os: define SECURE_RPC locally instead of global config header

Since this define is only used inside os subdir, move the definition there
and out of the global config header. This also makes some further steps,
e.g. checking whether it's supported, a litle bit easier.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1441>
(cherry picked from commit d2d3f4a700)

include/meson.build

@@ -131,7 +131,6 @@ conf_data.set_quoted('COMPILEDDEFAULTFONTPATH', default_font_path)
 conf_data.set('XORG_VERSION_CURRENT', release)
 
 conf_data.set('HASXDMAUTH', has_xdm_auth ? '1' : false)
-conf_data.set('SECURE_RPC', get_option('secure-rpc') ? '1' : false)
 
 conf_data.set('HAVE_DLFCN_H', cc.has_header('dlfcn.h') ? '1' : false)
 conf_data.set('HAVE_EXECINFO_H', cc.has_header('execinfo.h') ? '1' : false)

os/meson.build

@@ -54,6 +54,9 @@ if get_option('xdmcp')
     srcs_os += 'xdmcp.c'
 endif
 
+os_dep = []
+os_c_args = []
+
 rpc_dep = []
 if get_option('secure-rpc')
     # prefer libtirpc (if available), otherwise ensure RPC functions are
@@ -64,10 +67,10 @@ if get_option('secure-rpc')
     endif
     # XXX: also check if RPC library provides xdr_opaque_auth, authdes_(sec)create ???
     srcs_os += 'rpcauth.c'
+
+    os_c_args += '-DSECURE_RPC'
 endif
 
-os_dep = []
-os_c_args = []
 if get_option('xres')
     # Only the XRes extension cares about the client ID.
     os_c_args += '-DCLIENTIDS'