Bug 795 - System.MethodAccessException when creating generic class
Summary: System.MethodAccessException when creating generic class
Status: RESOLVED FIXED
Alias: None
Product: Runtime
Classification: Mono
Component: General ()
Version: unspecified
Hardware: PC Windows
: High major
Target Milestone: ---
Assignee: Bugzilla
URL:
Depends on:
Blocks:
 
Reported: 2011-09-13 21:15 UTC by Jonathan Pryor
Modified: 2017-08-28 15:05 UTC (History)
6 users (show)

Tags:
Is this bug a regression?: ---
Last known good build:

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Status:
RESOLVED FIXED

Description Jonathan Pryor 2011-09-13 21:15:31 UTC
Reported from Nicklas Petersson:

Add the following to a Mono for Android application, then run:

    public abstract class BaseClass<T> {}
    public class ClassA : BaseClass<ClassB> { }
    public class ClassB : ClassA {}

    public class TestClass
    {
        public void TestMethod()
        {
            var x = new ClassA();
        }
    }

Expected results: It works.

Actual results:

E/mono ( 788): Unhandled Exception: System.MethodAccessException: Method `Mono.Samples.Hello.BaseClass`1<Mono.Samples.Hello.ClassB>:.ctor ()' is inaccessible from method `Mono.Samples.Hello.ClassA:.ctor ()'
E/mono ( 788): 
E/mono ( 788): at Mono.Samples.Hello.TestClass.TestMethod () [0x00000] in <filename unknown>:0 
E/mono ( 788): at Mono.Samples.Hello.HelloActivity.OnCreate (Android.OS.Bundle bundle) [0x00000] in <filename unknown>:0 
E/mono ( 788): at Android.App.Activity.n_OnCreate_Landroid_os_Bundle_ (IntPtr jnienv, IntPtr native__this, IntPtr native_savedInstanceState) [0x00000] in <filename unknown>:0 
E/mono ( 788): at (wrapper dynamic-method) object:72e09863-b888-4aa4-96b8-099474ae1d79 (intptr,intptr,intptr)
Comment 1 Atsushi Eno 2011-10-04 21:35:08 UTC
I wonder if should even compile.
Comment 2 Jonathan Pryor 2012-01-16 16:12:41 UTC
The same code, with a "driver" Main, also dies on mono master/d901061:

    // same code as above...
    class Demo {
        public static void Main ()
        {
            new TestClass ().TestMethod ();
        }
    }

$ gmcs bxc795.cs
> bxc795.cs(18,21): warning CS0219: The variable `x' is assigned but its value is never used
> Compilation succeeded - 1 warning(s)

$ jon@melchior:csharp$ mono bxc795.exe 
> Unhandled Exception: System.MethodAccessException: Method `BaseClass`1<ClassB>:.ctor ()' is inaccessible from method `ClassA:.ctor ()'
> 
>   at TestClass.TestMethod () [0x00000] in <filename unknown>:0 
>   at Demo.Main () [0x00000] in <filename unknown>:0 

Looks like a JIT bug.
Comment 3 Rodrigo Kumpera 2012-01-23 20:46:34 UTC
Fixed on master, 2-10 and MM.