Function build_row_from_vars

src/pl/plpgsql/src/pl_comp.c:1996–2056

* Build a row-variable data structure given the component variables. * Include a rowtupdesc, since we will need to materialize the row result. */

 * Include a rowtupdesc, since we will need to materialize the row result.
 */
static PLpgSQL_row *
build_row_from_vars(PLpgSQL_variable **vars, int numvars)
{
	PLpgSQL_row *row;
	int			i;

	row = palloc0(sizeof(PLpgSQL_row));
	row->dtype = PLPGSQL_DTYPE_ROW;
	row->refname = "(unnamed row)";
	row->lineno = -1;
	row->rowtupdesc = CreateTemplateTupleDesc(numvars);
	row->nfields = numvars;
	row->fieldnames = palloc(numvars * sizeof(char *));
	row->varnos = palloc(numvars * sizeof(int));

	for (i = 0; i < numvars; i++)
	{
		PLpgSQL_variable *var = vars[i];
		Oid			typoid;
		int32		typmod;
		Oid			typcoll;

		/* Member vars of a row should never be const */
		Assert(!var->isconst);

		switch (var->dtype)
		{
			case PLPGSQL_DTYPE_VAR:
			case PLPGSQL_DTYPE_PROMISE:
				typoid = ((PLpgSQL_var *) var)->datatype->typoid;
				typmod = ((PLpgSQL_var *) var)->datatype->atttypmod;
				typcoll = ((PLpgSQL_var *) var)->datatype->collation;
				break;

			case PLPGSQL_DTYPE_REC:
				/* shouldn't need to revalidate rectypeid already... */
				typoid = ((PLpgSQL_rec *) var)->rectypeid;
				typmod = -1;	/* don't know typmod, if it's used at all */
				typcoll = InvalidOid;	/* composite types have no collation */
				break;

			default:
				elog(ERROR, "unrecognized dtype: %d", var->dtype);
				typoid = InvalidOid;	/* keep compiler quiet */
				typmod = 0;
				typcoll = InvalidOid;
				break;
		}

		row->fieldnames[i] = var->refname;
		row->varnos[i] = var->dno;

		TupleDescInitEntry(row->rowtupdesc, i + 1,
						   var->refname,
						   typoid, typmod,
						   0);
		TupleDescInitEntryCollation(row->rowtupdesc, i + 1, typcoll);
	}