meson: add option and build system plumbing for uniscribe on Windows

Untested though.

meson.build

@@ -123,6 +123,20 @@ if fontconfig_dep.found()
   deps += [fontconfig_dep]
 endif
 
+# uniscribe (windows) - FIXME: untested
+if host_machine.system() == 'windows' and not get_option('uniscribe').disabled()
+  # TODO: make nicer once we have https://github.com/mesonbuild/meson/issues/3940
+  if cpp.has_header('usp10.h') and cpp.has_header('windows.h')
+    foreach usplib : ['usp10', 'gdi32', 'rpcrt4']
+      deps += [cpp.find_library(usplib, required: true)]
+    endforeach
+    conf.set('HAVE_UNISCRIBE', 1)
+  elif get_option('uniscribe').enabled()
+    error('uniscribe was enabled explicitly, but some required headers are missing.')
+  endif
+endif
+
+# threads
 if host_machine.system() != 'windows'
   thread_dep = dependency('threads', required: false)
 

meson_options.txt

@@ -15,6 +15,8 @@ option('freetype', type: 'feature', value: 'auto',
   description: 'Enable freetype interop helpers')
 option('ucdn', type: 'feature', value: 'auto',
   description: 'Use internal HarfBuzz-provided UCDN library')
+option('uniscribe', type: 'feature', value: 'disabled',
+  description: 'Enable Uniscribe shaper backend (Windows only)')
 
 # Common feature options
 #option('tests', type : 'feature', value : 'auto', yield : true,

src/meson.build

@@ -112,10 +112,6 @@ hb_directwrite_sources = [
   'hb-directwrite.cc',
 ]
 
-hb_uniscribe_sources = [
-  'hb-uniscribe.cc',
-]
-
 hb_icu_sources = [
   'hb-icu.cc',
 ]
@@ -179,6 +175,11 @@ if conf.get('HAVE_ICU', 0) == 1
   hb_headers += hb_icu_headers
 endif
 
+if conf.get('HAVE_UNISCRIBE', 0) == 1
+  hb_sources += ['hb-uniscribe.cc']
+  hb_headers += ['hb-uniscribe.h']
+endif
+
 version = '0.' + '0'.join(meson.project_version().split('.')) + '.0'
 
 libharfbuzz = library('harfbuzz', hb_sources,