Beginnings of a debugger wire protocol

runtime/bin/main.cc

Index: runtime/bin/main.cc
===================================================================
--- runtime/bin/main.cc	(revision 7329)
+++ runtime/bin/main.cc	(working copy)
@@ -11,6 +11,7 @@
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
+#include "bin/dbg_connection.h"
 #include "bin/directory.h"
 #include "bin/eventhandler.h"
 #include "bin/extensions.h"
@@ -46,6 +47,15 @@
 static const char* breakpoint_at = NULL;
 
 
+// Global state that indicates whether we should open a connection
+// and listen for a debugger to connect.
+static bool start_debugger = false;
+static const int DEFAULT_DEBUG_PORT = 5858;
+static const char* DEFAULT_DEBUG_IP = "127.0.0.1";
+static const char* debug_ip = DEFAULT_DEBUG_IP;
+static int debug_port = 0;
+
+
 // Value of the --package-root flag.
 // (This pointer points into an argv buffer and does not need to be
 // free'd.)
@@ -84,6 +94,28 @@
 }
 
 
+static void ProcessDebugOption(const char* port) {
+  // TODO(hausner): Add support for specifying an IP address on which
+  // the debugger should listen.
+  ASSERT(port != NULL);
+  debug_port = 0;
+  if (*port == '\0') {
+    debug_port = DEFAULT_DEBUG_PORT;
+  } else {
+    if ((*port == '=') || (*port == ':')) {
+      debug_port = atoi(port + 1);
+    }
+  }
+  if (debug_port == 0) {
+    fprintf(stderr, "unrecognized --debug option syntax. "
+                    "Use --debug[:<port number>]\n");
+    return;
+  }
+  breakpoint_at = "main";
+  start_debugger = true;
+}
+
+
 static void ProcessPprofOption(const char* filename) {
   ASSERT(filename != NULL);
   generate_pprof_symbols_filename = filename;
@@ -102,6 +134,7 @@
 } main_options[] = {
   { "--break_at=", ProcessBreakpointOption },
   { "--compile_all", ProcessCompileAllOption },
+  { "--debug", ProcessDebugOption },
   { "--generate_pprof_symbols=", ProcessPprofOption },
   { "--import_map=", ProcessImportMapOption },
   { "--package-root=", ProcessPackageRootOption },
@@ -613,6 +646,13 @@
           Dart_GetError(result));
     }
   }
+
+  // Start the debugger wire protocol handler if necessary.
+  if (start_debugger) {
+    ASSERT(debug_port != 0);
+    DebuggerConnectionHandler::StartHandler(debug_ip, debug_port);
+  }
+
   // Lookup and invoke the top level main function.
   result = Dart_Invoke(library, Dart_NewString("main"), 0, NULL);
   if (Dart_IsError(result)) {