Ignore nested breakpoints

runtime/vm/debugger.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/debugger.h"
 
 #include "include/dart_api.h"
 
 #include "vm/code_generator.h"
 #include "vm/code_patcher.h"
@@ skipping 834 matching lines @@
     return true;
   }
   if (class_name.Equals("AssertionErrorImplementation")) {
     return true;
   }
   return false;
 }
 
 
 void Debugger::SignalExceptionThrown(const Object& exc) {
+  // We ignore this exception event when the VM is executing code invoked
+  // by the debugger to evaluate variables values, when we see a nested
+  // breakpoint or exception event, or if the debugger is not
+  // interested in exception events.
   if (ignore_breakpoints_ ||
+      (stack_trace_ != NULL) ||
       (event_handler_ == NULL) ||
       (exc_pause_info_ == kNoPauseOnExceptions)) {
     return;
   }
   DebuggerStackTrace* stack_trace = CollectStackTrace();
   if (!ShouldPauseOnException(stack_trace, exc)) {
     return;
   }
   // No single-stepping possible after this pause event.
   last_bpt_line_ = -1;
@@ skipping 459 matching lines @@
       (fkind == RawFunction::kConstImplicitGetter)) {
     return false;
   }
   const Class& cls = Class::Handle(func.Owner());
   const Library& lib = Library::Handle(cls.library());
   return lib.IsDebuggable();
 }
 
 
 void Debugger::SignalBpReached() {
-  if (ignore_breakpoints_) {
+  // We ignore this breakpoint when the VM is executing code invoked
+  // by the debugger to evaluate variables values, or when we see a nested
+  // breakpoint or exception event.
+  if (ignore_breakpoints_ || (stack_trace_ != NULL)) {
     return;
   }
   DebuggerStackTrace* stack_trace = CollectStackTrace();
   ASSERT(stack_trace->Length() > 0);
   ActivationFrame* top_frame = stack_trace->ActivationFrameAt(0);
   ASSERT(top_frame != NULL);
   CodeBreakpoint* bpt = GetCodeBreakpoint(top_frame->pc());
   ASSERT(bpt != NULL);
   if (FLAG_verbose_debug) {
     OS::Print(">>> hit %s breakpoint at %s:%"Pd" (Address %#"Px")\n",
@@ skipping 283 matching lines @@
 }
 
 
 void Debugger::RegisterCodeBreakpoint(CodeBreakpoint* bpt) {
   ASSERT(bpt->next() == NULL);
   bpt->set_next(code_breakpoints_);
   code_breakpoints_ = bpt;
 }
 
 }  // namespace dart