Re: Portable Use of Variables
On 2014-10-27 Eric Blake ebl...@redhat.com wrote: On 10/27/2014 11:11 AM, Nick Bowler wrote: On 2014-10-26 22:15 +0200, fr33domlover wrote: I'm a bit confused about all the expressive features and ways to use makefile variables, so just to be sure - http://www.gnu.org/software/make/manual/html_node/Substitution-Refs.html Are these uses of variables portable, or should a portable Makefile.am use only the plain $(var) form without the tricks? The first form of expansion on that page, $(var:.a=.b), should be OK. They are standard in POSIX and work on all make implementations that I know of. The version with % characters is not portable. That said, POSIX is hoping to standardize it in the next few years: http://austingroupbugs.net/view.php?id=519 Hmmm I was sure it's portable because `make distcheck` doesn't complain about the %s, and I'm using -Werror and -Wall automake flags. How bad is it? I suppose it's not specific to just GNU make alone? signature.asc Description: PGP signature
Re: Portable Use of Variables
On 11/11/2014 10:59 AM, fr33domlover wrote: The first form of expansion on that page, $(var:.a=.b), should be OK. They are standard in POSIX and work on all make implementations that I know of. The version with % characters is not portable. That said, POSIX is hoping to standardize it in the next few years: http://austingroupbugs.net/view.php?id=519 Hmmm I was sure it's portable because `make distcheck` doesn't complain about the %s, and I'm using -Werror and -Wall automake flags. How bad is it? I suppose it's not specific to just GNU make alone? automake can't warn about all non-portable aspects, although patches to make it warn about more cases would be welcome. And the fact that POSIX is planning to standardize % substitutions in make is a sign that existing implementations that already support it are in agreement (more than just GNU make), so if you want to be on the leading edge of the curve, you aren't excluding that many users. -- Eric Blake eblake redhat com+1-919-301-3266 Libvirt virtualization library http://libvirt.org signature.asc Description: OpenPGP digital signature
Re: Portable Use of Variables
On 2014-10-26 22:15 +0200, fr33domlover wrote: I'm a bit confused about all the expressive features and ways to use makefile variables, so just to be sure - http://www.gnu.org/software/make/manual/html_node/Substitution-Refs.html Are these uses of variables portable, or should a portable Makefile.am use only the plain $(var) form without the tricks? The first form of expansion on that page, $(var:.a=.b), should be OK. They are standard in POSIX and work on all make implementations that I know of. The version with % characters is not portable. Hope that helps, -- Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)
Re: Portable Use of Variables
On 10/27/2014 11:11 AM, Nick Bowler wrote: On 2014-10-26 22:15 +0200, fr33domlover wrote: I'm a bit confused about all the expressive features and ways to use makefile variables, so just to be sure - http://www.gnu.org/software/make/manual/html_node/Substitution-Refs.html Are these uses of variables portable, or should a portable Makefile.am use only the plain $(var) form without the tricks? The first form of expansion on that page, $(var:.a=.b), should be OK. They are standard in POSIX and work on all make implementations that I know of. The version with % characters is not portable. That said, POSIX is hoping to standardize it in the next few years: http://austingroupbugs.net/view.php?id=519 -- Eric Blake eblake redhat com+1-919-301-3266 Libvirt virtualization library http://libvirt.org signature.asc Description: OpenPGP digital signature
Portable Use of Variables
Hello, I'm a bit confused about all the expressive features and ways to use makefile variables, so just to be sure - http://www.gnu.org/software/make/manual/html_node/Substitution-Refs.html Are these uses of variables portable, or should a portable Makefile.am use only the plain $(var) form without the tricks? I'm adapting the doxygen Makefile.am from gtkmm (GTK+ C++ binding) for my use, but they use text functions and variable features a lot with -no-portability, so I'm trying to make it work with -Wall -Werror. I hope it's worth the effort :-) Just trying to have a clean makefile... -- fr33
