https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48200
--- Comment #21 from Xi Ruoyao <ryxi at stu dot xidian.edu.cn> --- I made up a (highly immature) patch in the days. This "thing" works with simple source code files but I believe there are many bugs in the patch. And I suggest to make "weakref" attribute to output ".symver" directive for arguments with "@" in it. For e.g. static void *old_memcpy (void *, void *, size_t) __attribute__((weakref("memcpy@GLIBC_2.2.5"))); should produce .symver old_memcpy memcpy@GLIBC_2.2.5 So we can "import" old functions.