meson: disallow the combination of cryptolib=openssl and dns-over-tls=gnutls

It could work, but it doesn't make much sense. If we already have openssl as
the cryptolib that provides the necessary support, let's not bring in another
library. Disallowing this simplifies things and reduces our support matrix.

diff --git a/meson.build b/meson.build
index 968d752fded808e34dc7b44a0ceb7e69b92fbec5..4cc97d664e31278f8be0ec4bdf9257ee040a1854 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -1448,9 +1448,25 @@ else
 endif
 conf.set10('HAVE_DBUS', have)
 
+# We support one or the other. If gcrypt is available, we assume it's there to
+# be used, and use it in preference.
+opt = get_option('cryptolib')
+if opt == 'openssl' and conf.get('HAVE_OPENSSL') == 0
+        error('openssl requested as the default cryptolib, but not available')
+endif
+conf.set10('PREFER_OPENSSL',
+           opt == 'openssl' or (opt == 'auto' and conf.get('HAVE_OPENSSL') == 1 and conf.get('HAVE_GCRYPT') == 0))
+conf.set10('HAVE_OPENSSL_OR_GCRYPT',
+           conf.get('HAVE_OPENSSL') == 1 or conf.get('HAVE_GCRYPT') == 1)
+lib_openssl_or_gcrypt = conf.get('PREFER_OPENSSL') == 1 ? libopenssl : libgcrypt
+
 dns_over_tls = get_option('dns-over-tls')
 if dns_over_tls != 'false'
-        if dns_over_tls == 'openssl'
+        if dns_over_tls == 'gnutls' and conf.get('PREFER_OPENSSL') == 1
+                error('Sorry, -Ddns-over-tls=gnutls is not supported when openssl is used as the cryptolib')
+        endif
+
+        if dns_over_tls == 'openssl' or conf.get('PREFER_OPENSSL') == 1
                 have_gnutls = false
         else
                 have_gnutls = (conf.get('HAVE_GNUTLS') == 1 and libgnutls.version().version_compare('>= 3.6.0'))
@@ -1511,18 +1527,6 @@ else
 endif
 conf.set10('ENABLE_REPART', have)
 
-# We support one or the other. If gcrypt is available, we assume it's there to
-# be used, and use it in preference.
-opt = get_option('cryptolib')
-if opt == 'openssl' and conf.get('HAVE_OPENSSL') == 0
-        error('openssl requested as the default cryptolib, but not available')
-endif
-conf.set10('PREFER_OPENSSL',
-           opt == 'openssl' or (opt == 'auto' and conf.get('HAVE_OPENSSL') == 1 and conf.get('HAVE_GCRYPT') == 0))
-conf.set10('HAVE_OPENSSL_OR_GCRYPT',
-           conf.get('HAVE_OPENSSL') == 1 or conf.get('HAVE_GCRYPT') == 1)
-lib_openssl_or_gcrypt = conf.get('PREFER_OPENSSL') == 1 ? libopenssl : libgcrypt
-
 default_dnssec = get_option('default-dnssec')
 if skip_deps
         default_dnssec = 'no'