Allow embedder service request handlers to return JSON-RPC errors.

runtime/bin/main.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 
 #include "include/dart_api.h"
 #include "include/dart_tools_api.h"
@@ skipping 917 matching lines @@
   snprintf(buffer, len, kFormat, script_name, func_name);
   return buffer;
 }
 
 static void ShutdownIsolate(void* callback_data) {
   IsolateData* isolate_data = reinterpret_cast<IsolateData*>(callback_data);
   delete isolate_data;
 }
 
 
-static const char* ServiceRequestError(Dart_Handle error) {
+static const char* InternalJsonRpcError(Dart_Handle error) {
   TextBuffer buffer(128);
-  buffer.Printf("{\"type\":\"Error\",\"text\":\"Internal error %s\"}",
+  buffer.Printf("{\"code\":-32603,"
+                "\"message\":\"Internal error\","
+                "\"details\": \"%s\"}",
                 Dart_GetError(error));
   return buffer.Steal();
 }
 
 
 class DartScope {
  public:
   DartScope() { Dart_EnterScope(); }
   ~DartScope() { Dart_ExitScope(); }
 };
 
 
-static const char* ServiceGetIOHandler(
+static bool ServiceGetIOHandler(
     const char* method,
     const char** param_keys,
     const char** param_values,
     intptr_t num_params,
-    void* user_data) {
+    void* user_data,
+    const char** response) {
   DartScope scope;
   // TODO(ajohnsen): Store the library/function in isolate data or user_data.
   Dart_Handle dart_io_str = Dart_NewStringFromCString("dart:io");
   if (Dart_IsError(dart_io_str)) {
-    return ServiceRequestError(dart_io_str);
+    *response = InternalJsonRpcError(dart_io_str);
+    return false;
   }
 
   Dart_Handle io_lib = Dart_LookupLibrary(dart_io_str);
   if (Dart_IsError(io_lib)) {
-    return ServiceRequestError(io_lib);
+    *response = InternalJsonRpcError(io_lib);
+    return false;
   }
 
   Dart_Handle handler_function_name =
       Dart_NewStringFromCString("_serviceObjectHandler");
   if (Dart_IsError(handler_function_name)) {
-    return ServiceRequestError(handler_function_name);
+    *response = InternalJsonRpcError(handler_function_name);
+    return false;
   }
 
   // TODO(johnmccutchan): paths is no longer used.  Update the io
   // _serviceObjectHandler function to use json rpc.
   Dart_Handle paths = Dart_NewList(0);
   Dart_Handle keys = Dart_NewList(num_params);
   Dart_Handle values = Dart_NewList(num_params);
   for (int i = 0; i < num_params; i++) {
     Dart_ListSetAt(keys, i, Dart_NewStringFromCString(param_keys[i]));
     Dart_ListSetAt(values, i, Dart_NewStringFromCString(param_values[i]));
   }
   Dart_Handle args[] = {paths, keys, values};
   Dart_Handle result = Dart_Invoke(io_lib, handler_function_name, 3, args);
   if (Dart_IsError(result)) {
-    return ServiceRequestError(result);
+    *response = InternalJsonRpcError(result);
+    return false;
   }
 
   const char *json;
   result = Dart_StringToCString(result, &json);
   if (Dart_IsError(result)) {
-    return ServiceRequestError(result);
+    *response = InternalJsonRpcError(result);
+    return false;
   }
-  return strdup(json);
+  *response = strdup(json);
+  return true;
 }
 
 
 static const char* kStdoutStreamId = "Stdout";
 static const char* kStderrStreamId = "Stderr";
 
 
 static bool ServiceStreamListenCallback(const char* stream_id) {
   if (strcmp(stream_id, kStdoutStreamId) == 0) {
     SetCaptureStdout(true);
@@ skipping 722 matching lines @@
   Platform::Exit(Process::GlobalExitCode());
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   dart::bin::main(argc, argv);
   UNREACHABLE();
 }