Horton

Re: Cleaning up historical portability baggage

Ibrar Ahmed <ibrar.ahmad@gmail.com>

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From: Ibrar Ahmed <ibrar.ahmad@gmail.com>
To: Thomas Munro <thomas.munro@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Andrew Dunstan <andrew@dunslane.net>, Robert Haas <robertmhaas@gmail.com>
Date: 2022-09-15T08:10:43Z
Lists: pgsql-hackers 
On Mon, Aug 29, 2022 at 3:13 AM Thomas Munro <thomas.munro@gmail.com> wrote:

> On Mon, Aug 29, 2022 at 9:40 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> > Here's another bit of baggage handling: fixing up the places that
> > were afraid to use fflush(NULL).  We could doubtless have done
> > this years ago (indeed, I found several places already using it)
> > but as long as we're making a push to get rid of obsolete code,
> > doing it now seems appropriate.
>
> +1, must be OK (pg_dump and pg_upgrade).
>
> Archeology:
>
> commit 79fcde48b229534fd4a5e07834e5e0e84dd38bee
> Author: Tom Lane <tgl@sss.pgh.pa.us>
> Date:   Sun Nov 29 01:51:56 1998 +0000
>
>     Portability fix for old SunOS releases: fflush(NULL)
>
>
> https://www.postgresql.org/message-id/199811241847.NAA04690%40tuna.uimage.com
>
> SunOS 4.x was still in some kind of support phase for a few more
> years, but I guess they weren't working too hard on conformance and
> features, given that SunOS 5 (the big BSD -> System V rewrite) had
> come out in '92...
>
> > One thing that's not clear to me is what the appropriate rules
> > should be for popen().  POSIX makes clear that you shouldn't
> > expect popen() to include an fflush() itself, but we seem quite
> > haphazard about whether to do one or not before popen().  In
> > the case of popen(..., "r") we can expect that the child can't
> > write on our stdout, but stderr could be a problem anyway.
> >
> > Likewise, there are some places that fflush before system(),
> > but they are a minority.  Again it seems like the main risk
> > is duplicated or mis-ordered stderr output.
> >
> > I'm inclined to add fflush(NULL) before any popen() or system()
> > that hasn't got one already, but did not do that in the attached.
>
> Couldn't hurt.  (Looking around at our setvbuf() setup to check the
> expected stream state in various places... and huh, I hadn't
> previously noticed the thing about Windows interpreting line buffering
> to mean full buffering.  Pfnghghl...)
>
>
> The patch does not apply successfully; please rebase the patch.

patching file src/backend/postmaster/fork_process.c
Hunk #1 FAILED at 37.
1 out of 1 hunk FAILED -- saving rejects to file
src/backend/postmaster/fork_process.c.rej
patching file src/backend/storage/file/fd.c
Hunk #1 FAILED at 2503.
1 out of 1 hunk FAILED -- saving rejects to file
src/backend/storage/file/fd.c.rej
patching file src/backend/utils/error/elog.c
Hunk #1 FAILED at 643.
Hunk #2 FAILED at 670.



-- 
Ibrar Ahmed

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)