Build with LTO / -flto on macOS

Wolfgang Walther <walther@technowledgy.de>

From: Wolfgang Walther <walther@technowledgy.de>

To: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Cc: Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>

Date: 2024-06-03T14:22:01Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Make building with LTO work on macOS
- 73275f093f89 18.0 landed
Require memory barrier support.
- 83aadbeb96f0 18.0 landed
Require compiler barrier support.
- a011dc399cc8 18.0 landed
autoconf: Move export_dynamic determination to configure
- 9db49fc5bfdc 16.0 cited

Attachments

v1-0001-Make-building-with-clang-s-LTO-work-on-macOS.patch (text/x-patch) patch v1-0001

Building with clang and -flto on macOS currently fails with errors 
similar to [1]. This is because the --export-dynamic flag is called 
-export_dynamic [2] instead and we have not been passing this variant to 
the linker, so far.

Attached patch fixes that for configure/make.

CC: Tom, who hit the same in [3] and Andres who last touched 
--export-dynamic in 9db49fc5bfdc0126be03f4b8986013e59d93b91d.

Will also create an issue upstream for meson, because the logic is 
built-in there.

Would be great if this could be back-patched, since this is the same in 
all live versions.

Best,

Wolfgang

[1]: https://postgr.es/m/1581936537572-0.post%40n3.nabble.com
[2]: 
https://opensource.apple.com/source/ld64/ld64-609/doc/man/man1/ld.1.auto.html 
(grep for export_dynamic)
[3]: https://postgr.es/m/21800.1499270547%40sss.pgh.pa.us