[interpreter, debugger] support debug breaks via bytecode array copy

src/factory.cc

 // Copyright 2014 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/factory.h"
 
 #include "src/allocation-site-scopes.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/conversions.h"
@@ skipping 1463 matching lines @@
                      Code);
 }
 
 
 Handle<Code> Factory::CopyCode(Handle<Code> code, Vector<byte> reloc_info) {
   CALL_HEAP_FUNCTION(isolate(),
                      isolate()->heap()->CopyCode(*code, reloc_info),
                      Code);
 }
 
+Handle<BytecodeArray> Factory::CopyBytecodeArray(
+    Handle<BytecodeArray> bytecode_array) {
+  CALL_HEAP_FUNCTION(isolate(),
+                     isolate()->heap()->CopyBytecodeArray(*bytecode_array),
+                     BytecodeArray);
+}
 
 Handle<JSObject> Factory::NewJSObject(Handle<JSFunction> constructor,
                                       PretenureFlag pretenure) {
   JSFunction::EnsureHasInitialMap(constructor);
   CALL_HEAP_FUNCTION(
       isolate(),
       isolate()->heap()->AllocateJSObject(*constructor, pretenure), JSObject);
 }
 
 
@@ skipping 628 matching lines @@
   share->set_code(*code);
   share->set_optimized_code_map(*cleared_optimized_code_map());
   share->set_scope_info(ScopeInfo::Empty(isolate()));
   Handle<Code> construct_stub =
       is_constructor ? isolate()->builtins()->JSConstructStubGeneric()
                      : isolate()->builtins()->ConstructedNonConstructable();
   share->set_construct_stub(*construct_stub);
   share->set_instance_class_name(*Object_string());
   share->set_function_data(*undefined_value(), SKIP_WRITE_BARRIER);
   share->set_script(*undefined_value(), SKIP_WRITE_BARRIER);
-  share->set_debug_info(*undefined_value(), SKIP_WRITE_BARRIER);
+  share->set_debug_info(DebugInfo::uninitialized(), SKIP_WRITE_BARRIER);
   share->set_inferred_name(*empty_string(), SKIP_WRITE_BARRIER);
   StaticFeedbackVectorSpec empty_spec;
   Handle<TypeFeedbackMetadata> feedback_metadata =
       TypeFeedbackMetadata::New(isolate(), &empty_spec);
   Handle<TypeFeedbackVector> feedback_vector =
       TypeFeedbackVector::New(isolate(), feedback_metadata);
   share->set_feedback_vector(*feedback_vector, SKIP_WRITE_BARRIER);
 #if TRACE_MAPS
   share->set_unique_id(isolate()->GetNextUniqueSharedFunctionInfoId());
 #endif
@@ skipping 101 matching lines @@
   Handle<FixedArray> break_points(
       NewFixedArray(DebugInfo::kEstimatedNofBreakPointsInFunction));
 
   // Create and set up the debug info object. Debug info contains function, a
   // copy of the original code, the executing code and initial fixed array for
   // active break points.
   Handle<DebugInfo> debug_info =
       Handle<DebugInfo>::cast(NewStruct(DEBUG_INFO_TYPE));
   debug_info->set_shared(*shared);
   if (shared->HasBytecodeArray()) {
-    debug_info->set_abstract_code(AbstractCode::cast(shared->bytecode_array()));
+    // Create a copy for debugging.
+    Handle<BytecodeArray> original(shared->bytecode_array(), isolate());
+    Handle<BytecodeArray> copy = CopyBytecodeArray(original);
+    debug_info->set_abstract_code(AbstractCode::cast(*copy));
   } else {
     debug_info->set_abstract_code(AbstractCode::cast(shared->code()));
   }
   debug_info->set_break_points(*break_points);
 
   // Link debug info to function.
   shared->set_debug_info(*debug_info);
 
   return debug_info;
 }
@@ skipping 126 matching lines @@
 }
 
 
 Handle<Object> Factory::ToBoolean(bool value) {
   return value ? true_value() : false_value();
 }
 
 
 }  // namespace internal
 }  // namespace v8