com.puppycrawl.tools.checkstyle.checks.coding

Class ModifiedControlVariableCheck

java.lang.Object

com.puppycrawl.tools.checkstyle.api.AutomaticBean

com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter

com.puppycrawl.tools.checkstyle.api.Check

com.puppycrawl.tools.checkstyle.checks.coding.ModifiedControlVariableCheck

All Implemented Interfaces:

Configurable, Contextualizable

public final class ModifiedControlVariableCheck
extends Check

Check for ensuring that for loop control variables are not modified inside the for block. An example is:

 
 for (int i = 0; i < 1; i++) {
     i++;//violation
 }
 
 

Rationale: If the control variable is modified inside the loop body, the program flow becomes more difficult to follow.
See FOR statement specification for more details.

Examples:

 <module name="ModifiedControlVariable">
 </module>
 

Such loop would be suppressed:

 
 for(int i=0; i < 10;) {
     i++;
 }
 
 

By default, This Check validates Enhanced For-Loop.

Option 'skipEnhancedForLoopVariable' could be used to skip check of variable from Enhanced For Loop.

An example of how to configure the check so that it skips enhanced For Loop Variable is:

 <module name="ModifiedControlVariable">
     <property name="skipEnhancedForLoopVariable" value="true"/>
 </module>
 

Example:

 
 for (String line: lines) {
     line = line.trim();   // it will skip this violation
 }
 
 

Author:

Daniel Grenner, liscju

Field Summary

Fields

Modifier and Type	Field and Description
static String	MSG_KEY A key is pointing to the warning message text in "messages.properties" file.

Constructor Summary

Constructors

Constructor and Description
ModifiedControlVariableCheck()

Method Summary

Modifier and Type	Method and Description
void	beginTree(DetailAST rootAST) Called before the starting to process a tree.
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.
void	leaveToken(DetailAST ast) Called after all the child nodes have been process.
void	setSkipEnhancedForLoopVariable(boolean skipEnhancedForLoopVariable) Whether to skip enhanced for-loop variable or not.
void	visitToken(DetailAST ast) Called to process a token.

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

destroy, finishTree, getClassLoader, getFileContents, getLine, getLines, getTabWidth, getTokenNames, init, isCommentNodesRequired, log, log, setClassLoader, setFileContents, setMessages, setTabWidth, setTokens

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

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

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

configure, contextualize, finishLocalSetup, getConfiguration, setupChild

Methods inherited from class java.lang.Object

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

Field Detail

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

Constructor Detail

ModifiedControlVariableCheck

public ModifiedControlVariableCheck()

Method Detail

setSkipEnhancedForLoopVariable

public void setSkipEnhancedForLoopVariable(boolean skipEnhancedForLoopVariable)

Whether to skip enhanced for-loop variable or not.

Parameters:

skipEnhancedForLoopVariable - whether to skip enhanced for-loop variable

getDefaultTokens

public int[] getDefaultTokens()

Description copied from class: Check

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 Check

Returns:

the default tokens

See Also:

TokenTypes

getRequiredTokens

public int[] getRequiredTokens()

Description copied from class: Check

The tokens that this check must be registered for.

Overrides:

getRequiredTokens in class Check

Returns:

the token set this must be registered for.

See Also:

TokenTypes

getAcceptableTokens

public int[] getAcceptableTokens()

Description copied from class: Check

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.

Overrides:

getAcceptableTokens in class Check

Returns:

the token set this check is designed for.

See Also:

TokenTypes

beginTree

public void beginTree(DetailAST rootAST)

Description copied from class: Check

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 Check

Parameters:

rootAST - the root of the tree

visitToken

public void visitToken(DetailAST ast)

Description copied from class: Check

Called to process a token.

Overrides:

visitToken in class Check

Parameters:

ast - the token to process

leaveToken

public void leaveToken(DetailAST ast)

Description copied from class: Check

Called after all the child nodes have been process.

Overrides:

leaveToken in class Check

Parameters:

ast - the token leaving