meson: add option and build system plumbing for CoreText on macOS/iOS

Untested though.

meson.build

@@ -146,6 +146,27 @@ if host_machine.system() == 'windows' and not get_option('directwrite').disabled
   endif
 endif
 
+# CoreText (macOS) - FIXME: untested
+if host_machine.system() == 'darwin' and not get_option('coretext').disabled()
+  app_services_dep = dependency('appleframeworks', modules : ['ApplicationServices'], required: false)
+  if cpp.has_type('CTFontRef', prefix: '#include <ApplicationServices/ApplicationServices.h>', dependencies: app_services_dep)
+    deps += [app_services_dep]
+    conf.set('HAVE_CORETEXT', 1)
+  # On iOS CoreText and CoreGraphics are stand-alone frameworks
+  # Check for a different symbol to avoid getting cached result
+  else
+    coretext_dep = dependency('appleframeworks', modules : ['CoreText'], required: false)
+    coregraphics_dep = dependency('appleframeworks', modules : ['CoreGraphics'], required: false)
+    corefoundation_dep = dependency('appleframeworks', modules : ['CoreFoundation'], required: false)
+    if cpp.has_type('CTRunRef', prefix: '#include <CoreText/CoreText.h>', dependencies: [coretext_dep, coregraphics_dep, corefoundation_dep])
+      deps += [coretext_dep, coregraphics_dep, corefoundation_dep]
+      conf.set('HAVE_CORETEXT', 1)
+    elif get_option('coretext').enabled()
+      error('CoreText was enabled explicitly, but required headers or frameworks are missing.')
+    endif
+  endif
+endif
+
 # threads
 if host_machine.system() != 'windows'
   thread_dep = dependency('threads', required: false)

meson_options.txt

@@ -19,6 +19,8 @@ option('uniscribe', type: 'feature', value: 'disabled',
   description: 'Enable Uniscribe shaper backend (Windows only)')
 option('directwrite', type: 'feature', value: 'disabled',
   description: 'Enable DirectWrite shaper backend on Windows (experimental)')
+option('coretext', type: 'feature', value: 'disabled',
+  description: 'Enable CoreText shaper backend on macOS')
 
 # Common feature options
 #option('tests', type : 'feature', value : 'auto', yield : true,

src/meson.build

@@ -104,10 +104,6 @@ hb_graphite2_headers = [
   'hb-graphite2.h',
 ]
 
-hb_coretext_sources = [
-  'hb-coretext.cc',
-]
-
 hb_icu_sources = [
   'hb-icu.cc',
 ]
@@ -181,6 +177,11 @@ if conf.get('HAVE_DIRECTWRITE', 0) == 1
   hb_headers += ['hb-directwrite.h']
 endif
 
+if conf.get('HAVE_CORETEXT', 0) == 1
+  hb_sources += ['hb-coretext.cc']
+  hb_headers += ['hb-coretext.h']
+endif
+
 version = '0.' + '0'.join(meson.project_version().split('.')) + '.0'
 
 libharfbuzz = library('harfbuzz', hb_sources,