Parse associated return type bounds
This PR implements parser support for associated return type bounds: `T: Foo<bar(): Send>`. This PR does not implement associated return types (`T::bar(): Send`) because it's not implemented even in rustc, and also removes `(..)`-style return type notation because it has been removed in rust-lang/rust#110203 (effectively reverting #14465).
I don't plan to proactively follow this unstable feature unless an RFC is accepted and my main motivation here is to remove no-longer-valid syntax `(..)` from our parser, nevertheless adding minimal parser support so anyone interested (as can be seen in #14465) can experiment it without rust-analyzer's syntax errors.
Expand more single ident macro calls upon item collection
Addresses https://github.com/rust-lang/rust-analyzer/pull/14781#issuecomment-1546201022
I believe this (almost) brings the number of unresolved names back to pre-#14781:
|r-a version|`analysis-stats compiler/rustc` (rust-lang/rust@69fef92ab2) |
|---|---|
|pre-#14781 (b069eb720bec6ce40ab224f57d271687b19b5a07) | exprs: 2747778, ??ty: 122236 (4%), ?ty: 107826 (3%), !ty: 728 |
| #14781 (a7944a93a1520b96f079bbbcd841d6aec9e4ba5d) | exprs: 2713080, ??ty: 139651 (5%), ?ty: 114444 (4%), !ty: 730 |
| with this fix | exprs: 2747871, ??ty: 122237 (4%), ?ty: 108171 (3%), !ty: 676 |
(I haven't investigated on the increase in some numbers but hopefully not too much of a problem)
This is only a temporary solution. The core problem is that we haven't fully implemented the textual scope of legacy macros. For example, we *have been* failing to resolve `foo` in the following snippet, even before #14781 or after this patch. As noted in a FIXME, we need a way to resolve names in textual scope without eager expansion during item collection.
```rust
//- /main.rs crate:main deps:lib
lib::mk_foo!();
const A: i32 = foo!();
//^^^^^^ unresolved-macro-call
//- /lib.rs crate:lib
#[macro_export]
macro_rules! mk_foo {
() => {
macro_rules! foo { () => { 42 } }
}
}
```
We've already removed non-sysroot proc macro server, which effectively
removed support for Rust <1.64.0, so this removal of fallback path
shouldn't be problem at this point.
fix: Fix pat fragment handling in 2021 edition
Fixes https://github.com/rust-lang/rust-analyzer/issues/9055
The fix isn't that great, but we are kind of forced to do it the quick and hacky way right now since std has changed the `matches` macro to make use of this now. And for a proper fix we need to track hygiene for identifiers which is a long way off anyways
fix: Resolve `$crate` in derive paths
Paths in derive meta item list may contain any kind of paths, including those that start with `$crate` generated by macros. We need to take hygiene into account when we lower paths in the list.
This issue was identified while investigating #14607, though this patch doesn't fix the broken trait resolution.
internal: Report macro definition errors on the definition
We still report them on the call site as well for the time being, and the diagnostic doesn't know where the error in the definition comes from, but that can be done later on
