Print invalid and unknown options on startup

src/plugin/plugin-bridge.cpp

@@ -684,20 +684,33 @@ void PluginBridge::log_init_message() {
     }
     init_msg << "'" << std::endl;
 
-    bool other_options_set = false;
-    init_msg << "other options: '";
+    init_msg << "other options: ";
+    std::vector<std::string> other_options;
     if (config.editor_double_embed) {
-        init_msg << "editor: double embed";
-        other_options_set = true;
+        other_options.push_back("editor: double embed");
     }
     if (config.hack_reaper_update_display) {
-        init_msg << "hack: REAPER 'audioMasterUpdateDisplay' workaround";
-        other_options_set = true;
+        other_options.push_back(
+            "hack: REAPER audioMasterUpdateDisplay() workaround");
     }
-    if (!other_options_set) {
-        init_msg << "<none>";
+    if (!other_options.empty()) {
+        init_msg << join_quoted_strings(other_options) << std::endl;
+    } else {
+        init_msg << "'<none>'" << std::endl;
+    }
+
+    // To make debugging easier, we'll print both unrecognized options (that
+    // might be left over when an option gets removed) as well as options have
+    // the wrong argument types
+    if (!config.invalid_options.empty()) {
+        init_msg << "invalid arguments: "
+                 << join_quoted_strings(config.invalid_options)
+                 << " (check the readme for more information)" << std::endl;
+    }
+    if (!config.unknown_options.empty()) {
+        init_msg << "unrecognized options: "
+                 << join_quoted_strings(config.unknown_options) << std::endl;
     }
-    init_msg << "'" << std::endl;
     init_msg << std::endl;
 
     // Include a list of enabled compile-tiem features, mostly to make debug

src/plugin/utils.cpp

@@ -269,6 +269,17 @@ std::string get_wine_version() {
     return version_string;
 }
 
+std::string join_quoted_strings(std::vector<std::string>& strings) {
+    bool is_first = true;
+    std::ostringstream joined_strigns{};
+    for (const auto& option : strings) {
+        joined_strigns << (is_first ? "'" : ", '") << option << "'";
+        is_first = false;
+    }
+
+    return joined_strigns.str();
+}
+
 Configuration load_config_for(const fs::path& yabridge_path) {
     // First find the closest `yabridge.tmol` file for the plugin, falling back
     // to default configuration settings if it doesn't exist

src/plugin/utils.h

@@ -166,6 +166,14 @@ boost::filesystem::path get_this_file_location();
  */
 std::string get_wine_version();
 
+/**
+ * Join a vector of strings with commas while wrapping the strings in quotes.
+ * For example, `join_quoted_strings(std::vector<string>{"string", "another
+ * string", "also a string"})` outputs `"'string', 'another string', 'also a
+ * string'"`. This is used to format the initialisation message.
+ */
+std::string join_quoted_strings(std::vector<std::string>& strings);
+
 /**
  * Load the configuration that belongs to a copy of or symlink to
  * `libyabridge.so`. If no configuration file could be found then this will