You cannot directly recognize an overflow of data (0...127) space from this number. If such an overflow occurs, it will be indicated by a separate error message (or several).

The "data" field of the linker summary is a mix of
Once again: You need to look at the linker listing files to get exact information on memory usage. The short summary given at the end of the linking process is meant as a rough overview only and lacks many details that only the listing file will provide.