Wireloom.Dds.Generator 0.3.0

Wireloom.Dds.Generator

Wireloom.Dds.Generator is a Roslyn source generator and MSBuild integration for generating C# types from the RTI Connext DDS IDL subset. Add it to a .NET project that owns DDS data contracts; the package generates source during the normal build and does not invoke Java, native tooling, or rtiddsgen.

This is a preview package. Support is feature-specific and evidence-driven; successful compilation of one IDL shape is not a blanket claim of RTI or wire compatibility.

Install

Add the generator and the RTI runtime explicitly. The generator package does not add Rti.ConnextDds transitively because the application owns its runtime version and configuration.

<ItemGroup>
  <PackageReference Include="Rti.ConnextDds" Version="7.3.1" />
  <PackageReference Include="Wireloom.Dds.Generator"
                    Version="0.2.0"
                    PrivateAssets="all" />
</ItemGroup>

The retained oracle corpus was generated with RTI Connext DDS 7.7.0 / rtiddsgen 4.7.0. The compatibility floor is RTI 7.3.1 and later because 7.3.1 ships the same rtiddsgen version. The consumer project must resolve a compatible Rti.ConnextDds reference and use C# 12 or later.

Declare an IDL generation root

Declare each file that starts generation with a DdsIdl item:

<ItemGroup>
  <DdsIdl Include="Contracts\Telemetry.idl" />
</ItemGroup>

The IDL root can include other files. Included files are tracked inputs and are not independently generated as roots.

module Telemetry {
  struct Sample {
    long id;
    string<64> label;
    sequence<float, 8> values;
  };
};

The generated API follows the IDL module structure. For the example above, the consumer can use the generated Telemetry.Sample data type and, when the selected feature shape has type support, Telemetry.SampleSupport:

var sample = new Telemetry.Sample
{
    Id = 42,
    Label = "temperature",
    Values = [20.5f, 21.0f]
};

var typeSupport = Telemetry.SampleSupport.Instance;

Generated types include the managed data contract and the RTI-specific support surface where the IDL shape is supported: native companions, type support, interpreted plugins, and DynamicType metadata.

Configure includes and preprocessing

Use project properties for defaults shared by roots, or root-item metadata for the project-wide generation batch:

<PropertyGroup>
  <DdsIdlIncludeDirectories>
    $(MSBuildProjectDirectory)\Contracts\Shared
  </DdsIdlIncludeDirectories>
</PropertyGroup>

<ItemGroup>
  <DdsIdl Include="Contracts\Telemetry.idl"
          IncludeDirectories="$(MSBuildProjectDirectory)\Contracts\Telemetry"
          Defines="ENABLE_DIAGNOSTICS;PRODUCT_VARIANT=Enterprise"
          Undefines="LEGACY_LAYOUT"
          Strict="true" />
</ItemGroup>

Supported metadata:

The current compiler combines these settings across all generating roots. It does not provide isolated preprocessing or validation settings per root.

Quoted relative includes resolve from the including file's directory. Angle includes use the configured include directories. Keep a shared file as an included input unless it is intentionally a separate generation root.

Inspect generated source

Roslyn exposes generated documents through the IDE. To also write physical generated files under obj, use the standard compiler options:

<PropertyGroup>
  <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
  <CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)generated</CompilerGeneratedFilesOutputPath>
</PropertyGroup>

The package does not create a separate command-line output directory or run a pre-generation step.

Diagnostics

Diagnostics are owned by the generator and use the original IDL/include location where one is available. Configure severity through standard .editorconfig entries, for example:

dotnet_diagnostic.DDSG0001.severity = error

Supported boundary

The current corpus exercises modules, structs, nested declarations, aliases, enums, unions, constants, primitive values, narrow and wide strings, bounded strings, sequences, arrays, include graphs, conditional preprocessing, keys, annotations, and extensibility. Several of these are supported only for the specific shapes covered by the retained RTI oracle evidence.

The package intentionally rejects unsupported declarations and directives instead of emitting an incomplete contract. Before adopting a feature, check the feature coverage matrix and the corpus rules.

The compatibility corpus compares source-generation behavior and generated C# shape. It does not automatically prove serialization-byte equivalence, live DDS behavior, or C++ interoperability.

What this package does not do

• It does not provide the RTI DDS runtime, transport, or serialization engine.
• It does not invoke or forward arbitrary arguments to rtiddsgen.
• It does not implicitly generate every .idl file in a project; roots are explicit DdsIdl items.
• It does not promise complete Connext IDL coverage or universal drop-in compatibility with RTI-generated C#.
• It does not silently omit unsupported declarations.

Troubleshooting

The generator reports DDSG0003

Add the runtime package to the consuming project. The generator package is private build tooling; the application must reference Rti.ConnextDds itself.

An include cannot be resolved

Check whether the include is quoted or angle-bracketed. Quoted includes are resolved relative to the including file. For angle includes, add the directory to DdsIdlIncludeDirectories or the root's IncludeDirectories metadata.

A shared file is generated twice

Keep the shared file as an included input and declare only the intended root in DdsIdl. A physical IDL file should normally have one generation identity per consumer project.

A feature is rejected

Read the source-located DDSG0001 diagnostic, then check the feature coverage matrix. Rejection is intentional when the current managed compiler does not have evidence for a safe generated contract.

Learn more

• Wireloom repository
• Architecture overview
• Corpus compliance tests
• Package integration test

RTI-generated reference material in the repository is retained under the applicable RTI license and review rules. It is not redistributed by this NuGet package.