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	/*
	* Copyright (c) 2012, 2018, 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. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* 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 java.lang.invoke;

	import jdk.internal.org.objectweb.asm.MethodVisitor;
	import jdk.internal.org.objectweb.asm.Opcodes;
	import jdk.internal.org.objectweb.asm.Type;
	import sun.invoke.util.BytecodeDescriptor;
	import sun.invoke.util.Wrapper;
	import static sun.invoke.util.Wrapper.*;

	class TypeConvertingMethodAdapter extends MethodVisitor {

	TypeConvertingMethodAdapter(MethodVisitor mv) {
	super(Opcodes.ASM7, mv);
	}

	private static final int NUM_WRAPPERS = Wrapper.COUNT;

	private static final String NAME_OBJECT = "java/lang/Object";
	private static final String WRAPPER_PREFIX = "Ljava/lang/";

	// Same for all primitives; name of the boxing method
	private static final String NAME_BOX_METHOD = "valueOf";

	// Table of opcodes for widening primitive conversions; NOP = no conversion
	private static final int[][] wideningOpcodes = new int[NUM_WRAPPERS][NUM_WRAPPERS];

	private static final Wrapper[] FROM_WRAPPER_NAME = new Wrapper[16];

	// Table of wrappers for primitives, indexed by ASM type sorts
	private static final Wrapper[] FROM_TYPE_SORT = new Wrapper[12];

	static {
	for (Wrapper w : Wrapper.values()) {
	if (w.basicTypeChar() != 'L') {
	int wi = hashWrapperName(w.wrapperSimpleName());
	assert (FROM_WRAPPER_NAME[wi] == null);
	FROM_WRAPPER_NAME[wi] = w;
	}
	}

	// wideningOpcodes[][] will be NOP-initialized by default
	assert(Opcodes.NOP == 0);

	initWidening(LONG, Opcodes.I2L, BYTE, SHORT, INT, CHAR);
	initWidening(LONG, Opcodes.F2L, FLOAT);
	initWidening(FLOAT, Opcodes.I2F, BYTE, SHORT, INT, CHAR);
	initWidening(FLOAT, Opcodes.L2F, LONG);
	initWidening(DOUBLE, Opcodes.I2D, BYTE, SHORT, INT, CHAR);
	initWidening(DOUBLE, Opcodes.F2D, FLOAT);
	initWidening(DOUBLE, Opcodes.L2D, LONG);

	FROM_TYPE_SORT[Type.BYTE] = Wrapper.BYTE;
	FROM_TYPE_SORT[Type.SHORT] = Wrapper.SHORT;
	FROM_TYPE_SORT[Type.INT] = Wrapper.INT;
	FROM_TYPE_SORT[Type.LONG] = Wrapper.LONG;
	FROM_TYPE_SORT[Type.CHAR] = Wrapper.CHAR;
	FROM_TYPE_SORT[Type.FLOAT] = Wrapper.FLOAT;
	FROM_TYPE_SORT[Type.DOUBLE] = Wrapper.DOUBLE;
	FROM_TYPE_SORT[Type.BOOLEAN] = Wrapper.BOOLEAN;
	}

	private static void initWidening(Wrapper to, int opcode, Wrapper... from) {
	for (Wrapper f : from) {
	wideningOpcodes[f.ordinal()][to.ordinal()] = opcode;
	}
	}

	/**
	* Class name to Wrapper hash, derived from Wrapper.hashWrap()
	* @param xn
	* @return The hash code 0-15
	*/
	private static int hashWrapperName(String xn) {
	if (xn.length() < 3) {
	return 0;
	}
	return (3 * xn.charAt(1) + xn.charAt(2)) % 16;
	}

	private Wrapper wrapperOrNullFromDescriptor(String desc) {
	if (!desc.startsWith(WRAPPER_PREFIX)) {
	// Not a class type (array or method), so not a boxed type
	// or not in the right package
	return null;
	}
	// Pare it down to the simple class name
	String cname = desc.substring(WRAPPER_PREFIX.length(), desc.length() - 1);
	// Hash to a Wrapper
	Wrapper w = FROM_WRAPPER_NAME[hashWrapperName(cname)];
	if (w == null \|\| w.wrapperSimpleName().equals(cname)) {
	return w;
	} else {
	return null;
	}
	}

	private static String wrapperName(Wrapper w) {
	return "java/lang/" + w.wrapperSimpleName();
	}

	private static String unboxMethod(Wrapper w) {
	return w.primitiveSimpleName() + "Value";
	}

	private static String boxingDescriptor(Wrapper w) {
	return "(" + w.basicTypeChar() + ")L" + wrapperName(w) + ";";
	}

	private static String unboxingDescriptor(Wrapper w) {
	return "()" + w.basicTypeChar();
	}

	void boxIfTypePrimitive(Type t) {
	Wrapper w = FROM_TYPE_SORT[t.getSort()];
	if (w != null) {
	box(w);
	}
	}

	void widen(Wrapper ws, Wrapper wt) {
	if (ws != wt) {
	int opcode = wideningOpcodes[ws.ordinal()][wt.ordinal()];
	if (opcode != Opcodes.NOP) {
	visitInsn(opcode);
	}
	}
	}

	void box(Wrapper w) {
	visitMethodInsn(Opcodes.INVOKESTATIC,
	wrapperName(w),
	NAME_BOX_METHOD,
	boxingDescriptor(w), false);
	}

	/**
	* Convert types by unboxing. The source type is known to be a primitive wrapper.
	* @param sname A primitive wrapper corresponding to wrapped reference source type
	* @param wt A primitive wrapper being converted to
	*/
	void unbox(String sname, Wrapper wt) {
	visitMethodInsn(Opcodes.INVOKEVIRTUAL,
	sname,
	unboxMethod(wt),
	unboxingDescriptor(wt), false);
	}

	private String descriptorToName(String desc) {
	int last = desc.length() - 1;
	if (desc.charAt(0) == 'L' && desc.charAt(last) == ';') {
	// In descriptor form
	return desc.substring(1, last);
	} else {
	// Already in internal name form
	return desc;
	}
	}

	void cast(String ds, String dt) {
	String ns = descriptorToName(ds);
	String nt = descriptorToName(dt);
	if (!nt.equals(ns) && !nt.equals(NAME_OBJECT)) {
	visitTypeInsn(Opcodes.CHECKCAST, nt);
	}
	}

	private Wrapper toWrapper(String desc) {
	char first = desc.charAt(0);
	if (first == '[' \|\| first == '(') {
	first = 'L';
	}
	return Wrapper.forBasicType(first);
	}

	/**
	* Convert an argument of type 'arg' to be passed to 'target' assuring that it is 'functional'.
	* Insert the needed conversion instructions in the method code.
	* @param arg
	* @param target
	* @param functional
	*/
	void convertType(Class<?> arg, Class<?> target, Class<?> functional) {
	if (arg.equals(target) && arg.equals(functional)) {
	return;
	}
	if (arg == Void.TYPE \|\| target == Void.TYPE) {
	return;
	}
	if (arg.isPrimitive()) {
	Wrapper wArg = Wrapper.forPrimitiveType(arg);
	if (target.isPrimitive()) {
	// Both primitives: widening
	widen(wArg, Wrapper.forPrimitiveType(target));
	} else {
	// Primitive argument to reference target
	String dTarget = BytecodeDescriptor.unparse(target);
	Wrapper wPrimTarget = wrapperOrNullFromDescriptor(dTarget);
	if (wPrimTarget != null) {
	// The target is a boxed primitive type, widen to get there before boxing
	widen(wArg, wPrimTarget);
	box(wPrimTarget);
	} else {
	// Otherwise, box and cast
	box(wArg);
	cast(wrapperName(wArg), dTarget);
	}
	}
	} else {
	String dArg = BytecodeDescriptor.unparse(arg);
	String dSrc;
	if (functional.isPrimitive()) {
	dSrc = dArg;
	} else {
	// Cast to convert to possibly more specific type, and generate CCE for invalid arg
	dSrc = BytecodeDescriptor.unparse(functional);
	cast(dArg, dSrc);
	}
	String dTarget = BytecodeDescriptor.unparse(target);
	if (target.isPrimitive()) {
	Wrapper wTarget = toWrapper(dTarget);
	// Reference argument to primitive target
	Wrapper wps = wrapperOrNullFromDescriptor(dSrc);
	if (wps != null) {
	if (wps.isSigned() \|\| wps.isFloating()) {
	// Boxed number to primitive
	unbox(wrapperName(wps), wTarget);
	} else {
	// Character or Boolean
	unbox(wrapperName(wps), wps);
	widen(wps, wTarget);
	}
	} else {
	// Source type is reference type, but not boxed type,
	// assume it is super type of target type
	String intermediate;
	if (wTarget.isSigned() \|\| wTarget.isFloating()) {
	// Boxed number to primitive
	intermediate = "java/lang/Number";
	} else {
	// Character or Boolean
	intermediate = wrapperName(wTarget);
	}
	cast(dSrc, intermediate);
	unbox(intermediate, wTarget);
	}
	} else {
	// Both reference types: just case to target type
	cast(dSrc, dTarget);
	}
	}
	}

	/**
	* The following method is copied from
	* org.objectweb.asm.commons.InstructionAdapter. Part of ASM: a very small
	* and fast Java bytecode manipulation framework.
	* Copyright (c) 2000-2005 INRIA, France Telecom All rights reserved.
	*/
	void iconst(final int cst) {
	if (cst >= -1 && cst <= 5) {
	mv.visitInsn(Opcodes.ICONST_0 + cst);
	} else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) {
	mv.visitIntInsn(Opcodes.BIPUSH, cst);
	} else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) {
	mv.visitIntInsn(Opcodes.SIPUSH, cst);
	} else {
	mv.visitLdcInsn(cst);
	}
	}
	}

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