ThisAssembly.Resources causes IL3000 warnings when publishing for AOT compilation in .NET 8

[atifaziz]

Describe the Bug

Using ThisAssembly.Resources to access resources produces IL3000 warning when published for AOT compilation using .NET 8. This is caused by the following code in EmbeddedResource that gets embedded into the user project:

ThisAssembly/src/EmbeddedResource.cs

Line 8 in 0e5f0c4

static readonly string baseDir = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location) ?? "";

It looks like that this is done to give an external file preference over the embedded resource (which is a surprising behaviour that should really be opted into via some option):

ThisAssembly/src/EmbeddedResource.cs

Lines 27 to 29 in 0e5f0c4

	var filePath = Path.Combine(baseDir, Path.GetFileName(relativePath));
	if (File.Exists(filePath))
	return File.OpenRead(filePath);

Steps to Reproduce

These steps assume .NET SDK 8 is in use.

1. Run dotnet new console to create a new console project
2. Run dotnet add package ThisAssembly.Resources to add a reference to the ThisAssembly.Resources package.
3. Add a resource to the project.
4. Add the <PublishAot>true</PublishAot> property to the project file.
5. Publish with dotnet publish -c Release -o dist

During compilation, the following warning is emitted:

ThisAssembly.Resource\ThisAssembly.ResourcesGenerator\ThisAssembly.Resources.EmbeddedResource.cs(8): warning IL3000: EmbeddedResource..cctor(): 'System.Reflection.Assembly.Location.get' always returns an empty string for assemblies embedded in a single-file app. If the path to the app directory is needed, consider calling 'System.AppContext.BaseDirectory'.

A fully working example can be found in ThisAssemblyApp.zip.

Expected Behavior

• Expected no warnings during dotnet publish when doing AOT compilation.
• Embedded resources are unaffected by files on disk.
  Of course, if the user project is treating warnings as errors then the compilation entirely fails. It is awkward, if not possible impossible, to isolate the suppression of IL3000 to just the generated code (since it doesn't technically exist on disk).

Version Info

Using version 1.41 of the package.

Additional Info

Running dotnet --info prints:

.NET SDK:
 Version:           8.0.100
 Commit:            57efcf1350
 Workload version:  8.0.100-manifests.6a1e483a

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.22621
 OS Platform: Windows
 RID:         win-x64
 Base Path:   C:\Program Files\dotnet\sdk\8.0.100\

.NET workloads installed:
 Workload version: 8.0.100-manifests.6a1e483a
 [wasm-tools]
   Installation Source: VS 17.8.34330.188
   Manifest Version:    8.0.0/8.0.100
   Manifest Path:       C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.workload.mono.toolchain.current\8.0.0\WorkloadManifest.json
   Install Type:              Msi


Host:
  Version:      8.0.0
  Architecture: x64
  Commit:       5535e31a71

.NET SDKs installed:
  3.1.426 [C:\Program Files\dotnet\sdk]
  5.0.416 [C:\Program Files\dotnet\sdk]
  6.0.417 [C:\Program Files\dotnet\sdk]
  7.0.203 [C:\Program Files\dotnet\sdk]
  7.0.404 [C:\Program Files\dotnet\sdk]
  8.0.100 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
  x86   [C:\Program Files (x86)\dotnet]
    registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
  Not set

global.json file:
  T:\ThisAssemblyApp\global.json

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download

[kzu]

Shipped in https://github.com/devlooped/ThisAssembly/releases/tag/v1.4.3