Snapshot clean ups

- Don't call eval() in mock_runtime - not allowed - see js2c.py.
- Don't use v8_use_external_startup_data
- Move MakeSnapshot to snapshot_creator.cc
- Use logging.h in from_snapshot.cc

deno2/snapshot_creator.cc

@@ -7,41 +7,59 @@
 #include "v8/include/v8.h"
 #include "v8/src/base/logging.h"
 
-v8::StartupData StringToStartupData(const std::string& s) {
-  return v8::StartupData{s.c_str(), s.size()};
+namespace deno {
+
+v8::StartupData SerializeInternalFields(v8::Local<v8::Object> holder, int index,
+                                        void* data) {
+  DCHECK_EQ(data, nullptr);
+  InternalFieldData* embedder_field = static_cast<InternalFieldData*>(
+      holder->GetAlignedPointerFromInternalField(index));
+  if (embedder_field == nullptr) return {nullptr, 0};
+  int size = sizeof(*embedder_field);
+  char* payload = new char[size];
+  // We simply use memcpy to serialize the content.
+  memcpy(payload, embedder_field, size);
+  return {payload, size};
 }
 
+v8::StartupData MakeSnapshot(const char* js_filename, const char* js_source) {
+  auto* creator = new v8::SnapshotCreator(external_references);
+  auto* isolate = creator->GetIsolate();
+  v8::Isolate::Scope isolate_scope(isolate);
+  {
+    v8::HandleScope handle_scope(isolate);
+    auto context = v8::Context::New(isolate);
+    InitializeContext(isolate, context, js_filename, js_source);
+    creator->SetDefaultContext(context, v8::SerializeInternalFieldsCallback(
+                                            SerializeInternalFields, nullptr));
+  }
+
+  // Note that using kKeep here will cause segfaults. This is demoed in the
+  // "SnapshotBug" test case.
+  auto snapshot_blob =
+      creator->CreateBlob(v8::SnapshotCreator::FunctionCodeHandling::kClear);
+
+  return snapshot_blob;
+}
+
+}  // namespace deno
+
 int main(int argc, char** argv) {
   const char* js_fn = argv[1];
-  const char* natives_in_bin = argv[2];
-  const char* snapshot_in_bin = argv[3];
-  const char* natives_out_cc = argv[4];
-  const char* snapshot_out_cc = argv[5];
-
-  CHECK_NE(js_fn, nullptr);
-  CHECK_NE(natives_in_bin, nullptr);
-  CHECK_NE(snapshot_in_bin, nullptr);
-  CHECK_NE(natives_out_cc, nullptr);
-  CHECK_NE(snapshot_out_cc, nullptr);
+  const char* snapshot_out_cc = argv[2];
 
   v8::V8::SetFlagsFromCommandLine(&argc, argv, true);
 
+  CHECK_EQ(argc, 3);
+  CHECK_NE(js_fn, nullptr);
+  CHECK_NE(snapshot_out_cc, nullptr);
+
   std::string js_source;
   CHECK(deno::ReadFileToString(js_fn, &js_source));
 
-  std::string natives_str;
-  CHECK(deno::ReadFileToString(natives_in_bin, &natives_str));
-  auto natives_blob = StringToStartupData(natives_str);
-
-  std::string snapshot_in_str;
-  CHECK(deno::ReadFileToString(snapshot_in_bin, &snapshot_in_str));
-  auto snapshot_in_blob = StringToStartupData(snapshot_in_str);
-
   deno_init();
-  auto snapshot_blob = deno::MakeSnapshot(&natives_blob, &snapshot_in_blob,
-                                          js_fn, js_source.c_str());
+  auto snapshot_blob = deno::MakeSnapshot(js_fn, js_source.c_str());
   std::string snapshot_str(snapshot_blob.data, snapshot_blob.raw_size);
 
-  CHECK(deno::WriteDataAsCpp("natives", natives_out_cc, natives_str));
   CHECK(deno::WriteDataAsCpp("snapshot", snapshot_out_cc, snapshot_str));
 }