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	/*
	* 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.
	*/

	/*
	* This file is available under and governed by the GNU General Public
	* License version 2 only, as published by the Free Software Foundation.
	* However, the following notice accompanied the original version of this
	* file:
	*
	* ASM: a very small and fast Java bytecode manipulation framework
	* Copyright (c) 2000-2011 INRIA, France Telecom
	* 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.
	* 3. Neither the name of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT OWNER 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.
	*/
	package jdk.internal.org.objectweb.asm.tree.analysis;

	import java.util.List;

	import jdk.internal.org.objectweb.asm.Type;
	import jdk.internal.org.objectweb.asm.tree.AbstractInsnNode;

	/**
	* A semantic bytecode interpreter. More precisely, this interpreter only
	* manages the computation of values from other values: it does not manage the
	* transfer of values to or from the stack, and to or from the local variables.
	* This separation allows a generic bytecode {@link Analyzer} to work with
	* various semantic interpreters, without needing to duplicate the code to
	* simulate the transfer of values.
	*
	* @param <V>
	* type of the Value used for the analysis.
	*
	* @author Eric Bruneton
	*/
	public abstract class Interpreter<V extends Value> {

	protected final int api;

	protected Interpreter(final int api) {
	this.api = api;
	}

	/**
	* Creates a new value that represents the given type.
	*
	* Called for method parameters (including <code>this</code>), exception
	* handler variable and with <code>null</code> type for variables reserved
	* by long and double types.
	*
	* @param type
	* a primitive or reference type, or <tt>null</tt> to represent
	* an uninitialized value.
	* @return a value that represents the given type. The size of the returned
	* value must be equal to the size of the given type.
	*/
	public abstract V newValue(Type type);

	/**
	* Interprets a bytecode instruction without arguments. This method is
	* called for the following opcodes:
	*
	* ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4,
	* ICONST_5, LCONST_0, LCONST_1, FCONST_0, FCONST_1, FCONST_2, DCONST_0,
	* DCONST_1, BIPUSH, SIPUSH, LDC, JSR, GETSTATIC, NEW
	*
	* @param insn
	* the bytecode instruction to be interpreted.
	* @return the result of the interpretation of the given instruction.
	* @throws AnalyzerException
	* if an error occured during the interpretation.
	*/
	public abstract V newOperation(AbstractInsnNode insn)
	throws AnalyzerException;

	/**
	* Interprets a bytecode instruction that moves a value on the stack or to
	* or from local variables. This method is called for the following opcodes:
	*
	* ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE, LSTORE, FSTORE, DSTORE,
	* ASTORE, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP
	*
	* @param insn
	* the bytecode instruction to be interpreted.
	* @param value
	* the value that must be moved by the instruction.
	* @return the result of the interpretation of the given instruction. The
	* returned value must be <tt>equal</tt> to the given value.
	* @throws AnalyzerException
	* if an error occured during the interpretation.
	*/
	public abstract V copyOperation(AbstractInsnNode insn, V value)
	throws AnalyzerException;

	/**
	* Interprets a bytecode instruction with a single argument. This method is
	* called for the following opcodes:
	*
	* INEG, LNEG, FNEG, DNEG, IINC, I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L,
	* F2D, D2I, D2L, D2F, I2B, I2C, I2S, IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE,
	* TABLESWITCH, LOOKUPSWITCH, IRETURN, LRETURN, FRETURN, DRETURN, ARETURN,
	* PUTSTATIC, GETFIELD, NEWARRAY, ANEWARRAY, ARRAYLENGTH, ATHROW, CHECKCAST,
	* INSTANCEOF, MONITORENTER, MONITOREXIT, IFNULL, IFNONNULL
	*
	* @param insn
	* the bytecode instruction to be interpreted.
	* @param value
	* the argument of the instruction to be interpreted.
	* @return the result of the interpretation of the given instruction.
	* @throws AnalyzerException
	* if an error occured during the interpretation.
	*/
	public abstract V unaryOperation(AbstractInsnNode insn, V value)
	throws AnalyzerException;

	/**
	* Interprets a bytecode instruction with two arguments. This method is
	* called for the following opcodes:
	*
	* IALOAD, LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IADD,
	* LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV,
	* LDIV, FDIV, DDIV, IREM, LREM, FREM, DREM, ISHL, LSHL, ISHR, LSHR, IUSHR,
	* LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, LCMP, FCMPL, FCMPG, DCMPL,
	* DCMPG, IF_ICMPEQ, IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE,
	* IF_ACMPEQ, IF_ACMPNE, PUTFIELD
	*
	* @param insn
	* the bytecode instruction to be interpreted.
	* @param value1
	* the first argument of the instruction to be interpreted.
	* @param value2
	* the second argument of the instruction to be interpreted.
	* @return the result of the interpretation of the given instruction.
	* @throws AnalyzerException
	* if an error occured during the interpretation.
	*/
	public abstract V binaryOperation(AbstractInsnNode insn, V value1, V value2)
	throws AnalyzerException;

	/**
	* Interprets a bytecode instruction with three arguments. This method is
	* called for the following opcodes:
	*
	* IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE, SASTORE
	*
	* @param insn
	* the bytecode instruction to be interpreted.
	* @param value1
	* the first argument of the instruction to be interpreted.
	* @param value2
	* the second argument of the instruction to be interpreted.
	* @param value3
	* the third argument of the instruction to be interpreted.
	* @return the result of the interpretation of the given instruction.
	* @throws AnalyzerException
	* if an error occured during the interpretation.
	*/
	public abstract V ternaryOperation(AbstractInsnNode insn, V value1,
	V value2, V value3) throws AnalyzerException;

	/**
	* Interprets a bytecode instruction with a variable number of arguments.
	* This method is called for the following opcodes:
	*
	* INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC, INVOKEINTERFACE,
	* MULTIANEWARRAY and INVOKEDYNAMIC
	*
	* @param insn
	* the bytecode instruction to be interpreted.
	* @param values
	* the arguments of the instruction to be interpreted.
	* @return the result of the interpretation of the given instruction.
	* @throws AnalyzerException
	* if an error occured during the interpretation.
	*/
	public abstract V naryOperation(AbstractInsnNode insn,
	List<? extends V> values) throws AnalyzerException;

	/**
	* Interprets a bytecode return instruction. This method is called for the
	* following opcodes:
	*
	* IRETURN, LRETURN, FRETURN, DRETURN, ARETURN
	*
	* @param insn
	* the bytecode instruction to be interpreted.
	* @param value
	* the argument of the instruction to be interpreted.
	* @param expected
	* the expected return type of the analyzed method.
	* @throws AnalyzerException
	* if an error occured during the interpretation.
	*/
	public abstract void returnOperation(AbstractInsnNode insn, V value,
	V expected) throws AnalyzerException;

	/**
	* Merges two values. The merge operation must return a value that
	* represents both values (for instance, if the two values are two types,
	* the merged value must be a common super type of the two types. If the two
	* values are integer intervals, the merged value must be an interval that
	* contains the previous ones. Likewise for other types of values).
	*
	* @param v
	* a value.
	* @param w
	* another value.
	* @return the merged value. If the merged value is equal to <tt>v</tt>,
	* this method <i>must</i> return <tt>v</tt>.
	*/
	public abstract V merge(V v, V w);
	}

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