Auto merge of #86031 - ssomers:btree_lazy_iterator, r=Mark-Simulacrum

[rust.git] / src / tools / clippy / clippy_lints / src / unused_unit.rs

diff --git a/src/tools/clippy/clippy_lints/src/unused_unit.rs b/src/tools/clippy/clippy_lints/src/unused_unit.rs
index ce2d0b3ab2f24962599d2ca957d5564641a2e193..9ed5e585f841d9bb8f92ee8b36507d8c386c1bc3 100644 (file)
--- a/src/tools/clippy/clippy_lints/src/unused_unit.rs
+++ b/src/tools/clippy/clippy_lints/src/unused_unit.rs
@@ -10,20 +10,24 @@
 use rustc_span::BytePos;
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for unit (`()`) expressions that can be removed.
+    /// ### What it does
+    /// Checks for unit (`()`) expressions that can be removed.
     ///
-    /// **Why is this bad?** Such expressions add no value, but can make the code
+    /// ### Why is this bad?
+    /// Such expressions add no value, but can make the code
     /// less readable. Depending on formatting they can make a `break` or `return`
     /// statement look like a function call.
     ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
+    /// ### Example
     /// ```rust
     /// fn return_unit() -> () {
     ///     ()
     /// }
     /// ```
+    /// is equivalent to
+    /// ```rust
+    /// fn return_unit() {}
+    /// ```
     pub UNUSED_UNIT,
     style,
     "needless unit expression"
@@ -47,7 +51,9 @@ fn check_block(&mut self, cx: &EarlyContext<'_>, block: &ast::Block) {
         if_chain! {
             if let Some(stmt) = block.stmts.last();
             if let ast::StmtKind::Expr(ref expr) = stmt.kind;
-            if is_unit_expr(expr) && !stmt.span.from_expansion();
+            if is_unit_expr(expr);
+            let ctxt = block.span.ctxt();
+            if stmt.span.ctxt() == ctxt && expr.span.ctxt() == ctxt;
             then {
                 let sp = expr.span;
                 span_lint_and_sugg(