From 6a566ee092cacf6e4b327e7fdbbb1003a514b820 Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Sun, 2 Feb 2025 16:06:16 +0000
Subject: Replace ParseSess::set_dcx with DiagCtxt::set_emitter

Replacing the error emitter doesn't accidentally clear the error count.
---
 compiler/rustc_errors/src/lib.rs                                  | 4 ++++
 compiler/rustc_session/src/parse.rs                               | 4 ----
 .../examples/rustc-interface-getting-diagnostics.rs               | 8 ++++----
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index e64bb003dde..f30b6921cfb 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -712,6 +712,10 @@ impl DiagCtxt {
         inner.emitter = new_emitter;
     }
 
+    pub fn set_emitter(&self, emitter: Box<dyn Emitter + DynSend>) {
+        self.inner.borrow_mut().emitter = emitter;
+    }
+
     /// Translate `message` eagerly with `args` to `SubdiagMessage::Eager`.
     pub fn eagerly_translate<'a>(
         &self,
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index b6b13a715ec..81ae06602cd 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -337,8 +337,4 @@ impl ParseSess {
     pub fn dcx(&self) -> DiagCtxtHandle<'_> {
         self.dcx.handle()
     }
-
-    pub fn set_dcx(&mut self, dcx: DiagCtxt) {
-        self.dcx = dcx;
-    }
 }
diff --git a/src/doc/rustc-dev-guide/examples/rustc-interface-getting-diagnostics.rs b/src/doc/rustc-dev-guide/examples/rustc-interface-getting-diagnostics.rs
index be37dd867b2..2355cb85ab3 100644
--- a/src/doc/rustc-dev-guide/examples/rustc-interface-getting-diagnostics.rs
+++ b/src/doc/rustc-dev-guide/examples/rustc-interface-getting-diagnostics.rs
@@ -10,6 +10,8 @@ extern crate rustc_interface;
 extern crate rustc_session;
 extern crate rustc_span;
 
+use std::sync::{Arc, Mutex};
+
 use rustc_errors::emitter::Emitter;
 use rustc_errors::registry::{self, Registry};
 use rustc_errors::translation::Translate;
@@ -17,8 +19,6 @@ use rustc_errors::{DiagCtxt, DiagInner, FluentBundle};
 use rustc_session::config;
 use rustc_span::source_map::SourceMap;
 
-use std::sync::{Arc, Mutex};
-
 struct DebugEmitter {
     source_map: Arc<SourceMap>,
     diagnostics: Arc<Mutex<Vec<DiagInner>>>,
@@ -67,10 +67,10 @@ fn main() {
         locale_resources: rustc_driver::DEFAULT_LOCALE_RESOURCES.to_owned(),
         lint_caps: rustc_hash::FxHashMap::default(),
         psess_created: Some(Box::new(|parse_sess| {
-            parse_sess.set_dcx(DiagCtxt::new(Box::new(DebugEmitter {
+            parse_sess.dcx().set_emitter(Box::new(DebugEmitter {
                 source_map: parse_sess.clone_source_map(),
                 diagnostics,
-            })));
+            }));
         })),
         register_lints: None,
         override_queries: None,
-- 
cgit 1.4.1-3-g733a5