How to get an exception detail in a function called in exception handler

Hello,

I am porting Oracle to PostgreSQL.

In oracle sqlcode and sqlerrm can be accessed in a function called from an
exception block.
How do I do this in PostgreSQL

For example:

How do I get exception details in function "myschema"."testerror" () in
function "myschema"."logerror"().
I understand that GET STACKED DIAGNOSTICS does not work here, but is there
any way to achieve this?

This is a function that will always generate an error (since columnName
does not exist in table)

CREATE OR REPLACE FUNCTION "myschema"."testerror" ()
RETURNS void AS $$
DECLARE
BEGIN
-- source data
select sirv.columnName
from "myschema"."tableName" sirv;

EXCEPTION
WHEN OTHERS THEN
-- log exception details like SQLERRM, SQLSTATE from function
"myschema"."logerror"()
PERFORM "myschema"."logerror"();

END; $$ LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION "myschema"."logerror" ()
RETURNS void AS $$
DECLARE
the_sqlcode int := 0;
the_sqlerrormessage varchar ;
BEGIN
GET STACKED DIAGNOSTICS the_sqlerrormessage = MESSAGE_TEXT,
the_sqlcode = RETURNED_SQLSTATE,

INSERT into "myschema"."error_trace"(
errorCode,
error_messaage)
VALUES (
the_sqlcode,
the_sqlerrormessage);

END; $$ LANGUAGE plpgsql;

Thanks,

Shakti Singh