Fix panic with closure inside array len

crates/hir-ty/src/consteval.rs

@@ -3,7 +3,8 @@
 use base_db::CrateId;
 use chalk_ir::{cast::Cast, BoundVar, DebruijnIndex};
 use hir_def::{
- hir::Expr,
+ body::Body,
+ hir::{Expr, ExprId},
  path::Path,
  resolver::{Resolver, ValueNs},
  type_ref::LiteralConstRef,
@@ -280,21 +281,32 @@ pub(crate) fn const_eval_discriminant_variant(
 // get an `InferenceResult` instead of an `InferenceContext`. And we should remove `ctx.clone().resolve_all()` here
 // and make this function private. See the fixme comment on `InferenceContext::resolve_all`.
 pub(crate) fn eval_to_const(
- expr: Idx<Expr>,
+ expr: ExprId,
  mode: ParamLoweringMode,
  ctx: &mut InferenceContext<'_>,
  args: impl FnOnce() -> Generics,
  debruijn: DebruijnIndex,
 ) -> Const {
  let db = ctx.db;
  let infer = ctx.clone().resolve_all();
+ fn has_closure(body: &Body, expr: ExprId) -> bool {
+ if matches!(body[expr], Expr::Closure { .. }) {
+ return true;
+ }
+ let mut r = false;
+ body[expr].walk_child_exprs(|idx| r |= has_closure(body, idx));
+ r
+ }
+ if has_closure(&ctx.body, expr) {
+ // Type checking clousres need an isolated body (See the above FIXME). Bail out early to prevent panic.
+ return unknown_const(infer[expr].clone());
+ }
  if let Expr::Path(p) = &ctx.body.exprs[expr] {
  let resolver = &ctx.resolver;
  if let Some(c) = path_to_const(db, resolver, p, mode, args, debruijn, infer[expr].clone()) {
  return c;
  }
  }
- let infer = ctx.clone().resolve_all();
  if let Ok(mir_body) = lower_to_mir(ctx.db, ctx.owner, &ctx.body, &infer, expr) {
  if let Ok(result) = interpret_mir(db, Arc::new(mir_body), true, None).0 {
  return result;

crates/hir-ty/src/tests/regression.rs

@@ -2000,3 +2000,15 @@ fn test() {
 "#,
  );
 }
+
+#[test]
+fn rustc_test_issue_52437() {
+ check_types(
+ r#"
+ fn main() {
+ let x = [(); &(&'static: loop { |x| {}; }) as *const _ as usize]
+ //^ [(); _]
+ }
+ "#,
+ );
+}