I'm in the process of taking some MEF code I wrote in VS2010, and writing it again in VS2012. Unfortunately, I got stuck on this simple interface:
public interface IModulesContainer
{
[ImportMany]
IEnumerable<Lazy<IModule, IModuleMetadata>> Container { get; }
}
VS2012 has a compile error on this:
Error Using the generic type 'System.Lazy<T>' requires 1 type arguments
I know there are two System.Lazy<> generic classes, one that takes one parameter type, and the other takes two (2nd being metadata).
I can't figure out how to get VS2012 to recognize the latter class. (Both are under the System namespace)
VS2010 sees it just fine. What am I missing?
Thanks in advance,
--Eric
Related
I'm in the process of trying to migrate a R# extension project from R# 6 to R# 8. (I've taken over a project that someone wrote, and I'm new to writing extensions.)
In the existing v6 project there is a class that derives from RenameWorkflow, and the constructor used to look like this;
public class RenameStepWorkflow : RenameWorkflow
{
public RenameStepWorkflow(ISolution Solution, string ActionId)
: base(Solution, ActionId)
{
}
This used to work in R# SDK v 6, but now in V8, RenameWorkflow no longer has a constructor that takes Solution and actionId. The new constructor signature now looks like this;
public RenameWorkflow(
IShellLocks locks,
SearchDomainFactory searchDomainFactory,
RenameRefactoringService renameRefactoringService,
ISolution solution,
string actionId);
now heres my problem that I need help with (I think)
I've copied the constructor, and now the constructor of this class has to satisfy these new dependancies. Through some digging I've managed to find a way to satisfy all the dependencies, except for 'SearchDomainFactory'. The closest I can come to instantiating via the updated constructor is as follows;
new RenameStepWorkflow(Solution.Locks, JetBrains.ReSharper.Psi.Search.SearchDomainFactory.Instance, RenameRefactoringService.Instance, this.Solution, null)
All looks good, except that JetBrains.ReSharper.Psi.Search.SearchDomainFactory.Instance is marked as Obsolete, and gives me a compile error that I cannot work around, even using #pragma does not allow me to compile the code. The exact error message I get when I compile is Error 16 'JetBrains.ReSharper.Psi.Search.SearchDomainFactory.Instance' is obsolete: 'Inject me!'
Obvious next question..ok, how? How do I 'inject you'? I cannot find any documentation over this new breaking change, in fact, I cannot find any documentation (or sample projects) that even mentions DrivenRefactoringWorkflow or RenameWorkflow, (the classes that now require the new SearchDomainFactory), or any information on SearchDomainFactory.Instance suddenly now obsolete and how to satisfy the need to 'inject' it.
Any help would be most appreciated! Thank you,
regards
Alan
ReSharper has its own IoC container, which is responsible for creating instances of classes, and "injecting" dependencies as constructor parameters. Classes marked with attributes such as [ShellComponent] or [SolutionComponent] are handled by the container, created when the application starts or a solution is loaded, respectively.
Dependencies should be injected as constructor parameters, rather than using methods like GetComponent<TDependency> or static Instance properties, as this allows the container to control dependency lifetime, and ensure you're depending on appropriate components, and not creating leaks - a shell component cannot depend on a solution component for instance, it won't exist when the shell component is being created.
ReSharper introduced the IoC container a few releases ago, and a large proportion of the codebase has been updated to use it correctly, but there are a few hold-outs, where things are still done in a less than ideal manner - static Instance properties and calls to GetComponent. This is what you've encountered. You should be able to get an instance of SearchDomainFactory by putting it as a constructor parameter in your component.
You can find out more about the Component Model (the IoC container and related functionality) in the devguide: https://www.jetbrains.com/resharper/devguide/Platform/ComponentModel.html
I've had to jump through hoops, but I've almost managed to get ServiceStack working on iOS with Monotouch in my project. One runtime JIT exception is holding out:
System.ExecutionEngineException: Attempting to JIT compile method 'ServiceStack.Text.Json.JsonTypeSerializer:GetWriteFn<int> ()' while running with --aot-only.
The offending code is quite simple:
internal WriteObjectDelegate GetWriteFn<T>()
{
return JsonWriter<T>.WriteFn();
}
As a test, I modified the SS code to make the internal methods and types public and included the following in the startup code of my project (to actually get called).
var ick = ServiceStack.Text.Json.JsonWriter<int>.WriteFn();
var erk = ServiceStack.Text.Json.JsonTypeSerializer.Instance.GetWriteFn<int>();
This still doesn't alert the AOT for some reason, I get the exception when the code above executes! Is this because the generic parameter is a value type? Or is it because these are static classes and methods? How can I force Monotouch to AOT the methods above?
The SS code in question is in JsonTypeSerializer.cs and JsonWriter.Generic.cs at:
https://github.com/ServiceStack/ServiceStack.Text/tree/master/src/ServiceStack.Text/Json
There are some generic limitations in monotouch now. I think you should check your code to one of them.
There are 2 ways to make Android native C/C++ to call Java code.
Java app calls the native functions first. The native functions save the JavaVM and JNIEnv, and then use them to call Java code, say Java class X.
The native functions call the same Java class X. In this case, we need a JVM to run the Java code. JNI_CreateJavaVM() can be used to do it.
I find the JVMs created by the above 2 ways are different.
Here is the Java class X.
public class X
{
public X()
{
Log.d("X", "X()");
}
}
The Log.d() can be run successfully in the way 1. However, in the way 2 I get the following error message from logcat:
"No implemention found for native Landroid/util/Log;.println_native(IILjava/lang/String;java/lang/String;)I"
I am thinking the JNIEnv got from JNI_CreateJavaVM() misses something. How could I solve the problem if I have to use the way 2?
Maybe the code in com.android.internal.util.WithFramework can help you.
See my similar question here
Since I don't know exactly what part of it alone that triggers the error, I'm not entirely sure how to better label it.
This question is a by-product of the SO question c# code seems to get optimized in an invalid way such that an object value becomes null, which I attempted to help Gary with yesterday evening. He was the one that found out that there was a problem, I've just reduced the problem to a simpler project, and want verification before I go further with it, hence this question here.
I'll post a note on Microsoft Connect if others can verify that they too get this problem, and of course I hope that either Jon, Mads or Eric will take a look at it as well :)
It involves:
3 projects, 2 of which are class libraries, one of which is a console program (this last one isn't needed to reproduce the problem, but just executing this shows the problem, whereas you need to use reflector and look at the compiled code if you don't add it)
Incomplete references and type inference
Generics
The code is available here: code repository.
I'll post a description below of how to make the projects if you rather want to get your hands dirty.
The problem exhibits itself by producing an invalid cast in a method call, before returning a simple generic list, casting it to something strange before returning it. The original code ended up with a cast to a boolean, yes, a boolean. The compiler added a cast from a List<SomeEntityObject> to a boolean, before returning the result, and the method signature said that it would return a List<SomeEntityObject>. This in turn leads to odd problems at runtime, everything from the result of the method call being considered "optimized away" (the original question), or a crash with either BadImageFormatException or InvalidProgramException or one of the similar exceptions.
During my work to reproduce this, I've seen a cast to void[], and the current version of my code now casts to a TypedReference. In one case, Reflector crashes so most likely the code was beyond hope in that case. Your mileage might vary.
Here's what to do to reproduce it:
Note: There is likely that there are more minimal forms that will reproduce the problem, but moving all the code to just one project made it go away. Removing the generics from the classes also makes the problem go away. The code below reproduces the problem each time for me, so I'm leaving it as is.
I apologize for the escaped html characters in the code below, this is Markdown playing a trick on me, if anyone knows how I can rectify it, please let me know, or just edit the question
Create a new Visual Studio 2010 solution containing a console application, for .NET 4.0
Add two new projects, both class libraries, also .NET 4.0 (I'm going to assume they're named ClassLibrary1 and ClassLibrary2)
Adjust all the projects to use the full .NET 4.0 runtime, not just the client profile
Add a reference in the console project to ClassLibrary2
Add a reference in ClassLibrary2 to ClassLibrary 1
Remove the two Class1.cs files that was added by default to the class libraries
In ClassLibrary1, add a reference to System.Runtime.Caching
Add a new file to ClassLibrary1, call it DummyCache.cs, and paste in the following code:
using System;
using System.Collections.Generic;
using System.Runtime.Caching;
namespace ClassLibrary1
{
public class DummyCache<TModel> where TModel : new()
{
public void TriggerMethod<T>()
{
}
// Try commenting this out, note that it is never called!
public void TriggerMethod<T>(T value, CacheItemPolicy policy)
{
}
public CacheItemPolicy GetDefaultCacheItemPolicy()
{
return null;
}
public CacheItemPolicy GetDefaultCacheItemPolicy(IEnumerable<string> dependentKeys, bool createInsertDependency = false)
{
return null;
}
}
}
Add a new file to ClassLibrary2, call it Dummy.cs and paste in the following code:
using System;
using System.Collections.Generic;
using ClassLibrary1;
namespace ClassLibrary2
{
public class Dummy
{
private DummyCache<Dummy> Cache { get; set; }
public void TryCommentingMeOut()
{
Cache.TriggerMethod<Dummy>();
}
public List<Dummy> GetDummies()
{
var policy = Cache.GetDefaultCacheItemPolicy();
return new List<Dummy>();
}
}
}
Paste in the following code in Program.cs in the console project:
using System;
using System.Collections.Generic;
using ClassLibrary2;
namespace ConsoleApplication23
{
class Program
{
static void Main(string[] args)
{
Dummy dummy = new Dummy();
// This will crash with InvalidProgramException
// or BadImageFormatException, or a similar exception
List<Dummy> dummies = dummy.GetDummies();
}
}
}
Build, and ensure there are no compiler errors
Now try running the program. This should crash with one of the more horrible exceptions. I've seen both InvalidProgramException and BadImageFormatException, depending on what the cast ended up as
Look at the generated code of Dummy.GetDummies in Reflector. The source code looks like this:
public List<Dummy> GetDummies()
{
var policy = Cache.GetDefaultCacheItemPolicy();
return new List<Dummy>();
}
however reflector says (for me, it might differ in which cast it chose for you, and in one case Reflector even crashed):
public List<Dummy> GetDummies()
{
List<Dummy> policy = (List<Dummy>)this.Cache.GetDefaultCacheItemPolicy();
TypedReference CS$1$0000 = (TypedReference) new List<Dummy>();
return (List<Dummy>) CS$1$0000;
}
Now, here's a couple of odd things, the above crash/invalid code aside:
Library2, which has Dummy.GetDummies, performs a call to get the default cache policy on the class from Library1. It uses type inference var policy = ..., and the result is an CacheItemPolicy object (null in the code, but type is important).
However, ClassLibrary2 does not have a reference to System.Runtime.Caching, so it should not compile.
And indeed, if you comment out the method in Dummy that is named TryCommentingMeOut, you get:
The type 'System.Runtime.Caching.CacheItemPolicy' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Runtime.Caching, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.
Why having this method present makes the compiler happy I don't know, and I don't even know if this is linked to the current problem or not. Perhaps it is a second bug.
There is a similar method in DummyCache, if you restore the method in Dummy, so that the code again compiles, and then comment out the method in DummyCache that has the "Try commenting this out" comment above it, you get the same compiler error
OK, I downloaded your code and can confirm the problem as described.
I have not done any extensive tinkering with this, but when I run & reflector a Release build all seems OK (= null ref exception and clean disassembly).
Reflector (6.10.11) crashed on the Debug builds.
One more experiment: I wondered about the use of CacheItemPolicies so I replaced it with my own MyCacheItemPolicy (in a 3rd classlib) and the same BadImageFormat exception pops up.
The exception mentions : {"Bad binary signature. (Exception from HRESULT: 0x80131192)"}
I have an [AllowPartiallyTrustedCallers] class library containing subtypes of the System.DataAnnotations.ValidationAttribute. The library is used on contract types of WCF services.
In .NET 2/3.5, this worked fine. Since .NET 4.0 however, running a client of the service in the Visual Studio debugger results in the exception "Inheritance security rules violated by type: '(my subtype of ValidationAttribute)'. Derived types must either match the security accessibility of the base type or be less accessible." (System.TypeLoadException)
The error appears to occure only when all of the following conditions are met:
a subclass of ValidationAttribute is in an AllowPartiallyTrustedCallers assembly
reflection is used to check for the attribute
the Visual Studio hosting process is enabled (checkbox on Project properties, Debug tab)
So basically, in Visual Studio.NET 2010:
create a new Console project,
add a reference to "System.ComponentModel.DataAnnotations" 4.0.0.0,
write the following code:
.
using System;
[assembly: System.Security.AllowPartiallyTrustedCallers()]
namespace TestingVaidationAttributeSecurity
{
public class MyValidationAttribute : System.ComponentModel.DataAnnotations.ValidationAttribute
{ }
[MyValidation]
public class FooBar
{ }
class Program
{
static void Main(string[] args)
{
Console.WriteLine("ValidationAttribute IsCritical: {0}",
typeof(System.ComponentModel.DataAnnotations.ValidationAttribute).IsSecurityCritical);
FooBar fb = new FooBar();
fb.GetType().GetCustomAttributes(true);
Console.WriteLine("Press enter to end.");
Console.ReadLine();
}
}
}
Press F5 and you get the exception !
Press Ctrl-F5 (start without debugging), and it all works fine without exception...
The strange thing is that the ValidationAttribute will or will not be securitycritical depending on the way you run the program (F5 or Ctrl+F5). As illustrated by the Console.WriteLine in the above code. But then again, this appear to happen with other attributes (and types?) too.
Now the questions...
Why do I have this behaviour when inheriting from ValidationAttribute, but not when inheriting from System.Attribute ? (Using Reflector I don't find special settings on the ValidationAttribute class or it's assembly)
And what can I do to solve this ? How can I keep MyValidationAttribute inheriting from ValidationAttribute in an AllowPartiallyTrustedCallers assembly without marking it SecurityCritical, still using the new .NET 4 level 2 security model and still have it work using the VS.NET debug host (or other hosts) ??
Thanks a lot!
Rudi
Why do I have this behaviour when inheriting from ValidationAttribute, but not when inheriting from System.Attribute ? (Using Reflector I don't find special settings on the ValidationAttribute class or it's assembly)
This is because the System.ComponentModel.DataAnnotations assembly is conditionally APTCA i.e. it is marked with the following attribute.
[assembly: AllowPartiallyTrustedCallers(PartialTrustVisibilityLevel = PartialTrustVisibilityLevel.NotVisibleByDefault)]
Something about the way Visual Studio starts the host process causes the CLR not to respect APTCA on this assembly even though the default AppDomain is fully trusted. This implies that all the types and methods in the DataAnnotations assembly are SecurityCritical. Since a security transparent type (MyValidationAttribute) cannot inherit from a security critical type (ValidationAttribute), this exception is thrown.
And what can I do to solve this ? How can I keep MyValidationAttribute inheriting from ValidationAttribute in an AllowPartiallyTrustedCallers assembly without marking it SecurityCritical, still using the new .NET 4 level 2 security model and still have it work using the VS.NET debug host (or other hosts) ??
It seems like this is a bug with the VS host, which is unfortunate for your situation. On the other hand, you should really be sure that you want your assembly to be APTCA. If it's necessary, then you have a couple of options.
You can leave your assembly as is. This is advantageous because in the most typical partial trust environment, ASP.NET, the DataAnnotations assembly will always be considered APTCA. Of course, you lose the ability to use the debugger in the VS hosting process.
You can mark your assembly C-APTCA as well. You'll be able to use the debugger in the VS hosting process, but consumers of your assembly in ASP.NET will need to add your assembly to the <partialTrustVisibleAssemblies> element in the web.config in order for it to be APTCA.
You could make your attribute SecurityCritical, so you'll be able to use the debugger and will not require any special configuration in ASP.NET, but all classes that use your attribute must also be critical.
For some reason the site posted the text into a completely different question from the one that was on the page when I was writing - weird.