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) 1992-2009, 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 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  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 with Interfaces;      use Interfaces;
  33 with System.Val_Util; use System.Val_Util;
  34 with System.WCh_Cnv;  use System.WCh_Cnv;
  35 with System.WCh_Con;  use System.WCh_Con;
  36
  37 package body System.Val_WChar is
  38
  39    --------------------------
  40    -- Value_Wide_Character --
  41    --------------------------
  42
  43    function Value_Wide_Character
  44      (Str : String;
  45       EM  : System.WCh_Con.WC_Encoding_Method) return Wide_Character
  46    is
  47       WC : constant Wide_Wide_Character := Value_Wide_Wide_Character (Str, EM);
  48       WV : constant Unsigned_32         := Wide_Wide_Character'Pos (WC);
  49    begin
  50       if WV > 16#FFFF# then
  51          raise Constraint_Error with
  52            "out of range character for Value attribute";
  53       else
  54          return Wide_Character'Val (WV);
  55       end if;
  56    end Value_Wide_Character;
  57
  58    -------------------------------
  59    -- Value_Wide_Wide_Character --
  60    -------------------------------
  61
  62    function Value_Wide_Wide_Character
  63      (Str : String;
  64       EM  : System.WCh_Con.WC_Encoding_Method) return Wide_Wide_Character
  65    is
  66       F : Natural;
  67       L : Natural;
  68       S : String (Str'Range) := Str;
  69
  70    begin
  71       Normalize_String (S, F, L);
  72
  73       --  Character literal case
  74
  75       if S (F) = ''' and then S (L) = ''' then
  76
  77          --  Must be at least three characters
  78
  79          if L - F < 2 then
  80             raise Constraint_Error;
  81
  82          --  If just three characters, simple character case
  83
  84          elsif L - F = 2 then
  85             return Wide_Wide_Character'Val (Character'Pos (S (F + 1)));
  86
  87          --  Only other possibility for quoted string is wide char sequence
  88
  89          else
  90             declare
  91                P : Natural;
  92                W : Wide_Wide_Character;
  93
  94                function In_Char return Character;
  95                --  Function for instantiations of Char_Sequence_To_UTF_32
  96
  97                -------------
  98                -- In_Char --
  99                -------------
 100
 101                function In_Char return Character is
 102                begin
 103                   P := P + 1;
 104
 105                   if P = Str'Last then
 106                      raise Constraint_Error;
 107                   end if;
 108
 109                   return Str (P);
 110                end In_Char;
 111
 112                function UTF_32 is
 113                  new Char_Sequence_To_UTF_32 (In_Char);
 114
 115             begin
 116                P := F + 1;
 117
 118                --  Brackets encoding
 119
 120                if S (F + 1) = '[' then
 121                   W := Wide_Wide_Character'Val (UTF_32 ('[', WCEM_Brackets));
 122                else
 123                   W := Wide_Wide_Character'Val (UTF_32 (S (F + 1), EM));
 124                end if;
 125
 126                if P /= L - 1 then
 127                   raise Constraint_Error;
 128                end if;
 129
 130                return W;
 131             end;
 132          end if;
 133
 134       --  Deal with Hex_hhhhhhhh cases for wide_[wide_]character cases
 135
 136       elsif Str'Length = 12
 137         and then Str (Str'First .. Str'First + 3) = "Hex_"
 138       then
 139          declare
 140             W : Unsigned_32 := 0;
 141
 142          begin
 143             for J in Str'First + 4 .. Str'First + 11 loop
 144                W := W * 16 + Character'Pos (Str (J));
 145
 146                if Str (J) in '0' .. '9' then
 147                   W := W - Character'Pos ('0');
 148                elsif Str (J) in 'A' .. 'F' then
 149                   W := W - Character'Pos ('A') + 10;
 150                elsif Str (J) in 'a' .. 'f' then
 151                   W := W - Character'Pos ('a') + 10;
 152                else
 153                   raise Constraint_Error;
 154                end if;
 155             end loop;
 156
 157             if W > 16#7FFF_FFFF# then
 158                raise Constraint_Error;
 159             else
 160                return Wide_Wide_Character'Val (W);
 161             end if;
 162          end;
 163
 164       --  Otherwise must be one of the special names for Character
 165
 166       else
 167          return
 168            Wide_Wide_Character'Val (Character'Pos (Character'Value (Str)));
 169       end if;
 170
 171    exception
 172       when Constraint_Error =>
 173          raise Constraint_Error with "invalid string for value attribute";
 174    end Value_Wide_Wide_Character;
 175
 176 end System.Val_WChar;