Support merged Dart-JS callstacks

Source/bindings/common/StackTrace.cpp

+/*
+ * Copyright (C) 2014 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "bindings/common/StackTrace.h"
+
+namespace WebCore {
+
+StackTrace::StackTrace() :
+    m_hasJavaScript(false),
+    m_hasDart(false),
+    m_dartStackTrace(0),
+    m_v8ScriptState(0),
+    m_dartScriptState(0)
+{
+}
+
+StackTrace::StackTrace(const StackTrace& javaScriptStackTrace, const StackTrace& dartStackTrace)
+{
+    ASSERT(!javaScriptStackTrace.hasDart() && !dartStackTrace.hasJavaScript());
+
+    if (javaScriptStackTrace.hasJavaScript()) {
+        m_hasJavaScript = true;
+        m_scriptValue = javaScriptStackTrace.asJavaScript();
+        m_v8ScriptState = javaScriptStackTrace.v8ScriptState();
+    } else {
+        m_hasJavaScript = false;
+        m_v8ScriptState = 0;
+    }
+
+    if (dartStackTrace.hasDart()) {
+        m_hasDart = true;
+        m_dartStackTrace = dartStackTrace.asDart();
+        m_dartScriptState = dartStackTrace.dartScriptState();
+    } else {
+        m_hasDart = false;
+        m_dartStackTrace = 0;
+        m_dartScriptState = 0;
+    }
+}
+
+StackTrace::StackTrace(const ScriptValue& stackTrace, V8ScriptState* v8ScriptState) :
+    m_hasJavaScript(!stackTrace.isEmpty()),
+    m_hasDart(false),
+    m_scriptValue(stackTrace),
+    m_dartStackTrace(0),
+    m_v8ScriptState(v8ScriptState),
+    m_dartScriptState(0)
+{
+}
+
+StackTrace::StackTrace(Dart_StackTrace stackTrace, DartScriptState* dartScriptState) :
+    m_hasJavaScript(false),
+    m_hasDart(!!stackTrace),
+    m_dartStackTrace(stackTrace),
+    m_v8ScriptState(0),
+    m_dartScriptState(dartScriptState)
+{
+}
+
+StackTraceTimestamp::StackTraceTimestamp(size_t stackDepth) : m_stackDepth(stackDepth)
+{
+    DEFINE_STATIC_LOCAL(int64_t, nextTimestamp, (0));
+    m_timestamp = ++nextTimestamp;
+}
+
+int64_t StackTraceTimestampTracker::getTimestamp(size_t frame)

[vsm, 2014/08/13 14:26:45]

Can you add a comment here?  Not really grokking what this function is doing.

[Jacob, 2014/08/13 21:36:15]

Done.

+{
+    ASSERT(!m_samples.isEmpty());
+    if (m_samples.isEmpty())
+        return 0;
+
+    // m_samples.size() will typically be less than 3 and will be at most
+    // kMaxRecursionDepth (20) so binary search isn't needed.
+    size_t i = 1;
+    while (i < m_samples.size() && m_samples[i].stackDepth() <= frame)
+        i++;
+    return m_samples[i-1].timestamp();
+}
+
+} // namespace WebCore