compiler: remove unnecessary imports and qualified paths
Some of these imports were necessary before Edition 2021, others were already in the prelude.
I hope it's fine that this PR is so spread-out across files :/
Rollup of 10 pull requests
Successful merges:
- #98391 (Reimplement std's thread parker on top of events on SGX)
- #104019 (Compute generator sizes with `-Zprint_type_sizes`)
- #104512 (Set `download-ci-llvm = "if-available"` by default when `channel = dev`)
- #104901 (Implement masking in FileType comparison on Unix)
- #105082 (Fix Async Generator ABI)
- #105109 (Add LLVM KCFI support to the Rust compiler)
- #105505 (Don't warn about unused parens when they are used by yeet expr)
- #105514 (Introduce `Span::is_visible`)
- #105516 (Update cargo)
- #105522 (Remove wrong note for short circuiting operators)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
use the correct `Reveal` during validation
supersedes #105454. Deals with https://github.com/rust-lang/rust/issues/105009#issuecomment-1342395333, not closing #105009 as the ICE may leak into beta
The issue was the following:
- we optimize the mir, using `Reveal::All`
- some optimization relies on the hidden type of an opaque type
- we then validate using `Reveal::UserFacing` again which is not able to observe the hidden type
r? `@jackh726`
make retagging work even with 'unstable' places
This is based on top of https://github.com/rust-lang/rust/pull/105301. Only the last two commits are new.
While investigating https://github.com/rust-lang/unsafe-code-guidelines/issues/381 I realized that we would have caught this issue much earlier if the add_retag pass wouldn't bail out on assignments of the form `*ptr = ...`.
So this PR changes our retag strategy:
- When a new reference is created via `Rvalue::Ref` (or a raw ptr via `Rvalue::AddressOf`), we do the retagging as part of just executing that address-taking operation.
- For everything else, we still insert retags -- these retags basically serve to ensure that references stored in local variables (and their fields) are always freshly tagged, so skipping this for assignments like `*ptr = ...` is less egregious.
r? ```@oli-obk```
Detect long types in E0308 and write them to disk
On type error with long types, print an abridged type and write the full type to disk.
Print the widest possible short type while still fitting in the terminal.
Put all cached values into a central struct instead of just the stable hash
cc `@nnethercote`
this allows re-use of the type for Predicate without duplicating all the logic for the non-hash cached fields
Make `note_obligation_cause_code` take a `impl ToPredicate` for predicate
The only usecase that wasn't `impl ToPredicate` was noting overflow errors while revealing opaque types, which passed in an `Obligation<'tcx, Ty<'tcx>>`... Since this only happens in a `RevealAll` environment, which is after typeck (and probably primarily within `normalize_erasing_regions`) we're unlikely to display anything useful while noting this code, evidenced by the lack of UI test changes.
Synthesize substitutions for bad auto traits in dyn types
Auto traits are stored as just `DefId`s inside a `dyn Trait`'s existential predicates list. This is usually fine, since auto traits are forbidden to have generics -- but this becomes a problem for an ill-formed auto trait.
But since this will always result in an error, just synthesize some dummy (error) substitutions which are used at least to keep trait selection code happy about the number of substs in a trait ref.
Fixes#104808
feed resolver_for_lowering instead of storing it in a field
r? `@cjgillot`
opening this as
* a discussion for `no_hash` + `feedable` queries. I think we'll want those, but I don't quite understand why they are rejected beyond a double check of the stable hashes for situations where the query is fed but also read from incremental caches.
* and a discussion on removing all untracked fields from TyCtxt and setting it up so that they are fed queries instead
This ensures that the error is printed even for unused variables,
as well as unifying the handling between the LLVM and GCC backends.
This also fixes unusual behavior around exported Rust-defined variables
with linkage attributes. With the previous behavior, it appears to be
impossible to define such a variable such that it can actually be imported
and used by another crate. This is because on the importing side, the
variable is required to be a pointer, but on the exporting side, the
type checker rejects static variables of pointer type because they do
not implement `Sync`. Even if it were possible to import such a type, it
appears that code generation on the importing side would add an unexpected
additional level of pointer indirection, which would break type safety.
This highlighted that the semantics of linkage on Rust-defined variables
is different to linkage on foreign items. As such, we now model the
difference with two different codegen attributes: linkage for Rust-defined
variables, and import_linkage for foreign items.
This change gives semantics to the test
src/test/ui/linkage-attr/auxiliary/def_illtyped_external.rs which was
previously expected to fail to compile. Therefore, convert it into a
test that is expected to successfully compile.
The update to the GCC backend is speculative and untested.
This makes sure that ICEing because of def ids created outside of ast lowering will be able to produce a query backtrace and not cause a double panic because of trying to call the `def_span` query
Rollup of 9 pull requests
Successful merges:
- #103065 (rustdoc-json: Document and Test that args can be patterns.)
- #104865 (Don't overwrite local changes when updating submodules)
- #104895 (Avoid Invalid code suggested when encountering unsatisfied trait bounds in derive macro code)
- #105063 (Rustdoc Json Tests: Don't assume that core::fmt::Debug will always have one item.)
- #105064 (rustdoc: add comment to confusing CSS `main { min-width: 0 }`)
- #105074 (Add Nicholas Bishop to `.mailmap`)
- #105081 (Add a regression test for #104322)
- #105086 (rustdoc: clean up sidebar link CSS)
- #105091 (add Tshepang Mbambo to .mailmap)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Allow to feed a value in another query's cache
Restricted version of https://github.com/rust-lang/rust/pull/96840
A query can create new definitions.
If those definitions are created after HIR lowering, they do not appear in the initial HIR map, and information for them cannot be provided in the normal pull-based way.
In order to make those definitions useful, we allow to feed values as query results for the newly created definition.
The API is as follows:
```rust
let feed = tcx.create_def(<parent def id>, <DefPathData>);
// `feed` is a TyCtxtFeed<'tcx>.
// Access the created definition.
let def_id: LocalDefId = feed.def_id;
// Assign `my_query(def_id) := my_value`.
feed.my_query(my_value).
```
This PR keeps the consistency checks introduced by https://github.com/rust-lang/rust/pull/96840, even if they are not reachable. This allows to extend the behaviour later without forgetting them.
cc `@oli-obk` `@spastorino`
Rollup of 14 pull requests
Successful merges:
- #103876 (type alias impl trait: add tests showing that hidden type only outlives lifetimes that occur in bounds)
- #104427 (Explain why `rematch_impl` fails to be infallible)
- #104436 (Add slice to the stack allocated string comment)
- #104523 (Don't use periods in target names)
- #104627 (Print all features with --print target-features)
- #104911 (Make inferred_outlives_crate return Clause)
- #105002 (Add `PathBuf::as_mut_os_string` and `Path::as_mut_os_str`)
- #105023 (Statics used in reachable function's inline asm are reachable)
- #105045 (`rustc_ast_{passes,pretty}`: remove `ref` patterns)
- #105049 (Hermit: Minor build fixes)
- #105051 (Replace a macro with a function)
- #105062 (rustdoc: use shorthand background for rustdoc toggle CSS)
- #105066 (move `candidate_from_obligation` out of assembly)
- #105068 (Run patchelf also on rust-analyzer-proc-macro-srv.)
Failed merges:
- #105050 (Remove useless borrows and derefs)
r? `@ghost`
`@rustbot` modify labels: rollup
Also cache the stable hash of interned Predicates
continuation of https://github.com/rust-lang/rust/pull/94299
This is a small perf improvement and shares more code between `Ty` and `Predicate`
On type error with long types, print an abridged type and write the full
type to disk.
Print the widest possible short type while still fitting in the
terminal.
`mk_const(ty::ConstKind::X(...), ty)` can now be simplified to
`mk_cosnt(..., ty)`.
I searched with the following regex: \mk_const\([\n\s]*(ty::)?ConstKind\
I've left `ty::ConstKind::{Bound, Error}` as-is, they seem clearer this
way.
- Accept `impl Into`
- Implement `From<>` for `ConstKind`
Note: this adds a dependency on `derive_more` (MIT license). It allows
to derive a lot of traits (like `From` here) that would be otherwise
tedious to implement.
Add documentation for `has_escaping_bound_vars`
Thanks to `@BoxyUwU` for explaining this to me. Adding docs with a helpful link if people get confused.
Prefer doc comments over `//`-comments in compiler
Doc comments are generally nicer: they show up in the documentation, they are shown in IDEs when you hover other mentions of items, etc. Thus it makes sense to use them instead of `//`-comments.
Rollup of 8 pull requests
Successful merges:
- #95836 (Use `rust_out{exe_suffix}` for doctests)
- #104882 (notify lcnr on changes to `ObligationCtxt`)
- #104892 (Explain how to get the discriminant out of a `#[repr(T)] enum` with payload)
- #104917 (Allow non-org members to label `requires-debug-assertions`)
- #104931 (Pretty-print generators with their `generator_kind`)
- #104934 (Remove redundant `all` in cfg)
- #104944 (Support unit tests for jsondoclint)
- #104946 (rustdoc: improve popover focus handling JS)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Pretty-print generators with their `generator_kind`
After removing `GenFuture`, I special-cased async generators to pretty-print as `impl Future<Output = X>` mainly to avoid too much diagnostics changes originally.
This now reverses that change so that async fn/blocks are pretty-printed as `[$async-type@$source-position]` in various diagnostics, and updates the tests that this touches.
Separate lifetime ident from lifetime resolution in HIR
Drive-by: change how suggested generic args are computed.
Fixes https://github.com/rust-lang/rust/issues/103815
I recommend reviewing commit-by-commit.
After removing `GenFuture`, I special-cased async generators to pretty-print as `impl Future<Output = X>` mainly to avoid too much diagnostics changes originally.
This now reverses that change so that async fn/blocks are pretty-printed as `[$movability `async` $something@$source-position]` in various diagnostics, and updates the tests that this touches.
Rollup of 7 pull requests
Successful merges:
- #104786 (Use the power of adding helper function to simplify code w/ `Mutability`)
- #104788 (Do not record unresolved const vars in generator interior)
- #104909 (Rename `normalize_opaque_types` to `reveal_opaque_types_in_bounds`)
- #104921 (Remove unnecessary binder from `get_impl_future_output_ty`)
- #104924 (jsondoclint: Accept trait alias is places where trait expected.)
- #104928 (rustdoc: use flexbox CSS to align sidebar button instead of position)
- #104943 (jsondoclint: Handle using enum variants and glob using enums.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Rename `normalize_opaque_types` to `reveal_opaque_types_in_bounds`
1. The query name is a bit misleading, since it doesn't do any associated type normalization, and
2. since it only takes a predicate list, it sounds a bit more powerful than it actually is.
Do not record unresolved const vars in generator interior
Don't record types in the generator interior when we see unresolved const variables.
We already do this for associated types -- this is important to avoid unresolved inference variables in the generator results during writeback, since the writeback results get stable hashed in incremental mode.
Fixes#104787
Unsupported query error now specifies if its unsupported for local or external crate
Fixes#101666.
I had to move `keys.rs` from `rustc_query_impl` to `rustc_middle`. I don't know if that is problematic. I couldn't think of any other way to get the needed information inside `rustc_middle`.
r? ```@jyn514```
Add `ConstKind::Expr`
Starting to implement `ty::ConstKind::Abstract`, most of the match cases are stubbed out, some I was unsure what to add, others I didn't want to add until a more complete implementation was ready.
r? `@lcnr`
Initial pass at expr/abstract const/s
Address comments
Switch to using a list instead of &[ty::Const], rm `AbstractConst`
Remove try_unify_abstract_consts
Update comments
Add edits
Recurse more
More edits
Prevent equating associated consts
Move failing test to ui
Changes this test from incremental to ui, and mark it as failing and a known bug.
Does not cause the compiler to ICE, so should be ok.
privacy: Fix more (potential) issues with effective visibilities
Continuation of https://github.com/rust-lang/rust/pull/103965.
See individual commits for more detailed description of the changes.
The shortcuts removed in 4eb63f618e and c7c7d16727 could actually be correct (or correct after some tweaks), but they used global reasoning like "we can skip this update because if the code compiles then some other update should do the same thing eventually".
I have some expertise in this area, but I still have doubt whether such global reasoning was correct or not, especially in presence of all possible exotic cases with imports.
After this PR all table changes should be "locally correct" after every update, even if it may be overcautious.
If similar optimizations are introduced again they will need detailed comments explaining why it's legal to do what they do and providing proofs.
Fixes https://github.com/rust-lang/rust/issues/104249.
Fixes https://github.com/rust-lang/rust/issues/104539.
make `error_reported` check for delayed bugs
Fixes#104768
`error_reported()` was only checking if there were errors emitted, not for `delay_bug`s which can also be a source of `ErrorGuaranteed`. I assume the same is true of `lint_err_count` but i dont know
Make rustc_target usable outside of rustc
I'm working on showing type size in rust-analyzer (https://github.com/rust-lang/rust-analyzer/pull/13490) and I currently copied rustc code inside rust-analyzer, which works, but is bad. With this change, I would become able to use `rustc_target` and `rustc_index` directly in r-a, reducing the amount of copy needed.
This PR contains some feature flag to put nightly features behind them to make crates buildable on the stable compiler + makes layout related types generic over index type + removes interning of nested layouts.
Avoid `GenFuture` shim when compiling async constructs
Previously, async constructs would be lowered to "normal" generators, with an additional `from_generator` / `GenFuture` shim in between to convert from `Generator` to `Future`.
The compiler will now special-case these generators internally so that async constructs will *directly* implement `Future` without the need to go through the `from_generator` / `GenFuture` shim.
The primary motivation for this change was hiding this implementation detail in stack traces and debuginfo, but it can in theory also help the optimizer as there is less abstractions to see through.
---
Given this demo code:
```rust
pub async fn a(arg: u32) -> Backtrace {
let bt = b().await;
let _arg = arg;
bt
}
pub async fn b() -> Backtrace {
Backtrace::force_capture()
}
```
I would get the following with the latest stable compiler (on Windows):
```
4: async_codegen:🅱️:async_fn$0
at .\src\lib.rs:10
5: core::future::from_generator::impl$1::poll<enum2$<async_codegen:🅱️:async_fn_env$0> >
at /rustc/897e37553bba8b42751c67658967889d11ecd120\library\core\src\future\mod.rs:91
6: async_codegen:🅰️:async_fn$0
at .\src\lib.rs:4
7: core::future::from_generator::impl$1::poll<enum2$<async_codegen:🅰️:async_fn_env$0> >
at /rustc/897e37553bba8b42751c67658967889d11ecd120\library\core\src\future\mod.rs:91
```
whereas now I get a much cleaner stack trace:
```
3: async_codegen:🅱️:async_fn$0
at .\src\lib.rs:10
4: async_codegen:🅰️:async_fn$0
at .\src\lib.rs:4
```
Previously, async constructs would be lowered to "normal" generators,
with an additional `from_generator` / `GenFuture` shim in between to
convert from `Generator` to `Future`.
The compiler will now special-case these generators internally so that
async constructs will *directly* implement `Future` without the need
to go through the `from_generator` / `GenFuture` shim.
The primary motivation for this change was hiding this implementation
detail in stack traces and debuginfo, but it can in theory also help
the optimizer as there is less abstractions to see through.
Previously if the parent was not in the table, and there was nothing to inherit from, the child's private visibility was used, but that's not correct - the parent may have a larger visibility so we should set it to at least the parent's private visibility.
That parent's private visibility is also inserted into the table for caching, so it's not recalculated later if used again.
First, they require eagerly calculating private visibility (current normal module), which is somewhat expensive.
Private visibilities are also lost once calculated, instead of being cached in the table.
Second, I cannot prove that the optimizations are correct.
Maybe they can be partially reinstated in the future in cases when it's cheap and provably correct to do them.
They will also probably be merged into `fn update` in that case.
Partially fixes https://github.com/rust-lang/rust/issues/104249
Fixes https://github.com/rust-lang/rust/issues/104539
Use `tcx.require_lang_item` instead of unwrapping lang items
I clearly remember esteban telling me that there is `require_lang_item` but he was from a phone atm and I couldn't find it, so I didn't use it. Stumbled on it today, so here we are :)
Rollup of 11 pull requests
Successful merges:
- #103396 (Pin::new_unchecked: discuss pinning closure captures)
- #104416 (Fix using `include_bytes` in pattern position)
- #104557 (Add a test case for async dyn* traits)
- #104559 (Split `MacArgs` in two.)
- #104597 (Probe + better error messsage for `need_migrate_deref_output_trait_object`)
- #104656 (Move tests)
- #104657 (Do not check transmute if has non region infer)
- #104663 (rustdoc: factor out common button CSS)
- #104666 (Migrate alias search result to CSS variables)
- #104674 (Make negative_impl and negative_impl_exists take the right types)
- #104692 (Update test's cfg-if dependency to 1.0)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Split `MacArgs` in two.
`MacArgs` is an enum with three variants: `Empty`, `Delimited`, and `Eq`. It's used in two ways:
- For representing attribute macro arguments (e.g. in `AttrItem`), where all three variants are used.
- For representing function-like macros (e.g. in `MacCall` and `MacroDef`), where only the `Delimited` variant is used.
In other words, `MacArgs` is used in two quite different places due to them having partial overlap. I find this makes the code hard to read. It also leads to various unreachable code paths, and allows invalid values (such as accidentally using `MacArgs::Empty` in a `MacCall`).
This commit splits `MacArgs` in two:
- `DelimArgs` is a new struct just for the "delimited arguments" case. It is now used in `MacCall` and `MacroDef`.
- `AttrArgs` is a renaming of the old `MacArgs` enum for the attribute macro case. Its `Delimited` variant now contains a `DelimArgs`.
Various other related things are renamed as well.
These changes make the code clearer, avoids several unreachable paths, and disallows the invalid values.
r? `@petrochenkov`
`MacArgs` is an enum with three variants: `Empty`, `Delimited`, and `Eq`. It's
used in two ways:
- For representing attribute macro arguments (e.g. in `AttrItem`), where all
three variants are used.
- For representing function-like macros (e.g. in `MacCall` and `MacroDef`),
where only the `Delimited` variant is used.
In other words, `MacArgs` is used in two quite different places due to them
having partial overlap. I find this makes the code hard to read. It also leads
to various unreachable code paths, and allows invalid values (such as
accidentally using `MacArgs::Empty` in a `MacCall`).
This commit splits `MacArgs` in two:
- `DelimArgs` is a new struct just for the "delimited arguments" case. It is
now used in `MacCall` and `MacroDef`.
- `AttrArgs` is a renaming of the old `MacArgs` enum for the attribute macro
case. Its `Delimited` variant now contains a `DelimArgs`.
Various other related things are renamed as well.
These changes make the code clearer, avoids several unreachable paths, and
disallows the invalid values.
Rollup of 9 pull requests
Successful merges:
- #104420 (Fix doc example for `wrapping_abs`)
- #104499 (rustdoc JSON: Use `Function` everywhere and remove `Method`)
- #104500 (`rustc_ast`: remove `ref` patterns)
- #104511 (Mark functions created for `raw-dylib` on x86 with DllImport storage class)
- #104595 (Add `PolyExistentialPredicate` type alias)
- #104605 (deduplicate constant evaluation in cranelift backend)
- #104628 (Revert "Update CI to use Android NDK r25b")
- #104662 (Streamline deriving on packed structs.)
- #104667 (Revert formatting changes of a test)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
deduplicate constant evaluation in cranelift backend
The cranelift backend had two matches on `ConstantKind`, which can be avoided, and used this `eval_for_mir` that nothing else uses... this makes things more consistent with the (better-tested) LLVM backend.
I noticed this because cranelift was the only user of `eval_for_mir`. However `try_eval_for_mir` still has one other user in `eval`... the odd thing is that the interpreter has its own `eval_mir_constant` which seems to duplicate the same functionality and does not use `try_eval_for_mir`. No idea what is happening here.
r? ``@bjorn3``
Cc ``@lcnr``
Add `PolyExistentialPredicate` type alias
Wrapping `ExistentialPredicate`s in a binder is very common, and this alias already exists for the `PolyExistential{TraitRef,Projection}` types.
Support using `Self` or projections inside an RPIT/async fn
I reuse the same idea as https://github.com/rust-lang/rust/pull/103449 to use variances to encode whether a lifetime parameter is captured by impl-trait.
The current implementation of async and RPIT replace all lifetimes from the parent generics by `'static`. This PR changes the scheme
```rust
impl<'a> Foo<'a> {
fn foo<'b, T>() -> impl Into<Self> + 'b { ... }
}
opaque Foo::<'_a>::foo::<'_b, T>::opaque<'b>: Into<Foo<'_a>> + 'b;
impl<'a> Foo<'a> {
// OLD
fn foo<'b, T>() -> Foo::<'static>::foo::<'static, T>::opaque::<'b> { ... }
^^^^^^^ the `Self` becomes `Foo<'static>`
// NEW
fn foo<'b, T>() -> Foo::<'a>::foo::<'b, T>::opaque::<'b> { ... }
^^ the `Self` stays `Foo<'a>`
}
```
There is the same issue with projections. In the example, substitute `Self` by `<T as Trait<'b>>::Assoc` in the sugared version, and `Foo<'_a>` by `<T as Trait<'_b>>::Assoc` in the desugared one.
This allows to support `Self` in impl-trait, since we do not replace lifetimes by `'static` any more. The same trick allows to use projections like `T::Assoc` where `Self` is allowed. The feature is gated behind a `impl_trait_projections` feature gate.
The implementation relies on 2 tweaking rules for opaques in 2 places:
- we only relate substs that correspond to captured lifetimes during TypeRelation;
- we only list captured lifetimes in choice region computation.
For simplicity, I encoded the "capturedness" of lifetimes as a variance, `Bivariant` vs `Invariant` for unused vs captured lifetimes. The `variances_of` query used to ICE for opaques.
Impl-trait that do not reference `Self` or projections will have their variances as:
- `o` (invariant) for each parent type or const;
- `*` (bivariant) for each parent lifetime --> will not participate in borrowck;
- `o` (invariant) for each own lifetime.
Impl-trait that does reference `Self` and/or projections will have some parent lifetimes marked as `o` (as the example above), and participate in type relation and borrowck. In the example above, `variances_of(opaque) = ['_a: o, '_b: *, T: o, 'b: o]`.
r? types
cc `@compiler-errors` , as you asked about the issue with `Self` and projections.
Improve spans for RPITIT object-safety errors
No reason why we can't point at the `impl Trait` that causes the object-safety violation.
Also [drive-by: Add is_async fn to hir::IsAsync](c4165f3a96), which touches clippy too.
Make "long type" printing type aware and trim types in E0275
Instead of simple string cutting, use a custom printer to hide parts of long printed types.
On E0275, check for type length before printing.
`_` might confuse people into believing that the type isn't known,
while `...` is not used anywhere else for types and is not valid
syntax, making it more likely to convey the right understanding.
Convert predicates into Predicate in the Obligation constructor
instead of having almost all callers do that.
This reduces a bit of boilerplate, and also paves the way for my work towards https://github.com/rust-lang/compiler-team/issues/531 (as it makes it easier to accept both goals and clauses where right now it only accepts predicates).
Record `LocalDefId` in HIR nodes instead of a side table
This is part of an attempt to remove the `HirId -> LocalDefId` table from HIR.
This attempt is a prerequisite to creation of `LocalDefId` after HIR lowering (https://github.com/rust-lang/rust/pull/96840), by controlling how `def_id` information is accessed.
This first part adds the information to HIR nodes themselves instead of a table.
The second part is https://github.com/rust-lang/rust/pull/103902
The third part will be to make `hir::Visitor::visit_fn` take a `LocalDefId` as last parameter.
The fourth part will be to completely remove the side table.
Perform simple scalar replacement of aggregates (SROA) MIR opt
This is a re-open of https://github.com/rust-lang/rust/pull/85796
I copied the debuginfo implementation (first commit) from `@eddyb's` own SROA PR.
This pass replaces plain field accesses by simple locals when possible.
To be eligible, the replaced locals:
- must not be enums or unions;
- must not be used whole;
- must not have their address taken.
The storage and deinit statements are duplicated on each created local.
cc `@tmiasko` who reviewed the former version of this PR.
interpret: support for per-byte provenance
Also factors the provenance map into its own module.
The third commit does the same for the init mask. I can move it in a separate PR if you prefer.
Fixes https://github.com/rust-lang/miri/issues/2181
r? `@oli-obk`
Rollup of 9 pull requests
Successful merges:
- #103439 (Show note where the macro failed to match)
- #103734 (Adjust stabilization version to 1.65.0 for wasi fds)
- #104148 (Visit attributes of trait impl items during AST validation)
- #104241 (Move most of unwind's build script to lib.rs)
- #104258 (Deduce closure signature from a type alias `impl Trait`'s supertraits)
- #104296 (Walk types more carefully in `ProhibitOpaqueTypes` visitor)
- #104309 (Slightly improve error message for invalid identifier)
- #104316 (Simplify suggestions for errors in generators.)
- #104339 (Add `rustc_deny_explicit_impl`)
Failed merges:
- #103484 (Add `rust` to `let_underscore_lock` example)
r? `@ghost`
`@rustbot` modify labels: rollup
Deduce closure signature from a type alias `impl Trait`'s supertraits
r? `@oli-obk`
Basically pass the TAIT's bounds through the same method that we're using to deduce a signature from infer var closure bounds.
Does this need a new FCP? I see it as a logical extension of #101834, but happy to rfcbot a new one if it does.
Add new MIR constant propagation based on dataflow analysis
The current constant propagation in `rustc_mir_transform/src/const_prop.rs` fails to handle many cases that would be expected from a constant propagation optimization. For example:
```rust
let x = if true { 0 } else { 0 };
```
This pull request adds a new constant propagation MIR optimization pass based on the existing dataflow analysis framework. Since most of the analysis is not unique to constant propagation, a generic framework has been extracted. It works on top of the existing framework and could be reused for other optimzations.
Closes#80038. Closes#81605.
## Todo
### Essential
- [x] [Writes to inactive enum variants](https://github.com/rust-lang/rust/pull/101168#pullrequestreview-1089493974). Resolved by rejecting the registration of places with downcast projections for now. Could be improved by flooding other variants if mutable access to a variant is observed.
- [X] Handle [`StatementKind::CopyNonOverlapping`](https://github.com/rust-lang/rust/pull/101168#discussion_r957774914). Resolved by flooding the destination.
- [x] Handle `UnsafeCell` / `!Freeze` correctly.
- [X] Overflow propagation of `CheckedBinaryOp`: Decided to not propagate if overflow flag is `true` (`false` will still be propagated)
- [x] More documentation in general.
- [x] Arguments for correctness, documentation of necessary assumptions.
- [x] Better performance, or alternatively, require `-Zmir-opt-level=3` for now.
### Extra
- [x] Add explicit unreachability, i.e. upgrading the lattice from $\mathbb{P} \to \mathbb{V}$ to $\set{\bot} \cup (\mathbb{P} \to \mathbb{V})$.
- [x] Use storage statements to improve precision.
- [ ] Consider opening issue for duplicate diagnostics: https://github.com/rust-lang/rust/pull/101168#issuecomment-1276609950
- [ ] Flood moved-from places with $\bot$ (requires some changes for places with tracked projections).
- [ ] Add downcast projections back in.
- [ ] [Algebraic simplifications](https://github.com/rust-lang/rust/pull/101168#discussion_r957967878) (possibly with a shared API; done by old const prop).
- [ ] Propagation through slices / arrays.
- [ ] Find other optimizations that are done by old `const_prop.rs`, but not by this one.
Resolve lifetimes independently for each item-like.
Now that the heavy-lifting is done on the AST and during lowering, we do not need to perform HIR lifetime resolution on a full item at once. Instead, we can treat each item-like independently, and look at `generics_of` the parent exceptionally for associated items.
Use `const_error_with_guaranteed` more
Better to pass down an ErrorGuaranteed rather than making a new one out of thin air, for some usages. Also for the ones where we *do* need to delay a bug, that delayed bug will have a more descriptive message.
