gcc/ada/s-valwch.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                     S Y S T E M . V A L _ W C H A R                      --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2005, 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,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, 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 with Interfaces;      use Interfaces;
  35 with System.Val_Util; use System.Val_Util;
  36
  37 package body System.Val_WChar is
  38
  39    --------------------------
  40    -- Value_Wide_Character --
  41    --------------------------
  42
  43    function Value_Wide_Character
  44       (Str : String) return Wide_Character
  45    is
  46       WWC : constant Wide_Wide_Character := Value_Wide_Wide_Character (Str);
  47       WWV : constant Unsigned_32         := Wide_Wide_Character'Pos (WWC);
  48    begin
  49       if WWV > 16#FFFF# then
  50          raise Constraint_Error
  51            with "out of range character for Value attribute";
  52       else
  53          return Wide_Character'Val (WWV);
  54       end if;
  55    end Value_Wide_Character;
  56
  57    -------------------------------
  58    -- Value_Wide_Wide_Character --
  59    -------------------------------
  60
  61    function Value_Wide_Wide_Character
  62       (Str : String) return Wide_Wide_Character
  63    is
  64       F : Natural;
  65       L : Natural;
  66       S : String (Str'Range) := Str;
  67
  68    begin
  69       Normalize_String (S, F, L);
  70
  71       --  Character literal case
  72
  73       if S (F) = ''' and then S (L) = ''' then
  74
  75          --  If just three characters, simple character case
  76
  77          if L - F = 2 then
  78             return Wide_Wide_Character'Val (Character'Pos (S (F + 1)));
  79
  80             --  Otherwise something is very wrong
  81
  82          else
  83             raise Constraint_Error with "invalid string for Value attribute";
  84          end if;
  85
  86       --  Deal with Hex_hhhhhhhh cases for wide_[wide_]character cases
  87
  88       elsif Str'Length = 12 and then Str (1 .. 4) = "Hex_" then
  89          declare
  90             W : Unsigned_32 := 0;
  91
  92          begin
  93             for J in 5 .. 12 loop
  94                W := W * 16 + Character'Pos (Str (J));
  95
  96                if Str (J) in '0' .. '9' then
  97                   W := W - Character'Pos ('0');
  98                elsif Str (J) in 'A' .. 'F' then
  99                   W := W - Character'Pos ('A') + 10;
 100                elsif Str (J) in 'a' .. 'f' then
 101                   W := W - Character'Pos ('a') + 10;
 102                else
 103                   raise Constraint_Error
 104                     with "illegal hex character for Value attribute";
 105                end if;
 106             end loop;
 107
 108             if W > 16#7FFF_FFFF# then
 109                raise Constraint_Error
 110                  with "out of range value for Value attribute";
 111             else
 112                return Wide_Wide_Character'Val (W);
 113             end if;
 114          end;
 115
 116       --  Otherwise must be one of the special names for Character
 117
 118       else
 119          return
 120            Wide_Wide_Character'Val (Character'Pos (Character'Value (Str)));
 121       end if;
 122    end Value_Wide_Wide_Character;
 123
 124 end System.Val_WChar;