Red box c++ exceptions thrown while executing sync hooks

Summary: Also adds support for creating JS Error objects. When we clean up the way global functions are installed on JSC, we'll be able to use this pattern to auto-catch all c++ exceptions at this level.

Reviewed By: lexs

Differential Revision: D3276663

fbshipit-source-id: bf3561690013019a25e2be5a4d1b69ba9e002c72

ReactCommon/bridge/JSCExecutor.cpp

@@ -628,14 +628,19 @@ JSValueRef JSCExecutor::nativeCallSyncHook(
     return JSValueMakeUndefined(ctx);
   }
 
-  MethodCallResult result = executor->m_bridge->callSerializableNativeHook(
+  try {
-      moduleId,
+    MethodCallResult result = executor->m_bridge->callSerializableNativeHook(
-      methodId,
+        moduleId,
-      argsJson);
+        methodId,
-  if (result.isUndefined) {
+        argsJson);
+    if (result.isUndefined) {
+      return JSValueMakeUndefined(ctx);
+    }
+    return Value::fromJSON(ctx, String(folly::toJson(result.result).c_str()));
+  } catch (...) {
+    *exception = translatePendingCppExceptionToJSError(ctx, "nativeCallSyncHook");
     return JSValueMakeUndefined(ctx);
   }
-  return Value::fromJSON(ctx, String(folly::toJson(result.result).c_str()));
 }
 
 static JSValueRef nativeInjectHMRUpdate(

ReactCommon/bridge/JSCHelpers.cpp

@@ -52,4 +52,32 @@ JSValueRef evaluateScript(JSContextRef context, JSStringRef script, JSStringRef
   return result;
 }
 
+JSValueRef makeJSError(JSContextRef ctx, const char *error) {
+  JSValueRef nestedException = nullptr;
+  JSValueRef args[] = { Value(ctx, String(error)) };
+  JSObjectRef errorObj = JSObjectMakeError(ctx, 1, args, &nestedException);
+  if (nestedException != nullptr) {
+    return std::move(args[0]);
+  }
+  return errorObj;
+}
+
+JSValueRef translatePendingCppExceptionToJSError(JSContextRef ctx, const char *exceptionLocation) {
+  std::ostringstream msg;
+  try {
+    throw;
+  } catch (const std::bad_alloc& ex) {
+    throw; // We probably shouldn't try to handle this in JS
+  } catch (const std::exception& ex) {
+    msg << "C++ Exception in '" << exceptionLocation << "': " << ex.what();
+    return makeJSError(ctx, msg.str().c_str());
+  } catch (const char* ex) {
+    msg << "C++ Exception (thrown as a char*) in '" << exceptionLocation << "': " << ex;
+    return makeJSError(ctx, msg.str().c_str());
+  } catch (...) {
+    msg << "Unknown C++ Exception in '" << exceptionLocation << "'";
+    return makeJSError(ctx, msg.str().c_str());
+  }
+}
+
 } }

ReactCommon/bridge/JSCHelpers.h

@@ -9,6 +9,8 @@
 #include <stdexcept>
 #include <algorithm>
 
+#include "Value.h"
+
 namespace facebook {
 namespace react {
 
@@ -43,4 +45,8 @@ JSValueRef evaluateScript(
     JSStringRef script,
     JSStringRef sourceURL);
 
+JSValueRef makeJSError(JSContextRef ctx, const char *error);
+
+JSValueRef translatePendingCppExceptionToJSError(JSContextRef ctx, const char *exceptionLocation);
+
 } }

ReactCommon/bridge/Value.cpp

@@ -13,6 +13,12 @@ Value::Value(JSContextRef context, JSValueRef value) :
 {
 }
 
+Value::Value(JSContextRef context, JSStringRef str) :
+  m_context(context),
+  m_value(JSValueMakeString(context, str))
+{
+}
+
 Value::Value(Value&& other) :
   m_context(other.m_context),
   m_value(other.m_value)

ReactCommon/bridge/Value.h

@@ -171,6 +171,7 @@ private:
 class Value : public noncopyable {
 public:
   Value(JSContextRef context, JSValueRef value);
+  Value(JSContextRef context, JSStringRef value);
   Value(Value&&);
 
   operator JSValueRef() const {