SQL> create or replace package tst_pck
  2  as
  3    procedure myproc;
  4  end;
  5  /

Package created.

SQL> create or replace package body tst_pck
  2  as
  3    procedure myproc
  4    is
  5    begin
  6      dbms_output.put_line($$PLSQL_UNIT);
  7    end;
  8  end;
  9  /

Package body created.

SQL> set serveroutput on size 1000000
SQL> exec tst_pck.myproc
TST_PCK

PL/SQL procedure successfully completed.

SQL> select banner from v$version;

BANNER
----------------------------------------------------------------
Oracle Database 10g Express Edition Release 10.2.0.1.0 - Product
PL/SQL Release 10.2.0.1.0 - Production
CORE    10.2.0.1.0      Production
TNS for 32-bit Windows: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production

SQL> create or replace package body tst_pck
  2  as
  3    procedure myproc
  4    is
  5    begin
  6        dbms_output.put_line(dbms_utility.format_call_stack);
  7    end;
  8  end;
  9  /

Package body created.

SQL> exec tst_pck.myproc
----- PL/SQL Call Stack -----
  object      line  object
  handle    number  name
21CCB080         6  package body MICHEL.TST_PCK
21CCA94C         1  anonymous block


PL/SQL procedure successfully completed.

SQL> create or replace package body tst_pck
  2  as
  3    procedure myproc
  4    is
  5    begin
  6        dbms_output.put_line(who_am_i);
  7    end;
  8  end;
  9  /

Package body created.

SQL> exec tst_pck.myproc
Package Body MICHEL.TST_PCK, line 6
PL/SQL procedure successfully completed.