MethodAccessException in emitted code "GetImplementation"

[Finn Nielsen]

Hi,
 
First of all, great work with iBATIS. :)
 
Now, on to the subject. I am not sure if my observation is a problem with 
iBATIS, a feature request or a problem with my own code. Therefore I will start 
out by sending this mail.
 

An example of my environment (heavily abstracted):
.NET version 2.0.
 
iBATIS binaries:
IBatisNet.Common 1.4.1
IBatisNet.DataMapper 1.5.1
IBatisNet.DataAccess 1.8.1
 
I have a Common assembly which defines common utility types for use within the 
domain model. The utility types often use generics. The Common assembly is 
dependant on two other assemblies not mentioned here, but naturally only using 
public stuff in the dependant assemblies.
One particular class is:
public class SpecialReference<T> where T : class
{
  // stuff omitted
 
  public T Value
  {
   get { /*...*/ }
   set { /*...*/ }
  }
}

I have a Model assembly which contains the domain model types. Is dependant on 
the Common assembly.
Two fictive domain model classes are:
public class DomainObjectA
{
  private int identifier;
  // stuff omitted
}


public class DomainObjectB
{
  private SpecialReference<DomainObjectA> domainObjectA;
  // stuff omitted
}
 
In my mapping xml file for DomainObjectB I got stuff like:
<insert id="insertDomainObjectB" parameterClass="DomainObjectB">
      INSERT INTO DOM_OBJ_B (columns) 
      VALUES (/* omitted stuff */, #domainObjectA.Value.identifier#, /* omitted 
stuff */)
</insert>
 
 
 
The symptom:
When I insert a DomainObjectB I get a MethodAccessException where the stack 
trace points to "GetImplementation". I know that domainObjectA within the 
DomainObjectB instance has been properly initialized.
 
 
Analysis
I tried referencing the iBATIS source (Source Revision 426164) with which I was 
able to reporduce the problem. The MethodAccessException occured in the emitted 
code within 
IBatisNet.Common.Utilities.Objects.Members.DelegatePropertyGetAccessor. That 
is, when the emitted code was invoked using the GetValue delegate. The odd 
thing is, that I am sure that the #specialDomainObjectA.Value.identifier#  is 
valid, in the sence that the SpecialReference<T> class is public, and so is the 
Value property.
 
Next I tried in the IBatis.Common.2005 project to reference the Model and 
Common assemblies, and implement my own hardcoded GetValue delegate which was 
typed for DomainObjectB, but basically did the same as the emitted code. That 
is, cast the input object to the specific type, invoke the get property and 
return the result. This worked, i.e. I got no MethodAccessException. Afterwards 
I removed my own experimentation code from the iBATIS source and also removed 
the references for the assemblies Model and Common.
 
After a couple of other unsuccessfull attempts i found a "cure". Within 
IBatisNet.Common.Utilities.Objects.Members.DelegatePropertyGetAccessor a line 
of code states:
DynamicMethod dynamicMethod = new DynamicMethod("GetImplementation", 
typeof(object), new Type[] { typeof(object) }, this.GetType().Module, false);
I flipped the last boolean to true, which means to skip JIT visibility checks 
on members of all the types in all modules. This worked.
 

Question
Is the need for changing the boolean from false to true:
1. A flaw in the IBatisNet.Common assembly 
(IBatisNet.Common.Utilities.Objects.Members.DelegatePropertyGetAccessor and  
IBatisNet.Common.Utilities.Objects.Members.DelegatePropertySetAccessor classes).
2. A flaw in my code,
or
3. A feature request for IBatisNet.Common
 
 
Thanks for taking the time to read my mail. :)
 
Kind regards
Finn Nielsen