added generic check for illegal regexps, RFEs #595254 and #621247

src/checkstyle/com/puppycrawl/tools/checkstyle/checks/GenericIllegalRegexpCheck.java

@@ -0,0 +1,60 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2002  Oliver Burn
+//
+// 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;
+
+/**
+ * A generic check for code problems, the user can search for any pattern.
+ * This is similar to a recursive grep, only that it's integrated in checkstyle.
+ *
+ * Rationale: This Check can be used to prototype checks and to find common
+ * bad pratice such as calling
+ * ex.printStacktrace(), System.out.println(), System.exit(), etc.
+ *
+ * @author lkuehne
+ */
+public class GenericIllegalRegexpCheck extends AbstractFormatCheck
+{
+    /**
+     * Instantiates an new GenericIllegalRegexpCheck.
+     */
+    public GenericIllegalRegexpCheck()
+    {
+        super("$^"); // the empty language
+    }
+
+    /** @see com.puppycrawl.tools.checkstyle.api.Check */
+    public int[] getDefaultTokens()
+    {
+        return new int[0];
+    }
+
+    /** @see com.puppycrawl.tools.checkstyle.api.Check */
+    public void beginTree()
+    {
+        final String[] lines = getLines();
+        for (int i = 0; i < lines.length; i++) {
+
+            final String line = lines[i];
+            if (super.getRegexp().match(line)) {
+                log(i + 1, "illegal.regexp", getFormat());
+            }
+        }
+    }
+}

src/tests/com/puppycrawl/tools/checkstyle/GenericIllegalRegexpCheckTest.java

@@ -0,0 +1,27 @@
+package com.puppycrawl.tools.checkstyle;
+
+import com.puppycrawl.tools.checkstyle.checks.GenericIllegalRegexpCheck;
+
+public class GenericIllegalRegexpCheckTest
+        extends BaseCheckTestCase
+{
+    public GenericIllegalRegexpCheckTest(String aName)
+    {
+        super(aName);
+    }
+
+    public void testIt()
+            throws Exception
+    {
+        String illegal = "System\\.(out)|(err)\\.print(ln)?\\(";
+        final CheckConfiguration checkConfig = new CheckConfiguration();
+        checkConfig.setClassname(GenericIllegalRegexpCheck.class.getName());
+        checkConfig.addProperty("format", illegal);
+        final Checker c = createChecker(checkConfig);
+        final String fname = getPath("InputSemantic.java");
+        final String[] expected = {
+            "68: Line matches the illegal pattern '" + illegal + "'."
+        };
+        verify(c, fname, expected);
+    }
+}