Package com.mebigfatguy.fbcontrib.detect
Class UnnecessaryStoreBeforeReturn
- 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.UnnecessaryStoreBeforeReturn
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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 UnnecessaryStoreBeforeReturn extends edu.umd.cs.findbugs.BytecodeScanningDetector
Looks for methods that store the return result in a local variable, and then immediately returns that local variable.
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Nested Class Summary
Nested Classes Modifier and Type Class Description (package private) static class
UnnecessaryStoreBeforeReturn.State
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Field Summary
Fields Modifier and Type Field Description private static java.util.BitSet
binaryOps
private static java.util.BitSet
branchInstructions
private java.util.BitSet
branchTargets
private edu.umd.cs.findbugs.BugReporter
bugReporter
private java.util.BitSet
catchTargets
private edu.umd.cs.findbugs.OpcodeStack
stack
private UnnecessaryStoreBeforeReturn.State
state
private int
storeReg
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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 UnnecessaryStoreBeforeReturn(edu.umd.cs.findbugs.BugReporter bugReporter)
constructs a USBR 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
lookForLoad(int seen)
looks for a load of the register that was just storedprivate boolean
lookForStore(int seen)
checks if the current opcode is a store, if so saves the registerprivate int
processBinOp(int seen)
looks for instructions that are binary operators, and if it is saves the left hand side register (if it exists) in the userValue.void
sawOpcode(int seen)
implements the visitor to look for store of registers immediately before returns of that registervoid
visitClassContext(edu.umd.cs.findbugs.ba.ClassContext classContext)
implements the visitor to create and clear the branchTargetsvoid
visitCode(org.apache.bcel.classfile.Code obj)
implements the visitor to make sure method returns a value, and then clears the targets-
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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branchInstructions
private static final java.util.BitSet branchInstructions
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binaryOps
private static final java.util.BitSet binaryOps
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bugReporter
private final edu.umd.cs.findbugs.BugReporter bugReporter
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branchTargets
private java.util.BitSet branchTargets
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catchTargets
private java.util.BitSet catchTargets
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stack
private edu.umd.cs.findbugs.OpcodeStack stack
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state
private UnnecessaryStoreBeforeReturn.State state
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storeReg
private int storeReg
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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 branchTargets- 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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visitCode
public void visitCode(org.apache.bcel.classfile.Code obj)
implements the visitor to make sure method returns a value, and then clears the targets- Specified by:
visitCode
in interfaceorg.apache.bcel.classfile.Visitor
- Overrides:
visitCode
in classedu.umd.cs.findbugs.visitclass.PreorderVisitor
- Parameters:
obj
- the context object of the currently parsed code block
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sawOpcode
public void sawOpcode(int seen)
implements the visitor to look for store of registers immediately before returns of that register- Overrides:
sawOpcode
in classedu.umd.cs.findbugs.visitclass.DismantleBytecode
- Parameters:
seen
- the opcode of the currently parsed instruction
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lookForStore
private boolean lookForStore(int seen)
checks if the current opcode is a store, if so saves the register- Parameters:
seen
- the opcode of the currently parsed instruction- Returns:
- if a store was seen
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lookForLoad
private boolean lookForLoad(int seen)
looks for a load of the register that was just stored- Parameters:
seen
- the opcode of the currently parsed instruction- Returns:
- if the load was seen
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processBinOp
private int processBinOp(int seen)
looks for instructions that are binary operators, and if it is saves the left hand side register (if it exists) in the userValue.- Parameters:
seen
- the opcode of the currently parsed instruction- Returns:
- the lhs register number if it exists or -1
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