Apply script preprocessor to Web page scripts only.

Source/bindings/v8/ScriptPreprocessor.cpp

Index: Source/bindings/v8/ScriptPreprocessor.cpp
diff --git a/Source/bindings/v8/ScriptPreprocessor.cpp b/Source/bindings/v8/ScriptPreprocessor.cpp
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index 0000000000000000000000000000000000000000..65bea727174cdaa501802b41cb9fcb443303bcef
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+++ b/Source/bindings/v8/ScriptPreprocessor.cpp
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+/*
+ * Copyright (C) 2008, 2009 Google Inc. All rights reserved.
+ * Copyright (C) 2009 Apple 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/v8/ScriptPreprocessor.h"
+
+#include "bindings/v8/ScriptController.h"
+#include "bindings/v8/ScriptDebugServer.h"
+#include "bindings/v8/ScriptSourceCode.h"
+#include "bindings/v8/ScriptValue.h"
+#include "bindings/v8/V8Binding.h"
+#include "bindings/v8/V8ScriptRunner.h"
+#include "bindings/v8/V8WindowShell.h"
+#include "core/page/DOMWindow.h"
+#include "core/page/Frame.h"
+#include "core/page/Page.h"
+#include "core/page/PageConsole.h"
+#include "wtf/TemporaryChange.h"
+
+namespace WebCore {
+
+ScriptPreprocessor::ScriptPreprocessor(const String& preprocessorScript, ScriptController* controller, PageConsole* console)
+    : m_isPreprocessing(false)
+{
+    v8::TryCatch tryCatch;
+    tryCatch.SetVerbose(true);
+    ScriptSourceCode preprocessor(preprocessorScript);
+    Vector<ScriptSourceCode> sources;
+    sources.append(preprocessor);
+    Vector<ScriptValue> scriptResults;
+    controller->executeScriptInIsolatedWorld(ScriptPreprocessorIsolatedWorldId, sources, DOMWrapperWorld::mainWorldExtensionGroup, &scriptResults);

[abarth-chromium, 2013/07/12 00:25:16]

Should this be "executeInternalScriptInIsolatedWorld?  It seems like the
preprocessorScript should count as an internal script.

[johnjbarton, 2013/07/12 17:56:49]

I'm unsure what you mean here. I was not able to find
"executeInternalScriptInIsolatedWorld", though I recall such a function in the
past. 

V8ScriptRunner has compileAndRunInternalScript() and callInternalFunction().
These functions, when compared to the similar functions without 'Internal', skip
the memory and stack-limitation checks. Since the preprocessor is developed
outside of Chrome and because preprocessor developers would benefit from these
checks, I believe the current code is the better choice.

[haraken, 2013/07/13 00:37:04]

I think we should implement executeInternalScriptInIsolatedWorld() and use it
here, since the script we're going to execute is an internal script (i.e. not a
user script from a web page).
More importantly, the difference between internal scripts and user scripts is
that user scripts have to clean up a couple of things (clear IDB transactions,
flush mutation observers etc) when the execution is finished. We should do the
clean-up for user scripts but shouldn't do the clean-up for internal scripts.

See here:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

+
+    if (scriptResults.size() != 1) {
+        console->addMessage(JSMessageSource, ErrorMessageLevel, "ScriptPreprocessor internal error, one ScriptSourceCode must give exactly one result.");
+        return;
+    }
+
+    ScriptValue preprocessorFunction = scriptResults[0];
+    if (!preprocessorFunction.isFunction()) {
+        console->addMessage(JSMessageSource, ErrorMessageLevel, "The preprocessor must compile to a function.");
+        return;
+    }
+
+    RefPtr<DOMWrapperWorld> world = DOMWrapperWorld::ensureIsolatedWorld(ScriptPreprocessorIsolatedWorldId, DOMWrapperWorld::mainWorldExtensionGroup);
+    V8WindowShell* isolatedWorldShell = controller->windowShell(world.get());
+    v8::Local<v8::Context> context = isolatedWorldShell->context();
+    m_isolate = context->GetIsolate();
+
+    m_context.set(m_isolate, context);
+    m_preprocessorFunction.set(m_isolate, v8::Handle<v8::Function>::Cast(preprocessorFunction.v8Value()));
+}
+
+String ScriptPreprocessor::preprocessSourceCode(const String& sourceCode, const String& sourceName)
+{
+    if (m_preprocessorFunction.isEmpty())
+        return sourceCode;
+
+    v8::HandleScope handleScope(m_isolate);
+    v8::Context::Scope contextScope(m_context.newLocal(m_isolate));
+
+    v8::Handle<v8::String> sourceCodeString = v8String(sourceCode, m_isolate);
+    v8::Handle<v8::String> sourceNameString = v8String(sourceName, m_isolate);
+    v8::Handle<v8::Value> argv[] = { sourceCodeString, sourceNameString };
+
+    v8::TryCatch tryCatch;
+    tryCatch.SetVerbose(true);
+    TemporaryChange<bool> isPreprocessing(m_isPreprocessing, true);
+    v8::Handle<v8::Value> resultValue = V8ScriptRunner::callAsFunction(m_preprocessorFunction.newLocal(m_isolate), m_context.newLocal(m_isolate)->Global(), WTF_ARRAY_LENGTH(argv), argv);
+
+    if (!resultValue.IsEmpty() && resultValue->IsString())
+        return toWebCoreStringWithNullCheck(resultValue);
+
+    return sourceCode;
+}
+
+void ScriptPreprocessor::preprocessEval(ScriptDebugServer* debugServer, v8::Handle<v8::Object> eventData)
+{
+    if (m_isPreprocessing)
+        return;
+
+    v8::Local<v8::Context> debugContext = v8::Debug::GetDebugContext();
+    v8::Context::Scope contextScope(debugContext);
+
+    // <script> tag source and attribute value source are preprocessed before we enter V8.
+    // Avoid preprocessing any internal scripts by processing only eval source in this V8 event handler.
+    v8::Handle<v8::Value> argvEventData[] = { eventData };
+    String typeInfo = toWebCoreStringWithUndefinedOrNullCheck(debugServer->callDebuggerMethod("getScriptCompilationTypeInfo", WTF_ARRAY_LENGTH(argvEventData), argvEventData));
+    if (!typeInfo.startsWith("eval"))
+        return;
+
+    // The name and source are in the JS event data.
+    String scriptName = toWebCoreStringWithUndefinedOrNullCheck(debugServer->callDebuggerMethod("getScriptName", WTF_ARRAY_LENGTH(argvEventData), argvEventData));
+    String script = toWebCoreStringWithUndefinedOrNullCheck(debugServer->callDebuggerMethod("getScriptSource", WTF_ARRAY_LENGTH(argvEventData), argvEventData));
+
+    String patchedScript = preprocessSourceCode(script, scriptName);
+
+    v8::Handle<v8::Value> argvPatchedScript[] = { eventData, v8String(patchedScript, debugContext->GetIsolate()) };
+    debugServer->callDebuggerMethod("setScriptSource", WTF_ARRAY_LENGTH(argvPatchedScript), argvPatchedScript);
+}
+
+
+} // namespace WebCore