Silverlight: reference to wrong version of system.dll

[einarwh]

Hi,

I'm a Mono.Cecil n00b trying to do some IL rewriting on Silverlight
assemblies, but I seem to be doing something wrong. The "tampered"
assemblies (after rewriting) look OK in ILSpy, except for the
references to .NET framework libraries, which include the
standard .NET v 4.0 (not Silverlight) of system.dll and mscorlib.dll.
I guess I must be doing something wrong when I'm importing types? I
tried to follow the recipe here:
http://stackoverflow.com/questions/9109506/mono-cecil-fails-to-process-a-silverlight-5-assembly
so I use the following code to read the assembly:

var resolver = new DefaultAssemblyResolver();
resolver.AddSearchDirectory(@"C:\Program Files (x86)\Reference
Assemblies\Microsoft\Framework\Silverlight\v4.0");
var assembly = AssemblyDefinition.ReadAssembly(
assemblyPath,
new ReaderParameters { AssemblyResolver = resolver });

I still seem to have the same problem, though. How do I best debug
this? How can I spot that I've inserted a faulty reference to the
regular .NET v4 dlls? I'm trying to inspect the
TypeReference.Module.Runtime and TypeDefinition.Module.Runtime of the
various types I use, does that make sense?

Any help would be greatly appreciated.

Kind regards,
Einar

[Jb Evain]

Hi,

It's hard to tell without you showing some actual IL rewriting code.
First thing that pops into my mind is that if you use the .net type system when rewriting the IL, you'll get references to the .net runtime type system.

Like, if you import a reference to typeof(int), or a System.Type, or a MethodInfo, then it will use the running one.
To avoid that you can simply use the Cecil type system.

Jb

> --
> --
> mono-cecil

[einarwh]

Hi,

You nailed it! Thanks! I was indeed using
TypeReference.Module.Import(typeof(...));

What would be the correct way to import a TypeReference?

Currently, I'm doing this to obtain a TypeReference that is used in
the definition of the TypeDefinition _typeDef:

var ns = "<namespace>";
var typeName = "<name>";
var typeRef = new TypeReference(ns, typeName, _typeDef.Module,
_typeDef.Scope);

Does that make sense?

Thanks again,
Einar

On Mar 5, 2:36 am, Jb Evain <jbev...@gmail.com> wrote:
> Hi,
>
> It's hard to tell without you showing some actual IL rewriting code.
> First thing that pops into my mind is that if you use the .net type system when rewriting the IL, you'll get references to the .net runtime type system.
>
> Like, if you import a reference to typeof(int), or a System.Type, or a MethodInfo, then it will use the running one.
> To avoid that you can simply use the Cecil type system.
>
> Jb
>
> On Mar 4, 2012, at 11:19 PM, einarwh wrote:
>
>
>
>
>
>
>
> > Hi,
>
> > I'm a Mono.Cecil n00b trying to do some IL rewriting on Silverlight
> > assemblies, but I seem to be doing something wrong. The "tampered"
> > assemblies (after rewriting) look OK in ILSpy, except for the
> > references to .NET framework libraries, which include the
> > standard .NET v 4.0 (not Silverlight) of system.dll and mscorlib.dll.
> > I guess I must be doing something wrong when I'm importing types? I
> > tried to follow the recipe here:

> >http://stackoverflow.com/questions/9109506/mono-cecil-fails-to-proces...

[einarwh]

Even better, how would I use the Cecil type system to create a
TypeReference for System.Void, for instance?

Kind regards,
Einar

[Jb Evain]

Two things,

For primitives, Cecil can automatically create references for you, based on the mscorlib you're referencing. So you can use:

myModule.TypeSystem.Void as a TypeReference.

If you need to import a reference to another type, you have to use Cecil to read the module the type is defined is, and call:

var reference = myModule.Import (theDefinition);

To create a reference scoped for myModule that you can use.

> --
> --
> mono-cecil

[einarwh]

Hi,

Thanks again! The references for the primitives are very useful, they
cover most of what I need.

I still don't fully understand the correct way to read modules and
type definitions, though (my apologies). Do I need to use
ModuleDefinition.ReadModule to do this? The types I need (such as
PropertyChangedEventHandler) all reside in system.dll and
mscorlib.dll.

In the example below, is theDefinition a TypeDefinition? Is this
something I get from the module I read, or something I create myself
and pass to myModule.Import?

I'm sorry for these basic and naive questions, hopefully my
understanding will improve soon!

Kind regards,
Einar

[Jb Evain]

Hi,

You need to use your custom silverlight resolver to resolve the silverlight mscorlib and System modules.
From those modules you can get TypeDefinition/FieldDefinition/MethodDefinition.

Then you import references for those in your module.

> --
> --
> mono-cecil

[einarwh]

Right, I got it now. Thanks a lot!