Package com.mebigfatguy.fbcontrib.detect
Class LiteralStringComparison
- java.lang.Object
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- edu.umd.cs.findbugs.visitclass.BetterVisitor
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- edu.umd.cs.findbugs.visitclass.PreorderVisitor
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- edu.umd.cs.findbugs.visitclass.AnnotationVisitor
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- edu.umd.cs.findbugs.visitclass.DismantleBytecode
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- edu.umd.cs.findbugs.BytecodeScanningDetector
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- com.mebigfatguy.fbcontrib.detect.LiteralStringComparison
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- All Implemented Interfaces:
edu.umd.cs.findbugs.Detector
,edu.umd.cs.findbugs.Priorities
,edu.umd.cs.findbugs.visitclass.Constants2
,org.apache.bcel.classfile.Visitor
,org.apache.bcel.Constants
@CustomUserValue public class LiteralStringComparison extends edu.umd.cs.findbugs.BytecodeScanningDetector
looks for methods that compare strings against literal strings, where the literal string is passed as the parameter. If the .equals or .compareTo is called on the literal itself, passing the variable as the parameter, you avoid the possibility of a NullPointerException. Updated for 1.7 to not throw false positives for string-based switch statements (which are susceptible to NPEs). String-based switch generate String.equals(Constant) bytecodes, and thus, must be accounted for
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Nested Class Summary
Nested Classes Modifier and Type Class Description (package private) static class
LiteralStringComparison.LookupDetails
holds information about a switch statement, and it's case PC values
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Field Summary
Fields Modifier and Type Field Description private edu.umd.cs.findbugs.BugReporter
bugReporter
private java.util.List<LiteralStringComparison.LookupDetails>
lookupSwitches
the object that was switched on, to the switch targets for that switchprivate edu.umd.cs.findbugs.OpcodeStack
stack
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Fields inherited from class edu.umd.cs.findbugs.visitclass.DismantleBytecode
codeBytes, lineNumberTable, M_BR, M_CP, M_INT, M_PAD, M_R, M_UINT
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Fields inherited from interface org.apache.bcel.Constants
AALOAD, AASTORE, ACC_ABSTRACT, ACC_ANNOTATION, ACC_BRIDGE, 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_SYPER, ACC_TRANSIENT, ACC_VARARGS, ACC_VOLATILE, ACCESS_NAMES, ACONST_NULL, ALOAD, ALOAD_0, ALOAD_1, ALOAD_2, ALOAD_3, ANEWARRAY, ANEWARRAY_QUICK, APPEND_FRAME, APPEND_FRAME_MAX, ARETURN, ARRAYLENGTH, ASTORE, ASTORE_0, ASTORE_1, ASTORE_2, ASTORE_3, ATHROW, ATTR_ANNOTATION_DEFAULT, ATTR_CODE, ATTR_CONSTANT_VALUE, ATTR_DEPRECATED, ATTR_ENCLOSING_METHOD, ATTR_EXCEPTIONS, ATTR_INNER_CLASSES, ATTR_LINE_NUMBER_TABLE, ATTR_LOCAL_VARIABLE_TABLE, ATTR_LOCAL_VARIABLE_TYPE_TABLE, ATTR_PMG, ATTR_RUNTIME_VISIBLE_ANNOTATIONS, ATTR_RUNTIME_VISIBLE_PARAMETER_ANNOTATIONS, ATTR_RUNTIMEIN_VISIBLE_ANNOTATIONS, ATTR_RUNTIMEIN_VISIBLE_PARAMETER_ANNOTATIONS, ATTR_SIGNATURE, ATTR_SOURCE_FILE, ATTR_STACK_MAP, ATTR_STACK_MAP_TABLE, ATTR_SYNTHETIC, ATTR_UNKNOWN, ATTRIBUTE_NAMES, BALOAD, BASTORE, BIPUSH, BREAKPOINT, CALOAD, CASTORE, CHECKCAST, CHECKCAST_QUICK, CHOP_FRAME, CHOP_FRAME_MAX, CLASS_TYPE_NAMES, CONSTANT_Class, CONSTANT_Double, CONSTANT_Fieldref, CONSTANT_Float, CONSTANT_Integer, CONSTANT_InterfaceMethodref, CONSTANT_InvokeDynamic, CONSTANT_Long, CONSTANT_MethodHandle, CONSTANT_Methodref, CONSTANT_MethodType, CONSTANT_NameAndType, CONSTANT_NAMES, CONSTANT_String, CONSTANT_Utf8, CONSTRUCTOR_NAME, CONSUME_STACK, D2F, D2I, D2L, DADD, DALOAD, DASTORE, DCMPG, DCMPL, DCONST_0, DCONST_1, DDIV, DLOAD, DLOAD_0, DLOAD_1, DLOAD_2, DLOAD_3, DMUL, DNEG, DREM, DRETURN, DSTORE, DSTORE_0, DSTORE_1, DSTORE_2, DSTORE_3, 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, FLOAD_0, FLOAD_1, FLOAD_2, FLOAD_3, FMUL, FNEG, FREM, FRETURN, FSTORE, FSTORE_0, FSTORE_1, FSTORE_2, FSTORE_3, FSUB, FULL_FRAME, GETFIELD, GETFIELD_QUICK, GETFIELD_QUICK_W, GETFIELD2_QUICK, GETSTATIC, GETSTATIC_QUICK, GETSTATIC2_QUICK, GOTO, GOTO_W, 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, ILLEGAL_OPCODE, ILLEGAL_TYPE, ILOAD, ILOAD_0, ILOAD_1, ILOAD_2, ILOAD_3, IMPDEP1, IMPDEP2, IMUL, INEG, INSTANCEOF, INSTANCEOF_QUICK, INT2BYTE, INT2CHAR, INT2SHORT, INTERFACES_IMPLEMENTED_BY_ARRAYS, INVOKEDYNAMIC, INVOKEINTERFACE, INVOKEINTERFACE_QUICK, INVOKENONVIRTUAL, INVOKENONVIRTUAL_QUICK, INVOKESPECIAL, INVOKESTATIC, INVOKESTATIC_QUICK, INVOKESUPER_QUICK, INVOKEVIRTUAL, INVOKEVIRTUAL_QUICK, INVOKEVIRTUAL_QUICK_W, INVOKEVIRTUALOBJECT_QUICK, IOR, IREM, IRETURN, ISHL, ISHR, ISTORE, ISTORE_0, ISTORE_1, ISTORE_2, ISTORE_3, ISUB, ITEM_Bogus, ITEM_Double, ITEM_Float, ITEM_InitObject, ITEM_Integer, ITEM_Long, ITEM_NAMES, ITEM_NewObject, ITEM_Null, ITEM_Object, IUSHR, IXOR, JSR, JSR_W, KNOWN_ATTRIBUTES, L2D, L2F, L2I, LADD, LALOAD, LAND, LASTORE, LCMP, LCONST_0, LCONST_1, LDC, LDC_QUICK, LDC_W, LDC_W_QUICK, LDC2_W, LDC2_W_QUICK, LDIV, LLOAD, LLOAD_0, LLOAD_1, LLOAD_2, LLOAD_3, LMUL, LNEG, LOOKUPSWITCH, LOR, LREM, LRETURN, LSHL, LSHR, LSTORE, LSTORE_0, LSTORE_1, LSTORE_2, LSTORE_3, LSUB, LUSHR, LXOR, MAJOR, MAJOR_1_1, MAJOR_1_2, MAJOR_1_3, MAJOR_1_4, MAJOR_1_5, MAJOR_1_6, MAJOR_1_7, MAJOR_1_8, MAX_ACC_FLAG, MAX_BYTE, MAX_CODE_SIZE, MAX_CP_ENTRIES, MAX_SHORT, MINOR, MINOR_1_1, MINOR_1_2, MINOR_1_3, MINOR_1_4, MINOR_1_5, MINOR_1_6, MINOR_1_7, MINOR_1_8, MONITORENTER, MONITOREXIT, MULTIANEWARRAY, MULTIANEWARRAY_QUICK, NEW, NEW_QUICK, NEWARRAY, NO_OF_OPERANDS, NOP, OPCODE_NAMES, POP, POP2, PRODUCE_STACK, PUSH, PUTFIELD, PUTFIELD_QUICK, PUTFIELD_QUICK_W, PUTFIELD2_QUICK, PUTSTATIC, PUTSTATIC_QUICK, PUTSTATIC2_QUICK, RESERVED, RET, RETURN, SALOAD, SAME_FRAME, SAME_FRAME_EXTENDED, SAME_FRAME_MAX, SAME_LOCALS_1_STACK_ITEM_FRAME, SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED, SAME_LOCALS_1_STACK_ITEM_FRAME_MAX, SASTORE, SHORT_TYPE_NAMES, SIPUSH, STATIC_INITIALIZER_NAME, SWAP, SWITCH, T_ADDRESS, T_ARRAY, T_BOOLEAN, T_BYTE, T_CHAR, T_DOUBLE, T_FLOAT, T_INT, T_LONG, T_OBJECT, T_REFERENCE, T_SHORT, T_UNKNOWN, T_VOID, TABLESWITCH, TYPE_NAMES, TYPE_OF_OPERANDS, UNDEFINED, UNPREDICTABLE, WIDE
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Constructor Summary
Constructors Constructor Description LiteralStringComparison(edu.umd.cs.findbugs.BugReporter bugReporter)
constructs a LSC detector given the reporter to report bugs on
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description private boolean
lookupSwitchOnString()
looks to see if the string used in a equals or compareTo is the same as that of a switch statement's switch on string.boolean
prescreen(org.apache.bcel.classfile.Method method)
looks for methods that contain a LDC or LDC_W opcodesvoid
sawOpcode(int seen)
looks for strings comparisons where the stack object is a literalvoid
visitClassContext(edu.umd.cs.findbugs.ba.ClassContext classContext)
implements the visitor to create and clear the stackvoid
visitCode(org.apache.bcel.classfile.Code obj)
overrides the visitor to reset the opcode stack-
Methods inherited from class edu.umd.cs.findbugs.BytecodeScanningDetector
getClassContext, report, shouldVisitCode
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Methods inherited from class edu.umd.cs.findbugs.visitclass.DismantleBytecode
afterOpcode, areOppositeBranches, atCatchBlock, beforeOpcode, 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, sawBranchTo, sawClass, sawDouble, sawField, sawFloat, sawIMethod, sawInt, sawLong, sawMethod, sawRegister, sawString, visit
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Methods inherited from class edu.umd.cs.findbugs.visitclass.AnnotationVisitor
getAnnotationParameterAsString, getAnnotationParameterAsStringArray, visitAnnotation, visitAnnotation, visitParameterAnnotation, visitParameterAnnotation, visitSyntheticParameterAnnotation
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Methods inherited from class edu.umd.cs.findbugs.visitclass.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, getSurroundingTryBlock, getSurroundingTryBlock, getThisClass, getXClass, getXField, getXMethod, hasInterestingClass, hasInterestingMethod, isVisitMethodsInCallOrder, setupVisitorForClass, setVisitMethodsInCallOrder, shouldVisit, toString, visitAfter, visitAfter, visitAnnotationDefault, visitAnnotationEntry, visitConstantPool, visitEnclosingMethod, visitingField, visitingMethod, visitInnerClasses, visitJavaClass, visitLineNumberTable, visitLocalVariableTable, visitStackMapTable, visitStackMapTableEntry
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Methods inherited from class edu.umd.cs.findbugs.visitclass.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, visitStackMap, visitStackMapEntry, visitSynthetic, visitUnknown
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Field Detail
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bugReporter
private edu.umd.cs.findbugs.BugReporter bugReporter
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stack
private edu.umd.cs.findbugs.OpcodeStack stack
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lookupSwitches
private java.util.List<LiteralStringComparison.LookupDetails> lookupSwitches
the object that was switched on, to the switch targets for that switch
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Method Detail
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visitClassContext
public void visitClassContext(edu.umd.cs.findbugs.ba.ClassContext classContext)
implements the visitor to create and clear the stack- Specified by:
visitClassContext
in interfaceedu.umd.cs.findbugs.Detector
- Overrides:
visitClassContext
in classedu.umd.cs.findbugs.BytecodeScanningDetector
- Parameters:
classContext
- the context object for the currently parsed class
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prescreen
public boolean prescreen(org.apache.bcel.classfile.Method method)
looks for methods that contain a LDC or LDC_W opcodes- Parameters:
method
- the context object of the current method- Returns:
- if the class loads constants
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visitCode
public void visitCode(org.apache.bcel.classfile.Code obj)
overrides the visitor to reset the opcode stack- Specified by:
visitCode
in interfaceorg.apache.bcel.classfile.Visitor
- Overrides:
visitCode
in classedu.umd.cs.findbugs.visitclass.PreorderVisitor
- Parameters:
obj
- the code object for the currently parsed method
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sawOpcode
public void sawOpcode(int seen)
looks for strings comparisons where the stack object is a literal- Overrides:
sawOpcode
in classedu.umd.cs.findbugs.visitclass.DismantleBytecode
- Parameters:
seen
- the currently parsed opcode
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lookupSwitchOnString
private boolean lookupSwitchOnString()
looks to see if the string used in a equals or compareTo is the same as that of a switch statement's switch on string.- Returns:
- if the string is used in a switch
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