Horton

Re: Cleaning up historical portability baggage

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Andres Freund <andres@anarazel.de>, Andrew Dunstan <andrew@dunslane.net>, Robert Haas <robertmhaas@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-08-13T22:03:19Z
Lists: pgsql-hackers 
On Sun, Aug 14, 2022 at 6:07 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Thomas Munro <thomas.munro@gmail.com> writes:
> > I pushed these, except I chopped out the HAVE_UNIX_SOCKETS part as
> > requested.  Here it is in a separate patch, with a commit message that
> > explains the rationale (essentially, what you said, it's basically a
> > runtime matter for a hypothetical AF_UNIX-less system to complain
> > about).  Tom, does this argument persuade you?
>
> I looked more closely and saw that basically what HAVE_UNIX_SOCKETS
> is guarding is code that assumes the existence of AF_UNIX and
> struct sockaddr_un.  As Peter said, we already rely on AF_UNIX
> in some other places; and I see that sys/un.h is required to exist
> and to define struct sockaddr_un as far back as SUSv2.  So it
> does seem like the worst consequence is that we'd be compiling
> some code that would be unreachable on platforms lacking support.
> Objection withdrawn.

Thanks, and pushed with a couple of minor doc tweaks.

I hadn't paid attention to our existing abstract Unix socket support
before and now I'm curious: do we have a confirmed sighting of that
working on Windows?  The thread didn't say so[1], and I'm suspicious
because I couldn't get simple standalone programs that bind() to
"\000c:\\xxx" to work sanely (but my method for investigating Windows
is to send the punch cards over to the CI system and wait for the
results to arrive by carrier pigeon which is cumbersome enough that I
haven't tried very hard).  Naively shoving a @ into PostreSQL's
PG_REGRESS_SOCK_DIR also breaks CI.

> As for the other two, they look like nice cleanup if we can actually
> get away with it.  I agree that the business about nonstandard libbind
> is not of interest anymore, but I have no idea about the state of
> play on Windows.  I guess we can push 'em and see what the buildfarm
> thinks.

All green on CI...  Next stop, build farm.

I'm a bit confused about why I had to #define gai_sterror
gai_strerrorA myself to get this working (my non-Windows-guy
understanding is that the A-for-ANSI [sic] variants of system
functions should be selected automatically unless you #define UNICODE
to get W-for-wide variants).  If anyone has any clues about that, I'd
be glad to clean it up.

I *guess* the main risk here is that different error messages might
show up in some scenarios on Windows (everything else was already
going directly to OS functions on Windows 8.1+ if I'm reading the code
right), but surely that'd be progress -- messages from the real netdb
implementation are surely preferable to our fallback stuff.

[1] https://www.postgresql.org/message-id/flat/6dee8574-b0ad-fc49-9c8c-2edc796f0033%402ndquadrant.com

Commits

  1. Make sure IOV_MAX is defined.

  2. Doc: Abstract AF_UNIX sockets don't work on Windows.

  3. Clean up inconsistent use of fflush().

  4. Remove configure probe for sockaddr_in6 and require AF_INET6.

  5. Remove configure probes for sockaddr_storage members.

  6. Remove configure probe for netinet/tcp.h.

  7. Fix macro problem with gai_strerror on Windows.

  8. Remove configure probe for net/if.h.

  9. mstcpip.h is not missing on MinGW.

  10. Remove dead ifaddr.c fallback code.

  11. Remove configure probe for gethostbyname_r.

  12. Remove replacement code for getaddrinfo.

  13. Remove configure probe for struct sockaddr_storage.

  14. Remove HAVE_UNIX_SOCKETS.

  15. Remove configurability of PPC spinlock assembly code.

  16. Remove configure probe for shl_load library.

  17. Remove configure probe for sys/select.h.

  18. Remove configure probes for sys/un.h and struct sockaddr_un.

  19. Remove configure probes for sys/ipc.h, sys/sem.h, sys/shm.h.

  20. Remove configure probe for sys/resource.h and refactor.

  21. Remove configure probe for sys/uio.h.

  22. Fix obsolete comments in instr_time.h.

  23. aix: fix misreading of condition in 8f12a4e7add

  24. aix: Remove checks for very old OS versions

  25. windows: Remove HAVE_MINIDUMP_TYPE test

  26. solaris: Remove unnecessary gcc / gnu ld vs sun studio differences

  27. Trust a few system headers to stand on their own

  28. Rely on __func__ being supported

  29. Simplify replacement code for strtof.

  30. Simplify gettimeofday for Windows.

  31. Simplify gettimeofday() fallback logic.

  32. Remove fallbacks for strtoll, strtoull.

  33. Remove configure probe for fdatasync.

  34. Remove configure probe for clock_gettime.

  35. Simplify replacement code for preadv and pwritev.

  36. Remove dead pread and pwrite replacement code.

  37. Remove dead setenv, unsetenv replacement code.

  38. Remove configure probes for poll and poll.h.

  39. Remove configure probe for link.

  40. Remove configure probes for symlink/readlink, and dead code.

  41. Remove configure probe for setsid.

  42. Remove configure probe for shm_open.

  43. Remove configure probe and related tests for getrlimit.

  44. Remove configure probe for dlopen, and refactor.

  45. Remove dead getpwuid_r replacement code.

  46. Remove dead handling for pre-POSIX sigwait().

  47. Remove dead getrusage replacement code.

  48. Cygwin and Mingw floating-point fixes.

  49. Support platforms where strtoll/strtoull are spelled __strtoll/__strtoull.

  50. Arrange to supply declarations for strtoll/strtoull if needed.

  51. Lock down regression testing temporary clusters on Windows.

  52. Secure Unix-domain sockets of "make check" temporary clusters.

  53. Add configure checks for strtoll, strtoull (or strto[u]q). Disable

  54. Portability fix for old SunOS releases: fflush(NULL)