Function plpgsql_parse_dblword

src/pl/plpgsql/src/pl_comp.c:1469–1542

---------- * plpgsql_parse_dblword Same lookup for two words * separated by a dot. * ---------- */

 * ----------
 */
bool
plpgsql_parse_dblword(char *word1, char *word2,
					  PLwdatum *wdatum, PLcword *cword)
{
	PLpgSQL_nsitem *ns;
	List	   *idents;
	int			nnames;

	idents = list_make2(makeString(word1),
						makeString(word2));

	/*
	 * We should do nothing in DECLARE sections.  In SQL expressions, we
	 * really only need to make sure that RECFIELD datums are created when
	 * needed.  In all the cases handled by this function, returning a T_DATUM
	 * with a two-word idents string is the right thing.
	 */
	if (plpgsql_IdentifierLookup != IDENTIFIER_LOOKUP_DECLARE)
	{
		/*
		 * Do a lookup in the current namespace stack
		 */
		ns = plpgsql_ns_lookup(plpgsql_ns_top(), false,
							   word1, word2, NULL,
							   &nnames);
		if (ns != NULL)
		{
			switch (ns->itemtype)
			{
				case PLPGSQL_NSTYPE_VAR:
					/* Block-qualified reference to scalar variable. */
					wdatum->datum = plpgsql_Datums[ns->itemno];
					wdatum->ident = NULL;
					wdatum->quoted = false; /* not used */
					wdatum->idents = idents;
					return true;

				case PLPGSQL_NSTYPE_REC:
					if (nnames == 1)
					{
						/*
						 * First word is a record name, so second word could
						 * be a field in this record.  We build a RECFIELD
						 * datum whether it is or not --- any error will be
						 * detected later.
						 */
						PLpgSQL_rec *rec;
						PLpgSQL_recfield *new;

						rec = (PLpgSQL_rec *) (plpgsql_Datums[ns->itemno]);
						new = plpgsql_build_recfield(rec, word2);

						wdatum->datum = (PLpgSQL_datum *) new;
					}
					else
					{
						/* Block-qualified reference to record variable. */
						wdatum->datum = plpgsql_Datums[ns->itemno];