studying late propagations in code clone evolution using software repository mining

I, Clone

The paper formerly known as

“Studying Late Propagations in Code Clone Evolution Using Software Repository Mining”

by Hsiao Hui Mui, Andy Zaidman, Martin PinzgerDelft University of Technology

IWSC 2014, Antwerp, Belgium

What you should know…

Hsiao Hui MuiFormer MSc student

Now working in industry

Main driver behind this research!

I, Robot

Plot

A robot goes against his “programming”……thereby disobeying the “three laws”1

1. A robot may not injure a human being

2. A robot must obey orders given by a human

3. A robot must protect its own existence

1. By Isaac Asimov

• D’oh!!!

• (wrong movie)

Plot

A robot goes against his “programming”……thereby disobeying the “three laws”1

1. A robot may not injure a programmer

2. A robot must obey orders given by a programmer

3. A robot must protect its own existence

1. By Andy Zaidman

I, Late Propagation

Law 1: A clone may not injure a programmer

Do late propagations cause bugs?Answer: this paper

Law 2: A clone must obey orders given by a programmer

Do late propagations obey?Answer: code clone management???

Law 3: A clone must protect its own existence

Do late propagations survive, or do they become inconsistent?Answer: this paper (partially)

Study

System Revisions # Clone Sets

Short-term LatePropagations

Long-termLate Propagations

# Bugs

Subclipse 1946 632 1 6 2

JEdit 2481 696 30 5 8

FreeCol 4935 311 8 0 0

Seam 3005 584 0 0 0

Q1: Are late propagations frequently occurring?

System Revisions # Clone Sets

Short-term LatePropagations

Long-termLate Propagations

# Bugs

Subclipse 1946 632 1 6 2

JEdit 2481 696 30 5 8

FreeCol 4935 311 8 0 0

Seam 3005 584 0 0 0

Q2: Do late propagations induce bugs?

System Revisions # Clone Sets

Short-term LatePropagations

Long-termLate Propagations

# Bugs

Subclipse 1946 632 1 6 2

JEdit 2481 696 30 5 8

FreeCol 4935 311 8 0 0

Seam 3005 584 0 0 0

Q3: Package distance of clone pairs involved in late propagations?

Questions?

I clone, you clone, we clone…