Horton

Re: [RFC] building postgres with meson

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Aleksander Alekseev <aleksander@timescale.com>, PostgreSQL Development <pgsql-hackers@postgresql.org>
Date: 2022-06-02T17:26:09Z
Lists: pgsql-hackers 
Hi,

On 2022-06-02 13:08:49 -0400, Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
> > I'm not quite sure what the proper behaviour is when doing an out-of-tree
> > build with meson (all builds are out-of-tree), with a pre-existing flex /
> > bison output in the source tree that is out of date.
> 
> Definitely sounds like a gotcha.
> 
> On the one hand, there's been some discussion already of removing all
> derived files from tarballs and just insisting that users provide all
> needed tools when building from source.  If we did that, it could be
> sufficient for the meson build to check that no such files are present
> in the source tree.  (Checking a couple of them would be enough, likely.)

There already is a check for pg_config.h, so the most obvious source of this
is addressed. Just didn't think about the files that make clean doesn't remove
:/.


> On the other hand, I'm not sure that I want such a change to be forced
> by a toolchain change.  It definitely seems a bit contrary to the plan
> we'd formed of allowing meson and make-based builds to coexist for
> a few years, because we'd be breaking at least some make-based build
> processes.

Agreed. I think it'd be pretty reasonable to not include flex / bison
output. They're not hard to acquire. The docs are perhaps another story.

I think it might be fine to say that make reallyclean (*) is required if
there's some conflicting in-source tree file?


> Could we have the meson build check that, say, if gram.c exists it
> is newer than gram.y?  Or get it to ignore an in-tree gram.c?

I suspect the problem with ignoring is gram.h, that's probably a bit harder to
ignore. Right now I'm leaning towards either always erroring out if there's
bison/flex output in the source tree (with a hint towards make
reallyclean(*)), or erroring out if they're out of date (again with a hint
towards reallyclean)?

Alternatively we could just remove the generated .c/h files from the source
dir, as a part of regenerating them in the build dir? But I like the idea of
the source dir being readonly outside of explicit targets modifying sources
(e.g. update-unicode or such).

Greetings,

Andres Freund

(*) do we really not have a target that removes bison / flex output?

Commits

  1. meson: Add 'running' test setup, as a replacement for installcheck

  2. meson: Add support for building with precompiled headers

  3. windows: Adjust FD_SETSIZE via commandline define

  4. meson: docs: Add xml{lint,proc} wrapper to collect dependencies

  5. meson: ecpg: Split definition of static and shared libraries

  6. windows: Set UMDF_USING_NTSTATUS globally, include ntstatus.h

  7. ci: Add hint about downloadable logs to README

  8. meson: Set up absolute rpaths to libdir

  9. meson: Include CFLAGS/c_args in summary and pg_config output

  10. windows: remove date from version number in win32ver.rc

  11. meson: Add initial version of meson based build system

  12. ci: windows: set error mode to not include SEM_NOGPFAULTERRORBOX

  13. Refactor PG_TEST_EXTRA logic in autoconf build

  14. Split TESTDIR into TESTLOGDIR and TESTDATADIR

  15. Don't hardcode tmp_check/ as test directory for tap tests

  16. Extend gendef.pl in preparation for meson

  17. Include c.h instead of postgres.h in src/port/*p{read,write}*.c

  18. Remove DLLTOOL, DLLWRAP from configure / Makefile.global.in

  19. Run xmllint validation only once

  20. Bump minimum Perl version to 5.14

  21. Move gramparse.h to src/backend/parser

  22. Run perltidy over Catalog.pm

  23. Parse catalog .dat files as a whole when compiling the backend

  24. Build all Flex files standalone

  25. Move private declarations shared between guc.c and guc-file.l to new header

  26. Preparatory refactoring for compiling guc-file.c standalone

  27. Move darwin sysroot determination into separate file

  28. Fix MSVC warning in compat_informix/rnull.pgc

  29. solaris: Use versioning scripts instead of -Bsymbolic

  30. Change shared library installation naming on macOS

  31. regress: allow to specify directory containing expected files, for ecpg

  32. Don't add HAVE_LDAP_H HAVE_WINLDAP_H to pg_config.h

  33. Refactor dtrace postprocessing make rules

  34. Add output directory option to gen_node_support.pl

  35. Add output directory argument to generate-unicode_norm_table.pl

  36. Add output file argument to generate-errcodes.pl

  37. Add output path arg in generate-lwlocknames.pl

  38. Move snowball_create.sql creation into perl file

  39. ecpg: Output dir, source dir, stamp file argument for preproc/*.pl

  40. psql: Output dir and dependency generation for sql_help

  41. Deal with paths containing \ and spaces in basebackup_to_shell tests

  42. Remove LLVM_CONFIG from Makefile.global.in

  43. Make update-unicode target work in vpath builds

  44. Refactor DLSUFFIX handling

  45. ldap tests: Add paths for openbsd.

  46. ldap tests: Don't run on unsupported operating systems.

  47. Remove check for accept() argument types

  48. Move our p{read,write}v replacements into their own files.

  49. Adjust yywrap macro for non-reentrant scanners for MSVC.

  50. Remove any -arch switches given in ExtUtils::Embed's ldopts from our

  51. Change PL/Perl and Pg interface build to use configured compiler and

  52. Apparently, on some systems, ExtUtils::Embed and MakeMaker are slightly