org.objectweb.asm.tree.analysis
Class Analyzer

java.lang.Object
  extended by org.objectweb.asm.tree.analysis.Analyzer
All Implemented Interfaces:
Constants

public class Analyzer
extends Object
implements Constants

A semantic bytecode analyzer.

Author:
Eric Bruneton

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
Analyzer(Interpreter interpreter)
          Constructs a new Analyzer.
 
Method Summary
 Frame[] analyze(ClassNode c, MethodNode m)
          Analyzes the given method.
 Frame[] getFrames()
          Returns the symbolic stack frame for each instruction of the last recently analyzed method.
 List getHandlers(int insn)
          Returns the exception handlers for the given instruction.
 int getIndex(Object insn)
          Returns the index of the given instruction.
protected  void newControlFlowEdge(Frame frame, Frame successor)
          Creates a control flow graph edge.
protected  Frame newFrame(Frame src)
          Constructs a new frame that is identical to the given frame.
protected  Frame newFrame(int nLocals, int nStack)
          Constructs a new frame with the given size.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Analyzer

public Analyzer(Interpreter interpreter)
Constructs a new Analyzer.

Parameters:
interpreter - the interpreter to be used to symbolically interpret the bytecode instructions.
Method Detail

analyze

public Frame[] analyze(ClassNode c,
                       MethodNode m)
                throws AnalyzerException
Analyzes the given method.

Parameters:
c - the class to which the method belongs.
m - the method to be analyzed.
Returns:
the symbolic state of the execution stack frame at each bytecode instruction of the method. The size of the returned array is equal to the number of instructions (and labels) of the method. A given frame is null if and only if the corresponding instruction cannot be reached (dead code).
Throws:
AnalyzerException - if a problem occurs during the analysis.

getFrames

public Frame[] getFrames()
Returns the symbolic stack frame for each instruction of the last recently analyzed method.

Returns:
the symbolic state of the execution stack frame at each bytecode instruction of the method. The size of the returned array is equal to the number of instructions (and labels) of the method. A given frame is null if the corresponding instruction cannot be reached, or if an error occured during the analysis of the method.

getIndex

public int getIndex(Object insn)
Returns the index of the given instruction.

Parameters:
insn - a Label or AbstractInsnNode of the last recently analyzed method.
Returns:
the index of the given instruction of the last recently analyzed method.

getHandlers

public List getHandlers(int insn)
Returns the exception handlers for the given instruction.

Parameters:
insn - the index of an instruction of the last recently analyzed method.
Returns:
a list of TryCatchBlockNode objects.

newFrame

protected Frame newFrame(int nLocals,
                         int nStack)
Constructs a new frame with the given size.

Parameters:
nLocals - the maximum number of local variables of the frame.
nStack - the maximum stack size of the frame.
Returns:
the created frame.

newFrame

protected Frame newFrame(Frame src)
Constructs a new frame that is identical to the given frame.

Parameters:
src - a frame.
Returns:
the created frame.

newControlFlowEdge

protected void newControlFlowEdge(Frame frame,
                                  Frame successor)
Creates a control flow graph edge. The default implementation of this method does nothing. It can be overriden in order to construct the control flow graph of a method (this method is called by the analyze method during its visit of the method's code).

Parameters:
frame - the frame corresponding to an instruction.
successor - the frame corresponding to a successor instruction.