Horton

Re: automatically generating node support functions

Andrew Dunstan <andrew@dunslane.net>

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From: Andrew Dunstan <andrew@dunslane.net>
To: Peter Eisentraut <peter.eisentraut@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2021-10-12T13:52:15Z
Lists: pgsql-hackers 
On 10/11/21 10:22 AM, Peter Eisentraut wrote:
>
> On 15.09.21 21:01, Peter Eisentraut wrote:
>> On 17.08.21 16:36, Peter Eisentraut wrote:
>>> Here is another set of preparatory patches that clean up various
>>> special cases and similar in the node support.
>>
>> This set of patches has been committed.  I'll close this commit fest
>> entry and come back with the main patch series in the future.
>
> Here is an updated version of my original patch, so we have something
> to continue the discussion around.  This takes into account all the
> preparatory patches that have been committed in the meantime.  I have
> also changed it so that the array size of a pointer is now explicitly
> declared using pg_node_attr(array_size(N)) instead of picking the most
> recent scalar field, which was admittedly hacky.  I have also added
> MSVC build support and made the Perl code more portable, so that the
> cfbot doesn't have to be sad.



I haven't been through the whole thing, but I did notice this: the
comment stripping code looks rather fragile. I think it would blow up if
there were a continuation line not starting with  qr/\s*\*/. It's a lot
simpler and more robust to do this if you slurp the file in whole.
Here's what we do in the buildfarm code:

    my $src = file_contents($_);
    # strip C comments
    # We used to use the recipe in perlfaq6 but there is actually no point.
    # We don't need to keep the quoted string values anyway, and
    # on some platforms the complex regex causes perl to barf and crash.
    $src =~ s{/\*.*?\*/}{}gs;

After you've done that splitting it into lines is pretty simple.

cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com

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