com.mebigfatguy.fbcontrib.detect

Class PossiblyRedundantMethodCalls

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

com.mebigfatguy.fbcontrib.detect.PossiblyRedundantMethodCalls

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

@OpcodeStack.CustomUserValue
public class PossiblyRedundantMethodCalls
extends edu.umd.cs.findbugs.BytecodeScanningDetector

looks for calls of the same method on the same object when that object hasn't changed. This often is redundant, and the second call can be removed, or combined.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static class	PossiblyRedundantMethodCalls.FieldInfo contains information about a field access
(package private) static class	PossiblyRedundantMethodCalls.MethodCall contains information about a method call

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.BitSet	branchTargets
private edu.umd.cs.findbugs.BugReporter	bugReporter
private static java.util.Set<FQMethod>	commonMethods
private java.util.Map<PossiblyRedundantMethodCalls.FieldInfo,PossiblyRedundantMethodCalls.MethodCall>	fieldMethodCalls
private static int	highByteCountLimit
private static int	highMethodCallLimit
private java.util.Map<java.lang.Integer,PossiblyRedundantMethodCalls.MethodCall>	localMethodCalls
private static int	lowByteCountLimit
private static int	lowMethodCallLimit
private static int	normalByteCountLimit
private static int	normalMethodCallLimit
static java.lang.String	PRMC_HIGH_BYTECOUNT
static java.lang.String	PRMC_HIGH_METHODCALLS
static java.lang.String	PRMC_LOW_BYTECOUNT
static java.lang.String	PRMC_LOW_METHODCALLS
static java.lang.String	PRMC_NORMAL_BYTECOUNT
static java.lang.String	PRMC_NORMAL_METHODCALLS
static java.lang.String	PRMC_RISKY_CLASS_USER_KEY
static java.lang.String	PRMC_RISKY_FIELD_USER_KEY
private static java.util.Set<java.lang.String>	riskyClassNames
private static java.util.Set<java.lang.String>	riskyMethodNameContents a collection of names that are to be checked against a currently parsed method, to see if that method is risky to be called redundant.
private edu.umd.cs.findbugs.OpcodeStack	stack
private java.util.Map<java.lang.String,PossiblyRedundantMethodCalls.MethodCall>	staticMethodCalls

Fields inherited from class edu.umd.cs.findbugs.visitclass.DismantleBytecode

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

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

EXP_PRIORITY, HIGH_PRIORITY, IGNORE_PRIORITY, LOW_PRIORITY, NORMAL_PRIORITY

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

Constructor Summary

Constructors

Constructor and Description
PossiblyRedundantMethodCalls(edu.umd.cs.findbugs.BugReporter bugReporter) constructs a PRMC detector given the reporter to report bugs on

Method Summary

Modifier and Type	Method and Description
private void	clearFieldMethods(java.lang.String fieldSource)
private static int	getBugPriority(java.lang.String methodName, MethodInfo mi) returns the bug priority based on metrics about the method
private int	getLineNumber(int pc) returns the source line number for the pc, or just the pc if the line number table doesn't exist
private static boolean	isRiskyName(java.lang.String className, java.lang.String methodName) returns true if the class or method name contains a pattern that is considered likely to be this modifying
void	sawOpcode(int seen) implements the visitor to look for repetitive calls to the same method on the same object using the same constant parameters.
void	visitClassContext(edu.umd.cs.findbugs.ba.ClassContext classContext) implements the visitor to create and clear the stack, method call maps, and branch targets
void	visitCode(org.apache.bcel.classfile.Code obj) implements the visitor to reset the stack, and method call maps for new method Note: that when collecting branch targets, it's unfortunately not good enough to just collect the handler pcs, as javac plays fast and loose, and will sometimes jam code below the end pc and before the first handler pc, which gets executed.

Methods inherited from class edu.umd.cs.findbugs.BytecodeScanningDetector

getClassContext, report, shouldVisitCode

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

Methods inherited from class edu.umd.cs.findbugs.visitclass.AnnotationVisitor

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

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

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

Methods inherited from class java.lang.Object

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

Field Detail

PRMC_RISKY_FIELD_USER_KEY

public static final java.lang.String PRMC_RISKY_FIELD_USER_KEY

See Also:

Constant Field Values

PRMC_RISKY_CLASS_USER_KEY

public static final java.lang.String PRMC_RISKY_CLASS_USER_KEY

See Also:

Constant Field Values

PRMC_HIGH_BYTECOUNT

public static final java.lang.String PRMC_HIGH_BYTECOUNT

See Also:

Constant Field Values

PRMC_HIGH_METHODCALLS

public static final java.lang.String PRMC_HIGH_METHODCALLS

See Also:

Constant Field Values

PRMC_NORMAL_BYTECOUNT

public static final java.lang.String PRMC_NORMAL_BYTECOUNT

See Also:

Constant Field Values

PRMC_NORMAL_METHODCALLS

public static final java.lang.String PRMC_NORMAL_METHODCALLS

See Also:

Constant Field Values

PRMC_LOW_BYTECOUNT

public static final java.lang.String PRMC_LOW_BYTECOUNT

See Also:

Constant Field Values

PRMC_LOW_METHODCALLS

public static final java.lang.String PRMC_LOW_METHODCALLS

See Also:

Constant Field Values

riskyMethodNameContents

private static java.util.Set<java.lang.String> riskyMethodNameContents

a collection of names that are to be checked against a currently parsed method, to see if that method is risky to be called redundant. The contents are either

• a simple name that can be found as part of the methodName, like "destroy" which would match destroy(), or destroyAll()
• a fully qualified method name that exactly matches a method, like "java/lang/String.valueOf"

highByteCountLimit

private static int highByteCountLimit

highMethodCallLimit

private static int highMethodCallLimit

normalByteCountLimit

private static int normalByteCountLimit

normalMethodCallLimit

private static int normalMethodCallLimit

lowByteCountLimit

private static int lowByteCountLimit

lowMethodCallLimit

private static int lowMethodCallLimit

riskyClassNames

private static java.util.Set<java.lang.String> riskyClassNames

commonMethods

private static final java.util.Set<FQMethod> commonMethods

bugReporter

private final edu.umd.cs.findbugs.BugReporter bugReporter

stack

private edu.umd.cs.findbugs.OpcodeStack stack

localMethodCalls

private java.util.Map<java.lang.Integer,PossiblyRedundantMethodCalls.MethodCall> localMethodCalls

fieldMethodCalls

private java.util.Map<PossiblyRedundantMethodCalls.FieldInfo,PossiblyRedundantMethodCalls.MethodCall> fieldMethodCalls

staticMethodCalls

private java.util.Map<java.lang.String,PossiblyRedundantMethodCalls.MethodCall> staticMethodCalls

branchTargets

private java.util.BitSet branchTargets

Constructor Detail

PossiblyRedundantMethodCalls

public PossiblyRedundantMethodCalls(edu.umd.cs.findbugs.BugReporter bugReporter)

constructs a PRMC detector given the reporter to report bugs on

Parameters:

bugReporter - the sync of bug reports

Method Detail

visitClassContext

public void visitClassContext(edu.umd.cs.findbugs.ba.ClassContext classContext)

implements the visitor to create and clear the stack, method call maps, and branch targets

Specified by:

visitClassContext in interface edu.umd.cs.findbugs.Detector

Overrides:

visitClassContext in class edu.umd.cs.findbugs.BytecodeScanningDetector

Parameters:

classContext - the context object of the currently visited class

visitCode

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

implements the visitor to reset the stack, and method call maps for new method Note: that when collecting branch targets, it's unfortunately not good enough to just collect the handler pcs, as javac plays fast and loose, and will sometimes jam code below the end pc and before the first handler pc, which gets executed. So we need to clear our maps if we go past the end pc as well.

Specified by:

visitCode in interface org.apache.bcel.classfile.Visitor

Overrides:

visitCode in class edu.umd.cs.findbugs.visitclass.PreorderVisitor

Parameters:

obj - the context object of the currently parsed code block

sawOpcode

public void sawOpcode(int seen)

implements the visitor to look for repetitive calls to the same method on the same object using the same constant parameters. These methods must return a value.

Overrides:

sawOpcode in class edu.umd.cs.findbugs.visitclass.DismantleBytecode

Parameters:

seen - the opcode of the currently parsed instruction

clearFieldMethods

private void clearFieldMethods(java.lang.String fieldSource)

getBugPriority

private static int getBugPriority(java.lang.String methodName,
                                  MethodInfo mi)

returns the bug priority based on metrics about the method

Parameters:

methodName - TODO

mi - metrics about the method

Returns:

the bug priority

isRiskyName

private static boolean isRiskyName(java.lang.String className,
                                   java.lang.String methodName)

returns true if the class or method name contains a pattern that is considered likely to be this modifying

Parameters:

className - the class name to check

methodName - the method name to check

Returns:

whether the method sounds like it modifies this

getLineNumber

private int getLineNumber(int pc)

returns the source line number for the pc, or just the pc if the line number table doesn't exist

Parameters:

pc - current pc

Returns:

the line number