meson: build a separate library for harfbuzz-icu

This adds a seperate library like with autotools.

This also fixes the ico feature option which was just set to required:false
when disabled instead of really disabling it.
Disabling is still broken with msvc because it then tries to find the library
another way, but that's broken for all other deps as well so I left it as is.

For tests only test-unicode.c is using icu specific functions so split it out
into its own category which depends on harfbuzz-icu.

Fixes #2338

meson.build

@@ -95,9 +95,13 @@ cairo_dep = dependency('cairo', required: false)
 fontconfig_dep = dependency('fontconfig', required: get_option('fontconfig'),
                             fallback: ['fontconfig', 'fontconfig_dep'])
 graphite2_dep = dependency('graphite2', required: get_option('graphite'))
-icu_dep = dependency('icu-uc', required: get_option('icu').enabled() and cpp.get_id() != 'msvc')
+icu_dep = dependency('icu-uc', required: false)
 m_dep = cpp.find_library('m', required: false)
 
+if not icu_dep.found() and get_option('icu').enabled()
+  icu_dep = dependency('icu-uc', required: cpp.get_id() != 'msvc')
+endif
+
 if not icu_dep.found() and cpp.get_id() == 'msvc'
   if cpp.has_header('unicode/uchar.h') and \
      cpp.has_header('unicode/unorm2.h') and \
@@ -187,7 +191,6 @@ endif
 if icu_dep.found()
   conf.set('HAVE_ICU', 1)
   conf.set('HAVE_ICU_BUILTIN', 1)
-  deps += [icu_dep]
 endif
 
 if freetype_dep.found()

src/meson.build

@@ -325,12 +325,6 @@ if get_option('amalgam')
   hb_sources = ['harfbuzz.cc']
 endif
 
-# FIXME: move into harfbuzz-icu module
-if conf.get('HAVE_ICU', 0) == 1
-  hb_sources += hb_icu_sources
-  hb_headers += hb_icu_headers
-endif
-
 # harfbuzz
 gen_def = find_program('gen-def.py')
 harfbuzz_def = custom_target('harfbuzz.def',
@@ -491,6 +485,33 @@ pkgmod.generate(libharfbuzz_subset,
   version: meson.project_version(),
 )
 
+have_icu = conf.get('HAVE_ICU', 0) == 1
+
+if have_icu
+  libharfbuzz_icu = library('harfbuzz-icu', [hb_icu_sources, hb_icu_headers],
+    include_directories: incconfig,
+    dependencies: icu_dep,
+    link_with: [libharfbuzz],
+    cpp_args: cpp_args + extra_hb_cpp_args,
+    soversion: hb_so_version,
+    version: version,
+    install: true,
+    name_prefix: hb_lib_prefix)
+
+  libharfbuzz_icu_dep = declare_dependency(
+    link_with: libharfbuzz_icu,
+    include_directories: incsrc,
+    dependencies: deps)
+
+  pkgmod.generate(libharfbuzz_icu,
+    description: 'HarfBuzz text shaping library ICU integration',
+    subdirs: [meson.project_name()],
+    version: meson.project_version(),
+  )
+else
+  libharfbuzz_icu_dep = dependency('', required: false)
+endif
+
 have_gobject = conf.get('HAVE_GOBJECT', 0) == 1
 
 cmake_config = configuration_data()

test/api/meson.build

@@ -24,7 +24,6 @@ if conf.get('HAVE_GLIB', 0) == 1
     'test-ot-metrics-tt-var.c',
     'test-set.c',
     'test-shape.c',
-    'test-unicode.c',
     'test-var-coords.c',
     'test-version.c',
   ]
@@ -51,6 +50,11 @@ if conf.get('HAVE_GLIB', 0) == 1
     'test-subset-cbdt.c',
   ]
 
+  icu_tests = []
+  if conf.get('HAVE_ICU', 0) == 1
+    icu_tests += 'test-unicode.c'
+  endif
+
   if conf.get('HAVE_FREETYPE', 0) == 1
     tests += 'test-ot-math.c'
   endif
@@ -86,6 +90,16 @@ if conf.get('HAVE_GLIB', 0) == 1
       install: false,
     ), env: env)
   endforeach
+
+  foreach source : icu_tests
+    test_name = source.split('.')[0]
+    test(test_name, executable(test_name, source,
+      include_directories: [incconfig, incsrc],
+      dependencies: deps,
+      link_with: [libharfbuzz, libharfbuzz_icu],
+      install: false,
+    ), env: env)
+  endforeach
 else
   message('You need to have glib support enabled to run test/api tests')
 endif