build(c/adbc): Add support to build Vala bindings

Vala VAPI file is generated for current GADBC 1.0 API version.

It is disable by default, but recommended to be enable when
a development package is distributed.

This commit force a 1.0 API versioning, replacing the old one
where 0 were used for GIR API version (gir_version), so now
shows '1.0' instead of '0.0'.

glib/adbc-glib/meson.build

@@ -86,7 +86,20 @@ pkgconfig.generate(libadbc_glib,
                    variables: pkgconfig_variables,
                    version: meson.project_version())
 
-adbc_glib_gir = gnome.generate_gir(libadbc_glib,
+
+gi_fatal_warnings = (build_machine.system() != 'windows')
+have_gi = dependency('gobject-introspection-1.0', required: false).found()
+if have_gi
+  pkgconfig_variables += ['girdir=@0@'.format(gir_dir)]
+endif
+generate_vapi = have_gi and get_option('vapi')
+if generate_vapi
+  pkgconfig_variables += ['vapidir=@0@'.format(vapi_dir)]
+  add_languages('vala')
+endif
+
+if have_gi
+  adbc_glib_gir = gnome.generate_gir(libadbc_glib,
                                    export_packages: 'adbc-glib',
                                    extra_args: [
                                      '--warn-all',
@@ -102,3 +115,10 @@ adbc_glib_gir = gnome.generate_gir(libadbc_glib,
                                    nsversion: api_version,
                                    sources: sources + definition_headers + enums,
                                    symbol_prefix: 'gadbc')
+  if generate_vapi
+    adbc_glib_vapi = gnome.generate_vapi('adbc-glib',
+                                          install: true,
+                                          packages: ['gio-2.0'],
+                                          sources: [adbc_glib_gir[0]])
+  endif
+endif

glib/meson.build

@@ -30,7 +30,7 @@ version_major = version_numbers[0].to_int()
 version_minor = version_numbers[1].to_int()
 version_micro = version_numbers[2].to_int()
 
-api_version = '@0@.0'.format(version_major)
+api_version = '1.0'
 so_version = version_major
 library_version = '.'.join(version_numbers)
 
@@ -39,6 +39,7 @@ include_dir = get_option('includedir')
 project_include_sub_dir = meson.project_name()
 data_dir = get_option('datadir')
 gir_dir = prefix / data_dir / 'gir-1.0'
+vapi_dir = data_dir / 'vala' / 'vapi'
 
 gnome = import('gnome')
 pkgconfig = import('pkgconfig')

glib/meson_options.txt

@@ -21,3 +21,9 @@ option('adbc_build_dir',
        type: 'string',
        value: '',
        description: 'Use this option to build with not installed ADBC')
+
+
+option('vapi',
+       type: 'boolean',
+       value: false,
+       description: 'Build Vala API')