Re: Building Gforth for Apple's new Arm-based Macs

On Tue, Jan 19, 2021 at 02:42:10PM -0500, Craig Treleaven wrote:
> Hi:
> 
> I contribute a little to the MacPorts project.  MacPorts packages many, many open source software titles for use on Macintosh.  I noticed that Gforth failed to build on our new buildbot running on an M1 machine(aka Apple’s 64 bit ARM SOC).  The configure phase reported the following error:
> 
> checking build system type... Invalid configuration `arm64-apple-darwin20.1.0': machine `arm64-apple' not recognized
> configure: error: /bin/sh ./config.sub arm64-apple-darwin20.1.0 failed

config.sub apparently does not know this architecture under the name
arm64, but instead under the name aarch64.

> For a number of years, we’ve invoked configure thusly on Intel 64 bit-based Macs:
> 
> ./configure --prefix=/opt/local --build=x86_64-apple-darwin14.5.0 
> 
> I browsed through configure.ac but I have only a rudimentary knowledge of auto tools and couldn’t determine if the “-build” flag was even necessary;

If you are not cross-building, you don't need --build.  configure then
looks at the current machine and guesses the machine from that (with
config.guess).

> Incidentally, MacPorts tries to support even very old Macintosh systems including PPC (both 32 and 64 bit) as well as Intel i386 and X86_64.  With arm64 added to the mix, that is up to 5 archs!

Nice!

- anton