Re: [PATCH] config.mak.uname: enable OPEN_RETURNS_EINTR for macOS Big Sur

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> I got another off-list report of the problem. I think we probably want
> to do this on top:

Queued and pushed out.

I wonder if these hits for SA_RESTART in config.mak.uname would be a
good way to guide us.

    [6c109904 (Port to HP NonStop, 2012-09-19)]
            # Not detected (nor checked for) by './configure'.
            # We don't have SA_RESTART on NonStop, unfortunalety.
            COMPAT_CFLAGS += -DSA_RESTART=0

    [40036bed (Port to QNX, 2012-12-18)]
    ifeq ($(uname_S),QNX)
            COMPAT_CFLAGS += -DSA_RESTART=0

One caveat is that we do not know if their system headers hide the
real implementation of open(2) behind a C preprocessor macro, in
whcih case OPEN_RETURNS_EINTR wrapper may not work correctly.

>  config.mak.uname | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/config.mak.uname b/config.mak.uname
> index e22d4b6d67..d204c20a64 100644
> --- a/config.mak.uname
> +++ b/config.mak.uname
> @@ -124,6 +124,9 @@ ifeq ($(uname_S),Darwin)
>  	ifeq ($(shell test "`expr "$(uname_R)" : '\([0-9][0-9]*\)\.'`" -ge 11 && echo 1),1)
>  		HAVE_GETDELIM = YesPlease
>  	endif
> +	ifeq ($(shell test "`expr "$(uname_R)" : '\([0-9][0-9]*\)\.'`" -ge 20 && echo 1),1)
> +		OPEN_RETURNS_EINTR = UnfortunatelyYes
> +	endif
>  	NO_MEMMEM = YesPlease
>  	USE_ST_TIMESPEC = YesPlease
>  	HAVE_DEV_TTY = YesPlease