Unify SourceFile::name_hash and StableSourceFileId
This PR adapts the existing `StableSourceFileId` type so that it can be used instead of the `name_hash` field of `SourceFile`. This simplifies a few things that were kind of duplicated before.
The PR should also fix issues https://github.com/rust-lang/rust/issues/112700 and https://github.com/rust-lang/rust/issues/115835, but I was not able to reproduce these issues in a regression test. As far as I can tell, the root cause of these issues is that the id of the originating crate is not hashed in the `HashStable` impl of `Span` and thus cache entries that should have been considered invalidated were loaded. After this PR, the `stable_id` field of `SourceFile` includes information about the originating crate, so that ICE should not occur anymore.
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.
We can just get the error level in the `match` and then use
`DiagnosticBuilder::new`. This then means a number of `DiagCtxt`
functions are no longer needed, because this was the one place that used
them.
Note: the commit changes the treatment of spans for `Expect`, which was
different to all the other cases, but this has no apparent effect.
-Znext-solver: adapt overflow rules to avoid breakage
Do not erase overflow constraints if they are from equating the impl header when normalizing[^1].
This should be the minimal change to not break crates depending on the old project behavior of "apply impl constraints while only lazily evaluating any nested goals".
Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/70, see https://hackmd.io/ATf4hN0NRY-w2LIVgeFsVg for the reasoning behind this.
Only keeping constraints on overflow for `normalize-to` goals as that's the only thing needed for backcompat. It also allows us to not track the origin of root obligations. The issue with root goals would be something like the following:
```rust
trait Foo {}
trait Bar {}
trait FooBar {}
impl<T: Foo + Bar> FooBar for T {}
// These two should behave the same, rn we can drop constraints for both,
// but if we don't drop `Misc` goals we would only drop the constraints for
// `FooBar` unless we track origins of root obligations.
fn func1<T: Foo + Bar>() {}
fn func2<T: FooBaz>() {}
```
[^1]: mostly, the actual rules are slightly different
r? ``@compiler-errors``
Replace some instances of FxHashMap/FxHashSet with stable alternatives (mostly in rustc_hir and rustc_ast_lowering)
Part of https://github.com/rust-lang/compiler-team/issues/533. We should be getting close to being able to remove the HashStable impl of HashMap.
And make all hand-written `IntoDiagnostic` impls generic, by using
`DiagnosticBuilder::new(dcx, level, ...)` instead of e.g.
`dcx.struct_err(...)`.
This means the `create_*` functions are the source of the error level.
This change will let us remove `struct_diagnostic`.
Note: `#[rustc_lint_diagnostics]` is added to `DiagnosticBuilder::new`,
it's necessary to pass diagnostics tests now that it's used in
`into_diagnostic` functions.
Don't pass lint back out of lint decorator
Change the decorator function in the signature of the `emit_lint`/`span_lint`/etc family of methods from `impl for<'a, 'b> FnOnce(&'b mut DiagnosticBuilder<'a, ()>) -> &'b mut DiagnosticBuilder<'a, ()>` to `impl for<'a, 'b> FnOnce(&'b mut DiagnosticBuilder<'a, ()>)`. I consider it easier to read this way, especially when there's control flow involved.
r? nnethercote though feel free to reassign
Uplift `TypeAndMut` and `ClosureKind` to `rustc_type_ir`
Uplifts `TypeAndMut` and `ClosureKind`
I know I said I was just going to get rid of `TypeAndMut` (https://github.com/rust-lang/types-team/issues/124) but I think this is much simpler, lol
r? `@jackh726` or `@lcnr`
cache param env canonicalization
Canonicalize ParamEnv only once and store it. Then whenever we try to canonicalize `ParamEnvAnd<'tcx, T>` we only have to canonicalize `T` and then merge the results.
Prelimiary results show ~3-4% savings in diesel and serde benchmarks.
Best to review commits individually. Some commits have a short description.
Initial implementation had a soundness bug (https://github.com/rust-lang/rust/pull/117749#issuecomment-1840453387) due to cache invalidation:
- When canonicalizing `Ty<'?0>` we first try to resolve region variables in the current InferCtxt which may have a constraint `?0 == 'static`. This means that we register `Ty<'?0> => Canonical<Ty<'static>>` in the cache, which is obviously incorrect in another inference context.
- This is fixed by not doing region resolution when canonicalizing the query *input* (vs. response), which is the only place where ParamEnv is used, and then in a later commit we *statically* guard against any form of inference variable resolution of the cached canonical ParamEnv's.
r? `@ghost`
This doesn't change behavior.
It should prevent unintentional resolution of inference variables
during canonicalization, which previously caused a soundness bug.
See PR description for more.
ParamEnv is canonicalized in *queries input* rather than query response.
In such case we don't "preserve universes" of canonical variable.
This means that `universe_map` always has the default value, which is
wasteful to store in the cache.
