Add an ExceptionBarrier around outbound calls to patched methods in IE. In so...

chrome_frame/exception_barrier.h

+// Copyright (c) 2009 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.
+
+// A class to make it easy to tag exception propagation boundaries and
+// get crash reports of exceptions that pass over same.
+#ifndef CHROME_FRAME_EXCEPTION_BARRIER_H_
+#define CHROME_FRAME_EXCEPTION_BARRIER_H_
+
+#include <windows.h>
+
+/// This is the type dictated for an exception handler by the platform ABI
+/// @see _except_handler in excpt.h
+typedef EXCEPTION_DISPOSITION (__cdecl *ExceptionHandlerFunc)(
+                                struct _EXCEPTION_RECORD *exception_record,
+                                void * establisher_frame,
+                                struct _CONTEXT *context,
+                                void * reserved);
+
+/// The type of an exception record in the exception handler chain
+struct EXCEPTION_REGISTRATION {
+  EXCEPTION_REGISTRATION *prev;
+  ExceptionHandlerFunc  handler;
+};
+
+/// This is our raw exception handler, it must be declared extern "C" to
+/// match up with the SAFESEH declaration in our corresponding ASM file
+extern "C" EXCEPTION_DISPOSITION __cdecl
+ExceptionBarrierHandler(struct _EXCEPTION_RECORD *exception_record,
+                        void * establisher_frame,
+                        struct _CONTEXT *context,
+                        void * reserved);
+
+/// An exception barrier is used to report exceptions that pass through
+/// a boundary where exceptions shouldn't pass, such as e.g. COM interface
+/// boundaries.
+/// This is handy for any kind of plugin code, where if the exception passes
+/// through unhindered, it'll either be swallowed by an SEH exception handler
+/// above us on the stack, or be reported as an unhandled exception for
+/// the application hosting the plugin code.
+///
+/// To use this class, simply instantiate an ExceptionBarrier just inside
+/// the code boundary, like this:
+/// @code
+/// HRESULT SomeObject::SomeCOMMethod(...) {
+///   ExceptionBarrier report_crashes;
+///
+///   ... other code here ...
+/// }
+/// @endcode
+class ExceptionBarrier {
+ public:
+  /// Register the barrier in the SEH chain
+  ExceptionBarrier();
+
+  /// And unregister on destruction
+  ~ExceptionBarrier();
+
+  /// Signature of the handler function which gets notified when
+  /// an exception propagates through a barrier.
+  typedef void (CALLBACK *ExceptionHandler)(EXCEPTION_POINTERS *ptrs);
+
+  /// @name Accessors
+  /// @{
+  static void set_handler(ExceptionHandler handler) { s_handler_ = handler; }
+  static ExceptionHandler handler() { return s_handler_; }
+  /// @}
+
+ private:
+  /// Our SEH frame
+  EXCEPTION_REGISTRATION registration_;
+
+  /// The function that gets invoked if an exception
+  /// propagates through a barrier
+  static ExceptionHandler s_handler_;
+};
+
+/// @name These are implemented in the associated .asm file
+/// @{
+extern "C" void WINAPI RegisterExceptionRecord(
+                          EXCEPTION_REGISTRATION *registration,
+                          ExceptionHandlerFunc func);
+extern "C" void WINAPI UnregisterExceptionRecord(
+                          EXCEPTION_REGISTRATION *registration);
+/// @}
+
+
+inline ExceptionBarrier::ExceptionBarrier() {
+  RegisterExceptionRecord(&registration_, ExceptionBarrierHandler);
+}
+
+inline ExceptionBarrier::~ExceptionBarrier() {
+  UnregisterExceptionRecord(&registration_);
+}
+
+#endif  // CHROME_FRAME_EXCEPTION_BARRIER_H_