--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/classfile/bytecodeAssembler.hpp	Thu Oct 11 12:25:42 2012 -0400
@@ -0,0 +1,214 @@
+/*
+ * Copyright (c) 2012, 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.
+ *
+ */
+
+#ifndef SHARE_VM_CLASSFILE_BYTECODEASSEMBLER_HPP
+#define SHARE_VM_CLASSFILE_BYTECODEASSEMBLER_HPP
+
+#include "memory/allocation.hpp"
+#include "oops/method.hpp"
+#include "oops/symbol.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "utilities/growableArray.hpp"
+#include "utilities/resourceHash.hpp"
+
+
+/**
+ * Bytecode Assembler
+ *
+ * These classes are used to synthesize code for creating new methods from
+ * within the VM.  This is only a partial implementation of an assembler;
+ * only the bytecodes that are needed by clients are implemented at this time.
+ * This is used during default method analysis to create overpass methods
+ * and add them to a call during parsing.  Other uses (such as creating
+ * bridges) may come later.  Any missing bytecodes can be implemented on an
+ * as-need basis.
+ */
+
+class BytecodeBuffer : public GrowableArray<u1> {
+ public:
+  BytecodeBuffer() : GrowableArray<u1>(20) {}
+};
+
+// Entries in a yet-to-be-created constant pool.  Limited types for now.
+class BytecodeCPEntry VALUE_OBJ_CLASS_SPEC {
+ public:
+  enum tag {
+    ERROR_TAG,
+    UTF8,
+    KLASS,
+    STRING,
+    NAME_AND_TYPE,
+    METHODREF
+  };
+
+  u1 _tag;
+  union {
+    Symbol* utf8;
+    u2 klass;
+    u2 string;
+    struct {
+      u2 name_index;
+      u2 type_index;
+    } name_and_type;
+    struct {
+      u2 class_index;
+      u2 name_and_type_index;
+    } methodref;
+    uintptr_t hash;
+  } _u;
+
+  BytecodeCPEntry() : _tag(ERROR_TAG) { _u.hash = 0; }
+  BytecodeCPEntry(u1 tag) : _tag(tag) { _u.hash = 0; }
+
+  static BytecodeCPEntry utf8(Symbol* symbol) {
+    BytecodeCPEntry bcpe(UTF8);
+    bcpe._u.utf8 = symbol;
+    return bcpe;
+  }
+
+  static BytecodeCPEntry klass(u2 index) {
+    BytecodeCPEntry bcpe(KLASS);
+    bcpe._u.klass = index;
+    return bcpe;
+  }
+
+  static BytecodeCPEntry string(u2 index) {
+    BytecodeCPEntry bcpe(STRING);
+    bcpe._u.string = index;
+    return bcpe;
+  }
+
+  static BytecodeCPEntry name_and_type(u2 name, u2 type) {
+    BytecodeCPEntry bcpe(NAME_AND_TYPE);
+    bcpe._u.name_and_type.name_index = name;
+    bcpe._u.name_and_type.type_index = type;
+    return bcpe;
+  }
+
+  static BytecodeCPEntry methodref(u2 class_index, u2 nat) {
+    BytecodeCPEntry bcpe(METHODREF);
+    bcpe._u.methodref.class_index = class_index;
+    bcpe._u.methodref.name_and_type_index = nat;
+    return bcpe;
+  }
+
+  static bool equals(BytecodeCPEntry const& e0, BytecodeCPEntry const& e1) {
+    return e0._tag == e1._tag && e0._u.hash == e1._u.hash;
+  }
+
+  static unsigned hash(BytecodeCPEntry const& e0) {
+    return (unsigned)(e0._tag ^ e0._u.hash);
+  }
+};
+
+class BytecodeConstantPool : ResourceObj {
+ private:
+  typedef ResourceHashtable<BytecodeCPEntry, u2,
+      &BytecodeCPEntry::hash, &BytecodeCPEntry::equals> IndexHash;
+
+  ConstantPool* _orig;
+  GrowableArray<BytecodeCPEntry> _entries;
+  IndexHash _indices;
+
+  u2 find_or_add(BytecodeCPEntry const& bcpe);
+
+ public:
+
+  BytecodeConstantPool(ConstantPool* orig) : _orig(orig) {}
+
+  BytecodeCPEntry const& at(u2 index) const { return _entries.at(index); }
+
+  InstanceKlass* pool_holder() const {
+    return InstanceKlass::cast(_orig->pool_holder());
+  }
+
+  u2 utf8(Symbol* sym) {
+    return find_or_add(BytecodeCPEntry::utf8(sym));
+  }
+
+  u2 klass(Symbol* class_name) {
+    return find_or_add(BytecodeCPEntry::klass(utf8(class_name)));
+  }
+
+  u2 string(Symbol* str) {
+    return find_or_add(BytecodeCPEntry::string(utf8(str)));
+  }
+
+  u2 name_and_type(Symbol* name, Symbol* sig) {
+    return find_or_add(BytecodeCPEntry::name_and_type(utf8(name), utf8(sig)));
+  }
+
+  u2 methodref(Symbol* class_name, Symbol* name, Symbol* sig) {
+    return find_or_add(BytecodeCPEntry::methodref(
+        klass(class_name), name_and_type(name, sig)));
+  }
+
+  ConstantPool* create_constant_pool(TRAPS) const;
+};
+
+// Partial bytecode assembler - only what we need for creating
+// overpass methods for default methods is implemented
+class BytecodeAssembler : StackObj {
+ private:
+  BytecodeBuffer* _code;
+  BytecodeConstantPool* _cp;
+
+  void append(u1 imm_u1);
+  void append(u2 imm_u2);
+  void append(u4 imm_u4);
+
+  void xload(u4 index, u1 quick, u1 twobyte);
+
+ public:
+  BytecodeAssembler(BytecodeBuffer* buffer, BytecodeConstantPool* cp)
+    : _code(buffer), _cp(cp) {}
+
+  void aload(u4 index);
+  void areturn();
+  void athrow();
+  void checkcast(Symbol* sym);
+  void dload(u4 index);
+  void dreturn();
+  void dup();
+  void fload(u4 index);
+  void freturn();
+  void iload(u4 index);
+  void invokespecial(Method* method);
+  void invokespecial(Symbol* cls, Symbol* name, Symbol* sig);
+  void invokevirtual(Method* method);
+  void invokevirtual(Symbol* cls, Symbol* name, Symbol* sig);
+  void ireturn();
+  void ldc(u1 index);
+  void ldc_w(u2 index);
+  void lload(u4 index);
+  void lreturn();
+  void _new(Symbol* sym);
+  void _return();
+
+  void load_string(Symbol* sym);
+  void load(BasicType bt, u4 index);
+  void _return(BasicType bt);
+};
+
+#endif // SHARE_VM_CLASSFILE_BYTECODEASSEMBLER_HPP