Horton

Re: automatically generating node support functions

Peter Eisentraut <peter.eisentraut@enterprisedb.com>

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From: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: David Rowley <dgrowleyml@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-07-08T12:44:00Z
Lists: pgsql-hackers

Attachments

On 06.07.22 22:46, Tom Lane wrote:
> Peter Eisentraut <peter.eisentraut@enterprisedb.com> writes:
>> [ v7-0001-Automatically-generate-node-support-functions.patch ]
> 
> I have gone through this and made some proposed changes (attached),

I have included those.

> and I think it is almost committable.  There is one nasty problem
> we need a solution to, which is that pgindent is not at all on board
> with this idea of attaching node attrs to typedefs.  It pushes them
> to the next line, like this:
> 
> @@ -691,7 +709,8 @@
>   	 (rel)->reloptkind == RELOPT_OTHER_JOINREL || \
>   	 (rel)->reloptkind == RELOPT_OTHER_UPPER_REL)
>   
> -typedef struct RelOptInfo pg_node_attr(no_copy_equal, no_read)
> +typedef struct RelOptInfo
> +pg_node_attr(no_copy_equal, no_read)
>   {
>   	NodeTag		type;

I have found that putting the attributes at the end of the struct 
definition, right before the semicolon, works, so I have changed it that 
way.  (This is also where a gcc __attribute__() would go, so it seems 
reasonable.)

The attached patch is stable under pgindent.

Finally, I have updated src/backend/nodes/README a bit.

I realize I've been confused various times about when a catversion 
change is required when changing nodes.  (I think the bump in 251154bebe 
was probably not needed.)  I have tried to put that in the README.  This 
could perhaps be expanded.

I think for this present patch, I would do a catversion bump, just to be 
sure, in case some of the printed node fields are different now.

It was also my plan to remove the #ifdef OBSOLETE sections in a separate 
commit right after, just to be clear.

Final thoughts?

Commits

  1. Fix MSVC build script's check for obsolete node support functions.

  2. Improve performance of ORDER BY / DISTINCT aggregates

  3. doc: Fix typos in protocol.sgml

  4. Tighten up parsing logic in gen_node_support.pl.

  5. Add defenses against unexpected changes in the NodeTag enum list.

  6. Add copy/equal support for XID lists

  7. Rationalize order of input files for gen_node_support.pl.

  8. Make assorted quality-of-life improvements in gen_node_support.pl.

  9. Doc: rearrange high-level commentary about node support coverage.

  10. Automatically generate node support functions

  11. Adjust node serialization tag of A_Expr for consistency

  12. Remove T_Join and T_Plan

  13. Reformat some more node comments

  14. Reformat some node comments

  15. Remove JsonPathSpec typedef

  16. Add missing enum tag in enum used in nodes

  17. Add Cardinality typedef

  18. Make node output prefix match node structure name

  19. Add WRITE_INDEX_ARRAY

  20. Add COPY_ARRAY_FIELD and COMPARE_ARRAY_FIELD

  21. Remove T_Expr

  22. Change NestPath node to contain JoinPath node

  23. Change SeqScan node to contain Scan node

  24. Check the size in COPY_POINTER_FIELD

  25. Remove T_MemoryContext

  26. Add missing enum tags in enums used in nodes

  27. Rename some node support functions for consistency

  28. Rename argument of _outValue()

  29. Rename NodeTag of ExprState