Veldrid fails to build on iOS

[frenzibyte]

Happens due to Veldrid referencing Vortice.Direct3D11, which depends on SharpGen.Runtime for generating bindings, and that library cannot be AOT'd on iOS.

0>Mono Ahead of Time compiler - compiling assembly /Users/salman/Projects/osu-framework/SampleGame.iOS/obj/iPhone/Debug/net6.0-ios/ios-arm64/linked/SharpGen.Runtime.dll
AOTID 7CA136D1-DC5C-CDE1-6269-4B4A034E7F8B
* Assertion at /Users/runner/work/1/s/src/mono/mono/metadata/custom-attrs.c:599, condition `out_obj' not met


0>Tool /usr/local/share/dotnet/packs/Microsoft.NETCore.App.Runtime.AOT.osx-x64.Cross.ios-arm64/6.0.11/Sdk/../tools/mono-aot-cross execution started with arguments: --aot=mtriple=arm64-ios,data-outfile=obj/iPhone/Debug/net6.0-ios/ios-arm64/nativelibraries/aot-output/arm64/System.Drawing.Common.aotdata,static,asmonly,direct-icalls,full,readonly-value=ObjCRuntime.Runtime.Arch=i4/0,soft-debug,dwarfdebug,no-direct-calls,outfile=obj/iPhone/Debug/net6.0-ios/ios-arm64/nativelibraries/aot-output/arm64/System.Drawing.Common.dll.s --aot= --debug -O=gsharedvt /Users/salman/Projects/osu-framework/SampleGame.iOS/obj/iPhone/Debug/net6.0-ios/ios-arm64/linked/System.Drawing.Common.dll
        
0>/usr/local/share/dotnet/packs/Microsoft.iOS.Sdk/16.0.527/targets/Xamarin.Shared.Sdk.targets(1003,3): Error  : Failed to AOT compile SharpGen.Runtime.dll, the AOT compiler exited with code 134
0>Tool /usr/local/share/dotnet/packs/Microsoft.NETCore.App.Runtime.AOT.osx-x64.Cross.ios-arm64/6.0.11/Sdk/../tools/mono-aot-cross execution started with arguments: --aot=mtriple=arm64-ios,data-outfile=obj/iPhone/Debug/net6.0-ios/ios-arm64/nativelibraries/aot-output/arm64/System.Security.Cryptography.Pkcs.aotdata,static,asmonly,direct-icalls,full,readonly-value=ObjCRuntime.Runtime.Arch=i4/0,soft-debug,dwarfdebug,no-direct-calls,outfile=obj/iPhone/Debug/net6.0-ios/ios-arm64/nativelibraries/aot-output/arm64/System.Security.Cryptography.Pkcs.dll.s --aot= --debug -O=gsharedvt /Users/salman/Projects/osu-framework/SampleGame.iOS/obj/iPhone/Debug/net6.0-ios/ios-arm64/linked/System.Security.Cryptography.Pkcs.dll
        
0>Tool /usr/local/share/dotnet/packs/Microsoft.NETCore.App.Runtime.AOT.osx-x64.Cross.ios-arm64/6.0.11/Sdk/../tools/mono-aot-cross execution finished (exit code = 134).
        
0>Mono Ahead of Time compiler - compiling assembly /Users/salman/Projects/osu-framework/SampleGame.iOS/obj/iPhone/Debug/net6.0-ios/ios-arm64/linked/SharpGen.Runtime.COM.dll
AOTID A48F61D9-2494-6DF6-EBD4-7824B1850F51
* Assertion at /Users/runner/work/1/s/src/mono/mono/metadata/custom-attrs.c:599, condition `out_obj' not met


0>/usr/local/share/dotnet/packs/Microsoft.iOS.Sdk/16.0.527/targets/Xamarin.Shared.Sdk.targets(1003,3): Error  : Failed to AOT compile SharpGen.Runtime.COM.dll, the AOT compiler exited with code 134

That's a major blocker from using Veldrid on iOS platforms, and there's no way to exclude such libraries manually as far as I've seen.

[frenzibyte]

I've worked around this by placing stub assemblies for the affected libraries using the following:

  <Target Name="CopyStubAssemblies" BeforeTargets="_AOTCompile">
    <Copy SourceFiles="@(StubFiles)" DestinationFolder="obj/$(Platform)/$(Configuration)/$(TargetFramework)/$(RuntimeIdentifier)/linked/" />
  </Target>