[mono] iOS FullAOT crashes with condition `method->is_inflated' not met

[EgorBo]

((null) error) * Assertion at class.c:1851, condition 'method->is_inflated' not met

(it happens in mono_class_inflate_generic_method_full_checked for Object.GetType)

Simple repro:

using System;
using System.Collections.Generic;

public class Program
{
    public static void Main() {
        Test(1, 2, GetComparer<int>());
    }

    static IComparer<T> GetComparer<T>() where T : IComparable {
        return new AssertComparer<T>();
    }

    static int Test<T>(T low, T high, IComparer<T> comparer) {
        return comparer.Compare(low, high);
    }
}

class AssertComparer<T> : IComparer<T> where T : IComparable
{
    public int Compare(T x, T y) {
        return x.GetType() != y.GetType() ? 1 : 0;
    }
}

Steps to reproduce:

cd src/mono/netcore/sample/iOS/Makefile

# next command should build the whole repo for arm64 and iOS
make runtimepack

# Open 'src/mono/netcore/sample/iOS/Program.cs' and use the repro ^

# generate an XCode project
make bundle USE_LLVM=False

# open Xcode project, deploy to a real device, observe the crash

Many tests crash because of it (some gsharedvt-related issue?)

[marek-safar]

@vargaz could you please look into this, it has now easy repro

[vargaz]

Does this happen with xamarin.ios as well ?

[EgorBo]

@vargaz no, so maybe it's some ENABLE_NETCORE changes or incorrect flags we use for AOT. Looks like iOS AOT is broken in master atm so let me fix it first

[EgorBo]

@vargaz ah, actually everything is OK if you want to try the repro locally, it might complain on

Program.dll.s:127:1: error: file number already allocated
.file 1 "<unknown>"

in Debug mode but if you remove that from Program.dll.s it should build (some new AOTCompiler Task issue)

[akoeplinger]

Xamarin.iOS is hitting this with their NUnit test suites running on .NET6 based mono too, so would be nice to get it fixed to unblock their tests.

[vargaz]

How can I reproduce this with the current setup ?