http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47802
--- Comment #19 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-02-23 18:24:20 UTC --- (In reply to comment #17) > Patch resolves ctime.c build. However, _REENTRANT is not defined, > so there are various warnings regarding the declaration of reentrant > functions such as localtime_r: As there localtime_r is also used in intrinsics/date_and_time.c, I would assume that one sees the same message there. I am also not quite sure that _REENTRANT is the correct solution. At least for Solaris, one should use _POSIX_C_SOURCE and not _REENTRANT to get the POSIX version, cf. http://download.oracle.com/docs/cd/E19455-01/806-5257/compile-4/ For HP-UX, I could not find anything (cf. also http://docs.hp.com/en/B2355-90683/ctime.3C.html). However, IBM has a statement regarding HP-UX, which is similar to Solaris's above: http://publib.boulder.ibm.com/infocenter/db2luw/v8/topic/com.ibm.db2.udb.doc/ad/t0007651.htm