Hi again and we are getting closer and closer. I just can't believe how difficult it is to work with generics.
It looks right now, but PEVerify throws an exception [MD]: Error: Signature has an invalid token (token: 0x0200031d; offset: 0x00000002). [token:0x1B000001] [MD]: Error: Signature has generic type of arity 0 instantiated at different arity 1 at byte=0x00000005. [token:0x1B000001] [IL]: Error: [C:\Users\Bernhard\Documents\Visual Studio 2010\Projects \MethodCaching\TestResults\Tests[1]\Out\SampleLibrary.dll : SampleLibrary.SampleClass::Calculate][mdToken=0x6000001][offset 0x00000001] Unable to resolve token. 3 Error(s) Verifying SampleLibrary.dll Could I ask you a BIG favor? Could you try this out yourself and see if it works on your side? I have been ripping my hair out for two days over this :) //Bernhard On May 8, 8:19 pm, Gábor Kozár <[email protected]> wrote: > Hey, > > Resolve() will make you lose all your generic arguments. If you can't change > the DeclaringType, then you have to clone the entire method. I have an > extension method for this, I believe it's also somewhere in Cecil.Rocks > (maybe under a different name). > > public static MethodReference MakeHostInstanceGeneric(this MethodReference > self, params TypeReference[] arguments) > { > var reference = new MethodReference(self.Name, self.ReturnType, > self.DeclaringType.MakeGenericInstanceType(arguments)) > { > HasThis = self.HasThis, > ExplicitThis = self.ExplicitThis, > CallingConvention = self.CallingConvention > }; > > foreach (var parameter in self.Parameters) > reference.Parameters.Add(new > ParameterDefinition(parameter.ParameterType)); > > foreach (var generic_parameter in self.GenericParameters) > reference.GenericParameters.Add(new > GenericParameter(generic_parameter.Name, reference)); > > return reference; > > } > > So your code: > > TypeReference genericArg = _moduleDefinition.TypeSystem.Int32; > GenericInstanceType genericType = > _moduleDefinition.Import(typeof(Nullable<>)).MakeGenericInstanceType(generi > cArg); > MethodReference ctor = genericType.Resolve().Methods.First(m => > m.IsConstructor && m.Parameters.Count == > 1).MakeHostInstanceGeneric(genericArg); > > And now you should be able to emit your call instruction. > > 2011/5/8 seesharper <[email protected]> > > > > > > > > > Hi Gábor and thanks for you help!! > > > Sadly it did not quite work out. > > > The ctor.DeclaringType is a TypeDefinition and I can't assign the > > result of > > > ctor.DeclaringType.MakeGenericInstanceType(genericArg) > > > If I do ctor.DeclaringType.MakeGenericInstanceType(genericArg).Resolve > > it will turn my generic type into a > > TypeDefiniton with all its generic type information lost. In other > > words back to where I started. > > > Any thoughts on this? > > > Regards > > > Bernhard Richter > > > On May 8, 12:11 pm, Gábor Kozár <[email protected]> wrote: > > > Hi, > > > > I've had the same issue before, but I've managed to solve it with the > > help > > > of Jb. > > > > What you need to do is the following: > > > > TypeReference genericArg = _moduleDefinition.TypeSystem.Int32; > > > GenericInstanceType genericType = > > > _moduleDefinition.Import(typeof(Nullable<>)) > > > .MakeGenericInstanceType(genericArg); > > > MethodDefinition ctor = genericType.Resolve().Methods.First(m => > > > m.IsConstructor && m.Parameters.Count == 1); > > > > Note that if you try to emit a newobj instruction with 'ctor' with its > > > operand at this point, you'll get invalid IL, because when you use > > > Resolve(), you lose all generic argument information. We need to provide > > > that manually. > > > For that, you have to add your generic argument to ctor.DeclaringType, or > > > alternatively, you can use Rocks' MakeGenericInstanceType, like so: > > > > ctor.DeclaringType = > > ctor.DeclaringType.MakeGenericInstanceType(genericArg); > > > > Now you can emit your newobj instruction with 'ctor' being its argument. > > > Note that you _might_ need to clone ctor.DeclaringType first (I'm not > > sure, > > > I don't have my code in front of me atm), but you get the general idea. > > > > Hope this helps! > > > > 2011/5/8 seesharper <[email protected]> > > > > > Hi! > > > > > I don't understand how to emit the code to create an instance of a > > > > generic type. > > > > > Mono.Cecil 0.9.4.0 > > > > > I will illustrate this with a very simple example. > > > > > This is the code that I want to emit. > > > > > public void TestNull(int value) > > > > { > > > > Nullable<int> test = value; > > > > } > > > > > NOTE: > > > > > I don't know that the generic argument is an int at the time of > > > > emitting the code. > > > > > I need to read the parameter type and create a Nullable<T> according > > > > to the parameter type. > > > > > This means that I CAN'T do something like: > > > > > MethodReference ctor = _moduleDefinition.Import(typeof > > > > (Nullable<int>).GetConstructor(new Type[] {typeof (int)})); > > > > > This is the IL code that needs to be emitted. > > > > > .maxstack 2 > > > > .locals init ( > > > > [0] valuetype [mscorlib]System.Nullable`1<int32> test) > > > > L_0000: nop > > > > L_0001: ldloca.s test > > > > L_0003: ldarg.1 > > > > L_0004: call instance void > > > > [mscorlib]System.Nullable`1<int32>::.ctor(!0) > > > > L_0009: nop > > > > L_000a: ret > > > > > So this is what I got so far. > > > > > First a create a GenericInstanceType: > > > > > var nullableType = _moduleDefinition.Import(typeof(Nullable<>)); > > > > var genericType = > > > nullableType.MakeGenericInstanceType(_moduleDefinition.Import(typeof(int))) > > ; > > > > > (yeah, I used the Cecil.Rocks extension method for creating the > > > > generic instance type, but that is not the issue here.) > > > > > The int would be the type from the value parameter of the TestNull > > > > method. > > > > > Now I have a GenericInstanceType that represents Nullable<int>. > > > > > But how do I create a MethodReference that represents the constructor > > > > passed to OpCodes.NewObj? > > > > > The GenericInstanceType which is derived from MethodReference does not > > > > have a collection of methods so I can't get it from there either. > > > > > Next I tried something like this: > > > > > MethodReference constructorReference = new MethodReference(".ctor", > > > > _moduleDefinition.Import(typeof(void)), genericType); > > > > > No luck on this either. > > > > > A lot of forum posts suggests that the methodreference should be added > > > > to the MemberReferences collection of the module. > > > > > But that is a read-only collection available from the > > > > GetMemberReferences method. > > > > > I must be missing something? > > > > > Any help on this issue would be great!!! > > > > > Regards > > > > > Bernhard Richter > > > > > -- > > > > -- > > > > mono-cecil > > > -- > > -- > > mono-cecil -- -- mono-cecil
