removing SEH exception restoration #2

The only real caller was the NPAPI plugin code trying to
prevent flash 9 from stealing the unhandled exception handler.

The need for that is long gone.

This is a followup of
https://codereview.chromium.org/122553003/

TBR=mark
BUG=none

Review URL: https://codereview.chromium.org/122583004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242926 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 1 insertions, 237 deletions

diff --git a/base/message_loop/message_loop.cc b/base/message_loop/message_loop.cc
index 52948e0..712fcfa 100644
--- a/base/message_loop/message_loop.cc
+++ b/base/message_loop/message_loop.cc
@@ -102,28 +102,6 @@ bool AlwaysNotifyPump(MessageLoop::Type type) {
 
 //------------------------------------------------------------------------------
 
-#if defined(OS_WIN)
-
-// Upon a SEH exception in this thread, it restores the original unhandled
-// exception filter.
-static int SEHFilter(LPTOP_LEVEL_EXCEPTION_FILTER old_filter) {
-  ::SetUnhandledExceptionFilter(old_filter);
-  return EXCEPTION_CONTINUE_SEARCH;
-}
-
-// Retrieves a pointer to the current unhandled exception filter. There
-// is no standalone getter method.
-static LPTOP_LEVEL_EXCEPTION_FILTER GetTopSEHFilter() {
-  LPTOP_LEVEL_EXCEPTION_FILTER top_filter = NULL;
-  top_filter = ::SetUnhandledExceptionFilter(0);
-  ::SetUnhandledExceptionFilter(top_filter);
-  return top_filter;
-}
-
-#endif  // defined(OS_WIN)
-
-//------------------------------------------------------------------------------
-
 MessageLoop::TaskObserver::TaskObserver() {
 }
 
@@ -137,7 +115,6 @@ MessageLoop::DestructionObserver::~DestructionObserver() {
 
 MessageLoop::MessageLoop(Type type)
     : type_(type),
-      exception_restoration_(false),
       nestable_tasks_allowed_(true),
 #if defined(OS_WIN)
       os_modal_loop_(false),
@@ -152,7 +129,6 @@ MessageLoop::MessageLoop(Type type)
 MessageLoop::MessageLoop(scoped_ptr<MessagePump> pump)
     : pump_(pump.Pass()),
       type_(TYPE_CUSTOM),
-      exception_restoration_(false),
       nestable_tasks_allowed_(true),
 #if defined(OS_WIN)
       os_modal_loop_(false),
@@ -405,34 +381,7 @@ void MessageLoop::Init() {
       new ThreadTaskRunnerHandle(message_loop_proxy_));
 }
 
-// Runs the loop in two different SEH modes:
-// enable_SEH_restoration_ = false : any unhandled exception goes to the last
-// one that calls SetUnhandledExceptionFilter().
-// enable_SEH_restoration_ = true : any unhandled exception goes to the filter
-// that was existed before the loop was run.
 void MessageLoop::RunHandler() {
-#if defined(OS_WIN)
-  if (exception_restoration_) {
-    RunInternalInSEHFrame();
-    return;
-  }
-#endif
-
-  RunInternal();
-}
-
-#if defined(OS_WIN)
-__declspec(noinline) void MessageLoop::RunInternalInSEHFrame() {
-  LPTOP_LEVEL_EXCEPTION_FILTER current_filter = GetTopSEHFilter();
-  __try {
-    RunInternal();
-  } __except(SEHFilter(current_filter)) {
-  }
-  return;
-}
-#endif
-
-void MessageLoop::RunInternal() {
   DCHECK_EQ(this, current());
 
   StartHistogrammer();
diff --git a/base/message_loop/message_loop.h b/base/message_loop/message_loop.h
index 29e0f7e..f4ed5a1 100644
--- a/base/message_loop/message_loop.h
+++ b/base/message_loop/message_loop.h
@@ -359,14 +359,6 @@ class BASE_EXPORT MessageLoop : public MessagePump::Delegate {
     bool old_state_;
   };
 
-  // Enables or disables the restoration during an exception of the unhandled
-  // exception filter that was active when Run() was called. This can happen
-  // if some third party code call SetUnhandledExceptionFilter() and never
-  // restores the previous filter.
-  void set_exception_restoration(bool restore) {
-    exception_restoration_ = restore;
-  }
-
   // Returns true if we are currently running a nested message loop.
   bool IsNested();
 
@@ -446,21 +438,9 @@ class BASE_EXPORT MessageLoop : public MessagePump::Delegate {
   // Configures various members for the two constructors.
   void Init();
 
-  // A function to encapsulate all the exception handling capability in the
-  // stacks around the running of a main message loop.  It will run the message
-  // loop in a SEH try block or not depending on the set_SEH_restoration()
-  // flag invoking respectively RunInternalInSEHFrame() or RunInternal().
+  // Invokes the actual run loop using the message pump.
   void RunHandler();
 
-#if defined(OS_WIN)
-  __declspec(noinline) void RunInternalInSEHFrame();
-#endif
-
-  // A surrounding stack frame around the running of the message loop that
-  // supports all saving and restoring of state, as is needed for any/all (ugly)
-  // recursive calls.
-  void RunInternal();
-
   // Called to process any delayed non-nestable tasks.
   bool ProcessNextDelayedNonNestableTask();
 
@@ -527,8 +507,6 @@ class BASE_EXPORT MessageLoop : public MessagePump::Delegate {
 
   ObserverList<DestructionObserver> destruction_observers_;
 
-  bool exception_restoration_;
-
   // A recursion block that prevents accidentally running additional tasks when
   // insider a (accidentally induced?) nested message pump.
   bool nestable_tasks_allowed_;
diff --git a/base/message_loop/message_loop_test.cc b/base/message_loop/message_loop_test.cc
index f39845d..eca6c8f 100644
--- a/base/message_loop/message_loop_test.cc
+++ b/base/message_loop/message_loop_test.cc
@@ -114,39 +114,6 @@ void RunTest_PostTask(MessagePumpFactory factory) {
   EXPECT_EQ(foo->result(), "abacad");
 }
 
-void RunTest_PostTask_SEH(MessagePumpFactory factory) {
-  scoped_ptr<MessagePump> pump(factory());
-  MessageLoop loop(pump.Pass());
-
-  // Add tests to message loop
-  scoped_refptr<Foo> foo(new Foo());
-  std::string a("a"), b("b"), c("c"), d("d");
-  MessageLoop::current()->PostTask(FROM_HERE, Bind(
-      &Foo::Test0, foo.get()));
-  MessageLoop::current()->PostTask(FROM_HERE, Bind(
-      &Foo::Test1ConstRef, foo.get(), a));
-  MessageLoop::current()->PostTask(FROM_HERE, Bind(
-      &Foo::Test1Ptr, foo.get(), &b));
-  MessageLoop::current()->PostTask(FROM_HERE, Bind(
-      &Foo::Test1Int, foo.get(), 100));
-  MessageLoop::current()->PostTask(FROM_HERE, Bind(
-      &Foo::Test2Ptr, foo.get(), &a, &c));
-  MessageLoop::current()->PostTask(FROM_HERE, Bind(
-      &Foo::Test2Mixed, foo.get(), a, &d));
-
-  // After all tests, post a message that will shut down the message loop
-  MessageLoop::current()->PostTask(FROM_HERE, Bind(
-      &MessageLoop::Quit, Unretained(MessageLoop::current())));
-
-  // Now kick things off with the SEH block active.
-  MessageLoop::current()->set_exception_restoration(true);
-  MessageLoop::current()->Run();
-  MessageLoop::current()->set_exception_restoration(false);
-
-  EXPECT_EQ(foo->test_count(), 105);
-  EXPECT_EQ(foo->result(), "abacad");
-}
-
 void RunTest_PostDelayedTask_Basic(MessagePumpFactory factory) {
   scoped_ptr<MessagePump> pump(factory());
   MessageLoop loop(pump.Pass());
diff --git a/base/message_loop/message_loop_test.h b/base/message_loop/message_loop_test.h
index 5d1a4f5..3d9889c 100644
--- a/base/message_loop/message_loop_test.h
+++ b/base/message_loop/message_loop_test.h
@@ -19,7 +19,6 @@ namespace test {
 typedef MessageLoop::MessagePumpFactory MessagePumpFactory;
 
 void RunTest_PostTask(MessagePumpFactory factory);
-void RunTest_PostTask_SEH(MessagePumpFactory factory);
 void RunTest_PostDelayedTask_Basic(MessagePumpFactory factory);
 void RunTest_PostDelayedTask_InDelayOrder(MessagePumpFactory factory);
 void RunTest_PostDelayedTask_InPostOrder(MessagePumpFactory factory);
@@ -52,9 +51,6 @@ void RunTest_RecursivePosts(MessagePumpFactory factory);
   TEST(MessageLoopTestType##id, PostTask) { \
     base::test::RunTest_PostTask(factory); \
   } \
-  TEST(MessageLoopTestType##id, PostTask_SEH) { \
-    base::test::RunTest_PostTask_SEH(factory); \
-  } \
   TEST(MessageLoopTestType##id, PostDelayedTask_Basic) { \
     base::test::RunTest_PostDelayedTask_Basic(factory); \
   } \
diff --git a/base/message_loop/message_loop_unittest.cc b/base/message_loop/message_loop_unittest.cc
index e6d25ece..64cf7c8 100644
--- a/base/message_loop/message_loop_unittest.cc
+++ b/base/message_loop/message_loop_unittest.cc
@@ -167,120 +167,6 @@ void RunTest_PostDelayedTask_SharedTimer_SubPump() {
   EXPECT_TRUE(run_time.is_null());
 }
 
-LONG WINAPI BadExceptionHandler(EXCEPTION_POINTERS *ex_info) {
-  ADD_FAILURE() << "bad exception handler";
-  ::ExitProcess(ex_info->ExceptionRecord->ExceptionCode);
-  return EXCEPTION_EXECUTE_HANDLER;
-}
-
-// This task throws an SEH exception: initially write to an invalid address.
-// If the right SEH filter is installed, it will fix the error.
-class Crasher : public RefCounted<Crasher> {
- public:
-  // Ctor. If trash_SEH_handler is true, the task will override the unhandled
-  // exception handler with one sure to crash this test.
-  explicit Crasher(bool trash_SEH_handler)
-      : trash_SEH_handler_(trash_SEH_handler) {
-  }
-
-  void Run() {
-    PlatformThread::Sleep(TimeDelta::FromMilliseconds(1));
-    if (trash_SEH_handler_)
-      ::SetUnhandledExceptionFilter(&BadExceptionHandler);
-    // Generate a SEH fault. We do it in asm to make sure we know how to undo
-    // the damage.
-
-#if defined(_M_IX86)
-
-    __asm {
-      mov eax, dword ptr [Crasher::bad_array_]
-      mov byte ptr [eax], 66
-    }
-
-#elif defined(_M_X64)
-
-    bad_array_[0] = 66;
-
-#else
-#error "needs architecture support"
-#endif
-
-    MessageLoop::current()->QuitWhenIdle();
-  }
-  // Points the bad array to a valid memory location.
-  static void FixError() {
-    bad_array_ = &valid_store_;
-  }
-
- private:
-  bool trash_SEH_handler_;
-  static volatile char* bad_array_;
-  static char valid_store_;
-};
-
-volatile char* Crasher::bad_array_ = 0;
-char Crasher::valid_store_ = 0;
-
-// This SEH filter fixes the problem and retries execution. Fixing requires
-// that the last instruction: mov eax, [Crasher::bad_array_] to be retried
-// so we move the instruction pointer 5 bytes back.
-LONG WINAPI HandleCrasherException(EXCEPTION_POINTERS *ex_info) {
-  if (ex_info->ExceptionRecord->ExceptionCode != EXCEPTION_ACCESS_VIOLATION)
-    return EXCEPTION_EXECUTE_HANDLER;
-
-  Crasher::FixError();
-
-#if defined(_M_IX86)
-
-  ex_info->ContextRecord->Eip -= 5;
-
-#elif defined(_M_X64)
-
-  ex_info->ContextRecord->Rip -= 5;
-
-#endif
-
-  return EXCEPTION_CONTINUE_EXECUTION;
-}
-
-void RunTest_Crasher(MessageLoop::Type message_loop_type) {
-  MessageLoop loop(message_loop_type);
-
-  if (::IsDebuggerPresent())
-    return;
-
-  LPTOP_LEVEL_EXCEPTION_FILTER old_SEH_filter =
-      ::SetUnhandledExceptionFilter(&HandleCrasherException);
-
-  MessageLoop::current()->PostTask(
-      FROM_HERE,
-      Bind(&Crasher::Run, new Crasher(false)));
-  MessageLoop::current()->set_exception_restoration(true);
-  MessageLoop::current()->Run();
-  MessageLoop::current()->set_exception_restoration(false);
-
-  ::SetUnhandledExceptionFilter(old_SEH_filter);
-}
-
-void RunTest_CrasherNasty(MessageLoop::Type message_loop_type) {
-  MessageLoop loop(message_loop_type);
-
-  if (::IsDebuggerPresent())
-    return;
-
-  LPTOP_LEVEL_EXCEPTION_FILTER old_SEH_filter =
-      ::SetUnhandledExceptionFilter(&HandleCrasherException);
-
-  MessageLoop::current()->PostTask(
-      FROM_HERE,
-      Bind(&Crasher::Run, new Crasher(true)));
-  MessageLoop::current()->set_exception_restoration(true);
-  MessageLoop::current()->Run();
-  MessageLoop::current()->set_exception_restoration(false);
-
-  ::SetUnhandledExceptionFilter(old_SEH_filter);
-}
-
 const wchar_t kMessageBoxTitle[] = L"MessageLoop Unit Test";
 
 enum TaskType {
@@ -781,18 +667,6 @@ TEST(MessageLoopTest, PostDelayedTask_SharedTimer_SubPump) {
   RunTest_PostDelayedTask_SharedTimer_SubPump();
 }
 
-TEST(MessageLoopTest, Crasher) {
-  RunTest_Crasher(MessageLoop::TYPE_DEFAULT);
-  RunTest_Crasher(MessageLoop::TYPE_UI);
-  RunTest_Crasher(MessageLoop::TYPE_IO);
-}
-
-TEST(MessageLoopTest, CrasherNasty) {
-  RunTest_CrasherNasty(MessageLoop::TYPE_DEFAULT);
-  RunTest_CrasherNasty(MessageLoop::TYPE_UI);
-  RunTest_CrasherNasty(MessageLoop::TYPE_IO);
-}
-
 // This test occasionally hangs http://crbug.com/44567
 TEST(MessageLoopTest, DISABLED_RecursiveDenial2) {
   RunTest_RecursiveDenial2(MessageLoop::TYPE_DEFAULT);