The document discusses the development of Java tools using SWT and WALA, focusing on SWT as a user interface toolkit and WALA for static analysis of Java bytecode. It includes a comparison of SWT and Swing, details WALA's features, and provides examples of building a profile generator and class analysis tools. The conclusion highlights SWT's advantages in terms of efficiency and WALA's advanced capabilities despite its installation challenges.

1. Development of Java tools
using
SWT and WALA
• Builder example
• SWT, - The Standard Widget Toolkit
• WALA, - for static analysis of Java bytecode
• Example: Profile generator
• Conclusion
Infinit Højniveausprog, 10 February 2010
Hans Søndergaard
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2. Model: JemBuilder
aJile Systems:
• Builder for the
aJile Java
processor
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3. GUI programming using SWT
• SWT : The Standard Widget Toolkit
– designed to provide efficient, portable access
to the user-interface facilities of the operating
systems on which it is implemented
– part of Eclipse
– many code snippets
– see http://www.eclipse.org/swt/
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4. SWT versus Swing
• No clear difference as to performance
• Swing
– has more memory consumption than SWT
– has all its components implemented by itself
• has much more classes to be loaded in runtime.
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5. Analysis of Java bytecode
• WALA provides static analysis capabilities for Java bytecode
• WALA features include:
 Java type system and class hierarchy analysis
 Interprocedural dataflow analysis
 Pointer analysis and call graph construction
 General framework for iterative dataflow
 General analysis utilities and data structures
 A dynamic load-time instrumentation library for Java
• open source license
• http://wala.sourceforge.net/wiki/index.php/Main_Page
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6. Example: PositiveListChecker
• Scans a list of classes to be checked
• A Profile must be available
– a positive list of classes with methods
• The result is written in a report file.
Generated report file:
Not on positive list
====================
(type, class, method)
(7, java/lang/Object, null)
(10, hello/NotPositiveClass, staticMethod1)
(7, hello/NotPositiveClass, null)
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7. Profile generator
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8. Profile generator:
Add to Available classes
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9. Code snippet:
Available classes: Add
Button addButton = new Button (composite, SWT.PUSH);
addButton.setText (" Add ");
addButton.addSelectionListener (new SelectionAdapter () {
public void widgetSelected (SelectionEvent e) {
FileDialog fileDialog = new FileDialog(fileList.getShell(), SWT.OPEN);
String[] filterNames = new String[] {"Class Files“,"Jar Files“,"All
Files(*)"};
String [] filterExtensions = new String [] {"*.class", "*.jar", "*"};
...
String fileName = fileDialog.open();
... // see next slide
}
});
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10. Code snippet:
Available classes: Add
String[] args = {fileName}; // class or jar file
try {
pjchecker.ClassList list = new ClassList (args); // uses WALA lib
HashSet<ClassInfo> classSet = list.getClassList();
Iterator<ClassInfo> itr = classSet.iterator();
for (; itr.hasNext(); )
{
ClassInfo info = itr.next();
if (info.methodName == null) // a class
availableClassList.addClass(info.className);
else // a method
availableClassList.addMethod(info.className, info.methodName);
}
createTree (availableListTree, availableClassList);
}
catch(...) {...}
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11. Code snippet:
Using WALA classes
• com.ibm.wala.shrikeBT.shrikeCT.OfflineInstrumenter;
OfflineInstrumenter oi = new OfflineInstrumenter();
oi.parseStandardArgs(args);
• com.ibm.wala.shrikeBT.shrikeCT.ClassInstrumenter;
ClassInstrumenter ci;
oi.beginTraversal();
while ((ci = oi.nextClass()) != null)
doClass( ci.getReader() );
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12. Code snippet:
Using WALA classes
• com.ibm.wala.shrikeCT.ClassReader;
String className = cr.getName();
ClassInfo c = new ClassInfo (ClassConstants.CONSTANT_Class, className, null);
classSet.add(c);
for (int i = 1; i < cr.getMethodCount(); i++) {
int accessFlag = cr.getMethodAccessFlags(i);
if ((accessFlag & 0x0002) != 0x0002) // private methods not included in
list
{
if (! cr.getMethodName(i).equals("<init>") &&
!cr.getMethodName(i).equals("<clinit>")) {
c = new ClassInfo ( ClassConstants.CONSTANT_MethodRef,
className, cr.getMethodName(i));
classSet.add(c);
}
}
}
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13. Conclusion
• SWT is an alternative to Swing
– part of Eclipse
– less classes and less memory consumption
– many code snippets
• WALA
– harder to install and get down to use
– but many features for static analysis of Java
bytecode
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