polyglot.visit

Class ReachChecker

java.lang.Object

polyglot.visit.NodeVisitor

polyglot.visit.HaltingVisitor

polyglot.visit.ErrorHandlingVisitor

polyglot.visit.DataFlow<ReachChecker.DataFlowItem>

polyglot.visit.ReachChecker

All Implemented Interfaces:

java.lang.Cloneable, Copy<NodeVisitor>

public class ReachChecker
extends DataFlow<ReachChecker.DataFlowItem>

Visitor which checks that all statements must be reachable

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	ReachChecker.DataFlowItem

Nested classes/interfaces inherited from class polyglot.visit.DataFlow

DataFlow.BoolItem<FlowItem extends DataFlow.Item>, DataFlow.ConditionNavigator<FlowItem extends DataFlow.Item>, DataFlow.FlowGraphSource<FlowItem extends DataFlow.Item>, DataFlow.Frame<FlowItem extends DataFlow.Item>, DataFlow.Item

Nested classes/interfaces inherited from interface polyglot.util.Copy

Copy.Util

Field Summary

Fields inherited from class polyglot.visit.DataFlow

dataflowOnEntry, detectBackEdges, flowCounter, flowgraphStack, forward, postordering

Fields inherited from class polyglot.visit.ErrorHandlingVisitor

error, job, nf, ts

Fields inherited from class polyglot.visit.HaltingVisitor

bypass, bypassParent

Constructor Summary

Constructors

Constructor and Description
ReachChecker(Job job, TypeSystem ts, NodeFactory nf)

Method Summary

Methods

Modifier and Type	Method and Description
void	check(FlowGraph<ReachChecker.DataFlowItem> graph, Term n, boolean entry, ReachChecker.DataFlowItem inItem, java.util.Map<FlowGraph.EdgeKey,ReachChecker.DataFlowItem> outItems) Check that the term n satisfies whatever properties this dataflow is checking for.
protected Node	checkReachability(Term n)
ReachChecker.DataFlowItem	confluence(java.util.List<ReachChecker.DataFlowItem> inItems, FlowGraph.Peer<ReachChecker.DataFlowItem> peer, FlowGraph<ReachChecker.DataFlowItem> graph) The confluence operator for many flows.
ReachChecker.DataFlowItem	confluence(java.util.List<ReachChecker.DataFlowItem> inItems, java.util.List<FlowGraph.EdgeKey> itemKeys, FlowGraph.Peer<ReachChecker.DataFlowItem> peer, FlowGraph<ReachChecker.DataFlowItem> graph) The confluence operator for many flows.
protected CFGBuilder<ReachChecker.DataFlowItem>	createCFGBuilder(TypeSystem ts, FlowGraph<ReachChecker.DataFlowItem> g) Construct a CFGBuilder.
ReachChecker.DataFlowItem	createInitialItem(FlowGraph<ReachChecker.DataFlowItem> graph, Term node, boolean entry) Create an initial Item for the term node.
java.util.Map<FlowGraph.EdgeKey,ReachChecker.DataFlowItem>	flow(ReachChecker.DataFlowItem in, FlowGraph<ReachChecker.DataFlowItem> graph, FlowGraph.Peer<ReachChecker.DataFlowItem> peer) Produce new Items as appropriate for the Peer and the input Items.
Node	leaveCall(Node old, Node n, NodeVisitor v) Overridden superclass method, to pop from the stack of FlowGraphs if necessary.
void	post(FlowGraph<ReachChecker.DataFlowItem> graph, Term root) Check all of the Peers in the graph, after the dataflow analysis has been performed.

Methods inherited from class polyglot.visit.DataFlow

check, constructItemsFromCondition, createFrame, createInitialItem, currentFlowGraph, dataflow, dataflow, dataflow, dumpFlowGraph, enterCall, filterItems, filterItemsExceptionSubclass, filterItemsNonError, filterItemsNonException, findSCCs, flow, flow, flow, flow, flowBooleanConditions, flowToBooleanFlow, hasTrueFalseBranches, initGraph, initGraph, itemsToMap, itemToMap, lang, leave, safeConfluence, safeConfluence, safeConfluence

Methods inherited from class polyglot.visit.ErrorHandlingVisitor

begin, catchErrors, enter, enterCall, enterError, errorQueue, hasErrors, job, leaveCall, leaveCall, nodeFactory, typeSystem

Methods inherited from class polyglot.visit.HaltingVisitor

bypass, bypass, bypassChildren, override, visitChildren

Methods inherited from class polyglot.visit.NodeVisitor

copy, enter, finish, finish, leave, override, toString, visitEdge, visitEdgeNoOverride

Methods inherited from class java.lang.Object

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

Constructor Detail

ReachChecker

public ReachChecker(Job job,
            TypeSystem ts,
            NodeFactory nf)

Method Detail

createCFGBuilder

protected CFGBuilder<ReachChecker.DataFlowItem> createCFGBuilder(TypeSystem ts,
                                                     FlowGraph<ReachChecker.DataFlowItem> g)

Description copied from class: DataFlow

Construct a CFGBuilder.

Overrides:

createCFGBuilder in class DataFlow<ReachChecker.DataFlowItem>

Parameters:

ts - The type system

g - The flow graph to that the CFGBuilder will construct.

Returns:

a new CFGBuilder

createInitialItem

public ReachChecker.DataFlowItem createInitialItem(FlowGraph<ReachChecker.DataFlowItem> graph,
                                          Term node,
                                          boolean entry)

Description copied from class: DataFlow

Create an initial Item for the term node. This is generally how the Item that will be given to the start node of a graph is created, although this method may also be called for other (non-start) nodes.

Specified by:

createInitialItem in class DataFlow<ReachChecker.DataFlowItem>

Returns:

a (possibly null) Item.

flow

public java.util.Map<FlowGraph.EdgeKey,ReachChecker.DataFlowItem> flow(ReachChecker.DataFlowItem in,
                                                              FlowGraph<ReachChecker.DataFlowItem> graph,
                                                              FlowGraph.Peer<ReachChecker.DataFlowItem> peer)

Description copied from class: DataFlow

Produce new Items as appropriate for the Peer and the input Items.

Overrides:

flow in class DataFlow<ReachChecker.DataFlowItem>

graph - the FlowGraph which the dataflow is operating on

peer - the Peer which this method must calculate the flow for.

Returns:

a Map from FlowGraph.EdgeKeys to Items. The map must have entries for all EdgeKeys in edgeKeys.

confluence

public ReachChecker.DataFlowItem confluence(java.util.List<ReachChecker.DataFlowItem> inItems,
                                   FlowGraph.Peer<ReachChecker.DataFlowItem> peer,
                                   FlowGraph<ReachChecker.DataFlowItem> graph)

Description copied from class: DataFlow

The confluence operator for many flows. This method produces a single Item from a List of Items, for the confluence just before flow enters node.

Specified by:

confluence in class DataFlow<ReachChecker.DataFlowItem>

Parameters:

inItems - List of Items that flow into node. this method will only be called if the list has at least 2 elements.

peer - Peer for which the items are flowing into.

Returns:

a non-null Item.

confluence

public ReachChecker.DataFlowItem confluence(java.util.List<ReachChecker.DataFlowItem> inItems,
                                   java.util.List<FlowGraph.EdgeKey> itemKeys,
                                   FlowGraph.Peer<ReachChecker.DataFlowItem> peer,
                                   FlowGraph<ReachChecker.DataFlowItem> graph)

Description copied from class: DataFlow

The confluence operator for many flows. This method produces a single Item from a List of Items, for the confluence just before flow enters node.

Overrides:

confluence in class DataFlow<ReachChecker.DataFlowItem>

Parameters:

inItems - List of Items that flow into node. This method will only be called if the list has at least 2 elements.

itemKeys - List of FlowGraph.ExceptionEdgeKeys for the edges that the corresponding Items in items flowed from.

peer - Peer for which the items are flowing into.

Returns:

a non-null Item.

leaveCall

public Node leaveCall(Node old,
             Node n,
             NodeVisitor v)
               throws SemanticException

Description copied from class: DataFlow

Overridden superclass method, to pop from the stack of FlowGraphs if necessary.

Overrides:

leaveCall in class DataFlow<ReachChecker.DataFlowItem>

Throws:

SemanticException

checkReachability

protected Node checkReachability(Term n)
                          throws SemanticException

Throws:

SemanticException

post

public void post(FlowGraph<ReachChecker.DataFlowItem> graph,
        Term root)
          throws SemanticException

Description copied from class: DataFlow

Check all of the Peers in the graph, after the dataflow analysis has been performed.

Overrides:

post in class DataFlow<ReachChecker.DataFlowItem>

Throws:

SemanticException

check

public void check(FlowGraph<ReachChecker.DataFlowItem> graph,
         Term n,
         boolean entry,
         ReachChecker.DataFlowItem inItem,
         java.util.Map<FlowGraph.EdgeKey,ReachChecker.DataFlowItem> outItems)
           throws SemanticException

Description copied from class: DataFlow

Check that the term n satisfies whatever properties this dataflow is checking for. Provided the method check(FlowGraph, Peer) is not overridden, this method is called for each term in a code declaration block after the dataflow for that block of code has been performed.

Specified by:

check in class DataFlow<ReachChecker.DataFlowItem>

Throws:

SemanticException - if the properties this dataflow analysis is checking for is not satisfied.