| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- G N A T . E X C E P T I O N S -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 2000-2023, 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 3, 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. -- |
| -- -- |
| -- As a special exception under Section 7 of GPL version 3, you are granted -- |
| -- additional permissions described in the GCC Runtime Library Exception, -- |
| -- version 3.1, as published by the Free Software Foundation. -- |
| -- -- |
| -- You should have received a copy of the GNU General Public License and -- |
| -- a copy of the GCC Runtime Library Exception along with this program; -- |
| -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- |
| -- <http://www.gnu.org/licenses/>. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This package provides an interface for raising predefined exceptions |
| -- with an exception message. It can be used from Pure units. |
| |
| -- There is no prohibition in Ada that prevents exceptions being raised |
| -- from within pure units. The raise statement is perfectly acceptable. |
| |
| -- However, it is not normally possible to raise an exception with a |
| -- message because the routine Ada.Exceptions.Raise_Exception is not in |
| -- a Pure unit. This is an annoying and unnecessary restriction and this |
| -- package allows for raising the standard predefined exceptions at least. |
| |
| package GNAT.Exceptions is |
| pragma Pure; |
| |
| type Exception_Type is limited null record; |
| -- Type used to specify which exception to raise |
| |
| -- Really Exception_Type is Exception_Id, but Exception_Id can't be |
| -- used directly since it is declared in the non-pure unit Ada.Exceptions, |
| |
| -- Exception_Id is in fact simply a pointer to the type Exception_Data |
| -- declared in System.Standard_Library (which is also non-pure). So what |
| -- we do is to define it here as a by reference type (any by reference |
| -- type would do), and then Import the definitions from Standard_Library. |
| -- Since this is a by reference type, these will be passed by reference, |
| -- which has the same effect as passing a pointer. |
| |
| -- This type is not private because keeping it by reference would require |
| -- defining it in a way (e.g. using a tagged type) that would drag in other |
| -- run-time files, which is unwanted in the case of e.g. Ravenscar where we |
| -- want to minimize the number of run-time files needed by default. |
| |
| CE : constant Exception_Type; -- Constraint_Error |
| PE : constant Exception_Type; -- Program_Error |
| SE : constant Exception_Type; -- Storage_Error |
| TE : constant Exception_Type; -- Tasking_Error |
| -- One of these constants is used in the call to specify the exception |
| |
| procedure Raise_Exception (E : Exception_Type; Message : String); |
| pragma Import (Ada, Raise_Exception, "__gnat_raise_exception"); |
| pragma No_Return (Raise_Exception); |
| -- Raise specified exception with specified message |
| |
| private |
| pragma Import (C, CE, "constraint_error"); |
| pragma Import (C, PE, "program_error"); |
| pragma Import (C, SE, "storage_error"); |
| pragma Import (C, TE, "tasking_error"); |
| -- References to the exception structures in the standard library |
| |
| end GNAT.Exceptions; |
