1. 1 Development of Java tools using SWT and WALA Infinit Højniveausprog, 10 February 2010 Hans Søndergaard Builder example SWT, - The Standard Widget Toolkit WALA, - for static analysis of Java bytecode Example: Profile generator Conclusion

2. Model: JemBuilder 2 aJile Systems: Builder for the aJile Java processor

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/http://www.eclipse.org/swt/ 3

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. 4

5. Analysis of Java bytecode 5 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

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) 6

7. Profile generator 7

8. Profile generator: Add to Available classes 8

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 } }); 9

10. Code snippet: Available classes: Add String[] args = {fileName}; // class or jar file try { pjchecker.ClassList list = new ClassList (args); // uses WALA lib HashSet classSet = list.getClassList(); Iterator 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(...) {...} 10

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() ); 11

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(" ") && !cr.getMethodName(i).equals(" ")) { c = new ClassInfo ( ClassConstants.CONSTANT_MethodRef, className, cr.getMethodName(i)); classSet.add(c); } 12

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 13