Auto merge of rust-lang#102236 - cjgillot:compute_lint_levels_by_def,…

… r=oli-obk

Compute lint levels by definition

Second attempt to rust-lang#101620.

I think that I have removed the perf regression.

compiler/rustc_data_structures/src/sorted_map.rs

@@ -96,6 +96,23 @@ impl<K: Ord, V> SortedMap<K, V> {
         }
     }
 
+    /// Gets a mutable reference to the value in the entry, or insert a new one.
+    #[inline]
+    pub fn get_mut_or_insert_default(&mut self, key: K) -> &mut V
+    where
+        K: Eq,
+        V: Default,
+    {
+        let index = match self.lookup_index_for(&key) {
+            Ok(index) => index,
+            Err(index) => {
+                self.data.insert(index, (key, V::default()));
+                index
+            }
+        };
+        unsafe { &mut self.data.get_unchecked_mut(index).1 }
+    }
+
     #[inline]
     pub fn clear(&mut self) {
         self.data.clear();

compiler/rustc_errors/src/diagnostic.rs

@@ -364,9 +364,10 @@ impl Diagnostic {
             // The lint index inside the attribute is manually transferred here.
             let lint_index = expectation_id.get_lint_index();
             expectation_id.set_lint_index(None);
-            let mut stable_id = *unstable_to_stable
+            let mut stable_id = unstable_to_stable
                 .get(&expectation_id)
-                .expect("each unstable `LintExpectationId` must have a matching stable id");
+                .expect("each unstable `LintExpectationId` must have a matching stable id")
+                .normalize();
 
             stable_id.set_lint_index(lint_index);
             *expectation_id = stable_id;

compiler/rustc_errors/src/lib.rs

@@ -1211,7 +1211,7 @@ impl HandlerInner {
 
         if let Some(expectation_id) = diagnostic.level.get_expectation_id() {
             self.suppressed_expected_diag = true;
-            self.fulfilled_expectations.insert(expectation_id);
+            self.fulfilled_expectations.insert(expectation_id.normalize());
         }
 
         if matches!(diagnostic.level, Warning(_))

compiler/rustc_lint/src/context.rs

@@ -558,7 +558,7 @@ pub struct LateContext<'tcx> {
 
 /// Context for lint checking of the AST, after expansion, before lowering to HIR.
 pub struct EarlyContext<'a> {
-    pub builder: LintLevelsBuilder<'a>,
+    pub builder: LintLevelsBuilder<'a, crate::levels::TopDown>,
     pub buffered: LintBuffer,
 }
 

compiler/rustc_lint/src/early.rs

@@ -58,6 +58,7 @@ impl<'a, T: EarlyLintPass> EarlyContextAndPass<'a, T> {
         F: FnOnce(&mut Self),
     {
         let is_crate_node = id == ast::CRATE_NODE_ID;
+        debug!(?id);
         let push = self.context.builder.push(attrs, is_crate_node, None);
 
         self.check_id(id);

compiler/rustc_lint/src/expect.rs

@@ -16,8 +16,10 @@ fn check_expectations(tcx: TyCtxt<'_>, tool_filter: Option<Symbol>) {
         return;
     }
 
+    let lint_expectations = tcx.lint_expectations(());
     let fulfilled_expectations = tcx.sess.diagnostic().steal_fulfilled_expectation_ids();
-    let lint_expectations = &tcx.lint_levels(()).lint_expectations;
+
+    tracing::debug!(?lint_expectations, ?fulfilled_expectations);
 
     for (id, expectation) in lint_expectations {
         // This check will always be true, since `lint_expectations` only