Po Lu wrote:
Jacob Bachmeyer <jcb62...@gmail.com> writes:
No: MinGW is Windows native "Win32" API while a future `windows-gnu'
would be the GNU system's POSIX API on an NT kernel. These are *very*
different configurations; `windows-gnu' would more closely resemble
Cygwin.
This is not what the `x86_64-pc-windows-gnu' configuration presently
canonicalized by config.sub represents.
Then its present use is *wrong* and a bug that should be fixed.
I say it would be more appropriate to accept `x86_64-pc-mingw64' as a
short form for `x86_64-pc-windows-mingw64', since Wine could enable a
`x86_64-pc-linux-mingw64' platform to exist. (Wine's goal is that
that platform should be indistinguishable from
`x86_64-pc-windows-mingw64', but it is certainly a distinct
configuration from the user's perspective.)
Wine is a compatibility layer that emulates the MS-Windows kernel. It
is not config's role to report the intricacies of the operating system
implementation, only details that affect user programs running under
that operating system.
As I said, Wine's goal is that `x86_64-pc-linux-mingw64' be
indistinguishable from `x86_64-pc-windows-mingw64' but that does not
preclude using the KERNEL-OS form.
But they already have drifted: config tuples were originally triplets
and now often feature a 4-element CPU-VENDOR-KERNEL-OS form
Only as a result of a technical need to distinguish Linux-based GNU
systems from other GNU systems. Absent that requirement, we would
simply call GNU/Linux systems *-*-gnu, Alpine *-*-alpine, and Android
*-*-android.
It is a little more complex than that: the GNU system theoretically can
run on any of multiple kernels. While Linux is most commonly used, GNU
HURD is still in development and I understand that there is a Debian
variant using the GNU utilities on a FreeBSD kernel.
but several existing tuples use a libc or ABI name in place of a
kernel and/or operating system.
In each of those cases, the ABI name _can_ be construed as a kernel
(since there is no kernel at all), or the libc name refers to a general
category of OS. Neither of these situations are applicable to MinGW or
MSVC.
Arguably, MinGW *is* an ABI name.
I simply note this and suggest recognizing this fact that config
tuples are actually now currently 3-or-4-of-5 elements. The GNU
system is definitely flexible enough for that 5-element form to be
appropriate: `CPU-VENDOR-linux-gnu' (GNU/Linux, implied to be using
glibc) and `CPU-VENDOR-linux-gnu-musl' (GNU/Linux using musl libc) are
plausibly distinguishable, for example, and could even both be useful
on the *same* machine, if, for example, some low-level system
utilities are linked against musl libc while most user programs use
glibc.
Such configurations do not exist, so we need not provide for them in
config.*. And in any case, these ``low level utilities'' would be
configured for *-*-linux-musl, while user programs would be configured
for *-*-linux-gnu. I see no reason config.* must take special measures
to recognize these Frankenstein systems, since the C library used to
build some system utilities has no bearing on the operation of other
user programs built for *-*-linux-gnu.
Think about why the GNU project pushes to call the common system
"GNU/Linux" and you should see the reason for using `*-*-linux-gnu-musl'
to express a GNU/Linux system using musl libc.
-- Jacob
