Various snapshot related clean ups

deno2/.gclient

@@ -1,5 +1,5 @@
 solutions = [{
-    'url': 'https://chromium.googlesource.com/v8/v8.git@2530a044126ae6a1d3dff0d8c61999762847d9f0',
+    'url': 'https://chromium.googlesource.com/v8/v8.git@6.8-lkgr',
     'name': 'v8',
     'deps_file': 'DEPS',
     'custom_deps': {

deno2/.gn

@@ -24,15 +24,12 @@ default_args = {
   v8_embedder_string = "-deno"
   v8_enable_gdbjit = false
   v8_enable_i18n_support = false
-  v8_enable_test_features = false
-  v8_experimental_extra_library_files = []
-  v8_extra_library_files = []
   v8_imminent_deprecation_warnings = false
   v8_monolithic = false
   v8_untrusted_code_mitigations = false
-
-  # This tells V8 to write out/Default/gen/v8/snapshot.bin
-  # Which we can use to build our own snapshot.
-  v8_use_external_startup_data = true
+  v8_use_multi_snapshots = false
+  v8_use_external_startup_data = false
   v8_use_snapshot = true
+  v8_experimental_extra_library_files = []
+  v8_extra_library_files = []
 }

deno2/deno.cc

@@ -194,19 +194,6 @@ bool Execute(v8::Local<v8::Context> context, const char* js_filename,
   return true;
 }
 
-v8::StartupData SerializeInternalFields(v8::Local<v8::Object> holder, int index,
-                                        void* data) {
-  DCHECK_EQ(data, nullptr);  // TODO(ry) pass Deno* object here.
-  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};
-}
-
 void InitializeContext(v8::Isolate* isolate, v8::Local<v8::Context> context,
                        const char* js_filename, const char* js_source) {
   v8::HandleScope handle_scope(isolate);
@@ -233,31 +220,6 @@ void InitializeContext(v8::Isolate* isolate, v8::Local<v8::Context> context,
   CHECK(r);
 }
 
-v8::StartupData MakeSnapshot(v8::StartupData* prev_natives_blob,
-                             v8::StartupData* prev_snapshot_blob,
-                             const char* js_filename, const char* js_source) {
-  v8::V8::SetNativesDataBlob(prev_natives_blob);
-  v8::V8::SetSnapshotDataBlob(prev_snapshot_blob);
-
-  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;
-}
-
 void AddIsolate(Deno* d, v8::Isolate* isolate) {
   d->isolate = isolate;
   // Leaving this code here because it will probably be useful later on, but

deno2/deno.gni

@@ -30,23 +30,16 @@ template("create_snapshot") {
     data = []
     exe = rebase_path(get_label_info(":snapshot_creator", "root_out_dir") +
                       "/snapshot_creator")
-    natives_in_bin = "$root_out_dir/natives_blob.bin"
-    snapshot_in_bin = "$root_out_dir/snapshot_blob.bin"
-    natives_out_cc = "$target_gen_dir/natives${suffix}.cc"
     snapshot_out_cc = "$target_gen_dir/snapshot${suffix}.cc"
     sources = [
       invoker.js,
     ]
     outputs = [
-      natives_out_cc,
       snapshot_out_cc,
     ]
     args = [
       exe,
       rebase_path(invoker.js, root_build_dir),
-      rebase_path(natives_in_bin, root_build_dir),
-      rebase_path(snapshot_in_bin, root_build_dir),
-      rebase_path(natives_out_cc, root_build_dir),
       rebase_path(snapshot_out_cc, root_build_dir),
     ]
 

deno2/deno_internal.h

@@ -38,10 +38,6 @@ Deno* NewFromSnapshot(void* data, deno_sub_cb cb);
 void InitializeContext(v8::Isolate* isolate, v8::Local<v8::Context> context,
                        const char* js_filename, const char* js_source);
 
-v8::StartupData MakeSnapshot(v8::StartupData* prev_natives_blob,
-                             v8::StartupData* prev_snapshot_blob,
-                             const char* js_filename, const char* js_source);
-
 void AddIsolate(Deno* d, v8::Isolate* isolate);
 
 }  // namespace deno

deno2/file_util.cc

@@ -44,16 +44,18 @@ class StartupDataCppWriter {
   void WritePrefix() {
     file_ << "// Autogenerated snapshot file. Do not edit.\n\n";
     file_ << "#include \"v8/include/v8.h\"\n\n";
+    file_ << "namespace deno { \n\n";
   }
 
   void WriteSuffix() {
     char buffer[500];
-    snprintf(buffer, sizeof(buffer),
-             "const v8::StartupData* StartupBlob_%s() {\n", name_);
+    snprintf(buffer, sizeof(buffer), "v8::StartupData* StartupBlob_%s() {\n",
+             name_);
     file_ << buffer;
     snprintf(buffer, sizeof(buffer), "  return &%s_blob;\n", name_);
     file_ << buffer;
     file_ << "}\n\n";
+    file_ << "}  // namespace deno\n\n";
   }
 
   void WriteBinaryContentsAsCArray() {
@@ -78,7 +80,7 @@ class StartupDataCppWriter {
     snprintf(buffer, sizeof(buffer), "static const int %s_blob_size = %llu;\n",
              name_, static_cast<unsigned long long>(data_.size()));
     file_ << buffer;
-    snprintf(buffer, sizeof(buffer), "static const v8::StartupData %s_blob =\n",
+    snprintf(buffer, sizeof(buffer), "static v8::StartupData %s_blob =\n",
              name_);
     file_ << buffer;
     snprintf(buffer, sizeof(buffer),

deno2/from_snapshot.cc

@@ -1,31 +1,29 @@
 // Copyright 2018 Ryan Dahl <[email protected]>
 // All rights reserved. MIT License.
-#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <string>
 
 #include "v8/include/v8.h"
+#include "v8/src/base/logging.h"
 
 #include "./deno_internal.h"
 #include "include/deno.h"
 
-namespace deno {
-
 #ifdef DENO_MOCK_RUNTIME
-#include "natives_mock_runtime.cc"
 #include "snapshot_mock_runtime.cc"
 #else
-#include "natives_deno.cc"
 #include "snapshot_deno.cc"
 #endif
 
+namespace deno {
+
 std::vector<InternalFieldData*> deserialized_data;
 
 void DeserializeInternalFields(v8::Local<v8::Object> holder, int index,
                                v8::StartupData payload, void* data) {
-  assert(data == nullptr);  // TODO(ry) pass Deno* object here.
+  DCHECK_EQ(data, nullptr);
   if (payload.raw_size == 0) {
     holder->SetAlignedPointerInInternalField(index, nullptr);
     return;
@@ -37,13 +35,6 @@ void DeserializeInternalFields(v8::Local<v8::Object> holder, int index,
 }
 
 Deno* NewFromSnapshot(void* data, deno_sub_cb cb) {
-  auto natives_blob = *StartupBlob_natives();
-  auto snapshot_blob = *StartupBlob_snapshot();
-
-  v8::V8::SetNativesDataBlob(&natives_blob);
-  v8::V8::SetSnapshotDataBlob(&snapshot_blob);
-  v8::DeserializeInternalFieldsCallback(DeserializeInternalFields, nullptr);
-
   Deno* d = new Deno;
   d->currentArgs = nullptr;
   d->cb = cb;
@@ -52,6 +43,7 @@ Deno* NewFromSnapshot(void* data, deno_sub_cb cb) {
   params.array_buffer_allocator =
       v8::ArrayBuffer::Allocator::NewDefaultAllocator();
   params.external_references = external_references;
+  params.snapshot_blob = StartupBlob_snapshot();
   v8::Isolate* isolate = v8::Isolate::New(params);
   AddIsolate(d, isolate);
 

deno2/js/mock_runtime.js

@@ -1,6 +1,5 @@
 // A simple runtime that doesn't involve typescript or protobufs to test
 // libdeno. Invoked by mock_runtime_test.cc
-const window = eval("this");
 
 function assert(cond) {
   if (!cond) throw Error("mock_runtime.js assert failed");
@@ -68,7 +67,6 @@ function DoubleSubFails() {
   deno.sub((channel, msg) => assert(false));
 }
 
-
 // The following join has caused SnapshotBug to segfault when using kKeep.
 [].join("");
 

deno2/mock_runtime_test.cc

@@ -99,5 +99,6 @@ TEST(MockRuntimeTest, SnapshotBug) {
 int main(int argc, char** argv) {
   testing::InitGoogleTest(&argc, argv);
   deno_init();
+  deno_set_flags(&argc, argv);
   return RUN_ALL_TESTS();
 }

deno2/snapshot_creator.cc

@@ -7,41 +7,76 @@
 #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];
+  const char* snapshot_out_cc = argv[2];
 
+  v8::V8::SetFlagsFromCommandLine(&argc, argv, true);
+
+  CHECK_EQ(argc, 3);
   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);
 
-  v8::V8::SetFlagsFromCommandLine(&argc, argv, true);
-
   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);
+  // Wrap the js_source in an IIFE to work around a bug in the V8 snapshot
+  // serializer. Without it, CreateBlob() triggers the following assert:
+  //   Debug check failed : outer_scope_info()->IsScopeInfo() || is_toplevel().
+  //   ==== C stack trace ====
+  //   v8::internal::SharedFunctionInfo::FlushCompiled
+  //   v8::SnapshotCreator::CreateBlob
+  //   deno::MakeSnapshot
+  // Avoid misaligning the source map, and ensure that the sourceMappingUrl
+  // comment remains at the last line.
+  auto smu_offset = js_source.rfind("//#");
+  CHECK(smu_offset != std::string::npos);
+  auto wrapped_js_source = "(function() {" + js_source.substr(0, smu_offset) +
+                           "\n})();\n" + js_source.substr(smu_offset);
+  // Double check that the source mapping url comment is at the last line.
+  auto last_line = wrapped_js_source.substr(wrapped_js_source.rfind('\n'));
+  CHECK(last_line.find("sourceMappingURL") != std::string::npos);
 
   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, wrapped_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));
 }