2002-05-31 Rafael Teixeira <rafaelteixeirabr@hotmail.com>
[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 && (mod_flags & INTERNAL) != 0)
114                                 fa |= FieldAttributes.FamORAssem;
115                         if ((mod_flags & PROTECTED) != 0)
116                                 fa |= FieldAttributes.Family;
117                         if ((mod_flags & INTERNAL) != 0)
118                                 fa |= FieldAttributes.Assembly;
119                         
120                         if ((mod_flags & STATIC) != 0)
121                                 fa |= FieldAttributes.Static;
122                         if ((mod_flags & READONLY) != 0)
123                                 fa |= FieldAttributes.InitOnly;
124
125                         return fa;
126                 }
127
128                 public static MethodAttributes MethodAttr (int mod_flags)
129                 {
130                         MethodAttributes ma = 0;
131
132                         if ((mod_flags & PUBLIC) != 0)
133                                 ma |= MethodAttributes.Public;
134                         if ((mod_flags & PRIVATE) != 0)
135                                 ma |= MethodAttributes.Private;
136                         if ((mod_flags & PROTECTED) != 0){
137                                 if ((mod_flags & INTERNAL) != 0)
138                                         ma |= MethodAttributes.FamORAssem;
139                                 else 
140                                         ma |= MethodAttributes.Family;
141                         } else {
142                                 if ((mod_flags & INTERNAL) != 0)
143                                         ma |= MethodAttributes.Assembly;
144                         }
145
146                         if ((mod_flags & STATIC) != 0)
147                                 ma |= MethodAttributes.Static;
148                         if ((mod_flags & ABSTRACT) != 0){
149                                 ma |= MethodAttributes.Abstract | MethodAttributes.Virtual |
150                                         MethodAttributes.HideBySig;
151                         }
152                         if ((mod_flags & SEALED) != 0)
153                                 ma |= MethodAttributes.Final;
154
155                         if ((mod_flags & VIRTUAL) != 0)
156                                 ma |= MethodAttributes.Virtual;
157
158                         if ((mod_flags & OVERRIDE) != 0)
159                                 ma |= MethodAttributes.Virtual | MethodAttributes.HideBySig;
160                         else {
161                                 if ((ma & MethodAttributes.Virtual) != 0)
162                                         ma |= MethodAttributes.NewSlot;
163                         }
164                         
165                         if ((mod_flags & NEW) != 0)
166                                 ma |= MethodAttributes.HideBySig;
167                         
168                         return ma;
169                 }
170
171                 // <summary>
172                 //   Checks the object @mod modifiers to be in @allowed.
173                 //   Returns the new mask.  Side effect: reports any
174                 //   incorrect attributes. 
175                 // </summary>
176                 public static int Check (int allowed, int mod, int def_access, Location l)
177                 {
178                         int invalid_flags  = (~allowed) & mod;
179                         int i;
180
181                         if (invalid_flags == 0){
182                                 int a = mod;
183
184                                 if ((mod & Modifiers.UNSAFE) != 0){
185                                         if (!RootContext.Unsafe){
186                                                 Report.Error (227, l,
187                                                               "Unsafe code requires the --unsafe command " +
188                                                               "line option to be specified");
189                                         }
190                                 }
191                                 
192                                 //
193                                 // If no accessibility bits provided
194                                 // then provide the defaults.
195                                 //
196                                 if ((mod & Accessibility) == 0){
197                                         mod |= def_access;
198                                         return mod;
199                                 }
200
201                                 //
202                                 // Make sure that no conflicting accessibility
203                                 // bits have been set.  Protected+Internal is
204                                 // allowed, that is why they are placed on bits
205                                 // 1 and 4 (so the shift 3 basically merges them)
206                                 //
207                                 a &= 15;
208                                 a |= (a >> 3);
209                                 a = ((a & 2) >> 1) + (a & 5);
210                                 a = ((a & 4) >> 2) + (a & 3);
211                                 if (a > 1)
212                                         Report.Error (107, l, "More than one protection modifier specified");
213                                 
214                                 return mod;
215                         }
216                         
217                         for (i = 1; i < TOP; i <<= 1){
218                                 if ((i & invalid_flags) == 0)
219                                         continue;
220
221                                 Report.Error (106, l, "the modifier `" + Name (i) +
222                                               "' is not valid for this item");
223                         }
224
225                         return allowed & mod;
226                 }
227         }
228 }