[gtk/gtk-doc-ci: 1/3] Add gtk-doc as a subproject

[Emmanuele Bassi <ebassi src gnome org>]

commit 058f82d03d499abdb89af4289954e0d8fbd2399c
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Tue Jan 28 16:50:53 2020 +0100

    Add gtk-doc as a subproject
    
    We rely on a specific minimum version of gtk-doc to be able to build the
    GTK API reference for the new API. In order to be able to use gtk-doc as
    a subproject, though, we need to use a recent version of Meson.

 docs/reference/meson.build | 9 +++++++++
 subprojects/gtk-doc.wrap   | 4 ++++
 2 files changed, 13 insertions(+)
---
diff --git a/docs/reference/meson.build b/docs/reference/meson.build
index a308cc4c87..842d3a68d9 100644
--- a/docs/reference/meson.build
+++ b/docs/reference/meson.build
@@ -1,4 +1,13 @@
 if get_option('gtk_doc')
+  if not meson.version().version_compare('>=0.52.0')
+    error('Building the GTK documentation requires Meson 0.52.0')
+  endif
+
+  # Use gtk-doc as a sub-project if the version isn't new enough
+  dependency('gtk-doc', version: '>=1.32',
+    fallback: ['gtk-doc', 'dummy_dep'],
+    default_options: ['tests=false'])
+
   glib_prefix = dependency('glib-2.0').get_pkgconfig_variable('prefix')
   glib_docpath = join_paths(glib_prefix, 'share', 'gtk-doc', 'html')
 
diff --git a/subprojects/gtk-doc.wrap b/subprojects/gtk-doc.wrap
new file mode 100644
index 0000000000..7469d027b0
--- /dev/null
+++ b/subprojects/gtk-doc.wrap
@@ -0,0 +1,4 @@
+[wrap-git]
+directory=gtk-doc
+url=https://gitlab.gnome.org/GNOME/gtk-doc.git
+revision=master