2 files changed, 26 insertions, 6 deletions
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index 6a36ae63c68..dd7682ebace 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -3,13 +3,14 @@
 
 use crate::config::CheckCfg;
 use crate::lint::{BufferedEarlyLint, BuiltinLintDiagnostics, Lint, LintId};
+use crate::SessionDiagnostic;
 use rustc_ast::node_id::NodeId;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::sync::{Lock, Lrc};
 use rustc_errors::{emitter::SilentEmitter, ColorConfig, Handler};
 use rustc_errors::{
     error_code, fallback_fluent_bundle, Applicability, Diagnostic, DiagnosticBuilder,
-    ErrorGuaranteed, MultiSpan,
+    DiagnosticMessage, ErrorGuaranteed, MultiSpan,
 };
 use rustc_feature::{find_feature_issue, GateIssue, UnstableFeatures};
 use rustc_span::edition::Edition;
@@ -287,4 +288,19 @@ impl ParseSess {
     pub fn proc_macro_quoted_spans(&self) -> Vec<Span> {
         self.proc_macro_quoted_spans.lock().clone()
     }
+
+    pub fn emit_err<'a>(&'a self, err: impl SessionDiagnostic<'a>) -> ErrorGuaranteed {
+        err.into_diagnostic(self).emit()
+    }
+
+    pub fn emit_warning<'a>(&'a self, warning: impl SessionDiagnostic<'a, ()>) {
+        warning.into_diagnostic(self).emit()
+    }
+
+    pub fn struct_err(
+        &self,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, ErrorGuaranteed> {
+        self.span_diagnostic.struct_err(msg)
+    }
 }
diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index b4548129689..2bc0c5f1228 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/compiler/rustc_session/src/session.rs
@@ -212,7 +212,7 @@ pub struct PerfStats {
 pub trait SessionDiagnostic<'a, T: EmissionGuarantee = ErrorGuaranteed> {
     /// Write out as a diagnostic out of `sess`.
     #[must_use]
-    fn into_diagnostic(self, sess: &'a Session) -> DiagnosticBuilder<'a, T>;
+    fn into_diagnostic(self, sess: &'a ParseSess) -> DiagnosticBuilder<'a, T>;
 }
 
 impl Session {
@@ -334,7 +334,7 @@ impl Session {
         &self,
         msg: impl Into<DiagnosticMessage>,
     ) -> DiagnosticBuilder<'_, ErrorGuaranteed> {
-        self.diagnostic().struct_err(msg)
+        self.parse_sess.struct_err(msg)
     }
     pub fn struct_err_with_code(
         &self,
@@ -414,10 +414,10 @@ impl Session {
         self.diagnostic().err(msg)
     }
     pub fn emit_err<'a>(&'a self, err: impl SessionDiagnostic<'a>) -> ErrorGuaranteed {
-        err.into_diagnostic(self).emit()
+        self.parse_sess.emit_err(err)
     }
     pub fn emit_warning<'a>(&'a self, warning: impl SessionDiagnostic<'a, ()>) {
-        warning.into_diagnostic(self).emit()
+        self.parse_sess.emit_warning(warning)
     }
     #[inline]
     pub fn err_count(&self) -> usize {
@@ -783,7 +783,11 @@ impl Session {
             Path::new(&rustlib_path),
             Path::new("bin"),
         ]);
-        if self_contained { vec![p.clone(), p.join("self-contained")] } else { vec![p] }
+        if self_contained {
+            vec![p.clone(), p.join("self-contained")]
+        } else {
+            vec![p]
+        }
     }
 
     pub fn init_incr_comp_session(