Re: cl.exe and system types

[Nick Bowler]

Hi Sébastien,

On 2018-08-21, Sébastien Hinderer <address@hidden> wrote:
> What I do not understand, though, is why it is necessary to specify
> --build. I know the manual says that when one specifies --host then one
> has to specify --build, too, for historical reasons, but the manual also
> says that this will be fixed in the next version. Moreover, I did try to
> run configure with --host and no --build and that seemed to work,
> independently of whether it was a cross-compilation scenario or not. So
> I came to wonder how up-to-date the manual actually is.

When you specify just --host (and not --build), configure autodetects
cross compiliation by attempting to run a compiled program.  If the
program runs, configure assumes you are not cross compiling.  If the
program does not run for any reason, configure assumes you are cross
compiling.

The problem is this heuristic tends to be wrong as often as it is right,
so the recommendation now is to always specify --build and --host, which
disables this autodetection (configure enters cross compilation mode if
and only if the build and host triplets are different).

The comment that "This will be fixed in the future" appears to have been
added in 2002.  Clearly we've not made it to the future yet. :)

Cheers,
  Nick