build-sys: use -Wno-clobbered for some BSD crap

* extend UL_WARN_ADD() for accept non-default CFLAGS variable
 * add BSD_WARN_CFLAGS with -Wno-clobbered
 * use all this for pg(1) and more(1)

Signed-off-by: Karel Zak <kzak@redhat.com>

configure.ac

@@ -120,6 +120,9 @@ UL_WARN_ADD([-Wstrict-prototypes])
 UL_WARN_ADD([-Wformat-security])
 AC_SUBST([WARN_CFLAGS])
 
+UL_WARN_ADD([-Wno-clobbered], BSD_WARN_CFLAGS)
+AC_SUBST([BSD_WARN_CFLAGS])
+
 dnl libtool-2
 LT_INIT
 

m4/compiler.m4

@@ -14,10 +14,11 @@ m4_ifdef([AS_VAR_APPEND],
 [m4_define([UL_AS_VAR_APPEND],
 [AS_VAR_SET([$1], [AS_VAR_GET([$1])$2])])])
 
-# UL_ADD_WARN([parameter])
+# UL_ADD_WARN(COMPILER_OPTION [, VARNAME])
 # ------------------------
-# Adds parameter to WARN_CFLAGS if the compiler supports it.
+# Adds parameter to WARN_CFLAGS (or to $VARNAME) if the compiler supports it.
 AC_DEFUN([UL_WARN_ADD], [
+  m4_define([warnvarname], m4_default([$2],WARN_CFLAGS))
   AS_VAR_PUSHDEF([ul_Warn], [ul_cv_warn_$1])dnl
   AC_CACHE_CHECK([whether compiler handles $1], m4_defn([ul_Warn]), [
     ul_save_CPPFLAGS="$CPPFLAGS"
@@ -27,6 +28,6 @@ AC_DEFUN([UL_WARN_ADD], [
                       [AS_VAR_SET(ul_Warn, [no])])
     CPPFLAGS="$ul_save_CPPFLAGS"
   ])
-  AS_VAR_IF(ul_Warn, [yes], [UL_AS_VAR_APPEND([WARN_CFLAGS], [" $1"])])
+  AS_VAR_IF(ul_Warn, [yes], [UL_AS_VAR_APPEND(warnvarname, [" $1"])])
 ])
 

text-utils/Makemodule.am

@@ -53,6 +53,7 @@ if BUILD_PG
 usrbin_exec_PROGRAMS += pg
 dist_man_MANS += text-utils/pg.1
 pg_SOURCES = text-utils/pg.c
+pg_CFLAGS = $(AM_CFLAGS) $(BSD_WARN_CFLAGS)
 pg_LDADD = $(LDADD) libcommon.la @NCURSES_LIBS@
 if HAVE_TINFO
 pg_LDADD += -ltinfo
@@ -77,6 +78,7 @@ if BUILD_MORE
 bin_PROGRAMS += more
 dist_man_MANS += text-utils/more.1
 more_SOURCES = text-utils/more.c
+more_CFLAGS = $(AM_CFLAGS) $(BSD_WARN_CFLAGS)
 more_LDADD = $(LDADD)
 if HAVE_TINFO
 more_LDADD += -ltinfo