Re: pg_preadv() and pg_pwritev()

Sergey Shinderuk <s.shinderuk@postgrespro.ru>

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From: Sergey Shinderuk <s.shinderuk@postgrespro.ru>

To: Tom Lane <tgl@sss.pgh.pa.us>, Thomas Munro <thomas.munro@gmail.com>

Cc: pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2021-01-14T06:32:54Z

Lists: pgsql-hackers

Attachments

config.log (text/plain)
make.log (text/plain)

Tom Lane wrote:
> The symptoms sound consistent with using bleeding-edge Xcode on a
> Catalina machine ... please report exact OS and Xcode versions.

macOS 10.15.7 (19H2)
Xcode 12.3 (12C33)
macOS SDK 11.1 (20C63)


> Attached is an untested quick hack to make that happen --- Sergey,
> can you verify that this fixes configure's results on your setup?

"-no_weak_imports" doesn't help.

configure:15161: checking for pwritev
configure:15161: gcc -o conftest -Wall -Wmissing-prototypes 
-Wpointer-arith -Wdeclaration-after-statement -Werror=vla -Wendif-labels 
-Wmissing-format-attribute -Wformat-security -fno-strict-aliasing 
-fwrapv -Wno-unused-command-line-argument -O2 -isysroot 
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk 
   -Wl,-no_weak_imports -isysroot 
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk 
   conftest.c -lz  -lm  >&5
configure:15161: $? = 0
configure:15161: result: yes


Then I get the same compiler warnings about pwritev and an unrelated 
link error:

ld: weak import of symbol '___darwin_check_fd_set_overflow' not 
supported because of option: -no_weak_imports for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see 
invocation)
make[2]: *** [postgres] Error 1
make[1]: *** [all-backend-recurse] Error 2
make: *** [all-src-recurse] Error 2

Please see the logs attached.

Commits

Improve our heuristic for selecting PG_SYSROOT on macOS.
- 3934543c2bb0 9.5.25 landed
- fc6d08b27a33 9.6.21 landed
- 5fa060c8f593 10.16 landed
- 046c8facecee 11.11 landed
- f5d044eaeff0 12.6 landed
- f44ae4db5fec 13.2 landed
- 4823621db312 14.0 landed
Move our p{read,write}v replacements into their own files.
- 0d56acfbaa79 14.0 landed
Don't use elog() in src/port/pwrite.c.
- df10ac625c16 14.0 landed
Use vectored I/O to fill new WAL segments.
- ce6a71fa5300 14.0 landed
Provide pg_preadv() and pg_pwritev().
- 13a021f3e8c9 14.0 landed