-----------------------------------------------------------------------

Ada-Belgium is pleased to announce the program for its

9th Ada Developer Room at FOSDEM 2019 (Ada at the Free and Open source Software Developers' European Meeting)

on Saturday 2 February 2019

Université Libre de Bruxelles (ULB), Solbosch Campus, Room AW1.125 Avenue Franklin D. Roosevelt Laan 50, B-1050 Brussels, Belgium

Organized in cooperation with Ada-Europe

www.cs.kuleuven.be/~dirk/ada-belgium/events/19/190202-fosdem.html fosdem.org/2019/schedule/track/ada

-----------------------------------------------------------------------

*** General Information

FOSDEM, the Free and Open source Software Developers' European Meeting, is a free and non-commercial two-day weekend event organized early each year in Brussels, Belgium. It is highly developer-oriented and brings together 8000+ participants from all over the world.

The goal is to provide open source developers and communities a place to meet with other developers and projects, to be informed about the latest developments in the open source world, to attend interesting talks and presentations on various topics by open source project leaders and committers, and to promote the development and the benefits of open source solutions.

The 2019 edition takes place on Saturday 2 and Sunday 3 February. It is free to attend and no registration is necessary.

In this edition, Ada-Belgium organizes once more a series of presentations related to the Ada Programming Language and Free or Open Software in a s.c. Developer Room. The "Ada DevRoom" at FOSDEM 2019 is held on the first day of the event, Saturday 2 February 2019.

This year FOSDEM has a total of 15 Ada-related presentations by 12 authors from 7 countries! A mini-poster about the Ada DevRoom [1], as well as a one-page Call for Participation for the Ada DevRoom [2] is available; they can be used to help announce the event, and to give an idea about its scope.

[1] www.cs.kuleuven.be/~dirk/ada-belgium/events/19/190202-fosdem-cfpart-poster.jpg [2] www.cs.kuleuven.be/~dirk/ada-belgium/events/19/190202-fosdem-cfpart-a4.pdf

*** Ada Programming Language and Technology

Ada is a general-purpose programming language originally designed for safety- and mission-critical software engineering. It is used extensively in air traffic control, rail transportation, aerospace, nuclear, financial services, medical devices, etc. It is also perfectly suited for open source development.

Awareness of safety and security issues in software systems is increasing. Multi-core platforms are now abundant. These are some of the reasons that the Ada programming language and technology attracts more and more attention, among others due to Ada's support for programming by contract and for multi-core targets. The latest Ada language definition was updated early 2016. Work on new features is ongoing, such as improved support for fine-grained parallelism, and will result in a new Ada standard scheduled for 2020. Ada-related technology such as SPARK provides a solution for the safety and security aspects stated above. More and more tools are available, many are open source, including for small and recent platforms. Interest in Ada keeps increasing, also in the open source community, and many exciting projects have been started.

The Ada DevRoom aims to present the facilities offered by the Ada language (such as for object-oriented, multicore, or embedded programming) as well as some of the many exciting tools and projects using Ada. FOSDEM is an ideal fit for an Ada Developer Room. On the one hand, it gives the general open source community an opportunity to see what is happening in the Ada community and how Ada technology can help to produce reliable and efficient open source software. On the other hand, it gives open source Ada projects an opportunity to present themselves, get feedback and ideas, and attract participants to their project and collaboration between projects.

*** Ada Developer Room Presentations (room: AW1.125, 76 seats)

The presentations in the Ada DevRoom start after the opening FOSDEM keynote. The program runs from 10:30 to 19:00.

10:00-10:30 - Arrival & Informal Discussions

Feel free to arrive early, to start the day with some informal discussions while the set-up of the DevRoom is finished.

10:30-10:35 - Welcome to the Ada DevRoom by Dirk Craeynest - Ada-Belgium

Welcome to the Ada Developer Room at FOSDEM 2019, which is organized by Ada-Belgium in cooperation with Ada-Europe. Ada-Belgium and Ada-Europe are non-profit organizations set up to promote the use of the Ada programming language and related technology, and to disseminate knowledge and experience into academia, research and industry in Belgium and Europe, resp. Ada-Europe has member-organizations, such as Ada-Belgium, in various countries, and direct members in many other countries.

10:35-11:20 - An Introduction to Ada for Beginning and Experienced Programmers - by Jean-Pierre Rosen - Adalog

An overview of the main features of the Ada language, with special emphasis on those features that make it especially attractive for free software development. Ada is a feature-rich language, but what really makes Ada stand-out is that the features are nicely integrated towards serving the goals of software engineering. If you prefer to spend your time on designing elegant solutions rather than on low-level debugging, if you think that software should not fail, if you like to build programs from readily available components that you can trust, you should really consider Ada!

11:30-11:50 - Sequential Programming in Ada: Lessons Learned by Joakim Strandberg - Mequinox

What's hot right now in the proposal for Ada 2020 is increased support of safe parallelism. However, the support for sequential programming in Ada 2012 is absolutely great and probably underestimated. This presentation will demonstrate lessons learned from making an Ada binding to the Wayland Client API: how to leverage nested subprograms, pragma Unmodified, subpools, Gnatcheck and GPS to provide a flexible/enjoyable way of working and at the same time maximize compile-time error checking when developing sequential algorithms.

12:00-12:50 - Autonomous Train Control Systems: a First Approach by Julia Teissl - FH Campus Wien

Numerous small villages in Austria have lost their connections to the railway network because it was no longer cost-effective to operate under a regular schedule. To re-establish these connections, FH Campus Wien started the project "autonome, schienengebundene, on-Demand, open-Track Systeme" AuSoDoTS (Autonomous rail bound on-Demand Open Track systems). The project's objective is to develop a concept for how to safely operate small autonomous trains, without a fixed schedule. Trains are only approaching to stations when a passenger explicitly requests them by pressing a button at the station or using a mobile app. A short track from Liesing at the edge of Vienna to Kaltenleutgeben, a small town in Lower Austria, could be one of the first test locations.

As a first approach a small model railway has been built. The model has two purposes. One is to find the optimal placement for passing loops where trains can pass each other, since the connection is mostly single track. The other is to test different scheduling algorithms for on-Demand service. To fulfill the strict safety aspects of a passenger transportation system, the programming language Ada is used and in following versions SPARK will be used as it can be formally verified to be correct then.

13:00-13:20 - Controlling the Execution of Parallel Algorithms in Ada by Jan Verschelde - University of Illinois at Chicago

Tasking in Ada provides an effective tool for shared memory parallelism. An "any time" algorithm is an algorithm that, given some more resources, will improve the accuracy of an estimate. For example, consider the estimation of Pi by a Monte Carlo method. With multitasking, the status of the running of an "any time" algorithm can be monitored without interrupts. The programming concepts will be illustrated with examples of algorithms in polyhedral geometry. The demonstrated code belongs to the free and open source PHCpack.

13:30-13:50 - Persistence with Ada Database Objects by Stephane Carrez - Twinlife

The presentation describes how Ada Database Objects helps in connecting to an SQLite/MySQL/PostgreSQL database from Ada. It explains how by mapping SQL tables in Ada records, it simplifies saving and updating database records and makes the application more safe and reliable. The presentation will briefly describe the Ada code generator (Dynamo) that is behind this.

14:00-14:50 - Shrink your Data to (almost) Nothing with Trained Compression - by Gautier de Montmollin - Ada-Switzerland

We will show a new Trained Compression generic plug-in, which can leverage prior information about the data to be transmitted for reducing further raw compressed streams. We will also present a pick-and-choose technique feature called "Preselection" for improving the Zip archiving process. The Zip-Ada library has met over the years the needs of several professional users who need the file archiving features, or the data compression features to reduce storage and shorten transmission times. We will show the evolution of this full-Ada portable library and the advantages of using it.

15:00-15:20 - GSH: an Ada POSIX Shell to Speed Up GNU Builds on Windows by Nicolas Roche - AdaCore

GSH is an implementation of a POSIX shell developed for the Windows platform. The aim of the project is to speed up builds of GNU projects on Windows in a large automated build infrastructures. GSH can be used to compile projects depending on autotools, UNIX make, ... It is up to 2-3 times faster than Cygwin shells for GCC builds.

In this talk I will present: - what makes GSH faster than other Windows shells for building GNU projects; - how GSH was developed; - how you can use it to speed up your builds; - the limitations; - what features of Ada we benefit from in this project.

15:30-15:50 - What is Safety-Critical Software, and How Can Ada and SPARK Help? - by Jean-Pierre Rosen - Adalog

We are (too much) used to software having bugs as an unavoidable fate. But for safety-critical software, like the code that's driving planes or trains, "Failure is Not an Option". This presentation exposes the constraints of such software, and how they require a special state of mind, special methods, and special tools - like Ada and SPARK. And these can be useful for more casual programming - zero bug software is nice, even when not safety-critical!

16:00-16:50 - Secure Web Applications with AWA by Stephane Carrez - Twinlife

Web application security is often underestimated, and using a secure framework can help reduce application vulnerabilities. Ada Web Application (AWA) is a web framework that leverages Ada's safety features to provide a secure environment on top of which safe applications are built. AWA is based on several Java-like technologies such as Java Beans, Java Servlet, Java Server Faces, other standards such as OAuth2, REST and OpenAPI, all implemented in Ada.

This presentation briefly describes the AWA architecture and how applications are built with it. The presentation highlights some of the Ada functionalities that contribute to the safety and make applications secure and reliable.

17:00-17:20 - Distributed Computing with Ada and CORBA using PolyORB by Frédéric Praca - Ada-France

Imagine you have a fantastic Ada program or library but you want more! You want it to be scalable and used by other developers with other languages. The goal of this presentation is to show you the way to achieve it without bending to fashion. :) As of today, we see distributed computing as Web services, mainly RESTful stuff. Some technologies exist since years and are working successfully in many systems. One of these is CORBA which allows Object-Oriented communication between applications in languages such as Ada or C++.

In this presentation, the chosen middleware providing CORBA infrastructure is PolyORB. We will use it to make a distributed version of an existing piece of software, the Corporate Bullshit Generator (CBSG), and create client applications in C++ and Ada. This will allow us to put the power of Ada and PolyORB into a distributed system.

17:30-17:50 - Cappulada: Smooth Ada Bindings for C++ by Johannes Kliemann - Componolit

Writing Ada bindings for C and especially for C++ is a tedious but not necessarily sophisticated task. There are several approaches to both C and C++ but many of them lack desired language features, generate non-compilable code or are project specific. With Cappulada (a coinage of coupling, CPP and Ada made pronounceable) we try a more general approach that aims to support complex language features such as templates or inheritance while providing a semantically appropriate mapping of object structures and types. The talk will also cover which features can be mapped and what is not feasible or possible.

18:00-18:20 - The AZip Archive Manager: a full-Ada Open-Source Portable Application - by Gautier de Montmollin - Ada-Switzerland

If you open the AZip application with a can opener, it will look like an Ada programmer's paradise: you'll find Ada on all levels: - the AZip user interface (UI framework specific); - the AZip abstract application layer (platform-independent); - the archive and data compression library (Zip-Ada); - the user interface framework (GWindows); - the run-time library (GNAT's). We will quantify this.

Portability is matched on three different definitions of the word: - platform-independence for the abstracted part and the Zip-Ada library - no porting effort at all there; - you can easily port the user interface layer since most of the job is done in the abstracted part; - no installation needed: the version built on GWindows is contained in a single executable file and can be run from a USB stick; it can be even run in a stealth mode, without writing settings to the registry of the host system.

18:30-18:50 - Proof of Pointer Programs with Ownership in SPARK by Yannick Moy - AdaCore

Pointers are a notorious "defect attractor", in particular when dynamic memory management is involved. Ada mitigates these issues by having much less need for pointers overall (thanks to first-class arrays, parameter modes, generics) and stricter rules for pointer manipulations that limit access to dangling memory. Still, dynamic memory management in Ada may lead to use-after-free, double-free and memory leaks, and dangling memory issues may lead to runtime exceptions.

The SPARK subset of Ada is focused on making it possible to guarantee properties of the program statically, in particular the absence of programming language errors, with a mostly automatic analysis. For that reason, and because static analysis of pointers is notoriously hard to automate, pointers have been forbidden in SPARK until now. We are working at AdaCore since 2017 on including pointer support in SPARK by restricting the use of pointers in programs so that they respect "ownership" constraints, like what is found in Rust.

In this talk, I will present the current state of the ownership rules for pointer support in SPARK, and the current state of the implementation in the GNAT compiler and GNATprove prover, as well as our roadmap for the future.

18:50-19:00 - Informal Discussions & Closing

Informal discussion on ideas and proposals for future events.

*** RISC-V Developer Room Presentation (room: AW1.126, 82 seats)

In addition to the above presentations in the Ada DevRoom, there's also an Ada-related presentation scheduled in the RISC-V Developer Room.

13:30-14:45 - Alternative Languages for Safe and Secure RISC-V Programming - by Fabien Chouteau - AdaCore

In this talk I want to open a window into the wonderful world of "alternative" programming languages for RISC-V. What can you get by looking beyond C/C++. So I will start with a quick introduction to the Ada and SPARK languages, the benefits, the hurdles. I will also present an overview of the applications and domains where they shine, when failure is not an option. I will then do a short getting started session and provide all the details for you to start RISC-V programming with Ada/SPARK on different platforms (QEMU, HiFive1, FPGAs with PicoRV32). At the end of the talk, I will give my view of the RISC-V architecture and community from the perspective of an alternative languages developer. I will cover the good points, the risks, and provide some ideas on how the RISC-V can keep the door open.

*** More information on Ada Developer Room

Speakers bios, pointers to relevant information, links to corresponding FOSDEM pages, etc., are available on the Ada-Belgium site at www.cs.kuleuven.be/~dirk/ada-belgium/events/19/190202-fosdem.html

We invite you to attend some or all of the presentations: they will be given in English. Everybody interested can attend FOSDEM 2019; no registration is necessary.

We hope to see many of you there!

Dirk Craeynest, FOSDEM Ada DevRoom coordinator Dirk.Craeynest@cs.kuleuven.be (for Ada-Belgium/Ada-Europe/SIGAda/WG9)