Horton

Re: [RFC] building postgres with meson - autogenerated headers

Peter Eisentraut <peter.eisentraut@enterprisedb.com>

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From: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
To: Andres Freund <andres@anarazel.de>, pgsql-hackers@postgresql.org, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2022-02-08T13:19:59Z
Lists: pgsql-hackers 
On 07.02.22 20:24, Andres Freund wrote:
> To be honest, I do not really understand the logic behind when autoconf ends
> up with #defines that define a macro to 0/1 and when a macro ends defined/or
> not and when we end up with a macro defined to 1 or not defined at all.

The default is to define to 1 or not at all.  The reason for this is 
presumably that originally, autoconf (or its predecessor practices) just 
populated the command line with a few -DHAVE_THIS options.  Creating a 
header file came later.  And -DFOO is equivalent to #define FOO 1. 
Also, this behavior allows code to use both the #ifdef HAVE_THIS and the 
#if HAVE_THIS style.

The cases that deviate from this have a special reason for this.  One 
issue to consider is that depending on how the configure script is set 
up or structured, a test might not run at all.  But for example, if you 
have a check for a declaration of a function, and the test doesn't run 
in a particular configuration, the fallback in your own code would 
normally be to then manually declare the function yourself.  But if you 
didn't even run the test, then adding a declaration of a function you 
didn't want in the first place might be bad.  In that case, you can 
check with #ifdef whether the test was run, and then check the value of 
the macro for the test outcome.

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