/* How the code in this directory is supposed to work... 2020/05/22 Mark Geisert localtime.cc is the Cygwin-specific module that is compiled into the Cygwin DLL when the latter is built. It's just a wrapper that #defines a bunch of stuff then #includes localtime.c. localtime.c, at any point in time, is a reasonably recent version of /src/lib/libc/time/localtime.c from NetBSD. The same goes for private.h and tzfile.h. An empty namespace.h suffices for Cygwin. The idea is that in the future, one just needs to bring over newer versions of localtime.c, private.h, and/or tzfile.h from NetBSD as they become available. With luck, you can drop those files into this directory and they can be immediately used to build a newer Cygwin DLL that has the newer NetBSD functionality. Without luck, you'll have to tweak the wrapper localtime.cc. In the worst case, some other strategy will need to be figured out, such as manually pulling out the parts of the NetBSD code Cygwin needs to build a stand-alone localtime.cc. Re tz_posixrules.h: The data elements can be generated from /usr/share/zoneinfo/posixrules in any version of Cygwin's tzdata package. Instructions are in the comment leading tz_posixrules.h. Addendum: Implementation of the strategy above has uncovered a small number of NetBSD-isms in localtime.c that cannot be worked around with preprocessor tricks. So there is another file localtime.c.patched that holds just these adjustments for Cygwin, and it's this file that localtime.cc #includes. localtime.c.patched is generated by winsup/cygwin/Makefile[.in] operating with localtime.c.patch. ..mark */