Add multithreaded variant to ICU port

embuilder.py

@@ -62,13 +62,14 @@
     'libunwind-except'
 ]
 
-# Variant builds that we want to support for cetain ports
+# Variant builds that we want to support for certain ports
 # TODO: It would be nice if the ports themselves could specify the variants that they
 # support.
 PORT_VARIANTS = {
     'regal-mt': ('regal', {'USE_PTHREADS': 1}),
     'harfbuzz-mt': ('harfbuzz', {'USE_PTHREADS': 1}),
     'sdl2-mt': ('sdl2', {'USE_PTHREADS': 1}),
+    'icu-mt': ('icu', {'USE_PTHREADS': 1}),
     'sdl2_mixer_mp3': ('sdl2_mixer', {'SDL2_MIXER_FORMATS': ["mp3"]}),
     'sdl2_mixer_none': ('sdl2_mixer', {'SDL2_MIXER_FORMATS': []}),
     'sdl2_image_png': ('sdl2_image', {'SDL2_IMAGE_FORMATS': ["png"]}),

tests/other/test_pthread_icu.cpp

@@ -0,0 +1,13 @@
+#include <thread>
+#include <iostream>
+#include <unicode/unistr.h>
+
+// Test that code using both pthread and icu compiles.
+int main () {
+	std::thread([] {
+		std::string str;
+		icu::UnicodeString ustr("Hello world!");
+		ustr.toUTF8String(str);
+		std::cout << str << std::endl;
+	}).detach();
+}

tests/test_other.py

@@ -11125,6 +11125,10 @@ def test_pthread_out_err(self):
     self.set_setting('EXIT_RUNTIME')
     self.do_other_test('test_pthread_out_err.c')
 
+  @node_pthreads
+  def test_icu_mt(self):
+    self.do_smart_test(test_file('other/test_pthread_icu.cpp'), emcc_args=['-pthread', '-sUSE_ICU', '-sPTHREAD_POOL_SIZE_STRICT=4', '-sEXIT_RUNTIME'])
+
   # unistd tests
 
   def test_unistd_confstr(self):

tools/ports/icu.py

@@ -11,15 +11,19 @@
 VERSION = '68_2'
 HASH = '12c3db5966c234c94e7918fb8acc8bd0838edc36a620f3faa788e7ff27b06f1aa431eb117401026e3963622b9323212f444b735d5c9dd3d0b82d772a4834b993'
 
-libname_libicu_common = 'libicu_common.a'
-libname_libicu_stubdata = 'libicu_stubdata.a'
-libname_libicu_i18n = 'libicu_i18n.a'
+libname_libicu_common = 'libicu_common'
+libname_libicu_stubdata = 'libicu_stubdata'
+libname_libicu_i18n = 'libicu_i18n'
 
 
 def needed(settings):
   return settings.USE_ICU
 
 
+def get_lib_name(base_name, settings):
+  return base_name + ('-mt' if settings.USE_PTHREADS else '') + '.a'
+
+
 def get(ports, settings, shared):
   url = 'https://github.com/unicode-org/icu/releases/download/%s/icu4c-%s-src.zip' % (TAG, VERSION)
   ports.fetch_project('icu', url, 'icu', sha512hash=HASH)
@@ -48,6 +52,9 @@ def build_lib(lib_output, lib_src, other_includes, build_flags):
         # CXXFLAGS
         '-std=c++11'
     ]
+    if settings.USE_PTHREADS:
+      additional_build_flags.append('-pthread')
+
     ports.build_port(lib_src, lib_output, other_includes, build_flags + additional_build_flags)
 
   # creator for libicu_common
@@ -71,16 +78,16 @@ def create_libicu_i18n(lib_output):
     build_lib(lib_output, lib_src, other_includes, ['-DU_I18N_IMPLEMENTATION=1'])
 
   return [
-      shared.Cache.get_lib(libname_libicu_common, create_libicu_common), # this also prepares the build
-      shared.Cache.get_lib(libname_libicu_stubdata, create_libicu_stubdata),
-      shared.Cache.get_lib(libname_libicu_i18n, create_libicu_i18n)
+      shared.Cache.get_lib(get_lib_name(libname_libicu_common, settings), create_libicu_common), # this also prepares the build
+      shared.Cache.get_lib(get_lib_name(libname_libicu_stubdata, settings), create_libicu_stubdata),
+      shared.Cache.get_lib(get_lib_name(libname_libicu_i18n, settings), create_libicu_i18n)
   ]
 
 
 def clear(ports, settings, shared):
-  shared.Cache.erase_lib(libname_libicu_common)
-  shared.Cache.erase_lib(libname_libicu_stubdata)
-  shared.Cache.erase_lib(libname_libicu_i18n)
+  shared.Cache.erase_lib(get_lib_name(libname_libicu_common, settings))
+  shared.Cache.erase_lib(get_lib_name(libname_libicu_stubdata, settings))
+  shared.Cache.erase_lib(get_lib_name(libname_libicu_i18n, settings))
 
 
 def process_args(ports):