diff -r 000000000000 -r 4f2f89ce4247 WebCore/html/HTMLScriptRunner.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/html/HTMLScriptRunner.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,311 @@
+/*
+ * Copyright (C) 2010 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:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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 "HTMLScriptRunner.h"
+
+#include "Attribute.h"
+#include "CachedScript.h"
+#include "DocLoader.h"
+#include "Element.h"
+#include "Event.h"
+#include "Frame.h"
+#include "HTMLScriptRunnerHost.h"
+#include "HTMLInputStream.h"
+#include "HTMLNames.h"
+#include "NotImplemented.h"
+#include "ScriptElement.h"
+#include "ScriptSourceCode.h"
+
+namespace WebCore {
+
+using namespace HTMLNames;
+
+class NestScript : public Noncopyable {
+public:
+    NestScript(unsigned& nestingLevel, HTMLInputStream& inputStream)
+        : m_nestingLevel(&nestingLevel)
+        , m_savedInsertionPoint(inputStream)
+    {
+        ++(*m_nestingLevel);
+    }
+
+    ~NestScript()
+    {
+        --(*m_nestingLevel);
+    }
+
+private:
+    unsigned* m_nestingLevel;
+    InsertionPointRecord m_savedInsertionPoint;
+};
+
+HTMLScriptRunner::HTMLScriptRunner(Document* document, HTMLScriptRunnerHost* host)
+    : m_document(document)
+    , m_host(host)
+    , m_scriptNestingLevel(0)
+    , m_hasScriptsWaitingForStylesheets(false)
+{
+    ASSERT(m_host);
+}
+
+HTMLScriptRunner::~HTMLScriptRunner()
+{
+    // FIXME: Should we be passed a "done loading/parsing" callback sooner than destruction?
+    if (m_parsingBlockingScript.cachedScript() && m_parsingBlockingScript.watchingForLoad())
+        stopWatchingForLoad(m_parsingBlockingScript);
+}
+
+static KURL documentURLForScriptExecution(Document* document)
+{
+    if (!document || !document->frame())
+        return KURL();
+
+    // Use the URL of the currently active document for this frame.
+    return document->frame()->document()->url();
+}
+
+inline PassRefPtr<Event> createScriptLoadEvent()
+{
+    return Event::create(eventNames().loadEvent, false, false);
+}
+
+inline PassRefPtr<Event> createScriptErrorEvent()
+{
+    return Event::create(eventNames().errorEvent, true, false);
+}
+
+ScriptSourceCode HTMLScriptRunner::sourceFromPendingScript(const PendingScript& script, bool& errorOccurred)
+{
+    if (script.cachedScript()) {
+        errorOccurred = script.cachedScript()->errorOccurred();
+        ASSERT(script.cachedScript()->isLoaded());
+        return ScriptSourceCode(script.cachedScript());
+    }
+    errorOccurred = false;
+    return ScriptSourceCode(script.element->textContent(), documentURLForScriptExecution(m_document), script.startingLineNumber);
+}
+
+bool HTMLScriptRunner::isPendingScriptReady(const PendingScript& script)
+{
+    m_hasScriptsWaitingForStylesheets = !m_document->haveStylesheetsLoaded();
+    if (m_hasScriptsWaitingForStylesheets)
+        return false;
+    if (script.cachedScript() && !script.cachedScript()->isLoaded())
+        return false;
+    return true;
+}
+
+void HTMLScriptRunner::executePendingScript()
+{
+    ASSERT(!m_scriptNestingLevel);
+    ASSERT(m_document->haveStylesheetsLoaded());
+    bool errorOccurred = false;
+    ASSERT(isPendingScriptReady(m_parsingBlockingScript));
+    ScriptSourceCode sourceCode = sourceFromPendingScript(m_parsingBlockingScript, errorOccurred);
+
+    // Stop watching loads before executeScript to prevent recursion if the script reloads itself.
+    if (m_parsingBlockingScript.cachedScript() && m_parsingBlockingScript.watchingForLoad())
+        stopWatchingForLoad(m_parsingBlockingScript);
+
+    // Clear the pending script before possible rentrancy from executeScript()
+    RefPtr<Element> scriptElement = m_parsingBlockingScript.releaseElementAndClear();
+    {
+        NestScript nestingLevel(m_scriptNestingLevel, m_host->inputStream());
+        if (errorOccurred)
+            scriptElement->dispatchEvent(createScriptErrorEvent());
+        else {
+            executeScript(scriptElement.get(), sourceCode);
+            scriptElement->dispatchEvent(createScriptLoadEvent());
+        }
+    }
+    ASSERT(!m_scriptNestingLevel);
+}
+
+void HTMLScriptRunner::executeScript(Element* element, const ScriptSourceCode& sourceCode)
+{
+    // FIXME: We do not block inline <script> tags on stylesheets for now.
+    // When we do,  || !element->hasAttribute(srcAttr) should be removed from
+    // the ASSERT below.  See https://bugs.webkit.org/show_bug.cgi?id=40047
+    ASSERT(m_document->haveStylesheetsLoaded() || !element->hasAttribute(srcAttr));
+    ScriptElement* scriptElement = toScriptElement(element);
+    ASSERT(scriptElement);
+    if (!scriptElement->shouldExecuteAsJavaScript())
+        return;
+    ASSERT(inScriptExecution());
+    if (!m_document->frame())
+        return;
+    m_document->frame()->script()->executeScript(sourceCode);
+}
+
+void HTMLScriptRunner::watchForLoad(PendingScript& pendingScript)
+{
+    ASSERT(!pendingScript.watchingForLoad());
+    m_host->watchForLoad(pendingScript.cachedScript());
+    pendingScript.setWatchingForLoad(true);
+}
+
+void HTMLScriptRunner::stopWatchingForLoad(PendingScript& pendingScript)
+{
+    ASSERT(pendingScript.watchingForLoad());
+    m_host->stopWatchingForLoad(pendingScript.cachedScript());
+    pendingScript.setWatchingForLoad(false);
+}
+
+// This function should match 10.2.5.11 "An end tag whose tag name is 'script'"
+// Script handling lives outside the tree builder to keep the each class simple.
+bool HTMLScriptRunner::execute(PassRefPtr<Element> scriptElement, int startLine)
+{
+    ASSERT(scriptElement);
+    // FIXME: If scripting is disabled, always just return true;
+
+    // Try to execute the script given to us.
+    runScript(scriptElement.get(), startLine);
+
+    if (haveParsingBlockingScript()) {
+        if (m_scriptNestingLevel)
+            return false; // Block the parser.  Unwind to the outermost HTMLScriptRunner::execute before continuing parsing.
+        if (!executeParsingBlockingScripts())
+            return false; // We still have a parsing blocking script, block the parser.
+    }
+    return true; // Scripts executed as expected, continue parsing.
+}
+
+bool HTMLScriptRunner::haveParsingBlockingScript() const
+{
+    return !!m_parsingBlockingScript.element;
+}
+
+bool HTMLScriptRunner::executeParsingBlockingScripts()
+{
+    while (haveParsingBlockingScript()) {
+        // We only really need to check once.
+        if (!isPendingScriptReady(m_parsingBlockingScript))
+            return false;
+        executePendingScript();
+    }
+    return true;
+}
+
+bool HTMLScriptRunner::executeScriptsWaitingForLoad(CachedResource* cachedScript)
+{
+    ASSERT(!m_scriptNestingLevel);
+    ASSERT(haveParsingBlockingScript());
+    ASSERT_UNUSED(cachedScript, m_parsingBlockingScript.cachedScript() == cachedScript);
+    ASSERT(m_parsingBlockingScript.cachedScript()->isLoaded());
+    return executeParsingBlockingScripts();
+}
+
+bool HTMLScriptRunner::executeScriptsWaitingForStylesheets()
+{
+    // Callers should check hasScriptsWaitingForStylesheets() before calling
+    // to prevent parser or script re-entry during </style> parsing.
+    ASSERT(hasScriptsWaitingForStylesheets());
+    ASSERT(!m_scriptNestingLevel);
+    ASSERT(m_document->haveStylesheetsLoaded());
+    return executeParsingBlockingScripts();
+}
+
+void HTMLScriptRunner::requestScript(Element* script)
+{
+    ASSERT(!m_parsingBlockingScript.element);
+    AtomicString srcValue = script->getAttribute(srcAttr);
+    // Allow the host to disllow script loads (using the XSSAuditor, etc.)
+    if (!m_host->shouldLoadExternalScriptFromSrc(srcValue))
+        return;
+    // FIXME: We need to resolve the url relative to the element.
+    if (!script->dispatchBeforeLoadEvent(srcValue))
+        return;
+    m_parsingBlockingScript.element = script;
+    // This should correctly return 0 for empty or invalid srcValues.
+    CachedScript* cachedScript = m_document->docLoader()->requestScript(srcValue, toScriptElement(script)->scriptCharset());
+    if (!cachedScript) {
+        notImplemented(); // Dispatch error event.
+        return;
+    }
+
+    m_parsingBlockingScript.setCachedScript(cachedScript);
+
+    // We only care about a load callback if cachedScript is not already
+    // in the cache.  Callers will attempt to run the m_parsingBlockingScript
+    // if possible before returning control to the parser.
+    if (!m_parsingBlockingScript.cachedScript()->isLoaded())
+        watchForLoad(m_parsingBlockingScript);
+}
+
+// This method is meant to match the HTML5 definition of "running a script"
+// http://www.whatwg.org/specs/web-apps/current-work/multipage/scripting-1.html#running-a-script
+void HTMLScriptRunner::runScript(Element* script, int startingLineNumber)
+{
+    ASSERT(!haveParsingBlockingScript());
+    {
+        NestScript nestingLevel(m_scriptNestingLevel, m_host->inputStream());
+
+        // Check script type and language, current code uses ScriptElement::shouldExecuteAsJavaScript(), but that may not be HTML5 compliant.
+        notImplemented(); // event for support
+
+        if (script->hasAttribute(srcAttr)) {
+            // FIXME: Handle defer and async
+            requestScript(script);
+        } else {
+            // FIXME: We do not block inline <script> tags on stylesheets to match the
+            // old parser for now.  See https://bugs.webkit.org/show_bug.cgi?id=40047
+            ScriptSourceCode sourceCode(script->textContent(), documentURLForScriptExecution(m_document), startingLineNumber);
+            executeScript(script, sourceCode);
+        }
+    }
+}
+
+HTMLScriptRunner::PendingScript::~PendingScript()
+{
+    if (m_cachedScript)
+        m_cachedScript->removeClient(this);
+}
+
+PassRefPtr<Element> HTMLScriptRunner::PendingScript::releaseElementAndClear()
+{
+    setCachedScript(0);
+    startingLineNumber = 0;
+    m_watchingForLoad = false;
+    return element.release();
+}
+
+void HTMLScriptRunner::PendingScript::setCachedScript(CachedScript* cachedScript)
+{
+    if (m_cachedScript == cachedScript)
+        return;
+    if (m_cachedScript)
+        m_cachedScript->removeClient(this);
+    m_cachedScript = cachedScript;
+    if (m_cachedScript)
+        m_cachedScript->addClient(this);
+}
+
+CachedScript* HTMLScriptRunner::PendingScript::cachedScript() const
+{
+    return m_cachedScript.get();
+}
+
+}