Add regression test for #11709

Author: profetia

clippy_lints/src/undocumented_unsafe_blocks.rs

@@ -339,6 +339,33 @@ fn is_unsafe_from_proc_macro(cx: &LateContext<'_>, span: Span) -> bool {
         .is_none_or(|src| !src.starts_with("unsafe"))
 }
 
+fn find_unsafe_block_parent_in_expr<'tcx>(
+    cx: &LateContext<'tcx>,
+    expr: &'tcx hir::Expr<'tcx>,
+) -> Option<(Span, HirId)> {
+    match cx.tcx.parent_hir_node(expr.hir_id) {
+        Node::LetStmt(hir::LetStmt { span, hir_id, .. })
+        | Node::Expr(hir::Expr {
+            hir_id,
+            kind: hir::ExprKind::Assign(_, _, span),
+            ..
+        }) => Some((*span, *hir_id)),
+        Node::Expr(expr) => find_unsafe_block_parent_in_expr(cx, expr),
+        node if let Some((span, hir_id)) = span_and_hid_of_item_alike_node(&node)
+            && is_const_or_static(&node) =>
+        {
+            Some((span, hir_id))
+        },
+
+        _ => {
+            if is_branchy(expr) {
+                return None;
+            }
+            Some((expr.span, expr.hir_id))
+        },
+    }
+}
+
 // Checks if any parent {expression, statement, block, local, const, static}
 // has a safety comment
 fn block_parents_have_safety_comment(
@@ -348,26 +375,7 @@ fn block_parents_have_safety_comment(
     id: HirId,
 ) -> bool {
     let (span, hir_id) = match cx.tcx.parent_hir_node(id) {
-        Node::Expr(expr) => match cx.tcx.parent_hir_node(expr.hir_id) {
-            Node::LetStmt(hir::LetStmt { span, hir_id, .. })
-            | Node::Expr(hir::Expr {
-                hir_id,
-                kind: hir::ExprKind::Assign(_, _, span),
-                ..
-            }) => (*span, *hir_id),
-            node if let Some((span, hir_id)) = span_and_hid_of_item_alike_node(&node)
-                && is_const_or_static(&node) =>
-            {
-                (span, hir_id)
-            },
-
-            _ => {
-                if is_branchy(expr) {
-                    return false;
-                }
-                (expr.span, expr.hir_id)
-            },
-        },
+        Node::Expr(expr) if let Some(inner) = find_unsafe_block_parent_in_expr(cx, expr) => inner,
         Node::Stmt(hir::Stmt {
             kind:
                 hir::StmtKind::Let(hir::LetStmt { span, hir_id, .. })
@@ -433,12 +441,12 @@ fn block_has_safety_comment(cx: &LateContext<'_>, span: Span) -> bool {
 }
 
 fn include_attrs_in_span(cx: &LateContext<'_>, hir_id: HirId, span: Span) -> Span {
-    span.to(cx
-        .tcx
-        .hir()
-        .attrs(hir_id)
-        .iter()
-        .fold(span, |acc, attr| acc.to(attr.span)))
+    span.to(cx.tcx.hir().attrs(hir_id).iter().fold(span, |acc, attr| {
+        if matches!(attr.kind, hir::AttrKind::DocComment(_, _)) {
+            return acc;
+        }
+        acc.to(attr.span)
+    }))
 }
 
 enum HasSafetyComment {

tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.disabled.stderr

@@ -430,5 +430,13 @@ LL |         unsafe { here_is_another_variable_with_long_name };
    |
    = help: consider adding a safety comment on the preceding line
 
-error: aborting due to 50 previous errors
+error: unsafe block missing a safety comment
+  --> tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs:702:9
+   |
+LL |         unsafe { Date::__from_ordinal_date_unchecked(1970, 1) }.into_julian_day_just_make_this_line_longer();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider adding a safety comment on the preceding line
+
+error: aborting due to 51 previous errors
 

tests/ui-toml/undocumented_unsafe_blocks/undocumented_unsafe_blocks.rs

@@ -674,4 +674,33 @@ fn issue_13024() {
     //~[disabled]^ undocumented_unsafe_blocks
 }
 
+// https://docs.rs/time/0.3.36/src/time/offset_date_time.rs.html#35
+mod issue_11709_regression {
+    use std::num::NonZeroI32;
+
+    struct Date {
+        value: NonZeroI32,
+    }
+
+    impl Date {
+        const unsafe fn __from_ordinal_date_unchecked(year: i32, ordinal: u16) -> Self {
+            Self {
+                // Safety: The caller must guarantee that `ordinal` is not zero.
+                value: unsafe { NonZeroI32::new_unchecked((year << 9) | ordinal as i32) },
+            }
+        }
+
+        const fn into_julian_day_just_make_this_line_longer(self) -> i32 {
+            42
+        }
+    }
+
+    /// The Julian day of the Unix epoch.
+    // SAFETY: fail ONLY if `accept-comment-above-attribute = false`
+    #[allow(unsafe_code)]
+    const UNIX_EPOCH_JULIAN_DAY: i32 =
+        unsafe { Date::__from_ordinal_date_unchecked(1970, 1) }.into_julian_day_just_make_this_line_longer();
+    //~[disabled]^ undocumented_unsafe_blocks
+}
+
 fn main() {}