Enable treating warnings as errors for target gRPC

src/objective-c/GRPCClient/GRPCCall+ChannelCredentials.h

@@ -41,7 +41,7 @@
  */
 + (BOOL)setTLSPEMRootCerts:(nullable NSString *)pemRootCert
                    forHost:(nonnull NSString *)host
-                     error:(NSError **)errorPtr;
+                     error:(NSError * _Nullable * _Nullable)errorPtr;
 /**
  * Configures @c host with TLS/SSL Client Credentials and optionally trusted root Certificate
  * Authorities. If @c pemRootCerts is nil, the default CA Certificates bundled with gRPC will be
@@ -51,6 +51,6 @@
             withPrivateKey:(nullable NSString *)pemPrivateKey
              withCertChain:(nullable NSString *)pemCertChain
                    forHost:(nonnull NSString *)host
-                     error:(NSError **)errorPtr;
+                     error:(NSError * _Nullable * _Nullable)errorPtr;
 
 @end

src/objective-c/ProtoRPC/ProtoMethod.h

@@ -54,6 +54,9 @@ __attribute__((deprecated("Please use GRPCProtoMethod.")))
  * This subclass is empty now. Eventually we'll remove ProtoMethod class
  * to avoid potential naming conflict
  */
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
 @interface GRPCProtoMethod : ProtoMethod
+#pragma clang diagnostic pop
 
 @end

src/objective-c/ProtoRPC/ProtoRPC.h

@@ -56,6 +56,9 @@ __attribute__((deprecated("Please use GRPCProtoCall.")))
  * This subclass is empty now. Eventually we'll remove ProtoRPC class
  * to avoid potential naming conflict
  */
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
 @interface GRPCProtoCall : ProtoRPC
+#pragma clang diagnostic pop
 
 @end

src/objective-c/ProtoRPC/ProtoService.h

@@ -55,6 +55,9 @@ __attribute__((deprecated("Please use GRPCProtoService.")))
  * This subclass is empty now. Eventually we'll remove ProtoService class
  * to avoid potential naming conflict
  */
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
 @interface GRPCProtoService : ProtoService
+#pragma clang diagnostic pop
 
 @end

src/objective-c/ProtoRPC/ProtoService.m

@@ -65,14 +65,14 @@
   return self;
 }
 
-- (ProtoRPC *)RPCToMethod:(NSString *)method
+- (GRPCProtoCall *)RPCToMethod:(NSString *)method
            requestsWriter:(GRXWriter *)requestsWriter
             responseClass:(Class)responseClass
        responsesWriteable:(id<GRXWriteable>)responsesWriteable {
-  ProtoMethod *methodName = [[ProtoMethod alloc] initWithPackage:_packageName
+  GRPCProtoMethod *methodName = [[GRPCProtoMethod alloc] initWithPackage:_packageName
                                                          service:_serviceName
                                                           method:method];
-  return [[ProtoRPC alloc] initWithHost:_host
+  return [[GRPCProtoCall alloc] initWithHost:_host
                                  method:methodName
                          requestsWriter:requestsWriter
                           responseClass:responseClass

src/objective-c/tests/Podfile

 source 'https://github.com/CocoaPods/Specs.git'
 platform :ios, '8.0'
 
-pod 'Protobuf', :path => "../../../third_party/protobuf"
-pod 'BoringSSL', :podspec => ".."
-pod 'CronetFramework', :podspec => ".."
+pod 'Protobuf', :path => "../../../third_party/protobuf", :inhibit_warnings => true
+pod 'BoringSSL', :podspec => "..", :inhibit_warnings => true
+pod 'CronetFramework', :podspec => "..", :inhibit_warnings => true
 pod 'gRPC', :path => "../../.."
 pod 'RemoteTest', :path => "RemoteTestClient"
 
@@ -30,3 +30,18 @@ end
 
 target 'InteropTestsLocalCleartext' do
 end
+
+post_install do |installer|
+  installer.pods_project.targets.each do |target|
+    target.build_configurations.each do |config|
+      config.build_settings['GCC_TREAT_WARNINGS_AS_ERRORS'] = 'YES'
+    end
+    if target.name == 'gRPC'
+      target.build_configurations.each do |config|
+        # GPR_UNREACHABLE_CODE causes "Control may reach end of non-void
+        # function" warning
+        config.build_settings['GCC_WARN_ABOUT_RETURN_TYPE'] = 'NO'
+      end
+    end
+  end
+end