--- /dev/null
+/*
+ * Copyright (C) 2015 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 "DirectArguments.h"
+
+#include "CopyVisitorInlines.h"
+#include "GenericArgumentsInlines.h"
+#include "JSCInlines.h"
+
+namespace JSC {
+
+STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(DirectArguments);
+
+const ClassInfo DirectArguments::s_info = { "Arguments", &Base::s_info, 0, CREATE_METHOD_TABLE(DirectArguments) };
+
+DirectArguments::DirectArguments(VM& vm, Structure* structure, unsigned length, unsigned capacity)
+ : GenericArguments(vm, structure)
+ , m_length(length)
+ , m_minCapacity(capacity)
+{
+ // When we construct the object from C++ code, we expect the capacity to be at least as large as
+ // length. JIT-allocated DirectArguments objects play evil tricks, though.
+ ASSERT(capacity >= length);
+}
+
+DirectArguments* DirectArguments::createUninitialized(
+ VM& vm, Structure* structure, unsigned length, unsigned capacity)
+{
+ DirectArguments* result =
+ new (NotNull, allocateCell<DirectArguments>(vm.heap, allocationSize(capacity)))
+ DirectArguments(vm, structure, length, capacity);
+ result->finishCreation(vm);
+ return result;
+}
+
+DirectArguments* DirectArguments::create(VM& vm, Structure* structure, unsigned length, unsigned capacity)
+{
+ DirectArguments* result = createUninitialized(vm, structure, length, capacity);
+
+ for (unsigned i = capacity; i--;)
+ result->storage()[i].clear();
+
+ return result;
+}
+
+DirectArguments* DirectArguments::createByCopying(ExecState* exec)
+{
+ VM& vm = exec->vm();
+
+ unsigned length = exec->argumentCount();
+ unsigned capacity = std::max(length, static_cast<unsigned>(exec->codeBlock()->numParameters() - 1));
+ DirectArguments* result = createUninitialized(
+ vm, exec->lexicalGlobalObject()->directArgumentsStructure(), length, capacity);
+
+ for (unsigned i = capacity; i--;)
+ result->storage()[i].set(vm, result, exec->getArgumentUnsafe(i));
+
+ result->callee().set(vm, result, jsCast<JSFunction*>(exec->callee()));
+
+ return result;
+}
+
+void DirectArguments::visitChildren(JSCell* thisCell, SlotVisitor& visitor)
+{
+ DirectArguments* thisObject = static_cast<DirectArguments*>(thisCell);
+ ASSERT_GC_OBJECT_INHERITS(thisObject, info());
+ Base::visitChildren(thisObject, visitor);
+
+ visitor.appendValues(thisObject->storage(), std::max(thisObject->m_length, thisObject->m_minCapacity));
+ visitor.append(&thisObject->m_callee);
+
+ if (thisObject->m_overrides) {
+ visitor.copyLater(
+ thisObject, DirectArgumentsOverridesCopyToken,
+ thisObject->m_overrides.get(), thisObject->overridesSize());
+ }
+}
+
+void DirectArguments::copyBackingStore(JSCell* thisCell, CopyVisitor& visitor, CopyToken token)
+{
+ DirectArguments* thisObject = static_cast<DirectArguments*>(thisCell);
+ ASSERT_GC_OBJECT_INHERITS(thisObject, info());
+
+ RELEASE_ASSERT(token == DirectArgumentsOverridesCopyToken);
+
+ bool* oldOverrides = thisObject->m_overrides.get();
+ if (!oldOverrides)
+ return;
+
+ if (visitor.checkIfShouldCopy(oldOverrides)) {
+ bool* newOverrides = static_cast<bool*>(visitor.allocateNewSpace(thisObject->overridesSize()));
+ memcpy(newOverrides, oldOverrides, thisObject->m_length);
+ thisObject->m_overrides.setWithoutWriteBarrier(newOverrides);
+ visitor.didCopy(oldOverrides, thisObject->overridesSize());
+ }
+}
+
+Structure* DirectArguments::createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
+{
+ return Structure::create(vm, globalObject, prototype, TypeInfo(DirectArgumentsType, StructureFlags), info());
+}
+
+void DirectArguments::overrideThings(VM& vm)
+{
+ RELEASE_ASSERT(!m_overrides);
+
+ putDirect(vm, vm.propertyNames->length, jsNumber(m_length), DontEnum);
+ putDirect(vm, vm.propertyNames->callee, m_callee.get(), DontEnum);
+ putDirect(vm, vm.propertyNames->iteratorSymbol, globalObject()->arrayProtoValuesFunction(), DontEnum);
+
+ void* backingStore;
+ RELEASE_ASSERT(vm.heap.tryAllocateStorage(this, overridesSize(), &backingStore));
+ m_overrides.set(vm, this, static_cast<bool*>(backingStore));
+ for (unsigned i = m_length; i--;)
+ m_overrides.get()[i] = false;
+}
+
+void DirectArguments::overrideThingsIfNecessary(VM& vm)
+{
+ if (!m_overrides)
+ overrideThings(vm);
+}
+
+void DirectArguments::overrideArgument(VM& vm, unsigned index)
+{
+ overrideThingsIfNecessary(vm);
+ m_overrides.get()[index] = true;
+}
+
+void DirectArguments::copyToArguments(ExecState* exec, VirtualRegister firstElementDest, unsigned offset, unsigned length)
+{
+ if (!m_overrides) {
+ unsigned limit = std::min(length + offset, m_length);
+ unsigned i;
+ VirtualRegister start = firstElementDest - offset;
+ for (i = offset; i < limit; ++i)
+ exec->r(start + i) = storage()[i].get();
+ for (; i < length; ++i)
+ exec->r(start + i) = get(exec, i);
+ return;
+ }
+
+ GenericArguments::copyToArguments(exec, firstElementDest, offset, length);
+}
+
+unsigned DirectArguments::overridesSize()
+{
+ // We always allocate something; in the relatively uncommon case of overriding an empty argument we
+ // still allocate so that m_overrides is non-null. We use that to indicate that the other properties
+ // (length, etc) are overridden.
+ return WTF::roundUpToMultipleOf<8>(m_length ? m_length : 1);
+}
+
+} // namespace JSC
+
projects / apple / javascriptcore.git / blobdiff