Utility functions to interact with the NT loader's data structures and associated tests.

This is in preparation for squelching false positive crash reports during DLL load.

BUG=31980
TEST=Unittests in this change.

Review URL: http://codereview.chromium.org/882001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@41289 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 39 insertions, 0 deletions

diff --git a/chrome_frame/crash_reporting/crash_dll.cc b/chrome_frame/crash_reporting/crash_dll.cc
new file mode 100644
index 0000000..97f41c9
--- /dev/null
+++ b/chrome_frame/crash_reporting/crash_dll.cc
@@ -0,0 +1,39 @@
+// Copyright (c) 2010 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.
+//
+// Main entry point for a DLL that can be instructed to crash on
+// load or unload by setting an environment variable appropriately.
+//
+// Note: This code has no CRT to lean on, because some versions of the CRT
+//    have a bug whereby they leave dangling state after taking an exception
+//    during DLL_PROCESS_ATTACH. This in turn causes the loading process to
+//    crash on exit. To work around this, this DLL has its entrypoint set
+//    to the DllMain routine and does not link with the CRT.
+#include <windows.h>
+#include "crash_dll.h"
+
+void Crash() {
+  char* null_pointer = reinterpret_cast<char*>(kCrashAddress);
+
+  *null_pointer = '\0';
+}
+
+void CrashConditionally(const wchar_t* name) {
+  wchar_t value[1024];
+  DWORD ret = ::GetEnvironmentVariable(name, value, ARRAYSIZE(value));
+  if (ret != 0 || ERROR_ENVVAR_NOT_FOUND != ::GetLastError())
+    Crash();
+}
+
+extern "C" BOOL WINAPI DllMain(HINSTANCE instance,
+                               DWORD reason,
+                               LPVOID reserved) {
+  if (reason == DLL_PROCESS_ATTACH) {
+    CrashConditionally(kCrashOnLoadMode);
+  } else if (reason == DLL_PROCESS_DETACH) {
+    CrashConditionally(kCrashOnUnloadMode);
+  }
+
+  return 1;
+}