Package com.puppycrawl.tools.checkstyle

Class TreeWalker

java.lang.Object

com.puppycrawl.tools.checkstyle.AbstractAutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck

com.puppycrawl.tools.checkstyle.TreeWalker

All Implemented Interfaces:

Configurable, Contextualizable, ExternalResourceHolder, FileSetCheck

public final class TreeWalker
extends AbstractFileSetCheck
implements ExternalResourceHolder

Responsible for walking an abstract syntax tree and notifying interested checks at each node.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static enum	TreeWalker.AstState	State of AST.

Nested classes/interfaces inherited from class com.puppycrawl.tools.checkstyle.AbstractAutomaticBean

AbstractAutomaticBean.OutputStreamOptions

Field Summary

Fields

Modifier and Type	Field	Description
private Context	childContext	Context of child components.
private final Set<AbstractCheck>	commentChecks	Registered comment checks.
private final Set<TreeWalkerFilter>	filters	The ast filters.
private SeverityLevel	javaParseExceptionSeverity	Specify severity Level to log Java parsing exceptions when they are skipped.
private ModuleFactory	moduleFactory	A factory for creating submodules (i.e. the Checks)
private final Set<AbstractCheck>	ordinaryChecks	Registered ordinary checks, that don't use comment nodes.
static final String	PARSE_EXCEPTION_MSG	Message to use when an exception occurs and should be printed as a violation.
private boolean	skipFileOnJavaParseException	Control whether to skip files with Java parsing exceptions.
private final Map<Integer,Set<AbstractCheck>>	tokenToCommentChecks	Maps from token name to comment checks.
private final Map<Integer,Set<AbstractCheck>>	tokenToOrdinaryChecks	Maps from token name to ordinary checks.
private final SortedSet<Violation>	violations	The sorted set of violations.

Constructor Summary

Constructors

Constructor	Description
TreeWalker()	Creates a new TreeWalker instance.

Method Summary

Modifier and Type	Method	Description
private static SortedSet<AbstractCheck>	createNewCheckSortedSet()	Creates a new SortedSet with a deterministic order based on the Check's name before the default ordering.
void	destroy()	Cleans up the object.
void	finishLocalSetup()	Provides a hook to finish the part of this component's setup that was not handled by the bean introspection.
Set<String>	getExternalResourceLocations()	Returns a set of external configuration resource locations which are used by the module.
private SortedSet<Violation>	getFilteredViolations(String fileName, FileContents fileContents, DetailAST rootAST)	Returns filtered set of Violation.
private Collection<AbstractCheck>	getListOfChecks(DetailAST ast, TreeWalker.AstState astState)	Method returns list of checks.
private void	notifyBegin(DetailAST rootAST, FileContents contents, TreeWalker.AstState astState)	Notify checks that we are about to begin walking a tree.
private void	notifyEnd(DetailAST rootAST, TreeWalker.AstState astState)	Notify checks that we have finished walking a tree.
private void	notifyLeave(DetailAST ast, TreeWalker.AstState astState)	Notify checks that leaving a node.
private void	notifyVisit(DetailAST ast, TreeWalker.AstState astState)	Notify checks that visiting a node.
protected void	processFiltered(File file, FileText fileText)	Called to process a file that matches the specified file extensions.
private void	processIter(DetailAST root, TreeWalker.AstState astState)	Processes a node calling interested checks at each node.
private void	registerCheck(int tokenId, AbstractCheck check)	Register a check for a specified token id.
private void	registerCheck(AbstractCheck check)	Register a check for a given configuration.
void	setJavaParseExceptionSeverity(SeverityLevel javaParseExceptionSeverity)	Setter to specify the severity level to log Java parsing exceptions when they are skipped.
void	setModuleFactory(ModuleFactory moduleFactory)	Sets the module factory for creating child modules (Checks).
void	setSkipFileOnJavaParseException(boolean skipFileOnJavaParseException)	Setter to control whether to skip files with Java parsing exceptions.
void	setupChild(Configuration childConf)	Called by configure() for every child of this component's Configuration.
private void	walk(DetailAST ast, FileContents contents, TreeWalker.AstState astState)	Initiates the walk of an AST.

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck

addViolations, beginProcessing, finishProcessing, fireErrors, getFileContents, getFileExtensions, getMessageDispatcher, getTabWidth, getViolations, init, log, log, process, setFileContents, setFileExtensions, setMessageDispatcher, setTabWidth

Methods inherited from class com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

getCustomMessages, getId, getMessageBundle, getSeverity, getSeverityLevel, setId, setSeverity

Methods inherited from class com.puppycrawl.tools.checkstyle.AbstractAutomaticBean

configure, contextualize, getConfiguration

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.puppycrawl.tools.checkstyle.api.Configurable

configure

Methods inherited from interface com.puppycrawl.tools.checkstyle.api.Contextualizable

contextualize

Field Details

PARSE_EXCEPTION_MSG

public static final String PARSE_EXCEPTION_MSG

Message to use when an exception occurs and should be printed as a violation.

See Also:

• Constant Field Values

tokenToOrdinaryChecks

private final Map<Integer,Set<AbstractCheck>> tokenToOrdinaryChecks

Maps from token name to ordinary checks.

tokenToCommentChecks

private final Map<Integer,Set<AbstractCheck>> tokenToCommentChecks

Maps from token name to comment checks.

ordinaryChecks

private final Set<AbstractCheck> ordinaryChecks

Registered ordinary checks, that don't use comment nodes.

commentChecks

private final Set<AbstractCheck> commentChecks

Registered comment checks.

filters

private final Set<TreeWalkerFilter> filters

The ast filters.

violations

private final SortedSet<Violation> violations

The sorted set of violations.

childContext

private Context childContext

Context of child components.

moduleFactory

private ModuleFactory moduleFactory

A factory for creating submodules (i.e. the Checks)

skipFileOnJavaParseException

private boolean skipFileOnJavaParseException

Control whether to skip files with Java parsing exceptions.

javaParseExceptionSeverity

private SeverityLevel javaParseExceptionSeverity

Specify severity Level to log Java parsing exceptions when they are skipped.

Constructor Details

TreeWalker

public TreeWalker()

Creates a new TreeWalker instance.

Method Details

setModuleFactory

public void setModuleFactory(ModuleFactory moduleFactory)

Sets the module factory for creating child modules (Checks).

Parameters:

moduleFactory - the factory

setSkipFileOnJavaParseException

public void setSkipFileOnJavaParseException(boolean skipFileOnJavaParseException)

Setter to control whether to skip files with Java parsing exceptions.

Parameters:

skipFileOnJavaParseException - whether to skip files with Java parsing errors.

Since:

10.18.0

setJavaParseExceptionSeverity

public void setJavaParseExceptionSeverity(SeverityLevel javaParseExceptionSeverity)

Setter to specify the severity level to log Java parsing exceptions when they are skipped.

Parameters:

javaParseExceptionSeverity - severity level to log parsing exceptions when they are skipped.

Since:

10.18.0

finishLocalSetup

public void finishLocalSetup()

Description copied from class: AbstractAutomaticBean

Provides a hook to finish the part of this component's setup that was not handled by the bean introspection.

The default implementation does nothing.

Overrides:

finishLocalSetup in class AbstractViolationReporter

setupChild

public void setupChild(Configuration childConf)
                throws CheckstyleException

Called by configure() for every child of this component's Configuration.

The default implementation throws CheckstyleException if childConf is null because it doesn't support children. It must be overridden to validate and support children that are wanted.

Creates child module.

Overrides:

setupChild in class AbstractAutomaticBean

Parameters:

childConf - a child of this component's Configuration

Throws:

CheckstyleException - if there is a configuration error.

See Also:

• Configuration.getChildren()

processFiltered

protected void processFiltered(File file,
 FileText fileText)
                        throws CheckstyleException

Called to process a file that matches the specified file extensions. Processes the file.

Specified by:

processFiltered in class AbstractFileSetCheck

Parameters:

file - the file to be processed

fileText - the contents of the file.

Throws:

CheckstyleException - if error condition within Checkstyle occurs.

getFilteredViolations

private SortedSet<Violation> getFilteredViolations(String fileName,
 FileContents fileContents,
 DetailAST rootAST)

Returns filtered set of Violation.

Parameters:

fileName - path to the file

fileContents - the contents of the file

rootAST - root AST element DetailAST of the file

Returns:

filtered set of violations

registerCheck

private void registerCheck(AbstractCheck check)
                    throws CheckstyleException

Register a check for a given configuration.

Parameters:

check - the check to register

Throws:

CheckstyleException - if an error occurs

registerCheck

private void registerCheck(int tokenId,
 AbstractCheck check)
                    throws CheckstyleException

Register a check for a specified token id.

Parameters:

tokenId - the id of the token

check - the check to register

Throws:

CheckstyleException - if Check is misconfigured

walk

private void walk(DetailAST ast,
 FileContents contents,
 TreeWalker.AstState astState)

Initiates the walk of an AST.

Parameters:

ast - the root AST

contents - the contents of the file the AST was generated from.

astState - state of AST.

notifyBegin

private void notifyBegin(DetailAST rootAST,
 FileContents contents,
 TreeWalker.AstState astState)

Notify checks that we are about to begin walking a tree.

Parameters:

rootAST - the root of the tree.

contents - the contents of the file the AST was generated from.

astState - state of AST.

notifyEnd

private void notifyEnd(DetailAST rootAST,
 TreeWalker.AstState astState)

Notify checks that we have finished walking a tree.

Parameters:

rootAST - the root of the tree.

astState - state of AST.

notifyVisit

private void notifyVisit(DetailAST ast,
 TreeWalker.AstState astState)

Notify checks that visiting a node.

Parameters:

ast - the node to notify for.

astState - state of AST.

notifyLeave

private void notifyLeave(DetailAST ast,
 TreeWalker.AstState astState)

Notify checks that leaving a node.

Parameters:

ast - the node to notify for

astState - state of AST.

getListOfChecks

private Collection<AbstractCheck> getListOfChecks(DetailAST ast,
 TreeWalker.AstState astState)

Method returns list of checks.

Parameters:

ast - the node to notify for

astState - state of AST.

Returns:

list of visitors

destroy

public void destroy()

Description copied from interface: FileSetCheck

Cleans up the object.

Specified by:

destroy in interface FileSetCheck

Overrides:

destroy in class AbstractFileSetCheck

getExternalResourceLocations

public Set<String> getExternalResourceLocations()

Description copied from interface: ExternalResourceHolder

Returns a set of external configuration resource locations which are used by the module. ATTENTION! If 'getExternalResourceLocations()' return null, there will be NullPointerException in Checker. Such behaviour will signal that your module (check or filter) is designed incorrectly. It makes sense to return an empty set from 'getExternalResourceLocations()' only for composite modules like TreeWalker.

Specified by:

getExternalResourceLocations in interface ExternalResourceHolder

Returns:

a set of external configuration resource locations which are used by the module.

processIter

private void processIter(DetailAST root,
 TreeWalker.AstState astState)

Processes a node calling interested checks at each node. Uses iterative algorithm.

Parameters:

root - the root of tree for process

astState - state of AST.

createNewCheckSortedSet

private static SortedSet<AbstractCheck> createNewCheckSortedSet()

Creates a new SortedSet with a deterministic order based on the Check's name before the default ordering.

Returns:

The new SortedSet.