Package com.puppycrawl.tools.checkstyle.checks

Class AvoidEscapedUnicodeCharactersCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.AbstractAutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.AbstractCheck

com.puppycrawl.tools.checkstyle.checks.AvoidEscapedUnicodeCharactersCheck

All Implemented Interfaces:

Configurable, Contextualizable

public class AvoidEscapedUnicodeCharactersCheck
extends AbstractCheck

Restricts using Unicode escapes (such as \u221e). It is possible to allow using escapes for non-printable, control characters. Also, this check can be configured to allow using escapes if trail comment is present. By the option it is possible to allow using escapes if literal contains only them.

• Property allowByTailComment - Allow use escapes if trail comment is present. Type is boolean. Default value is false.
• Property allowEscapesForControlCharacters - Allow use escapes for non-printable, control characters. Type is boolean. Default value is false.
• Property allowIfAllCharactersEscaped - Allow if all characters in literal are escaped. Type is boolean. Default value is false.
• Property allowNonPrintableEscapes - Allow use escapes for non-printable, whitespace characters. Type is boolean. Default value is false.

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:

• forbid.escaped.unicode.char

Since:

5.8

Nested Class Summary

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

AbstractAutomaticBean.OutputStreamOptions

Field Summary

Fields

Modifier and Type	Field	Description
private static final Pattern	ALL_ESCAPED_CHARS	Regular expression for all escaped chars.
private boolean	allowByTailComment	Allow use escapes if trail comment is present.
private boolean	allowEscapesForControlCharacters	Allow use escapes for non-printable, control characters.
private boolean	allowIfAllCharactersEscaped	Allow if all characters in literal are escaped.
private boolean	allowNonPrintableEscapes	Allow use escapes for non-printable, whitespace characters.
private Map<Integer,List<TextBlock>>	blockComments	C style comments.
private static final Pattern	ESCAPED_BACKSLASH	Regular expression for escaped backslash.
static final String	MSG_KEY	A key is pointing to the warning message text in "messages.properties" file.
private static final Pattern	NON_PRINTABLE_CHARS	Regular expression for non-printable unicode chars.
private Map<Integer,TextBlock>	singlelineComments	Cpp style comments.
private static final Pattern	UNICODE_CONTROL	Regular expression Unicode control characters.
private static final Pattern	UNICODE_REGEXP	Regular expression for Unicode chars.

Constructor Summary

Constructors

Constructor	Description
AvoidEscapedUnicodeCharactersCheck()

Method Summary

Modifier and Type	Method	Description
void	beginTree(DetailAST rootAST)	Called before the starting to process a tree.
private static int	countMatches(Pattern pattern, String target)	Count regexp matches into String literal.
int[]	getAcceptableTokens()	The configurable token set.
int[]	getDefaultTokens()	Returns the default token a check is interested in.
int[]	getRequiredTokens()	The tokens that this check must be registered for.
private boolean	hasTrailComment(DetailAST ast)	Check if trail comment is present after ast token.
private static boolean	hasUnicodeChar(String literal)	Checks if literal has Unicode chars.
private boolean	isAllCharactersEscaped(String literal)	Checks if all characters in String literal is escaped.
private static boolean	isOnlyUnicodeValidChars(String literal, Pattern pattern)	Check if String literal contains Unicode control chars.
private static boolean	isTrailingBlockComment(TextBlock comment, int... codePoints)	Whether the C style comment is trailing.
final void	setAllowByTailComment(boolean allow)	Setter to allow use escapes if trail comment is present.
final void	setAllowEscapesForControlCharacters(boolean allow)	Setter to allow use escapes for non-printable, control characters.
final void	setAllowIfAllCharactersEscaped(boolean allow)	Setter to allow if all characters in literal are escaped.
final void	setAllowNonPrintableEscapes(boolean allow)	Setter to allow use escapes for non-printable, whitespace characters.
void	visitToken(DetailAST ast)	Called to process a token.

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

clearViolations, destroy, finishTree, getFileContents, getFilePath, 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.AbstractAutomaticBean

configure, contextualize, getConfiguration, setupChild

Methods inherited from class java.lang.Object

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

Field Details

MSG_KEY

public static final String MSG_KEY

A key is pointing to the warning message text in "messages.properties" file.

See Also:

• Constant Field Values

UNICODE_REGEXP

private static final Pattern UNICODE_REGEXP

Regular expression for Unicode chars.

UNICODE_CONTROL

private static final Pattern UNICODE_CONTROL

Regular expression Unicode control characters.

See Also:

• Appendix:Control characters

ALL_ESCAPED_CHARS

private static final Pattern ALL_ESCAPED_CHARS

Regular expression for all escaped chars. See EscapeSequence

ESCAPED_BACKSLASH

private static final Pattern ESCAPED_BACKSLASH

Regular expression for escaped backslash.

NON_PRINTABLE_CHARS

private static final Pattern NON_PRINTABLE_CHARS

Regular expression for non-printable unicode chars.

singlelineComments

private Map<Integer,TextBlock> singlelineComments

Cpp style comments.

blockComments

private Map<Integer,List<TextBlock>> blockComments

C style comments.

allowEscapesForControlCharacters

private boolean allowEscapesForControlCharacters

Allow use escapes for non-printable, control characters.

allowByTailComment

private boolean allowByTailComment

Allow use escapes if trail comment is present.

allowIfAllCharactersEscaped

private boolean allowIfAllCharactersEscaped

Allow if all characters in literal are escaped.

allowNonPrintableEscapes

private boolean allowNonPrintableEscapes

Allow use escapes for non-printable, whitespace characters.

Constructor Details

AvoidEscapedUnicodeCharactersCheck

public AvoidEscapedUnicodeCharactersCheck()

Method Details

setAllowEscapesForControlCharacters

public final void setAllowEscapesForControlCharacters(boolean allow)

Setter to allow use escapes for non-printable, control characters.

Parameters:

allow - user's value.

Since:

5.8

setAllowByTailComment

public final void setAllowByTailComment(boolean allow)

Setter to allow use escapes if trail comment is present.

Parameters:

allow - user's value.

Since:

5.8

setAllowIfAllCharactersEscaped

public final void setAllowIfAllCharactersEscaped(boolean allow)

Setter to allow if all characters in literal are escaped.

Parameters:

allow - user's value.

Since:

5.8

setAllowNonPrintableEscapes

public final void setAllowNonPrintableEscapes(boolean allow)

Setter to allow use escapes for non-printable, whitespace characters.

Parameters:

allow - user's value.

Since:

5.8

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

hasUnicodeChar

private static boolean hasUnicodeChar(String literal)

Checks if literal has Unicode chars.

Parameters:

literal - String literal.

Returns:

true if literal has Unicode chars.

isOnlyUnicodeValidChars

private static boolean isOnlyUnicodeValidChars(String literal,
 Pattern pattern)

Check if String literal contains Unicode control chars.

Parameters:

literal - String literal.

pattern - RegExp for valid characters.

Returns:

true, if String literal contains Unicode control chars.

hasTrailComment

private boolean hasTrailComment(DetailAST ast)

Check if trail comment is present after ast token.

Parameters:

ast - current token.

Returns:

true if trail comment is present after ast token.

isTrailingBlockComment

private static boolean isTrailingBlockComment(TextBlock comment,
 int... codePoints)

Whether the C style comment is trailing.

Parameters:

comment - the comment to check.

codePoints - the first line of the comment, in unicode code points

Returns:

true if the comment is trailing.

countMatches

private static int countMatches(Pattern pattern,
 String target)

Count regexp matches into String literal.

Parameters:

pattern - pattern.

target - String literal.

Returns:

count of regexp matches.

isAllCharactersEscaped

private boolean isAllCharactersEscaped(String literal)

Checks if all characters in String literal is escaped.

Parameters:

literal - current literal.

Returns:

true if all characters in String literal is escaped.