Fix OSS compiler warnings

As observed in #449, the OSS
build currently produces various compiler warnings, mostly from
OSS-specific stubs.

Fix the following warnings:
* Fix -Wunused-parameter in stub functions by commenting out the
  relevant parameters.
* Fix -Wunused-local-typedef by removing unused typedefs.
* Fix -Wreturn-local-addr in SRHost by returning a reference to a
  member variable instead.
* Fix -Wredundant-move by removing a redundant std::move() call when
  returning a function parameter.

Author: mszabo-wikia

mcrouter/Server-inl.h

@@ -292,7 +292,6 @@ bool runServerDual(
     const McrouterOptions& mcrouterOpts,
     const McrouterStandaloneOptions& standaloneOpts,
     StandalonePreRunCb preRunCb) {
-  using RequestHandlerType = RequestHandler<ServerOnRequest<RouterInfo>>;
   std::shared_ptr<folly::IOThreadPoolExecutorBase> ioThreadPool;
   CarbonRouterInstance<RouterInfo>* router;
   std::shared_ptr<AsyncMcServer> asyncMcServer;

mcrouter/StandaloneConfig.cpp

@@ -15,12 +15,12 @@ namespace memcache {
 namespace mcrouter {
 
 void standalonePreInitFromCommandLineOpts(
-    const std::unordered_map<std::string, std::string>& standaloneOptionsDict) {
+    const std::unordered_map<std::string, std::string>& /* standaloneOptionsDict */) {
 }
 
 void standaloneInit(
-    const McrouterOptions& opts,
-    const McrouterStandaloneOptions& standaloneOpts) {}
+    const McrouterOptions& /* opts */,
+    const McrouterStandaloneOptions& /* standaloneOpts */) {}
 
 void initStandaloneSSL() {}
 

mcrouter/ThriftAcceptor-impl.h

@@ -32,7 +32,7 @@ class ThriftAcceptorFactory final : public wangle::AcceptorFactory {
   explicit ThriftAcceptorFactory(
       apache::thrift::ThriftServer& server,
       ThriftAclCheckerFunc /* unused */,
-      int trafficClass /* unused */)
+      int /* trafficClass */)
       : server_(server) {}
   ~ThriftAcceptorFactory() override = default;
 

mcrouter/ThriftAcceptor.cpp

@@ -30,7 +30,6 @@ namespace memcache {
 std::shared_ptr<wangle::Acceptor> ThriftAcceptorFactory::newAcceptor(
     folly::EventBase* evb) {
   class ThriftAcceptor : public apache::thrift::Cpp2Worker {
-    using ThriftAclCheckerFunc = ThriftAcceptorFactory::ThriftAclCheckerFunc;
 
    protected:
     struct Tag {};

mcrouter/lib/SelectionRouteFactory.h

@@ -49,7 +49,7 @@ typename RouterInfo::RouteHandlePtr createSelectionRoute(
         mcrouter::createErrorRoute<RouterInfo>("Invalid destination index.");
   }
   if (children.empty() && shadowChildren.empty()) {
-    return std::move(outOfRangeDestination);
+    return outOfRangeDestination;
   }
   if (shadowChildren.empty()) {
     return makeRouteHandleWithInfo<RouterInfo, SelectionRoute, Selector>(

mcrouter/lib/carbon/Artillery-inl.h

@@ -19,12 +19,12 @@ namespace tracing {
 #ifdef LIBMC_FBTRACE_DISABLE
 
 inline std::pair<uint64_t, uint64_t> serializeTraceContext(
-    const std::string& traceContext) {
+    const std::string& /* traceContext */) {
   return {0, 0};
 }
 
 inline std::string deserializeTraceContext(
-    std::pair<uint64_t, uint64_t> serializedTraceId) {
+    std::pair<uint64_t, uint64_t> /* serializedTraceId */) {
   return "";
 }
 

mcrouter/lib/network/FBTrace-inl.h

@@ -31,8 +31,8 @@ inline uint64_t traceGetCount() {
 }
 
 inline std::nullptr_t traceRequestReceived(
-    const std::string& traceContext,
-    folly::StringPiece requestType) {
+    const std::string& /* traceContext */,
+    folly::StringPiece /* requestType */) {
   // Do nothing by default.
   return nullptr;
 }

mcrouter/mcrouter_config.cpp

@@ -95,9 +95,9 @@ std::vector<std::string> defaultTestCommandLineArgs() {
   return {"--disable-failure-logging", "--stats-logging-interval=0"};
 }
 
-void logTkoEvent(ProxyBase& proxy, const TkoLog& tkoLog) {}
+void logTkoEvent(ProxyBase& /* proxy */, const TkoLog& /* tkoLog */) {}
 
-void logFailover(ProxyBase& proxy, const FailoverContext& failoverContext) {}
+void logFailover(ProxyBase& /* proxy */, const FailoverContext& /* failoverContext */) {}
 
 void initFailureLogger() {}
 
@@ -111,7 +111,7 @@ std::unordered_map<std::string, folly::dynamic> additionalConfigParams() {
   return std::unordered_map<std::string, folly::dynamic>();
 }
 
-void insertCustomStartupOpts(folly::dynamic& options) {}
+void insertCustomStartupOpts(folly::dynamic& /* options */) {}
 
 std::string getBinPath(folly::StringPiece name) {
   if (name == "mcrouter") {

mcrouter/mcrouter_config.h

@@ -184,8 +184,8 @@ folly::dynamic readStaticJsonFile(folly::StringPiece file);
 
 inline folly::Optional<folly::observer::Observer<std::string>>
 startObservingRuntimeVarsFileCustom(
-    folly::StringPiece file,
-    std::function<void(std::string)> onUpdate) {
+    folly::StringPiece /* file */,
+    std::function<void(std::string)> /* onUpdate */) {
   return folly::none;
 }
 
@@ -194,7 +194,7 @@ inline bool isInLocalDatacenter(const std::string& /* host */) {
 }
 
 inline Transport::SvcIdentAuthCallbackFunc getAuthChecker(
-    const McrouterOptions& opts) {
+    const McrouterOptions& /* opts */) {
   return nullptr;
 }
 

mcrouter/mcrouter_sr_deps-impl.h

@@ -49,14 +49,16 @@ struct SRHost {
  public:
   SRHost(){};
   const std::string& getIp() const {
-    return "127.0.0.1";
+    return ip_;
   }
   uint16_t getPort() const {
     return 0;
   }
   const std::optional<uint16_t> getTwTaskId() const {
     return std::nullopt;
   }
+ private:
+  const std::string ip_ = "127.0.0.1";
 };
 
 } // namespace memcache