Add a +editor flag to YABRIDGE_DEBUG_LEVEL

src/common/logging/common.cpp

@@ -41,21 +41,39 @@ constexpr char logging_file_environment_variable[] = "YABRIDGE_DEBUG_FILE";
 constexpr char logging_verbosity_environment_variable[] =
     "YABRIDGE_DEBUG_LEVEL";
 
+/**
+ * The `YABRIDGE_DEBUG_LEVEL` flag for enabling editor tracing.
+ */
+constexpr char editor_tracing_flag[] = "+editor";
+
 Logger::Logger(std::shared_ptr<std::ostream> stream,
                Verbosity verbosity_level,
+               bool editor_tracing,
                std::string prefix,
                bool prefix_timestamp)
     : verbosity(verbosity_level),
+      editor_tracing(editor_tracing),
       stream(stream),
       prefix(prefix),
       prefix_timestamp(prefix_timestamp) {}
 
-Logger Logger::create_from_environment(std::string prefix) {
+Logger Logger::create_from_environment(std::string prefix,
+                                       std::shared_ptr<std::ostream> stream) {
     bp::environment env = boost::this_process::environment();
-    std::string file_path = env[logging_file_environment_variable].to_string();
+    const std::string file_path =
+        env[logging_file_environment_variable].to_string();
     std::string verbosity =
         env[logging_verbosity_environment_variable].to_string();
 
+    // Editor debug tracing is an optional flag that can be added to any debug
+    // level (and technically it will also work fine if it's the only option,
+    // but you're not supposed to do that ;))
+    const bool editor_tracing = verbosity.ends_with(editor_tracing_flag);
+    if (editor_tracing) {
+        verbosity =
+            verbosity.substr(0, verbosity.size() - strlen(editor_tracing_flag));
+    }
+
     // Default to `Verbosity::basic` if the environment variable has not
     // been set or if it is not an integer.
     Verbosity verbosity_level;
@@ -65,41 +83,35 @@ Logger Logger::create_from_environment(std::string prefix) {
         verbosity_level = Verbosity::basic;
     }
 
-    // If `file` points to a valid location then use create/truncate the
-    // file and write all of the logs there, otherwise use STDERR
-    auto log_file = std::make_shared<std::ofstream>(
-        file_path, std::fstream::out | std::fstream::app);
-    if (log_file->is_open()) {
-        return Logger(log_file, verbosity_level, prefix);
-    } else {
-        // For STDERR we sadly can't just use `std::cerr`. In the group process
-        // we need to capture all output generated by the process itself, and
-        // the only way to do this is by reopening the STDERR and STDOUT streams
-        // to a pipe. Luckily `/dev/stderr` stays unaffected, so we can still
-        // write there without causing infinite loops.
-        return Logger(std::make_shared<std::ofstream>(
-                          "/dev/stderr", std::fstream::out | std::fstream::app),
-                      verbosity_level, prefix);
+    if (!stream) {
+        // If `file` points to a valid location then use create/truncate the
+        // file and write all of the logs there, otherwise use STDERR
+        const auto log_file = std::make_shared<std::ofstream>(
+            file_path, std::fstream::out | std::fstream::app);
+        if (log_file->is_open()) {
+            stream = log_file;
+            return Logger(log_file, verbosity_level, editor_tracing, prefix);
+        } else {
+            // For STDERR we sadly can't just use `std::cerr`. In the group
+            // process we need to capture all output generated by the process
+            // itself, and the only way to do this is by reopening the STDERR
+            // and STDOUT streams to a pipe. Luckily `/dev/stderr` stays
+            // unaffected, so we can still write there without causing infinite
+            // loops.
+            stream = std::make_shared<std::ofstream>(
+                "/dev/stderr", std::fstream::out | std::fstream::app);
+        }
     }
+
+    return Logger(stream, verbosity_level, editor_tracing, prefix);
 }
 
 Logger Logger::create_wine_stderr() {
-    bp::environment env = boost::this_process::environment();
-    std::string verbosity =
-        env[logging_verbosity_environment_variable].to_string();
-
-    Verbosity verbosity_level;
-    try {
-        verbosity_level = static_cast<Verbosity>(std::stoi(verbosity));
-    } catch (const std::invalid_argument&) {
-        verbosity_level = Verbosity::basic;
-    }
-
     // We're logging directly to `std::cerr` instead of to `/dev/stderr` because
     // we want the STDERR redirection from the group host processes to still
     // function here
-    return Logger(std::shared_ptr<std::ostream>(&std::cerr, [](auto*) {}),
-                  verbosity_level, "", false);
+    return create_from_environment(
+        "", std::shared_ptr<std::ostream>(&std::cerr, [](auto*) {}));
 }
 
 void Logger::log(const std::string& message) {

src/common/logging/common.h

@@ -96,6 +96,9 @@ class Logger {
      * @param verbosity_level The verbosity of the logging, see the
      *   `Logger::Verbosity` constants above for a description of the verbosity
      *   levels.
+     * @param editor_tracing Whether we should enable debug tracing for the
+     *   editor window handling. If we end up adding more of these options, we
+     *   should move to a bitfield or something.
      * @param prefix An optional prefix for the logger. Useful for differentiate
      *   messages coming from the Wine VST host. Should end with a single space
      *   character.
@@ -107,6 +110,7 @@ class Logger {
      */
     Logger(std::shared_ptr<std::ostream> stream,
            Verbosity verbosity_level,
+           bool editor_tracing,
            std::string prefix = "",
            bool prefix_timestamp = true);
 
@@ -116,8 +120,12 @@ class Logger {
      *
      * @param prefix A message to prepend for every log message, useful to
      *   differentiate between the Wine process and the Linux VST plugin.
+     * @param stream If specified, disregard `YABRIDGE_DEBUG_FILE` and output
+     *   the log to this stream isntead.
      */
-    static Logger create_from_environment(std::string prefix = "");
+    static Logger create_from_environment(
+        std::string prefix = "",
+        std::shared_ptr<std::ostream> stream = nullptr);
 
     /**
      * Create a special logger instance that outputs directly to STDERR without
@@ -173,7 +181,21 @@ class Logger {
      */
     template <invocable_returning<std::string> F>
     void log_trace(F&& fn) {
-        if (verbosity >= Verbosity::all_events) {
+        if (verbosity >= Verbosity::all_events) [[unlikely]] {
+            log(fn());
+        }
+    }
+
+    /**
+     * Log a message that should only be printed when the `editor_tracing`
+     * option is enabled. This can be useful to provide debugging information
+     * for weird setup-specific bugs.
+     *
+     * @param message A lambda producing a string that should be written.
+     */
+    template <invocable_returning<std::string> F>
+    void log_editor_trace(F&& fn) {
+        if (editor_tracing) [[unlikely]] {
             log(fn());
         }
     }
@@ -184,6 +206,12 @@ class Logger {
      */
     const Verbosity verbosity;
 
+    /**
+     * If this is set to true, then we'll print debug traces for the plugin
+     * editor.
+     */
+    const bool editor_tracing;
+
    private:
     /**
      * The output stream to write the log messages to. Typically either STDERR