Build gRPC for Firestore C++ (#652)

* Clean up quoting and other minor issues

* Reorganize CMake build output

Make it clearer which parts of the output pertain to external projects.

* Use a consistent ordering of ExternalProject arguments

* Prevent the top-level build from running in parallel

This prevents spurious failures when running make -j.

* Actually parse arguments in the xcodebuild function

* Use ExternalProject features when available

  * submodule limits from CMake 3.0
  * shallow clones from CMake 3.6
  * git progress output from CMake 3.8

* Only build the parts of leveldb we need

Skip building the tools and other libraries

* Avoid installing ExternalProjects

Consume build output directly so that we can build just the targets we
need. Installing causes all targets to be built.

This doesn't matter as much for these targets but the gRPC build
includes a ton of stuff we don't need so it's worth adopting this as a
general strategy.

* Define an external build for grpc

* Test that grpc can link successfully.

* Add a FindGRPC CMake module

* Actually comment ExternalProjext_GitSource

6 files changed, 147 insertions, 0 deletions

diff --git a/Firestore/core/CMakeLists.txt b/Firestore/core/CMakeLists.txt
index c49b6db..9291fbd 100644
--- a/Firestore/core/CMakeLists.txt
+++ b/Firestore/core/CMakeLists.txt
@@ -13,4 +13,7 @@
 # limitations under the License.
 
 add_subdirectory(src/firebase/firestore/util)
+add_subdirectory(src/firebase/firestore/remote)
+
 add_subdirectory(test/firebase/firestore/util)
+add_subdirectory(test/firebase/firestore/remote)
diff --git a/Firestore/core/src/firebase/firestore/remote/CMakeLists.txt b/Firestore/core/src/firebase/firestore/remote/CMakeLists.txt
new file mode 100644
index 0000000..74ad80b
--- /dev/null
+++ b/Firestore/core/src/firebase/firestore/remote/CMakeLists.txt
@@ -0,0 +1,23 @@
+# Copyright 2018 Google
+#
+# 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.
+
+add_library(
+  firebase_firestore_remote
+  datastore.h
+  datastore.cc
+)
+target_link_libraries(
+  firebase_firestore_remote
+  grpc::grpc
+)
diff --git a/Firestore/core/src/firebase/firestore/remote/datastore.cc b/Firestore/core/src/firebase/firestore/remote/datastore.cc
new file mode 100644
index 0000000..f8a8988
--- /dev/null
+++ b/Firestore/core/src/firebase/firestore/remote/datastore.cc
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2018 Google
+ *
+ * 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 "Firestore/core/src/firebase/firestore/remote/datastore.h"
+
+namespace firebase {
+namespace firestore {
+namespace remote {
+
+Datastore::Datastore() {
+}
+
+Datastore::~Datastore() {
+}
+
+}  // namespace remote
+}  // namespace firestore
+}  // namespace firebase
diff --git a/Firestore/core/src/firebase/firestore/remote/datastore.h b/Firestore/core/src/firebase/firestore/remote/datastore.h
new file mode 100644
index 0000000..807b75f
--- /dev/null
+++ b/Firestore/core/src/firebase/firestore/remote/datastore.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2018 Google
+ *
+ * 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.
+ */
+
+#ifndef FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_REMOTE_DATASTORE_H_
+#define FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_REMOTE_DATASTORE_H_
+
+namespace firebase {
+namespace firestore {
+namespace remote {
+
+class Datastore {
+ public:
+  Datastore();
+  ~Datastore();
+
+  Datastore(const Datastore& other) = delete;
+  Datastore(Datastore&& other) = delete;
+
+  Datastore& operator=(const Datastore& other) = delete;
+  Datastore& operator=(Datastore&& other) = delete;
+};
+
+}  // namespace remote
+}  // namespace firestore
+}  // namespace firebase
+
+#endif  // FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_REMOTE_DATASTORE_H_
diff --git a/Firestore/core/test/firebase/firestore/remote/CMakeLists.txt b/Firestore/core/test/firebase/firestore/remote/CMakeLists.txt
new file mode 100644
index 0000000..f0731c3
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/remote/CMakeLists.txt
@@ -0,0 +1,22 @@
+# Copyright 2018 Google
+#
+# 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.
+
+cc_test(
+  firebase_firestore_remote_test
+  datastore_test.cc
+)
+target_link_libraries(
+  firebase_firestore_remote_test
+  firebase_firestore_remote
+)
diff --git a/Firestore/core/test/firebase/firestore/remote/datastore_test.cc b/Firestore/core/test/firebase/firestore/remote/datastore_test.cc
new file mode 100644
index 0000000..46a19cc
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/remote/datastore_test.cc
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2018 Google
+ *
+ * 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 "Firestore/core/src/firebase/firestore/remote/datastore.h"
+
+#include <grpc/grpc.h>
+#include <gtest/gtest.h>
+
+TEST(Datastore, CanLinkToGrpc) {
+  // This test doesn't actually do anything interesting as far as actually
+  // using gRPC is concerned but that it can run at all is proof that all the
+  // libraries required for gRPC to work are actually linked correctly into the
+  // test.
+  grpc_init();
+}