http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40411
po...@gcc.gnu.org <pogma at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |pogma at gcc dot gnu.org --- Comment #20 from pogma at gcc dot gnu.org <pogma at gcc dot gnu.org> 2010-12-27 19:17:18 UTC --- (In reply to comment #19) > Whether using it is enabled via -std or > not, linking to values-xpg6.o can cause unexpected behaviour for applications > or shared objects. Yes, it can, and that behaviour change is surprising, especially if relinking a library with a newer gcc (using the same flags as it was linked with using an older version of the compiler) can cause clients of that library to stop working or to behave in a different manner. If a user really wants the xpg6 behaviour from libc they can simply add the relevant object file to their output or even just define the __xpg4 and __xpg6 symbols in their application, or, as Bruno suggests - use gnulib.