Package edu.umd.cs.findbugs.ba

Class BlockType

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable
    public class BlockType
extends java.util.BitSet
    Dataflow value representing the current nesting of catch and finally blocks. We assume that any catch block with a non-empty catch type is a user catch block, and any catch block with an empty catch type (i.e., catch all exceptions) is a finally block. This assumption isn't quite accurate, but it seems to be a reasonable first approximation.

    If valid (isValid() returns true), a BlockType value is a stack of elements, which are either CATCH or FINALLY values. Call getDepth() to get the current nesting depth. Call get(int n) to get the nth stack item. Call getTopValue() to get the current top of the stack.

    If invalid (isValid() returns false), a BlockType value is either top or bottom. These are the special values at the top and bottom of the dataflow lattice.

    The dataflow lattice is effectively finite-height because real Java methods are guaranteed to have a finite catch and finally block nesting level.

    Author:
    David Hovemeyer
    See Also:
    BlockTypeAnalysis, Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static boolean CATCH  
      static boolean FINALLY  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void copyFrom​(BlockType other)
      Make this object an exact duplicate of given object.
      boolean equals​(java.lang.Object obj)  
      int getDepth()
      Get the current nesting depth.
      boolean getTopValue()
      Get the top value on the catch and finally block nesting stack.
      int hashCode()  
      boolean isBottom()
      Return whether or not this is the special "bottom" dataflow value.
      boolean isNormal()
      Return whether or not this value represents "normal" control-flow.
      boolean isTop()
      Return whether or not this is the special "top" dataflow value.
      boolean isValid()
      Return whether or not this value is valid, meaning it contains a valid representation of the nesting of catch and finally blocks.
      void mergeWith​(BlockType other)
      Merge other dataflow value into this value.
      void pushCatch()
      Enter a catch block.
      void pushFinally()
      Enter a finally block.
      boolean sameAs​(BlockType other)
      Return whether or not this object is identical to the one given.
      void setBottom()
      Make this the special "bottom" dataflow value.
      void setNormal()
      Make this value represent "normal" control flow.
      void setTop()
      Make this the special "top" dataflow value.
      java.lang.String toString()  

      • Methods inherited from class java.util.BitSet

        and, andNot, cardinality, clear, clear, clear, clone, flip, flip, get, get, intersects, isEmpty, length, nextClearBit, nextSetBit, or, previousClearBit, previousSetBit, set, set, set, set, size, stream, toByteArray, toLongArray, valueOf, valueOf, valueOf, valueOf, xor

      • Methods inherited from class java.lang.Object

        finalize, getClass, notify, notifyAll, wait, wait, wait

    • Method Detail

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.util.BitSet

      • equals

        public boolean equals​(java.lang.Object obj)
        Overrides:
        equals in class java.util.BitSet

      • isValid

        public boolean isValid()
        Return whether or not this value is valid, meaning it contains a valid representation of the nesting of catch and finally blocks.

      • getDepth

        public int getDepth()
        Get the current nesting depth. The value must be valid.

      • getTopValue

        public boolean getTopValue()
        Get the top value on the catch and finally block nesting stack.

      • isNormal

        public boolean isNormal()
        Return whether or not this value represents "normal" control-flow. Normal control flow are all blocks outside any catch or finally block.

      • setNormal

        public void setNormal()
        Make this value represent "normal" control flow.

      • isTop

        public boolean isTop()
        Return whether or not this is the special "top" dataflow value.

      • setTop

        public void setTop()
        Make this the special "top" dataflow value.

      • isBottom

        public boolean isBottom()
        Return whether or not this is the special "bottom" dataflow value.

      • setBottom

        public void setBottom()
        Make this the special "bottom" dataflow value.

      • copyFrom

        public void copyFrom​(BlockType other)
        Make this object an exact duplicate of given object.
        Parameters:
        other - the other BlockType object

      • sameAs

        public boolean sameAs​(BlockType other)
        Return whether or not this object is identical to the one given.
        Parameters:
        other - the other BlockType object
        Returns:
        true if this object is identical to the one given, false otherwise

      • mergeWith

        public void mergeWith​(BlockType other)
        Merge other dataflow value into this value.
        Parameters:
        other - the other BlockType value

      • pushCatch

        public void pushCatch()
        Enter a catch block.

      • pushFinally

        public void pushFinally()
        Enter a finally block.

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.util.BitSet