1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- G N A T . E X C E P T I O N _ A C T I O N S -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 2002-2003 Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 2, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING. If not, write -- 19-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- 20-- MA 02111-1307, USA. -- 21-- -- 22-- As a special exception, if other files instantiate generics from this -- 23-- unit, or you link this unit with other files to produce an executable, -- 24-- this unit does not by itself cause the resulting executable to be -- 25-- covered by the GNU General Public License. This exception does not -- 26-- however invalidate any other reasons why the executable file might be -- 27-- covered by the GNU Public License. -- 28-- -- 29-- GNAT was originally developed by the GNAT team at New York University. -- 30-- Extensive contributions were provided by Ada Core Technologies Inc. -- 31-- -- 32------------------------------------------------------------------------------ 33 34-- This package provides support for callbacks on exceptions. 35 36-- These callbacks are called immediately when either a specific exception, 37-- or any exception, is raised, before any other actions taken by raise, in 38-- particular before any unwinding of the stack occcurs. 39 40-- Callbacks for specific exceptions are registered through calls to 41-- Register_Id_Action. Here is an example of code that uses this package to 42-- automatically core dump when the exception Constraint_Error is raised. 43 44-- Register_Id_Action (Constraint_Error'Identity, Core_Dump'Access); 45 46-- Subprograms are also provided to list the currently registered exceptions, 47-- or to convert from a string to an exception id. 48 49-- This package can easily be extended, for instance to provide a callback 50-- whenever an exception matching a regular expression is raised. The idea 51-- is to register a global action, called whenever any exception is raised. 52-- Dispatching can then be done directly in this global action callback. 53 54with Ada.Exceptions; use Ada.Exceptions; 55 56package GNAT.Exception_Actions is 57 58 type Exception_Action is access 59 procedure (Occurence : Exception_Occurrence); 60 -- General callback type whenever an exception is raised. The callback 61 -- procedure must not propagate an exception (execution of the program 62 -- is erroneous if such an exception is propagated). 63 64 procedure Register_Global_Action (Action : Exception_Action); 65 -- Action will be called whenever an exception is raised. Only one such 66 -- action can be registered at any given time, and registering a new action 67 -- will override any previous action that might have been registered. 68 -- 69 -- Action is called before the exception is propagated to user's code. 70 -- If Action is null, this will in effect cancel all exception actions. 71 72 procedure Register_Id_Action 73 (Id : Exception_Id; 74 Action : Exception_Action); 75 -- Action will be called whenever an exception of type Id is raised. Only 76 -- one such action can be registered for each exception id, and registering 77 -- a new action will override any previous action registered for this 78 -- Exception_Id. Program_Error is raised if Id is Null_Id. 79 80 function Name_To_Id (Name : String) return Exception_Id; 81 -- Convert an exception name to an exception id. Null_Id is returned 82 -- if no such exception exists. Name must be an all upper-case string, 83 -- or the exception will not be found. The exception name must be fully 84 -- qualified (but not including Standard). It is not possible to convert 85 -- an exception that is declared within an unlabeled block. 86 -- 87 -- Note: All non-predefined exceptions will return Null_Id for programs 88 -- compiled with pragma Restriction (No_Exception_Registration) 89 90 function Registered_Exceptions_Count return Natural; 91 -- Return the number of exceptions that have been registered so far. 92 -- Exceptions declared locally will not appear in this list until their 93 -- block has been executed at least once. 94 -- 95 -- Note: The count includes only predefined exceptions for programs 96 -- compiled with pragma Restrictions (No_Exception_Registration). 97 98 type Exception_Id_Array is array (Natural range <>) of Exception_Id; 99 100 procedure Get_Registered_Exceptions 101 (List : out Exception_Id_Array; 102 Last : out Integer); 103 -- Return the list of registered exceptions. 104 -- Last is the index in List of the last exception returned. 105 -- 106 -- An exception is registered the first time the block containing its 107 -- declaration is elaborated. Exceptions defined at library-level are 108 -- therefore immediately visible, whereas exceptions declared in local 109 -- blocks will not be visible until the block is executed at least once. 110 -- 111 -- Note: The list contains only the predefined exceptions if the program 112 -- is compiled with pragma Restrictions (No_Exception_Registration); 113 114 procedure Core_Dump (Occurrence : Exception_Occurrence); 115 -- Dump memory (called a core dump in some systems), and abort execution 116 -- of the application. 117 118end GNAT.Exception_Actions; 119