This allows inplace_vector to use these functions without including the entire <memory> header. Preprocessor checks are changed to use __glibcxx macros, so new functions are available outside memory header, that exports __cpp_lib macros. PR libstdc++/106658 libstdc++-v3/ChangeLog: * include/bits/stl_construct.h (std::start_lifetime_as_array) (std::start_lifetime_as): Moved from std/memory, with update to guard macros. * include/std/memory (std::start_lifetime_as_array) (std::start_lifetime_as): Moved to bits/stl_construct.h. Reviewed-by: Jonathan Wakely <jwakely@redhat.com> Signed-off-by: Tomasz Kamiński <tkaminsk@redhat.com>
As I can't think of how the middle-end would treat
__builtin_start_lifetime_as other than a blackbox and probably would
need to be implemented as such inline asm in RTL, this patch
just implements it using inline asm in the library.
If not anything else, it can serve as fallback before we and/or clang
get some builtin for it.
Right now the inline asms pretend (potential) read from and write to the whole
memory region and make optimizers forget where the return value points to.
If the optimizers don't know where it points to, I think that should be
good enough, but I'm a little bit afraid of possibly future optimizations
trying to optimize
q->c = 1;
q->d = 2;
auto p = std::start_lifetime_as<S>(q);
if (p == reinterpret_cast<decltype (p)>(q))
return p->a + p->b;
that because of the guarding condition or perhaps assertion we could
simply use the q pointer in MEM_REFs with S type and be surprised by TBAA.
Though if it is a must-alias case, then we should be fine as well.
Though guess that would be the same case with a builtin.
2025-09-18 Jakub Jelinek <jakub@redhat.com>
PR c++/106658
* include/bits/version.def: Implement C++23 P2590R2 - Explicit
lifetime management.
(start_lifetime_as): New.
* include/bits/version.h: Regenerate.
* include/std/memory (std::start_lifetime_as,
std::start_lifetime_as_array): New function templates.
* src/c++23/std.cc.in (std::start_lifetime_as,
std::start_lifetime_as_array): Export.
* testsuite/std/memory/start_lifetime_as/start_lifetime_as.cc: New test.
This commit implements and tests the function is_sufficiently_aligned from P2897R7. PR libstdc++/120994 libstdc++-v3/ChangeLog: * include/bits/align.h (is_sufficiently_aligned): New function. * include/bits/version.def (is_sufficiently_aligned): Add. * include/bits/version.h: Regenerate. * include/std/memory: Add __glibcxx_want_is_sufficiently_aligned. * src/c++23/std.cc.in (is_sufficiently_aligned): Add. * testsuite/20_util/headers/memory/version.cc: Add test for __cpp_lib_is_sufficiently_aligned. * testsuite/20_util/is_sufficiently_aligned/1.cc: New test. Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com> Signed-off-by: Luc Grosheintz <luc.grosheintz@gmail.com>
New structs and member functions added to C++26 by P1901R2. libstdc++-v3/ChangeLog: PR libstdc++/117403 * include/bits/shared_ptr.h (shared_ptr::owner_equal) (shared_ptr::owner_hash, weak_ptr::owner_equal) (weak_ptr::owner_hash): Define new member functions. * include/bits/shared_ptr_base.h (owner_equal, owner_hash): Define new structs. * include/bits/version.def (smart_ptr_owner_equality): Define. * include/bits/version.h: Regenerate. * include/std/memory: Added define for __glibcxx_want_smart_ptr_owner_equality. * testsuite/20_util/owner_equal/version.cc: New test. * testsuite/20_util/owner_equal/cmp.cc: New test. * testsuite/20_util/owner_equal/noexcept.cc: New test. * testsuite/20_util/owner_hash/cmp.cc: New test. * testsuite/20_util/owner_hash/noexcept.cc: New test. * testsuite/20_util/shared_ptr/observers/owner_equal.cc: New test. * testsuite/20_util/shared_ptr/observers/owner_hash.cc: New test. * testsuite/20_util/weak_ptr/observers/owner_equal.cc: New test. * testsuite/20_util/weak_ptr/observers/owner_hash.cc: New test. Signed-off-by: Paul Keir <paul.keir@uws.ac.uk>
This patch implements C++26 std::polymorphic as specified in P3019 with amendment to move assignment from LWG 4251. The implementation always allocate stored object on the heap. The manager function (_M_manager) is similary keep with the object (polymorphic::_Obj), which reduces the size of the polymorphic to size of the single pointer plus allocator (that is declared with [[no_unique_address]]). The implementation does not not use small-object optimization (SSO). We may consider adding this in the future, as SSO is allowed by the standard. However, storing any polimorphic object will require providing space for two pointers (manager function and vtable pointer) and user-declared data members. PR libstdc++/119152 libstdc++-v3/ChangeLog: * include/bits/indirect.h (std::polymorphic, pmr::polymorphic) [__glibcxx_polymorphic]: Define. * include/bits/version.def (polymorphic): Define. * include/bits/version.h: Regenerate. * include/std/memory: Define __cpp_lib_polymorphic. * testsuite/std/memory/polymorphic/copy.cc: New test. * testsuite/std/memory/polymorphic/copy_alloc.cc: New test. * testsuite/std/memory/polymorphic/ctor.cc: New test. * testsuite/std/memory/polymorphic/ctor_poly.cc: New test. * testsuite/std/memory/polymorphic/incomplete.cc: New test. * testsuite/std/memory/polymorphic/invalid_neg.cc: New test. * testsuite/std/memory/polymorphic/move.cc: New test. * testsuite/std/memory/polymorphic/move_alloc.cc: New test. Co-authored-by: Tomasz Kamiński <tkaminsk@redhat.com> Signed-off-by: Tomasz Kamiński <tkaminsk@redhat.com>
This patch implements C++26 std::indirect as specified in P3019 with amendment to move assignment from LWG 4251. PR libstdc++/119152 libstdc++-v3/ChangeLog: * doc/doxygen/stdheader.cc: Added indirect.h file. * include/Makefile.am: Add new header. * include/Makefile.in: Regenerate. * include/bits/indirect.h: New file. * include/bits/version.def (indirect): Define. * include/bits/version.h: Regenerate. * include/std/memory: Include new header. * testsuite/std/memory/indirect/copy.cc * testsuite/std/memory/indirect/copy_alloc.cc * testsuite/std/memory/indirect/ctor.cc * testsuite/std/memory/indirect/incomplete.cc * testsuite/std/memory/indirect/invalid_neg.cc * testsuite/std/memory/indirect/move.cc * testsuite/std/memory/indirect/move_alloc.cc * testsuite/std/memory/indirect/relops.cc Co-authored-by: Tomasz Kamiński <tkaminsk@redhat.com> Signed-off-by: Tomasz Kamiński <tkaminsk@redhat.com>
Per version.syn#2, <memory> is required to define __cpp_lib_addressof_constexpr as 201603L. Bootstrapped and tested on aarch64-linux-gnu. Signed-off-by: Dhruv Chawla <dhruvc@nvidia.com> libstdc++-v3/ChangeLog: * include/std/memory: Define __glibcxx_want_addressof_constexpr. * testsuite/20_util/headers/memory/version.cc: Test for macro value.
In r15-3714-gd3a7302ec5985a I added -Wsystem-headers to the libstdc++ build flags to help catch problems in the library. This patch takes a different approach, of disabling the #pragma system_header unless _GLIBCXX_SYSHDR is defined. As a result, the testsuites will treat them as non-system-headers to get better warning coverage during regression testing of both gcc and libstdc++, not just when building the library. My rationale for the #ifdef instead of just removing the #pragma is the three G++ tests that want to test libstdc++ system header behavior, so we need a way to select it. This doesn't affect installed libraries, as they get their system-header status from the lookup path. But testsuite_flags --build-includes gives -I directives rather than -isystem. This patch doesn't change the headers in config/ because I'm not compiling with most of them, so won't see any warnings that need fixing. Adjusting them could happen later, or we can not bother. libstdc++-v3/ChangeLog: * acinclude.m4 (WARN_FLAGS): Remove -Wsystem-headers. * configure: Regenerate. * include/bits/algorithmfwd.h: #ifdef out #pragma GCC system_header. * include/bits/atomic_base.h * include/bits/atomic_futex.h * include/bits/atomic_timed_wait.h * include/bits/atomic_wait.h * include/bits/basic_ios.h * include/bits/basic_string.h * include/bits/boost_concept_check.h * include/bits/char_traits.h * include/bits/charconv.h * include/bits/chrono.h * include/bits/chrono_io.h * include/bits/codecvt.h * include/bits/concept_check.h * include/bits/cpp_type_traits.h * include/bits/elements_of.h * include/bits/enable_special_members.h * include/bits/erase_if.h * include/bits/forward_list.h * include/bits/functional_hash.h * include/bits/gslice.h * include/bits/gslice_array.h * include/bits/hashtable.h * include/bits/indirect_array.h * include/bits/invoke.h * include/bits/ios_base.h * include/bits/iterator_concepts.h * include/bits/locale_classes.h * include/bits/locale_facets.h * include/bits/locale_facets_nonio.h * include/bits/localefwd.h * include/bits/mask_array.h * include/bits/max_size_type.h * include/bits/memory_resource.h * include/bits/memoryfwd.h * include/bits/move_only_function.h * include/bits/node_handle.h * include/bits/ostream_insert.h * include/bits/out_ptr.h * include/bits/parse_numbers.h * include/bits/postypes.h * include/bits/quoted_string.h * include/bits/range_access.h * include/bits/ranges_base.h * include/bits/refwrap.h * include/bits/sat_arith.h * include/bits/semaphore_base.h * include/bits/slice_array.h * include/bits/std_abs.h * include/bits/std_function.h * include/bits/std_mutex.h * include/bits/std_thread.h * include/bits/stl_iterator_base_funcs.h * include/bits/stl_iterator_base_types.h * include/bits/stl_tree.h * include/bits/stream_iterator.h * include/bits/streambuf_iterator.h * include/bits/stringfwd.h * include/bits/this_thread_sleep.h * include/bits/unique_lock.h * include/bits/uses_allocator_args.h * include/bits/utility.h * include/bits/valarray_after.h * include/bits/valarray_array.h * include/bits/valarray_before.h * include/bits/version.h * include/c_compatibility/fenv.h * include/c_compatibility/inttypes.h * include/c_compatibility/stdint.h * include/decimal/decimal.h * include/experimental/bits/net.h * include/experimental/bits/shared_ptr.h * include/ext/aligned_buffer.h * include/ext/alloc_traits.h * include/ext/atomicity.h * include/ext/concurrence.h * include/ext/numeric_traits.h * include/ext/pod_char_traits.h * include/ext/pointer.h * include/ext/stdio_filebuf.h * include/ext/stdio_sync_filebuf.h * include/ext/string_conversions.h * include/ext/type_traits.h * include/ext/vstring.h * include/ext/vstring_fwd.h * include/ext/vstring_util.h * include/parallel/algorithmfwd.h * include/parallel/numericfwd.h * include/tr1/functional_hash.h * include/tr1/hashtable.h * include/tr1/random.h * libsupc++/exception.h * libsupc++/hash_bytes.h * include/bits/basic_ios.tcc * include/bits/basic_string.tcc * include/bits/fstream.tcc * include/bits/istream.tcc * include/bits/locale_classes.tcc * include/bits/locale_facets.tcc * include/bits/locale_facets_nonio.tcc * include/bits/ostream.tcc * include/bits/sstream.tcc * include/bits/streambuf.tcc * include/bits/string_view.tcc * include/bits/version.tpl * include/experimental/bits/string_view.tcc * include/ext/pb_ds/detail/resize_policy/hash_prime_size_policy_imp.hpp * include/ext/random.tcc * include/ext/vstring.tcc * include/tr2/bool_set.tcc * include/tr2/dynamic_bitset.tcc * include/bits/c++config * include/c/cassert * include/c/cctype * include/c/cerrno * include/c/cfloat * include/c/ciso646 * include/c/climits * include/c/clocale * include/c/cmath * include/c/csetjmp * include/c/csignal * include/c/cstdarg * include/c/cstddef * include/c/cstdio * include/c/cstdlib * include/c/cstring * include/c/ctime * include/c/cuchar * include/c/cwchar * include/c/cwctype * include/c_global/cassert * include/c_global/ccomplex * include/c_global/cctype * include/c_global/cerrno * include/c_global/cfenv * include/c_global/cfloat * include/c_global/cinttypes * include/c_global/ciso646 * include/c_global/climits * include/c_global/clocale * include/c_global/cmath * include/c_global/csetjmp * include/c_global/csignal * include/c_global/cstdalign * include/c_global/cstdarg * include/c_global/cstdbool * include/c_global/cstddef * include/c_global/cstdint * include/c_global/cstdio * include/c_global/cstdlib * include/c_global/cstring * include/c_global/ctgmath * include/c_global/ctime * include/c_global/cuchar * include/c_global/cwchar * include/c_global/cwctype * include/c_std/cassert * include/c_std/cctype * include/c_std/cerrno * include/c_std/cfloat * include/c_std/ciso646 * include/c_std/climits * include/c_std/clocale * include/c_std/cmath * include/c_std/csetjmp * include/c_std/csignal * include/c_std/cstdarg * include/c_std/cstddef * include/c_std/cstdio * include/c_std/cstdlib * include/c_std/cstring * include/c_std/ctime * include/c_std/cuchar * include/c_std/cwchar * include/c_std/cwctype * include/debug/array * include/debug/bitset * include/debug/deque * include/debug/forward_list * include/debug/list * include/debug/map * include/debug/set * include/debug/string * include/debug/unordered_map * include/debug/unordered_set * include/debug/vector * include/decimal/decimal * include/experimental/algorithm * include/experimental/any * include/experimental/array * include/experimental/buffer * include/experimental/chrono * include/experimental/contract * include/experimental/deque * include/experimental/executor * include/experimental/filesystem * include/experimental/forward_list * include/experimental/functional * include/experimental/internet * include/experimental/io_context * include/experimental/iterator * include/experimental/list * include/experimental/map * include/experimental/memory * include/experimental/memory_resource * include/experimental/net * include/experimental/netfwd * include/experimental/numeric * include/experimental/propagate_const * include/experimental/ratio * include/experimental/regex * include/experimental/scope * include/experimental/set * include/experimental/socket * include/experimental/string * include/experimental/string_view * include/experimental/synchronized_value * include/experimental/system_error * include/experimental/timer * include/experimental/tuple * include/experimental/type_traits * include/experimental/unordered_map * include/experimental/unordered_set * include/experimental/vector * include/ext/algorithm * include/ext/cmath * include/ext/functional * include/ext/iterator * include/ext/memory * include/ext/numeric * include/ext/random * include/ext/rb_tree * include/ext/rope * include/parallel/algorithm * include/std/algorithm * include/std/any * include/std/array * include/std/atomic * include/std/barrier * include/std/bit * include/std/bitset * include/std/charconv * include/std/chrono * include/std/codecvt * include/std/complex * include/std/concepts * include/std/condition_variable * include/std/coroutine * include/std/deque * include/std/execution * include/std/expected * include/std/filesystem * include/std/format * include/std/forward_list * include/std/fstream * include/std/functional * include/std/future * include/std/generator * include/std/iomanip * include/std/ios * include/std/iosfwd * include/std/iostream * include/std/istream * include/std/iterator * include/std/latch * include/std/limits * include/std/list * include/std/locale * include/std/map * include/std/memory * include/std/memory_resource * include/std/mutex * include/std/numbers * include/std/numeric * include/std/optional * include/std/ostream * include/std/print * include/std/queue * include/std/random * include/std/ranges * include/std/ratio * include/std/regex * include/std/scoped_allocator * include/std/semaphore * include/std/set * include/std/shared_mutex * include/std/span * include/std/spanstream * include/std/sstream * include/std/stack * include/std/stacktrace * include/std/stdexcept * include/std/streambuf * include/std/string * include/std/string_view * include/std/syncstream * include/std/system_error * include/std/text_encoding * include/std/thread * include/std/tuple * include/std/type_traits * include/std/typeindex * include/std/unordered_map * include/std/unordered_set * include/std/utility * include/std/valarray * include/std/variant * include/std/vector * include/std/version * include/tr1/array * include/tr1/cfenv * include/tr1/cinttypes * include/tr1/cmath * include/tr1/complex * include/tr1/cstdbool * include/tr1/cstdint * include/tr1/cstdio * include/tr1/cstdlib * include/tr1/cwchar * include/tr1/cwctype * include/tr1/functional * include/tr1/memory * include/tr1/random * include/tr1/regex * include/tr1/tuple * include/tr1/type_traits * include/tr1/unordered_map * include/tr1/unordered_set * include/tr1/utility * include/tr2/bool_set * include/tr2/dynamic_bitset * include/tr2/type_traits * libsupc++/atomic_lockfree_defines.h * libsupc++/compare * libsupc++/cxxabi.h * libsupc++/cxxabi_forced.h * libsupc++/cxxabi_init_exception.h * libsupc++/exception * libsupc++/initializer_list * libsupc++/new * libsupc++/typeinfo: Likewise. * testsuite/20_util/ratio/operations/ops_overflow_neg.cc * testsuite/23_containers/array/tuple_interface/get_neg.cc * testsuite/23_containers/vector/cons/destructible_debug_neg.cc * testsuite/24_iterators/operations/prev_neg.cc * testsuite/ext/type_traits/add_unsigned_floating_neg.cc * testsuite/ext/type_traits/add_unsigned_integer_neg.cc * testsuite/ext/type_traits/remove_unsigned_floating_neg.cc * testsuite/ext/type_traits/remove_unsigned_integer_neg.cc: Adjust line numbers. gcc/testsuite/ChangeLog * g++.dg/analyzer/fanalyzer-show-events-in-system-headers-default.C * g++.dg/analyzer/fanalyzer-show-events-in-system-headers-no.C * g++.dg/diagnostic/disable.C: #define _GLIBCXX_SYSHDR.