/***
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (c) 2000-2007 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 org.codehaus.groovy.gjit;
import java.util.List;
import org.objectweb.asm.Type;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.analysis.AnalyzerException;
import org.objectweb.asm.tree.analysis.Value;
/**
* 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.
*
* @author Eric Bruneton
*/
public interface Interpreter {
/**
* 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.
*/
Value 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.
*/
Value 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.
*/
Value copyOperation(AbstractInsnNode insn, Value 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.
*/
Value unaryOperation(AbstractInsnNode insn, Value 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.
*/
Value binaryOperation(AbstractInsnNode insn, Value value1, Value 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.
*/
Value ternaryOperation(
AbstractInsnNode insn,
Value value1,
Value value2,
Value 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
*
* @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.
*/
Value naryOperation(AbstractInsnNode insn, List<Value> values)
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>.
*/
Value merge(Value v, Value w);
}