Package edu.umd.cs.findbugs.detect

Class FindRefComparison

java.lang.Object

edu.umd.cs.findbugs.detect.FindRefComparison

All Implemented Interfaces:

ExtendedTypes, Detector, Priorities

public class FindRefComparison
extends Object
implements Detector, ExtendedTypes

Find suspicious reference comparisons. This includes:

• Strings and other java.lang objects compared by reference equality
• Calls to equals(Object) where the argument is a different type than the receiver object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	FindRefComparison.DynamicStringType	Type representing a dynamically created String.
static class	FindRefComparison.EmptyStringType
static class	FindRefComparison.FinalConstant
static class	FindRefComparison.ParameterStringType	Type representing a String passed as a parameter.
private static class	FindRefComparison.RefComparisonTypeFrameModelingVisitor
private static class	FindRefComparison.RefComparisonTypeMerger	Type merger to use the extended String types.
private static final class	FindRefComparison.SpecialTypeAnalysis
static class	FindRefComparison.StaticStringType	Type representing a static String.
private static interface	FindRefComparison.WarningDecorator
private static class	FindRefComparison.WarningWithProperties	A BugInstance and its WarningPropertySet.

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	BASE_ES_PRIORITY
private final BugAccumulator	bugAccumulator
private final BugReporter	bugReporter
private ClassContext	classContext
private Map<String,Integer>	comparedForEqualityInThisMethod
private static final boolean	DEBUG
private static final HashSet<String>	DEFAULT_SUSPICIOUS_SET	Classes that are suspicious if compared by reference.
private static final org.apache.bcel.generic.Type	dynamicStringTypeInstance
private static final org.apache.bcel.generic.Type	emptyStringTypeInstance
private static final BitSet	invokeInstanceSet	Set of opcodes that invoke instance methods on an object.
private static final org.apache.bcel.generic.Type	parameterStringTypeInstance
private static final BitSet	prescreenSet	Set of bytecodes using for prescreening.
private static final boolean	REPORT_ALL_REF_COMPARISONS
private static final org.apache.bcel.generic.Type	staticStringTypeInstance
private static final String	STRING_SIGNATURE
private final Set<String>	suspiciousSet
private static final byte	T_DYNAMIC_STRING
private static final byte	T_PARAMETER_STRING
private static final byte	T_STATIC_STRING
private final boolean	testingEnabled

Fields inherited from interface edu.umd.cs.findbugs.ba.type.ExtendedTypes

T_AVAIL_TYPE, T_BOTTOM, T_DOUBLE_EXTRA, T_EXCEPTION, T_LONG_EXTRA, T_NULL, T_TOP

Fields inherited from interface edu.umd.cs.findbugs.Priorities

EXP_PRIORITY, HIGH_PRIORITY, IGNORE_PRIORITY, LOW_PRIORITY, NORMAL_PRIORITY

Constructor Summary

Constructors

Constructor	Description
FindRefComparison(BugReporter bugReporter)

Method Summary

Modifier and Type	Method	Description
(package private) void	addEqualsCheck(String type, int pc)
private void	analyzeMethod(ClassContext classContext, org.apache.bcel.classfile.Method method)
private void	checkEqualsComparison(Location location, org.apache.bcel.classfile.JavaClass jclass, org.apache.bcel.classfile.Method method, org.apache.bcel.generic.MethodGen methodGen, org.apache.bcel.generic.ConstantPoolGen cpg, TypeDataflow typeDataflow)
private boolean	checkForWeirdEquals(String lhsSig, String rhsSig, Set<XMethod> targets)
private void	checkRefComparison(Location location, org.apache.bcel.classfile.JavaClass jclass, org.apache.bcel.classfile.Method method, org.apache.bcel.generic.MethodGen methodGen, FindRefComparison.RefComparisonTypeFrameModelingVisitor visitor, TypeDataflow typeDataflow, List<FindRefComparison.WarningWithProperties> stringComparisonList, List<FindRefComparison.WarningWithProperties> refComparisonList)
private void	decorateWarnings(LinkedList<FindRefComparison.WarningWithProperties> stringComparisonList, FindRefComparison.WarningDecorator warningDecorator)
MethodDescriptor	getInvokedMethod(org.apache.bcel.generic.ConstantPoolGen cpg, org.apache.bcel.generic.InvokeInstruction inv)
MethodAnnotation	getMethodCalledAnnotation(org.apache.bcel.generic.ConstantPoolGen cpg, org.apache.bcel.generic.InvokeInstruction inv)
private void	handleStringComparison(org.apache.bcel.classfile.JavaClass jclass, org.apache.bcel.classfile.Method method, org.apache.bcel.generic.MethodGen methodGen, FindRefComparison.RefComparisonTypeFrameModelingVisitor visitor, List<FindRefComparison.WarningWithProperties> stringComparisonList, Location location, org.apache.bcel.generic.Type lhsType, org.apache.bcel.generic.Type rhsType)
private void	handleSuspiciousRefComparison(org.apache.bcel.classfile.JavaClass jclass, org.apache.bcel.classfile.Method method, org.apache.bcel.generic.MethodGen methodGen, List<FindRefComparison.WarningWithProperties> refComparisonList, Location location, String lhs, org.apache.bcel.generic.ReferenceType lhsType, org.apache.bcel.generic.ReferenceType rhsType)
private void	inspectLocation(org.apache.bcel.classfile.JavaClass jclass, org.apache.bcel.generic.ConstantPoolGen cpg, org.apache.bcel.classfile.Method method, org.apache.bcel.generic.MethodGen methodGen, LinkedList<FindRefComparison.WarningWithProperties> refComparisonList, LinkedList<FindRefComparison.WarningWithProperties> stringComparisonList, FindRefComparison.RefComparisonTypeFrameModelingVisitor visitor, TypeDataflow typeDataflow, Location location)
(package private) boolean	mightBeLaterCheckedUsingEquals(FindRefComparison.WarningWithProperties warning)
void	report()	This method is called after all classes to be visited.
private void	reportBest(ClassContext classContext, org.apache.bcel.classfile.Method method, LinkedList<FindRefComparison.WarningWithProperties> warningList, boolean relaxed)
void	visitClassContext(ClassContext classContext)	Visit the ClassContext for a class which should be analyzed for instances of bug patterns.

Methods inherited from class java.lang.Object

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

Field Details

DEBUG

private static final boolean DEBUG

REPORT_ALL_REF_COMPARISONS

private static final boolean REPORT_ALL_REF_COMPARISONS

See Also:

• Constant Field Values

BASE_ES_PRIORITY

private static final int BASE_ES_PRIORITY

DEFAULT_SUSPICIOUS_SET

@StaticConstant
private static final HashSet<String> DEFAULT_SUSPICIOUS_SET

Classes that are suspicious if compared by reference.

invokeInstanceSet

private static final BitSet invokeInstanceSet

Set of opcodes that invoke instance methods on an object.

prescreenSet

private static final BitSet prescreenSet

Set of bytecodes using for prescreening.

T_DYNAMIC_STRING

private static final byte T_DYNAMIC_STRING

See Also:

• Constant Field Values

T_STATIC_STRING

private static final byte T_STATIC_STRING

See Also:

• Constant Field Values

T_PARAMETER_STRING

private static final byte T_PARAMETER_STRING

See Also:

• Constant Field Values

STRING_SIGNATURE

private static final String STRING_SIGNATURE

See Also:

• Constant Field Values

dynamicStringTypeInstance

private static final org.apache.bcel.generic.Type dynamicStringTypeInstance

staticStringTypeInstance

private static final org.apache.bcel.generic.Type staticStringTypeInstance

emptyStringTypeInstance

private static final org.apache.bcel.generic.Type emptyStringTypeInstance

parameterStringTypeInstance

private static final org.apache.bcel.generic.Type parameterStringTypeInstance

bugReporter

private final BugReporter bugReporter

bugAccumulator

private final BugAccumulator bugAccumulator

classContext

private ClassContext classContext

suspiciousSet

private final Set<String> suspiciousSet

testingEnabled

private final boolean testingEnabled

comparedForEqualityInThisMethod

private Map<String,Integer> comparedForEqualityInThisMethod

Constructor Details

FindRefComparison

public FindRefComparison(BugReporter bugReporter)

Method Details

visitClassContext

public void visitClassContext(ClassContext classContext)

Description copied from interface: Detector

Visit the ClassContext for a class which should be analyzed for instances of bug patterns.

Specified by:

visitClassContext in interface Detector

Parameters:

classContext - the ClassContext

analyzeMethod

private void analyzeMethod(ClassContext classContext,
 org.apache.bcel.classfile.Method method)
                    throws CFGBuilderException,
DataflowAnalysisException

Throws:

CFGBuilderException

DataflowAnalysisException

mightBeLaterCheckedUsingEquals

boolean mightBeLaterCheckedUsingEquals(FindRefComparison.WarningWithProperties warning)

inspectLocation

private void inspectLocation(org.apache.bcel.classfile.JavaClass jclass,
 org.apache.bcel.generic.ConstantPoolGen cpg,
 org.apache.bcel.classfile.Method method,
 org.apache.bcel.generic.MethodGen methodGen,
 LinkedList<FindRefComparison.WarningWithProperties> refComparisonList,
 LinkedList<FindRefComparison.WarningWithProperties> stringComparisonList,
 FindRefComparison.RefComparisonTypeFrameModelingVisitor visitor,
 TypeDataflow typeDataflow,
 Location location)
                      throws DataflowAnalysisException

Throws:

DataflowAnalysisException

decorateWarnings

private void decorateWarnings(LinkedList<FindRefComparison.WarningWithProperties> stringComparisonList,
 FindRefComparison.WarningDecorator warningDecorator)

reportBest

private void reportBest(ClassContext classContext,
 org.apache.bcel.classfile.Method method,
 LinkedList<FindRefComparison.WarningWithProperties> warningList,
 boolean relaxed)

checkRefComparison

private void checkRefComparison(Location location,
 org.apache.bcel.classfile.JavaClass jclass,
 org.apache.bcel.classfile.Method method,
 org.apache.bcel.generic.MethodGen methodGen,
 FindRefComparison.RefComparisonTypeFrameModelingVisitor visitor,
 TypeDataflow typeDataflow,
 List<FindRefComparison.WarningWithProperties> stringComparisonList,
 List<FindRefComparison.WarningWithProperties> refComparisonList)
                         throws DataflowAnalysisException

Throws:

DataflowAnalysisException

handleStringComparison

private void handleStringComparison(org.apache.bcel.classfile.JavaClass jclass,
 org.apache.bcel.classfile.Method method,
 org.apache.bcel.generic.MethodGen methodGen,
 FindRefComparison.RefComparisonTypeFrameModelingVisitor visitor,
 List<FindRefComparison.WarningWithProperties> stringComparisonList,
 Location location,
 org.apache.bcel.generic.Type lhsType,
 org.apache.bcel.generic.Type rhsType)

handleSuspiciousRefComparison

private void handleSuspiciousRefComparison(org.apache.bcel.classfile.JavaClass jclass,
 org.apache.bcel.classfile.Method method,
 org.apache.bcel.generic.MethodGen methodGen,
 List<FindRefComparison.WarningWithProperties> refComparisonList,
 Location location,
 String lhs,
 org.apache.bcel.generic.ReferenceType lhsType,
 org.apache.bcel.generic.ReferenceType rhsType)

addEqualsCheck

void addEqualsCheck(String type,
 int pc)

checkEqualsComparison

private void checkEqualsComparison(Location location,
 org.apache.bcel.classfile.JavaClass jclass,
 org.apache.bcel.classfile.Method method,
 org.apache.bcel.generic.MethodGen methodGen,
 org.apache.bcel.generic.ConstantPoolGen cpg,
 TypeDataflow typeDataflow)
                            throws DataflowAnalysisException

Throws:

DataflowAnalysisException

getMethodCalledAnnotation

@CheckForNull
public MethodAnnotation getMethodCalledAnnotation(org.apache.bcel.generic.ConstantPoolGen cpg,
 org.apache.bcel.generic.InvokeInstruction inv)

getInvokedMethod

public MethodDescriptor getInvokedMethod(org.apache.bcel.generic.ConstantPoolGen cpg,
 org.apache.bcel.generic.InvokeInstruction inv)

checkForWeirdEquals

private boolean checkForWeirdEquals(String lhsSig,
 String rhsSig,
 Set<XMethod> targets)

report

public void report()

Description copied from interface: Detector

This method is called after all classes to be visited. It should be used by any detectors which accumulate information over all visited classes to generate results.

Specified by:

report in interface Detector