl/src/lib.rs` and
`compiler/rustc_lint/src/context.rs`. External lints are now called
"loaded" lints, rather than "plugins" to avoid confusion with the old
plugins. This only has a tiny effect on the output of `-W help`.
- E0457 and E0498 are no longer used.
- E0463 is narrowed, now only relating to unfound crates, not plugins.
- The `plugin` feature was moved from "active" to "removed".
- It removes the entire plugins chapter from the unstable book.
- It removes quite a few tests, mostly all of those in
`tests/ui-fulldeps/plugin/`.
Closes#29597.
Fix missing leading space in suggestion
For a local pattern with no space between `let` and `(` e.g.:
```rust
let(_a) = 3;
```
we were previously suggesting this illegal code:
```rust
let_a = 3;
```
After this change the suggestion will instead be:
```rust
let _a = 3;
```
Fixes#117380
For a local pattern with no space between `let` and `(` e.g.:
let(_a) = 3;
we were previously suggesting this illegal code:
let_a =3;
After this change the suggestion will instead be:
let _a =3;
(Note the space after `let`)
- Sort dependencies and features sections.
- Add `tidy` markers to the sorted sections so they stay sorted.
- Remove empty `[lib`] sections.
- Remove "See more keys..." comments.
Excluded files:
- rustc_codegen_{cranelift,gcc}, because they're external.
- rustc_lexer, because it has external use.
- stable_mir, because it has external use.
This simplifies the code by removing all the `self` assignments and
makes the flow of data clearer - always into the printer.
Especially in v0 mangling, which already used `&mut self` in some
places, it gets a lot more uniform.
Remove lots of generics from `ty::print`
All of these generics mostly resolve to the same thing, which means we can remove them, greatly simplifying the types involved in pretty printing and unlocking another simplification (that is not performed in this PR): Using `&mut self` instead of passing `self` through the return type.
cc `@eddyb` you probably know why it's like this, just checking in and making sure I didn't do anything bad
r? oli-obk
