Title: CFAAR: Control Flow Alteration to Assist Repair,
Abstract: We present CFAAR, a program repair assistance technique that operates by
selectively altering the outcome of suspicious predicates in order to yield
expected behavior. CFAAR is applicable to defects that are repairable by
negating predicates under specific conditions. CFAAR proceeds as follows: 1) it
identifies predicates such that negating them at given instances would make the
failing tests exhibit correct behavior; 2) for each candidate predicate, it
uses the program state information to build a classifier that dictates when the
predicate should be negated; 3) for each classifier, it leverages a Decision
Tree to synthesize a patch to be presented to the developer. We evaluated our
toolset using 149 defects from the IntroClass and Siemens benchmarks. CFAAR
identified 91 potential candidate defects and generated plausible patches for
41 of them. Twelve of the patches are believed to be correct, whereas the rest
provide repair assistance to the developer.