com.puppycrawl.tools.checkstyle.checks

Class SuppressWarningsHolder

java.lang.Object

com.puppycrawl.tools.checkstyle.api.AutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.AbstractCheck

com.puppycrawl.tools.checkstyle.checks.SuppressWarningsHolder

All Implemented Interfaces:

Configurable, Contextualizable

public class SuppressWarningsHolder
extends AbstractCheck

Maintains a set of check suppressions from @SuppressWarnings annotations. It allows to prevent Checkstyle from reporting violations from parts of code that were annotated with @SuppressWarnings and using name of the check to be excluded. You can also define aliases for check names that need to be suppressed.

• Property aliasList - Specify aliases for check names that can be used in code within SuppressWarnings. Type is java.lang.String[]. Default value is null.

To prevent FooCheck violations from being reported write:

 @SuppressWarnings("foo") interface I { }
 @SuppressWarnings("foo") enum E { }
 @SuppressWarnings("foo") InputSuppressWarningsFilter() { }
 

Some real check examples:

This will prevent from invocation of the MemberNameCheck:

 @SuppressWarnings({"membername"})
 private int J;
 

You can also use a checkstyle prefix to prevent compiler from processing this annotations. For example this will prevent ConstantNameCheck:

 @SuppressWarnings("checkstyle:constantname")
 private static final int m = 0;
 

The general rule is that the argument of the @SuppressWarnings will be matched against class name of the checker in lower case and without Check suffix if present.

If aliasList property was provided you can use your own names e.g below code will work if there was provided a ParameterNumberCheck=paramnum in the aliasList:

 @SuppressWarnings("paramnum")
 public void needsLotsOfParameters(@SuppressWarnings("unused") int a,
   int b, int c, int d, int e, int f, int g, int h) {
   ...
 }
 

It is possible to suppress all the checkstyle warnings with the argument "all":

 @SuppressWarnings("all")
 public void someFunctionWithInvalidStyle() {
   //...
 }
 

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Since:

5.7

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	SuppressWarningsHolder.Entry Records a particular suppression for a region of a file.

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

AutomaticBean.OutputStreamOptions

Field Summary

Fields

Modifier and Type	Field and Description
private static java.lang.String	ALL_WARNING_MATCHING_ID Special warning id for matching all the warnings.
private static java.util.Map<java.lang.String,java.lang.String>	CHECK_ALIAS_MAP A map from check source names to suppression aliases.
private static java.lang.String	CHECK_SUFFIX Suffix to be removed from subclasses of Check.
private static java.lang.String	CHECKSTYLE_PREFIX Optional prefix for warning suppressions that are only intended to be recognized by checkstyle.
private static java.lang.ThreadLocal<java.util.List<SuppressWarningsHolder.Entry>>	ENTRIES A thread-local holder for the list of suppression entries for the last file parsed.
private static java.lang.String	JAVA_LANG_PREFIX Java.lang namespace prefix, which is stripped from SuppressWarnings
private static java.util.regex.Pattern	NEWLINE Compiled pattern used to match preceding newline in text block content.
private static java.util.regex.Pattern	WHITESPACE Compiled pattern used to match whitespace in text block content.

Constructor Summary

Constructors

Constructor and Description
SuppressWarningsHolder()

Method Summary

Modifier and Type	Method and Description
private static void	addSuppressions(java.util.List<java.lang.String> values, DetailAST targetAST) Method to populate list of suppression entries.
void	beginTree(DetailAST rootAST) Called before the starting to process a tree.
void	destroy() Destroy the check.
private static java.util.List<java.lang.String>	findAllExpressionsInChildren(DetailAST parent) Method looks at children and returns list of expressions in strings.
int[]	getAcceptableTokens() The configurable token set.
static java.lang.String	getAlias(java.lang.String sourceName) Returns the alias for the source name of a check.
private static java.util.List<java.lang.String>	getAllAnnotationValues(DetailAST ast) Get all annotation values.
private static java.util.Optional<DetailAST>	getAnnotationTarget(DetailAST ast) Get target of annotation.
private static java.util.List<java.lang.String>	getAnnotationValues(DetailAST ast) Returns the annotation values represented by an AST.
private static java.lang.String	getContentWithoutPrecedingWhitespace(java.lang.String textBlockContent) Remove preceding newline and whitespace from the content of a text block.
static java.lang.String	getDefaultAlias(java.lang.String sourceName) Returns the default alias for the source name of a check, which is the source name in lower case with any dotted prefix or "Check" suffix removed.
int[]	getDefaultTokens() Returns the default token a check is interested in.
private static java.lang.String	getIdentifier(DetailAST ast) Returns the Java identifier represented by an AST.
private static DetailAST	getNthChild(DetailAST ast, int index) Returns the n'th child of an AST node.
int[]	getRequiredTokens() The tokens that this check must be registered for.
private static java.lang.String	getStringExpr(DetailAST ast) Returns the literal string expression represented by an AST.
static boolean	isSuppressed(AuditEvent event) Checks for a suppression of a check with the given source name and location in the last file processed.
private static boolean	isSuppressedAfterEventStart(int line, int column, SuppressWarningsHolder.Entry entry) Checks whether suppression entry position is after the audit event occurrence position in the source file.
private static boolean	isSuppressedBeforeEventEnd(int line, int column, SuppressWarningsHolder.Entry entry) Checks whether suppression entry position is before the audit event occurrence position in the source file.
private static void	registerAlias(java.lang.String sourceName, java.lang.String checkAlias) Registers an alias for the source name of a check.
private static java.lang.String	removeCheckstylePrefixIfExists(java.lang.String checkName) Method removes checkstyle prefix (checkstyle:) from check name if exists.
void	setAliasList(java.lang.String... aliasList) Setter to specify aliases for check names that can be used in code within SuppressWarnings.
void	visitToken(DetailAST ast) Called to process a token.

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

clearViolations, finishTree, getFileContents, getLine, getLineCodePoints, getLines, getTabWidth, getTokenNames, getViolations, init, isCommentNodesRequired, leaveToken, log, log, log, setFileContents, setTabWidth, setTokens

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

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

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

configure, contextualize, getConfiguration, setupChild

Methods inherited from class java.lang.Object

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

Field Detail

CHECKSTYLE_PREFIX

private static final java.lang.String CHECKSTYLE_PREFIX

Optional prefix for warning suppressions that are only intended to be recognized by checkstyle. For instance, to suppress FallThroughCheck only in checkstyle (and not in javac), use the suppression "checkstyle:fallthrough" or "checkstyle:FallThrough". To suppress the warning in both tools, just use "fallthrough".

See Also:

Constant Field Values

JAVA_LANG_PREFIX

private static final java.lang.String JAVA_LANG_PREFIX

Java.lang namespace prefix, which is stripped from SuppressWarnings

See Also:

Constant Field Values

CHECK_SUFFIX

private static final java.lang.String CHECK_SUFFIX

Suffix to be removed from subclasses of Check.

See Also:

Constant Field Values

ALL_WARNING_MATCHING_ID

private static final java.lang.String ALL_WARNING_MATCHING_ID

Special warning id for matching all the warnings.

See Also:

Constant Field Values

CHECK_ALIAS_MAP

private static final java.util.Map<java.lang.String,java.lang.String> CHECK_ALIAS_MAP

A map from check source names to suppression aliases.

ENTRIES

private static final java.lang.ThreadLocal<java.util.List<SuppressWarningsHolder.Entry>> ENTRIES

A thread-local holder for the list of suppression entries for the last file parsed.

WHITESPACE

private static final java.util.regex.Pattern WHITESPACE

Compiled pattern used to match whitespace in text block content.

NEWLINE

private static final java.util.regex.Pattern NEWLINE

Compiled pattern used to match preceding newline in text block content.

Constructor Detail

SuppressWarningsHolder

public SuppressWarningsHolder()

Method Detail

getDefaultAlias

public static java.lang.String getDefaultAlias(java.lang.String sourceName)

Returns the default alias for the source name of a check, which is the source name in lower case with any dotted prefix or "Check" suffix removed.

Parameters:

sourceName - the source name of the check (generally the class name)

Returns:

the default alias for the given check

getAlias

public static java.lang.String getAlias(java.lang.String sourceName)

Returns the alias for the source name of a check. If an alias has been explicitly registered via setAliasList(String...), that alias is returned; otherwise, the default alias is used.

Parameters:

sourceName - the source name of the check (generally the class name)

Returns:

the current alias for the given check

registerAlias

private static void registerAlias(java.lang.String sourceName,
                                  java.lang.String checkAlias)

Registers an alias for the source name of a check.

Parameters:

sourceName - the source name of the check (generally the class name)

checkAlias - the alias used in SuppressWarnings annotations

setAliasList

public void setAliasList(java.lang.String... aliasList)

Setter to specify aliases for check names that can be used in code within SuppressWarnings.

Parameters:

aliasList - the list of comma-separated alias assignments

Throws:

java.lang.IllegalArgumentException - when alias item does not have '='

isSuppressed

public static boolean isSuppressed(AuditEvent event)

Checks for a suppression of a check with the given source name and location in the last file processed.

Parameters:

event - audit event.

Returns:

whether the check with the given name is suppressed at the given source location

isSuppressedAfterEventStart

private static boolean isSuppressedAfterEventStart(int line,
                                                   int column,
                                                   SuppressWarningsHolder.Entry entry)

Checks whether suppression entry position is after the audit event occurrence position in the source file.

Parameters:

line - the line number in the source file where the event occurred.

column - the column number in the source file where the event occurred.

entry - suppression entry.

Returns:

true if suppression entry position is after the audit event occurrence position in the source file.

isSuppressedBeforeEventEnd

private static boolean isSuppressedBeforeEventEnd(int line,
                                                  int column,
                                                  SuppressWarningsHolder.Entry entry)

Checks whether suppression entry position is before the audit event occurrence position in the source file.

Parameters:

line - the line number in the source file where the event occurred.

column - the column number in the source file where the event occurred.

entry - suppression entry.

Returns:

true if suppression entry position is before the audit event occurrence position in the source file.

getDefaultTokens

public int[] getDefaultTokens()

Description copied from class: AbstractCheck

Returns the default token a check is interested in. Only used if the configuration for a check does not define the tokens.

Specified by:

getDefaultTokens in class AbstractCheck

Returns:

the default tokens

See Also:

TokenTypes

getAcceptableTokens

public int[] getAcceptableTokens()

Description copied from class: AbstractCheck

The configurable token set. Used to protect Checks against malicious users who specify an unacceptable token set in the configuration file. The default implementation returns the check's default tokens.

Specified by:

getAcceptableTokens in class AbstractCheck

Returns:

the token set this check is designed for.

See Also:

TokenTypes

getRequiredTokens

public int[] getRequiredTokens()

Description copied from class: AbstractCheck

The tokens that this check must be registered for.

Specified by:

getRequiredTokens in class AbstractCheck

Returns:

the token set this must be registered for.

See Also:

TokenTypes

beginTree

public void beginTree(DetailAST rootAST)

Description copied from class: AbstractCheck

Called before the starting to process a tree. Ideal place to initialize information that is to be collected whilst processing a tree.

Overrides:

beginTree in class AbstractCheck

Parameters:

rootAST - the root of the tree

visitToken

public void visitToken(DetailAST ast)

Description copied from class: AbstractCheck

Called to process a token.

Overrides:

visitToken in class AbstractCheck

Parameters:

ast - the token to process

addSuppressions

private static void addSuppressions(java.util.List<java.lang.String> values,
                                    DetailAST targetAST)

Method to populate list of suppression entries.

Parameters:

values - - list of check names

targetAST - - annotation target

removeCheckstylePrefixIfExists

private static java.lang.String removeCheckstylePrefixIfExists(java.lang.String checkName)

Method removes checkstyle prefix (checkstyle:) from check name if exists.

Parameters:

checkName - - name of the check

Returns:

check name without prefix

getAllAnnotationValues

private static java.util.List<java.lang.String> getAllAnnotationValues(DetailAST ast)

Get all annotation values.

Parameters:

ast - annotation token

Returns:

list values

Throws:

java.lang.IllegalArgumentException - if there is an unknown annotation value type.

getAnnotationTarget

private static java.util.Optional<DetailAST> getAnnotationTarget(DetailAST ast)

Get target of annotation.

Parameters:

ast - the AST node to get the child of

Returns:

get target of annotation

Throws:

java.lang.IllegalArgumentException - if there is an unexpected container type.

getNthChild

private static DetailAST getNthChild(DetailAST ast,
                                     int index)

Returns the n'th child of an AST node.

Parameters:

ast - the AST node to get the child of

index - the index of the child to get

Returns:

the n'th child of the given AST node, or null if none

getIdentifier

private static java.lang.String getIdentifier(DetailAST ast)

Returns the Java identifier represented by an AST.

Parameters:

ast - an AST node for an IDENT or DOT

Returns:

the Java identifier represented by the given AST subtree

Throws:

java.lang.IllegalArgumentException - if the AST is invalid

getStringExpr

private static java.lang.String getStringExpr(DetailAST ast)

Returns the literal string expression represented by an AST.

Parameters:

ast - an AST node for an EXPR

Returns:

the Java string represented by the given AST expression or empty string if expression is too complex

Throws:

java.lang.IllegalArgumentException - if the AST is invalid

getAnnotationValues

private static java.util.List<java.lang.String> getAnnotationValues(DetailAST ast)

Returns the annotation values represented by an AST.

Parameters:

ast - an AST node for an EXPR or ANNOTATION_ARRAY_INIT

Returns:

the list of Java string represented by the given AST for an expression or annotation array initializer

Throws:

java.lang.IllegalArgumentException - if the AST is invalid

findAllExpressionsInChildren

private static java.util.List<java.lang.String> findAllExpressionsInChildren(DetailAST parent)

Method looks at children and returns list of expressions in strings.

Parameters:

parent - ast, that contains children

Returns:

list of expressions in strings

getContentWithoutPrecedingWhitespace

private static java.lang.String getContentWithoutPrecedingWhitespace(java.lang.String textBlockContent)

Remove preceding newline and whitespace from the content of a text block.

Parameters:

textBlockContent - the actual text in a text block.

Returns:

content of text block with preceding whitespace and newline removed.

destroy

public void destroy()

Description copied from class: AbstractCheck

Destroy the check. It is being retired from service.

Overrides:

destroy in class AbstractCheck