From 5674be29fa5819cf5d1578f5a53f7a9603a38d90 Mon Sep 17 00:00:00 2001
From: Alan Egerton <eggyal@gmail.com>
Date: Fri, 9 Jan 2026 12:04:23 +0000
Subject: [PATCH] Don't suggest breaking with value from `for` or `while` loops

---
 .../src/fn_ctxt/suggestions.rs                | 22 ++++++----
 ...nt-suggest-break-from-unbreakable-loops.rs | 39 +++++++++++++++++
 ...uggest-break-from-unbreakable-loops.stderr | 42 +++++++++++++++++++
 3 files changed, 96 insertions(+), 7 deletions(-)
 create mode 100644 tests/ui/for-loop-while/dont-suggest-break-from-unbreakable-loops.rs
 create mode 100644 tests/ui/for-loop-while/dont-suggest-break-from-unbreakable-loops.stderr

diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
index d51b052e0d1b..3e4c194147f9 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
@@ -10,8 +10,8 @@
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{
     self as hir, Arm, CoroutineDesugaring, CoroutineKind, CoroutineSource, Expr, ExprKind,
-    GenericBound, HirId, Node, PatExpr, PatExprKind, Path, QPath, Stmt, StmtKind, TyKind,
-    WherePredicateKind, expr_needs_parens, is_range_literal,
+    GenericBound, HirId, LoopSource, Node, PatExpr, PatExprKind, Path, QPath, Stmt, StmtKind,
+    TyKind, WherePredicateKind, expr_needs_parens, is_range_literal,
 };
 use rustc_hir_analysis::hir_ty_lowering::HirTyLowerer;
 use rustc_hir_analysis::suggest_impl_trait;
@@ -1170,15 +1170,23 @@ pub(in super::super) fn suggest_missing_break_or_return_expr(
         }
         let found = self.resolve_vars_if_possible(found);
 
-        let in_loop = self.is_loop(id)
-            || self
-                .tcx
+        let innermost_loop = if self.is_loop(id) {
+            Some(self.tcx.hir_node(id))
+        } else {
+            self.tcx
                 .hir_parent_iter(id)
                 .take_while(|(_, node)| {
                     // look at parents until we find the first body owner
                     node.body_id().is_none()
                 })
-                .any(|(parent_id, _)| self.is_loop(parent_id));
+                .find_map(|(parent_id, node)| self.is_loop(parent_id).then_some(node))
+        };
+        let can_break_with_value = innermost_loop.is_some_and(|node| {
+            matches!(
+                node,
+                Node::Expr(Expr { kind: ExprKind::Loop(_, _, LoopSource::Loop, ..), .. })
+            )
+        });
 
         let in_local_statement = self.is_local_statement(id)
             || self
@@ -1186,7 +1194,7 @@ pub(in super::super) fn suggest_missing_break_or_return_expr(
                 .hir_parent_iter(id)
                 .any(|(parent_id, _)| self.is_local_statement(parent_id));
 
-        if in_loop && in_local_statement {
+        if can_break_with_value && in_local_statement {
             err.multipart_suggestion(
                 "you might have meant to break the loop with this value",
                 vec![
diff --git a/tests/ui/for-loop-while/dont-suggest-break-from-unbreakable-loops.rs b/tests/ui/for-loop-while/dont-suggest-break-from-unbreakable-loops.rs
new file mode 100644
index 000000000000..69b57486138d
--- /dev/null
+++ b/tests/ui/for-loop-while/dont-suggest-break-from-unbreakable-loops.rs
@@ -0,0 +1,39 @@
+//! Don't suggest breaking with value from `for` or `while` loops
+//!
+//! Regression test for https://github.com/rust-lang/rust/issues/150850
+
+fn returns_i32() -> i32 { 0 }
+
+fn suggest_breaking_from_loop() {
+    let _ = loop {
+        returns_i32() //~ ERROR mismatched types
+        //~^ SUGGESTION ;
+        //~| SUGGESTION break
+    };
+}
+
+fn dont_suggest_breaking_from_for() {
+    let _ = for _ in 0.. {
+        returns_i32() //~ ERROR mismatched types
+        //~^ SUGGESTION ;
+    };
+}
+
+fn dont_suggest_breaking_from_while() {
+    let cond = true;
+    let _ = while cond {
+        returns_i32() //~ ERROR mismatched types
+        //~^ SUGGESTION ;
+    };
+}
+
+fn dont_suggest_breaking_from_for_nested_in_loop() {
+    let _ = loop {
+        for _ in 0.. {
+            returns_i32() //~ ERROR mismatched types
+            //~^ SUGGESTION ;
+        }
+    };
+}
+
+fn main() {}
diff --git a/tests/ui/for-loop-while/dont-suggest-break-from-unbreakable-loops.stderr b/tests/ui/for-loop-while/dont-suggest-break-from-unbreakable-loops.stderr
new file mode 100644
index 000000000000..880cc53f9a7c
--- /dev/null
+++ b/tests/ui/for-loop-while/dont-suggest-break-from-unbreakable-loops.stderr
@@ -0,0 +1,42 @@
+error[E0308]: mismatched types
+  --> $DIR/dont-suggest-break-from-unbreakable-loops.rs:9:9
+   |
+LL |         returns_i32()
+   |         ^^^^^^^^^^^^^ expected `()`, found `i32`
+   |
+help: consider using a semicolon here
+   |
+LL |         returns_i32();
+   |                      +
+help: you might have meant to break the loop with this value
+   |
+LL |         break returns_i32();
+   |         +++++              +
+
+error[E0308]: mismatched types
+  --> $DIR/dont-suggest-break-from-unbreakable-loops.rs:17:9
+   |
+LL |         returns_i32()
+   |         ^^^^^^^^^^^^^- help: consider using a semicolon here: `;`
+   |         |
+   |         expected `()`, found `i32`
+
+error[E0308]: mismatched types
+  --> $DIR/dont-suggest-break-from-unbreakable-loops.rs:25:9
+   |
+LL |         returns_i32()
+   |         ^^^^^^^^^^^^^- help: consider using a semicolon here: `;`
+   |         |
+   |         expected `()`, found `i32`
+
+error[E0308]: mismatched types
+  --> $DIR/dont-suggest-break-from-unbreakable-loops.rs:33:13
+   |
+LL |             returns_i32()
+   |             ^^^^^^^^^^^^^- help: consider using a semicolon here: `;`
+   |             |
+   |             expected `()`, found `i32`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0308`.