[libcxx] libc++ changes necessary for the externally threaded libcxxabi variant

[rmaprath]

Summary

This patch adds support for D27575. A couple of new threading API calls has been introduced (libc++abi requires these).

I've also done a few minor cleanups/renames here.

[EricWF]

This bit LGTM.

include/__threading_support

193 ↗

(On Diff #80765)

These should have inline. In fact all of the functions in this header must be declared inline but have not been.

test/libcxx/test/config.py

605 ↗

(On Diff #80765)

I would rather use libc++external_threads since it uses the same prefix as -lc++ and -lc++experimental

[rmaprath]

include/__threading_support

193 ↗

(On Diff #80765)

Actually, all the declarations on this header have _LIBCPP_THREAD_ABI_VISIBILITY , which includes the inline modifier. I've forgotten to include any context with this patch though, that might've made it bit unclear.

[rmaprath]

Gentle ping.

[rmaprath]

Ping.

[EricWF]

LGTM.

test/CMakeLists.txt

58 ↗

(On Diff #81059)

I always prefer set(LIBCXX_TEST_DEPS "") to initialize an empty list. Then list(APPEND LIBCXX_TEST_DEPS cxx_experimental) to add new items.

libcxx/trunk/CMakeLists.txt

 
 # Ensure LIBCXX_ENABLE_MONOTONIC_CLOCK is set to ON only when
 # LIBCXX_ENABLE_THREADS is on.
 if(LIBCXX_ENABLE_THREADS AND NOT LIBCXX_ENABLE_MONOTONIC_CLOCK)
   message(FATAL_ERROR "LIBCXX_ENABLE_MONOTONIC_CLOCK can only be set to OFF"
                       " when LIBCXX_ENABLE_THREADS is also set to OFF.")
 endif()
 
-if(LIBCXX_HAS_PTHREAD_API AND NOT LIBCXX_ENABLE_THREADS)
+if(NOT LIBCXX_ENABLE_THREADS)
+  if(LIBCXX_HAS_PTHREAD_API)
     message(FATAL_ERROR "LIBCXX_HAS_PTHREAD_API can only be set to ON"
                         " when LIBCXX_ENABLE_THREADS is also set to ON.")
   endif()
-
-if(LIBCXX_HAS_EXTERNAL_THREAD_API AND NOT LIBCXX_ENABLE_THREADS)
+  if(LIBCXX_HAS_EXTERNAL_THREAD_API)
     message(FATAL_ERROR "LIBCXX_HAS_EXTERNAL_THREAD_API can only be set to ON"
                         " when LIBCXX_ENABLE_THREADS is also set to ON.")
   endif()
+endif()
+
+if(LIBCXX_HAS_PTHREAD_API AND LIBCXX_HAS_EXTERNAL_THREAD_API)
+  message(FATAL_ERROR "The options LIBCXX_HAS_EXTERNAL_THREAD_API"
+                      "and LIBCXX_HAS_PTHREAD_API cannot be both"
+                      "set to ON at the same time.")
+endif()
 
 # Ensure LLVM_USE_SANITIZER is not specified when LIBCXX_GENERATE_COVERAGE
 # is ON.
 if (LLVM_USE_SANITIZER AND LIBCXX_GENERATE_COVERAGE)
   message(FATAL_ERROR "LLVM_USE_SANITIZER cannot be used with LIBCXX_GENERATE_COVERAGE")
 endif()
 
 # Set LIBCXX_BUILD_32_BITS to (LIBCXX_BUILD_32_BITS OR LLVM_BUILD_32_BITS)

libcxx/trunk/include/__threading_support

 // Mutex
 typedef pthread_mutex_t __libcpp_mutex_t;
 #define _LIBCPP_MUTEX_INITIALIZER PTHREAD_MUTEX_INITIALIZER
 
 // Condition Variable
 typedef pthread_cond_t __libcpp_condvar_t;
 #define _LIBCPP_CONDVAR_INITIALIZER PTHREAD_COND_INITIALIZER
 
-// THread ID
+// Execute once
+typedef pthread_once_t __libcpp_exec_once_flag;
+#define _LIBCPP_EXEC_ONCE_INITIALIZER PTHREAD_ONCE_INIT
+
+// Thread id
 typedef pthread_t __libcpp_thread_id;
 
 // Thread
 typedef pthread_t __libcpp_thread_t;
 
 // Thrad Local Storage
 typedef pthread_key_t __libcpp_tls_key;
 #endif

 
 _LIBCPP_THREAD_ABI_VISIBILITY
 int __libcpp_condvar_timedwait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m,
                                timespec *__ts);
 
 _LIBCPP_THREAD_ABI_VISIBILITY
 int __libcpp_condvar_destroy(__libcpp_condvar_t* __cv);
 
-// Thread ID
+// Execute once
+_LIBCPP_THREAD_ABI_VISIBILITY
+int __libcpp_execute_once(__libcpp_exec_once_flag *flag,
+                          void (*init_routine)(void));
+
+// Thread id
+#if defined(__APPLE__) && !defined(__arm__)
+_LIBCPP_THREAD_ABI_VISIBILITY
+mach_port_t __libcpp_thread_get_port();
+#endif
+
 _LIBCPP_THREAD_ABI_VISIBILITY
 bool __libcpp_thread_id_equal(__libcpp_thread_id t1, __libcpp_thread_id t2);
 
 _LIBCPP_THREAD_ABI_VISIBILITY
 bool __libcpp_thread_id_less(__libcpp_thread_id t1, __libcpp_thread_id t2);
 
 // Thread
 _LIBCPP_THREAD_ABI_VISIBILITY

 // Thread local storage
 _LIBCPP_THREAD_ABI_VISIBILITY
 int __libcpp_tls_create(__libcpp_tls_key *__key, void (*__at_exit)(void *));
 
 _LIBCPP_THREAD_ABI_VISIBILITY
 void *__libcpp_tls_get(__libcpp_tls_key __key);
 
 _LIBCPP_THREAD_ABI_VISIBILITY
-void __libcpp_tls_set(__libcpp_tls_key __key, void *__p);
+int __libcpp_tls_set(__libcpp_tls_key __key, void *__p);
 
 #if defined(_LIBCPP_HAS_THREAD_API_PTHREAD) || \
     defined(_LIBCPP_BUILDING_THREAD_API_EXTERNAL_PTHREAD)
 
 int __libcpp_recursive_mutex_init(__libcpp_mutex_t *__m)
 {
   pthread_mutexattr_t attr;
   int __ec = pthread_mutexattr_init(&attr);
int __libcpp_condvar_timedwait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m,
   return pthread_cond_timedwait(__cv, __m, __ts);
 }
 
 int __libcpp_condvar_destroy(__libcpp_condvar_t *__cv)
 {
   return pthread_cond_destroy(__cv);
 }
 
+// Execute once
+int __libcpp_execute_once(__libcpp_exec_once_flag *flag,
+                          void (*init_routine)(void)) {
+  return pthread_once(flag, init_routine);
+}
+
+// Thread id
+#if defined(__APPLE__) && !defined(__arm__)
+mach_port_t __libcpp_thread_get_port() {
+    return pthread_mach_thread_np(pthread_self());
+}
+#endif
+
 // Returns non-zero if the thread ids are equal, otherwise 0
 bool __libcpp_thread_id_equal(__libcpp_thread_id t1, __libcpp_thread_id t2)
 {
   return pthread_equal(t1, t2) != 0;
 }
 
 // Returns non-zero if t1 < t2, otherwise 0
 bool __libcpp_thread_id_less(__libcpp_thread_id t1, __libcpp_thread_id t2)
int __libcpp_tls_create(__libcpp_tls_key *__key, void (*__at_exit)(void *))
   return pthread_key_create(__key, __at_exit);
 }
 
 void *__libcpp_tls_get(__libcpp_tls_key __key)
 {
   return pthread_getspecific(__key);
 }
 
-void __libcpp_tls_set(__libcpp_tls_key __key, void *__p)
+int __libcpp_tls_set(__libcpp_tls_key __key, void *__p)
 {
-  pthread_setspecific(__key, __p);
+    return pthread_setspecific(__key, __p);
 }
 
 #endif // _LIBCPP_HAS_THREAD_API_PTHREAD
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // !_LIBCPP_HAS_THREAD_API_EXTERNAL || !__libcpp_has_include(<__external_threading>)
 
 #endif // _LIBCPP_HAS_NO_THREADS
 
 #endif // _LIBCPP_THREADING_SUPPORT

libcxx/trunk/test/CMakeLists.txt

 
 set(AUTO_GEN_COMMENT "## Autogenerated by libcxx configuration.\n# Do not edit!")
 
 configure_file(
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
   @ONLY)
 
+set(LIBCXX_TEST_DEPS "")
+
 if (LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY)
-  set(experimental_dep cxx_experimental)
+  set(LIBCXX_TEST_DEPS cxx_experimental)
 endif()
 
 if (LIBCXX_HAS_EXTERNAL_THREAD_API)
-  set(external_threads_dep cxx_external_threads)
+  list(APPEND LIBCXX_TEST_DEPS cxx_external_threads)
 endif()
 
 add_lit_testsuite(check-cxx
   "Running libcxx tests"
   ${CMAKE_CURRENT_BINARY_DIR}
-  DEPENDS cxx ${experimental_dep} ${external_threads_dep})
+  DEPENDS cxx ${LIBCXX_TEST_DEPS})
 
 add_custom_target(check-libcxx DEPENDS check-cxx)
 
 if (LIBCXX_GENERATE_COVERAGE)
   include(CodeCoverage)
   set(output_dir "${CMAKE_CURRENT_BINARY_DIR}/coverage")
   set(capture_dirs "${LIBCXX_LIB_CMAKEFILES_DIR}/cxx.dir/;${LIBCXX_LIB_CMAKEFILES_DIR}/cxx_experimental.dir/;${CMAKE_CURRENT_BINARY_DIR}")
   set(extract_dirs "${LIBCXX_SOURCE_DIR}/include;${LIBCXX_SOURCE_DIR}/src")
   setup_lcov_test_target_coverage("cxx" "${output_dir}" "${capture_dirs}" "${extract_dirs}")
 endif()

libcxx/trunk/test/libcxx/test/config.py

def configure_link_flags_cxx_library(self):
             self.cxx.link_flags += ['-lc++']
         else:
             cxx_library_root = self.get_lit_conf('cxx_library_root')
             if cxx_library_root:
                 abs_path = os.path.join(cxx_library_root, 'libc++.a')
                 self.cxx.link_flags += [abs_path]
             else:
                 self.cxx.link_flags += ['-lc++']
-        # This needs to come after -lc++ as we want its unresolved thread-api symbols
-        # to be picked up from this one.
-        if self.get_lit_bool('libcxx_external_thread_api', default=False):
-            self.cxx.link_flags += ['-lc++external_threads']
 
     def configure_link_flags_abi_library(self):
         cxx_abi = self.get_lit_conf('cxx_abi', 'libcxxabi')
         if cxx_abi == 'libstdc++':
             self.cxx.link_flags += ['-lstdc++']
         elif cxx_abi == 'libsupc++':
             self.cxx.link_flags += ['-lsupc++']
         elif cxx_abi == 'libcxxabi':
def configure_link_flags_abi_library(self):
             self.cxx.link_flags += ['-lcxxrt']
         elif cxx_abi == 'none' or cxx_abi == 'default':
             pass
         else:
             self.lit_config.fatal(
                 'C++ ABI setting %s unsupported for tests' % cxx_abi)
 
     def configure_extra_library_flags(self):
+        if self.get_lit_bool('cxx_ext_threads', default=False):
+            self.cxx.link_flags += ['-lc++external_threads']
         self.target_info.add_cxx_link_flags(self.cxx.link_flags)
 
     def configure_color_diagnostics(self):
         use_color = self.get_lit_conf('color_diagnostics')
         if use_color is None:
             use_color = os.environ.get('LIBCXX_COLOR_DIAGNOSTICS')
         if use_color is None:
             return

libcxx/trunk/test/lit.site.cfg.in

 config.generate_coverage        = "@LIBCXX_GENERATE_COVERAGE@"
 config.target_info              = "@LIBCXX_TARGET_INFO@"
 config.executor                 = "@LIBCXX_EXECUTOR@"
 config.llvm_unwinder            = "@LIBCXXABI_USE_LLVM_UNWINDER@"
 config.has_libatomic            = "@LIBCXX_HAS_ATOMIC_LIB@"
 config.use_libatomic            = "@LIBCXX_HAVE_CXX_ATOMICS_WITH_LIB@"
 
 config.libcxxabi_shared         = "@LIBCXXABI_ENABLE_SHARED@"
-config.libcxx_external_thread_api  = "@LIBCXX_HAS_EXTERNAL_THREAD_API@"
+config.cxx_ext_threads          = "@LIBCXX_HAS_EXTERNAL_THREAD_API@"
 
 # Let the main config do the real work.
 config.loaded_site_config = True
 lit_config.load_config(config, "@LIBCXX_SOURCE_DIR@/test/lit.cfg")