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Diffstat (limited to 'gcc-4.2.1/gcc/ada/g-except.ads')
| -rw-r--r-- | gcc-4.2.1/gcc/ada/g-except.ads | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/gcc-4.2.1/gcc/ada/g-except.ads b/gcc-4.2.1/gcc/ada/g-except.ads new file mode 100644 index 000000000..9daa08d5d --- /dev/null +++ b/gcc-4.2.1/gcc/ada/g-except.ads @@ -0,0 +1,84 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME COMPONENTS -- +-- -- +-- G N A T . E X C E P T I O N S -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2000-2005, 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 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 restrictiona 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 a tagged type) that would drag 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; |