@andy5995 `_GNU_SOURCE` is something the user sets (or user code sets) to get access to library functions that are not normally available, Google will tell you the list this enables, its pretty huge. Its not often used in user code except to choose between two implementations depending on a non-standard function being available. If you just use the non-standard function there is no point in testing the macro.
Ctags does define it in one file (from your list) so it wants non-standard for something. But Geany may be using functions enabled by this anywhere since `AC_USE_SYSTEM_EXTENSIONS` sets `_GNU_SOURCE` on _all_ compiles IIUC. -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/geany/geany/pull/2057#issuecomment-455720193
