UnusedLocalVariableCheck (checkstyle 9.3 API)

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.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.

To configure the check:

 <module name="UnusedLocalVariable"/>

Example:

 class Test {

     int a;

     {
         int k = 12; // violation, assigned and updated but never used
         k++;
     }

     Test(int a) {   // ok as 'a' is a constructor parameter not a local variable
         this.a = 12;
     }

     void method(int b) {
         int a = 10;             // violation
         int[] arr = {1, 2, 3};  // violation
         int[] anotherArr = {1}; // ok
         anotherArr[0] = 4;
     }

     String convertValue(String newValue) {
         String s = newValue.toLowerCase(); // violation
         return newValue.toLowerCase();
     }

     void read() throws IOException {
         BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
         String s; // violation
         while ((s = reader.readLine()) != null) {
         }
         try (BufferedReader reader1 // ok as 'reader1' is a resource and resources are closed
                                     // at the end of the statement
             = new BufferedReader(new FileReader("abc.txt"))) {
         }
         try {
         } catch (Exception e) {     // ok as e is an exception parameter
         }
     }

     void loops() {
         int j = 12;
         for (int i = 0; j < 11; i++) { // violation, unused local variable 'i'.
         }
         for (int p = 0; j < 11; p++)   // ok
             p /= 2;
     }

     void lambdas() {
         Predicate<String> obj = (String str) -> { // ok as 'str' is a lambda parameter
             return true;
         };
         obj.test("test");
     }
 }

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:

unused.local.var

Since:: 9.3

Nested Class Summary

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

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

Field Summary

Fields
Modifier and Type	Field and Description
`private java.util.Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc>`	`anonInnerAstToTypeDeclDesc` Maps local anonymous inner class to the TypeDeclDesc object containing it.
`private java.util.Set<DetailAST>`	`anonInnerClassHolders` Set of tokens of type `CONTAINERS_FOR_ANON_INNERS` and `TokenTypes.LAMBDA` in some cases.
`private static int[]`	`CONTAINERS_FOR_ANON_INNERS` 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 int[]`	`INCREMENT_AND_DECREMENT_TOKENS` An array of increment and decrement tokens.
`static java.lang.String`	`MSG_UNUSED_LOCAL_VARIABLE` A key is pointing to the warning message text in "messages.properties" file.
`private static java.lang.String`	`PACKAGE_SEPARATOR` Package separator.
`private java.lang.String`	`packageName` Name of the package.
`private static int[]`	`SCOPES` An array of scope tokens.
`private java.util.Deque<UnusedLocalVariableCheck.TypeDeclDesc>`	`typeDeclarations` Keeps track of all the type declarations present in the file.
`private java.util.Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc>`	`typeDeclAstToTypeDeclDesc` Maps type declaration ast to their respective TypeDeclDesc objects.
`private static int[]`	`UNACCEPTABLE_CHILD_OF_DOT` An array of unacceptable children of ast of type `TokenTypes.DOT`.
`private static int[]`	`UNACCEPTABLE_PARENT_OF_IDENT` An array of unacceptable parent of ast of type `TokenTypes.IDENT`.
`private java.util.Deque<UnusedLocalVariableCheck.VariableDesc>`	`variables` Keeps tracks of the variables declared in file.

Constructor Summary

Constructors
Constructor and Description

UnusedLocalVariableCheck()
Creates a new UnusedLocalVariableCheck instance.

Constructors
Constructor and Description
`UnusedLocalVariableCheck()` Creates a new `UnusedLocalVariableCheck` instance.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`private void`	`addInstanceOrClassVar(DetailAST varDefAst)` Add instance variables and class variables to the `UnusedLocalVariableCheck.TypeDeclDesc.instanceAndClassVarStack`.
`private static void`	`addLocalVariables(DetailAST varDefAst, java.util.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 void`	`checkIdentifierAst(DetailAST identAst, java.util.Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)` Checks the identifier ast.
`private void`	`customLeaveToken(DetailAST ast, java.util.Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)` Leave all ast nodes under `anonInnerClassHolders` once again.
`private void`	`customVisitToken(DetailAST ast, java.util.Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)` Visit all ast nodes under `anonInnerClassHolders` once again.
`private static java.lang.String`	`extractQualifiedName(DetailAST ast)` Get name of package and super class of anon inner class by concatenating the identifier values under `TokenTypes.DOT`.
`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.
`int[]`	`getDefaultTokens()` Returns the default token a check is interested in.
`private java.lang.String`	`getQualifiedTypeDeclarationName(DetailAST typeDeclAst)` Get qualified type declaration name from type ast.
`private static java.lang.String`	`getQualifiedTypeDeclarationName(java.lang.String packageName, java.lang.String outerClassQualifiedName, java.lang.String className)` Get the qualified name of type declaration by combining `packageName`, `outerClassQualifiedName` and `className`.
`int[]`	`getRequiredTokens()` The tokens that this check must be registered for.
`static java.lang.String`	`getShortNameOfAnonInnerClass(DetailAST literalNewAst)` Get the short name of super class of anonymous inner class.
`private UnusedLocalVariableCheck.TypeDeclDesc`	`getSuperClassOfAnonInnerClass(DetailAST literalNewAst)` Get the `UnusedLocalVariableCheck.TypeDeclDesc` of the super class of anonymous inner class.
`private static UnusedLocalVariableCheck.TypeDeclDesc`	`getTheNearestClass(java.lang.String outerTypeDeclName, java.util.List<UnusedLocalVariableCheck.TypeDeclDesc> typeDeclWithSameName)` For all type declarations with the same name as the superclass, gets the nearest type declaration.
`private boolean`	`hasSameNameAsSuperClass(java.lang.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, java.util.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, java.util.Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)` Traverse `variablesStack` stack and log the violations.
`private void`	`modifyVariablesStack(UnusedLocalVariableCheck.TypeDeclDesc obtainedClass, java.util.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.
`static boolean`	`shouldCheckIdentTokenNestedUnderDot(DetailAST dotAst)` Whether to check identifier token nested under dotAst.
`static boolean`	`shouldCheckIdentWithMethodRefParent(DetailAST identAst)` Whether an ident with parent node of type `TokenTypes.METHOD_REF` should be checked or not.
`private static int`	`typeDeclNameMatchingCount(java.lang.String patternClass, java.lang.String classToBeMatched)` Calculates and returns the type declaration name matching count.
`private java.util.List<UnusedLocalVariableCheck.TypeDeclDesc>`	`typeDeclWithSameName(java.lang.String superClassName)` Checks if there is a type declaration with same name as the super class.
`private static void`	`visitDotToken(DetailAST dotAst, java.util.Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)` Visit ast of type `TokenTypes.DOT`.
`private static void`	`visitIdentToken(DetailAST identAst, java.util.Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)` Visit ast of type `TokenTypes.IDENT`.
`private void`	`visitLocalAnonInnerClass(DetailAST literalNewAst)` Visit the local anon inner class.
`void`	`visitToken(DetailAST ast)` Called to process a token.
`private void`	`visitTypeDeclarationToken(DetailAST typeDeclAst)` Visit the type declaration 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, 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.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
  - MSG_UNUSED_LOCAL_VARIABLE
```
public static final java.lang.String MSG_UNUSED_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.
  - CONTAINERS_FOR_ANON_INNERS
```
private static final int[] CONTAINERS_FOR_ANON_INNERS
```
    An array of blocks in which local anon inner classes can exist.
  - PACKAGE_SEPARATOR
```
private static final java.lang.String PACKAGE_SEPARATOR
```
    Package separator.
    
    See Also:
    
    Constant Field Values
  - variables
```
private final java.util.Deque<UnusedLocalVariableCheck.VariableDesc> variables
```
    Keeps tracks of the variables declared in file.
  - typeDeclarations
```
private final java.util.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 java.util.Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc> typeDeclAstToTypeDeclDesc
```
    Maps type declaration ast to their respective TypeDeclDesc objects.
  - anonInnerAstToTypeDeclDesc
```
private final java.util.Map<DetailAST,UnusedLocalVariableCheck.TypeDeclDesc> anonInnerAstToTypeDeclDesc
```
    Maps local anonymous inner class to the TypeDeclDesc object containing it.
  - anonInnerClassHolders
```
private final java.util.Set<DetailAST> anonInnerClassHolders
```
    Set of tokens of type CONTAINERS_FOR_ANON_INNERS and TokenTypes.LAMBDA in some cases.
  - packageName
```
private java.lang.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 Detail
  - UnusedLocalVariableCheck
```
public UnusedLocalVariableCheck()
```
    Creates a new UnusedLocalVariableCheck instance.
- Method Detail
  - 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,
                                  java.util.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,
                                    java.util.Deque<UnusedLocalVariableCheck.VariableDesc> variablesStack)
```
    Visit ast of type TokenTypes.IDENT.
    
    Parameters:
    
    identAst - identAst
    
    variablesStack - stack of all the relevant variables in the scope
  - visitTypeDeclarationToken
```
private void visitTypeDeclarationToken(DetailAST typeDeclAst)
```
    Visit the type declaration token.
    
    Parameters:
    
    typeDeclAst - type declaration ast
  - visitLocalAnonInnerClass
```
private void visitLocalAnonInnerClass(DetailAST literalNewAst)
```
    Visit the local anon inner class.
    
    Parameters:
    
    literalNewAst - literalNewAst
  - extractQualifiedName
```
private static java.lang.String extractQualifiedName(DetailAST ast)
```
    Get name of package and super class of anon inner class by concatenating the identifier values under TokenTypes.DOT. Duplicated, until https://github.com/checkstyle/checkstyle/issues/11201
    
    Parameters:
    
    ast - ast to extract superclass or package name from
    
    Returns:
    
    qualified name
  - 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,
                           java.util.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,
                                      java.util.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
  - getShortNameOfAnonInnerClass
```
public static java.lang.String getShortNameOfAnonInnerClass(DetailAST literalNewAst)
```
    Get the short name of super class of anonymous inner class. Example-
```
 TestClass.NestedClass obj = new Test().new NestedClass() {};
 // Short name will be Test.NestedClass
 
```
    Parameters:
    
    literalNewAst - ast node of type TokenTypes.LITERAL_NEW
    
    Returns:
    
    short name of base class of anonymous inner class
  - modifyVariablesStack
```
private void modifyVariablesStack(UnusedLocalVariableCheck.TypeDeclDesc obtainedClass,
                                  java.util.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 java.util.List<UnusedLocalVariableCheck.TypeDeclDesc> typeDeclWithSameName(java.lang.String superClassName)
```
    Checks if there is a type declaration with same name as the super class. Duplicated, until https://github.com/checkstyle/checkstyle/issues/11201
    
    Parameters:
    
    superClassName - name of the super class
    
    Returns:
    
    true if there is another type declaration with same name.
  - hasSameNameAsSuperClass
```
private boolean hasSameNameAsSuperClass(java.lang.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
  - getTheNearestClass
```
private static UnusedLocalVariableCheck.TypeDeclDesc getTheNearestClass(java.lang.String outerTypeDeclName,
                                                                        java.util.List<UnusedLocalVariableCheck.TypeDeclDesc> typeDeclWithSameName)
```
    For all type declarations with the same name as the superclass, gets the nearest type declaration. Duplicated, until https://github.com/checkstyle/checkstyle/issues/11201
    
    Parameters:
    
    outerTypeDeclName - outer type declaration of anonymous inner class
    
    typeDeclWithSameName - typeDeclarations which have the same name as the super class
    
    Returns:
    
    the nearest class
  - typeDeclNameMatchingCount
```
private static int typeDeclNameMatchingCount(java.lang.String patternClass,
                                             java.lang.String classToBeMatched)
```
    Calculates and returns the type declaration name matching count.
    Suppose our pattern class is foo.a.b and class to be matched is foo.a.ball then type declaration name matching count would be calculated by comparing every character, and updating main counter when we hit "." to prevent matching "a.b" with "a.ball". In this case type declaration name matching count would be equal to 6 and not 7 (b of ball is not counted).
    Duplicated, until https://github.com/checkstyle/checkstyle/issues/11201
    
    Parameters:
    
    patternClass - class against which the given class has to be matched
    
    classToBeMatched - class to be matched
    
    Returns:
    
    class name matching count
  - getQualifiedTypeDeclarationName
```
private java.lang.String getQualifiedTypeDeclarationName(DetailAST typeDeclAst)
```
    Get qualified type declaration name from type ast. Duplicated, until https://github.com/checkstyle/checkstyle/issues/11201
    
    Parameters:
    
    typeDeclAst - type declaration ast
    
    Returns:
    
    qualified name of type declaration
  - getQualifiedTypeDeclarationName
```
private static java.lang.String getQualifiedTypeDeclarationName(java.lang.String packageName,
                                                                java.lang.String outerClassQualifiedName,
                                                                java.lang.String className)
```
    Get the qualified name of type declaration by combining packageName, outerClassQualifiedName and className. Duplicated, until https://github.com/checkstyle/checkstyle/issues/11201
    
    Parameters:
    
    packageName - packageName
    
    outerClassQualifiedName - outerClassQualifiedName
    
    className - className
    
    Returns:
    
    the qualified name of type declaration by combining packageName, outerClassQualifiedName and className
  - iterateOverBlockContainingLocalAnonInnerClass
```
private void iterateOverBlockContainingLocalAnonInnerClass(DetailAST ast,
                                                           java.util.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,
                              java.util.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,
                              java.util.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
  - shouldCheckIdentWithMethodRefParent
```
public static boolean shouldCheckIdentWithMethodRefParent(DetailAST identAst)
```
    Whether an ident with parent node of type TokenTypes.METHOD_REF should be checked or not.
    
    Parameters:
    
    identAst - identAst
    
    Returns:
    
    true if an ident with parent node of type TokenTypes.METHOD_REF should be checked or if the parent type is not TokenTypes.METHOD_REF
  - shouldCheckIdentTokenNestedUnderDot
```
public 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,
                                       java.util.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

Class UnusedLocalVariableCheck

Nested Class Summary

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

Field Summary

Constructor Summary

Method Summary

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

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

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

Methods inherited from class java.lang.Object

Field Detail

MSG_UNUSED_LOCAL_VARIABLE

INCREMENT_AND_DECREMENT_TOKENS

SCOPES

UNACCEPTABLE_CHILD_OF_DOT

UNACCEPTABLE_PARENT_OF_IDENT

CONTAINERS_FOR_ANON_INNERS

PACKAGE_SEPARATOR

variables

typeDeclarations

typeDeclAstToTypeDeclDesc

anonInnerAstToTypeDeclDesc

anonInnerClassHolders

packageName

depth

Constructor Detail

UnusedLocalVariableCheck

Method Detail

getDefaultTokens

getAcceptableTokens

getRequiredTokens

beginTree

visitToken

leaveToken

visitDotToken

visitVariableDefToken

visitIdentToken

visitTypeDeclarationToken

visitLocalAnonInnerClass

extractQualifiedName

isInsideLocalAnonInnerClass

logViolations

leaveCompilationUnit

isNonLocalTypeDeclaration

getBlockContainingLocalAnonInnerClass

addLocalVariables

addInstanceOrClassVar

isPrivateInstanceVariable

getSuperClassOfAnonInnerClass

getShortNameOfAnonInnerClass

modifyVariablesStack

typeDeclWithSameName

hasSameNameAsSuperClass

getTheNearestClass

typeDeclNameMatchingCount

getQualifiedTypeDeclarationName

getQualifiedTypeDeclarationName

iterateOverBlockContainingLocalAnonInnerClass

customVisitToken

customLeaveToken

shouldCheckIdentWithMethodRefParent

shouldCheckIdentTokenNestedUnderDot

checkIdentifierAst

findScopeOfVariable

isLeftHandSideValue

isStandAloneIncrementOrDecrement

isIncrementOrDecrementVariableUsed