Auto merge of rust-lang#139597 - Kobzol:lint-skip, r=<try>

Do not run per-module lints if they can be all skipped

We run ~70 late lints for all dependencies even if they use `--cap-lints=allow`, which seems wasteful. It looks like these lints are super fast, but still.

r? `@ghost`

Author: bors

compiler/rustc_lint/src/late.rs

@@ -356,7 +356,14 @@ pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx> + 'tcx>(
     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);
+        // If all builtin lints can be skipped, there is no point in running `late_lint_mod_inner`
+        // at all. This happens often for dependencies built with `--cap-lints=allow`.
+        let dont_need_to_run = tcx.lints_that_dont_need_to_run(());
+        let can_skip_lints =
+            builtin_lints.get_lints().iter().all(|l| dont_need_to_run.contains(&LintId::of(l)));
+        if !can_skip_lints {
+            late_lint_mod_inner(tcx, module_def_id, context, builtin_lints);
+        }
     } else {
         let builtin_lints = Box::new(builtin_lints) as Box<dyn LateLintPass<'tcx>>;
         let mut binding = store

compiler/rustc_lint/src/passes.rs

@@ -92,7 +92,7 @@ macro_rules! expand_combined_late_lint_pass_methods {
 /// Combines multiple lints passes into a single lint pass, at compile time,
 /// for maximum speed. Each `check_foo` method in `$methods` within this pass
 /// simply calls `check_foo` once per `$pass`. Compare with
-/// `LateLintPassObjects`, which is similar, but combines lint passes at
+/// `RuntimeCombinedLateLintPass`, which is similar, but combines lint passes at
 /// runtime.
 #[macro_export]
 macro_rules! declare_combined_late_lint_pass {
@@ -123,10 +123,10 @@ macro_rules! declare_combined_late_lint_pass {
         #[allow(rustc::lint_pass_impl_without_macro)]
         impl $crate::LintPass for $name {
             fn name(&self) -> &'static str {
-                panic!()
+                stringify!($name)
             }
             fn get_lints(&self) -> LintVec {
-                panic!()
+                $name::get_lints()
             }
         }
     )