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Il giorno Thu, 22 Dec 2016 21:11:45 +0100 |
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Michał Górny <mgorny@g.o> ha scritto: |
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> On Thu, 22 Dec 2016 14:55:05 +0100 |
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> Alfredo Tupone <tupone@g.o> wrote: |
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> |
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> > > > I would like to start including, in the gentoo tree, GNAT-GPL |
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> > > > built in the same way as sys-devel-gcc and selectable with |
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> > > > gcc-config |
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> > > |
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> > > 1. Does this mean that GNAT-GPL build will include building a C |
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> > > compiler? If yes, will the C compiler be installed? |
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> > Yes, a C and a C++ compiler, and they will be installed |
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> > > |
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> > > 2. Will it be possible to combine GNAT-GPL with a different |
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> > > version of regular gcc C/C++ compilers? |
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> > No, not easily |
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> |
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> To be honest, I don't like this at all. This sounds like doubling |
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> the effort on maintaining gcc, and it sounds like people using |
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> GNAT-GPL would end up being forced to use old versions of GCC (also |
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> possibly missing patches). |
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All the patch that we (gentoo) apply to sys-devel/gcc-4.7.4 are applied |
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to gnat-gpl without any changes. Well I actually did two small patches |
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to the piepatches that apply to gcc, but the rest goes well. |
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It seems that gcc-4.7.4 and gcc included in gnat-gpl-2014 are very near. |
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I have still to check the newest 2015 (4.9.3) and 2016 (4.9.4) version. |
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The other path to provide gnat compiler to gentoo is using the one in |
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the FSF gcc. |
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The advantage are |
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a) that you don't have two gcc to align, |
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b) you can compile closed source. |
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but |
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a) when you provide a new version of gcc you also need to check the |
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ada compiler |
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b) the ada compiler is an older version even if it is running on a new |
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gcc |
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> |
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> If the Ada compiler requires Ada to boostrap anyway, can't you just |
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> make it build the Ada compiler alone? |
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> |
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To bootstrap it needs a C, C++, and an Ada Compiler. and they should be |
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provided by using the gcc driver. (At least without changing a lot the |
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compilation scripts). So a standalone ada compiler cannot be used to |
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boostrap. |
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More over, as the gnat provide interfaces between languages, the layer |
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of interface between Ada and C++ depends on the version. |
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Sometimes happened that Ada and C++ had problems for differences in |
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the vtable layout (if I remember well, when going from gcc-3 to |
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gcc-4), or in mangling (gcc-2.8.1 to gcc-3, yes long time ago) |
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that caused problems when passing objects between languages. It |
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is better that the version of C++ and Ada used in a program are aligned. |
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If both are provided by the same gcc, that is automatic. |
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