Can use external dependencies in Vala.

ninjabackend.py

@@ -16,6 +16,7 @@ import backends
 import environment
 import build
 import mlog
+import dependencies
 from meson_install import InstallData
 from build import InvalidArguments
 from coredata import MesonException
@@ -455,6 +456,9 @@ class NinjaBackend(backends.Backend):
             relsc = os.path.join(self.get_target_dir(target), target.get_basename() + '.dir', sc)
             rel_s = os.path.join(self.build_to_src, s)
             flags += ['--deps', relsc + '.d']
+            for d in target.external_deps:
+                if isinstance(d, dependencies.PkgConfigDependency):
+                    flags += ['--pkg', d.name]
             generated_c += [relsc]
             element = NinjaBuildElement(relsc, valac.get_language() + '_COMPILER', rel_s)
             element.add_item('FLAGS', flags)

test cases/vala/3 dep/gioprog.vala

@@ -0,0 +1,8 @@
+class GioProg {
+
+    public static int main(string[] args) {
+        var homedir = File.new_for_path(Environment.get_home_dir());
+        stdout.printf("Home directory as told by gio is " + homedir.get_path() + "\n");
+        return 0;
+    }
+}

test cases/vala/3 dep/meson.build

@@ -0,0 +1,9 @@
+project('giotest', 'vala', 'c')
+
+glib = dependency('glib-2.0')
+gobject = dependency('gobject-2.0')
+gio = dependency('gio-2.0')
+
+e = executable('gioprog', 'gioprog.vala',
+deps : [glib, gobject, gio])
+test('giotest', e)