I have a suspicion that quite a few delayed bug paths are impossible to
reach, so I did an experiment.
I converted every `delayed_bug` to a `bug`, ran the full test suite,
then converted back every `bug` that was hit. A surprising number were
never hit.
The next commit will convert some more back, based on human judgment.
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`
Drive-by `DUMMY_SP` -> `Span` and fmt changes
Noticed these while doing something else. There's no practical change, but it's preferable to use `DUMMY_SP` as little as possible, particularly when we have perfectlly useful `Span`s available.
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.
deduplicate infer var instantiation
Having 3 separate implementations of one of the most subtle parts of our type system is not a good strategy if we want to maintain a sound type system ✨ while working on this I already found some subtle bugs in the existing code, so that's awesome 🎉 cc #121159
This was necessary as I am not confident in my nll changes in #119106, so I am first cleaning this up in a separate PR.
r? `@BoxyUwU`
Noticed these while doing something else. There's no practical change, but it's preferable to use `DUMMY_SP` as little as possible, particularly when we have perfectlly useful `Span`s available.
There are lots of functions that modify a diagnostic. This can be via a
`&mut Diagnostic` or a `&mut DiagnosticBuilder`, because the latter type
wraps the former and impls `DerefMut`.
This commit converts all the `&mut Diagnostic` occurrences to `&mut
DiagnosticBuilder`. This is a step towards greatly simplifying
`Diagnostic`. Some of the relevant function are made generic, because
they deal with both errors and warnings. No function bodies are changed,
because all the modifier methods are available on both `Diagnostic` and
`DiagnosticBuilder`.
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```
Add and use a simple extension trait derive macro in the compiler
Adds `#[extension]` to `rustc_macros` for implementing an extension trait. This expands an impl (with an optional visibility) into two parallel trait + impl definitions.
before:
```rust
pub trait Extension {
fn a();
}
impl Extension for () {
fn a() {}
}
```
to:
```rust
#[extension]
pub impl Extension for () {
fn a() {}
}
```
Opted to just implement it by hand because I couldn't figure if there was a "canonical" choice of extension trait macro in the ecosystem. It's really lightweight anyways, and can always be changed.
I'm interested in adding this because I'd like to later split up the large `TypeErrCtxtExt` traits into several different files. This should make it one step easier.
we already use `instantiate_const_var`. This does lose some debugging
info for nll because we stop populating the `reg_var_to_origin` table with
`RegionCtxt::Existential(None)`, I don't think that matters however.
Supporting this adds additional complexity to one of the most involved
parts of the type system, so I really don't think it's worth it.
Avoid an ICE in diagnostics
fixes#121004
just a slice usage in diagnostics code. Sadly we can't yet bubble the `ErrorGuaranteed` from wf check to borrowck for these cases, as that causes cycle errors iirc
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>
`cargo update`
Run `cargo update`, with some pinning and fixes necessitated by that. This *should* unblock #112865
There's a couple of places where I only pinned a dependency in one location - this seems like a bit of a hack, but better than duplicating the FIXME across all `Cargo.toml` where a dependency is introduced.
cc `@Nilstrieb`
Dejargonize `subst`
In favor of #110793, replace almost every occurence of `subst` and `substitution` from rustc codes, but they still remains in subtrees under `src/tools/` like clippy and test codes (I'd like to replace them after this)
Fix async closures in CTFE
First commit renames `is_coroutine_or_closure` into `is_closure_like`, because `is_coroutine_or_closure_or_coroutine_closure` seems confusing and long.
Second commit fixes some forgotten cases where we want to handle `TyKind::CoroutineClosure` the same as closures and coroutines.
The test exercises the change to `ValidityVisitor::aggregate_field_path_elem` which is the source of #120946, but not the change to `UsedParamsNeedSubstVisitor`, though I feel like it's not that big of a deal. Let me know if you'd like for me to look into constructing a test for the latter, though I have no idea what it'd look like (we can't assert against `TooGeneric` anywhere?).
Fixes#120946
r? oli-obk cc ``@RalfJung``
Remove a bunch of dead parameters in functions
Found this kind of issue when working on https://github.com/rust-lang/rust/pull/119650
I wrote a trivial toy lint and manual review to find these.
A drive-by rewrite of `give_region_a_name()`
This drive-by rewrite makes the cache-updating nature of the method clearer, using the Entry API into the hash table for region names to capture the update-insert nature of the method. May be marginally more efficient since it only runtime-borrows and indexes the map once, but in this context the performance impact is almost certainly completely negligible.
Note that this commit should preserve all externally visible behaviour. Notably, it preserves the debug logging:
1. printing even in the case of a `None` for the new computed name, and
2. only printing on new values, begin silent on reused values
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````
Toggle assert_unsafe_precondition in codegen instead of expansion
The goal of this PR is to make some of the unsafe precondition checks in the standard library available in debug builds. Some UI tests are included to verify that it does that.
The diff is large, but most of it is blessing mir-opt tests and I've also split up this PR so it can be reviewed commit-by-commit.
This PR:
1. Adds a new intrinsic, `debug_assertions` which is lowered to a new MIR NullOp, and only to a constant after monomorphization
2. Rewrites `assume_unsafe_precondition` to check the new intrinsic, and be monomorphic.
3. Skips codegen of the `assume` intrinsic in unoptimized builds, because that was silly before but with these checks it's *very* silly
4. The checks with the most overhead are `ptr::read`/`ptr::write` and `NonNull::new_unchecked`. I've simply added `#[cfg(debug_assertions)]` to the checks for `ptr::read`/`ptr::write` because I was unable to come up with any (good) ideas for decreasing their impact. But for `NonNull::new_unchecked` I found that the majority of callers can use a different function, often a safe one.
Yes, this PR slows down the compile time of some programs. But in our benchmark suite it's never more than 1% icount, and the average icount change in debug-full programs is 0.22%. I think that is acceptable for such an improvement in developer experience.
https://github.com/rust-lang/rust/issues/120539#issuecomment-1922687101
Remove unused args from functions
`#[instrument]` suppresses the unused arguments from a function, *and* suppresses unused methods too! This PR removes things which are only used via `#[instrument]` calls, and fixes some other errors (privacy?) that I will comment inline.
It's possible that some of these arguments were being passed in for the purposes of being instrumented, but I am unconvinced by most of them.
Rollup of 9 pull requests
Successful merges:
- #119592 (resolve: Unload speculatively resolved crates before freezing cstore)
- #120103 (Make it so that async-fn-in-trait is compatible with a concrete future in implementation)
- #120206 (hir: Make sure all `HirId`s have corresponding HIR `Node`s)
- #120214 (match lowering: consistently lower bindings deepest-first)
- #120688 (GVN: also turn moves into copies with projections)
- #120702 (docs: also check the inline stmt during redundant link check)
- #120727 (exhaustiveness: Prefer "`0..MAX` not covered" to "`_` not covered")
- #120734 (Add `SubdiagnosticMessageOp` as a trait alias.)
- #120739 (improve pretty printing for associated items in trait objects)
r? `@ghost`
`@rustbot` modify labels: rollup
Normalize type outlives obligations in NLL for new solver
Normalize the type outlives assumptions and obligations in MIR borrowck. This should fix any of the lazy-norm-related MIR borrowck problems.
Also some cleanups from last PR:
1. Normalize obligations in a loop in lexical region resolution
2. Use `deeply_normalize_with_skipped_universes` in lexical resolution since we may have, e.g. `for<'a> Alias<'a>: 'b`.
r? lcnr
This rewrite makes the cache-updating nature of the function slightly clearer, using the Entry API into the hash table for region names to capture the update-insert nature of the method. May be marginally more efficient since it only runtime-borrows the map once, but in this context the performance impact is almost certainly completely negligible.
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.
Remove `BorrowckErrors::tainted_by_errors`
This PR removes one of the `tainted_by_errors` occurrences, replacing it with direct use of `ErrorGuaranteed`.
r? `@oli-obk`
`BorrowckErrors` stores a mix of error and non-error diags in
`buffered`. As a result, it downgrades `DiagnosticBuilder`s to
`Diagnostic`s, losing the emission guarantees, and so has to use a
`tainted_by_errors` field to record whether an error has occurred.
This commit splits `buffered` into `buffered_errors` and
`buffered_non_errors`, keeping them as `DiagnosticBuilder`s and
preserving the emission guarantees.
This also requires fixing a bunch of incorrect lifetimes on
`DiagnosticBuilder` use points.
Normalize region obligation in lexical region resolution with next-gen solver
This normalizes region obligations when we `resolve_regions`, since they may be unnormalized with deferred projection equality.
It's pretty hard to add tests that exercise this without also triggering MIR borrowck errors (because we don't normalize there yet). I've added one test with two revisions that should test that we both 1. normalize region obligations in the param env, and 2. normalize registered region obligations during lexical region resolution.
Because it's almost always static.
This makes `impl IntoDiagnosticArg for DiagnosticArgValue` trivial,
which is nice.
There are a few diagnostics constructed in
`compiler/rustc_mir_build/src/check_unsafety.rs` and
`compiler/rustc_mir_transform/src/errors.rs` that now need symbols
converted to `String` with `to_string` instead of `&str` with `as_str`,
but that' no big deal, and worth it for the simplifications elsewhere.
Borrow check inline const patterns
Add type annotations to MIR so that borrowck can pass constraints from inline constants in patterns to the containing function.
Also enables some inline constant pattern tests that were fixed by the THIR unsafeck stabilization.
cc #76001
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.
Only use dense bitsets in dataflow analyses
When a dataflow state has the size close to the number of locals, we should prefer a dense bitset, like we already store locals in a dense vector.
Other occurrences of `ChunkedBitSet` need to be justified by the size of the dataflow state.
perf: Don't track specific live points for promoteds
We don't query this information out of the promoted (it's basically a single "unit" regardless of the complexity within it) and this saves on re-initializing the SparseIntervalMatrix's backing IndexVec with mostly empty rows for all of the leading regions in the function. Typical promoteds will only contain a few regions that need up be uplifted, while the parent function can have thousands.
For a simple function repeating println!("Hello world"); 50,000 times this reduces compile times from 90 to 15 seconds in debug mode. The previous implementations re-initialization led to an overall roughly n^2 runtime as each promoted initialized slots for ~n regions, now we scale closer to linearly (5000 hello worlds takes 1.1 seconds).
cc https://github.com/rust-lang/rust/issues/50994, https://github.com/rust-lang/rust/issues/86244
Don't use `ReErased` to detect type test promotion failed
Using `ReErased` here is convenient because it implicitly stores the state that we are explicitly recording with the `failed` variable now, but I also think it adds a tiny bit of complexity that is not worth it.
r? `@aliemjay`
We don't query this information out of the promoted (it's basically a
single "unit" regardless of the complexity within it) and this saves on
re-initializing the SparseIntervalMatrix's backing IndexVec with mostly
empty rows for all of the leading regions in the function. Typical
promoteds will only contain a few regions that need up be uplifted,
while the parent function can have thousands.
For a simple function repeating println!("Hello world"); 50,000 times
this reduces compile times from 90 to 15 seconds in debug mode. The
previous implementations re-initialization led to an overall roughly n^2
runtime as each promoted initialized slots for ~n regions, now we scale
closer to linearly (5000 hello worlds takes 1.1 seconds).
Suggest `.swap()` when encountering conflicting borrows from `mem::swap` on a slice
This PR modifies the existing suggestion by matching on `[ProjectionElem::Deref, ProjectionElem::Index(_)]` instead of just `[ProjectionElem::Index(_)]`, which caused us to miss many cases. Additionally, it adds a more specific, machine-applicable suggestion in the case we determine `mem::swap` was used to swap elements in a slice.
Closes#102269
Save liveness results for DestinationPropagation
`DestinationPropagation` needs to verify that merge candidates do not conflict with each other. This is done by verifying that a local is not live when its counterpart is written to.
To get the liveness information, the pass runs `MaybeLiveLocals` dataflow analysis repeatedly, once for each propagation round. This is quite costly, and the main driver for the perf impact on `ucd` and `diesel`. (See https://github.com/rust-lang/rust/pull/115105#issuecomment-1689205908)
In order to mitigate this cost, this PR proposes to save the result of the analysis into a `SparseIntervalMatrix`, and mirror merges of locals into that matrix: `liveness(destination) := liveness(destination) union liveness(source)`.
<details>
<summary>Proof</summary>
We denote by `'` all the quantities of the transformed program. Let $\varphi$ be a mapping of locals, which maps `source` to `destination`, and is identity otherwise. The exact liveness set after a statement is $out'(statement)$, and the proposed liveness set is $\varphi(out(statement))$.
Consider a statement. Suppose that the output state verifies $out' \subset phi(out)$. We want to prove that $in' \subset \varphi(in)$ where $in = (out - kill) \cup gen$, and conclude by induction.
We have 2 cases: either that statement is kept with locals renumbered by $\varphi$, or it is a tautological assignment and it removed.
1. If the statement is kept: the gen-set and the kill-set of $statement' = \varphi(statement)$ are $gen' = \varphi(gen)$ and $kill' = \varphi(kill)$ exactly.
From soundness requirement 3, $\varphi(in)$ is disjoint from $\varphi(kill)$.
This implies that $\varphi(out - kill)$ is disjoint from $\varphi(kill)$, and so $\varphi(out - kill) = \varphi(out) - \varphi(kill)$. Then $\varphi(in) = (\varphi(out) - \varphi(kill)) \cup \varphi(gen) = (\varphi(out) - kill') \cup gen'$.
We can conclude that $out' \subset \varphi(out) \implies in' \subset \varphi(in)$.
2. If the statement is removed. As $\varphi(statement)$ is a tautological assignment, we know that $\varphi(gen) = \varphi(kill) = \\{ destination \\}$, while $gen' = kill' = \emptyset$. So $\varphi(in) = \varphi(out) \cup \\{ destination \\}$. Then $in' = out' \subset out \subset \varphi(in)$.
By recursion, we can conclude by that $in' \subset \varphi(in)$ everywhere.
</details>
This approximate liveness results is only suboptimal if there are locals that fully disappear from the CFG due to an assignment cycle. These cases are quite unlikely, so we do not bother with them.
This change allows to reduce the perf impact of DestinationPropagation by half on diesel and ucd (https://github.com/rust-lang/rust/pull/115105#issuecomment-1694701904).
cc ````@JakobDegen````
fix fn/const items implied bounds and wf check (rebase)
A rebase of #104098, see that PR for discussion. This is pretty much entirely the work of `@aliemjay.` I received his permission for this rebase.
---
These are two distinct changes (edit: actually three, see below):
1. Wf-check all fn item args. This is a soundness fix.
Fixes#104005
2. Use implied bounds from impl header in borrowck of associated functions/consts. This strictly accepts more code and helps to mitigate the impact of other breaking changes.
Fixes#98852Fixes#102611
The first is a breaking change and will likely have a big impact without the the second one. See the first commit for how it breaks libstd.
Landing the second one without the first will allow more incorrect code to pass. For example an exploit of #104005 would be as simple as:
```rust
use core::fmt::Display;
trait ExtendLt<Witness> {
fn extend(self) -> Box<dyn Display>;
}
impl<T: Display> ExtendLt<&'static T> for T {
fn extend(self) -> Box<dyn Display> {
Box::new(self)
}
}
fn main() {
let val = (&String::new()).extend();
println!("{val}");
}
```
The third change is to to check WF of user type annotations before normalizing them (fixes#104764, fixes#104763). It is mutually dependent on the second change above: an attempt to land it separately in #104746 caused several crater regressions that can all be mitigated by using the implied from the impl header. It is also necessary for the soundness of associated consts that use the implied bounds of impl header. See #104763 and how the third commit fixes the soundness issue in `tests/ui/wf/wf-associated-const.rs` that was introduces by the previous commit.
r? types
Simplify `closure_env_ty` and `closure_env_param`
Random cleanup that I found when working on async closures. This makes it easier to separate the latter into a new tykind.
Use `zip_eq` to enforce that things being zipped have equal sizes
Some `zip`s are best enforced to be equal, since size mismatches suggest deeper bugs in the compiler.
`OutputTypeParameterMismatch` -> `SignatureMismatch`
I'm probably missing something that made this rename more complicated. What did you end up getting stuck on when renaming this selection error, `@lcnr?`
**also** I renamed the `FulfillmentErrorCode` variants. This is just churn but I wanted to do it forever. I can move it out of this PR if desired.
r? lcnr
But we can't easily switch from `Vec<Diagnostic>` to
`Vec<DiagnosticBuilder<G>>` because there's a mix of errors and warnings
which result in different `G` types. So we must make
`DiagnosticBuilder::into_diagnostic` public, but that's ok, and it will
get more use in subsequent commits.
In #119606 I added them and used a `_mv` suffix, but that wasn't great.
A `with_` prefix has three different existing uses.
- Constructors, e.g. `Vec::with_capacity`.
- Wrappers that provide an environment to execute some code, e.g.
`with_session_globals`.
- Consuming chaining methods, e.g. `Span::with_{lo,hi,ctxt}`.
The third case is exactly what we want, so this commit changes
`DiagnosticBuilder::foo_mv` to `DiagnosticBuilder::with_foo`.
Thanks to @compiler-errors for the suggestion.
We have `span_delayed_bug` and often pass it a `DUMMY_SP`. This commit
adds `delayed_bug`, which matches pairs like `err`/`span_err` and
`warn`/`span_warn`.
Because it takes an error code after the span. This avoids the confusing
overlap with the `DiagCtxt::struct_span_err` method, which doesn't take
an error code.
This works for most of its call sites. This is nice, because `emit` very
much makes sense as a consuming operation -- indeed,
`DiagnosticBuilderState` exists to ensure no diagnostic is emitted
twice, but it uses runtime checks.
For the small number of call sites where a consuming emit doesn't work,
the commit adds `DiagnosticBuilder::emit_without_consuming`. (This will
be removed in subsequent commits.)
Likewise, `emit_unless` becomes consuming. And `delay_as_bug` becomes
consuming, while `delay_as_bug_without_consuming` is added (which will
also be removed in subsequent commits.)
All this requires significant changes to `DiagnosticBuilder`'s chaining
methods. Currently `DiagnosticBuilder` method chaining uses a
non-consuming `&mut self -> &mut Self` style, which allows chaining to
be used when the chain ends in `emit()`, like so:
```
struct_err(msg).span(span).emit();
```
But it doesn't work when producing a `DiagnosticBuilder` value,
requiring this:
```
let mut err = self.struct_err(msg);
err.span(span);
err
```
This style of chaining won't work with consuming `emit` though. For
that, we need to use to a `self -> Self` style. That also would allow
`DiagnosticBuilder` production to be chained, e.g.:
```
self.struct_err(msg).span(span)
```
However, removing the `&mut self -> &mut Self` style would require that
individual modifications of a `DiagnosticBuilder` go from this:
```
err.span(span);
```
to this:
```
err = err.span(span);
```
There are *many* such places. I have a high tolerance for tedious
refactorings, but even I gave up after a long time trying to convert
them all.
Instead, this commit has it both ways: the existing `&mut self -> Self`
chaining methods are kept, and new `self -> Self` chaining methods are
added, all of which have a `_mv` suffix (short for "move"). Changes to
the existing `forward!` macro lets this happen with very little
additional boilerplate code. I chose to add the suffix to the new
chaining methods rather than the existing ones, because the number of
changes required is much smaller that way.
This doubled chainging is a bit clumsy, but I think it is worthwhile
because it allows a *lot* of good things to subsequently happen. In this
commit, there are many `mut` qualifiers removed in places where
diagnostics are emitted without being modified. In subsequent commits:
- chaining can be used more, making the code more concise;
- more use of chaining also permits the removal of redundant diagnostic
APIs like `struct_err_with_code`, which can be replaced easily with
`struct_err` + `code_mv`;
- `emit_without_diagnostic` can be removed, which simplifies a lot of
machinery, removing the need for `DiagnosticBuilderState`.
Check yield terminator's resume type in borrowck
In borrowck, we didn't check that the lifetimes of the `TerminatorKind::Yield`'s `resume_place` were actually compatible with the coroutine's signature. That means that the lifetimes were totally going unchecked. Whoops!
This PR implements this checking.
Fixes#119564
r? types
Make closures carry their own ClosureKind
Right now, we use the "`movability`" field of `hir::Closure` to distinguish a closure and a coroutine. This is paired together with the `CoroutineKind`, which is located not in the `hir::Closure`, but the `hir::Body`. This is strange and redundant.
This PR introduces `ClosureKind` with two variants -- `Closure` and `Coroutine`, which is put into `hir::Closure`. The `CoroutineKind` is thus removed from `hir::Body`, and `Option<Movability>` no longer needs to be a stand-in for "is this a closure or a coroutine".
r? eholk
Split coroutine desugaring kind from source
What a coroutine is desugared from (gen/async gen/async) should be separate from where it comes (fn/block/closure).
`IntoDiagnostic` defaults to `ErrorGuaranteed`, because errors are the
most common diagnostic level. It makes sense to do likewise for the
closely-related (and much more widely used) `DiagnosticBuilder` type,
letting us write `DiagnosticBuilder<'a, ErrorGuaranteed>` as just
`DiagnosticBuilder<'a>`. This cuts over 200 lines of code due to many
multi-line things becoming single line things.
Currently, `emit_diagnostic` takes `&mut self`.
This commit changes it so `emit_diagnostic` takes `self` and the new
`emit_diagnostic_without_consuming` function takes `&mut self`.
I find the distinction useful. The former case is much more common, and
avoids a bunch of `mut` and `&mut` occurrences. We can also restrict the
latter with `pub(crate)` which is nice.
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`
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.
`GenKillAnalysis` has five methods that take a transfer function arg:
- `statement_effect`
- `before_statement_effect`
- `terminator_effect`
- `before_terminator_effect`
- `call_return_effect`
All the transfer function args have type `&mut impl GenKill<Self::Idx>`,
except for `terminator_effect`, which takes the simpler `Self::Domain`.
But only the first two need to be `impl GenKill`. The other
three can all be `Self::Domain`, just like `Analysis`. So this commit
changes the last two to take `Self::Domain`, making `GenKillAnalysis`
and `Analysis` more similar.
(Another idea would be to make all these methods `impl GenKill`. But
that doesn't work: `MaybeInitializedPlaces::terminator_effect` requires
the arg be `Self::Domain` so that `self_is_unwind_dead(place, state)`
can be called on it.)
This results in two non-generic types being used: `BorrowckResults` and
`BorrowckFlowState`. It's a net reduction in lines of code, and a little
easier to read.
It is used just once. With it removed, the relevant code is a little
boilerplate-y but much easier to read, and is the same length. Overall I
think it's an improvement.
When encountering multiple mutable borrows, suggest cloning and adding
derive annotations as needed.
```
error[E0596]: cannot borrow `sm.x` as mutable, as it is behind a `&` reference
--> $DIR/accidentally-cloning-ref-borrow-error.rs:32:9
|
LL | foo(&mut sm.x);
| ^^^^^^^^^ `sm` is a `&` reference, so the data it refers to cannot be borrowed as mutable
|
help: `Str` doesn't implement `Clone`, so this call clones the reference `&Str`
--> $DIR/accidentally-cloning-ref-borrow-error.rs:31:21
|
LL | let mut sm = sr.clone();
| ^^^^^^^
help: consider annotating `Str` with `#[derive(Clone)]`
|
LL + #[derive(Clone)]
LL | struct Str {
|
help: consider specifying this binding's type
|
LL | let mut sm: &mut Str = sr.clone();
| ++++++++++
```
```
error[E0596]: cannot borrow `*inner` as mutable, as it is behind a `&` reference
--> $DIR/issue-91206.rs:14:5
|
LL | inner.clear();
| ^^^^^ `inner` is a `&` reference, so the data it refers to cannot be borrowed as mutable
|
help: you can `clone` the `Vec<usize>` value and consume it, but this might not be your desired behavior
--> $DIR/issue-91206.rs:11:17
|
LL | let inner = client.get_inner_ref();
| ^^^^^^^^^^^^^^^^^^^^^^
help: consider specifying this binding's type
|
LL | let inner: &mut Vec<usize> = client.get_inner_ref();
| +++++++++++++++++
```
When encountering a move error, look for implementations of `Clone` for
the moved type. If there is one, check if all its obligations are met.
If they are, we suggest cloning without caveats. If they aren't, we
suggest cloning while mentioning the unmet obligations, potentially
suggesting `#[derive(Clone)]` when appropriate.
```
error[E0507]: cannot move out of a shared reference
--> $DIR/suggest-clone-when-some-obligation-is-unmet.rs:20:28
|
LL | let mut copy: Vec<U> = map.clone().into_values().collect();
| ^^^^^^^^^^^ ------------- value moved due to this method call
| |
| move occurs because value has type `HashMap<T, U, Hash128_1>`, which does not implement the `Copy` trait
|
note: `HashMap::<K, V, S>::into_values` takes ownership of the receiver `self`, which moves value
--> $SRC_DIR/std/src/collections/hash/map.rs:LL:COL
help: you could `clone` the value and consume it, if the `Hash128_1: Clone` trait bound could be satisfied
|
LL | let mut copy: Vec<U> = <HashMap<T, U, Hash128_1> as Clone>::clone(&map.clone()).into_values().collect();
| ++++++++++++++++++++++++++++++++++++++++++++ +
help: consider annotating `Hash128_1` with `#[derive(Clone)]`
|
LL + #[derive(Clone)]
LL | pub struct Hash128_1;
|
```
Fix#109429.
