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::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
  11 declare_clippy_lint! {
  12     /// ### What it does
  13     /// Checks for non-octal values used to set Unix file permissions.
  14     ///
  15     /// ### Why is this bad?
  16     /// They will be converted into octal, creating potentially
  17     /// unintended file permissions.
  18     ///
  19     /// ### Example
  20     /// ```rust,ignore
  21     /// use std::fs::OpenOptions;
  22     /// use std::os::unix::fs::OpenOptionsExt;
  23     ///
  24     /// let mut options = OpenOptions::new();
  25     /// options.mode(644);
  26     /// ```
  27     /// Use instead:
  28     /// ```rust,ignore
  29     /// use std::fs::OpenOptions;
  30     /// use std::os::unix::fs::OpenOptionsExt;
  31     ///
  32     /// let mut options = OpenOptions::new();
  33     /// options.mode(0o644);
  34     /// ```
  35     #[clippy::version = "1.53.0"]
  36     pub NON_OCTAL_UNIX_PERMISSIONS,
  37     correctness,
  38     "use of non-octal value to set unix file permissions, which will be translated into octal"
  39 }
  40
  41 declare_lint_pass!(NonOctalUnixPermissions => [NON_OCTAL_UNIX_PERMISSIONS]);
  42
  43 impl LateLintPass<'_> for NonOctalUnixPermissions {
  44     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
  45         match &expr.kind {
  46             ExprKind::MethodCall(path, _, [func, param], _) => {
  47                 let obj_ty = cx.typeck_results().expr_ty(func).peel_refs();
  48
  49                 if_chain! {
  50                     if (path.ident.name == sym!(mode)
  51                         && (match_type(cx, obj_ty, &paths::OPEN_OPTIONS)
  52                             || match_type(cx, obj_ty, &paths::DIR_BUILDER)))
  53                         || (path.ident.name == sym!(set_mode) && match_type(cx, obj_ty, &paths::PERMISSIONS));
  54                     if let ExprKind::Lit(_) = param.kind;
  55
  56                     then {
  57                         let snip = match snippet_opt(cx, param.span) {
  58                             Some(s) => s,
  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
  75                     then {
  76                         let snip = match snippet_opt(cx, param.span) {
  77                             Some(s) => s,
  78                             _ => return,
  79                         };
  80
  81                         if !snip.starts_with("0o") {
  82                             show_error(cx, param);
  83                         }
  84                     }
  85                 }
  86             },
  87             _ => {},
  88         };
  89     }
  90 }
  91
  92 fn show_error(cx: &LateContext<'_>, param: &Expr<'_>) {
  93     let mut applicability = Applicability::MachineApplicable;
  94     span_lint_and_sugg(
  95         cx,
  96         NON_OCTAL_UNIX_PERMISSIONS,
  97         param.span,
  98         "using a non-octal value to set unix file permissions",
  99         "consider using an octal literal instead",
 100         format!(
 101             "0o{}",
 102             snippet_with_applicability(cx, param.span, "0o..", &mut applicability,),
 103         ),
 104         applicability,
 105     );
 106 }