Download Dias nummer 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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Model: JemBuilder
aJile Systems:
• Builder for the
aJile Java
processor
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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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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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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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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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Profile generator
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Profile generator:
Add to Available classes
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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
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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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.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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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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