Added automatic debug break for processing debugger commands

src/execution.cc

Index: src/execution.cc
===================================================================
--- src/execution.cc	(revision 1507)
+++ src/execution.cc	(working copy)
@@ -318,6 +318,21 @@
 }
 
 
+bool StackGuard::IsDebugCommand() {
+  ExecutionAccess access;
+  return thread_local_.interrupt_flags_ & DEBUGCOMMAND;
+}
+
+
+void StackGuard::DebugCommand() {
+  if (FLAG_debugger_auto_break) {
+    ExecutionAccess access;
+    thread_local_.interrupt_flags_ |= DEBUGCOMMAND;
+    set_limits(kInterruptLimit, access);
+  }
+}
+
+
 void StackGuard::Continue(InterruptFlag after_what) {
   ExecutionAccess access;
   thread_local_.interrupt_flags_ &= ~static_cast<int>(after_what);
@@ -556,9 +571,19 @@
     }
   }
 
-  // Clear the debug request flag.
+  // Check for debug command break only.
+  bool debug_command_only =
+      StackGuard::IsDebugCommand() && !StackGuard::IsDebugBreak();
+
+  // Clear the debug request flags.
   StackGuard::Continue(DEBUGBREAK);
+  StackGuard::Continue(DEBUGCOMMAND);
 
+  // If debug command only and already in debugger ignore it.
+  if (debug_command_only && Debug::InDebugger()) {
+    return Heap::undefined_value();
+  }
+
   HandleScope scope;
   // Enter the debugger. Just continue if we fail to enter the debugger.
   EnterDebugger debugger;
@@ -567,7 +592,7 @@
   }
 
   // Notify the debug event listeners.
-  Debugger::OnDebugBreak(Factory::undefined_value());
+  Debugger::OnDebugBreak(Factory::undefined_value(), debug_command_only);
 
   // Return to continue execution.
   return Heap::undefined_value();
@@ -575,7 +600,9 @@
 
 
 Object* Execution::HandleStackGuardInterrupt() {
-  if (StackGuard::IsDebugBreak()) DebugBreakHelper();
+  if (StackGuard::IsDebugBreak() || StackGuard::IsDebugCommand()) {
+    DebugBreakHelper();
+  }
   if (StackGuard::IsPreempted()) RuntimePreempt();
   if (StackGuard::IsInterrupted()) {
     // interrupt