Add --log-process-args to log the arguments whenever a truffleruby process is created

Author: eregon

src/launcher/java/org/truffleruby/launcher/CommandLineOptions.java

@@ -48,6 +48,9 @@ public class CommandLineOptions {
     boolean showVersion = false;
     boolean showCopyright = false;
     ShowHelp showHelp = ShowHelp.NONE;
+    /** All command-line arguments passed to truffleruby */
+    final String[] initialArguments;
+    boolean logProcessArguments = false;
     /** Read the RUBYOPT and TRUFFLERUBYOPT environment variables */
     boolean readRubyOptEnv = true;
     /** What should be done after context is created */
@@ -58,11 +61,13 @@ public class CommandLineOptions {
     String toExecute = "";
 
     private final Map<String, String> options;
+    /** Application arguments */
     private String[] arguments;
     private final List<String> unknownArguments;
     private Boolean gemOrBundle = null;
 
-    public CommandLineOptions() {
+    public CommandLineOptions(List<String> initialArguments) {
+        this.initialArguments = initialArguments.toArray(EMPTY_STRING_ARRAY);
         this.options = new HashMap<>();
         this.arguments = EMPTY_STRING_ARRAY;
         this.unknownArguments = new ArrayList<>();

src/launcher/java/org/truffleruby/launcher/CommandLineParser.java

@@ -425,6 +425,9 @@ private void processArgument() throws CommandLineException {
                         String feature = grabValue(getArgumentError("missing argument for " + argument), false);
                         config.getUnknownArguments().add(argument + "=" + feature);
                         break FOR;
+                    } else if (argument.equals("--log-process-args") || argument.equals("--log-process-args=true")) {
+                        config.logProcessArguments = true;
+                        break FOR;
                     } else if (argument.equals("--yydebug")) {
                         disallowedInRubyOpts(argument);
                         warnInternalDebugTool(argument);

src/launcher/java/org/truffleruby/launcher/RubyLauncher.java

@@ -74,7 +74,7 @@ protected List<String> preprocessArguments(List<String> args, Map<String, String
         // TruffleRuby is never distributed without the GraalVM compiler, so this warning is not necessary
         polyglotOptions.put("engine.WarnInterpreterOnly", "false");
 
-        config = new CommandLineOptions();
+        config = new CommandLineOptions(args);
 
         try {
             config.executionAction = ExecutionAction.UNSET;
@@ -249,6 +249,15 @@ private int runContext(Context.Builder builder, CommandLineOptions config) {
                 }
             }
 
+            if (config.logProcessArguments) {
+                Value logInfo = context.eval(
+                        "ruby",
+                        // language=ruby
+                        "-> message { Truffle::Debug.log_info(message) }");
+                String message = "new process: truffleruby " + String.join(" ", config.initialArguments);
+                logInfo.executeVoid(message);
+            }
+
             final Source source = Source.newBuilder(
                     TruffleRuby.LANGUAGE_ID,
                     // language=ruby

src/main/java/org/truffleruby/debug/TruffleDebugNodes.java

@@ -360,12 +360,12 @@ public abstract static class LogInfoNode extends CoreMethodArrayArgumentsNode {
         @Specialization
         protected Object logInfo(Object value,
                 @Cached ToJavaStringNode toJavaStringNode) {
-            config(toJavaStringNode.executeToJavaString(value));
+            info(toJavaStringNode.executeToJavaString(value));
             return nil;
         }
 
         @TruffleBoundary
-        static void config(String message) {
+        static void info(String message) {
             RubyLanguage.LOGGER.info(message);
         }