Merge #9097

9097: feat: Implement per-edition preludes r=jonas-schievink a=jonas-schievink

Part of https://github.com/rust-analyzer/rust-analyzer/issues/9056

Our previous implementation was incorrect (presumably because of the misleading comment in libstd [here](https://github.com/rust-lang/rust/blob/a7890c7952bdc9445eb6c63dc671fa7a1ab0260d/library/std/src/lib.rs#L339-L343)). `#[prelude_import]` does not define the prelude, it can only override the implicit prelude for the current crate.

This PR fixes that, which also makes the prelude imports in `rustc_span` work. Closes https://github.com/rust-analyzer/rust-analyzer/issues/8815.

bors r+

Co-authored-by: Jonas Schievink <[email protected]>

1 files changed, 4 insertions, 0 deletions

diff --git a/crates/hir_expand/src/name.rs b/crates/hir_expand/src/name.rs
index b07fbf8b3..abc6753bf 100644
--- a/crates/hir_expand/src/name.rs
+++ b/crates/hir_expand/src/name.rs
@@ -176,6 +176,10 @@ pub mod known {
         result,
         boxed,
         option,
+        prelude,
+        rust_2015,
+        rust_2018,
+        rust_2021,
         // Components of known path (type name)
         Iterator,
         IntoIterator,