Auto merge of #9539 - Jarcho:ice_9445, r=flip1995

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

diff --git a/clippy_lints/src/redundant_closure_call.rs b/clippy_lints/src/redundant_closure_call.rs
index a79b2fe76e2d57f100996e94239f5fbb1b1a96f1..74eea6de4bbeff43d30c92d83a8553c73d6cfab9 100644 (file)
--- a/clippy_lints/src/redundant_closure_call.rs
+++ b/clippy_lints/src/redundant_closure_call.rs
@@ -1,5 +1,5 @@
 use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
-use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::sugg::Sugg;
 use if_chain::if_chain;
 use rustc_ast::ast;
 use rustc_ast::visit as ast_visit;
@@ -9,7 +9,7 @@
 use rustc_hir::intravisit as hir_visit;
 use rustc_hir::intravisit::Visitor as HirVisitor;
 use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
-use rustc_middle::hir::map::Map;
+use rustc_middle::hir::nested_filter;
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
@@ -23,13 +23,15 @@
     /// complexity.
     ///
     /// ### Example
-    /// ```rust,ignore
-    /// // Bad
-    /// let a = (|| 42)()
+    /// ```rust
+    /// let a = (|| 42)();
+    /// ```
     ///
-    /// // Good
-    /// let a = 42
+    /// Use instead:
+    /// ```rust
+    /// let a = 42;
     /// ```
+    #[clippy::version = "pre 1.29.0"]
     pub REDUNDANT_CLOSURE_CALL,
     complexity,
     "throwaway closures called in the expression they are defined"
@@ -51,9 +53,7 @@ fn new() -> Self {
 
 impl<'ast> ast_visit::Visitor<'ast> for ReturnVisitor {
     fn visit_expr(&mut self, ex: &'ast ast::Expr) {
-        if let ast::ExprKind::Ret(_) = ex.kind {
-            self.found_return = true;
-        } else if let ast::ExprKind::Try(_) = ex.kind {
+        if let ast::ExprKind::Ret(_) | ast::ExprKind::Try(_) = ex.kind {
             self.found_return = true;
         }
 
@@ -69,7 +69,7 @@ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
         if_chain! {
             if let ast::ExprKind::Call(ref paren, _) = expr.kind;
             if let ast::ExprKind::Paren(ref closure) = paren.kind;
-            if let ast::ExprKind::Closure(_, _, _, ref decl, ref block, _) = closure.kind;
+            if let ast::ExprKind::Closure(_, _, ref r#async, _, ref decl, ref block, _) = closure.kind;
             then {
                 let mut visitor = ReturnVisitor::new();
                 visitor.visit_expr(block);
@@ -81,10 +81,19 @@ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
                         "try not to call a closure in the expression where it is declared",
                         |diag| {
                             if decl.inputs.is_empty() {
-                                let mut app = Applicability::MachineApplicable;
-                                let hint =
-                                    snippet_with_applicability(cx, block.span, "..", &mut app).into_owned();
-                                diag.span_suggestion(expr.span, "try doing something like", hint, app);
+                                let app = Applicability::MachineApplicable;
+                                let mut hint = Sugg::ast(cx, block, "..");
+
+                                if r#async.is_async() {
+                                    // `async x` is a syntax error, so it becomes `async { x }`
+                                    if !matches!(block.kind, ast::ExprKind::Block(_, _)) {
+                                        hint = hint.blockify();
+                                    }
+
+                                    hint = hint.asyncify();
+                                }
+
+                                diag.span_suggestion(expr.span, "try doing something like", hint.to_string(), app);
                             }
                         },
                     );
@@ -107,7 +116,7 @@ struct ClosureUsageCount<'a, 'tcx> {
                 count: usize,
             }
             impl<'a, 'tcx> hir_visit::Visitor<'tcx> for ClosureUsageCount<'a, 'tcx> {
-                type Map = Map<'tcx>;
+                type NestedFilter = nested_filter::OnlyBodies;
 
                 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
                     if_chain! {
@@ -122,8 +131,8 @@ fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
                     hir_visit::walk_expr(self, expr);
                 }
 
-                fn nested_visit_map(&mut self) -> hir_visit::NestedVisitorMap<Self::Map> {
-                    hir_visit::NestedVisitorMap::OnlyBodies(self.cx.tcx.hir())
+                fn nested_visit_map(&mut self) -> Self::Map {
+                    self.cx.tcx.hir()
                 }
             }
             let mut closure_usage_count = ClosureUsageCount { cx, path, count: 0 };
@@ -135,7 +144,7 @@ fn nested_visit_map(&mut self) -> hir_visit::NestedVisitorMap<Self::Map> {
             if_chain! {
                 if let hir::StmtKind::Local(local) = w[0].kind;
                 if let Option::Some(t) = local.init;
-                if let hir::ExprKind::Closure(..) = t.kind;
+                if let hir::ExprKind::Closure { .. } = t.kind;
                 if let hir::PatKind::Binding(_, _, ident, _) = local.pat.kind;
                 if let hir::StmtKind::Semi(second) = w[1].kind;
                 if let hir::ExprKind::Assign(_, call, _) = second.kind;