https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43565
--- Comment #5 from Marc Nieper-Wißkirchen <m...@nieper-wisskirchen.de> --- If that was possible (that symbols are aliased in the TU in which they are defined, but not (explicitly) in a TU where they are declared), there would be the need of a "no_alias" (or "never_alias") attribute, for otherwise, the optimization we are talking about here would never be possible.