--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.replacements/src/org/graalvm/compiler/replacements/classfile/Classfile.java	2017-02-15 17:09:11.703333628 -0800
@@ -0,0 +1,176 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package org.graalvm.compiler.replacements.classfile;
+
+import java.io.DataInputStream;
+import java.io.IOException;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.graalvm.compiler.replacements.classfile.ClassfileConstant.Utf8;
+
+import jdk.vm.ci.meta.ResolvedJavaMethod;
+import jdk.vm.ci.meta.ResolvedJavaType;
+
+/**
+ * Container for objects representing the {@code Code} attributes parsed from a class file.
+ *
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.3">Code
+ *      attributes</a>
+ * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.4">Constant
+ *      Pool</a>
+ */
+public class Classfile {
+
+    private final ResolvedJavaType type;
+    private final List<ClassfileBytecode> codeAttributes;
+
+    private static final int MAJOR_VERSION_JAVA7 = 51;
+    private static final int MAJOR_VERSION_JAVA9 = 53;
+
+    /**
+     * Creates a {@link Classfile} by parsing the class file bytes for {@code type} loadable from
+     * {@code context}.
+     *
+     * @throws NoClassDefFoundError if there is an IO error while parsing the class file
+     */
+    public Classfile(ResolvedJavaType type, DataInputStream stream, ClassfileBytecodeProvider context) throws IOException {
+        this.type = type;
+
+        // magic
+        int magic = stream.readInt();
+        assert magic == 0xCAFEBABE;
+
+        int minor = stream.readUnsignedShort();
+        int major = stream.readUnsignedShort();
+        if (major < MAJOR_VERSION_JAVA7 || major > MAJOR_VERSION_JAVA9) {
+            throw new UnsupportedClassVersionError("Unsupported class file version: " + major + "." + minor);
+        }
+
+        ClassfileConstantPool cp = new ClassfileConstantPool(stream, context);
+
+        // access_flags, this_class, super_class
+        skipFully(stream, 6);
+
+        // interfaces
+        skipFully(stream, stream.readUnsignedShort() * 2);
+
+        // fields
+        skipFields(stream);
+
+        // methods
+        codeAttributes = readMethods(stream, cp);
+
+        // attributes
+        skipAttributes(stream);
+    }
+
+    public ClassfileBytecode getCode(String name, String descriptor) {
+        for (ClassfileBytecode code : codeAttributes) {
+            ResolvedJavaMethod method = code.getMethod();
+            if (method.getName().equals(name) && method.getSignature().toMethodDescriptor().equals(descriptor)) {
+                return code;
+            }
+        }
+        throw new NoSuchMethodError(type.toJavaName() + "." + name + descriptor);
+    }
+
+    private static void skipAttributes(DataInputStream stream) throws IOException {
+        int attributesCount;
+        attributesCount = stream.readUnsignedShort();
+        for (int i = 0; i < attributesCount; i++) {
+            skipFully(stream, 2); // name_index
+            int attributeLength = stream.readInt();
+            skipFully(stream, attributeLength);
+        }
+    }
+
+    static void skipFully(DataInputStream stream, int n) throws IOException {
+        long skipped = 0;
+        do {
+            long s = stream.skip(n - skipped);
+            skipped += s;
+            if (s == 0 && skipped != n) {
+                // Check for EOF (i.e., truncated class file)
+                if (stream.read() == -1) {
+                    throw new IOException("truncated stream");
+                }
+                skipped++;
+            }
+        } while (skipped != n);
+    }
+
+    private ClassfileBytecode findCodeAttribute(DataInputStream stream, ClassfileConstantPool cp, String name, String descriptor, boolean isStatic) throws IOException {
+        int attributesCount;
+        attributesCount = stream.readUnsignedShort();
+        ClassfileBytecode code = null;
+        for (int i = 0; i < attributesCount; i++) {
+            String attributeName = cp.get(Utf8.class, stream.readUnsignedShort()).value;
+            int attributeLength = stream.readInt();
+            if (code == null && attributeName.equals("Code")) {
+                ResolvedJavaMethod method = ClassfileBytecodeProvider.findMethod(type, name, descriptor, isStatic);
+                // Even if we will discard the Code attribute (see below), we still
+                // need to parse it to reach the following class file content.
+                code = new ClassfileBytecode(method, stream, cp);
+                if (method == null) {
+                    // This is a method hidden from reflection
+                    // (see sun.reflect.Reflection.filterMethods)
+                    code = null;
+                }
+            } else {
+                skipFully(stream, attributeLength);
+            }
+        }
+        return code;
+    }
+
+    private static void skipFields(DataInputStream stream) throws IOException {
+        int count = stream.readUnsignedShort();
+        for (int i = 0; i < count; i++) {
+            skipFully(stream, 6); // access_flags, name_index, descriptor_index
+            skipAttributes(stream);
+        }
+    }
+
+    private List<ClassfileBytecode> readMethods(DataInputStream stream, ClassfileConstantPool cp) throws IOException {
+        int count = stream.readUnsignedShort();
+        List<ClassfileBytecode> result = new ArrayList<>(count);
+        for (int i = 0; i < count; i++) {
+            int accessFlags = stream.readUnsignedShort();
+            boolean isStatic = Modifier.isStatic(accessFlags);
+            String name = cp.get(Utf8.class, stream.readUnsignedShort()).value;
+            String descriptor = cp.get(Utf8.class, stream.readUnsignedShort()).value;
+            ClassfileBytecode code = findCodeAttribute(stream, cp, name, descriptor, isStatic);
+            if (code != null) {
+                result.add(code);
+            }
+        }
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return getClass().getSimpleName() + "<" + type.toJavaName() + ">";
+    }
+}