Fix name resolution in lexical scopes
Currently, `resolve_item_in_lexical_scope` does not check the "ribs" (type parameters and local variables). This can allow items that should be shadowed by type parameters to be named.
For example,
```rust
struct T { i: i32 }
fn f<T>() {
let t = T { i: 0 }; // This use of `T` resolves to the struct, not the type parameter
}
mod Foo {
pub fn f() {}
}
fn g<Foo>() {
Foo::f(); // This use of `Foo` resolves to the module, not the type parameter
}
```
This PR changes `resolve_item_in_lexical_scope` so that it fails when the item is shadowed by a rib (fixes#32120).
This is a [breaking-change], but it looks unlikely to cause breakage in practice.
r? @nikomatsakis
Forbid glob-importing from a type alias
This PR forbids glob-importing from a type alias or trait (fixes#30560):
```rust
type Alias = ();
use Alias::*; // This is currently allowed but shouldn't be
```
This is a [breaking-change]. Since the disallowed glob imports don't actually import anything, any breakage can be fixed by removing the offending glob import.
r? @alexcrichton
Now that #31461 is merged, a failing resolution can never become indeterminate or succeed, so we no longer have to keep trying to resolve failing import directives.
r? @nrc
This PR fixes two unrelated diagnostics bugs in resolve.
First, it reports privacy errors for an import only after the import resolution is determined, fixing #31402.
Second, it expands the per-module map from block ids to anonymous modules so that it also maps module declarations ids to modules, and it uses this map to in `with_scope` to fix#31644.
r? @nrc
Refactor away resolve_name_in_module in resolve_imports.rs
Rewrite and improve the core name resolution procedure in NameResolution::result and Module::resolve_name
Refactor the duplicate checking code into NameResolution::try_define
This PR refactors away `Module`'s `external_module_children` and instead puts `extern crate` declarations in `children` like other items, simplifying duplicate checking and name resolution.
This PR also allows values to share a name with extern crates, which are only defined in the type namespace. Other than that, it is a pure refactoring.
r? @nrc
