Issue #2451: removed excess hierarchy from CyclomaticComplexityCheck

pom.xml

@@ -1719,6 +1719,7 @@
                   <exclude>com/puppycrawl/tools/checkstyle/checks/coding/AbstractIllegalCheck.class</exclude>
                   <exclude>com/puppycrawl/tools/checkstyle/checks/coding/AbstractIllegalMethodCheck.class</exclude>
                   <exclude>com/puppycrawl/tools/checkstyle/checks/coding/AbstractNestedDepthCheck.class</exclude>
+                  <exclude>com/puppycrawl/tools/checkstyle/checks/metrics/AbstractComplexityCheck.class</exclude>
                   <exclude>com/puppycrawl/tools/checkstyle/checks/naming/AbstractTypeParameterNameCheck.class</exclude>
                 </excludes>
               </instrumentation>

src/main/java/com/puppycrawl/tools/checkstyle/checks/metrics/CyclomaticComplexityCheck.java

@@ -20,7 +20,10 @@
 package com.puppycrawl.tools.checkstyle.checks.metrics;
 
 import java.math.BigInteger;
+import java.util.ArrayDeque;
+import java.util.Deque;
 
+import com.puppycrawl.tools.checkstyle.api.Check;
 import com.puppycrawl.tools.checkstyle.api.DetailAST;
 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
 
@@ -43,7 +46,7 @@ import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  * @author <a href="mailto:andreyselkin@gmail.com">Andrei Selkin</a>
  */
 public class CyclomaticComplexityCheck
-    extends AbstractComplexityCheck {
+    extends Check {
 
     /**
      * A key is pointing to the warning message text in "messages.properties"
@@ -51,16 +54,23 @@ public class CyclomaticComplexityCheck
      */
     public static final String MSG_KEY = "cyclomaticComplexity";
 
+    /** The initial current value. */
+    private static final BigInteger INITIAL_VALUE = BigInteger.ONE;
+
     /** Default allowed complexity. */
-    private static final int DEFAULT_VALUE = 10;
+    private static final int DEFAULT_COMPLEXITY_VALUE = 10;
 
     /** Whether to treat the whole switch block as a single decision point.*/
     private boolean switchBlockAsSingleDecisionPoint;
 
-    /** Create an instance. */
-    public CyclomaticComplexityCheck() {
-        super(DEFAULT_VALUE);
-    }
+    /** Stack of values - all but the current value. */
+    private final Deque<BigInteger> valueStack = new ArrayDeque<>();
+
+    /** The current value. */
+    private BigInteger currentValue = INITIAL_VALUE;
+
+    /** Threshold to report error for. */
+    private int max = DEFAULT_COMPLEXITY_VALUE;
 
     /**
      * Sets whether to treat the whole switch block as a single decision point.
@@ -71,6 +81,15 @@ public class CyclomaticComplexityCheck
         this.switchBlockAsSingleDecisionPoint = switchBlockAsSingleDecisionPoint;
     }
 
+    /**
+     * Set the maximum threshold allowed.
+     *
+     * @param max the maximum threshold
+     */
+    public final void setMax(int max) {
+        this.max = max;
+    }
+
     @Override
     public int[] getDefaultTokens() {
         return new int[] {
@@ -112,6 +131,49 @@ public class CyclomaticComplexityCheck
     }
 
     @Override
+    public final int[] getRequiredTokens() {
+        return new int[] {
+            TokenTypes.CTOR_DEF,
+            TokenTypes.METHOD_DEF,
+            TokenTypes.INSTANCE_INIT,
+            TokenTypes.STATIC_INIT,
+        };
+    }
+
+    @Override
+    public void visitToken(DetailAST ast) {
+        switch (ast.getType()) {
+            case TokenTypes.CTOR_DEF:
+            case TokenTypes.METHOD_DEF:
+            case TokenTypes.INSTANCE_INIT:
+            case TokenTypes.STATIC_INIT:
+                visitMethodDef();
+                break;
+            default:
+                visitTokenHook(ast);
+        }
+    }
+
+    @Override
+    public void leaveToken(DetailAST ast) {
+        switch (ast.getType()) {
+            case TokenTypes.CTOR_DEF:
+            case TokenTypes.METHOD_DEF:
+            case TokenTypes.INSTANCE_INIT:
+            case TokenTypes.STATIC_INIT:
+                leaveMethodDef(ast);
+                break;
+            default:
+                break;
+        }
+    }
+
+    /**
+     * Hook called when visiting a token. Will not be called the method
+     * definition tokens.
+     *
+     * @param ast the token being visited
+     */
     protected final void visitTokenHook(DetailAST ast) {
         if (switchBlockAsSingleDecisionPoint) {
             if (ast.getType() != TokenTypes.LITERAL_CASE) {
@@ -123,13 +185,45 @@ public class CyclomaticComplexityCheck
         }
     }
 
-    @Override
-    protected final String getMessageID() {
-        return MSG_KEY;
+    /**
+     * Process the end of a method definition.
+     *
+     * @param ast the token representing the method definition
+     */
+    private void leaveMethodDef(DetailAST ast) {
+        final BigInteger bigIntegerMax = BigInteger.valueOf(max);
+        if (currentValue.compareTo(bigIntegerMax) > 0) {
+            log(ast, MSG_KEY, currentValue, bigIntegerMax);
+        }
+        popValue();
     }
 
-    @Override
-    protected void leaveTokenHook(DetailAST ast) {
-        // no code
+    /**
+     * Increments the current value by a specified amount.
+     *
+     * @param by the amount to increment by
+     */
+    protected final void incrementCurrentValue(BigInteger by) {
+        currentValue = currentValue.add(by);
+    }
+
+    /** Push the current value on the stack. */
+    protected final void pushValue() {
+        valueStack.push(currentValue);
+        currentValue = INITIAL_VALUE;
+    }
+
+    /**
+     * Pops a value off the stack and makes it the current value.
+     * @return pop a value off the stack and make it the current value
+     */
+    protected final BigInteger popValue() {
+        currentValue = valueStack.pop();
+        return currentValue;
+    }
+
+    /** Process the start of the method definition. */
+    private void visitMethodDef() {
+        pushValue();
     }
 }

src/test/java/com/puppycrawl/tools/checkstyle/checks/metrics/CyclomaticComplexityCheckTest.java

@@ -24,6 +24,7 @@ import static com.puppycrawl.tools.checkstyle.checks.metrics.CyclomaticComplexit
 import java.io.File;
 import java.io.IOException;
 
+import org.apache.commons.lang3.ArrayUtils;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -113,4 +114,14 @@ public class CyclomaticComplexityCheckTest
         };
         Assert.assertArrayEquals(expected, actual);
     }
+
+    @Test
+    public void testHighMax() throws Exception {
+        final DefaultConfiguration checkConfig =
+            createCheckConfig(CyclomaticComplexityCheck.class);
+        checkConfig.addAttribute("max", "100");
+        final String[] expected = ArrayUtils.EMPTY_STRING_ARRAY;
+
+        verify(checkConfig, getPath("InputComplexitySwitchBlocks.java"), expected);
+    }
 }