Find the correct library file from the chainloader

Instead of using this hardcdoed path.

src/chainloader/meson.build

@@ -2,15 +2,19 @@
 # main `meson.build` file so everything gets bundled to a single directory.
 
 vst2_chainloader_sources = files(
-  'vst2-chainloader.cpp',
+  '../common/logging/common.cpp',
   '../common/linking.cpp',
   '../common/notifications.cpp',
   '../common/process.cpp',
+  'utils.cpp',
+  'vst2-chainloader.cpp',
 )
 
 vst3_chainloader_sources = files(
-  'vst3-chainloader.cpp',
+  '../common/logging/common.cpp',
   '../common/linking.cpp',
   '../common/notifications.cpp',
   '../common/process.cpp',
+  'utils.cpp',
+  'vst3-chainloader.cpp',
 )

src/chainloader/utils.cpp

@@ -0,0 +1,81 @@
+// yabridge: a Wine plugin bridge
+// Copyright (C) 2020-2022 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 <dlfcn.h>
+
+// Generated inside of the build directory
+#include <config.h>
+
+#include "../common/linking.h"
+#include "../common/logging/common.h"
+#include "../common/notifications.h"
+#include "../common/process.h"
+
+namespace fs = ghc::filesystem;
+
+void* find_plugin_library(const std::string& name) {
+    // Just using a goto for this would probably be cleaner, but yeah...
+    const auto impl = [&name]() -> void* {
+        // If `name` exists right next to the Wine plugin host binary, then
+        // we'll try loading that. Otherwise we'll fall back to regular
+        // `dlopen()` for distro packaged versions of yabridge
+        const std::vector<fs::path> search_path = get_augmented_search_path();
+        if (const auto& yabridge_host_path =
+                search_in_path(search_path, yabridge_individual_host_name)) {
+            const fs::path candidate = yabridge_host_path->parent_path() / name;
+            if (fs::exists(candidate)) {
+                return dlopen(candidate.c_str(), RTLD_LAZY | RTLD_LOCAL);
+            }
+        }
+
+        if (const auto& yabridge_host_32_path = search_in_path(
+                search_path, yabridge_individual_host_name_32bit)) {
+            const fs::path candidate =
+                yabridge_host_32_path->parent_path() / name;
+            if (fs::exists(candidate)) {
+                return dlopen(candidate.c_str(), RTLD_LAZY | RTLD_LOCAL);
+            }
+        }
+
+        return dlopen(name.c_str(), RTLD_LAZY | RTLD_LOCAL);
+    };
+
+    void* handle = impl();
+    if (!handle) {
+        const fs::path this_plugin_path = get_this_file_location();
+
+        Logger logger = Logger::create_exception_logger();
+
+        logger.log("");
+        logger.log("Could not find '" + name + "'.");
+        logger.log("Make sure you followed the installation instructions from");
+        logger.log("yabridge's readme");
+        logger.log("");
+        logger.log("Source: '" + this_plugin_path.string() + "'");
+        logger.log("");
+
+        // Also show a desktop notification since most people likely won't see
+        // the above message
+        send_notification("Could not find '" + name + "'",
+                          "Make sure you followed the installation "
+                          "instructions from yabridge's readme",
+                          this_plugin_path);
+    }
+
+    return handle;
+}

src/chainloader/utils.h

@@ -0,0 +1,37 @@
+// yabridge: a Wine plugin bridge
+// Copyright (C) 2020-2022 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 <string>
+
+/**
+ * Finds the matching `libyabridge-*.so` for this chainloader. Returns the
+ * handle if it is found. Otherwise, we'll log an error and show a desktop
+ * notification, and this function returns a null pointer. The pointer may be
+ * `dlclose()`'d when it's no longer needed. This search works in the following
+ * order:
+ *
+ * - First we'll try to locate `yabridge-host.exe` using the same method used by
+ *   the yabridge plugin bridges themselves. We'll search in `$PATH`, followed
+ *   by `${XDG_DATA_HOME:-$HOME/.local/share}/yabridge`. If that file exists and
+ *   the target plugin library exists right next to it, then we'll use that.
+ * - For compatibility with 32-bit only builds of yabridge, we'll repeat this
+ *   process for `yabridge-host-32.exe`.
+ * - When those don't exist, we'll try to `dlopen()` the file directly. This
+ *   will use the correct path for the system.
+ */
+void* find_plugin_library(const std::string& name);

src/chainloader/vst2-chainloader.cpp

@@ -20,8 +20,12 @@
 
 #include <dlfcn.h>
 
+// Generated inside of the build directory
+#include <config.h>
+
 #include "../common/linking.h"
 #include "../common/utils.h"
+#include "utils.h"
 
 // These chainloader libraries are tiny, mostly dependencyless libraries that
 // `dlopen()` the actual `libyabridge-{vst2,vst3}.so` files and forward the
@@ -35,8 +39,6 @@
 // distro packaging, because updates to Boost might require the package to be
 // rebuilt, which in turn would also require a resync.
 
-// TODO: Order to check in: See Discord
-
 namespace fs = ghc::filesystem;
 
 using audioMasterCallback = void*;
@@ -65,11 +67,10 @@ bool initialize_library() {
         return true;
     }
 
-    // FIXME: Hardcoded path
-    library_handle = dlopen(
-        "/home/robbert/Documenten/projecten/yabridge/build/libyabridge-vst2.so",
-        RTLD_LAZY | RTLD_LOCAL);
-    assert(library_handle);
+    library_handle = find_plugin_library(yabridge_vst2_plugin_name);
+    if (!library_handle) {
+        return false;
+    }
 
 #define LOAD_FUNCTION(name)                                                 \
     do {                                                                    \
@@ -89,7 +90,9 @@ extern "C" YABRIDGE_EXPORT AEffect* VSTPluginMain(
     audioMasterCallback host_callback) {
     assert(host_callback);
 
-    initialize_library();
+    if (!initialize_library()) {
+        return nullptr;
+    }
 
     const fs::path this_plugin_path = get_this_file_location();
     return yabridge_plugin_init(host_callback, this_plugin_path.c_str());

src/chainloader/vst3-chainloader.cpp

@@ -20,8 +20,12 @@
 
 #include <dlfcn.h>
 
+// Generated inside of the build directory
+#include <config.h>
+
 #include "../common/linking.h"
 #include "../common/utils.h"
+#include "utils.h"
 
 // These chainloader libraries are tiny, mostly dependencyless libraries that
 // `dlopen()` the actual `libyabridge-{vst2,vst3}.so` files and forward the
@@ -35,8 +39,6 @@
 // distro packaging, because updates to Boost might require the package to be
 // rebuilt, which in turn would also require a resync.
 
-// TODO: Order to check in: See Discord
-
 namespace fs = ghc::filesystem;
 
 using Vst3PluginBridge = void;
@@ -83,11 +85,10 @@ bool initialize_library() {
         return true;
     }
 
-    // FIXME: Hardcoded path
-    library_handle = dlopen(
-        "/home/robbert/Documenten/projecten/yabridge/build/libyabridge-vst3.so",
-        RTLD_LAZY | RTLD_LOCAL);
-    assert(library_handle);
+    library_handle = find_plugin_library(yabridge_vst3_plugin_name);
+    if (!library_handle) {
+        return false;
+    }
 
 #define LOAD_FUNCTION(name)                                                 \
     do {                                                                    \
@@ -109,7 +110,9 @@ extern "C" YABRIDGE_EXPORT bool ModuleEntry(void*) {
     // This function can be called multiple times, so we should make sure to
     // only initialize the bridge on the first call
     if (active_instances.fetch_add(1, std::memory_order_seq_cst) == 0) {
-        assert(initialize_library());
+        if (!initialize_library()) {
+            return false;
+        }
 
         // You can't change the deleter function with `.reset()` so we'll need
         // this abomination instead

src/plugin/bridges/common.h

@@ -142,6 +142,7 @@ class PluginBridge {
                  << " (32-bit build)"
 #endif
                  << std::endl;
+        // TODO: Show this library's path now that we're chainloading
         init_msg << "host:          '" << plugin_host_->path().string() << "'"
                  << std::endl;
         init_msg << "plugin:        '" << info_.windows_plugin_path_.string()

src/plugin/vst2-plugin.cpp

@@ -52,8 +52,8 @@ void log_init_error(const std::exception& error, const fs::path& plugin_path) {
     logger.log(error.what());
     logger.log("");
 
-    // Also show a desktop notification most people likely won't see the above
-    // message
+    // Also show a desktop notification since most people likely won't see the
+    // above message
     send_notification(
         "Failed to initialize VST2 plugin",
         error.what() +

src/plugin/vst3-plugin.cpp

@@ -77,8 +77,8 @@ void log_init_exception(const std::exception& error,
     logger.log(error.what());
     logger.log("");
 
-    // Also show a desktop notification most people likely won't see the above
-    // message
+    // Also show a desktop notification since most people likely won't see the
+    // above message
     // FIXME: Go through these messages and update them to reflect the
     //        chainloading changes
     send_notification(