Vidl - Simple IDL generator for C++

Vidl is a lightweight Python script that parses C++ header files for // VIDL_GENERATE comments and generates corresponding C++ structs and a command handler. It is useful for creating type-safe command buffers or RPC mechanisms.

NOTE: Vidl is vide coded, without too much code oversight. Intended as a throwaway tool of sorts. Use at your own risk.

What does Vidl do?

Vidl turns this:

// VIDL_GENERATE
uint32_t FunctionTest1(
    uint32_t x,
    uint32_t y,
    bool a,
    TestEnum enum
);

into:

struct VIDL_FunctionTest1
{
    static constexpr uint64_t kMagic = 0x68CE8796;
    uint64_t MAGIC = kMagic;
    uint32_t x;
    uint32_t y;
    bool a;
    TestEnum enum_;

    VIDL_FunctionTest1() = default;

    VIDL_FunctionTest1(uint32_t _x, uint32_t _y, bool _a, TestEnum _enum_)
        : x(_x), y(_y), a(_a), enum_(_enum_) {}
};

along with a corresponding handler:

struct VIDLHandler
{
    virtual void Handle_FunctionTest1( VIDL_FunctionTest1* cmd ) { (void) cmd; };

    virtual void HandleCmd( void* cmd )
    {
        uint64_t magic = *(uint64_t*)cmd;
        switch ( magic )
        {
        case 0x68CE8796:
            Handle_FunctionTest1( (VIDL_FunctionTest1*) cmd );
            break;
        }
    }
};

Usage

You can use vidl.py directly to generate code from a source file.

python vidl.py tests/test.cpp
python vidl.py tests/test.cpp output.h

Prerequisites For Building

• Python 3
• CMake (3.10 or higher)
• A C++ Compiler (MSVC, GCC, Clang)

Running Unit Tests

To verify that the vidl.py generator is working correctly, you can run the provided Python test suite:

# Run tests using the unittest module
python test.py

Building with CMake

The project includes a CMakeLists.txt that automates the generation and compilation process.

mkdir build
cd build
cmake ..
cmake --build .

This command will:

• Locate the Python interpreter.
• Run vidl.py to generate vidl_generated.h from tests/test.cpp.
• Compile main.cpp (which includes the generated header).
• Link everything into an executable named MyGame and a test suite named VidlTest.

Run the executable:

On Windows:

.\Debug\MyGame.exe

On Linux/macOS:

./MyGame

Run the C++ Integration Tests:

The CMake build also generates a VidlTest executable that verifies the runtime behavior of the generated code.

On Windows:

.\Debug\VidlTest.exe

On Linux/macOS:

./VidlTest

Expected output for MyGame:

Successfully instantiated VIDL_FunctionTest0 with magic: 0x610d85fb

Expected output for VidlTest:

Running C++ Integration Tests...

[Test 1] Constructors

[Test 2] Polymorphism & Dispatch

Handle_FunctionTest0 called with x=10

[Test 3] Pointers

Handle_FunctionTest2 called with pointer checking

[Test 4] Unique Magic Numbers

Magic 0: 610d85fb

Magic 1: 68ce8796

All C++ Tests Passed!