[Fb-contrib-commit] SF.net SVN: fb-contrib: [562] trunk/fb-contrib/etc

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

Revision: 562
Author:   dbrosius
Date:     2006-06-08 19:04:31 -0700 (Thu, 08 Jun 2006)
ViewCVS:  http://svn.sourceforge.net/fb-contrib/?rev=562&view=rev

Log Message:
-----------
add ISB_EMPTY_STRING_APPENDING bug pattern to ISB

Modified Paths:
--------------
    trunk/fb-contrib/etc/findbugs.xml
    trunk/fb-contrib/etc/messages.xml
    trunk/fb-contrib/samples/ISB_Sample.java
    trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/InefficientStringBuffering.java
Modified: trunk/fb-contrib/etc/findbugs.xml
===================================================================
--- trunk/fb-contrib/etc/findbugs.xml	2006-06-08 17:52:39 UTC (rev 561)
+++ trunk/fb-contrib/etc/findbugs.xml	2006-06-09 02:04:31 UTC (rev 562)
@@ -15,7 +15,7 @@
     
 	<Detector class="com.mebigfatguy.fbcontrib.detect.InefficientStringBuffering" 
 	        speed="fast"
-            reports="ISB_INEFFICIENT_STRING_BUFFERING" />
+            reports="ISB_INEFFICIENT_STRING_BUFFERING,ISB_EMPTY_STRING_APPENDING" />
             
     <Detector class="com.mebigfatguy.fbcontrib.detect.SyncCollectionIterators"
     		speed="slow"
@@ -214,6 +214,7 @@
    	<!-- BugPattern -->
 	
 	<BugPattern abbrev="ISB" type="ISB_INEFFICIENT_STRING_BUFFERING" category="PERFORMANCE" />
+	<BugPattern abbrev="ISB" type="ISB_EMPTY_STRING_APPENDING" category="PERFORMANCE" />
     <BugPattern abbrev="SCI" type="SCI_SYNCHRONIZED_COLLECTION_ITERATORS" category="CORRECTNESS" />
     <BugPattern abbrev="CC" type="CC_CYCLOMATIC_COMPLEXITY" category="STYLE" />
     <BugPattern abbrev="OCP" type="OCP_OVERLY_CONCRETE_PARAMETER" category="STYLE" />

Modified: trunk/fb-contrib/etc/messages.xml
===================================================================
--- trunk/fb-contrib/etc/messages.xml	2006-06-08 17:52:39 UTC (rev 561)
+++ trunk/fb-contrib/etc/messages.xml	2006-06-09 02:04:31 UTC (rev 562)
@@ -615,6 +615,19 @@
 	    </Details>
 	</BugPattern>
 	
+	<BugPattern type="ISB_EMPTY_STRING_APPENDING">
+	    <ShortDescription>method concatenates an empty string to effect type conversion</ShortDescription>
+	    <LongDescription>method {1} concatenates an empty string to effect type conversion</LongDescription>
+	    <Details>
+			<![CDATA[
+			<p> This method concatenates an empty string with a literal value, in order to convert
+			the literal value into a string. It is more efficient to use String.valueOf() to do the same
+			thing as you do not incur the cost of creating a StringBuffer/Builder and calling methods on it
+			to accomplish this.</p>
+			]]>
+	    </Details>
+	</BugPattern>
+	
 	<BugPattern type="SCI_SYNCHRONIZED_COLLECTION_ITERATORS">
 	    <ShortDescription>method creates iterators on synchronized collections</ShortDescription>
 	    <LongDescription>method {1} creates iterators on synchronized collections</LongDescription>

Modified: trunk/fb-contrib/samples/ISB_Sample.java
===================================================================
--- trunk/fb-contrib/samples/ISB_Sample.java	2006-06-08 17:52:39 UTC (rev 561)
+++ trunk/fb-contrib/samples/ISB_Sample.java	2006-06-09 02:04:31 UTC (rev 562)
@@ -38,6 +38,11 @@
 		return msg;
 	}
 	
+	public String testISB8(int a)
+	{
+		return "" + a;
+	}
+	
 	public String toString()
 	{
 		String a = System.getProperty("foo");

Modified: trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/InefficientStringBuffering.java
===================================================================
--- trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/InefficientStringBuffering.java	2006-06-08 17:52:39 UTC (rev 561)
+++ trunk/fb-contrib/src/com/mebigfatguy/fbcontrib/detect/InefficientStringBuffering.java	2006-06-09 02:04:31 UTC (rev 562)
@@ -19,6 +19,8 @@
  package com.mebigfatguy.fbcontrib.detect;
 
 import org.apache.bcel.classfile.Code;
+import org.apache.bcel.classfile.Constant;
+import org.apache.bcel.classfile.ConstantString;
 
 import edu.umd.cs.findbugs.BugInstance;
 import edu.umd.cs.findbugs.BugReporter;
@@ -75,6 +77,26 @@
 									.addSourceLine(this));
 					}
 				}
+			} else if (seen == INVOKEVIRTUAL) {
+				String calledClass = getClassConstantOperand();
+				if (("java/lang/StringBuffer".equals(calledClass)
+				||  "java/lang/StringBuilder".equals(calledClass))
+				&&  "append".equals(getNameConstantOperand())
+				&&  getSigConstantOperand().startsWith("(Ljava/lang/String;)")) {
+					if (opStack.getStackDepth() > 0) {
+						OpcodeStack.Item itm = opStack.getStackItem(0);
+						Object cons = itm.getConstant();
+						if ((cons instanceof String) && (itm.getRegisterNumber() < 0)) {
+							if (((String)cons).length() == 0) {
+								bugReporter.reportBug(
+									new BugInstance(this, "ISB_EMPTY_STRING_APPENDING", NORMAL_PRIORITY)
+										.addClass(this)
+										.addMethod(this)
+										.addSourceLine(this));
+							}
+						}
+					}
+				}
 			} else if (seen == GOTO) {
 				int depth = opStack.getStackDepth();
 				for (int i = 0; i < depth; i++) {


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