2026-01-15  Jakub Jelinek  <jakub@redhat.com>

	* include/std/type_traits (std::is_reflection, std::is_fundamental,
	std::is_reflection_v, std::is_consteval_only): Compare
	__cpp_impl_reflection >= 202506L instead of 202500L.
	* testsuite/20_util/variable_templates_for_traits.cc: Likewise.

2026-01-15  Marek Polacek  <polacek@redhat.com>
	    Jakub Jelinek  <jakub@redhat.com>

	PR c++/120775
	PR c++/123081
	PR c++/122634
	* include/Makefile.am (std_headers): Add ${std_srcdir}/meta.
	* include/Makefile.in: Regenerate.
	* include/bits/iterator_concepts.h (std::ranges::__access::__begin): Add
	constexpr.
	* include/bits/version.def (reflection): New.
	* include/bits/version.h: Regenerate.
	* include/precompiled/stdc++.h: Include <meta> for C++26.
	* include/std/meta: New file.
	* include/std/type_traits (std::is_reflection): New trait.
	(std::is_fundamental): Include is_reflection for C++26 -freflection.
	(std::is_reflection_v): New variable template.
	(std::is_consteval_only): New trait.
	(std::is_consteval_only_v): New variable template.
	* src/c++23/std.cc.in: Add <meta> exports.
	* testsuite/20_util/variable_templates_for_traits.cc: Add -freflection as
	dg-additional-options for C++26.  Add std::is_reflection_v test in that case.
	* testsuite/20_util/is_consteval_only/requirements/explicit_instantiation.cc: New test.
	* testsuite/20_util/is_consteval_only/requirements/typedefs.cc: New test.
	* testsuite/20_util/is_consteval_only/value.cc: New test.
	* testsuite/20_util/is_reflection/requirements/explicit_instantiation.cc: New test.
	* testsuite/20_util/is_reflection/requirements/typedefs.cc: New test.
	* testsuite/20_util/is_reflection/value.cc: New test.

2026-01-14  Tomasz Kamiński  <tkaminsk@redhat.com>

	* testsuite/util/testsuite_iterators.h: Modify comment.

2026-01-13  Tomasz Kamiński  <tkaminsk@redhat.com>

	* include/bits/stl_heap.h (std::__is_heap_until, std::__push_heap)
	(std::__adjust_heap): Replace subscript with dereference of
	advanced iterator.
	* testsuite/util/testsuite_iterators.h (__gnu_test::subscript_proxy)
	(__gnu_test::proxy_random_access_iterator_wrapper): Define.
	* testsuite/25_algorithms/sort_heap/check_proxy_brackets.cc: New test.

2026-01-12  Jakub Jelinek  <jakub@redhat.com>

	* config/abi/pre/gnu.ver (CXXABI_1.3.14): Don't export _ZTI*DF16_ on
	s390x.
	(CXXABI_1.3.17): Export _ZTI*DF16_ on s390x.
	* config/abi/post/s390x-linux-gnu/baseline_symbols.txt: Remove
	_ZTI{,P,K}DF16_.

2026-01-12  Jonathan Wakely  <jwakely@redhat.com>

	* src/c++20/atomic.cc (__detail::__spin_impl): Do not use
	reserved names for variables.

2026-01-12  Jonathan Wakely  <jwakely@redhat.com>

	* include/bits/atomic_wait.h (__wait_args): Improve comments.
	* src/c++20/atomic.cc (__wait_args::_M_setup_proxy_wait):
	Improve comment.

2026-01-12  Tomasz Kamiński  <tkaminsk@redhat.com>

	* testsuite/26_numerics/random/uniform_real_distribution/operators/gencanon.cc:
	Updated test.

2026-01-10  Stefan Schulze Frielinghaus  <stefansf@gcc.gnu.org>

	* config/abi/post/s390x-linux-gnu/baseline_symbols.txt: Add
	names {,P,K}DF16.

2026-01-10  Wang Jinghao  <zheng.xianyuwang@gmail.com>

	* src/c++11/system_error.cc (system_error_category) [_WIN32]:
	Use FormatMessageA function instead of FormatMessage macro.
	* testsuite/19_diagnostics/error_category/system_category.cc:
	Fix typo in __MINGW32__ macro name.  Adjust behavior on the
	mingw32 target.

2026-01-10  Yuao Ma  <c8ef@outlook.com>

	* include/bits/version.def: Add FTM.
	* include/bits/version.h: Regenerate.
	* include/std/flat_map: Add constexpr.
	* testsuite/23_containers/flat_map/1.cc: Add constexpr test.
	* testsuite/23_containers/flat_multimap/1.cc: Add constexpr test.

2026-01-09  Jonathan Wakely  <jwakely@redhat.com>

	* src/c++20/atomic.cc (use_proxy_wait): Remove unused second
	parameter.
	(__wait_args::_M_setup_proxy_wait): Remove second argument.
	(__notify_impl): Likewise.

2026-01-09  Jonathan Wakely  <jwakely@redhat.com>

	* include/bits/atomic_timed_wait.h (__atomic_wait_address_until):
	Use _M_on_wake instead of _M_setup_wait after waking.
	(__atomic_wait_address_for): Likewise.
	* include/bits/atomic_wait.h (__atomic_wait_address): Likewise.
	(__wait_args::_M_setup_wait): Remove third parameter and move
	code to update _M_old to ...
	(__wait_args::_M_on_wake): New member function to update _M_old
	after waking, only calling _M_setup_proxy_wait if needed.
	(__wait_args::_M_store): New member function to update _M_old
	from a value, for non-proxy waits.
	* src/c++20/atomic.cc (__wait_args::_M_setup_proxy_wait): If
	_M_obj is not addr, only load a new value and return true.

2026-01-09  Jonathan Wakely  <jwakely@redhat.com>
	    Tomasz Kamiński  <tkaminsk@redhat.com>

	PR libstdc++/122878
	* include/bits/semaphore_base.h (_M_try_acquire): Replace
	_M_try_acquire_for call with explicit loop and call to
	__atomic_wait_address_for.
	(_M_try_acquire_for): Replace loop with call to
	_M_try_acquire_until.

2026-01-09  Keith Packard  <keithp@keithp.com>

	* acinclude.m4 (GLIBCXX_CONFIGURE): Add --with-picolibc.
	* configure: Regenerate.
	* configure.ac: Add handling for with_picolibc=yes.
	* config/os/picolibc/ctype_base.h: New file.
	* config/os/picolibc/ctype_configure_char.cc: New file.
	* config/os/picolibc/ctype_inline.h: New file.
	* config/os/picolibc/os_defines.h: New file.

2026-01-08  Tomasz Kamiński  <tkaminsk@redhat.com>

	* testsuite/20_util/variant/constinit.cc: Use scan-tree-dump
	for matching of constructor.
	* testsuite/20_util/variant/constinit_compat.cc: Likewise.
	* testsuite/lib/libstdc++.exp: Load scantree.exp and scandump.exp.

2026-01-07  Jonathan Wakely  <jwakely@redhat.com>

	PR libstdc++/123100
	* include/std/sstream (basic_stringbuf::str()&&): Handle the
	case where _M_string is not being used for the buffer.
	* testsuite/27_io/basic_stringbuf/str/char/123100.cc: New test.

2026-01-07  Jonathan Wakely  <jwakely@redhat.com>

	* include/bits/atomic_wait.h (__wait_args::_M_setup_wait):
	Remove unreachable return statement.

2026-01-07  Jonathan Wakely  <jwakely@redhat.com>

	PR libstdc++/123406
	* acinclude.m4 (GLIBCXX_CHECK_STDIO_LOCKING): Override detection
	of flockfile for non-cygwin newlib targets.
	* configure: Regenerate.

2026-01-07  Jonathan Wakely  <jwakely@redhat.com>

	PR libstdc++/123378
	* include/std/barrier (~__tree_barrier_base): Define.

2026-01-07  Jakub Jelinek  <jakub@redhat.com>

	PR libstdc++/123183
	PR libstdc++/123326
	* libsupc++/exception (std::bad_exception::~bad_exception(),
	std::bad_exception::what()): Add inline keyword and
	[[__gnu__::__gnu_inline__]] attribute to the C++26 constexpr
	exceptions definitions.
	* libsupc++/exception.h (std::exception::~exception(),
	std::exception::what()): Likewise.
	* libsupc++/exception_ptr.h (std::exception_ptr::exception_ptr(void*)):
	Likewise.
	* libsupc++/nested_exception.h
	(std::nested_exception::~nested_exception()): Likewise.
	* libsupc++/typeinfo (std::bad_cast::~bad_cast(),
	std::bad_cast::what(), std::bad_typeid::~bad_typeid(),
	std::bad_typeid::what()): Likewise.
	* include/bits/new_except.h (std::bad_alloc::~bad_alloc(),
	std::bad_alloc::what(),
	std::bad_array_new_length::~bad_array_new_length(),
	std::bad_array_new_length::what()): Likewise.
	* include/bits/stdexcept_except.h
	(std::logic_error::logic_error(const string&),
	std::logic_error::logic_error(const char*),
	std::logic_error::~logic_error(), std::logic_error::what(),
	std::domain_error::domain_error(const string&),
	std::domain_error::domain_error(const char*),
	std::invalid_argument::invalid_argument(const string&),
	std::invalid_argument::invalid_argument(const char*),
	std::length_error::length_error(const string&),
	std::length_error::length_error(const char*),
	std::out_of_range::out_of_range(const string&),
	std::out_of_range::out_of_range(const char*),
	std::runtime_error::runtime_error(const string&),
	std::runtime_error::runtime_error(const char*),
	std::runtime_error::~runtime_error(), std::runtime_error::what(),
	std::overflow_error::overflow_error(const string&),
	std::overflow_error::overflow_error(const char*),
	std::overflow_error::~overflow_error(),
	std::underflow_error::underflow_error(const string&),
	std::underflow_error::underflow_error(const char*),
	std::underflow_error::~underflow_error()): Likewise.
	(std::domain_error::~domain_error(),
	std::invalid_argument::~invalid_argument(),
	std::length_error::~length_error(),
	std::out_of_range::~out_of_range()): Likewise.  Also change
	_GLIBCXX_NOTHROW to noexcept on those definitions.


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