Horton

Re: allow benign typedef redefinitions (C11)

Álvaro Herrera <alvherre@kurilemu.de>

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From: Álvaro Herrera <alvherre@kurilemu.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Peter Eisentraut <peter@eisentraut.org>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2025-09-28T16:54:23Z
Lists: pgsql-hackers

Attachments

On 2025-Sep-28, Tom Lane wrote:

> =?UTF-8?Q?=C3=81lvaro_Herrera?= <alvherre@kurilemu.de> writes:
> > The changes to inet.h and varbit.h are surprising, but required.
> 
> Why?  Those headers compile now, and you've not removed any includes
> that they might indirectly depend on.

That's true.

> If what you mean is that some of the macros in these headers require
> varatt.h to be used, I do not agree that that means we should put
> varatt.h into these headers.  We've frequently relied on exactly
> that property of macro definitions to avoid excessive or circular
> inclusions.  Moreover, even if we wanted to change that policy,
> I know of no simple way to check it.

We used to have a script called pgdefine that would create a .c file
that would expand all macros defined in a header, and then ensure that
the C file compiled.  It was removed only recently (Dec. 2024), in
commit 5af699066f81, though it's true that apparently nobody had used in
a while.

> I think what we're trying to do here is reduce the #includes of
> header files to be just enough to compile the headers themselves.
> That will bleed out into more #include's required in .c files,
> but that's fine by me.

Ok, that requires adding varatt.h to just two .c files -- attached.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/

Commits

  1. Move instrumentation-related structs to instrument_node.h

  2. Don't include access/htup_details.h in executor/tuptable.h

  3. Don't include execnodes.h in brin.h or gin.h

  4. Do a tiny bit of header file maintenance

  5. Don't include execnodes.h in replication/conflict.h

  6. Update some more forward declarations to use typedef

  7. Change fmgr.h typedefs to use original names

  8. Improve ExplainState type handling in header files

  9. Remove hbaPort type

  10. Remove workarounds against repeat typedefs

  11. Update various forward declarations to use typedef

  12. Allow redeclaration of typedef yyscan_t

  13. Improve pgbench definition of yyscan_t

  14. Delay extraction of TIDBitmap per page offsets

  15. Remove pgrminclude and associated scripts

  16. Allow to use HeapTupleData embedded in [Buffer]HeapTupleTableSlot.