We show how to underapproximate the procedure summaries of recursive programs
over the integers using off-the-shelf analyzers for non-recursive programs. The
novelty of our approach is that the non-recursive program we compute may
capture unboundedly many behaviors of the original recursive program for which
stack usage cannot be bounded. Moreover, we identify a class of recursive
programs on which our method terminates and returns the precise summary
relations without underapproximation. Doing so, we generalize a similar result
for non-recursive programs to the recursive case. Finally, we present
experimental results of an implementation of our method applied on a number of
examples.Comment: 35 pages, 3 figures (this report supersedes the STTT version which in
turn supersedes the TACAS'13 version
