Package boomerang.flowfunction

Class DefaultBackwardFlowFunction

java.lang.Object

boomerang.flowfunction.DefaultBackwardFlowFunction

All Implemented Interfaces:

IBackwardFlowFunction

public class DefaultBackwardFlowFunction
extends Object
implements IBackwardFlowFunction

Constructor Summary

Constructors

Constructor	Description
DefaultBackwardFlowFunction(BoomerangOptions opts)

Method Summary

Modifier and Type	Method	Description
Collection<Val>	callFlow(Statement callSite, Val fact, Method callee, Statement calleeSp)	Called by the backward analysis, when the backward solver reaches the callSite.
Collection<wpds.interfaces.State>	callToReturnFlow(ControlFlowGraph.Edge edge, Val fact)	Called by the backward analysis, when data-flow by-passes a call site with data-flow fact.
Collection<wpds.interfaces.State>	normalFlow(ControlFlowGraph.Edge currEdge, Val fact)	Called by the backward analysis, for any non return statements or call site statements.
Collection<Val>	returnFlow(Method callee, Statement returnStmt, Val returnedVal)	Called by the backward analysis, when the backward solver reaches the returnStmt (first statement of callee method) of callee method with data-flow fact returnedVal.
void	setSolver(BackwardBoomerangSolver solver, com.google.common.collect.Multimap<Field,Statement> fieldLoadStatements, com.google.common.collect.Multimap<Field,Statement> fieldStoreStatements)
protected Collection<wpds.interfaces.State>	systemArrayCopyFlow(ControlFlowGraph.Edge edge, Val fact)

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultBackwardFlowFunction

public DefaultBackwardFlowFunction(BoomerangOptions opts)

Method Detail

returnFlow

public Collection<Val> returnFlow(Method callee,
                                  Statement returnStmt,
                                  Val returnedVal)

Description copied from interface: IBackwardFlowFunction

Called by the backward analysis, when the backward solver reaches the returnStmt (first statement of callee method) of callee method with data-flow fact returnedVal.

Specified by:

returnFlow in interface IBackwardFlowFunction

Parameters:

callee - The method the data-flow analysis returns from. The caller method is not available, as it will be internally added by the framework.

returnStmt - The statement from which the method returns from (will be the first statement of the callee method)

returnedVal - The data-flow fact that is returned.

Returns:

A set of data-flow facts (Val) which will be propagated at any call site of the callee method.

callFlow

public Collection<Val> callFlow(Statement callSite,
                                Val fact,
                                Method callee,
                                Statement calleeSp)

Description copied from interface: IBackwardFlowFunction

Called by the backward analysis, when the backward solver reaches the callSite. Will be invoked once per available callee (in the call graph).

Specified by:

callFlow in interface IBackwardFlowFunction

Parameters:

callSite - A call site reached by the backward analysis.

fact - The data-flow fact reaching the callSite

callee - The callee that may be invoked at the callSite

calleeSp - The start point of callee (in the backward analysis, this typically will be return or throw statements)

Returns:

A set of data-flow facts (Val) that will be propagated at the calleeSp

normalFlow

public Collection<wpds.interfaces.State> normalFlow(ControlFlowGraph.Edge currEdge,
                                                    Val fact)

Description copied from interface: IBackwardFlowFunction

Called by the backward analysis, for any non return statements or call site statements. Note: The logic differs from general IFDS logic here. edge.getTarget() can also contain a call site, but fact is not used in the call site (no parameter or base variable of the call expression) .

Specified by:

normalFlow in interface IBackwardFlowFunction

Parameters:

currEdge - The control-flow graph edge that will be propagated next.

fact - The incoming data-flow fact that reaches the edge.

Returns:

A set of data-flow states (states in the pushdown system, typically of type Node).

callToReturnFlow

public Collection<wpds.interfaces.State> callToReturnFlow(ControlFlowGraph.Edge edge,
                                                          Val fact)

Description copied from interface: IBackwardFlowFunction

Called by the backward analysis, when data-flow by-passes a call site with data-flow fact. Here logic can be added to handle native calls, or methods that are excluded from propagation. Note: The logic differs from general IFDS logic here. callToReturn is _only_ invoked when fact is also used in the call site (edge.getTarget()), i.e. fact is a parameter or the base variable of the call expression. As a consequence, special handling for call site may need to be implemented as part of callToReturn and normalFlow.

Specified by:

callToReturnFlow in interface IBackwardFlowFunction

Parameters:

edge - Edge that bypasses the call site. edge.getTarget() is the call site, edge.getStart() is any predecessor

fact - The fact that by-passes the call site.

Returns:

A set of data-flow states (states in the pushdown system, typically of type Node)

setSolver

public void setSolver(BackwardBoomerangSolver solver,
                      com.google.common.collect.Multimap<Field,Statement> fieldLoadStatements,
                      com.google.common.collect.Multimap<Field,Statement> fieldStoreStatements)

Specified by:

setSolver in interface IBackwardFlowFunction

systemArrayCopyFlow

protected Collection<wpds.interfaces.State> systemArrayCopyFlow(ControlFlowGraph.Edge edge,
                                                                Val fact)