src: move OnMessage to node_errors.cc

Rename the per-isolate message listener to `PerIsolateMessageListener`
and move it to `node_errors.cc` since it's part of the error
handling process. It also creates an external reference so it needs
to be exposed in `node_errors.h` for a snapshot builder to know.

PR-URL: #27304
Reviewed-By: Anna Henningsen <anna@addaleax.net>

src/api/environment.cc

@@ -5,7 +5,6 @@
 #include "node_internals.h"
 #include "node_native_module_env.h"
 #include "node_platform.h"
-#include "node_process.h"
 #include "node_v8_platform-inl.h"
 #include "uv.h"
 
@@ -46,32 +45,6 @@ static bool ShouldAbortOnUncaughtException(Isolate* isolate) {
          !env->inside_should_not_abort_on_uncaught_scope();
 }
 
-static void OnMessage(Local<Message> message, Local<Value> error) {
-  Isolate* isolate = message->GetIsolate();
-  switch (message->ErrorLevel()) {
-    case Isolate::MessageErrorLevel::kMessageWarning: {
-      Environment* env = Environment::GetCurrent(isolate);
-      if (!env) {
-        break;
-      }
-      Utf8Value filename(isolate, message->GetScriptOrigin().ResourceName());
-      // (filename):(line) (message)
-      std::stringstream warning;
-      warning << *filename;
-      warning << ":";
-      warning << message->GetLineNumber(env->context()).FromMaybe(-1);
-      warning << " ";
-      v8::String::Utf8Value msg(isolate, message->Get());
-      warning << *msg;
-      USE(ProcessEmitWarningGeneric(env, warning.str().c_str(), "V8"));
-      break;
-    }
-    case Isolate::MessageErrorLevel::kMessageError:
-      FatalException(isolate, error, message);
-      break;
-  }
-}
-
 void* NodeArrayBufferAllocator::Allocate(size_t size) {
   if (zero_fill_field_ || per_process::cli_options->zero_fill_all_buffers)
     return UncheckedCalloc(size);
@@ -187,7 +160,7 @@ void SetIsolateUpForNode(v8::Isolate* isolate, IsolateSettingCategories cat) {
   switch (cat) {
     case IsolateSettingCategories::kErrorHandlers:
       isolate->AddMessageListenerWithErrorLevel(
-          OnMessage,
+          errors::PerIsolateMessageListener,
           Isolate::MessageErrorLevel::kMessageError |
               Isolate::MessageErrorLevel::kMessageWarning);
       isolate->SetAbortOnUncaughtExceptionCallback(

src/node_errors.cc

@@ -6,6 +6,7 @@
 #ifdef NODE_REPORT
 #include "node_report.h"
 #endif
+#include "node_process.h"
 #include "node_v8_platform-inl.h"
 
 namespace node {
@@ -739,6 +740,32 @@ const char* errno_string(int errorno) {
   }
 }
 
+void PerIsolateMessageListener(Local<Message> message, Local<Value> error) {
+  Isolate* isolate = message->GetIsolate();
+  switch (message->ErrorLevel()) {
+    case Isolate::MessageErrorLevel::kMessageWarning: {
+      Environment* env = Environment::GetCurrent(isolate);
+      if (!env) {
+        break;
+      }
+      Utf8Value filename(isolate, message->GetScriptOrigin().ResourceName());
+      // (filename):(line) (message)
+      std::stringstream warning;
+      warning << *filename;
+      warning << ":";
+      warning << message->GetLineNumber(env->context()).FromMaybe(-1);
+      warning << " ";
+      v8::String::Utf8Value msg(isolate, message->Get());
+      warning << *msg;
+      USE(ProcessEmitWarningGeneric(env, warning.str().c_str(), "V8"));
+      break;
+    }
+    case Isolate::MessageErrorLevel::kMessageError:
+      FatalException(isolate, error, message);
+      break;
+  }
+}
+
 }  // namespace errors
 
 void DecorateErrorStack(Environment* env,

src/node_errors.h

@@ -191,6 +191,8 @@ class TryCatchScope : public v8::TryCatch {
 };
 
 const char* errno_string(int errorno);
+void PerIsolateMessageListener(v8::Local<v8::Message> message,
+                               v8::Local<v8::Value> error);
 
 }  // namespace errors