[debugger] flood function for stepping before calling it.

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 982 matching lines @@
   static ExternalReference invoke_accessor_getter_callback(Isolate* isolate);
 
   static ExternalReference virtual_handler_register(Isolate* isolate);
   static ExternalReference virtual_slot_register(Isolate* isolate);
 
   static ExternalReference runtime_function_table_address(Isolate* isolate);
 
   Address address() const { return reinterpret_cast<Address>(address_); }
 
   // Used to check if single stepping is enabled in generated code.
-  static ExternalReference debug_step_in_fp_address(Isolate* isolate);
+  static ExternalReference debug_last_step_action_address(Isolate* isolate);
 
 #ifndef V8_INTERPRETED_REGEXP
   // C functions called from RegExp generated code.
 
   // Function NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16()
   static ExternalReference re_case_insensitive_compare_uc16(Isolate* isolate);
 
   // Function RegExpMacroAssembler*::CheckStackGuardState()
   static ExternalReference re_check_stack_guard_state(Isolate* isolate);
 
@@ skipping 129 matching lines @@
 // generate safepoint data after calls for crankshaft.
 class CallWrapper {
  public:
   CallWrapper() { }
   virtual ~CallWrapper() { }
   // Called just before emitting a call. Argument is the size of the generated
   // call code.
   virtual void BeforeCall(int call_size) const = 0;
   // Called just after emitting a call, i.e., at the return site for the call.
   virtual void AfterCall() const = 0;
+  // Return whether call needs to check for debug stepping.
+  virtual bool NeedsDebugStepCheck() const { return false; }
 };
 
+
 class NullCallWrapper : public CallWrapper {
  public:
   NullCallWrapper() { }
   virtual ~NullCallWrapper() { }
   virtual void BeforeCall(int call_size) const { }
   virtual void AfterCall() const { }
 };
 
 
+class CheckDebugStepCallWrapper : public CallWrapper {
+ public:
+  CheckDebugStepCallWrapper() {}
+  virtual ~CheckDebugStepCallWrapper() {}
+  virtual void BeforeCall(int call_size) const {}
+  virtual void AfterCall() const {}
+  virtual bool NeedsDebugStepCheck() const { return true; }
+};
+
+
 // -----------------------------------------------------------------------------
 // Constant pool support
 
 class ConstantPoolEntry {
  public:
   ConstantPoolEntry() {}
   ConstantPoolEntry(int position, intptr_t value, bool sharing_ok)
       : position_(position),
         merged_index_(sharing_ok ? SHARING_ALLOWED : SHARING_PROHIBITED),
         value_(value) {}
@@ skipping 102 matching lines @@
     std::vector<ConstantPoolEntry> shared_entries;
   };
 
   Label emitted_label_;  // Records pc_offset of emitted pool
   PerTypeEntryInfo info_[ConstantPoolEntry::NUMBER_OF_TYPES];
 };
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_ASSEMBLER_H_