Function ExecInitFunctionResultSet

src/backend/executor/execSRF.c:447–485

* Prepare targetlist SRF function call for execution. * * This is used by nodeProjectSet.c. */

 * This is used by nodeProjectSet.c.
 */
SetExprState *
ExecInitFunctionResultSet(Expr *expr,
						  ExprContext *econtext, PlanState *parent)
{
	SetExprState *state = makeNode(SetExprState);

	state->funcReturnsSet = true;
	state->expr = expr;
	state->func.fn_oid = InvalidOid;

	/*
	 * Initialize metadata.  The expression node could be either a FuncExpr or
	 * an OpExpr.
	 */
	if (IsA(expr, FuncExpr))
	{
		FuncExpr   *func = (FuncExpr *) expr;

		state->args = ExecInitExprList(func->args, parent);
		init_sexpr(func->funcid, func->inputcollid, expr, state, parent,
				   econtext->ecxt_per_query_memory, true, true);
	}
	else if (IsA(expr, OpExpr))
	{
		OpExpr	   *op = (OpExpr *) expr;

		state->args = ExecInitExprList(op->args, parent);
		init_sexpr(op->opfuncid, op->inputcollid, expr, state, parent,
				   econtext->ecxt_per_query_memory, true, true);
	}
	else
		elog(ERROR, "unrecognized node type: %d",
			 (int) nodeTag(expr));

	/* shouldn't get here unless the selected function returns set */
	Assert(state->func.fn_retset);

	return state;
}

/*
 *		ExecMakeFunctionResultSet