From 6e3cd7dd06bce74c8b9b9d1526e01436076773a6 Mon Sep 17 00:00:00 2001
From: Sam Atkins <sam@ladybird.org>
Date: Tue, 2 Sep 2025 15:13:22 +0100
Subject: [PATCH] LibIDL: Support partial namespaces

---
 Libraries/LibIDL/IDLParser.cpp | 18 ++++++++++++++++++
 Libraries/LibIDL/IDLParser.h   |  1 +
 Libraries/LibIDL/Types.h       |  1 +
 3 files changed, 20 insertions(+)

diff --git a/Libraries/LibIDL/IDLParser.cpp b/Libraries/LibIDL/IDLParser.cpp
index 4e854a9e131..3210d1b6128 100644
--- a/Libraries/LibIDL/IDLParser.cpp
+++ b/Libraries/LibIDL/IDLParser.cpp
@@ -858,6 +858,17 @@ void Parser::parse_namespace(Interface& interface)
     consume_whitespace();
 }
 
+void Parser::parse_partial_namespace(Interface& parent)
+{
+    assert_string("partial"sv);
+    consume_whitespace();
+    assert_string("namespace"sv);
+
+    auto partial_namespace = make<Interface>();
+    parse_namespace(*partial_namespace);
+    parent.partial_namespaces.append(move(partial_namespace));
+}
+
 // https://webidl.spec.whatwg.org/#prod-Enum
 void Parser::parse_enumeration(HashMap<ByteString, ByteString> extended_attributes, Interface& interface)
 {
@@ -1077,6 +1088,8 @@ void Parser::parse_non_interface_entities(bool allow_interface, Interface& inter
             parse_partial_interface(extended_attributes, interface);
         } else if (lexer.next_is("interface mixin"sv)) {
             parse_interface_mixin(interface);
+        } else if (lexer.next_is("partial namespace"sv)) {
+            parse_partial_namespace(interface);
         } else if (lexer.next_is("callback"sv)) {
             parse_callback_function(extended_attributes, interface);
         } else if ((allow_interface && !lexer.next_is("interface"sv) && !lexer.next_is("namespace"sv)) || !allow_interface) {
@@ -1229,6 +1242,11 @@ Interface& Parser::parse()
             interface.enumerations.set(enumeration.key, move(enumeration_copy));
         }
 
+        for (auto& partial_namespace : import.partial_namespaces) {
+            if (partial_namespace->namespace_class == interface.namespace_class)
+                interface.extend_with_partial_interface(*partial_namespace);
+        }
+
         interface.typedefs.update(import.typedefs);
 
         for (auto& mixin : import.mixins) {
diff --git a/Libraries/LibIDL/IDLParser.h b/Libraries/LibIDL/IDLParser.h
index cf6fc465db8..afa74554d1e 100644
--- a/Libraries/LibIDL/IDLParser.h
+++ b/Libraries/LibIDL/IDLParser.h
@@ -47,6 +47,7 @@ private:
     void parse_interface(Interface&);
     void parse_partial_interface(HashMap<ByteString, ByteString> extended_attributes, Interface& parent);
     void parse_namespace(Interface&);
+    void parse_partial_namespace(Interface& parent);
     void parse_non_interface_entities(bool allow_interface, Interface&);
     void parse_enumeration(HashMap<ByteString, ByteString>, Interface&);
     void parse_typedef(Interface&);
diff --git a/Libraries/LibIDL/Types.h b/Libraries/LibIDL/Types.h
index bd3ca7304cf..32851be0dba 100644
--- a/Libraries/LibIDL/Types.h
+++ b/Libraries/LibIDL/Types.h
@@ -323,6 +323,7 @@ public:
 
     ByteString module_own_path;
     Vector<NonnullOwnPtr<Interface>> partial_interfaces;
+    Vector<NonnullOwnPtr<Interface>> partial_namespaces;
     Vector<Interface&> imported_modules;
 
     OrderedHashMap<ByteString, Vector<Function&>> overload_sets;