Do not run lints that cannot emit

Before this change, adding a lint was a difficult matter
because it always had some overhead involved. This was
because all lints would run, no matter their default level,
or if the user had #![allow]ed them. This PR changes that

Cargo.lock

@@ -4029,6 +4029,7 @@ dependencies = [
  "rustc_hir",
  "rustc_hir_pretty",
  "rustc_index",
+ "rustc_lint_defs",
  "rustc_macros",
  "rustc_query_system",
  "rustc_serialize",

compiler/rustc_ast/src/attr/mod.rs

@@ -223,7 +223,7 @@ pub fn span(&self) -> Span {
         self.args.span().map_or(self.path.span, |args_span| self.path.span.to(args_span))
     }
 
-    fn meta_item_list(&self) -> Option<ThinVec<MetaItemInner>> {
+    pub fn meta_item_list(&self) -> Option<ThinVec<MetaItemInner>> {
         match &self.args {
             AttrArgs::Delimited(args) if args.delim == Delimiter::Parenthesis => {
                 MetaItemKind::list_from_tokens(args.tokens.clone())

compiler/rustc_lint/src/builtin.rs

@@ -74,6 +74,12 @@
     fluent_generated as fluent,
 };
 
+use std::default::Default;
+use std::fmt::Write;
+
+// hardwired lints from rustc_lint_defs
+pub use rustc_session::lint::builtin::*;
+
 declare_lint! {
     /// The `while_true` lint detects `while true { }`.
     ///
@@ -241,7 +247,8 @@ fn check_pat(&mut self, cx: &LateContext<'_>, pat: &hir::Pat<'_>) {
     /// behavior.
     UNSAFE_CODE,
     Allow,
-    "usage of `unsafe` code and other potentially unsound constructs"
+    "usage of `unsafe` code and other potentially unsound constructs",
+    [loadbearing: true]
 }
 
 declare_lint_pass!(UnsafeCode => [UNSAFE_CODE]);
@@ -389,6 +396,7 @@ fn check_fn(&mut self, cx: &EarlyContext<'_>, fk: FnKind<'_>, span: Span, _: ast
     report_in_external_macro
 }
 
+#[derive(Default)]
 pub struct MissingDoc;
 
 impl_lint_pass!(MissingDoc => [MISSING_DOCS]);
@@ -819,8 +827,8 @@ pub struct DeprecatedAttr {
 
 impl_lint_pass!(DeprecatedAttr => []);
 
-impl DeprecatedAttr {
-    pub fn new() -> DeprecatedAttr {
+impl Default for DeprecatedAttr {
+    fn default() -> Self {
         DeprecatedAttr { depr_attrs: deprecated_attributes() }
     }
 }

compiler/rustc_lint/src/early.rs

@@ -312,6 +312,9 @@ impl LintPass for RuntimeCombinedEarlyLintPass<'_> {
     fn name(&self) -> &'static str {
         panic!()
     }
+    fn get_lints(&self) -> crate::LintVec {
+        panic!()
+    }
 }
 
 macro_rules! impl_early_lint_pass {

compiler/rustc_lint/src/internal.rs

@@ -429,7 +429,8 @@ fn check_item(&mut self, cx: &LateContext<'_>, item: &rustc_hir::Item<'_>) {
     pub rustc::UNTRANSLATABLE_DIAGNOSTIC,
     Deny,
     "prevent creation of diagnostics which cannot be translated",
-    report_in_external_macro: true
+    report_in_external_macro: true,
+    [loadbearing: true]
 }
 
 declare_tool_lint! {
@@ -442,7 +443,8 @@ fn check_item(&mut self, cx: &LateContext<'_>, item: &rustc_hir::Item<'_>) {
     pub rustc::DIAGNOSTIC_OUTSIDE_OF_IMPL,
     Deny,
     "prevent diagnostic creation outside of `Diagnostic`/`Subdiagnostic`/`LintDiagnostic` impls",
-    report_in_external_macro: true
+    report_in_external_macro: true,
+    [loadbearing: true]
 }
 
 declare_lint_pass!(Diagnostics => [UNTRANSLATABLE_DIAGNOSTIC, DIAGNOSTIC_OUTSIDE_OF_IMPL]);

compiler/rustc_lint/src/late.rs

@@ -326,6 +326,9 @@ impl LintPass for RuntimeCombinedLateLintPass<'_, '_> {
     fn name(&self) -> &'static str {
         panic!()
     }
+    fn get_lints(&self) -> crate::LintVec {
+        panic!()
+    }
 }
 
 macro_rules! impl_late_lint_pass {
@@ -361,13 +364,38 @@ pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx> + 'tcx>(
     // Note: `passes` is often empty. In that case, it's faster to run
     // `builtin_lints` directly rather than bundling it up into the
     // `RuntimeCombinedLateLintPass`.
-    let late_module_passes = &unerased_lint_store(tcx.sess).late_module_passes;
-    if late_module_passes.is_empty() {
+    let store = unerased_lint_store(tcx.sess);
+
+    if store.late_module_passes.is_empty() {
         late_lint_mod_inner(tcx, module_def_id, context, builtin_lints);
     } else {
-        let mut passes: Vec<_> = late_module_passes.iter().map(|mk_pass| (mk_pass)(tcx)).collect();
-        passes.push(Box::new(builtin_lints));
-        let pass = RuntimeCombinedLateLintPass { passes: &mut passes[..] };
+        let passes: Vec<_> =
+            store.late_module_passes.iter().map(|mk_pass| (mk_pass)(tcx)).collect();
+
+        // Filter unused lints
+        let (lints_to_emit, lints_allowed) = &**tcx.lints_that_can_emit(());
+        // let lints_to_emit = &lints_that_can_emit.0;
+        // let lints_allowed = &lints_that_can_emit.1;
+
+        // Now, we'll filtered passes in a way that discards any lint that won't trigger.
+        // If any lint is a given pass is detected to be emitted, we will keep that pass.
+        // Otherwise, we don't
+        let mut filtered_passes: Vec<Box<dyn LateLintPass<'tcx>>> = passes
+            .into_iter()
+            .filter(|pass| {
+                let pass = LintPass::get_lints(pass);
+                pass.iter().any(|&lint| {
+                    let lint_name = name_without_tool(&lint.name.to_lowercase()).to_string();
+                    lints_to_emit.contains(&lint_name)
+                        || (!lints_allowed.contains(&lint_name)
+                            && lint.default_level != crate::Level::Allow)
+                })
+            })
+            .collect();
+
+        filtered_passes.push(Box::new(builtin_lints));
+
+        let pass = RuntimeCombinedLateLintPass { passes: &mut filtered_passes[..] };
         late_lint_mod_inner(tcx, module_def_id, context, pass);
     }
 }
@@ -454,3 +482,10 @@ pub fn check_crate<'tcx>(tcx: TyCtxt<'tcx>) {
         },
     );
 }
+
+/// Format name ignoring the name, useful for filtering non-used lints.
+/// For example, 'clippy::my_lint' will turn into 'my_lint'
+pub(crate) fn name_without_tool(name: &str) -> &str {
+    // Doing some calculations here to account for those separators
+    name.rsplit("::").next().unwrap_or(name)
+}

compiler/rustc_lint/src/levels.rs

@@ -1,6 +1,6 @@
 use rustc_ast_pretty::pprust;
-use rustc_data_structures::fx::FxIndexMap;
-use rustc_errors::{Diag, LintDiagnostic, MultiSpan};
+use rustc_data_structures::{fx::FxIndexMap, sync::Lrc};
+use rustc_errors::{Diag, DiagMessage, LintDiagnostic, MultiSpan};
 use rustc_feature::{Features, GateIssue};
 use rustc_hir::HirId;
 use rustc_hir::intravisit::{self, Visitor};
@@ -31,7 +31,7 @@
     OverruledAttributeSub, RequestedLevel, UnknownToolInScopedLint, UnsupportedGroup,
 };
 use crate::fluent_generated as fluent;
-use crate::late::unerased_lint_store;
+use crate::late::{unerased_lint_store, name_without_tool};
 use crate::lints::{
     DeprecatedLintName, DeprecatedLintNameFromCommandLine, IgnoredUnlessCrateSpecified,
     OverruledAttributeLint, RemovedLint, RemovedLintFromCommandLine, RenamedLint,
@@ -115,6 +115,36 @@ fn raw_lint_id_level(
     }
 }
 
+/// Walk the whole crate collecting nodes where lint levels change
+/// (e.g. `#[allow]` attributes), and joins that list with the warn-by-default
+/// (and not allowed in the crate) and CLI lints. The returned value is a tuple
+/// of 1. The lints that will emit (or at least, should run), and 2.
+/// The lints that are allowed at the crate level and will not emit.
+pub fn lints_that_can_emit(tcx: TyCtxt<'_>, (): ()) -> Lrc<(Vec<String>, Vec<String>)> {
+    let mut visitor = LintLevelMinimum::new(tcx);
+    visitor.process_opts();
+    tcx.hir().walk_attributes(&mut visitor);
+
+    let store = unerased_lint_store(&tcx.sess);
+
+    let lint_groups = store.get_lint_groups();
+    for group in lint_groups {
+        let binding = group.0.to_lowercase();
+        let group_name = name_without_tool(&binding).to_string();
+        if visitor.lints_to_emit.contains(&group_name) {
+            for lint in group.1 {
+                visitor.lints_to_emit.push(name_without_tool(&lint.to_string()).to_string());
+            }
+        } else if visitor.lints_allowed.contains(&group_name) {
+            for lint in &group.1 {
+                visitor.lints_allowed.push(name_without_tool(&lint.to_string()).to_string());
+            }
+        }
+    }
+
+    Lrc::new((visitor.lints_to_emit, visitor.lints_allowed))
+}
+
 #[instrument(level = "trace", skip(tcx), ret)]
 fn shallow_lint_levels_on(tcx: TyCtxt<'_>, owner: hir::OwnerId) -> ShallowLintLevelMap {
     let store = unerased_lint_store(tcx.sess);
@@ -301,6 +331,88 @@ fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
     }
 }
 
+/// Visitor with the only function of visiting every item-like in a crate and
+/// computing the highest level that every lint gets put to.
+///
+/// E.g., if a crate has a global #![allow(lint)] attribute, but a single item
+/// uses #[warn(lint)], this visitor will set that lint level as `Warn`
+struct LintLevelMinimum<'tcx> {
+    tcx: TyCtxt<'tcx>,
+    /// The actual list of detected lints.
+    lints_to_emit: Vec<String>,
+    lints_allowed: Vec<String>,
+}
+
+impl<'tcx> LintLevelMinimum<'tcx> {
+    pub fn new(tcx: TyCtxt<'tcx>) -> Self {
+        Self {
+            tcx,
+            // That magic number is the current number of lints + some more for possible future lints
+            lints_to_emit: Vec::with_capacity(230),
+            lints_allowed: Vec::with_capacity(100),
+        }
+    }
+
+    fn process_opts(&mut self) {
+        for (lint, level) in &self.tcx.sess.opts.lint_opts {
+            if *level == Level::Allow {
+                self.lints_allowed.push(lint.clone());
+            } else {
+                self.lints_to_emit.push(lint.to_string());
+            }
+        }
+    }
+}
+
+impl<'tcx> Visitor<'tcx> for LintLevelMinimum<'tcx> {
+    type NestedFilter = nested_filter::All;
+
+    fn nested_visit_map(&mut self) -> Self::Map {
+        self.tcx.hir()
+    }
+
+    fn visit_attribute(&mut self, attribute: &'tcx ast::Attribute) {
+        if let Some(meta) = attribute.meta() {
+            if [sym::warn, sym::deny, sym::forbid, sym::expect]
+                .iter()
+                .any(|kind| meta.has_name(*kind))
+            {
+                // SAFETY: Lint attributes are always a metalist inside a
+                // metalist (even with just one lint).
+                for meta_list in meta.meta_item_list().unwrap() {
+                    // If it's a tool lint (e.g. clippy::my_clippy_lint)
+                    if let ast::NestedMetaItem::MetaItem(meta_item) = meta_list {
+                        if meta_item.path.segments.len() == 1 {
+                            self.lints_to_emit.push(
+                                // SAFETY: Lint attributes can only have literals
+                                meta_list.ident().unwrap().name.as_str().to_string(),
+                            );
+                        } else {
+                            self.lints_to_emit
+                                .push(meta_item.path.segments[1].ident.name.as_str().to_string());
+                        }
+                    }
+                }
+            // We handle #![allow]s differently, as these remove checking rather than adding.
+            } else if meta.has_name(sym::allow)
+                && let ast::AttrStyle::Inner = attribute.style
+            {
+                for meta_list in meta.meta_item_list().unwrap() {
+                    // If it's a tool lint (e.g. clippy::my_clippy_lint)
+                    if let ast::NestedMetaItem::MetaItem(meta_item) = meta_list {
+                        if meta_item.path.segments.len() == 1 {
+                            self.lints_allowed.push(meta_list.name_or_empty().as_str().to_string())
+                        } else {
+                            self.lints_allowed
+                                .push(meta_item.path.segments[1].ident.name.as_str().to_string());
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
 pub struct LintLevelsBuilder<'s, P> {
     sess: &'s Session,
     features: &'s Features,
@@ -931,7 +1043,8 @@ pub fn emit_lint(&self, lint: &'static Lint, decorate: impl for<'a> LintDiagnost
 }
 
 pub(crate) fn provide(providers: &mut Providers) {
-    *providers = Providers { shallow_lint_levels_on, ..*providers };
+    *providers =
+        Providers { shallow_lint_levels_on, lints_that_can_emit, ..*providers };
 }
 
 pub(crate) fn parse_lint_and_tool_name(lint_name: &str) -> (Option<Symbol>, &str) {

compiler/rustc_lint/src/lib.rs

@@ -170,7 +170,7 @@ fn lint_mod(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     [
         pub BuiltinCombinedEarlyLintPass,
         [
-            UnusedParens: UnusedParens::new(),
+            UnusedParens: UnusedParens::default(),
             UnusedBraces: UnusedBraces,
             UnusedImportBraces: UnusedImportBraces,
             UnsafeCode: UnsafeCode,
@@ -178,7 +178,7 @@ fn lint_mod(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
             AnonymousParameters: AnonymousParameters,
             EllipsisInclusiveRangePatterns: EllipsisInclusiveRangePatterns::default(),
             NonCamelCaseTypes: NonCamelCaseTypes,
-            DeprecatedAttr: DeprecatedAttr::new(),
+            DeprecatedAttr: DeprecatedAttr::default(),
             WhileTrue: WhileTrue,
             NonAsciiIdents: NonAsciiIdents,
             HiddenUnicodeCodepoints: HiddenUnicodeCodepoints,
@@ -601,25 +601,25 @@ macro_rules! add_lint_group {
 }
 
 fn register_internals(store: &mut LintStore) {
-    store.register_lints(&LintPassImpl::get_lints());
+    store.register_lints(&LintPassImpl::default().get_lints());
     store.register_early_pass(|| Box::new(LintPassImpl));
-    store.register_lints(&DefaultHashTypes::get_lints());
+    store.register_lints(&DefaultHashTypes::default().get_lints());
     store.register_late_mod_pass(|_| Box::new(DefaultHashTypes));
-    store.register_lints(&QueryStability::get_lints());
+    store.register_lints(&QueryStability::default().get_lints());
     store.register_late_mod_pass(|_| Box::new(QueryStability));
-    store.register_lints(&ExistingDocKeyword::get_lints());
+    store.register_lints(&ExistingDocKeyword::default().get_lints());
     store.register_late_mod_pass(|_| Box::new(ExistingDocKeyword));
-    store.register_lints(&TyTyKind::get_lints());
+    store.register_lints(&TyTyKind::default().get_lints());
     store.register_late_mod_pass(|_| Box::new(TyTyKind));
-    store.register_lints(&TypeIr::get_lints());
+    store.register_lints(&TypeIr::default().get_lints());
     store.register_late_mod_pass(|_| Box::new(TypeIr));
-    store.register_lints(&Diagnostics::get_lints());
+    store.register_lints(&Diagnostics::default().get_lints());
     store.register_late_mod_pass(|_| Box::new(Diagnostics));
-    store.register_lints(&BadOptAccess::get_lints());
+    store.register_lints(&BadOptAccess::default().get_lints());
     store.register_late_mod_pass(|_| Box::new(BadOptAccess));
-    store.register_lints(&PassByValue::get_lints());
+    store.register_lints(&PassByValue::default().get_lints());
     store.register_late_mod_pass(|_| Box::new(PassByValue));
-    store.register_lints(&SpanUseEqCtxt::get_lints());
+    store.register_lints(&SpanUseEqCtxt::default().get_lints());
     store.register_late_mod_pass(|_| Box::new(SpanUseEqCtxt));
     // FIXME(davidtwco): deliberately do not include `UNTRANSLATABLE_DIAGNOSTIC` and
     // `DIAGNOSTIC_OUTSIDE_OF_IMPL` here because `-Wrustc::internal` is provided to every crate and

compiler/rustc_lint/src/passes.rs

@@ -110,7 +110,7 @@ impl $name {
 
             $v fn get_lints() -> $crate::LintVec {
                 let mut lints = Vec::new();
-                $(lints.extend_from_slice(&$pass::get_lints());)*
+                $(lints.extend_from_slice(&$pass::default().get_lints());)*
                 lints
             }
         }
@@ -124,6 +124,9 @@ impl $crate::LintPass for $name {
             fn name(&self) -> &'static str {
                 panic!()
             }
+            fn get_lints(&self) -> LintVec {
+                panic!()
+            }
         }
     )
 }
@@ -222,7 +225,7 @@ impl $name {
 
             $v fn get_lints() -> $crate::LintVec {
                 let mut lints = Vec::new();
-                $(lints.extend_from_slice(&$pass::get_lints());)*
+                $(lints.extend_from_slice(&$pass::default().get_lints());)*
                 lints
             }
         }
@@ -236,6 +239,9 @@ impl $crate::LintPass for $name {
             fn name(&self) -> &'static str {
                 panic!()
             }
+            fn get_lints(&self) -> LintVec {
+                panic!()
+            }
         }
     )
 }

compiler/rustc_lint/src/types.rs

@@ -165,7 +165,7 @@
     "detects ambiguous wide pointer comparisons"
 }
 
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Default)]
 pub(crate) struct TypeLimits {
     /// Id of the last visited negated expression
     negated_expr_id: Option<hir::HirId>,

compiler/rustc_lint/src/unused.rs

@@ -1025,8 +1025,8 @@ pub(crate) struct UnusedParens {
     parens_in_cast_in_lt: Vec<ast::NodeId>,
 }
 
-impl UnusedParens {
-    pub(crate) fn new() -> Self {
+impl Default for UnusedParens {
+    fpub(crate) fn default() -> Self {
         Self { with_self_ty_parens: false, parens_in_cast_in_lt: Vec::new() }
     }
 }

compiler/rustc_lint_defs/src/builtin.rs

@@ -378,7 +378,8 @@
     /// will not overflow.
     pub ARITHMETIC_OVERFLOW,
     Deny,
-    "arithmetic operation overflows"
+    "arithmetic operation overflows",
+    [loadbearing: true]
 }
 
 declare_lint! {
@@ -633,7 +634,8 @@
     /// is only available in a newer version.
     pub UNKNOWN_LINTS,
     Warn,
-    "unrecognized lint attribute"
+    "unrecognized lint attribute",
+    [loadbearing: true]
 }
 
 declare_lint! {

compiler/rustc_lint_defs/src/lib.rs

@@ -312,6 +312,10 @@ pub struct Lint {
     pub feature_gate: Option<Symbol>,
 
     pub crate_level_only: bool,
+
+    /// `true` if this lint should not be filtered out under any circustamces
+    /// (e.g. the unknown_attributes lint)
+    pub loadbearing: bool,
 }
 
 /// Extra information for a future incompatibility lint.
@@ -456,6 +460,7 @@ pub const fn default_fields_for_macro() -> Self {
             future_incompatible: None,
             feature_gate: None,
             crate_level_only: false,
+            loadbearing: false,
         }
     }
 
@@ -863,7 +868,7 @@ macro_rules! declare_lint {
             $(#[$attr])* $vis $NAME, $Level, $desc,
         );
     );
-    ($(#[$attr:meta])* $vis: vis $NAME: ident, $Level: ident, $desc: expr,
+    ($(#[$attr:meta])* $vis: vis $NAME: ident, $Level: ident, $desc: expr, $([loadbearing: $loadbearing: literal])?
      $(@feature_gate = $gate:ident;)?
      $(@future_incompatible = FutureIncompatibleInfo {
         reason: $reason:expr,
@@ -885,6 +890,7 @@ macro_rules! declare_lint {
                 ..$crate::FutureIncompatibleInfo::default_fields_for_macro()
             }),)?
             $(edition_lint_opts: Some(($crate::Edition::$lint_edition, $crate::$edition_level)),)?
+            $(loadbearing: $loadbearing,)?
             ..$crate::Lint::default_fields_for_macro()
         };
     );
@@ -895,6 +901,7 @@ macro_rules! declare_tool_lint {
     (
         $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level: ident, $desc: expr
         $(, @feature_gate = $gate:ident;)?
+        $(, [loadbearing: $loadbearing: literal])?
     ) => (
         $crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, false $(, @feature_gate = $gate;)?}
     );
@@ -902,6 +909,7 @@ macro_rules! declare_tool_lint {
         $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr,
         report_in_external_macro: $rep:expr
         $(, @feature_gate = $gate:ident;)?
+        $(, [loadbearing: $loadbearing: literal])?
     ) => (
          $crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, $rep $(, @feature_gate = $gate;)?}
     );
@@ -909,6 +917,7 @@ macro_rules! declare_tool_lint {
         $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr,
         $external:expr
         $(, @feature_gate = $gate:ident;)?
+        $(, [loadbearing: $loadbearing: literal])?
     ) => (
         $(#[$attr])*
         $vis static $NAME: &$crate::Lint = &$crate::Lint {
@@ -921,6 +930,7 @@ macro_rules! declare_tool_lint {
             is_externally_loaded: true,
             $(feature_gate: Some(rustc_span::symbol::sym::$gate),)?
             crate_level_only: false,
+            $(loadbearing: $loadbearing,)?
             ..$crate::Lint::default_fields_for_macro()
         };
     );
@@ -930,6 +940,7 @@ macro_rules! declare_tool_lint {
 
 pub trait LintPass {
     fn name(&self) -> &'static str;
+    fn get_lints(&self) -> LintVec;
 }
 
 /// Implements `LintPass for $ty` with the given list of `Lint` statics.
@@ -938,9 +949,7 @@ macro_rules! impl_lint_pass {
     ($ty:ty => [$($lint:expr),* $(,)?]) => {
         impl $crate::LintPass for $ty {
             fn name(&self) -> &'static str { stringify!($ty) }
-        }
-        impl $ty {
-            pub fn get_lints() -> $crate::LintVec { vec![$($lint),*] }
+            fn get_lints(&self) -> $crate::LintVec { vec![$($lint),*] }
         }
     };
 }
@@ -950,7 +959,18 @@ pub fn get_lints() -> $crate::LintVec { vec![$($lint),*] }
 #[macro_export]
 macro_rules! declare_lint_pass {
     ($(#[$m:meta])* $name:ident => [$($lint:expr),* $(,)?]) => {
-        $(#[$m])* #[derive(Copy, Clone)] pub struct $name;
+        $(#[$m])* #[derive(Copy, Clone, Default)] pub struct $name;
         $crate::impl_lint_pass!($name => [$($lint),*]);
     };
 }
+
+#[allow(rustc::lint_pass_impl_without_macro)]
+impl<P: LintPass + ?Sized> LintPass for Box<P> {
+    fn name(&self) -> &'static str {
+        (**self).name()
+    }
+
+    fn get_lints(&self) -> LintVec {
+        (**self).get_lints()
+    }
+}

compiler/rustc_middle/Cargo.toml

@@ -27,6 +27,7 @@ rustc_graphviz = { path = "../rustc_graphviz" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_hir_pretty = { path = "../rustc_hir_pretty" }
 rustc_index = { path = "../rustc_index" }
+rustc_lint_defs = { path = "../rustc_lint_defs" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_query_system = { path = "../rustc_query_system" }
 rustc_serialize = { path = "../rustc_serialize" }

compiler/rustc_middle/src/lint.rs

@@ -117,7 +117,7 @@ impl ShallowLintLevelMap {
     /// This lint level is not usable for diagnostics, it needs to be corrected by
     /// `reveal_actual_level` beforehand.
     #[instrument(level = "trace", skip(self, tcx), ret)]
-    fn probe_for_lint_level(
+    pub fn probe_for_lint_level(
         &self,
         tcx: TyCtxt<'_>,
         id: LintId,

compiler/rustc_middle/src/query/mod.rs

@@ -422,6 +422,11 @@
         desc { "computing `#[expect]`ed lints in this crate" }
     }
 
+    query lints_that_can_emit(_: ()) -> &'tcx Lrc<(Vec<String>, Vec<String>)> {
+        arena_cache
+        desc { "Computing all lints that are explicitly enabled or with a default level greater than Allow" }
+    }
+
     query expn_that_defined(key: DefId) -> rustc_span::ExpnId {
         desc { |tcx| "getting the expansion that defined `{}`", tcx.def_path_str(key) }
         separate_provide_extern

src/librustdoc/lint.rs

@@ -2,7 +2,7 @@
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_lint::LintStore;
-use rustc_lint_defs::{Lint, LintId, declare_tool_lint};
+use rustc_lint_defs::{Lint, LintId, LintPass, declare_tool_lint};
 use rustc_session::{Session, lint};
 
 /// This function is used to setup the lint initialization. By default, in rustdoc, everything
@@ -31,9 +31,10 @@ pub(crate) fn init_lints<F>(
     allowed_lints.extend(lint_opts.iter().map(|(lint, _)| lint).cloned());
 
     let lints = || {
-        lint::builtin::HardwiredLints::get_lints()
+        lint::builtin::HardwiredLints::default()
+            .get_lints()
             .into_iter()
-            .chain(rustc_lint::SoftLints::get_lints())
+            .chain(rustc_lint::SoftLints::default().get_lints())
     };
 
     let lint_opts = lints()

src/tools/clippy/clippy_lints/src/asm_syntax.rs

@@ -3,7 +3,7 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use rustc_ast::ast::{Expr, ExprKind, InlineAsmOptions};
 use rustc_ast::{InlineAsm, Item, ItemKind};
-use rustc_lint::{EarlyContext, EarlyLintPass, Lint, LintContext};
+use rustc_lint::{EarlyContext, EarlyLintPass, Lint, LintPass, LintContext};
 use rustc_session::declare_lint_pass;
 use rustc_span::Span;
 use rustc_target::asm::InlineAsmArch;

src/tools/clippy/clippy_lints/src/utils/internal_lints/author.rs

@@ -12,7 +12,7 @@
 use std::cell::Cell;
 use std::fmt::{Display, Formatter, Write as _};
 
-declare_lint_pass!(
+declare_clippy_lint!{
     /// ### What it does
     /// Generates clippy code that detects the offending pattern
     ///
@@ -44,8 +44,13 @@
     ///     // report your lint here
     /// }
     /// ```
-    Author => []
-);
+    #[clippy::version = "1.0.0"]
+    pub AUTHOR,
+    internal,
+    "The author lint, see documentation at <https://doc.rust-lang.org/nightly/clippy/development/adding_lints.html#author-lint>"
+};
+
+declare_lint_pass! { Author => [AUTHOR] }
 
 /// Writes a line of output with indentation added
 macro_rules! out {

src/tools/clippy/clippy_lints/src/utils/mod.rs

@@ -1,4 +1,3 @@
-pub mod author;
 pub mod dump_hir;
 pub mod format_args_collector;
 #[cfg(feature = "internal")]

src/tools/clippy/tests/ui-internal/author.rs

@@ -1,3 +1,5 @@
+#![warn(clippy::author)]
+
 fn main() {
     #[clippy::author]
     let x: char = 0x45 as char;

src/tools/clippy/tests/ui/no_lints.rs

@@ -0,0 +1,3 @@
+#![deny(clippy::all)]
+
+fn main() {}

tests/ui-fulldeps/internal-lints/lint_pass_impl_without_macro.rs

@@ -6,7 +6,7 @@
 extern crate rustc_middle;
 extern crate rustc_session;
 
-use rustc_session::lint::{LintPass, LintVec};
+use rustc_session::lint::{LintPass, LintVec, Lint};
 use rustc_session::{declare_lint, declare_lint_pass, impl_lint_pass};
 
 declare_lint! {
@@ -21,6 +21,10 @@ impl LintPass for Foo { //~ERROR implementing `LintPass` by hand
     fn name(&self) -> &'static str {
         "Foo"
     }
+
+    fn get_lints(&self) -> Vec<&'static Lint> {
+        vec![TEST_LINT]
+    }
 }
 
 macro_rules! custom_lint_pass_macro {
@@ -31,6 +35,10 @@ impl LintPass for Custom { //~ERROR implementing `LintPass` by hand
             fn name(&self) -> &'static str {
                 "Custom"
             }
+
+            fn get_lints(&self) -> Vec<&'static Lint> {
+                vec![TEST_LINT]
+            }
         }
     };
 }

tests/ui-fulldeps/internal-lints/lint_pass_impl_without_macro.stderr

@@ -12,7 +12,7 @@ LL | #![deny(rustc::lint_pass_impl_without_macro)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: implementing `LintPass` by hand
-  --> $DIR/lint_pass_impl_without_macro.rs:30:14
+  --> $DIR/lint_pass_impl_without_macro.rs:34:14
    |
 LL |         impl LintPass for Custom {
    |              ^^^^^^^^