[Note: do we need entries in config/abi/pre/gnu.ver for these?]
This declares and defines explicit instantiations of std::syncbuf<T>::
__mutex::_S_get_mutex for T=char and T=wchar_t, where the function
is defined at all, the wchar_t case gated on _GLIBCXX_USE_WCHAR_T.
libstdc++-v3/ChangeLog:
* include/std/syncstream: Declare 'extern template syncbuf...'
* src/c++20/syncbuf.cc: Define 'template syncbuf...
* src/c++20/Makefile.am: Mention syncbuf.cc.
* src/c++20/Makefile.in: Regenerate.
---
libstdc++-v3/include/std/syncstream | 11 +++++++-
libstdc++-v3/src/c++20/Makefile.am | 2 +-
libstdc++-v3/src/c++20/Makefile.in | 2 +-
libstdc++-v3/src/c++20/syncbuf.cc | 41 +++++++++++++++++++++++++++++
4 files changed, 53 insertions(+), 3 deletions(-)
create mode 100644 libstdc++-v3/src/c++20/syncbuf.cc
diff --git a/libstdc++-v3/include/std/syncstream
b/libstdc++-v3/include/std/syncstream
index e2b5a199ec9..df07934f3b4 100644
--- a/libstdc++-v3/include/std/syncstream
+++ b/libstdc++-v3/include/std/syncstream
@@ -221,7 +221,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_mtx->unlock();
}
- // FIXME: This should be put in the .so
+ // Specializations on char, wchar_t defined in src/c++20/syncbuf.cc .
static mutex&
_S_get_mutex(void* __t)
{
@@ -243,6 +243,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__mutex _M_mtx;
};
+#if _GLIBCXX_HAS_GTHREADS
+#if _GLIBCXX_EXTERN_TEMPLATE
+ extern template mutex& basic_syncbuf<char>::__mutex::_S_get_mutex(void*);
+#ifdef _GLIBCXX_USE_WCHAR_T
+ extern template mutex& basic_syncbuf<wchar_t>::__mutex::_S_get_mutex(void*);
+#endif
+#endif
+#endif
+
template <typename _CharT, typename _Traits, typename _Alloc>
class basic_osyncstream : public basic_ostream<_CharT, _Traits>
{
diff --git a/libstdc++-v3/src/c++20/Makefile.am
b/libstdc++-v3/src/c++20/Makefile.am
index 736558ff24a..e90a1ad15b3 100644
--- a/libstdc++-v3/src/c++20/Makefile.am
+++ b/libstdc++-v3/src/c++20/Makefile.am
@@ -30,7 +30,7 @@ headers =
if ENABLE_EXTERN_TEMPLATE
# XTEMPLATE_FLAGS = -fno-implicit-templates
inst_sources = \
- sstream-inst.cc
+ sstream-inst.cc syncbuf.cc
else
# XTEMPLATE_FLAGS =
inst_sources =
diff --git a/libstdc++-v3/src/c++20/Makefile.in
b/libstdc++-v3/src/c++20/Makefile.in
index 3cb6d6fea5f..7ead76afa22 100644
--- a/libstdc++-v3/src/c++20/Makefile.in
+++ b/libstdc++-v3/src/c++20/Makefile.in
@@ -430,7 +430,7 @@ headers =
# XTEMPLATE_FLAGS = -fno-implicit-templates
@ENABLE_EXTERN_TEMPLATE_TRUE@inst_sources = \
-@ENABLE_EXTERN_TEMPLATE_TRUE@ sstream-inst.cc
+@ENABLE_EXTERN_TEMPLATE_TRUE@ sstream-inst.cc syncbuf.cc
sources = tzdb.cc format.cc atomic.cc clock.cc
@GLIBCXX_HOSTED_FALSE@libc__20convenience_la_SOURCES =
diff --git a/libstdc++-v3/src/c++20/syncbuf.cc
b/libstdc++-v3/src/c++20/syncbuf.cc
new file mode 100644
index 00000000000..72c7904245b
--- /dev/null
+++ b/libstdc++-v3/src/c++20/syncbuf.cc
@@ -0,0 +1,41 @@
+// Explicit instantiation file.
+
+// Copyright (C) 2020-2025 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+#include <syncstream>
+
+#if _GLIBCXX_USE_CXX11_ABI
+#if _GLIBCXX_HAS_GTHREADS
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+template mutex& basic_syncbuf<char>::__mutex::_S_get_mutex(void* t);
+#ifdef _GLIBCXX_USE_WCHAR_T
+template mutex& basic_syncbuf<wchar_t>::__mutex::_S_get_mutex(void* t);
+#endif
+
+_GLIBCXX_END_NAMESPACE_VERSION
+}
+#endif // GTHREADS
+#endif // ABI
--
2.50.1
