Re: pgsql: Add more SQL/JSON constructor functions

On Thu, Jun 27, 2024 at 7:48 PM Amit Langote <amitlangote09(at)gmail(dot)com> wrote:
> >
> > I've attempted that in the attached 0001, which removes
> > JsonExpr.coercion_expr and a bunch of code around it.
> >
> > 0002 is now the original patch minus the changes to make
> > JSON_EXISTS(), JSON_QUERY(), and JSON_VALUE() behave as we would like,
> > because the changes in 0001 covers them. The changes for JsonBehavior
> > expression coercion as they were in the last version of the patch are
> > still needed, but I decided to move those into 0001 so that the
> > changes for query functions are all in 0001 and those for constructors
> > in 0002. It would be nice to get rid of that coerce_to_target_type()
> > call to coerce the "behavior expression" to RETURNING type, but I'm
> > leaving that as a task for another day.
>
> Updated 0001 to remove outdated references, remove some more unnecessary code.
>

i found some remaining references of "coercion_expr" should be removed.

src/include/nodes/primnodes.h
/* JsonExpr's collation, if coercion_expr is NULL. */

src/include/nodes/execnodes.h
/*
* Address of the step to coerce the result value of jsonpath evaluation
* to the RETURNING type using JsonExpr.coercion_expr. -1 if no coercion
* is necessary or if either JsonExpr.use_io_coercion or
* JsonExpr.use_json_coercion is true.
*/
int jump_eval_coercion;

src/backend/jit/llvm/llvmjit_expr.c
/* coercion_expr code */
LLVMPositionBuilderAtEnd(b, b_coercion);
if (jsestate->jump_eval_coercion >= 0)
LLVMBuildBr(b, opblocks[jsestate->jump_eval_coercion]);
else
LLVMBuildUnreachable(b);

src/backend/executor/execExprInterp.c
/*
* Checks if an error occurred either when evaluating JsonExpr.coercion_expr or
* in ExecEvalJsonCoercion(). If so, this sets JsonExprState.error to trigger
* the ON ERROR handling steps.
*/
void
ExecEvalJsonCoercionFinish(ExprState *state, ExprEvalStep *op)
{
}

if (jbv == NULL)
{
/* Will be coerced with coercion_expr, if any. */
*op->resvalue = (Datum) 0;
*op->resnull = true;
}

src/backend/executor/execExpr.c
/*
* Jump to coerce the NULL using coercion_expr if present. Coercing NULL
* is only interesting when the RETURNING type is a domain whose
* constraints must be checked. jsexpr->coercion_expr containing a
* CoerceToDomain node must have been set in that case.
*/

/*
* Jump to coerce the NULL using coercion_expr if present. Coercing NULL
* is only interesting when the RETURNING type is a domain whose
* constraints must be checked. jsexpr->coercion_expr containing a
* CoerceToDomain node must have been set in that case.
*/