[Fb-contrib-commit] SF.net SVN: fb-contrib: [589] trunk/fb-contrib/samples

[<dbr...@us...>]

Revision: 589
Author:   dbrosius
Date:     2006-08-07 20:19:37 -0700 (Mon, 07 Aug 2006)
ViewCVS:  http://svn.sourceforge.net/fb-contrib/?rev=589&view=rev

Log Message:
-----------
start working on LEST detector

Added Paths:
-----------
    trunk/fb-contrib/samples/LEST_Sample.java
    trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/LostExceptionStackTrace.java
Added: trunk/fb-contrib/samples/LEST_Sample.java
===================================================================
--- trunk/fb-contrib/samples/LEST_Sample.java	                        (rev 0)
+++ trunk/fb-contrib/samples/LEST_Sample.java	2006-08-08 03:19:37 UTC (rev 589)
@@ -0,0 +1,20 @@
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+public class LEST_Sample 
+{
+	public Date testLest1(String input)
+	{
+		try
+		{
+			DateFormat df = new SimpleDateFormat("YYYY");
+			return df.parse(input);
+		} 
+		catch (ParseException pe)
+		{
+			throw new IllegalArgumentException(pe.getMessage());
+		}
+	}
+}

Added: trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/LostExceptionStackTrace.java
===================================================================
--- trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/LostExceptionStackTrace.java	                        (rev 0)
+++ trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/LostExceptionStackTrace.java	2006-08-08 03:19:37 UTC (rev 589)
@@ -0,0 +1,114 @@
+/*
+ * fb-contrib - Auxilliary detectors for Java programs
+ * Copyright (C) 2005-2006 Dave Brosius
+ * 
+ * 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.mebigfatguy.fbcontrib.detect;
+
+import java.util.BitSet;
+
+import org.apache.bcel.Constants;
+import org.apache.bcel.classfile.Code;
+import org.apache.bcel.classfile.CodeException;
+import org.apache.bcel.classfile.ExceptionTable;
+import org.apache.bcel.classfile.Method;
+
+import edu.umd.cs.findbugs.BugReporter;
+import edu.umd.cs.findbugs.BytecodeScanningDetector;
+import edu.umd.cs.findbugs.OpcodeStack;
+import edu.umd.cs.findbugs.ba.ClassContext;
+
+/**
+ * looks for methods that catch exceptions, and rethrow another exception without encapsulating
+ * the original exception within it. Doing this loses the stack history, and where the original
+ * problem occurred. This makes finding and fixing errors difficult.
+ */
+public class LostExceptionStackTrace extends BytecodeScanningDetector 
+{
+	private BugReporter bugReporter;
+	private OpcodeStack stack;
+	
+    /**
+     * constructs a LEST detector given the reporter to report bugs on
+
+     * @param bugReporter the sync of bug reports
+     */	
+	public LostExceptionStackTrace(BugReporter bugReporter) {
+		this.bugReporter = bugReporter;
+	}
+	
+	/**
+	 * implements the visitor to make sure the jdk is 1.4 or better
+	 * 
+	 * @param classContext the context object of the currently parsed class
+	 */
+	@Override
+	public void visitClassContext(ClassContext classContext) {
+		try {
+			int majorVersion = classContext.getJavaClass().getMajor();
+			if (majorVersion >= Constants.MAJOR_1_4) {
+				stack = new OpcodeStack();
+				super.visitClassContext(classContext);
+			}
+		} finally {
+			stack = null;
+		}
+	}
+	
+    /**
+	 * looks for methods that contain a catch block and an ATHROW opcode
+	 * 
+	 * @param code the context object of the current code block
+	 * @param method the context object of the current method
+	 * @return if the class throws exceptions
+	 */
+	public boolean prescreen(Code code, Method method) {
+		CodeException[] ce = code.getExceptionTable();
+		if ((ce == null) || (ce.length == 0))
+			return false;
+
+		BitSet bytecodeSet = getClassContext().getBytecodeSet(method);
+		return (bytecodeSet != null) && (bytecodeSet.get(Constants.ATHROW));
+	}
+
+	/**
+	 * implements the visitor to filter out methods that don't throw exceptions
+	 * 
+	 * @param obj the context object of the currently parsed code block
+	 */
+	@Override
+	public void visitCode(Code obj) {
+		if (prescreen(obj, getMethod())) {
+			stack.resetForMethodEntry(this);
+			super.visitCode(obj);
+		}
+	}
+	
+	/**
+	 * implements the visitor to find throwing alternative exceptions from a catch block, without
+	 * forwarding along the original exception
+	 */
+	@Override
+	public void sawOpcode(int seen) {
+		try {
+			stack.mergeJumps(this);
+			
+		}
+		finally {
+			stack.sawOpcode(this, seen);
+		}
+	}
+}


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