wait_stdin.patch

diff --git a/clang-tools-extra/clangd/JSONTransport.cpp b/clang-tools-extra/clangd/JSONTransport.cpp
index 9dc0df807..b1a4e9bd1 100644
--- a/clang-tools-extra/clangd/JSONTransport.cpp
+++ b/clang-tools-extra/clangd/JSONTransport.cpp
@@ -1,3 +1,26 @@
+#ifdef __EMSCRIPTEN__
+
+#include <emscripten.h>
+
+#include "support/Shutdown.h"
+#include <utility>
+
+EM_ASYNC_JS(void, waitForStdin, (), {
+  await Module.stdinReady();
+})
+
+template <typename Fun, typename Ret = decltype(std::declval<Fun>()())>
+Ret doUntilStdinAvailable(
+    const std::enable_if_t<true, Ret>& fail,
+    const Fun& f) {
+  waitForStdin();
+  return clang::clangd::retryAfterSignalUnlessShutdown(fail, f);
+}
+
+#define retryAfterSignalUnlessShutdown doUntilStdinAvailable
+
+#endif
+
 //===--- JSONTransport.cpp - sending and receiving LSP messages over JSON -===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.