Initial import of the Generic MCS tree.
[mono.git] / mcs / gmcs / 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                 //
31                 // We use this internally to flag that the method contains an iterator
32                 //
33                 public const int METHOD_YIELDS = 0x8000;
34                 public const int METHOD_GENERIC = 0x10000;
35
36                 public const int Accessibility =
37                         PUBLIC | PROTECTED | INTERNAL | PRIVATE;
38                 
39                 static public string Name (int i)
40                 {
41                         string s = "";
42                         
43                         switch (i) {
44                         case Modifiers.NEW:
45                                 s = "new"; break;
46                         case Modifiers.PUBLIC:
47                                 s = "public"; break;
48                         case Modifiers.PROTECTED:
49                                 s = "protected"; break;
50                         case Modifiers.INTERNAL:
51                                 s = "internal"; break;
52                         case Modifiers.PRIVATE:
53                                 s = "private"; break;
54                         case Modifiers.ABSTRACT:
55                                 s = "abstract"; break;
56                         case Modifiers.SEALED:
57                                 s = "sealed"; break;
58                         case Modifiers.STATIC:
59                                 s = "static"; break;
60                         case Modifiers.READONLY:
61                                 s = "readonly"; break;
62                         case Modifiers.VIRTUAL:
63                                 s = "virtual"; break;
64                         case Modifiers.OVERRIDE:
65                                 s = "override"; break;
66                         case Modifiers.EXTERN:
67                                 s = "extern"; break;
68                         case Modifiers.VOLATILE:
69                                 s = "volatile"; break;
70                         }
71
72                         return s;
73                 }
74
75                 public static TypeAttributes TypeAttr (int mod_flags, bool is_toplevel)
76                 {
77                         TypeAttributes t = 0;
78
79                         if (is_toplevel){
80                                 if ((mod_flags & PUBLIC) != 0)
81                                         t |= TypeAttributes.Public;
82                                 if ((mod_flags & PRIVATE) != 0)
83                                         t |= TypeAttributes.NotPublic;
84                         } else {
85                                 if ((mod_flags & PUBLIC) != 0)
86                                         t |= TypeAttributes.NestedPublic;
87                                 if ((mod_flags & PRIVATE) != 0)
88                                         t |= TypeAttributes.NestedPrivate;
89                                 if ((mod_flags & PROTECTED) != 0 && (mod_flags & INTERNAL) != 0)
90                                         t |= TypeAttributes.NestedFamORAssem;
91                                 if ((mod_flags & PROTECTED) != 0)
92                                         t |= TypeAttributes.NestedFamily;
93                                 if ((mod_flags & INTERNAL) != 0)
94                                         t |= TypeAttributes.NestedAssembly;
95                         }
96                         
97                         if ((mod_flags & SEALED) != 0)
98                                 t |= TypeAttributes.Sealed;
99                         if ((mod_flags & ABSTRACT) != 0)
100                                 t |= TypeAttributes.Abstract;
101
102                         return t;
103                 }
104                 
105                 public static TypeAttributes TypeAttr (int mod_flags, TypeContainer caller)
106                 {
107                         TypeAttributes t = TypeAttr (mod_flags, caller.IsTopLevel);
108
109                         // If we do not have static constructors, static methods
110                         // can be invoked without initializing the type.
111                         if (!caller.HaveStaticConstructor)
112                                 t |= TypeAttributes.BeforeFieldInit;
113                                 
114                         return t;
115                 }
116
117                 public static FieldAttributes FieldAttr (int mod_flags)
118                 {
119                         FieldAttributes fa = 0;
120
121                         if ((mod_flags & PUBLIC) != 0)
122                                 fa |= FieldAttributes.Public;
123                         if ((mod_flags & PRIVATE) != 0)
124                                 fa |= FieldAttributes.Private;
125                         if ((mod_flags & PROTECTED) != 0){
126                                 if ((mod_flags & INTERNAL) != 0)
127                                         fa |= FieldAttributes.FamORAssem;
128                                 else 
129                                         fa |= FieldAttributes.Family;
130                         } else {
131                                 if ((mod_flags & INTERNAL) != 0)
132                                         fa |= FieldAttributes.Assembly;
133                         }
134                         
135                         if ((mod_flags & STATIC) != 0)
136                                 fa |= FieldAttributes.Static;
137                         if ((mod_flags & READONLY) != 0)
138                                 fa |= FieldAttributes.InitOnly;
139
140                         return fa;
141                 }
142
143                 public static MethodAttributes MethodAttr (int mod_flags)
144                 {
145                         MethodAttributes ma = 0;
146
147                         if ((mod_flags & PUBLIC) != 0)
148                                 ma |= MethodAttributes.Public;
149                         if ((mod_flags & PRIVATE) != 0)
150                                 ma |= MethodAttributes.Private;
151                         if ((mod_flags & PROTECTED) != 0){
152                                 if ((mod_flags & INTERNAL) != 0)
153                                         ma |= MethodAttributes.FamORAssem;
154                                 else 
155                                         ma |= MethodAttributes.Family;
156                         } else {
157                                 if ((mod_flags & INTERNAL) != 0)
158                                         ma |= MethodAttributes.Assembly;
159                         }
160
161                         if ((mod_flags & STATIC) != 0)
162                                 ma |= MethodAttributes.Static;
163                         if ((mod_flags & ABSTRACT) != 0){
164                                 ma |= MethodAttributes.Abstract | MethodAttributes.Virtual |
165                                         MethodAttributes.HideBySig;
166                         }
167                         if ((mod_flags & SEALED) != 0)
168                                 ma |= MethodAttributes.Final;
169
170                         if ((mod_flags & VIRTUAL) != 0)
171                                 ma |= MethodAttributes.Virtual;
172
173                         if ((mod_flags & OVERRIDE) != 0)
174                                 ma |= MethodAttributes.Virtual | MethodAttributes.HideBySig;
175                         else {
176                                 if ((ma & MethodAttributes.Virtual) != 0)
177                                         ma |= MethodAttributes.NewSlot;
178                         }
179                         
180                         if ((mod_flags & NEW) != 0)
181                                 ma |= MethodAttributes.HideBySig;
182                         
183                         return ma;
184                 }
185
186                 // <summary>
187                 //   Checks the object @mod modifiers to be in @allowed.
188                 //   Returns the new mask.  Side effect: reports any
189                 //   incorrect attributes. 
190                 // </summary>
191                 public static int Check (int allowed, int mod, int def_access, Location l)
192                 {
193                         int invalid_flags  = (~allowed) & mod;
194                         int i;
195
196                         if (invalid_flags == 0){
197                                 int a = mod;
198
199                                 if ((mod & Modifiers.UNSAFE) != 0){
200                                         if (!RootContext.Unsafe){
201                                                 Report.Error (227, l,
202                                                               "Unsafe code requires the --unsafe command " +
203                                                               "line option to be specified");
204                                         }
205                                 }
206                                 
207                                 //
208                                 // If no accessibility bits provided
209                                 // then provide the defaults.
210                                 //
211                                 if ((mod & Accessibility) == 0){
212                                         mod |= def_access;
213                                         return mod;
214                                 }
215
216                                 //
217                                 // Make sure that no conflicting accessibility
218                                 // bits have been set.  Protected+Internal is
219                                 // allowed, that is why they are placed on bits
220                                 // 1 and 4 (so the shift 3 basically merges them)
221                                 //
222                                 a &= 15;
223                                 a |= (a >> 3);
224                                 a = ((a & 2) >> 1) + (a & 5);
225                                 a = ((a & 4) >> 2) + (a & 3);
226                                 if (a > 1)
227                                         Report.Error (107, l, "More than one protection modifier specified");
228                                 
229                                 return mod;
230                         }
231                         
232                         for (i = 1; i < TOP; i <<= 1){
233                                 if ((i & invalid_flags) == 0)
234                                         continue;
235
236                                 Error_InvalidModifier (l, Name (i));
237                         }
238
239                         return allowed & mod;
240                 }
241
242                 public static void Error_InvalidModifier (Location l, string name)
243                 {
244                         Report.Error (106, l, "the modifier " + name + " is not valid for this item");
245                 }
246         }
247 }