edu.umd.cs.findbugs.ba
Class ValueNumberFrameModelingVisitor

java.lang.Object
  edu.umd.cs.findbugs.ba.AbstractFrameModelingVisitor<ValueNumber,ValueNumberFrame>
      edu.umd.cs.findbugs.ba.ValueNumberFrameModelingVisitor

All Implemented Interfaces:

Debug, ValueNumberAnalysisFeatures, org.apache.bcel.generic.Visitor

public class ValueNumberFrameModelingVisitor
extends AbstractFrameModelingVisitor<ValueNumber,ValueNumberFrame>
implements Debug, ValueNumberAnalysisFeatures

Visitor which models the effects of bytecode instructions on value numbers of values in the operand stack frames.

Author:

David Hovemeyer

See Also:

ValueNumber, ValueNumberFrame, ValueNumberAnalysis

Field Summary

private ValueNumberCache	cache
private java.util.HashMap<java.lang.String,ValueNumber>	classObjectValueMap
private java.util.IdentityHashMap<org.apache.bcel.generic.InstructionHandle,ValueNumber>	constantValueMap
private static ValueNumber[]	EMPTY_INPUT_VALUE_LIST
private ValueNumberFactory	factory
private org.apache.bcel.generic.InstructionHandle	handle
private LoadedFieldSet	loadedFieldSet
private RepositoryLookupFailureCallback	lookupFailureCallback
private org.apache.bcel.generic.MethodGen	methodGen
private java.util.HashMap<ValueNumber,java.lang.String>	stringConstantMap

Fields inherited from interface edu.umd.cs.findbugs.ba.Debug

CHECK_ASSERTIONS, VERIFY_INTEGRITY

Fields inherited from interface edu.umd.cs.findbugs.ba.ValueNumberAnalysisFeatures

REDUNDANT_LOAD_ELIMINATION, RLE_DEBUG

Constructor Summary

ValueNumberFrameModelingVisitor(org.apache.bcel.generic.MethodGen methodGen, ValueNumberFactory factory, ValueNumberCache cache, LoadedFieldSet loadedFieldSet, RepositoryLookupFailureCallback lookupFailureCallback)
Constructor.

Method Summary

private void	checkConsumedAndProducedValues(org.apache.bcel.generic.Instruction ins, ValueNumber[] consumedValueList, ValueNumber[] producedValueList)
private boolean	doForwardSubstitution() Determine whether forward substitution should be performed for the heap location referenced by the current instruction.
private boolean	doRedundantLoadElimination() Determine whether redundant load elimination should be performed for the heap location referenced by the current instruction.
private ValueNumber	getClassObjectValue(java.lang.String className) Get the ValueNumber for given class's Class object.
ValueNumber	getDefaultValue() Produce a "default" value.
private ValueNumber[]	getOutputValues(ValueNumber[] inputValueList, int numWordsProduced) Get output values for current instruction from the ValueNumberCache.
private ValueNumber[]	getOutputValues(ValueNumber[] inputValueList, int numWordsProduced, int flags)
private void	loadInstanceField(InstanceField instanceField, org.apache.bcel.generic.Instruction obj) Load an instance field.
private void	loadStaticField(StaticField staticField, org.apache.bcel.generic.Instruction obj) Load a static field.
void	modelNormalInstruction(org.apache.bcel.generic.Instruction ins, int numWordsConsumed, int numWordsProduced) This is the default instruction modeling method.
private ValueNumber[]	popInputValues(int numWordsConsumed) Pop the input values for the given instruction from the current frame.
private void	pushOutputValues(ValueNumber[] outputValueList) Push given output values onto the current frame.
void	setHandle(org.apache.bcel.generic.InstructionHandle handle) Set the instruction handle of the instruction currently being visited.
private void	storeInstanceField(InstanceField instanceField, org.apache.bcel.generic.Instruction obj, boolean pushStoredValue) Store an instance field.
private void	storeStaticField(StaticField staticField, org.apache.bcel.generic.Instruction obj, boolean pushStoredValue) Store a static field.
void	visitGETFIELD(org.apache.bcel.generic.GETFIELD obj)
void	visitGETSTATIC(org.apache.bcel.generic.GETSTATIC obj)
void	visitINVOKESTATIC(org.apache.bcel.generic.INVOKESTATIC obj)
void	visitLDC(org.apache.bcel.generic.LDC obj)
void	visitPUTFIELD(org.apache.bcel.generic.PUTFIELD obj)
void	visitPUTSTATIC(org.apache.bcel.generic.PUTSTATIC obj)
private static java.lang.String	vlts(ValueNumber[] vl)

Methods inherited from class edu.umd.cs.findbugs.ba.AbstractFrameModelingVisitor

getCPG, getFrame, getNumWordsConsumed, getNumWordsProduced, handleLoadInstruction, handleNormalInstruction, handleStoreInstruction, setFrame, visitAALOAD, visitAASTORE, visitACONST_NULL, visitAllocationInstruction, visitALOAD, visitANEWARRAY, visitARETURN, visitArithmeticInstruction, visitArrayInstruction, visitARRAYLENGTH, visitASTORE, visitATHROW, visitBALOAD, visitBASTORE, visitBIPUSH, visitBranchInstruction, visitBREAKPOINT, visitCALOAD, visitCASTORE, visitCHECKCAST, visitConstantPushInstruction, visitConversionInstruction, visitCPInstruction, visitD2F, visitD2I, visitD2L, visitDADD, visitDALOAD, visitDASTORE, visitDCMPG, visitDCMPL, visitDCONST, visitDDIV, visitDLOAD, visitDMUL, visitDNEG, visitDREM, visitDRETURN, visitDSTORE, visitDSUB, visitDUP_X1, visitDUP_X2, visitDUP, visitDUP2_X1, visitDUP2_X2, visitDUP2, visitExceptionThrower, visitF2D, visitF2I, visitF2L, visitFADD, visitFALOAD, visitFASTORE, visitFCMPG, visitFCMPL, visitFCONST, visitFDIV, visitFieldInstruction, visitFieldOrMethod, visitFLOAD, visitFMUL, visitFNEG, visitFREM, visitFRETURN, visitFSTORE, visitFSUB, visitGOTO_W, visitGOTO, visitGotoInstruction, visitI2B, visitI2C, visitI2D, visitI2F, visitI2L, visitI2S, visitIADD, visitIALOAD, visitIAND, visitIASTORE, visitICONST, visitIDIV, visitIF_ACMPEQ, visitIF_ACMPNE, visitIF_ICMPEQ, visitIF_ICMPGE, visitIF_ICMPGT, visitIF_ICMPLE, visitIF_ICMPLT, visitIF_ICMPNE, visitIFEQ, visitIFGE, visitIFGT, visitIfInstruction, visitIFLE, visitIFLT, visitIFNE, visitIFNONNULL, visitIFNULL, visitIINC, visitILOAD, visitIMPDEP1, visitIMPDEP2, visitIMUL, visitINEG, visitINSTANCEOF, visitInvokeInstruction, visitINVOKEINTERFACE, visitINVOKESPECIAL, visitINVOKEVIRTUAL, visitIOR, visitIREM, visitIRETURN, visitISHL, visitISHR, visitISTORE, visitISUB, visitIUSHR, visitIXOR, visitJSR_W, visitJSR, visitJsrInstruction, visitL2D, visitL2F, visitL2I, visitLADD, visitLALOAD, visitLAND, visitLASTORE, visitLCMP, visitLCONST, visitLDC2_W, visitLDIV, visitLLOAD, visitLMUL, visitLNEG, visitLoadClass, visitLoadInstruction, visitLocalVariableInstruction, visitLOOKUPSWITCH, visitLOR, visitLREM, visitLRETURN, visitLSHL, visitLSHR, visitLSTORE, visitLSUB, visitLUSHR, visitLXOR, visitMONITORENTER, visitMONITOREXIT, visitMULTIANEWARRAY, visitNEW, visitNEWARRAY, visitNOP, visitPOP, visitPOP2, visitPopInstruction, visitPushInstruction, visitRET, visitRETURN, visitReturnInstruction, visitSALOAD, visitSASTORE, visitSelect, visitSIPUSH, visitStackConsumer, visitStackInstruction, visitStackProducer, visitStoreInstruction, visitSWAP, visitTABLESWITCH, visitTypedInstruction, visitUnconditionalBranch, visitVariableLengthInstruction

Methods inherited from class java.lang.Object

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

Field Detail

methodGen

private org.apache.bcel.generic.MethodGen methodGen

factory

private ValueNumberFactory factory

cache

private ValueNumberCache cache

loadedFieldSet

private LoadedFieldSet loadedFieldSet

classObjectValueMap

private java.util.HashMap<java.lang.String,ValueNumber> classObjectValueMap

constantValueMap

private java.util.IdentityHashMap<org.apache.bcel.generic.InstructionHandle,ValueNumber> constantValueMap

stringConstantMap

private java.util.HashMap<ValueNumber,java.lang.String> stringConstantMap

lookupFailureCallback

private RepositoryLookupFailureCallback lookupFailureCallback

handle

private org.apache.bcel.generic.InstructionHandle handle

EMPTY_INPUT_VALUE_LIST

private static final ValueNumber[] EMPTY_INPUT_VALUE_LIST

Constructor Detail

ValueNumberFrameModelingVisitor

public ValueNumberFrameModelingVisitor(org.apache.bcel.generic.MethodGen methodGen,
                                       ValueNumberFactory factory,
                                       ValueNumberCache cache,
                                       LoadedFieldSet loadedFieldSet,
                                       RepositoryLookupFailureCallback lookupFailureCallback)

Constructor.

Parameters:

methodGen - the method being analyzed

factory - factory for ValueNumbers for the method

cache - cache of input/output transformations for each instruction

loadedFieldSet - fields loaded/stored by each instruction and entire method

lookupFailureCallback - callback to use to report class lookup failures

Method Detail

getDefaultValue

public ValueNumber getDefaultValue()

Description copied from class: AbstractFrameModelingVisitor

Produce a "default" value. This is what is pushed onto the stack by the handleNormalInstruction() method for instructions which produce stack values.

Specified by:

getDefaultValue in class AbstractFrameModelingVisitor<ValueNumber,ValueNumberFrame>

setHandle

public void setHandle(org.apache.bcel.generic.InstructionHandle handle)

Set the instruction handle of the instruction currently being visited. This must be called before the instruction accepts this visitor!

doRedundantLoadElimination

private boolean doRedundantLoadElimination()

Determine whether redundant load elimination should be performed for the heap location referenced by the current instruction.

Returns:

true if we should do redundant load elimination for the current instruction, false if not

doForwardSubstitution

private boolean doForwardSubstitution()

Determine whether forward substitution should be performed for the heap location referenced by the current instruction.

Returns:

true if we should do forward substitution for the current instruction, false if not

checkConsumedAndProducedValues

private void checkConsumedAndProducedValues(org.apache.bcel.generic.Instruction ins,
                                            ValueNumber[] consumedValueList,
                                            ValueNumber[] producedValueList)

modelNormalInstruction

public void modelNormalInstruction(org.apache.bcel.generic.Instruction ins,
                                   int numWordsConsumed,
                                   int numWordsProduced)

This is the default instruction modeling method.

Overrides:

modelNormalInstruction in class AbstractFrameModelingVisitor<ValueNumber,ValueNumberFrame>

visitGETFIELD

public void visitGETFIELD(org.apache.bcel.generic.GETFIELD obj)

Specified by:

visitGETFIELD in interface org.apache.bcel.generic.Visitor

Overrides:

visitGETFIELD in class AbstractFrameModelingVisitor<ValueNumber,ValueNumberFrame>

visitPUTFIELD

public void visitPUTFIELD(org.apache.bcel.generic.PUTFIELD obj)

Specified by:

visitPUTFIELD in interface org.apache.bcel.generic.Visitor

Overrides:

visitPUTFIELD in class AbstractFrameModelingVisitor<ValueNumber,ValueNumberFrame>

visitGETSTATIC

public void visitGETSTATIC(org.apache.bcel.generic.GETSTATIC obj)

Specified by:

visitGETSTATIC in interface org.apache.bcel.generic.Visitor

Overrides:

visitGETSTATIC in class AbstractFrameModelingVisitor<ValueNumber,ValueNumberFrame>

visitPUTSTATIC

public void visitPUTSTATIC(org.apache.bcel.generic.PUTSTATIC obj)

Specified by:

visitPUTSTATIC in interface org.apache.bcel.generic.Visitor

Overrides:

visitPUTSTATIC in class AbstractFrameModelingVisitor<ValueNumber,ValueNumberFrame>

visitINVOKESTATIC

public void visitINVOKESTATIC(org.apache.bcel.generic.INVOKESTATIC obj)

Specified by:

visitINVOKESTATIC in interface org.apache.bcel.generic.Visitor

Overrides:

visitINVOKESTATIC in class AbstractFrameModelingVisitor<ValueNumber,ValueNumberFrame>

visitLDC

public void visitLDC(org.apache.bcel.generic.LDC obj)

Specified by:

visitLDC in interface org.apache.bcel.generic.Visitor

Overrides:

visitLDC in class AbstractFrameModelingVisitor<ValueNumber,ValueNumberFrame>

popInputValues

private ValueNumber[] popInputValues(int numWordsConsumed)

Pop the input values for the given instruction from the current frame.

pushOutputValues

private void pushOutputValues(ValueNumber[] outputValueList)

Push given output values onto the current frame.

getOutputValues

private ValueNumber[] getOutputValues(ValueNumber[] inputValueList,
                                      int numWordsProduced)

Get output values for current instruction from the ValueNumberCache.

getOutputValues

private ValueNumber[] getOutputValues(ValueNumber[] inputValueList,
                                      int numWordsProduced,
                                      int flags)

vlts

private static java.lang.String vlts(ValueNumber[] vl)

loadInstanceField

private void loadInstanceField(InstanceField instanceField,
                               org.apache.bcel.generic.Instruction obj)

Load an instance field.

Parameters:

instanceField - the field

obj - the Instruction loading the field

loadStaticField

private void loadStaticField(StaticField staticField,
                             org.apache.bcel.generic.Instruction obj)

Load a static field.

Parameters:

staticField - the field

obj - the Instruction loading the field

storeInstanceField

private void storeInstanceField(InstanceField instanceField,
                                org.apache.bcel.generic.Instruction obj,
                                boolean pushStoredValue)

Store an instance field.

Parameters:

instanceField - the field

obj - the instruction which stores the field

pushStoredValue - push the stored value onto the stack (because we are modeling an inner-class field access method)

storeStaticField

private void storeStaticField(StaticField staticField,
                              org.apache.bcel.generic.Instruction obj,
                              boolean pushStoredValue)

Store a static field.

Parameters:

staticField - the static field

obj - the instruction which stores the field

pushStoredValue - push the stored value onto the stack (because we are modeling an inner-class field access method)

getClassObjectValue

private ValueNumber getClassObjectValue(java.lang.String className)

Get the ValueNumber for given class's Class object.

Parameters:

className - the class