Fri 30 Oct 2015 15:52 - 16:15 at Grand Station 1 - 13. Type Systems Chair(s): Nobuko Yoshida

Aliasing is crucial for supporting useful implementation patterns, but it makes reasoning about programs difficult. To deal with this problem, numerous type-based aliasing control mechanisms have been proposed, expressing properties such as uniqueness. Uniqueness, however, is black-and-white: either a reference is unique or it can be arbitrarily aliased; and global: excluding aliases throughout the entire system, making code brittle to changing requirements. Disjointness domains, a new approach to alias control, address this problem by enabling more graduations between uniqueness and arbitrary reference sharing. They allow expressing aliasing constraints local to a certain set of variables (either stack variables or fields) for instance that no aliasing occurs between variables within some set of variables but between such sets or the opposite, that aliasing occurs within that set but not between different sets. A hierarchy of disjointness domains controls the flow of references through a program, helping the programmer reason about disjointness and enforce local alias invariants. The resulting system supports fine-grained control of aliasing between both variables and objects, making aliasing explicit to programmers, compilers, and tooling. This paper presents a formal account of disjointness domains along with examples. Disjointness domains provide novel means of expressing may-alias kinds of constraints, which may prove useful in compiler optimisation and verification.

Slides (pdf) (disjointness_domains.pdf)4.19MiB
Slides (keynote) (disjointness_domains.key)3.43MiB

Fri 30 Oct
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15:30 - 17:00: OOPSLA - 13. Type Systems at Grand Station 1
Chair(s): Nobuko YoshidaImperial College London, UK
oopsla201515:30 - 15:52
Sebastian ErdwegTU Darmstadt, Germany, Oliver BračevacTU Darmstadt, Edlira KuciTU Darmstadt, Germany, Matthias KrebsTU Darmstadt, Germany, Mira MeziniTU Darmstadt
Link to publication Pre-print
oopsla201515:52 - 16:15
Stephan BrandauerUppsala University, Dave ClarkeUppsala University, Sweden and KU Leuven, Belgium, Tobias WrigstadUppsala University
Link to publication File Attached
oopsla201516:15 - 16:37
Silvia CrafaUniversità di Padova, Italy, Luca Padovani
oopsla201516:37 - 17:00
Matías ToroUniversity of Chile, Chile, Éric TanterUniversity of Chile, Chile