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*                       Ecole Normale Supe'rieure                   *
*                                                                   *
*                              Se'minaire                           *
*                SEMANTIQUE ET INTERPRETATION ABSTRAITE             *
*                              P. Cousot                            *
*                                                                   *
*                        Vendredi, 14h00--15h30                     *
*                             Salle R, etage -1                     *
*                  DI  ENS  45 rue d'Ulm  75005 Paris               *
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*** Vendredi 18 mai 2001 **** 14h00 *********************************

Barbara G. RYDER (Rutgers University, New Brunswick, New Jersey, USA 
                  & professeur invit'ee au LIX, Ecole Polytechnique)

Data-flow Analysis of Program Fragments

Re'sume' : Traditional data-flow analysis is performed on whole programs;
however,such whole-program analysis is not feasible for large or incomplete
programs. We propose fragment data-flow analysis as an alternative approach
which computes data-flow information for a specific program fragment.  The
analysis is parameterized by the additional information available about the
rest of the program.

We have developed a model of how to design a fragment analysis for an
existing whole-program data-flow analysis, and have explored two specific
uses of our model. The first refines the results of an inexpensive
whole-program pointer alias analysis for a module of a C program, obtaining
more fine-grained information for this fragment (i.e., module).  The second
performs separable points-to and side effect analyses of a C client program
which uses a library.  In this second application, we show how to analyze
the library separate from the client code, summarize the possible effects
the library code can have on client code, and then separately analyze the
client code using this summary. In this case, the analysis of the client
code is a fragment analysis.  Both uses of fragment analysis have been
empirically evaluated. Initial results on the cost and precision indicate
possible applicability to real-world software.

This work was presented, in part, at the Conference on the Foundations of
Software Engineering (1999), the International Conference on Compiler
Construction (2001), and in technical report DCS-TR-423 October 2000,
available from the PROLANGS website (http://www.prolangs.rutgers.edu).

This research was funded, in part, by NSF grants CCR-980465 and CCR-9900989,
Siemens Corporate Research, and Edison Design Group.

Travail commun avec Atanas ROUNTEV, Rutgers University.

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Pour recevoir l'annonce par courrier electronique: cousot@di.ens.fr
WWW: http://www.di.ens.fr/~cousot/annonceseminaire.shtml
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