org.objectweb.asm.tree.analysis
Class BasicInterpreter

java.lang.Object
  extended by org.objectweb.asm.tree.analysis.BasicInterpreter
All Implemented Interfaces:
Constants, Interpreter
Direct Known Subclasses:
BasicVerifier

public class BasicInterpreter
extends Object
implements Constants, Interpreter

An Interpreter for BasicValue values.

Author:
Eric Bruneton, Bing Ran

Field Summary
 
Fields inherited from interface org.objectweb.asm.Constants
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, DREM, DRETURN, DSTORE, DSUB, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, F2D, F2I, F2L, FADD, FALOAD, FASTORE, FCMPG, FCMPL, FCONST_0, FCONST_1, FCONST_2, FDIV, FLOAD, 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, 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, LOOKUPSWITCH, LOR, LREM, LRETURN, LSHL, LSHR, LSTORE, LSUB, LUSHR, LXOR, MONITORENTER, MONITOREXIT, MULTIANEWARRAY, NEW, NEWARRAY, NOP, 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, V1_1, V1_2, V1_3, V1_4, V1_5
 
Constructor Summary
BasicInterpreter()
           
 
Method Summary
 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.
 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 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

BasicInterpreter

public BasicInterpreter()
Method Detail

newValue

public Value newValue(Type type)
Description copied from interface: Interpreter
Creates a new value that represents the given type.

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)
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.

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.

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.