main: add more control over logging

Allow the verbosity to be adjusted.

Allow logging to be sent to stderr even when running in interpreter mode.

Allow uptime (time since program start) to be disabled. This makes it
easier to compare logs across successive runs.

main.cpp

@@ -72,25 +72,35 @@ int main(int argc, char** argv) {
     app.allow_windows_style_options(); /* we want Windows-style options */
     app.allow_extras();
 
-    bool   realtime_enabled, debugger_enabled;
-    string machine_str;
+    bool   realtime_enabled = false;
+    bool   debugger_enabled = false;
     string bootrom_path("bootrom.bin");
 
     app.add_flag("-r,--realtime", realtime_enabled,
         "Run the emulator in real-time");
-
     app.add_flag("-d,--debugger", debugger_enabled,
         "Enter the built-in debugger");
-
     app.add_option("-b,--bootrom", bootrom_path, "Specifies BootROM path")
         ->check(CLI::ExistingFile);
 
+    bool              log_to_stderr = false;
+    loguru::Verbosity log_verbosity = loguru::Verbosity_INFO;
+    bool              log_no_uptime = false;
+    app.add_flag("--log-to-stderr", log_to_stderr,
+        "Send internal logging to stderr (instead of dingusppc.log)");
+    app.add_flag("--log-verbosity", log_verbosity,
+        "Adjust logging verbosity (default is 0 a.k.a. INFO)")
+        ->check(CLI::Number);
+    app.add_flag("--log-no-uptime", log_no_uptime,
+        "Disable the uptime preamble of logged messages");
+
     uint32_t profiling_interval_ms = 0;
 #ifdef CPU_PROFILING
     app.add_option("--profiling-interval-ms", profiling_interval_ms,
         "Specifies periodic interval (in ms) at which to output CPU profiling information");
 #endif
 
+    string       machine_str;
     CLI::Option* machine_opt = app.add_option("-m,--machine",
         machine_str, "Specify machine ID");
 
@@ -118,20 +128,21 @@ int main(int argc, char** argv) {
     if (debugger_enabled) {
         if (realtime_enabled)
             cout << "Both realtime and debugger enabled! Using debugger" << endl;
-        execution_mode = 1;
+        execution_mode = debugger;
     }
 
     /* initialize logging */
     loguru::g_preamble_date    = false;
     loguru::g_preamble_time    = false;
     loguru::g_preamble_thread  = false;
+    loguru::g_preamble_uptime  = !log_no_uptime;
 
-    if (!execution_mode) {
+    if (execution_mode == interpreter && !log_to_stderr) {
         loguru::g_stderr_verbosity = loguru::Verbosity_OFF;
         loguru::init(argc, argv);
-        loguru::add_file("dingusppc.log", loguru::Append, 0);
+        loguru::add_file("dingusppc.log", loguru::Append, log_verbosity);
     } else {
-        loguru::g_stderr_verbosity = loguru::Verbosity_INFO;
+        loguru::g_stderr_verbosity = log_verbosity;
         loguru::init(argc, argv);
     }