Re: cl.exe and system types

[Sébastien Hinderer]

Dear Earnie and Bob,

Many thanks for your replies.

Earnie (2018/08/20 16:07 -0400):
> On 8/20/2018 2:19 PM, Sébastien Hinderer wrote:
> > Bob Friesenhahn (2018/08/20 12:52 -0500):
> >> Are you using Cygwin for your shell environment?
> > 
> > Yes, absolutely. Do you think this makes things better, or worse? :)
> > 
> 
> Well MSYS2 might work better because it caters to the Windows
> applications but perhaps not.

Okay. Well I think I'll try to make things work under Cygwin first,
because that's the build environment the project currently uses. Only if
I am not able to make things work will I start considering another
build environment, I think.

> You need to declare the --build environment and the --host environment
> so that configure isn't trying to find it.

Thanks for mentionning this, because that's a point I am unclear about.

> You'll not only need to set
> CC but also LD and maybe other such variables.

Sure, I am prepared to do that if they can not be automatically
detected.

> The values for --build and --host need to be the same and can be
> whatever you desire but something sensible like x86_64-pc-msvc might
> work well.

So here it seems Bob and you disagree, because as far as I understand
his mail quoted below he says that build and host should be different. I
tend to think they should be different, too, because although the
resulting binaries will be usable under Cygwin, they will not be cygwin
applications but rather native Windows applications. So in my
understanding even if the built binaries can be run in the build
environemnt, this is a case of cross-compiling.

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.

Oh and also, x86_64-pc-msvc is not recognized. I am wondering whether
there is a list somewhere of the valid parameters for --build and
--host? I tried running config.sub and config.guess with -h but that
didn't help.

Bob Friesenhahn (2018/08/20 16:02 -0500):
> On Mon, 20 Aug 2018, Sébastien Hinderer wrote:
> 
> > Bob Friesenhahn (2018/08/20 12:52 -0500):
> > > Are you using Cygwin for your shell environment?
> > 
> > Yes, absolutely. Do you think this makes things better, or worse? :)
> 
> It does mean that you are effectively cross-compiling so you would need to
> execute the configure script with options for cross-compiling.

Yeah that's my understanding, too, with the restriction mentionned
above, i.e. I am not sure it is still necessary to specify --build when
specifying --host since my experiments tend to show a normal behaviour in
the case where --host is specified and --build is omitted.

Any input welcome because I am really in an unknown territory, here.

Many thanks in advance,

Sébastien.