Class ContainerContextSelector

java.lang.Object

com.ibm.wala.ipa.callgraph.propagation.cfa.ContainerContextSelector

All Implemented Interfaces:

ContextSelector

public class ContainerContextSelector
extends Object
implements ContextSelector

This context selector returns a context customized for the InstanceKey of the receiver if

• receiver is a container, or
• was allocated in a node whose context was a ReceiverInstanceContext, and the type is interesting according to a delegate ZeroXInstanceKeys

Additionally, we add one level of call string context to a few well-known static factory methods from the standard libraries.

Field Summary

Fields

Modifier and Type	Field	Description
static final Atom	arraycopyAtom
static final TypeReference	JavaUtilHashtable
static final MethodReference	synthArraycopy
static final TypeReference	SyntheticSystem

Constructor Summary

Constructors

Constructor	Description
ContainerContextSelector(IClassHierarchy cha, ZeroXInstanceKeys delegate)

Method Summary

Modifier and Type	Method	Description
static CGNode	findNodeRecursiveMatchingContext(IMethod m, Context c)	This method walks recursively up the definition of a context C, to see if the chain of contexts that give rise to C includes the method M.
static Context	findRecursiveMatchingContext(IMethod M, Context C)	This method walks recursively up the definition of a context C, to see if the chain of contexts that give rise to C includes the method M.
static Context	findRecursiveMatchingContext(IMethod M, Context C, InstanceKey receiver)	This method walks recursively up the definition of a context C, to see if the chain of contexts that give rise to C a) includes the method M.
Context	getCalleeTarget(CGNode caller, CallSiteReference site, IMethod callee, InstanceKey[] keys)	Given a calling node and a call site, returns the Context in which the callee should be evaluated.
protected IClassHierarchy	getClassHierarchy()
IntSet	getRelevantParameters(CGNode caller, CallSiteReference site)	Given a calling node and a call site, return the set of parameters based on which this selector may choose to specialize contexts.
static boolean	isArrayCopyingMethod(MethodReference m)	Does m represent a library method that copies arrays?
protected boolean	isContainer(IClass C)
static boolean	isWellKnownStaticFactory(MethodReference m)	Does m represent a static factory method we know about from the standard libraries, that we usually wish to model with one level of call-string context?
boolean	mayUnderstand(CallSiteReference site, IMethod targetMethod, InstanceKey receiver)

Methods inherited from class Object

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

Field Details

SyntheticSystem

public static final TypeReference SyntheticSystem

JavaUtilHashtable

public static final TypeReference JavaUtilHashtable

arraycopyAtom

public static final Atom arraycopyAtom

synthArraycopy

public static final MethodReference synthArraycopy

Constructor Details

ContainerContextSelector

public ContainerContextSelector(IClassHierarchy cha,
 ZeroXInstanceKeys delegate)

Parameters:

cha - governing class hierarchy

delegate - object which determines which classes are "interesting"

Method Details

getCalleeTarget

public Context getCalleeTarget(CGNode caller,
 CallSiteReference site,
 IMethod callee,
 InstanceKey[] keys)

Description copied from interface: ContextSelector

Given a calling node and a call site, returns the Context in which the callee should be evaluated.

Specified by:

getCalleeTarget in interface ContextSelector

Parameters:

caller - the node containing the call site

site - description of the call site

keys - the abstract objects (InstanceKeys) of parameters of interest to the selector

Returns:

the Context in which the callee should be evaluated, or null if no information is available.

isWellKnownStaticFactory

public static boolean isWellKnownStaticFactory(MethodReference m)

Does m represent a static factory method we know about from the standard libraries, that we usually wish to model with one level of call-string context?

isArrayCopyingMethod

public static boolean isArrayCopyingMethod(MethodReference m)

Does m represent a library method that copies arrays?

findRecursiveMatchingContext

public static Context findRecursiveMatchingContext(IMethod M,
 Context C,
 InstanceKey receiver)

This method walks recursively up the definition of a context C, to see if the chain of contexts that give rise to C a) includes the method M. or b) includes the method in which the receiver was allocated

Returns:

the matching context if found, null otherwise

findNodeRecursiveMatchingContext

public static CGNode findNodeRecursiveMatchingContext(IMethod m,
 Context c)

This method walks recursively up the definition of a context C, to see if the chain of contexts that give rise to C includes the method M.

If C is a ReceiverInstanceContext, Let N be the node that allocated C.instance. If N.method == M, return N. Else return findRecursiveMatchingContext(M, N.context) Else return null

findRecursiveMatchingContext

public static Context findRecursiveMatchingContext(IMethod M,
 Context C)

This method walks recursively up the definition of a context C, to see if the chain of contexts that give rise to C includes the method M.

If C is a ReceiverInstanceContext, Let N be the node that allocated C.instance. If N.method == M, return N.context. Else return findRecursiveMatchingContext(M, N.context) Else return null

mayUnderstand

public boolean mayUnderstand(CallSiteReference site,
 IMethod targetMethod,
 InstanceKey receiver)

isContainer

protected boolean isContainer(IClass C)

Returns:

true iff C is a container class

getClassHierarchy

protected IClassHierarchy getClassHierarchy()

getRelevantParameters

public IntSet getRelevantParameters(CGNode caller,
 CallSiteReference site)

Description copied from interface: ContextSelector

Given a calling node and a call site, return the set of parameters based on which this selector may choose to specialize contexts.

Specified by:

getRelevantParameters in interface ContextSelector

Parameters:

caller - the calling node

site - the specific call site

Returns:

the set of parameters of interest