1 use clippy_utils::diagnostics::span_lint;
2 use clippy_utils::fn_def_id;
4 use rustc_data_structures::fx::FxHashSet;
6 use rustc_lint::{LateContext, LateLintPass};
7 use rustc_session::{declare_tool_lint, impl_lint_pass};
8 use rustc_span::Symbol;
10 declare_clippy_lint! {
11 /// **What it does:** Denies the configured methods and functions in clippy.toml
13 /// **Why is this bad?** Some methods are undesirable in certain contexts,
14 /// and it's beneficial to lint for them as needed.
16 /// **Known problems:** Currently, you must write each function as a
17 /// fully-qualified path. This lint doesn't support aliases or reexported
18 /// names; be aware that many types in `std` are actually reexports.
20 /// For example, if you want to disallow `Duration::as_secs`, your clippy.toml
21 /// configuration would look like
22 /// `disallowed-methods = ["core::time::Duration::as_secs"]` and not
23 /// `disallowed-methods = ["std::time::Duration::as_secs"]` as you might expect.
27 /// An example clippy.toml configuration:
30 /// disallowed-methods = ["alloc::vec::Vec::leak", "std::time::Instant::now"]
34 /// // Example code where clippy issues a warning
35 /// let xs = vec![1, 2, 3, 4];
36 /// xs.leak(); // Vec::leak is disallowed in the config.
38 /// let _now = Instant::now(); // Instant::now is disallowed in the config.
43 /// // Example code which does not raise clippy warning
44 /// let mut xs = Vec::new(); // Vec::new is _not_ disallowed in the config.
45 /// xs.push(123); // Vec::push is _not_ disallowed in the config.
47 pub DISALLOWED_METHOD,
49 "use of a disallowed method call"
52 #[derive(Clone, Debug)]
53 pub struct DisallowedMethod {
54 disallowed: FxHashSet<Vec<Symbol>>,
57 impl DisallowedMethod {
58 pub fn new(disallowed: &FxHashSet<String>) -> Self {
60 disallowed: disallowed
62 .map(|s| s.split("::").map(|seg| Symbol::intern(seg)).collect::<Vec<_>>())
68 impl_lint_pass!(DisallowedMethod => [DISALLOWED_METHOD]);
70 impl<'tcx> LateLintPass<'tcx> for DisallowedMethod {
71 fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
72 if let Some(def_id) = fn_def_id(cx, expr) {
73 let func_path = cx.get_def_path(def_id);
74 if self.disallowed.contains(&func_path) {
75 let func_path_string = func_path
77 .map(Symbol::to_ident_string)
85 &format!("use of a disallowed method `{}`", func_path_string),