BindGen-CS

BindGen-CS is a code generation toolkit for native interop, focused on generating C# bindings from C/C++ headers and generating C bridges from C++ APIs. With proper configurations, this code-generation tool allows you to output a SINGLE-FILE bindings.

This project is a modified derivative of a fork of HexaGen. It has been adapted and extended with a focus on a streamlined, single-file-oriented workflow. Contributions are welcome ⭐. Feel free to open issues or submit pull requests if you encounter problems or have suggestions.

Features

• C# binding generation for C-style native APIs
• C++ to C bridge generation (BGCS.Cpp2C)
• Config-driven generation with JSON config composition (BaseConfig)
• Function-table and direct import modes for generated bindings
• Optional standalone runtime source generation (Runtime.cs)
• Single-file merge auto-removes split generated files
• Configurable naming, filtering, and mapping pipelines
• Runtime support libraries for generated interop code

Requirements

• .NET SDK 9.0
• Clang/LibClang available in the environment (for parsing C/C++ headers)
• A C/C++ toolchain for validating generated native bridge outputs when needed

Documentation

Quick Start Cases

BGCS (C/C++ header -> C# bindings):

using BGCS;

var config = CsCodeGeneratorConfig.Load("config.json");
var generator = new CsCodeGenerator(config);
bool ok = generator.Generate("headers/api.h", "Output");

Cpp2C (C++ header -> C bridge):

using BGCS.Cpp2C;

var config = Cpp2CGeneratorConfig.Load("config.json");
var generator = new Cpp2CCodeGenerator(config);
generator.Generate("include/demo.hpp", "Output");

A basic start up with configuration file:

{
  "BaseConfig": {
    "Url": "file://config.base.json"
  }
  "ApiName": "MyApi",
  "Namespace": "My.Generated",
  "LibName": "mylib",
  "ImportType": "DllImport",
  "EntryFiles": ["headers/api.h"],
  "allowedHeaders": ["headers/api.h"]
}

using BGCS;

var cfg = new CsCodeGeneratorConfig("config.json");
var gen = new CsCodeGenerator(cfg);
bool ok = gen.Generate("headers/api.h", "Output");

Single-file/runtime behavior summary:

• When MergeGeneratedFilesToSingleFile = true, BGCS merges output into SingleFileOutputName and automatically removes split generated files.
• Runtime source generation is explicit:
  • GenerateRuntimeSource = true: generate standalone Runtime.cs in output root.
  • GenerateRuntimeSource = false: do not generate runtime source.
• Generated bindings always use using BGCS.Runtime; and runtime namespace remains BGCS.Runtime.
• If your project already references external BGCS.Runtime, define compile symbol BGCS_RUNTIME_EXTERNAL to exclude generated runtime source and avoid duplicate type declarations.

Full Documents

• Basic API Usage
• Config Settings for BGCS
• Config Settings for Cpp2C

Project Layout

• src/BGCS - Main C# binding generator
• src/BGCS.Cpp2C - C++ to C bridge generator
• src/BGCS.Runtime - Runtime support for generated bindings
• src/BGCS.CppAst - C/C++ AST parsing layer
• tests/* - Unit/integration/regression test projects
• demo/* - Local demo apps for manual generation validation

License

BindGen-CS is licensed under the MIT License. See LICENSE.