diff -r 000000000000 -r 6474c204b198 js/src/vm/Xdr.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/vm/Xdr.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,133 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "vm/Xdr.h"
+
+#include <string.h>
+
+#include "jsapi.h"
+#include "jsscript.h"
+
+#include "vm/Debugger.h"
+
+using namespace js;
+
+void
+XDRBuffer::freeBuffer()
+{
+    js_free(base);
+#ifdef DEBUG
+    memset(this, 0xe2, sizeof *this);
+#endif
+}
+
+bool
+XDRBuffer::grow(size_t n)
+{
+    JS_ASSERT(n > size_t(limit - cursor));
+
+    const size_t MEM_BLOCK = 8192;
+    size_t offset = cursor - base;
+    size_t newCapacity = JS_ROUNDUP(offset + n, MEM_BLOCK);
+    if (isUint32Overflow(newCapacity)) {
+        JS_ReportErrorNumber(cx(), js_GetErrorMessage, nullptr, JSMSG_TOO_BIG_TO_ENCODE);
+        return false;
+    }
+
+    void *data = js_realloc(base, newCapacity);
+    if (!data) {
+        js_ReportOutOfMemory(cx());
+        return false;
+    }
+    base = static_cast<uint8_t *>(data);
+    cursor = base + offset;
+    limit = base + newCapacity;
+    return true;
+}
+
+template<XDRMode mode>
+bool
+XDRState<mode>::codeChars(jschar *chars, size_t nchars)
+{
+    size_t nbytes = nchars * sizeof(jschar);
+    if (mode == XDR_ENCODE) {
+        uint8_t *ptr = buf.write(nbytes);
+        if (!ptr)
+            return false;
+        mozilla::NativeEndian::copyAndSwapToLittleEndian(ptr, chars, nchars);
+    } else {
+        const uint8_t *ptr = buf.read(nbytes);
+        mozilla::NativeEndian::copyAndSwapFromLittleEndian(chars, ptr, nchars);
+    }
+    return true;
+}
+
+template<XDRMode mode>
+static bool
+VersionCheck(XDRState<mode> *xdr)
+{
+    uint32_t bytecodeVer;
+    if (mode == XDR_ENCODE)
+        bytecodeVer = XDR_BYTECODE_VERSION;
+
+    if (!xdr->codeUint32(&bytecodeVer))
+        return false;
+
+    if (mode == XDR_DECODE && bytecodeVer != XDR_BYTECODE_VERSION) {
+        /* We do not provide binary compatibility with older scripts. */
+        JS_ReportErrorNumber(xdr->cx(), js_GetErrorMessage, nullptr, JSMSG_BAD_SCRIPT_MAGIC);
+        return false;
+    }
+
+    return true;
+}
+
+template<XDRMode mode>
+bool
+XDRState<mode>::codeFunction(MutableHandleObject objp)
+{
+    if (mode == XDR_DECODE)
+        objp.set(nullptr);
+
+    if (!VersionCheck(this))
+        return false;
+
+    return XDRInterpretedFunction(this, NullPtr(), NullPtr(), objp);
+}
+
+template<XDRMode mode>
+bool
+XDRState<mode>::codeScript(MutableHandleScript scriptp)
+{
+    if (mode == XDR_DECODE)
+        scriptp.set(nullptr);
+
+    if (!VersionCheck(this))
+        return false;
+
+    if (!XDRScript(this, NullPtr(), NullPtr(), NullPtr(), scriptp))
+        return false;
+
+    return true;
+}
+
+template<XDRMode mode>
+bool
+XDRState<mode>::codeConstValue(MutableHandleValue vp)
+{
+    return XDRScriptConst(this, vp);
+}
+
+XDRDecoder::XDRDecoder(JSContext *cx, const void *data, uint32_t length,
+                       JSPrincipals *originPrincipals)
+  : XDRState<XDR_DECODE>(cx)
+{
+    buf.setData(data, length);
+    this->originPrincipals_ = originPrincipals;
+}
+
+template class js::XDRState<XDR_ENCODE>;
+template class js::XDRState<XDR_DECODE>;