Package com.puppycrawl.tools.checkstyle.checks.coding

Class UnusedLocalVariableCheck

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.coding.UnusedLocalVariableCheck

All Implemented Interfaces:

Configurable, Contextualizable

public class UnusedLocalVariableCheck
extends AbstractCheck

Checks that a local variable is declared and/or assigned, but not used. Doesn't support pattern variables yet. Doesn't check array components as array components are classified as different kind of variables by JLS.

Since:

9.3

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	UnusedLocalVariableCheck.TypeDeclDesc	Maintains information about the type declaration.
private static final class	UnusedLocalVariableCheck.VariableDesc	Maintains information about the variable.

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

AbstractAutomaticBean.OutputStreamOptions

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	allowUnnamedVariables	Allow variables named with a single underscore (known as unnamed variables in Java 21+).
private final Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc>	anonInnerAstToTypeDeclDesc	Maps local anonymous inner class to the TypeDeclDesc object containing it.
private final Set<DetailAST>	anonInnerClassHolders	Set of tokens of type ANONYMOUS_CLASS_PARENT_TOKENS and TokenTypes.LAMBDA in some cases.
private static final int[]	ANONYMOUS_CLASS_PARENT_TOKENS	An array of blocks in which local anon inner classes can exist.
private int	depth	Depth at which a type declaration is nested, 0 for top level type declarations.
private static final int[]	INCREMENT_AND_DECREMENT_TOKENS	An array of increment and decrement tokens.
private static final int[]	INCREMENT_DECREMENT_VARIABLE_USAGE_TYPES	An array of token types that indicate a variable is being used within an expression involving increment or decrement operators, or within a switch statement.
static final String	MSG_UNUSED_LOCAL_VARIABLE	A key is pointing to the warning message text in "messages.properties" file.
static final String	MSG_UNUSED_NAMED_LOCAL_VARIABLE	A key is pointing to the warning message text in "messages.properties" file.
private static final String	PACKAGE_SEPARATOR	Package separator.
private String	packageName	Name of the package.
private static final int[]	SCOPES	An array of scope tokens.
private final Deque<UnusedLocalVariableCheck.TypeDeclDesc>	typeDeclarations	Keeps track of all the type declarations present in the file.
private final Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc>	typeDeclAstToTypeDeclDesc	Maps type declaration ast to their respective TypeDeclDesc objects.
private static final int[]	UNACCEPTABLE_CHILD_OF_DOT	An array of unacceptable children of ast of type TokenTypes.DOT.
private static final int[]	UNACCEPTABLE_PARENT_OF_IDENT	An array of unacceptable parent of ast of type TokenTypes.IDENT.
private final Deque<UnusedLocalVariableCheck.VariableDesc>	variables	Keeps tracks of the variables declared in file.

Constructor Summary

Constructors

Constructor	Description
UnusedLocalVariableCheck()

Method Summary

Modifier and Type	Method	Description
private void	addInstanceOrClassVar(DetailAST varDefAst)	Add instance variables and class variables to the UnusedLocalVariableCheck.TypeDeclDesc.instanceAndClassVarStack.
private static void	addLocalVariables(DetailAST varDefAst, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)	Add local variables to the variablesStack stack.
void	beginTree(DetailAST root)	Called before the starting to process a tree.
private static int	calculateTypeDeclarationDistance(String outerTypeName, UnusedLocalVariableCheck.TypeDeclDesc firstType, UnusedLocalVariableCheck.TypeDeclDesc secondType)	Get the difference between type declaration name matching count.
private static void	checkIdentifierAst(DetailAST identAst, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)	Checks the identifier ast.
private static int	countMatchingQualifierChars(String pattern, String candidate)	Calculates the type declaration matching count for the superclass of an anonymous inner class.
private void	customLeaveToken(DetailAST ast, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)	Leave all ast nodes under anonInnerClassHolders once again.
private void	customVisitToken(DetailAST ast, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)	Visit all ast nodes under anonInnerClassHolders once again.
private static DetailAST	findScopeOfVariable(DetailAST variableDef)	Find the scope of variable.
int[]	getAcceptableTokens()	The configurable token set.
private static DetailAST	getBlockContainingLocalAnonInnerClass(DetailAST literalNewAst)	Get the block containing local anon inner class.
private static UnusedLocalVariableCheck.TypeDeclDesc	getClosestMatchingTypeDeclaration(String outerTypeDeclName, List<UnusedLocalVariableCheck.TypeDeclDesc> typeDeclWithSameName)	For all type declarations with the same name as the superclass, gets the nearest type declaration.
int[]	getDefaultTokens()	Returns the default token a check is interested in.
private String	getQualifiedTypeDeclarationName(DetailAST typeDeclAst)	Get qualified type declaration name from type ast.
int[]	getRequiredTokens()	The tokens that this check must be registered for.
private UnusedLocalVariableCheck.TypeDeclDesc	getSuperClassOfAnonInnerClass(DetailAST literalNewAst)	Get the UnusedLocalVariableCheck.TypeDeclDesc of the super class of anonymous inner class.
private boolean	hasSameNameAsSuperClass(String superClassName, UnusedLocalVariableCheck.TypeDeclDesc typeDeclDesc)	Whether the qualified name of typeDeclDesc matches the super class name.
private static boolean	isIncrementOrDecrementVariableUsed(DetailAST exprAst)	A variable with increment or decrement operator is considered used if it is used as an argument or as an array index or for assigning value to a variable.
private static boolean	isInsideLocalAnonInnerClass(DetailAST literalNewAst)	Whether ast node of type TokenTypes.LITERAL_NEW is a part of a local anonymous inner class.
private static boolean	isLeftHandSideValue(DetailAST identAst)	Checks whether the ast of type TokenTypes.IDENT is used as left-hand side value.
private static boolean	isNonLocalTypeDeclaration(DetailAST typeDeclAst)	Whether a type declaration is non-local.
private static boolean	isPrivateInstanceVariable(DetailAST varDefAst)	Whether instance variable or class variable have private access modifier.
private static boolean	isStandAloneIncrementOrDecrement(DetailAST identAst)	Checks whether the ast of type TokenTypes.IDENT is used as an operand of a stand-alone increment or decrement.
private void	iterateOverBlockContainingLocalAnonInnerClass(DetailAST ast, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)	Iterate over all the ast nodes present under ast.
private void	leaveCompilationUnit()	We process all the blocks containing local anonymous inner classes separately after processing all the other nodes.
void	leaveToken(DetailAST ast)	Called after all the child nodes have been process.
private void	logViolations(DetailAST scopeAst, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)	Traverse variablesStack stack and log the violations.
private void	modifyVariablesStack(UnusedLocalVariableCheck.TypeDeclDesc obtainedClass, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack, DetailAST literalNewAst)	Add non-private instance and class variables of the super class of the anonymous class to the variables stack.
void	setAllowUnnamedVariables(boolean allowUnnamedVariables)	Setter to allow variables named with a single underscore (known as unnamed variables in Java 21+).
private static boolean	shouldCheckIdentTokenNestedUnderDot(DetailAST dotAst)	Whether to check identifier token nested under dotAst.
private boolean	skipUnnamedVariables(DetailAST varDefAst)	Check for skip current TokenTypes.VARIABLE_DEF due to allowUnnamedVariable option.
private List<UnusedLocalVariableCheck.TypeDeclDesc>	typeDeclWithSameName(String superClassName)	Checks if there is a type declaration with same name as the super class.
private static void	visitDotToken(DetailAST dotAst, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)	Visit ast of type TokenTypes.DOT.
private static void	visitIdentToken(DetailAST identAst, Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)	Visit ast of type TokenTypes.IDENT.
private void	visitLocalAnonInnerClass(DetailAST literalNewAst)	Visit the local anon inner class.
private void	visitNonLocalTypeDeclarationToken(DetailAST typeDeclAst)	Visit the non-local type declaration token.
void	visitToken(DetailAST ast)	Called to process a token.
private void	visitVariableDefToken(DetailAST varDefAst)	Visit ast of type TokenTypes.VARIABLE_DEF.

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

clearViolations, destroy, finishTree, getFileContents, getFilePath, getLine, getLineCodePoints, getLines, getTabWidth, getTokenNames, getViolations, init, isCommentNodesRequired, 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_UNUSED_LOCAL_VARIABLE

public static final String MSG_UNUSED_LOCAL_VARIABLE

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

See Also:

• Constant Field Values

MSG_UNUSED_NAMED_LOCAL_VARIABLE

public static final String MSG_UNUSED_NAMED_LOCAL_VARIABLE

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

See Also:

• Constant Field Values

INCREMENT_AND_DECREMENT_TOKENS

private static final int[] INCREMENT_AND_DECREMENT_TOKENS

An array of increment and decrement tokens.

SCOPES

private static final int[] SCOPES

An array of scope tokens.

UNACCEPTABLE_CHILD_OF_DOT

private static final int[] UNACCEPTABLE_CHILD_OF_DOT

An array of unacceptable children of ast of type TokenTypes.DOT.

UNACCEPTABLE_PARENT_OF_IDENT

private static final int[] UNACCEPTABLE_PARENT_OF_IDENT

An array of unacceptable parent of ast of type TokenTypes.IDENT.

ANONYMOUS_CLASS_PARENT_TOKENS

private static final int[] ANONYMOUS_CLASS_PARENT_TOKENS

An array of blocks in which local anon inner classes can exist.

INCREMENT_DECREMENT_VARIABLE_USAGE_TYPES

private static final int[] INCREMENT_DECREMENT_VARIABLE_USAGE_TYPES

An array of token types that indicate a variable is being used within an expression involving increment or decrement operators, or within a switch statement. When a token of one of these types is the parent of an expression, it indicates that the variable associated with the increment or decrement operation is being used. Ex:- TokenTypes.LITERAL_SWITCH: Indicates a switch statement. Variables used within the switch expression are considered to be used

PACKAGE_SEPARATOR

private static final String PACKAGE_SEPARATOR

Package separator.

See Also:

• Constant Field Values

variables

private final Deque<UnusedLocalVariableCheck.VariableDesc> variables

Keeps tracks of the variables declared in file.

typeDeclarations

private final Deque<UnusedLocalVariableCheck.TypeDeclDesc> typeDeclarations

Keeps track of all the type declarations present in the file. Pops the type out of the stack while leaving the type in visitor pattern.

typeDeclAstToTypeDeclDesc

private final Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc> typeDeclAstToTypeDeclDesc

Maps type declaration ast to their respective TypeDeclDesc objects.

anonInnerAstToTypeDeclDesc

private final Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc> anonInnerAstToTypeDeclDesc

Maps local anonymous inner class to the TypeDeclDesc object containing it.

anonInnerClassHolders

private final Set<DetailAST> anonInnerClassHolders

Set of tokens of type ANONYMOUS_CLASS_PARENT_TOKENS and TokenTypes.LAMBDA in some cases.

allowUnnamedVariables

private boolean allowUnnamedVariables

Allow variables named with a single underscore (known as unnamed variables in Java 21+).

packageName

private String packageName

Name of the package.

depth

private int depth

Depth at which a type declaration is nested, 0 for top level type declarations.

Constructor Details

UnusedLocalVariableCheck

public UnusedLocalVariableCheck()

Method Details

setAllowUnnamedVariables

public void setAllowUnnamedVariables(boolean allowUnnamedVariables)

Setter to allow variables named with a single underscore (known as unnamed variables in Java 21+).

Parameters:

allowUnnamedVariables - true or false.

Since:

10.18.0

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 root)

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:

root - 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

leaveToken

public void leaveToken(DetailAST ast)

Description copied from class: AbstractCheck

Called after all the child nodes have been process.

Overrides:

leaveToken in class AbstractCheck

Parameters:

ast - the token leaving

visitDotToken

private static void visitDotToken(DetailAST dotAst,
 Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)

Visit ast of type TokenTypes.DOT.

Parameters:

dotAst - dotAst

variablesStack - stack of all the relevant variables in the scope

visitVariableDefToken

private void visitVariableDefToken(DetailAST varDefAst)

Visit ast of type TokenTypes.VARIABLE_DEF.

Parameters:

varDefAst - varDefAst

visitIdentToken

private static void visitIdentToken(DetailAST identAst,
 Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)

Visit ast of type TokenTypes.IDENT.

Parameters:

identAst - identAst

variablesStack - stack of all the relevant variables in the scope

visitNonLocalTypeDeclarationToken

private void visitNonLocalTypeDeclarationToken(DetailAST typeDeclAst)

Visit the non-local type declaration token.

Parameters:

typeDeclAst - type declaration ast

visitLocalAnonInnerClass

private void visitLocalAnonInnerClass(DetailAST literalNewAst)

Visit the local anon inner class.

Parameters:

literalNewAst - literalNewAst

skipUnnamedVariables

private boolean skipUnnamedVariables(DetailAST varDefAst)

Check for skip current TokenTypes.VARIABLE_DEF due to allowUnnamedVariable option.

Parameters:

varDefAst - varDefAst variable to check

Returns:

true if the current variable should be skipped.

isInsideLocalAnonInnerClass

private static boolean isInsideLocalAnonInnerClass(DetailAST literalNewAst)

Whether ast node of type TokenTypes.LITERAL_NEW is a part of a local anonymous inner class.

Parameters:

literalNewAst - ast node of type TokenTypes.LITERAL_NEW

Returns:

true if variableDefAst is an instance variable in local anonymous inner class

logViolations

private void logViolations(DetailAST scopeAst,
 Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)

Traverse variablesStack stack and log the violations.

Parameters:

scopeAst - ast node of type SCOPES

variablesStack - stack of all the relevant variables in the scope

leaveCompilationUnit

private void leaveCompilationUnit()

We process all the blocks containing local anonymous inner classes separately after processing all the other nodes. This is being done due to the fact the instance variables of local anon inner classes can cast a shadow on local variables.

isNonLocalTypeDeclaration

private static boolean isNonLocalTypeDeclaration(DetailAST typeDeclAst)

Whether a type declaration is non-local. Annotated interfaces are always non-local.

Parameters:

typeDeclAst - type declaration ast

Returns:

true if type declaration is non-local

getBlockContainingLocalAnonInnerClass

private static DetailAST getBlockContainingLocalAnonInnerClass(DetailAST literalNewAst)

Get the block containing local anon inner class.

Parameters:

literalNewAst - ast node of type TokenTypes.LITERAL_NEW

Returns:

the block containing local anon inner class

addLocalVariables

private static void addLocalVariables(DetailAST varDefAst,
 Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)

Add local variables to the variablesStack stack. Also adds the instance variables defined in a local anonymous inner class.

Parameters:

varDefAst - ast node of type TokenTypes.VARIABLE_DEF

variablesStack - stack of all the relevant variables in the scope

addInstanceOrClassVar

private void addInstanceOrClassVar(DetailAST varDefAst)

Add instance variables and class variables to the UnusedLocalVariableCheck.TypeDeclDesc.instanceAndClassVarStack.

Parameters:

varDefAst - ast node of type TokenTypes.VARIABLE_DEF

isPrivateInstanceVariable

private static boolean isPrivateInstanceVariable(DetailAST varDefAst)

Whether instance variable or class variable have private access modifier.

Parameters:

varDefAst - ast node of type TokenTypes.VARIABLE_DEF

Returns:

true if instance variable or class variable have private access modifier

getSuperClassOfAnonInnerClass

private UnusedLocalVariableCheck.TypeDeclDesc getSuperClassOfAnonInnerClass(DetailAST literalNewAst)

Get the UnusedLocalVariableCheck.TypeDeclDesc of the super class of anonymous inner class.

Parameters:

literalNewAst - ast node of type TokenTypes.LITERAL_NEW

Returns:

UnusedLocalVariableCheck.TypeDeclDesc of the super class of anonymous inner class

modifyVariablesStack

private void modifyVariablesStack(UnusedLocalVariableCheck.TypeDeclDesc obtainedClass,
 Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack,
 DetailAST literalNewAst)

Add non-private instance and class variables of the super class of the anonymous class to the variables stack.

Parameters:

obtainedClass - super class of the anon inner class

variablesStack - stack of all the relevant variables in the scope

literalNewAst - ast node of type TokenTypes.LITERAL_NEW

typeDeclWithSameName

private List<UnusedLocalVariableCheck.TypeDeclDesc> typeDeclWithSameName(String superClassName)

Checks if there is a type declaration with same name as the super class.

Parameters:

superClassName - name of the super class

Returns:

list if there is another type declaration with same name.

hasSameNameAsSuperClass

private boolean hasSameNameAsSuperClass(String superClassName,
 UnusedLocalVariableCheck.TypeDeclDesc typeDeclDesc)

Whether the qualified name of typeDeclDesc matches the super class name.

Parameters:

superClassName - name of the super class

typeDeclDesc - type declaration description

Returns:

true if the qualified name of typeDeclDesc matches the super class name

getClosestMatchingTypeDeclaration

private static UnusedLocalVariableCheck.TypeDeclDesc getClosestMatchingTypeDeclaration(String outerTypeDeclName,
 List<UnusedLocalVariableCheck.TypeDeclDesc> typeDeclWithSameName)

For all type declarations with the same name as the superclass, gets the nearest type declaration.

Parameters:

outerTypeDeclName - outer type declaration of anonymous inner class

typeDeclWithSameName - typeDeclarations which have the same name as the super class

Returns:

the nearest class

calculateTypeDeclarationDistance

private static int calculateTypeDeclarationDistance(String outerTypeName,
 UnusedLocalVariableCheck.TypeDeclDesc firstType,
 UnusedLocalVariableCheck.TypeDeclDesc secondType)

Get the difference between type declaration name matching count. If the difference between them is zero, then their depth is compared to obtain the result.

Parameters:

outerTypeName - outer type declaration of anonymous inner class

firstType - first input type declaration

secondType - second input type declaration

Returns:

difference between type declaration name matching count

countMatchingQualifierChars

private static int countMatchingQualifierChars(String pattern,
 String candidate)

Calculates the type declaration matching count for the superclass of an anonymous inner class.

For example, if the pattern class is Main.ClassOne and the class to be matched is Main.ClassOne.ClassTwo.ClassThree, then the matching count would be calculated by comparing the characters at each position, and updating the count whenever a '.' is encountered. This is necessary because pattern class can include anonymous inner classes, unlike regular inheritance where nested classes cannot be extended.

Parameters:

pattern - type declaration to match against

candidate - type declaration to be matched

Returns:

the type declaration matching count

getQualifiedTypeDeclarationName

private String getQualifiedTypeDeclarationName(DetailAST typeDeclAst)

Get qualified type declaration name from type ast.

Parameters:

typeDeclAst - type declaration ast

Returns:

qualified name of type declaration

iterateOverBlockContainingLocalAnonInnerClass

private void iterateOverBlockContainingLocalAnonInnerClass(DetailAST ast,
 Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)

Iterate over all the ast nodes present under ast.

Parameters:

ast - ast

variablesStack - stack of all the relevant variables in the scope

customVisitToken

private void customVisitToken(DetailAST ast,
 Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)

Visit all ast nodes under anonInnerClassHolders once again.

Parameters:

ast - ast

variablesStack - stack of all the relevant variables in the scope

customLeaveToken

private void customLeaveToken(DetailAST ast,
 Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)

Leave all ast nodes under anonInnerClassHolders once again.

Parameters:

ast - ast

variablesStack - stack of all the relevant variables in the scope

shouldCheckIdentTokenNestedUnderDot

private static boolean shouldCheckIdentTokenNestedUnderDot(DetailAST dotAst)

Whether to check identifier token nested under dotAst.

Parameters:

dotAst - dotAst

Returns:

true if ident nested under dotAst should be checked

checkIdentifierAst

private static void checkIdentifierAst(DetailAST identAst,
 Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)

Checks the identifier ast.

Parameters:

identAst - ast of type TokenTypes.IDENT

variablesStack - stack of all the relevant variables in the scope

findScopeOfVariable

private static DetailAST findScopeOfVariable(DetailAST variableDef)

Find the scope of variable.

Parameters:

variableDef - ast of type TokenTypes.VARIABLE_DEF

Returns:

scope of variableDef

isLeftHandSideValue

private static boolean isLeftHandSideValue(DetailAST identAst)

Checks whether the ast of type TokenTypes.IDENT is used as left-hand side value. An identifier is being used as a left-hand side value if it is used as the left operand of an assignment or as an operand of a stand-alone increment or decrement.

Parameters:

identAst - ast of type TokenTypes.IDENT

Returns:

true if identAst is used as a left-hand side value

isStandAloneIncrementOrDecrement

private static boolean isStandAloneIncrementOrDecrement(DetailAST identAst)

Checks whether the ast of type TokenTypes.IDENT is used as an operand of a stand-alone increment or decrement.

Parameters:

identAst - ast of type TokenTypes.IDENT

Returns:

true if identAst is used as an operand of stand-alone increment or decrement

isIncrementOrDecrementVariableUsed

private static boolean isIncrementOrDecrementVariableUsed(DetailAST exprAst)

A variable with increment or decrement operator is considered used if it is used as an argument or as an array index or for assigning value to a variable.

Parameters:

exprAst - ast of type TokenTypes.EXPR

Returns:

true if variable nested in exprAst is used