What might cause this ExecutionEngineException?
- by Qwertie
I am trying to use Reflection.Emit to generate a wrapper class in a dynamic assembly. Automatic wrapper generation is part of a new open-source library I'm writing called "GoInterfaces".
The wrapper class implements IEnumerable<string> and wraps List<string>. In C# terms, all it does is this:
class List1_7931B0B4_79328AA0 : IEnumerable<string>
{
private readonly List<string> _obj;
public List1_7931B0B4_79328AA0(List<string> obj)
{
this._obj = obj;
}
IEnumerator IEnumerable.GetEnumerator()
{
return this._obj.GetEnumerator();
}
public sealed IEnumerator<string> GetEnumerator()
{
return this._obj.GetEnumerator();
}
}
However, when I try to call the GetEnumerator() method on my wrapper class, I get ExecutionEngineException. So I saved my dynamic assembly to a DLL and used ildasm on it. Is there anything wrong with the following code?
.class public auto ansi sealed List`1_7931B0B4_79328AA0
extends [mscorlib]System.Object
implements [mscorlib]System.Collections.Generic.IEnumerable`1<string>,
[Loyc.Runtime]Loyc.Runtime.IGoInterfaceWrapper
{
.field private initonly class
[mscorlib]System.Collections.Generic.List`1<string> _obj
.method public hidebysig virtual final instance
class [mscorlib]System.Collections.Generic.IEnumerator`1<string>
GetEnumerator() cil managed
{
// Code size 12 (0xc)
.maxstack 1
IL_0000: ldarg.0
IL_0001: ldfld class [mscorlib]System.Collections.Generic.List`1<string> List`1_7931B0B4_79328AA0::_obj
IL_0006: call instance valuetype [mscorlib]System.Collections.Generic.List`1/Enumerator<!0> class [mscorlib]System.Collections.Generic.List`1<string>::GetEnumerator()
IL_000b: ret
} // end of method List`1_7931B0B4_79328AA0::GetEnumerator
.method public hidebysig virtual final instance
class [mscorlib]System.Collections.IEnumerator
System.Collections.IEnumerable.GetEnumerator() cil managed
{
.override [mscorlib]System.Collections.IEnumerable::GetEnumerator
// Code size 12 (0xc)
.maxstack 1
IL_0000: ldarg.0
IL_0001: ldfld class [mscorlib]System.Collections.Generic.List`1<string> List`1_7931B0B4_79328AA0::_obj
IL_0006: call instance valuetype [mscorlib]System.Collections.Generic.List`1/Enumerator<!0> class [mscorlib]System.Collections.Generic.List`1<string>::GetEnumerator()
IL_000b: ret
} // end of method List`1_7931B0B4_79328AA0::System.Collections.IEnumerable.GetEnumerator
...
I have a test suite that wraps all sorts of different things, including interfaces derived from other interfaces, and multiple interface methods with identical signatures. It's only when I try to wrap IEnumerable<T> that this problem occurs. I'd be happy to send the source code (2 *.cs files, no dependencies) if anyone would like.
