Ok, it's hard to explain what happens, but identifier's hygienic contexts need to be "adjusted" to modules/scopes before they are resolved in them.
To be resolved in all kinds on preludes the identifier needs to be adjusted to the root expansion (aka "no expansion").
Previously this was done for the `macro m() { ::my_crate::foo }` case, but forgotten for all other cases.
Also move macro stability checking closer to other checks performed on obtained resolutions.
Tighten the stability spans as well, it is an error to *refer* to and unstable entity in any way, not only "call" it.
This way we are processing all of them in a single point, rather than separately for each syntax extension kind.
Also, the standard expected/found wording is used.
It either returns the indeterminacy error, or valid (but perhaps dummy) `SyntaxExtension`.
With this change enum `Determinacy` is no longer used in libsyntax and can be moved to resolve.
The regressions in diagnosics are fixed in the next commits.
Create real working and registered (even if dummy) `SyntaxExtension`s for them.
This improves error recovery and allows to avoid all special cases for proc macro stubs (except for the error on use, of course).
The introduced dummy `SyntaxExtension`s can be used for any other inappropriately resolved macros as well.
Avoid the tricky scheme with callbacks and keep the invocation parent data where it logically belongs - in `Definitions`.
This also allows to create `InvocationData` entries in resolve when the data is actually ready, and remove cells and "uninitialized" variants from it.
It was used to choose whether to apply derive markers like `#[rustc_copy_clone_marker]` or not,
but it was called before all the data required for resolution is available, so it could work incorrectly in some corner cases (like user-defined derives name `Copy` or `Eq`).
Delay the decision about markers until the proper resolution results are available instead.
It's internal to resolve and always results in `Res::Err` outside of resolve.
Instead put `DefKind::Fn`s themselves into the macro namespace, it's ok.
Proc macro stubs are items placed into macro namespase for functions that define proc macros.
https://github.com/rust-lang/rust/pull/52383
The rustdoc test is changed because the old test didn't actually reproduce the ICE it was supposed to reproduce.
Fix ICEs when `Self` is used in type aliases
I think it is right just to disallow this at resolution stage rather than let typeck produce a cyclic error. This is in line with previous behaviour. There was probably no need at all for the change that introduced this bug in #57428, so I've simply reversed it.
Fixes#62263, #62364, #62305.
r? @eddyb
Now that procedural macros no longer link transitively to libsyntax,
this shouldn't be needed any more! This commit is an experiment in
removing all dynamic libraries from rustc except for librustc_driver
itself. Let's see how far we can get with that!
Implement another internal lints
cc #49509
This adds ~~two~~ one internal lint~~s~~:
1. LINT_PASS_IMPL_WITHOUT_MACRO: Make sure, that the `{declare,impl}_lint_pass` macro is used to implement lint passes. cc #59669
2. ~~USAGE_OF_TYCTXT_AND_SPAN_ARGS: item 2 on the list in #49509~~
~~With 2. I wasn't sure, if this lint should be applied everywhere. That means a careful review of 0955835 would be great. Also 73fb9b4 allows this lint on some functions. Should I also apply this lint there?~~
TODO (not directly relevant for review):
- [ ] https://github.com/rust-lang/rust/pull/59316#discussion_r280186517 (not sure yet, if this works or how to query for `rustc_private`, since it's not in [`Features`](https://doc.rust-lang.org/nightly/nightly-rustc/syntax/feature_gate/struct.Features.html) 🤔 cc @eddyb)
- [x] https://github.com/rust-lang/rust/pull/61735#discussion_r292389870
- [x] Check explicitly for the `{declare,impl}_lint_pass!` macros
r? @oli-obk
Stabilize `type_alias_enum_variants` in Rust 1.37.0
Stabilize `#![feature(type_alias_enum_variants)]` which allows type-relative resolution with highest priority to `enum` variants in both expression and pattern contexts. For example, you may now write:
```rust
enum Option<T> {
None,
Some(T),
}
type OptAlias<T> = Option<T>;
fn work_on_alias(x: Option<u8>) -> u8 {
match x {
OptAlias::Some(y) => y + 1,
OptAlias::None => 0,
}
}
```
Closes https://github.com/rust-lang/rfcs/issues/2218
Closes https://github.com/rust-lang/rust/issues/52118
r? @petrochenkov
Remove `ast::Guard`
With the introduction of `ast::ExprKind::Let` in https://github.com/rust-lang/rust/pull/60861, the `ast::Guard` structure is now redundant in terms of representing [`if let` guards](https://github.com/rust-lang/rust/issues/51114) in AST since it can be represented by `ExprKind::Let` syntactically. Therefore, we remove `ast::Guard` here.
However, we keep `hir::Guard` because the semantic representation is a different matter and this story is more unclear right now (might involve `goto 'arm` in HIR or something...).
r? @petrochenkov
