JUCE/modules/juce_audio_plugin_client/LV2/juce_LV2ManifestHelper.cpp

/*
  ==============================================================================

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
   copyrightable work, you agree to the terms of the JUCE End User Licence
   Agreement, and all incorporated terms including the JUCE Privacy Policy and
   the JUCE Website Terms of Service, as applicable, which will bind you. If you
   do not agree to the terms of these agreements, we will not license the JUCE
   framework to you, and you must discontinue the installation or download
   process and cease use of the JUCE framework.

   JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/

   Or:

   You may also use this code under the terms of the AGPLv3:
   https://www.gnu.org/licenses/agpl-3.0.en.html

   THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
   WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.

  ==============================================================================
*/

#include <cstdint>
#include <cstdio>
#include <cstring>
#include <vector>

#ifdef _WIN32
 #undef UNICODE
 #undef _UNICODE

 #define UNICODE 1
 #define _UNICODE 1

 #include <windows.h>
 #include <tchar.h>
 HMODULE dlopen (const TCHAR* filename, int) { return LoadLibrary (filename); }
 FARPROC dlsym (HMODULE handle, const char* name) { return GetProcAddress (handle, name); }
 static void printError()
 {
     constexpr DWORD numElements = 256;
     TCHAR messageBuffer[numElements]{};

     FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
                    nullptr,
                    GetLastError(),
                    MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
                    messageBuffer,
                    numElements - 1,
                    nullptr);

     _tprintf (_T ("%s"), messageBuffer);
 }

 enum { RTLD_LAZY = 0 };

 class ArgList
 {
 public:
     ArgList (int, const char**) {}
     ArgList (const ArgList&) = delete;
     ArgList (ArgList&&) = delete;
     ArgList& operator= (const ArgList&) = delete;
     ArgList& operator= (ArgList&&) = delete;
     ~ArgList() { LocalFree (argv); }

     LPWSTR get (int i) const { return argv[i]; }

     int size() const { return argc; }

 private:
     int argc = 0;
     LPWSTR* argv = CommandLineToArgvW (GetCommandLineW(), &argc);
 };

 static std::vector<char> toUTF8 (const TCHAR* str)
 {
     const auto numBytes = WideCharToMultiByte (CP_UTF8, 0, str, -1, nullptr, 0, nullptr, nullptr);
     std::vector<char> result (numBytes);
     WideCharToMultiByte (CP_UTF8, 0, str, -1, result.data(), static_cast<int> (result.size()), nullptr, nullptr);
     return result;
 }

#else
 #include <dlfcn.h>
 static void printError() { printf ("%s\n", dlerror()); }
 class ArgList
 {
 public:
     ArgList (int argcIn, const char** argvIn) : argc (argcIn), argv (argvIn) {}
     ArgList (const ArgList&) = delete;
     ArgList (ArgList&&) = delete;
     ArgList& operator= (const ArgList&) = delete;
     ArgList& operator= (ArgList&&) = delete;
     ~ArgList() = default;

     const char* get (int i) const { return argv[i]; }

     int size() const { return argc; }

 private:
     int argc = 0;
     const char** argv = nullptr;
 };

 static std::vector<char> toUTF8 (const char* str) { return std::vector<char> (str, str + std::strlen (str) + 1); }
#endif

// Replicating part of the LV2 header here so that we don't have to set up any
// custom include paths for this file.
// Normally this would be a bad idea, but the LV2 API has to keep these definitions
// in order to remain backwards-compatible.

extern "C"
{
    typedef struct LV2_Descriptor
    {
        const void* a;
        const void* b;
        const void* c;
        const void* d;
        const void* e;
        const void* f;
        const void* g;
        const void* (*extension_data)(const char* uri);
    } LV2_Descriptor;
}

int main (int argc, const char** argv)
{
    const ArgList argList { argc, argv };

    if (argList.size() != 2)
        return 1;

    const auto* libraryPath = argList.get (1);

    struct RecallFeature
    {
        int (*doRecall) (const char*);
    };

    if (auto* handle = dlopen (libraryPath, RTLD_LAZY))
    {
        if (auto* getDescriptor = reinterpret_cast<const LV2_Descriptor* (*) (uint32_t)> (dlsym (handle, "lv2_descriptor")))
        {
            if (auto* descriptor = getDescriptor (0))
            {
                if (auto* extensionData = descriptor->extension_data)
                {
                    if (auto* recallFeature = reinterpret_cast<const RecallFeature*> (extensionData ("https://lv2-extensions.juce.com/turtle_recall")))
                    {
                        if (auto* doRecall = recallFeature->doRecall)
                        {
                            const auto converted = toUTF8 (libraryPath);
                            return doRecall (converted.data());
                        }
                    }
                }
            }
        }
    }
    else
    {
        printError();
    }

    return 1;
}