src: add IsolateScopes before using isolates

The V8 API requires entering an isolate before using it. We were often
not doing this, which worked fine in practice. However when (multi-cage)
pointer compression is enabled, the correct isolate needs to be active
in order to decompress pointers correctly, otherwise it causes crashes.

Fix this by sprinkling in some calls to v8::Isolate::Scope::Scope where
they were missing.

Tested by compiling with `--experimental-enable-pointer-compression`
locally and running all tests.

Refs: nodejs/build#3204 (comment)
Refs: https://bugs.chromium.org/p/v8/issues/detail?id=14292

src/api/environment.cc

@@ -313,6 +313,8 @@ void SetIsolateMiscHandlers(v8::Isolate* isolate, const IsolateSettings& s) {
 
 void SetIsolateUpForNode(v8::Isolate* isolate,
                          const IsolateSettings& settings) {
+  Isolate::Scope isolate_scope(isolate);
+
   SetIsolateErrorHandlers(isolate, settings);
   SetIsolateMiscHandlers(isolate, settings);
 }
@@ -354,6 +356,9 @@ Isolate* NewIsolate(Isolate::CreateParams* params,
 
   SetIsolateCreateParamsForNode(params);
   Isolate::Initialize(isolate, *params);
+
+  Isolate::Scope isolate_scope(isolate);
+
   if (snapshot_data == nullptr) {
     // If in deserialize mode, delay until after the deserialization is
     // complete.
@@ -428,6 +433,8 @@ Environment* CreateEnvironment(
     ThreadId thread_id,
     std::unique_ptr<InspectorParentHandle> inspector_parent_handle) {
   Isolate* isolate = isolate_data->isolate();
+
+  Isolate::Scope isolate_scope(isolate);
   HandleScope handle_scope(isolate);
 
   const bool use_snapshot = context.IsEmpty();

src/env.cc

@@ -349,6 +349,8 @@ IsolateDataSerializeInfo IsolateData::Serialize(SnapshotCreator* creator) {
 
 void IsolateData::DeserializeProperties(const IsolateDataSerializeInfo* info) {
   size_t i = 0;
+
+  v8::Isolate::Scope isolate_scope(isolate_);
   HandleScope handle_scope(isolate_);
 
   if (per_process::enabled_debug_list.enabled(DebugCategory::MKSNAPSHOT)) {
@@ -431,6 +433,7 @@ void IsolateData::CreateProperties() {
   // One byte because our strings are ASCII and we can safely skip V8's UTF-8
   // decoding step.
 
+  v8::Isolate::Scope isolate_scope(isolate_);
   HandleScope handle_scope(isolate_);
 
 #define V(PropertyName, StringValue)                                           \

src/json_parser.cc

@@ -12,7 +12,8 @@ using v8::String;
 using v8::Value;
 
 JSONParser::JSONParser()
-    : handle_scope_(isolate_.get()),
+    : isolate_scope_(isolate_.get()),
+      handle_scope_(isolate_.get()),
       context_(isolate_.get(), Context::New(isolate_.get())),
       context_scope_(context_.Get(isolate_.get())) {}
 

src/json_parser.h

@@ -25,7 +25,10 @@ class JSONParser {
   // We might want a lighter-weight JSON parser for this use case. But for now
   // using V8 is good enough.
   RAIIIsolate isolate_;
+
+  v8::Isolate::Scope isolate_scope_;
   v8::HandleScope handle_scope_;
+
   v8::Global<v8::Context> context_;
   v8::Context::Scope context_scope_;
   v8::Global<v8::Object> content_;

src/node_sea.cc

@@ -414,7 +414,9 @@ std::optional<std::string> GenerateCodeCache(std::string_view main_path,
   RAIIIsolate raii_isolate(SnapshotBuilder::GetEmbeddedSnapshotData());
   Isolate* isolate = raii_isolate.get();
 
+  v8::Isolate::Scope isolate_scope(isolate);
   HandleScope handle_scope(isolate);
+
   Local<Context> context = Context::New(isolate);
   Context::Scope context_scope(context);