This code has not worked for a long time. Most systems now maintain
the password entries so that a password is not accessible through the
getpwent() interface. The SUBR that calls this interface may be
removed at a future time.
This might have been necessary before where we had bits of code
that were still `#ifdef LINUX`, but that's mostly gone now, so
this should no longer be required.
The NOFORN flag controls foreign function interface code, which
was written using the dld_* APIs which haven't existed in years.
There was a GNU dld that provided this API, but it was withdrawn
in 2006.
If this code is to be re-enabled, it will have to be changed to
use the `dlopen` family of APIs.
This removes SYSVSIGNALS as we're always and only using POSIX
signals now.
Some platform differences have been papered over. We used to
only ignore SIGPIPE when using BSD signals, but we now ignore
it all the time.
While the SIGFPE code will now compile, it hasn't been updated
to work on modern OSes fully yet as it will need to enable
the correct FP exceptions.
* Remove F_SETSIG call from Linux on X11 display.
Presumably, this was added to be like the `I_SETSIG` call on Solaris.
But it is the only `F_SETSIG` done on Linux and there isn't an
equivalent on the other platforms that we support as it is a GNU
extension.
Also, `F_SETSIG` with an argument of `0`, as here, means to send
the `SIGIO` signal, which is what is done by default.
From the man page:
F_SETSIG (int)
Set the signal sent when input or output becomes possible
to the value given in arg. A value of zero means to send
the default SIGIO signal. Any other value (including SIGIO)
is the signal to send instead, and in this case additional
info is available to the signal handler if installed with
SA_SIGINFO.
By using F_SETSIG with a nonzero value, and setting
SA_SIGINFO for the signal handler (see sigaction(2)),
extra information about I/O events is passed to the
handler in a siginfo_t structure. If the si_code field
indicates the source is SI_SIGIO, the si_fd field gives
the file descriptor associated with the event. Otherwise,
there is no indication which file descriptors are
pending, and you should use the usual mechanisms
(select(2), poll(2), read(2) with O_NONBLOCK set etc.)
to determine which file descriptors are available for I/O.
We aren't setting a non-zero value and we aren't establishing signal
handlers via `sigaction` with `SA_SIGINFO` set, so this shouldn't
be doing anything important for us.
* Stop setting _GNU_SOURCE for GNU libc extensions.
We were previously doing this to get access to the
`F_SETSIG` flag for `fcntl`, but this isn't being
used any longer.
* Always follow NEW_STORAGE code paths.
This removes the code paths for the pre-NEW_STORAGE code.
* Remove NEW_STORAGE from build system.
The code no longer refers to `NEW_STORAGE`, so we can remove
this from the build system.
