Getting Static and Instance Property Values in MDbg
I've always wondered how to do this and only took the time to figure it out recently - how do you get the values of C# properties, especially if they're static, in MDbg? It was the magic keyword "funceval" and the knowledge of how properties live in IL that answered that question for me. In this particular case, I needed to get the app domain's configuration file. This is what I had to do:
[p#:1, t#:2] mdbg> funceval System.AppDomain.get_CurrentDomain
result = System.AppDomain
_domainManager=<null>
_LocalStore=System.Collections.Hashtable.SyncHashtable
_FusionStore=System.AppDomainSetup
_SecurityIdentity=<null>
_Policies=<null>
AssemblyLoad=<null>
TypeResolve=<null>
ResourceResolve=<null>
AssemblyResolve=<null>
ReflectionOnlyAssemblyResolve=<null>
_DefaultContext=System.Runtime.Remoting.Contexts.Context
_activationContext=<null>
_applicationIdentity=<null>
_applicationTrust=<null>
_DefaultPrincipal=<null>
_RemotingData=System.Runtime.Remoting.DomainSpecificRemotingData
_processExit=System.EventHandler
_domainUnload=System.EventHandler
_unhandledException=System.UnhandledExceptionEventHandler
_dummyField=1433136
_PrincipalPolicy=System.Security.Principal.PrincipalPolicy
_HasSetPolicy=False
__identity=<null>
results saved to $result
STOP EvalComplete
IP: 133 @ ... - MAPPING_EXACT
[p#:1, t#:2] mdbg> funceval System.AppDomain.get_SetupInformation $result
result = System.AppDomainSetup
_Entries=array [16]
_LoaderOptimization=System.LoaderOptimization
_AppBase=<null>
_AppDomainInitializer=<null>
_AppDomainInitializerArguments=<null>
_ActivationArguments=<null>
_ApplicationTrust=<null>
_ConfigurationBytes=<null>
results saved to $result
STOP EvalComplete
IP: 133 @ ... - MAPPING_EXACT
[p#:1, t#:2] mdbg> funceval System.AppDomainSetup.get_ConfigurationFile $result
result = "C:\Test\Test.exe.config"
results saved to $result
STOP EvalComplete
IP: 133 @ ... - MAPPING_EXACT
[p#:1, t#:2] mdbg>
Clearly, no rocket science. All one needed to know is that a property lives as two methods in IL - get_PropertyName for the getter and set_PropertyName for the setter - and that the object the method is to be executed against (in the case of instance properties) must be provided as the first argument, just like it normally is. I'd love to hear about a better and easier way.
By the way, MDbg ships as a sample with the Whidbey SDK. You can get it at http://www.microsoft.com/downloads/details.aspx?FamilyID=38449A42-6B7A-4E28-80CE-C55645AB1310&displaylang=en.
