Horton

Re: [HACKERS] [PATCH] Generic type subscripting

Tom Lane <tgl@sss.pgh.pa.us>

View thread View on postgr.es
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Dmitry Dolgov <9erthalion6@gmail.com>, Pavel Stehule <pavel.stehule@gmail.com>, Alexander Korotkov <aekorotkov@gmail.com>, Justin Pryzby <pryzby@telsasoft.com>, David Steele <david@pgmasters.net>, Nikita Glukhov <n.gluhov@postgrespro.ru>, Alvaro Herrera <alvherre@2ndquadrant.com>, David Fetter <david@fetter.org>, Thomas Munro <thomas.munro@gmail.com>, Oleksandr Shulgin <oleksandr.shulgin@zalando.de>, Robert Haas <robertmhaas@gmail.com>, Michael Paquier <michael.paquier@gmail.com>, Oleg Bartunov <obartunov@gmail.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2020-12-07T21:32:32Z
Lists: pgsql-hackers 
Andres Freund <andres@anarazel.de> writes:
> The TypeParamBool stuff here is ok. Basically LLVM uses a '1bit' integer
> to represent booleans in the IR. But when it comes to storing such a
> value in memory, it uses 1 byte, for obvious reasons. Hence the two
> types.

Cool, thanks for taking a look.

> I think it'd be a better to rely on the backend's definition of
> ExecEvalBoolSubroutine etc. For the functions implementing expression
> steps I've found that far easier to work with over time (because you can
> get LLVM to issue type mismatch errors when the signature changes,
> instead of seeing compile failures).

I'm a little unclear on what you mean here?  There wasn't such a
thing as ExecEvalBoolSubroutine until I added it in this patch.

> I've attached a prototype conversion for two other such places. Which
> immediately pointed to a bug. And one harmless issue (using a pointer to
> size_t instead of ExprEvalOp* to represent the 'op' parameter), which
> you promptly copied...
> If I pushed a slightly cleaned up version of that, it should be fairly
> easy to adapt your code to it, I think?

Sure.  I just copied the existing code for EEOP_PARAM_CALLBACK;
if that changes, I'll just copy the new code.

What did you think of the idea of merging EEOP_SBSREF_OLD / ASSIGN / FETCH
into a single step type distinguished only by the callback function?

			regards, tom lane

Commits

  1. Throw error when assigning jsonb scalar instead of a composite object

  2. Filling array gaps during jsonb subscripting

  3. Implementation of subscripting for jsonb

  4. Allow ALTER TYPE to update an existing type's typsubscript value.

  5. Allow subscripting of hstore values.

  6. Support subscripting of arbitrary types, not only arrays.

  7. jit: Reference function pointer types via llvmjit_types.c.

  8. Teach contain_leaked_vars that assignment SubscriptingRefs are leaky.

  9. jit: Correct parameter type for generated expression evaluation functions.

  10. Renaming for new subscripting mechanism

  11. Fix assertion failure for SSL connections.

  12. Teach eval_const_expressions() to handle some more cases.