Visualization of Clone Detection Results

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Visualization of Clone Detection Results
Eclipse Technology Exchange Workshop OOPSLA
2006 Portland, Oregon
Robert Tairas
with Jeff Gray and Ira Baxter
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Code Clones

• A sequence of statements that are duplicated in
  multiple locations in a program

Source Code
ClonedCode
_____ _______ _________ ___ ______ ___ ______ ____
__ _____ ________ ___ _______________ ____ _____
__ ______ _________ _____ _______ ________ ___ __
_____________
_______ _____ _________ _______ ___ ______ _______
_ __________ _______ ____ _______ ________ ___ __
_____________ ____ ______ _________ _____ ____
________ ____
__________ _______ ___ ________ ___ ____________
___ _____ ________ ___ _______________ ______ ___
____ ______ _______ _________ _______ ___ _______
_ ___ _____________
________ ___ _______________
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Clones in Source Code

• Copy-and-paste parts of code from one location to
  another
• The copied code alreadyworks correctly
• No time to be efficient
• Research shows that5-10 of large scalecomputer
  programsare clones (Baxter, 98)

Source Code
_____ _______ _________ ___ ______ ___ ______ ____
__ _____ ________ ___ _______________ ____ _____
__ ______ _________ _____ _______ ________ ___ __
_____________
_______ _____ _________ _______ ___ ______ _______
_ __________ _______ ____ _______ ________ ___ __
_____________ ____ ______ _________ _____ ____
________ ____
__________ _______ ___ ________ ___ ____________
___ _____ ________ ___ _______________ ______ ___
____ ______ _______ _________ _______ ___ _______
_ ___ _____________
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Supporting Tool CloneDR

• Commercial clone detection tool developed by
  Semantic Designs
• Finds clones by examining the abstract syntax
  tree representation of a program
• Java version freely available athttp//www.seman
  ticdesigns.com/Products/Clone/register-download.ht
  ml

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Supporting tool AJDT Visualiser Plugin

• Part of the AspectJ Development Tools (AJDT)
  project
• AJDT Visualiser website http//www.eclipse.org/aj
  dt/visualiser
• An extension point to pass information

Bars Implement IContentProvider Interface
Stripes Implement IMarkupProvider Interface
Visualiser View
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Clone Detection Results
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Process
Clone Detection Results Plugin
CloneDR
Detection Info View
Config Wizard
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3
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Detected Clones View
Results Text File Parser
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Eclipse Platform
Detected Clones View
AJDT Visualiser Plugin

• Initially, user is assisted by detection process
  configuration wizard.
• CloneDR executes and generates a text file
  containing its results. These results are parsed
  by the plugin.
• Detection statistics sent to information view and
  detected clones sent to both textual and
  graphical view (step 3).

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Configuration Wizard

• The detection of clones can run on all files or
  just on pre-selected files
• The detection settings for CloneDR are also set
  in the wizard
• Wizard generates a configuration file that will
  be used by CloneDR

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Detection Information

• Statistical information about the clone detection
  procedure itself in addition to the configuration
  settings are displayed in the clone detection
  results information view.

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List of Clones

• Clone information
• grouped by similarity
• source file
• starting line number
• ending line number
• Not new, Simian and SimScan plugins also provide
  similar reporting

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Visualiser View

• Bars Source files
• Stripes (Kinds) Clones
• Mouse over
• Length of clone
• Other clones in the same clone group

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Visualiser View

• Additional Options
• Display all bars containing the same clones as in
  the selected bar
• Display all bars containing the selected clone
• Open the file containing the selected clone
• Open all files containing clones in the same
  clone group as the selected clone

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The Big Picture
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Case Study

• Performed on open source applications
• JavaGenes, scientific evolutionary software
• JHotDraw, a GUI framework
• Understanding the results
• Clone group in the same class (JavaGenes)

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Case Study

• Understanding the results (continued)
• Ubitiquous clones (JHotDraw), methods that
• return a new Rectangle object
• draw two ovals (including setting their colors)
• setting the undo and redo flags for the drawing
  view

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Future Work

• A more structured view of the source code files
• For OO languages, classes could be displayed in
  UML-like form.
• Demarcation of methods in bars representing
  source files
• Displaying the borders of methods in the view can
  assist in determining which clones are
  method-level clones.
• Tighter integration of CloneDR in Eclipse
• Simplify and speed up the detection and
  visualization process.

• Eclipse

CloneDR
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Thank you. Questions?

• Visualization of Clone Detection Results
  http//www.cis.uab.edu/tairasr/visual
• Clone Detection Literature http//www.cis.uab.edu
  /tairasr/clones/literature
• SoftCom Laboratory http//www.cis.uab.edu/softcom