Source generator for options validation leads to trimming warnings/errors in AOT

[rstropek]

Description

If you follow the guide in the docs, you get trimming warnings related to data annotations. In my own program, these warnings lead to errors.

Reproduction Steps

• Create a new app: dotnet new webapiaot

• Add NuGet.config:

  <?xml version="1.0" encoding="utf-8"?>
  <configuration>
    <packageSources>
      <add key="dotnet8" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet8/nuget/v3/index.json" />
    </packageSources>
  </configuration>

• Add nightly package references in .csproj:

  <ItemGroup>
    <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="8.0.0-rc.2.23466.4" />
    <PackageReference Include="Microsoft.Extensions.Options" Version="8.0.0-rc.2.23466.4" />
  </ItemGroup>

• Copy sample code from the docs into your Program.cs

• Build app: dotnet run build

Expected behavior

Program compiles without error and warnings.

Actual behavior

You get a bunch of trimming warnings related to data annotations:

/tmp/optionsvalidator/Microsoft.Extensions.Options.SourceGeneration/Microsoft.Extensions.Options.Generators.OptionsValidatorGenerator/Validators.g.cs(50): Trim analysis warning IL2026: SecondValidatorNoNamespace.Validate(String,SecondModelNoNamespace): Using member 'System.ComponentModel.DataAnnotations.ValidationContext.ValidationContext(Object)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. The Type of instance cannot be statically discovered and the Type's properties can be trimmed. [/tmp/optionsvalidator/optionsvalidator.csproj]
/tmp/optionsvalidator/Microsoft.Extensions.Options.SourceGeneration/Microsoft.Extensions.Options.Generators.OptionsValidatorGenerator/Validators.g.cs(17): Trim analysis warning IL2026: FirstValidatorNoNamespace.Validate(String,FirstModelNoNamespace): Using member 'System.ComponentModel.DataAnnotations.ValidationContext.ValidationContext(Object)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. The Type of instance cannot be statically discovered and the Type's properties can be trimmed. [/tmp/optionsvalidator/optionsvalidator.csproj]
/tmp/optionsvalidator/Microsoft.Extensions.Options.SourceGeneration/Microsoft.Extensions.Options.Generators.OptionsValidatorGenerator/Validators.g.cs(73): Trim analysis warning IL2026: __OptionValidationStaticInstances.<Validators_g>F1872690B80E3D4EBF0BB4EEFEFFBD255387F31D123553B47D3D3ED7D782424E7____Attributes..cctor(): Using member 'System.ComponentModel.DataAnnotations.MinLengthAttribute.MinLengthAttribute(Int32)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. Uses reflection to get the 'Count' property on types that don't implement ICollection. This 'Count' property may be trimmed. Ensure it is preserved. [/tmp/optionsvalidator/optionsvalidator.csproj]

Regression?

No response

Known Workarounds

No response

Configuration

• Runtime: Microsoft.AspNetCore.App 8.0.0-rc.1.23421.29
• SDK: 8.0.100-rc.1.23455.8
• OS: Linux

Other information

No response

Tagging subscribers to this area: @dotnet/area-system-componentmodel-dataannotations
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

If you follow the guide in the docs, you get trimming warnings related to data annotations. In my own program, these warnings lead to errors.

Reproduction Steps

• Create a new app: dotnet new webapiaot

• Add NuGet.config:

  <?xml version="1.0" encoding="utf-8"?>
  <configuration>
    <packageSources>
      <add key="dotnet8" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet8/nuget/v3/index.json" />
    </packageSources>
  </configuration>

• Add nightly package references in .csproj:

  <ItemGroup>
    <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="8.0.0-rc.2.23466.4" />
    <PackageReference Include="Microsoft.Extensions.Options" Version="8.0.0-rc.2.23466.4" />
  </ItemGroup>

• Copy sample code from the docs into your Program.cs

• Build app: dotnet run build

Expected behavior

Program compiles without error and warnings.

Actual behavior

You get a bunch of trimming warnings related to data annotations:

/tmp/optionsvalidator/Microsoft.Extensions.Options.SourceGeneration/Microsoft.Extensions.Options.Generators.OptionsValidatorGenerator/Validators.g.cs(50): Trim analysis warning IL2026: SecondValidatorNoNamespace.Validate(String,SecondModelNoNamespace): Using member 'System.ComponentModel.DataAnnotations.ValidationContext.ValidationContext(Object)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. The Type of instance cannot be statically discovered and the Type's properties can be trimmed. [/tmp/optionsvalidator/optionsvalidator.csproj]
/tmp/optionsvalidator/Microsoft.Extensions.Options.SourceGeneration/Microsoft.Extensions.Options.Generators.OptionsValidatorGenerator/Validators.g.cs(17): Trim analysis warning IL2026: FirstValidatorNoNamespace.Validate(String,FirstModelNoNamespace): Using member 'System.ComponentModel.DataAnnotations.ValidationContext.ValidationContext(Object)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. The Type of instance cannot be statically discovered and the Type's properties can be trimmed. [/tmp/optionsvalidator/optionsvalidator.csproj]
/tmp/optionsvalidator/Microsoft.Extensions.Options.SourceGeneration/Microsoft.Extensions.Options.Generators.OptionsValidatorGenerator/Validators.g.cs(73): Trim analysis warning IL2026: __OptionValidationStaticInstances.<Validators_g>F1872690B80E3D4EBF0BB4EEFEFFBD255387F31D123553B47D3D3ED7D782424E7____Attributes..cctor(): Using member 'System.ComponentModel.DataAnnotations.MinLengthAttribute.MinLengthAttribute(Int32)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. Uses reflection to get the 'Count' property on types that don't implement ICollection. This 'Count' property may be trimmed. Ensure it is preserved. [/tmp/optionsvalidator/optionsvalidator.csproj]

Regression?

No response

Known Workarounds

No response

Configuration

• Runtime: Microsoft.AspNetCore.App 8.0.0-rc.1.23421.29
• SDK: 8.0.100-rc.1.23455.8
• OS: Linux

Other information

No response

Author:	rstropek
Assignees:	-
Labels:	area-System.ComponentModel.DataAnnotations
Milestone:	-

[rstropek]

Did further testing. The functionality seems to work. So the problem is the warnings.

Tagging subscribers to this area: @dotnet/area-extensions-options
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

If you follow the guide in the docs, you get trimming warnings related to data annotations. In my own program, these warnings lead to errors.

Reproduction Steps

• Create a new app: dotnet new webapiaot

• Add NuGet.config:

  <?xml version="1.0" encoding="utf-8"?>
  <configuration>
    <packageSources>
      <add key="dotnet8" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet8/nuget/v3/index.json" />
    </packageSources>
  </configuration>

• Add nightly package references in .csproj:

  <ItemGroup>
    <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="8.0.0-rc.2.23466.4" />
    <PackageReference Include="Microsoft.Extensions.Options" Version="8.0.0-rc.2.23466.4" />
  </ItemGroup>

• Copy sample code from the docs into your Program.cs

• Build app: dotnet run build

Expected behavior

Program compiles without error and warnings.

Actual behavior

You get a bunch of trimming warnings related to data annotations:

/tmp/optionsvalidator/Microsoft.Extensions.Options.SourceGeneration/Microsoft.Extensions.Options.Generators.OptionsValidatorGenerator/Validators.g.cs(50): Trim analysis warning IL2026: SecondValidatorNoNamespace.Validate(String,SecondModelNoNamespace): Using member 'System.ComponentModel.DataAnnotations.ValidationContext.ValidationContext(Object)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. The Type of instance cannot be statically discovered and the Type's properties can be trimmed. [/tmp/optionsvalidator/optionsvalidator.csproj]
/tmp/optionsvalidator/Microsoft.Extensions.Options.SourceGeneration/Microsoft.Extensions.Options.Generators.OptionsValidatorGenerator/Validators.g.cs(17): Trim analysis warning IL2026: FirstValidatorNoNamespace.Validate(String,FirstModelNoNamespace): Using member 'System.ComponentModel.DataAnnotations.ValidationContext.ValidationContext(Object)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. The Type of instance cannot be statically discovered and the Type's properties can be trimmed. [/tmp/optionsvalidator/optionsvalidator.csproj]
/tmp/optionsvalidator/Microsoft.Extensions.Options.SourceGeneration/Microsoft.Extensions.Options.Generators.OptionsValidatorGenerator/Validators.g.cs(73): Trim analysis warning IL2026: __OptionValidationStaticInstances.<Validators_g>F1872690B80E3D4EBF0BB4EEFEFFBD255387F31D123553B47D3D3ED7D782424E7____Attributes..cctor(): Using member 'System.ComponentModel.DataAnnotations.MinLengthAttribute.MinLengthAttribute(Int32)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. Uses reflection to get the 'Count' property on types that don't implement ICollection. This 'Count' property may be trimmed. Ensure it is preserved. [/tmp/optionsvalidator/optionsvalidator.csproj]

Regression?

No response

Known Workarounds

No response

Configuration

• Runtime: Microsoft.AspNetCore.App 8.0.0-rc.1.23421.29
• SDK: 8.0.100-rc.1.23455.8
• OS: Linux

Other information

No response

Author:	rstropek
Assignees:	tarekgh
Labels:	untriaged, area-Extensions-Options
Milestone:	8.0.0

[tarekgh]

Thanks @rstropek. I will look at that.

[tarekgh]

@rstropek I am trying the exact steps, but I am getting the warnings:

C:\Temp\OptionsTrimming\Program.cs(55,6): warning IL2026: Using member 'System.ComponentModel.DataAnnotations.MinLengthAttribute.MinLengthAttribute(Int32)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. Uses 
 reflection to get the 'Count' property on types that don't implement ICollection. This 'Count' property may be trimmed. Ensure it is preserved. [C:\Temp\OptionsTrimming\OptionsTrimming.csproj]
C:\Temp\OptionsTrimming\Program.cs(43,6): warning IL2026: Using member 'System.ComponentModel.DataAnnotations.MinLengthAttribute.MinLengthAttribute(Int32)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. Uses 
 reflection to get the 'Count' property on types that don't implement ICollection. This 'Count' property may be trimmed. Ensure it is preserved. [C:\Temp\OptionsTrimming\OptionsTrimming.csproj]

these are expected and for this specific example which has the MinLengthAttribute on a string property, it is safe to disable this warning because no reflection will be executed at those cases.

Now, I am trying to get the same failures you are getting on the generated code Validators.g.cs. Somehow it is not happening on my repo. Is there anything else you missed in the repro? I'll keep trying.

[tarekgh]

@rstropek never mind, I can see the warnings now when publishing.