[json-glib] build: Rework the introspection option

[Emmanuele Bassi <ebassi src gnome org>]

commit bc4748ec89ef04fe9de7024185d1e78609d13c15
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Sat Sep 2 12:07:38 2017 +0100

    build: Rework the introspection option
    
    Instead of using `disable_introspection=false`, flip the condition
    around, and use `enable-introspection=true`. This avoids the double
    negative.
    
    Additionally, we should drop the cross-compilation check; it's entirely
    possible to cross-compile introspection data for different platforms and
    architectures; this allows the Yocto project to drop a patch for
    JSON-GLib.

 json-glib/meson.build |    2 ++
 meson.build           |    2 --
 meson_options.txt     |   10 +++++-----
 3 files changed, 7 insertions(+), 7 deletions(-)
---
diff --git a/json-glib/meson.build b/json-glib/meson.build
index 45c3247..b229ad8 100644
--- a/json-glib/meson.build
+++ b/json-glib/meson.build
@@ -84,6 +84,8 @@ pkgg.generate(libraries: [ json_lib ],
               description: 'JSON Parser for GLib.',
               requires: 'gio-2.0')
 
+gir = find_program('g-ir-scanner', required: false)
+build_gir = gir.found() and get_option('enable-introspection')
 if build_gir
   gir_args = [
     '--quiet',
diff --git a/meson.build b/meson.build
index 5d33c64..59ee0b1 100644
--- a/meson.build
+++ b/meson.build
@@ -156,8 +156,6 @@ endif
 root_dir = include_directories('.')
 
 gnome = import('gnome')
-gir = find_program('g-ir-scanner', required: false)
-build_gir = gir.found() and not meson.is_cross_build() and not get_option('disable_introspection')
 
 python3 = import('python3').find_python()
 gen_installed_test = files('build-aux/gen-installed-test.py')
diff --git a/meson_options.txt b/meson_options.txt
index 4dc2a01..6c078cb 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -1,9 +1,9 @@
-option('disable_introspection',
-        type: 'boolean', value: false,
-        description: 'Whether to disable the introspection generation')
+option('enable-introspection',
+       type: 'boolean', value: true,
+       description: 'Whether to generate introspection data (requires gobject-introspection)')
 option('enable-gtk-doc',
        type: 'boolean', value: false,
-       description: 'Whether to generate the API reference for JSON-GLib')
+       description: 'Whether to generate the API reference (requires gtk-doc)')
 option('enable-man',
        type: 'boolean', value: false,
-       description: 'Whether to generate the man pages for JSON-GLib tools')
+       description: 'Whether to generate man pages (requires xsltproc)')