Package edu.umd.cs.findbugs.ba.npe

Class IsNullValueFrameModelingVisitor

java.lang.Object

edu.umd.cs.findbugs.ba.AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

edu.umd.cs.findbugs.ba.npe.IsNullValueFrameModelingVisitor

All Implemented Interfaces:

org.apache.bcel.generic.Visitor

public class IsNullValueFrameModelingVisitor
extends AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

Field Summary

Fields

Modifier and Type	Field	Description
private AssertionMethods	assertionMethods
private static boolean	MODEL_NONNULL_RETURN
private static boolean	NO_ASSERT_HACK
private int	slotContainingNewNullValue
private boolean	trackValueNumbers
private TypeDataflow	typeDataflow
private ValueNumberDataflow	vnaDataflow

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

cpg

Constructor Summary

Constructors

Constructor	Description
IsNullValueFrameModelingVisitor(org.apache.bcel.generic.ConstantPoolGen cpg, AssertionMethods assertionMethods, ValueNumberDataflow vnaDataflow, TypeDataflow typeDataflow, boolean trackValueNumbers)

Method Summary

Modifier and Type	Method	Description
void	analyzeInstruction(org.apache.bcel.generic.Instruction ins)	Analyze the given Instruction.
private boolean	checkForKnownValue(org.apache.bcel.generic.Instruction obj)	Check given Instruction to see if it produces a known value.
IsNullValue	getDefaultValue()	Produce a "default" value.
IsNullValue	getReturnValueNullness(XMethod calledMethod)
int	getSlotContainingNewNullValue()
private void	handleInvoke(org.apache.bcel.generic.InvokeInstruction obj)	Handle method invocations.
private void	newValueOnTOS()	Hook indicating that a new (possibly-null) value is on the top of the stack.
private void	produce(IsNullValue value)
private void	produce2(IsNullValue value)
void	visitACONST_NULL(org.apache.bcel.generic.ACONST_NULL obj)
void	visitANEWARRAY(org.apache.bcel.generic.ANEWARRAY obj)
void	visitCHECKCAST(org.apache.bcel.generic.CHECKCAST obj)
void	visitGETFIELD(org.apache.bcel.generic.GETFIELD obj)
void	visitGETSTATIC(org.apache.bcel.generic.GETSTATIC obj)
void	visitINVOKEINTERFACE(org.apache.bcel.generic.INVOKEINTERFACE obj)
void	visitINVOKESPECIAL(org.apache.bcel.generic.INVOKESPECIAL obj)
void	visitINVOKESTATIC(org.apache.bcel.generic.INVOKESTATIC obj)
void	visitINVOKEVIRTUAL(org.apache.bcel.generic.INVOKEVIRTUAL obj)
void	visitLDC(org.apache.bcel.generic.LDC obj)
void	visitLDC2_W(org.apache.bcel.generic.LDC2_W obj)
void	visitMULTIANEWARRAY(org.apache.bcel.generic.MULTIANEWARRAY obj)
void	visitNEW(org.apache.bcel.generic.NEW obj)
void	visitNEWARRAY(org.apache.bcel.generic.NEWARRAY obj)
void	visitPUTFIELD(org.apache.bcel.generic.PUTFIELD obj)

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

getCPG, getFrame, getLocation, getNumWordsConsumed, getNumWordsProduced, handleLoadInstruction, handleNormalInstruction, handleStoreInstruction, modelInstruction, modelNormalInstruction, setFrameAndLocation, visitAALOAD, visitAASTORE, visitAllocationInstruction, visitALOAD, visitARETURN, visitArithmeticInstruction, visitArrayInstruction, visitARRAYLENGTH, visitASTORE, visitATHROW, visitBALOAD, visitBASTORE, visitBIPUSH, visitBranchInstruction, visitBREAKPOINT, visitCALOAD, visitCASTORE, visitConstantPushInstruction, visitConversionInstruction, visitConversionInstruction2, visitCPInstruction, visitD2F, visitD2I, visitD2L, visitDADD, visitDALOAD, visitDASTORE, visitDCMPG, visitDCMPL, visitDCONST, visitDDIV, visitDLOAD, visitDMUL, visitDNEG, visitDREM, visitDRETURN, visitDSTORE, visitDSUB, visitDUP, visitDUP_X1, visitDUP_X2, visitDUP2, visitDUP2_X1, visitDUP2_X2, visitExceptionThrower, visitF2D, visitF2I, visitF2L, visitFADD, visitFALOAD, visitFASTORE, visitFCMPG, visitFCMPL, visitFCONST, visitFDIV, visitFieldInstruction, visitFieldOrMethod, visitFLOAD, visitFMUL, visitFNEG, visitFREM, visitFRETURN, visitFSTORE, visitFSUB, visitGOTO, visitGOTO_W, 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, visitINVOKEDYNAMIC, visitInvokeInstruction, visitIOR, visitIREM, visitIRETURN, visitISHL, visitISHR, visitISTORE, visitISUB, visitIUSHR, visitIXOR, visitJSR, visitJSR_W, visitJsrInstruction, visitL2D, visitL2F, visitL2I, visitLADD, visitLALOAD, visitLAND, visitLASTORE, visitLCMP, visitLCONST, visitLDIV, visitLLOAD, visitLMUL, visitLNEG, visitLoadClass, visitLoadInstruction, visitLocalVariableInstruction, visitLOOKUPSWITCH, visitLOR, visitLREM, visitLRETURN, visitLSHL, visitLSHR, visitLSTORE, visitLSUB, visitLUSHR, visitLXOR, visitMONITORENTER, visitMONITOREXIT, visitNONNULL2Z, visitNOP, visitNULL2Z, visitPOP, visitPOP2, visitPopInstruction, visitPushInstruction, visitPUTSTATIC, 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

NO_ASSERT_HACK

private static final boolean NO_ASSERT_HACK

MODEL_NONNULL_RETURN

private static final boolean MODEL_NONNULL_RETURN

assertionMethods

private final AssertionMethods assertionMethods

vnaDataflow

private final ValueNumberDataflow vnaDataflow

typeDataflow

private final TypeDataflow typeDataflow

trackValueNumbers

private final boolean trackValueNumbers

slotContainingNewNullValue

private int slotContainingNewNullValue

Constructor Detail

IsNullValueFrameModelingVisitor

public IsNullValueFrameModelingVisitor(org.apache.bcel.generic.ConstantPoolGen cpg,
                                       AssertionMethods assertionMethods,
                                       ValueNumberDataflow vnaDataflow,
                                       TypeDataflow typeDataflow,
                                       boolean trackValueNumbers)

Method Detail

analyzeInstruction

public void analyzeInstruction(org.apache.bcel.generic.Instruction ins)
                        throws DataflowAnalysisException

Description copied from class: AbstractFrameModelingVisitor

Analyze the given Instruction.

Overrides:

analyzeInstruction in class AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

Parameters:

ins - the Instruction

Throws:

DataflowAnalysisException - if an error occurs analyzing the instruction; in most cases, this indicates that the bytecode for the method being analyzed is invalid

getSlotContainingNewNullValue

public int getSlotContainingNewNullValue()

Returns:

Returns the slotContainingNewNullValue; or -1 if no new null value was produced

getDefaultValue

public IsNullValue 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<IsNullValue,IsNullValueFrame>

produce

private void produce(IsNullValue value)

produce2

private void produce2(IsNullValue value)

handleInvoke

private void handleInvoke(org.apache.bcel.generic.InvokeInstruction obj)

Handle method invocations. Generally, we want to get rid of null information following a call to a likely exception thrower or assertion.

getReturnValueNullness

public IsNullValue getReturnValueNullness(XMethod calledMethod)

newValueOnTOS

private void newValueOnTOS()

Hook indicating that a new (possibly-null) value is on the top of the stack.

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<IsNullValue,IsNullValueFrame>

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<IsNullValue,IsNullValueFrame>

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<IsNullValue,IsNullValueFrame>

checkForKnownValue

private boolean checkForKnownValue(org.apache.bcel.generic.Instruction obj)

Check given Instruction to see if it produces a known value. If so, model the instruction and return true. Otherwise, do nothing and return false. Should only be used for instructions that produce a single value on the top of the stack.

Parameters:

obj - the Instruction the instruction

Returns:

true if the instruction produced a known value and was modeled, false otherwise

visitACONST_NULL

public void visitACONST_NULL(org.apache.bcel.generic.ACONST_NULL obj)

Specified by:

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

Overrides:

visitACONST_NULL in class AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

visitNEW

public void visitNEW(org.apache.bcel.generic.NEW obj)

Specified by:

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

Overrides:

visitNEW in class AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

visitNEWARRAY

public void visitNEWARRAY(org.apache.bcel.generic.NEWARRAY obj)

Specified by:

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

Overrides:

visitNEWARRAY in class AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

visitANEWARRAY

public void visitANEWARRAY(org.apache.bcel.generic.ANEWARRAY obj)

Specified by:

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

Overrides:

visitANEWARRAY in class AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

visitMULTIANEWARRAY

public void visitMULTIANEWARRAY(org.apache.bcel.generic.MULTIANEWARRAY obj)

Specified by:

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

Overrides:

visitMULTIANEWARRAY in class AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

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<IsNullValue,IsNullValueFrame>

visitLDC2_W

public void visitLDC2_W(org.apache.bcel.generic.LDC2_W obj)

Specified by:

visitLDC2_W in interface org.apache.bcel.generic.Visitor

Overrides:

visitLDC2_W in class AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

visitCHECKCAST

public void visitCHECKCAST(org.apache.bcel.generic.CHECKCAST obj)

Specified by:

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

Overrides:

visitCHECKCAST in class AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

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<IsNullValue,IsNullValueFrame>

visitINVOKESPECIAL

public void visitINVOKESPECIAL(org.apache.bcel.generic.INVOKESPECIAL obj)

Specified by:

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

Overrides:

visitINVOKESPECIAL in class AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

visitINVOKEINTERFACE

public void visitINVOKEINTERFACE(org.apache.bcel.generic.INVOKEINTERFACE obj)

Specified by:

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

Overrides:

visitINVOKEINTERFACE in class AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>

visitINVOKEVIRTUAL

public void visitINVOKEVIRTUAL(org.apache.bcel.generic.INVOKEVIRTUAL obj)

Specified by:

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

Overrides:

visitINVOKEVIRTUAL in class AbstractFrameModelingVisitor<IsNullValue,IsNullValueFrame>