Re: config.guess and $CC

[Bruno Haible]

Ron Garret wrote:
> The fundamental problem is that uname -m does not and CAN not contain  
> enough information to decide which architecture to build for, because  
> on a biarch system there are three different possibilities (32-bit, 64- 
> bit and fat binary), and which one is right depends on the user's  
> desires.

Indeed. Another example of this problem is GNU gmp, which - on a Solaris 7
system, where config.guess returns "sparc-sun-solaris2.7" - detects that
the CPU is more capable than what most programs use, and decides to build
in 64-bit mode:

    checking build system type... ultrasparc2i-sun-solaris2.7
    checking host system type... ultrasparc2i-sun-solaris2.7
    ...
    using ABI="64"
          CC="gcc"
          CFLAGS="-O2 -m64 -mptr64 -mcpu=ultrasparc"
          CPPFLAGS=""

Unfortunately, this is not what I desired, because I cannot link 32-bit
mode programs with a 64-bit mode library.

Also, when I specify a --prefix and a --libdir to configure, I'm assuming
a build for a particular architecture. If configure makes a random decision
about the architecture, and the package then installs 64-bit libraries in
/usr/local/lib (rather than /usr/local/lib64 on Linux or /usr/local/lib/64
on Solaris), the system will get into trouble.

Bruno