diff --git a/React/Base/RCTBridge+Private.h b/React/Base/RCTBridge+Private.h
index 2996d3794..c6e518e83 100644
--- a/React/Base/RCTBridge+Private.h
+++ b/React/Base/RCTBridge+Private.h
@@ -149,7 +149,8 @@ RCT_EXTERN void RCTRegisterModule(Class);
 
 @interface RCTCxxBridge : RCTBridge
 
-@property (nonatomic) void *runtime;
+// TODO(cjhopman): this seems unsafe unless we require that it is only called on the main js queue.
+@property (nonatomic, readonly) void *runtime;
 
 - (instancetype)initWithParentBridge:(RCTBridge *)bridge NS_DESIGNATED_INITIALIZER;
 
diff --git a/React/React.xcodeproj/project.pbxproj b/React/React.xcodeproj/project.pbxproj
index ada4ecd12..ff871363e 100644
--- a/React/React.xcodeproj/project.pbxproj
+++ b/React/React.xcodeproj/project.pbxproj
@@ -4959,6 +4959,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_STATIC_ANALYZER_MODE = deep;
+				CLANG_WARN_COMMA = NO;
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -4972,6 +4973,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_STATIC_ANALYZER_MODE = deep;
+				CLANG_WARN_COMMA = NO;
 				GCC_PREPROCESSOR_DEFINITIONS = "$(inherited)";
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
@@ -4986,6 +4988,7 @@
 			buildSettings = {
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
+				CLANG_WARN_COMMA = NO;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
@@ -5004,6 +5007,7 @@
 			buildSettings = {
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
+				CLANG_WARN_COMMA = NO;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
@@ -5023,6 +5027,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_STATIC_ANALYZER_MODE = deep;
+				CLANG_WARN_COMMA = NO;
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -5037,6 +5042,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_STATIC_ANALYZER_MODE = deep;
+				CLANG_WARN_COMMA = NO;
 				GCC_PREPROCESSOR_DEFINITIONS = "$(inherited)";
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
@@ -5052,6 +5058,7 @@
 			buildSettings = {
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
+				CLANG_WARN_COMMA = NO;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
@@ -5071,6 +5078,7 @@
 			buildSettings = {
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
+				CLANG_WARN_COMMA = NO;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
@@ -5259,6 +5267,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_STATIC_ANALYZER_MODE = deep;
+				CLANG_WARN_COMMA = NO;
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -5273,6 +5282,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_STATIC_ANALYZER_MODE = deep;
+				CLANG_WARN_COMMA = NO;
 				GCC_PREPROCESSOR_DEFINITIONS = "$(inherited)";
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
@@ -5288,6 +5298,7 @@
 			buildSettings = {
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
+				CLANG_WARN_COMMA = NO;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
@@ -5307,6 +5318,7 @@
 			buildSettings = {
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
+				CLANG_WARN_COMMA = NO;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
@@ -5325,6 +5337,7 @@
 			buildSettings = {
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
+				CLANG_WARN_COMMA = NO;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
@@ -5353,6 +5366,7 @@
 			buildSettings = {
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
+				CLANG_WARN_COMMA = NO;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
@@ -5381,6 +5395,7 @@
 			buildSettings = {
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
+				CLANG_WARN_COMMA = NO;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
@@ -5409,6 +5424,7 @@
 			buildSettings = {
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
+				CLANG_WARN_COMMA = NO;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
@@ -5438,6 +5454,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_STATIC_ANALYZER_MODE = deep;
+				CLANG_WARN_COMMA = NO;
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -5452,6 +5469,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_STATIC_ANALYZER_MODE = deep;
+				CLANG_WARN_COMMA = NO;
 				GCC_PREPROCESSOR_DEFINITIONS = "$(inherited)";
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
@@ -5467,6 +5485,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_STATIC_ANALYZER_MODE = deep;
+				CLANG_WARN_COMMA = NO;
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -5481,6 +5500,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_STATIC_ANALYZER_MODE = deep;
+				CLANG_WARN_COMMA = NO;
 				GCC_PREPROCESSOR_DEFINITIONS = "$(inherited)";
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
diff --git a/ReactCommon/cxxreact/JSBigString.h b/ReactCommon/cxxreact/JSBigString.h
index 497b9f7b5..8e0f2128a 100644
--- a/ReactCommon/cxxreact/JSBigString.h
+++ b/ReactCommon/cxxreact/JSBigString.h
@@ -133,7 +133,7 @@ public:
 private:
   int m_fd;                     // The file descriptor being mmaped
   size_t m_size;                // The size of the mmaped region
-  size_t m_pageOff;             // The offset in the mmaped region to the data.
+  off_t m_pageOff;             // The offset in the mmaped region to the data.
   off_t m_mapOff;               // The offset in the file to the mmaped region.
   mutable const char *m_data;   // Pointer to the mmaped region.
 };
diff --git a/ReactCommon/cxxreact/JSExecutor.h b/ReactCommon/cxxreact/JSExecutor.h
index 4e8d682c0..f7cfd9752 100644
--- a/ReactCommon/cxxreact/JSExecutor.h
+++ b/ReactCommon/cxxreact/JSExecutor.h
@@ -103,7 +103,7 @@ public:
    */
   virtual std::string getDescription() = 0;
 
-  virtual void handleMemoryPressure(int pressureLevel) {}
+  virtual void handleMemoryPressure(__unused int pressureLevel) {}
 
   virtual void destroy() {}
   virtual ~JSExecutor() {}
diff --git a/ReactCommon/cxxreact/MethodCall.cpp b/ReactCommon/cxxreact/MethodCall.cpp
index 79c7f49a2..7141513d1 100644
--- a/ReactCommon/cxxreact/MethodCall.cpp
+++ b/ReactCommon/cxxreact/MethodCall.cpp
@@ -53,7 +53,7 @@ std::vector<MethodCall> parseMethodCalls(folly::dynamic&& jsonData) {
       throw std::invalid_argument(
         folly::to<std::string>(errorPrefix, "invalid callId", jsonData[REQUEST_CALLID].typeName()));
     }
-    callId = jsonData[REQUEST_CALLID].asInt();
+    callId = (int)jsonData[REQUEST_CALLID].asInt();
   }
 
   std::vector<MethodCall> methodCalls;
diff --git a/ReactCommon/cxxreact/NativeToJsBridge.cpp b/ReactCommon/cxxreact/NativeToJsBridge.cpp
index b5401267d..27c54a373 100644
--- a/ReactCommon/cxxreact/NativeToJsBridge.cpp
+++ b/ReactCommon/cxxreact/NativeToJsBridge.cpp
@@ -43,7 +43,7 @@ public:
   }
 
   void callNativeModules(
-      JSExecutor& executor, folly::dynamic&& calls, bool isEndOfBatch) override {
+      __unused JSExecutor& executor, folly::dynamic&& calls, bool isEndOfBatch) override {
 
     CHECK(m_registry || calls.empty()) <<
       "native module calls cannot be completed with no native modules";
@@ -68,7 +68,7 @@ public:
   }
 
   MethodCallResult callSerializableNativeHook(
-      JSExecutor& executor, unsigned int moduleId, unsigned int methodId,
+      __unused JSExecutor& executor, unsigned int moduleId, unsigned int methodId,
       folly::dynamic&& args) override {
     return m_registry->callSerializableNativeHook(moduleId, methodId, std::move(args));
   }
diff --git a/ReactCommon/cxxreact/SampleCxxModule.cpp b/ReactCommon/cxxreact/SampleCxxModule.cpp
index 1862c0f08..e1bfb04d2 100644
--- a/ReactCommon/cxxreact/SampleCxxModule.cpp
+++ b/ReactCommon/cxxreact/SampleCxxModule.cpp
@@ -94,13 +94,13 @@ auto SampleCxxModule::getMethods() -> std::vector<Method> {
                             jsArgAsString(args, 1))});
       }),
     Method("repeat", [this](dynamic args, Callback cb) {
-        cb({sample_->repeat(jsArgAsInt(args, 0),
+        cb({sample_->repeat((int)jsArgAsInt(args, 0),
                             jsArgAsString(args, 1))});
       }),
     Method("save", this, &SampleCxxModule::save),
     Method("load", this, &SampleCxxModule::load),
     Method("call_later", [this](dynamic args, Callback cb) {
-        sample_->call_later(jsArgAsInt(args, 0), [cb] {
+        sample_->call_later((int)jsArgAsInt(args, 0), [cb] {
             cb({});
           });
       }),
@@ -145,7 +145,7 @@ void SampleCxxModule::save(folly::dynamic args) {
   sample_->save(std::move(m));
 }
 
-void SampleCxxModule::load(folly::dynamic args, Callback cb) {
+void SampleCxxModule::load(__unused folly::dynamic args, Callback cb) {
   dynamic d = dynamic::object;
   for (const auto& p : sample_->load()) {
     d.insert(p.first, p.second);
diff --git a/ReactCommon/cxxreact/SystraceSection.h b/ReactCommon/cxxreact/SystraceSection.h
index 381d099c9..1cd6fa92c 100644
--- a/ReactCommon/cxxreact/SystraceSection.h
+++ b/ReactCommon/cxxreact/SystraceSection.h
@@ -26,7 +26,7 @@ struct ConcreteSystraceSection {
 public:
   template<typename... ConvertsToStringPiece>
   explicit
-  ConcreteSystraceSection(const char* name, ConvertsToStringPiece&&... args)
+  ConcreteSystraceSection(__unused const char* name, __unused ConvertsToStringPiece&&... args)
     : m_section(TRACE_TAG_REACT_CXX_BRIDGE, name, args...)
   {}
 
@@ -39,7 +39,7 @@ struct DummySystraceSection {
 public:
   template<typename... ConvertsToStringPiece>
   explicit
-  DummySystraceSection(const char* name, ConvertsToStringPiece&&... args)
+  DummySystraceSection(__unused const char* name, __unused ConvertsToStringPiece&&... args)
     {}
 };
 using SystraceSection = DummySystraceSection;
diff --git a/ReactCommon/jsiexecutor/jsireact/JSIExecutor.cpp b/ReactCommon/jsiexecutor/jsireact/JSIExecutor.cpp
index ce65d9f83..8025d9672 100644
--- a/ReactCommon/jsiexecutor/jsireact/JSIExecutor.cpp
+++ b/ReactCommon/jsiexecutor/jsireact/JSIExecutor.cpp
@@ -170,7 +170,7 @@ void JSIExecutor::setBundleRegistry(std::unique_ptr<RAMBundleRegistry> r) {
             PropNameID::forAscii(*runtime_, "nativeRequire"),
             2,
             [this](
-                Runtime& rt,
+                __unused Runtime& rt,
                 const facebook::jsi::Value&,
                 const facebook::jsi::Value* args,
                 size_t count) { return nativeRequire(args, count); }));