| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT LIBRARY COMPONENTS -- |
| -- -- |
| -- G N A T . C U R R E N T _ E X C E P T I O N -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1996-2000 Ada Core Technologies, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 2, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING. If not, write -- |
| -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- |
| -- MA 02111-1307, USA. -- |
| -- -- |
| -- As a special exception, if other files instantiate generics from this -- |
| -- unit, or you link this unit with other files to produce an executable, -- |
| -- this unit does not by itself cause the resulting executable to be -- |
| -- covered by the GNU General Public License. This exception does not -- |
| -- however invalidate any other reasons why the executable file might be -- |
| -- covered by the GNU Public License. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This package provides routines for obtaining the current exception |
| -- information in Ada 83 style. In Ada 83, there was no official method |
| -- for obtaining exception information, but a number of vendors supplied |
| -- routines for this purpose, and this package closely approximates the |
| -- interfaces supplied by DEC Ada 83 and VADS Ada. |
| |
| -- The routines in this package are associated with a particular exception |
| -- handler, and can only be called from within an exception handler. See |
| -- also the package GNAT.Most_Recent_Exception, which provides access to |
| -- the most recently raised exception, and is not limited to static calls |
| -- from an exception handler. |
| |
| package GNAT.Current_Exception is |
| pragma Pure (Current_Exception); |
| |
| ----------------- |
| -- Subprograms -- |
| ----------------- |
| |
| function Exception_Information return String; |
| -- Returns the result of calling Ada.Exceptions.Exception_Information |
| -- with an argument that is the Exception_Occurrence corresponding to |
| -- the current exception. Returns the null string if called from outside |
| -- an exception handler. |
| |
| function Exception_Message return String; |
| -- Returns the result of calling Ada.Exceptions.Exception_Message with |
| -- an argument that is the Exception_Occurrence corresponding to the |
| -- current exception. Returns the null string if called from outside an |
| -- exception handler. |
| |
| function Exception_Name return String; |
| -- Returns the result of calling Ada.Exceptions.Exception_Name with |
| -- an argument that is the Exception_Occurrence corresponding to the |
| -- current exception. Returns the null string if called from outside |
| -- an exception handler. |
| |
| -- Note: all these functions return useful information only if |
| -- called statically from within an exception handler, and they |
| -- return information about the exception corresponding to the |
| -- handler in which they appear. This is NOT the same as the most |
| -- recently raised exception. Consider the example: |
| |
| -- exception |
| -- when Constraint_Error => |
| -- begin |
| -- ... |
| -- exception |
| -- when Tasking_Error => ... |
| -- end; |
| -- |
| -- -- Exception_xxx at this point returns the information about |
| -- -- the constraint error, not about any exception raised within |
| -- -- the nested block since it is the static nesting that counts. |
| |
| ----------------------------------- |
| -- Use of Library Level Renaming -- |
| ----------------------------------- |
| |
| -- For greater compatibility with existing legacy software, library |
| -- level renaming may be used to create a function with a name matching |
| -- one that is in use. For example, some versions of VADS Ada provided |
| -- a functin called Current_Exception whose semantics was identical to |
| -- that of GNAT. The following library level renaming declaration: |
| |
| -- with GNAT.Current_Exception; |
| -- function Current_Exception |
| -- renames GNAT.Current_Exception.Exception_Name; |
| |
| -- placed in a file called current_exception.ads and compiled into the |
| -- application compilation environment, will make the function available |
| -- in a manner exactly compatible with that in VADS Ada 83. |
| |
| private |
| pragma Import (Intrinsic, Exception_Information); |
| pragma Import (intrinsic, Exception_Message); |
| pragma Import (Intrinsic, Exception_Name); |
| |
| end GNAT.Current_Exception; |
