Xen devel - Nov 2011 - [PATCH] use ncurses-config to find all curses related libs

After a split of libtinfo from libncurses in openSuSE Factory the tools
will not link anymore. In the URL below it was suggested to use
''ncurses-config --libs'' to find the correct linker options.
But
ncurses-config does not exist neither in SLES11 nor in openSuSE. So
check for both ncurses5-config and ncurses-config, if the latter happens
to exist in other environments.

With this change xen-unstable tools build succeeds again in SLES11 and
the latest openSuSE development branch.

http://lists.opensuse.org/opensuse-packaging/2011-11/msg00055.html

Signed-off-by: Olaf Hering <olaf@aepfle.de>

diff -r 0b1ac7b3ee4d config/StdGNU.mk
--- a/config/StdGNU.mk
+++ b/config/StdGNU.mk
@@ -67,7 +67,7 @@ XEN_CONFIG_DIR = $(CONFIG_DIR)/xen
 XEN_SCRIPT_DIR = $(XEN_CONFIG_DIR)/scripts
 
 SOCKET_LIBS -CURSES_LIBS = -lncurses
+CURSES_LIBS = $(shell if ! ncurses5-config --libs 2>/dev/null ; then
ncurses-config --libs ; fi)
 PTHREAD_LIBS = -lpthread
 UTIL_LIBS = -lutil
 DLOPEN_LIBS = -ldl

Olaf Hering writes ("[Xen-devel] [PATCH] use ncurses-config to find all
curses related libs"):
> After a split of libtinfo from libncurses in openSuSE Factory the tools
> will not link anymore. In the URL below it was suggested to use
> ''ncurses-config --libs'' to find the correct linker
options. But
> ncurses-config does not exist neither in SLES11 nor in openSuSE. So
> check for both ncurses5-config and ncurses-config, if the latter happens
> to exist in other environments.
> 
> With this change xen-unstable tools build succeeds again in SLES11 and
> the latest openSuSE development branch.
Thanks.  However:
> -CURSES_LIBS = -lncurses
> +CURSES_LIBS = $(shell if ! ncurses5-config --libs 2>/dev/null ; then
ncurses-config --libs ; fi)
In the case where ncurses5-config is not provided, this will fail.

Ian.

On Thu, Nov 24, Ian Jackson wrote:
> Olaf Hering writes ("[Xen-devel] [PATCH] use ncurses-config to find
all curses related libs"):
> > -CURSES_LIBS = -lncurses
> > +CURSES_LIBS = $(shell if ! ncurses5-config --libs 2>/dev/null ;
then ncurses-config --libs ; fi)
> 
> In the case where ncurses5-config is not provided, this will fail.
It seems to work for me, with this example foo is printed:

if ! ABC 2>/dev/null ; then echo foo ; fi

Olaf

Olaf Hering writes ("Re: [Xen-devel] [PATCH] use ncurses-config to find all
curses related libs"):
> On Thu, Nov 24, Ian Jackson wrote:
> > Olaf Hering writes ("[Xen-devel] [PATCH] use ncurses-config to
find all curses related libs"):
> > > -CURSES_LIBS = -lncurses
> > > +CURSES_LIBS = $(shell if ! ncurses5-config --libs 2>/dev/null
; then ncurses-config --libs ; fi)
> > 
> > In the case where ncurses5-config is not provided, this will fail.
Sorry, I wasn''t sufficiently clear.  The case that fails is if neither
ncurses5-config nor ncurses-config is provided.  The default should be
to use -lncurses as before.
> It seems to work for me, with this example foo is printed:
> 
> if ! ABC 2>/dev/null ; then echo foo ; fi
Yes, but it won''t include -lncurses in CURSES_LIBS.

Ian.

On Thu, Nov 24, Ian Jackson wrote:
> Olaf Hering writes ("Re: [Xen-devel] [PATCH] use ncurses-config to
find all curses related libs"):
> > On Thu, Nov 24, Ian Jackson wrote:
> > > Olaf Hering writes ("[Xen-devel] [PATCH] use ncurses-config
to find all curses related libs"):
> > > > -CURSES_LIBS = -lncurses
> > > > +CURSES_LIBS = $(shell if ! ncurses5-config --libs
2>/dev/null ; then ncurses-config --libs ; fi)
> > > 
> > > In the case where ncurses5-config is not provided, this will
fail.
> 
> Sorry, I wasn''t sufficiently clear.  The case that fails is if
neither
> ncurses5-config nor ncurses-config is provided.  The default should be
> to use -lncurses as before.
I see. Another if construct, or a check_ncurses script which looks for
ncurses5-config or ncurses-config. After some digging in old SuSE
releases, ncurses5-config appeared in 11.0 (2008), SLES10 does not have
it yes . So blindly relying on -config scripts will likely break
building on old distributions.

This should work:

if ! ncurses5-config --libs 2>/dev/null;then if ! ncurses-config --libs ;
then echo ''-lncurses'' ; fi ; fi

Olaf

Olaf Hering writes ("Re: [Xen-devel] [PATCH] use ncurses-config to find all
curses related libs"):
> This should work:
> 
> if ! ncurses5-config --libs 2>/dev/null;then if ! ncurses-config --libs
; then echo ''-lncurses'' ; fi ; fi
That''s an improvement, but it reruns the shell rune for every time
CURSES_LIBS is expanded.

Ian.

On Thu, Nov 24, Ian Jackson wrote:
> Olaf Hering writes ("Re: [Xen-devel] [PATCH] use ncurses-config to
find all curses related libs"):
> > This should work:
> > 
> > if ! ncurses5-config --libs 2>/dev/null;then if ! ncurses-config
--libs ; then echo ''-lncurses'' ; fi ; fi
> 
> That''s an improvement, but it reruns the shell rune for every time
> CURSES_LIBS is expanded.
Right. I remember there are ways to assign a variable only once, I will
check the make documentation.

Olaf

After a split of libtinfo from libncurses in openSuSE Factory the tools
will not link anymore. In the URL below it was suggested to use
''ncurses-config --libs'' to find the correct linker options.
But
ncurses-config does not exist neither in SLES11 nor in openSuSE. So
check for both ncurses5-config and ncurses-config, if the latter happens
to exist in other environments.

With this change xen-unstable tools build succeeds again in SLES11 and
the latest openSuSE development branch.

http://lists.opensuse.org/opensuse-packaging/2011-11/msg00055.html

Signed-off-by: Olaf Hering <olaf@aepfle.de>

diff -r 4319d77f5b3b config/StdGNU.mk
--- a/config/StdGNU.mk
+++ b/config/StdGNU.mk
@@ -67,7 +67,7 @@ XEN_CONFIG_DIR = $(CONFIG_DIR)/xen
 XEN_SCRIPT_DIR = $(XEN_CONFIG_DIR)/scripts
 
 SOCKET_LIBS -CURSES_LIBS = -lncurses
+CURSES_LIBS ?= $(shell if ! ncurses5-config --libs 2>/dev/null;then if !
ncurses-config --libs 2>/dev/null;then echo -lncurses;fi;fi)
 PTHREAD_LIBS = -lpthread
 UTIL_LIBS = -lutil
 DLOPEN_LIBS = -ldl