Package soot.jimple.toolkits.pointer

Class LocalMayAliasAnalysis

java.lang.Object

soot.toolkits.scalar.AbstractFlowAnalysis<N,A>

soot.toolkits.scalar.FlowAnalysis<N,A>

soot.toolkits.scalar.ForwardFlowAnalysis<Unit,Set<Set<Value>>>

soot.jimple.toolkits.pointer.LocalMayAliasAnalysis

public class LocalMayAliasAnalysis
extends ForwardFlowAnalysis<Unit,Set<Set<Value>>>

Conducts a method-local, equality-based may-alias analysis.

Author:

Eric Bodden

Nested Class Summary

Nested classes/interfaces inherited from class soot.toolkits.scalar.FlowAnalysis

FlowAnalysis.Flow

Field Summary

Fields inherited from class soot.toolkits.scalar.FlowAnalysis

filterUnitToAfterFlow, unitToAfterFlow

Fields inherited from class soot.toolkits.scalar.AbstractFlowAnalysis

filterUnitToBeforeFlow, graph, unitToBeforeFlow

Constructor Summary

Constructors

Constructor	Description
LocalMayAliasAnalysis(UnitGraph graph)

Method Summary

Modifier and Type	Method	Description
protected void	copy(Set<Set<Value>> source, Set<Set<Value>> target)	Creates a copy of the source flow object in dest.
protected Set<Set<Value>>	entryInitialFlow()	Returns the initial flow value for entry/exit graph nodes.
protected void	flowThrough(Set<Set<Value>> source, Unit unit, Set<Set<Value>> target)	Given the merge of the out sets, compute the in set for s (or in to out, depending on direction).
boolean	mayAlias(Value v1, Value v2, Unit u)	Returns true if v1 and v2 may alias before u.
Set<Value>	mayAliases(Value v, Unit u)	Returns all values that may-alias with v before u.
Set<Value>	mayAliasesAtExit(Value v)	Returns all values that may-alias with v at the end of the procedure.
protected void	merge(Set<Set<Value>> source1, Set<Set<Value>> source2, Set<Set<Value>> target)	Compute the merge of the in1 and in2 sets, putting the result into out.
protected Set<Set<Value>>	newInitialFlow()	Returns the flow object corresponding to the initial values for each graph node.

Methods inherited from class soot.toolkits.scalar.ForwardFlowAnalysis

doAnalysis, isForward

Methods inherited from class soot.toolkits.scalar.FlowAnalysis

copyFreshToExisting, getFlow, getFlowAfter, getFlowBefore, omissible

Methods inherited from class soot.toolkits.scalar.AbstractFlowAnalysis

merge, mergeInto, treatTrapHandlersAsEntries

Methods inherited from class java.lang.Object

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

Constructor Detail

LocalMayAliasAnalysis

public LocalMayAliasAnalysis(UnitGraph graph)

Method Detail

flowThrough

protected void flowThrough(Set<Set<Value>> source,
                           Unit unit,
                           Set<Set<Value>> target)

Description copied from class: FlowAnalysis

Given the merge of the out sets, compute the in set for s (or in to out, depending on direction). This function often causes confusion, because the same interface is used for both forward and backward flow analyses. The first parameter is always the argument to the flow function (i.e. it is the "in" set in a forward analysis and the "out" set in a backward analysis), and the third parameter is always the result of the flow function (i.e. it is the "out" set in a forward analysis and the "in" set in a backward analysis).

Specified by:

flowThrough in class FlowAnalysis<Unit,Set<Set<Value>>>

Parameters:

source - the input flow

unit - the current node

target - the returned flow

copy

protected void copy(Set<Set<Value>> source,
                    Set<Set<Value>> target)

Description copied from class: AbstractFlowAnalysis

Creates a copy of the source flow object in dest.

Specified by:

copy in class AbstractFlowAnalysis<Unit,Set<Set<Value>>>

entryInitialFlow

protected Set<Set<Value>> entryInitialFlow()

Description copied from class: AbstractFlowAnalysis

Returns the initial flow value for entry/exit graph nodes. This is equal to AbstractFlowAnalysis.newInitialFlow()

Overrides:

entryInitialFlow in class AbstractFlowAnalysis<Unit,Set<Set<Value>>>

merge

protected void merge(Set<Set<Value>> source1,
                     Set<Set<Value>> source2,
                     Set<Set<Value>> target)

Description copied from class: AbstractFlowAnalysis

Compute the merge of the in1 and in2 sets, putting the result into out. The behavior of this function depends on the implementation ( it may be necessary to check whether in1 and in2 are equal or aliased ). Used by the doAnalysis method.

Specified by:

merge in class AbstractFlowAnalysis<Unit,Set<Set<Value>>>

newInitialFlow

protected Set<Set<Value>> newInitialFlow()

Description copied from class: AbstractFlowAnalysis

Returns the flow object corresponding to the initial values for each graph node.

Specified by:

newInitialFlow in class AbstractFlowAnalysis<Unit,Set<Set<Value>>>

mayAlias

public boolean mayAlias(Value v1,
                        Value v2,
                        Unit u)

Returns true if v1 and v2 may alias before u.

mayAliases

public Set<Value> mayAliases(Value v,
                             Unit u)

Returns all values that may-alias with v before u.

mayAliasesAtExit

public Set<Value> mayAliasesAtExit(Value v)

Returns all values that may-alias with v at the end of the procedure.