Auto merge of #160187 - cjgillot:lint-should-be-skipped, r=<try>

Hide skippable_lints.

Author: bors

compiler/rustc_hir_analysis/src/check/region.rs

@@ -146,10 +146,7 @@ fn resolve_block<'tcx>(
             let edition = blk.span.edition();
             let terminating = edition.at_least_rust_2024();
             if !terminating
-                && !visitor
-                    .tcx
-                    .skippable_lints(())
-                    .contains(&lint::LintId::of(lint::builtin::TAIL_EXPR_DROP_ORDER))
+                && !visitor.tcx.lint_should_be_skipped(lint::builtin::TAIL_EXPR_DROP_ORDER)
             {
                 // If this temporary scope will be changing once the codebase adopts Rust 2024,
                 // and we are linting about possible semantic changes that would result,

compiler/rustc_lint/src/if_let_rescope.rs

@@ -11,7 +11,7 @@ use rustc_middle::ty::significant_drop_order::{
     extract_component_with_significant_dtor, ty_dtor_span,
 };
 use rustc_middle::ty::{self, Ty, TyCtxt};
-use rustc_session::lint::{LintId, fcw};
+use rustc_session::lint::fcw;
 use rustc_session::{declare_lint, impl_lint_pass};
 use rustc_span::{DUMMY_SP, Span};
 use smallvec::SmallVec;
@@ -268,8 +268,7 @@ impl_lint_pass!(
 
 impl<'tcx> LateLintPass<'tcx> for IfLetRescope {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'tcx>) {
-        if expr.span.edition().at_least_rust_2024()
-            || cx.tcx.skippable_lints(()).contains(&LintId::of(IF_LET_RESCOPE))
+        if expr.span.edition().at_least_rust_2024() || cx.tcx.lint_should_be_skipped(IF_LET_RESCOPE)
         {
             return;
         }

compiler/rustc_lint/src/late.rs

@@ -348,18 +348,16 @@ pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx> + 'tcx>(
         only_module: true,
     };
 
-    let skippable_lints = tcx.skippable_lints(());
-
     // 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 mut passes: Vec<_> = unerased_lint_store(tcx.sess)
         .late_lint_mod_passes
         .iter()
         .map(|mk_pass| mk_pass(tcx))
-        .filter(|pass| is_lint_pass_required(skippable_lints, &pass.get_lints()))
+        .filter(|pass| is_lint_pass_required(tcx, &pass.get_lints()))
         .collect();
-    let builtin_lints_must_run = is_lint_pass_required(skippable_lints, &builtin_lints.get_lints());
+    let builtin_lints_must_run = is_lint_pass_required(tcx, &builtin_lints.get_lints());
     if passes.is_empty() {
         if builtin_lints_must_run {
             late_lint_mod_inner(tcx, mod_id, context, builtin_lints);
@@ -398,14 +396,12 @@ fn late_lint_mod_inner<'tcx, T: LateLintPass<'tcx>>(
 }
 
 fn late_lint_crate<'tcx>(tcx: TyCtxt<'tcx>) {
-    let skippable_lints = tcx.skippable_lints(());
-
     // Note: `passes` is often empty after filtering.
     let passes: Vec<_> = unerased_lint_store(tcx.sess)
         .late_lint_passes
         .iter()
         .map(|mk_pass| mk_pass(tcx))
-        .filter(|pass| is_lint_pass_required(skippable_lints, &pass.get_lints()))
+        .filter(|pass| is_lint_pass_required(tcx, &pass.get_lints()))
         .collect();
     if passes.is_empty() {
         return;

compiler/rustc_lint/src/levels.rs

@@ -121,12 +121,6 @@ fn skippable_lints(tcx: TyCtxt<'_>, (): ()) -> UnordSet<LintId> {
     let mut skippable: FxHashSet<LintId> = store
         .get_lints()
         .into_iter()
-        .filter(|lint| {
-            // Lints that show up in future-compat reports must always be run.
-            let has_future_breakage =
-                lint.future_incompatible.is_some_and(|fut| fut.report_in_deps);
-            !has_future_breakage && !lint.eval_always
-        })
         .filter(|lint| {
             let level_spec =
                 root_map.lint_level_spec_at_node(tcx, LintId::of(lint), hir::CRATE_HIR_ID);

compiler/rustc_lint/src/lib.rs

@@ -120,7 +120,6 @@ use ptr_nulls::*;
 use redundant_semicolon::*;
 use reference_casting::*;
 use runtime_symbols::*;
-use rustc_data_structures::unord::UnordSet;
 use rustc_hir::def_id::LocalModId;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::TyCtxt;
@@ -754,15 +753,15 @@ fn register_internals(store: &mut LintStore) {
 ///
 /// Note: this is a conservative estimate intended for optimization purposes. It might return
 /// `true` for a pass that need not run, but it will never return `false` for a pass that must run.
-pub fn is_lint_pass_required(skippable: &UnordSet<LintId>, lints: &LintVec) -> bool {
+pub fn is_lint_pass_required(tcx: TyCtxt<'_>, lints: &LintVec) -> bool {
     // A pass without any lints? Clippy sometimes does this, to collect things while traversing.
     // Such a pass must always run.
     if lints.is_empty() {
         return true;
     }
 
     // Otherwise, the pass must run unless all lints within are skippable.
-    !lints.iter().all(|lint| skippable.contains(&LintId::of(lint)))
+    !lints.iter().all(|lint| tcx.lint_should_be_skipped(lint))
 }
 
 #[cfg(test)]

compiler/rustc_middle/src/lint.rs

@@ -244,6 +244,22 @@ impl ShallowLintLevelMap {
 }
 
 impl TyCtxt<'_> {
+    /// Return whether the code to produce this lint can be skipped.
+    pub fn lint_should_be_skipped(self, lint: &'static Lint) -> bool {
+        if lint.eval_always {
+            return false;
+        }
+
+        // Lints that show up in future-compat reports must always be run.
+        if let Some(fut) = lint.future_incompatible
+            && fut.report_in_deps
+        {
+            return false;
+        }
+
+        self.skippable_lints(()).contains(&LintId::of(lint))
+    }
+
     /// Fetch and return the user-visible lint level spec for the given lint at the given HirId.
     pub fn lint_level_spec_at_node(self, lint: &'static Lint, id: HirId) -> StableLevelSpec {
         self.shallow_lint_levels_on(id.owner).lint_level_spec_at_node(self, LintId::of(lint), id)

compiler/rustc_middle/src/queries.rs

@@ -547,6 +547,8 @@ rustc_queries! {
         desc { "computing `#[expect]`ed lints in this crate" }
     }
 
+    /// Gathers lints that are alloed in the whole crate and do not need to be computed.
+    /// Do not use this query directly, use `tcx.lint_should_be_skipped(lint)` instead.
     query skippable_lints(_: ()) -> &'tcx UnordSet<LintId> {
         arena_cache
         // This depends on the lint store, which includes internal lints when the

compiler/rustc_mir_transform/src/lint_tail_expr_drop_order.rs

@@ -186,8 +186,7 @@ pub(crate) fn run_lint<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId, body: &Body<
         // A synthetic coroutine has no HIR body and it is enough to just analyse the original body
         return;
     }
-    if body.span.edition().at_least_rust_2024()
-        || tcx.skippable_lints(()).contains(&lint::LintId::of(TAIL_EXPR_DROP_ORDER))
+    if body.span.edition().at_least_rust_2024() || tcx.lint_should_be_skipped(TAIL_EXPR_DROP_ORDER)
     {
         return;
     }

src/tools/clippy/clippy_lints/src/lib.rs

@@ -469,8 +469,7 @@ pub fn register_lint_passes(store: &mut rustc_lint::LintStore, conf: &'static Co
     }
 
     store.register_late_lint_pass(Box::new(move |tcx: TyCtxt<'_>| {
-        let skippable_lints = tcx.skippable_lints(());
-        let is_active = |lints: &rustc_lint::LintVec| is_lint_pass_required(skippable_lints, lints);
+        let is_active = |lints: &rustc_lint::LintVec| is_lint_pass_required(tcx, lints);
         Box::new(CombinedLateLintPass::new(
             tcx,
             conf,