8 files changed, 189 insertions, 9 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 63e1a39..52a4376 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,15 +22,22 @@ if(NOT CMAKE_BUILD_TYPE)
   set(CMAKE_BUILD_TYPE Debug)
 endif()
 
+if(APPLE)
+  # When building on the apple platform certain Objective-C++ classes bridge
+  # back into other Firebase Cocoapods. This requires shelling out to xcodebuild
+  # to verify the built frameworks are up-to-date. You can disable this to speed
+  # up the build.
+  option(BUILD_PODS, "Always build dependent cocoapods." ON)
+endif(APPLE)
+
 list(INSERT CMAKE_MODULE_PATH 0 ${PROJECT_SOURCE_DIR}/cmake)
 
-# External Projects install into this prefix and download into the source tree
-# to avoid re-downloading repeatedly during development.
-set(FIREBASE_INSTALL_DIR "${PROJECT_BINARY_DIR}/usr")
-set(FIREBASE_DOWNLOAD_DIR "${PROJECT_SOURCE_DIR}/.downloads")
+set(FIREBASE_INSTALL_DIR ${PROJECT_BINARY_DIR})
 
 enable_testing()
 
+include(external/FirebaseCore)
+
 include(external/googletest)
 include(external/leveldb)
 include(external/abseil-cpp)
diff --git a/Firestore/CMakeLists.txt b/Firestore/CMakeLists.txt
index 906b6e4..ba9998d 100644
--- a/Firestore/CMakeLists.txt
+++ b/Firestore/CMakeLists.txt
@@ -24,6 +24,10 @@ include(utils)
 find_package(GTest REQUIRED)
 find_package(LevelDB REQUIRED)
 
+if(APPLE)
+  find_package(FirebaseCore REQUIRED)
+endif()
+
 # We use C++11
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
diff --git a/Firestore/core/src/firebase/firestore/base/port.h b/Firestore/core/src/firebase/firestore/base/port.h
index 37d1041..5e3959d 100644
--- a/Firestore/core/src/firebase/firestore/base/port.h
+++ b/Firestore/core/src/firebase/firestore/base/port.h
@@ -18,7 +18,7 @@
 #define FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_BASE_PORT_H_
 
 #if defined(__APPLE__)
-// On Apple platforms we support building via Cocoapods without CMake. When
+// On Apple platforms we support building via CocoaPods without CMake. When
 // building this way we can't test the presence of features so predefine all
 // the platform-support feature macros to their expected values.
 
diff --git a/cmake/FindFirebaseCore.cmake b/cmake/FindFirebaseCore.cmake
new file mode 100644
index 0000000..e23d6db
--- /dev/null
+++ b/cmake/FindFirebaseCore.cmake
@@ -0,0 +1,57 @@
+# Copyright 2017 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.
+
+find_library(
+  FIREBASECORE_LIBRARY
+  FirebaseCore
+  PATHS ${FIREBASE_BINARY_DIR}/Frameworks
+)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(
+  FirebaseCore
+  DEFAULT_MSG
+  FIREBASECORE_LIBRARY
+)
+
+if(FIREBASECORE_FOUND)
+  # Emulate CocoaPods behavior which makes all headers available unqualified.
+  set(
+    FIREBASECORE_INCLUDE_DIRS
+    ${FIREBASECORE_LIBRARY}/Headers
+    ${FIREBASECORE_LIBRARY}/PrivateHeaders
+  )
+
+  # TODO(mcg): on iOS this should depend on UIKit.
+  set(
+    FIREBASECORE_LIBRARIES
+    ${FIREBASECORE_LIBRARY}
+    "-framework AppKit"
+  )
+
+  if(NOT TARGET FirebaseCore)
+    # Add frameworks as INTERFACE libraries rather than IMPORTED so that
+    # framework behavior is preserved.
+    add_library(FirebaseCore INTERFACE)
+
+    set_property(
+      TARGET FirebaseCore APPEND PROPERTY
+      INTERFACE_INCLUDE_DIRECTORIES ${FIREBASECORE_INCLUDE_DIRS}
+    )
+    set_property(
+      TARGET FirebaseCore APPEND PROPERTY
+      INTERFACE_LINK_LIBRARIES ${FIREBASECORE_LIBRARIES}
+    )
+  endif()
+endif(FIREBASECORE_FOUND)
diff --git a/cmake/external/FirebaseCore.cmake b/cmake/external/FirebaseCore.cmake
new file mode 100644
index 0000000..8be6969
--- /dev/null
+++ b/cmake/external/FirebaseCore.cmake
@@ -0,0 +1,23 @@
+# Copyright 2017 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(xcodebuild)
+
+if(APPLE)
+  # FirebaseCore is only available as a CocoaPod build.
+  xcodebuild(FirebaseCore)
+else()
+  # On non-Apple platforms, there's no way to build FirebaseCore.
+  add_custom_target(FirebaseCore)
+endif()
diff --git a/cmake/external/firestore.cmake b/cmake/external/firestore.cmake
index 9fb673e..61f79f3 100644
--- a/cmake/external/firestore.cmake
+++ b/cmake/external/firestore.cmake
@@ -19,7 +19,7 @@ set(binary_dir ${PROJECT_BINARY_DIR}/Firestore)
 
 ExternalProject_Add(
   Firestore
-  DEPENDS abseil-cpp googletest leveldb
+  DEPENDS abseil-cpp FirebaseCore googletest leveldb
 
   # Lay the binary directory out as if this were a subproject. This makes it
   # possible to build and test in it directly.
diff --git a/cmake/external/googletest.cmake b/cmake/external/googletest.cmake
index a956e9f..128f849 100644
--- a/cmake/external/googletest.cmake
+++ b/cmake/external/googletest.cmake
@@ -17,12 +17,11 @@ include(ExternalProject)
 ExternalProject_Add(
   googletest
 
-  URL "https://github.com/google/googletest/archive/release-1.8.0.tar.gz"
-  URL_HASH "SHA256=58a6f4277ca2bc8565222b3bbd58a177609e9c488e8a72649359ba51450db7d8"
+  GIT_REPOSITORY "https://github.com/google/googletest.git"
+  GIT_TAG "release-1.8.0"
 
   PREFIX ${PROJECT_BINARY_DIR}/third_party/googletest
 
-  DOWNLOAD_DIR ${FIREBASE_DOWNLOAD_DIR}
   INSTALL_DIR ${FIREBASE_INSTALL_DIR}
 
   TEST_COMMAND ""
diff --git a/cmake/xcodebuild.cmake b/cmake/xcodebuild.cmake
new file mode 100644
index 0000000..8312f6d
--- /dev/null
+++ b/cmake/xcodebuild.cmake
@@ -0,0 +1,90 @@
+# Copyright 2017 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(CMakeParseArguments)
+include(ExternalProject)
+
+# Builds an existing Xcode project or workspace as an external project in CMake.
+#
+# xcodebuild(<framework> [<option>...])
+#
+# Options:
+# ``DEPENDS <projects>...``
+#   Targets on which the project depends
+# ``SCHEME <scheme>``
+#   The scheme to build in the workspace, defaults to <framework>-<platform>,
+#   where <platform> is always "macOS".
+# ``WORKSPACE <workspace>``
+#   Location of the xcworkspace file containing the target to build. Defaults to
+#   Example/Firebase.xcworkspace.
+function(xcodebuild framework)
+  # Parse arguments
+  set(options "")
+  set(single_value SCHEME WORKSPACE)
+  set(multi_value DEPENDS)
+  cmake_parse_arguments(xcb "${options}" "${single_value}" "${multi_value}")
+
+  if(NOT xcb_WORKSPACE)
+    set(xcb_WORKSPACE ${PROJECT_SOURCE_DIR}/Example/Firebase.xcworkspace)
+  endif()
+
+  # TODO(mcg): Investigate supporting non-macOS platforms
+  # The canonical way to build and test for iOS is via Xcode and CocoaPods so
+  # it's not super important to make this work here
+  set(platform macOS)
+  set(destination "platform=macOS,arch=x86_64")
+  set(scheme "${framework}-${platform}")
+
+  set(binary_dir ${PROJECT_BINARY_DIR}/${scheme})
+
+  # CMake has a variety of release types, but Xcode has just one by default.
+  if(CMAKE_BUILD_TYPE STREQUAL Debug)
+    set(configuration Debug)
+  else()
+    set(configuration Release)
+  endif()
+
+  # Pipe build output through xcpretty if it's available
+  find_program(xcpretty_cmd xcpretty)
+  if(xcpretty_cmd)
+    set(pipe_xcpretty "|" ${xcpretty_cmd})
+  endif()
+
+  ExternalProject_Add(
+    ${framework}
+    DEPENDS ${xcb_DEPENDS}
+
+    PREFIX ${binary_dir}
+
+    # The source directory doesn't actually matter
+    SOURCE_DIR ${PROJECT_SOURCE_DIR}
+    BINARY_DIR ${binary_dir}
+
+    CONFIGURE_COMMAND ""
+
+    BUILD_COMMAND
+      xcodebuild
+        -workspace ${xcb_WORKSPACE}
+        -scheme ${scheme}
+        -configuration ${configuration}
+        -destination ${destination}
+        CONFIGURATION_BUILD_DIR=${FIREBASE_INSTALL_DIR}/Frameworks
+        build
+        ${pipe_xcpretty}
+    BUILD_ALWAYS ${BUILD_PODS}
+
+    INSTALL_COMMAND ""
+    TEST_COMMAND ""
+  )
+endfunction()