Re: Which GCC compiler for Linux-GNAT

[Simon Wright <simon@pushface.org>]

Bernard WEISSER <bernard.weisser@wanadoo.fr> writes:

> Until now, I used GNAT 3.15 compiler built on top of a GCC 2.8.1
> compiler and all was perfect for me, except that I has to use this GCC
> 2.8.1 compiler for all my regular C sources (in fact not a really a
> problem). I got that GNAT distribution from the FTP 'cs.nyu.edu'
> server.
> 
> With the arrival of the new LINUX Slackware 9.0 release, it appeared
> to me that now a full bunch of compilers is provided (and ready to
> use), namely : C, C++, F77 and GNAT 3.15. All these front-ends are
> based on the unique GCC 3.2.2 compiler version. Using this new GNAT
> version, I succeded to compile a rather complex Ada application, but
> it turned out that the binary run quickly ended with a
> CONSTRAINT_ERROR.
> 
> Does anybody know which GCC compiler is the "official one" required to
> build the GNAT 3.15 compiler ? Are there 2 different teams working on
> the GNAT development and using 2 different GCC compiler ?

There is one team, Ada Core Technologies. GNAT 3.15, 3.16 are based on
GCC 2.8.1 and can only be built over 2.8.1. The GCC-3 series
integrates GNAT with the base GCC as one parallel set of sources.

If you need to keep a GCC-3 gcc etc for your C, F77 software but also
want GNAT 3.15, you need to be very careful NOT to install your 3.15
over the Slackware gcc binaries.

I have a utility at http://www.pushface.org/gnatfe/ which is designed
to let you do this with minimal grief: on this (Mandrake 8.2) machine,
I have GNAT 3.12a2, 3.13p, 3.14p, 3.15p, 3.16a, gcc-3.2, and
gcc-3.3-20030201:

smaug.pushface.org[4]$ gcc -v
Reading specs from /usr/lib/gcc-lib/i586-mandrake-linux-gnu/2.96/specs
gcc version 2.96 20000731 (Mandrake Linux 8.2 2.96-0.76mdk)

smaug.pushface.org[5]$ gnatgcc -v
Reading specs from /opt/3.16a/lib/gcc-lib/i686-pc-linux-gnu/2.8.1/specs
gcc version 2.8.1

smaug.pushface.org[6]$ GNAT_PREFIX=/opt/gcc-3.2 gnatgcc -v
Reading specs from /opt/gcc-3.2/lib/gcc-lib/i686-pc-linux-gnu/3.2/specs
Configured with: ../gcc-3.2/configure --prefix=/opt/gcc-3.2 --enable-languages=c,ada,gcov
Thread model: posix
gcc version 3.2