Vector ICs: Clear the vector ic slots appropriately during debugging.

src/debug.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 303 matching lines @@
 
   if (IsExit()) {
     // Restore the frame exit code with a break point.
     RestoreFromOriginal(Assembler::kJSReturnSequenceLength);
   } else if (IsDebugBreakSlot()) {
     // Restore the code in the break slot.
     RestoreFromOriginal(Assembler::kDebugBreakSlotLength);
   } else {
     // Restore the IC call.
     rinfo().set_target_address(original_rinfo().target_address());
+    // Some ICs store data in the feedback vector. Clear this to ensure we
+    // won't miss future stepping requirements.
+    SharedFunctionInfo* shared = debug_info_->shared();
+    shared->feedback_vector()->ClearICSlots(shared);
   }
   DCHECK(!IsDebugBreak());
 }
 
 
 void BreakLocation::RestoreFromOriginal(int length_in_bytes) {
   memcpy(pc(), original_pc(), length_in_bytes);
   CpuFeatures::FlushICache(pc(), length_in_bytes);
 }
 
@@ skipping 1777 matching lines @@
 
   // There will be at least one break point when we are done.
   has_break_points_ = true;
 
   // Ensure function is compiled. Return false if this failed.
   if (!function.is_null() &&
       !Compiler::EnsureCompiled(function, CLEAR_EXCEPTION)) {
     return false;
   }
 
+  // Make sure IC state is clean.
+  shared->code()->ClearInlineCaches();
+  shared->feedback_vector()->ClearICSlots(*shared);
+
   // Create the debug info object.
   Handle<DebugInfo> debug_info = isolate->factory()->NewDebugInfo(shared);
 
   // Add debug info to the list.
   DebugInfoListNode* node = new DebugInfoListNode(*debug_info);
   node->set_next(debug_info_list_);
   debug_info_list_ = node;
 
   return true;
 }
@@ skipping 1251 matching lines @@
   logger_->DebugEvent("Put", message.text());
 }
 
 
 void LockingCommandMessageQueue::Clear() {
   base::LockGuard<base::Mutex> lock_guard(&mutex_);
   queue_.Clear();
 }
 
 } }  // namespace v8::internal