From 9d90a6794c6aad0cde4ae77e12e1733aa45221a0 Mon Sep 17 00:00:00 2001
From: HolonProduction <holonproduction@gmail.com>
Date: Fri, 9 Jan 2026 13:58:13 +0100
Subject: [PATCH] LSP: Reuse stale parsers in request

---
 .../gdscript_language_protocol.cpp            | 23 ++++++++++---------
 .../gdscript_language_protocol.h              |  8 +++----
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/modules/gdscript/language_server/gdscript_language_protocol.cpp b/modules/gdscript/language_server/gdscript_language_protocol.cpp
index 7662252c62..2d01c49cf2 100644
--- a/modules/gdscript/language_server/gdscript_language_protocol.cpp
+++ b/modules/gdscript/language_server/gdscript_language_protocol.cpp
@@ -107,6 +107,7 @@ Error GDScriptLanguageProtocol::LSPeer::handle_data() {
 
 		// Response
 		String output = GDScriptLanguageProtocol::get_singleton()->process_message(msg);
+		clear_stale_parsers();
 		if (!output.is_empty()) {
 			res_queue.push_back(output.utf8());
 		}
@@ -397,13 +398,18 @@ ExtendGDScriptParser *GDScriptLanguageProtocol::LSPeer::parse_script(const Strin
 		GDScriptLanguageProtocol::get_singleton()->get_workspace()->publish_diagnostics(p_path);
 	} else {
 		// Don't keep cached for further requests since we can't invalidate the cache properly.
-		parse_results.erase(p_path);
-		stale_parsers[p_path] = parser;
+		stale_parsers.insert(p_path);
 	}
 
 	return parser;
 }
 
+void GDScriptLanguageProtocol::LSPeer::clear_stale_parsers() {
+	while (!stale_parsers.is_empty()) {
+		remove_cached_parser(*stale_parsers.begin());
+	}
+}
+
 void GDScriptLanguageProtocol::LSPeer::remove_cached_parser(const String &p_path) {
 	HashMap<String, ExtendGDScriptParser *>::Iterator cached = parse_results.find(p_path);
 	if (cached) {
@@ -411,11 +417,7 @@ void GDScriptLanguageProtocol::LSPeer::remove_cached_parser(const String &p_path
 		parse_results.remove(cached);
 	}
 
-	HashMap<String, ExtendGDScriptParser *>::Iterator stale = stale_parsers.find(p_path);
-	if (stale) {
-		memdelete(stale->value);
-		stale_parsers.remove(stale);
-	}
+	stale_parsers.erase(p_path);
 }
 
 ExtendGDScriptParser *GDScriptLanguageProtocol::get_parse_result(const String &p_path) {
@@ -531,11 +533,10 @@ void GDScriptLanguageProtocol::resolve_related_symbols(const LSP::TextDocumentPo
 
 GDScriptLanguageProtocol::LSPeer::~LSPeer() {
 	while (!parse_results.is_empty()) {
-		remove_cached_parser(parse_results.begin()->key);
-	}
-	while (!stale_parsers.is_empty()) {
-		remove_cached_parser(stale_parsers.begin()->key);
+		String path = parse_results.begin()->key;
+		remove_cached_parser(path);
 	}
+	stale_parsers.clear();
 }
 
 // clang-format off
diff --git a/modules/gdscript/language_server/gdscript_language_protocol.h b/modules/gdscript/language_server/gdscript_language_protocol.h
index bff630e177..c0f30cb9c3 100644
--- a/modules/gdscript/language_server/gdscript_language_protocol.h
+++ b/modules/gdscript/language_server/gdscript_language_protocol.h
@@ -78,10 +78,10 @@ private:
 		~LSPeer();
 
 	private:
-		// We can't cache parsers for scripts not managed by the editor since we have
-		// no way to invalidate the cache. We still need to keep track of those parsers
-		// to clean them up properly.
-		HashMap<String, ExtendGDScriptParser *> stale_parsers;
+		void clear_stale_parsers();
+		// Paths of parsers which we can't cache longterm.
+		// Can be cleared up using `clear_stale_parsers()`.
+		HashSet<String> stale_parsers;
 	};
 
 	enum LSPErrorCode {