src/tools/clippy/clippy_lints/src/non_octal_unix_permissions.rs

   1 use clippy_utils::diagnostics::span_lint_and_sugg;
   2 use clippy_utils::source::{snippet_opt, snippet_with_applicability};
   3 use clippy_utils::ty::{is_type_diagnostic_item, match_type};
   4 use clippy_utils::{match_def_path, paths};
   5 use if_chain::if_chain;
   6 use rustc_errors::Applicability;
   7 use rustc_hir::{Expr, ExprKind};
   8 use rustc_lint::{LateContext, LateLintPass};
   9 use rustc_session::{declare_lint_pass, declare_tool_lint};
  10 use rustc_span::sym;
  11
  12 declare_clippy_lint! {
  13     /// ### What it does
  14     /// Checks for non-octal values used to set Unix file permissions.
  15     ///
  16     /// ### Why is this bad?
  17     /// They will be converted into octal, creating potentially
  18     /// unintended file permissions.
  19     ///
  20     /// ### Example
  21     /// ```rust,ignore
  22     /// use std::fs::OpenOptions;
  23     /// use std::os::unix::fs::OpenOptionsExt;
  24     ///
  25     /// let mut options = OpenOptions::new();
  26     /// options.mode(644);
  27     /// ```
  28     /// Use instead:
  29     /// ```rust,ignore
  30     /// use std::fs::OpenOptions;
  31     /// use std::os::unix::fs::OpenOptionsExt;
  32     ///
  33     /// let mut options = OpenOptions::new();
  34     /// options.mode(0o644);
  35     /// ```
  36     #[clippy::version = "1.53.0"]
  37     pub NON_OCTAL_UNIX_PERMISSIONS,
  38     correctness,
  39     "use of non-octal value to set unix file permissions, which will be translated into octal"
  40 }
  41
  42 declare_lint_pass!(NonOctalUnixPermissions => [NON_OCTAL_UNIX_PERMISSIONS]);
  43
  44 impl<'tcx> LateLintPass<'tcx> for NonOctalUnixPermissions {
  45     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
  46         match &expr.kind {
  47             ExprKind::MethodCall(path, func, [param], _) => {
  48                 let obj_ty = cx.typeck_results().expr_ty(func).peel_refs();
  49
  50                 if_chain! {
  51                     if (path.ident.name == sym!(mode)
  52                         && (match_type(cx, obj_ty, &paths::OPEN_OPTIONS)
  53                             || is_type_diagnostic_item(cx, obj_ty, sym::DirBuilder)))
  54                         || (path.ident.name == sym!(set_mode) && match_type(cx, obj_ty, &paths::PERMISSIONS));
  55                     if let ExprKind::Lit(_) = param.kind;
  56
  57                     then {
  58                         let Some(snip) = snippet_opt(cx, param.span) else {
  59                             return
  60                         };
  61
  62                         if !snip.starts_with("0o") {
  63                             show_error(cx, param);
  64                         }
  65                     }
  66                 }
  67             },
  68             ExprKind::Call(func, [param]) => {
  69                 if_chain! {
  70                     if let ExprKind::Path(ref path) = func.kind;
  71                     if let Some(def_id) = cx.qpath_res(path, func.hir_id).opt_def_id();
  72                     if match_def_path(cx, def_id, &paths::PERMISSIONS_FROM_MODE);
  73                     if let ExprKind::Lit(_) = param.kind;
  74                     if let Some(snip) = snippet_opt(cx, param.span);
  75                     if !snip.starts_with("0o");
  76                     then {
  77                         show_error(cx, param);
  78                     }
  79                 }
  80             },
  81             _ => {},
  82         };
  83     }
  84 }
  85
  86 fn show_error(cx: &LateContext<'_>, param: &Expr<'_>) {
  87     let mut applicability = Applicability::MachineApplicable;
  88     span_lint_and_sugg(
  89         cx,
  90         NON_OCTAL_UNIX_PERMISSIONS,
  91         param.span,
  92         "using a non-octal value to set unix file permissions",
  93         "consider using an octal literal instead",
  94         format!(
  95             "0o{}",
  96             snippet_with_applicability(cx, param.span, "0o..", &mut applicability,),
  97         ),
  98         applicability,
  99     );
 100 }