Add an ExceptionBarrier around outbound calls to patched methods in IE. In so doing, we have an SEH present in the SEH chain and so the VEH won't erroneously report crashes that occur in other modules when we happen to be on the stack.

BUG=42660
TEST=Less false positives in the crash reports.


Review URL: http://codereview.chromium.org/1733021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@45764 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 96 insertions, 0 deletions

diff --git a/chrome_frame/exception_barrier.h b/chrome_frame/exception_barrier.h
new file mode 100644
index 0000000..26cbc44
--- /dev/null
+++ b/chrome_frame/exception_barrier.h
@@ -0,0 +1,96 @@
+// 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_