File : 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) 1992-2012, 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 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 Bad_Value (Str);
52 else
53 return Wide_Character'Val (WV);
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;
63 EM : System.WCh_Con.WC_Encoding_Method) return Wide_Wide_Character
64 is
65 F : Natural;
66 L : Natural;
67 S : String (Str'Range) := Str;
68
69 begin
70 Normalize_String (S, F, L);
71
72 -- Character literal case
73
74 if S (F) = ''' and then S (L) = ''' then
75
76 -- Must be at least three characters
77
78 if L - F < 2 then
79 Bad_Value (Str);
80
81 -- If just three characters, simple character case
82
83 elsif L - F = 2 then
84 return Wide_Wide_Character'Val (Character'Pos (S (F + 1)));
85
86 -- Only other possibility for quoted string is wide char sequence
87
88 else
89 declare
90 P : Natural;
91 W : Wide_Wide_Character;
92
93 function In_Char return Character;
94 -- Function for instantiations of Char_Sequence_To_UTF_32
95
96 -------------
97 -- In_Char --
98 -------------
99
100 function In_Char return Character is
101 begin
102 P := P + 1;
103
104 if P = Str'Last then
105 Bad_Value (Str);
106 end if;
107
108 return Str (P);
109 end In_Char;
110
111 function UTF_32 is
112 new Char_Sequence_To_UTF_32 (In_Char);
113
114 begin
115 P := F + 1;
116
117 -- Brackets encoding
118
119 if S (F + 1) = '[' then
120 W := Wide_Wide_Character'Val (UTF_32 ('[', WCEM_Brackets));
121 else
122 W := Wide_Wide_Character'Val (UTF_32 (S (F + 1), EM));
123 end if;
124
125 if P /= L - 1 then
126 Bad_Value (Str);
127 end if;
128
129 return W;
130 end;
131 end if;
132
133 -- Deal with Hex_hhhhhhhh cases for wide_[wide_]character cases
134
135 elsif Str'Length = 12
136 and then Str (Str'First .. Str'First + 3) = "Hex_"
137 then
138 declare
139 W : Unsigned_32 := 0;
140
141 begin
142 for J in Str'First + 4 .. Str'First + 11 loop
143 W := W * 16 + Character'Pos (Str (J));
144
145 if Str (J) in '0' .. '9' then
146 W := W - Character'Pos ('0');
147 elsif Str (J) in 'A' .. 'F' then
148 W := W - Character'Pos ('A') + 10;
149 elsif Str (J) in 'a' .. 'f' then
150 W := W - Character'Pos ('a') + 10;
151 else
152 Bad_Value (Str);
153 end if;
154 end loop;
155
156 if W > 16#7FFF_FFFF# then
157 Bad_Value (Str);
158 else
159 return Wide_Wide_Character'Val (W);
160 end if;
161 end;
162
163 -- Otherwise must be one of the special names for Character
164
165 else
166 return
167 Wide_Wide_Character'Val (Character'Pos (Character'Value (Str)));
168 end if;
169
170 exception
171 when Constraint_Error =>
172 Bad_Value (Str);
173 end Value_Wide_Wide_Character;
174
175 end System.Val_WChar;