bootstrapping gnat GCC on amd64

[Daniel Eischen]

How's this all going?

I'm updating lang/gnat to gnat-2009 right now.  In the
GNAT sources, it has build instructions including how
to build the cross - see below.

-- 
DE

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-- BUILDING GNAT - EXAMPLE SEQUENCE --
--------------------------------------

Supposing you have one tarball for the GCC sources and one for the GNAT
sources, here is a possible way to proceed:

0/ If not available on your system, build libgmp and libmpfr following
    build instructions from these packages.

1/ Create a root directory into which you'll later setup the source and
    build subdirectories:

    ~ $ mkdir GNAT
    ~ $ cd GNAT

2/ Setup an initial source tree from the GCC and the GNAT tarballs:

   ~/GNAT $ gzip -dc [...]/gcc-4.3*.tgz | tar xf -
   ~/GNAT $ mv gcc-4* src
   ~/GNAT $ cd src

   ~/GNAT/src $ gzip -dc [...]/gnat-xxx-src.tgz  | tar xf -
   ~/GNAT/src $ mv gnat-xxx-src/src/ada gcc
   ~/GNAT/src $ patch -p0 < gnat-xxx-src/src/gcc-43.dif
   ~/GNAT/src $ touch gcc/cstamp-h.in

3/ Prepare and configure the build tree:

   ~/GNAT/src $ mkdir ../obj; cd ../obj
   ~/GNAT/obj $ ../src/configure --enable-languages="c,ada" --disable-libada ...
   [see the GCC documentation for other relevant configure options]

4/ Build the compiler, run time and tools:

   Note that the use of "GNU Make" is required by the GCC Makefiles.

   ~/GNAT/obj $ make bootstrap
   ~/GNAT/obj $ make -C gcc gnatlib gnattools

   If you are building a cross compiler, you will need to replace
   the above sequence by something similar to:

   ~/GNAT/obj $ make
   ~/GNAT/obj $ make -C gcc gnatlib cross-gnattools ada.all.cross

5/ Install the whole package:

   ~/GNAT/obj $ make install