2002-07-02 Martin Baulig <martin@gnome.org>
[mono.git] / mcs / mbas / 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                 public const int TOP       = 0x2000;
29
30                 public const int Accessibility =
31                         PUBLIC | PROTECTED | INTERNAL | PRIVATE;
32                 
33                 static public string Name (int i)
34                 {
35                         string s = "";
36                         
37                         switch (i) {
38                         case Modifiers.NEW:
39                                 s = "new"; break;
40                         case Modifiers.PUBLIC:
41                                 s = "public"; break;
42                         case Modifiers.PROTECTED:
43                                 s = "protected"; break;
44                         case Modifiers.INTERNAL:
45                                 s = "internal"; break;
46                         case Modifiers.PRIVATE:
47                                 s = "private"; break;
48                         case Modifiers.ABSTRACT:
49                                 s = "abstract"; break;
50                         case Modifiers.SEALED:
51                                 s = "sealed"; break;
52                         case Modifiers.STATIC:
53                                 s = "static"; break;
54                         case Modifiers.READONLY:
55                                 s = "readonly"; break;
56                         case Modifiers.VIRTUAL:
57                                 s = "virtual"; break;
58                         case Modifiers.OVERRIDE:
59                                 s = "override"; break;
60                         case Modifiers.EXTERN:
61                                 s = "extern"; break;
62                         case Modifiers.VOLATILE:
63                                 s = "volatile"; break;
64                         }
65
66                         return s;
67                 }
68
69                 public static TypeAttributes TypeAttr (int mod_flags, TypeContainer caller)
70                 {
71                         TypeAttributes t = 0;
72                         bool top_level = caller.IsTopLevel;
73
74                         if (top_level){
75                                 if ((mod_flags & PUBLIC) != 0)
76                                         t |= TypeAttributes.Public;
77                                 if ((mod_flags & PRIVATE) != 0)
78                                         t |= TypeAttributes.NotPublic;
79                         } else {
80                                 if ((mod_flags & PUBLIC) != 0)
81                                         t |= TypeAttributes.NestedPublic;
82                                 if ((mod_flags & PRIVATE) != 0)
83                                         t |= TypeAttributes.NestedPrivate;
84                                 if ((mod_flags & PROTECTED) != 0 && (mod_flags & INTERNAL) != 0)
85                                         t |= TypeAttributes.NestedFamORAssem;
86                                 if ((mod_flags & PROTECTED) != 0)
87                                         t |= TypeAttributes.NestedFamily;
88                                 if ((mod_flags & INTERNAL) != 0)
89                                         t |= TypeAttributes.NestedAssembly;
90                         }
91                         
92                         if ((mod_flags & SEALED) != 0)
93                                 t |= TypeAttributes.Sealed;
94                         if ((mod_flags & ABSTRACT) != 0)
95                                 t |= TypeAttributes.Abstract;
96
97                         // If we do not have static constructors, static methods
98                         // can be invoked without initializing the type.
99                         if (!caller.HaveStaticConstructor)
100                                 t |= TypeAttributes.BeforeFieldInit;
101                                 
102                         return t;
103                 }
104
105                 public static FieldAttributes FieldAttr (int mod_flags)
106                 {
107                         FieldAttributes fa = 0;
108
109                         if ((mod_flags & PUBLIC) != 0)
110                                 fa |= FieldAttributes.Public;
111                         if ((mod_flags & PRIVATE) != 0)
112                                 fa |= FieldAttributes.Private;
113                         if ((mod_flags & PROTECTED) != 0){
114                                 if ((mod_flags & INTERNAL) != 0)
115                                         fa |= FieldAttributes.FamORAssem;
116                                 else 
117                                         fa |= FieldAttributes.Family;
118                         } else {
119                                 if ((mod_flags & INTERNAL) != 0)
120                                         fa |= FieldAttributes.Assembly;
121                         }
122                         
123                         if ((mod_flags & STATIC) != 0)
124                                 fa |= FieldAttributes.Static;
125                         if ((mod_flags & READONLY) != 0)
126                                 fa |= FieldAttributes.InitOnly;
127
128                         return fa;
129                 }
130
131                 public static MethodAttributes MethodAttr (int mod_flags)
132                 {
133                         MethodAttributes ma = 0;
134
135                         if ((mod_flags & PUBLIC) != 0)
136                                 ma |= MethodAttributes.Public;
137                         if ((mod_flags & PRIVATE) != 0)
138                                 ma |= MethodAttributes.Private;
139                         if ((mod_flags & PROTECTED) != 0){
140                                 if ((mod_flags & INTERNAL) != 0)
141                                         ma |= MethodAttributes.FamORAssem;
142                                 else 
143                                         ma |= MethodAttributes.Family;
144                         } else {
145                                 if ((mod_flags & INTERNAL) != 0)
146                                         ma |= MethodAttributes.Assembly;
147                         }
148
149                         if ((mod_flags & STATIC) != 0)
150                                 ma |= MethodAttributes.Static;
151                         if ((mod_flags & ABSTRACT) != 0){
152                                 ma |= MethodAttributes.Abstract | MethodAttributes.Virtual |
153                                         MethodAttributes.HideBySig;
154                         }
155                         if ((mod_flags & SEALED) != 0)
156                                 ma |= MethodAttributes.Final;
157
158                         if ((mod_flags & VIRTUAL) != 0)
159                                 ma |= MethodAttributes.Virtual;
160
161                         if ((mod_flags & OVERRIDE) != 0)
162                                 ma |= MethodAttributes.Virtual | MethodAttributes.HideBySig;
163                         else {
164                                 if ((ma & MethodAttributes.Virtual) != 0)
165                                         ma |= MethodAttributes.NewSlot;
166                         }
167                         
168                         if ((mod_flags & NEW) != 0)
169                                 ma |= MethodAttributes.HideBySig;
170                         
171                         return ma;
172                 }
173
174                 // <summary>
175                 //   Checks the object @mod modifiers to be in @allowed.
176                 //   Returns the new mask.  Side effect: reports any
177                 //   incorrect attributes. 
178                 // </summary>
179                 public static int Check (int allowed, int mod, int def_access, Location l)
180                 {
181                         int invalid_flags  = (~allowed) & mod;
182                         int i;
183
184                         if (invalid_flags == 0){
185                                 int a = mod;
186
187                                 if ((mod & Modifiers.UNSAFE) != 0){
188                                         if (!RootContext.Unsafe){
189                                                 Report.Error (227, l,
190                                                               "Unsafe code requires the --unsafe command " +
191                                                               "line option to be specified");
192                                         }
193                                 }
194                                 
195                                 //
196                                 // If no accessibility bits provided
197                                 // then provide the defaults.
198                                 //
199                                 if ((mod & Accessibility) == 0){
200                                         mod |= def_access;
201                                         return mod;
202                                 }
203
204                                 //
205                                 // Make sure that no conflicting accessibility
206                                 // bits have been set.  Protected+Internal is
207                                 // allowed, that is why they are placed on bits
208                                 // 1 and 4 (so the shift 3 basically merges them)
209                                 //
210                                 a &= 15;
211                                 a |= (a >> 3);
212                                 a = ((a & 2) >> 1) + (a & 5);
213                                 a = ((a & 4) >> 2) + (a & 3);
214                                 if (a > 1)
215                                         Report.Error (107, l, "More than one protection modifier specified");
216                                 
217                                 return mod;
218                         }
219                         
220                         for (i = 1; i < TOP; i <<= 1){
221                                 if ((i & invalid_flags) == 0)
222                                         continue;
223
224                                 Report.Error (106, l, "the modifier `" + Name (i) +
225                                               "' is not valid for this item");
226                         }
227
228                         return allowed & mod;
229                 }
230         }
231 }