1 //
2 // Permission is hereby granted, free of charge, to any person obtaining
3 // a copy of this software and associated documentation files (the
4 // "Software"), to deal in the Software without restriction, including
5 // without limitation the rights to use, copy, modify, merge, publish,
6 // distribute, sublicense, and/or sell copies of the Software, and to
7 // permit persons to whom the Software is furnished to do so, subject to
8 // the following conditions:
9 //
10 // The above copyright notice and this permission notice shall be
11 // included in all copies or substantial portions of the Software.
12 //
13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
14 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
15 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
16 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
17 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
18 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
19 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
20 //
21 // Copyright (C) Lluis Sanchez Gual, 2004
22 //
23 
24 #if !FULL_AOT_RUNTIME
25 using System;
26 using System.Reflection;
27 using System.Reflection.Emit;
28 
29 namespace Mono.CodeGeneration
30 {
31 	public class CodeWhen: CodeExpression
32 	{
33 		CodeExpression condition;
34 		CodeExpression trueBlock;
35 		CodeExpression falseBlock;
36 
CodeWhen(CodeExpression condition, CodeExpression trueResult, CodeExpression falseResult)37 		public CodeWhen (CodeExpression condition, CodeExpression trueResult, CodeExpression falseResult)
38 		{
39 			this.condition = condition;
40 			if (condition.GetResultType () != typeof(bool))
41 				throw new InvalidOperationException ("Condition expression is not boolean");
42 			if (trueResult.GetResultType() != falseResult.GetResultType())
43 				throw new InvalidOperationException ("The types of the true and false expressions must be the same");
44 			trueBlock = trueResult;
45 			falseBlock = falseResult;
46 		}
47 
Generate(ILGenerator gen)48 		public override void Generate (ILGenerator gen)
49 		{
50 			Label falseLabel = gen.DefineLabel ();
51 			Label endLabel = gen.DefineLabel ();
52 
53 			GenerateCondition (gen, falseLabel);
54 			trueBlock.Generate (gen);
55 			gen.Emit (OpCodes.Br, endLabel);
56 			gen.MarkLabel(falseLabel);
57 			falseBlock.Generate (gen);
58 
59 			gen.MarkLabel(endLabel);
60 		}
61 
GenerateCondition(ILGenerator gen, Label falseLabel)62 		void GenerateCondition (ILGenerator gen, Label falseLabel)
63 		{
64 			if (condition is CodeConditionExpression)
65 				((CodeConditionExpression)condition).GenerateForBranch (gen, falseLabel, false);
66 			else {
67 				condition.Generate (gen);
68 				gen.Emit (OpCodes.Brfalse, falseLabel);
69 			}
70 		}
71 
PrintCode(CodeWriter cp)72 		public override void PrintCode (CodeWriter cp)
73 		{
74 			cp.Write ("(");
75 			condition.PrintCode (cp);
76 			cp.Write (") ? ");
77 			trueBlock.PrintCode (cp);
78 			cp.Write (" : ");
79 			falseBlock.PrintCode (cp);
80 		}
81 
GetResultType()82 		public override Type GetResultType ()
83 		{
84 			return trueBlock.GetResultType();
85 		}
86 	}
87 }
88 #endif
89