Package org.checkerframework.dataflow.analysis

Class AbstractAnalysis<V extends AbstractValue<V>,S extends Store<S>,T extends TransferFunction<V,S>>

java.lang.Object

org.checkerframework.dataflow.analysis.AbstractAnalysis<V,S,T>

Type Parameters:

V - the abstract value type to be tracked by the analysis

S - the store type used in the analysis

T - the transfer function type that is used to approximate run-time behavior

All Implemented Interfaces:

Analysis<V,S,T>

Direct Known Subclasses:

BackwardAnalysisImpl, ForwardAnalysisImpl

public abstract class AbstractAnalysis<V extends AbstractValue<V>,S extends Store<S>,T extends TransferFunction<V,S>>
extends Object
implements Analysis<V,S,T>

Implementation of common features for BackwardAnalysisImpl and ForwardAnalysisImpl.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	AbstractAnalysis.Worklist	A worklist is a priority queue of blocks in which the order is given by depth-first ordering to place non-loop predecessors ahead of successors.

Nested classes/interfaces inherited from interface org.checkerframework.dataflow.analysis.Analysis

Analysis.BeforeOrAfter, Analysis.Direction

Field Summary

Fields

Modifier and Type	Field	Description
protected @MonotonicNonNull ControlFlowGraph	cfg	The current control flow graph to perform the analysis on.
protected @Nullable TransferInput<V,S>	currentInput	The current transfer input when the analysis is running.
protected @InternedDistinct @Nullable Node	currentNode	The node that is currently handled in the analysis (if it is running).
protected @InternedDistinct @Nullable Tree	currentTree	The tree that is currently being looked at.
protected final Analysis.Direction	direction	The direction of this analysis.
protected final HashMap<VariableElement,V>	finalLocalValues	Map from (effectively final) local variable elements to their abstract value.
protected final IdentityHashMap<Block,TransferInput<V,S>>	inputs	The transfer inputs of every basic block; assumed to be 'no information' if not present.
protected boolean	isRunning	Is the analysis currently running?
protected final IdentityHashMap<Node,V>	nodeValues	Abstract values of nodes.
protected @MonotonicNonNull T	transferFunction	The transfer function for regular nodes.
protected final AbstractAnalysis.Worklist	worklist	The worklist used for the fix-point iteration.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractAnalysis(Analysis.Direction direction)	Implementation of common features for BackwardAnalysisImpl and ForwardAnalysisImpl.

Method Summary

Modifier and Type	Method	Description
protected void	addToWorklist(Block b)	Add a basic block to worklist.
protected TransferResult<V,S>	callTransferFunction(Node node, TransferInput<V,S> transferInput)	Call the transfer function for node node, and set that node as current node first.
@Nullable ClassTree	getContainingClass(Tree t)	Deprecated. use getEnclosingClass(com.sun.source.tree.Tree)
@Nullable MethodTree	getContainingMethod(Tree t)	Deprecated. use getEnclosingMethod(com.sun.source.tree.Tree)
@Nullable Tree	getCurrentTree()	Returns the tree that is currently being looked at.
Analysis.Direction	getDirection()	Get the direction of this analysis.
@Nullable ClassTree	getEnclosingClass(Tree t)	Get the ClassTree of the current CFG if the argument Tree maps to a Node in the CFG or null otherwise.
@Nullable MethodTree	getEnclosingMethod(Tree t)	Get the MethodTree of the current CFG if the argument Tree maps to a Node in the CFG or null otherwise.
@Nullable S	getExceptionalExitStore()	Returns the exceptional exit store.
@Nullable Set<Node>	getNodesForTree(Tree t)	Get the set of Nodes for a given Tree.
IdentityHashMap<Node,V>	getNodeValues()	Returns all current node values.
@Nullable S	getRegularExitStore()	Returns the regular exit store, or null, if there is no such store (because the method cannot exit through the regular exit block).
AnalysisResult<V,S>	getResult()	The result of running the analysis.
@Nullable T	getTransferFunction()	Get the transfer function of this analysis.
@Nullable V	getValue(Tree t)	Return the abstract value for Tree t, or null if no information is available.
@Nullable V	getValue(Node n)	Returns the abstract value for Node n, or null if no information is available.
protected final void	init(ControlFlowGraph cfg)	Initialize the analysis with a new control flow graph.
protected void	initFields(ControlFlowGraph cfg)	Initialize fields of this object based on a given control flow graph.
protected abstract void	initInitialInputs()	Initialize the transfer inputs of every basic block before performing the analysis.
protected boolean	isIgnoredExceptionType(TypeMirror exceptionType)	Should exceptional control flow for a particular exception type be ignored?
boolean	isRunning()	Is the analysis currently running?
protected abstract void	propagateStoresTo(Block nextBlock, Node node, TransferInput<V,S> currentInput, Store.FlowRule flowRule, boolean addToWorklistAgain)	Propagate the stores in currentInput to the next block in the direction of analysis, according to the flowRule.
protected void	setCurrentNode(@Nullable Node currentNode)	Set the node that is currently being looked at.
void	setCurrentTree(Tree currentTree)	Set the tree that is currently being looked at.
protected boolean	updateNodeValues(Node node, TransferResult<V,S> transferResult)	Updates the value of node node in nodeValues to the value of the transferResult.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.checkerframework.dataflow.analysis.Analysis

getInput, performAnalysis, performAnalysisBlock, runAnalysisFor

Field Details

direction

protected final Analysis.Direction direction

The direction of this analysis.

isRunning

protected boolean isRunning

Is the analysis currently running?

transferFunction

protected @MonotonicNonNull T extends TransferFunction<V,S> transferFunction

The transfer function for regular nodes.

cfg

protected @MonotonicNonNull ControlFlowGraph cfg

The current control flow graph to perform the analysis on.

inputs

protected final IdentityHashMap<Block,TransferInput<V extends AbstractValue<V>,S extends Store<S>>> inputs

The transfer inputs of every basic block; assumed to be 'no information' if not present. The inputs are before blocks in forward analysis, and are after blocks in backward analysis.

worklist

protected final AbstractAnalysis.Worklist worklist

The worklist used for the fix-point iteration.

nodeValues

protected final IdentityHashMap<Node,V extends AbstractValue<V>> nodeValues

Abstract values of nodes.

finalLocalValues

protected final HashMap<VariableElement,V extends AbstractValue<V>> finalLocalValues

Map from (effectively final) local variable elements to their abstract value.

currentNode

protected @InternedDistinct @Nullable Node currentNode

The node that is currently handled in the analysis (if it is running). The following invariant holds:

   !isRunning ⇒ (currentNode == null)
 

currentTree

protected @InternedDistinct @Nullable Tree currentTree

The tree that is currently being looked at. The transfer function can set this tree to make sure that calls to getValue will not return information for this given tree.

currentInput

protected @Nullable TransferInput<V extends AbstractValue<V>,S extends Store<S>> currentInput

The current transfer input when the analysis is running.

Constructor Details

AbstractAnalysis

protected AbstractAnalysis(Analysis.Direction direction)

Implementation of common features for BackwardAnalysisImpl and ForwardAnalysisImpl.

Parameters:

direction - direction of the analysis

Method Details

getCurrentTree

public @Nullable Tree getCurrentTree()

Returns the tree that is currently being looked at. The transfer function can set this tree to make sure that calls to getValue will not return information for this given tree.

Returns:

the tree that is currently being looked at

setCurrentTree

public void setCurrentTree(@FindDistinct
 Tree currentTree)

Set the tree that is currently being looked at.

Parameters:

currentTree - the tree that should be currently looked at

setCurrentNode

protected void setCurrentNode(@FindDistinct
 @Nullable Node currentNode)

Set the node that is currently being looked at.

Parameters:

currentNode - the node that should be currently looked at

initInitialInputs

@RequiresNonNull("cfg")
protected abstract void initInitialInputs()

Initialize the transfer inputs of every basic block before performing the analysis.

propagateStoresTo

protected abstract void propagateStoresTo(Block nextBlock,
 Node node,
 TransferInput<V,S> currentInput,
 Store.FlowRule flowRule,
 boolean addToWorklistAgain)

Propagate the stores in currentInput to the next block in the direction of analysis, according to the flowRule.

Parameters:

nextBlock - the target block to propagate the stores to

node - the node of the target block

currentInput - the current transfer input

flowRule - the flow rule being used

addToWorklistAgain - whether the block should be added to worklist again

isRunning

public boolean isRunning()

Description copied from interface: Analysis

Is the analysis currently running?

Specified by:

isRunning in interface Analysis<V extends AbstractValue<V>,S extends Store<S>,T extends TransferFunction<V,S>>

Returns:

true if the analysis is running currently, else false

getDirection

public Analysis.Direction getDirection()

Description copied from interface: Analysis

Get the direction of this analysis.

Specified by:

getDirection in interface Analysis<V extends AbstractValue<V>,S extends Store<S>,T extends TransferFunction<V,S>>

Returns:

the direction of this analysis

getResult

@RequiresNonNull("cfg")
public AnalysisResult<V,S> getResult()

Description copied from interface: Analysis

The result of running the analysis. This is only available once the analysis finished running.

Specified by:

getResult in interface Analysis<V extends AbstractValue<V>,S extends Store<S>,T extends TransferFunction<V,S>>

Returns:

the result of running the analysis

getTransferFunction

public @Nullable T getTransferFunction()

Description copied from interface: Analysis

Get the transfer function of this analysis.

Specified by:

getTransferFunction in interface Analysis<V extends AbstractValue<V>,S extends Store<S>,T extends TransferFunction<V,S>>

Returns:

the transfer function of this analysis

getValue

public @Nullable V getValue(Node n)

Description copied from interface: Analysis

Returns the abstract value for Node n, or null if no information is available. Note that if the analysis has not finished yet, this value might not represent the final value for this node.

Specified by:

getValue in interface Analysis<V extends AbstractValue<V>,S extends Store<S>,T extends TransferFunction<V,S>>

Parameters:

n - n a node

Returns:

the abstract value for node n, or null if no information is available

getNodeValues

public IdentityHashMap<Node,V> getNodeValues()

Returns all current node values.

Returns:

nodeValues

getRegularExitStore

@RequiresNonNull("cfg")
public @Nullable S getRegularExitStore()

Description copied from interface: Analysis

Returns the regular exit store, or null, if there is no such store (because the method cannot exit through the regular exit block).

Specified by:

getRegularExitStore in interface Analysis<V extends AbstractValue<V>,S extends Store<S>,T extends TransferFunction<V,S>>

Returns:

the regular exit store, or null, if there is no such store (because the method cannot exit through the regular exit block)

getExceptionalExitStore

@RequiresNonNull("cfg")
public @Nullable S getExceptionalExitStore()

Description copied from interface: Analysis

Returns the exceptional exit store.

Specified by:

getExceptionalExitStore in interface Analysis<V extends AbstractValue<V>,S extends Store<S>,T extends TransferFunction<V,S>>

Returns:

the exceptional exit store

getNodesForTree

public @Nullable Set<Node> getNodesForTree(Tree t)

Get the set of Nodes for a given Tree. Returns null for trees that don't produce a value.

Parameters:

t - the given tree

Returns:

the set of corresponding nodes to the given tree

getValue

public @Nullable V getValue(Tree t)

Description copied from interface: Analysis

Return the abstract value for Tree t, or null if no information is available. Note that if the analysis has not finished yet, this value might not represent the final value for this node.

Specified by:

getValue in interface Analysis<V extends AbstractValue<V>,S extends Store<S>,T extends TransferFunction<V,S>>

Parameters:

t - the given tree

Returns:

the abstract value for the given tree

getContainingMethod

@Deprecated
public @Nullable MethodTree getContainingMethod(Tree t)

Deprecated.

use getEnclosingMethod(com.sun.source.tree.Tree)

Get the MethodTree of the current CFG if the argument Tree maps to a Node in the CFG or null otherwise.

Parameters:

t - the given tree

Returns:

the contained method tree of the given tree

getEnclosingMethod

public @Nullable MethodTree getEnclosingMethod(Tree t)

Get the MethodTree of the current CFG if the argument Tree maps to a Node in the CFG or null otherwise.

Parameters:

t - the given tree

Returns:

the contained method tree of the given tree

getContainingClass

@Deprecated
public @Nullable ClassTree getContainingClass(Tree t)

Deprecated.

use getEnclosingClass(com.sun.source.tree.Tree)

Get the ClassTree of the current CFG if the argument Tree maps to a Node in the CFG or null otherwise.

Parameters:

t - the given tree

Returns:

the contained class tree of the given tree

getEnclosingClass

public @Nullable ClassTree getEnclosingClass(Tree t)

Get the ClassTree of the current CFG if the argument Tree maps to a Node in the CFG or null otherwise.

Parameters:

t - the given tree

Returns:

the contained class tree of the given tree

callTransferFunction

protected TransferResult<V,S> callTransferFunction(Node node,
 TransferInput<V,S> transferInput)

Call the transfer function for node node, and set that node as current node first. This method requires a transferInput that the method can modify.

Parameters:

node - the given node

transferInput - the transfer input

Returns:

the output of the transfer function

init

protected final void init(ControlFlowGraph cfg)

Initialize the analysis with a new control flow graph.

Parameters:

cfg - the control flow graph to use

isIgnoredExceptionType

protected boolean isIgnoredExceptionType(TypeMirror exceptionType)

Should exceptional control flow for a particular exception type be ignored?

The default implementation always returns false. Subclasses should override the method to implement a different policy.

Parameters:

exceptionType - the exception type

Returns:

true if exceptional control flow due to exceptionType should be ignored, false otherwise

initFields

@EnsuresNonNull("this.cfg")
protected void initFields(ControlFlowGraph cfg)

Initialize fields of this object based on a given control flow graph. Sub-class may override this method to initialize customized fields.

Parameters:

cfg - a given control flow graph

updateNodeValues

protected boolean updateNodeValues(Node node,
 TransferResult<V,S> transferResult)

Updates the value of node node in nodeValues to the value of the transferResult. Returns true if the node's value changed, or a store was updated.

Parameters:

node - the node to update

transferResult - the transfer result being updated

Returns:

true if the node's value changed, or a store was updated

addToWorklist

protected void addToWorklist(Block b)

Add a basic block to worklist. If b is already present, the method does nothing.

Parameters:

b - the block to add to worklist