src: add LoadEnvironment() variant taking a string

Allow passing a string as the main module rather than using
the callback variant.

PR-URL: https://github.com/nodejs/node/pull/30467
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>

src/api/environment.cc

@@ -422,7 +422,9 @@ NODE_EXTERN std::unique_ptr<InspectorParentHandle> GetInspectorParentHandle(
 }
 
 void LoadEnvironment(Environment* env) {
-  USE(LoadEnvironment(env, nullptr, {}));
+  USE(LoadEnvironment(env,
+                      StartExecutionCallback{},
+                      {}));
 }
 
 MaybeLocal<Value> LoadEnvironment(
@@ -445,6 +447,38 @@ MaybeLocal<Value> LoadEnvironment(
   return StartExecution(env, cb);
 }
 
+MaybeLocal<Value> LoadEnvironment(
+    Environment* env,
+    const char* main_script_source_utf8,
+    std::unique_ptr<InspectorParentHandle> inspector_parent_handle) {
+  CHECK_NOT_NULL(main_script_source_utf8);
+  return LoadEnvironment(
+      env,
+      [&](const StartExecutionCallbackInfo& info) -> MaybeLocal<Value> {
+        // This is a slightly hacky way to convert UTF-8 to UTF-16.
+        Local<String> str =
+            String::NewFromUtf8(env->isolate(),
+                                main_script_source_utf8,
+                                v8::NewStringType::kNormal).ToLocalChecked();
+        auto main_utf16 = std::make_unique<String::Value>(env->isolate(), str);
+
+        // TODO(addaleax): Avoid having a global table for all scripts.
+        std::string name = "embedder_main_" + std::to_string(env->thread_id());
+        native_module::NativeModuleEnv::Add(
+            name.c_str(),
+            UnionBytes(**main_utf16, main_utf16->length()));
+        env->set_main_utf16(std::move(main_utf16));
+        std::vector<Local<String>> params = {
+            env->process_string(),
+            env->require_string()};
+        std::vector<Local<Value>> args = {
+            env->process_object(),
+            env->native_module_require()};
+        return ExecuteBootstrapper(env, name.c_str(), &params, &args);
+      },
+      std::move(inspector_parent_handle));
+}
+
 Environment* GetCurrentEnvironment(Local<Context> context) {
   return Environment::GetCurrent(context);
 }

src/env-inl.h

@@ -1266,6 +1266,11 @@ int64_t Environment::base_object_count() const {
   return base_object_count_;
 }
 
+void Environment::set_main_utf16(std::unique_ptr<v8::String::Value> str) {
+  CHECK(!main_utf16_);
+  main_utf16_ = std::move(str);
+}
+
 #define VP(PropertyName, StringValue) V(v8::Private, PropertyName)
 #define VY(PropertyName, StringValue) V(v8::Symbol, PropertyName)
 #define VS(PropertyName, StringValue) V(v8::String, PropertyName)

src/env.h

@@ -1253,6 +1253,8 @@ class Environment : public MemoryRetainer {
 
 #endif  // HAVE_INSPECTOR
 
+  inline void set_main_utf16(std::unique_ptr<v8::String::Value>);
+
  private:
   template <typename Fn>
   inline void CreateImmediate(Fn&& cb, bool ref);
@@ -1462,6 +1464,11 @@ class Environment : public MemoryRetainer {
 #undef V
 
   v8::Global<v8::Context> context_;
+
+  // Keeps the main script source alive is one was passed to LoadEnvironment().
+  // We should probably find a way to just use plain `v8::String`s created from
+  // the source passed to LoadEnvironment() directly instead.
+  std::unique_ptr<v8::String::Value> main_utf16_;
 };
 
 }  // namespace node

src/node.h

@@ -453,6 +453,10 @@ NODE_EXTERN v8::MaybeLocal<v8::Value> LoadEnvironment(
     Environment* env,
     StartExecutionCallback cb,
     std::unique_ptr<InspectorParentHandle> inspector_parent_handle = {});
+NODE_EXTERN v8::MaybeLocal<v8::Value> LoadEnvironment(
+    Environment* env,
+    const char* main_script_source_utf8,
+    std::unique_ptr<InspectorParentHandle> inspector_parent_handle = {});
 NODE_EXTERN void FreeEnvironment(Environment* env);
 
 // This may return nullptr if context is not associated with a Node instance.

src/node_native_module.cc

@@ -33,6 +33,14 @@ bool NativeModuleLoader::Exists(const char* id) {
   return source_.find(id) != source_.end();
 }
 
+bool NativeModuleLoader::Add(const char* id, const UnionBytes& source) {
+  if (Exists(id)) {
+    return false;
+  }
+  source_.emplace(id, source);
+  return true;
+}
+
 Local<Object> NativeModuleLoader::GetSourceObject(Local<Context> context) {
   Isolate* isolate = context->GetIsolate();
   Local<Object> out = Object::New(isolate);

src/node_native_module.h

@@ -47,6 +47,8 @@ class NativeModuleLoader {
   UnionBytes GetConfig();       // Return data for config.gypi
 
   bool Exists(const char* id);
+  bool Add(const char* id, const UnionBytes& source);
+
   v8::Local<v8::Object> GetSourceObject(v8::Local<v8::Context> context);
   v8::Local<v8::String> GetConfigString(v8::Isolate* isolate);
   std::vector<std::string> GetModuleIds();

src/node_native_module_env.cc

@@ -33,6 +33,10 @@ Local<Set> ToJsSet(Local<Context> context, const std::set<std::string>& in) {
   return out;
 }
 
+bool NativeModuleEnv::Add(const char* id, const UnionBytes& source) {
+  return NativeModuleLoader::GetInstance()->Add(id, source);
+}
+
 bool NativeModuleEnv::Exists(const char* id) {
   return NativeModuleLoader::GetInstance()->Exists(id);
 }

src/node_native_module_env.h

@@ -29,6 +29,7 @@ class NativeModuleEnv {
   // Returns config.gypi as a JSON string
   static v8::Local<v8::String> GetConfigString(v8::Isolate* isolate);
   static bool Exists(const char* id);
+  static bool Add(const char* id, const UnionBytes& source);
 
   // Loads data into NativeModuleLoader::.instance.code_cache_
   // Generated by mkcodecache as node_code_cache.cc when

src/node_worker.cc

@@ -323,7 +323,7 @@ void Worker::Run() {
         CreateEnvMessagePort(env_.get());
         Debug(this, "Created message port for worker %llu", thread_id_.id);
         if (LoadEnvironment(env_.get(),
-                            nullptr,
+                            StartExecutionCallback{},
                             std::move(inspector_parent_handle_))
                 .IsEmpty()) {
           return;

test/cctest/test_environment.cc

@@ -80,6 +80,33 @@ TEST_F(EnvironmentTest, LoadEnvironmentWithCallback) {
   CHECK(called_cb);
 }
 
+TEST_F(EnvironmentTest, LoadEnvironmentWithSource) {
+  const v8::HandleScope handle_scope(isolate_);
+  const Argv argv;
+  Env env {handle_scope, argv};
+
+  v8::Local<v8::Context> context = isolate_->GetCurrentContext();
+  v8::Local<v8::Value> main_ret =
+      node::LoadEnvironment(*env,
+                            "return { process, require };").ToLocalChecked();
+
+  CHECK(main_ret->IsObject());
+  CHECK(main_ret.As<v8::Object>()->Get(
+      context,
+      v8::String::NewFromOneByte(
+          isolate_,
+          reinterpret_cast<const uint8_t*>("process"),
+          v8::NewStringType::kNormal).ToLocalChecked())
+          .ToLocalChecked()->IsObject());
+  CHECK(main_ret.As<v8::Object>()->Get(
+      context,
+      v8::String::NewFromOneByte(
+          isolate_,
+          reinterpret_cast<const uint8_t*>("require"),
+          v8::NewStringType::kNormal).ToLocalChecked())
+          .ToLocalChecked()->IsFunction());
+}
+
 TEST_F(EnvironmentTest, AtExitWithEnvironment) {
   const v8::HandleScope handle_scope(isolate_);
   const Argv argv;