Change flag name and invert the bool

src/core/lib/config/config_vars.cc

@@ -72,8 +72,10 @@ ABSL_FLAG(absl::optional<bool>, grpc_not_use_system_ssl_roots, {},
           "Disable loading system root certificates.");
 ABSL_FLAG(absl::optional<std::string>, grpc_ssl_cipher_suites, {},
           "A colon separated list of cipher suites to use with OpenSSL");
-ABSL_FLAG(absl::optional<bool>, grpc_cpp_enable_reflection, {},
-          "Whether to automatically add a reflection handler.");
+ABSL_FLAG(absl::optional<bool>, grpc_cpp_experimental_disable_reflection, {},
+          "EXPERIMENTAL. Only respected when there is a dependency on "
+          ":grpc++_reflection. If true, no reflection server will be "
+          "automatically added.");
 
 namespace grpc_core {
 
@@ -91,9 +93,10 @@ ConfigVars::ConfigVars(const Overrides& overrides)
       not_use_system_ssl_roots_(LoadConfig(
           FLAGS_grpc_not_use_system_ssl_roots, "GRPC_NOT_USE_SYSTEM_SSL_ROOTS",
           overrides.not_use_system_ssl_roots, false)),
-      cpp_enable_reflection_(LoadConfig(FLAGS_grpc_cpp_enable_reflection,
-                                        "GRPC_CPP_ENABLE_REFLECTION",
-                                        overrides.cpp_enable_reflection, true)),
+      cpp_experimental_disable_reflection_(
+          LoadConfig(FLAGS_grpc_cpp_experimental_disable_reflection,
+                     "GRPC_CPP_EXPERIMENTAL_DISABLE_REFLECTION",
+                     overrides.cpp_experimental_disable_reflection, false)),
       dns_resolver_(LoadConfig(FLAGS_grpc_dns_resolver, "GRPC_DNS_RESOLVER",
                                overrides.dns_resolver, "")),
       verbosity_(LoadConfig(FLAGS_grpc_verbosity, "GRPC_VERBOSITY",
@@ -142,7 +145,8 @@ std::string ConfigVars::ToString() const {
       absl::CEscape(DefaultSslRootsFilePath()), "\"",
       ", not_use_system_ssl_roots: ", NotUseSystemSslRoots() ? "true" : "false",
       ", ssl_cipher_suites: ", "\"", absl::CEscape(SslCipherSuites()), "\"",
-      ", cpp_enable_reflection: ", CppEnableReflection() ? "true" : "false");
+      ", cpp_experimental_disable_reflection: ",
+      CppExperimentalDisableReflection() ? "true" : "false");
 }
 
 }  // namespace grpc_core

src/core/lib/config/config_vars.h

@@ -38,7 +38,7 @@ class GPR_DLL ConfigVars {
     absl::optional<bool> enable_fork_support;
     absl::optional<bool> abort_on_leaks;
     absl::optional<bool> not_use_system_ssl_roots;
-    absl::optional<bool> cpp_enable_reflection;
+    absl::optional<bool> cpp_experimental_disable_reflection;
     absl::optional<std::string> dns_resolver;
     absl::optional<std::string> verbosity;
     absl::optional<std::string> poll_strategy;
@@ -98,8 +98,12 @@ class GPR_DLL ConfigVars {
   bool NotUseSystemSslRoots() const { return not_use_system_ssl_roots_; }
   // A colon separated list of cipher suites to use with OpenSSL
   absl::string_view SslCipherSuites() const { return ssl_cipher_suites_; }
-  // Whether to automatically add a reflection handler.
-  bool CppEnableReflection() const { return cpp_enable_reflection_; }
+  // EXPERIMENTAL. Only respected when there is a dependency on
+  // :grpc++_reflection. If true, no reflection server will be automatically
+  // added.
+  bool CppExperimentalDisableReflection() const {
+    return cpp_experimental_disable_reflection_;
+  }
 
  private:
   explicit ConfigVars(const Overrides& overrides);
@@ -109,7 +113,7 @@ class GPR_DLL ConfigVars {
   bool enable_fork_support_;
   bool abort_on_leaks_;
   bool not_use_system_ssl_roots_;
-  bool cpp_enable_reflection_;
+  bool cpp_experimental_disable_reflection_;
   std::string dns_resolver_;
   std::string verbosity_;
   std::string poll_strategy_;

src/core/lib/config/config_vars.yaml

@@ -120,7 +120,7 @@
     ECDHE-ECDSA-AES256-GCM-SHA384:\
     ECDHE-RSA-AES128-GCM-SHA256:\
     ECDHE-RSA-AES256-GCM-SHA384"
-- name: cpp_enable_reflection
+- name: cpp_experimental_disable_reflection
   type: bool
-  description: Whether to automatically add a reflection handler.
-  default: true
+  description: "EXPERIMENTAL. Only respected when there is a dependency on :grpc++_reflection. If true, no reflection server will be automatically added."
+  default: false

src/cpp/ext/proto_server_reflection_plugin.cc

@@ -45,7 +45,7 @@ void ProtoServerReflectionPlugin::InitServer(grpc::ServerInitializer* si) {
   // We cannot simply keep the plugin from being unregistered because this must
   // happen at static initialization time, whereas flag configuration that
   // controls this is not received until later.
-  if (grpc_core::ConfigVars::Get().CppEnableReflection()) {
+  if (!grpc_core::ConfigVars::Get().CppExperimentalDisableReflection()) {
     si->RegisterService(reflection_service_v1_);
     si->RegisterService(reflection_service_v1alpha_);
   }
@@ -59,7 +59,7 @@ void ProtoServerReflectionPlugin::ChangeArguments(const std::string& /*name*/,
                                                   void* /*value*/) {}
 
 bool ProtoServerReflectionPlugin::has_sync_methods() const {
-  if (grpc_core::ConfigVars::Get().CppEnableReflection()) {
+  if (!grpc_core::ConfigVars::Get().CppExperimentalDisableReflection()) {
     return (reflection_service_v1_ &&
             reflection_service_v1_->has_synchronous_methods()) ||
            (reflection_service_v1alpha_ &&
@@ -69,7 +69,7 @@ bool ProtoServerReflectionPlugin::has_sync_methods() const {
 }
 
 bool ProtoServerReflectionPlugin::has_async_methods() const {
-  if (grpc_core::ConfigVars::Get().CppEnableReflection()) {
+  if (!grpc_core::ConfigVars::Get().CppExperimentalDisableReflection()) {
     return (reflection_service_v1_ &&
             reflection_service_v1_->has_async_methods()) ||
            (reflection_service_v1alpha_ &&

tools/codegen/core/gen_config_vars.py

@@ -39,7 +39,9 @@
         print("config has no name: %r" % attr)
         error = True
         continue
-    if "experiment" in attr["name"] and attr["name"] != "experiments":
+    if (
+        "experiment" in attr["name"] and "experimental" not in attr["name"]
+    ) and attr["name"] != "experiments":
         print("use experiment system for experiments")
         error = True
     if "description" not in attr: