Don't trigger needless_return lint in macros

Author: flip1995

clippy_lints/src/returns.rs

@@ -217,6 +217,9 @@ fn check_final_expr<'tcx>(
 }
 
 fn emit_return_lint(cx: &LateContext<'_>, ret_span: Span, inner_span: Option<Span>, replacement: RetReplacement) {
+    if ret_span.from_expansion() {
+        return;
+    }
     match inner_span {
         Some(inner_span) => {
             if in_external_macro(cx.tcx.sess, inner_span) || inner_span.from_expansion() {

tests/ui/needless_return.fixed

@@ -86,6 +86,21 @@ fn borrows_but_not_last(value: bool) -> String {
     }
 }
 
+macro_rules! needed_return {
+    ($e:expr) => {
+        if $e > 3 {
+            return;
+        }
+    };
+}
+
+fn test_return_in_macro() {
+    // This will return and the macro below won't be executed. Removing the `return` from the macro
+    // will change semantics.
+    needed_return!(10);
+    needed_return!(0);
+}
+
 fn main() {
     let _ = test_end_of_fn();
     let _ = test_no_semicolon();

tests/ui/needless_return.rs

@@ -86,6 +86,21 @@ fn borrows_but_not_last(value: bool) -> String {
     }
 }
 
+macro_rules! needed_return {
+    ($e:expr) => {
+        if $e > 3 {
+            return;
+        }
+    };
+}
+
+fn test_return_in_macro() {
+    // This will return and the macro below won't be executed. Removing the `return` from the macro
+    // will change semantics.
+    needed_return!(10);
+    needed_return!(0);
+}
+
 fn main() {
     let _ = test_end_of_fn();
     let _ = test_no_semicolon();