kconfig: if ncurses-devel is missing then say so

With this patch when ncurses-devel (or whatever it is named)
is missing trying to run menuconfig will result in this:

$ make menuconfig
  HOSTCC  scripts/kconfig/conf.o
  HOSTCC  scripts/kconfig/kxgettext.o
 *** Unable to find the ncurses libraries or the
 *** required header files.
 *** 'make menuconfig' requires the ncurses libraries.
 ***
 *** Install ncurses (ncurses-devel) and try again.
 ***
make[1]: *** [scripts/kconfig/dochecklxdialog] Error 1
make: *** [menuconfig] Error 2

Much better than before where we just listed some build errors.
The other *config targets will work indepenednt on ncurses
being present or not.

Includes improvements suggested by: Frans Pop <elendil@planet.nl>

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Frans Pop <elendil@planet.nl>

1 files changed, 8 insertions, 6 deletions

diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
index 1ad6f7fc490a..80914358817e 100644
--- a/scripts/kconfig/Makefile
+++ b/scripts/kconfig/Makefile
@@ -93,12 +93,6 @@ HOST_LOADLIBES   = $(shell $(CONFIG_SHELL) $(check-lxdialog) -ldflags $(HOSTCC))
 
 HOST_EXTRACFLAGS += -DLOCALE
 
-PHONY += $(obj)/dochecklxdialog
-$(obj)/dochecklxdialog:
-        $(Q)$(CONFIG_SHELL) $(check-lxdialog) -check $(HOSTCC) $(HOST_LOADLIBES)
-
-always := dochecklxdialog
-
 
 # ===========================================================================
 # Shared Makefile for the various kconfig executables:
@@ -145,6 +139,14 @@ clean-files	:= lkc_defs.h qconf.moc .tmp_qtcheck \
                    .tmp_gtkcheck zconf.tab.c lex.zconf.c zconf.hash.c
 clean-files     += mconf qconf gconf
 
+# Check that we have the required ncurses stuff installed for lxdialog (menuconfig)
+PHONY += $(obj)/dochecklxdialog
+$(addprefix $(obj)/,$(lxdialog)): $(obj)/dochecklxdialog
+$(obj)/dochecklxdialog:
+        $(Q)$(CONFIG_SHELL) $(check-lxdialog) -check $(HOSTCC) $(HOST_EXTRACFLAGS) $(HOST_LOADLIBES)
+
+always := dochecklxdialog
+
 # Add environment specific flags
 HOST_EXTRACFLAGS += $(shell $(CONFIG_SHELL) $(srctree)/$(src)/check.sh $(HOSTCC) $(HOSTCFLAGS))