summaryrefslogtreecommitdiff
path: root/ICSharpCode.Decompiler/FlowAnalysis/OpCodeInfo.cs
blob: e0dc724f00420bac5a301a6cb2ebd3e46251f7c7 (plain)
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
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
// Copyright (c) 2011 AlphaSierraPapa for the SharpDevelop Team
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

using System;
using System.Collections.Generic;
using System.Linq;

using Mono.Cecil.Cil;

namespace ICSharpCode.Decompiler.FlowAnalysis
{
	/// <summary>
	/// Additional info about opcodes.
	/// </summary>
	internal sealed class OpCodeInfo
	{
		public static bool IsUnconditionalBranch(OpCode opcode)
		{
			if (opcode.OpCodeType == OpCodeType.Prefix)
				return false;
			switch (opcode.FlowControl) {
				case FlowControl.Branch:
				case FlowControl.Throw:
				case FlowControl.Return:
					return true;
				case FlowControl.Next:
				case FlowControl.Call:
				case FlowControl.Cond_Branch:
					return false;
				default:
					throw new NotSupportedException(opcode.FlowControl.ToString());
			}
		}
		
		static readonly OpCodeInfo[] knownOpCodes = {
			#region Base Instructions
			new OpCodeInfo(OpCodes.Add)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Add_Ovf)    { CanThrow = true  },
			new OpCodeInfo(OpCodes.Add_Ovf_Un) { CanThrow = true  },
			new OpCodeInfo(OpCodes.And)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Arglist)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Beq)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Beq_S)      { CanThrow = false },
			new OpCodeInfo(OpCodes.Bge)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Bge_S)      { CanThrow = false },
			new OpCodeInfo(OpCodes.Bge_Un)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Bge_Un_S)   { CanThrow = false },
			new OpCodeInfo(OpCodes.Bgt)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Bgt_S)      { CanThrow = false },
			new OpCodeInfo(OpCodes.Bgt_Un)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Bgt_Un_S)   { CanThrow = false },
			new OpCodeInfo(OpCodes.Ble)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Ble_S)      { CanThrow = false },
			new OpCodeInfo(OpCodes.Ble_Un)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Ble_Un_S)   { CanThrow = false },
			new OpCodeInfo(OpCodes.Blt)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Blt_S)      { CanThrow = false },
			new OpCodeInfo(OpCodes.Blt_Un)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Blt_Un_S)   { CanThrow = false },
			new OpCodeInfo(OpCodes.Bne_Un)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Bne_Un_S)   { CanThrow = false },
			new OpCodeInfo(OpCodes.Br)         { CanThrow = false },
			new OpCodeInfo(OpCodes.Br_S)       { CanThrow = false },
			new OpCodeInfo(OpCodes.Break)      { CanThrow = true  },
			new OpCodeInfo(OpCodes.Brfalse)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Brfalse_S)  { CanThrow = false },
			new OpCodeInfo(OpCodes.Brtrue)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Brtrue_S)   { CanThrow = false },
			new OpCodeInfo(OpCodes.Call)       { CanThrow = true  },
			new OpCodeInfo(OpCodes.Calli)      { CanThrow = true  },
			new OpCodeInfo(OpCodes.Ceq)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Cgt)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Cgt_Un)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Ckfinite)   { CanThrow = true  },
			new OpCodeInfo(OpCodes.Clt)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Clt_Un)     { CanThrow = false },
			// conv.<to type>
			new OpCodeInfo(OpCodes.Conv_I1)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_I2)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_I4)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_I8)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_R4)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_R8)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_U1)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_U2)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_U4)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_U8)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_I)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_U)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Conv_R_Un)  { CanThrow = false },
			// conv.ovf.<to type>
			new OpCodeInfo(OpCodes.Conv_Ovf_I1) { CanThrow = true},
			new OpCodeInfo(OpCodes.Conv_Ovf_I2) { CanThrow = true},
			new OpCodeInfo(OpCodes.Conv_Ovf_I4) { CanThrow = true},
			new OpCodeInfo(OpCodes.Conv_Ovf_I8) { CanThrow = true},
			new OpCodeInfo(OpCodes.Conv_Ovf_U1) { CanThrow = true},
			new OpCodeInfo(OpCodes.Conv_Ovf_U2) { CanThrow = true},
			new OpCodeInfo(OpCodes.Conv_Ovf_U4) { CanThrow = true},
			new OpCodeInfo(OpCodes.Conv_Ovf_U8) { CanThrow = true},
			new OpCodeInfo(OpCodes.Conv_Ovf_I)  { CanThrow = true},
			new OpCodeInfo(OpCodes.Conv_Ovf_U)  { CanThrow = true},
			// conv.ovf.<to type>.un
			new OpCodeInfo(OpCodes.Conv_Ovf_I1_Un) { CanThrow = true },
			new OpCodeInfo(OpCodes.Conv_Ovf_I2_Un) { CanThrow = true },
			new OpCodeInfo(OpCodes.Conv_Ovf_I4_Un) { CanThrow = true },
			new OpCodeInfo(OpCodes.Conv_Ovf_I8_Un) { CanThrow = true },
			new OpCodeInfo(OpCodes.Conv_Ovf_U1_Un) { CanThrow = true },
			new OpCodeInfo(OpCodes.Conv_Ovf_U2_Un) { CanThrow = true },
			new OpCodeInfo(OpCodes.Conv_Ovf_U4_Un) { CanThrow = true },
			new OpCodeInfo(OpCodes.Conv_Ovf_U8_Un) { CanThrow = true },
			new OpCodeInfo(OpCodes.Conv_Ovf_I_Un)  { CanThrow = true },
			new OpCodeInfo(OpCodes.Conv_Ovf_U_Un)  { CanThrow = true },
			
			//new OpCodeInfo(OpCodes.Cpblk)      { CanThrow = true }, - no idea whether this might cause trouble for the type system, C# shouldn't use it so I'll disable it
			new OpCodeInfo(OpCodes.Div)        { CanThrow = true },
			new OpCodeInfo(OpCodes.Div_Un)     { CanThrow = true },
			new OpCodeInfo(OpCodes.Dup)        { CanThrow = true, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Endfilter)  { CanThrow = false },
			new OpCodeInfo(OpCodes.Endfinally) { CanThrow = false },
			//new OpCodeInfo(OpCodes.Initblk)    { CanThrow = true }, - no idea whether this might cause trouble for the type system, C# shouldn't use it so I'll disable it
			//new OpCodeInfo(OpCodes.Jmp)        { CanThrow = true } - We don't support non-local control transfers.
			new OpCodeInfo(OpCodes.Ldarg)   { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldarg_0) { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldarg_1) { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldarg_2) { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldarg_3) { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldarg_S) { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldarga)   { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldarga_S) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4_M1) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4_0) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4_1) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4_2) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4_3) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4_4) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4_5) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4_6) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4_7) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4_8) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I4_S) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_I8) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_R4) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldc_R8) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldftn)  { CanThrow = false },
			// ldind.<type>
			new OpCodeInfo(OpCodes.Ldind_I1)  { CanThrow = true },
			new OpCodeInfo(OpCodes.Ldind_I2)  { CanThrow = true },
			new OpCodeInfo(OpCodes.Ldind_I4)  { CanThrow = true },
			new OpCodeInfo(OpCodes.Ldind_I8)  { CanThrow = true },
			new OpCodeInfo(OpCodes.Ldind_U1)  { CanThrow = true },
			new OpCodeInfo(OpCodes.Ldind_U2)  { CanThrow = true },
			new OpCodeInfo(OpCodes.Ldind_U4)  { CanThrow = true },
			new OpCodeInfo(OpCodes.Ldind_R4)  { CanThrow = true },
			new OpCodeInfo(OpCodes.Ldind_R8)  { CanThrow = true },
			new OpCodeInfo(OpCodes.Ldind_I)   { CanThrow = true },
			new OpCodeInfo(OpCodes.Ldind_Ref) { CanThrow = true },
			// the ldloc exceptions described in the spec can only occur on methods without .localsinit - but csc always sets that flag
			new OpCodeInfo(OpCodes.Ldloc)      { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldloc_0)    { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldloc_1)    { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldloc_2)    { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldloc_3)    { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldloc_S)    { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Ldloca)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldloca_S)   { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldnull)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Leave)      { CanThrow = false },
			new OpCodeInfo(OpCodes.Leave_S)    { CanThrow = false },
			new OpCodeInfo(OpCodes.Localloc)   { CanThrow = true  },
			new OpCodeInfo(OpCodes.Mul)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Mul_Ovf)    { CanThrow = true  },
			new OpCodeInfo(OpCodes.Mul_Ovf_Un) { CanThrow = true  },
			new OpCodeInfo(OpCodes.Neg)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Nop)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Not)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Or)         { CanThrow = false },
			new OpCodeInfo(OpCodes.Pop)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Rem)        { CanThrow = true  },
			new OpCodeInfo(OpCodes.Rem_Un)     { CanThrow = true  },
			new OpCodeInfo(OpCodes.Ret)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Shl)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Shr)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Shr_Un)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Starg)      { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Starg_S)    { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Stind_I1)   { CanThrow = true },
			new OpCodeInfo(OpCodes.Stind_I2)   { CanThrow = true },
			new OpCodeInfo(OpCodes.Stind_I4)   { CanThrow = true },
			new OpCodeInfo(OpCodes.Stind_I8)   { CanThrow = true },
			new OpCodeInfo(OpCodes.Stind_R4)   { CanThrow = true },
			new OpCodeInfo(OpCodes.Stind_R8)   { CanThrow = true },
			new OpCodeInfo(OpCodes.Stind_I)    { CanThrow = true },
			new OpCodeInfo(OpCodes.Stind_Ref)  { CanThrow = true },
			new OpCodeInfo(OpCodes.Stloc)      { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Stloc_0)    { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Stloc_1)    { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Stloc_2)    { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Stloc_3)    { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Stloc_S)    { CanThrow = false, IsMoveInstruction = true },
			new OpCodeInfo(OpCodes.Sub)        { CanThrow = false },
			new OpCodeInfo(OpCodes.Sub_Ovf)    { CanThrow = true  },
			new OpCodeInfo(OpCodes.Sub_Ovf_Un) { CanThrow = true  },
			new OpCodeInfo(OpCodes.Switch)     { CanThrow = false },
			new OpCodeInfo(OpCodes.Xor)        { CanThrow = false },
			#endregion
			#region Object model instructions
			// CanThrow is true by default - most OO instructions can throw, so we don't specify CanThrow all of the time
			new OpCodeInfo(OpCodes.Box),
			new OpCodeInfo(OpCodes.Callvirt),
			new OpCodeInfo(OpCodes.Castclass),
			new OpCodeInfo(OpCodes.Cpobj),
			new OpCodeInfo(OpCodes.Initobj) { CanThrow = false },
			new OpCodeInfo(OpCodes.Isinst)  { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldelem_Any),
			// ldelem.<type>
			new OpCodeInfo(OpCodes.Ldelem_I) ,
			new OpCodeInfo(OpCodes.Ldelem_I1),
			new OpCodeInfo(OpCodes.Ldelem_I2),
			new OpCodeInfo(OpCodes.Ldelem_I4),
			new OpCodeInfo(OpCodes.Ldelem_I8),
			new OpCodeInfo(OpCodes.Ldelem_R4),
			new OpCodeInfo(OpCodes.Ldelem_R8),
			new OpCodeInfo(OpCodes.Ldelem_Ref),
			new OpCodeInfo(OpCodes.Ldelem_U1),
			new OpCodeInfo(OpCodes.Ldelem_U2),
			new OpCodeInfo(OpCodes.Ldelem_U4),
			new OpCodeInfo(OpCodes.Ldelema)  ,
			new OpCodeInfo(OpCodes.Ldfld) ,
			new OpCodeInfo(OpCodes.Ldflda),
			new OpCodeInfo(OpCodes.Ldlen) ,
			new OpCodeInfo(OpCodes.Ldobj) ,
			new OpCodeInfo(OpCodes.Ldsfld),
			new OpCodeInfo(OpCodes.Ldsflda),
			new OpCodeInfo(OpCodes.Ldstr) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldtoken) { CanThrow = false },
			new OpCodeInfo(OpCodes.Ldvirtftn),
			new OpCodeInfo(OpCodes.Mkrefany),
			new OpCodeInfo(OpCodes.Newarr),
			new OpCodeInfo(OpCodes.Newobj),
			new OpCodeInfo(OpCodes.Refanytype) { CanThrow = false },
			new OpCodeInfo(OpCodes.Refanyval),
			new OpCodeInfo(OpCodes.Rethrow),
			new OpCodeInfo(OpCodes.Sizeof) { CanThrow = false },
			new OpCodeInfo(OpCodes.Stelem_Any),
			new OpCodeInfo(OpCodes.Stelem_I1),
			new OpCodeInfo(OpCodes.Stelem_I2),
			new OpCodeInfo(OpCodes.Stelem_I4),
			new OpCodeInfo(OpCodes.Stelem_I8),
			new OpCodeInfo(OpCodes.Stelem_R4),
			new OpCodeInfo(OpCodes.Stelem_R8),
			new OpCodeInfo(OpCodes.Stelem_Ref),
			new OpCodeInfo(OpCodes.Stfld),
			new OpCodeInfo(OpCodes.Stobj),
			new OpCodeInfo(OpCodes.Stsfld),
			new OpCodeInfo(OpCodes.Throw),
			new OpCodeInfo(OpCodes.Unbox),
			new OpCodeInfo(OpCodes.Unbox_Any),
			#endregion
		};
		static readonly Dictionary<Code, OpCodeInfo> knownOpCodeDict = knownOpCodes.ToDictionary(info => info.OpCode.Code);
		
		public static OpCodeInfo Get(OpCode opCode)
		{
			return Get(opCode.Code);
		}
		
		public static OpCodeInfo Get(Code code)
		{
			OpCodeInfo info;
			if (knownOpCodeDict.TryGetValue(code, out info))
				return info;
			else
				throw new NotSupportedException(code.ToString());
		}
		
		OpCode opcode;

		OpCodeInfo(OpCode opcode)
		{
			this.opcode = opcode;
			CanThrow = true;
		}
		
		public OpCode OpCode { get { return opcode; } }
		
		/// <summary>
		/// 'Move' kind of instructions have one input (may be stack or local variable) and copy that value to all outputs (again stack or local variable).
		/// </summary>
		public bool IsMoveInstruction { get; private set; }
		
		/// <summary>
		/// Specifies whether this opcode is capable of throwing exceptions.
		/// </summary>
		public bool CanThrow { get; private set; }
	}
}