Darwin: Move warning settings into the Xcode project

.github/workflows/darwin-tests.yaml

@@ -72,15 +72,7 @@ jobs:
 
             - name: Run macOS Darwin Framework Tool Build Debug
               working-directory: src/darwin/Framework
-              # Keep whatever Xcode settings
-              # for OTHER_CFLAGS exist by using ${inherited}.
-              #
-              # Enable -Wconversion by hand as well, because it seems to not be
-              # enabled by default in the Xcode config.
-              #
-              # Disable availability annotations, since we are not building against a system
-              # Matter.framework.
-              run: xcodebuild -target "darwin-framework-tool" -sdk macosx -configuration Debug OTHER_CFLAGS='${inherited} -Wconversion' GCC_PREPROCESSOR_DEFINITIONS='${inherited} MTR_NO_AVAILABILITY=1'
+              run: xcodebuild -target "darwin-framework-tool" -sdk macosx -configuration Debug
             - name: Delete Defaults
               run: defaults delete com.apple.dt.xctest.tool
               continue-on-error: true

.github/workflows/darwin.yaml

@@ -36,15 +36,15 @@ jobs:
             matrix:
                 options: # We don't need a full matrix
                     - flavor: macos-release-availability
-                      arguments: -sdk macosx -configuration Release   WARNING_CFLAGS='${inherited} -Werror -Wconversion -Wno-unguarded-availability-new'
+                      arguments: -sdk macosx -configuration Release   WARNING_CFLAGS='${inherited} -Wno-unguarded-availability-new' OTHER_CFLAGS='${inherited} -UMTR_NO_AVAILABILITY'
                     - flavor: ios-release
-                      arguments: -sdk iphoneos -configuration Release WARNING_CFLAGS='${inherited} -Werror -Wconversion' GCC_PREPROCESSOR_DEFINITIONS='${inherited} MTR_NO_AVAILABILITY=1'
+                      arguments: -sdk iphoneos -configuration Release
                     - flavor: ios-debug
-                      arguments: -sdk iphoneos -configuration Debug   WARNING_CFLAGS='${inherited} -Werror -Wconversion' GCC_PREPROCESSOR_DEFINITIONS='${inherited} MTR_NO_AVAILABILITY=1'
+                      arguments: -sdk iphoneos -configuration Debug
                     - flavor: tvos-debug
-                      arguments: -sdk appletvos -configuration Debug  WARNING_CFLAGS='${inherited} -Werror -Wconversion' GCC_PREPROCESSOR_DEFINITIONS='${inherited} MTR_NO_AVAILABILITY=1'
+                      arguments: -sdk appletvos -configuration Debug
                     - flavor: watchos-debug
-                      arguments: -sdk watchos -configuration Debug    WARNING_CFLAGS='${inherited} -Werror -Wconversion' GCC_PREPROCESSOR_DEFINITIONS='${inherited} MTR_NO_AVAILABILITY=1'
+                      arguments: -sdk watchos -configuration Debug
         steps:
             - name: Checkout
               uses: actions/checkout@v4

src/darwin/Framework/CHIPTests/MTRAvailabilityTest.m

@@ -0,0 +1,25 @@
+/**
+ *    Copyright (c) 2024 Project CHIP 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.
+ */
+
+#import <Matter/Matter.h>
+
+// The purpose of this test is to ensure that our availablity annotations are
+// at least syntactically valid, because within the project we generally
+// compile everything with MTR_NO_AVAILABILITY=1 (so that we can internally use
+// and test features of Matter.framework  independently of when they will ship.)
+#if MTR_NO_AVAILABILITY
+#error This test must be compiled with MTR_NO_AVAILABILITY=0
+#endif