Indexing is similar to method calls in having an arbitrary
left-hand-side and then something on the right, which is the main part
of the expression. Method calls already have a span for that right part,
but indexing does not. This means that long method chains that use
indexing have really bad spans, especially when the indexing panics and
that span in coverted into a panic location.
This does the same thing as method calls for the AST and HIR, storing an
extra span which is then put into the `fn_span` field in THIR.
It's the same as `Delimiter`, minus the `Invisible` variant. I'm
generally in favour of using types to make impossible states
unrepresentable, but this one feels very low-value, and the conversions
between the two types are annoying and confusing.
Look at the change in `src/tools/rustfmt/src/expr.rs` for an example:
the old code converted from `MacDelimiter` to `Delimiter` and back
again, for no good reason. This suggests the author was confused about
the types.
`TokenCursor` currently does doc comment desugaring on the fly, if the
`desugar_doc_comment` field is set. This requires also modifying the
token stream on the fly with `replace_prev_and_rewind`.
This commit moves the doc comment desugaring out of `TokenCursor`, by
introducing a new `TokenStream::desugar_doc_comment` method. This
separation of desugaring and iterating makes the code nicer.
Optimize `TokenKind::clone`.
`TokenKind` would impl `Copy` if it weren't for
`TokenKind::Interpolated`. This commit makes `clone` reflect that.
r? `@ghost`
Less `TokenTree` cloning
`TokenTreeCursor` has this comment on it:
```
// FIXME: Many uses of this can be replaced with by-reference iterator to avoid clones.
```
This PR completes that FIXME. It doesn't have much perf effect, but at least we now know that.
r? `@petrochenkov`
This is surprising, but the new comment explains why. It's a logical
conclusion in the drive to avoid `TokenTree` clones.
`TokenTreeCursor` is now only used within `Parser`. It's still needed
due to `replace_prev_and_rewind`.
Tweak spans for self arg, fix borrow suggestion for signature mismatch
1. Adjust a suggestion message that was annoying me
2. Fix#112503 by recording the right spans for the `self` part of the `&self` 0th argument
3. Remove the suggestion for adjusting a trait signature on type mismatch, bc that's gonna probably break all the other impls of the trait even if it fixes its one usage 😅
`#[cfg]`s are frequently used to gate crate content behind cargo
features. This can lead to very confusing errors when features are
missing. For example, `serde` doesn't have the `derive` feature by
default. Therefore, `serde::Serialize` fails to resolve with a generic
error, even though the macro is present in the docs.
This commit adds a list of all stripped item names to metadata. This is
filled during macro expansion and then, through a fed query, persisted
in metadata. The downstream resolver can then access the metadata to
look at possible candidates for mentioning in the errors.
This slightly increases metadata (800k->809k for the feature-heavy
windows crate), but not enough to really matter.
Support #[global_allocator] without the allocator shim
This makes it possible to use liballoc/libstd in combination with `--emit obj` if you use `#[global_allocator]`. This is what rust-for-linux uses right now and systemd may use in the future. Currently they have to depend on the exact implementation of the allocator shim to create one themself as `--emit obj` doesn't create an allocator shim.
Note that currently the allocator shim also defines the oom error handler, which is normally required too. Once `#![feature(default_alloc_error_handler)]` becomes the only option, this can be avoided. In addition when using only fallible allocator methods and either `--cfg no_global_oom_handling` for liballoc (like rust-for-linux) or `--gc-sections` no references to the oom error handler will exist.
To avoid this feature being insta-stable, you will have to define `__rust_no_alloc_shim_is_unstable` to avoid linker errors.
(Labeling this with both T-compiler and T-lang as it originally involved both an implementation detail and had an insta-stable user facing change. As noted above, the `__rust_no_alloc_shim_is_unstable` symbol requirement should prevent unintended dependence on this unstable feature.)
Introduce `DynSend` and `DynSync` auto trait for parallel compiler
part of parallel-rustc #101566
This PR introduces `DynSend / DynSync` trait and `FromDyn / IntoDyn` structure in rustc_data_structure::marker. `FromDyn` can dynamically check data structures for thread safety when switching to parallel environments (such as calling `par_for_each_in`). This happens only when `-Z threads > 1` so it doesn't affect single-threaded mode's compile efficiency.
r? `@cjgillot`
You will need to add the following as replacement for the old __rust_*
definitions when not using the alloc shim.
#[no_mangle]
static __rust_no_alloc_shim_is_unstable: u8 = 0;
This makes it possible to use liballoc/libstd in combination with
`--emit obj` if you use `#[global_allocator]`. Making it work for the
default libstd allocator would require weak functions, which are not
well supported on all systems.
Various changes to name resolution of anon consts
Sorry this PR is kind of all over the place ^^'
Fixes#111012
- Rewrites anon const nameres to all go through `fn resolve_anon_const` explicitly instead of `visit_anon_const` to ensure that we do not accidentally resolve anon consts as if they are allowed to use generics when they aren't. Also means that we dont have bits of code for resolving anon consts that will get out of sync (i.e. legacy const generics and resolving path consts that were parsed as type arguments)
- Renames two of the `LifetimeRibKind`, `AnonConst -> ConcreteAnonConst` and `ConstGeneric -> ConstParamTy`
- Noticed while doing this that under `generic_const_exprs` all lifetimes currently get resolved to errors without any error being emitted which was causing a bunch of tests to pass without their bugs having been fixed, incidentally fixed that in this PR and marked those tests as `// known-bug:`. I'm fine to break those since `generic_const_exprs` is a very unstable incomplete feature and this PR _does_ make generic_const_exprs "less broken" as a whole, also I can't be assed to figure out what the underlying causes of all of them are. This PR reopens#77357#83993
- Changed `generics_of` to stop providing generics and predicates to enum variant discriminant anon consts since those are not allowed to use generic parameters
- Updated the error for non 'static lifetime in const arguments and the error for non 'static lifetime in const param tys to use `derive(Diagnostic)`
I have a vague idea why const-arg-in-const-arg.rs, in-closure.rs and simple.rs have started failing which is unfortunate since these were deliberately made to work, I think lifetime resolution being broken just means this regressed at some point and nobody noticed because the tests were not testing anything :( I'm fine breaking these too for the same reason as the tests for #77357#83993. I couldn't get `// known-bug` to work for these ICEs and just kept getting different stderr between CI and local `--bless` so I just removed them and will create an issue to track re-adding (and fixing) the bugs if this PR lands.
r? `@cjgillot` cc `@compiler-errors`
My type ascription
Oh rip it out
Ah
If you think we live too much then
You can sacrifice diagnostics
Don't mix your garbage
Into my syntax
So many weird hacks keep diagnostics alive
Yet I don't even step outside
So many bad diagnostics keep tyasc alive
Yet tyasc doesn't even bother to survive!
Tweak await span to not contain dot
Fixes a discrepancy between method calls and await expressions where the latter are desugared to have a span that *contains* the dot (i.e. `.await`) but method call identifiers don't contain the dot. This leads to weird suggestions suggestions in borrowck -- see linked issue.
Fixes#110761
This mostly touches a bunch of tests to tighten their `await` span.
