1 files changed, 113 insertions, 0 deletions
diff --git a/src/tools/clippy/clippy_lints/src/disallowed_methods.rs b/src/tools/clippy/clippy_lints/src/disallowed_methods.rs
new file mode 100644
index 000000000..53973ab79
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/disallowed_methods.rs
@@ -0,0 +1,113 @@
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::{fn_def_id, get_parent_expr, path_def_id};
+
+use rustc_hir::{def::Res, def_id::DefIdMap, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+
+use crate::utils::conf;
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Denies the configured methods and functions in clippy.toml
+    ///
+    /// Note: Even though this lint is warn-by-default, it will only trigger if
+    /// methods are defined in the clippy.toml file.
+    ///
+    /// ### Why is this bad?
+    /// Some methods are undesirable in certain contexts, and it's beneficial to
+    /// lint for them as needed.
+    ///
+    /// ### Example
+    /// An example clippy.toml configuration:
+    /// ```toml
+    /// # clippy.toml
+    /// disallowed-methods = [
+    ///     # Can use a string as the path of the disallowed method.
+    ///     "std::boxed::Box::new",
+    ///     # Can also use an inline table with a `path` key.
+    ///     { path = "std::time::Instant::now" },
+    ///     # When using an inline table, can add a `reason` for why the method
+    ///     # is disallowed.
+    ///     { path = "std::vec::Vec::leak", reason = "no leaking memory" },
+    /// ]
+    /// ```
+    ///
+    /// ```rust,ignore
+    /// // Example code where clippy issues a warning
+    /// let xs = vec![1, 2, 3, 4];
+    /// xs.leak(); // Vec::leak is disallowed in the config.
+    /// // The diagnostic contains the message "no leaking memory".
+    ///
+    /// let _now = Instant::now(); // Instant::now is disallowed in the config.
+    ///
+    /// let _box = Box::new(3); // Box::new is disallowed in the config.
+    /// ```
+    ///
+    /// Use instead:
+    /// ```rust,ignore
+    /// // Example code which does not raise clippy warning
+    /// let mut xs = Vec::new(); // Vec::new is _not_ disallowed in the config.
+    /// xs.push(123); // Vec::push is _not_ disallowed in the config.
+    /// ```
+    #[clippy::version = "1.49.0"]
+    pub DISALLOWED_METHODS,
+    style,
+    "use of a disallowed method call"
+}
+
+#[derive(Clone, Debug)]
+pub struct DisallowedMethods {
+    conf_disallowed: Vec<conf::DisallowedMethod>,
+    disallowed: DefIdMap<usize>,
+}
+
+impl DisallowedMethods {
+    pub fn new(conf_disallowed: Vec<conf::DisallowedMethod>) -> Self {
+        Self {
+            conf_disallowed,
+            disallowed: DefIdMap::default(),
+        }
+    }
+}
+
+impl_lint_pass!(DisallowedMethods => [DISALLOWED_METHODS]);
+
+impl<'tcx> LateLintPass<'tcx> for DisallowedMethods {
+    fn check_crate(&mut self, cx: &LateContext<'_>) {
+        for (index, conf) in self.conf_disallowed.iter().enumerate() {
+            let segs: Vec<_> = conf.path().split("::").collect();
+            if let Res::Def(_, id) = clippy_utils::def_path_res(cx, &segs) {
+                self.disallowed.insert(id, index);
+            }
+        }
+    }
+
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+        let uncalled_path = if let Some(parent) = get_parent_expr(cx, expr)
+            && let ExprKind::Call(receiver, _) = parent.kind
+            && receiver.hir_id == expr.hir_id
+        {
+            None
+        } else {
+            path_def_id(cx, expr)
+        };
+        let def_id = match uncalled_path.or_else(|| fn_def_id(cx, expr)) {
+            Some(def_id) => def_id,
+            None => return,
+        };
+        let conf = match self.disallowed.get(&def_id) {
+            Some(&index) => &self.conf_disallowed[index],
+            None => return,
+        };
+        let msg = format!("use of a disallowed method `{}`", conf.path());
+        span_lint_and_then(cx, DISALLOWED_METHODS, expr.span, &msg, |diag| {
+            if let conf::DisallowedMethod::WithReason {
+                reason: Some(reason), ..
+            } = conf
+            {
+                diag.note(&format!("{} (from clippy.toml)", reason));
+            }
+        });
+    }
+}