1 files changed, 140 insertions, 0 deletions
diff --git a/src/tools/clippy/clippy_lints/src/disallowed_types.rs b/src/tools/clippy/clippy_lints/src/disallowed_types.rs
new file mode 100644
index 000000000..14f89edce
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/disallowed_types.rs
@@ -0,0 +1,140 @@
+use clippy_utils::diagnostics::span_lint_and_then;
+
+use rustc_data_structures::fx::FxHashMap;
+use rustc_hir::{
+    def::Res, def_id::DefId, Item, ItemKind, PolyTraitRef, PrimTy, TraitBoundModifier, Ty, TyKind, UseKind,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::Span;
+
+use crate::utils::conf;
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Denies the configured types in clippy.toml.
+    ///
+    /// Note: Even though this lint is warn-by-default, it will only trigger if
+    /// types are defined in the clippy.toml file.
+    ///
+    /// ### Why is this bad?
+    /// Some types are undesirable in certain contexts.
+    ///
+    /// ### Example:
+    /// An example clippy.toml configuration:
+    /// ```toml
+    /// # clippy.toml
+    /// disallowed-types = [
+    ///     # Can use a string as the path of the disallowed type.
+    ///     "std::collections::BTreeMap",
+    ///     # Can also use an inline table with a `path` key.
+    ///     { path = "std::net::TcpListener" },
+    ///     # When using an inline table, can add a `reason` for why the type
+    ///     # is disallowed.
+    ///     { path = "std::net::Ipv4Addr", reason = "no IPv4 allowed" },
+    /// ]
+    /// ```
+    ///
+    /// ```rust,ignore
+    /// use std::collections::BTreeMap;
+    /// // or its use
+    /// let x = std::collections::BTreeMap::new();
+    /// ```
+    /// Use instead:
+    /// ```rust,ignore
+    /// // A similar type that is allowed by the config
+    /// use std::collections::HashMap;
+    /// ```
+    #[clippy::version = "1.55.0"]
+    pub DISALLOWED_TYPES,
+    style,
+    "use of disallowed types"
+}
+#[derive(Clone, Debug)]
+pub struct DisallowedTypes {
+    conf_disallowed: Vec<conf::DisallowedType>,
+    def_ids: FxHashMap<DefId, Option<String>>,
+    prim_tys: FxHashMap<PrimTy, Option<String>>,
+}
+
+impl DisallowedTypes {
+    pub fn new(conf_disallowed: Vec<conf::DisallowedType>) -> Self {
+        Self {
+            conf_disallowed,
+            def_ids: FxHashMap::default(),
+            prim_tys: FxHashMap::default(),
+        }
+    }
+
+    fn check_res_emit(&self, cx: &LateContext<'_>, res: &Res, span: Span) {
+        match res {
+            Res::Def(_, did) => {
+                if let Some(reason) = self.def_ids.get(did) {
+                    emit(cx, &cx.tcx.def_path_str(*did), span, reason.as_deref());
+                }
+            },
+            Res::PrimTy(prim) => {
+                if let Some(reason) = self.prim_tys.get(prim) {
+                    emit(cx, prim.name_str(), span, reason.as_deref());
+                }
+            },
+            _ => {},
+        }
+    }
+}
+
+impl_lint_pass!(DisallowedTypes => [DISALLOWED_TYPES]);
+
+impl<'tcx> LateLintPass<'tcx> for DisallowedTypes {
+    fn check_crate(&mut self, cx: &LateContext<'_>) {
+        for conf in &self.conf_disallowed {
+            let (path, reason) = match conf {
+                conf::DisallowedType::Simple(path) => (path, None),
+                conf::DisallowedType::WithReason { path, reason } => (
+                    path,
+                    reason.as_ref().map(|reason| format!("{} (from clippy.toml)", reason)),
+                ),
+            };
+            let segs: Vec<_> = path.split("::").collect();
+            match clippy_utils::def_path_res(cx, &segs) {
+                Res::Def(_, id) => {
+                    self.def_ids.insert(id, reason);
+                },
+                Res::PrimTy(ty) => {
+                    self.prim_tys.insert(ty, reason);
+                },
+                _ => {},
+            }
+        }
+    }
+
+    fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) {
+        if let ItemKind::Use(path, UseKind::Single) = &item.kind {
+            self.check_res_emit(cx, &path.res, item.span);
+        }
+    }
+
+    fn check_ty(&mut self, cx: &LateContext<'tcx>, ty: &'tcx Ty<'tcx>) {
+        if let TyKind::Path(path) = &ty.kind {
+            self.check_res_emit(cx, &cx.qpath_res(path, ty.hir_id), ty.span);
+        }
+    }
+
+    fn check_poly_trait_ref(&mut self, cx: &LateContext<'tcx>, poly: &'tcx PolyTraitRef<'tcx>, _: TraitBoundModifier) {
+        self.check_res_emit(cx, &poly.trait_ref.path.res, poly.trait_ref.path.span);
+    }
+}
+
+fn emit(cx: &LateContext<'_>, name: &str, span: Span, reason: Option<&str>) {
+    span_lint_and_then(
+        cx,
+        DISALLOWED_TYPES,
+        span,
+        &format!("`{}` is not allowed according to config", name),
+        |diag| {
+            if let Some(reason) = reason {
+                diag.note(reason);
+            }
+        },
+    );
+}