Changes to prepare for allowing script snapshots to be taken after running the main application

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 80 matching lines @@
 #error RAW_NULL should not be defined.
 #endif
 #define RAW_NULL kHeapObjectTag
 Object* Object::null_object_ = NULL;
 Array* Object::null_array_ = NULL;
 String* Object::null_string_ = NULL;
 Instance* Object::null_instance_ = NULL;
 TypeArguments* Object::null_type_arguments_ = NULL;
 Array* Object::empty_array_ = NULL;
 Array* Object::zero_array_ = NULL;
+ContextScope* Object::empty_context_scope_ = NULL;
 ObjectPool* Object::empty_object_pool_ = NULL;
 PcDescriptors* Object::empty_descriptors_ = NULL;
 LocalVarDescriptors* Object::empty_var_descriptors_ = NULL;
 ExceptionHandlers* Object::empty_exception_handlers_ = NULL;
 Array* Object::extractor_parameter_types_ = NULL;
 Array* Object::extractor_parameter_names_ = NULL;
 Instance* Object::sentinel_ = NULL;
 Instance* Object::transition_sentinel_ = NULL;
 Instance* Object::unknown_constant_ = NULL;
 Instance* Object::non_constant_ = NULL;
@@ skipping 309 matching lines @@
   Heap* heap = isolate->heap();
 
   // Allocate the read only object handles here.
   null_object_ = Object::ReadOnlyHandle();
   null_array_ = Array::ReadOnlyHandle();
   null_string_ = String::ReadOnlyHandle();
   null_instance_ = Instance::ReadOnlyHandle();
   null_type_arguments_ = TypeArguments::ReadOnlyHandle();
   empty_array_ = Array::ReadOnlyHandle();
   zero_array_ = Array::ReadOnlyHandle();
+  empty_context_scope_ = ContextScope::ReadOnlyHandle();
   empty_object_pool_ = ObjectPool::ReadOnlyHandle();
   empty_descriptors_ = PcDescriptors::ReadOnlyHandle();
   empty_var_descriptors_ = LocalVarDescriptors::ReadOnlyHandle();
   empty_exception_handlers_ = ExceptionHandlers::ReadOnlyHandle();
   extractor_parameter_types_ = Array::ReadOnlyHandle();
   extractor_parameter_names_ = Array::ReadOnlyHandle();
   sentinel_ = Instance::ReadOnlyHandle();
   transition_sentinel_ = Instance::ReadOnlyHandle();
   unknown_constant_ =  Instance::ReadOnlyHandle();
   non_constant_ =  Instance::ReadOnlyHandle();
@@ skipping 209 matching lines @@
     uword address = heap->Allocate(Array::InstanceSize(1), Heap::kOld);
     InitializeObject(address, kImmutableArrayCid, Array::InstanceSize(1), true);
     Array::initializeHandle(
         zero_array_,
         reinterpret_cast<RawArray*>(address + kHeapObjectTag));
     zero_array_->StoreSmi(&zero_array_->raw_ptr()->length_, Smi::New(1));
     smi = Smi::New(0);
     zero_array_->SetAt(0, smi);
   }
 
+  // Allocate and initialize the canonical empty context scope object.
+  {
+    uword address = heap->Allocate(ContextScope::InstanceSize(0), Heap::kOld);
+    InitializeObject(address,
+                     kContextScopeCid,
+                     ContextScope::InstanceSize(0),
+                     true);
+    ContextScope::initializeHandle(
+        empty_context_scope_,
+        reinterpret_cast<RawContextScope*>(address + kHeapObjectTag));
+    empty_context_scope_->StoreNonPointer(
+        &empty_context_scope_->raw_ptr()->num_variables_, 0);
+    empty_context_scope_->StoreNonPointer(
+        &empty_context_scope_->raw_ptr()->is_implicit_, true);
+  }
+
   // Allocate and initialize the canonical empty object pool object.
   {
     uword address =
         heap->Allocate(ObjectPool::InstanceSize(0), Heap::kOld);
     InitializeObject(address,
                      kObjectPoolCid,
                      ObjectPool::InstanceSize(0),
                      true);
     ObjectPool::initializeHandle(
         empty_object_pool_,
@@ skipping 100 matching lines @@
   ASSERT(!null_string_->IsSmi());
   ASSERT(null_string_->IsString());
   ASSERT(!null_instance_->IsSmi());
   ASSERT(null_instance_->IsInstance());
   ASSERT(!null_type_arguments_->IsSmi());
   ASSERT(null_type_arguments_->IsTypeArguments());
   ASSERT(!empty_array_->IsSmi());
   ASSERT(empty_array_->IsArray());
   ASSERT(!zero_array_->IsSmi());
   ASSERT(zero_array_->IsArray());
+  ASSERT(!empty_context_scope_->IsSmi());
+  ASSERT(empty_context_scope_->IsContextScope());
   ASSERT(!empty_descriptors_->IsSmi());
   ASSERT(empty_descriptors_->IsPcDescriptors());
   ASSERT(!empty_var_descriptors_->IsSmi());
   ASSERT(empty_var_descriptors_->IsLocalVarDescriptors());
   ASSERT(!empty_exception_handlers_->IsSmi());
   ASSERT(empty_exception_handlers_->IsExceptionHandlers());
   ASSERT(!sentinel_->IsSmi());
   ASSERT(sentinel_->IsInstance());
   ASSERT(!transition_sentinel_->IsSmi());
   ASSERT(transition_sentinel_->IsInstance());
@@ skipping 5595 matching lines @@
   if (implicit_closure_function() != Function::null()) {
     return implicit_closure_function();
   }
   ASSERT(!IsSignatureFunction() && !IsClosureFunction());
   // Create closure function.
   const String& closure_name = String::Handle(name());
   const Function& closure_function = Function::Handle(
       NewClosureFunction(closure_name, *this, token_pos()));
 
   // Set closure function's context scope.
-  ContextScope& context_scope = ContextScope::Handle();
   if (is_static()) {
-    context_scope = ContextScope::New(0);
+    closure_function.set_context_scope(Object::empty_context_scope());
   } else {
-    context_scope = LocalScope::CreateImplicitClosureScope(*this);
+    const ContextScope& context_scope =
+        ContextScope::Handle(LocalScope::CreateImplicitClosureScope(*this));
+    closure_function.set_context_scope(context_scope);
   }
-  closure_function.set_context_scope(context_scope);
 
   // Set closure function's result type to this result type.
   closure_function.set_result_type(AbstractType::Handle(result_type()));
 
   // Set closure function's end token to this end token.
   closure_function.set_end_token_pos(end_token_pos());
 
   // The closurized method stub just calls into the original method and should
   // therefore be skipped by the debugger and in stack traces.
   closure_function.set_is_debuggable(false);
@@ skipping 7163 matching lines @@
   JSONArray jsarr(&jsobj, "variables");
   Object& var = Object::Handle();
   for (intptr_t index = 0; index < num_variables(); index++) {
     var = At(index);
     JSONObject jselement(&jsarr);
     jselement.AddProperty("value", var);
   }
 }
 
 
-RawContextScope* ContextScope::New(intptr_t num_variables) {
+RawContextScope* ContextScope::New(intptr_t num_variables, bool is_implicit) {
   ASSERT(Object::context_scope_class() != Class::null());
   if (num_variables < 0 || num_variables > kMaxElements) {
     // This should be caught before we reach here.
     FATAL1("Fatal error in ContextScope::New: invalid num_variables %" Pd "\n",
            num_variables);
   }
   intptr_t size = ContextScope::InstanceSize(num_variables);
   ContextScope& result = ContextScope::Handle();
   {
     RawObject* raw = Object::Allocate(ContextScope::kClassId,
                                       size,
                                       Heap::kOld);
     NoSafepointScope no_safepoint;
     result ^= raw;
     result.set_num_variables(num_variables);
+    result.set_is_implicit(is_implicit);
   }
   return result.raw();
 }
 
 
 intptr_t ContextScope::TokenIndexAt(intptr_t scope_index) const {
   return Smi::Value(VariableDescAddr(scope_index)->token_pos);
 }
 
 
@@ skipping 7859 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart