When creating a JIT app snapshot, don't recreate the VM isolate snapshot.

runtime/vm/clustered_snapshot.cc

 // Copyright (c) 2016, 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/clustered_snapshot.h"
 
 #include "platform/assert.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
@@ skipping 4648 matching lines @@
   ClassTable* table = isolate()->class_table();
   for (intptr_t cid = kClassCid; cid < kInstanceCid; cid++) {
     // Error has no class object.
     if (cid != kErrorCid) {
       ASSERT(table->HasValidClassAt(cid));
       AddBaseObject(table->At(cid));
     }
   }
   AddBaseObject(table->At(kDynamicCid));
   AddBaseObject(table->At(kVoidCid));
+
+  if (kind_ != Snapshot::kAppAOT) {
+    for (intptr_t i = 0; i < StubCode::NumEntries(); i++) {
+      AddBaseObject(StubCode::EntryAt(i)->code());
+    }
+  }
 }
 
 
 intptr_t Serializer::WriteVMSnapshot(const Array& symbols,
                                      const Array& scripts) {
   NoSafepointScope no_safepoint;
 
   AddVMIsolateBaseObjects();
 
   // Push roots.
   Push(symbols.raw());
   Push(scripts.raw());
   if (Snapshot::IncludesCode(kind_)) {
-    StubCode::Push(this);
+    for (intptr_t i = 0; i < StubCode::NumEntries(); i++) {
+      Push(StubCode::EntryAt(i)->code());
+    }
   }
 
   Serialize();
 
   // Write roots.
   WriteRef(symbols.raw());
   WriteRef(scripts.raw());
   if (Snapshot::IncludesCode(kind_)) {
-    StubCode::WriteRef(this);
+    for (intptr_t i = 0; i < StubCode::NumEntries(); i++) {
+      WriteRef(StubCode::EntryAt(i)->code());
+    }
   }
 
 #if defined(DEBUG)
   Write<int32_t>(kSectionMarker);
 #endif
 
   // Note we are not clearing the object id table. The full ref table
   // of the vm isolate snapshot serves as the base objects for the
   // regular isolate snapshot.
 
@@ skipping 341 matching lines @@
   ClassTable* table = isolate()->class_table();
   for (intptr_t cid = kClassCid; cid <= kUnwindErrorCid; cid++) {
     // Error has no class object.
     if (cid != kErrorCid) {
       ASSERT(table->HasValidClassAt(cid));
       AddBaseObject(table->At(cid));
     }
   }
   AddBaseObject(table->At(kDynamicCid));
   AddBaseObject(table->At(kVoidCid));
+
+  if (kind_ != Snapshot::kAppAOT) {
+    for (intptr_t i = 0; i < StubCode::NumEntries(); i++) {
+      AddBaseObject(StubCode::EntryAt(i)->code());
+    }
+  }
 }
 
 
 void Deserializer::ReadVMSnapshot() {
   Array& symbol_table = Array::Handle(zone_);
   Array& refs = Array::Handle(zone_);
   Prepare();
 
   {
     NoSafepointScope no_safepoint;
     HeapLocker hl(thread(), heap_->old_space());
 
     AddVMIsolateBaseObjects();
 
     Deserialize();
 
     // Read roots.
     symbol_table ^= ReadRef();
     isolate()->object_store()->set_symbol_table(symbol_table);
     ReadRef();  // Script list.
     if (Snapshot::IncludesCode(kind_)) {
-      StubCode::ReadRef(this);
+      Code& code = Code::Handle(zone_);
+      for (intptr_t i = 0; i < StubCode::NumEntries(); i++) {
+        code ^= ReadRef();
+        StubCode::EntryAtPut(i, new StubEntry(code));
+      }
     }
 
 #if defined(DEBUG)
     int32_t section_marker = Read<int32_t>();
     ASSERT(section_marker == kSectionMarker);
 #endif
 
     refs = refs_;
     refs_ = NULL;
   }
@@ skipping 224 matching lines @@
   WriteIsolateFullSnapshot(num_base_objects);
 
   if (FLAG_print_snapshot_sizes) {
     OS::Print("VMIsolate(CodeSize): %" Pd "\n", VmIsolateSnapshotSize());
     OS::Print("Isolate(CodeSize): %" Pd "\n", IsolateSnapshotSize());
   }
   intptr_t total_size = VmIsolateSnapshotSize() + IsolateSnapshotSize();
 
   if (Snapshot::IncludesCode(kind_)) {
     instructions_writer_->Write(
-        *vm_isolate_snapshot_buffer_, vm_isolate_snapshot_size_,
-        *isolate_snapshot_buffer_, isolate_snapshot_size_);
+        vm_isolate_snapshot_buffer_ == NULL ? NULL
+                                            : *vm_isolate_snapshot_buffer_,
+        vm_isolate_snapshot_size_, *isolate_snapshot_buffer_,
+        isolate_snapshot_size_);
 
     if (FLAG_print_snapshot_sizes) {
       OS::Print("ReadOnlyData(CodeSize): %" Pd "\n",
                 instructions_writer_->data_size());
       OS::Print("Instructions(CodeSize): %" Pd "\n",
                 instructions_writer_->text_size());
     }
     total_size +=
         instructions_writer_->data_size() + instructions_writer_->text_size();
   }
@@ skipping 30 matching lines @@
 
   deserializer.ReadVMSnapshot();
 
   Dart::set_instructions_snapshot_buffer(instructions_buffer_);
   Dart::set_data_snapshot_buffer(data_buffer_);
 
   return ApiError::null();
 }
 
 }  // namespace dart