[Fb-contrib-commit] SF.net SVN: fb-contrib: [923] trunk/fb-contrib

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

Revision: 923
          http://fb-contrib.svn.sourceforge.net/fb-contrib/?rev=923&view=rev
Author:   dbrosius
Date:     2007-10-06 15:29:47 -0700 (Sat, 06 Oct 2007)

Log Message:
-----------
initial checkin - EXS detector - not even close to working

Modified Paths:
--------------
    trunk/fb-contrib/etc/findbugs.xml
    trunk/fb-contrib/etc/messages.xml

Added Paths:
-----------
    trunk/fb-contrib/samples/EXS_Sample.java
    trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/ExceptionSoftening.java

Modified: trunk/fb-contrib/etc/findbugs.xml
===================================================================
--- trunk/fb-contrib/etc/findbugs.xml	2007-10-01 03:27:47 UTC (rev 922)
+++ trunk/fb-contrib/etc/findbugs.xml	2007-10-06 22:29:47 UTC (rev 923)
@@ -295,6 +295,10 @@
 			speed="fast"
 			reports="MOM_MISLEADING_OVERLOAD_MODEL" />
 			
+	<Detector class="com.mebigfatguy.fbcontrib.detect.ExceptionSoftening"
+			speed="moderate"
+			reports="EXS_EXCEPTION_SOFTENING_NO_CONSTRAINTS,EXS_EXCEPTION_SOFTENING_HAS_CHECKED,EXS_EXCEPTION_SOFTENING_NO_CHECKED" />
+			
    	<!-- BugPattern -->
 	
 	<BugPattern abbrev="ISB" type="ISB_INEFFICIENT_STRING_BUFFERING" category="PERFORMANCE" />
@@ -387,4 +391,7 @@
 	<BugPattern abbrev="MRC" type="MRC_METHOD_RETURNS_CONSTANT" category="STYLE" experimental="true" />
 	<BugPattern abbrev="NCS" type="NCS_NEEDLESS_CUSTOM_SERIALIZATION" category="CORRECTNESS" experimental="true" />
 	<BugPattern abbrev="MOM" type="MOM_MISLEADING_OVERLOAD_MODEL" category="STYLE" experimental="true" />
+	<BugPattern abbrev="EXS" type="EXS_EXCEPTION_SOFTENING_NO_CONSTRAINTS" category="STYLE" experimental="true" />
+	<BugPattern abbrev="EXS" type="EXS_EXCEPTION_SOFTENING_HAS_CHECKED" category="STYLE" experimental="true" />
+	<BugPattern abbrev="EXS" type="EXS_EXCEPTION_SOFTENING_NO_CHECKED" category="STYLE" experimental="true" />
 </FindbugsPlugin>
\ No newline at end of file

Modified: trunk/fb-contrib/etc/messages.xml
===================================================================
--- trunk/fb-contrib/etc/messages.xml	2007-10-01 03:27:47 UTC (rev 922)
+++ trunk/fb-contrib/etc/messages.xml	2007-10-06 22:29:47 UTC (rev 923)
@@ -801,6 +801,21 @@
 		</Details>
 	</Detector>
 	
+	<Detector class="com.mebigfatguy.fbcontrib.detect.ExceptionSoftening">
+		<Details>
+			<![CDATA[
+			<p>looks for methods that catch checked exceptions, and throw unchecked
+			exceptions in their place. There are several levels of concern. Least
+			concerning are methods constrained by interface or super class contracts
+			not to throw checked exceptions but appear owned by the same author. Next
+			are methods constrained by interface or super class contracts and throw other
+			types of checked exceptions. Most egregious are method not constrained by any interface
+			or superclass contract.</p>
+			<p>It is a moderately fast detector</p>
+			]]>
+		</Details>
+	</Detector>
+	
 	<!-- BugPattern -->	
 	                
 	<BugPattern type="ISB_INEFFICIENT_STRING_BUFFERING">
@@ -1991,6 +2006,44 @@
 		</Details>
 	</BugPattern>
 	
+	<BugPattern type="EXS_EXCEPTION_SOFTENING_NO_CONSTRAINTS">
+		<ShortDescription>constrained method converts checked exception to unchecked</ShortDescription>
+		<LongDescription>constrained method {1} converts checked exception to unchecked</LongDescription>
+		<Details>
+			<![CDATA[
+			<p>This method's exception signature is constrained by an interface or super class to not throw
+			any checked exceptions. Therefore a caught checked exception was converted to an unchecked exception
+			and thrown. However it appears that the class in question is owned by the same author as the constraining
+			interface or superclass. Consider changes the signature of this method to include the checked exception.</p>
+			]]>
+		</Details>
+	</BugPattern>
+	
+	<BugPattern type="EXS_EXCEPTION_SOFTENING_HAS_CHECKED">
+		<ShortDescription>constrained method converts checked exception to unchecked instead of another allowable checked exception</ShortDescription>
+		<LongDescription>constrained method {1} converts checked exception to unchecked instead of another allowable checked exception</LongDescription>
+		<Details>
+			<![CDATA[
+			<p>This method's exception signature is constrained by an interface of super class to not throw a 
+			checked exception that was caught. Therefore this exception was converted to an unchecked exception and 
+			thrown. It would probably be better to throw the closest checked exception allowed, and to annotate
+			the new exception with the original exception using the initial cause field.</p>
+			]]>
+		</Details>
+	</BugPattern>
+	
+	<BugPattern type="EXS_EXCEPTION_SOFTENING_NO_CHECKED">
+		<ShortDescription>unconstrained method converts checked exception to unchecked</ShortDescription>
+		<LongDescription>unconstrained method {1} converts checked exception to unchecked</LongDescription>
+		<Details>
+			<![CDATA[
+			<p>This method is not constrained by an interface or superclass, but converts a caught checked exception
+			to unchecked exception and thrown. It would be more appropriate just throw the checked exception, adding
+			the exception to the throws clause of the method.
+			]]>
+		</Details>
+	</BugPattern>
+	
 	<!-- BugCode -->
 	
 	<BugCode abbrev="ISB">Inefficient String Buffering</BugCode>
@@ -2059,4 +2112,5 @@
 	<BugCode abbrev="MRC">Method Returns Constant</BugCode>
 	<BugCode abbrev="NCS">Needless Custom Serialization</BugCode>
 	<BugCode abbrev="MOM">Misleading Overload Model</BugCode>
+	<BugCode abbrev="EXS">Exception Softening</BugCode>
 </MessageCollection>
\ No newline at end of file

Added: trunk/fb-contrib/samples/EXS_Sample.java
===================================================================
--- trunk/fb-contrib/samples/EXS_Sample.java	                        (rev 0)
+++ trunk/fb-contrib/samples/EXS_Sample.java	2007-10-06 22:29:47 UTC (rev 923)
@@ -0,0 +1,55 @@
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.sql.SQLException;
+
+
+public class EXS_Sample extends Super
+{
+	@Override
+	public void constrainedNone()
+	{
+		try
+		{
+			InputStream is = new FileInputStream("c:\\test.txt");
+		}
+		catch (IOException ioe)
+		{
+			throw new RuntimeException("Ooops");
+		}
+	}
+	
+	@Override
+	public void constrainedNon() throws SQLException
+	{
+		try
+		{
+			InputStream is = new FileInputStream("c:\\test.txt");
+		}
+		catch (IOException ioe)
+		{
+			throw new RuntimeException("Ooops");
+		}
+	}
+	
+	public void notConstrained()
+	{
+		try
+		{
+			InputStream is = new FileInputStream("c:\\test.txt");
+		}
+		catch (IOException ioe)
+		{
+			throw new RuntimeException("Ooops");
+		}
+	}
+}
+
+class Super
+{
+	public void constrainedNone()
+	{}
+	
+	public void constrainedNon() throws SQLException
+	{}
+}
\ No newline at end of file


Property changes on: trunk/fb-contrib/samples/EXS_Sample.java
___________________________________________________________________
Name: svn:mime-type
   + text/plain
Name: svn:eol-style
   + native

Added: trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/ExceptionSoftening.java
===================================================================
--- trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/ExceptionSoftening.java	                        (rev 0)
+++ trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/ExceptionSoftening.java	2007-10-06 22:29:47 UTC (rev 923)
@@ -0,0 +1,182 @@
+/*
+ * fb-contrib - Auxilliary detectors for Java programs
+ * Copyright (C) 2005-2007 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.ArrayList;
+import java.util.BitSet;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.bcel.Constants;
+import org.apache.bcel.classfile.Code;
+import org.apache.bcel.classfile.CodeException;
+import org.apache.bcel.classfile.ConstantClass;
+import org.apache.bcel.classfile.ConstantPool;
+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 checked exceptions, and throw unchecked
+ * exceptions in their place. There are several levels of concern. Least
+ * important are methods constrained by interface or super class contracts
+ * not to throw checked exceptions but appear owned by the same author. Next
+ * are methods constrained by interface or super class contracts and throw other
+ * types of checked exceptions. Lastly are method not constrained by any interface
+ * or superclass contract.
+ */
+public class ExceptionSoftening extends BytecodeScanningDetector 
+{
+	private BugReporter bugReporter;
+	private OpcodeStack stack;
+	private LinkedHashMap<Integer, CodeException> catchHandlerPCs;
+	private Set<CatchInfo> catchInfos;
+
+	
+    /** constructs a EXS detector given the reporter to report bugs on.
+
+     * @param bugReporter the sync of bug reports
+     */		
+	public ExceptionSoftening(BugReporter bugReporter) {
+		this.bugReporter = bugReporter;
+	}
+	
+	/** overrides the visitor to reset the stack
+	 * 
+	 * @param classContext the context object of the currently parsed class
+	 */
+	@Override
+	public void visitClassContext(ClassContext classContext) {
+		try {
+			stack = new OpcodeStack();
+			super.visitClassContext(classContext);
+		} finally {
+			stack = null;
+		}
+	}
+		
+	/** overrides the visitor to look for methods that catch exceptions
+	 * 
+	 * @param obj the context object of the currently parsed code block
+	 */
+	@Override
+	public void visitCode(Code obj) {
+		try {
+			Method method = getMethod();
+			if (prescreen(method)) {
+				stack.resetForMethodEntry(this);
+				catchHandlerPCs = collectExceptions(obj.getExceptionTable());
+				catchInfos = new HashSet<CatchInfo>();
+				super.visitCode(obj);
+			}
+		} finally {
+			catchInfos = null;
+			catchHandlerPCs = null;
+		}
+	}
+	
+	/** overrides the visitor to find catch blocks that throw runtime exceptions
+	 * 
+	 * @param seen the opcode of the currently parsed instruction
+	 */
+	@Override
+	public void sawOpcode(int seen) {
+		try {
+			stack.mergeJumps(this);
+			int nextPC = getNextPC();
+			CodeException ex = catchHandlerPCs.get(Integer.valueOf(nextPC));
+			if (ex != null) {
+				int endPC;
+				if ((seen == GOTO) || (seen == GOTO_W))
+					endPC = this.getBranchTarget();
+				else
+					endPC = Integer.MAX_VALUE;
+				ConstantPool pool = getConstantPool();
+				ConstantClass ccls = (ConstantClass)pool.getConstant(ex.getCatchType());
+				String catchSig = ccls.getBytes(pool);
+				CatchInfo ci = new CatchInfo(ex.getHandlerPC(), endPC, catchSig);
+				catchInfos.add(ci);
+			}
+		} finally {
+			stack.sawOpcode(this, seen);
+		}
+	}
+	
+	/**
+	 * collects all the valid exception objects (ones where start and finish are before the target)
+	 * and with a catch type
+	 * 
+	 * @param exceptions the exceptions from the class file
+	 * @return the filtered exceptions keyed by catch handler pc
+	 */
+	private LinkedHashMap<Integer, CodeException> collectExceptions(CodeException[] exceptions) {
+		List<CodeException> filteredEx = new ArrayList<CodeException>();
+		for (CodeException ce : exceptions) {
+			if ((ce.getCatchType() != 0) && (ce.getStartPC() < ce.getEndPC()) && (ce.getEndPC() <= ce.getHandlerPC())) {
+				filteredEx.add(ce);
+			}
+		}
+		
+		LinkedHashMap<Integer, CodeException> handlers = new LinkedHashMap<Integer, CodeException>();
+		
+		for (CodeException ex : filteredEx) {
+			handlers.put(Integer.valueOf(ex.getHandlerPC()), ex);
+		}
+		
+		return handlers;
+	}
+	
+	/** returns whether a method explicitly throws an exception
+	 * 
+	 * @param method the currently parsed method
+	 * @return if the method throws an exception
+	 */
+	private boolean prescreen(Method method) {
+		BitSet bytecodeSet = getClassContext().getBytecodeSet(method);
+		return (bytecodeSet != null) && (bytecodeSet.get(Constants.ATHROW));
+	}
+
+	private static class CatchInfo {
+		private int catchStart;
+		private int catchFinish;
+		private String catchSignature;
+		
+		public CatchInfo(int start, int finish, String signature) {
+			catchStart = start;
+			catchFinish = finish;
+			catchSignature = signature;
+		}
+		
+		public int getStart() {
+			return catchStart;
+		}
+		
+		public int getFinish() {
+			return catchFinish;
+		}
+		
+		public String getSignature() {
+			return catchSignature;
+		}
+	}
+}


Property changes on: trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/ExceptionSoftening.java
___________________________________________________________________
Name: svn:mime-type
   + text/plain
Name: svn:eol-style
   + native


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