Re: cl.exe and system types

[Earnie]

On 8/21/2018 10:32 AM, Nick Bowler wrote:
> 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.
> 

Yes, exactly.  And MSVC isn't setup for autotools style cross compiling
so you need to specify both to stop the auto-detection process.

> 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. :)

Should it ever get here?  Maybe the fix is to remove the comment.  What
we have has worked for many years with no one bugged about it enough to
supply a patch to do otherwise.

-- 
Earnie