Development of Java tools using SWT and WALA

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
2
Model JemBuilder

• 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/

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.

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

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)

7
Profile generator
8
Profile generator Add to Available classes
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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Code snippet Available classes Add

• String args fileName // class or jar file
• try
• pjchecker.ClassList list new ClassList
  (args) // uses WALA lib
• HashSetltClassInfogt classSet
  list.getClassList()
• IteratorltClassInfogt 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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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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Code snippet Using WALA classes

• com.ibm.wala.shrikeCT.ClassReader
• String className cr.getName()
• ClassInfo c new ClassInfo (ClassConstants.CONST
  ANT_Class, className, null)
• classSet.add(c)
• for (int i 1 i lt cr.getMethodCount() i)
  
• int accessFlag cr.getMethodAccessFlags(i)
  
• if ((accessFlag 0x0002) ! 0x0002) //
  private methods not included in list
• if (! cr.getMethodName(i).equals("ltinitgt")
  
• !cr.getMethodName(i).equals("ltclinitgt"))
• c new ClassInfo ( ClassConstants.CONST
  ANT_MethodRef,
• className,
  cr.getMethodName(i))
• classSet.add(c)

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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