1 files changed, 148 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/wasm/js/JSWebAssemblyMemory.cpp b/Source/JavaScriptCore/wasm/js/JSWebAssemblyMemory.cpp
new file mode 100644
index 000000000..f4253b5bf
--- /dev/null
+++ b/Source/JavaScriptCore/wasm/js/JSWebAssemblyMemory.cpp
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2016 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 "JSWebAssemblyMemory.h"
+
+#if ENABLE(WEBASSEMBLY)
+
+#include "JSCInlines.h"
+
+#include "ArrayBuffer.h"
+#include "JSArrayBuffer.h"
+
+namespace JSC {
+
+const ClassInfo JSWebAssemblyMemory::s_info = { "WebAssembly.Memory", &Base::s_info, 0, CREATE_METHOD_TABLE(JSWebAssemblyMemory) };
+
+JSWebAssemblyMemory* JSWebAssemblyMemory::create(VM& vm, Structure* structure, Wasm::Memory&& memory)
+{
+    auto* instance = new (NotNull, allocateCell<JSWebAssemblyMemory>(vm.heap)) JSWebAssemblyMemory(vm, structure, std::forward<Wasm::Memory>(memory));
+    instance->finishCreation(vm);
+    return instance;
+}
+
+Structure* JSWebAssemblyMemory::createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
+{
+    return Structure::create(vm, globalObject, prototype, TypeInfo(ObjectType, StructureFlags), info());
+}
+
+JSWebAssemblyMemory::JSWebAssemblyMemory(VM& vm, Structure* structure, Wasm::Memory&& memory)
+    : Base(vm, structure)
+    , m_memory(WTFMove(memory))
+{
+}
+
+JSArrayBuffer* JSWebAssemblyMemory::buffer(VM& vm, JSGlobalObject* globalObject)
+{
+    if (m_bufferWrapper)
+        return m_bufferWrapper.get();
+
+    auto destructor = [] (void*) {
+        // We don't need to do anything here to destroy the memory.
+        // The ArrayBuffer backing the JSArrayBuffer is only owned by us,
+        // so we guarantee its lifecycle.
+    };
+    m_buffer = ArrayBuffer::createFromBytes(memory()->memory(), memory()->size(), WTFMove(destructor));
+    m_bufferWrapper.set(vm, this, JSArrayBuffer::create(vm, globalObject->m_arrayBufferStructure.get(), m_buffer.get()));
+    RELEASE_ASSERT(m_bufferWrapper);
+    return m_bufferWrapper.get();
+}
+
+Wasm::PageCount JSWebAssemblyMemory::grow(ExecState* exec, uint32_t delta, bool shouldThrowExceptionsOnFailure)
+{
+    VM& vm = exec->vm();
+    auto throwScope = DECLARE_THROW_SCOPE(vm);
+
+    Wasm::PageCount oldPageCount = memory()->sizeInPages();
+
+    if (!Wasm::PageCount::isValid(delta)) {
+        if (shouldThrowExceptionsOnFailure)
+            throwException(exec, throwScope, createRangeError(exec, ASCIILiteral("WebAssembly.Memory.grow expects the delta to be a valid page count")));
+        return Wasm::PageCount();
+    }
+
+    Wasm::PageCount newSize = oldPageCount + Wasm::PageCount(delta);
+    if (!newSize) {
+        if (shouldThrowExceptionsOnFailure)
+            throwException(exec, throwScope, createRangeError(exec, ASCIILiteral("WebAssembly.Memory.grow expects the grown size to be a valid page count")));
+        return Wasm::PageCount();
+    }
+
+    if (delta) {
+        bool success = memory()->grow(newSize);
+        if (!success) {
+            if (shouldThrowExceptionsOnFailure)
+                throwException(exec, throwScope, createOutOfMemoryError(exec));
+            return Wasm::PageCount();
+        }
+    }
+
+    // We need to clear out the old array buffer because it might now be pointing
+    // to stale memory.
+    // Neuter the old array.
+    if (m_buffer) {
+        ArrayBufferContents dummyContents;
+        m_buffer->transferTo(vm, dummyContents);
+        m_buffer = nullptr;
+        m_bufferWrapper.clear();
+    }
+
+    return oldPageCount;
+}
+
+void JSWebAssemblyMemory::finishCreation(VM& vm)
+{
+    Base::finishCreation(vm);
+    ASSERT(inherits(vm, info()));
+}
+
+void JSWebAssemblyMemory::destroy(JSCell* cell)
+{
+    auto memory = static_cast<JSWebAssemblyMemory*>(cell);
+    ASSERT(memory->classInfo() == info());
+    VM& vm = *memory->vm();
+
+    if (memory->m_buffer) {
+        ArrayBufferContents dummyContents;
+        memory->m_buffer->transferTo(vm, dummyContents);
+        memory->m_buffer = nullptr;
+    }
+
+    memory->JSWebAssemblyMemory::~JSWebAssemblyMemory();
+}
+
+void JSWebAssemblyMemory::visitChildren(JSCell* cell, SlotVisitor& visitor)
+{
+    auto* thisObject = jsCast<JSWebAssemblyMemory*>(cell);
+    ASSERT_GC_OBJECT_INHERITS(thisObject, info());
+
+    Base::visitChildren(thisObject, visitor);
+    visitor.append(thisObject->m_bufferWrapper);
+}
+
+} // namespace JSC
+
+#endif // ENABLE(WEBASSEMBLY)