Perf check for Diag migration

compiler/rustc_hir_analysis/src/lib.rs

@@ -148,21 +148,32 @@ pub fn provide(providers: &mut Providers) {
     };
 }
 
-fn emit_delayed_lint(lint: &DelayedLint, tcx: TyCtxt<'_>) {
+pub fn emit_delayed_lint(lint: &DelayedLint, tcx: TyCtxt<'_>) {
+    struct DiagEmitter<'tcx> {
+        hir_id: rustc_hir::HirId,
+        tcx: TyCtxt<'tcx>,
+        span: Span,
+        lint: &'static rustc_lint::Lint,
+    }
+
+    impl rustc_lint::EmitDiag for DiagEmitter<'_> {
+        fn emit(&self, diag: impl for<'a> rustc_errors::Diagnostic<'a, ()>) {
+            self.tcx.emit_node_span_lint(self.lint, self.hir_id, self.span, diag);
+        }
+    }
+
     match lint {
         DelayedLint::AttributeParsing(attribute_lint) => {
-            tcx.node_span_lint(
-                attribute_lint.lint_id.lint,
-                attribute_lint.id,
-                attribute_lint.span,
-                |diag| {
-                    rustc_lint::decorate_attribute_lint(
-                        tcx.sess,
-                        Some(tcx),
-                        &attribute_lint.kind,
-                        diag,
-                    );
+            rustc_lint::decorate_attribute_lint(
+                &DiagEmitter {
+                    hir_id: attribute_lint.id,
+                    tcx,
+                    span: attribute_lint.span,
+                    lint: attribute_lint.lint_id.lint,
                 },
+                tcx.sess,
+                Some(tcx),
+                &attribute_lint.kind,
             );
         }
     }

compiler/rustc_lint/src/context.rs

@@ -535,8 +535,8 @@ pub trait LintContext {
         decorate: impl for<'a> Diagnostic<'a, ()>,
     );
 
-    /// Emit a lint at `span` from a lint struct (some type that implements `LintDiagnostic`,
-    /// typically generated by `#[derive(LintDiagnostic)]`).
+    /// Emit a lint at `span` from a lint struct (some type that implements `Diagnostic`,
+    /// typically generated by `#[derive(Diagnostic)]`).
     fn emit_span_lint<S: Into<MultiSpan>>(
         &self,
         lint: &'static Lint,
@@ -573,16 +573,8 @@ pub trait LintContext {
         self.opt_span_lint(lint, Some(span), decorate);
     }
 
-    /// Emit a lint from a lint struct (some type that implements `LintDiagnostic`, typically
-    /// generated by `#[derive(LintDiagnostic)]`).
-    fn emit_lint(&self, lint: &'static Lint, decorator: impl for<'a> LintDiagnostic<'a, ()>) {
-        self.opt_span_lint(lint, None as Option<Span>, |lint| {
-            decorator.decorate_lint(lint);
-        });
-    }
-
-    /// Emit a lint from a lint struct (some type that implements `LintDiagnostic`, typically
-    /// generated by `#[derive(LintDiagnostic)]`).
+    /// Emit a lint from a lint struct (some type that implements `Diagnostic`, typically
+    /// generated by `#[derive(Diagnostic)]`).
     fn emit_diag_lint(&self, lint: &'static Lint, decorator: impl for<'a> Diagnostic<'a, ()>) {
         self.opt_span_diag_lint(lint, None as Option<Span>, decorator);
     }

compiler/rustc_lint/src/early.rs

@@ -7,14 +7,15 @@
 use rustc_ast::visit::{self as ast_visit, Visitor, walk_list};
 use rustc_ast::{self as ast, AttrVec, HasAttrs};
 use rustc_data_structures::stack::ensure_sufficient_stack;
-use rustc_errors::{BufferedEarlyLint, DecorateDiagCompat, LintBuffer};
+use rustc_errors::{BufferedEarlyLint, DecorateDiagCompat, Diagnostic, LintBuffer, MultiSpan};
 use rustc_feature::Features;
 use rustc_middle::ty::{RegisteredTools, TyCtxt};
 use rustc_session::Session;
 use rustc_session::lint::LintPass;
 use rustc_span::{Ident, Span};
 use tracing::debug;
 
+use crate::Lint;
 use crate::context::{EarlyContext, LintContext, LintStore};
 use crate::passes::{EarlyLintPass, EarlyLintPassObject};
 
@@ -32,16 +33,40 @@ pub struct EarlyContextAndPass<'ecx, 'tcx, T: EarlyLintPass> {
     pass: T,
 }
 
+pub trait EmitDiag {
+    fn emit(&self, diag: impl for<'a> Diagnostic<'a, ()>);
+}
+
+struct DiagEmitter<'a, 'b> {
+    ctx: &'a EarlyContext<'b>,
+    span: Option<MultiSpan>,
+    lint: &'static Lint,
+}
+
+impl EmitDiag for DiagEmitter<'_, '_> {
+    fn emit(&self, diag: impl for<'a> Diagnostic<'a, ()>) {
+        self.ctx.opt_span_diag_lint(self.lint, self.span.clone(), diag);
+    }
+}
+
 impl<'ecx, 'tcx, T: EarlyLintPass> EarlyContextAndPass<'ecx, 'tcx, T> {
     fn check_id(&mut self, id: ast::NodeId) {
         for early_lint in self.context.buffered.take(id) {
             let BufferedEarlyLint { span, node_id: _, lint_id, diagnostic } = early_lint;
-            self.context.opt_span_lint(lint_id.lint, span, |diag| match diagnostic {
+            match diagnostic {
                 DecorateDiagCompat::Builtin(b) => {
-                    diagnostics::decorate_builtin_lint(self.context.sess(), self.tcx, b, diag);
+                    diagnostics::decorate_builtin_lint(
+                        &DiagEmitter { ctx: &self.context, span, lint: lint_id.lint },
+                        self.context.sess(),
+                        self.tcx,
+                        b,
+                    );
                 }
-                DecorateDiagCompat::Dynamic(d) => d.decorate_lint_box(diag),
-            });
+                DecorateDiagCompat::Dynamic(d) => {
+                    self.context
+                        .opt_span_lint(lint_id.lint, span, |diag| d.decorate_lint_box(diag));
+                }
+            }
         }
     }