This set of slides accompanied my lecture on reverse engineering held at the University of Bern. More information at: scglectures.unibe.ch/evo2008

1. Reverse Engineering
Tudor Gîrba
www.tudorgirba.com

2. Reverse engineering is analyzing a subject system to:
identify components and their relationships, and
create more abstract representations.
0
& Cross, 9
C hikofky

3. Why reverse engineer?

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12. Disas semble Run

13. Disas semble Run
a nd co mpare
Test

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16. Why reverse engineer software?

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21. Setting direction
First contact
Initial understanding
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22. Setting direction patterns
First contact patterns
Initial understanding patterns
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What are patterns?

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First contact
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25. You got to be careful if you don't know where you're
going, because you might not get there.
ra
Yogi Ber

26. Setting direction patterns
Set Where
direction to start
Agree Most valuable
on maxims first
Maintain Coordinate What not What
direction direction to do to do
Appoint Speak to the If it ain’t broke Fix problems
a navigator round table don’t fix it not symptoms
How to do
Keep it simple

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First contact
Initial understanding
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28. Interview during demo Chat with maintainers
What is the usage? What is the history?
What are the bugs? What is the process?
What do you like? What are the problems?

29. Interview during demo Chat with maintainers
What is the usage? What is the history?
What are the bugs? What is the process?
What do you like? What are the problems?
all humans:
that th ey are
mber
Reme plain
h
t ey com usiastic
they are enth eir jobs
tect th
they pro

31. Read all code in one hour

32. Read all code in one hour ?

33. Read all code in one hour ?
100’000 lines of code

34. Read all code in one hour ?
100’000 lines of code
* 2 = 200’000 seconds

35. Read all code in one hour ?
100’000 lines of code
* 2 = 200’000 seconds
/ 3600 = 56 hours

36. Read all code in one hour ?
100’000 lines of code
* 2 = 200’000 seconds
/ 3600 = 56 hours
/ 8 = 7 days

37. A rgoUML

38. Moose

39. I took a course in speed reading and read “War and
Peace” in twenty minutes.
It’s about Russia.
n
Woody Alle

41. First contact patterns
Talk with Talk with
developers users
Talk
Chat with Interview about it
maintainers during demo
Verify what Read Read about Compile
you hear the code the code the code
Read all code Skim Do a mock
in one hour documentation installation

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First contact
Initial understanding
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43. Speculate about design
Layout Abstract
Item
Graph Node Edge

44. Identify exceptional entities

45. Identify exceptional entities
for i in $( ls ); do
echo `wc -l $i` >> temp
done
sort -nr temp | head -10

46. Initial understanding patterns
Top down
Recover
design
Speculate
about design
Iteration
Analyze Study
persistent data exceptional entities
Recover Identify
database problems
Bottom up

47. Setting direction
First contact
Initial understanding
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Detailed model capture
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48. To understand: refactor

49. To understand: refactor
write tests

50. To understand: refactor
write tests
step through execution

51. Learn from the past

52. Detailed model capture patterns
Tie code and
questions
Track your Expose
understanding design
Refactor
to understand
Expose Encode
collaborations assumptions
Step through Write tests
execution to understand
Expose
contracts Expose
evolution
Look for Learn from
the contracts the past

53. Setting direction
First contact
Initial understanding
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Detailed model capture
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54. Tudor Gîrba
www.tudorgirba.com
creativecommons.org/licenses/by/3.0/