Log when a Result is created from Error::ok (pytorch#8577)

Summary:

If this ctor is firing someone is probably returning Error::ok from a function that should return a Result not an Error. I found it a little hard to debug when this was happening so adding logging to hopefully save someone else time in the future.

Differential Revision: D69870978

Author: JacobSzwejbka

runtime/core/result.h

@@ -59,8 +59,13 @@ class Result final {
    * a non-Ok value.
    */
   /* implicit */ Result(Error error)
-      : error_(error == Error::Ok ? Error::Internal : error),
-        hasValue_(false) {}
+      : error_(error == Error::Ok ? Error::Internal : error), hasValue_(false) {
+    if ET_UNLIKELY (error == Error::Ok) {
+      ET_LOG(
+          Info,
+          "Attempted to create Result from Error::Ok, this has been converted to Error::Internal.");
+    }
+  }
 
   /// Value copy constructor.
   /* implicit */ Result(const T& val) : value_(val), hasValue_(true) {}

runtime/core/test/error_handling_test.cpp

@@ -110,6 +110,7 @@ TEST(ErrorHandlingTest, ResultBasic) {
 }
 
 TEST(ErrorHandlingTest, OkErrorNotPossible) {
+  executorch::runtime::runtime_init();
   Result<uint32_t> r(Error::Ok);
   ASSERT_FALSE(r.ok());
   ASSERT_NE(r.error(), Error::Ok);