Package com.ibm.wala.dalvik.ipa.callgraph.androidModel.parameters

Class AndroidModelParameterManager

java.lang.Object
com.ibm.wala.dalvik.ipa.callgraph.androidModel.parameters.AndroidModelParameterManager
public class AndroidModelParameterManager extends Object
Manages SSA-Numbers for the arguments to Entrypoints.

This class comes in handy if you want to use loops or mix a return value of a function into the parameter of a later function. It supports multiple levels of cascading code blocks and delivers information which SSA-Value is the latest to use or which aught to be combined using a Phi-Statement.

However it does no allocations or Phi-Statements on its own. It just juggles with the numbers.

Since:
2013-09-19

TODO:

  • Track if a variable has been refered to to be able to prune unused Phi-Instructions later
  • Trim Memory consumption? The whole class should not be in * memory for long time so this might be not neccessary.
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    AndroidModelParameterManager(com.ibm.wala.core.util.ssa.ParameterAccessor acc)
     
    AndroidModelParameterManager(IInstantiationBehavior behaviour)
    Setting the behaviour may be handy in the later model.
    AndroidModelParameterManager(com.ibm.wala.types.MethodReference mRef, boolean isStatic)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    List<Integer>
    getAllForPhi(com.ibm.wala.types.TypeReference type)
     
    int
    getCurrent(com.ibm.wala.types.TypeReference type)
    Retreive the SSA-Number that is valid for a type in the current scope.
    int
    getFree(com.ibm.wala.types.TypeReference type)
    Returns and registers a free SSA-Number to a Type.
    int
    getSuper(com.ibm.wala.types.TypeReference type)
    Retreive the SSA-Number that is valid for a type in the super-ordinate scope.
    int
    getUnallocated(com.ibm.wala.types.TypeReference type)
    Get an unused number to assign to.
    int
    getUnmanaged()
    Retreive a SSA-Value that is not under management.
    void
    invalidate(com.ibm.wala.types.TypeReference type)
     
    boolean
    isCreate(com.ibm.wala.types.TypeReference type)
    Shorthand for not(isReuse(TypeReference).
    boolean
    isReuse(com.ibm.wala.types.TypeReference type)
    Handed through to an IInstantiationBehavior if set in the constructor.
    boolean
    isSeen(com.ibm.wala.types.TypeReference type)
     
    boolean
    isSeen(com.ibm.wala.types.TypeReference type, boolean withSuper)
    Return if the type is managed by this class.
    boolean
    needsAllocation(com.ibm.wala.types.TypeReference type)
    Returns if an instance for that type needs to be allocated.
    boolean
    needsPhi(com.ibm.wala.types.TypeReference type)
    Returns if a PhiInstruction (still) has to be added.
    int
    scopeDown(boolean doesLoop)
    Enter a subordinate scope.
    int
    scopeUp()
    Leave a subordinate scope.
    void
    setAllocation(com.ibm.wala.core.util.ssa.SSAValue val)
     
    void
    setAllocation(com.ibm.wala.types.TypeReference type, int ssaValue)
     
    void
    setAllocation(com.ibm.wala.types.TypeReference type, int ssaValue, com.ibm.wala.ssa.SSAInstruction setBy)
    Register a variable _after_ allocation.
    void
    setPhi(com.ibm.wala.types.TypeReference type, int ssaValue, com.ibm.wala.ssa.SSAInstruction setBy)
    Register a Phi-Instruction _after_ added to the model.
    String
    toString()
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • AndroidModelParameterManager

      public AndroidModelParameterManager(IInstantiationBehavior behaviour)
      Setting the behaviour may be handy in the later model.

      However it brings no benefit to the AndroidModelParameterManager.

    • AndroidModelParameterManager

      public AndroidModelParameterManager(com.ibm.wala.types.MethodReference mRef, boolean isStatic)

    • AndroidModelParameterManager

      public AndroidModelParameterManager(com.ibm.wala.core.util.ssa.ParameterAccessor acc)

  • Method Details

    • setAllocation

      public void setAllocation(com.ibm.wala.types.TypeReference type, int ssaValue, com.ibm.wala.ssa.SSAInstruction setBy)
      Register a variable _after_ allocation.

      The proper way to add an allocation is to get a Variable using getUnallocated(com.ibm.wala.types.TypeReference). Then assign it a value. And at last call this function.

      You can however directly call the function if the type has not been seen before.

      Parameters:
      type - The type allocated
      ssaValue - an unallocated SSA-Variable to assign the allocation to
      setBy - The instruction that set the value
      Throws:
      IllegalStateException - if you set more than one allocation for that type (TODO better check!)
      IllegalArgumentException - if type is null or ssaValue is zero or negative

    • setAllocation

      public void setAllocation(com.ibm.wala.types.TypeReference type, int ssaValue)

    • setAllocation

      public void setAllocation(com.ibm.wala.core.util.ssa.SSAValue val)

    • setPhi

      public void setPhi(com.ibm.wala.types.TypeReference type, int ssaValue, com.ibm.wala.ssa.SSAInstruction setBy)
      Register a Phi-Instruction _after_ added to the model.
      Parameters:
      type - the type the Phi-Instruction sets
      ssaValue - the number the SSA-Instruction assignes to
      setBy - the Phi-Instruction itself - may be null
      Throws:
      IllegalArgumentException - if you assign to a number requested using getFree(TypeReference) but types mismach.
      IllegalStateException - if you forgot to close some Phis

    • getFree

      public int getFree(com.ibm.wala.types.TypeReference type)
      Returns and registers a free SSA-Number to a Type.

      You have to set the type using a Phi-Instruction. Also you don't have to add that instruction immediatly it is required that it is added before the Model gets finished.

      You can request the List of unmet Phi-Instructions by using XXX

      Returns:
      an unused SSA-Number
      Throws:
      IllegalArgumentException - if type is null

    • getUnallocated

      public int getUnallocated(com.ibm.wala.types.TypeReference type)
      Get an unused number to assign to.

      There may only be one unallocated value for each type at a time. XXX: Really?

      Returns:
      SSA-Variable
      Throws:
      IllegalStateException - if there is already an unallocated variable of that type
      IllegalArgumentException - if type is null

    • getUnmanaged

      public int getUnmanaged()
      Retreive a SSA-Value that is not under management.

      Use instead of 'nextLocal++', else SSA-Values will clash!

      Returns:
      SSA-Variable

    • getCurrent

      public int getCurrent(com.ibm.wala.types.TypeReference type)
      Retreive the SSA-Number that is valid for a type in the current scope.

      Either that number origins from an allocation or a PhiInstruction (to be).

      Returns:
      a ssa number
      Throws:
      IllegalStateException - if no number is assignable
      IllegalArgumentException - if type was not seen before or is null

    • getSuper

      public int getSuper(com.ibm.wala.types.TypeReference type)
      Retreive the SSA-Number that is valid for a type in the super-ordinate scope.

      Either that number origins from an allocation or a PhiInstruction (to be).

      Returns:
      a ssa number
      Throws:
      IllegalStateException - if no number is assignable
      IllegalArgumentException - if type was not seen before or is null

    • getAllForPhi

      public List<Integer> getAllForPhi(com.ibm.wala.types.TypeReference type)
      Throws:
      IllegalArgumentException - if type was not seen before or is null

    • isSeen

      public boolean isSeen(com.ibm.wala.types.TypeReference type, boolean withSuper)
      Return if the type is managed by this class.
      Parameters:
      withSuper - when true return true if a managed key may be cast to type, when false type has to match exactly
      type - the type in question
      Throws:
      IllegalArgumentException - if type is null

    • isSeen

      public boolean isSeen(com.ibm.wala.types.TypeReference type)

    • needsAllocation

      public boolean needsAllocation(com.ibm.wala.types.TypeReference type)
      Returns if an instance for that type needs to be allocated.

      However this function does not respect weather a PhiInstruction is needed.

      Throws:
      IllegalArgumentException - if type is null

    • needsPhi

      public boolean needsPhi(com.ibm.wala.types.TypeReference type)
      Returns if a PhiInstruction (still) has to be added.

      This is true if the Value has changed in a deeper scope, has been invalidated or requested using getFree

      Throws:
      IllegalArgumentException - if type is null or has not been seen before

    • invalidate

      public void invalidate(com.ibm.wala.types.TypeReference type)
      Throws:
      IllegalArgumentException - if type was not seen before or is null

    • scopeDown

      public int scopeDown(boolean doesLoop)
      Enter a subordinate scope.

      Call this whenever a new code block starts i.e. when ever you would have to put a left curly-bracket in yout java code.

      This function influences the placement of Phi-Functions. Thus if you don't change values you don't have to call it.

      Parameters:
      doesLoop - set to true if the scope is introduced for a loop
      Returns:
      The depth

    • scopeUp

      public int scopeUp()
      Leave a subordinate scope.

      All changes are marked invalid thus to be expected to be collected by a PhiInstruction.

      Throws:
      IllegalStateException - if already at top level

    • isReuse

      public boolean isReuse(com.ibm.wala.types.TypeReference type)
      Handed through to an IInstantiationBehavior if set in the constructor.
      Returns:
      true if Type is a REUSE type
      Throws:
      IllegalStateException - if AndroidModelParameterManager was constructed without an IInstanciationBehavior

    • isCreate

      public boolean isCreate(com.ibm.wala.types.TypeReference type)
      Shorthand for not(isReuse(TypeReference).
      Returns:
      true if type is a CREATE-Type
      Throws:
      IllegalStateException - if AndroidModelParameterManager was constructed without an IInstanciationBehavior

    • toString

      public String toString()
      Overrides:
      toString in class Object