[Mono-bugs] [Bug 575941] New: Mono crashes (assert) when compiling generic code in F# Interactive

[bugzilla_noreply at novell.com]

http://bugzilla.novell.com/show_bug.cgi?id=575941

http://bugzilla.novell.com/show_bug.cgi?id=575941#c0


           Summary: Mono crashes (assert) when compiling generic code in
                    F# Interactive
    Classification: Mono
           Product: Mono: Runtime
           Version: 2.6.x
          Platform: PC
        OS/Version: Windows 7
            Status: NEW
          Severity: Major
          Priority: P5 - None
         Component: misc
        AssignedTo: mono-bugs at lists.ximian.com
        ReportedBy: aChrisSmith at gmail.com
         QAContact: mono-bugs at lists.ximian.com
          Found By: Third Party Developer/Partner
           Blocker: Yes


Description of Problem:

The Mono runtime asserts when emiting somewhat exotic generic code in the F#
interactive window.

ERROR:class.c:2884:mono_class_setup_vtable: assertion failed: (inflated)

Steps to reproduce the problem:
1. Download the latest F# CTP
http://www.microsoft.com/downloads/details.aspx?FamilyID=b55f0532-ac3c-4106-918c-5586a953a7da&displaylang=en
2. Run FSI.exe through Mono
3. Enter the following code:
-------------
type IFoo<'a> =
    abstract InterfaceMethod<'b> : 'a -> 'b

type Foo<'a, 'b>() =
    interface IFoo<'a> with
        override this.InterfaceMethod (x : 'a) = (Array.zeroCreate 1).[0]
    override this.ToString() = "Foo"

let test = new Foo<string, float>();;
---------------

Actual Results:

ERROR:class.c:2884:mono_class_setup_vtable: assertion failed: (inflated)

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.

Expected Results:

The code to compile successfully. (FSI.exe prints "val test : Foo<string,
float>")

How often does this happen? 

Every time.

Additional Information:

The code compiles and JITS just fine when using the F# compiler (fsc.exe). This
only repros when using F# Interactive. (Which would indicate the issue might
have something to do with Reflection.Emit.)

Here is a full console session showing the bug:

------------------------

C:\Program Files (x86)\FSharp-1.9.7.8\bin>type repro.fs
type IFoo<'a> =
    abstract InterfaceMethod<'b> : 'a -> 'b

type Foo<'a, 'b>() =
    interface IFoo<'a> with
        override this.InterfaceMethod (x : 'a) = (Array.zeroCreate 1).[0]
    override this.ToString() = "Foo"

let test = new Foo<string, float>()

printfn "Test passed successfully"

exit 0
C:\Program Files (x86)\FSharp-1.9.7.8\bin>echo Compiling and testing JIT
Compiling and testing JIT

C:\Program Files (x86)\FSharp-1.9.7.8\bin>mono fsc repro.fs
Cannot open assembly 'fsc': Result too large.

C:\Program Files (x86)\FSharp-1.9.7.8\bin>mono fsc.exe repro.fs
Microsoft F# Compiler, (c) Microsoft Corporation, All Rights Reserved
F# Version 1.9.7.8, compiling for .NET Framework Version v2.0.50727

C:\Program Files (x86)\FSharp-1.9.7.8\bin>mono repro.exe
Test passed successfully

C:\Program Files (x86)\FSharp-1.9.7.8\bin>echo Using Reflection.Emit in the FSI
Using Reflection.Emit in the FSI

C:\Program Files (x86)\FSharp-1.9.7.8\bin>mono fsi.exe

Microsoft F# Interactive, (c) Microsoft Corporation, All Rights Reserved
F# Version 1.9.7.8, compiling for .NET Framework Version v2.0.50727

For help type #help;;

> type IFoo<'a> =
    abstract InterfaceMethod<'b> : 'a -> 'b

type Foo<'a, 'b>() =
    interface IFoo<'a> with
        override this.InterfaceMethod (x : 'a) = (Array.zeroCreate 1).[0]
    override this.ToString() = "Foo"

let test = new Foo<string, float>();;
**
ERROR:class.c:2884:mono_class_setup_vtable: assertion failed: (inflated)

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.

-- 
Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug.
You are the assignee for the bug.