src/coreclr/tools/Common/TypeSystem/Ecma/EcmaGenericParameter.cs


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System;
using System.Collections.Generic;
using System.Reflection.Metadata;
using Internal.NativeFormat;

using Debug = System.Diagnostics.Debug;
using GenericParameterAttributes = System.Reflection.GenericParameterAttributes;

namespace Internal.TypeSystem.Ecma
{
    public sealed partial class EcmaGenericParameter : GenericParameterDesc
    {
        private EcmaModule _module;
        private GenericParameterHandle _handle;

        internal EcmaGenericParameter(EcmaModule module, GenericParameterHandle handle)
        {
            _module = module;
            _handle = handle;
        }

        public GenericParameterHandle Handle
        {
            get
            {
                return _handle;
            }
        }

        public MetadataReader MetadataReader
        {
            get
            {
                return _module.MetadataReader;
            }
        }

        public EcmaModule Module
        {
            get
            {
                return _module;
            }
        }

        public override TypeSystemContext Context
        {
            get
            {
                return _module.Context;
            }
        }

        public override string Name
        {
            get
            {
                MetadataReader reader = _module.MetadataReader;
                return reader.GetString(reader.GetGenericParameter(_handle).Name);
            }
        }

        public override GenericParameterKind Kind
        {
            get
            {
                GenericParameter parameter = _module.MetadataReader.GetGenericParameter(_handle);
                if (parameter.Parent.Kind == HandleKind.MethodDefinition)
                {
                    return GenericParameterKind.Method;
                }
                else
                {
                    Debug.Assert(parameter.Parent.Kind == HandleKind.TypeDefinition);
                    return GenericParameterKind.Type;
                }
            }
        }

        public override int Index
        {
            get
            {
                GenericParameter parameter = _module.MetadataReader.GetGenericParameter(_handle);
                return parameter.Index;
            }
        }

        public override GenericVariance Variance
        {
            get
            {
                Debug.Assert((int)GenericVariance.Contravariant == (int)GenericParameterAttributes.Contravariant);
                GenericParameter parameter = _module.MetadataReader.GetGenericParameter(_handle);
                return (GenericVariance)(parameter.Attributes & GenericParameterAttributes.VarianceMask);
            }
        }

        public override GenericConstraints Constraints
        {
            get
            {
                Debug.Assert((int)GenericConstraints.DefaultConstructorConstraint == (int)GenericParameterAttributes.DefaultConstructorConstraint);
                GenericParameter parameter = _module.MetadataReader.GetGenericParameter(_handle);
                return (GenericConstraints)(parameter.Attributes & GenericParameterAttributes.SpecialConstraintMask);
            }
        }
        
        public override IEnumerable<TypeDesc> TypeConstraints
        {
            get
            {
                MetadataReader reader = _module.MetadataReader;

                GenericParameter parameter = reader.GetGenericParameter(_handle);
                GenericParameterConstraintHandleCollection constraintHandles = parameter.GetConstraints();

                if (constraintHandles.Count == 0)
                    return TypeDesc.EmptyTypes;

                TypeDesc[] constraintTypes = new TypeDesc[constraintHandles.Count];

                for (int i = 0; i < constraintTypes.Length; i++)
                {
                    GenericParameterConstraint constraint = reader.GetGenericParameterConstraint(constraintHandles[i]);
                    constraintTypes[i] = _module.GetType(constraint.Type);
                };

                return constraintTypes;
            }
        }
    }
}