Toward precompiled snapshots.

runtime/vm/raw_object_snapshot.cc

Index: runtime/vm/raw_object_snapshot.cc
diff --git a/runtime/vm/raw_object_snapshot.cc b/runtime/vm/raw_object_snapshot.cc
index da3c3a646719b30974de152695bc6150a87bc1f3..49ee85b237c2f47106247e2e2c9ff031ff003d99 100644
--- a/runtime/vm/raw_object_snapshot.cc
+++ b/runtime/vm/raw_object_snapshot.cc
@@ -707,6 +707,8 @@ RawFunction* Function::ReadFrom(SnapshotReader* reader,
     // Initialize all fields that are not part of the snapshot.
     func.ClearICDataArray();
     func.ClearCode();
+  } else {
+    // TODO(rmacnak): Fix entry_point_.
   }
   return func.raw();
 }
@@ -1188,7 +1190,6 @@ RawCode* Code::ReadFrom(SnapshotReader* reader,
                         intptr_t object_id,
                         intptr_t tags,
                         Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
@@ -1211,6 +1212,8 @@ RawCode* Code::ReadFrom(SnapshotReader* reader,
                         reader->PassiveObjectHandle()->raw());
   }
 
+  // TODO(rmacnak): Fix entry_point_.
+
   return result.raw();
 }
 
@@ -1252,15 +1255,22 @@ RawInstructions* Instructions::ReadFrom(SnapshotReader* reader,
                                         intptr_t object_id,
                                         intptr_t tags,
                                         Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
-  intptr_t id = reader->Read<int32_t>();
+  intptr_t full_tags = static_cast<uword>(reader->Read<intptr_t>());
+  intptr_t offset = reader->Read<int32_t>();
   Instructions& result =
       Instructions::ZoneHandle(reader->zone(),
-                               reader->GetInstructionsById(id));
+                               reader->GetInstructionsAt(offset, full_tags));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
+
+  {
+    // TODO(rmacnak): Drop after calling convention change.
+    Code::CheckedHandle(reader->ReadObjectImpl(kAsReference));
+    ObjectPool::CheckedHandle(reader->ReadObjectImpl(kAsReference));
+  }
+
   return result.raw();
 }
 
@@ -1276,11 +1286,23 @@ void RawInstructions::WriteTo(SnapshotWriter* writer,
     writer->WriteInlinedObjectHeader(object_id);
     writer->WriteVMIsolateObject(kInstructionsCid);
     writer->WriteTags(writer->GetObjectTags(this));
-    writer->WriteObjectImpl(ptr()->code_, kAsReference);
-    writer->WriteObjectImpl(ptr()->object_pool_, kAsReference);
   }
 
+  writer->Write<intptr_t>(writer->GetObjectTags(this));  // For sanity check.
+
+  // Temporarily restore the object header for writing to the text section.
+  // TODO(asiva): Don't mutate object headers during serialization.
+  uword object_tags = writer->GetObjectTags(this);
+  uword snapshot_tags = ptr()->tags_;
+  ptr()->tags_ = object_tags;
   writer->Write<int32_t>(writer->GetInstructionsId(this));
+  ptr()->tags_ = snapshot_tags;
+
+  {
+    // TODO(rmacnak): Drop after calling convention change.
+    writer->WriteObjectImpl(ptr()->code_, kAsReference);
+    writer->WriteObjectImpl(ptr()->object_pool_, kAsReference);
+  }
 }
 
 
@@ -1288,7 +1310,6 @@ RawObjectPool* ObjectPool::ReadFrom(SnapshotReader* reader,
                                     intptr_t object_id,
                                     intptr_t tags,
                                     Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
@@ -1299,15 +1320,15 @@ RawObjectPool* ObjectPool::ReadFrom(SnapshotReader* reader,
                              NEW_OBJECT_WITH_LEN(ObjectPool, length));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
-  RawTypedData* info_array = result.raw_ptr()->info_array_->ptr();
+  const TypedData& info_array =
+      TypedData::Handle(reader->NewTypedData(kTypedDataInt8ArrayCid, length));
+  result.set_info_array(info_array);
 
-  // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
+  NoSafepointScope no_safepoint;
   for (intptr_t i = 0; i < length; i++) {
     ObjectPool::EntryType entry_type =
-        static_cast<ObjectPool::EntryType>(reader->Read<uint8_t>());
-    info_array->data()[i] = entry_type;
+        static_cast<ObjectPool::EntryType>(reader->Read<int8_t>());
+    *reinterpret_cast<int8_t*>(info_array.DataAddr(i)) = entry_type;
     switch (entry_type) {
       case ObjectPool::kTaggedObject: {
         (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
@@ -1355,7 +1376,7 @@ void RawObjectPool::WriteTo(SnapshotWriter* writer,
   for (intptr_t i = 0; i < length; i++) {
     ObjectPool::EntryType entry_type =
         static_cast<ObjectPool::EntryType>(info_array->data()[i]);
-    writer->Write<uint8_t>(entry_type);
+    writer->Write<int8_t>(entry_type);
     Entry& entry = ptr()->data()[i];
     switch (entry_type) {
       case ObjectPool::kTaggedObject:
@@ -1379,12 +1400,13 @@ RawPcDescriptors* PcDescriptors::ReadFrom(SnapshotReader* reader,
                                           intptr_t object_id,
                                           intptr_t tags,
                                           Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   const int32_t length = reader->Read<int32_t>();
-  PcDescriptors& result = PcDescriptors::ZoneHandle(reader->zone(),
-                                                    PcDescriptors::New(length));
+  PcDescriptors& result =
+      PcDescriptors::ZoneHandle(reader->zone(),
+                                NEW_OBJECT_WITH_LEN(PcDescriptors, length));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
   if (result.Length() > 0) {
@@ -1402,6 +1424,7 @@ void RawPcDescriptors::WriteTo(SnapshotWriter* writer,
                                intptr_t object_id,
                                Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
@@ -1420,19 +1443,19 @@ RawStackmap* Stackmap::ReadFrom(SnapshotReader* reader,
                                 intptr_t object_id,
                                 intptr_t tags,
                                 Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   const int32_t length = reader->Read<int32_t>();
-  const int32_t register_bit_count = reader->Read<int32_t>();
-  const uword pc_offset = reader->Read<uint32_t>();
-
   Stackmap& result =
       Stackmap::ZoneHandle(reader->zone(),
-        Stackmap::New(length, register_bit_count, pc_offset));
+                           reader->NewStackmap(length));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
-  if (result.Length() > 0) {
+  result.SetRegisterBitCount(reader->Read<int32_t>());
+  result.SetPcOffset(reader->Read<uint32_t>());
+
+  if (length > 0) {
     NoSafepointScope no_safepoint;
     intptr_t len = (result.Length() + 7) / 8;
     uint8_t* data = result.UnsafeMutableNonPointer(result.raw_ptr()->data());
@@ -1447,11 +1470,13 @@ void RawStackmap::WriteTo(SnapshotWriter* writer,
                           intptr_t object_id,
                           Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
   writer->WriteIndexedObject(kStackmapCid);
   writer->WriteTags(writer->GetObjectTags(this));
+
   writer->Write<int32_t>(ptr()->length_);
   writer->Write<int32_t>(ptr()->register_bit_count_);
   writer->Write<uint32_t>(ptr()->pc_offset_);
@@ -1467,14 +1492,15 @@ RawLocalVarDescriptors* LocalVarDescriptors::ReadFrom(SnapshotReader* reader,
                                                       intptr_t object_id,
                                                       intptr_t tags,
                                                       Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   const int32_t num_entries = reader->Read<int32_t>();
 
   LocalVarDescriptors& result =
       LocalVarDescriptors::ZoneHandle(reader->zone(),
-        LocalVarDescriptors::New(num_entries));
+                                      NEW_OBJECT_WITH_LEN(LocalVarDescriptors,
+                                                          num_entries));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
   for (intptr_t i = 0; i < num_entries; i++) {
@@ -1499,6 +1525,7 @@ void RawLocalVarDescriptors::WriteTo(SnapshotWriter* writer,
                                      intptr_t object_id,
                                      Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
@@ -1520,15 +1547,14 @@ RawExceptionHandlers* ExceptionHandlers::ReadFrom(SnapshotReader* reader,
                                                   intptr_t object_id,
                                                   intptr_t tags,
                                                   Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
-  // handled_types_data.
-  *(reader->ArrayHandle()) ^= reader->ReadObjectImpl(kAsInlinedObject);
-
+  const int32_t num_entries = reader->Read<int32_t>();
   ExceptionHandlers& result =
       ExceptionHandlers::ZoneHandle(reader->zone(),
-        ExceptionHandlers::New(*reader->ArrayHandle()));
+                                    NEW_OBJECT_WITH_LEN(ExceptionHandlers,
+                                                        num_entries));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
   if (result.num_entries() > 0) {
@@ -1540,6 +1566,10 @@ RawExceptionHandlers* ExceptionHandlers::ReadFrom(SnapshotReader* reader,
     reader->ReadBytes(data, len);
   }
 
+  *(reader->ArrayHandle()) ^= reader->ReadObjectImpl(kAsInlinedObject);
+  result.StorePointer(&result.raw_ptr()->handled_types_data_,
+                      reader->ArrayHandle()->raw());
+
   return result.raw();
 }
 
@@ -1548,18 +1578,21 @@ void RawExceptionHandlers::WriteTo(SnapshotWriter* writer,
                                    intptr_t object_id,
                                    Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
   writer->WriteIndexedObject(kExceptionHandlersCid);
   writer->WriteTags(writer->GetObjectTags(this));
-  writer->WriteObjectImpl(ptr()->handled_types_data_, kAsInlinedObject);
+  writer->Write<int32_t>(ptr()->num_entries_);
 
   if (ptr()->num_entries_ > 0) {
     intptr_t len = ptr()->num_entries_ * sizeof(HandlerInfo);
     uint8_t* data = reinterpret_cast<uint8_t*>(ptr()->data());
     writer->WriteBytes(data, len);
   }
+
+  writer->WriteObjectImpl(ptr()->handled_types_data_, kAsInlinedObject);
 }
 
 
@@ -1635,7 +1668,6 @@ RawICData* ICData::ReadFrom(SnapshotReader* reader,
                             intptr_t object_id,
                             intptr_t tags,
                             Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
@@ -1686,7 +1718,6 @@ RawMegamorphicCache* MegamorphicCache::ReadFrom(SnapshotReader* reader,
                                                 intptr_t object_id,
                                                 intptr_t tags,
                                                 Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
@@ -1737,7 +1768,6 @@ RawSubtypeTestCache* SubtypeTestCache::ReadFrom(SnapshotReader* reader,
                                                 intptr_t object_id,
                                                 intptr_t tags,
                                                 Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
@@ -2539,13 +2569,18 @@ RawLinkedHashMap* LinkedHashMap::ReadFrom(SnapshotReader* reader,
 
   LinkedHashMap& map = LinkedHashMap::ZoneHandle(
       reader->zone(), LinkedHashMap::null());
-  if (kind == Snapshot::kFull || kind == Snapshot::kScript) {
+  if ((kind == Snapshot::kFull && !reader->snapshot_code()) ||
+      kind == Snapshot::kScript) {
     // The immutable maps that seed map literals are not yet VM-internal, so
     // we don't reach this.
     UNREACHABLE();
   } else {
     // Since the map might contain itself as a key or value, allocate first.
-    map = LinkedHashMap::NewUninitialized(HEAP_SPACE(kind));
+    if (kind == Snapshot::kFull) {
+      map = reader->NewLinkedHashMap();
+    } else {
+      map = LinkedHashMap::NewUninitialized(HEAP_SPACE(kind));
+    }
   }
   reader->AddBackRef(object_id, &map, kIsDeserialized);
 
@@ -2566,7 +2601,9 @@ RawLinkedHashMap* LinkedHashMap::ReadFrom(SnapshotReader* reader,
       Utils::RoundUpToPowerOfTwo(used_data),
       static_cast<uintptr_t>(LinkedHashMap::kInitialIndexSize));
   Array& data = Array::ZoneHandle(reader->zone(),
-                                  Array::New(data_size, HEAP_SPACE(kind)));
+                                  NEW_OBJECT_WITH_LEN_SPACE(Array,
+                                                            data_size,
+                                                            kind));
   map.SetData(data);
   map.SetDeletedKeys(0);
 
@@ -2590,10 +2627,10 @@ RawLinkedHashMap* LinkedHashMap::ReadFrom(SnapshotReader* reader,
 void RawLinkedHashMap::WriteTo(SnapshotWriter* writer,
                                intptr_t object_id,
                                Snapshot::Kind kind) {
-  if (kind == Snapshot::kFull || kind == Snapshot::kScript) {
+  if ((kind == Snapshot::kFull && !writer->snapshot_code()) ||
+      kind == Snapshot::kScript) {
     // The immutable maps that seed map literals are not yet VM-internal, so
     // we don't reach this.
-    UNREACHABLE();
   }
   ASSERT(writer != NULL);
 
@@ -3039,11 +3076,18 @@ RawSendPort* SendPort::ReadFrom(SnapshotReader* reader,
                                 intptr_t object_id,
                                 intptr_t tags,
                                 Snapshot::Kind kind) {
+  ASSERT(kind == Snapshot::kMessage || reader->snapshot_code());
+
   uint64_t id = reader->Read<uint64_t>();
   uint64_t origin_id = reader->Read<uint64_t>();
 
-  SendPort& result = SendPort::ZoneHandle(reader->zone(),
-                                          SendPort::New(id, origin_id));
+  SendPort& result = SendPort::ZoneHandle(reader->zone());
+  if (reader->snapshot_code()) {
+    // TODO(rmacnak): Reset fields in precompiled snapshots and assert
+    // this is unreachable.
+  } else {
+    result = SendPort::New(id, origin_id);
+  }
   reader->AddBackRef(object_id, &result, kIsDeserialized);
   return result.raw();
 }