Class InfiniteLoop

java.lang.Object

edu.umd.cs.findbugs.visitclass.BetterVisitor

edu.umd.cs.findbugs.visitclass.PreorderVisitor

edu.umd.cs.findbugs.visitclass.AnnotationVisitor

edu.umd.cs.findbugs.visitclass.DismantleBytecode

edu.umd.cs.findbugs.BytecodeScanningDetector

edu.umd.cs.findbugs.bcel.OpcodeStackDetector

edu.umd.cs.findbugs.detect.InfiniteLoop

All Implemented Interfaces:

Detector, Priorities, org.apache.bcel.classfile.Visitor

public class InfiniteLoop
extends OpcodeStackDetector

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	InfiniteLoop.BackwardsBranch
(package private) static class	InfiniteLoop.ForwardConditionalBranch
(package private) static class	InfiniteLoop.Jump

Nested classes/interfaces inherited from class OpcodeStackDetector

OpcodeStackDetector.WithCustomJumpInfo

Field Summary

Fields

Modifier and Type	Field	Description
(package private) HashSet<InfiniteLoop.BackwardsBranch>	backwardBranches
(package private) HashSet<InfiniteLoop.Jump>	backwardReach
(package private) BugReporter	bugReporter
(package private) static final boolean	DEBUG
(package private) HashSet<InfiniteLoop.ForwardConditionalBranch>	forwardConditionalBranches
(package private) LinkedList<InfiniteLoop.Jump>	forwardJumps
(package private) ArrayList<BitSet>	regModifiedAt

Fields inherited from class OpcodeStackDetector

stack

Fields inherited from class DismantleBytecode

codeBytes, lineNumberTable, M_BR, M_CP, M_INT, M_PAD, M_R, M_UINT

Fields inherited from interface Priorities

EXP_PRIORITY, HIGH_PRIORITY, IGNORE_PRIORITY, LOW_PRIORITY, NORMAL_PRIORITY

Constructor Summary

Constructors

Constructor	Description
InfiniteLoop(BugReporter bugReporter)

Method Summary

Modifier and Type	Method	Description
private void	addBackwardsReach()
(package private) void	addForwardJump(int from, int to)
private void	clearRegModified()
private int	constantSince(OpcodeStack.Item item1)
private boolean	constantSince(OpcodeStack.Item item1, int branchTarget)
private int	getBackwardsReach(int target)
(package private) int	getFurthestJump(int from)
(package private) BitSet	getModifiedBitSet(int reg)
private boolean	isConstant(OpcodeStack.Item item0, InfiniteLoop.BackwardsBranch bb)
private boolean	isRegModified(int reg, int firstPC, int lastPC)
private void	regModifiedAt(int reg, int pc)
(package private) void	reportPossibleBug(BugInstance bug)
void	sawBranchTo(int target)
void	sawOpcode(int seen)	By default, this method will not be called when stack is TOP.
void	visit(org.apache.bcel.classfile.Code obj)

Methods inherited from class OpcodeStackDetector

afterOpcode, beforeOpcode, getStack, isUsingCustomUserValue, visitCode

Methods inherited from class BytecodeScanningDetector

getClassContext, report, shouldVisitCode, visitClassContext

Methods inherited from class DismantleBytecode

areOppositeBranches, atCatchBlock, getBranchFallThrough, getBranchOffset, getBranchTarget, getClassConstantOperand, getClassDescriptorOperand, getCodeByte, getConstantRefOperand, getDefaultSwitchOffset, getDottedClassConstantOperand, getFieldDescriptorOperand, getIntConstant, getLongConstant, getMaxPC, getMethodDescriptorOperand, getNameConstantOperand, getNextCodeByte, getNextOpcode, getNextPC, getOpcode, getPC, getPrevOpcode, getRefConstantOperand, getRefFieldIsStatic, getRegisterOperand, getSigConstantOperand, getStringConstantOperand, getSwitchLabels, getSwitchOffsets, getXClassOperand, getXFieldOperand, getXMethodOperand, isBranch, isMethodCall, isRegisterLoad, isRegisterStore, isRegisterStore, isReturn, isShift, isSwitch, isWideOpcode, printOpCode, sawClass, sawDouble, sawField, sawFloat, sawIMethod, sawInt, sawLong, sawMethod, sawRegister, sawString

Methods inherited from class AnnotationVisitor

getAnnotationParameterAsEnum, getAnnotationParameterAsString, getAnnotationParameterAsStringArray, visitAnnotation, visitAnnotation, visitParameterAnnotation, visitParameterAnnotation, visitSyntheticParameterAnnotation

Methods inherited from class PreorderVisitor

amVisitingMainMethod, asUnsignedByte, doVisitMethod, getClassDescriptor, getClassName, getCode, getConstantPool, getDottedClassName, getDottedFieldSig, getDottedMethodSig, getDottedSuperclassName, getField, getFieldDescriptor, getFieldIsStatic, getFieldName, getFieldSig, getFullyQualifiedFieldName, getFullyQualifiedMethodName, getMethod, getMethodDescriptor, getMethodName, getMethodSig, getMethodVisitOrder, getNumberArguments, getNumberMethodArguments, getPackageName, getSizeOfSurroundingTryBlock, getSizeOfSurroundingTryBlock, getSourceFile, getStringFromIndex, getSuperclassName, getSurroundingCaughtExceptions, getSurroundingCaughtExceptions, getSurroundingCaughtExceptionTypes, getSurroundingTryBlock, getSurroundingTryBlock, getThisClass, getXClass, getXField, getXMethod, hasInterestingClass, hasInterestingMethod, isVisitMethodsInCallOrder, setupVisitorForClass, setVisitMethodsInCallOrder, shouldVisit, toString, visitAfter, visitAfter, visitAnnotationDefault, visitAnnotationEntry, visitBootstrapMethods, visitConstantInvokeDynamic, visitConstantMethodHandle, visitConstantMethodType, visitConstantModule, visitConstantPackage, visitConstantPool, visitEnclosingMethod, visitingField, visitingMethod, visitInnerClasses, visitJavaClass, visitLineNumberTable, visitLocalVariableTable, visitMethodParameters, visitParameterAnnotationEntry, visitStackMap, visitStackMapEntry

Methods inherited from class BetterVisitor

clone, report, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visitCodeException, visitConstantClass, visitConstantDouble, visitConstantFieldref, visitConstantFloat, visitConstantInteger, visitConstantInterfaceMethodref, visitConstantLong, visitConstantMethodref, visitConstantNameAndType, visitConstantString, visitConstantUtf8, visitConstantValue, visitDeprecated, visitExceptionTable, visitField, visitInnerClass, visitLineNumber, visitLocalVariable, visitLocalVariableTypeTable, visitMethod, visitSignature, visitSourceFile, visitSynthetic, visitUnknown

Methods inherited from class Object

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

Methods inherited from interface org.apache.bcel.classfile.Visitor

visitConstantDynamic, visitMethodParameter, visitModule, visitModuleExports, visitModuleMainClass, visitModuleOpens, visitModulePackages, visitModuleProvides, visitModuleRequires, visitNestHost, visitNestMembers, visitRecord, visitRecordComponent, visitStackMapType

Field Details

regModifiedAt

ArrayList<BitSet> regModifiedAt

bugReporter

BugReporter bugReporter

backwardReach

HashSet<InfiniteLoop.Jump> backwardReach

backwardBranches

HashSet<InfiniteLoop.BackwardsBranch> backwardBranches

forwardConditionalBranches

HashSet<InfiniteLoop.ForwardConditionalBranch> forwardConditionalBranches

forwardJumps

LinkedList<InfiniteLoop.Jump> forwardJumps

DEBUG

static final boolean DEBUG

See Also:

• Constant Field Values

Constructor Details

InfiniteLoop

public InfiniteLoop(BugReporter bugReporter)

Method Details

getModifiedBitSet

@Nonnull
BitSet getModifiedBitSet(int reg)

regModifiedAt

private void regModifiedAt(int reg,
 int pc)

clearRegModified

private void clearRegModified()

isRegModified

private boolean isRegModified(int reg,
 int firstPC,
 int lastPC)

addForwardJump

void addForwardJump(int from,
 int to)

getFurthestJump

int getFurthestJump(int from)

visit

public void visit(org.apache.bcel.classfile.Code obj)

Overrides:

visit in class DismantleBytecode

isConstant

private boolean isConstant(OpcodeStack.Item item0,
 InfiniteLoop.BackwardsBranch bb)

sawBranchTo

public void sawBranchTo(int target)

Overrides:

sawBranchTo in class DismantleBytecode

sawOpcode

public void sawOpcode(int seen)

Description copied from class: OpcodeStackDetector

By default, this method will not be called when stack is TOP. To change this behavior, override #beforeOpcode(int) and change to return true even if stack is TOP.

see Using FindBugs for Research to learn lattice and what TOP means.

Specified by:

sawOpcode in class OpcodeStackDetector

See Also:

• OpcodeStackDetector.beforeOpcode(int)

addBackwardsReach

private void addBackwardsReach()

getBackwardsReach

private int getBackwardsReach(int target)

constantSince

private boolean constantSince(OpcodeStack.Item item1,
 int branchTarget)

constantSince

private int constantSince(OpcodeStack.Item item1)

reportPossibleBug

void reportPossibleBug(BugInstance bug)