From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!news.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Ludovic Brenta Newsgroups: comp.lang.ada Subject: Re: some questions on installing Ada on Linux Date: Fri, 04 Jul 2014 19:40:35 +0200 Organization: A noiseless patient Spider Message-ID: <87simhowdo.fsf@ludovic-brenta.org> References: <2871836a-3b86-4c5e-b7d9-7da3e9acf775@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: mx05.eternal-september.org; posting-host="66c43c3977f7279d9c83961adcbdb356"; logging-data="29057"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18xFqwWxow7xIEJQgKSse7V" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) Cancel-Lock: sha1:PwcnKkk43Ct6PMD9wSYC+l3r6z8= sha1:IY0sJz5I6zIsoAew1+GaQnl2wys= Xref: news.eternal-september.org comp.lang.ada:20714 Date: 2014-07-04T19:40:35+02:00 List-Id: Simon Clubley writes on comp.lang.ada: > Therefore, as I understand it, AdaCore could stop contributing code to > the FSF gcc branch if it chooses, provided it makes the source code > for the binaries it actually supplies to customers available under the > GPL. Yes, that is correct, AFAIU, but IANAL. You must actually make a strong distinction between the compiler and the libraries. The compiler is and has always been pure GPL; that does not matter to users of the compiler as long as they don't link the compiler into their executables. As far as libraries are concerned, you have to distinguish between libgnat and the other libraries (such as GtkAda, XML/Ada, etc.). libgnat from the FSF is licensed under GPL version 3 or later with Runtime Library Exception, just like libstdc++. In contrast, libgnat from GNAT GPL is pure GPL i.e. no Runtime Library Exception. (The "GMGPL" license disappeared long ago; see the timeline in the Debian Policy for Ada). The sources for libgnat are distributed together with the compiler (gnat), so are available from the FSF. The other libraries are distributed separately and are not available from the FSF. They are available from libre.adacore.com in source only form and they are also available from several distributions in source and binary (precompiled) forms. Paying customers receive the Runtime Library Exception on all libraries but not on the compiler or on GPS, AFAICT, but again that doesn't matter since they don't incorporate the compiler or GPS into their software (and, in fact, few of them even distribute their software to anyone, so the redistribution terms of the license matter very little to them). >> I was of the understanding that they are substantially merged >> approximately once per year. What obstructs a wholesale merge is the >> fact that AdaCore's GNAT lags behind 2 or 3 versions from the latest >> stable back-end. FSF merges the vast majority of AdaCore's evolution >> of GNAT that does not conflict with changes in the back-end. It is >> bit-rot, not legalese, that naturally causes 2 source bases for GNAT. >> The relationship is symbiotic: FSF depends on AdaCore for most of the >> evolution of the Ada front-end, whereas AdaCore depends on FSF for >> most of the evolution of the back-end. AdaCore merges in a newer >> (but still lagging) back-end version approximately once per year to >> AdaCore's state-of-the-art front-end. Separately, FSF merges in a >> newer (but still lagging) GNAT front-end version approximately once >> per year to FSF's state-of-the-art back-end. The once-per-year merges have long been banned by the FSF. Nowadays, AdaCore merge their changes in small chunks, almost daily, and obey the GCC development schedule [1]. [1] https://gcc.gnu.org/develop.html Looking at the bottom of that page: right now GCC 4.10 is in Stage 1, so AdaCore are busy merging almost every day from GNAT Pro into the future GCC 4.10. If you want examples, look for emails tagged "[Ada]" on https://gcc.gnu.org/ml/gcc-patches/2014-06/. Again, please read the Debian Policy for Ada :) > Unless there's some contract I am unaware of, there's nothing to stop > AdaCore saying that future releases to the FSF gcc codebase are done > under the terms of the pure GPL. Yes, the FSF can stop AdaCore because the FSF owns the copyright on GNAT and libgnat, so only the FSF gets to decide on the licensing terms. > They have already done this once with another product. GtkAda used to > have a GMGPL style licence up to around GtkAda 2.4, but the public > version of GtkAda was converted (overnight) to a pure GPL licence. > Existing releases of GtkAda stayed under the GMGPL; new releases were > under the pure GPL. Here comes the big distinction between libgnat which belongs to the FSF and the other libraries which belong to AdaCore. -- Ludovic Brenta.