2009-03-17 Marek Safar <marek.safar@gmail.com>
[mono.git] / mcs / mcs / modifiers.cs
1 //
2 // modifiers.cs: Modifier handling.
3 // 
4 using System;
5 using System.Reflection;
6
7 namespace Mono.CSharp {
8         public class Modifiers {
9
10                 //
11                 // The ordering of the following 4 constants
12                 // has been carefully done.
13                 //
14                 public const int PROTECTED = 0x0001;
15                 public const int PUBLIC    = 0x0002;
16                 public const int PRIVATE   = 0x0004;
17                 public const int INTERNAL  = 0x0008;
18                 public const int NEW       = 0x0010;
19                 public const int ABSTRACT  = 0x0020;
20                 public const int SEALED    = 0x0040;
21                 public const int STATIC    = 0x0080;
22                 public const int READONLY  = 0x0100;
23                 public const int VIRTUAL   = 0x0200;
24                 public const int OVERRIDE  = 0x0400;
25                 public const int EXTERN    = 0x0800;
26                 public const int VOLATILE  = 0x1000;
27                 public const int UNSAFE    = 0x2000;
28                 private const int TOP      = 0x4000;
29
30                 public const int PROPERTY_CUSTOM = 0x4000; // Custom property modifier
31
32                 //
33                 // Compiler specific flags
34                 //
35                 public const int PARTIAL                                = 0x20000;
36                 public const int DEFAULT_ACCESS_MODIFER = 0x40000;
37                 public const int METHOD_EXTENSION               = 0x80000;
38                 public const int COMPILER_GENERATED             = 0x100000;
39                 public const int BACKING_FIELD                  = 0x200000;
40                 public const int DEBUGGER_HIDDEN                = 0x400000;
41
42                 public const int Accessibility =
43                         PUBLIC | PROTECTED | INTERNAL | PRIVATE;
44                 public const int AllowedExplicitImplFlags =
45                         UNSAFE | EXTERN;
46                 
47                 static public string Name (int i)
48                 {
49                         string s = "";
50                         
51                         switch (i) {
52                         case Modifiers.NEW:
53                                 s = "new"; break;
54                         case Modifiers.PUBLIC:
55                                 s = "public"; break;
56                         case Modifiers.PROTECTED:
57                                 s = "protected"; break;
58                         case Modifiers.INTERNAL:
59                                 s = "internal"; break;
60                         case Modifiers.PRIVATE:
61                                 s = "private"; break;
62                         case Modifiers.ABSTRACT:
63                                 s = "abstract"; break;
64                         case Modifiers.SEALED:
65                                 s = "sealed"; break;
66                         case Modifiers.STATIC:
67                                 s = "static"; break;
68                         case Modifiers.READONLY:
69                                 s = "readonly"; break;
70                         case Modifiers.VIRTUAL:
71                                 s = "virtual"; break;
72                         case Modifiers.OVERRIDE:
73                                 s = "override"; break;
74                         case Modifiers.EXTERN:
75                                 s = "extern"; break;
76                         case Modifiers.VOLATILE:
77                                 s = "volatile"; break;
78                         case Modifiers.UNSAFE:
79                                 s = "unsafe"; break;
80                         }
81
82                         return s;
83                 }
84
85                 public static string GetDescription (MethodAttributes ma)
86                 {
87                         ma &= MethodAttributes.MemberAccessMask;
88
89                         if (ma == MethodAttributes.Assembly)
90                                 return "internal";
91
92                         if (ma == MethodAttributes.Family)
93                                 return "protected";
94
95                         if (ma == MethodAttributes.Public)
96                                 return "public";
97
98                         if (ma == MethodAttributes.FamORAssem)
99                                 return "protected internal";
100
101                         if (ma == MethodAttributes.Private)
102                                 return "private";
103
104                         throw new NotImplementedException (ma.ToString ());
105                 }
106
107                 public static TypeAttributes TypeAttr (int mod_flags, bool is_toplevel)
108                 {
109                         TypeAttributes t = 0;
110
111                         if (is_toplevel){
112                                 if ((mod_flags & PUBLIC) != 0)
113                                         t = TypeAttributes.Public;
114                                 else if ((mod_flags & PRIVATE) != 0)
115                                         t = TypeAttributes.NotPublic;
116                         } else {
117                                 if ((mod_flags & PUBLIC) != 0)
118                                         t = TypeAttributes.NestedPublic;
119                                 else if ((mod_flags & PRIVATE) != 0)
120                                         t = TypeAttributes.NestedPrivate;
121                                 else if ((mod_flags & (PROTECTED | INTERNAL)) == (PROTECTED | INTERNAL))
122                                         t = TypeAttributes.NestedFamORAssem;
123                                 else if ((mod_flags & PROTECTED) != 0)
124                                         t = TypeAttributes.NestedFamily;
125                                 else if ((mod_flags & INTERNAL) != 0)
126                                         t = TypeAttributes.NestedAssembly;
127                         }
128                         
129                         if ((mod_flags & SEALED) != 0)
130                                 t |= TypeAttributes.Sealed;
131                         if ((mod_flags & ABSTRACT) != 0)
132                                 t |= TypeAttributes.Abstract;
133
134                         return t;
135                 }
136
137                 public static FieldAttributes FieldAttr (int mod_flags)
138                 {
139                         FieldAttributes fa = 0;
140
141                         if ((mod_flags & PUBLIC) != 0)
142                                 fa |= FieldAttributes.Public;
143                         if ((mod_flags & PRIVATE) != 0)
144                                 fa |= FieldAttributes.Private;
145                         if ((mod_flags & PROTECTED) != 0){
146                                 if ((mod_flags & INTERNAL) != 0)
147                                         fa |= FieldAttributes.FamORAssem;
148                                 else 
149                                         fa |= FieldAttributes.Family;
150                         } else {
151                                 if ((mod_flags & INTERNAL) != 0)
152                                         fa |= FieldAttributes.Assembly;
153                         }
154                         
155                         if ((mod_flags & STATIC) != 0)
156                                 fa |= FieldAttributes.Static;
157                         if ((mod_flags & READONLY) != 0)
158                                 fa |= FieldAttributes.InitOnly;
159
160                         return fa;
161                 }
162
163                 public static MethodAttributes MethodAttr (int mod_flags)
164                 {
165                         MethodAttributes ma = MethodAttributes.HideBySig;
166
167                         if ((mod_flags & PUBLIC) != 0)
168                                 ma |= MethodAttributes.Public;
169                         else if ((mod_flags & PRIVATE) != 0)
170                                 ma |= MethodAttributes.Private;
171                         else if ((mod_flags & PROTECTED) != 0){
172                                 if ((mod_flags & INTERNAL) != 0)
173                                         ma |= MethodAttributes.FamORAssem;
174                                 else 
175                                         ma |= MethodAttributes.Family;
176                         } else {
177                                 if ((mod_flags & INTERNAL) != 0)
178                                         ma |= MethodAttributes.Assembly;
179                         }
180
181                         if ((mod_flags & STATIC) != 0)
182                                 ma |= MethodAttributes.Static;
183                         if ((mod_flags & ABSTRACT) != 0){
184                                 ma |= MethodAttributes.Abstract | MethodAttributes.Virtual;
185                         }
186                         if ((mod_flags & SEALED) != 0)
187                                 ma |= MethodAttributes.Final;
188
189                         if ((mod_flags & VIRTUAL) != 0)
190                                 ma |= MethodAttributes.Virtual;
191
192                         if ((mod_flags & OVERRIDE) != 0)
193                                 ma |= MethodAttributes.Virtual;
194                         else {
195                                 if ((ma & MethodAttributes.Virtual) != 0)
196                                         ma |= MethodAttributes.NewSlot;
197                         }
198                         
199                         return ma;
200                 }
201
202                 // <summary>
203                 //   Checks the object @mod modifiers to be in @allowed.
204                 //   Returns the new mask.  Side effect: reports any
205                 //   incorrect attributes. 
206                 // </summary>
207                 public static int Check (int allowed, int mod, int def_access, Location l)
208                 {
209                         int invalid_flags  = (~allowed) & (mod & (Modifiers.TOP - 1));
210                         int i;
211
212                         if (invalid_flags == 0){
213                                 int a = mod;
214
215                                 if ((mod & Modifiers.UNSAFE) != 0){
216                                         RootContext.CheckUnsafeOption (l);
217                                 }
218                                 
219                                 //
220                                 // If no accessibility bits provided
221                                 // then provide the defaults.
222                                 //
223                                 if ((mod & Accessibility) == 0){
224                                         mod |= def_access;
225                                         if (def_access != 0)
226                                                 mod |= DEFAULT_ACCESS_MODIFER;
227                                         return mod;
228                                 }
229
230                                 //
231                                 // Make sure that no conflicting accessibility
232                                 // bits have been set.  Protected+Internal is
233                                 // allowed, that is why they are placed on bits
234                                 // 1 and 4 (so the shift 3 basically merges them)
235                                 //
236                                 a &= 15;
237                                 a |= (a >> 3);
238                                 a = ((a & 2) >> 1) + (a & 5);
239                                 a = ((a & 4) >> 2) + (a & 3);
240                                 if (a > 1)
241                                         Report.Error (107, l, "More than one protection modifier specified");
242                                 
243                                 return mod;
244                         }
245                         
246                         for (i = 1; i <= TOP; i <<= 1){
247                                 if ((i & invalid_flags) == 0)
248                                         continue;
249
250                                 Error_InvalidModifier (l, Name (i));
251                         }
252
253                         return allowed & mod;
254                 }
255
256                 public static void Error_InvalidModifier (Location l, string name)
257                 {
258                         Report.Error (106, l, "The modifier `" + name + "' is not valid for this item");
259                 }
260         }
261 }