by Fabien Chouteau
Ada for micro:bit Part 1: Getting Started
Welcome to the Ada for micro:bit series where we look at simple examples to learn how to program the BBC micro:bit with Ada.
100 entries tagged with #GNAT
by Pierre-Marie de Rodat
GNATcoverage: getting started with instrumentation
This is the second post of a series about GNATcoverage and source code instrumentation. The previous post introduced how GNATcoverage worked originally and why we extended it to support source instrumentation-based code coverage computation. Let’s now see it in action in the most simple case: a basic program running on the host machine, i.e. the Linux/Windows machine that runs GNATcoverage itself.
by Emma Adby
Make with Ada 2020: Disaster Management with Smart Circuit Breaker
Shahariar's project ensures safety against electrical fire or shock during an earthquake, flood, gas leakage or fire breakout by disconnecting the mains with a smart circuit breaker. Additionally, this project won a finalist prize in the 2019/20 Make with Ada competition.by Emma Adby
Make with Ada 2020: CryptAda - (Nuclear) Crypto on Embedded Device
Team CryptAda's project collects entropy, manages an entropy pool, implements a homemade PRNG, and generates RSA keys directly on the board with an accent on security. Additionally, this project won a finalist prize in the 2019/20 Make with Ada competition.by Emma Adby
Make with Ada 2020: The SmartBase - IoT Adjustable Bed
John Singleton's The SmartBase makes your existing adjustable bed safer and easier to use by adding voice control and safe (and fun!) LED underbed lighting! Additionally, this project won first place prize in the 2019/20 Make with Ada competition.by Jon Andrew
CuBit: A General-Purpose Operating System in SPARK/Ada
Last year, I started evaluating programming languages for a formally-verified operating system. I've been developing software for a while, but only recently began work in high integrity software development and formal methods. There are several operating system projects, like the SeL4 microkernel and the Muen separation kernel, that make use of formal verification. But I was interested in using a formally-verified language to write a general-purpose OS - an environment for abstracting the underlying hardware while acting as an arbiter for running the normal applications we're used to.by Nicolas Setton
GNAT Community 2020 is here!
We are happy to announce that the GNAT Community 2020 release is now available! Read the post for access to download and to find out about this year's release highlights.by Pat Rogers
From Ada to Platinum SPARK: A Case Study for Reusable Bounded Stacks
This blog entry describes the transformation of an Ada stack ADT into a completely proven SPARK implementation that relies on static verification instead of run-time enforcement of the abstraction’s semantics. We will prove that there are no reads of unassigned variables, no array indexing errors, no range errors, no numeric overflow errors, no attempts to push onto a full stack, no attempts to pop from an empty stack, that subprogram bodies implement their functional requirements, and so on. As a result, we get a maximally robust implementation of a reusable stack abstraction providing all the facilities required for production use.by Johannes Kliemann
Ada on the ESP8266
Not long ago, AdaCore published its LLVM frontend for GNAT. Also quite recently Espressif updated their LLVM backend to LLVM 9 which also happens to be the LLVM version of GNAT. This gave me to the idea to try out if LLVMs promise of providing modular and reusable toolchain technologies is true.by Martyn Pike
A Trivial File Transfer Protocol Server written in Ada
For an upcoming project, I needed a simple way of transferring binary files over an Ethernet connection with minimal (if any at all) user interaction. A protocol that's particularly appropriate for this kind of usage is the Trivial File Transfer Protocol (TFTP).by Ghjuvan Lacambre
Time travel debugging in GNAT Studio with GDB and RR
Learn how to use GDB and RR's advanced time traveling features in GNAT Studio.by Pierre-Marie de Rodat
A Further Expedition into Libadalang: Save Time with Libadalang.Helpers.App
Martyn’s recent blog post showed small programs based on Libadalang to find uses of access types in Ada sources. Albeit short, these programs need to take care of all the tedious logistics around processing Ada sources: find the files to work on, create a Libadalang analysis context, use it to read the source files, etc. Besides, they are not very convenient to run:
by Vadim Godunko
Using GNAT-LLVM to target Ada to WebAssembly
The GNAT-LLVM project provides an opportunity to port Ada to new platforms, one of which is WebAssembly. We conducted an experiment to evaluate the porting of Ada and the development of bindings to use Web API provided by the browser directly from Ada applications.
by Fabien Chouteau
Ada on a Feather
I was quite happy to see AdaFruit release their first Feather format board including a micro-controller with plenty of Ada support, the STM32F4. I bought a board right away and implemented some support code for it.by Quentin Ochem
Witnessing the Emergence of a New Ada Era
For nearly four decades the Ada language (in all versions of the standard) has been helping developers meet the most stringent reliability, safety and security requirements in the embedded market. As such, Ada has become an entrenched player in its historic A&D niche, where its technical advantages are recognized and well understood. Ada has also seen usage in other domains (such as medical and transportation) but its penetration has progressed at a somewhat slower pace. In these other markets Ada stands in particular contrast with the C language, which, although suffering from extremely well known and documented flaws, remains a strong and seldom questioned default choice. Or at least, when it’s not the choice, C is still the starting point (a gateway drug?) for alternatives such as C++ or Java, which in the end still lack the software engineering benefits that Ada embodies..
by Martyn Pike
An Expedition into Libadalang
I’ve been telling Ada developers for a while now that Libadalang will open up the possibility of more-easily writing Ada source code analysis tools. (You can read more about Libadalang here and here and can also access the project on Github.)
by Alexander Senier
RecordFlux: From Message Specifications to SPARK Code
Handling binary data is hard. Errors in parsers routinely lead to critical security vulnerabilities. In this post we show how the RecordFlux toolset eases the creation of formally verified binary parsers in SPARK.by Arnaud Charlet
The Power of Technology Integration and Open Source
Part of our core expertise at AdaCore is to integrate multiple technologies as smoothly as possible and make it a product. This started at the very beginning of our company by integrating a code generator (GCC) with an Ada front-end (GNAT) which was then followed by integrating a debugger engine (GDB) and led to today's rich GNAT Pro offering.
by Arnaud Charlet
Combining GNAT with LLVM
Presenting the GNAT LLVM project At AdaCore labs, we have been working for some time now on combining the GNAT Ada front-end with a different code generator than GCC.
by Emma Adby
The Make with Ada competition is back!
AdaCore’s fourth annual Make with Ada competition launched this week with over $8K in cash and prizes to be awarded for the most innovative embedded systems projects developed using Ada and/or SPARK.
by Juan Zamorano
Using Ada for a Spanish Satellite Project
I am an Associate Professor at Polytechnic University of Madrid’s (Universidad Politécnica de Madrid / UPM) in the Department of Architecture and Technology of Computer Systems. For the past several years I have been directing a team of colleagues and students in the development of a UPMSat-2 microsatellite. The project originally started in 2013 as a follow-to the UPM-SAT 1, launched by an Ariane-4 in 1995.
by Claire Dross
Using Pointers in SPARK
In this blog post, I will present one of the most interesting additions to the community 2019 version of SPARK: pointer support. One of the core assumption in SPARK has always been the absence of aliasing, so adding pointers without breaking this assumption was quite a challenge. I will explain how this was achieved using an ownership model for pointers (like is done in Rust) through small examples.by Nicolas Setton
GNAT Community 2019 is here!
We are pleased to announce that GNAT Community 2019 has been released! See https://www.adacore.com/download.
by Boran Car
Bringing Ada To MultiZone
C is the dominant language of the embedded world, almost to the point of exclusivity. Due to its age, and its goal of being a “portable assembler”, it deliberately lacks type-safety, opening up exploit vectors. Proposed solutions are partitioning the application into smaller intercommunicating blocks, designed with the principle of least privilege in mind; and rewriting the application in a type-safe language. We believe that both approaches are complementary and want to show you how to combine separation and isolation provided by MultiZone together with iteratively rewriting parts in Ada. We will take the MultiZone SDK demo and rewrite one of the zones in Ada.by Allan Ascanius, Per Dalgas Jakobsen
Winning DTU RoboCup with Ada and SPARK
The Danish Technical University has a yearly RoboCup where autonomous vehicles solve a number of challenges. We participated with RoadRunner, a 3D printed robot with wheel suspension, based on the BeagleBone Blue ARM-based board and the Pixy 1 camera with custom firmware enabling real-time line detection. Code is written in Ada and formally proved correct with SPARK at Silver level.by Pamela Trevino
Public Ada Training Paris June 3-7, 2019
This course is geared to software professionals looking for a practical introduction to the Ada language with a focus on embedded systems, including real-time features as well as critical features introduced in Ada 2012. By attending this course you will understand and know how to use Ada for both sequential and concurrent applications, through a combination of live lectures from AdaCore's expert instructors and hands-on workshops using AdaCore's latest GNAT technology. AdaCore will provide an Ada 2012 tool-chain and ARM-based target boards for embedded workshops. No previous experience with Ada is required.
by Arnaud Charlet
How Do We Use CodePeer at AdaCore
A question that our users sometimes ask us is "do you use CodePeer at AdaCore and if so, how?". The answer is yes! and this blog post will hopefully give you some insights into how we are doing it for our own needs.
by Rob Tice
AdaFractal Part1: Ada with a Portable GUI
The is the first part of a multiple part post that covers the development of the AdaFractal project. The idea was to create fractals in Ada. Here we will cover how to use AWS to create a flexible and portable way to display the generated fractals without using bulky graphics libraries.by Pamela Trevino
Public Ada Training Paris, France Dec 3 - 7, 2018
This course is geared to software professionals looking for a practical introduction to the Ada language with a focus on embedded systems, including real-time features as well as critical features introduced in Ada 2012. By attending this course you will understand and know how to use Ada for both sequential and concurrent applications, through a combination of live lectures from AdaCore's expert instructors and hands-on workshops using AdaCore's latest GNAT technology. AdaCore will provide an Ada 2012 tool-chain and ARM-based target boards for embedded workshops. No previous experience with Ada is required.
by Fabien Chouteau
Ada on FPGAs with PicoRV32
When I bought the TinyFPGA-BX board, I thought it would be an opportunity to play a little bit with FPGA, learn some Verilog or VHDL. But when I discovered that it was possible to have a RISC-V CPU on it, I knew I had to run Ada code on it.by Emma Adby, Fabien Chouteau
GNAT Community 2018 is here!
Calling all members of the Ada and SPARK community, we are pleased to announce that GNAT Community 2018 is here! adacore.com/download
by Thomas Quinot
PolyORB now lives on Github
PolyORB, AdaCore's versatile distribution middleware, now lives on Github. Its new home is https://github.com/AdaCore/polyorb
by Rob Tice
SPARKZumo Part 2: Integrating the Arduino Build Environment Into GPS
This is part #2 of the SPARKZumo series of blog posts. This post covers the build system that was used to build the SPARKZumo project and how to automate the process in GPS.by Rob Tice
SPARKZumo Part 1: Ada and SPARK on Any Platform
So you want to use SPARK for your next microcontroller project? Great choice! All you need is an Ada 2012 ready compiler and the SPARK tools. But what happens when an Ada 2012 compiler isn’t available for your architecture?
by Fabien Chouteau
Ada on the micro:bit
Updated July 2018
by Felix Krause
The Road to a Thick OpenGL Binding for Ada: Part 2
This blog post is part two of a tutorial based on the OpenGLAda project and will cover implementation details such as a type system for interfacing with C, error handling, memory management, and loading functions.by Johannes Kanig
Bitcoin blockchain in Ada: Lady Ada meets Satoshi Nakamoto
Bitcoin is getting a lot of press recently, but let's be honest, that's mostly because a single bitcoin worth 800 USD in January 2017 was worth almost 20,000 USD in December 2017. However, bitcoin and its underlying blockchain are beautiful technologies that are worth a closer look. Let’s take that look with our Ada hat on!
by Felix Krause
The Road to a Thick OpenGL Binding for Ada: Part 1
This blog post is part one of a tutorial based on the OpenGLAda project and will cover some the background of the OpenGL API and the basic steps involved in importing platform-dependent C functions.
by Lionel Matias
Leveraging Ada Run-Time Checks with Fuzz Testing in AFL
Fuzzing is a very popular bug finding method. The concept, very simple, is to continuously inject random (garbage) data as input of a software component, and wait for it to crash. If, like me, you find writing robustness test tedious and not very efficient in finding bugs, you might want to try fuzzing your Ada code. Here's a recipe to fuzz-test your Ada code, using American Fuzzy Lop and all the runtime checks your favorite Ada compiler can provide. Let's see (quickly) how AFL works, then jump right into fuzzing 3 open-source Ada libraries: ZipAda, AdaYaml, and GNATCOLL.JSON.by Manuel Iglesias Abbatermarco
Make with Ada 2017- Ada Based IoT Framework
Summary The Ada IoT Stack consists of an lwIp (“lightweight IP”) stack implementation written in Ada, with an associated high-level protocol to support embedded device connectivity nodes for today’s IoT world. The project was developed for the Make With Ada 2017 competition based on existing libraries and ported to embedded STM32 devices.
by Jamie Ayre
Welcoming New Members to the GNAT Pro Family
As we see the importance of software grow in applications, the quality of that software has become more and more important. Even outside the mission- and safety-critical arena customers are no longer accepting software failures (the famous blue screens of death, and there are many...). Ada has a very strong answer here and we are seeing more and more interest in using the language from a range of industries. It is for this reason that we have completed our product line by including an entry-level offer for C/C++ developers wanting to switch to Ada and reinforced our existing offer with GNAT Pro Assurance for programmers building the most robust software platforms with life cycles spanning decades.
by Fabien Chouteau
There's a mini-RTOS in my language
The first thing that struck me when I started to learn about the Ada programing language was the tasking support. In Ada, creating tasks, synchronizing them, sharing access to resources, are part of the language
by J. German Rivera
Make with Ada 2017- A "Swiss Army Knife" Watch
Summary The Hexiwear is an IoT wearable development board that has two NXP Kinetis microcontrollers. One is a K64F (Cortex-M4 core) for running the main embedded application software. The other one is a KW40 (Cortex M0+ core) for running a wireless connectivity stack (e.g., Bluetooth BLE or Thread). The Hexiwear board also has a rich set of peripherals, including OLED display, accelerometer, magnetometer, gryroscope, pressure sensor, temperature sensor and heart-rate sensor. This blog article describes the development of a "Swiss Army Knife" watch on the Hexiwear platform. It is a bare-metal embedded application developed 100% in Ada 2012, from the lowest level device drivers all the way up to the application-specific code, for the Hexiwear's K64F microcontroller. I developed Ada drivers for Hexiwear-specific peripherals from scratch, as they were not supported by AdaCore's Ada drivers library. Also, since I wanted to use the GNAT GPL 2017 Ada compiler but the GNAT GPL distribution did not include a port of the Ada Runtime for the Hexiwear board, I also had to port the GNAT GPL 2017 Ada runtime to the Hexiwear. All this application-independent code can be leveraged by anyone interested in developing Ada applications for the Hexiwear wearable device.
by Yannick Moy, Martin Becker, Emanuel Regnath
Physical Units Pass the Generic Test
The support for physical units in programming languages is a long-standing issue, which very few languages have even attempted to solve. This issue has been mostly solved for Ada in 2012 by our colleagues Ed Schonberg and Vincent Pucci who introduced special aspects for specifying physical dimensions on types. This dimension system did not attempt to deal with generics though. As was noted by others, handling generics in a dimensional analysis that is, like in GNAT, a compile-time analysis with no impact on the executable size or running time, is the source of the problem of dimension handling. Together with our partners from Technical Universitat München, we have finally solved this remaining difficulty.by Yannick Moy
Prove in the Cloud
We have put together a byte (8 bits) of examples of SPARK code on a server in the cloud. The benefit with this webpage is that anyone can now experiment live with SPARK without installing first the toolset. Something particularly interesting for academics is that all the code for this widget is open source. So you can setup your own proof server for hands-on sessions, with your own exercises, in a matter of minutes.by Pierre-Marie de Rodat
Pretty-Printing Ada Containers with GDB Scripts
When things don’t work as expected, developers usually do one of two things: either add debug prints to their programs, or run their programs under a debugger. Today we’ll focus on the latter activity.
by Yannick Moy
Research Corner - Focused Certification of SPARK in Coq
The SPARK toolset aims at giving guarantees to its users about the properties of the software analyzed, be it absence of runtime errors or more complex properties. But the SPARK toolset being itself a complex tool, it is not free of errors. To get confidence in its results, we have worked with academic partners to establish mathematical evidence of the correctness of a critical part of the SPARK toolset. The part on which we focused is the tagging of nodes requiring run-time checks by the frontend of the SPARK technology. This work has been accepted at SEFM 2017 conference.by Rob Tice
The Adaroombot Project
The Adaroombot project consists of an iRobot CreateⓇ 2 and Ada running on a Raspberry Pi with a Linux OS. This is a great Intro-to-Ada project as it focuses on a control algorithm and a simple serial communications protocol. The iRobot CreateⓇ 2 platform was originally design for STEM education and has great documentation and support - making it very easy to create a control application using Ada. This blog looks at the creation of the project and some cool features of Ada that were learned along the way.by Pierre-Marie de Rodat, Nicolas Setton
GNAT GPL 2017 is out!
For those users of the GNAT GPL edition, we are pleased to announce the availability of the 2017 release of GNAT GPL and SPARK GPL.
by Fabien Chouteau
Ada on the first RISC-V microcontroller
Updated July 2018
by Yannick Moy
(Many) More Low Hanging Bugs
We reported in a previous post our initial experiments to create lightweight checkers for Ada source code, based on the new Libadalang technology. The two checkers we described discovered 12 issues in the codebase of the tools we develop at AdaCore. In this post, we are reporting on 6 more lightweight checkers, which have discovered 114 new issues in our codebase. This is definitely showing that these kind of checkers are worth integrating in static analysis tools, and we look forward to integrating these and more in our static analyzer CodePeer for Ada programs.by Yannick Moy, Nicolas Roche
A Usable Copy-Paste Detector in A Few Lines of Python
After we created lightweight checkers based on the recent Libadalang technology developed at AdaCore, a colleague gave us the challenge of creating a copy-paste detector based on Libadalang. It turned out to be both easier than anticipated, and much more efficient and effective than we could have hoped for. In the end, we hope to use this new detector to refactor the codebase of some of our tools, and we expect to integrate it in our IDEs.by Emmanuel Briot
User-friendly strings API
User friendly strings API In a previous post, we described the design of a new strings package, with improved performance compared to the standard Ada unbounded strings implementation. That post focused on various programming techniques used to make that package as fast as possible.
by Emmanuel Briot
New strings package in GNATCOLL
This post describes the new GNATCOLL.Strings package, and the various optimizations it performs to provide improved performance.by Jerome Guitton, Jérôme Lambourg, Joel Brobecker
Simics helps run 60 000 GNAT Pro tests in 24 hours
This post has been updated in March 2017 and was originally posted in March 2016.
by Pierre-Marie de Rodat
GNATcoverage moves to GitHub
Following the current trend, the GNATcoverage project moves to GitHub! Our new address is: https://github.com/AdaCore/gnatcoverage
by Jorge Real
Writing on Air
While searching for motivating projects for students of the Real-Time Systems course here at Universitat Politècnica de València, we found a curious device that produces a fascinating effect. It holds a 12 cm bar from its bottom and makes it swing, like an upside-down pendulum, at a frequency of nearly 9 Hz. The free end of the bar holds a row of eight LEDs. With careful and timely switching of those LEDs, and due to visual persistence, it creates the illusion of text... floating in the air!
by Fabien Chouteau, Arnaud Charlet, Yannick Moy
SPARK Tetris on the Arduboy
One of us got hooked on the promise of a credit-card-size programmable pocket game under the name of Arduboy and participated in its kickstarter in 2015. The kickstarter was successful (but late) and delivered the expected working board in mid 2016. Of course, the idea from the start was to program it in Ada , but this is an 8-bits AVR microcontroller (the ATmega32u4 by Atmel) not supported anymore by GNAT Pro. One solution would have been to rebuild our own GNAT compiler for 8-bit AVR from the GNAT FSF repository and use the AVR-Ada project. Another solution, which we explore in this blog post, is to use the SPARK-to-C compiler that we developed at AdaCore to turn our Ada code into C and then use the Arduino toolchain to compile for the Arduboy board.
by Pat Rogers
Getting started with the Ada Drivers Library device drivers
The Ada Drivers Library (ADL) is a collection of Ada device drivers and examples for ARM-based embedded targets. The library is maintained by AdaCore, with development originally (and predominantly) by AdaCore personnel but also by the Ada community at large. It is available on GitHub and is licensed for both proprietary and non-proprietary use.
by Raphaël Amiard, Yannick Moy, Pierre-Marie de Rodat
Going After the Low Hanging Bug
At AdaCore, we have a strong expertise in deep static analysis tools (CodePeer and SPARK), and we have been relying on the compiler GNAT and our coding standard checker GNATcheck to deal with more syntactic or weakly-semantic checks. The recent Libadalang technology, developed at AdaCore, provided us with an ideal basis to develop specialized light-weight static analyzers. As an experiment, we implemented two simple checkers using the Python binding of Libadalang. The results on our own codebase were eye-opening: we found a dozen bugs in the codebases of the tools we develop at AdaCore (including the compiler and static analyzers).by Raphaël Amiard, Pierre-Marie de Rodat
Introducing Libadalang
AdaCore is working on a host of tools that works on Ada code. The compiler, GNAT, is the most famous and prominent one, but it is far from being the only one. At AdaCore, we already have several other tools to process Ada code: the ASIS library, GNAT2XML, the GPS IDE. A realization of the past years, however, has been that we were lacking a unified solution to process code that is potentially evolving, potentially incorrect Ada code. Hence Libadalang.by Emmanuel Briot
Integrate new tools in GPS (2)
Customizing build target switches In the first post in this series (Integrate new tools in GPS) we saw how to create new build targets in GPS to spawn external tools via a menu or toolbar button, and then display the output of that tool in its own console, as well as show error messages in the Locations view.
by Yannick Moy
GNATprove Tips and Tricks: What’s Provable for Real Now?
One year ago, we presented on this blog what was provable about fixed-point and floating-point computations (the two forms of real types in SPARK). Since then, we have integrated static analysis in SPARK, and modified completely the way floating-point numbers are seen by SMT provers. Both of these features lead to dramatic changes in provability for code doing fixed-point and floating-point computations.by Emmanuel Briot
Integrate new tools in GPS
This blog, the first in a series, explains the basic mechanisms that GPS (the GNAT Programming Studio) provides to integrate external tools. A small plugin might make your daily workflow more convenient by providing toolbar buttons and menus to spawn your tool and parse its output.by Piotr Trojanek
Verifying Tasking in Extended, Relaxed Style
Tasking was one of the big features introduced in the previous release of SPARK 2014. However, GNATprove only supported tasking-related constructs allowed by the Ravenscar profile. Now it also supports the more relaxed GNAT Extended Ravenscar profile.by Emmanuel Briot
GNAT On macOS Sierra
GNAT and all the tools work great on the newly released macOS Sierra, but gdb needs some tweaking of the system.by Emmanuel Briot
Debugger improvements in GPS 17
The GNAT Programming Studio support for the debugger has been enhanced. This post describes the various changes you can expect in this year's new release of GPS.by Quentin Ochem
Unity & Ada
Using Ada technologies to develop video games doesn’t sound like an an obvious choice - although it seems like there could be an argument to be made. The reverse, however, opens some more straightforward perspectives.by Emmanuel Briot
GNAT Programming Studio (GPS) on GitHub
The GPS source repository has been published on GitHub. This post briefly describes how you can access it, and hopefully contribute.by Emmanuel Briot
Bookmarks in the GNAT Programming Studio (GPS)
As we improve existing views in GPS, we discover new ways to use them. This post shows some of the improvements done recently in the Bookmarks view, and how you can now use it as a TODO list.by Jérôme Lambourg
Efficient use of Simics for testing
As seen in the previous blog article, AdaCore relies heavily on virtualisation to perform the testing of its GNAT Pro products for VxWorks.
by AdaCore Admin
Provably safe programming at Embedded World
AdaCore continues to build reliable and secure software for embedded software development tools. Last month, we attended Embedded World 2016, one of the largest conferences of its kind in Europe, to present our embedded solutions and our expertise for safety, and mission critical applications in a variety of domains.
by Fabien Chouteau
Make with Ada: Candy dispenser, with a twist...
A few months ago, my colleague Rebecca installed a candy dispenser in our kitchen here at AdaCore. I don’t remember how exactly, but I was challenged to make it more… fun.
by AdaCore Admin
Embedded Product Line Updates
Embedded products are not stand alone, this allows them to have safety, mission critical and real-time requirements that they wouldn’t necessarily have otherwise. The embedded product line provides analyzable, verifiable, and certifiable software for both static and dynamic analysis tools.
by Jérôme Lambourg
Porting the Ada Runtime to a new ARM board
A step by step tutorial to adapt the ARM runtime to new MCUs/boards.by Yannick Moy
GNATprove Tips and Tricks: What’s Provable for Real?
SPARK supports two ways of encoding reals in a program: the usual floating-point reals, following the standard IEEE 754, and the lesser known fixed-point reals, called this way because their precision is fixed (contrary to floating-points whose precision varies with the magnitude of the encoded number). This support is limited in some ways when it comes to proving properties of computations on real numbers, and these limitations depend strongly in the encoding chosen. In this post, I show the results of applying GNATprove on simple programs using either floating-point or fixed-point reals, to explain these differences.by Fabien Chouteau
Make with Ada: Formal proof on my wrist
When the Pebble Time kickstarter went through the roof, I looked at the specification and noticed the watch was running on an STM32F4, an ARM cortex-M4 CPU which is supported by GNAT. So I backed the campaign, first to be part of the cool kids and also to try some Ada hacking on the device.by Emma Adby
Modernizing Adacore's Open-Source Involvement
Through the adoption of GitHub we have taken our first step on the way to having a more collaborative and dynamic interaction with, both our users and open source technologies.
by AdaCore Admin
AdaCore Tech Days 2015
by Emmanuel Briot
Traits-Based Containers
This post describes the design of a new containers library. It highlights some of the limitations of the standard Ada containers, and proposes a new approach using generic packages as formal parameters to make these new containers highly configurable at compile time.by Jack Mellor
2015: A Space Ada‑ssey
AdaCore has a long history of providing tools and support to develop mission critical applications for Space. Check out this video we made and showed at the conference to see which ones!by Fabien Chouteau
Make with Ada: "The Eagle has landed"
July 20, 1969, 8:18 p.m. UTC, while a bunch of guys were about to turn blue on Earth, commander Neil A. Armstrong confirms the landing of his Lunar Module (LM), code name Eagle, on the moon. Will you be able to manually land Eagle on the Sea of Tranquillity?by Cyrille Comar
Farewell Robert...
It is with great sadness that I have to announce the death of Robert Dewar...
by Yannick Moy
How Our Compiler Learnt From Our Analyzers
Program analyzers interpret the source code of a program to compute some information. Hopefully, the way they interpret the program is consistent with the way that the compiler interprets it to generate an executable, or the information computed is irrelevant, possibly misleading. For example, if the analyzer says that there are no possible run-time errors in a program, and you rely on this information to compile with dynamic checking off, it is crucial that no run-time error could occur as a result of a divergence of opinion between the analyzer and the compiler on the meaning of an instruction. We recently discovered such an inconsistency in how our compiler and analyzers dealt with floating-point exponentiation, which lead to a change in how GNAT now compile these operations.by Emmanuel Briot
Count them all (reference counting)
Reference countingReference counting is a way to automatically reclaim unused memory. An element is automatically deallocated as soon as there are no more references to it in the program.
by Emmanuel Briot
Larger than it looks (storage pools)
This post shows how to implement a special storage pool that allocates an extra header every time it allocates some memory. This can be used to store type specific information, outside of the type itself.by Jamie Ayre
20 years on...
20 Years of AdaCore: Company as Committed as Ever on Safety-Critical Software Solutions
by Olivier Ramonat
AdaCore Releases GNAT Pro 7.3, QGen 1.0 and GNATdashboard 1.0
February saw the annual customer release of a number of important products. This is no mean task when you consider the fact that GNAT Pro is available on over 50 platforms and supports over 150 runtime profiles (ranging from Full Ada Support to the very restricted Zero Footprint Profile suitable for safety-critical development). All in all, from the branching of the preview version to the customer release it takes us nearly 4 months to package everything up! Quality is assured through the internally developed AdaCore Factory.
by Yannick Moy
AdaCore Tech Days Prez on SPARK
Hristian Kirtchev, who leads the developments of the GNAT compiler frontend, gave a very clear presentation of SPARK at the last AdaCore Tech Days in Boston. This was recorded, here is the video.
by Yannick Moy
GNATprove Tips and Tricks: Catching Mistakes in Contracts
Contracts may be quite complex, as complex as code in fact, so it is not surprising that they contain errors sometimes. GNATprove can help by pinpointing suspicious constructs that, although legal, do not make much sense. These constructs are likely to be caused by mistakes made by the programmer when writing the contract. In this post, I show examples of incorrect constructs that are signaled by GNATprove.by Tristan Gingold
AdaCore at FOSDEM'15
I was at Bruxelles on January 31st to present the components of GNAT GPL 2015 : SPARK 2014 and GNAT GPL for ARM bare-board. This is not unrelated to a previous blog entry on Tetris in SPARK on ARM Cortex M4, in particular I presented that Tetris demo (I brought some boards with me and despite the simple package, none were broken!). The slides contain technical details on the ravenscar profile (main principles), how to build a program for the stm32f4-discovery board and how to port the runtime. There are also less technical slides such as why we choose the stm32f4 board and photos of some graphical demos. As that could be useful to anyone interested in Ravenscar or in porting the runtime to other boards or other platforms, we've made the slides available here.
by Yannick Moy
GNATprove Tips and Tricks: Keeping Justifications Up-To-Date
GNATprove supports the suppression of warnings and justification of check messages with pragmas inserted in the source code. But these justifications may become obsolete across time. To help with that, GNATprove now issues a warning on useless justifications.by Tristan Gingold, Yannick Moy
Tetris in SPARK on ARM Cortex M4
Tetris is a well-known game from the 80's, which has been ported in many versions to all game platforms since then. There are even versions of Tetris written in Ada. But there was no version of Tetris written in SPARK, so we've repaired that injustice. Also, there was no version of Tetris for the Atmel SAM4S ARM processor, another injustice we've repaired.