Changeset 290869 in webkit for trunk/Source/JavaScriptCore/interpreter/FrameTracers.h

Timestamp:

Mar 5, 2022, 10:55:21 AM (3 years ago)

Author:

[email protected]

Message:

Fix broken SuspendExceptionScope and remove redundant VM::DeferExceptionScope.
​https://bugs.webkit.org/show_bug.cgi?id=237441
<rdar://problem/89769627>

Reviewed by Yusuke Suzuki.

Source/JavaScriptCore:

SuspendExceptionScope was meant to do exactly the same thing that VM::DeferExceptionScope
does, except that SuspendExceptionScope hasn't been updated to handle exception
handling via VMTraps bits.

This patch will fix SuspendExceptionScope to work like VM::DeferExceptionScope,
and remove the now redundant VM::DeferExceptionScope. SuspendExceptionScope is
the better name here because the scope actually suspends any pending exception.
This is different from other Defer scopes where we prevent some new event from
arising and defer the event to a later time.

• interpreter/FrameTracers.h:

(JSC::SuspendExceptionScope::SuspendExceptionScope):
(JSC::SuspendExceptionScope::~SuspendExceptionScope):

• interpreter/Interpreter.cpp:

(JSC::UnwindFunctor::notifyDebuggerOfUnwinding):

• runtime/TypeProfilerLog.cpp:

(JSC::TypeProfilerLog::processLogEntries):

• runtime/VM.h:

(JSC::VM::restorePreviousException): Deleted.
(JSC::VM::DeferExceptionScope::DeferExceptionScope): Deleted.
(JSC::VM::DeferExceptionScope::~DeferExceptionScope): Deleted.

Source/WebCore:

• inspector/InspectorFrontendAPIDispatcher.cpp:

(WebCore::InspectorFrontendAPIDispatcher::evaluateExpression):

• inspector/InspectorFrontendHost.cpp:

(WebCore::InspectorFrontendHost::evaluateScriptInExtensionTab):

File:

• trunk/Source/JavaScriptCore/interpreter/FrameTracers.h (modified) (2 diffs)

trunk/Source/JavaScriptCore/interpreter/FrameTracers.h

@@ -1 +1 @@
 /*
- * Copyright (C) 2016-2019 Apple Inc. All rights reserved.
+ * Copyright (C) 2016-2022 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -36 +36 @@
 class SuspendExceptionScope {
 public:
-    SuspendExceptionScope(VM* vm)
+    SuspendExceptionScope(VM& vm)
         : m_vm(vm)
+        , m_exceptionWasSet(vm.m_exception)
+        , m_savedException(vm.m_exception, nullptr)
+        , m_savedLastException(vm.m_lastException, nullptr)
     {
-        auto scope = DECLARE_CATCH_SCOPE(*vm);
-        oldException = scope.exception();
-        scope.clearException();
+        if (m_exceptionWasSet)
+            m_vm.traps().clearTrapBit(VMTraps::NeedExceptionHandling);
     }
     ~SuspendExceptionScope()
     {
-        m_vm->restorePreviousException(oldException);
+        if (m_exceptionWasSet)
+            m_vm.traps().setTrapBit(VMTraps::NeedExceptionHandling);
     }
 private:
-    Exception* oldException;
-    VM* m_vm;
+    VM& m_vm;
+    bool m_exceptionWasSet;
+    SetForScope<Exception*> m_savedException;
+    SetForScope<Exception*> m_savedLastException;
 };