Parsing support for adapt declarations. (#3871)

toolchain/parse/handle_adapt.cpp

@@ -0,0 +1,32 @@
+// 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
+
+#include "toolchain/parse/context.h"
+
+namespace Carbon::Parse {
+
+// Handles processing of a complete `adapt T` declaration.
+auto HandleAdaptDecl(Context& context) -> void {
+  // TODO: This is identical to HandleBaseDecl other than the `NodeKind`,
+  // and very similar to `HandleNamespaceFinish` and `HandleAliasFinish`.
+  // We should factor out this common work.
+  auto state = context.PopState();
+
+  auto semi = context.ConsumeIf(Lex::TokenKind::Semi);
+  if (!semi && !state.has_error) {
+    context.EmitExpectedDeclSemi(context.tokens().GetKind(state.token));
+    state.has_error = true;
+  }
+
+  if (state.has_error) {
+    context.RecoverFromDeclError(state, NodeKind::AdaptDecl,
+                                 /*skip_past_likely_end=*/true);
+    return;
+  }
+
+  context.AddNode(NodeKind::AdaptDecl, *semi, state.subtree_start,
+                  state.has_error);
+}
+
+}  // namespace Carbon::Parse