Horton

Re: Cleaning up historical portability baggage

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Thomas Munro <thomas.munro@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Andrew Dunstan <andrew@dunslane.net>, Robert Haas <robertmhaas@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-08-25T19:47:29Z
Lists: pgsql-hackers 
Hi,

On 2022-08-18 18:13:38 +1200, Thomas Munro wrote:
> Here's a slightly better AF_INET6 one.  I'm planning to push it
> tomorrow if there are no objections.

You didn't yet, I think. Any chance you could? The HAVE_IPV6 stuff is
wrong/ugly in the meson build, right now, and I'd rather not spend time fixing
it up ;)


> It does something a little more aggressive than the preceding stuff, because
> SUSv3 says that IPv6 is an "option".  I don't see that as an issue: it also
> says that various other ubiquitous stuff we're using is optional.  Of
> course, it would be absurd for a new socket implementation to appear today
> that can't talk to a decent chunk of the internet, and all we require here
> is the headers.  That optionality was relevant for the transition period a
> couple of decades ago.

> From f162a15a6d723f8c94d9daa6236149e1f39b0d9a Mon Sep 17 00:00:00 2001
> From: Thomas Munro <tmunro@postgresql.org>
> Date: Thu, 18 Aug 2022 11:55:10 +1200
> Subject: [PATCH] Remove configure probe for sockaddr_in6 and require AF_INET6.
> 
> SUSv3 <netinet/in.h> defines struct sockaddr_in6, and all targeted Unix
> systems have it.  Windows has it in <ws2ipdef.h>.  Remove the configure
> probe, the macro and a small amount of dead code.
> 
> Also remove a mention of IPv6-less builds from the documentation, since
> there aren't any.
> 
> This is similar to commits f5580882 and 077bf2f2 for Unix sockets.
> Even though AF_INET6 is an "optional" component of SUSv3, there are no
> known modern operating system without it, and it seems even less likely
> to be omitted from future systems than AF_UNIX.
> 
> Discussion: https://postgr.es/m/CA+hUKGKErNfhmvb_H0UprEmp4LPzGN06yR2_0tYikjzB-2ECMw@mail.gmail.com

Looks good to me.


I'm idly wondering whether it's worth at some point to introduce a configure
test of just compiling a file referencing all the headers and symbols we exist
to be there...

Greetings,

Andres Freund

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)