Anyone creating or planning to create an Ada language track on Exercism ( https://exercism.org/ )? This would be a really good pace to put Ada in front of those looking to learn programming languages.
Jeff.
6 posts - 3 participants
I’m trying to instantiate a generic hash map package in SPARK. The instantiation compiles as legal Ada, but SPARK is giving me the additional error
error: unmatched actual in instantiation of “Formal_Hashed_Maps” declared at a-cfhama.ads:33
package Boolean_Maps is new Ada.Containers.Formal_Hashed_Maps(Module_ID_Type, Boolean, Hash_Func, Equivalent_Key, Standard.“=”);
with a red underline under Module_ID_Type.
Module_ID_Type is defined in a non-generic package as type Module_ID_Type is new Positive range 1..255. I’m using the GNAT compiler. The code compiles and works as expected.
What does this error mean?
Thanks.
2 posts - 2 participants
Main URL: https://hacadacompiler.sourceforge.io/
Sources, site #1: HAC Ada Compiler download | SourceForge.net
Sources, site #2: GitHub - zertovitch/hac: HAC Ada Compiler - a small, quick Ada compiler fully in Ada
Alire Crate: Alire - Hac
What’s new:
exit statement: exit Loop_Name.exit Loop_Name.(i)(j) (array of array) and (i,j) (multi-dimensional array) are no more treated as equivalent (this feature was a remnant of the Pascal syntax).+, -, &) are visible without prefix only in the scope of a use HAT; clause.Note that correct Ada programs, in relation to the above points, were already accepted and parsed correctly by HAC before that change.
Finally, a bit of cosmetics in the build messages:
C:\Ada\hac\exm>..\hac -v2 -c pkg_demo.adb
*******[ HAC ]******* HAC is free and open-source. Type "hac" for license.
[ HAC ] HAC Ada Compiler version 0.26, 08-Jul-2023
[ HAC ] Compiling main: pkg_demo.adb
[ HAC ] | Compiling x_pkg_demo_s.ads (specification)
[ HAC ] \ Compiling x_pkg_demo_s1.ads (specification)
[ HAC ] \ Compiling x_pkg_demo_s11.ads (specification)
[ HAC ] / x_pkg_demo_s11.ads: done.
[ HAC ] \ Compiling x_pkg_demo_s12.ads (specification)
[ HAC ] / x_pkg_demo_s12.ads: done.
[ HAC ] \ Compiling x_pkg_demo_s13.ads (specification)
[ HAC ] / x_pkg_demo_s13.ads: done.
[ HAC ] / x_pkg_demo_s1.ads: done.
[ HAC ] \ Compiling x_pkg_demo_s2.ads (specification)
[ HAC ] \ Compiling x_pkg_demo_s21.ads (specification)
[ HAC ] / x_pkg_demo_s21.ads: done.
[ HAC ] \ Compiling x_pkg_demo_s22.ads (specification)
[ HAC ] / x_pkg_demo_s22.ads: done.
[ HAC ] \ Compiling x_pkg_demo_s23.ads (specification)
[ HAC ] / x_pkg_demo_s23.ads: done.
[ HAC ] / x_pkg_demo_s2.ads: done.
[ HAC ] \ Compiling x_pkg_demo_s3.ads (specification)
[ HAC ] \ Compiling x_pkg_demo_s31.ads (specification)
[ HAC ] / x_pkg_demo_s31.ads: done.
[ HAC ] \ Compiling x_pkg_demo_s32.ads (specification)
[ HAC ] / x_pkg_demo_s32.ads: done.
[ HAC ] \ Compiling x_pkg_demo_s33.ads (specification)
[ HAC ] / x_pkg_demo_s33.ads: done.
[ HAC ] / x_pkg_demo_s3.ads: done.
[ HAC ] | x_pkg_demo_s.ads: done.
[ HAC ] | Compiling x_pkg_demo_m.ads (specification)
[ HAC ] | x_pkg_demo_m.ads: done.
[ HAC ] | Compiling x_pkg_demo_b.ads (specification)
[ HAC ] | x_pkg_demo_b.ads: done.
[ HAC ] Compilation of pkg_demo.adb (main) completed
[ HAC ] ------ Compilation of eventual with'ed unit's bodies ------
[ HAC ] | Compiling x_pkg_demo_s.adb (body)
[ HAC ] | x_pkg_demo_s.adb: done.
[ HAC ] | Compiling x_pkg_demo_s1.adb (body)
6 posts - 3 participants
AdaCore posted an updated roadmap for GNAT Pro. Lots to look forward to here: LLVM, CUDA, FreeRTOS, Alire integration.
6 posts - 6 participants
Is there a good ada cheatsheet that anyone prefers for printing and putting on a wall?
5 posts - 3 participants
I’m working on a system in SPARK and am confused by a warning SPARK is giving about data races.
I’m working on a message passing system that manages several endpoints. There are multiple types of messages. Each message is a record with a Message_Type component specifying the type of the message. To use the system, endpoints use a register procedure and declare what message types they’re allowed to receive.
The system tracks what types of messages can be received by each endpoint in an abstract package state Metadata with Ghost belonging to the message system package. The Send_Message procedure then has preconditions that check with the message system to verify that the receiving endpoint has declared it can receive the type of message being sent.
All the endpoints are initialized at the start of the program by a single thread. Later in the program they’re used by different threads. These later threads will never need to alter Metadata. They take it as a Proof_In global variable.
SPARK is saying that there is a data race possible because the multiple threads are using the Metadata state.
cubedos-time_server-messages.adb:85:09: high: possible data race when accessing variable “message_manager.mailbox_metadata”[#2]
cubedos-time_server-messages.adb:85:09: high: task “cubedos.time_server.messages.send_tick_messages” accesses “message_manager.mailbox_metadata”[#3]
cubedos-time_server-messages.adb:85:09: high: task “cubedos.time_server.messages.message_loop” accesses “message_manager.mailbox_metadata”[#4]
How is this possible? If Metadata is Ghost, shouldn’t it never actually be evaluated at runtime?
Suppose that Metadata wasn’t Ghost. Is there a way I can communicate to SPARK that Metadata should be immutable after all the endpoints are initialized?
Thank you.
Any light
4 posts - 3 participants
By default when you use AWS in an Alire project, you have executed some alr with aws command or added the following line to your Alire toml configuration file:
[[depends-on]]
aws = "~23.0"
Then you are happy to compile your project and use AWS but you may get a cryptic Program_Error exception that is raised when you have your AWS client that tries to connect to a server using https:
aws-client.adb:608 finalize/adjust raised exception
Despite the fact that AWS project is configured with OpenSSL support, it will not use it by default.
Indeed, the AWS project is using the SOCKET configuration which is not configured by default in the GNAT project. Hopefully, you can fix that by building your project with:
alr build -- -XSOCKET=openssl
Now, to avoid the cryptic Program_Error exception, it is also best to check for SSL support in AWS by using a test such as:
if not AWS.Net.SSL.Is_Supported then
-- No SSL support, report a cleaver error message
end if;
3 posts - 3 participants
Lisbon, Portugal, June 14, 2023. Ada-Europe today announced, at
its 27th International Conference on Reliable Software Technologies
(AEiC 2023), that the Ada 2022 Language Reference Manual (LRM) will
be published by Springer in its LNCS series later this year.
Ada 2022 is the latest edition of the Ada programming language
standard, technically denominated ISO/IEC 8652:2023, which was
formally approved and officially published by ISO, the Geneva-based
International Organization for Standardization, on May 2, 2023.
The Ada 2022 LRM is available online:
Ada 2022 Language Reference Manual.
An overview of Ada 2022 is at:
Ada 2022 Overview.
To mark this official milestone, and in continuation of its established
practice, Ada-Europe undertook to support the production of the new
LRM as a dedicated issue of the Springer-published LNCS series.
www.ada-europe.org/press/20230614-Ada2022-Springer.pdf
#Ada2022 #AdaEurope #AdaProgramming
5 posts - 3 participants
Tue 13 - Fri 16 June 2023
Final call: check out rich conference, tutorial, and workshop program!
Final Program available on conference web site.
Interested in Ada or reliable software? See you in Lisbon, Portugal!
For all information: Ada-Europe 2023, and our Usenet newsgroup postings for an overview.
#AEiC2023 #AdaEurope #AdaProgramming
1 post - 1 participant
Hello,
I have been struggling to make my Ada program run on Android (through a Java native interface), with so far no results. As I understand it, the generic Linux GCC compiler will not make the job, because even if it targets the right architecture (arm64), the compiler toolchain needs to be built using Android “binutils”. Is it like that (or even more complex than that)?
In any case, frustrated by the fact that my SAL generated with gprbuild and GCC will refuse to work (at least with the FSF compiler), I posted my issue on Stack Overflow, and somebody threw the idea of using LLVM instead. So I was wondering if the Gnat LLVM project could help me here.
I started reading about LLVM, and I find it a bit hard to grasp. My current understanding is that I could use it to compile Ada into IR code, that would be then compiled into machine code for an specific architecture, without requiring the installation of a particular cross compiler. Is that right?
Is it theoretically feasible to generate a SAL with a Java interface for Android using this toolchain? And if so, how?
Otherwise, could somebody expose the purpose and/or usages of Gnat LLVM?
Before you react, please know that my understanding of compilers is very limited…
In case you are curious about what I am doing, my project is open source, you can take a look at it here:
8 posts - 3 participants
Seen on c.l.a:
I have created Qplt (Quick Plot), an Ada-GUI program to quickly produce a plot of a data set, and make it publicly available in hopes that it might prove useful. The program automatically selects axis ranges and tick intervals. The user may select whether points, lines, or both are plotted, and supply a title and axis labels.
Qplt is available at
Enjoy.
10 posts - 4 participants
Hello here,
The agenda for the 2023 GAP Workshop is available and registrations open (for GAP members only):
2 posts - 2 participants
For whatever reason I had serious performance issues with st-link v2 on Linux. I shall see if they apply to v3 but I have found that openocd works much better for me.
1 post - 1 participant
LEA is a Lightweight Editor for Ada
Web site: http://l-e-a.sf.net/
Source repository #1: LEA / Code / [r343]
Source repository #2: GitHub - zertovitch/lea: LEA is a Lightweight Editor for Ada
Recent changes:
( inserts ).-- if the cursor is within a comment when the Return key& between them.Features:
Currently available on Windows.
Gtk or other implementations are possible: the LEA_Common[.*] packages
are pure Ada, as well as HAC.
Enjoy!
3 posts - 2 participants
GWindows is a full Microsoft Windows Rapid Application Development
framework for programming GUIs (Graphical User Interfaces) with Ada.
GWindows works only with the GNAT development system,
but with some effort, GWindows could be made pure Ada.
GWindows is free and open-source!
Changes to the framework are detailed in gwindows/changes.txt or
in the News forum on the project site.
GWindows Project site:
GWindows GitHub clone:
Enjoy!
1 post - 1 participant
