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POPL 2019
Sun 13 - Sat 19 January 2019 Cascais, Portugal
Fri 18 Jan 2019 16:05 - 16:27 at Sala II - Program Analysis I Chair(s): Michael D. Adams

Precise static analyses are context-, field- and flow-sensitive. Context- and field-sensitivity are both expressible as context-free language (CFL) reachability problems. Solving both CFL problems along the same data-flow path is undecidable, which is why most flow-sensitive data-flow analyses over-approximate field-sensitivity through k-limited access-path, or through access graphs. Unfortunately, as our experience and this paper show, both representations do not scale very well when used to analyze programs with recursive data structures.

Any single CFL-reachablity problem is efficiently solvable, by means of a pushdown system. This work thus introduces the concept of synchronized pushdown systems (SPDS). SPDS encode both procedure calls/returns and field stores/loads as separate but synchronized CFL reachability problems. An SPDS solves both individual problems precisely, and approximation occurs only in corner cases that are apparently rare in practice: at statements where both problems are satisfied but not along the same data-flow path.

SPDS are also efficient: formal complexity analysis shows that SPDS shift the complexity from |F|^{3k} under $k$-limiting to |S||F|^2, where F is the set of fields and S the set of statements involved in a data-flow. Our evaluation using DaCapo shows this shift to pay off in practice: SPDS are almost as efficient as k-limiting with k=1 although their precision equals the case k is infinite. For a typestate analysis SPDS accelerate the analysis up to 83x for data-flows of objects that involve many field accesses but span rather few methods.

We conclude that SPDS can provide high precision and further improve scalability, in particularly when used in analyses that expose rather local data flows.

Fri 18 Jan

15:21 - 16:27: Research Papers - Program Analysis I at Sala II
Chair(s): Michael D. AdamsUniversity of Utah
POPL-2019-Research-Papers15:21 - 15:43
Umang MathurUniversity of Illinois at Urbana-Champaign, P. MadhusudanUniversity of Illinois at Urbana-Champaign, Mahesh ViswanathanUniversity of Illinois at Urbana-Champaign
Link to publication DOI Pre-print Media Attached File Attached
POPL-2019-Research-Papers15:43 - 16:05
Oana-Fabiana AndreescuInternet of Trust, Thomas P. JensenINRIA Rennes, Stéphane LescuyerProve & Run, Benoît MontaguProve & Run
Link to publication DOI Pre-print File Attached
POPL-2019-Research-Papers16:05 - 16:27
Johannes SpäthFraunhofer IEM, Karim AliUniversity of Alberta, Eric BoddenHeinz Nixdorf Institut, Paderborn University and Fraunhofer IEM
Link to publication DOI Pre-print File Attached