------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S Y S T E M . S T O R A G E _ E L E M E N T S -- -- -- -- S p e c -- -- -- -- Copyright (C) 2002-2024, Free Software Foundation, Inc. -- -- -- -- This specification is derived from the Ada Reference Manual for use with -- -- GNAT. The copyright notice above, and the license provisions that follow -- -- apply solely to the implementation dependent sections of this file. -- -- -- -- 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 -- -- . -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This package provides the ``Storage_Elements`` package as defined by the -- Ada ARM 13.7.1 to allow for arithmetic operations on memory addresses. -- Warning: declarations in this package are ambiguous with respect to the -- extra declarations that can be introduced into System using Extend_System. -- It is a good idea to avoid use clauses for this package. package System.Storage_Elements with Always_Terminates is pragma Pure; -- Note that we take advantage of the implementation permission to make -- this unit Pure instead of Preelaborable; see RM 13.7.1(15). In Ada 2005, -- this is Pure in any case (AI-362). pragma No_Elaboration_Code_All; -- Allow the use of that restriction in units that WITH this unit type Storage_Offset is range -Memory_Size / 2 .. Memory_Size / 2 - 1; subtype Storage_Count is Storage_Offset range 0 .. Storage_Offset'Last; -- *Storage_Count* is a subtype of *Storage_Offset* with only the null or -- positive values. type Storage_Element is mod 2 ** Storage_Unit; for Storage_Element'Size use Storage_Unit; -- The type *Storage_Element* represents a byte pragma Universal_Aliasing (Storage_Element); -- This type is used by the expander to implement aggregate copy type Storage_Array is array (Storage_Offset range <>) of aliased Storage_Element; for Storage_Array'Component_Size use Storage_Unit; -- The type *Storage_Array* represents a part of the memory -- Address arithmetic function "+" (Left : Address; Right : Storage_Offset) return Address; function "+" (Left : Storage_Offset; Right : Address) return Address; pragma Import (Intrinsic, "+"); -- Returns the sum of ``Left`` and ``Right`` function "-" (Left : Address; Right : Storage_Offset) return Address; function "-" (Left, Right : Address) return Storage_Offset; pragma Import (Intrinsic, "-"); -- Returns the difference between ``Left`` and ``Right`` function "mod" (Left : Address; Right : Storage_Offset) return Storage_Offset; pragma Import (Intrinsic, "mod"); -- Returns the modulus between ``Left`` and ``Right`` -- Conversion to/from integers type Integer_Address is mod Memory_Size; -- Finally, *Integer_Address* is a non-private modular -- type that represents an address. function To_Address (Value : Integer_Address) return Address; pragma Import (Intrinsic, To_Address); -- Converts the *Integer_Address* ``Value`` to an *Address* function To_Integer (Value : Address) return Integer_Address; pragma Import (Intrinsic, To_Integer); -- Converts the *Address* ``Value`` to an *Integer_Address* end System.Storage_Elements;