Overview

This library helps developers to generate dart:ffi bindings. You can contribute at github.com/dart-interop/ffi_tool.

The advantages over handwritten dart:ffi code are:

Less boilerplate
- You don't have to define multiple types for each C function.
- You can require the generated code to use cupertino_ffi reference counting methods (arcPush, arcPop, arcReturn).
Possibly better readability
- You can use the original identifiers (such as *size_t instead of Pointer<IntPtr>).
- You can define aliases, e.g. const len_t = 'int32';.
- You can configure how a shared library is loaded at runtime.

Getting started

1.Add dependency

In 'pubspec.yaml':

dev_dependencies:
  ffi_tool: ^0.3.0

Run pub get.

2.Write a script

Create 'tool/generate_example.dart'.

Example

import 'package:ffi_tool/c.dart';
import 'dart:io';

void main() {
  // Generates source code and runs 'dartfmt'
  generateFile(File('lib/src/generated.dart'), library);
}

final library = const Library.platformAware(
  // Configure, how the dynamic library should be loaded depending on the platform
  dynamicLibraryConfig: DynamicLibraryConfig(
      windows: DynamicLibraryPlatformConfig.open('path/to/library.dll'),
      android: DynamicLibraryPlatformConfig.open('path/to/library.so'),
      iOS: DynamicLibraryPlatformConfig.process()),

  // Optional library preamble
  preamble = '// Licensed under MIT license\r\n// AUTOMATICALLY GENERATED. DO NOT EDIT.'
  
  // Optional imports
  importedUris: {
    ImportedUri('package:example/library.dart'),
  },

  /// List of generated functions, structs, and global variables
  elements: <Element>[
    // A definition for a function in C
    Func(
      name: 'Example',
      documentation: 'Takes parameters and does stuff.',
      parameterTypes: ['int32', 'float32', '*void'],
      returnType: 'void',
    ),

    // A definition for a struct in C
    Struct(
      name: 'ExampleStruct',
      fields: [
        StructField(
          name: 'length',
          type: 'size_t',
        ),
      ],
    ),

    // A definition for a global variable in C
    Global(
      name: 'ExampleGlobal',
      type: 'Int32',
    ),
  ],
);

3.Run the script

With Dart SDK:

pub run tool/generate_example.dart

With Flutter SDK:

flutter pub run tool/generate_example.dart

derolf / ffi_tool