Fix --define=grpc_no_xds=true build

BUILD

@@ -42,6 +42,7 @@ config_setting(
     values = {"define": "grpc_no_ares=true"},
 )
 
+# TODO(yashykt): Add a build target with this flag.
 config_setting(
     name = "grpc_no_xds",
     values = {"define": "grpc_no_xds=true"},
@@ -367,6 +368,12 @@ grpc_cc_library(
     ],
     language = "c++",
     public_hdrs = GRPCXX_PUBLIC_HDRS,
+    select_deps = {
+        "grpc_no_xds": [],
+        "//conditions:default": [
+            "grpc++_xds_credentials",
+        ],
+    },
     standalone = True,
     deps = [
         "gpr",
@@ -379,6 +386,20 @@ grpc_cc_library(
     ],
 )
 
+grpc_cc_library(
+    name = "grpc++_xds_credentials",
+    srcs = [
+        "src/cpp/client/xds_credentials.cc",
+    ],
+    hdrs = [
+        "src/cpp/client/secure_credentials.h",
+    ],
+    language = "c++",
+    deps = [
+        "grpc++_base",
+    ],
+)
+
 grpc_cc_library(
     name = "grpc++_unsecure",
     srcs = [

BUILD.gn

@@ -1415,6 +1415,7 @@ config("grpc_config") {
         "src/cpp/client/insecure_credentials.cc",
         "src/cpp/client/secure_credentials.cc",
         "src/cpp/client/secure_credentials.h",
+        "src/cpp/client/xds_credentials.cc",
         "src/cpp/codegen/codegen_init.cc",
         "src/cpp/common/alarm.cc",
         "src/cpp/common/auth_property_iterator.cc",

CMakeLists.txt

@@ -2656,6 +2656,7 @@ add_library(grpc++
   src/cpp/client/credentials_cc.cc
   src/cpp/client/insecure_credentials.cc
   src/cpp/client/secure_credentials.cc
+  src/cpp/client/xds_credentials.cc
   src/cpp/codegen/codegen_init.cc
   src/cpp/common/alarm.cc
   src/cpp/common/auth_property_iterator.cc

Makefile

@@ -2831,6 +2831,7 @@ LIBGRPC++_SRC = \
     src/cpp/client/credentials_cc.cc \
     src/cpp/client/insecure_credentials.cc \
     src/cpp/client/secure_credentials.cc \
+    src/cpp/client/xds_credentials.cc \
     src/cpp/codegen/codegen_init.cc \
     src/cpp/common/alarm.cc \
     src/cpp/common/auth_property_iterator.cc \
@@ -4851,6 +4852,7 @@ src/core/tsi/ssl_transport_security.cc: $(OPENSSL_DEP)
 src/core/tsi/transport_security.cc: $(OPENSSL_DEP)
 src/core/tsi/transport_security_grpc.cc: $(OPENSSL_DEP)
 src/cpp/client/secure_credentials.cc: $(OPENSSL_DEP)
+src/cpp/client/xds_credentials.cc: $(OPENSSL_DEP)
 src/cpp/common/alts_context.cc: $(OPENSSL_DEP)
 src/cpp/common/alts_util.cc: $(OPENSSL_DEP)
 src/cpp/common/auth_property_iterator.cc: $(OPENSSL_DEP)

build_autogenerated.yaml

@@ -2295,6 +2295,7 @@ libs:
   - src/cpp/client/credentials_cc.cc
   - src/cpp/client/insecure_credentials.cc
   - src/cpp/client/secure_credentials.cc
+  - src/cpp/client/xds_credentials.cc
   - src/cpp/codegen/codegen_init.cc
   - src/cpp/common/alarm.cc
   - src/cpp/common/auth_property_iterator.cc

gRPC-C++.podspec

@@ -708,6 +708,7 @@ Pod::Spec.new do |s|
                       'src/cpp/client/insecure_credentials.cc',
                       'src/cpp/client/secure_credentials.cc',
                       'src/cpp/client/secure_credentials.h',
+                      'src/cpp/client/xds_credentials.cc',
                       'src/cpp/codegen/codegen_init.cc',
                       'src/cpp/common/alarm.cc',
                       'src/cpp/common/auth_property_iterator.cc',

grpc.gyp

@@ -1388,6 +1388,7 @@
         'src/cpp/client/credentials_cc.cc',
         'src/cpp/client/insecure_credentials.cc',
         'src/cpp/client/secure_credentials.cc',
+        'src/cpp/client/xds_credentials.cc',
         'src/cpp/codegen/codegen_init.cc',
         'src/cpp/common/alarm.cc',
         'src/cpp/common/auth_property_iterator.cc',

src/cpp/client/secure_credentials.cc

@@ -80,7 +80,8 @@ bool SecureCallCredentials::ApplyToCall(grpc_call* call) {
   return grpc_call_set_credentials(call, c_creds_) == GRPC_CALL_OK;
 }
 
-namespace {
+namespace internal {
+
 std::shared_ptr<ChannelCredentials> WrapChannelCredentials(
     grpc_channel_credentials* creds) {
   return creds == nullptr ? nullptr
@@ -88,6 +89,10 @@ std::shared_ptr<ChannelCredentials> WrapChannelCredentials(
                                 new SecureChannelCredentials(creds));
 }
 
+}  // namespace internal
+
+namespace {
+
 std::shared_ptr<CallCredentials> WrapCallCredentials(
     grpc_call_credentials* creds) {
   return creds == nullptr ? nullptr
@@ -98,7 +103,7 @@ std::shared_ptr<CallCredentials> WrapCallCredentials(
 
 std::shared_ptr<ChannelCredentials> GoogleDefaultCredentials() {
   grpc::GrpcLibraryCodegen init;  // To call grpc_init().
-  return WrapChannelCredentials(
+  return internal::WrapChannelCredentials(
       grpc_google_default_credentials_create(nullptr));
 }
 
@@ -113,7 +118,7 @@ std::shared_ptr<ChannelCredentials> SslCredentials(
       options.pem_root_certs.empty() ? nullptr : options.pem_root_certs.c_str(),
       options.pem_private_key.empty() ? nullptr : &pem_key_cert_pair, nullptr,
       nullptr);
-  return WrapChannelCredentials(c_creds);
+  return internal::WrapChannelCredentials(c_creds);
 }
 
 namespace experimental {
@@ -278,39 +283,23 @@ std::shared_ptr<ChannelCredentials> AltsCredentials(
   }
   grpc_channel_credentials* c_creds = grpc_alts_credentials_create(c_options);
   grpc_alts_credentials_options_destroy(c_options);
-  return WrapChannelCredentials(c_creds);
+  return internal::WrapChannelCredentials(c_creds);
 }
 
 // Builds Local Credentials
 std::shared_ptr<ChannelCredentials> LocalCredentials(
     grpc_local_connect_type type) {
   grpc::GrpcLibraryCodegen init;  // To call grpc_init().
-  return WrapChannelCredentials(grpc_local_credentials_create(type));
+  return internal::WrapChannelCredentials(grpc_local_credentials_create(type));
 }
 
 // Builds TLS Credentials given TLS options.
 std::shared_ptr<ChannelCredentials> TlsCredentials(
     const TlsCredentialsOptions& options) {
-  return WrapChannelCredentials(
+  return internal::WrapChannelCredentials(
       grpc_tls_credentials_create(options.c_credentials_options()));
 }
 
-// Builds XDS Credentials
-std::shared_ptr<ChannelCredentials> XdsCredentials(
-    const std::shared_ptr<ChannelCredentials>& fallback_creds) {
-  if (fallback_creds->IsInsecure()) {
-    grpc_channel_credentials* insecure_creds =
-        grpc_insecure_credentials_create();
-    auto xds_creds =
-        WrapChannelCredentials(grpc_xds_credentials_create(insecure_creds));
-    grpc_channel_credentials_release(insecure_creds);
-    return xds_creds;
-  } else {
-    return WrapChannelCredentials(grpc_xds_credentials_create(
-        fallback_creds->AsSecureCredentials()->GetRawCreds()));
-  }
-}
-
 }  // namespace experimental
 
 // Builds credentials for use when running in GCE
@@ -373,8 +362,10 @@ std::shared_ptr<ChannelCredentials> CompositeChannelCredentials(
       channel_creds->AsSecureCredentials();
   SecureCallCredentials* s_call_creds = call_creds->AsSecureCredentials();
   if (s_channel_creds && s_call_creds) {
-    return WrapChannelCredentials(grpc_composite_channel_credentials_create(
-        s_channel_creds->GetRawCreds(), s_call_creds->GetRawCreds(), nullptr));
+    return internal::WrapChannelCredentials(
+        grpc_composite_channel_credentials_create(
+            s_channel_creds->GetRawCreds(), s_call_creds->GetRawCreds(),
+            nullptr));
   }
   return nullptr;
 }

src/cpp/client/secure_credentials.h

@@ -75,6 +75,13 @@ class SecureCallCredentials final : public CallCredentials {
   grpc_call_credentials* const c_creds_;
 };
 
+namespace internal {
+
+std::shared_ptr<ChannelCredentials> WrapChannelCredentials(
+    grpc_channel_credentials* creds);
+
+}  // namespace internal
+
 namespace experimental {
 
 // Transforms C++ STS Credentials options to core options. The pointers of the

src/cpp/client/xds_credentials.cc

@@ -0,0 +1,40 @@
+//
+//
+// Copyright 2020 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+
+#include "src/cpp/client/secure_credentials.h"
+
+namespace grpc {
+namespace experimental {
+
+std::shared_ptr<ChannelCredentials> XdsCredentials(
+    const std::shared_ptr<ChannelCredentials>& fallback_creds) {
+  if (fallback_creds->IsInsecure()) {
+    grpc_channel_credentials* insecure_creds =
+        grpc_insecure_credentials_create();
+    auto xds_creds = internal::WrapChannelCredentials(
+        grpc_xds_credentials_create(insecure_creds));
+    grpc_channel_credentials_release(insecure_creds);
+    return xds_creds;
+  } else {
+    return internal::WrapChannelCredentials(grpc_xds_credentials_create(
+        fallback_creds->AsSecureCredentials()->GetRawCreds()));
+  }
+}
+
+}  // namespace experimental
+}  // namespace grpc

tools/doxygen/Doxyfile.c++.internal

@@ -2111,6 +2111,7 @@ src/cpp/client/credentials_cc.cc \
 src/cpp/client/insecure_credentials.cc \
 src/cpp/client/secure_credentials.cc \
 src/cpp/client/secure_credentials.h \
+src/cpp/client/xds_credentials.cc \
 src/cpp/codegen/codegen_init.cc \
 src/cpp/common/alarm.cc \
 src/cpp/common/auth_property_iterator.cc \