Class BasicInterpreter

java.lang.Object

org.objectweb.asm.tree.analysis.BasicInterpreter

All Implemented Interfaces:

Opcodes, Interpreter

Direct Known Subclasses:

BasicVerifier

public class BasicInterpreter
extends Object
implements Opcodes, Interpreter

An Interpreter for BasicValue values.

Author:

Eric Bruneton, Bing Ran

Field Summary

Fields inherited from interface Opcodes

AALOAD, AASTORE, ACC_ABSTRACT, ACC_ANNOTATION, ACC_BRIDGE, ACC_DEPRECATED, ACC_ENUM, ACC_FINAL, ACC_INTERFACE, ACC_NATIVE, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_SYNTHETIC, ACC_TRANSIENT, ACC_VARARGS, ACC_VOLATILE, ACONST_NULL, ALOAD, ANEWARRAY, ARETURN, ARRAYLENGTH, ASTORE, ATHROW, BALOAD, BASTORE, BIPUSH, CALOAD, CASTORE, CHECKCAST, D2F, D2I, D2L, DADD, DALOAD, DASTORE, DCMPG, DCMPL, DCONST_0, DCONST_1, DDIV, DLOAD, DMUL, DNEG, DOUBLE, DREM, DRETURN, DSTORE, DSUB, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, F_APPEND, F_CHOP, F_FULL, F_NEW, F_SAME, F_SAME1, F2D, F2I, F2L, FADD, FALOAD, FASTORE, FCMPG, FCMPL, FCONST_0, FCONST_1, FCONST_2, FDIV, FLOAD, FLOAT, FMUL, FNEG, FREM, FRETURN, FSTORE, FSUB, GETFIELD, GETSTATIC, GOTO, I2B, I2C, I2D, I2F, I2L, I2S, IADD, IALOAD, IAND, IASTORE, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, ICONST_M1, IDIV, IF_ACMPEQ, IF_ACMPNE, IF_ICMPEQ, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ICMPLT, IF_ICMPNE, IFEQ, IFGE, IFGT, IFLE, IFLT, IFNE, IFNONNULL, IFNULL, IINC, ILOAD, IMUL, INEG, INSTANCEOF, INTEGER, INVOKEDYNAMIC, INVOKEDYNAMIC_OWNER, INVOKEINTERFACE, INVOKESPECIAL, INVOKESTATIC, INVOKEVIRTUAL, IOR, IREM, IRETURN, ISHL, ISHR, ISTORE, ISUB, IUSHR, IXOR, JSR, L2D, L2F, L2I, LADD, LALOAD, LAND, LASTORE, LCMP, LCONST_0, LCONST_1, LDC, LDIV, LLOAD, LMUL, LNEG, LONG, LOOKUPSWITCH, LOR, LREM, LRETURN, LSHL, LSHR, LSTORE, LSUB, LUSHR, LXOR, MONITORENTER, MONITOREXIT, MULTIANEWARRAY, NEW, NEWARRAY, NOP, NULL, POP, POP2, PUTFIELD, PUTSTATIC, RET, RETURN, SALOAD, SASTORE, SIPUSH, SWAP, T_BOOLEAN, T_BYTE, T_CHAR, T_DOUBLE, T_FLOAT, T_INT, T_LONG, T_SHORT, TABLESWITCH, TOP, UNINITIALIZED_THIS, V1_1, V1_2, V1_3, V1_4, V1_5, V1_6, V1_7

Constructor Summary

Constructors

Constructor	Description
BasicInterpreter()

Method Summary

Modifier and Type	Method	Description
Value	binaryOperation(AbstractInsnNode insn, Value value1, Value value2)	Interprets a bytecode instruction with two arguments.
Value	copyOperation(AbstractInsnNode insn, Value value)	Interprets a bytecode instruction that moves a value on the stack or to or from local variables.
Value	merge(Value v, Value w)	Merges two values.
Value	naryOperation(AbstractInsnNode insn, List values)	Interprets a bytecode instruction with a variable number of arguments.
Value	newOperation(AbstractInsnNode insn)	Interprets a bytecode instruction without arguments.
Value	newValue(Type type)	Creates a new value that represents the given type.
void	returnOperation(AbstractInsnNode insn, Value value, Value expected)	Interprets a bytecode return instruction.
Value	ternaryOperation(AbstractInsnNode insn, Value value1, Value value2, Value value3)	Interprets a bytecode instruction with three arguments.
Value	unaryOperation(AbstractInsnNode insn, Value value)	Interprets a bytecode instruction with a single argument.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

BasicInterpreter

public BasicInterpreter()

Method Details

newValue

public Value newValue(Type type)

Description copied from interface: Interpreter

Creates a new value that represents the given type. Called for method parameters (including this), exception handler variable and with null type for variables reserved by long and double types.

Specified by:

newValue in interface Interpreter

Parameters:

type - a primitive or reference type, or null to represent an uninitialized value.

Returns:

a value that represents the given type. The size of the returned value must be equal to the size of the given type.

newOperation

public Value newOperation(AbstractInsnNode insn)
                   throws AnalyzerException

Description copied from interface: Interpreter

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

Specified by:

newOperation in interface Interpreter

Parameters:

insn - the bytecode instruction to be interpreted.

Returns:

the result of the interpretation of the given instruction.

Throws:

AnalyzerException - if an error occured during the interpretation.

copyOperation

public Value copyOperation(AbstractInsnNode insn,
 Value value)
                    throws AnalyzerException

Description copied from interface: Interpreter

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

Specified by:

copyOperation in interface Interpreter

Parameters:

insn - the bytecode instruction to be interpreted.

value - the value that must be moved by the instruction.

Returns:

the result of the interpretation of the given instruction. The returned value must be equal to the given value.

Throws:

AnalyzerException - if an error occured during the interpretation.

unaryOperation

public Value unaryOperation(AbstractInsnNode insn,
 Value value)
                     throws AnalyzerException

Description copied from interface: Interpreter

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

Specified by:

unaryOperation in interface Interpreter

Parameters:

insn - the bytecode instruction to be interpreted.

value - the argument of the instruction to be interpreted.

Returns:

the result of the interpretation of the given instruction.

Throws:

AnalyzerException - if an error occured during the interpretation.

binaryOperation

public Value binaryOperation(AbstractInsnNode insn,
 Value value1,
 Value value2)
                      throws AnalyzerException

Description copied from interface: Interpreter

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

Specified by:

binaryOperation in interface Interpreter

Parameters:

insn - the bytecode instruction to be interpreted.

value1 - the first argument of the instruction to be interpreted.

value2 - the second argument of the instruction to be interpreted.

Returns:

the result of the interpretation of the given instruction.

Throws:

AnalyzerException - if an error occured during the interpretation.

ternaryOperation

public Value ternaryOperation(AbstractInsnNode insn,
 Value value1,
 Value value2,
 Value value3)
                       throws AnalyzerException

Description copied from interface: Interpreter

Interprets a bytecode instruction with three arguments. This method is called for the following opcodes: IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE, SASTORE

Specified by:

ternaryOperation in interface Interpreter

Parameters:

insn - the bytecode instruction to be interpreted.

value1 - the first argument of the instruction to be interpreted.

value2 - the second argument of the instruction to be interpreted.

value3 - the third argument of the instruction to be interpreted.

Returns:

the result of the interpretation of the given instruction.

Throws:

AnalyzerException - if an error occured during the interpretation.

naryOperation

public Value naryOperation(AbstractInsnNode insn,
 List values)
                    throws AnalyzerException

Description copied from interface: Interpreter

Interprets a bytecode instruction with a variable number of arguments. This method is called for the following opcodes: INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC, INVOKEINTERFACE, MULTIANEWARRAY

Specified by:

naryOperation in interface Interpreter

Parameters:

insn - the bytecode instruction to be interpreted.

values - the arguments of the instruction to be interpreted.

Returns:

the result of the interpretation of the given instruction.

Throws:

AnalyzerException - if an error occured during the interpretation.

returnOperation

public void returnOperation(AbstractInsnNode insn,
 Value value,
 Value expected)
                     throws AnalyzerException

Description copied from interface: Interpreter

Interprets a bytecode return instruction. This method is called for the following opcodes: IRETURN, LRETURN, FRETURN, DRETURN, ARETURN

Specified by:

returnOperation in interface Interpreter

Parameters:

insn - the bytecode instruction to be interpreted.

value - the argument of the instruction to be interpreted.

expected - the expected return type of the analyzed method.

Throws:

AnalyzerException - if an error occured during the interpretation.

merge

public Value merge(Value v,
 Value w)

Description copied from interface: Interpreter

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).

Specified by:

merge in interface Interpreter

Parameters:

v - a value.

w - another value.

Returns:

the merged value. If the merged value is equal to v, this method must return v.