bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Rollup merge of #125293 - dingxiangfei2009:tail-expr-temp-lifetime, r=estebank,davidtwco

Browse source 
Place tail expression behind terminating scope

This PR implements #123739 so that we can do further experiments in nightly.

A little rewrite has been applied to `for await` lowering. It was previously `unsafe { Pin::unchecked_new(into_async_iter(..)) }`. Under the edition 2024 rule, however, `into_async_iter` gets dropped at the end of the `unsafe` block. This presumably the first Edition 2024 migration rule goes by hoisting `into_async_iter(..)` into `match` one level above, so it now looks like the following.
```rust
match into_async_iter($iter_expr) {
  ref mut iter => match unsafe { Pin::unchecked_new(iter) } {
    ...
  }
}
```
This commit is contained in:
许杰友 Jieyou Xu (Joe) 2024-06-19 01:51:38 +01:00 • committed by GitHub
commit 8eb2e5f4c8
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
19 changed files with 377 additions and 24 deletions
Download patch file Download diff file Expand all files Collapse all files

10
compiler/rustc_hir_analysis/src/check/region.rs
View file

@ -6,7 +6,6 @@
//!
//! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/borrow_check.html
use rustc_ast::visit::visit_opt;
use rustc_data_structures::fx::FxHashSet;
use rustc_hir as hir;
use rustc_hir::def_id::DefId;
@ -168,7 +167,14 @@ fn resolve_block<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, blk: &'tcx h
hir::StmtKind::Expr(..) | hir::StmtKind::Semi(..) => visitor.visit_stmt(statement),
}
}
visit_opt!(visitor, visit_expr, &blk.expr);
if let Some(tail_expr) = blk.expr {
if visitor.tcx.features().shorter_tail_lifetimes
&& blk.span.edition().at_least_rust_2024()
{
visitor.terminating_scopes.insert(tail_expr.hir_id.local_id);
}
visitor.visit_expr(tail_expr);
}
}
visitor.cx = prev_cx;