Rollup merge of #87385 - Aaron1011:final-enable-semi, r=petrochenkov

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

diff --git a/clippy_lints/src/unused_unit.rs b/clippy_lints/src/unused_unit.rs
index f61fd2ecd735d915964c5b3ce80bfaa6da56e29e..9ed5e585f841d9bb8f92ee8b36507d8c386c1bc3 100644 (file)
--- a/clippy_lints/src/unused_unit.rs
+++ b/clippy_lints/src/unused_unit.rs
@@ -1,3 +1,5 @@
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::position_before_rarrow;
 use if_chain::if_chain;
 use rustc_ast::ast;
 use rustc_ast::visit::FnKind;
@@ -7,23 +9,25 @@
 use rustc_span::source_map::Span;
 use rustc_span::BytePos;
 
-use crate::utils::{position_before_rarrow, span_lint_and_sugg};
-
 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"
@@ -45,9 +49,11 @@ fn check_fn(&mut self, cx: &EarlyContext<'_>, kind: FnKind<'_>, span: Span, _: a
 
     fn check_block(&mut self, cx: &EarlyContext<'_>, block: &ast::Block) {
         if_chain! {
-            if let Some(ref stmt) = block.stmts.last();
+            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(
@@ -120,7 +126,7 @@ fn is_unit_expr(expr: &ast::Expr) -> bool {
 
 fn lint_unneeded_unit_return(cx: &EarlyContext<'_>, ty: &ast::Ty, span: Span) {
     let (ret_span, appl) = if let Ok(fn_source) = cx.sess().source_map().span_to_snippet(span.with_hi(ty.span.hi())) {
-        position_before_rarrow(fn_source).map_or((ty.span, Applicability::MaybeIncorrect), |rpos| {
+        position_before_rarrow(&fn_source).map_or((ty.span, Applicability::MaybeIncorrect), |rpos| {
             (
                 #[allow(clippy::cast_possible_truncation)]
                 ty.span.with_lo(BytePos(span.lo().0 + rpos as u32)),