Move is_parent_stmt to clippy_utils

Author: samueltardieu

clippy_lints/src/needless_bool.rs

@@ -6,11 +6,12 @@ use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg};
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::sugg::Sugg;
 use clippy_utils::{
-    higher, is_else_clause, is_expn_of, peel_blocks, peel_blocks_with_stmt, span_extract_comment, SpanlessEq,
+    higher, is_else_clause, is_expn_of, is_parent_stmt, peel_blocks, peel_blocks_with_stmt, span_extract_comment,
+    SpanlessEq,
 };
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
-use rustc_hir::{BinOpKind, Block, Expr, ExprKind, HirId, Node, UnOp};
+use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::declare_lint_pass;
 use rustc_span::source_map::Spanned;
@@ -135,13 +136,6 @@ fn condition_needs_parentheses(e: &Expr<'_>) -> bool {
     false
 }
 
-fn is_parent_stmt(cx: &LateContext<'_>, id: HirId) -> bool {
-    matches!(
-        cx.tcx.parent_hir_node(id),
-        Node::Stmt(..) | Node::Block(Block { stmts: &[], .. })
-    )
-}
-
 impl<'tcx> LateLintPass<'tcx> for NeedlessBool {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
         use self::Expression::{Bool, RetBool};

clippy_utils/src/lib.rs

@@ -3335,3 +3335,12 @@ fn maybe_get_relative_path(from: &DefPath, to: &DefPath, max_super: usize) -> St
         repeat(String::from("super")).take(go_up_by).chain(path).join("::")
     }
 }
+
+/// Returns true if the specified `HirId` is the top-level expression of a statement or the only
+/// expression in a block.
+pub fn is_parent_stmt(cx: &LateContext<'_>, id: HirId) -> bool {
+    matches!(
+        cx.tcx.parent_hir_node(id),
+        Node::Stmt(..) | Node::Block(Block { stmts: &[], .. })
+    )
+}