linkCppImplStubs function

void linkCppImplStubs(List<ModuleInfo> moduleInfos, { String baseDir = '.', })

For each NativeImpl.cpp module that targets Android or Linux, creates a starter src/Hybrid${Module}.cpp stub if one doesn't already exist.

Only android/linux modules need this in src/ — Windows-only cpp modules use windows/CMakeLists.txt and their stub belongs in windows/src/. The check uses ModuleInfo.isNativeCpp (narrow: android|linux) rather than ModuleInfo.isCpp (broad: any platform) to avoid creating a HybridBenchmark.cpp stub for a module that is only C++ on Windows.

Implementation

void linkCppImplStubs(List<ModuleInfo> moduleInfos, {String baseDir = '.'}) {
  for (final m in moduleInfos.where((m) => m.isNativeCpp)) {
    final className = _toPascalCase(m.lib);
    final stubFile = File(p.join(baseDir, 'src', 'Hybrid$className.cpp'));
    if (stubFile.existsSync()) continue; // never overwrite user code
    stubFile.writeAsStringSync(
      '// Hybrid$className — NativeImpl.cpp implementation.\n'
      '// Generated by nitrogen link. Fill in the method bodies.\n'
      '#include "../lib/src/generated/cpp/${m.lib}.native.g.h"\n'
      '\n'
      '#include <string>\n'
      '\n'
      'class Hybrid${className}Impl final : public Hybrid$className {\n'
      'public:\n'
      '    // TODO: implement all pure-virtual methods declared in Hybrid$className\n'
      '};\n'
      '\n'
      'static Hybrid${className}Impl g_impl;\n'
      '\n'
      '// Auto-register on shared library load — no manual init call needed.\n'
      '#if defined(_WIN32)\n'
      '// MSVC lacks __attribute__((constructor)); use a static object instead.\n'
      'namespace {\n'
      '  struct _AutoRegister {\n'
      '    _AutoRegister() { ${m.lib}_register_impl(&g_impl); }\n'
      '  };\n'
      '  _AutoRegister _auto_register_instance;\n'
      '}\n'
      '#else\n'
      '__attribute__((constructor))\n'
      'static void ${m.lib}_auto_register() {\n'
      '    ${m.lib}_register_impl(&g_impl);\n'
      '}\n'
      '#endif\n',
    );
  }
}