gcc/ada/a-stunau.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                          GNAT RUNTIME COMPONENTS                         --
   4 --                                                                          --
   5 --            A D A . S T R I N G S . U N B O U N D E D . A U X             --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2002, 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 package body Ada.Strings.Unbounded.Aux is
  35
  36    ----------------
  37    -- Get_String --
  38    ----------------
  39
  40    function Get_String (U : Unbounded_String) return String_Access is
  41    begin
  42       if U.Last = U.Reference'Length then
  43          return U.Reference;
  44
  45       else
  46          declare
  47             type Unbounded_String_Access is access all Unbounded_String;
  48
  49             U_Ptr : constant Unbounded_String_Access := U'Unrestricted_Access;
  50             --  Unbounded_String is a controlled type which is always passed
  51             --  by copy it is always safe to take the pointer to such object
  52             --  here. This pointer is used to set the U.Reference value which
  53             --  would not be possible otherwise as U is read-only.
  54
  55             Old : String_Access := U.Reference;
  56
  57          begin
  58             U_Ptr.Reference := new String'(U.Reference (1 .. U.Last));
  59             Free (Old);
  60             return U.Reference;
  61          end;
  62       end if;
  63    end Get_String;
  64
  65    ----------------
  66    -- Set_String --
  67    ----------------
  68
  69    procedure Set_String (UP : in out Unbounded_String; S : String) is
  70    begin
  71       if UP.Last = S'Length then
  72          UP.Reference.all := S;
  73
  74       else
  75          declare
  76             subtype String_1 is String (1 .. S'Length);
  77             Tmp : String_Access;
  78
  79          begin
  80             Tmp := new String'(String_1 (S));
  81             Finalize (UP);
  82             UP.Reference := Tmp;
  83             UP.Last := UP.Reference'Length;
  84          end;
  85       end if;
  86    end Set_String;
  87
  88    procedure Set_String (UP : in out Unbounded_String; S : String_Access) is
  89    begin
  90       Finalize (UP);
  91       UP.Reference := S;
  92       UP.Last := UP.Reference'Length;
  93    end Set_String;
  94
  95 end Ada.Strings.Unbounded.Aux;