File: MemberAssignmentAnalysis.cs

package info (click to toggle)
mono 4.6.2.7+dfsg-1
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 778,148 kB
  • ctags: 914,052
  • sloc: cs: 5,779,509; xml: 2,773,713; ansic: 432,645; sh: 14,749; makefile: 12,361; perl: 2,488; python: 1,434; cpp: 849; asm: 531; sql: 95; sed: 16; php: 1
file content (278 lines) | stat: -rw-r--r-- 9,140 bytes parent folder | download
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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
//Copyright 2010 Microsoft Corporation
//
//Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. 
//You may obtain a copy of the License at 
//
//http://www.apache.org/licenses/LICENSE-2.0 
//
//Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an 
//"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
//See the License for the specific language governing permissions and limitations under the License.


namespace System.Data.Services.Client
{
    #region Namespaces.

    using System;
    using System.Collections.Generic;
    using System.Diagnostics;
    using System.Linq;
    using System.Linq.Expressions;
    using System.Reflection;

    #endregion Namespaces.

    internal class MemberAssignmentAnalysis : ExpressionVisitor
    {
        #region Fields.

        internal static readonly Expression[] EmptyExpressionArray = new Expression[0];

        private readonly Expression entity;

        private Exception incompatibleAssignmentsException;

        private bool multiplePathsFound;

        private List<Expression> pathFromEntity;

        #endregion Fields.

        #region Constructor.

        private MemberAssignmentAnalysis(Expression entity)
        {
            Debug.Assert(entity != null, "entity != null");

            this.entity = entity;
            this.pathFromEntity = new List<Expression>();
        }

        #endregion Constructor.

        #region Properties.

        internal Exception IncompatibleAssignmentsException
        {
            get { return this.incompatibleAssignmentsException; }
        }

        internal bool MultiplePathsFound
        {
            get { return this.multiplePathsFound; }
        }

        #endregion Properites.

        #region Methods.

        internal static MemberAssignmentAnalysis Analyze(Expression entityInScope, Expression assignmentExpression)
        {
            Debug.Assert(entityInScope != null, "entityInScope != null");
            Debug.Assert(assignmentExpression != null, "assignmentExpression != null");

            MemberAssignmentAnalysis result = new MemberAssignmentAnalysis(entityInScope);
            result.Visit(assignmentExpression);
            return result;
        }

        internal Exception CheckCompatibleAssignments(Type targetType, ref MemberAssignmentAnalysis previous)
        {
            if (previous == null)
            {
                previous = this;
                return null;
            }

            Expression[] previousExpressions = previous.GetExpressionsToTargetEntity();
            Expression[] candidateExpressions = this.GetExpressionsToTargetEntity();
            return CheckCompatibleAssignments(targetType, previousExpressions, candidateExpressions);
        }

        internal override Expression Visit(Expression expression)
        {
            if (this.multiplePathsFound || this.incompatibleAssignmentsException != null)
            {
                return expression;
            }

            return base.Visit(expression);
        }

        internal override Expression VisitConditional(ConditionalExpression c)
        {
            Expression result;

            var nullCheck = ResourceBinder.PatternRules.MatchNullCheck(this.entity, c);
            if (nullCheck.Match)
            {
                this.Visit(nullCheck.AssignExpression);
                result = c;
            }
            else
            {
                result = base.VisitConditional(c);
            }

            return result;
        }

        internal override Expression VisitParameter(ParameterExpression p)
        {
            if (p == this.entity)
            {
                if (this.pathFromEntity.Count != 0)
                {
                    this.multiplePathsFound = true;
                }
                else
                {
                    this.pathFromEntity.Add(p);
                }
            }

            return p;
        }

        internal override Expression VisitMemberInit(MemberInitExpression init)
        {
            Expression result = init;
            MemberAssignmentAnalysis previousNested = null;
            foreach (var binding in init.Bindings)
            {
                MemberAssignment assignment = binding as MemberAssignment;
                if (assignment == null)
                {
                    continue;
                }

                MemberAssignmentAnalysis nested = MemberAssignmentAnalysis.Analyze(this.entity, assignment.Expression);
                if (nested.MultiplePathsFound)
                {
                    this.multiplePathsFound = true;
                    break;
                }

                Exception incompatibleException = nested.CheckCompatibleAssignments(init.Type, ref previousNested);
                if (incompatibleException != null)
                {
                    this.incompatibleAssignmentsException = incompatibleException;
                    break;
                }

                if (this.pathFromEntity.Count == 0)
                {
                    this.pathFromEntity.AddRange(nested.GetExpressionsToTargetEntity());
                }
            }

            return result;
        }

        internal override Expression VisitMemberAccess(MemberExpression m)
        {
            Expression result = base.VisitMemberAccess(m);
            if (this.pathFromEntity.Contains(m.Expression))
            {
                this.pathFromEntity.Add(m);
            }

            return result;
        }

        internal override Expression VisitMethodCall(MethodCallExpression call)
        {
            if (ReflectionUtil.IsSequenceMethod(call.Method, SequenceMethod.Select))
            {
                this.Visit(call.Arguments[0]);
                return call;
            }

            return base.VisitMethodCall(call);
        }

        internal Expression[] GetExpressionsBeyondTargetEntity()
        {
            Debug.Assert(!this.multiplePathsFound, "this.multiplePathsFound -- otherwise GetExpressionsToTargetEntity won't return reliable (consistent) results");

            if (this.pathFromEntity.Count <= 1)
            {
                return EmptyExpressionArray;
            }

            Expression[] result = new Expression[1];
            result[0] = this.pathFromEntity[this.pathFromEntity.Count - 1];
            return result;
        }

        internal Expression[] GetExpressionsToTargetEntity()
        {
            Debug.Assert(!this.multiplePathsFound, "this.multiplePathsFound -- otherwise GetExpressionsToTargetEntity won't return reliable (consistent) results");

            if (this.pathFromEntity.Count <= 1)
            {
                return EmptyExpressionArray;
            }

            Expression[] result = new Expression[this.pathFromEntity.Count - 1];
            for (int i = 0; i < result.Length; i++)
            {
                result[i] = this.pathFromEntity[i];
            }

            return result;
        }

        private static Exception CheckCompatibleAssignments(Type targetType, Expression[] previous, Expression[] candidate)
        {
            Debug.Assert(targetType != null, "targetType != null");
            Debug.Assert(previous != null, "previous != null");
            Debug.Assert(candidate != null, "candidate != null");

            if (previous.Length != candidate.Length)
            {
                throw CheckCompatibleAssignmentsFail(targetType, previous, candidate);
            }

            for (int i = 0; i < previous.Length; i++)
            {
                Expression p = previous[i];
                Expression c = candidate[i];
                if (p.NodeType != c.NodeType)
                {
                    throw CheckCompatibleAssignmentsFail(targetType, previous, candidate);
                }

                if (p == c)
                {
                    continue;
                }

                if (p.NodeType != ExpressionType.MemberAccess)
                {
                    return CheckCompatibleAssignmentsFail(targetType, previous, candidate);
                }

                if (((MemberExpression)p).Member.Name != ((MemberExpression)c).Member.Name)
                {
                    return CheckCompatibleAssignmentsFail(targetType, previous, candidate);
                }
            }

            return null;
        }

        private static Exception CheckCompatibleAssignmentsFail(Type targetType, Expression[] previous, Expression[] candidate)
        {
            Debug.Assert(targetType != null, "targetType != null");
            Debug.Assert(previous != null, "previous != null");
            Debug.Assert(candidate != null, "candidate != null");

            string message = Strings.ALinq_ProjectionMemberAssignmentMismatch(targetType.FullName, previous.LastOrDefault(), candidate.LastOrDefault());
            return new NotSupportedException(message);
        }

        #endregion Methods.
    }
}