Omit unused code metadata from precompiled snapshots.

runtime/vm/raw_object_snapshot.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/native_entry.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/snapshot.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
@@ skipping 650 matching lines @@
   bool is_in_fullsnapshot = reader->Read<bool>();
   if ((kind == Snapshot::kFull) || !is_in_fullsnapshot) {
     // Allocate function object.
     Function& func = Function::ZoneHandle(
         reader->zone(), NEW_OBJECT(Function));
     reader->AddBackRef(object_id, &func, kIsDeserialized);
 
     // Set all the non object fields.
     func.set_token_pos(reader->Read<int32_t>());
     func.set_end_token_pos(reader->Read<int32_t>());
-    func.set_usage_counter(reader->Read<int32_t>());
     func.set_num_fixed_parameters(reader->Read<int16_t>());
     func.set_num_optional_parameters(reader->Read<int16_t>());
-    func.set_deoptimization_counter(reader->Read<int16_t>());
     func.set_kind_tag(reader->Read<uint32_t>());
-    func.set_optimized_instruction_count(reader->Read<uint16_t>());
-    func.set_optimized_call_site_count(reader->Read<uint16_t>());
+    if (!reader->snapshot_code()) {
+      func.set_usage_counter(reader->Read<int32_t>());
+      func.set_deoptimization_counter(reader->Read<int16_t>());
+      func.set_optimized_instruction_count(reader->Read<uint16_t>());
+      func.set_optimized_call_site_count(reader->Read<uint16_t>());
+    } else {
+      func.set_usage_counter(0);
+      func.set_deoptimization_counter(0);
+      func.set_optimized_instruction_count(0);
+      func.set_optimized_call_site_count(0);
+    }
 
     // Set all the object fields.
     READ_OBJECT_FIELDS(func,
                        func.raw()->from(), func.raw()->to_snapshot(),
                        kAsReference);
     // Initialize all fields that are not part of the snapshot.
     if (reader->snapshot_code()) {
       func.ClearICDataArray();
       func.ClearCode();
       // Read the code object and fixup entry point.
@@ skipping 46 matching lines @@
   // help the reader decide how the rest of the information needs
   // to be interpreted.
   writer->Write<bool>(is_in_fullsnapshot);
 
   if (kind == Snapshot::kFull || !is_in_fullsnapshot) {
     bool is_optimized = Code::IsOptimized(ptr()->code_);
 
     // Write out all the non object fields.
     writer->Write<int32_t>(ptr()->token_pos_);
     writer->Write<int32_t>(ptr()->end_token_pos_);
-    if (is_optimized) {
-      writer->Write<int32_t>(FLAG_optimization_counter_threshold);
-    } else {
-      writer->Write<int32_t>(0);
-    }
     writer->Write<int16_t>(ptr()->num_fixed_parameters_);
     writer->Write<int16_t>(ptr()->num_optional_parameters_);
-    writer->Write<int16_t>(ptr()->deoptimization_counter_);
     writer->Write<uint32_t>(ptr()->kind_tag_);
-    writer->Write<uint16_t>(ptr()->optimized_instruction_count_);
-    writer->Write<uint16_t>(ptr()->optimized_call_site_count_);
+    if (!writer->snapshot_code()) {

[srdjan, 2015/11/13 21:14:02]

ditto

[rmacnak, 2015/11/13 21:56:02]

Done.

+      if (is_optimized) {
+        writer->Write<int32_t>(FLAG_optimization_counter_threshold);
+      } else {
+        writer->Write<int32_t>(0);
+      }
+      writer->Write<int16_t>(ptr()->deoptimization_counter_);
+      writer->Write<uint16_t>(ptr()->optimized_instruction_count_);
+      writer->Write<uint16_t>(ptr()->optimized_call_site_count_);
+    }
 
     // Write out all the object pointer fields.
     SnapshotWriterVisitor visitor(writer, kAsReference);
     visitor.VisitPointers(from(), to_snapshot());
     if (writer->snapshot_code()) {
       ASSERT(ptr()->ic_data_array_ == Array::null());
       ASSERT((ptr()->code_ == ptr()->unoptimized_code_) ||
              (ptr()->unoptimized_code_ == Code::null()));
       // Write out the code object as we are generating a precompiled snapshot.
       writer->WriteObjectImpl(ptr()->code_, kAsInlinedObject);
@@ skipping 482 matching lines @@
                         intptr_t object_id,
                         intptr_t tags,
                         Snapshot::Kind kind,
                         bool as_reference) {
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
   Code& result = Code::ZoneHandle(reader->zone(), NEW_OBJECT_WITH_LEN(Code, 0));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
-  result.set_compile_timestamp(reader->Read<int64_t>());
+  result.set_compile_timestamp(0);
   result.set_state_bits(reader->Read<int32_t>());
-  result.set_lazy_deopt_pc_offset(reader->Read<int32_t>());
+  result.set_lazy_deopt_pc_offset(-1);
 
   // Set all the object fields.
   READ_OBJECT_FIELDS(result,
-                     result.raw()->from(), result.raw()->to(),
+                     result.raw()->from(), result.raw()->to_snapshot(),
                      kAsReference);
+  for (RawObject** ptr = result.raw()->to();
+       ptr > result.raw()->to_snapshot();
+       ptr--) {
+    result.StorePointer(ptr, Object::null());
+  }
 
   // Fix entry point.
   uword new_entry = result.EntryPoint();
   ASSERT(Dart::vm_isolate()->heap()->CodeContains(new_entry));
   result.StoreNonPointer(&result.raw_ptr()->entry_point_, new_entry);
 
   return result.raw();
 }
 
 
 void RawCode::WriteTo(SnapshotWriter* writer,
                       intptr_t object_id,
                       Snapshot::Kind kind,
                       bool as_reference) {
   ASSERT(writer->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
   intptr_t pointer_offsets_length =
       Code::PtrOffBits::decode(ptr()->state_bits_);
   if (pointer_offsets_length != 0) {
     // Should only be IA32.
-    FATAL("Serializing embedded pointer offsets unimplemented");
+    FATAL("Cannot serialize code with embedded pointers");
   }
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
 
   // Write out the class and tags information.
   writer->WriteVMIsolateObject(kCodeCid);
   writer->WriteTags(writer->GetObjectTags(this));
 
   // Write out all the non object fields.
-  writer->Write<int64_t>(ptr()->compile_timestamp_);
   writer->Write<int32_t>(ptr()->state_bits_);
-  writer->Write<int32_t>(ptr()->lazy_deopt_pc_offset_);
 
   // Write out all the object pointer fields.
   SnapshotWriterVisitor visitor(writer, kAsReference);
-  visitor.VisitPointers(from(), to());
+  visitor.VisitPointers(from(), to_snapshot());
 
   writer->SetInstructionsCode(ptr()->instructions_, this);
 }
 
 
 RawInstructions* Instructions::ReadFrom(SnapshotReader* reader,
                                         intptr_t object_id,
                                         intptr_t tags,
                                         Snapshot::Kind kind,
                                         bool as_reference) {
@@ skipping 2167 matching lines @@
     // We do not allow objects with native fields in an isolate message.
     writer->SetWriteException(Exceptions::kArgument,
                               "Illegal argument in isolate message"
                               " : (object is a UserTag)");
   } else {
     UNREACHABLE();
   }
 }
 
 }  // namespace dart