From 9693552c5ca6694bd9b60917a98bda10f7aea158 Mon Sep 17 00:00:00 2001
From: Job Bautista <jobbautista9@aol.com>
Date: Sat, 6 May 2023 15:15:33 +0800
Subject: [PATCH] Issue #2232 - Parse exported async functions.

---
 js/src/frontend/Parser.cpp | 19 +++++++++++++++++--
 js/src/frontend/Parser.h   |  3 ++-
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/js/src/frontend/Parser.cpp b/js/src/frontend/Parser.cpp
index a33b3d0d90..841eb5f096 100644
--- a/js/src/frontend/Parser.cpp
+++ b/js/src/frontend/Parser.cpp
@@ -5778,14 +5778,15 @@ Parser<ParseHandler>::exportVariableStatement(uint32_t begin)
 
 template <typename ParseHandler>
 typename ParseHandler::UnaryNodeType
-Parser<ParseHandler>::exportFunctionDeclaration(uint32_t begin)
+Parser<ParseHandler>::exportFunctionDeclaration(uint32_t begin,
+                                                FunctionAsyncKind asyncKind /* = SyncFunction */)
 {
     if (!abortIfSyntaxParser())
         return null();
 
     MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_FUNCTION));
 
-    Node kid = functionStmt(pos().begin, YieldIsKeyword, NameRequired);
+    Node kid = functionStmt(pos().begin, YieldIsKeyword, NameRequired, asyncKind);
     if (!kid)
         return null();
 
@@ -6008,6 +6009,20 @@ Parser<ParseHandler>::exportDeclaration()
       case TOK_FUNCTION:
         return exportFunctionDeclaration(begin);
 
+      case TOK_ASYNC: {
+        TokenKind nextSameLine = TOK_EOF;
+        if (!tokenStream.peekTokenSameLine(&nextSameLine))
+            return null();
+
+        if (nextSameLine == TOK_FUNCTION) {
+            tokenStream.consumeKnownToken(TOK_FUNCTION);
+            return exportFunctionDeclaration(begin, AsyncFunction);
+        }
+
+        error(JSMSG_DECLARATION_AFTER_EXPORT);
+        return null();
+      }
+
       case TOK_CLASS:
         return exportClassDeclaration(begin);
 
diff --git a/js/src/frontend/Parser.h b/js/src/frontend/Parser.h
index 6976487c50..1819873308 100644
--- a/js/src/frontend/Parser.h
+++ b/js/src/frontend/Parser.h
@@ -1337,7 +1337,8 @@ FOR_EACH_PARSENODE_SUBCLASS(DECLARE_TYPE)
     BinaryNodeType exportBatch(uint32_t begin);
     bool checkLocalExportNames(ListNodeType node);
     Node exportClause(uint32_t begin);
-    UnaryNodeType exportFunctionDeclaration(uint32_t begin);
+    UnaryNodeType exportFunctionDeclaration(uint32_t begin,
+                                            FunctionAsyncKind asyncKind = SyncFunction);
     UnaryNodeType exportVariableStatement(uint32_t begin);
     UnaryNodeType exportClassDeclaration(uint32_t begin);
     UnaryNodeType exportLexicalDeclaration(uint32_t begin, DeclarationKind kind);