On 2023-01-14 01:30:24 -0500, Nick Bowler wrote: > Does adding .POSIX: to a Makefile actually solve any real-world > portability problem with Automake generated makefiles, or is all of > this just hypothetical?
For MPFR, when I initially added it, this was just in case. The real issue at that time was that I was using $< in a case where it was unspecified by POSIX, and this was failing on FreeBSD. Unfortunately there doesn't seem to be a way to get a failure on non-portable features (which would ease maintenance). Though I test the tarball on various systems before a release candidate, this is not the case of the development branch (and the Makefiles would typically be more affected than the C code, on which various portability checks are done under Linux). Well, I use autoreconf with --warnings=all,error (passed to automake), but I didn't get any portability error. Later I noted: # The ".POSIX" line is needed in particular for GNU "make", so that # recipes are invoked as if the shell had been passed the -e flag. as this is really what we want, both for consistency with other "make" implementations and to be able to detect errors. -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
