Imported WebKit commit 68645295d2e3e09af2c942f092556f06aa5f8b0d (http://svn.webkit.org/repository/webkit/trunk@128073)

New snapshot

1 files changed, 262 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/runtime/JSScope.cpp b/Source/JavaScriptCore/runtime/JSScope.cpp
new file mode 100644
index 000000000..b22211970
--- /dev/null
+++ b/Source/JavaScriptCore/runtime/JSScope.cpp
@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2012 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:
+ * 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 "JSScope.h"
+
+#include "JSActivation.h"
+#include "JSGlobalObject.h"
+#include "JSNameScope.h"
+#include "JSWithScope.h"
+
+namespace JSC {
+
+ASSERT_CLASS_FITS_IN_CELL(JSScope);
+
+void JSScope::visitChildren(JSCell* cell, SlotVisitor& visitor)
+{
+    JSScope* thisObject = jsCast<JSScope*>(cell);
+    ASSERT_GC_OBJECT_INHERITS(thisObject, &s_info);
+    COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
+    ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
+
+    Base::visitChildren(thisObject, visitor);
+    visitor.append(&thisObject->m_next);
+}
+
+bool JSScope::isDynamicScope(bool& requiresDynamicChecks) const
+{
+    switch (structure()->typeInfo().type()) {
+    case GlobalObjectType:
+        return static_cast<const JSGlobalObject*>(this)->isDynamicScope(requiresDynamicChecks);
+    case ActivationObjectType:
+        return static_cast<const JSActivation*>(this)->isDynamicScope(requiresDynamicChecks);
+    case NameScopeObjectType:
+        return static_cast<const JSNameScope*>(this)->isDynamicScope(requiresDynamicChecks);
+    default:
+        ASSERT_NOT_REACHED();
+        break;
+    }
+
+    return false;
+}
+
+JSObject* JSScope::objectAtScope(JSScope* scope)
+{
+    JSObject* object = scope;
+    if (object->structure()->typeInfo().type() == WithScopeType)
+        return jsCast<JSWithScope*>(object)->object();
+
+    return object;
+}
+
+int JSScope::localDepth()
+{
+    int scopeDepth = 0;
+    ScopeChainIterator iter = this->begin();
+    ScopeChainIterator end = this->end();
+    while (!iter->inherits(&JSActivation::s_info)) {
+        ++iter;
+        if (iter == end)
+            break;
+        ++scopeDepth;
+    }
+    return scopeDepth;
+}
+
+JSValue JSScope::resolve(CallFrame* callFrame, const Identifier& identifier)
+{
+    JSScope* scope = callFrame->scope();
+    ASSERT(scope);
+
+    do {
+        JSObject* object = JSScope::objectAtScope(scope);
+        PropertySlot slot(object);
+        if (object->getPropertySlot(callFrame, identifier, slot))
+            return slot.getValue(callFrame, identifier);
+    } while ((scope = scope->next()));
+
+    return throwError(callFrame, createUndefinedVariableError(callFrame, identifier));
+}
+
+JSValue JSScope::resolveSkip(CallFrame* callFrame, const Identifier& identifier, int skip)
+{
+    JSScope* scope = callFrame->scope();
+    ASSERT(scope);
+
+    CodeBlock* codeBlock = callFrame->codeBlock();
+
+    bool checkTopLevel = codeBlock->codeType() == FunctionCode && codeBlock->needsFullScopeChain();
+    ASSERT(skip || !checkTopLevel);
+    if (checkTopLevel && skip--) {
+        if (callFrame->uncheckedR(codeBlock->activationRegister()).jsValue())
+            scope = scope->next();
+    }
+    while (skip--) {
+        scope = scope->next();
+        ASSERT(scope);
+    }
+
+    do {
+        JSObject* object = JSScope::objectAtScope(scope);
+        PropertySlot slot(object);
+        if (object->getPropertySlot(callFrame, identifier, slot))
+            return slot.getValue(callFrame, identifier);
+    } while ((scope = scope->next()));
+
+    return throwError(callFrame, createUndefinedVariableError(callFrame, identifier));
+}
+
+JSValue JSScope::resolveGlobal(
+    CallFrame* callFrame,
+    const Identifier& identifier,
+    JSGlobalObject* globalObject,
+    WriteBarrierBase<Structure>* cachedStructure,
+    PropertyOffset* cachedOffset
+)
+{
+    if (globalObject->structure() == cachedStructure->get())
+        return globalObject->getDirectOffset(*cachedOffset);
+
+    PropertySlot slot(globalObject);
+    if (!globalObject->getPropertySlot(callFrame, identifier, slot))
+        return throwError(callFrame, createUndefinedVariableError(callFrame, identifier));
+
+    JSValue result = slot.getValue(callFrame, identifier);
+    if (callFrame->globalData().exception)
+        return JSValue();
+
+    if (slot.isCacheableValue() && !globalObject->structure()->isUncacheableDictionary() && slot.slotBase() == globalObject) {
+        cachedStructure->set(callFrame->globalData(), callFrame->codeBlock()->ownerExecutable(), globalObject->structure());
+        *cachedOffset = slot.cachedOffset();
+    }
+    return result;
+}
+
+JSValue JSScope::resolveGlobalDynamic(
+    CallFrame* callFrame,
+    const Identifier& identifier,
+    int skip,
+    WriteBarrierBase<Structure>* cachedStructure,
+    PropertyOffset* cachedOffset
+)
+{
+    JSScope* scope = callFrame->scope();
+    ASSERT(scope);
+
+    CodeBlock* codeBlock = callFrame->codeBlock();
+
+    bool checkTopLevel = codeBlock->codeType() == FunctionCode && codeBlock->needsFullScopeChain();
+    ASSERT(skip || !checkTopLevel);
+    if (checkTopLevel && skip--) {
+        if (callFrame->uncheckedR(codeBlock->activationRegister()).jsValue())
+            scope = scope->next();
+    }
+    while (skip--) {
+        JSObject* object = JSScope::objectAtScope(scope);
+        if (!object->hasCustomProperties())
+            continue;
+
+        PropertySlot slot(object);
+        if (!object->getPropertySlot(callFrame, identifier, slot))
+            continue;
+
+        JSValue result = slot.getValue(callFrame, identifier);
+        if (callFrame->globalData().exception)
+            return JSValue();
+        return result;
+    }
+
+    return resolveGlobal(callFrame, identifier, callFrame->lexicalGlobalObject(), cachedStructure, cachedOffset);
+}
+
+JSValue JSScope::resolveBase(CallFrame* callFrame, const Identifier& identifier, bool isStrict)
+{
+    JSScope* scope = callFrame->scope();
+    ASSERT(scope);
+
+    do {
+        JSObject* object = JSScope::objectAtScope(scope);
+
+        PropertySlot slot(object);
+        if (!object->getPropertySlot(callFrame, identifier, slot))
+            continue;
+
+        return JSValue(object);
+    } while ((scope = scope->next()));
+
+    if (!isStrict)
+        return callFrame->lexicalGlobalObject();
+
+    return throwError(callFrame, createErrorForInvalidGlobalAssignment(callFrame, identifier.string()));
+}
+
+JSValue JSScope::resolveWithBase(CallFrame* callFrame, const Identifier& identifier, Register* base)
+{
+    JSScope* scope = callFrame->scope();
+    ASSERT(scope);
+
+    do {
+        JSObject* object = JSScope::objectAtScope(scope);
+
+        PropertySlot slot(object);
+        if (!object->getPropertySlot(callFrame, identifier, slot))
+            continue;
+
+        JSValue value = slot.getValue(callFrame, identifier);
+        if (callFrame->globalData().exception)
+            return JSValue();
+
+        *base = JSValue(object);
+        return value;
+    } while ((scope = scope->next()));
+
+    return throwError(callFrame, createUndefinedVariableError(callFrame, identifier));
+}
+
+JSValue JSScope::resolveWithThis(CallFrame* callFrame, const Identifier& identifier, Register* base)
+{
+    JSScope* scope = callFrame->scope();
+    ASSERT(scope);
+
+    do {
+        JSObject* object = JSScope::objectAtScope(scope);
+
+        PropertySlot slot(object);
+        if (!object->getPropertySlot(callFrame, identifier, slot))
+            continue;
+
+        JSValue value = slot.getValue(callFrame, identifier);
+        if (callFrame->globalData().exception)
+            return JSValue();
+
+        *base = object->structure()->typeInfo().isEnvironmentRecord() ? jsUndefined() : JSValue(object);
+        return value;
+    } while ((scope = scope->next()));
+
+    return throwError(callFrame, createUndefinedVariableError(callFrame, identifier));
+}
+
+} // namespace JSC