rust/clippy_lints/src/non_octal_unix_permissions.rs

106 lines
3.6 KiB
Rust

use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::source::{snippet_opt, snippet_with_applicability};
use clippy_utils::ty::match_type;
use clippy_utils::{match_def_path, paths};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{Expr, ExprKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
/// ### What it does
/// Checks for non-octal values used to set Unix file permissions.
///
/// ### Why is this bad?
/// They will be converted into octal, creating potentially
/// unintended file permissions.
///
/// ### Example
/// ```rust,ignore
/// use std::fs::OpenOptions;
/// use std::os::unix::fs::OpenOptionsExt;
///
/// let mut options = OpenOptions::new();
/// options.mode(644);
/// ```
/// Use instead:
/// ```rust,ignore
/// use std::fs::OpenOptions;
/// use std::os::unix::fs::OpenOptionsExt;
///
/// let mut options = OpenOptions::new();
/// options.mode(0o644);
/// ```
pub NON_OCTAL_UNIX_PERMISSIONS,
correctness,
"use of non-octal value to set unix file permissions, which will be translated into octal"
}
declare_lint_pass!(NonOctalUnixPermissions => [NON_OCTAL_UNIX_PERMISSIONS]);
impl LateLintPass<'_> for NonOctalUnixPermissions {
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
match &expr.kind {
ExprKind::MethodCall(path, _, [func, param], _) => {
let obj_ty = cx.typeck_results().expr_ty(func).peel_refs();
if_chain! {
if (path.ident.name == sym!(mode)
&& (match_type(cx, obj_ty, &paths::OPEN_OPTIONS)
|| match_type(cx, obj_ty, &paths::DIR_BUILDER)))
|| (path.ident.name == sym!(set_mode) && match_type(cx, obj_ty, &paths::PERMISSIONS));
if let ExprKind::Lit(_) = param.kind;
then {
let snip = match snippet_opt(cx, param.span) {
Some(s) => s,
_ => return,
};
if !snip.starts_with("0o") {
show_error(cx, param);
}
}
}
},
ExprKind::Call(func, [param]) => {
if_chain! {
if let ExprKind::Path(ref path) = func.kind;
if let Some(def_id) = cx.qpath_res(path, func.hir_id).opt_def_id();
if match_def_path(cx, def_id, &paths::PERMISSIONS_FROM_MODE);
if let ExprKind::Lit(_) = param.kind;
then {
let snip = match snippet_opt(cx, param.span) {
Some(s) => s,
_ => return,
};
if !snip.starts_with("0o") {
show_error(cx, param);
}
}
}
},
_ => {},
};
}
}
fn show_error(cx: &LateContext<'_>, param: &Expr<'_>) {
let mut applicability = Applicability::MachineApplicable;
span_lint_and_sugg(
cx,
NON_OCTAL_UNIX_PERMISSIONS,
param.span,
"using a non-octal value to set unix file permissions",
"consider using an octal literal instead",
format!(
"0o{}",
snippet_with_applicability(cx, param.span, "0o..", &mut applicability,),
),
applicability,
);
}