Move plugin bridge helper functions to utils.h

meson.build

@@ -62,6 +62,7 @@ shared_library(
     'src/common/serialization.cpp',
     'src/plugin/plugin.cpp',
     'src/plugin/plugin-bridge.cpp',
+    'src/plugin/utils.cpp',
     version_header,
   ],
   native : true,

src/plugin/plugin-bridge.cpp

@@ -17,14 +17,9 @@
 #include "plugin-bridge.h"
 
 #include <boost/asio/read_until.hpp>
-#include <boost/dll/runtime_symbol_info.hpp>
-#include <boost/filesystem.hpp>
 #include <boost/process/env.hpp>
 #include <boost/process/io.hpp>
-#include <boost/process/search_path.hpp>
-#include <boost/process/system.hpp>
 #include <iostream>
-#include <random>
 
 #ifdef USE_WINEDBG
 #include <boost/process/start_dir.hpp>
@@ -42,116 +37,12 @@ namespace bp = boost::process;
 // boost::filesystem
 namespace fs = boost::filesystem;
 
-/**
- * Used for generating random identifiers.
- */
-constexpr char alphanumeric_characters[] =
-    "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
-
 intptr_t dispatch_proxy(AEffect*, int, int, intptr_t, void*, float);
 void process_proxy(AEffect*, float**, float**, int);
 void process_replacing_proxy(AEffect*, float**, float**, int);
 void setParameter_proxy(AEffect*, int, float);
 float getParameter_proxy(AEffect*, int);
 
-/**
- * Create a logger prefix based on the unique socket path for easy
- * identification. The socket path contains both the plugin's name and a unique
- * identifier.
- *
- * @param socket_path The path to the socket endpoint in use.
- *
- * @return A prefix string for log messages.
- */
-std::string create_logger_prefix(const fs::path& socket_path);
-
-/**
- * Determine the architecture of a VST plugin (or rather, a .dll file) based on
- * it's header values.
- *
- * See https://docs.microsoft.com/en-us/windows/win32/debug/pe-format for more
- * information on the PE32 format.
- *
- * @param plugin_path The path to the .dll file we're going to check.
- *
- * @return The detected architecture.
- * @throw std::runtime_error If the file is not a .dll file.
- */
-PluginArchitecture find_vst_architecture(fs::path);
-
-/**
- * Finds the Wine VST hsot (either `yabridge-host.exe` or `yabridge-host.exe`
- * depending on the plugin). For this we will search in two places:
- *
- *   1. Alongside libyabridge.so if the file got symlinked. This is useful
- *      when developing, as you can simply symlink the the libyabridge.so
- *      file in the build directory without having to install anything to
- *      /usr.
- *   2. In the regular search path.
- *
- * @param plugin_arch The architecture of the plugin, either 64-bit or 32-bit.
- *   Used to determine which host application to use, if available.
- *
- * @return The a path to the VST host, if found.
- * @throw std::runtime_error If the Wine VST host could not be found.
- */
-fs::path find_vst_host(PluginArchitecture plugin_arch);
-
-/**
- * Find the VST plugin .dll file that corresponds to this copy of
- * `libyabridge.so`. This should be the same as the name of this file but with a
- * `.dll` file extension instead of `.so`. In case this file does not exist and
- * the `.so` file is a symlink, we'll also repeat this check for the file it
- * links to. This is to support the workflow described in issue #3 where you use
- * symlinks to copies of `libyabridge.so`.
- *
- * @return The a path to the accompanying VST plugin .dll file.
- * @throw std::runtime_error If no matching .dll file could be found.
- */
-fs::path find_vst_plugin();
-
-/**
- * Locate the Wine prefix this file is located in, if it is inside of a wine
- * prefix.
- *
- * @return Either the path to the Wine prefix (containing the `drive_c?`
- *   directory), or `std::nullopt` if it is not inside of a wine prefix.
- */
-std::optional<fs::path> find_wineprefix();
-
-/**
- * Generate a unique name for the Unix domain socket endpoint based on the VST
- * plugin's name. This will also generate the parent directory if it does not
- * yet exist since we're using this in the constructor's initializer list.
- *
- * @return A path to a not yet existing Unix domain socket endpoint.
- * @throw std::runtime_error If no matching .dll file could be found.
- */
-fs::path generate_endpoint_name();
-
-/**
- * Return a path to this `.so` file. This can be used to find out from where
- * this link to or copy of `libyabridge.so` was loaded.
- */
-fs::path get_this_file_location();
-
-/**
- * Return the installed Wine version. This is obtained by from `wine --version`
- * and then stripping the `wine-` prefix. This respects the `WINELOADER`
- * environment variable used in the scripts generated by winegcc.
- *
- * This will *not* throw when Wine can not be found, but will instead return
- * '<NOT FOUND>'. This way the user will still get some useful log files.
- */
-std::string get_wine_version();
-
-/**
- * Locate the Wine prefix and set the `WINEPREFIX` environment variable if
- * found. This way it's also possible to run .dll files outside of a Wine prefix
- * using the user's default prefix.
- */
-bp::environment set_wineprefix();
-
 /**
  * Fetch the bridge instance stored in an unused pointer from a VST plugin. This
  * is sadly needed as a workaround to avoid using globals since we need free
@@ -718,227 +609,6 @@ void PluginBridge::async_log_pipe_lines(patched_async_pipe& pipe,
         });
 }
 
-std::string create_logger_prefix(const fs::path& socket_path) {
-    // Use the socket filename as the logger prefix, but strip the `yabridge-`
-    // part since that's redundant
-    std::string socket_name =
-        socket_path.filename().replace_extension().string();
-    const std::string socket_prefix("yabridge-");
-    assert(socket_name.find(socket_prefix) == 0);
-    socket_name = socket_name.substr(socket_prefix.size());
-
-    std::ostringstream prefix;
-    prefix << "[" << socket_name << "] ";
-
-    return prefix.str();
-}
-
-std::optional<fs::path> find_wineprefix() {
-    // Try to locate the Wine prefix the plugin's .dll file is located in by
-    // finding the first parent directory that contains a directory named
-    // `dosdevices`
-    fs::path wineprefix_path = find_vst_plugin();
-    while (wineprefix_path != "") {
-        if (fs::is_directory(wineprefix_path / "dosdevices")) {
-            return wineprefix_path;
-        }
-
-        wineprefix_path = wineprefix_path.parent_path();
-    }
-
-    return std::nullopt;
-}
-
-PluginArchitecture find_vst_architecture(fs::path plugin_path) {
-    std::ifstream file(plugin_path, std::ifstream::binary | std::ifstream::in);
-
-    // The linker will place the offset where the PE signature is placed at the
-    // end of the MS-DOS stub, at offset 0x3c
-    uint32_t pe_signature_offset;
-    file.seekg(0x3c);
-    file.read(reinterpret_cast<char*>(&pe_signature_offset),
-              sizeof(pe_signature_offset));
-
-    // The PE32 signature will be followed by a magic number that indicates the
-    // target architecture of the binary
-    uint32_t pe_signature;
-    uint16_t machine_type;
-    file.seekg(pe_signature_offset);
-    file.read(reinterpret_cast<char*>(&pe_signature), sizeof(pe_signature));
-    file.read(reinterpret_cast<char*>(&machine_type), sizeof(machine_type));
-
-    constexpr char expected_pe_signature[4] = {'P', 'E', '\0', '\0'};
-    if (pe_signature !=
-        *reinterpret_cast<const uint32_t*>(expected_pe_signature)) {
-        throw std::runtime_error("'" + plugin_path.string() +
-                                 "' is not a valid .dll file");
-    }
-
-    // These constants are specified in
-    // https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#machine-types
-    switch (machine_type) {
-        case 0x014c:  // IMAGE_FILE_MACHINE_I386
-            return PluginArchitecture::vst_32;
-            break;
-        case 0x8664:  // IMAGE_FILE_MACHINE_AMD64
-        case 0x0000:  // IMAGE_FILE_MACHINE_UNKNOWN
-            return PluginArchitecture::vst_64;
-            break;
-    }
-
-    // When compiled without optimizations, GCC 9.3 will warn that the function
-    // does not return if we put this in a `default:` case instead.
-    std::ostringstream error_msg;
-    error_msg << "'" << plugin_path
-              << "' is neither a x86 nor a x86_64 PE32 file. Actual "
-                 "architecture: 0x"
-              << std::hex << machine_type;
-    throw std::runtime_error(error_msg.str());
-}
-
-fs::path find_vst_host(PluginArchitecture plugin_arch) {
-    auto host_name = yabridge_wine_host_name;
-    if (plugin_arch == PluginArchitecture::vst_32) {
-        host_name = yabridge_wine_host_name_32bit;
-    }
-
-    fs::path host_path =
-        fs::canonical(get_this_file_location()).remove_filename() / host_name;
-    if (fs::exists(host_path)) {
-        return host_path;
-    }
-
-    // Bosot will return an empty path if the file could not be found in the
-    // search path
-    const fs::path vst_host_path = bp::search_path(host_name);
-    if (vst_host_path == "") {
-        throw std::runtime_error("Could not locate '" + std::string(host_name) +
-                                 "'");
-    }
-
-    return vst_host_path;
-}
-
-fs::path find_vst_plugin() {
-    const fs::path this_plugin_path =
-        "/" / fs::path("/" + get_this_file_location().string());
-
-    fs::path plugin_path(this_plugin_path);
-    plugin_path.replace_extension(".dll");
-    if (fs::exists(plugin_path)) {
-        // Also resolve symlinks here, to support symlinked .dll files
-        return fs::canonical(plugin_path);
-    }
-
-    // In case this files does not exist and our `.so` file is a symlink, we'll
-    // also repeat this check after resolving that symlink to support links to
-    // copies of `libyabridge.so` as described in issue #3
-    fs::path alternative_plugin_path = fs::canonical(this_plugin_path);
-    alternative_plugin_path.replace_extension(".dll");
-    if (fs::exists(alternative_plugin_path)) {
-        return fs::canonical(alternative_plugin_path);
-    }
-
-    // This function is used in the constructor's initializer list so we have to
-    // throw when the path could not be found
-    throw std::runtime_error("'" + plugin_path.string() +
-                             "' does not exist, make sure to rename "
-                             "'libyabridge.so' to match a "
-                             "VST plugin .dll file.");
-}
-
-fs::path generate_endpoint_name() {
-    const auto plugin_name =
-        find_vst_plugin().filename().replace_extension("").string();
-
-    std::random_device random_device;
-    std::mt19937 rng(random_device());
-    fs::path candidate_endpoint;
-    do {
-        std::string random_id;
-        std::sample(
-            alphanumeric_characters,
-            alphanumeric_characters + strlen(alphanumeric_characters) - 1,
-            std::back_inserter(random_id), 8, rng);
-
-        // We'll get rid of the file descriptors immediately after accepting the
-        // sockets, so putting them inside of a subdirectory would only leave
-        // behind an empty directory
-        std::ostringstream socket_name;
-        socket_name << "yabridge-" << plugin_name << "-" << random_id
-                    << ".sock";
-
-        candidate_endpoint = fs::temp_directory_path() / socket_name.str();
-    } while (fs::exists(candidate_endpoint));
-
-    // TODO: Should probably try creating the endpoint right here and catch any
-    //       exceptions since this could technically result in a race condition
-    //       when two instances of yabridge decide to use the same endpoint name
-    //       at the same time
-
-    return candidate_endpoint;
-}
-
-fs::path get_this_file_location() {
-    // HACK: Not sure why, but `boost::dll::this_line_location()` returns a path
-    //       starting with a double slash on some systems. I've seen this happen
-    //       on both Ubuntu 18.04 and 20.04, but not on Arch based distros.
-    //       Under Linux a path starting with two slashes is treated the same as
-    //       a path starting with only a single slash, but Wine will refuse to
-    //       load any files when the path starts with two slashes. Prepending
-    //       `/` to a pad coerces theses two slashes into a single slash.
-    return "/" / boost::dll::this_line_location();
-}
-
-std::string get_wine_version() {
-    // The '*.exe' scripts generated by winegcc allow you to override the binary
-    // used to run Wine, so will will respect this as well
-    std::string wine_command = "wine";
-
-    bp::native_environment env = boost::this_process::environment();
-    if (!env["WINELOADER"].empty()) {
-        wine_command = env.get("WINELOADER");
-    }
-
-    bp::ipstream output;
-    try {
-        const fs::path wine_path = bp::search_path(wine_command);
-        bp::system(wine_path, "--version", bp::std_out = output);
-    } catch (const std::system_error&) {
-        return "<NOT FOUND>";
-    }
-
-    // `wine --version` might contain additional output in certain custom Wine
-    // builds, so we only want to look at the first line
-    std::string version_string;
-    std::getline(output, version_string);
-
-    // Strip the `wine-` prefix from the output, could potentially be absent in
-    // custom Wine builds
-    const std::string version_prefix("wine-");
-    if (version_string.find(version_prefix) == 0) {
-        version_string = version_string.substr(version_prefix.size());
-    }
-
-    return version_string;
-}
-
-bp::environment set_wineprefix() {
-    bp::native_environment env = boost::this_process::environment();
-
-    // Allow the wine prefix to be overridden manually
-    if (!env["WINEPREFIX"].empty()) {
-        return env;
-    }
-
-    const auto wineprefix_path = find_wineprefix();
-    if (wineprefix_path.has_value()) {
-        env["WINEPREFIX"] = wineprefix_path->string();
-    }
-
-    return env;
-}
-
 // The below functions are proxy functions for the methods defined in
 // `Bridge.cpp`
 

src/plugin/plugin-bridge.h

@@ -21,35 +21,12 @@
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/local/stream_protocol.hpp>
 #include <boost/asio/streambuf.hpp>
-#include <boost/process/async_pipe.hpp>
 #include <boost/process/child.hpp>
 #include <mutex>
 #include <thread>
 
 #include "../common/logging.h"
-
+#include "utils.h"
-/**
- * Boost 1.72 was released with a known breaking bug caused by a missing
- * typedef: https://github.com/boostorg/process/issues/116.
- *
- * Luckily this is easy to fix since it's not really possible to downgrade Boost
- * as it would break other applications.
- *
- * Check if this is still needed for other distros after Arch starts packaging
- * Boost 1.73.
- */
-class patched_async_pipe : public boost::process::async_pipe {
-   public:
-    using boost::process::async_pipe::async_pipe;
-
-    typedef typename handle_type::executor_type executor_type;
-};
-
-/**
- * A tag to differentiate between 32 and 64-bit plugins, used to determine which
- * host application to use.
- */
-enum class PluginArchitecture { vst_32, vst_64 };
 
 /**
  * This handles the communication between the Linux native VST plugin and the

src/plugin/utils.cpp

@@ -0,0 +1,259 @@
+// yabridge: a Wine VST bridge
+// Copyright (C) 2020  Robbert van der Helm
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#include "utils.h"
+
+#include <boost/dll/runtime_symbol_info.hpp>
+#include <boost/process/io.hpp>
+#include <boost/process/pipe.hpp>
+#include <boost/process/search_path.hpp>
+#include <boost/process/system.hpp>
+#include <fstream>
+#include <random>
+#include <sstream>
+
+// Generated inside of build directory
+#include <src/common/config/config.h>
+
+namespace bp = boost::process;
+namespace fs = boost::filesystem;
+
+/**
+ * Used for generating random identifiers.
+ */
+constexpr char alphanumeric_characters[] =
+    "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+std::string create_logger_prefix(const fs::path& socket_path) {
+    // Use the socket filename as the logger prefix, but strip the `yabridge-`
+    // part since that's redundant
+    std::string socket_name =
+        socket_path.filename().replace_extension().string();
+    const std::string socket_prefix("yabridge-");
+    assert(socket_name.find(socket_prefix) == 0);
+    socket_name = socket_name.substr(socket_prefix.size());
+
+    std::ostringstream prefix;
+    prefix << "[" << socket_name << "] ";
+
+    return prefix.str();
+}
+
+std::optional<fs::path> find_wineprefix() {
+    // Try to locate the Wine prefix the plugin's .dll file is located in by
+    // finding the first parent directory that contains a directory named
+    // `dosdevices`
+    fs::path wineprefix_path = find_vst_plugin();
+    while (wineprefix_path != "") {
+        if (fs::is_directory(wineprefix_path / "dosdevices")) {
+            return wineprefix_path;
+        }
+
+        wineprefix_path = wineprefix_path.parent_path();
+    }
+
+    return std::nullopt;
+}
+
+PluginArchitecture find_vst_architecture(fs::path plugin_path) {
+    std::ifstream file(plugin_path, std::ifstream::binary | std::ifstream::in);
+
+    // The linker will place the offset where the PE signature is placed at the
+    // end of the MS-DOS stub, at offset 0x3c
+    uint32_t pe_signature_offset;
+    file.seekg(0x3c);
+    file.read(reinterpret_cast<char*>(&pe_signature_offset),
+              sizeof(pe_signature_offset));
+
+    // The PE32 signature will be followed by a magic number that indicates the
+    // target architecture of the binary
+    uint32_t pe_signature;
+    uint16_t machine_type;
+    file.seekg(pe_signature_offset);
+    file.read(reinterpret_cast<char*>(&pe_signature), sizeof(pe_signature));
+    file.read(reinterpret_cast<char*>(&machine_type), sizeof(machine_type));
+
+    constexpr char expected_pe_signature[4] = {'P', 'E', '\0', '\0'};
+    if (pe_signature !=
+        *reinterpret_cast<const uint32_t*>(expected_pe_signature)) {
+        throw std::runtime_error("'" + plugin_path.string() +
+                                 "' is not a valid .dll file");
+    }
+
+    // These constants are specified in
+    // https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#machine-types
+    switch (machine_type) {
+        case 0x014c:  // IMAGE_FILE_MACHINE_I386
+            return PluginArchitecture::vst_32;
+            break;
+        case 0x8664:  // IMAGE_FILE_MACHINE_AMD64
+        case 0x0000:  // IMAGE_FILE_MACHINE_UNKNOWN
+            return PluginArchitecture::vst_64;
+            break;
+    }
+
+    // When compiled without optimizations, GCC 9.3 will warn that the function
+    // does not return if we put this in a `default:` case instead.
+    std::ostringstream error_msg;
+    error_msg << "'" << plugin_path
+              << "' is neither a x86 nor a x86_64 PE32 file. Actual "
+                 "architecture: 0x"
+              << std::hex << machine_type;
+    throw std::runtime_error(error_msg.str());
+}
+
+fs::path find_vst_host(PluginArchitecture plugin_arch) {
+    auto host_name = yabridge_wine_host_name;
+    if (plugin_arch == PluginArchitecture::vst_32) {
+        host_name = yabridge_wine_host_name_32bit;
+    }
+
+    fs::path host_path =
+        fs::canonical(get_this_file_location()).remove_filename() / host_name;
+    if (fs::exists(host_path)) {
+        return host_path;
+    }
+
+    // Bosot will return an empty path if the file could not be found in the
+    // search path
+    const fs::path vst_host_path = bp::search_path(host_name);
+    if (vst_host_path == "") {
+        throw std::runtime_error("Could not locate '" + std::string(host_name) +
+                                 "'");
+    }
+
+    return vst_host_path;
+}
+
+fs::path find_vst_plugin() {
+    const fs::path this_plugin_path =
+        "/" / fs::path("/" + get_this_file_location().string());
+
+    fs::path plugin_path(this_plugin_path);
+    plugin_path.replace_extension(".dll");
+    if (fs::exists(plugin_path)) {
+        // Also resolve symlinks here, to support symlinked .dll files
+        return fs::canonical(plugin_path);
+    }
+
+    // In case this files does not exist and our `.so` file is a symlink, we'll
+    // also repeat this check after resolving that symlink to support links to
+    // copies of `libyabridge.so` as described in issue #3
+    fs::path alternative_plugin_path = fs::canonical(this_plugin_path);
+    alternative_plugin_path.replace_extension(".dll");
+    if (fs::exists(alternative_plugin_path)) {
+        return fs::canonical(alternative_plugin_path);
+    }
+
+    // This function is used in the constructor's initializer list so we have to
+    // throw when the path could not be found
+    throw std::runtime_error("'" + plugin_path.string() +
+                             "' does not exist, make sure to rename "
+                             "'libyabridge.so' to match a "
+                             "VST plugin .dll file.");
+}
+
+fs::path generate_endpoint_name() {
+    const auto plugin_name =
+        find_vst_plugin().filename().replace_extension("").string();
+
+    std::random_device random_device;
+    std::mt19937 rng(random_device());
+    fs::path candidate_endpoint;
+    do {
+        std::string random_id;
+        std::sample(
+            alphanumeric_characters,
+            alphanumeric_characters + strlen(alphanumeric_characters) - 1,
+            std::back_inserter(random_id), 8, rng);
+
+        // We'll get rid of the file descriptors immediately after accepting the
+        // sockets, so putting them inside of a subdirectory would only leave
+        // behind an empty directory
+        std::ostringstream socket_name;
+        socket_name << "yabridge-" << plugin_name << "-" << random_id
+                    << ".sock";
+
+        candidate_endpoint = fs::temp_directory_path() / socket_name.str();
+    } while (fs::exists(candidate_endpoint));
+
+    // TODO: Should probably try creating the endpoint right here and catch any
+    //       exceptions since this could technically result in a race condition
+    //       when two instances of yabridge decide to use the same endpoint name
+    //       at the same time
+
+    return candidate_endpoint;
+}
+
+fs::path get_this_file_location() {
+    // HACK: Not sure why, but `boost::dll::this_line_location()` returns a path
+    //       starting with a double slash on some systems. I've seen this happen
+    //       on both Ubuntu 18.04 and 20.04, but not on Arch based distros.
+    //       Under Linux a path starting with two slashes is treated the same as
+    //       a path starting with only a single slash, but Wine will refuse to
+    //       load any files when the path starts with two slashes. Prepending
+    //       `/` to a pad coerces theses two slashes into a single slash.
+    return "/" / boost::dll::this_line_location();
+}
+
+std::string get_wine_version() {
+    // The '*.exe' scripts generated by winegcc allow you to override the binary
+    // used to run Wine, so will will respect this as well
+    std::string wine_command = "wine";
+
+    bp::native_environment env = boost::this_process::environment();
+    if (!env["WINELOADER"].empty()) {
+        wine_command = env.get("WINELOADER");
+    }
+
+    bp::ipstream output;
+    try {
+        const fs::path wine_path = bp::search_path(wine_command);
+        bp::system(wine_path, "--version", bp::std_out = output);
+    } catch (const std::system_error&) {
+        return "<NOT FOUND>";
+    }
+
+    // `wine --version` might contain additional output in certain custom Wine
+    // builds, so we only want to look at the first line
+    std::string version_string;
+    std::getline(output, version_string);
+
+    // Strip the `wine-` prefix from the output, could potentially be absent in
+    // custom Wine builds
+    const std::string version_prefix("wine-");
+    if (version_string.find(version_prefix) == 0) {
+        version_string = version_string.substr(version_prefix.size());
+    }
+
+    return version_string;
+}
+
+bp::environment set_wineprefix() {
+    bp::native_environment env = boost::this_process::environment();
+
+    // Allow the wine prefix to be overridden manually
+    if (!env["WINEPREFIX"].empty()) {
+        return env;
+    }
+
+    const auto wineprefix_path = find_wineprefix();
+    if (wineprefix_path.has_value()) {
+        env["WINEPREFIX"] = wineprefix_path->string();
+    }
+
+    return env;
+}

src/plugin/utils.h

@@ -0,0 +1,142 @@
+// yabridge: a Wine VST bridge
+// Copyright (C) 2020  Robbert van der Helm
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include <boost/filesystem.hpp>
+#include <boost/process/async_pipe.hpp>
+#include <boost/process/environment.hpp>
+
+/**
+ * Boost 1.72 was released with a known breaking bug caused by a missing
+ * typedef: https://github.com/boostorg/process/issues/116.
+ *
+ * Luckily this is easy to fix since it's not really possible to downgrade Boost
+ * as it would break other applications.
+ *
+ * Check if this is still needed for other distros after Arch starts packaging
+ * Boost 1.73.
+ */
+class patched_async_pipe : public boost::process::async_pipe {
+   public:
+    using boost::process::async_pipe::async_pipe;
+
+    typedef typename handle_type::executor_type executor_type;
+};
+
+/**
+ * A tag to differentiate between 32 and 64-bit plugins, used to determine which
+ * host application to use.
+ */
+enum class PluginArchitecture { vst_32, vst_64 };
+
+/**
+ * Create a logger prefix based on the unique socket path for easy
+ * identification. The socket path contains both the plugin's name and a unique
+ * identifier.
+ *
+ * @param socket_path The path to the socket endpoint in use.
+ *
+ * @return A prefix string for log messages.
+ */
+std::string create_logger_prefix(const boost::filesystem::path& socket_path);
+
+/**
+ * Determine the architecture of a VST plugin (or rather, a .dll file) based on
+ * it's header values.
+ *
+ * See https://docs.microsoft.com/en-us/windows/win32/debug/pe-format for more
+ * information on the PE32 format.
+ *
+ * @param plugin_path The path to the .dll file we're going to check.
+ *
+ * @return The detected architecture.
+ * @throw std::runtime_error If the file is not a .dll file.
+ */
+PluginArchitecture find_vst_architecture(boost::filesystem::path);
+
+/**
+ * Finds the Wine VST hsot (either `yabridge-host.exe` or `yabridge-host.exe`
+ * depending on the plugin). For this we will search in two places:
+ *
+ *   1. Alongside libyabridge.so if the file got symlinked. This is useful
+ *      when developing, as you can simply symlink the the libyabridge.so
+ *      file in the build directory without having to install anything to
+ *      /usr.
+ *   2. In the regular search path.
+ *
+ * @param plugin_arch The architecture of the plugin, either 64-bit or 32-bit.
+ *   Used to determine which host application to use, if available.
+ *
+ * @return The a path to the VST host, if found.
+ * @throw std::runtime_error If the Wine VST host could not be found.
+ */
+boost::filesystem::path find_vst_host(PluginArchitecture plugin_arch);
+
+/**
+ * Find the VST plugin .dll file that corresponds to this copy of
+ * `libyabridge.so`. This should be the same as the name of this file but with a
+ * `.dll` file extension instead of `.so`. In case this file does not exist and
+ * the `.so` file is a symlink, we'll also repeat this check for the file it
+ * links to. This is to support the workflow described in issue #3 where you use
+ * symlinks to copies of `libyabridge.so`.
+ *
+ * @return The a path to the accompanying VST plugin .dll file.
+ * @throw std::runtime_error If no matching .dll file could be found.
+ */
+boost::filesystem::path find_vst_plugin();
+
+/**
+ * Locate the Wine prefix this file is located in, if it is inside of a wine
+ * prefix.
+ *
+ * @return Either the path to the Wine prefix (containing the `drive_c?`
+ *   directory), or `std::nullopt` if it is not inside of a wine prefix.
+ */
+std::optional<boost::filesystem::path> find_wineprefix();
+
+/**
+ * Generate a unique name for the Unix domain socket endpoint based on the VST
+ * plugin's name. This will also generate the parent directory if it does not
+ * yet exist since we're using this in the constructor's initializer list.
+ *
+ * @return A path to a not yet existing Unix domain socket endpoint.
+ * @throw std::runtime_error If no matching .dll file could be found.
+ */
+boost::filesystem::path generate_endpoint_name();
+
+/**
+ * Return a path to this `.so` file. This can be used to find out from where
+ * this link to or copy of `libyabridge.so` was loaded.
+ */
+boost::filesystem::path get_this_file_location();
+
+/**
+ * Return the installed Wine version. This is obtained by from `wine --version`
+ * and then stripping the `wine-` prefix. This respects the `WINELOADER`
+ * environment variable used in the scripts generated by winegcc.
+ *
+ * This will *not* throw when Wine can not be found, but will instead return
+ * '<NOT FOUND>'. This way the user will still get some useful log files.
+ */
+std::string get_wine_version();
+
+/**
+ * Locate the Wine prefix and set the `WINEPREFIX` environment variable if
+ * found. This way it's also possible to run .dll files outside of a Wine prefix
+ * using the user's default prefix.
+ */
+boost::process::environment set_wineprefix();