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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;
	import jdk.internal.org.objectweb.asm.tree.TryCatchBlockNode;

	/**
	* 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> {

	/**
	* The ASM API version supported by this interpreter. The value of this field must be one of
	* {@link jdk.internal.org.objectweb.asm.Opcodes#ASM4}, {@link jdk.internal.org.objectweb.asm.Opcodes#ASM5}, {@link
	* jdk.internal.org.objectweb.asm.Opcodes#ASM6} or {@link jdk.internal.org.objectweb.asm.Opcodes#ASM7}.
	*/
	protected final int api;

	/**
	* Constructs a new {@link Interpreter}.
	*
	* @param api the ASM API version supported by this interpreter. Must be one of {@link
	* jdk.internal.org.objectweb.asm.Opcodes#ASM4}, {@link jdk.internal.org.objectweb.asm.Opcodes#ASM5}, {@link
	* jdk.internal.org.objectweb.asm.Opcodes#ASM6} or {@link jdk.internal.org.objectweb.asm.Opcodes#ASM7}.
	*/
	protected Interpreter(final int api) {
	this.api = api;
	}

	/**
	* Creates a new value that represents the given type.
	*
	* <p>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.
	*
	* <p>An interpreter may choose to implement one or more of {@link
	* Interpreter#newReturnTypeValue(Type)}, {@link Interpreter#newParameterValue(boolean, int,
	* Type)}, {@link Interpreter#newEmptyValue(int)}, {@link
	* Interpreter#newExceptionValue(TryCatchBlockNode, Frame, Type)} to distinguish different types
	* of new value.
	*
	* @param type a primitive or reference type, or {@literal null} 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);

	/**
	* Creates a new value that represents the given parameter type. This method is called to
	* initialize the value of a local corresponding to a method parameter in a frame.
	*
	* <p>By default, calls <code>newValue(type)</code>.
	*
	* @param isInstanceMethod {@literal true} if the method is non-static.
	* @param local the local variable index.
	* @param type a primitive or reference type.
	* @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 V newParameterValue(final boolean isInstanceMethod, final int local, final Type type) {
	return newValue(type);
	}

	/**
	* Creates a new value that represents the given return type. This method is called to initialize
	* the return type value of a frame.
	*
	* <p>By default, calls <code>newValue(type)</code>.
	*
	* @param type a primitive or reference type.
	* @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 V newReturnTypeValue(final Type type) {
	return newValue(type);
	}

	/**
	* Creates a new uninitialized value for a local variable. This method is called to initialize the
	* value of a local that does not correspond to a method parameter, and to reset one half of a
	* size-2 value when the other half is assigned a size-1 value.
	*
	* <p>By default, calls <code>newValue(null)</code>.
	*
	* @param local the local variable index.
	* @return a value representing an uninitialized value. The size of the returned value must be
	* equal to 1.
	*/
	public V newEmptyValue(final int local) {
	return newValue(null);
	}

	/**
	* Creates a new value that represents the given exception type. This method is called to
	* initialize the exception value on the call stack at the entry of an exception handler.
	*
	* <p>By default, calls <code>newValue(exceptionType)</code>.
	*
	* @param tryCatchBlockNode the exception handler.
	* @param handlerFrame the exception handler frame.
	* @param exceptionType the exception type handled by this handler.
	* @return a value that represents the given {@code exceptionType}. The size of the returned value
	* must be equal to 1.
	*/
	public V newExceptionValue(
	final TryCatchBlockNode tryCatchBlockNode,
	final Frame<V> handlerFrame,
	final Type exceptionType) {
	return newValue(exceptionType);
	}

	/**
	* Interprets a bytecode instruction without arguments. This method is called for the following
	* opcodes:
	*
	* <p>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 occurred 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:
	*
	* <p>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
	* {@code equal} to the given value.
	* @throws AnalyzerException if an error occurred 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:
	*
	* <p>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 occurred 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:
	*
	* <p>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 occurred 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:
	*
	* <p>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 occurred 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:
	*
	* <p>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 occurred 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:
	*
	* <p>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 occurred 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 value1 a value.
	* @param value2 another value.
	* @return the merged value. If the merged value is equal to {@code value1}, this method
	* <i>must</i> return {@code value1}.
	*/
	public abstract V merge(V value1, V value2);
	}

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