Package edu.umd.cs.findbugs.ba

Interface ResourceTracker<Resource>

  • All Known Implementing Classes:
    StreamResourceTracker
    public interface ResourceTracker<Resource>
    A ResourceTracker is used with ResourceValueAnalysis to determine where in a method a certain kind of resource is created, and to model the effect of instructions on the state of that resource.
    Author:
    David Hovemeyer
    See Also:
    ResourceValueAnalysis

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      ResourceValueFrameModelingVisitor createVisitor​(Resource resource, org.apache.bcel.generic.ConstantPoolGen cpg)
      Create a ResourceValueFrameModelingVisitor to model the effect of instructions on the state of the resource.
      boolean ignoreExceptionEdge​(Edge edge, Resource resource, org.apache.bcel.generic.ConstantPoolGen cpg)
      Determine whether the analysis should ignore given exception edge.
      boolean ignoreImplicitExceptions​(Resource resource)
      Determine whether the analysis should ignore exception edges on which only implicit exceptions are propagated.
      boolean isParamInstance​(Resource resource, int slot)
      Return if the given parameter slot contains the resource instance upon entry to the method.
      boolean isResourceClose​(BasicBlock basicBlock, org.apache.bcel.generic.InstructionHandle handle, org.apache.bcel.generic.ConstantPoolGen cpg, Resource resource, ResourceValueFrame frame)
      Determine if the given instruction is the site where a resource is closed.
      Resource isResourceCreation​(BasicBlock basicBlock, org.apache.bcel.generic.InstructionHandle handle, org.apache.bcel.generic.ConstantPoolGen cpg)
      Determine if the given instruction is the site where a resource is created.
      boolean mightCloseResource​(BasicBlock basicBlock, org.apache.bcel.generic.InstructionHandle handle, org.apache.bcel.generic.ConstantPoolGen cpg)
      Determine if the given instruction is the site where a resource is closed.

    • Method Detail

      • isResourceCreation

        Resource isResourceCreation​(BasicBlock basicBlock,
                            org.apache.bcel.generic.InstructionHandle handle,
                            org.apache.bcel.generic.ConstantPoolGen cpg)
                     throws DataflowAnalysisException
        Determine if the given instruction is the site where a resource is created.
        Parameters:
        basicBlock - basic block containing the instruction
        handle - the instruction
        cpg - the ConstantPoolGen for the method
        Returns:
        an opaque Resource object if it is a creation site, or null if it is not a creation site
        Throws:
        DataflowAnalysisException

      • isResourceClose

        boolean isResourceClose​(BasicBlock basicBlock,
                        org.apache.bcel.generic.InstructionHandle handle,
                        org.apache.bcel.generic.ConstantPoolGen cpg,
                        Resource resource,
                        ResourceValueFrame frame)
                 throws DataflowAnalysisException
        Determine if the given instruction is the site where a resource is closed.
        Parameters:
        basicBlock - basic block containing the instruction
        handle - the instruction
        cpg - the ConstantPoolGen for the method
        resource - the resource, as returned by isResourceCreation()
        frame - the ResourceValueFrame representing the stack prior to executing the instruction
        Returns:
        true if the resource is closed here, false otherwise
        Throws:
        DataflowAnalysisException

      • mightCloseResource

        boolean mightCloseResource​(BasicBlock basicBlock,
                           org.apache.bcel.generic.InstructionHandle handle,
                           org.apache.bcel.generic.ConstantPoolGen cpg)
                    throws DataflowAnalysisException
        Determine if the given instruction is the site where a resource is closed.
        Parameters:
        basicBlock - basic block containing the instruction
        handle - the instruction
        cpg - the ConstantPoolGen for the method
        Returns:
        true if the resource is closed here, false otherwise
        Throws:
        DataflowAnalysisException

      • createVisitor

        ResourceValueFrameModelingVisitor createVisitor​(Resource resource,
                                                org.apache.bcel.generic.ConstantPoolGen cpg)
        Create a ResourceValueFrameModelingVisitor to model the effect of instructions on the state of the resource.
        Parameters:
        resource - the resource we are tracking
        cpg - the ConstantPoolGen of the method
        Returns:
        a ResourceValueFrameModelingVisitor

      • ignoreImplicitExceptions

        boolean ignoreImplicitExceptions​(Resource resource)
        Determine whether the analysis should ignore exception edges on which only implicit exceptions are propagated. This allows different resource types to be tracked with varying precision. For example, we might want to ignore implicit exceptions for stream objects, but treat them as significant for database resources.
        Parameters:
        resource - the resource being tracked
        Returns:
        true if implicit exceptions are significant, false if they should be ignore

      • ignoreExceptionEdge

        boolean ignoreExceptionEdge​(Edge edge,
                            Resource resource,
                            org.apache.bcel.generic.ConstantPoolGen cpg)
        Determine whether the analysis should ignore given exception edge. This allows the analysis to customize which kinds of exceptions are significant.
        Parameters:
        edge - the exception edge
        resource - the resource
        cpg - the ConstantPoolGen
        Returns:
        true if exception edge should be ignored, false if it should be considered

      • isParamInstance

        boolean isParamInstance​(Resource resource,
                        int slot)
        Return if the given parameter slot contains the resource instance upon entry to the method. This is for resources passed as parameters.
        Parameters:
        resource - the resource
        slot - the local variable slot
        Returns:
        true if the slot contains the resource instance, false otherwise