From c58b7c9c81cf150bf307ca13375f12fb1c8f6420 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Thu, 23 May 2024 19:48:54 -0400
Subject: [PATCH] Don't skip inner const when looking for body for suggestion

---
 compiler/rustc_hir_typeck/src/coercion.rs       |  9 +++------
 .../return/dont-suggest-through-inner-const.rs  |  9 +++++++++
 .../dont-suggest-through-inner-const.stderr     | 17 +++++++++++++++++
 3 files changed, 29 insertions(+), 6 deletions(-)
 create mode 100644 tests/ui/return/dont-suggest-through-inner-const.rs
 create mode 100644 tests/ui/return/dont-suggest-through-inner-const.stderr

diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index 11a1c65b74956..ebdc558282a91 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -1871,11 +1871,8 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
         // If this is due to a block, then maybe we forgot a `return`/`break`.
         if due_to_block
             && let Some(expr) = expression
-            && let Some((parent_fn_decl, parent_id)) = fcx
-                .tcx
-                .hir()
-                .parent_iter(block_or_return_id)
-                .find_map(|(_, node)| Some((node.fn_decl()?, node.associated_body()?.0)))
+            && let Some(parent_fn_decl) =
+                fcx.tcx.hir().fn_decl_by_hir_id(fcx.tcx.local_def_id_to_hir_id(fcx.body_id))
         {
             fcx.suggest_missing_break_or_return_expr(
                 &mut err,
@@ -1884,7 +1881,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                 expected,
                 found,
                 block_or_return_id,
-                parent_id,
+                fcx.body_id,
             );
         }
 
diff --git a/tests/ui/return/dont-suggest-through-inner-const.rs b/tests/ui/return/dont-suggest-through-inner-const.rs
new file mode 100644
index 0000000000000..b2347dedd52d1
--- /dev/null
+++ b/tests/ui/return/dont-suggest-through-inner-const.rs
@@ -0,0 +1,9 @@
+const fn f() -> usize {
+    //~^ ERROR mismatched types
+    const FIELD: usize = loop {
+        0
+        //~^ ERROR mismatched types
+    };
+}
+
+fn main() {}
diff --git a/tests/ui/return/dont-suggest-through-inner-const.stderr b/tests/ui/return/dont-suggest-through-inner-const.stderr
new file mode 100644
index 0000000000000..6aeee74b0adf9
--- /dev/null
+++ b/tests/ui/return/dont-suggest-through-inner-const.stderr
@@ -0,0 +1,17 @@
+error[E0308]: mismatched types
+  --> $DIR/dont-suggest-through-inner-const.rs:4:9
+   |
+LL |         0
+   |         ^ expected `()`, found integer
+
+error[E0308]: mismatched types
+  --> $DIR/dont-suggest-through-inner-const.rs:1:17
+   |
+LL | const fn f() -> usize {
+   |          -      ^^^^^ expected `usize`, found `()`
+   |          |
+   |          implicitly returns `()` as its body has no tail or `return` expression
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.