Custom MIR: Many more improvements
Commits are each atomic changes, best reviewed one at a time, with the exception that the last commit includes all the documentation.
### First commit
Unsafetyck was not correctly disabled before for `dialect = "built"` custom MIR. This is fixed and a regression test is added.
### Second commit
Implements `Discriminant`, `SetDiscriminant`, and `SwitchInt`.
### Third commit
Implements indexing, field, and variant projections.
### Fourth commit
Documents the previous commits and everything else.
There is some amount of weirdness here due to having to beat Rust syntax into cooperating with MIR concepts, but it hopefully should not be too much. All of it is documented.
r? `@oli-obk`
Auto traits in `dyn Trait + Auto` are suggestable
Not sure why I had made the `IsSuggestableVisitor` have that rule to not consider `dyn Trait + Auto` to be suggestable.
It's possible that this was done because of the fact that we don't print the right parentheses for `&(dyn Trait + Auto)`, but that's a problem with printing these types in general that we probably have tracked somewhere else...
Combine `ty::Projection` and `ty::Opaque` into `ty::Alias`
Implements https://github.com/rust-lang/types-team/issues/79.
This PR consolidates `ty::Projection` and `ty::Opaque` into a single `ty::Alias`, with an `AliasKind` and `AliasTy` type (renamed from `ty::ProjectionTy`, which is the inner data of `ty::Projection`) defined as so:
```
enum AliasKind {
Projection,
Opaque,
}
struct AliasTy<'tcx> {
def_id: DefId,
substs: SubstsRef<'tcx>,
}
```
Since we don't have access to `TyCtxt` in type flags computation, and because repeatedly calling `DefKind` on the def-id is expensive, these two types are distinguished with `ty::AliasKind`, conveniently glob-imported into `ty::{Projection, Opaque}`. For example:
```diff
match ty.kind() {
- ty::Opaque(..) =>
+ ty::Alias(ty::Opaque, ..) => {}
_ => {}
}
```
This PR also consolidates match arms that treated `ty::Opaque` and `ty::Projection` identically.
r? `@ghost`
use ty::Binder in rustdoc instead of `skip_binder`
r? `@GuillaumeGomez`
this is a preliminary cleanup required to be able to normalize correctly/conveniently in rustdoc
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 :)
