Fixes crashes in VM isolate shutdown.

runtime/vm/object.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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 360 matching lines @@
   } else if (value == '\\') {
     return '\\';
   } else if (value == '$') {
     return '$';
   }
   UNREACHABLE();
   return '\0';
 }
 
 
+void Object::InitNull(Isolate* isolate) {
+  // Should only be run by the vm isolate.
+  ASSERT(isolate == Dart::vm_isolate());
+
+  // TODO(iposva): NoSafepointScope needs to be added here.
+  ASSERT(class_class() == null_);
+
+  Heap* heap = isolate->heap();
+
+  // Allocate and initialize the null instance.
+  // 'null_' must be the first object allocated as it is used in allocation to
+  // clear the object.
+  {
+    uword address = heap->Allocate(Instance::InstanceSize(), Heap::kOld);
+    null_ = reinterpret_cast<RawInstance*>(address + kHeapObjectTag);
+    // The call below is using 'null_' to initialize itself.
+    InitializeObject(address, kNullCid, Instance::InstanceSize());
+  }
+}
+
+
 void Object::InitOnce(Isolate* isolate) {
   // Should only be run by the vm isolate.
   ASSERT(isolate == Dart::vm_isolate());
 
-  // TODO(iposva): NoSafepointScope needs to be added here.
-  ASSERT(class_class() == null_);
   // Initialize the static vtable values.
   {
     Object fake_object;
     Smi fake_smi;
     Object::handle_vtable_ = fake_object.vtable();
     Smi::handle_vtable_ = fake_smi.vtable();
   }
 
   Heap* heap = isolate->heap();
 
@@ skipping 14 matching lines @@
   transition_sentinel_ = Instance::ReadOnlyHandle();
   unknown_constant_ =  Instance::ReadOnlyHandle();
   non_constant_ =  Instance::ReadOnlyHandle();
   bool_true_ = Bool::ReadOnlyHandle();
   bool_false_ = Bool::ReadOnlyHandle();
   smi_illegal_cid_ = Smi::ReadOnlyHandle();
   snapshot_writer_error_ = LanguageError::ReadOnlyHandle();
   branch_offset_error_ = LanguageError::ReadOnlyHandle();
   vm_isolate_snapshot_object_table_ = Array::ReadOnlyHandle();
 
-
-  // Allocate and initialize the null instance.
-  // 'null_' must be the first object allocated as it is used in allocation to
-  // clear the object.
-  {
-    uword address = heap->Allocate(Instance::InstanceSize(), Heap::kOld);
-    null_ = reinterpret_cast<RawInstance*>(address + kHeapObjectTag);
-    // The call below is using 'null_' to initialize itself.
-    InitializeObject(address, kNullCid, Instance::InstanceSize());
-  }
-
   *null_object_ = Object::null();
   *null_array_ = Array::null();
   *null_string_ = String::null();
   *null_instance_ = Instance::null();
   *null_type_arguments_ = TypeArguments::null();
 
   // Initialize the empty and zero array handles to null_ in order to be able to
   // check if the empty and zero arrays were allocated (RAW_NULL is not
   // available).
   *empty_array_ = Array::null();
@@ skipping 4647 matching lines @@
   StorePointer(&raw_ptr()->patched_class_, value.raw());
 }
 
 
 void PatchClass::set_source_class(const Class& value) const {
   StorePointer(&raw_ptr()->source_class_, value.raw());
 }
 
 
 bool Function::HasBreakpoint() const {
+  ASSERT(Isolate::Current()->debugger() != NULL);
   return Isolate::Current()->debugger()->HasBreakpoint(*this);
 }
 
 
 void Function::SetInstructions(const Code& value) const {
   StorePointer(&raw_ptr()->instructions_, value.instructions());
 }
 
 void Function::AttachCode(const Code& value) const {
   SetInstructions(value);
@@ skipping 511 matching lines @@
 }
 
 
 void Function::SetIsNativeAutoSetupScope(bool value) const {
   ASSERT(is_native());
   set_is_optimizable(value);
 }
 
 
 bool Function::CanBeInlined() const {
+  ASSERT(Isolate::Current()->debugger() != NULL);
   return is_inlinable() &&
          !is_generated_body() &&
          HasCode() &&
          !Isolate::Current()->debugger()->HasBreakpoint(*this);
 }
 
 
 intptr_t Function::NumParameters() const {
   return num_fixed_parameters() + NumOptionalParameters();
 }
@@ skipping 6582 matching lines @@
   for (intptr_t i = kSCallTableEntryLength;
       i < value.Length();
       i += kSCallTableEntryLength) {
     ASSERT(value.At(i - kSCallTableEntryLength) < value.At(i));
   }
 #endif  // DEBUG
 }
 
 
 bool Code::HasBreakpoint() const {
+  ASSERT(Isolate::Current()->debugger() != NULL);
   return Isolate::Current()->debugger()->HasBreakpoint(*this);
 }
 
 
 RawTypedData* Code::GetDeoptInfoAtPc(uword pc,
                                      ICData::DeoptReasonId* deopt_reason,
                                      uint32_t* deopt_flags) const {
   ASSERT(is_optimized());
   const Instructions& instrs = Instructions::Handle(instructions());
   uword code_entry = instrs.EntryPoint();
@@ skipping 8610 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart