net8 regression: cannot build appextensions on iOS without workaround #19037
Labels
bug
If an issue is a bug or a pull request a bug fix
regression
The issue or pull request is a regression
Milestone
Comments
rolfbjarne
added
bug
|
I can reproduce this. |
rolfbjarne
added a commit
to rolfbjarne/xamarin-macios
that referenced
this issue
Sep 19, 2023
…ry projects. Fixes xamarin#19037. ILLink doesn't handle library projects the way we need: the library is automatically treated as a root assembly, with the entry point as the root. This doesn't work, because library projects don't have an entry point. In earlier versions of .NET (and Xamarin), we'd solved this by a custom linker step that would manually root everything that needed to be rooted, but that doesn't work anymore because we hit this sanity check in ILLink: > ILLink : error IL1034: Root assembly 'MyExtension, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' does not have entry point. Technically this happens because the library project is configured as a root assembly, where the entry point is the root point (and in that regards the sanity check is rather sane). The best solution would be if we could just treat the library assembly as any other assembly, and manually root it in our custom linker steps - but the custom linker step we have for this kind of rooting will only iterate over types in assemblies that are already marked somehow, and that's not necessarily the case for app extension projects - the end result is that the entire app extension assembly is linked away. A close runner-up as the second best solution is to provide the API that needs to be rooted as an xml file to the linker. This works, but we currently don't have the infrastructure in the code to generate this xml file before running the linker (it would be a rather major undertaking). This work is tentatively scheduled for .NET 9 (xamarin#17693). So I went for the third option: set RootMode="Library" for the library assembly. I'm not sure exactly what that means ILLink will mark, but as long as _anything_ is marked, our custom linker step will run. This seems like an acceptable workaround until we can implement the previous solution. Fixes xamarin#19037.
This was referenced Sep 19, 2023
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Steps to Reproduce
<IsAppExtension>true</IsAppExtension>).Expected Behavior
Build completes ok.
Actual Behavior
Receive a linker error:
I have to add the following Target to the extension project file to make it work:
This was inspired by what I think is a related issue: dotnet/linker#3165
Environment
Only building from the command-line right now (no VS on this Mac); as much version information as possible attached.
Version information
Build Logs
msbuild.binlog.zip
Example Project
Example project where this failure occurs is here: https://github.com/enclave-alistair/dotnet-ios-netextension/tree/without-trimming-workaround
Workaround is applied on
mainof that repo, thewithout-trimming-workaroundbranch fails to build.The text was updated successfully, but these errors were encountered: