analysis

Type Members

1. class AliasingAnalyzer[V <: Value] extends Analyzer[V]

   

   An analyzer that uses AliasingFrames instead of bare Frames.

   An analyzer that uses AliasingFrames instead of bare Frames. This can be used when an analysis needs to track aliases, but doesn't require a more specific Frame subclass.

2. class AliasingFrame[V <: Value] extends Frame[V]

   

3. case class ExceptionProducer(handlerFrame: Frame[_ <: Value]) extends InitialProducer with Product with Serializable

   

4. abstract class InitialProducer extends AbstractInsnNode

   

   A class for pseudo-instructions representing the initial producers of local values that have no producer instruction in the method:

   A class for pseudo-instructions representing the initial producers of local values that have no producer instruction in the method:

   • parameters, including this
   • uninitialized local variables
   • exception values in handlers

   The ASM built-in SourceValue analysis yields an empty producers set for such values. This leads to ambiguities. Example (in Java one can re-assign parameter):

   void foo(int a) { if (a == 0) a = 1; return a; }

   In the first frame of the method, the SoruceValue for parameter a gives an empty set of producer instructions.

   In the frame of the IRETURN instruction, the SoruceValue for parameter a lists a single producer instruction: the ISTORE 1. This makes it look as if there was a single producer for a, where in fact it might still hold the parameter's initial value.

5. class InitialProducerSourceInterpreter extends SourceInterpreter

   

6. sealed trait Nullness extends AnyRef

   

   Type to represent nullness of values.

7. class NullnessAnalyzer extends Analyzer[NullnessValue]

   

   This class is required to override the newFrame methods, which makes makes sure the analyzer uses NullnessFrames.

8. class NullnessFrame extends AliasingFrame[NullnessValue]

   

9. final class NullnessInterpreter extends Interpreter[NullnessValue]

   

10. sealed trait NullnessValue extends Value

    

    Represents the nullness state for a local variable or stack value.

    Represents the nullness state for a local variable or stack value.

    Note that nullness of primitive values is not tracked, it will be always Unknown.

11. case class ParameterProducer(local: Int) extends InitialProducer with Product with Serializable

    

12. class ProdConsAnalyzer extends AnyRef

    

    This class provides additional queries over ASM's built-in SourceValue analysis.

    This class provides additional queries over ASM's built-in SourceValue analysis.

    The analysis computes for each value in a frame a set of source instructions, which are the potential producers. Most instructions produce either nothing or a stack value. For example, a LOAD instruction is the producer of the value pushed onto the stack. The exception are STORE instructions, which produce a new value for a local variable slot, so they are used as producers for the value they stored.

    Note that pseudo-instructions are used as initial producers for parameters and local variables. See the documentation on class InitialProducer.

    This class implements the following queries over the data computed by the SourceValue analysis:

    • producersForValueAt(insn, slot)
    • consumersOfValueAt(insn, slot)
    • producersForInputsOf(insn)
    • consumersOfOutputsFrom(insn)
    • initialProducersForValueAt(insn, slot)
    • ultimateConsumersOfValueAt(insn, slot)
    • initialProducersForInputsOf(insn)
    • ultimateConsumersOfOutputsFrom(insn)

    The following operations are considered as copying operations:

    • xLOAD, xSTORE
    • DUP, DUP2, DUP_X1, DUP_X2, DUP2_X1, DUP2_X2
    • SWAP
    • CHECKCAST

    If ever needed, we could introduce a mode where primitive conversions (l2i) are considered as copying operations.

13. case class UninitializedLocalProducer(local: Int) extends InitialProducer with Product with Serializable