Start enabling -Wextra and -Wconversion in "rn_xplat_cxx_library" (1/2)

Summary:
## Stack

These can suss out some real bugs, and helps further avoid mismatch with downstream MSVC on /W4 as used by MSFT.

I enabled the families of warnings, but suppressed some major individual warnings that weren't clean. But I did clean some up, notably, missing initializer, and shortening 64 bit to 32 bit. We can do some of the rest incrementally (e.g. `-Wunused-parameter` has a fixit).

This change illuminates that MapBuffer is missing 64 bit integer support, but we often pass 64 bit counters to it, which is a bug. For now I just left TODOs around those.

`rn_xplat_cxx_library` is used for external libraries interfacing with RN, which we probably don't want to police, so I structured these stricter warnings as an opt-in flag, only enabled for our own rules.

## Diff

This fixes up source code to avoid emitting the extra warnings now enforced. Of what is enabled, this is mostly shortening 64 to 32, or missing field in initializer.

Changelog: [Internal]

Reviewed By: christophpurrer

Differential Revision: D52589303

fbshipit-source-id: 11cb778d065799fd0ead3ae706934146d13500bb

Author: NickGerleman

packages/react-native/React/Base/RCTBridgeModule.h

@@ -236,7 +236,7 @@ RCT_EXTERN_C_END
  */
 #define RCT_REMAP_METHOD(js_name, method)       \
   _RCT_EXTERN_REMAP_METHOD(js_name, method, NO) \
-  -(void)method RCT_DYNAMIC;
+  -(void)method RCT_DYNAMIC
 
 /**
  * Similar to RCT_EXPORT_BLOCKING_SYNCHRONOUS_METHOD but lets you set
@@ -248,7 +248,7 @@ RCT_EXTERN_C_END
  */
 #define RCT_REMAP_BLOCKING_SYNCHRONOUS_METHOD(js_name, returnType, method) \
   _RCT_EXTERN_REMAP_METHOD(js_name, method, YES)                           \
-  -(returnType)method RCT_DYNAMIC;
+  -(returnType)method RCT_DYNAMIC
 
 /**
  * Use this macro in a private Objective-C implementation file to automatically

packages/react-native/ReactAndroid/src/main/jni/react/fabric/CoreComponentsRegistry.cpp

@@ -85,14 +85,16 @@ CoreComponentsRegistry::initHybrid(
       [](const EventDispatcher::Weak& eventDispatcher,
          const ContextContainer::Shared& contextContainer)
       -> ComponentDescriptorRegistry::Shared {
+    ComponentDescriptorParameters params{
+        .eventDispatcher = eventDispatcher,
+        .contextContainer = contextContainer,
+        .flavor = nullptr};
+
     auto registry = CoreComponentsRegistry::sharedProviderRegistry()
-                        ->createComponentDescriptorRegistry(
-                            {eventDispatcher, contextContainer});
+                        ->createComponentDescriptorRegistry(params);
     auto& mutableRegistry = const_cast<ComponentDescriptorRegistry&>(*registry);
     mutableRegistry.setFallbackComponentDescriptor(
-        std::make_shared<UnimplementedNativeViewComponentDescriptor>(
-            ComponentDescriptorParameters{
-                eventDispatcher, contextContainer, nullptr}));
+        std::make_shared<UnimplementedNativeViewComponentDescriptor>(params));
 
     return registry;
   };

packages/react-native/ReactAndroid/src/main/jni/react/fabric/FabricMountingManager.cpp

@@ -85,7 +85,7 @@ static inline int getIntBufferSizeForType(CppMountItem::Type mountItemType) {
 
 static inline void updateBufferSizes(
     CppMountItem::Type mountItemType,
-    int numInstructions,
+    size_t numInstructions,
     int& batchMountItemIntsSize,
     int& batchMountItemObjectsSize) {
   if (numInstructions == 0) {
@@ -182,7 +182,7 @@ static inline void computeBufferSizes(
 
 static inline void writeIntBufferTypePreamble(
     int mountItemType,
-    int numItems,
+    size_t numItems,
     _JNIEnv* env,
     jintArray& intBufferArray,
     int& intBufferPosition) {
@@ -193,7 +193,7 @@ static inline void writeIntBufferTypePreamble(
     intBufferPosition += 1;
   } else {
     temp[0] = mountItemType | CppMountItem::Type::Multiple;
-    temp[1] = numItems;
+    temp[1] = static_cast<jint>(numItems);
     env->SetIntArrayRegion(intBufferArray, intBufferPosition, 2, temp);
     intBufferPosition += 2;
   }

packages/react-native/ReactAndroid/src/main/jni/react/fabric/ReactNativeConfigHolder.cpp

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#import "ReactNativeConfigHolder.h"
+#include "ReactNativeConfigHolder.h"
 
 #include <fbjni/fbjni.h>
 

packages/react-native/ReactAndroid/src/main/jni/react/jni/MethodInvoker.cpp

@@ -59,7 +59,8 @@ jint extractInteger(const folly::dynamic& value) {
   // The logic here is taken from convertDynamicIfIntegral, but the
   // return type and exception are different.
   if (value.isInt()) {
-    return value.getInt();
+    // TODO: this truncates 64 bit ints, valid in JS
+    return static_cast<jint>(value.getInt());
   }
   double dbl = value.getDouble();
   jint result = static_cast<jint>(dbl);
@@ -227,7 +228,7 @@ MethodCallResult MethodInvoker::invoke(
 
   auto env = Environment::current();
   auto argCount = signature_.size() - 2;
-  JniLocalScope scope(env, argCount);
+  JniLocalScope scope(env, static_cast<int>(argCount));
   jvalue args[argCount];
   std::transform(
       signature_.begin() + 2,

packages/react-native/ReactAndroid/src/main/jni/react/jni/ReadableNativeArray.cpp

@@ -23,7 +23,7 @@ void ReadableNativeArray::mapException(std::exception_ptr ex) {
 }
 
 local_ref<JArrayClass<jobject>> ReadableNativeArray::importArray() {
-  jint size = array_.size();
+  auto size = static_cast<jint>(array_.size());
   auto jarray = JArrayClass<jobject>::newArray(size);
   for (jint ii = 0; ii < size; ii++) {
     addDynamicToJArray(jarray, ii, array_.at(ii));
@@ -32,7 +32,7 @@ local_ref<JArrayClass<jobject>> ReadableNativeArray::importArray() {
 }
 
 local_ref<JArrayClass<jobject>> ReadableNativeArray::importTypeArray() {
-  jint size = array_.size();
+  auto size = static_cast<jint>(array_.size());
   auto jarray = JArrayClass<jobject>::newArray(size);
   for (jint ii = 0; ii < size; ii++) {
     (*jarray)[ii] = ReadableType::getType(array_.at(ii).type());

packages/react-native/ReactAndroid/src/main/jni/react/jni/ReadableNativeMap.cpp

@@ -80,7 +80,7 @@ local_ref<JArrayClass<jstring>> ReadableNativeMap::importKeys() {
 local_ref<JArrayClass<jobject>> ReadableNativeMap::importValues() {
   throwIfConsumed();
 
-  jint size = keys_.value().size();
+  auto size = static_cast<jint>(keys_.value().size());
   auto jarray = JArrayClass<jobject>::newArray(size);
   for (jint ii = 0; ii < size; ii++) {
     const std::string& key = (*keys_)[ii].getString();
@@ -92,7 +92,7 @@ local_ref<JArrayClass<jobject>> ReadableNativeMap::importValues() {
 local_ref<JArrayClass<jobject>> ReadableNativeMap::importTypes() {
   throwIfConsumed();
 
-  jint size = keys_.value().size();
+  auto size = static_cast<jint>(keys_.value().size());
   auto jarray = JArrayClass<jobject>::newArray(size);
   for (jint ii = 0; ii < size; ii++) {
     const std::string& key = (*keys_)[ii].getString();

packages/react-native/ReactAndroid/src/main/jni/react/newarchdefaults/DefaultComponentsRegistry.cpp

@@ -40,15 +40,17 @@ DefaultComponentsRegistry::initHybrid(
       [](const EventDispatcher::Weak& eventDispatcher,
          const ContextContainer::Shared& contextContainer)
       -> ComponentDescriptorRegistry::Shared {
+    ComponentDescriptorParameters params{
+        .eventDispatcher = eventDispatcher,
+        .contextContainer = contextContainer,
+        .flavor = nullptr};
+
     auto registry = DefaultComponentsRegistry::sharedProviderRegistry()
-                        ->createComponentDescriptorRegistry(
-                            {eventDispatcher, contextContainer});
+                        ->createComponentDescriptorRegistry(params);
 
     auto& mutableRegistry = const_cast<ComponentDescriptorRegistry&>(*registry);
     mutableRegistry.setFallbackComponentDescriptor(
-        std::make_shared<UnimplementedNativeViewComponentDescriptor>(
-            ComponentDescriptorParameters{
-                eventDispatcher, contextContainer, nullptr}));
+        std::make_shared<UnimplementedNativeViewComponentDescriptor>(params));
 
     return registry;
   };

packages/react-native/ReactCommon/cxxreact/JSBigString.cpp

@@ -38,8 +38,8 @@ JSBigFileString::JSBigFileString(int fd, size_t size, off_t offset /*= 0*/)
     const static auto ps = sysconf(_SC_PAGESIZE);
     auto d = lldiv(offset, ps);
 
-    m_mapOff = d.quot;
-    m_pageOff = d.rem;
+    m_mapOff = static_cast<off_t>(d.quot);
+    m_pageOff = static_cast<off_t>(d.rem);
     m_size = size + m_pageOff;
   } else {
     m_mapOff = 0;

packages/react-native/ReactCommon/react/nativemodule/core/platform/android/ReactCommon/JavaTurboModule.cpp

@@ -250,13 +250,15 @@ JNIArgs convertJSIArgsToJNIArgs(
     size_t count,
     const std::shared_ptr<CallInvoker>& jsInvoker,
     TurboModuleMethodValueKind valueKind) {
-  unsigned int expectedArgumentCount = valueKind == PromiseKind
+  size_t expectedArgumentCount = valueKind == PromiseKind
       ? methodArgTypes.size() - 1
       : methodArgTypes.size();
 
   if (expectedArgumentCount != count) {
     throw JavaTurboModuleInvalidArgumentCountException(
-        methodName, count, expectedArgumentCount);
+        methodName,
+        static_cast<int>(count),
+        static_cast<int>(expectedArgumentCount));
   }
 
   JNIArgs jniArgs(valueKind == PromiseKind ? count + 1 : count);
@@ -505,7 +507,8 @@ jsi::Value JavaTurboModule::invokeJavaMethod(
    * GlobalReferences. The LocalReferences are then promptly deleted
    * after the conversion.
    */
-  unsigned int actualArgCount = valueKind == VoidKind ? 0 : argCount;
+  unsigned int actualArgCount =
+      valueKind == VoidKind ? 0 : static_cast<unsigned int>(argCount);
   unsigned int estimatedLocalRefCount =
       actualArgCount + maxReturnObjects + buffer;