do not override CFLAGS during configure, remove USER_CFLAGS

compat/Makefile.am

@@ -26,7 +26,6 @@ libcompatnoopt_la_SOURCES += explicit_bzero.c
 endif
 
 # other compatibility functions
-libcompat_la_CFLAGS = $(CFLAGS) $(USER_CFLAGS)
 libcompat_la_SOURCES =
 libcompat_la_LIBADD = $(PLATFORM_LDADD)
 

configure.ac

@@ -25,8 +25,11 @@ AC_CONFIG_MACRO_DIR([m4])
 
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 
-AC_SUBST([USER_CFLAGS], "$CFLAGS")
-CFLAGS="-O2 -Wall -std=gnu99 -g"
+AC_PROG_CC
+AC_PROG_CC_STDC
+AM_PROG_CC_C_O
+AC_PROG_LIBTOOL
+AC_PROG_YACC
 
 case $host_os in
 	*darwin*)
@@ -72,12 +75,6 @@ AM_CONDITIONAL([HOST_SOLARIS], [test x$HOST_OS = xsolaris])
 AC_CHECK_FUNC([dl_iterate_phdr],,
 	[AC_SEARCH_LIBS([dl_iterate_phdr],[dl])])
 
-AC_PROG_CC
-AC_PROG_CC_STDC
-AM_PROG_CC_C_O
-AC_PROG_LIBTOOL
-AC_PROG_YACC
-
 save_cflags="$CFLAGS"
 CFLAGS=-Wno-pointer-sign
 AC_MSG_CHECKING([whether CC supports -Wno-pointer-sign])

src/Makefile.am

@@ -23,7 +23,7 @@ CLEANFILES = parse.c
 sbin_PROGRAMS = ntpd
 dist_man_MANS = ntpctl.8 ntpd.8 ntpd.conf.5
 
-ntpd_CFLAGS = $(CFLAGS) $(USER_CFLAGS)
+ntpd_CFLAGS = $(CFLAGS)
 ntpd_CFLAGS += -DSYSCONFDIR=\"$(sysconfdir)\"
 ntpd_CFLAGS += -DLOCALSTATEDIR=\"$(localstatedir)\"