zombie_processes: do not complain about early early returns

clippy_lints/src/zombie_processes.rs

@@ -5,7 +5,7 @@ use rustc_ast::Mutability;
 use rustc_ast::visit::visit_opt;
 use rustc_errors::Applicability;
 use rustc_hir::def_id::LocalDefId;
-use rustc_hir::intravisit::{Visitor, walk_block, walk_expr, walk_local};
+use rustc_hir::intravisit::{Visitor, walk_block, walk_expr};
 use rustc_hir::{Expr, ExprKind, HirId, LetStmt, Node, PatKind, Stmt, StmtKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::nested_filter;
@@ -69,8 +69,9 @@ impl<'tcx> LateLintPass<'tcx> for ZombieProcesses {
                     let mut vis = WaitFinder {
                         cx,
                         local_id,
+                        create_id: expr.hir_id,
                         body_id: cx.tcx.hir_enclosing_body_owner(expr.hir_id),
-                        state: VisitorState::WalkUpToLocal,
+                        state: VisitorState::WalkUpToCreate,
                         early_return: None,
                         missing_wait_branch: None,
                     };
@@ -131,6 +132,7 @@ struct MaybeWait(Span);
 struct WaitFinder<'a, 'tcx> {
     cx: &'a LateContext<'tcx>,
     local_id: HirId,
+    create_id: HirId,
     body_id: LocalDefId,
     state: VisitorState,
     early_return: Option<Span>,
@@ -141,8 +143,8 @@ struct WaitFinder<'a, 'tcx> {
 
 #[derive(PartialEq)]
 enum VisitorState {
-    WalkUpToLocal,
-    LocalFound,
+    WalkUpToCreate,
+    CreateFound,
 }
 
 #[derive(Copy, Clone)]
@@ -155,19 +157,13 @@ impl<'tcx> Visitor<'tcx> for WaitFinder<'_, 'tcx> {
     type NestedFilter = nested_filter::OnlyBodies;
     type Result = ControlFlow<MaybeWait>;
 
-    fn visit_local(&mut self, l: &'tcx LetStmt<'tcx>) -> Self::Result {
-        if self.state == VisitorState::WalkUpToLocal
-            && let PatKind::Binding(_, pat_id, ..) = l.pat.kind
-            && self.local_id == pat_id
-        {
-            self.state = VisitorState::LocalFound;
+    fn visit_expr(&mut self, ex: &'tcx Expr<'tcx>) -> Self::Result {
+        if ex.hir_id == self.create_id {
+            self.state = VisitorState::CreateFound;
+            return Continue(());
         }
 
-        walk_local(self, l)
-    }
-
-    fn visit_expr(&mut self, ex: &'tcx Expr<'tcx>) -> Self::Result {
-        if self.state != VisitorState::LocalFound {
+        if self.state != VisitorState::CreateFound {
             return walk_expr(self, ex);
         }
 

tests/ui/zombie_processes.rs

@@ -198,3 +198,13 @@ mod issue14677 {
         child.wait().unwrap();
     }
 }
+
+fn issue14911() -> std::io::Result<String> {
+    let (mut recv, send) = std::io::pipe()?;
+    let mut command = Command::new("ls")
+        .stdout(send.try_clone()?)
+        .spawn()
+        .expect("Could not spawn new process...");
+    command.wait()?;
+    Ok("".into())
+}