don't build RLS on mobile (#27838)

* don't build RLS on mobile

* buildifier

* fix build rules to avoid "Illegal ambiguous match" bazel error

BUILD

@@ -44,7 +44,7 @@ config_setting(
 )
 
 config_setting(
-    name = "grpc_no_xds_define",
+    name = "grpc_no_xds",
     values = {"define": "grpc_no_xds=true"},
 )
 
@@ -58,25 +58,20 @@ config_setting(
     values = {"apple_platform_type": "ios"},
 )
 
-# Fuzzers can be built as fuzzers or as tests
-config_setting(
-    name = "grpc_build_fuzzers",
-    values = {"define": "grpc_build_fuzzers=true"},
-)
-
 selects.config_setting_group(
-    name = "grpc_no_xds",
+    name = "grpc_mobile",
     match_any = [
-        ":grpc_no_xds_define",
-        # In addition to disabling XDS support when --define=grpc_no_xds=true is
-        # specified, we also disable it on mobile platforms where it is not
-        # likely to be needed and where reducing the binary size is more
-        # important.
         ":android",
         ":ios",
     ],
 )
 
+# Fuzzers can be built as fuzzers or as tests
+config_setting(
+    name = "grpc_build_fuzzers",
+    values = {"define": "grpc_build_fuzzers=true"},
+)
+
 config_setting(
     name = "grpc_allow_exceptions",
     values = {"define": "GRPC_ALLOW_EXCEPTIONS=1"},
@@ -368,6 +363,16 @@ grpc_cc_library(
     ],
 )
 
+GRPC_XDS_TARGETS = [
+    "grpc_lb_policy_cds",
+    "grpc_lb_policy_xds_cluster_impl",
+    "grpc_lb_policy_xds_cluster_manager",
+    "grpc_lb_policy_xds_cluster_resolver",
+    "grpc_resolver_xds",
+    "grpc_resolver_c2p",
+    "grpc_xds_server_config_fetcher",
+]
+
 grpc_cc_library(
     name = "grpc",
     srcs = [
@@ -375,22 +380,25 @@ grpc_cc_library(
         "src/core/plugin_registry/grpc_plugin_registry.cc",
     ],
     defines = select({
+        # On mobile, don't build RLS or xDS.
+        "grpc_mobile": [
+            "GRPC_NO_XDS",
+            "GRPC_NO_RLS",
+        ],
+        # Don't build xDS if --define=grpc_no_xds=true is used.
         "grpc_no_xds": ["GRPC_NO_XDS"],
+        # By default, build both RLS and xDS.
         "//conditions:default": [],
     }),
     language = "c++",
     public_hdrs = GRPC_PUBLIC_HDRS + GRPC_SECURE_PUBLIC_HDRS,
     select_deps = {
-        "grpc_no_xds": [],
-        "//conditions:default": [
-            "grpc_lb_policy_cds",
-            "grpc_lb_policy_xds_cluster_impl",
-            "grpc_lb_policy_xds_cluster_manager",
-            "grpc_lb_policy_xds_cluster_resolver",
-            "grpc_resolver_xds",
-            "grpc_resolver_c2p",
-            "grpc_xds_server_config_fetcher",
-        ],
+        # On mobile, don't build RLS or xDS.
+        "grpc_mobile": [],
+        # Don't build xDS if --define=grpc_no_xds=true is used.
+        "grpc_no_xds": ["grpc_lb_policy_rls"],
+        # By default, build both RLS and xDS.
+        "//conditions:default": ["grpc_lb_policy_rls"] + GRPC_XDS_TARGETS,
     },
     standalone = True,
     visibility = [
@@ -402,7 +410,6 @@ grpc_cc_library(
         "grpc_base",
         "grpc_common",
         "grpc_lb_policy_grpclb_secure",
-        "grpc_lb_policy_rls",
         "grpc_secure",
         "grpc_trace",
         "grpc_transport_chttp2_client_secure",

src/core/plugin_registry/grpc_plugin_registry.cc

@@ -54,8 +54,10 @@ void FaultInjectionFilterInit(void);
 void FaultInjectionFilterShutdown(void);
 void GrpcLbPolicyRingHashInit(void);
 void GrpcLbPolicyRingHashShutdown(void);
+#ifndef GRPC_NO_RLS
 void RlsLbPluginInit();
 void RlsLbPluginShutdown();
+#endif  // !GRPC_NO_RLS
 void ServiceConfigParserInit(void);
 void ServiceConfigParserShutdown(void);
 }  // namespace grpc_core
@@ -101,8 +103,10 @@ void grpc_register_built_in_plugins(void) {
   grpc_register_plugin(grpc_resolver_fake_init, grpc_resolver_fake_shutdown);
   grpc_register_plugin(grpc_lb_policy_grpclb_init,
                        grpc_lb_policy_grpclb_shutdown);
+#ifndef GRPC_NO_RLS
   grpc_register_plugin(grpc_core::RlsLbPluginInit,
                        grpc_core::RlsLbPluginShutdown);
+#endif  // !GRPC_NO_RLS
   grpc_register_plugin(grpc_lb_policy_priority_init,
                        grpc_lb_policy_priority_shutdown);
   grpc_register_plugin(grpc_lb_policy_weighted_target_init,

test/core/client_channel/BUILD

@@ -66,6 +66,7 @@ grpc_cc_test(
         "gtest",
     ],
     language = "C++",
+    tags = ["no_test_ios"],
     deps = [
         "//:grpc",
         "//test/core/util:grpc_test_util",

test/cpp/end2end/BUILD

@@ -484,6 +484,7 @@ grpc_cc_test(
         "gtest",
         "absl/types:optional",
     ],
+    tags = ["no_test_ios"],
     deps = [
         ":counted_service",
         ":test_service_impl",