clippy_dev: check that all lints are registered with a lint pass

Author: Jarcho

clippy_dev/src/update_lints.rs

@@ -3,6 +3,7 @@ use crate::utils::{FileUpdater, UpdateMode, UpdateStatus, update_text_region_fn}
 use itertools::Itertools;
 use std::fmt::Write;
 use std::path::Path;
+use std::process;
 
 const GENERATED_FILE_COMMENT: &str = "// This file was generated by `cargo dev update_lints`.\n\
      // Use that command to update this file and do not edit by hand.\n\
@@ -20,7 +21,24 @@ const DOCS_LINK: &str = "https://rust-lang.github.io/rust-clippy/master/index.ht
 ///
 /// Panics if a file path could not read from or then written to
 pub fn update(update_mode: UpdateMode) {
-    generate_lint_files(update_mode, &ParsedData::collect());
+    let mut data = ParsedData::collect();
+    let mut is_missing = false;
+    data.lint_registrations.sort_by(|x, y| x.name.cmp(&y.name));
+    for (name, lint) in &data.lints {
+        if matches!(lint.kind, LintKind::Active(_))
+            && data.lint_registrations.binary_search_by(|x| x.name.cmp(name)).is_err()
+        {
+            is_missing = true;
+            eprint!(
+                "error: lint `{name}` is not registered in a lint pass\n  declared here: {}\n",
+                lint.name_span.display(&data.source_map)
+            );
+        }
+    }
+    if is_missing {
+        process::exit(1);
+    }
+    generate_lint_files(update_mode, &data);
 }
 
 #[expect(clippy::too_many_lines)]

clippy_lints/src/doc/mod.rs

@@ -1,5 +1,3 @@
-#![allow(clippy::lint_without_lint_pass)]
-
 use clippy_config::Conf;
 use clippy_utils::attrs::is_doc_hidden;
 use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_then};

clippy_lints_internal/src/lib.rs

@@ -50,7 +50,6 @@ static LINTS: &[&Lint] = &[
     derive_deserialize_allowing_unknown::DERIVE_DESERIALIZE_ALLOWING_UNKNOWN,
     lint_without_lint_pass::DEFAULT_LINT,
     lint_without_lint_pass::INVALID_CLIPPY_VERSION_ATTRIBUTE,
-    lint_without_lint_pass::LINT_WITHOUT_LINT_PASS,
     lint_without_lint_pass::MISSING_CLIPPY_VERSION_ATTRIBUTE,
     msrv_attr_impl::MISSING_MSRV_ATTR_IMPL,
     outer_expn_data_pass::OUTER_EXPN_EXPN_DATA,
@@ -69,7 +68,7 @@ pub fn register_lints(store: &mut LintStore) {
     store.register_late_pass(|_| Box::new(collapsible_calls::CollapsibleCalls));
     store.register_late_pass(|_| Box::new(derive_deserialize_allowing_unknown::DeriveDeserializeAllowingUnknown));
     store.register_late_pass(|_| Box::<symbols::Symbols>::default());
-    store.register_late_pass(|_| Box::<lint_without_lint_pass::LintWithoutLintPass>::default());
+    store.register_late_pass(|_| Box::new(lint_without_lint_pass::LintWithoutLintPass));
     store.register_late_pass(|_| Box::new(unnecessary_def_path::UnnecessaryDefPath));
     store.register_late_pass(|_| Box::new(outer_expn_data_pass::OuterExpnDataPass));
     store.register_late_pass(|_| Box::new(msrv_attr_impl::MsrvAttrImpl));

clippy_lints_internal/src/lint_without_lint_pass.rs

@@ -1,49 +1,14 @@
 use crate::internal_paths;
 use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
-use clippy_utils::is_lint_allowed;
-use clippy_utils::macros::root_macro_call_first_node;
 use rustc_ast::ast::LitKind;
-use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::hir_id::CRATE_HIR_ID;
-use rustc_hir::intravisit::Visitor;
-use rustc_hir::{ExprKind, HirId, Item, MutTy, Mutability, Path, TyKind};
+use rustc_hir::{ExprKind, Item, MutTy, Mutability, TyKind};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::hir::nested_filter;
-use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Spanned;
+use rustc_span::sym;
 use rustc_span::symbol::Symbol;
-use rustc_span::{Span, sym};
-
-declare_tool_lint! {
-    /// ### What it does
-    /// Ensures every lint is associated to a `LintPass`.
-    ///
-    /// ### Why is this bad?
-    /// The compiler only knows lints via a `LintPass`. Without
-    /// putting a lint to a `LintPass::lint_vec()`'s return, the compiler will not
-    /// know the name of the lint.
-    ///
-    /// ### Known problems
-    /// Only checks for lints associated using the `declare_lint_pass!` and
-    /// `impl_lint_pass!` macros.
-    ///
-    /// ### Example
-    /// ```rust,ignore
-    /// declare_lint! { pub LINT_1, ... }
-    /// declare_lint! { pub LINT_2, ... }
-    /// declare_lint! { pub FORGOTTEN_LINT, ... }
-    /// // ...
-    /// declare_lint_pass!(Pass => [LINT_1, LINT_2]);
-    /// // missing FORGOTTEN_LINT
-    /// ```
-    pub clippy::LINT_WITHOUT_LINT_PASS,
-    Warn,
-    "declaring a lint without associating it in a LintPass",
-    report_in_external_macro: true
-
-}
 
 declare_tool_lint! {
     /// ### What it does
@@ -90,109 +55,47 @@ declare_tool_lint! {
     report_in_external_macro: true
 }
 
-#[derive(Clone, Debug, Default)]
-pub struct LintWithoutLintPass {
-    declared_lints: FxIndexMap<Symbol, Span>,
-    registered_lints: FxIndexSet<Symbol>,
-}
-
-impl_lint_pass!(LintWithoutLintPass => [
+declare_lint_pass!(LintWithoutLintPass => [
     DEFAULT_LINT,
-    LINT_WITHOUT_LINT_PASS,
     INVALID_CLIPPY_VERSION_ATTRIBUTE,
     MISSING_CLIPPY_VERSION_ATTRIBUTE,
 ]);
 
 impl<'tcx> LateLintPass<'tcx> for LintWithoutLintPass {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
-        if let hir::ItemKind::Static(Mutability::Not, ident, ty, body_id) = item.kind {
-            if is_lint_ref_type(cx, ty) {
-                check_invalid_clippy_version_attribute(cx, item);
+        if let hir::ItemKind::Static(Mutability::Not, ident, ty, body_id) = item.kind
+            && is_lint_ref_type(cx, ty)
+        {
+            check_invalid_clippy_version_attribute(cx, item);
 
-                let expr = &cx.tcx.hir_body(body_id).value;
-                let fields = if let ExprKind::AddrOf(_, _, inner_exp) = expr.kind
-                    && let ExprKind::Struct(_, struct_fields, _) = inner_exp.kind
-                {
-                    struct_fields
-                } else {
-                    return;
-                };
+            let expr = &cx.tcx.hir_body(body_id).value;
+            let fields = if let ExprKind::AddrOf(_, _, inner_exp) = expr.kind
+                && let ExprKind::Struct(_, struct_fields, _) = inner_exp.kind
+            {
+                struct_fields
+            } else {
+                return;
+            };
 
-                let field = fields
-                    .iter()
-                    .find(|f| f.ident.as_str() == "desc")
-                    .expect("lints must have a description field");
+            let field = fields
+                .iter()
+                .find(|f| f.ident.as_str() == "desc")
+                .expect("lints must have a description field");
 
-                if let ExprKind::Lit(Spanned {
-                    node: LitKind::Str(sym, _),
-                    ..
-                }) = field.expr.kind
-                {
-                    let sym_str = sym.as_str();
-                    if sym_str == "default lint description" {
-                        span_lint(
-                            cx,
-                            DEFAULT_LINT,
-                            item.span,
-                            format!("the lint `{}` has the default lint description", ident.name),
-                        );
-                    }
-                    self.declared_lints.insert(ident.name, item.span);
-                }
-            }
-        } else if let Some(macro_call) = root_macro_call_first_node(cx, item) {
-            if !matches!(
-                cx.tcx.item_name(macro_call.def_id).as_str(),
-                "impl_lint_pass" | "declare_lint_pass"
-            ) {
-                return;
-            }
-            if let hir::ItemKind::Impl(hir::Impl {
-                of_trait: None,
-                items: impl_item_refs,
+            if let ExprKind::Lit(Spanned {
+                node: LitKind::Str(sym, _),
                 ..
-            }) = item.kind
+            }) = field.expr.kind
             {
-                let mut collector = LintCollector {
-                    output: &mut self.registered_lints,
-                    cx,
-                };
-                let body = cx.tcx.hir_body_owned_by(
-                    impl_item_refs
-                        .iter()
-                        .find(|iiref| iiref.ident.as_str() == "lint_vec")
-                        .expect("LintPass needs to implement lint_vec")
-                        .id
-                        .owner_id
-                        .def_id,
-                );
-                collector.visit_expr(body.value);
-            }
-        }
-    }
-
-    fn check_crate_post(&mut self, cx: &LateContext<'tcx>) {
-        if is_lint_allowed(cx, LINT_WITHOUT_LINT_PASS, CRATE_HIR_ID) {
-            return;
-        }
-
-        for (lint_name, &lint_span) in &self.declared_lints {
-            // When using the `declare_tool_lint!` macro, the original `lint_span`'s
-            // file points to "<rustc macros>".
-            // `compiletest-rs` thinks that's an error in a different file and
-            // just ignores it. This causes the test in compile-fail/lint_pass
-            // not able to capture the error.
-            // Therefore, we need to climb the macro expansion tree and find the
-            // actual span that invoked `declare_tool_lint!`:
-            let lint_span = lint_span.ctxt().outer_expn_data().call_site;
-
-            if !self.registered_lints.contains(lint_name) {
-                span_lint(
-                    cx,
-                    LINT_WITHOUT_LINT_PASS,
-                    lint_span,
-                    format!("the lint `{lint_name}` is not added to any `LintPass`"),
-                );
+                let sym_str = sym.as_str();
+                if sym_str == "default lint description" {
+                    span_lint(
+                        cx,
+                        DEFAULT_LINT,
+                        item.span,
+                        format!("the lint `{}` has the default lint description", ident.name),
+                    );
+                }
             }
         }
     }
@@ -261,22 +164,3 @@ pub(super) fn extract_clippy_version_value(cx: &LateContext<'_>, item: &'_ Item<
         }
     })
 }
-
-struct LintCollector<'a, 'tcx> {
-    output: &'a mut FxIndexSet<Symbol>,
-    cx: &'a LateContext<'tcx>,
-}
-
-impl<'tcx> Visitor<'tcx> for LintCollector<'_, 'tcx> {
-    type NestedFilter = nested_filter::All;
-
-    fn visit_path(&mut self, path: &Path<'_>, _: HirId) {
-        if path.segments.len() == 1 {
-            self.output.insert(path.segments[0].ident.name);
-        }
-    }
-
-    fn maybe_tcx(&mut self) -> Self::MaybeTyCtxt {
-        self.cx.tcx
-    }
-}

tests/ui-internal/check_formulation.rs

@@ -1,5 +1,4 @@
 #![deny(clippy::almost_standard_lint_formulation)]
-#![allow(clippy::lint_without_lint_pass)]
 #![feature(rustc_private)]
 
 #[macro_use]

tests/ui-internal/check_formulation.stderr

@@ -1,5 +1,5 @@
 error: non-standard lint formulation
-  --> tests/ui-internal/check_formulation.rs:24:5
+  --> tests/ui-internal/check_formulation.rs:23:5
    |
 LL |     /// Check for lint formulations that are correct
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -12,7 +12,7 @@ LL | #![deny(clippy::almost_standard_lint_formulation)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: non-standard lint formulation
-  --> tests/ui-internal/check_formulation.rs:35:5
+  --> tests/ui-internal/check_formulation.rs:34:5
    |
 LL |     /// Detects uses of incorrect formulations
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^