4 files changed, 249 insertions, 223 deletions
diff --git a/src/compiler/cpp_generator.cc b/src/compiler/cpp_generator.cc
index acac1475f7..b0d2b5d229 100644
--- a/src/compiler/cpp_generator.cc
+++ b/src/compiler/cpp_generator.cc
@@ -86,23 +86,25 @@ grpc::string FilenameIdentifier(const grpc::string &filename) {
 grpc::string GetHeaderPrologue(const grpc::protobuf::FileDescriptor *file,
                                const Parameters &params) {
   grpc::string output;
-  grpc::protobuf::io::StringOutputStream output_stream(&output);
-  grpc::protobuf::io::Printer printer(&output_stream, '$');
-  std::map<grpc::string, grpc::string> vars;
-
-  vars["filename"] = file->name();
-  vars["filename_identifier"] = FilenameIdentifier(file->name());
-  vars["filename_base"] = grpc_generator::StripProto(file->name());
-
-  printer.Print(vars, "// Generated by the gRPC protobuf plugin.\n");
-  printer.Print(vars, "// If you make any local change, they will be lost.\n");
-  printer.Print(vars, "// source: $filename$\n");
-  printer.Print(vars, "#ifndef GRPC_$filename_identifier$__INCLUDED\n");
-  printer.Print(vars, "#define GRPC_$filename_identifier$__INCLUDED\n");
-  printer.Print(vars, "\n");
-  printer.Print(vars, "#include \"$filename_base$.pb.h\"\n");
-  printer.Print(vars, "\n");
-
+  {
+    // Scope the output stream so it closes and finalizes output to the string.
+    grpc::protobuf::io::StringOutputStream output_stream(&output);
+    grpc::protobuf::io::Printer printer(&output_stream, '$');
+    std::map<grpc::string, grpc::string> vars;
+
+    vars["filename"] = file->name();
+    vars["filename_identifier"] = FilenameIdentifier(file->name());
+    vars["filename_base"] = grpc_generator::StripProto(file->name());
+
+    printer.Print(vars, "// Generated by the gRPC protobuf plugin.\n");
+    printer.Print(vars, "// If you make any local change, they will be lost.\n");
+    printer.Print(vars, "// source: $filename$\n");
+    printer.Print(vars, "#ifndef GRPC_$filename_identifier$__INCLUDED\n");
+    printer.Print(vars, "#define GRPC_$filename_identifier$__INCLUDED\n");
+    printer.Print(vars, "\n");
+    printer.Print(vars, "#include \"$filename_base$.pb.h\"\n");
+    printer.Print(vars, "\n");
+  }
   return output;
 }
 
@@ -626,100 +628,108 @@ void PrintHeaderService(grpc::protobuf::io::Printer *printer,
 grpc::string GetHeaderServices(const grpc::protobuf::FileDescriptor *file,
                                const Parameters &params) {
   grpc::string output;
-  grpc::protobuf::io::StringOutputStream output_stream(&output);
-  grpc::protobuf::io::Printer printer(&output_stream, '$');
-  std::map<grpc::string, grpc::string> vars;
-
-  if (!params.services_namespace.empty()) {
-    vars["services_namespace"] = params.services_namespace;
-    printer.Print(vars, "\nnamespace $services_namespace$ {\n\n");
-  }
+  {
+	// Scope the output stream so it closes and finalizes output to the string.
+    grpc::protobuf::io::StringOutputStream output_stream(&output);
+    grpc::protobuf::io::Printer printer(&output_stream, '$');
+    std::map<grpc::string, grpc::string> vars;
+
+    if (!params.services_namespace.empty()) {
+      vars["services_namespace"] = params.services_namespace;
+      printer.Print(vars, "\nnamespace $services_namespace$ {\n\n");
+    }
 
-  for (int i = 0; i < file->service_count(); ++i) {
-    PrintHeaderService(&printer, file->service(i), &vars);
-    printer.Print("\n");
-  }
+    for (int i = 0; i < file->service_count(); ++i) {
+      PrintHeaderService(&printer, file->service(i), &vars);
+      printer.Print("\n");
+    }
 
-  if (!params.services_namespace.empty()) {
-    printer.Print(vars, "}  // namespace $services_namespace$\n\n");
+    if (!params.services_namespace.empty()) {
+      printer.Print(vars, "}  // namespace $services_namespace$\n\n");
+    }
   }
-
   return output;
 }
 
 grpc::string GetHeaderEpilogue(const grpc::protobuf::FileDescriptor *file,
                                const Parameters &params) {
   grpc::string output;
-  grpc::protobuf::io::StringOutputStream output_stream(&output);
-  grpc::protobuf::io::Printer printer(&output_stream, '$');
-  std::map<grpc::string, grpc::string> vars;
-
-  vars["filename"] = file->name();
-  vars["filename_identifier"] = FilenameIdentifier(file->name());
-
-  if (!file->package().empty()) {
-    std::vector<grpc::string> parts =
-        grpc_generator::tokenize(file->package(), ".");
-
-    for (auto part = parts.rbegin(); part != parts.rend(); part++) {
-      vars["part"] = *part;
-      printer.Print(vars, "}  // namespace $part$\n");
+  {
+    // Scope the output stream so it closes and finalizes output to the string.
+    grpc::protobuf::io::StringOutputStream output_stream(&output);
+    grpc::protobuf::io::Printer printer(&output_stream, '$');
+    std::map<grpc::string, grpc::string> vars;
+
+    vars["filename"] = file->name();
+    vars["filename_identifier"] = FilenameIdentifier(file->name());
+
+    if (!file->package().empty()) {
+      std::vector<grpc::string> parts =
+          grpc_generator::tokenize(file->package(), ".");
+
+      for (auto part = parts.rbegin(); part != parts.rend(); part++) {
+        vars["part"] = *part;
+        printer.Print(vars, "}  // namespace $part$\n");
+      }
+      printer.Print(vars, "\n");
     }
+
     printer.Print(vars, "\n");
+    printer.Print(vars, "#endif  // GRPC_$filename_identifier$__INCLUDED\n");
   }
-
-  printer.Print(vars, "\n");
-  printer.Print(vars, "#endif  // GRPC_$filename_identifier$__INCLUDED\n");
-
   return output;
 }
 
 grpc::string GetSourcePrologue(const grpc::protobuf::FileDescriptor *file,
                                const Parameters &params) {
   grpc::string output;
-  grpc::protobuf::io::StringOutputStream output_stream(&output);
-  grpc::protobuf::io::Printer printer(&output_stream, '$');
-  std::map<grpc::string, grpc::string> vars;
-
-  vars["filename"] = file->name();
-  vars["filename_base"] = grpc_generator::StripProto(file->name());
-
-  printer.Print(vars, "// Generated by the gRPC protobuf plugin.\n");
-  printer.Print(vars, "// If you make any local change, they will be lost.\n");
-  printer.Print(vars, "// source: $filename$\n\n");
-  printer.Print(vars, "#include \"$filename_base$.pb.h\"\n");
-  printer.Print(vars, "#include \"$filename_base$.grpc.pb.h\"\n");
-  printer.Print(vars, "\n");
-
+  {
+    // Scope the output stream so it closes and finalizes output to the string.
+    grpc::protobuf::io::StringOutputStream output_stream(&output);
+    grpc::protobuf::io::Printer printer(&output_stream, '$');
+    std::map<grpc::string, grpc::string> vars;
+
+    vars["filename"] = file->name();
+    vars["filename_base"] = grpc_generator::StripProto(file->name());
+
+    printer.Print(vars, "// Generated by the gRPC protobuf plugin.\n");
+    printer.Print(vars, "// If you make any local change, they will be lost.\n");
+    printer.Print(vars, "// source: $filename$\n\n");
+    printer.Print(vars, "#include \"$filename_base$.pb.h\"\n");
+    printer.Print(vars, "#include \"$filename_base$.grpc.pb.h\"\n");
+    printer.Print(vars, "\n");
+  }
   return output;
 }
 
 grpc::string GetSourceIncludes(const grpc::protobuf::FileDescriptor *file,
                                const Parameters &param) {
   grpc::string output;
-  grpc::protobuf::io::StringOutputStream output_stream(&output);
-  grpc::protobuf::io::Printer printer(&output_stream, '$');
-  std::map<grpc::string, grpc::string> vars;
-
-  printer.Print(vars, "#include <grpc++/async_unary_call.h>\n");
-  printer.Print(vars, "#include <grpc++/channel_interface.h>\n");
-  printer.Print(vars, "#include <grpc++/impl/client_unary_call.h>\n");
-  printer.Print(vars, "#include <grpc++/impl/rpc_service_method.h>\n");
-  printer.Print(vars, "#include <grpc++/impl/service_type.h>\n");
-  printer.Print(vars, "#include <grpc++/stream.h>\n");
-
-  if (!file->package().empty()) {
-    std::vector<grpc::string> parts =
-        grpc_generator::tokenize(file->package(), ".");
-
-    for (auto part = parts.begin(); part != parts.end(); part++) {
-      vars["part"] = *part;
-      printer.Print(vars, "namespace $part$ {\n");
+  {
+    // Scope the output stream so it closes and finalizes output to the string.
+    grpc::protobuf::io::StringOutputStream output_stream(&output);
+    grpc::protobuf::io::Printer printer(&output_stream, '$');
+    std::map<grpc::string, grpc::string> vars;
+
+    printer.Print(vars, "#include <grpc++/async_unary_call.h>\n");
+    printer.Print(vars, "#include <grpc++/channel_interface.h>\n");
+    printer.Print(vars, "#include <grpc++/impl/client_unary_call.h>\n");
+    printer.Print(vars, "#include <grpc++/impl/rpc_service_method.h>\n");
+    printer.Print(vars, "#include <grpc++/impl/service_type.h>\n");
+    printer.Print(vars, "#include <grpc++/stream.h>\n");
+
+    if (!file->package().empty()) {
+      std::vector<grpc::string> parts =
+          grpc_generator::tokenize(file->package(), ".");
+
+      for (auto part = parts.begin(); part != parts.end(); part++) {
+        vars["part"] = *part;
+        printer.Print(vars, "namespace $part$ {\n");
+      }
     }
-  }
-
-  printer.Print(vars, "\n");
 
+    printer.Print(vars, "\n");
+  }
   return output;
 }
 
@@ -1077,26 +1087,29 @@ void PrintSourceService(grpc::protobuf::io::Printer *printer,
 grpc::string GetSourceServices(const grpc::protobuf::FileDescriptor *file,
                                const Parameters &params) {
   grpc::string output;
-  grpc::protobuf::io::StringOutputStream output_stream(&output);
-  grpc::protobuf::io::Printer printer(&output_stream, '$');
-  std::map<grpc::string, grpc::string> vars;
-  // Package string is empty or ends with a dot. It is used to fully qualify
-  // method names.
-  vars["Package"] = file->package();
-  if (!file->package().empty()) {
-    vars["Package"].append(".");
-  }
-  if (!params.services_namespace.empty()) {
-    vars["ns"] = params.services_namespace + "::";
-    vars["prefix"] = params.services_namespace;
-  } else {
-    vars["ns"] = "";
-    vars["prefix"] = "";
-  }
+  {
+    // Scope the output stream so it closes and finalizes output to the string.
+    grpc::protobuf::io::StringOutputStream output_stream(&output);
+    grpc::protobuf::io::Printer printer(&output_stream, '$');
+    std::map<grpc::string, grpc::string> vars;
+    // Package string is empty or ends with a dot. It is used to fully qualify
+    // method names.
+    vars["Package"] = file->package();
+    if (!file->package().empty()) {
+      vars["Package"].append(".");
+    }
+    if (!params.services_namespace.empty()) {
+      vars["ns"] = params.services_namespace + "::";
+      vars["prefix"] = params.services_namespace;
+    } else {
+      vars["ns"] = "";
+      vars["prefix"] = "";
+    }
 
-  for (int i = 0; i < file->service_count(); ++i) {
-    PrintSourceService(&printer, file->service(i), &vars);
-    printer.Print("\n");
+    for (int i = 0; i < file->service_count(); ++i) {
+      PrintSourceService(&printer, file->service(i), &vars);
+      printer.Print("\n");
+    }
   }
   return output;
 }
diff --git a/src/compiler/csharp_generator.cc b/src/compiler/csharp_generator.cc
index 5dd078b303..ccb0b688b6 100644
--- a/src/compiler/csharp_generator.cc
+++ b/src/compiler/csharp_generator.cc
@@ -474,35 +474,39 @@ void GenerateService(Printer* out, const ServiceDescriptor *service) {
 
 grpc::string GetServices(const FileDescriptor *file) {
   grpc::string output;
-  StringOutputStream output_stream(&output);
-  Printer out(&output_stream, '$');
+  {
+    // Scope the output stream so it closes and finalizes output to the string.
 
-  // Don't write out any output if there no services, to avoid empty service
-  // files being generated for proto files that don't declare any.
-  if (file->service_count() == 0) {
-    return output;
-  }
+    StringOutputStream output_stream(&output);
+    Printer out(&output_stream, '$');
+
+    // Don't write out any output if there no services, to avoid empty service
+    // files being generated for proto files that don't declare any.
+    if (file->service_count() == 0) {
+      return output;
+    }
 
-  // Write out a file header.
-  out.Print("// Generated by the protocol buffer compiler.  DO NOT EDIT!\n");
-  out.Print("// source: $filename$\n", "filename", file->name());
-  out.Print("#region Designer generated code\n");
-  out.Print("\n");
-  out.Print("using System;\n");
-  out.Print("using System.Threading;\n");
-  out.Print("using System.Threading.Tasks;\n");
-  out.Print("using Grpc.Core;\n");
-  // TODO(jtattermusch): add using for protobuf message classes
-  out.Print("\n");
-
-  out.Print("namespace $namespace$ {\n", "namespace", GetFileNamespace(file));
-  out.Indent();
-  for (int i = 0; i < file->service_count(); i++) {
-    GenerateService(&out, file->service(i));
+    // Write out a file header.
+    out.Print("// Generated by the protocol buffer compiler.  DO NOT EDIT!\n");
+    out.Print("// source: $filename$\n", "filename", file->name());
+    out.Print("#region Designer generated code\n");
+    out.Print("\n");
+    out.Print("using System;\n");
+    out.Print("using System.Threading;\n");
+    out.Print("using System.Threading.Tasks;\n");
+    out.Print("using Grpc.Core;\n");
+    // TODO(jtattermusch): add using for protobuf message classes
+    out.Print("\n");
+
+    out.Print("namespace $namespace$ {\n", "namespace", GetFileNamespace(file));
+    out.Indent();
+    for (int i = 0; i < file->service_count(); i++) {
+      GenerateService(&out, file->service(i));
+    }
+    out.Outdent();
+    out.Print("}\n");
+    out.Print("#endregion\n");
   }
-  out.Outdent();
-  out.Print("}\n");
-  out.Print("#endregion\n");
   return output;
 }
 
diff --git a/src/compiler/objective_c_generator.cc b/src/compiler/objective_c_generator.cc
index 8f35302bee..1bf0254f5b 100644
--- a/src/compiler/objective_c_generator.cc
+++ b/src/compiler/objective_c_generator.cc
@@ -176,65 +176,71 @@ void PrintMethodImplementations(Printer *printer,
 
 string GetHeader(const ServiceDescriptor *service, const string prefix) {
   string output;
-  grpc::protobuf::io::StringOutputStream output_stream(&output);
-  Printer printer(&output_stream, '$');
+  {
+    // Scope the output stream so it closes and finalizes output to the string.
+    grpc::protobuf::io::StringOutputStream output_stream(&output);
+    Printer printer(&output_stream, '$');
   
-  printer.Print("@protocol GRXWriteable;\n");
-  printer.Print("@protocol GRXWriter;\n\n");
-
-  map<string, string> vars = {{"service_name", service->name()},
-                              {"prefix",       prefix}};
-  printer.Print(vars, "@protocol $prefix$$service_name$ <NSObject>\n\n");
-
-  for (int i = 0; i < service->method_count(); i++) {
-    PrintMethodDeclarations(&printer, service->method(i), vars);
+    printer.Print("@protocol GRXWriteable;\n");
+    printer.Print("@protocol GRXWriter;\n\n");
+
+    map<string, string> vars = {{"service_name", service->name()},
+                                {"prefix",       prefix}};
+    printer.Print(vars, "@protocol $prefix$$service_name$ <NSObject>\n\n");
+
+    for (int i = 0; i < service->method_count(); i++) {
+      PrintMethodDeclarations(&printer, service->method(i), vars);
+    }
+    printer.Print("@end\n\n");
+
+    printer.Print("// Basic service implementation, over gRPC, that only does"
+        " marshalling and parsing.\n");
+    printer.Print(vars, "@interface $prefix$$service_name$ :"
+      " ProtoService<$prefix$$service_name$>\n");
+    printer.Print("- (instancetype)initWithHost:(NSString *)host"
+      " NS_DESIGNATED_INITIALIZER;\n");
+    printer.Print("@end\n");
   }
-  printer.Print("@end\n\n");
-
-  printer.Print("// Basic service implementation, over gRPC, that only does"
-      " marshalling and parsing.\n");
-  printer.Print(vars, "@interface $prefix$$service_name$ :"
-    " ProtoService<$prefix$$service_name$>\n");
-  printer.Print("- (instancetype)initWithHost:(NSString *)host"
-    " NS_DESIGNATED_INITIALIZER;\n");
-  printer.Print("@end\n");
   return output;
 }
 
 string GetSource(const ServiceDescriptor *service, const string prefix) {
   string output;
-  grpc::protobuf::io::StringOutputStream output_stream(&output);
-  Printer printer(&output_stream, '$');
-
-  map<string, string> vars = {{"service_name", service->name()},
-                              {"package", service->file()->package()},
-                              {"prefix",       prefix}};
-
-  printer.Print(vars,
-      "static NSString *const kPackageName = @\"$package$\";\n");
-  printer.Print(vars,
-      "static NSString *const kServiceName = @\"$service_name$\";\n\n");
-
-  printer.Print(vars, "@implementation $prefix$$service_name$\n\n");
-
-  printer.Print("// Designated initializer\n");
-  printer.Print("- (instancetype)initWithHost:(NSString *)host {\n");
-  printer.Print("  return (self = [super initWithHost:host"
-      " packageName:kPackageName serviceName:kServiceName]);\n");
-  printer.Print("}\n\n");
-  printer.Print("// Override superclass initializer to disallow different"
-      " package and service names.\n");
-  printer.Print("- (instancetype)initWithHost:(NSString *)host\n");
-  printer.Print("                 packageName:(NSString *)packageName\n");
-  printer.Print("                 serviceName:(NSString *)serviceName {\n");
-  printer.Print("  return [self initWithHost:host];\n");
-  printer.Print("}\n\n\n");
-
-  for (int i = 0; i < service->method_count(); i++) {
-    PrintMethodImplementations(&printer, service->method(i), vars);
-  }
+  {
+    // Scope the output stream so it closes and finalizes output to the string.
+    grpc::protobuf::io::StringOutputStream output_stream(&output);
+    Printer printer(&output_stream, '$');
+
+    map<string, string> vars = {{"service_name", service->name()},
+                                {"package", service->file()->package()},
+                                {"prefix",       prefix}};
 
-  printer.Print("@end\n");
+    printer.Print(vars,
+        "static NSString *const kPackageName = @\"$package$\";\n");
+    printer.Print(vars,
+        "static NSString *const kServiceName = @\"$service_name$\";\n\n");
+
+    printer.Print(vars, "@implementation $prefix$$service_name$\n\n");
+  
+    printer.Print("// Designated initializer\n");
+    printer.Print("- (instancetype)initWithHost:(NSString *)host {\n");
+    printer.Print("  return (self = [super initWithHost:host"
+        " packageName:kPackageName serviceName:kServiceName]);\n");
+    printer.Print("}\n\n");
+    printer.Print("// Override superclass initializer to disallow different"
+        " package and service names.\n");
+    printer.Print("- (instancetype)initWithHost:(NSString *)host\n");
+    printer.Print("                 packageName:(NSString *)packageName\n");
+    printer.Print("                 serviceName:(NSString *)serviceName {\n");
+    printer.Print("  return [self initWithHost:host];\n");
+    printer.Print("}\n\n\n");
+
+    for (int i = 0; i < service->method_count(); i++) {
+      PrintMethodImplementations(&printer, service->method(i), vars);
+    }
+
+    printer.Print("@end\n");
+  }
   return output;
 }
 
diff --git a/src/compiler/ruby_generator.cc b/src/compiler/ruby_generator.cc
index a0bb92848b..299137519f 100644
--- a/src/compiler/ruby_generator.cc
+++ b/src/compiler/ruby_generator.cc
@@ -119,49 +119,52 @@ void PrintService(const ServiceDescriptor *service, const grpc::string &package,
 
 grpc::string GetServices(const FileDescriptor *file) {
   grpc::string output;
-  StringOutputStream output_stream(&output);
-  Printer out(&output_stream, '$');
-
-  // Don't write out any output if there no services, to avoid empty service
-  // files being generated for proto files that don't declare any.
-  if (file->service_count() == 0) {
-    return output;
-  }
-
-  // Write out a file header.
-  std::map<grpc::string, grpc::string> header_comment_vars = ListToDict(
-      {"file.name", file->name(), "file.package", file->package(), });
-  out.Print("# Generated by the protocol buffer compiler.  DO NOT EDIT!\n");
-  out.Print(header_comment_vars,
-            "# Source: $file.name$ for package '$file.package$'\n");
-
-  out.Print("\n");
-  out.Print("require 'grpc'\n");
-  // Write out require statemment to import the separately generated file
-  // that defines the messages used by the service. This is generated by the
-  // main ruby plugin.
-  std::map<grpc::string, grpc::string> dep_vars =
-      ListToDict({"dep.name", MessagesRequireName(file), });
-  out.Print(dep_vars, "require '$dep.name$'\n");
-
-  // Write out services within the modules
-  out.Print("\n");
-  std::vector<grpc::string> modules = Split(file->package(), '.');
-  for (size_t i = 0; i < modules.size(); ++i) {
-    std::map<grpc::string, grpc::string> module_vars =
-        ListToDict({"module.name", CapitalizeFirst(modules[i]), });
-    out.Print(module_vars, "module $module.name$\n");
-    out.Indent();
+  {
+    // Scope the output stream so it closes and finalizes output to the string.
+
+    StringOutputStream output_stream(&output);
+    Printer out(&output_stream, '$');
+
+    // Don't write out any output if there no services, to avoid empty service
+    // files being generated for proto files that don't declare any.
+    if (file->service_count() == 0) {
+      return output;
+    }
+
+    // Write out a file header.
+    std::map<grpc::string, grpc::string> header_comment_vars = ListToDict(
+        {"file.name", file->name(), "file.package", file->package(), });
+    out.Print("# Generated by the protocol buffer compiler.  DO NOT EDIT!\n");
+    out.Print(header_comment_vars,
+              "# Source: $file.name$ for package '$file.package$'\n");
+
+    out.Print("\n");
+    out.Print("require 'grpc'\n");
+    // Write out require statemment to import the separately generated file
+    // that defines the messages used by the service. This is generated by the
+    // main ruby plugin.
+    std::map<grpc::string, grpc::string> dep_vars =
+        ListToDict({"dep.name", MessagesRequireName(file), });
+    out.Print(dep_vars, "require '$dep.name$'\n");
+
+    // Write out services within the modules
+    out.Print("\n");
+    std::vector<grpc::string> modules = Split(file->package(), '.');
+    for (size_t i = 0; i < modules.size(); ++i) {
+      std::map<grpc::string, grpc::string> module_vars =
+          ListToDict({"module.name", CapitalizeFirst(modules[i]), });
+      out.Print(module_vars, "module $module.name$\n");
+      out.Indent();
+    }
+    for (int i = 0; i < file->service_count(); ++i) {
+      auto service = file->service(i);
+      PrintService(service, file->package(), &out);
+    }
+    for (size_t i = 0; i < modules.size(); ++i) {
+      out.Outdent();
+      out.Print("end\n");
+    }
   }
-  for (int i = 0; i < file->service_count(); ++i) {
-    auto service = file->service(i);
-    PrintService(service, file->package(), &out);
-  }
-  for (size_t i = 0; i < modules.size(); ++i) {
-    out.Outdent();
-    out.Print("end\n");
-  }
-
   return output;
 }