Simplify check function, weirdly binary format literals happen not often

Author: cocodery

clippy_lints/src/non_octal_unix_permissions.rs

@@ -1,8 +1,6 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::numeric_literal::{NumericLiteral, Radix};
 use clippy_utils::source::{snippet_opt, snippet_with_applicability};
 use clippy_utils::{match_def_path, paths};
-use rustc_ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
@@ -41,29 +39,6 @@ declare_clippy_lint! {
 
 declare_lint_pass!(NonOctalUnixPermissions => [NON_OCTAL_UNIX_PERMISSIONS]);
 
-fn check_binary_unix_permissions(lit_kind: &LitKind, snip: &str) -> bool {
-    // support binary unix permissions
-    if let Some(num_lit) = NumericLiteral::from_lit_kind(snip, lit_kind) {
-        if num_lit.radix != Radix::Binary {
-            return false;
-        }
-
-        let group_sizes: Vec<usize> = num_lit.integer.split('_').map(str::len).collect();
-        // check whether is binary format unix permissions
-        if group_sizes.len() == 1 && (num_lit.integer.len() == 9 || num_lit.integer.len() == 12) {
-            // 0bxxxxxxxxx or 0bxxxxxxxxxxxx
-            true
-        } else if group_sizes.len() == 3 || group_sizes.len() == 4 {
-            // 0bxxx_xxx_xxx or 0bxxx_xxx_xxx_xxx
-            group_sizes.iter().all(|len| *len == 3)
-        } else {
-            false
-        }
-    } else {
-        false
-    }
-}
-
 impl<'tcx> LateLintPass<'tcx> for NonOctalUnixPermissions {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
         match &expr.kind {
@@ -76,10 +51,10 @@ impl<'tcx> LateLintPass<'tcx> for NonOctalUnixPermissions {
                         ))
                         || (path.ident.name == sym!(set_mode)
                             && cx.tcx.is_diagnostic_item(sym::FsPermissions, adt.did())))
-                    && let ExprKind::Lit(lit_kind) = param.kind
+                    && let ExprKind::Lit(_) = param.kind
                     && param.span.eq_ctxt(expr.span)
                     && let Some(snip) = snippet_opt(cx, param.span)
-                    && !(snip.starts_with("0o") || check_binary_unix_permissions(&lit_kind.node, &snip))
+                    && !(snip.starts_with("0o") || snip.starts_with("0b"))
                 {
                     show_error(cx, param);
                 }
@@ -88,10 +63,10 @@ impl<'tcx> LateLintPass<'tcx> for NonOctalUnixPermissions {
                 if let ExprKind::Path(ref path) = func.kind
                     && let Some(def_id) = cx.qpath_res(path, func.hir_id).opt_def_id()
                     && match_def_path(cx, def_id, &paths::PERMISSIONS_FROM_MODE)
-                    && let ExprKind::Lit(lit_kind) = param.kind
+                    && let ExprKind::Lit(_) = param.kind
                     && param.span.eq_ctxt(expr.span)
                     && let Some(snip) = snippet_opt(cx, param.span)
-                    && !(snip.starts_with("0o") || check_binary_unix_permissions(&lit_kind.node, &snip))
+                    && !(snip.starts_with("0o") || snip.starts_with("0b"))
                 {
                     show_error(cx, param);
                 }