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-rw-r--r--compiler/rustc_lint/src/types.rs22
1 files changed, 20 insertions, 2 deletions
diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
index 0c58c804353..c0371b1f606 100644
--- a/compiler/rustc_lint/src/types.rs
+++ b/compiler/rustc_lint/src/types.rs
@@ -4,7 +4,7 @@ use std::ops::ControlFlow;
 use rustc_abi::{BackendRepr, ExternAbi, TagEncoding, Variants, WrappingRange};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::DiagMessage;
-use rustc_hir::{Expr, ExprKind};
+use rustc_hir::{Expr, ExprKind, LangItem};
 use rustc_middle::bug;
 use rustc_middle::ty::layout::{LayoutOf, SizeSkeleton};
 use rustc_middle::ty::{
@@ -444,7 +444,25 @@ fn lint_fn_pointer<'tcx>(
     let (l_ty, l_ty_refs) = peel_refs(l_ty);
     let (r_ty, r_ty_refs) = peel_refs(r_ty);
 
-    if !l_ty.is_fn() || !r_ty.is_fn() {
+    if l_ty.is_fn() && r_ty.is_fn() {
+        // both operands are function pointers, fallthrough
+    } else if let ty::Adt(l_def, l_args) = l_ty.kind()
+        && let ty::Adt(r_def, r_args) = r_ty.kind()
+        && cx.tcx.is_lang_item(l_def.did(), LangItem::Option)
+        && cx.tcx.is_lang_item(r_def.did(), LangItem::Option)
+        && let Some(l_some_arg) = l_args.get(0)
+        && let Some(r_some_arg) = r_args.get(0)
+        && l_some_arg.expect_ty().is_fn()
+        && r_some_arg.expect_ty().is_fn()
+    {
+        // both operands are `Option<{function ptr}>`
+        return cx.emit_span_lint(
+            UNPREDICTABLE_FUNCTION_POINTER_COMPARISONS,
+            e.span,
+            UnpredictableFunctionPointerComparisons::Warn,
+        );
+    } else {
+        // types are not function pointers, nothing to do
         return;
     }