build: make --disable-gl disable all the gl backends

Fixes #369

DOCS/waf-buildsystem.rst

@@ -135,6 +135,11 @@ For example::
 will override the value of ``func`` with ``check_pthreads_w32_static`` only
 if the target OS of the build is Windows.
 
+``groups``: groups a dependency with another one. This can be used to disabled
+all the grouped dependencies with one ``--disable-``. At the moment this is
+only used for OpenGL backends, where you want to disable them when
+``--disable-gl`` is passed to the configure.
+
 mpv's custom build step on top of waf
 =====================================
 

waftools/dependencies.py

@@ -34,6 +34,7 @@ class Dependency(object):
         self.ctx.start_msg('Checking for {0}'.format(self.desc))
 
         try:
+            self.check_group_disabled()
             self.check_disabled()
             self.check_any_dependencies()
             self.check_dependencies()
@@ -49,6 +50,14 @@ class Dependency(object):
 
         self.check_autodetect_func()
 
+    def check_group_disabled(self):
+        if 'groups' in self.attributes:
+            groups = self.attributes['groups']
+            disabled = (self.enabled_option(g) == False for g in groups)
+            if any(disabled):
+                self.skip()
+                raise DependencyError
+
     def check_disabled(self):
         if self.enabled_option() == False:
             self.skip()
@@ -89,15 +98,15 @@ the autodetection check failed.".format(self.identifier)
             self.fail()
             self.fatal_if_needed()
 
-    def enabled_option(self):
+    def enabled_option(self, identifier=None):
         try:
-            return getattr(self.ctx.options, self.enabled_option_repr())
+            return getattr(self.ctx.options, self.enabled_option_repr(identifier))
         except AttributeError:
             pass
         return None
 
-    def enabled_option_repr(self):
+    def enabled_option_repr(self, identifier):
-        return "enable_{0}".format(self.identifier)
+        return "enable_{0}".format(identifier or self.identifier)
 
     def success(self, depname):
         self.ctx.mark_satisfied(depname)

wscript

@@ -497,11 +497,13 @@ video_output_features = [
         'name': '--gl-cocoa',
         'desc': 'OpenGL Cocoa Backend',
         'deps': [ 'cocoa' ],
+        'groups': [ 'gl' ],
         'func': check_true
     } , {
         'name': '--gl-x11',
         'desc': 'OpenGL X11 Backend',
         'deps': [ 'x11' ],
+        'groups': [ 'gl' ],
         'func': check_libs(['GL', 'GL Xdamage'],
                    check_cc(fragment=load_fragment('gl_x11.c'),
                             use=['x11', 'libdl', 'pthreads']))
@@ -509,12 +511,14 @@ video_output_features = [
         'name': '--gl-wayland',
         'desc': 'OpenGL Wayland Backend',
         'deps': [ 'wayland' ],
+        'groups': [ 'gl' ],
         'func': check_pkg_config('wayland-egl', '>= 9.0.0',
                                  'egl',         '>= 9.0.0')
     } , {
         'name': '--gl-win32',
         'desc': 'OpenGL Win32 Backend',
         'deps': [ 'gdi' ],
+        'groups': [ 'gl' ],
         'func': check_statement('windows.h', 'wglCreateContext(0)',
                                 lib='opengl32')
     } , {