fix: define HAVE_SEMAPHORE preprocessor symbol when header is available

Signed-off-by: Christopher Arndt <[email protected]>

Author: SpotlightKid

meson.build

@@ -72,6 +72,7 @@ coremidi_support = host_machine.system() == 'darwin' and coremidi_dep.found() an
 winmm_support = host_machine.system() == 'windows' and winmm_dep.found() and get_option('winmm')
 
 threads_dep = dependency('threads', required: alsa_support or jack_support)
+have_semaphore = cpp.has_header('semaphore.h')
 
 pymod = import('python')
 python = pymod.find_installation(get_option('python'), required: true)

rtmidi/meson.build

@@ -34,6 +34,9 @@ endif
 
 if jack_support
     defines += ['-D__UNIX_JACK__', '-DJACK_HAS_PORT_RENAME']
+    if have_semaphore
+        defines += ['-DHAVE_SEMAPHORE']
+    endif
     dependencies += [jack_dep]
 endif