Clones & Macro-Co-Changes

Angela Lozano*, Fehmi Jaafar, Kim Mens, Yann-Gael Gueheneuc*Software Languages Lab (SOFT)

Vrije Universiteit Brussel-VUBBelgium

Clones & Macro-Co-Changes

Friday 31 January 14

MotivationWhat we didResultsDiscussion

Agenda


Require replication of

changes

PlowAction

ChangeAction

UnloadAction


Clones need consistent changesall

PlowAction ChangeAction

UnloadAction


Clones need consistent changesall + same way


UnloadAction

Unit selectedOne = super.getActiveUnit();Unit unit = super.getActiveUnit();

Unit unit = super.getActiveUnit();


PlowAction

ChangeAction

UnloadAction

PlowAction

ChangeAction

UnloadAction

PlowAction

ChangeAction

UnloadAction

PlowAction

ChangeAction

UnloadAction

Clones need consistent changesall + same way + same time

✗

> !=< ==

> !=< ==

> !=< ==

✔ ︎Friday 31 January 14

Do they need consistent changes?• Percentage of inconsistent changes to clone groups:

• ~50% (exact clones) [Krinke07], ~50% [Juergens09]

• At least 30% (exact clones) [Gode09]

• Most common type of change (ignores patterns per clone groups):

• Consistent (~45% with a 24h delay) [Aversano07]

• Depends on the application analyzed, either Independent Evolution or Consistent Changes [Thummalapenta10]

• Consecutive consistent changes [Gode11]

• At least 1/3 of clone groups require at least 1 consistent change [Kim05]

• Weak correlation between files sharing a clone and co-changes [Geiger06]


MAYBE the definition of consistent changes is

too restrictive


Clones need consistent changesall + same way + same time✗

PlowAction

ChangeAction

UnloadAction

PlowAction

ChangeAction

UnloadAction

> !=< ==

> !=< ==

> !=< ==


Clones need consistent changesall + same way + same time✗

PlowAction

ChangeAction

UnloadAction

PlowAction

ChangeAction

UnloadAction

> !=< ==

> !=< ==

> !=< ==

✔ ︎Friday 31 January 14

Commit transactions

file1

file2

file4

file3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15


file1

file2

file4

file3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Macro Changes(MC)

1 2 3 4 5 6


file1

file2

file4

file3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Macro Changes(MC)

1 2 3 4 5 6


file1

file2

file4

file3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Macro Co Changes(MCC)

1 2 3 4 5 6


file1

file2

file4

file3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15


1 2 3 4 5 6

✔ ︎✔ ︎

✔ ︎✔ ︎

✔ ︎✔ ︎

MCC


file1

file2

file4

file3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15


1 2 3 4 5 6

✔ ︎✔ ︎

✔ ︎✔ ︎

✔ ︎✔ ︎

MCC

✔ ︎✔ ︎

✔ ︎✔ ︎

✔ ︎✔ ︎

✔ ︎ ✔ ︎ ✔ ︎✗

AMCC


Are MCC at file level a good proxy to discard consistent changes?


Research question

• Null hypothesis

• Cloned files tend to co-change equally with:

• cloned files with which they have cloning relations

• and with other cloned files

• Alternative hypothesis

• Cloned files tend to co-change more with:

• cloned files with which they have cloning relations

• than with other cloned files.


• Did it change with files with which it shares clones?

• Did it change with cloned files with which it does not share clones?

• Did it change with both?

For all cloned files


Example

file2

file3

file4

file5

file6

file7

file8

file9

file10

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Macro Changes

file1


Example

file2

file3

file4

file5

file6

file7

file8

file9

file10

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Macro Changes

1 2 3 4 965 87 10 11 12Macro CO Changes

file1


Example

file2

file3

file4

file5

file6

file7

file8

file9

file10

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Macro Changes

1 2 3 4 965 87 10 11 12Macro CO Changes

✔ ✔ ✔

file1


Example

file2

file3

file4

file5

file6

file7

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file10

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Macro Changes

1 2 3 4 965 87 10 11 12Macro CO Changes

✔ ✔ ✔✔ ✔ ✔ ✔

file1


Example

file2

file3

file4

file5

file6

file7

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file10

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Macro Changes

1 2 3 4 965 87 10 11 12Macro CO Changes

✔ ✔ ✔✔ ✔ ✔ ✔

✔ ✔ ✔

file1


Example

file2

file3

file4

file5

file6

file7

file8

file9

file10

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Macro Changes

1 2 3 4 965 87 10 11 12Macro CO Changes

✔ ✔ ✔✔ ✔ ✔ ✔

✔ ✔ ✔

file1


Example

file2

file3

file4

file5

file6

file7

file8

file9

file10

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Macro Changes

1 2 3 4 965 87 10 11 12Macro CO Changes

✔ ✔ ✔✔ ✔ ✔ ✔

✔ ✔ ✔

RESULTSCO

CO

CO

CO

O

C

C

C

O

-

file1


Experimental Method

• Selection of applications to analyze:

• OSS, SVN

• Detection of cloning relations:

• CCFinderX default settings


Data collected

Language Commits MCCs Files Cloned

ArgoUML Java 2285 190 847

JFreeChart Java 1534 130 692

XercesC C++ 1809 203 79

XalanC C++ 2244 218 38

OpenSER C 2303 246 170

FreeBSD C 23907 84 4


Results: changes Clones Othersboth

cloned files that were not part of any MCC or AMCC

ArgoUMLJFreeChart XercesC XalanC OpenSER FreeBSD

CC


MCC


AMCC

bothboth

Clones

Clones


Results: bugs

AMCC in bug fixes


Changed in bug fixes


MCC in

bug fixes


(A)MCC with its clonesChanged in bugfixes

(A)MCC with others

Cloned files


Does that mean that clones need consistent (A)MCC?

all?


UnloadAction



all?


UnloadAction Future work



UnloadAction


Unit selectedOne = null; Unit unit = Factory.getUnit();


same way?



UnloadAction


Unit selectedOne = null; Unit unit = Factory.getUnit();


Future work

same way?


Angela Lozano

[email protected]

Clones & Macro-Co-Changes

MCC analysis did not discard the assumption of consistent changes

Cloned files tend to co-change more with cloned files with which they have cloning relations.

The files that (A)MCC with others are not modified in bug-fixes, few files that (A)MCC with their clones are modified in bug-fixes.


mailto:[email protected]

mailto:[email protected]