001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2014  Oliver Burn
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018////////////////////////////////////////////////////////////////////////////////
019package com.puppycrawl.tools.checkstyle.checks.sizes;
020
021import com.puppycrawl.tools.checkstyle.api.Check;
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.FastStack;
024import com.puppycrawl.tools.checkstyle.api.TokenTypes;
025
026/**
027 * Restricts the number of executable statements to a specified limit
028 * (default = 30).
029 * @author Simon Harris
030 */
031public final class ExecutableStatementCountCheck
032    extends Check
033{
034    /** default threshold */
035    private static final int DEFAULT_MAX = 30;
036
037    /** threshold to report error for */
038    private int mMax;
039
040    /** Stack of method contexts. */
041    private final FastStack<Context> mContextStack = FastStack.newInstance();
042
043    /** Current method context. */
044    private Context mContext;
045
046    /** Constructs a <code>ExecutableStatementCountCheck</code>. */
047    public ExecutableStatementCountCheck()
048    {
049        setMax(DEFAULT_MAX);
050    }
051
052    @Override
053    public int[] getDefaultTokens()
054    {
055        return new int[] {
056            TokenTypes.CTOR_DEF,
057            TokenTypes.METHOD_DEF,
058            TokenTypes.INSTANCE_INIT,
059            TokenTypes.STATIC_INIT,
060            TokenTypes.SLIST,
061        };
062    }
063
064    @Override
065    public int[] getRequiredTokens()
066    {
067        return new int[] {TokenTypes.SLIST};
068    }
069
070    /**
071     * Gets the maximum threshold.
072     * @return the maximum threshold.
073     */
074    public int getMax()
075    {
076        return mMax;
077    }
078
079    /**
080     * Sets the maximum threshold.
081     * @param aMax the maximum threshold.
082     */
083    public void setMax(int aMax)
084    {
085        mMax = aMax;
086    }
087
088    @Override
089    public void beginTree(DetailAST aRootAST)
090    {
091        mContext = null;
092        mContextStack.clear();
093    }
094
095    @Override
096    public void visitToken(DetailAST aAST)
097    {
098        switch (aAST.getType()) {
099        case TokenTypes.CTOR_DEF:
100        case TokenTypes.METHOD_DEF:
101        case TokenTypes.INSTANCE_INIT:
102        case TokenTypes.STATIC_INIT:
103            visitMemberDef(aAST);
104            break;
105        case TokenTypes.SLIST:
106            visitSlist(aAST);
107            break;
108        default:
109            throw new IllegalStateException(aAST.toString());
110        }
111    }
112
113    @Override
114    public void leaveToken(DetailAST aAST)
115    {
116        switch (aAST.getType()) {
117        case TokenTypes.CTOR_DEF:
118        case TokenTypes.METHOD_DEF:
119        case TokenTypes.INSTANCE_INIT:
120        case TokenTypes.STATIC_INIT:
121            leaveMemberDef(aAST);
122            break;
123        case TokenTypes.SLIST:
124            // Do nothing
125            break;
126        default:
127            throw new IllegalStateException(aAST.toString());
128        }
129    }
130
131    /**
132     * Process the start of the member definition.
133     * @param aAST the token representing the member definition.
134     */
135    private void visitMemberDef(DetailAST aAST)
136    {
137        mContextStack.push(mContext);
138        mContext = new Context(aAST);
139    }
140
141    /**
142     * Process the end of a member definition.
143     *
144     * @param aAST the token representing the member definition.
145     */
146    private void leaveMemberDef(DetailAST aAST)
147    {
148        final int count = mContext.getCount();
149        if (count > getMax()) {
150            log(aAST.getLineNo(), aAST.getColumnNo(),
151                    "executableStatementCount", count, getMax());
152        }
153        mContext = mContextStack.pop();
154    }
155
156    /**
157     * Process the end of a statement list.
158     *
159     * @param aAST the token representing the statement list.
160     */
161    private void visitSlist(DetailAST aAST)
162    {
163        if (mContext != null) {
164            // find member AST for the statement list
165            final DetailAST contextAST = mContext.getAST();
166            DetailAST parent = aAST.getParent();
167            while (parent != null) {
168                final int type = parent.getType();
169                if ((type == TokenTypes.CTOR_DEF)
170                    || (type == TokenTypes.METHOD_DEF)
171                    || (type == TokenTypes.INSTANCE_INIT)
172                    || (type == TokenTypes.STATIC_INIT))
173                {
174                    if (parent == contextAST) {
175                        mContext.addCount(aAST.getChildCount() / 2);
176                    }
177                    break;
178                }
179                parent = parent.getParent();
180            }
181        }
182    }
183
184    /**
185     * Class to encapsulate counting information about one member.
186     * @author Simon Harris
187     */
188    private static class Context
189    {
190        /** Member AST node. */
191        private final DetailAST mAST;
192
193        /** Counter for context elements. */
194        private int mCount;
195
196        /**
197         * Creates new member context.
198         * @param aAST member AST node.
199         */
200        public Context(DetailAST aAST)
201        {
202            mAST = aAST;
203            mCount = 0;
204        }
205
206        /**
207         * Increase count.
208         * @param aCount the count increment.
209         */
210        public void addCount(int aCount)
211        {
212            mCount += aCount;
213        }
214
215        /**
216         * Gets the member AST node.
217         * @return the member AST node.
218         */
219        public DetailAST getAST()
220        {
221            return mAST;
222        }
223
224        /**
225         * Gets the count.
226         * @return the count.
227         */
228        public int getCount()
229        {
230            return mCount;
231        }
232    }
233}