------------------------------------------------------------------------------ -- -- -- 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) 1996-2005, AdaCore -- -- -- -- 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, 51 Franklin Street, Fifth Floor, -- -- Boston, MA 02110-1301, 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; ----------------- -- Subprograms -- ----------------- -- Note: the lower bound of returnd String values is always one 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;