large_futures: Delay macro check

Author: Jarcho

clippy_lints/src/large_futures.rs

@@ -54,29 +54,26 @@ impl_lint_pass!(LargeFuture => [LARGE_FUTURES]);
 
 impl<'tcx> LateLintPass<'tcx> for LargeFuture {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
-        if matches!(expr.span.ctxt().outer_expn_data().kind, rustc_span::ExpnKind::Macro(..)) {
-            return;
-        }
-        if let ExprKind::Match(expr, _, MatchSource::AwaitDesugar) = expr.kind {
-            if let ExprKind::Call(func, [expr, ..]) = expr.kind
-                && let ExprKind::Path(QPath::LangItem(LangItem::IntoFutureIntoFuture, ..)) = func.kind
-                && let ty = cx.typeck_results().expr_ty(expr)
-                && let Some(future_trait_def_id) = cx.tcx.lang_items().future_trait()
-                && implements_trait(cx, ty, future_trait_def_id, &[])
-                && let Ok(layout) = cx.tcx.layout_of(cx.param_env.and(ty))
-                && let size = layout.layout.size()
-                && size >= Size::from_bytes(self.future_size_threshold)
-            {
-                span_lint_and_sugg(
-                    cx,
-                    LARGE_FUTURES,
-                    expr.span,
-                    format!("large future with a size of {} bytes", size.bytes()),
-                    "consider `Box::pin` on it",
-                    format!("Box::pin({})", snippet(cx, expr.span, "..")),
-                    Applicability::Unspecified,
-                );
-            }
+        if let ExprKind::Match(scrutinee, _, MatchSource::AwaitDesugar) = expr.kind
+            && let ExprKind::Call(func, [arg, ..]) = scrutinee.kind
+            && let ExprKind::Path(QPath::LangItem(LangItem::IntoFutureIntoFuture, ..)) = func.kind
+            && !expr.span.from_expansion()
+            && let ty = cx.typeck_results().expr_ty(arg)
+            && let Some(future_trait_def_id) = cx.tcx.lang_items().future_trait()
+            && implements_trait(cx, ty, future_trait_def_id, &[])
+            && let Ok(layout) = cx.tcx.layout_of(cx.param_env.and(ty))
+            && let size = layout.layout.size()
+            && size >= Size::from_bytes(self.future_size_threshold)
+        {
+            span_lint_and_sugg(
+                cx,
+                LARGE_FUTURES,
+                arg.span,
+                format!("large future with a size of {} bytes", size.bytes()),
+                "consider `Box::pin` on it",
+                format!("Box::pin({})", snippet(cx, arg.span, "..")),
+                Applicability::Unspecified,
+            );
         }
     }
 }