Add an internal helper for logging (upcoming).

PiperOrigin-RevId: 452134803
Change-Id: I8660df850ab537c441399545b25eb32399b2a3ef

absl/status/internal/status_internal.h

@@ -69,6 +69,15 @@ struct StatusRep {
 };
 
 absl::StatusCode MapToLocalCode(int value);
+
+// If `status` is not OK, returns a pointer to a newly-allocated string with the
+// given `prefix`, suitable for output as an error message in assertion/CHECK()
+// failures. Otherwise returns nullptr.
+//
+// This is an internal implementation detail for Abseil logging.
+std::string* MakeCheckFailString(const absl::Status& status,
+                                 const char* prefix);
+
 }  // namespace status_internal
 
 ABSL_NAMESPACE_END

absl/status/status.cc

@@ -599,5 +599,17 @@ Status ErrnoToStatus(int error_number, absl::string_view message) {
                 MessageForErrnoToStatus(error_number, message));
 }
 
+namespace status_internal {
+
+std::string* MakeCheckFailString(const absl::Status& status,
+                                 const char* prefix) {
+  if (status.ok()) { return nullptr; }
+  return new std::string(
+      absl::StrCat(prefix, " (",
+                   status.ToString(StatusToStringMode::kWithEverything), ")"));
+}
+
+}  // namespace status_internal
+
 ABSL_NAMESPACE_END
 }  // namespace absl