On 13:49 Thu 22 Dec , Michał Górny wrote: > On Wed, 21 Dec 2016 23:00:47 +0100 > Alfredo Tupone <tup...@gentoo.org> wrote: > > > I would like to revive the Ada support in gentoo. > > > > One ada compiler is produced by AdaCore and is provided in three > > versions, in the order starting from the best supported : > > > > 1) GnatPro, available with a contract support. > > > > 2) Gnat-GPL that can only build GPL-3 product > > > > 3) The gnat included in the gcc tree that is GPL-3 with exception. > > > > Gnat-GPL is very like the gnat in the gcc-tree so it can be built in > > the same way of sys-devel/gcc > > > > To be compiled from source the gcc compiler needs a C, C++, and Ada > > Compiler. I will provide one with the gnat-gpl-bin tar that could be > > installed under /opt . When the gcc is properly compiled we don't need > > it any more. > > Do I correctly understand that this is also true for gnat-gpl? Is there > any Ada compiler that could be used to bootstrap Ada on platforms that > lack prebuilt binaries? There is no difference between gcc and gnat-gpl. >From what I see adacore take a snapshot of gcc and make its own changes to add ada supports. So gnat-gpl needs a gnat compiler to be built, like vanilla gcc does.
>From my research on internet adacore "guarantees" that the compiler can be built with itself or a version "-1" of it. Normally any version of a gnat compiler that is enough near can build it, but, without any big work, I don't expect that either gcc or gnat-gpl can be built with other non gcc/gnat Ada compilers. I have read of gcc ada compilers built on several platforms using cross compilation. Maybe those could be used, like suggested in https://bugs.gentoo.org/show_bug.cgi?id=592060 However I am for adding the boostrap via the binary provided by adacore only, via gnat-gpl-bin packages. At least for the beginning. > > > I would like to start including, in the gentoo tree, GNAT-GPL > > built in the same way as sys-devel-gcc and selectable with gcc-config > > 1. Does this mean that GNAT-GPL build will include building a C > compiler? If yes, will the C compiler be installed? Yes, a C and a C++ compiler, and they will be installed > > 2. Will it be possible to combine GNAT-GPL with a different version of > regular gcc C/C++ compilers? No, not easily > > > As for instance gnat-gpl-2014 is based on gcc-4.7.4 they cannot coexist > > and gnat-gpl-2014 will block sys-devel/gcc-4.7.4 > > Block the whole sys-devel/ or just sys-devel/gcc[ada]? Block the whole sys-devel/gcc-4.7.4 > > > As a reference I have my overlay on https://github.com/atupone/overlay > > and a pull request at https://github.com/gentoo/gentoo/pull/3186 > > > > To start I need to change the toolchain.eclass > > > > - tc_version_is_at_least 4.7 && IUSE+=" go" > > + tc_version_is_at_least 4.7 && IUSE+=" go ada" > > > > - # We do NOT want 'ADA support' in here! > > - # is_ada && GCC_LANG+=",ada" > > + # We do want 'ADA support' here! > > + is_ada && GCC_LANG+=",ada" > > > > - for x in cpp gcc g++ c++ gcov g77 gcj gcjh gfortran gccgo ; do > > + for x in cpp gcc g++ c++ gcov g77 gcj gcjh gfortran gccgo gnatbind; do > > > > Thats all for that. > > > > Then, to not change the behaviour of the gcc-compiler, we could mask the > > ada use flag for sys-devel/gcc, at least temporarily > > > > --------------------- > > > > I would like to have comments on that, particularly because: > > a) it is going to add a use flag to sys-devel/gcc that will bring gcc > > to be rebuilt on most system, > > That's a minor problem. Toolchain people do this on us all the time, > so... > > > b) the gnat-gpl, if selected with gcc-config, can be used to recompile > > all the system, and maybe is not so good ? > > I don't really understand what you mean here. But it's probably related > to the questions I asked above. > > -- > Best regards, > Michał Górny > <http://dev.gentoo.org/~mgorny/>
