Handle possible difference between function code and activated code on preparation for break points

src/debug.cc

 // Copyright 2011 the V8 project authors. 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1778 matching lines @@
         if (frame->is_optimized()) {
           List<JSFunction*> functions(Compiler::kMaxInliningLevels + 1);
           frame->GetFunctions(&functions);
           for (int i = 0; i < functions.length(); i++) {
             if (!functions[i]->shared()->code()->has_debug_break_slots()) {
               active_functions.Add(Handle<JSFunction>(functions[i]));
             }
           }
         } else if (frame->function()->IsJSFunction()) {
           JSFunction* function = JSFunction::cast(frame->function());
-          if (function->code()->kind() == Code::FUNCTION &&
-              !function->code()->has_debug_break_slots()) {
+          ASSERT(frame->LookupCode()->kind() == Code::FUNCTION);
+          if (!frame->LookupCode()->has_debug_break_slots() ||
+              !function->shared()->code()->has_debug_break_slots()) {
             active_functions.Add(Handle<JSFunction>(function));
           }
         }
       }
 
       // Sort the functions on the object pointer value to prepare for
       // the binary search below.
       active_functions.Sort(HandleObjectPointerCompare<JSFunction>);
 
       // Scan the heap for all non-optimized functions which has no
@@ skipping 35 matching lines @@
           !shared->allows_lazy_compilation() ||
           shared->code()->kind() == Code::BUILTIN) {
         continue;
       }
 
       // Make sure that the shared full code is compiled with debug
       // break slots.
       if (function->code() == *lazy_compile) {
         function->set_code(shared->code());
       }
-      Handle<Code> current_code(function->code());
-      if (shared->code()->has_debug_break_slots()) {
-        // if the code is already recompiled to have break slots skip
-        // recompilation.
-        ASSERT(!function->code()->has_debug_break_slots());
-      } else {
+      if (!shared->code()->has_debug_break_slots()) {
         // Try to compile the full code with debug break slots. If it
         // fails just keep the current code.
-        ASSERT(shared->code() == *current_code);
+        Handle<Code> current_code(function->shared()->code());
         ZoneScope zone_scope(isolate_, DELETE_ON_EXIT);
         shared->set_code(*lazy_compile);
         bool prev_force_debugger_active =
             isolate_->debugger()->force_debugger_active();
         isolate_->debugger()->set_force_debugger_active(true);
+        ASSERT(current_code->kind() == Code::FUNCTION);
         CompileFullCodeForDebugging(shared, current_code);
         isolate_->debugger()->set_force_debugger_active(
             prev_force_debugger_active);
         if (!shared->is_compiled()) {
           shared->set_code(*current_code);
           continue;
         }
       }
       Handle<Code> new_code(shared->code());
 
       // Find the function and patch the return address.
       for (JavaScriptFrameIterator it(isolate_); !it.done(); it.Advance()) {
         JavaScriptFrame* frame = it.frame();
         // If the current frame is for this function in its
         // non-optimized form rewrite the return address to continue
         // in the newly compiled full code with debug break slots.
-        if (frame->function()->IsJSFunction() &&
-            frame->function() == *function &&
-            frame->LookupCode()->kind() == Code::FUNCTION) {
-          intptr_t delta = frame->pc() - current_code->instruction_start();
+        if (!frame->is_optimized() &&
+            frame->function()->IsJSFunction() &&
+            frame->function() == *function) {
+          ASSERT(frame->LookupCode()->kind() == Code::FUNCTION);
+          Handle<Code> frame_code(frame->LookupCode());
+          if (frame_code->has_debug_break_slots()) continue;
+          intptr_t delta = frame->pc() - frame_code->instruction_start();
           int debug_break_slot_count = 0;
           int mask = RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT);
           for (RelocIterator it(*new_code, mask); !it.done(); it.next()) {
             // Check if the pc in the new code with debug break
             // slots is before this slot.
             RelocInfo* info = it.rinfo();
             int debug_break_slot_bytes =
                 debug_break_slot_count * Assembler::kDebugBreakSlotLength;
             intptr_t new_delta =
                 info->pc() -
                 new_code->instruction_start() -
                 debug_break_slot_bytes;
             if (new_delta > delta) {
               break;
             }
 
             // Passed a debug break slot in the full code with debug
             // break slots.
             debug_break_slot_count++;
           }
           int debug_break_slot_bytes =
               debug_break_slot_count * Assembler::kDebugBreakSlotLength;
           if (FLAG_trace_deopt) {
             PrintF("Replacing code %08" V8PRIxPTR " - %08" V8PRIxPTR " (%d) "
                    "with %08" V8PRIxPTR " - %08" V8PRIxPTR " (%d) "
                    "for debugging, "
                    "changing pc from %08" V8PRIxPTR " to %08" V8PRIxPTR "\n",
                    reinterpret_cast<intptr_t>(
-                       current_code->instruction_start()),
+                       frame_code->instruction_start()),
                    reinterpret_cast<intptr_t>(
-                       current_code->instruction_start()) +
-                       current_code->instruction_size(),
-                   current_code->instruction_size(),
+                       frame_code->instruction_start()) +
+                       frame_code->instruction_size(),
+                   frame_code->instruction_size(),
                    reinterpret_cast<intptr_t>(new_code->instruction_start()),
                    reinterpret_cast<intptr_t>(new_code->instruction_start()) +
                        new_code->instruction_size(),
                    new_code->instruction_size(),
                    reinterpret_cast<intptr_t>(frame->pc()),
                    reinterpret_cast<intptr_t>(new_code->instruction_start()) +
                        delta + debug_break_slot_bytes);
           }
 
           // Patch the return address to return into the code with
@@ skipping 1557 matching lines @@
     {
       Locker locker;
       Isolate::Current()->debugger()->CallMessageDispatchHandler();
     }
   }
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal