Horton

Re: [HACKERS] [PATCH] Generic type subscripting

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

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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: 2020-12-08T16:05:05Z
Lists: pgsql-hackers 
Andres Freund <andres@anarazel.de> writes:
> 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?

I've now studied this patch and it seems sane to me, although
I wondered why you wrote "extern"s here:

@@ -48,6 +48,10 @@
 PGFunction	TypePGFunction;
 size_t		TypeSizeT;
 bool		TypeStorageBool;
+extern ExprStateEvalFunc TypeExprStateEvalFunc;
+ExprStateEvalFunc TypeExprStateEvalFunc;
+extern ExecEvalSubroutine TypeExecEvalSubroutine;
+ExecEvalSubroutine TypeExecEvalSubroutine;
 
 NullableDatum StructNullableDatum;
 AggState	StructAggState;

The other variables in that file don't have that.  Other than that nit,
please finish this up and push it so I can finish the generic-subscripting
patch.

> WRT the prototype, I think it may be worth removing most of the types
> from llvmjit.h. Worth keeping the most common ones, but most aren't used
> all the time so terseness doesn't matter that much, and
> the llvm_pg_var_type() would suffice.

Hm, that would mean redoing llvm_pg_var_type() often wouldn't it?
I don't have a very good feeling for how expensive that is, so I'm
not sure if this seems like a good idea or not.

			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.