meson: print docs backend as part of the summary

Our documentation can be built with either Asciidoc or Asciidoctor as
backend. When Meson is configured to build documentation, then it will
automatically detect which of these tools is available and use them.
It's not obvious to the user though which of these backends is used
unless the user explicitly asks for one backend via `-Ddocs_backend=`.

Improve the status quo by printing the docs backend as part of the
"backends" summary.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/meson.build b/meson.build
index f7dd6ee30d7251ede7a333ede7684e5d16d1d7e9..cfaae83488c164117df44bab183d30d45da15b50 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -2101,6 +2101,8 @@ subdir('bin-wrappers')
 if get_option('docs') != []
   doc_targets = []
   subdir('Documentation')
+else
+  docs_backend = 'none'
 endif
 
 subdir('contrib')
@@ -2249,6 +2251,7 @@ summary({
 
 summary({
   'csprng': csprng_backend,
+  'docs': docs_backend,
   'https': https_backend,
   'sha1': sha1_backend,
   'sha1_unsafe': sha1_unsafe_backend,