Add compile time warning for C++14 upgrade (#1219)

* Add compile time warning for C++14 upgrade

* Rename cpp warning file and change #warning to #message to avoid "warning as error"

* Add release note

Author: cherylEnkidu

admob/src/include/firebase/admob.h

@@ -28,6 +28,7 @@
 #include "firebase/admob/rewarded_video.h"
 #include "firebase/admob/types.h"
 #include "firebase/app.h"
+#include "firebase/cpp_version_warning.h"
 #include "firebase/internal/common.h"
 
 #if !defined(DOXYGEN) && !defined(SWIG)

analytics/src/include/firebase/analytics.h

@@ -23,6 +23,7 @@
 #include <string>
 
 #include "firebase/app.h"
+#include "firebase/cpp_version_warning.h"
 #include "firebase/future.h"
 #include "firebase/internal/common.h"
 #include "firebase/variant.h"

app/CMakeLists.txt

@@ -251,6 +251,7 @@ endif()
 
 set(internal_HDRS
     src/include/firebase/app.h
+        src/include/firebase/cpp_version_warning.h
     src/include/firebase/future.h
     src/include/firebase/internal/common.h
     src/include/firebase/internal/future_impl.h

app/src/include/firebase/app.h

@@ -17,6 +17,7 @@
 #ifndef FIREBASE_APP_SRC_INCLUDE_FIREBASE_APP_H_
 #define FIREBASE_APP_SRC_INCLUDE_FIREBASE_APP_H_
 
+#include "cpp_version_warning.h"
 #include "firebase/internal/platform.h"
 
 #if FIREBASE_PLATFORM_ANDROID

app/src/include/firebase/cpp_version_warning.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * 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.
+ */
+
+#if __cplusplus < 201400
+#pragma message                                            \
+    "The next major release of the Firebase C++ SDK will " \
+    "drop support for C++11, setting the new minimum C++ version to C++14."
+#endif

app_check/src/include/firebase/app_check.h

@@ -18,6 +18,7 @@
 #include <string>
 
 #include "firebase/app.h"
+#include "firebase/cpp_version_warning.h"
 #include "firebase/future.h"
 
 namespace firebase {

auth/src/include/firebase/auth.h

@@ -21,6 +21,7 @@
 
 #include "firebase/app.h"
 #include "firebase/auth/user.h"
+#include "firebase/cpp_version_warning.h"
 #include "firebase/future.h"
 #include "firebase/internal/common.h"
 

database/src/include/firebase/database.h

@@ -16,6 +16,7 @@
 #define FIREBASE_DATABASE_SRC_INCLUDE_FIREBASE_DATABASE_H_
 
 #include "firebase/app.h"
+#include "firebase/cpp_version_warning.h"
 #include "firebase/database/common.h"
 #include "firebase/database/data_snapshot.h"
 #include "firebase/database/database_reference.h"

dynamic_links/src/include/firebase/dynamic_links.h

@@ -18,6 +18,7 @@
 #include <string>
 
 #include "firebase/app.h"
+#include "firebase/cpp_version_warning.h"
 #include "firebase/internal/common.h"
 
 #if !defined(DOXYGEN) && !defined(SWIG)

firestore/src/include/firebase/firestore.h

@@ -23,6 +23,7 @@
 #include "firebase/internal/common.h"
 
 #include "firebase/app.h"
+#include "firebase/cpp_version_warning.h"
 #include "firebase/future.h"
 #include "firebase/log.h"
 // Include *all* the public headers to make sure including just "firestore.h" is