Made logging logic dynamic to log string length

Reviewed By: emilsjolander

Differential Revision: D6784491

fbshipit-source-id: 26e4520a84be355ff992b808297ce7a95b3d09e3

ReactAndroid/src/main/jni/first-party/yogajni/jni/YGJNI.cpp

@@ -158,8 +158,9 @@ static int YGJNILogFunc(const YGConfigRef config,
                         YGLogLevel level,
                         const char *format,
                         va_list args) {
-  char buffer[256];
-  int result = vsnprintf(buffer, sizeof(buffer), format, args);
+  int result = vsnprintf(NULL, 0, format, args);
+  std::vector<char> buffer(1 + result);
+  vsnprintf(buffer.data(), buffer.size(), format, args);
 
   static auto logFunc =
       findClassStatic("com/facebook/yoga/YogaLogger")
@@ -170,10 +171,12 @@ static int YGJNILogFunc(const YGConfigRef config,
 
   if (auto obj = YGNodeJobject(node)->lockLocal()) {
     auto jlogger = reinterpret_cast<global_ref<jobject> *>(YGConfigGetContext(config));
-    logFunc(jlogger->get(),
-            obj,
-            logLevelFromInt(JYogaLogLevel::javaClassStatic(), static_cast<jint>(level)),
-            Environment::current()->NewStringUTF(buffer));
+    logFunc(
+        jlogger->get(),
+        obj,
+        logLevelFromInt(
+            JYogaLogLevel::javaClassStatic(), static_cast<jint>(level)),
+        Environment::current()->NewStringUTF(buffer.data()));
   }
 
   return result;

ReactCommon/yoga/yoga/YGNodePrint.cpp

@@ -29,15 +29,15 @@ static bool areFourValuesEqual(const std::array<YGValue, YGEdgeCount>& four) {
 }
 
 static void appendFormatedString(string* str, const char* fmt, ...) {
-  char buffer[1024];
   va_list args;
   va_start(args, fmt);
   va_list argsCopy;
   va_copy(argsCopy, args);
+  std::vector<char> buf(1 + vsnprintf(NULL, 0, fmt, args));
   va_end(args);
-  vsnprintf(buffer, 1024, fmt, argsCopy);
+  vsnprintf(buf.data(), buf.size(), fmt, argsCopy);
   va_end(argsCopy);
-  string result = string(buffer);
+  string result = string(buf.begin(), buf.end() - 1);
   str->append(result);
 }