Package edu.umd.cs.findbugs.ba.constant
Class ConstantAnalysis
- java.lang.Object
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- edu.umd.cs.findbugs.ba.BasicAbstractDataflowAnalysis<Fact>
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- edu.umd.cs.findbugs.ba.AbstractDataflowAnalysis<Fact>
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- edu.umd.cs.findbugs.ba.ForwardDataflowAnalysis<FrameType>
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- edu.umd.cs.findbugs.ba.FrameDataflowAnalysis<Constant,ConstantFrame>
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- edu.umd.cs.findbugs.ba.constant.ConstantAnalysis
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- All Implemented Interfaces:
DataflowAnalysis<ConstantFrame>
public class ConstantAnalysis extends FrameDataflowAnalysis<Constant,ConstantFrame>
Dataflow analysis to find constant values.- Author:
- David Hovemeyer
- See Also:
Constant
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Constructor Summary
Constructors Constructor Description ConstantAnalysis(org.apache.bcel.generic.MethodGen methodGen, DepthFirstSearch dfs)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description ConstantFrame
createFact()
Create empty (uninitialized) dataflow facts for one program point.void
initEntryFact(ConstantFrame frame)
Initialize the "entry" fact for the graph.void
meetInto(ConstantFrame fact, Edge edge, ConstantFrame result)
Meet a dataflow fact associated with an incoming edge into another fact.protected void
mergeValues(ConstantFrame otherFrame, ConstantFrame resultFrame, int slot)
Merge the values contained in a given slot of two Frames.void
transferInstruction(org.apache.bcel.generic.InstructionHandle handle, BasicBlock basicBlock, ConstantFrame frame)
Transfer function for a single instruction.-
Methods inherited from class edu.umd.cs.findbugs.ba.FrameDataflowAnalysis
copy, getFactAtPC, getFactBeforeExceptionCheck, getLastUpdateTimestamp, isFactValid, isTop, makeFactTop, mergeInto, modifyFrame, same, setLastUpdateTimestamp
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Methods inherited from class edu.umd.cs.findbugs.ba.ForwardDataflowAnalysis
getBlockOrder, getDepthFirstSearch, isForwards
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Methods inherited from class edu.umd.cs.findbugs.ba.AbstractDataflowAnalysis
getFactAfterLocation, getFactAtLocation, transfer
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Methods inherited from class edu.umd.cs.findbugs.ba.BasicAbstractDataflowAnalysis
edgeTransfer, factToString, finishIteration, getFactOnEdge, getResultFact, getStartFact, resultFactIterator, startIteration
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Constructor Detail
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ConstantAnalysis
public ConstantAnalysis(org.apache.bcel.generic.MethodGen methodGen, DepthFirstSearch dfs)
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Method Detail
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createFact
public ConstantFrame createFact()
Description copied from interface:DataflowAnalysis
Create empty (uninitialized) dataflow facts for one program point. A valid value will be copied into it before it is used.
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initEntryFact
public void initEntryFact(ConstantFrame frame)
Description copied from interface:DataflowAnalysis
Initialize the "entry" fact for the graph.
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transferInstruction
public void transferInstruction(org.apache.bcel.generic.InstructionHandle handle, BasicBlock basicBlock, ConstantFrame frame) throws DataflowAnalysisException
Description copied from class:AbstractDataflowAnalysis
Transfer function for a single instruction.- Specified by:
transferInstruction
in classAbstractDataflowAnalysis<ConstantFrame>
- Parameters:
handle
- the instructionbasicBlock
- the BasicBlock containing the instruction; needed to disambiguate instructions in inlined JSR subroutinesframe
- which should be modified based on the instruction- Throws:
DataflowAnalysisException
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meetInto
public void meetInto(ConstantFrame fact, Edge edge, ConstantFrame result) throws DataflowAnalysisException
Description copied from interface:DataflowAnalysis
Meet a dataflow fact associated with an incoming edge into another fact. This is used to determine the start fact for a basic block.- Parameters:
fact
- the predecessor fact (incoming edge)edge
- the edge from the predecessorresult
- the result fact- Throws:
DataflowAnalysisException
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mergeValues
protected void mergeValues(ConstantFrame otherFrame, ConstantFrame resultFrame, int slot) throws DataflowAnalysisException
Description copied from class:FrameDataflowAnalysis
Merge the values contained in a given slot of two Frames.- Specified by:
mergeValues
in classFrameDataflowAnalysis<Constant,ConstantFrame>
- Parameters:
otherFrame
- a FrameresultFrame
- a Frame which will contain the resulting merged valueslot
- a slot in both frames- Throws:
DataflowAnalysisException
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