From c29b565eba44383d46f86635c43aca0d035d0c63 Mon Sep 17 00:00:00 2001
From: sjwang05 <63834813+sjwang05@users.noreply.github.com>
Date: Wed, 27 Dec 2023 12:48:33 -0800
Subject: [PATCH] Fix ICE when suggesting dereferencing binop operands

---
 .../src/traits/error_reporting/suggestions.rs | 15 ++++++++++++
 tests/ui/binop/binary-op-suggest-deref.rs     |  8 +++++++
 tests/ui/binop/binary-op-suggest-deref.stderr | 23 ++++++++++++++++++-
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 1143b9d33606a..bd4991d34ef01 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -860,6 +860,21 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             && let hir::Node::Expr(lhs) = self.tcx.hir_node(*lhs_hir_id)
             && let hir::Node::Expr(rhs) = self.tcx.hir_node(*rhs_hir_id)
             && let Some(rhs_ty) = typeck_results.expr_ty_opt(rhs)
+            && let trait_pred = predicate.unwrap_or(trait_pred)
+            // Only run this code on binary operators
+            && hir::lang_items::OPERATORS
+                .iter()
+                .filter_map(|&op|
+                    (!matches!(
+                        op,
+                        LangItem::Neg | LangItem::Not | LangItem::Index | LangItem::IndexMut
+                    ))
+                        .then_some(self.tcx.lang_items().get(op))
+                        .flatten()
+                )
+                .any(|op| {
+                    op == trait_pred.skip_binder().trait_ref.def_id
+                })
         {
             // Suggest dereferencing the LHS, RHS, or both terms of a binop if possible
 
diff --git a/tests/ui/binop/binary-op-suggest-deref.rs b/tests/ui/binop/binary-op-suggest-deref.rs
index 57f24a4c28ed4..ae442a0d0b481 100644
--- a/tests/ui/binop/binary-op-suggest-deref.rs
+++ b/tests/ui/binop/binary-op-suggest-deref.rs
@@ -72,4 +72,12 @@ fn baz() {
     //~^ERROR can't compare `str` with `&String` [E0277]
 }
 
+fn qux() {
+    // Issue #119352
+    const FOO: i32 = 42;
+    let _ = FOO & (*"Sized".to_string().into_boxed_str());
+    //~^ ERROR the size for values of type `str` cannot be known at compilation time
+    //~| ERROR no implementation for `i32 & str` [E0277]
+}
+
 fn main() {}
diff --git a/tests/ui/binop/binary-op-suggest-deref.stderr b/tests/ui/binop/binary-op-suggest-deref.stderr
index f5de64e3ab1ae..289a821758795 100644
--- a/tests/ui/binop/binary-op-suggest-deref.stderr
+++ b/tests/ui/binop/binary-op-suggest-deref.stderr
@@ -300,7 +300,28 @@ help: consider dereferencing here
 LL |     _ = partial[..3] == *string_ref;
    |                         +
 
-error: aborting due to 22 previous errors
+error[E0277]: no implementation for `i32 & str`
+  --> $DIR/binary-op-suggest-deref.rs:78:17
+   |
+LL |     let _ = FOO & (*"Sized".to_string().into_boxed_str());
+   |                 ^ no implementation for `i32 & str`
+   |
+   = help: the trait `BitAnd<str>` is not implemented for `i32`
+   = help: the following other types implement trait `BitAnd<Rhs>`:
+             <i32 as BitAnd>
+             <i32 as BitAnd<&i32>>
+             <&'a i32 as BitAnd<i32>>
+             <&i32 as BitAnd<&i32>>
+
+error[E0277]: the size for values of type `str` cannot be known at compilation time
+  --> $DIR/binary-op-suggest-deref.rs:78:17
+   |
+LL |     let _ = FOO & (*"Sized".to_string().into_boxed_str());
+   |                 ^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `str`
+
+error: aborting due to 24 previous errors
 
 Some errors have detailed explanations: E0277, E0308, E0369.
 For more information about an error, try `rustc --explain E0277`.