ExecutableStatementCountCheck.java
////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2021 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.sizes;
import java.util.ArrayDeque;
import java.util.Deque;
import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
/**
* <p>
* Restricts the number of executable statements to a specified limit.
* </p>
* <ul>
* <li>
* Property {@code max} - Specify the maximum threshold allowed.
* Type is {@code int}.
* Default value is {@code 30}.
* </li>
* <li>
* Property {@code tokens} - tokens to check
* Type is {@code java.lang.String[]}.
* Validation type is {@code tokenSet}.
* Default value is:
* <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CTOR_DEF">
* CTOR_DEF</a>,
* <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#METHOD_DEF">
* METHOD_DEF</a>,
* <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#INSTANCE_INIT">
* INSTANCE_INIT</a>,
* <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#STATIC_INIT">
* STATIC_INIT</a>,
* <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#COMPACT_CTOR_DEF">
* COMPACT_CTOR_DEF</a>,
* <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#LAMBDA">
* LAMBDA</a>.
* </li>
* </ul>
* <p>
* To configure the check:
* </p>
* <pre>
* <module name="ExecutableStatementCount"/>
* </pre>
* <p>
* To configure the check with a threshold of 20 for constructor and method definitions:
* </p>
* <pre>
* <module name="ExecutableStatementCount">
* <property name="max" value="20"/>
* <property name="tokens" value="CTOR_DEF,METHOD_DEF"/>
* </module>
* </pre>
* <p>
* Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
* </p>
* <p>
* Violation Message Keys:
* </p>
* <ul>
* <li>
* {@code executableStatementCount}
* </li>
* </ul>
*
* @since 3.2
*/
@FileStatefulCheck
public final class ExecutableStatementCountCheck
extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY = "executableStatementCount";
/** Default threshold. */
private static final int DEFAULT_MAX = 30;
/** Stack of method contexts. */
private final Deque<Context> contextStack = new ArrayDeque<>();
/** Specify the maximum threshold allowed. */
private int max;
/** Current method context. */
private Context context;
/** Constructs a {@code ExecutableStatementCountCheck}. */
public ExecutableStatementCountCheck() {
max = DEFAULT_MAX;
}
@Override
public int[] getDefaultTokens() {
return new int[] {
TokenTypes.CTOR_DEF,
TokenTypes.METHOD_DEF,
TokenTypes.INSTANCE_INIT,
TokenTypes.STATIC_INIT,
TokenTypes.SLIST,
TokenTypes.COMPACT_CTOR_DEF,
TokenTypes.LAMBDA,
};
}
@Override
public int[] getRequiredTokens() {
return new int[] {TokenTypes.SLIST};
}
@Override
public int[] getAcceptableTokens() {
return new int[] {
TokenTypes.CTOR_DEF,
TokenTypes.METHOD_DEF,
TokenTypes.INSTANCE_INIT,
TokenTypes.STATIC_INIT,
TokenTypes.SLIST,
TokenTypes.COMPACT_CTOR_DEF,
TokenTypes.LAMBDA,
};
}
/**
* Setter to specify the maximum threshold allowed.
*
* @param max the maximum threshold.
*/
public void setMax(int max) {
this.max = max;
}
@Override
public void beginTree(DetailAST rootAST) {
context = new Context(null);
contextStack.clear();
}
@Override
public void visitToken(DetailAST ast) {
if (isContainerNode(ast)) {
visitContainerNode(ast);
}
else if (TokenUtil.isOfType(ast, TokenTypes.SLIST)) {
visitSlist(ast);
}
else {
throw new IllegalStateException(ast.toString());
}
}
@Override
public void leaveToken(DetailAST ast) {
if (isContainerNode(ast)) {
leaveContainerNode(ast);
}
else if (!TokenUtil.isOfType(ast, TokenTypes.SLIST)) {
throw new IllegalStateException(ast.toString());
}
}
/**
* Process the start of the container node.
*
* @param ast the token representing the container node.
*/
private void visitContainerNode(DetailAST ast) {
contextStack.push(context);
context = new Context(ast);
}
/**
* Process the end of a container node.
*
* @param ast the token representing the container node.
*/
private void leaveContainerNode(DetailAST ast) {
final int count = context.getCount();
if (count > max) {
log(ast, MSG_KEY, count, max);
}
context = contextStack.pop();
}
/**
* Process the end of a statement list.
*
* @param ast the token representing the statement list.
*/
private void visitSlist(DetailAST ast) {
final DetailAST contextAST = context.getAST();
DetailAST parent = ast.getParent();
while (parent != null && !isContainerNode(parent)) {
parent = parent.getParent();
}
if (parent == contextAST) {
context.addCount(ast.getChildCount() / 2);
}
}
/**
* Check if the node is of type ctor (compact or canonical),
* instance/ static initializer, method definition or lambda.
*
* @param node AST node we are checking
* @return true if node is of the given types
*/
private static boolean isContainerNode(DetailAST node) {
return TokenUtil.isOfType(node, TokenTypes.METHOD_DEF,
TokenTypes.LAMBDA, TokenTypes.CTOR_DEF, TokenTypes.INSTANCE_INIT,
TokenTypes.STATIC_INIT, TokenTypes.COMPACT_CTOR_DEF);
}
/**
* Class to encapsulate counting information about one member.
*/
private static class Context {
/** Member AST node. */
private final DetailAST ast;
/** Counter for context elements. */
private int count;
/**
* Creates new member context.
*
* @param ast member AST node.
*/
/* package */ Context(DetailAST ast) {
this.ast = ast;
count = 0;
}
/**
* Increase count.
*
* @param addition the count increment.
*/
public void addCount(int addition) {
count += addition;
}
/**
* Gets the member AST node.
*
* @return the member AST node.
*/
public DetailAST getAST() {
return ast;
}
/**
* Gets the count.
*
* @return the count.
*/
public int getCount() {
return count;
}
}
}