SEKE 2012 Proceedings - Knowledge Systems Institute

in the change set. The BFS in call graph stops searching
when the methods in the initial impact set can satisfy the
core condition as defined in Definition 4.
From this definition, we know that the methods in the
IIS are generated from the change set, and satisfy the core
definition as defined above. The methods in the IIS are the
methods most likely impacted by these multiple changes,
that is, the IIS is expected to have few false-positives.
However, it can not meet practical use. On the one hand,
some methods in the IIS are still the noise methods (falsepositives).
These methods are expected to be removed. On
the other hand, there are many other methods that are really
impacted but not included in the IIS, i.e., false-negatives.
These methods should be included in the impact set to guarantee
the consistency of the modification. Therefore, similar
to the propagation of the ripples of the water wave ripple
phenomenon, we should expand the IIS to perform the
propagation analysis to get a final impact set (FIS), which
is hoped to cover more false-negatives and remove some
false-positives from the IIS. The definition of FIS is as
follows:
Algorithm 1 FISComputation
Input:
P : Original program
IIS: Initial impact set
Declare:
m: A method
AS: A set of adjacent methods of the method m in call graph
θ: A threshold
Use:
Adjacent(m): it returns a set of adjacent methods of the method m in call
graph.
Output:
Final impact set FIS
1: FIS = IIS
2: while FIS is not stable do
3: for each m in call graph do
4: AS = Adjacent(m)
5: S = AS ∩ FIS
6: if m/∈ FIS ∧|S|/|AS| θ then
7: FIS = FIS ∪{m}
8: end if
9: if m ∈ FIS ∧|S|/|AS|