File : s-memmov.ads


   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                     S Y S T E M .  M E M O R Y _ M O V E                 --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --            Copyright (C) 2006-2014, 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 3,  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.                                     --
  17 --                                                                          --
  18 --                                                                          --
  19 --                                                                          --
  20 --                                                                          --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31 
  32 --  This package provides a general block copy mechanism analogous to that
  33 --  provided by the C routine memmove allowing for copies with overlap.
  34 
  35 pragma Restrictions (No_Elaboration_Code);
  36 
  37 with Interfaces.C;
  38 
  39 package System.Memory_Move is
  40    pragma Preelaborate;
  41 
  42    function memmove
  43      (Dest : Address; Src : Address; N : Interfaces.C.size_t) return Address;
  44    pragma Export (C, memmove, "memmove");
  45    --  Copies N storage units from area starting at Src to area starting
  46    --  at Dest without any check for buffer overflow. The difference between
  47    --  this memmove and memcpy is that with memmove, the storage areas may
  48    --  overlap (forwards or backwards) and the result is correct (i.e. it
  49    --  is as if Src is first moved to a temporary area, and then this area
  50    --  is copied to Dst in a separate step).
  51 
  52 end System.Memory_Move;