From 773a82f99570ece85e34b91f4a10181b72782c24 Mon Sep 17 00:00:00 2001
From: Jon Ross-Perkins <jperkins@google.com>
Date: Tue, 13 Dec 2022 14:32:37 -0800
Subject: [PATCH] Add support for empty declarations. (#2467)

---
 .../semantics_parse_tree_handler.cpp          |  6 +++--
 .../testdata/basics/empty_decl.carbon         | 23 +++++++++++++++++++
 2 files changed, 27 insertions(+), 2 deletions(-)
 create mode 100644 toolchain/semantics/testdata/basics/empty_decl.carbon

diff --git a/toolchain/semantics/semantics_parse_tree_handler.cpp b/toolchain/semantics/semantics_parse_tree_handler.cpp
index ba8142b2e02a..fa8749f5bae6 100644
--- a/toolchain/semantics/semantics_parse_tree_handler.cpp
+++ b/toolchain/semantics/semantics_parse_tree_handler.cpp
@@ -221,8 +221,10 @@ auto SemanticsParseTreeHandler::HandleDesignatorExpression(
 }
 
 auto SemanticsParseTreeHandler::HandleEmptyDeclaration(
-    ParseTree::Node /*parse_node*/) -> void {
-  CARBON_FATAL() << "TODO";
+    ParseTree::Node parse_node) -> void {
+  // Empty declarations have no actions associated, but we still balance the
+  // tree.
+  Push(parse_node);
 }
 
 auto SemanticsParseTreeHandler::HandleExpressionStatement(
diff --git a/toolchain/semantics/testdata/basics/empty_decl.carbon b/toolchain/semantics/testdata/basics/empty_decl.carbon
new file mode 100644
index 000000000000..392c8194518f
--- /dev/null
+++ b/toolchain/semantics/testdata/basics/empty_decl.carbon
@@ -0,0 +1,23 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+// RUN: %{carbon-run-semantics}
+// CHECK:STDOUT: cross_reference_irs.size == 2,
+// CHECK:STDOUT: cross_references = {
+// CHECK:STDOUT:   node_xref0 = xref(ir0, block0, node0);
+// CHECK:STDOUT:   node_xref1 = xref(ir0, block0, node1);
+// CHECK:STDOUT:   node_xref2 = xref(ir0, block0, node2);
+// CHECK:STDOUT:   node_xref3 = xref(ir0, block0, node3);
+// CHECK:STDOUT: },
+// CHECK:STDOUT: identifiers = {
+// CHECK:STDOUT: },
+// CHECK:STDOUT: integer_literals = {
+// CHECK:STDOUT: },
+// CHECK:STDOUT: node_blocks = {
+// CHECK:STDOUT:   block0 = {
+// CHECK:STDOUT:   },
+// CHECK:STDOUT: }
+
+;