In a testdir created with --with-c++-tests, on FreeBSD 12, I see these errors:
depbase=`echo test-pthread-c++.o | sed 's|[^/]*$|.deps/&|;s|\.o$||'`;\
c++ -DHAVE_CONFIG_H -DEXEEXT=\"\" -I. -I../../gltests -I..
-DGNULIB_STRICT_CHECKING=1 -DIN_GNULIB_TESTS=1 -I. -I../../gltests -I..
-I../../gltests/.. -I../gllib -I../../gltests/../gllib -I/home/bruno/include
-Wall -D_THREAD_SAFE -MT test-pthread-c++.o -MD -MP -MF $depbase.Tpo -c -o
test-pthread-c++.o ../../gltests/test-pthread-c++.cc &&\
mv -f $depbase.Tpo $depbase.Po
In file included from ../../gltests/test-pthread-c++.cc:22:
../gllib/pthread.h:1207:38: error: an attribute list cannot appear here
_GL_CXXALIAS_SYS_CAST (pthread_exit, _Noreturn void, (void *value));
^~~~~~~~~
/usr/include/sys/cdefs.h:280:20: note: expanded from macro '_Noreturn'
#define _Noreturn [[noreturn]]
^~~~~~~~~~~~
../gllib/time.h:267:17: note: expanded from macro '_GL_CXXALIAS_SYS_CAST'
typedef rettype (*type) parameters; \
^~~~~~~
../../gltests/test-pthread-c++.cc:71:50: error: an attribute list cannot appear
here
SIGNATURE_CHECK (GNULIB_NAMESPACE::pthread_exit, _Noreturn void, (void *));
^~~~~~~~~
/usr/include/sys/cdefs.h:280:20: note: expanded from macro '_Noreturn'
#define _Noreturn [[noreturn]]
^~~~~~~~~~~~
../../gltests/signature.h:39:25: note: expanded from macro 'SIGNATURE_CHECK'
SIGNATURE_CHECK1 (fn, ret, args, __LINE__)
^~~
../../gltests/signature.h:44:25: note: expanded from macro 'SIGNATURE_CHECK1'
SIGNATURE_CHECK2 (fn, ret, args, id) /* macroexpand line */
^~~
../../gltests/signature.h:46:10: note: expanded from macro 'SIGNATURE_CHECK2'
static ret (* _GL_UNUSED signature_check ## id) args = fn
^~~
2 errors generated.
gmake[2]: *** [Makefile:9875: test-pthread-c++.o] Error 1
depbase=`echo test-threads-c++.o | sed 's|[^/]*$|.deps/&|;s|\.o$||'`;\
c++ -DHAVE_CONFIG_H -DEXEEXT=\"\" -I. -I../../gltests -I..
-DGNULIB_STRICT_CHECKING=1 -DIN_GNULIB_TESTS=1 -I. -I../../gltests -I..
-I../../gltests/.. -I../gllib -I../../gltests/../gllib -I/home/bruno/include
-Wall -D_THREAD_SAFE -MT test-threads-c++.o -MD -MP -MF $depbase.Tpo -c -o
test-threads-c++.o ../../gltests/test-threads-c++.cc &&\
mv -f $depbase.Tpo $depbase.Po
In file included from ../../gltests/test-threads-c++.cc:22:
../gllib/threads.h:786:35: error: an attribute list cannot appear here
_GL_CXXALIAS_SYS_CAST (thrd_exit, _Noreturn void, (int));
^~~~~~~~~
/usr/include/sys/cdefs.h:280:20: note: expanded from macro '_Noreturn'
#define _Noreturn [[noreturn]]
^~~~~~~~~~~~
../gllib/time.h:267:17: note: expanded from macro '_GL_CXXALIAS_SYS_CAST'
typedef rettype (*type) parameters; \
^~~~~~~
../../gltests/test-threads-c++.cc:37:47: error: an attribute list cannot appear
here
SIGNATURE_CHECK (GNULIB_NAMESPACE::thrd_exit, _Noreturn void, (int));
^~~~~~~~~
/usr/include/sys/cdefs.h:280:20: note: expanded from macro '_Noreturn'
#define _Noreturn [[noreturn]]
^~~~~~~~~~~~
../../gltests/signature.h:39:25: note: expanded from macro 'SIGNATURE_CHECK'
SIGNATURE_CHECK1 (fn, ret, args, __LINE__)
^~~
../../gltests/signature.h:44:25: note: expanded from macro 'SIGNATURE_CHECK1'
SIGNATURE_CHECK2 (fn, ret, args, id) /* macroexpand line */
^~~
../../gltests/signature.h:46:10: note: expanded from macro 'SIGNATURE_CHECK2'
static ret (* _GL_UNUSED signature_check ## id) args = fn
^~~
2 errors generated.
gmake[2]: *** [Makefile:9875: test-threads-c++.o] Error 1
Although gnulib no longer maps '_Noreturn' to '[[noreturn]]', since
<https://lists.gnu.org/archive/html/bug-gnulib/2019-12/msg00013.html>, the
<sys/cdefs.h> file of FreeBSD still does the same thing. While not a universal
fix, the following fixes the issues shown above. It is still necessary to use
_GL_CXXALIAS_SYS_CAST on these two functions, because of AIX.
2019-12-08 Bruno Haible <br...@clisp.org>
Fix compilation errors in C++ mode on FreeBSD.
* lib/pthread.in.h (pthread_exit): Remove _Noreturn from prototype.
* tests/test-pthread-c++.cc (GNULIB_NAMESPACE::pthread_exit): Likewise.
* lib/threads.in.h (thrd_exit): Likewise.
* tests/test-threads-c++.cc (GNULIB_NAMESPACE::thrd_exit): Likewise.
diff --git a/lib/pthread.in.h b/lib/pthread.in.h
index 4ba7e7b..a70d023 100644
--- a/lib/pthread.in.h
+++ b/lib/pthread.in.h
@@ -689,9 +689,8 @@ _GL_CXXALIAS_RPL (pthread_exit, _Noreturn void, (void
*value));
# if !@HAVE_PTHREAD_EXIT@
_GL_FUNCDECL_SYS (pthread_exit, _Noreturn void, (void *value));
# endif
-/* Need to cast, because on AIX with xlclang++, the return type is
- void. */
-_GL_CXXALIAS_SYS_CAST (pthread_exit, _Noreturn void, (void *value));
+/* Need to cast because of AIX with xlclang++. */
+_GL_CXXALIAS_SYS_CAST (pthread_exit, void, (void *value));
# endif
_GL_CXXALIASWARN (pthread_exit);
#elif defined GNULIB_POSIXCHECK
diff --git a/lib/threads.in.h b/lib/threads.in.h
index 3136257..5fcbb09 100644
--- a/lib/threads.in.h
+++ b/lib/threads.in.h
@@ -268,9 +268,8 @@ _GL_WARN_ON_USE (thrd_join, "thrd_join is unportable - "
# if !@HAVE_THREADS_H@
_GL_FUNCDECL_SYS (thrd_exit, _Noreturn void, (int));
# endif
-/* Need to cast, because on AIX with xlclang++, the return type is
- void. */
-_GL_CXXALIAS_SYS_CAST (thrd_exit, _Noreturn void, (int));
+/* Need to cast because of AIX with xlclang++. */
+_GL_CXXALIAS_SYS_CAST (thrd_exit, void, (int));
_GL_CXXALIASWARN (thrd_exit);
#elif defined GNULIB_POSIXCHECK
# undef thrd_exit
diff --git a/tests/test-pthread-c++.cc b/tests/test-pthread-c++.cc
index aa221bc..43f1b97 100644
--- a/tests/test-pthread-c++.cc
+++ b/tests/test-pthread-c++.cc
@@ -68,7 +68,7 @@ SIGNATURE_CHECK (GNULIB_NAMESPACE::pthread_join, int,
(pthread_t, void **));
#endif
#if GNULIB_TEST_PTHREAD_THREAD
-SIGNATURE_CHECK (GNULIB_NAMESPACE::pthread_exit, _Noreturn void, (void *));
+SIGNATURE_CHECK (GNULIB_NAMESPACE::pthread_exit, void, (void *));
#endif
/* =========== Once-only control (initialization) functions =========== */
diff --git a/tests/test-threads-c++.cc b/tests/test-threads-c++.cc
index ae0d865..07da403 100644
--- a/tests/test-threads-c++.cc
+++ b/tests/test-threads-c++.cc
@@ -34,7 +34,7 @@ SIGNATURE_CHECK (GNULIB_NAMESPACE::thrd_sleep, int,
SIGNATURE_CHECK (GNULIB_NAMESPACE::thrd_yield, void, (void));
SIGNATURE_CHECK (GNULIB_NAMESPACE::thrd_detach, int, (thrd_t));
SIGNATURE_CHECK (GNULIB_NAMESPACE::thrd_join, int, (thrd_t, int *));
-SIGNATURE_CHECK (GNULIB_NAMESPACE::thrd_exit, _Noreturn void, (int));
+SIGNATURE_CHECK (GNULIB_NAMESPACE::thrd_exit, void, (int));
#endif
#if GNULIB_TEST_MTX
