docs: Port from gtk-doc to gi-docgen

gtk-doc has been slowly dying for the past few years. With gi-docgen we
have a clear successor in sight to replace the voodoo magic one needs to
get the whole documentation setup.

See the [gi-docgen tutorial] for more info on how the system works.

Since we're now only the C compiler (and GIR) parse the C code, that
means we can also get rid of all the special escapes for the # character
in PKCS#11.

[gi-docgen tutorial]: https://gnome.pages.gitlab.gnome.org/gi-docgen/tutorial.html

1 files changed, 5 insertions, 1 deletions

diff --git a/meson.build b/meson.build
index 6fa0ff4..dea1b69 100644
--- a/meson.build
+++ b/meson.build
@@ -1,6 +1,6 @@
 project('gcr', 'c',
   version: '3.41.0',
-  meson_version: '>= 0.49',
+  meson_version: '>= 0.52',
   license: 'GPL2+',
 )
 
@@ -101,6 +101,10 @@ if get_option('gtk')
   subdir('ui')
 endif
 if get_option('gtk_doc')
+  if not get_option('introspection')
+    error('Can\'t generate docs without introspection enabled!')
+  endif
+
   subdir('docs')
 endif