configure: check for argp

argp is only present in the GNU C library, so add a specific check for it in
configure. Also check if -largp is needed for linking against it.

Please run autoconf after applying.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: George Dunlap <george.dunlap@eu.citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Olaf Hering <olaf@aepfle.de>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
[ ijc -- ran autogen.sh ]

config/Tools.mk.in

@@ -78,5 +78,6 @@ CONFIG_GCRYPT       := @libgcrypt@
 EXTFS_LIBS          := @EXTFS_LIBS@
 CURSES_LIBS         := @CURSES_LIBS@
 TINFO_LIBS          := @TINFO_LIBS@
+ARGP_LDFLAGS        := @argp_ldflags@
 
 FILE_OFFSET_BITS    := @FILE_OFFSET_BITS@

tools/configure

@@ -632,6 +632,7 @@ systemd
 remus_netbuf
 LIBNL3_LIBS
 LIBNL3_CFLAGS
+argp_ldflags
 libiconv
 PTYFUNCS_LIBS
 PTHREAD_LIBS
@@ -8793,6 +8794,56 @@ else
 fi
 
 
+ac_fn_c_check_header_mongrel "$LINENO" "argp.h" "ac_cv_header_argp_h" "$ac_includes_default"
+if test "x$ac_cv_header_argp_h" = xyes; then :
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for argp_usage in -largp" >&5
+$as_echo_n "checking for argp_usage in -largp... " >&6; }
+if ${ac_cv_lib_argp_argp_usage+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-largp  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char argp_usage ();
+int
+main ()
+{
+return argp_usage ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_argp_argp_usage=yes
+else
+  ac_cv_lib_argp_argp_usage=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_argp_argp_usage" >&5
+$as_echo "$ac_cv_lib_argp_argp_usage" >&6; }
+if test "x$ac_cv_lib_argp_argp_usage" = xyes; then :
+  argp_ldflags="-largp"
+fi
+
+
+else
+  as_fn_error $? "Could not find argp" "$LINENO" 5
+fi
+
+
+
 
 # FDT is needed only on ARM
 case "$host_cpu" in

tools/configure.ac

@@ -356,6 +356,10 @@ AC_CHECK_LIB([yajl], [yajl_alloc], [],
 AC_CHECK_LIB([z], [deflateCopy], [], [AC_MSG_ERROR([Could not find zlib])])
 AC_CHECK_LIB([iconv], [libiconv_open], [libiconv="y"], [libiconv="n"])
 AC_SUBST(libiconv)
+AC_CHECK_HEADER([argp.h], [
+AC_CHECK_LIB([argp], [argp_usage], [argp_ldflags="-largp"])
+], [AC_MSG_ERROR([Could not find argp])])
+AC_SUBST(argp_ldflags)
 
 # FDT is needed only on ARM
 case "$host_cpu" in

tools/xentrace/Makefile

@@ -4,7 +4,7 @@ include $(XEN_ROOT)/tools/Rules.mk
 CFLAGS += -Werror
 
 CFLAGS += $(CFLAGS_libxenctrl)
-LDLIBS += $(LDLIBS_libxenctrl)
+LDLIBS += $(LDLIBS_libxenctrl) $(ARGP_LDFLAGS)
 
 BIN-$(CONFIG_X86) = xenalyze
 BIN      = $(BIN-y)