build-sys: meson: change oss-output boolean to Meson feature

Part-of: <https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/merge_requests/437>

meson.build

@@ -616,8 +616,7 @@ if x11_dep.found()
 endif
 
 # Module dependencies
-if get_option('oss-output')
-  assert(cc.has_header('sys/soundcard.h'), 'Need header file for OSS support')
+if cc.has_header('sys/soundcard.h', required: get_option('oss-output'))
   cdata.set('HAVE_OSS_OUTPUT', 1)
   cdata.set('HAVE_OSS_WRAPPER', 1)
   cdata.set('PULSEDSP_LOCATION', pulsedsp_location)
@@ -811,8 +810,8 @@ summary = [
   '',
   'Enable memfd shared memory:    @0@'.format(cdata.has('HAVE_MEMFD')),
   'Enable X11:                    @0@'.format(x11_dep.found()),
-  'Enable OSS Output:             @0@'.format(get_option('oss-output')),
-#  'Enable OSS Wrapper:            @0@'.format(${ENABLE_OSS_WRAPPER}),
+  'Enable OSS Output:             @0@'.format(cdata.has('HAVE_OSS_OUTPUT')),
+  'Enable OSS Wrapper:            @0@'.format(cdata.has('HAVE_OSS_WRAPPER')),
 #  'Enable EsounD:                 @0@'.format(${ENABLE_ESOUND}),
   'Enable Alsa:                   @0@'.format(alsa_dep.found()),
 #  'Enable CoreAudio:              @0@'.format(${ENABLE_COREAUDIO}),

meson_options.txt

@@ -124,7 +124,7 @@ option('orc',
        type : 'feature', value : 'auto',
        description : 'Optimized Inner Loop Runtime Compiler')
 option('oss-output',
-       type : 'boolean',
+       type : 'feature', value : 'auto',
        description : 'Optional OSS output support')
 option('samplerate',
        type : 'feature', value : 'disabled',

src/modules/meson.build

@@ -73,7 +73,7 @@ if cc.has_header('linux/input.h')
   ]
 endif
 
-if get_option('oss-output')
+if cdata.has('HAVE_OSS_OUTPUT')
   subdir('oss')
   all_modules += [
     [ 'module-oss', 'oss/module-oss.c', [], [], [], liboss_util ],

src/utils/meson.build

@@ -84,7 +84,7 @@ if x11_dep.found()
   )
 endif
 
-if get_option('oss-output')
+if cdata.has('HAVE_OSS_WRAPPER')
   libpulsecommon_sources = [
     'padsp.c',
   ]