split_link tool, config, and scripts for windows build

chrome/split_dll_fake_entry.cc

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <windows.h>
+
+extern "C" {
+
+// This entry point and file is used to work around circular dependencies
+// between the split DLLs. The CRT initialization will fail if done at attach
+// time. Instead, we defer initialization until after both DLLs are loaded and
+// then manually call the CRT initialization function (via DoDeferredCrtInit).
+//
+// ChromeEmptyEntry is the DLL's entry point.
+
+BOOL WINAPI _DllMainCRTStartup(HINSTANCE, DWORD, LPVOID);
+
+BOOL WINAPI ChromeEmptyEntry(HINSTANCE hinstance,
+                             DWORD reason,
+                             LPVOID reserved) {
+  if (reason != DLL_PROCESS_ATTACH)
+    _DllMainCRTStartup(hinstance, reason, reserved);
+  return 1;
+}
+
+__declspec(dllexport) void __stdcall DoDeferredCrtInit(HINSTANCE hinstance) {
+  _DllMainCRTStartup(hinstance, DLL_PROCESS_ATTACH, NULL);
+}
+
+// This function is needed for the linker to succeed. It seems to pick the
+// CRT lib based on the existence of "DllMain", and since we're renaming that,
+// it instead chooses the one that links against "main". This function should
+// never be called.
+int main() {
+  __debugbreak();
+}
+
+}