mcs/mcs/attribute.cs

   1 //\r
   2 // attribute.cs: Attribute Handler\r
   3 //\r
   4 // Author: Ravi Pratap (ravi@ximian.com)\r
   5 //\r
   6 // Licensed under the terms of the GNU GPL\r
   7 //\r
   8 // (C) 2001 Ximian, Inc (http://www.ximian.com)\r
   9 //\r
  10 //\r
  11 \r
  12 using System;\r
  13 using System.Collections;\r
  14 using System.Reflection;\r
  15 using System.Reflection.Emit;\r
  16 \r
  17 namespace CIR {\r
  18 \r
  19         public class Attribute {\r
  20                 \r
  21                 public readonly string    Name;\r
  22                 public readonly ArrayList Arguments;\r
  23 \r
  24                 Location Location;\r
  25                 \r
  26                 public Attribute (string name, ArrayList args, Location loc)\r
  27                 {\r
  28                         Name = name;\r
  29                         Arguments = args;\r
  30                         Location = loc;\r
  31                 }\r
  32 \r
  33                 public CustomAttributeBuilder Resolve (EmitContext ec)\r
  34                 {\r
  35                         string name = Name;\r
  36 \r
  37                         if (Name.IndexOf ("Attribute") == -1)\r
  38                                 name = Name + "Attribute";\r
  39                         else if (Name.LastIndexOf ("Attribute") == 0)\r
  40                                 name = Name + "Attribute";\r
  41                         \r
  42                         Type attribute_type = ec.TypeContainer.LookupType (name, false);\r
  43 \r
  44                         if (attribute_type == null) {\r
  45                                 Report.Error (246, Location, "Could not find attribute '" + Name + "' (are you" +\r
  46                                               " missing a using directive or an assembly reference ?)");\r
  47                                 return null;\r
  48                         }\r
  49                         \r
  50                         // Now we extract the positional and named arguments\r
  51                         \r
  52                         // FIXME : For now we handle only positional arguments\r
  53 \r
  54                         if (Arguments != null)\r
  55                                 if (Arguments.Count != 1)\r
  56                                         Console.WriteLine ("Warning : Cannot handle named arguments in attributes yet");\r
  57                         \r
  58                         \r
  59                         ArrayList pos_args = new ArrayList ();\r
  60                         \r
  61                         if (Arguments != null)\r
  62                                 pos_args = (ArrayList) Arguments [0];\r
  63                                 \r
  64                         object [] values = new object [pos_args.Count];\r
  65                         \r
  66                         for (int i = 0; i < pos_args.Count; i++) {\r
  67 \r
  68                                 Argument a = (Argument) pos_args [i];\r
  69 \r
  70                                 if (!a.Resolve (ec))\r
  71                                         return null;\r
  72 \r
  73                                 Expression e = Expression.Reduce (ec, a.Expr);\r
  74 \r
  75                                 if (e is Literal) \r
  76                                         values [i] = ((Literal) e).GetValue ();\r
  77                                 else { \r
  78                                         Report.Error (182, Location,\r
  79                                                       "An attribute argument must be a constant expression, typeof " +\r
  80                                                       "expression or array creation expression");\r
  81                                         return null;\r
  82                                 }\r
  83                         }\r
  84                         \r
  85                         Expression mg = Expression.MemberLookup (ec, attribute_type, ".ctor", false,\r
  86                                                                  MemberTypes.Constructor,\r
  87                                                                  BindingFlags.Public | BindingFlags.Instance,\r
  88                                                                  Location);\r
  89 \r
  90                         if (mg == null) {\r
  91                                 Report.Error (-6, Location, "Could not find a constructor for this argument list.");\r
  92                                 return null;\r
  93                         }\r
  94 \r
  95                         MethodBase constructor = Invocation.OverloadResolve (ec, (MethodGroupExpr) mg, pos_args, Location);\r
  96 \r
  97                         if (constructor == null) {\r
  98                                 Report.Error (-6, Location, "Could not find a constructor for this argument list.");\r
  99                                 return null;\r
 100                         }\r
 101 \r
 102                         CustomAttributeBuilder cb = new CustomAttributeBuilder ((ConstructorInfo) constructor, values); \r
 103 \r
 104                         return cb;\r
 105                 }\r
 106 \r
 107         }\r
 108         \r
 109         public class AttributeSection {\r
 110                 \r
 111                 public readonly string    Target;\r
 112                 public readonly ArrayList Attributes;\r
 113                 \r
 114                 public AttributeSection (string target, ArrayList attrs)\r
 115                 {\r
 116                         Target = target;\r
 117                         Attributes = attrs;\r
 118                 }\r
 119                 \r
 120         }\r
 121 \r
 122         public class Attributes {\r
 123 \r
 124                 public ArrayList AttributeSections;\r
 125 \r
 126                 public Attributes (AttributeSection a)\r
 127                 {\r
 128                         AttributeSections = new ArrayList ();\r
 129                         AttributeSections.Add (a);\r
 130 \r
 131                 }\r
 132 \r
 133                 public void AddAttribute (AttributeSection a)\r
 134                 {\r
 135                         if (a != null)\r
 136                                 AttributeSections.Add (a);\r
 137                 }\r
 138                 \r
 139         }\r
 140 }\r