I have zero experience with Ada so please bear with me. We inherited a 20 year old system written in the late 90's. The compiled code is currently running on a Sun Solaris 10 system. No one has touched the code in years. The compiler for Ada is APEX. I am tasked to know if this will run on Solaris 11 and if so what compiler to use. So my question is - does apex even exist anymore? I found an article that references it and the website (www.rational.com) is no longer active - it reroutes you to an IBM site. The 800 number does not work either. So am I to assume this is no longer an option? What do I do now to migrate and recompile all our code on the new system? C C++ Ada etc. Do I need to buy new compilers - will it take coding changes to work? Any help is greatly appreciated.
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1Ada is designed to allow writing portable code. GNAT is a free Ada implementation. It's impossible to predict how many problems you'll have compiling old Ada code on a new implementation. As a first step, I'd copy the code to the new system and try building it with GNAT. – Keith Thompson Oct 21 '20 at 20:53
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3A quick check on Google shows that IBM Rational Apex was sold to Atego in 2011. Atego was acquired by PTC in 2014 (see also [this Wiki page](https://en.m.wikipedia.org/wiki/Atego_(company))). The Apex Ada compiler is now marketed and sold by PTC (see [the product website](https://www.ptc.com/en/products/developer-tools/apexada)). It does seem to support Solaris, although no specifc version is mentioned. – DeeDee Oct 21 '20 at 21:01
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So, try it under Gnat first, and see if you can negotiate a demo license from PTC for the compiler (NOTE : PTC sell more than one Ada compiler ) Code changes should be minimal; you'll probably have to rename files to Gnat's .ads/.adb convention though. Do you need to stick with Solaris? – Oct 21 '20 at 21:33
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Just curious : did this software work for 20+ years without maintenance? Or was it sleeping on a disk somewhere? – Zerte Oct 22 '20 at 01:16
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Yes I must stick with Solaris. It worked without maintenance for at least 12 years. DeeDee thanks so much for the research. I am afraid to touch the code since I never compiled or touched an ADA program in my life. Will I be able to do this successfully based on reading your comments here and elsewhere in this forum regarding GNAT - (whatever that is). – Sheldon Oct 22 '20 at 02:09
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2"It worked without maintenance for at least 12 years." What a reliable system. Are any of your systems written in other languages that reliable? What does that suggest for language choice for future systems? – Jeffrey R. Carter Oct 22 '20 at 10:04
3 Answers
ApexAda v5.2 added Solaris 11.4 support. You can found out more about the current state of ApexAda from PTC's recent August 2020 webinar https://www.ptc.com/en/resources/plm/webcast/ada-developer-tools-webinar/thank-you
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There's a good chance you don't even need to recompile. Oracle guarantees backwards binary compatibility on Solaris:
Oracle Solaris Guarantee Program (valid through 12/31/2021)
Oracle Solaris is designed and tested to protect customer investments in software.
While new functionality may be introduced in new releases, Oracle Solaris is designed with continuity of binary interfaces, so applications developed on earlier releases can continue to run. This enables customers to purchase new systems or upgrade the OS on older systems and continue to run their existing applications.
Customers and Partners who have purchased Oracle Premier Support for Operating Systems can receive assistance in resolving compatibility issues identified when moving a binary application from an earlier OS release.
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A binary application built on Solaris 2.6 or later that makes use of operating system interfaces as defined in
stability.5run on subsequent releases of Oracle Solaris, including their initial releases and all updates, even if the application has not been recompiled for those latest releases. If an application experiences a compatibility problem when running on your latest supported Oracle Solaris Operating System, support is offered as described below:For Oracle Solaris 10
Use the integrated "appcert" utility (see the man page for
appcert) to check your application. If no errors are reported but problems running the application remain, a Service Request (SR) should be opened to obtain support.For Oracle Solaris 11 and subsequent releases
The Preflight Application Checker tool is used to verify application compatibility and can be downloaded from: http://www.oracle.com/technetwork/server-storage/solaris11/downloads/index.html. The package includes documentation that describes how to check an application for compatibility with Oracle Solaris.
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Note that if you have an Oracle Solaris support contract, and your compiled application passes the above compatibility checks (appcheck for Solaris 10, "Preflight Application Checker tool" for Solaris 11), it's Oracle's problem, not yours. Even if the binary was compiled 20+ years ago on Solaris 2.6.
For another 14 months or so, anyway.
In my experience, your binary compiled on Solaris 10 will work just fine on Solaris 11 without being recompiled.
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I worked recently re-porting a flight simulator from 1995 era that run on an Silicon Graphics servers, IRIX OS, Apex Ada with low level C code. This interfaced to display hosts that were running C and SL-GMS graphics. Its a bit hopeful to say it will run on the latest OS version when talking about a 20+ year old legacy system. Some issues you will find is legacy systems used 32 bit pointers, which are now almost universally 64 bit pointers. Many of the low level code routines, especially in C were manipulating pointers using "int", they will all needed to be changed to "long" to accommodate 64 bit pointers. If the system interfaces to external equipment, there may be big-endian to little-endian issues on top of the 32-64 bit issue. Ditto if the new host equipment has changed from a processor that used big endian but now uses little endian (say Intel) or vice versa. Any packed formats need to take into account that the pointers will be 64 bit so will require 8 bytes not 4 in any packed structure. That's just pointing out the main issues, there will also most likely be deprecation issues, such as 32 bit libraries, ...
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1*Its a bit hopeful to say it will run on the latest OS version when talking about a 20+ year old legacy system.* It's not just expected to work, Oracle actually guarantees it will work. Solaris isn't Linux. *Many of the low level code routines, especially in C were manipulating pointers using "int", they will all needed to be changed to "long" to accommodate 64 bit pointers.* It's fundamentally **wrong** to use either `int` or `long` to hold pointers in any code. *Any packed formats ...* You've never programmed on something like SPARC hardware that actually cares about alignment, have you? – Andrew Henle Nov 09 '20 at 10:39
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Actually I have sorted out unaligned accesses before, but not on a Sparc hardware. If you read the comment I did not mention unaligned access issues! As for using int and long for pointers, I did not say I used them! They were being used in the LEGACY code, hence the original coders made it “unportable”. Don’t infer things I did not state please! – DenzilDexter Nov 15 '20 at 08:01
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You stated "all needed to be changed to "long" to accommodate 64 bit pointers". Are you even aware there's a **huge** base of 64-bit platforms where `long` can't hold a pointer? You never would have posted anything like that if you knew how utterly broken putting pointers into `int` or `long` values is - that code doesn't need to be changed to use `long` - it needs to have its entire pointer usage recoded to stop cramming pointers into non-pointer values. You posted that you worked on that type of code, porting it to 64 bit. If you used `long` for pointers, **you did it wrong**. – Andrew Henle Nov 16 '20 at 00:47
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(cont) And please read the link I posted in my answer about how binary compatibility is **guaranteed** in Solaris across releases. I'd fully expect a binary compiled twenty years ago to work just fine on Solaris today. The most "stable" Linux literally guarantees nothing - read [Red Hat's compatibility guide](https://access.redhat.com/articles/rhel-abi-compatibility) and note the weasel words where they reserve the right to change anything at any time. – Andrew Henle Nov 16 '20 at 00:52