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Rewrite a loop as tail recursion

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dianne 2025-12-31 08:51:49 -08:00
parent 15f7c553a3
commit 6b60e81e8c
1 changed files with 14 additions and 20 deletions
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34
compiler/rustc_hir_analysis/src/check/region.rs
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@ -701,31 +701,25 @@ fn resolve_local<'tcx>(
/// Note: ET is intended to match "rvalues or places based on rvalues".
fn record_subexpr_extended_temp_scopes(
scope_tree: &mut ScopeTree,
mut expr: &hir::Expr<'_>,
expr: &hir::Expr<'_>,
lifetime: Option<Scope>,
) {
debug!(?expr, ?lifetime);
// Note: give all the expressions matching `ET` with the
// extended temporary lifetime, not just the innermost rvalue,
// because in MIR building if we must compile e.g., `*rvalue()`
// into a temporary, we request the temporary scope of the
// outer expression.
loop {
// Note: give all the expressions matching `ET` with the
// extended temporary lifetime, not just the innermost rvalue,
// because in MIR building if we must compile e.g., `*rvalue()`
// into a temporary, we request the temporary scope of the
// outer expression.
scope_tree.record_extended_temp_scope(expr.hir_id.local_id, lifetime);
scope_tree.record_extended_temp_scope(expr.hir_id.local_id, lifetime);
match expr.kind {
hir::ExprKind::AddrOf(_, _, subexpr)
| hir::ExprKind::Unary(hir::UnOp::Deref, subexpr)
| hir::ExprKind::Field(subexpr, _)
| hir::ExprKind::Index(subexpr, _, _) => {
expr = subexpr;
}
_ => {
return;
}
match expr.kind {
hir::ExprKind::AddrOf(_, _, subexpr)
| hir::ExprKind::Unary(hir::UnOp::Deref, subexpr)
| hir::ExprKind::Field(subexpr, _)
| hir::ExprKind::Index(subexpr, _, _) => {
record_subexpr_extended_temp_scopes(scope_tree, subexpr, lifetime);
}
_ => {}
}
}