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136 Commits

Author SHA1 Message Date
Matthias Kretz
8be0893fd9 libstdc++: Implement [simd] for C++26 
This implementation differs significantly from the
std::experimental::simd implementation. One goal was a reduction in
template instantiations wrt. what std::experimental::simd did.

Design notes:

- bits/vec_ops.h contains concepts, traits, and functions for working
  with GNU vector builtins that are mostly independent from std::simd.
  These could move from std::simd:: to std::__vec (or similar). However,
  we would then need to revisit naming. For now we kept everything in
  the std::simd namespace with __vec_ prefix in the names. The __vec_*
  functions can be called unqualified because they can never be called
  on user-defined types (no ADL). If we ever get simd<UDT> support this
  will be implemented via bit_cast to/from integral vector
  builtins/intrinsics.

- bits/simd_x86.h extends vec_ops.h with calls to __builtin_ia32_* that
  can only be used after uttering the right GCC target pragma.

- basic_vec and basic_mask are built on top of register-size GNU vector
  builtins (for now / x86). Any larger vec/mask is a tree of power-of-2
  #elements on the "first" branch. Anything non-power-of-2 that is
  smaller than register size uses padding elements that participate in
  element-wise operations. The library ensures that padding elements
  lead to no side effects. The implementation makes no assumption on the
  values of these padding elements since the user can bit_cast to
  basic_vec/basic_mask.

Implementation status:

- The implementation is prepared for more than x86 but is x86-only for
  now.

- Parts of [simd] *not* implemented in this patch:

  - std::complex<floating-point> as vectorizable types
  - [simd.permute.dynamic]
  - [simd.permute.mask]
  - [simd.permute.memory]
  - [simd.bit]
  - [simd.math]
  - mixed operations with vec-mask and bit-mask types
  - some conversion optimizations (open questions wrt. missed
    optimizations in the compiler)

- This patch implements P3844R3 "Restore simd::vec broadcast from int",
  which is not part of the C++26 WD draft yet. If the paper does not get
  accepted the feature will be reverted.

- This patch implements D4042R0 "incorrect cast between simd::vec and
simd::mask via conversion to and from impl-defined vector types" (to be
published once the reported LWG issue gets a number).

- The standard feature test macro __cpp_lib_simd is not defined yet.

Tests:

- Full coverage requires testing
  1. constexpr,
  2. constant-propagating inputs, and
  3. unknown (to the optimizer) inputs
  - for all vectorizable types
  * for every supported width (1–64 and higher)
  + for all possible ISA extensions (combinations)
  = with different fast-math flags
  ... leading to a test matrix that's far out of reach for regular
  testsuite builds.

- The tests in testsuite/std/simd/ try to cover all of the API. The
  tests can be build in every combination listed above. Per default only
  a small subset is built and tested.

- Use GCC_TEST_RUN_EXPENSIVE=something to compile the more expensive
  tests (constexpr and const-prop testing) and to enable more /
  different widths for the test type.

- Tests can still emit bogus -Wpsabi warnings (see PR98734) which are
  filtered out via dg-prune-output.

Benchmarks:

- The current implementation has been benchmarked in some aspects on
  x86_64 hardware. There is more optimization potential. However, it is
  not always clear whether optimizations should be part of the library
  if they can be implemented in the compiler.

- No benchmark code is included in this patch.

libstdc++-v3/ChangeLog:

	* include/Makefile.am: Add simd headers.
	* include/Makefile.in: Regenerate.
	* include/bits/version.def (simd): New.
	* include/bits/version.h: Regenerate.
	* include/bits/simd_alg.h: New file.
	* include/bits/simd_details.h: New file.
	* include/bits/simd_flags.h: New file.
	* include/bits/simd_iterator.h: New file.
	* include/bits/simd_loadstore.h: New file.
	* include/bits/simd_mask.h: New file.
	* include/bits/simd_mask_reductions.h: New file.
	* include/bits/simd_reductions.h: New file.
	* include/bits/simd_vec.h: New file.
	* include/bits/simd_x86.h: New file.
	* include/bits/vec_ops.h: New file.
	* include/std/simd: New file.
	* testsuite/std/simd/arithmetic.cc: New test.
	* testsuite/std/simd/arithmetic_expensive.cc: New test.
	* testsuite/std/simd/create_tests.h: New file.
	* testsuite/std/simd/creation.cc: New test.
	* testsuite/std/simd/creation_expensive.cc: New test.
	* testsuite/std/simd/loads.cc: New test.
	* testsuite/std/simd/loads_expensive.cc: New test.
	* testsuite/std/simd/mask2.cc: New test.
	* testsuite/std/simd/mask2_expensive.cc: New test.
	* testsuite/std/simd/mask.cc: New test.
	* testsuite/std/simd/mask_expensive.cc: New test.
	* testsuite/std/simd/reductions.cc: New test.
	* testsuite/std/simd/reductions_expensive.cc: New test.
	* testsuite/std/simd/shift_left.cc: New test.
	* testsuite/std/simd/shift_left_expensive.cc: New test.
	* testsuite/std/simd/shift_right.cc: New test.
	* testsuite/std/simd/shift_right_expensive.cc: New test.
	* testsuite/std/simd/simd_alg.cc: New test.
	* testsuite/std/simd/simd_alg_expensive.cc: New test.
	* testsuite/std/simd/sse_intrin.cc: New test.
	* testsuite/std/simd/stores.cc: New test.
	* testsuite/std/simd/stores_expensive.cc: New test.
	* testsuite/std/simd/test_setup.h: New file.
	* testsuite/std/simd/traits_common.cc: New test.
	* testsuite/std/simd/traits_impl.cc: New test.
	* testsuite/std/simd/traits_math.cc: New test.

Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
 2026-03-21 12:44:15 +01:00
Nathan Myers
02926c0abb libstdc++: Add allocate_at_least (P0401) [PR118030] 
Implement proposals adopted for C++23:
P0401R6, "Providing size feedback in the Allocator interface"
P2652R2, "Disallow User Specialization of allocator_traits".

This is the minimal conforming implementation, i.e. without the
useful parts. Useful parts, to come in future patches, would
include giving access to any extra storage reserved, and use of
it in vector, string, and other contiguous containers.

libstdc++-v3/ChangeLog:
	PR libstdc++/118030
	* include/bits/alloc_traits.h (allocate_at_least (2x)): Define.
	* include/bits/allocator.h (allocate_at_least): Define.
	* include/std/memory (__glibcxx_want_allocate_at_least): Define.
	* include/bits/memoryfwd.h (allocation_result): Define, #include
	<bits/version.h> first so that will work.
	* include/bits/version.def (allocate_at_least): Add.
	* include/bits/version.h: Regenerate.
	* testsuite/20_util/allocator/allocate_at_least.cc: New test.
	* testsuite/20_util/allocator/allocate_at_least_neg.cc: New test.
 2026-03-10 13:38:23 -04:00
Nathan Myers
94d5ca4583 libstdc++: container heterogeneous insertion (P2363) [PR117402] 
Implements P2353R5 "Extending associative containers with the
remaining heterogeneous overloads". Adds overloads templated on
heterogeneous key types for several members of associative
containers, particularly insertions:

                      /-- unordered --\
 set  map  mset mmap set  map  mset mmap
  @    .    .    .    @    .    .    .    insert
  .    @    .    .    .    @    .    .    op[], at, try_emplace,
                                            insert_or_assign
  .    .    .    .    @    @    @    @    bucket

(Nothing is added to the multiset or multimap tree containers.)
All the insert*() and try_emplace() members also get a hinted
overload.  The at() members get const and non-const overloads.

The new overloads enforce concept __heterogeneous_tree_key or
__heterogeneous_hash_key, as in P2077, to enforce that the
function objects provided meet requirements, and that the key
supplied is not an iterator or the native key. Insertions
implicitly construct the required key_type object from the
argument, by move where permitted.

libstdc++-v3/ChangeLog:
	PR libstdc++/117402
	* include/bits/stl_map.h (operator[], at (2x), try_emplace (2x),
	insert_or_assign (2x)): Add overloads.
	* include/bits/unordered_map.h (operator[], at (2x),
	try_emplace (2x), insert_or_assign (2x), bucket (2x)): Add overloads.
	* include/bits/stl_set.h (insert (2x)): Add overloads.
	* include/bits/unordered_set.h (insert (2x), bucket (2x)): Add overloads.
	* include/bits/hashtable.h (_M_bucket_tr, _M_insert_tr): Define.
	* include/bits/hashtable_policy.h (_M_at_tr (2x)): Define.
	* include/bits/stl_tree.h (_M_emplace_here, _M_get_insert_unique_pos_tr,
	_M_get_insert_hint_unique_pos_tr): Define new heterogeneous insertion
	code path for set and map.
	* include/bits/version.def (associative_heterogeneous_insertion):
	Define.
	* include/bits/version.h: Regenerate.
	* include/std/map (__glibcxx_want_associative_heterogeneous_insertion):
	Define macro.
	* include/std/set: Same.
	* include/std/unordered_map: Same.
	* include/std/unordered_set: Same.
	* testsuite/23_containers/map/modifiers/hetero/insert.cc: New tests.
	* testsuite/23_containers/set/modifiers/hetero/insert.cc: Same.
	* testsuite/23_containers/unordered_map/modifiers/hetero/insert.cc:
	Same.
	* testsuite/23_containers/unordered_multimap/modifiers/hetero/insert.cc:
	Same.
	* testsuite/23_containers/unordered_multiset/modifiers/hetero/insert.cc:
	Same.
	* testsuite/23_containers/unordered_set/modifiers/hetero/insert.cc:
	Same.
 2026-03-04 03:59:15 -05:00
Ivan Lazaric
642020ab7e libstdc++: implement formatter for std::filesystem::path 
This patch implements formatting for std::filesystem::path from P2845R8,
and defines the feature test macro __cpp_lib_format_path to 202403L,
provided only in <filesystem>.

Formatting options are performed (if applicable) in order:
'g', '?', transcoding, fill-and-align & width

The standard specifies transcoding behaviour only when literal encoding
is UTF-8, leaving all other cases implementation defined.
Current implementation of filesystem::path assumes:
* char encoding is UTF-8
* wchar_t encoding is either UTF-32 or UTF-16

libstdc++-v3/ChangeLog:

	* include/bits/fs_path.h: Include bits/formatfwd.h.
	(std::formatter<filesystem::path, _CharT>): Define.
	* include/bits/version.def (format_path): Define.
	* include/bits/version.h: Regenerate.
	* include/std/filesystem: Expose __cpp_lib_format_path.
	* testsuite/std/format/fs_path.cc: New test.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Signed-off-by: Ivan Lazaric <ivan.lazaric1@gmail.com>
Co-authored-by: Jonathan Wakely <jwakely@redhat.com>
 2026-02-16 12:34:18 +01:00
Nathan Myers
3f79055504 libstdc++: container erasure overloads (P2077) [PR117404] 
Remaining to do:
 * Add new declarations in debug headers too.

Implement C++23 P2077R3 "Heterogeneous erasure overloads for
associative containers". Adds template overloads for members
erase and extract to address elements using an alternative key
type, such as string_view for a container of strings, without
need to construct an actual key object.

The new overloads enforce concept __heterogeneous_tree_key or
__heterogeneous_hash_key to verify the function objects provided
meet requirements, and that the key supplied is not an iterator
or the native key.

libstdc++-v3/ChangeLog:
	PR libstdc++/117404
	* include/bits/version.def (associative_heterogeneous_erasure):
	Define.
	* include/bits/version.h: Regenerate.
	* include/std/map: Request new feature from version.h.
	* include/std/set: Same.
	* include/std/unordered_map: Same.
	* include/std/unordered_set: Same.
	* include/bits/stl_map.h (extract, erase): Define overloads.
	* include/bits/stl_set.h: Same.
	* include/bits/stl_multimap.h: Same.
	* include/bits/stl_multiset.h: Same.
	* include/bits/unordered_map.h: Same, 2x.
	* include/bits/unordered_set.h: Same, 2x.
	* include/bits/stl_function.h (concepts __not_container_iterator,
	__heterogeneous_key): Define.
	* include/bits/hashtable.h (_M_find_before_node, _M_locate, extract):
	Delegate to more-general _tr version.
	(_M_find_before_node_tr, _M_locate_tr, _M_extract_tr, _M_erase_tr):
	Add new members to support a heterogeneous key argument.
	(_M_erase_some): Add new helper function.
	(concept __heterogeneous_hash_key): Define.
	* include/bits/stl_tree.h (_M_lower_bound_tr, _M_upper_bound_tr,
	_M_erase_tr, _M_extract_tr): Add new members to support a
	heterogeneous key argument.
	(concept __heterogeneous_tree_key): Define.
	* testsuite/23_containers/map/modifiers/hetero/erase.cc: New test.
	* testsuite/23_containers/multimap/modifiers/hetero/erase.cc: Same.
	* testsuite/23_containers/multiset/modifiers/hetero/erase.cc: Same.
	* testsuite/23_containers/set/modifiers/hetero/erase.cc: Same.
	* testsuite/23_containers/unordered_map/modifiers/hetero/erase.cc: Same.
	* testsuite/23_containers/unordered_multimap/modifiers/hetero/erase.cc:
	Same.
	* testsuite/23_containers/unordered_multiset/modifiers/hetero/erase.cc:
	Same.
	* testsuite/23_containers/unordered_set/modifiers/hetero/erase.cc: Same.
 2026-02-04 17:39:51 -05:00
Jakub Jelinek
4a514ea759 libstdc++: Define __cpp_lib_define_static [PR123921] 
I've totally missed the P3491R3 paper (define_static_{string,object,array})
comes with its own feature test macro - __cpp_lib_define_static 202506
which should appear in <version> and <meta>.
The paper contains 3 parts, std::is_string_literal,
std::meta::reflect_constant_{string,array} and
std::define_static_{string,object,array}.
The first part is implementable without reflection, the third part in theory
would be also implementable without reflection but usually will be (and in
libstdc++ is) implemented using reflection, and the middle part is really
part of reflection.  So dunno how useful this FTM actually is, maybe just
for cases where some implementation does implement reflection and doesn't
implement this paper for a while.

Anyway, the FTM is in C++26 draft, so this patch adds it, with the same
condition as __cpp_lib_reflection.

2026-02-03  Jakub Jelinek  <jakub@redhat.com>

	PR libstdc++/123921
	* include/bits/version.def (define_static): New with the
	same values as reflection.
	* include/bits/version.h: Regenerate.
	* include/std/meta: Define also __glibcxx_want_define_static before
	including bits/version.h.

	* g++.dg/reflect/feat2.C: Add also test for __cpp_lib_define_static.
	* g++.dg/reflect/feat3.C: New test.
 2026-02-03 14:22:46 +01:00
Soumya AR
68a1218c18 libstdc++: Implement std::atomic::fetch_min/max 
This patch extends libstdc++ to implement C++26's atomic fetch min/max
operations.

The __atomic_fetch_minmaxable concept checks if __atomic_fetch_min and
__atomic_fetch_max builtins are implemented by the compiler. If not, fall back
to a CAS loop.

This patch was bootstrapped and regtested on aarch64-linux-gnu and
x86_64-linux-gnu, no regression.

Signed-off-by: Soumya AR <soumyaa@nvidia.com>

libstdc++-v3/ChangeLog:

	* include/bits/atomic_base.h:
	Add fetch_min and fetch_max memberfunctions.
	* include/bits/version.def:
	Add __cpp_lib_atomic_min_max feature test macro.
	* include/bits/version.h (defined): Regenerate.
	* include/std/atomic: Extend for fetch_min/max non-member functions.
	* src/c++23/std.cc.in: Export atomic_fetch_min, atomic_fetch_max,
	atomic_fetch_min_explicit, atomic_fetch_max_explicit.
	* testsuite/29_atomics/atomic_integral/nonmembers_fetch_minmax.cc:
	New test.
	* testsuite/29_atomics/atomic_ref/integral_fetch_minmax.cc: New test.
 2026-01-28 10:57:37 +05:30
Nina Ranns
fbde291af6 libstdc++, contracts: Add base P2900R14 contracts support. 
What we need to do here (and, of course, in the code synthesis
that produces the objects) needs to be interoperable with other
platforms that share ABI.  For the present, this means Itanium
and to interoperate with clang and libc++.

The model we have followed in the development is essentially the
same as the model used for the C++2a edition.  However there is some
concern that the read-only data footprint of this is potentially
high and alternate schemes are in discussion with the clang folks.

Since the layout of the violation object is ABI let's leave this
in experimental until an agreed solution is fixed.

Remove the cxx2a support at the same time, GCC no longer supports
this mode.

libstdc++-v3/ChangeLog:

	* include/Makefile.am: Add contract include.
	* include/Makefile.in: Regenerate.
	* include/bits/version.def: Add ftm for contracts.
	* include/bits/version.h: Regenerate.
	* include/precompiled/stdc++.h: Add contracts header.
	* include/std/source_location: Befriend the contract_violation
	class so that we can initialise a source_location from an
	existing __impl *.
	* src/c++23/std.cc.in: Add contracts support.
	* src/experimental/Makefile.am: Add new contract violation
	implementation, remove the old one.
	* src/experimental/Makefile.in: Regenerate.
	* include/experimental/contract: Removed.
	* src/experimental/contract.cc: Removed.
	* include/std/contracts: New file.
	* src/experimental/contract26.cc: New file.
	* testsuite/18_support/contracts/invoke_default_cvh.cc: New test.
	* testsuite/18_support/contracts/invoke_default_cvh2.cc: New test.

Co-Authored-by: Iain Sandoe <iain@sandoe.co.uk>
Co-Authored-by: Ville Voutilainen <ville.voutilainen@gmail.com>
Signed-off-by: Nina Ranns <dinka.ranns@gmail.com>
 2026-01-28 01:25:12 +00:00
Jakub Jelinek
23cd6f3bcb libstdc++: Disable __cpp_lib_reflection for old CXX ABI 
Reflection currently doesn't work with -D_GLIBCXX_USE_CXX11_ABI=0.
The problem is that std::meta::exception currently uses under the
hood std::string and std::u8string and those aren't constexpr in
the old ABI.
While those members are in the standard exposition-only and so
we could make it to work by writing a custom class template that
just remembers const char{,8_t} * and size_t, there shouldn't be
many people trying to use C++26 features with the ABI that isn't
even compatible with C++11.

2026-01-20  Jakub Jelinek  <jakub@redhat.com>

	* include/bits/version.def (reflection): Add cxx11abi = yes;.
	* include/bits/version.h: Regenerate.
 2026-01-20 12:01:07 +01:00
Marek Polacek
4b0e94b394 c++: C++26 Reflection [PR120775] 
This patch implements C++26 Reflection as specified by P2996R13, which allows
users to perform magic.  This patch also implements related papers:
Annotations for Reflection (P3394R4),
Splicing a base class subobject (P3293R3),
define_static_{string,object,array} (P3491R3),
Function Parameter Reflection (P3096R12).
(I already implemented consteval blocks back in July.)
(We do not yet implement P3795.)

We also implemented some CWG issues that had been approved in Kona;
e.g., CWG 3101, 3109, 3111, 3115, 3117.

All metafunctions are implemented in this patch.

The feature needs to be enabled by -std=c++26 -freflection.

Some stats: the v1 patch was over 51,200 LOC which were written in ~335
commits.  It came with over 400 tests with 11,722 static_asserts.  We still
had about 50 TODOs and FIXMEs in the code.
v2 consists of about 56,000 LOC which were created in 440 commits.  We
now have 446 tests with 40 TODOs remaining.
v3 brought another 77 commits, mostly clean-ups and various bug fixes.

I'd like to thank:
Jakub Jelinek, whose efforts can only be described as heroic and who
never ceases to amaze me even after nearly 15 years of working together,
he implemented many difficult metafunctions, annotations, mangling,
converted our metafunction dispatch to using gperf, and so on and on;
Jonathan Wakely for his libstdc++ patch review and generous & impeccable
advice even at odd hours; Dan Katz for his work on the Reflection papers,
writing Reflection tests for clang++ (many of which I've stolen^Wused),
for his advice, bug reports, and generally cheering me on; Jason Merrill
for his guidance, patch review, and, in fact, encouraging me to take on
this project in the first place; Michael Levine, Valentyn Yukhymenko, and
Alex Yesmanchyk for their nice contributions to Reflection; and Tomasz
Kamiński for providing test cases, finding bugs, and answering my C++
questions.

	PR c++/120775
	PR c++/123081
	PR c++/122634

gcc/ChangeLog:

	* attribs.cc (attribute_value_equal): Return false if either attribute
	is ATTR_UNIQUE_VALUE_P.
	(merge_attributes): Handle lists with ATTR_UNIQUE_VALUE_P values.
	* doc/invoke.texi: Document -freflection.
	* dwarf2out.cc (is_base_type) <case default>: Check
	TREE_CODE >= LAST_AND_UNUSED_TREE_CODE instead of is_cxx_auto.
	(gen_type_die_with_usage): For TREE_CODE >= LAST_AND_UNUSED_TREE_CODE
	trees use use DW_TAG_unspecified_type.
	* tree-core.h (struct tree_base): Update a comment.
	* tree.h (ATTR_UNIQUE_VALUE_P): Define.
	(BINFO_BASE_ACCESSES): Update the comment.

gcc/c-family/ChangeLog:

	* c-attribs.cc (attribute_takes_identifier_p): Return false for C++
	annotations.  Handle "old parm name".
	* c-cppbuiltin.cc (c_cpp_builtins): Define __cpp_impl_reflection.
	* c.opt (freflection): New.

gcc/cp/ChangeLog:

	* Make-lang.in: Add cp/reflect.o.  Add a rule for cp/metafns.h.
	* config-lang.in: Add reflect.cc.
	* constexpr.cc (constexpr_global_ctx): Add consteval_block and
	metafns_called members.  Initialize them.
	(cxx_constexpr_quiet_p): New.
	(cxx_constexpr_manifestly_const_eval): New.
	(cxx_constexpr_caller): New.
	(cxx_constexpr_consteval_block): New.
	(enum value_cat): Move into cp-tree.h.
	(cxx_eval_constant_expression): Move the declaration into cp-tree.h.
	No longer static.  Handle REFLECT_EXPR.  Handle conversion of
	a reflection to the meta::info type.
	(cxx_eval_cxa_builtin_fn): Override current_function_decl.
	(cxx_eval_builtin_function_call): Handle __builtin_is_string_literal.
	(is_std_allocator): Also check __new_allocator.
	(is_std_allocator_allocate): No longer static.
	(cxa_allocate_and_throw_exception): New.
	(cxx_eval_call_expression): Handle metafunctions.  Maybe set
	metafns_called.
	(reduced_constant_expression_p): Handle REFLECT_EXPR.
	(cxx_eval_binary_expression): Use compare_reflections for comparing
	reflections.
	(find_immediate_fndecl): Don't walk REFLECT_EXPR_P.
	(cxx_eval_outermost_constant_expr): Set global_ctx.consteval_block.
	Detect consteval-only smuggling.
	(potential_constant_expression_1): Return true for REFLECT_EXPR
	and SPLICE_EXPR.
	* constraint.cc (diagnose_trait_expr): Add CPTK_IS_CONSTEVAL_ONLY case.
	* cp-gimplify.cc (immediate_escalating_function_p): No longer static.
	(promote_function_to_consteval): Likewise.
	(cp_gimplify_expr) <case CALL_EXPR>: Detect any surviving consteval-only
	expressions.
	<case CP_BUILT_IN_IS_STRING_LITERAL>: Handle.
	(wipe_consteval_only_r): New.
	(cp_fold_immediate_r): Detect invalid uses of consteval-only types.
	Clear consteval-only DECL_EXPRs.
	(cp_genericize_r): Wipe consteval-only vars from BIND_EXPR_VARS and
	BLOCK_VARS.
	* cp-objcp-common.cc (cp_common_init_ts): Mark META_TYPE, SPLICE_SCOPE,
	SPLICE_EXPR, and REFLECT_EXPR.
	* cp-trait.def (IS_CONSTEVAL_ONLY): New trait.
	* cp-tree.def (REFLECT_EXPR, META_TYPE, SPLICE_EXPR, SPLICE_SCOPE): New
	trees.
	* cp-tree.h (enum cp_tree_index): Add CPTI_ANNOTATION_IDENTIFIER,
	CPTI_STD_META, and CPTI_META_INFO_TYPE.
	(std_meta_node): Define.
	(meta_info_type_node): Define.
	(annotation_identifier): Define.
	(REFLECTION_TYPE_P): Define.
	(REFLECT_EXPR_P): Define.
	(REFLECT_EXPR_HANDLE): Define.
	(enum reflect_kind): New.
	(REFLECT_EXPR_KIND): Define.
	(SET_REFLECT_EXPR_KIND): Define.
	(SPLICE_EXPR_EXPRESSION_P): Define.
	(SET_SPLICE_EXPR_EXPRESSION_P): Define.
	(SPLICE_EXPR_MEMBER_ACCESS_P): Define.
	(SET_SPLICE_EXPR_MEMBER_ACCESS_P): Define.
	(SPLICE_EXPR_ADDRESS_P): Define.
	(SET_SPLICE_EXPR_ADDRESS_P): Define.
	(SPLICE_SCOPE_EXPR): Define.
	(SPLICE_SCOPE_TYPE_P): Define.
	(WILDCARD_TYPE_P): Include SPLICE_SCOPE.
	(COMPONENT_REF_SPLICE_P): Define.
	(SCALAR_TYPE_P): Include REFLECTION_TYPE_P.
	(ENUM_BEING_DEFINED_P): Define.
	(OLD_PARM_DECL_P): Define.
	(MULTIPLE_NAMES_PARM_P): Define.
	(cp_preserve_using_decl): Declare.
	(DEF_OPERATOR, DEF_ASSN_OPERATOR): Include META.
	(struct ovl_op_info_t): Add meta_name member.
	(enum cp_built_in_function): Add CP_BUILT_IN_IS_STRING_LITERAL.
	(build_stub_type): Declare.
	(current_function_decl_without_access_scope): Declare.
	(dependent_namespace_p): Declare.
	(convert_reflect_constant_arg): Declare.
	(finish_base_specifier): Adjust declaration.
	(parsing_lambda_declarator): Declare.
	(fold_builtin_is_string_literal): Declare.
	(annotation_p): Declare.
	(finish_class_member_access_expr): Adjust declaration.
	(immediate_escalating_function_p): Declare.
	(promote_function_to_consteval): Declare.
	(is_std_allocator_allocate): Declare.
	(cxa_allocate_and_throw_exception): Declare.
	(enum value_cat): Define.
	(cxx_eval_constant_expression): Declare.
	(cxx_constexpr_quiet_p): Declare.
	(cxx_constexpr_manifestly_const_eval): Declare.
	(cxx_constexpr_caller): Declare.
	(cxx_constexpr_consteval_block): Declare.
	(init_reflection): Declare.
	(metafunction_p): Declare.
	(direct_base_parent): Declare.
	(process_metafunction): Declare.
	(get_reflection): Declare.
	(get_null_reflection): Declare.
	(splice): Declare.
	(check_out_of_consteval_use): Declare.
	(consteval_only_p): Declare.
	(compare_reflections): Declare.
	(valid_splice_type_p): Declare.
	(valid_splice_scope_p): Declare.
	(check_splice_expr): Declare.
	(make_splice_scope): Declare.
	(dependent_splice_p): Declare.
	(reflection_mangle_prefix): Declare.
	(check_consteval_only_fn): Declare.
	* cvt.cc (convert_to_void): Call check_out_of_consteval_use.
	* cxx-pretty-print.cc (cxx_pretty_printer::unary_expression): New
	REFLECT_EXPR case.
	(cxx_pretty_printer::expression): Likewise.
	(cxx_pretty_printer::simple_type_specifier): New META_TYPE case.
	(cxx_pretty_printer::type_id): Likewise.
	* decl.cc (duplicate_decls): Merge parameter names for Reflection.
	Maybe set OLD_PARM_DECL_P.
	(initialize_predefined_identifiers): Add "annotation ".
	(cxx_init_decl_processing): Add __builtin_is_string_literal.  Call
	init_reflection.
	(maybe_commonize_var): Do nothing for consteval_only_p.
	(check_initializer): Default-initialize std::meta::info.
	(make_rtl_for_nonlocal_decl): For consteval_only_p vars, set
	DECL_EXTERNAL and return early.
	(cp_finish_decl): Call check_out_of_consteval_use.  Don't go
	creating a varpool node for consteval_only_p.
	(get_tuple_size): Check the instantiation instead of the type.
	(grokfndecl): Call check_consteval_only_fn.
	(xref_basetypes): Stitch annotations onto BINFO_BASE_ACCESSES.
	(finish_enum_value_list): Clear ENUM_BEING_DEFINED_P.
	* decl2.cc (is_late_template_attribute): Handle all annotations as
	late.
	(cp_check_const_attributes): Don't handle annotations here.
	(maybe_make_one_only): Do nothing for consteval_only_p.
	(mark_needed): Likewise.
	(min_vis_expr_r): Handle reflections.
	(prune_vars_needing_no_initialization): Skip consteval_only_p.
	(no_linkage_error): Return early for metafunctions.
	(c_parse_final_cleanups): Don't write out consteval_only_p vars.  Avoid
	complaining about metafunctions.
	* error.cc (dump_type): New cases for CONST_DECL, META_TYPE, and
	SPLICE_SCOPE.
	(dump_type_prefix): New cases for META_TYPE and SPLICE_SCOPE.
	(dump_type_suffix): Likewise.
	(dump_decl): Dump SPLICE_EXPR.
	(dump_expr): Dump REFLECT_EXPR and SPLICE_EXPR.
	* init.cc (build_zero_init_1): Build a null reflection value.
	(perform_member_init): Call check_out_of_consteval_use.
	* lex.cc (DEF_OPERATOR, OPERATOR_TRANSITION): Update defines.
	* mangle.cc (write_type): Mangle META_TYPE.
	(write_expression): Handle REFLECT_EXPR.
	(write_reflection): New.
	(write_template_arg_literal): New REFLECT_EXPR case.
	(write_template_arg): Handle REFLECT_EXPR.
	* method.cc (build_stub_type): No longer static.
	* module.cc (trees_out::type_node): Handle META_TYPE.
	(trees_in::tree_node): Likewise.
	* name-lookup.cc (name_lookup::adl_type): std::meta is an associated
	namespace of std::meta::info.
	(strip_using_decl): Don't strip when cp_preserve_using_decl.
	(handle_namespace_attrs): Handle annotations.
	(do_namespace_alias): Handle SPLICE_EXPR.
	(lookup_qualified_name): When cp_preserve_using_decl, don't do
	OVL_FUNCTION.
	(finish_using_directive): Detect annotations on using directive.
	* operators.def: Update for META_NAME.
	* parser.cc: New cp_preserve_using_decl global.
	(enum required_token): Add RT_CLOSE_SPLICE.
	(get_required_cpp_ttype): Return CPP_CLOSE_SPLICE for RT_CLOSE_SPLICE.
	(cp_parser_next_tokens_start_splice_type_spec_p): New.
	(cp_parser_next_tokens_can_start_splice_scope_spec_p): New.
	(cp_parser_splice_specifier): New.
	(cp_parser_splice_type_specifier): New.
	(cp_parser_splice_expression): New.
	(cp_parser_splice_scope_specifier): New.
	(cp_parser_splice_spec_is_nns_p): New.
	(cp_parser_nth_token_starts_splice_without_nns_p): New.
	(cp_parser_primary_expression): Handle CPP_OPEN_SPLICE.  Give an
	error for ^^ outside reflection.
	(cp_parser_unqualified_id): Allow r.~typename [:R:].
	(cp_parser_nested_name_specifier_opt): Cope with splice-scope-specifier.
	(cp_parser_qualifying_entity): Parse splice-scope-specifier.
	(cp_parser_postfix_expression): Deal with [: :] after a typename.
	(cp_parser_postfix_dot_deref_expression): Parse & handle splices
	in a class member access.  Pass splice_p to
	finish_class_member_access_expr.
	(cp_parser_reflection_name): New.
	(cp_parser_reflect_expression): New.
	(cp_parser_unary_expression): Parse reflect-expression.
	(cp_parser_declaration): Parse splice-scope-specifier.
	(cp_parser_decomposition_declaration): Detect annotations on structured
	bindings.
	(cp_parser_decltype_expr): Parse splice-expression.
	(cp_parser_template_id): New parsed_templ argument.  If it's nonnull,
	don't parse the template name.  Turn an assert into a condition.
	(cp_parser_type_specifier): Handle typename [: :].
	(cp_parser_simple_type_specifier): Parse splice-type-specifier.
	(cp_parser_enum_specifier): Set ENUM_BEING_DEFINED_P.
	(cp_parser_namespace_alias_definition): Parse splice-specifier.
	(cp_parser_using_directive): Likewise.
	(cp_parser_type_id_1): New bool * parameter to distinguish between
	types and type aliases.  Set it.
	(cp_parser_type_id): Adjust the call to cp_parser_type_id_1.
	(cp_parser_template_type_arg): Likewise.
	(cp_parser_trailing_type_id): Likewise.
	(cp_parser_base_specifier): Handle annotations.  Maybe give an error
	for splice-scope-specifier.  Parse splice-type-specifier.  Pass
	annotations to finish_base_specifier.
	(cp_parser_annotation): New.
	(cp_parser_std_attribute_list): Detect mixing annotations and attributes
	in the same list.
	(cp_parser_annotation_list): New.
	(cp_parser_std_attribute_spec): Parse annotations.
	(cp_parser_skip_balanced_tokens): Also handle CPP_OPEN_SPLICE
	and CPP_CLOSE_SPLICE.
	(cp_parser_type_requirement): Parse splice-type-specifier.
	(cp_parser_lookup_name): Also consider dependent namespaces.  Don't
	call check_accessibility_of_qualified_id for USING_DECLs.
	(cp_parser_required_error): Handle RT_CLOSE_SPLICE.
	* pt.cc (current_function_decl_without_access_scope): New.
	(verify_unstripped_args_1): REFLECT_EXPR_P is OK.
	(iterative_hash_template_arg): Handle REFLECT_EXPR.
	(convert_nontype_argument): Maybe give an error for REFLECTION_TYPE_P.
	(for_each_template_parm_r): Handle SPLICE_SCOPE.
	(instantiate_class_template): Handle annotations.
	(tsubst_pack_index): Make static.
	(tsubst_decl): Handle NAMESPACE_DECL.
	(tsubst_splice_scope): New.
	(tsubst_splice_expr): New.
	(tsubst): Don't return early for NAMESPACE_DECL.   New META_TYPE case.
	Handle a splice-specifier that expanded into a NAMESPACE_DECL.  Handle
	SPLICE_SCOPE, SPLICE_EXPR, and TEMPLATE_ID_EXPR.
	(tsubst_scope): Also accept NAMESPACE_DECL.
	(tsubst_qualified_id): Check dependent_namespace_p.
	(tsubst_lambda_expr): Set LAMBDA_EXPR_CONSTEVAL_BLOCK_P.
	(tsubst_expr): Allow dependent_splice_p in an assert.  Check
	COMPONENT_REF_SPLICE_P and pass it to finish_class_member_access_expr.
	<case NAMESPACE_DECL>: Remove.
	New REFLECT_EXPR and SPLICE_EXPR cases.
	(unify): Handle META_TYPE.
	(instantiate_body): Call check_consteval_only_fn.
	(tsubst_enum): Set ENUM_BEING_DEFINED_P.
	(dependent_type_p_r): A splice-scope-specifier is dependent.
	(dependent_namespace_p): New.
	(value_dependent_expression_p): Handle REFLECT_EXPR.  Also handle
	[meta.reflection.access.context]/8.
	(type_dependent_expression_p): REFLECT_EXPR_P is not type-dependent.
	(convert_reflect_constant_arg): New.
	* search.cc (check_final_overrider): Adjust for CWG 3117.
	* semantics.cc (finish_base_specifier): Handle annotations.
	(parsing_lambda_declarator): No longer static.
	(finish_id_expression_1): Check dependent_namespace_p.
	(fold_builtin_is_string_literal): New.
	(trait_expr_value): Handle CPTK_IS_CONSTEVAL_ONLY.
	(finish_trait_expr): Likewise.
	* tree.cc (handle_annotation_attribute): New.
	(builtin_valid_in_constant_expr_p): Return true for
	CP_BUILT_IN_IS_STRING_LITERAL.
	(cp_tree_equal): Handle comparing REFLECT_EXPRs.
	(internal_attributes): Add "annotation ".
	(annotation_p): New.
	* typeck.cc (finish_class_member_access_expr): New splice_p argument.
	Handle dependent splices.  Implement splicing a base class subobject.
	Handle class member access using a splice-expression.
	(cp_build_binary_op): Handle comparing std::meta::infos.
	(check_return_expr): Call check_out_of_consteval_use.
	* metafns.gperf: New file.
	* metafns.h: New file.
	* reflect.cc: New file.

libcc1/ChangeLog:

	* libcp1plugin.cc (start_class_def): Update the call to
	finish_base_specifier.

libcpp/ChangeLog:

	* charset.cc (_cpp_destroy_iconv): Destroy narrow_cset_desc and
	utf8_cset_desc.
	(cpp_translate_string): New.
	(cpp_valid_identifier): New.
	* include/cpplib.h: Add OPEN_SPLICE, CLOSE_SPLICE, and REFLECT_OP to
	TTYPE_TABLE.
	(cpp_translate_string): Declare.
	(cpp_valid_identifier): Declare.
	* internal.h (struct cpp_reader): Add reverse_narrow_cset_desc and
	reverse_utf8_cset_desc fields.
	* lex.cc (_cpp_lex_direct): Emit CPP_CLOSE_SPLICE, CPP_REFLECT_OP,
	and CPP_OPEN_SPLICE tokens.

libstdc++-v3/ChangeLog:

	* 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.

gcc/testsuite/ChangeLog:

	* g++.dg/DRs/dr2581-1.C: Add -freflection.
	* g++.dg/DRs/dr2581-2.C: Likewise.
	* g++.dg/reflect/access_context1.C: New test.
	* g++.dg/reflect/access_context2.C: New test.
	* g++.dg/reflect/access_context3.C: New test.
	* g++.dg/reflect/adl1.C: New test.
	* g++.dg/reflect/alignment_of1.C: New test.
	* g++.dg/reflect/alignment_of2.C: New test.
	* g++.dg/reflect/annotations1.C: New test.
	* g++.dg/reflect/annotations2.C: New test.
	* g++.dg/reflect/annotations3.C: New test.
	* g++.dg/reflect/annotations4.C: New test.
	* g++.dg/reflect/annotations5.C: New test.
	* g++.dg/reflect/annotations6.C: New test.
	* g++.dg/reflect/annotations7.C: New test.
	* g++.dg/reflect/annotations8.C: New test.
	* g++.dg/reflect/anon1.C: New test.
	* g++.dg/reflect/anon2.C: New test.
	* g++.dg/reflect/anon3.C: New test.
	* g++.dg/reflect/bases_of1.C: New test.
	* g++.dg/reflect/bases_of2.C: New test.
	* g++.dg/reflect/bases_of3.C: New test.
	* g++.dg/reflect/bit_size_of1.C: New test.
	* g++.dg/reflect/bitfield1.C: New test.
	* g++.dg/reflect/can_substitute1.C: New test.
	* g++.dg/reflect/class1.C: New test.
	* g++.dg/reflect/class2.C: New test.
	* g++.dg/reflect/common_reference1.C: New test.
	* g++.dg/reflect/common_type1.C: New test.
	* g++.dg/reflect/compare1.C: New test.
	* g++.dg/reflect/compare10.C: New test.
	* g++.dg/reflect/compare2.C: New test.
	* g++.dg/reflect/compare3.C: New test.
	* g++.dg/reflect/compare4.C: New test.
	* g++.dg/reflect/compare5.C: New test.
	* g++.dg/reflect/compare6.C: New test.
	* g++.dg/reflect/compare7.C: New test.
	* g++.dg/reflect/compare8.C: New test.
	* g++.dg/reflect/compare9.C: New test.
	* g++.dg/reflect/compat1.C: New test.
	* g++.dg/reflect/complete1.C: New test.
	* g++.dg/reflect/constant_of1.C: New test.
	* g++.dg/reflect/constant_of2.C: New test.
	* g++.dg/reflect/constant_of3.C: New test.
	* g++.dg/reflect/constant_of4.C: New test.
	* g++.dg/reflect/constant_of5.C: New test.
	* g++.dg/reflect/constant_of6.C: New test.
	* g++.dg/reflect/constant_of7.C: New test.
	* g++.dg/reflect/constant_of8.C: New test.
	* g++.dg/reflect/constant_of9.C: New test.
	* g++.dg/reflect/crash1.C: New test.
	* g++.dg/reflect/crash10.C: New test.
	* g++.dg/reflect/crash11.C: New test.
	* g++.dg/reflect/crash12.C: New test.
	* g++.dg/reflect/crash13.C: New test.
	* g++.dg/reflect/crash14.C: New test.
	* g++.dg/reflect/crash15.C: New test.
	* g++.dg/reflect/crash16.C: New test.
	* g++.dg/reflect/crash17.C: New test.
	* g++.dg/reflect/crash18.C: New test.
	* g++.dg/reflect/crash2.C: New test.
	* g++.dg/reflect/crash3.C: New test.
	* g++.dg/reflect/crash4.C: New test.
	* g++.dg/reflect/crash5.C: New test.
	* g++.dg/reflect/crash6.C: New test.
	* g++.dg/reflect/crash7.C: New test.
	* g++.dg/reflect/crash8.C: New test.
	* g++.dg/reflect/crash9.C: New test.
	* g++.dg/reflect/data_member_spec1.C: New test.
	* g++.dg/reflect/data_member_spec2.C: New test.
	* g++.dg/reflect/data_member_spec3.C: New test.
	* g++.dg/reflect/data_member_spec4.C: New test.
	* g++.dg/reflect/dealias1.C: New test.
	* g++.dg/reflect/dealias2.C: New test.
	* g++.dg/reflect/dealias3.C: New test.
	* g++.dg/reflect/define_aggregate1.C: New test.
	* g++.dg/reflect/define_aggregate2.C: New test.
	* g++.dg/reflect/define_aggregate3.C: New test.
	* g++.dg/reflect/define_aggregate4.C: New test.
	* g++.dg/reflect/define_aggregate5.C: New test.
	* g++.dg/reflect/define_static_array1.C: New test.
	* g++.dg/reflect/define_static_array2.C: New test.
	* g++.dg/reflect/define_static_array3.C: New test.
	* g++.dg/reflect/define_static_array4.C: New test.
	* g++.dg/reflect/define_static_object1.C: New test.
	* g++.dg/reflect/define_static_object2.C: New test.
	* g++.dg/reflect/define_static_string1.C: New test.
	* g++.dg/reflect/dep1.C: New test.
	* g++.dg/reflect/dep10.C: New test.
	* g++.dg/reflect/dep11.C: New test.
	* g++.dg/reflect/dep2.C: New test.
	* g++.dg/reflect/dep3.C: New test.
	* g++.dg/reflect/dep4.C: New test.
	* g++.dg/reflect/dep5.C: New test.
	* g++.dg/reflect/dep6.C: New test.
	* g++.dg/reflect/dep7.C: New test.
	* g++.dg/reflect/dep8.C: New test.
	* g++.dg/reflect/dep9.C: New test.
	* g++.dg/reflect/diag1.C: New test.
	* g++.dg/reflect/diag2.C: New test.
	* g++.dg/reflect/diag3.C: New test.
	* g++.dg/reflect/diag4.C: New test.
	* g++.dg/reflect/display_string_of1.C: New test.
	* g++.dg/reflect/eh1.C: New test.
	* g++.dg/reflect/eh2.C: New test.
	* g++.dg/reflect/eh3.C: New test.
	* g++.dg/reflect/eh4.C: New test.
	* g++.dg/reflect/eh5.C: New test.
	* g++.dg/reflect/eh6.C: New test.
	* g++.dg/reflect/eh7.C: New test.
	* g++.dg/reflect/eh8.C: New test.
	* g++.dg/reflect/eh9.C: New test.
	* g++.dg/reflect/enumerators_of1.C: New test.
	* g++.dg/reflect/error1.C: New test.
	* g++.dg/reflect/error10.C: New test.
	* g++.dg/reflect/error2.C: New test.
	* g++.dg/reflect/error3.C: New test.
	* g++.dg/reflect/error4.C: New test.
	* g++.dg/reflect/error5.C: New test.
	* g++.dg/reflect/error6.C: New test.
	* g++.dg/reflect/error8.C: New test.
	* g++.dg/reflect/error9.C: New test.
	* g++.dg/reflect/expr1.C: New test.
	* g++.dg/reflect/expr10.C: New test.
	* g++.dg/reflect/expr11.C: New test.
	* g++.dg/reflect/expr12.C: New test.
	* g++.dg/reflect/expr13.C: New test.
	* g++.dg/reflect/expr14.C: New test.
	* g++.dg/reflect/expr2.C: New test.
	* g++.dg/reflect/expr3.C: New test.
	* g++.dg/reflect/expr4.C: New test.
	* g++.dg/reflect/expr5.C: New test.
	* g++.dg/reflect/expr6.C: New test.
	* g++.dg/reflect/expr7.C: New test.
	* g++.dg/reflect/expr8.C: New test.
	* g++.dg/reflect/expr9.C: New test.
	* g++.dg/reflect/extract1.C: New test.
	* g++.dg/reflect/extract2.C: New test.
	* g++.dg/reflect/extract3.C: New test.
	* g++.dg/reflect/extract4.C: New test.
	* g++.dg/reflect/extract5.C: New test.
	* g++.dg/reflect/extract6.C: New test.
	* g++.dg/reflect/extract7.C: New test.
	* g++.dg/reflect/extract8.C: New test.
	* g++.dg/reflect/extract9.C: New test.
	* g++.dg/reflect/feat1.C: New test.
	* g++.dg/reflect/feat2.C: New test.
	* g++.dg/reflect/has_c_language_linkage1.C: New test.
	* g++.dg/reflect/has_default_argument1.C: New test.
	* g++.dg/reflect/has_default_argument2.C: New test.
	* g++.dg/reflect/has_default_member_initializer1.C: New test.
	* g++.dg/reflect/has_ellipsis_parameter1.C: New test.
	* g++.dg/reflect/has_external_linkage1.C: New test.
	* g++.dg/reflect/has_external_linkage2.C: New test.
	* g++.dg/reflect/has_identifier1.C: New test.
	* g++.dg/reflect/has_identifier2.C: New test.
	* g++.dg/reflect/has_internal_linkage1.C: New test.
	* g++.dg/reflect/has_internal_linkage2.C: New test.
	* g++.dg/reflect/has_linkage1.C: New test.
	* g++.dg/reflect/has_module_linkage1.C: New test.
	* g++.dg/reflect/has_module_linkage2.C: New test.
	* g++.dg/reflect/has_parent1.C: New test.
	* g++.dg/reflect/has_template_arguments1.C: New test.
	* g++.dg/reflect/has_template_arguments2.C: New test.
	* g++.dg/reflect/has_template_arguments3.C: New test.
	* g++.dg/reflect/has_template_arguments4.C: New test.
	* g++.dg/reflect/identifier_of1.C: New test.
	* g++.dg/reflect/identifier_of2.C: New test.
	* g++.dg/reflect/init1.C: New test.
	* g++.dg/reflect/init10.C: New test.
	* g++.dg/reflect/init11.C: New test.
	* g++.dg/reflect/init12.C: New test.
	* g++.dg/reflect/init13.C: New test.
	* g++.dg/reflect/init14.C: New test.
	* g++.dg/reflect/init15.C: New test.
	* g++.dg/reflect/init16.C: New test.
	* g++.dg/reflect/init17.C: New test.
	* g++.dg/reflect/init2.C: New test.
	* g++.dg/reflect/init3.C: New test.
	* g++.dg/reflect/init4.C: New test.
	* g++.dg/reflect/init5.C: New test.
	* g++.dg/reflect/init6.C: New test.
	* g++.dg/reflect/init7.C: New test.
	* g++.dg/reflect/init8.C: New test.
	* g++.dg/reflect/init9.C: New test.
	* g++.dg/reflect/is_accessible1.C: New test.
	* g++.dg/reflect/is_accessible2.C: New test.
	* g++.dg/reflect/is_alias_template1.C: New test.
	* g++.dg/reflect/is_assignment1.C: New test.
	* g++.dg/reflect/is_bit_field1.C: New test.
	* g++.dg/reflect/is_class_member1.C: New test.
	* g++.dg/reflect/is_class_template1.C: New test.
	* g++.dg/reflect/is_complete_type1.C: New test.
	* g++.dg/reflect/is_complete_type2.C: New test.
	* g++.dg/reflect/is_concept1.C: New test.
	* g++.dg/reflect/is_const1.C: New test.
	* g++.dg/reflect/is_consteval_only1.C: New test.
	* g++.dg/reflect/is_constructible_type1.C: New test.
	* g++.dg/reflect/is_constructible_type2.C: New test.
	* g++.dg/reflect/is_constructor_template1.C: New test.
	* g++.dg/reflect/is_constuctor1.C: New test.
	* g++.dg/reflect/is_conversion_function1.C: New test.
	* g++.dg/reflect/is_conversion_function_template1.C: New test.
	* g++.dg/reflect/is_copy_assignment1.C: New test.
	* g++.dg/reflect/is_copy_constructor1.C: New test.
	* g++.dg/reflect/is_data_member_spec1.C: New test.
	* g++.dg/reflect/is_default_constructor1.C: New test.
	* g++.dg/reflect/is_defaulted1.C: New test.
	* g++.dg/reflect/is_defaulted2.C: New test.
	* g++.dg/reflect/is_deleted1.C: New test.
	* g++.dg/reflect/is_deleted2.C: New test.
	* g++.dg/reflect/is_destructor1.C: New test.
	* g++.dg/reflect/is_enumerable_type1.C: New test.
	* g++.dg/reflect/is_enumerator1.C: New test.
	* g++.dg/reflect/is_explicit1.C: New test.
	* g++.dg/reflect/is_explicit2.C: New test.
	* g++.dg/reflect/is_explicit_object_parameter1.C: New test.
	* g++.dg/reflect/is_final1.C: New test.
	* g++.dg/reflect/is_function1.C: New test.
	* g++.dg/reflect/is_function2.C: New test.
	* g++.dg/reflect/is_function3.C: New test.
	* g++.dg/reflect/is_function_parameter1.C: New test.
	* g++.dg/reflect/is_function_parameter2.C: New test.
	* g++.dg/reflect/is_function_template1.C: New test.
	* g++.dg/reflect/is_function_template2.C: New test.
	* g++.dg/reflect/is_function_type1.C: New test.
	* g++.dg/reflect/is_literal_operator1.C: New test.
	* g++.dg/reflect/is_literal_operator_template1.C: New test.
	* g++.dg/reflect/is_lrvalue_reference_qualified1.C: New test.
	* g++.dg/reflect/is_move_assignment1.C: New test.
	* g++.dg/reflect/is_move_constructor1.C: New test.
	* g++.dg/reflect/is_mutable_member1.C: New test.
	* g++.dg/reflect/is_namespace1.C: New test.
	* g++.dg/reflect/is_namespace_alias1.C: New test.
	* g++.dg/reflect/is_namespace_member1.C: New test.
	* g++.dg/reflect/is_noexcept1.C: New test.
	* g++.dg/reflect/is_noexcept2.C: New test.
	* g++.dg/reflect/is_noexcept3.C: New test.
	* g++.dg/reflect/is_noexcept4.C: New test.
	* g++.dg/reflect/is_nonstatic_data_member1.C: New test.
	* g++.dg/reflect/is_object1.C: New test.
	* g++.dg/reflect/is_object2.C: New test.
	* g++.dg/reflect/is_operator_function1.C: New test.
	* g++.dg/reflect/is_operator_function_template1.C: New test.
	* g++.dg/reflect/is_override1.C: New test.
	* g++.dg/reflect/is_pure_virtual1.C: New test.
	* g++.dg/reflect/is_special_member_function1.C: New test.
	* g++.dg/reflect/is_static_member1.C: New test.
	* g++.dg/reflect/is_string_literal1.C: New test.
	* g++.dg/reflect/is_structured_binding1.C: New test.
	* g++.dg/reflect/is_structured_binding2.C: New test.
	* g++.dg/reflect/is_template1.C: New test.
	* g++.dg/reflect/is_template2.C: New test.
	* g++.dg/reflect/is_type1.C: New test.
	* g++.dg/reflect/is_type_alias1.C: New test.
	* g++.dg/reflect/is_type_alias2.C: New test.
	* g++.dg/reflect/is_type_alias3.C: New test.
	* g++.dg/reflect/is_user_declared1.C: New test.
	* g++.dg/reflect/is_user_declared2.C: New test.
	* g++.dg/reflect/is_user_provided1.C: New test.
	* g++.dg/reflect/is_user_provided2.C: New test.
	* g++.dg/reflect/is_variable1.C: New test.
	* g++.dg/reflect/is_variable_template1.C: New test.
	* g++.dg/reflect/is_virtual1.C: New test.
	* g++.dg/reflect/is_volatile1.C: New test.
	* g++.dg/reflect/lex1.C: New test.
	* g++.dg/reflect/lex2.C: New test.
	* g++.dg/reflect/mangle1.C: New test.
	* g++.dg/reflect/member-visibility1.C: New test.
	* g++.dg/reflect/member-visibility2.C: New test.
	* g++.dg/reflect/member1.C: New test.
	* g++.dg/reflect/member10.C: New test.
	* g++.dg/reflect/member11.C: New test.
	* g++.dg/reflect/member12.C: New test.
	* g++.dg/reflect/member13.C: New test.
	* g++.dg/reflect/member14.C: New test.
	* g++.dg/reflect/member15.C: New test.
	* g++.dg/reflect/member16.C: New test.
	* g++.dg/reflect/member17.C: New test.
	* g++.dg/reflect/member18.C: New test.
	* g++.dg/reflect/member19.C: New test.
	* g++.dg/reflect/member2.C: New test.
	* g++.dg/reflect/member20.C: New test.
	* g++.dg/reflect/member3.C: New test.
	* g++.dg/reflect/member4.C: New test.
	* g++.dg/reflect/member5.C: New test.
	* g++.dg/reflect/member6.C: New test.
	* g++.dg/reflect/member7.C: New test.
	* g++.dg/reflect/member8.C: New test.
	* g++.dg/reflect/member9.C: New test.
	* g++.dg/reflect/members_of1.C: New test.
	* g++.dg/reflect/members_of2.C: New test.
	* g++.dg/reflect/members_of3.C: New test.
	* g++.dg/reflect/members_of4.C: New test.
	* g++.dg/reflect/members_of5.C: New test.
	* g++.dg/reflect/members_of6.C: New test.
	* g++.dg/reflect/members_of7.C: New test.
	* g++.dg/reflect/metafn-ptr1.C: New test.
	* g++.dg/reflect/ns1.C: New test.
	* g++.dg/reflect/ns2.C: New test.
	* g++.dg/reflect/ns3.C: New test.
	* g++.dg/reflect/ns4.C: New test.
	* g++.dg/reflect/ns5.C: New test.
	* g++.dg/reflect/ns6.C: New test.
	* g++.dg/reflect/null1.C: New test.
	* g++.dg/reflect/null2.C: New test.
	* g++.dg/reflect/null3.C: New test.
	* g++.dg/reflect/null4.C: New test.
	* g++.dg/reflect/null5.C: New test.
	* g++.dg/reflect/object_of1.C: New test.
	* g++.dg/reflect/object_of2.C: New test.
	* g++.dg/reflect/odr1.C: New test.
	* g++.dg/reflect/offset_of1.C: New test.
	* g++.dg/reflect/operator_of1.C: New test.
	* g++.dg/reflect/override1.C: New test.
	* g++.dg/reflect/p2996-1.C: New test.
	* g++.dg/reflect/p2996-10.C: New test.
	* g++.dg/reflect/p2996-11.C: New test.
	* g++.dg/reflect/p2996-12.C: New test.
	* g++.dg/reflect/p2996-13.C: New test.
	* g++.dg/reflect/p2996-14.C: New test.
	* g++.dg/reflect/p2996-15.C: New test.
	* g++.dg/reflect/p2996-16.C: New test.
	* g++.dg/reflect/p2996-17.C: New test.
	* g++.dg/reflect/p2996-18.C: New test.
	* g++.dg/reflect/p2996-19.C: New test.
	* g++.dg/reflect/p2996-2.C: New test.
	* g++.dg/reflect/p2996-20.C: New test.
	* g++.dg/reflect/p2996-21.C: New test.
	* g++.dg/reflect/p2996-3.C: New test.
	* g++.dg/reflect/p2996-4.C: New test.
	* g++.dg/reflect/p2996-5.C: New test.
	* g++.dg/reflect/p2996-6.C: New test.
	* g++.dg/reflect/p2996-7.C: New test.
	* g++.dg/reflect/p2996-8.C: New test.
	* g++.dg/reflect/p2996-9.C: New test.
	* g++.dg/reflect/p3394-1.C: New test.
	* g++.dg/reflect/p3491-1.C: New test.
	* g++.dg/reflect/p3491-2.C: New test.
	* g++.dg/reflect/p3491-3.C: New test.
	* g++.dg/reflect/pack-index1.C: New test.
	* g++.dg/reflect/parameters_of1.C: New test.
	* g++.dg/reflect/parameters_of2.C: New test.
	* g++.dg/reflect/parameters_of3.C: New test.
	* g++.dg/reflect/parameters_of4.C: New test.
	* g++.dg/reflect/parameters_of5.C: New test.
	* g++.dg/reflect/parameters_of6.C: New test.
	* g++.dg/reflect/parent_of1.C: New test.
	* g++.dg/reflect/parm1.C: New test.
	* g++.dg/reflect/parm2.C: New test.
	* g++.dg/reflect/parm3.C: New test.
	* g++.dg/reflect/parm4.C: New test.
	* g++.dg/reflect/pr122634-1.C: New test.
	* g++.dg/reflect/pr122634-2.C: New test.
	* g++.dg/reflect/qrn1.C: New test.
	* g++.dg/reflect/qrn2.C: New test.
	* g++.dg/reflect/range_args.C: New test.
	* g++.dg/reflect/reflect_constant1.C: New test.
	* g++.dg/reflect/reflect_constant2.C: New test.
	* g++.dg/reflect/reflect_constant3.C: New test.
	* g++.dg/reflect/reflect_constant4.C: New test.
	* g++.dg/reflect/reflect_constant5.C: New test.
	* g++.dg/reflect/reflect_constant6.C: New test.
	* g++.dg/reflect/reflect_constant7.C: New test.
	* g++.dg/reflect/reflect_constant8.C: New test.
	* g++.dg/reflect/reflect_constant9.C: New test.
	* g++.dg/reflect/reflect_constant_array1.C: New test.
	* g++.dg/reflect/reflect_constant_array2.C: New test.
	* g++.dg/reflect/reflect_constant_array3.C: New test.
	* g++.dg/reflect/reflect_constant_array4.C: New test.
	* g++.dg/reflect/reflect_constant_string1.C: New test.
	* g++.dg/reflect/reflect_constant_string2.C: New test.
	* g++.dg/reflect/reflect_function1.C: New test.
	* g++.dg/reflect/reflect_function2.C: New test.
	* g++.dg/reflect/reflect_object1.C: New test.
	* g++.dg/reflect/reflect_object2.C: New test.
	* g++.dg/reflect/reflect_object3.C: New test.
	* g++.dg/reflect/reflect_object4.C: New test.
	* g++.dg/reflect/return_type_of1.C: New test.
	* g++.dg/reflect/return_type_of2.C: New test.
	* g++.dg/reflect/serialize1.C: New test.
	* g++.dg/reflect/serialize2.C: New test.
	* g++.dg/reflect/size_of1.C: New test.
	* g++.dg/reflect/source_location_of1.C: New test.
	* g++.dg/reflect/source_location_of2.C: New test.
	* g++.dg/reflect/splice1.C: New test.
	* g++.dg/reflect/splice2.C: New test.
	* g++.dg/reflect/splice3.C: New test.
	* g++.dg/reflect/splice4.C: New test.
	* g++.dg/reflect/splice5.C: New test.
	* g++.dg/reflect/splice6.C: New test.
	* g++.dg/reflect/splice7.C: New test.
	* g++.dg/reflect/splicing-base1.C: New test.
	* g++.dg/reflect/splicing-base2.C: New test.
	* g++.dg/reflect/splicing-base3.C: New test.
	* g++.dg/reflect/splicing-base4.C: New test.
	* g++.dg/reflect/storage_duration1.C: New test.
	* g++.dg/reflect/storage_duration2.C: New test.
	* g++.dg/reflect/storage_duration3.C: New test.
	* g++.dg/reflect/subobjects_of1.C: New test.
	* g++.dg/reflect/substitute1.C: New test.
	* g++.dg/reflect/substitute2.C: New test.
	* g++.dg/reflect/symbol_of1.C: New test.
	* g++.dg/reflect/symbol_of2.C: New test.
	* g++.dg/reflect/template_arguments_of1.C: New test.
	* g++.dg/reflect/template_arguments_of2.C: New test.
	* g++.dg/reflect/template_arguments_of3.C: New test.
	* g++.dg/reflect/template_of1.C: New test.
	* g++.dg/reflect/template_of2.C: New test.
	* g++.dg/reflect/template_of3.C: New test.
	* g++.dg/reflect/tuple1.C: New test.
	* g++.dg/reflect/tuple2.C: New test.
	* g++.dg/reflect/type1.C: New test.
	* g++.dg/reflect/type10.C: New test.
	* g++.dg/reflect/type2.C: New test.
	* g++.dg/reflect/type3.C: New test.
	* g++.dg/reflect/type4.C: New test.
	* g++.dg/reflect/type5.C: New test.
	* g++.dg/reflect/type6.C: New test.
	* g++.dg/reflect/type7.C: New test.
	* g++.dg/reflect/type8.C: New test.
	* g++.dg/reflect/type9.C: New test.
	* g++.dg/reflect/type_of1.C: New test.
	* g++.dg/reflect/type_of2.C: New test.
	* g++.dg/reflect/type_rels1.C: New test.
	* g++.dg/reflect/type_trait1.C: New test.
	* g++.dg/reflect/type_trait10.C: New test.
	* g++.dg/reflect/type_trait11.C: New test.
	* g++.dg/reflect/type_trait12.C: New test.
	* g++.dg/reflect/type_trait13.C: New test.
	* g++.dg/reflect/type_trait2.C: New test.
	* g++.dg/reflect/type_trait3.C: New test.
	* g++.dg/reflect/type_trait4.C: New test.
	* g++.dg/reflect/type_trait5.C: New test.
	* g++.dg/reflect/type_trait6.C: New test.
	* g++.dg/reflect/type_trait8.C: New test.
	* g++.dg/reflect/type_trait9.C: New test.
	* g++.dg/reflect/u8display_string_of1.C: New test.
	* g++.dg/reflect/u8identifier_of1.C: New test.
	* g++.dg/reflect/u8symbol_of1.C: New test.
	* g++.dg/reflect/underlying_type1.C: New test.
	* g++.dg/reflect/using1.C: New test.
	* g++.dg/reflect/value_or_object1.C: New test.
	* g++.dg/reflect/variable_of1.C: New test.
	* g++.dg/reflect/variable_of2.C: New test.
	* g++.dg/reflect/variable_of3.C: New test.
	* g++.dg/reflect/variant1.C: New test.
	* g++.dg/reflect/variant2.C: New test.
	* g++.dg/reflect/vector1.C: New test.
	* g++.dg/reflect/visibility1.C: New test.

Co-authored-by: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Valentyn Yukhymenko <vyuhimenko@bloomberg.net>
Signed-off-by: Alex Yesmanchyk <ayesmanchyk@bloomberg.net>
Signed-off-by: Michael Levine <mlevine55@bloomberg.net>
Reviewed-by: Jason Merrill <jason@redhat.com>
 2026-01-15 10:17:43 -05:00
Yuao Ma
2226b67bbe libstdc++: constexpr flat_map and flat_multimap 
This patch makes flat_map and flat_multimap constexpr as part of P3372R3.

libstdc++-v3/ChangeLog:

	* 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.
 2026-01-10 15:08:53 +08:00
Jakub Jelinek
254a858ae7 Update copyright years. 2026-01-02 09:56:11 +01:00
Jonathan Wakely
278eb0a081 libstdc++: Make __cpp_lib_constexpr_exceptions depend on cxx11 ABI 
The COW std::string is not constexpr, so the <stdexcept> exception
classes can't be constexpr either when they're defined in terms of the
COW string.

While constexpr exceptions for <typeinfo>, <new>, and <exception>
classes would work, __cpp_constexpr_exceptions >= 202411L implies that
everything including <stdexcept> should work. So when we can't support
it fully, we shouldn't announce it.

libstdc++-v3/ChangeLog:

	* include/bits/version.def (constexpr_exceptions): Add
	cxx11abi=yes.
	* include/bits/version.h: Regenerate.
	* testsuite/18_support/exception/version.cc: Require effectiove
	target cxx11_abi.
	* testsuite/18_support/exception_ptr/exception_ptr_cast.cc: Only
	check for constexpr support in cxx11 ABI.
	* testsuite/19_diagnostics/headers/stdexcept/version.cc: Require
	effective target cxx11_abi.
	* testsuite/19_diagnostics/logic_error/constexpr.cc: Likewise.
	* testsuite/19_diagnostics/runtime_error/constexpr.cc: Likewise.
	* testsuite/20_util/expected/version.cc: Only check for
	__cpp_lib_constexpr_exceptions macro for cxx11 ABI.
	* testsuite/20_util/optional/version.cc: Likewise.
	* testsuite/20_util/variant/version.cc: Likewise.

Reviewed-by: Jakub Jelinek <jakub@redhat.com>
 2025-12-17 21:28:57 +00:00
Jonathan Wakely
12084561db libstdc++: Implement std::philox_engine for targets without __int128 
This moves the __detail::_Select_uint_least_t<N>::type class to
namespace scope and extends it with more 128-bit arithmetic operations,
implemented in terms of uint64_t.

Now std::philox_engine can use _Select_uint_least_t<w*2>::type instead
of __uint128_t, so that it works on targets without 128-bit integers.
This also means that targets that do support __uint128_t only use it
when actually necessary, so that we use uint64_t when generating a
32-bit result (e.g. with std::philox4x32).

libstdc++-v3/ChangeLog:

	* include/bits/random.h [!__SIZEOF_INT128__] (__rand_uint128):
	Refactor and rename _Select_uint_least_t<128>::type to a new
	class. Make all members constexpr. Add new member functions for
	additional arithmetic and bitwise operations, and comparisons.
	(__detail::_Select_uint_least_t<>::type): Define as an alias of
	__rand_uint128.
	* include/bits/random.tcc (philox_engine::_M_mulhi): Use
	_Select_uint_least_t<w*2>::type instead of __uint128_t.
	(philox_engine::_M_transition): Likewise.
	* include/bits/version.def (philox_engine): Remove extra_cond.
	* include/bits/version.h: Regenerate.
	* testsuite/26_numerics/random/philox4x32.cc: Remove
	dg-require-cpp-feature-test directive.
	* testsuite/26_numerics/random/philox4x64.cc: Likewise.
	* testsuite/26_numerics/random/philox_engine/cons/copy.cc:
	Likewise.
	* testsuite/26_numerics/random/philox_engine/cons/default.cc:
	Likewise.
	* testsuite/26_numerics/random/philox_engine/cons/seed.cc:
	Likewise.
	* testsuite/26_numerics/random/philox_engine/operators/equal.cc:
	Likewise.
	* testsuite/26_numerics/random/philox_engine/operators/serialize.cc:
	Likewise.
	* testsuite/26_numerics/random/philox_engine/requirements/constants.cc:
	Likewise.
	* testsuite/26_numerics/random/philox_engine/requirements/typedefs.cc:
	Likewise.

Co-authored-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
 2025-12-17 20:41:31 +00:00
Patrick Palka
1d29b68562 libstdc++: Implement P2408R5 C++20 iterators as inputs to STL algos 
From the paper's abstract:

  Change the iterator requirements for non-Ranges algorithms. For
  forward iterators and above that are constant iterators, instead of
  requiring that iterators meet certain Cpp17...Iterator requirements,
  require that the iterators model certain iterator concepts. This makes
  iterators from several standard views usable with non-Ranges
  algorithms that require forward iterators or above, such as the
  parallel overloads of most algorithms.

This patch narrowly implements P2408R5 in C++23 mode and C++20 mode
(as an extension).  "Narrowly" because just as in the paper, we don't
attempt to relax the requirements of mutable iterators even though it's
possible in theory.  Note that the PSTL algorithm requirements have
already been relaxed in r15-3650.  And we don't bother touching the
deprecated parallel mode algorithms under ./include/parallel.

The main workhorse of this paper is a new helper
__iterator_concept_or_category that replaces eligible uses of
__iterator_category and iterator_traits::iterator_category.  This new
helper considers both the iterator_concept and iterator_category of the
given iterator and returns the former if it's at least as strong as the
latter.  It's implemented in terms of the __promotable_iterator concept
added in r16-2588 that made std::advance etc aware of C++20 iterators.
Note that this helper doesn't check the actual C++20 iterator concepts
(which check syntactic requirements along with iterator_concept if it's
defined) and instead just checks for, and fully trusts, the
iterator_concept defined by the iterator type.  This is a slight
deviation from the paper but IMHO it's consistent with the existing
trusting of iterator_category and should be good enough in practice,
though it means C++20 iterators that don't define iterator_concept will
not be recognized as such by this helper even if they otherwise model
the std::foo_iterator concept.  (An undefined iterator_concept
effectively defaults to random_access_iterator_tag.)

Most of the changes made here are effectively optimizations that don't
have a semantic impact, e.g. for std::reduce.  I added tests for a
couple of algorithms where these changes are observable.

The new __iterator_concept_or_category helper can probably also be used
to fix PR100070 "Standard library container iterator-pair constructors
should check C++20 iterator concepts".

As a follow-up to this patch we should either remove the Boost-style
concept checks, or relax them accordingly.  It seems we're leaning
towards removing them outright; see this thread:
https://gcc.gnu.org/pipermail/libstdc++/2025-May/061568.html

As suggested by Tomasz, this patch also introduces a _GLIBCXX_ITER_MOVE
wrapper around ranges::iter_move that also converts to the iterator's
value type (and is usable before C++20 as well).

	PR libstdc++/113299

libstdc++-v3/ChangeLog:

	* include/bits/deque.tcc (__copy_move_a1): Constrain with
	__is_any_random_access_iter instead of __is_random_access_iter.
	(__copy_move_backward_a1): Likewise.
	(__equal_aux1): Likewise.
	* include/bits/stl_algo.h (__search_n): Use
	__iter_concept_or_category instead of __iterator_category
	or iterator_traits::iterator_category.
	(find_end): Likewise.
	(__is_permutation): Likewise.
	(for_each_n): Likewise.
	(unique_copy): Likewise, for constant iterators.
	(sample): Likewise, for constant iterators.
	* include/bits/stl_algobase.h (__copy_move_a1): Adjust
	deque-based forward declaration accordingly.
	(__copy_move_backward_a1): Likewise.
	(__equal_aux1): Likewise.
	(__lexicographical_compare_impl): Use
	__iter_concept_or_category instead of __iterator_category or
	iterator_traits::iterator_category.
	(__equal4): Likewise.
	* include/bits/stl_iterator_base_funcs.h
	(__iter_concept_or_category): New.
	(__is_any_random_access_iter): New.
	(_GLIBCXX_ITER_MOVE): New.
	* include/bits/stl_uninitialized.h (uninitialized_copy_n):
	Use __iterator_concept_or_category instead of
	__iterator_category for the constant iterator __first.
	(__uninitialized_copy_n_pair): Likewise.
	* include/bits/version.def (algorithm_iterator_requirements):
	Define.
	* include/bits/version.h: Regenerate.
	* include/std/algorithm: Provide the FTM
	__cpp_lib_algorithm_iterator_requirements.
	* include/std/memory: Likewise.
	* include/std/numeric: Likewise.  Include
	<bits/stl_iterator_base_funcs.h>.
	(reduce): Use __is_any_random_access_iter instead of
	__is_random_access_iter.
	(transform_reduce): Likewise.
	(inclusive_scan): Use _GLIBCXX_ITER_MOVE instead of std::move.
	* testsuite/25_algorithms/find_end/c++20_iter.cc: New test.
	* testsuite/25_algorithms/sample/c++20_iter.cc: New test.
	* testsuite/25_algorithms/search_n/c++20_iter.cc: New test.
	* testsuite/25_algorithms/unique_copy/c++20_iter.cc: New test.
	* testsuite/26_numerics/inclusive_scan/c++20_iter.cc: New test.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
 2025-12-16 11:22:58 -05:00
Jakub Jelinek
62c126db6b libstdc++: Implement C++26 P3378R2 - constexpr exception types 
The following patch attempts to implement the C++26 P3378R2 - constexpr
exception types paper.

This is quite complicated, because most of these classes which should
be constexpr-ized use solely or mostly out of line definitions in
libstdc++, both for historical, code size and dual ABI reasons, so that
one can throw these as exceptions between TUs with old vs. new (or vice
versa) ABIs.
For this reason, logic_error/runtime_error and classes derived from it
have the old ABI std::string object inside of them and the exported
APIs from libstdc++.so.6 ensure the right thing.

Now, because new invoked during constant evaluation needs to be deleted
during the same constant evaluation and can't leak into the constant
expressions, I think we don't have to use COW strings under the hood
(which aren't constexpr I guess because of reference counting/COW) and
we can use something else, the patch uses heap allocated std::string
object (where __cow_constexpr_string class has just a pointer to that).
As I think we still want to hide the ugly details if !consteval in the
library, the patch exports 8 __cow_string class symbols (6 existing which
were previously just not exported and 2 new ones) and if !consteval
calls those through extern "C" _Zmangled_name symbols.  The functions
are always_inline.

And then logic_error etc. have for C++26 (precisely for
__cpp_lib_constexpr_exceptions >= 202502L) constexpr definitions of
cdtors/methods.  This results in slightly larger code (a few insns at most)
at runtime for C++26, e.g. instead of calling say some logic error
cdtor/method with 2 arguments it calls some __cow_string one with 2
arguments but + 8 bytes pointer additions on both.

The patch also removes the __throw_format_error forward declaration
which apparently wasn't needed for anything as all __throw_format_error
users were either in <format> or included <format> before the uses,
reverts the
https://gcc.gnu.org/pipermail/libstdc++/2025-July/062598.html
patch and makes sure __throw_* functions (only those for exception types
which the P3378R2 or P3068R5 papers made constexpr usable and there are
actually constexpr/consteval uses of those) are constexpr for C++26
constexpr exceptions.

The patch does that by splitting the bits/functexcept.h header:
1) bits/functexcept.h stays for the __throw_* functions which are (at
least for now) never constexpr (the <ios>, <system_error>, <future>
and <functional> std::exception derived classes) or are never used
or never used in constexpr/consteval contexts (<exception>, <typeinfo>
std::exception derived classes and std::range_error).
2) bits/new_{throw,except}.h for __throw_bad_alloc/__throw_bad_array_new_length
and std::bad_alloc/std::bad_array_new_length (where <new> includes
<bits/new_except.h> and <bits/new_throw.h> as well for the C++26 constexpr
exceptions case)
3) for the most complicated <stdexcept> stuff, one header
addition to bits/stdexcept.h one header for the __throw_logic_error etc.
forward declarations, one header for the __throw_logic_error etc.
definitions and one header without header guards which will
depending on __glibcxx_exc_in_string include one or the other because
<string> vs. <string_view> vs. <stdexcept> have heavy interdependencies

2025-12-11  Jakub Jelinek  <jakub@redhat.com>

	PR libstdc++/121114
libstdc++-v3/
	* include/bits/version.def: Implement C++26 P3378R2 - constexpr
	exception types.
	(constexpr_exceptions): Change value from 1 to 202502, remove
	no_stdname and TODO comments.
	* include/bits/version.h: Regenerate.
	* src/c++11/cow-stdexcept.cc (__cow_string(const char*)): New
	ctor.
	(__cow_string::c_str()): New method.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.35): Export 8 __cow_string
	symbols.
	* include/bits/new_except.h: New file.
	* include/bits/new_throw.h: New file.
	* include/bits/stdexcept_throw.h: New file.
	* include/bits/stdexcept_throwdef.h: New file.
	* include/bits/stdexcept_throwfwd.h: New file.
	* include/std/stdexcept: Include bits/stdexcept_except.h and move
	everything after <string> include except for std::range_error into
	include/bits/stdexcept_except.h.
	(std::range_error): If __cpp_lib_constexpr_exceptions >= 202502L
	make all cdtors and methods constexpr.
	* include/bits/stdexcept_except.h: New file.
	* include/std/optional (__glibcxx_want_constexpr_exceptions): Define
	before including bits/version.h.
	(bad_optional_access::what): Make constexpr for
	__cpp_lib_constexpr_exceptions >= 202502L.
	(__throw_bad_optional_access): Likewise.
	* include/std/expected (__glibcxx_want_constexpr_exceptions): Define
	before including bits/version.h.
	(bad_expected_access): Make cdtors and all methods constexpr for
	__cpp_lib_constexpr_exceptions >= 202502L.
	* include/std/format (__glibcxx_want_constexpr_exceptions): Define
	before including bits/version.h.
	(_GLIBCXX_CONSTEXPR_FORMAT_ERROR): Define and undef later.
	(format_error): Use _GLIBCXX_CONSTEXPR_FORMAT_ERROR on ctors.
	* include/std/variant (__glibcxx_want_constexpr_exceptions): Define
	before including bits/version.h.
	(_GLIBCXX_CONSTEXPR_BAD_VARIANT_ACCESS): Define and undef later.
	(bad_variant_access): Use it on ctors and what() method.
	(__throw_bad_variant_access): Use it here too.
	* testsuite/18_support/exception/version.cc: Adjust expected
	__cpp_lib_constexpr_exceptions value.
	* testsuite/19_diagnostics/runtime_error/constexpr.cc: New test.
	* testsuite/19_diagnostics/headers/stdexcept/version.cc: New test.
	* testsuite/19_diagnostics/logic_error/constexpr.cc: New test.
	* testsuite/20_util/expected/observers.cc (test_value_throw): Change
	return type to bool from void, return true at the end, add test
	to dereference what() first character.  Make it constexpr for
	__cpp_lib_constexpr_exceptions >= 202502L and add static_assert.
	* testsuite/20_util/expected/version.cc: Add tests for
	__cpp_lib_constexpr_exceptions value.
	* testsuite/20_util/variant/constexpr.cc: For
	__cpp_lib_constexpr_exceptions >= 202502L include <string>.
	(test_get): New function if __cpp_lib_constexpr_exceptions >= 202502L,
	assert calling it is true.
	* testsuite/20_util/variant/version.cc: Add tests for
	__cpp_lib_constexpr_exceptions value.
	* testsuite/20_util/optional/constexpr/observers/3.cc: Include
	testsuite_hooks.h.
	(eat, test01): New functions.  Assert test01() is true.
	* testsuite/20_util/optional/version.cc: Add tests for
	__cpp_lib_constexpr_exceptions value.
	* include/std/future: Add #include <bits/functexcept.h>.
	* include/std/shared_mutex: Include <bits/new_throw.h>.
	* include/std/flat_map: Include <bits/stdexcept_throw.h> instead of
	<bits/functexcept.h>.
	* include/std/syncstream: Remove <bits/functexcept.h> include.
	* include/std/flat_set: Likewise.
	* include/std/bitset: Include <bits/stdexcept_throw.h> instead of
	<bits/functexcept.h>.
	* include/std/string_view: Don't include <bits/functexcept.h>, include
	<bits/stdexcept_throw.h> early if __glibcxx_exc_in_string is not
	defined and include <bits/stdexcept_throw.h> at the end of
	the header again if __glibcxx_exc_in_string is 2 and C++26 constexpr
	exceptions are enabled.
	(__glibcxx_exc_in_string): Define if __glibcxx_exc_in_string wasn't
	defined before including <bits/stdexcept_throw.h>.
	* include/std/array: Include <bits/stdexcept_throw.h> instead of
	<bits/functexcept.h>.
	* include/std/inplace_vector: Likewise.
	* include/std/string: Include <bits/stdexcept_except.h> and
	<bits/stdexcept_throw.h> after bits/basic_string.tcc include if
	C++26 constexpr exceptions are enabled and include
	<bits/stdexcept_throw.h> instead of <bits/functexcept.h> early.
	(__glibcxx_exc_in_string): Define early to 1, undefine at the end.
	* include/std/deque: Include <bits/stdexcept_throw.h>.
	* include/bits/new_allocator.h: Include <bits/new_throw.h> instead
	of <bits/functexcept.h>.
	* include/bits/stl_algobase.h: Remove <bits/functexcept.h> include.
	* include/bits/stl_vector.h: Include <bits/stdexcept_throw.h> instead
	of <bits/functexcept.h>.
	* include/bits/memory_resource.h: Include <bits/new_throw.h> instead
	of <bits/functexcept.h>.
	* include/bits/functexcept.h: Guard everything after includes with
	#if _GLIBCXX_HOSTED.
	(__throw_bad_alloc, __throw_bad_array_new_length,  __throw_logic_error,
	__throw_domain_error, __throw_invalid_argument, __throw_length_error,
	__throw_out_of_range, __throw_out_of_range_fmt, __throw_runtime_error,
	__throw_overflow_error, __throw_underflow_error): Move declarations to
	other headers - <bits/new_throw.h> and <bits/stdexcept_throwfwd.h>.
	* include/bits/stl_map.h: Include <bits/stdexcept_throw.h> instead
	of <bits/functexcept.h>.
	* include/bits/hashtable_policy.h: Include <bits/stdexcept_throw.h>
	instead of <bits/functexcept.h>.
	* include/bits/formatfwd.h (std::__throw_format_error): Remove
	declaration.
	* include/bits/specfun.h: Include <bits/stdexcept_throw.h> instead of
	<bits/functexcept.h>.
	* include/bits/basic_ios.h: Include <bits/functexcept.h>.
	* include/bits/locale_classes.h: Likewise.
	* include/tr1/cmath: Include <bits/stdexcept_throw.h> instead of
	<bits/functexcept.h>.
	* include/tr1/memory: Remove <bits/functexcept.h> include.
	* include/tr1/array: Include <bits/stdexcept_throw.h>.
	* include/ext/vstring_util.h: Include <bits/stdexcept_throw.h> instead
	of <bits/functexcept.h>.
	* include/ext/bitmap_allocator.h: Include <bits/new_throw.h> instead
	of <bits/functexcept.h>.
	* include/ext/mt_allocator.h: Likewise.
	* include/ext/malloc_allocator.h: Likewise.
	* include/ext/debug_allocator.h: Include <bits/stdexcept_throw.h>
	instead of <bits/functexcept.h>.
	* include/ext/concurrence.h: Include <bits/exception_defines.h>
	instead of <bits/functexcept.h>.
	* include/ext/throw_allocator.h: Include <bits/new_throw.h> and
	<bits/stdexcept_throw.h> instead of <bits/functexcept.h>.
	* include/ext/string_conversions.h: Include <bits/stdexcept_throw.h>
	instead of <bits/functexcept.h>.
	* include/ext/pool_allocator.h: Include <bits/new_throw.h> instead
	of <bits/functexcept.h>.
	* include/ext/ropeimpl.h: Include <bits/stdexcept_throw.h> instead of
	<bits/functexcept.h>.
	* include/tr2/dynamic_bitset: Likewise.
	* include/experimental/optional: Include <bits/exception_defines.h>
	instead of <bits/functexcept.h>.
	* include/Makefile.am (bits_freestanding): Add
	${bits_srcdir}/{new,stdexcept}_{except,throw}.h
	and ${bits_srcdir}/stdexcept_throw{fwd,def}.h.
	* include/Makefile.in: Regenerate.
	* src/c++17/floating_from_chars.cc: Remove <bits/functexcept.h>
	include.
	* src/c++11/regex.cc: Likewise.
	* src/c++11/functexcept.cc: Likewise.
	* src/c++11/snprintf_lite.cc: Include <bits/stdexcept_throw.h> instead
	of <bits/functexcept.h>.
	* src/c++11/thread.cc: Include <bits/functexcept.h>.
	* testsuite/util/testsuite_hooks.h: Include <bits/stdexcept_throw.h>
	instead of <bits/functexcept.h>.
	* testsuite/util/io/verified_cmd_line_input.cc: Include
	<bits/exception_defines.h> instead of <bits/functexcept.h>.
	* testsuite/20_util/allocator/105975.cc: Expect different diagnostics
	for C++26.
	* testsuite/23_containers/inplace_vector/access/capacity.cc: Remove
	#error, guard if consteval { return; } with
	#ifndef __cpp_lib_constexpr_exceptions.
	* testsuite/23_containers/inplace_vector/access/elem.cc: Likewise.
	* testsuite/23_containers/inplace_vector/cons/1.cc: Likewise.
	* testsuite/23_containers/inplace_vector/cons/from_range.cc: Likewise.
	* testsuite/23_containers/inplace_vector/modifiers/single_insert.cc:
	Likewise.
	* testsuite/23_containers/inplace_vector/modifiers/assign.cc:
	Likewise.
	* testsuite/23_containers/inplace_vector/modifiers/multi_insert.cc:
	Likewise.
	* libsupc++/new: Include <bits/new_except.h>.
	(std::bad_alloc, std::bad_array_new_length): Move defintion to
	<bits/new_except.h>.
libgomp/
	* omp.h.in: Include <bits/new_throw.h> instead of
	<bits/functexcept.h>.
gcc/testsuite/
	* g++.dg/tree-ssa/pr110819.C: Guard scan-tree-dump-not delete on
	c++23_down and add comment explaining why C++26 fails that.
	* g++.dg/tree-ssa/pr96945.C: Likewise.
	* g++.dg/tree-ssa/pr109442.C: Likewise.
	* g++.dg/tree-ssa/pr116868.C: Likewise.
	* g++.dg/tree-ssa/pr58483.C: Likewise.
 2025-12-11 19:54:44 +01:00
Yuao Ma
bf9dd44a97 libstdc++: constexpr flat_set and flat_multiset 
This patch makes flat_set and flat_multiset constexpr as part of P3372R3.

libstdc++-v3/ChangeLog:

	* include/bits/version.def: Add FTM.
	* include/bits/version.h: Regenerate.
	* include/std/flat_set: Add constexpr.
	* testsuite/23_containers/flat_multiset/1.cc: Add constexpr test.
	* testsuite/23_containers/flat_set/1.cc: Add constexpr test.
 2025-12-11 22:24:42 +08:00
Luc Grosheintz
e2026d74f6 libstdc++: Set __cpp_lib_submdspan to 202411. 
The submdspan feature is complete and this commit sets the feature
testing macros accordingly. Also makes the feature testing macro
submdspan depend on constant_wrapper.

Also changes the value of the internal feature testing macro for padded
layouts to 202403.

libstdc++-v3/ChangeLog:

	* include/bits/version.def (padded_layouts): Set to 202403.
	(submdspan): Set to 202411 add dependency.
	* include/bits/version.h: Regenerate.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Signed-off-by: Luc Grosheintz <luc.grosheintz@gmail.com>
 2025-12-09 17:38:56 +01:00
Jonathan Wakely
03562c1e02 libstdc++: Implement P2404R3 relaxations to comparable_with concepts [PR122946] 
This implements the C++23 proposal P2404R3 "Move-only types for
equality_comparable_with, totally_ordered_with, and
three_way_comparable_with". As agreed with the maintainers of libc++ and
MSVC STL, we treat this as a DR for C++20. It allows reasonable code to
compile which wasn't originally allowed in C++20, and only affects some
obscure subsumption cases for valid C++20 code.

libstdc++-v3/ChangeLog:

	PR libstdc++/122946
	* include/bits/version.def (concepts): Set value to 202207.
	* include/bits/version.h: Regenerate.
	* include/std/concepts (__comparison_common_type_with_impl)
	(__comparison_common_type_with): New helper concepts.
	(equality_comparable_with): Use __comparison_common_type_with.
	* libsupc++/compare (three_way_comparable_with): Likewise.
	(__glibcxx_want_concepts): Define to get __cpp_lib_concepts
	here.
	* testsuite/std/concepts/concepts.compare/move_only.cc: New
	test.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
 2025-12-08 18:55:02 +00:00
Patrick Palka
d1ac432c5a libstdc++: Implement rest of P2655R3 common_reference of reference_wrapper 
PR libstdc++/120446

libstdc++-v3/ChangeLog:

	* include/bits/refwrap.h (__detail::__is_ref_wrapper):
	Define as per P2655R3 for C++20.
	(__detail::__ref_wrap_common_reference_exists_with): Likewise.
	(basic_common_reference): Define partial specializations using
	the above as per P2655R3 for C++20.
	* include/bits/version.def (common_reference_wrapper): New.
	* include/bits/version.h: Regenerate.
	* include/std/functional (__glibcxx_want_common_reference_wrapper):
	Define.
	* testsuite/20_util/reference_wrapper/p2655r3.cc: New test.

Co-authored-by: Tomasz Kamiński <tkaminsk@redhat.com>
Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
 2025-12-05 13:43:40 -05:00
Patrick Palka
a9fd651fbb libstdc++: Implement P2655R3 changes to common_reference bullet 1 
We implement this paper as a DR against C++20 (as do MSVC and libc++).

	PR libstdc++/120446

libstdc++-v3/ChangeLog:

	* include/bits/version.def (common_reference): New.
	* include/bits/version.h: Regenerate.
	* include/std/type_traits (__glibcxx_want_common_reference):
	Define.
	(__common_reference_impl<T1, T2, 1>): Add pointer convertibility
	constraints as per P2655R3.
	* testsuite/20_util/common_reference/p2655r3.cc: New test.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
 2025-12-05 13:43:29 -05:00
Yuao Ma
475933164f libstdc++: implement P3044R2 - sub-string_view from string (string_view part) 
libstdc++-v3/ChangeLog:

	* include/bits/version.def: Add string_subview FTM.
	* include/bits/version.h: Regenerate.
	* include/std/string_view: Add subview.
	* testsuite/21_strings/basic_string_view/operations/subview/char.cc: New test.
	* testsuite/21_strings/basic_string_view/operations/subview/wchar_t.cc: New test.
 2025-12-03 23:55:06 +08:00
Tomasz Kamiński
1c9d93bfcd libstdc++: Hashing support for chrono value classes [PR110357] 
This patch implements P2592R3 Hashing support for std::chrono value classes.

To avoid the know issues with current hashing of integer types (see PR104945),
we use chrono::__int_hash function that hash the bytes of representation,
instead of hash<T>, as the later simply cast to value. Currently _Hash_impl
it used, but we should consider replacing it (see PR55815) before C++26 ABI
is made stable. The function is declared inside <chrono> header and chrono
namespace, to make sure that only chrono components would be affected by
such change. Finally, chrono::__int_hash is made variadic, to support
combining hashes of multiple integers.

To reduce the number of calls to hasher (defined out of line), the calendar
types are packed into single unsigned integer value. This is done by
chrono::__hash helper, that calls:
* chrono::__as_int to cast the value of single component, to unsigned integer
  with size matching the one used by internal representation: unsigned short
  for year/weekday_indexed, and unsigned char in all other cases,
* chrono::__pack_ints to pack integers (if more than one) into single integer
  by performing bit shift operations,
* chrono::__int_hash to hash the value produced by above.

Hashing of duration, time_point, and zoned_time only hashes the value and
ignores any difference in the period, i.e. hashes of nanoseconds(2) and
seconds(2) are the same. This does not affect the usages inside unordered
containers, as the arguments are converted to key type first. To address
that period::num and period::den could be included in the hash, however
such approach will not make hashes of equal durations (2000ms, 2s) equal,
so they would remain unusable for precomputed hashes. In consequence,
including period in hash, would only increase runtime cost, withou any
clear benefits.

Futhermore,  chrono::__int_hash is used when the duration representation
is integral type, and for other types (floating point due special handling
of +/-0.0 and user defined types) we delegate to hash specialization.
This is automatically picked up by time_point, that delegates to hasher
of duration. Similarly for leap_second that is specified to use integer
durations, we simply hash representations of date() and value(). Finally
zoned_time in addition to handling integer durations as described above,
we also use __int_hash for const time_zone* (if used), as hash<T*> have
similar problems as hash specialization for integers. This is limited
only to _TimeZonePtr being const time_zone* (default), as user can define
hash specializations for raw pointers to they zones.

As accessing the representation for duration requires calling count()
method that returns a copy of representation by value, the noexcept
specification of the hasher needs to take into consideration copy
constructor of duration. Similar reasoning applies for time_since_epoch
for time_points, and get_sys_time, get_time_zone for zoned_time.
For all this cases we use internal __is_nothrow_copy_hashable concept.

Finally support for zoned_time is provided only for CXX11 string ABI,
__cpp_lib_chrono feature test macro cannot be bumped if COW string are used.
To indicate presence of hasher for remaining types this patch also bumps
the internal __glibcxx_chrono_cxx20 macro, and uses it as guard to new
features.

	PR libstdc++/110357

libstdc++-v3/ChangeLog:

	* include/bits/version.def (chrono, chrono_cxx20): Bump values.
	* include/bits/version.h: Regenerate.
	* include/std/chrono (__is_nothrow_copy_hashable)
	(chrono::__pack_ints, chrono::__as_int, chrono::__int_hash)
	(chrono::__hash): Define.
	(std::hash): Define partial specialization for duration, time_point,
	and zoned_time, and full specializations for calendar types and
	leap_second.
	(std::__is_fast_hash): Define partial specializations for duration,
	time_point, zoned_time.
	* testsuite/std/time/hash.cc: New test.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Co-authored-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Signed-off-by: Tomasz Kamiński <tkaminsk@redhat.com>
Signed-off-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
 2025-11-26 08:35:48 +01:00
Jakub Jelinek
acdf675933 libstd++: Implement C++23 P2674R1 - A trait for implicit lifetime types 
The following patch attempts to implement the library side of the
C++23 P2674R1 paper.  As mentioned in the paper, since CWG2605
the trait isn't really implementable purely on the library side.

The compiler side has been committed earlier, so this just uses
the new builtin trait on the library side.

2025-10-30  Jakub Jelinek  <jakub@redhat.com>

	* include/bits/version.def (is_implicit_lifetime): New.
	* include/bits/version.h: Regenerate.
	* include/std/type_traits (std::is_implicit_lifetime,
	std::is_implicit_lifetime_v): New trait.
	* src/c++23/std.cc.in (std::is_implicit_lifetime,
	std::is_implicit_lifetime_v): Export.
	* testsuite/20_util/is_implicit_lifetime/version.cc: New test.
	* testsuite/20_util/is_implicit_lifetime/value.cc: New test.
 2025-10-30 08:46:26 +01:00
Giuseppe D'Angelo
23657d3972 libstdc++: Implement optional<T&> from P2988R12 [PR121748] 
This patch implements optional<T&> based on the P2988R12 paper, incorporating
corrections from LWG4300, LWG4304, and LWG3467. The resolution for LWG4015
is also extended to cover optional<T&>.

We introduce _M_fwd() helper, that is equivalent to operator*(), except that
it does not check non-empty precondition. It is used in to correctly propagate
the value during move construction from optional<T&>. This is necessary because
moving an optional<T&> must not move the contained object, which is the key
distinction between *std::move(opt) and std::move(*opt).

The implementation deviates from the standard by providing a separate std::swap
overload for std::optional<T&>, which simplifies preserving the resolution of
LWG2766.

This introduces a few changes to make_optional behavior (see included test):
* some previously valid uses of make_optional<T>({...}) (where T is not a
  reference type) now become ill-formed (see optional/make_optional_neg.cc).
* make_optional<T&>(t) and make_optional<const T&>(ct), where decltype(t) is T&,
  and decltype(ct) is const T& now produce optional<T&> and optional<const T&>
  respectively, instead of optional<T>.
* a few other uses of make_optional<R> with reference type R are now ill-formed.

	PR libstdc++/121748

libstdc++-v3/ChangeLog:

	* include/bits/version.def: Bump value for optional,
	* include/bits/version.h: Regenerate.
	* include/std/optional (std::__is_valid_contained_type_for_optional):
	Define.
	(std::optional<T>): Use __is_valid_contained_type_for_optional.
	(optional<T>(const optional<_Up>&), optional<T>(optional<_Up>&&))
	(optional<T>::operator=(const optional<_Up>&))
	(optional<T>::operator=(optional<_Up>&&)): Replacex._M_get() with
	x._M_fwd(), and std::move(x._M_get()) with std::move(x)._M_fwd().
	(optional<T>::and_then): Remove uncessary remove_cvref_t.
	(optional<T>::_M_fwd): Define.
	(std::optional<T&>): Define new partial specialization.
	(std::swap(std::optional<T&>, std::optional<T&>)): Define.
	(std::make_optional(_Tp&&)): Add non-type template parameter.
	(std::make_optional): Use parenthesis to constructor optional.
	(std::hash<optional<T>>): Add comment.
	* testsuite/20_util/optional/make_optional-2.cc: Guarded not longer
	working example.
	* testsuite/20_util/optional/relops/constrained.cc: Expand test to
	cover optionals of reference.
	* testsuite/20_util/optional/requirements.cc: Ammend for
	optional<T&>.
	* testsuite/20_util/optional/requirements_neg.cc: Likewise.
	* testsuite/20_util/optional/version.cc: Test new value of
	__cpp_lib_optional.
	* testsuite/20_util/optional/make_optional_neg.cc: New test.
	* testsuite/20_util/optional/monadic/ref_neg.cc: New test.
	* testsuite/20_util/optional/ref/access.cc: New test.
	* testsuite/20_util/optional/ref/assign.cc: New test.
	* testsuite/20_util/optional/ref/cons.cc: New test.
	* testsuite/20_util/optional/ref/internal_traits.cc: New test.
	* testsuite/20_util/optional/ref/make_optional/1.cc: New test.
	* testsuite/20_util/optional/ref/make_optional/from_args_neg.cc:
	New test.
	* testsuite/20_util/optional/ref/make_optional/from_lvalue_neg.cc:
	New test.
	* testsuite/20_util/optional/ref/make_optional/from_rvalue_neg.cc:
	New test.
	* testsuite/20_util/optional/ref/monadic.cc: New test.
	* testsuite/20_util/optional/ref/relops.cc: New test.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Co-authored-by: Tomasz Kamiński <tkaminsk@redhat.com>
 2025-10-22 09:53:04 +02:00
Yuao Ma
7aefb48bb0 libstdc++: Implement P3060R3: Add std::views::indices(n) 
This patch adds the views::indices function using iota.

libstdc++-v3/ChangeLog:

	* include/bits/version.def: Add ranges_indices FTM.
	* include/bits/version.h: Regenerate.
	* include/std/ranges: Implement views::indices.
	* testsuite/std/ranges/indices/1.cc: New test.
 2025-10-21 00:18:23 +08:00
Iain Sandoe
1e84849cb2 libstdc++: Implement P1494 and P3641 Partial program correctness [PR119060] 
This implements the library parts of P1494 as amended by P3641.  For GCC the
compiler itself treats stdio operations as equivalent to the observable
checkpoint and thus it does not appear to be necessary to add calls to those
functions (it will not alter the outcome).

This adds the facility for C++26, although there is no reason, in principle,
that it would not work back to C++11 at least.

	PR c++/119060

libstdc++-v3/ChangeLog:

	* include/bits/version.def: Add observable_checkpoint at present
	allowed from C++26.
	* include/bits/version.h: Regenerate.
	* include/std/utility: Add std::observable_checkpoint().
	* src/c++23/std.cc.in: Add obervable_checkpoint () to utility.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
 2025-10-18 23:18:02 +01:00
Yuao Ma
1c5e1093a7 libstdc++: Implement P2835R7 Expose std::atomic_ref's object address 
This patch adds the address function to __atomic_ref_base.

libstdc++-v3/ChangeLog:

	* include/bits/atomic_base.h: Implement address().
	* include/bits/version.def: Bump version number.
	* include/bits/version.h: Regenerate.
	* testsuite/29_atomics/atomic_ref/address.cc: New test.
 2025-10-13 23:03:41 +08:00
Tomasz Kamiński
c8b388a948 libstdc++: Implement P3235R3 optimizations for std::print [PR121790] 
This patch implements additional enable_nonlocking_formatter_optimization
specializations listed in P3235R3.

	PR libstdc++/121790

libstdc++-v3/ChangeLog:

	* include/bits/chrono_io.h
	(enable_nonlocking_formatter_optimization): Define specializations
	for chrono types.
	* include/bits/version.def (print): Bump.
	* include/bits/version.h: Regenerate.
	* include/std/format (enable_nonlocking_formatter_optimization):
	Define specializations for pair, tuple and ranges.
	* include/std/queue (enable_nonlocking_formatter_optimization):
	Define specializations for queue and priority_queue.
	* include/std/stack (enable_nonlocking_formatter_optimization):
	Define specialization for stack.
	* include/std/stacktrace (enable_nonlocking_formatter_optimization):
	Define specialization for basic_stacktrace and stacktrace_entry.
	* include/std/thread (enable_nonlocking_formatter_optimization):
	Define specialization for thread::id.
	* include/std/vector (enable_nonlocking_formatter_optimization):
	Define specialization for vector<bool>::reference.
	* testsuite/23_containers/vector/bool/format.cc: Test value of
	enable_nonlocking_formatter_optimization.
	* testsuite/30_threads/thread/id/output.cc: Likewise.
	* testsuite/std/format/ranges/adaptors.cc: Likewise.
	* testsuite/std/format/ranges/formatter.cc: Likewise.
	* testsuite/std/format/tuple.cc: Likewise.
	* testsuite/std/time/format/empty_spec.cc: Extract Rep class
	to custom_rep.h.
	* testsuite/std/time/format/custom_rep.h: Extracted from
	empty_spec.cc.
	* testsuite/std/time/format/nonlocking.cc: New test.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
 2025-10-10 09:13:00 +02:00
Jonathan Wakely
8bd872f1ea libstdc++: Implement P3107R5 optimizations for std::print [PR121790] 
The names of the vprint functions follow the convention from P3235R3.

This takes advantage of the additional permission proposed by P3107R5 so
that std::print can write directly to a FILE stream, rather than
formatting to an intermediate std::string temporary and then writing
that to the stream. The change is to write to a new _File_sink type
instead of a _Str_sink that populates a std::string. There are three
implementations of _File_sink.

For non-Glibc targets that support POSIX flockfile and putc_unlocked,
the stream will be locked and then formatted characters will be buffered
on the stack (instead of allocating a std::string) and copied to the
stream when the buffer fills up.

For Glibc, _File_sink will lock the stream but then if the file is
line-buffered or fully buffered, characters will be written directly
into the file's output buffer. This avoids two levels of buffering and
copying the characters from one to the other. For an unbuffered stream
(like stderr) the _File_sink buffer will still be used, to avoid the
overhead of lots of small writes to the stream.  Because this version of
_File_sink accesses the stream's buffer directly it relies on
glibc-specific implementation details that are exposed in public
headers.

A fallback definition of _File_sink just wraps a _Str_sink so is
equivalent to the original code, and is used when flockfile isn't
available.

Both forms of std::println (taking a FILE* and a std::ostream) can be
implemented more efficiently by appending a newline to the format
string, to avoid formatting twice.

	PR libstdc++/121790

libstdc++-v3/ChangeLog:

	* acinclude.m4 (GLIBCXX_CHECK_STDIO_LOCKING): New macro to check
	for std::print dependencies.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Use GLIBCXX_CHECK_STDIO_LOCKING.
	* include/bits/formatfwd.h (enable_nonlocking_formatter_optimization):
	Define new variable template.
	* include/bits/version.def (print): Bump value.
	* include/bits/version.h: Regenerate.
	* include/std/format (enable_nonlocking_formatter_optimization):
	Define specializations for variable template.
	* include/std/ostream (print) [!_WIN32]: Do not use
	vprint_unicode at all.
	(println): Append newline to format string instead of formatting
	twice.
	* include/std/print (_File_sink): New class.
	(vprint_nonunicode_locking): New function.
	(vprint_unicode_locking): New function reusing previous code
	from vprint_unicode.
	(vprintf_unicode): Defer to vprint_nonunicode for Windows or to
	vprint_unicode_locking otherwise.
	(print): [!_WIN32]: Do no use vprint_unicode at all.
	Check enable_nonlocking_formatter_optimization and defer to
	either vprint_nonunicode_locking or vprint_nonunicode.
	(println): Use vprint_unicode or format directly to a _File_sink
	instead of formatting twice.
	* testsuite/27_io/print/1.cc: Updated and added new tests.
	* testsuite/std/format/formatter/nonlocking.cc: New tests.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Co-authored-by: Tomasz Kamiński <tkaminsk@redhat.com>
 2025-10-10 09:00:22 +02:00
Luc Grosheintz
61061664e8 libstdc++: Implement strided_slice from <mdspan>. [PR110352] 
Adds strided_slice as standardized in N5014. Also creates
the internal feature testing macro for submdspan.

	PR libstdc++/110352

libstdc++-v3/ChangeLog:

	* include/bits/version.def (submdspan): New internal macro.
	* include/bits/version.h: Regenerate.
	* include/std/mdspan (strided_slice): New class.
	* src/c++23/std.cc.in (strided_slice): Add.
	* testsuite/23_containers/mdspan/submdspan/strided_slice.cc: New test.
	* testsuite/23_containers/mdspan/submdspan/strided_slice_neg.cc: New test.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Signed-off-by: Luc Grosheintz <luc.grosheintz@gmail.com>
 2025-10-08 12:32:17 +02:00
Luc Grosheintz
8c71d18f54 libstdc++: Implement std::layout_left_padded [PR110352]. 
This commit adds a new layout layout_left_padded as standardized in
N5014. It adds a purely internal feature testing macro padded_layouts
and registers layout_left_padded in the std module.

This commit implements LWG4372, because without it's not possible
to properly test padded layouts with a dynamic padding value. It also
implements LWG4314, for consistency with prior layouts.

The implementation uses a _PaddedStorage to deduplicate most of the code
shared between left- and right-padded layouts. It's implemented through
aggregation rather than inheritence, because of a bug related to
inheriting conditionally explicit ctors.

The tests are written such that the canonical version works for
layout_left_padded. A version for layout_right_padded is derived
essentially by reversing the order of the extents.

	PR libstdc++/110352

libstdc++-v3/ChangeLog:

	* include/bits/version.def (padded_layouts): Add new internal
	feature testing macro.
	* include/bits/version.h: Regenerate.
	* include/std/mdspan (__fwd_prod): New overload.
	(layout_left_padded): Add declaration and implementation.
	(layout_right_padded): Add declaration only.
	(layout_left::mapping::mapping): New overload for left
	padded mappings.
	(__index_type_cast): New function that performs a checked cast
	to index_type.
	(__is_left_padded_mapping): New concept.
	(__is_right_padded_mapping): Ditto.
	(__standardized_mapping): Recognize left and right padded
	mappings.
	(_LeftPaddedIndices): Traits for left padded details.
	(_PaddedStorage): New class for implementing padded layouts.
	* src/c++23/std.cc.in (layout_left_padded): Add.
	* testsuite/23_containers/mdspan/layouts/class_mandate_neg.cc:
	Refactor and add tests for layout_left_padded.
	* testsuite/23_containers/mdspan/layouts/ctors.cc: Ditto.
	* testsuite/23_containers/mdspan/layouts/empty.cc: Ditto.
	* testsuite/23_containers/mdspan/layouts/mapping.cc: Ditto.
	* testsuite/23_containers/mdspan/layouts/padded.cc: Ditto.
	* testsuite/23_containers/mdspan/layouts/padded_neg.cc: Ditto.
	* testsuite/23_containers/mdspan/layouts/padded_traits.h: New
	traits.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Signed-off-by: Luc Grosheintz <luc.grosheintz@gmail.com>
 2025-10-08 11:22:32 +02:00
1nfocalypse
1c06243e65 libstdc++: Implement Philox Engine (PR119794) 
Conforms with errata LWG4143, LWG4153 for Philox Engine.

	PR libstdc++/119794

libstdc++-v3/ChangeLog:

	* include/bits/random.h (philox_engine): Define.
	* include/bits/random.tcc (philox_engine): Define member
	functions.
	* include/bits/version.def (philox_engine): New macro.
	* include/bits/version.h: Regenerated.
	* include/std/random: Define __glibcxx_want_philox_engine and
	include <bits/version.h>.
	* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error
	line number.
	* testsuite/26_numerics/random/philox4x32.cc: New test.
	* testsuite/26_numerics/random/philox4x64.cc: New test.
	* testsuite/26_numerics/random/philox_engine/cons/119794.cc: New test.
	* testsuite/26_numerics/random/philox_engine/cons/copy.cc: New test.
	* testsuite/26_numerics/random/philox_engine/cons/default.cc: New test.
	* testsuite/26_numerics/random/philox_engine/cons/seed.cc: New test.
	* testsuite/26_numerics/random/philox_engine/cons/seed_seq.cc: New test.
	* testsuite/26_numerics/random/philox_engine/operators/equal.cc: New test.
	* testsuite/26_numerics/random/philox_engine/operators/inequal.cc: New test.
	* testsuite/26_numerics/random/philox_engine/operators/serialize.cc: New test.
	* testsuite/26_numerics/random/philox_engine/requirements/constants.cc: New test.
	* testsuite/26_numerics/random/philox_engine/requirements/constexpr_data.cc: New test.
	* testsuite/26_numerics/random/philox_engine/requirements/constexpr_functions.cc: New test.
	* testsuite/26_numerics/random/philox_engine/requirements/typedefs.cc: New test.
 2025-09-23 16:38:29 +01:00
Nathan Myers
a77146f015 libstdc++: Add NTTP bind_front, -back, not_fn (P2714) [PR119744] 
Add non-type template parameter function-object/-pointer argument
versions of bind_front, bind_back, and not_fn.

This introduces a new internal type _Bind_fn_t to carry the
template-argument function object when no arguments are bound,
used in both bind_front and bind_back. Otherwise they return
a lambda object that has captured the arguments.

There is no need to change libstdc++-v3/src/c++23/std.cc.in
because existing exports: "using std::bind_front;" etc. export
the new overloads.

libstdc++-v3/ChangeLog:
	PR libstdc++/119744
	* include/bits/version.def: Redefine __cpp_lib_bind_front etc.
	* include/bits/version.h: Ditto.
	* include/std/functional: Add new bind_front etc. overloads
	* testsuite/20_util/function_objects/bind_back/1.cc:
	Check plumbing better
	* testsuite/20_util/function_objects/bind_back/nttp.cc: New test.
	* testsuite/20_util/function_objects/bind_back/nttp_neg.cc: New test.
	* testsuite/20_util/function_objects/bind_front/1.cc:
	Check plumbing better
	* testsuite/20_util/function_objects/bind_front/nttp.cc: New test.
	* testsuite/20_util/function_objects/bind_front/nttp_neg.cc: New test.
	* testsuite/20_util/function_objects/not_fn/nttp.cc: New test.
	* testsuite/20_util/function_objects/not_fn/nttp_neg.cc: New test.
	* testsuite/20_util/headers/functional/synopsis.cc: New decls.
 2025-09-19 17:31:31 -04:00
Jonathan Wakely
acfd5ab079 libstdc++: Reorder start_lifetime_as macro in version.def 
libstdc++-v3/ChangeLog:

	* include/bits/version.def (start_lifetime_as): Move adjacent to
	other C++23 macros.
	* include/bits/version.h: Regenerate.
 2025-09-19 10:22:24 +01:00
Jakub Jelinek
c1e1691b95 libstdc++: Implement C++23 P2590R2 - Explicit lifetime management [PR106658] 
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.
 2025-09-18 07:44:54 +02:00
Luc Grosheintz
c440b585ba libstdc++: Implement constant_wrapper, cw from P2781R9. 
This is a partial implementation of P2781R9. It adds std::cw and
std::constant_wrapper, but doesn't modify __integral_constant_like for
span/mdspan.

libstdc++-v3/ChangeLog:

	* include/bits/version.def (constant_wrapper): Add.
	* include/bits/version.h: Regenerate.
	* include/std/type_traits (_CwFixedValue): New class.
	(_IndexSequence): New struct.
	(_BuildIndexSequence): New struct.
	(_ConstExprParam): New concept.
	(_CwOperators): New struct.
	(constant_wrapper): New struct.
	(cw): New global constant.
	* src/c++23/std.cc.in (constant_wrapper): Add.
	(cw): Add.
	* testsuite/20_util/constant_wrapper/adl.cc: New test.
	* testsuite/20_util/constant_wrapper/ex.cc: New test.
	* testsuite/20_util/constant_wrapper/generic.cc: New test.
	* testsuite/20_util/constant_wrapper/instantiate.cc: New test.
	* testsuite/20_util/constant_wrapper/op_comma_neg.cc: New test.
	* testsuite/20_util/constant_wrapper/version.cc: New test.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Co-authored-by: Tomasz Kamiński <tkaminsk@redhat.com>
Signed-off-by: Luc Grosheintz <luc.grosheintz@gmail.com>
Signed-off-by: Tomasz Kamiński <tkaminsk@redhat.com>
 2025-09-08 09:38:53 +02:00
Jonathan Wakely
381dbd4a95 libstdc++: Restore C++20 <chrono> support for old std::string ABI 
The r16-3416-g806de30f51c8b9 change to use __cpp_lib_chrono in
preprocessor conditions broke support for <chrono> for freestanding and
the COW std::string ABI. That happened because __cpp_lib_chrono is only
defined to the C++20 value for hosted and for the new ABI, because the
full set of C++20 features are not defined for freestanding and tzdb is
not defined for the old ABI.

This introduces a new internal feature test macro that corresponds to
the features that are always supported (e.g. chrono::local_time,
chrono::year, chrono::weekday).

libstdc++-v3/ChangeLog:

	* include/bits/version.def (chrono_cxx20): Define.
	* include/bits/version.h: Regenerate.
	* include/std/chrono: Check __glibcxx_chrono_cxx20 instead of
	__cpp_lib_chrono for C++20 features that don't require the new
	std::string ABI and/or can be used for freestanding.
	* src/c++20/clock.cc: Adjust preprocessor condition.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
 2025-09-03 10:49:06 +01:00
Jonathan Wakely
3c95766e92 libstdc++: Implement C++26 <debugging> features [PR119670] 
This implements P2546R5 (Debugging Support), including the P2810R4
(is_debugger_present is_replaceable) changes, allowing
std::is_debugger_present to be replaced by the program.

It would be good to provide a macOS definition of is_debugger_present as
per https://developer.apple.com/library/archive/qa/qa1361/_index.html
but that isn't included in this change.

The src/c++26/debugging.cc file defines a global volatile int which can
be set by debuggers to indicate when they are attached and detached from
a running process. This allows std::is_debugger_present() to give a
reliable answer, and additionally allows a debugger to choose how
std::breakpoint() should behave. Setting the global to a positive value
will cause std::breakpoint() to use that value as an argument to
std::raise, so debuggers that prefer SIGABRT for breakpoints can select
that. By default std::breakpoint() will use a platform-specific action
such as the INT3 instruction on x86, or GCC's __builtin_trap().

On Linux the std::is_debugger_present() function checks whether the
process is being traced by a process named "gdb", "gdbserver" or
"lldb-server", to try to avoid interpreting other tracing processes
(such as strace) as a debugger. There have been comments suggesting this
isn't desirable and that std::is_debugger_present() should just return
true for any tracing process (which is the case for non-Linux targets
that support the ptrace system call).

libstdc++-v3/ChangeLog:

	PR libstdc++/119670
	* acinclude.m4 (GLIBCXX_CHECK_DEBUGGING): Check for facilities
	needed by <debugging>.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Use GLIBCXX_CHECK_DEBUGGING.
	* include/Makefile.am: Add new header.
	* include/Makefile.in: Regenerate.
	* include/bits/version.def (debugging): Add.
	* include/bits/version.h: Regenerate.
	* include/precompiled/stdc++.h: Add new header.
	* src/c++26/Makefile.am: Add new file.
	* src/c++26/Makefile.in: Regenerate.
	* include/std/debugging: New file.
	* src/c++26/debugging.cc: New file.
	* testsuite/19_diagnostics/debugging/breakpoint.cc: New test.
	* testsuite/19_diagnostics/debugging/breakpoint_if_debugging.cc:
	New test.
	* testsuite/19_diagnostics/debugging/is_debugger_present.cc: New
	test.
	* testsuite/19_diagnostics/debugging/is_debugger_present-2.cc:
	New test.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
 2025-08-28 17:47:00 +01:00
Luc Grosheintz
d147e7a20a libstdc++: Implement aligned_accessor from mdspan [PR120994] 
This commit completes the implementation of P2897R7 by implementing and
testing the template class aligned_accessor.

	PR libstdc++/120994

libstdc++-v3/ChangeLog:

	* include/bits/version.def (aligned_accessor): Add.
	* include/bits/version.h: Regenerate.
	* include/std/mdspan (aligned_accessor): New class.
	* src/c++23/std.cc.in (aligned_accessor): Add.
	* testsuite/23_containers/mdspan/accessors/generic.cc: Add tests
	for aligned_accessor.
	* testsuite/23_containers/mdspan/accessors/aligned_neg.cc: New test.
	* testsuite/23_containers/mdspan/version.cc: Add test for
	__cpp_lib_aligned_accessor.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Signed-off-by: Luc Grosheintz <luc.grosheintz@gmail.com>
 2025-08-21 11:55:02 +02:00
Luc Grosheintz
5227ec972a libstdc++: Implement is_sufficiently_aligned [PR120994] 
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>
 2025-08-21 11:54:41 +02:00
Luc Grosheintz
985684e9b3 libstdc++: Implement std::dims from <mdspan>. 
This commit implements the C++26 feature std::dims described in P2389R2.
It sets the feature testing macro to 202406 and adds tests.

Also fixes the test mdspan/version.cc

libstdc++-v3/ChangeLog:

	* include/bits/version.def (mdspan): Set value for C++26.
	* include/bits/version.h: Regenerate.
	* include/std/mdspan (dims): Add.
	* src/c++23/std.cc.in (dims): Add.
	* testsuite/23_containers/mdspan/extents/misc.cc: Add tests.
	* testsuite/23_containers/mdspan/version.cc: Update test.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Signed-off-by: Luc Grosheintz <luc.grosheintz@gmail.com>
 2025-08-21 10:45:17 +02:00
Jonathan Wakely
9e33097738 libstdc++: Add std::inplace_vector for C++26 (P0843R14) [PR119137] 
Implement std::inplace_vector as specified in P0843R14, without follow
up papers, in particular P3074R7 (trivial unions). In consequence
inplace_vector<T, N> can be used inside constant evaluations only
if T is trivial or N is equal to zero.

We provide a separate specialization for inplace_vector<T, 0> to meet
the requirements of N5008 [inplace.vector.overview] p5. In particular
objects of such types needs to be empty.

To allow constexpr variable of inplace_vector v, where v.size() < v.capacity(),
we need to guaranteed that all elements of the storage array are initialized,
even ones in range [v.data() + v.size(), v.data() + v.capacity()). This is
perfoirmed by _M_init function, that is called by each constructor. By storing
the array in anonymous union, we can perform this initialization in constant
evaluation, avoiding the impact on runtime path.

The size() function conveys the information that _M_size <= _Nm to compiler,
by calling __builtin_unreachable(). In particular this allows us to eliminate
FP warnings by using _Nm - size() instead of _Nm - _M_size, when computing
available elements.

The included test cover almost all code paths at runtime, however some
compile time evaluation test are not yet implemented:
* operations on range, they depend on making testsuite_iterators constexpr
* negative test for invoking operations with preconditions at compile time,
  especially for zero size specialization.

	PR libstdc++/119137

libstdc++-v3/ChangeLog:

	* doc/doxygen/user.cfg.in (INPUT): Add new header.
	* include/Makefile.am: Add new header.
	* include/Makefile.in: Regenerate.
	* include/bits/stl_iterator_base_types.h (__any_input_iterator):
	Define.
	* include/bits/version.def (inplace_vector): Define.
	* include/bits/version.h: Regenerate.
	* include/precompiled/stdc++.h: Include new header.
	* src/c++23/std.cc.in: Export contents if new header.
	* include/std/inplace_vector: New file.
	* testsuite/23_containers/inplace_vector/access/capacity.cc: New file.
	* testsuite/23_containers/inplace_vector/access/elem.cc: New file.
	* testsuite/23_containers/inplace_vector/access/elem_neg.cc: New file.
	* testsuite/23_containers/inplace_vector/cons/1.cc: New file.
	* testsuite/23_containers/inplace_vector/cons/from_range.cc: New file.
	* testsuite/23_containers/inplace_vector/cons/throws.cc: New file.
	* testsuite/23_containers/inplace_vector/copy.cc: New file.
	* testsuite/23_containers/inplace_vector/erasure.cc: New file.
	* testsuite/23_containers/inplace_vector/modifiers/assign.cc: New file.
	* testsuite/23_containers/inplace_vector/modifiers/erase.cc: New file.
	* testsuite/23_containers/inplace_vector/modifiers/multi_insert.cc:
	New file.
	* testsuite/23_containers/inplace_vector/modifiers/single_insert.cc:
	New file.
	* testsuite/23_containers/inplace_vector/move.cc: New file.
	* testsuite/23_containers/inplace_vector/relops.cc: New file.
	* testsuite/23_containers/inplace_vector/version.cc: New file.
	* testsuite/util/testsuite_iterators.h (input_iterator_wrapper::base):
	Define.

Reviewed-by: Patrick Palka <ppalka@redhat.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Co-authored-by: Tomasz Kamiński <tkaminsk@redhat.com>
Signed-off-by: Tomasz Kamiński <tkaminsk@redhat.com>
 2025-07-18 09:49:34 +02:00
Tomasz Kamiński
c163bbd75b libstdc++: Do not define __cpp_lib_constexpr_exceptions [PR121114] 
Do not advertise library support for constexpr exceptions, as our
solution to throwing by __throw_* functions from <bits/functexcept.h>,
caues constant evaluation to fail, as these functions are not constexpr.

	PR libstdc++/121114

libstdc++-v3/ChangeLog:

	* include/bits/version.def (constexpr_exceptions): Add no_stdname
	and changed value.
	* include/bits/version.h: Regenerated.
	* testsuite/18_support/exception/version.cc: Test that macro is
	not exported.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Signed-off-by: Tomasz Kaminski <tkaminsk@redhat.com>
 2025-07-16 12:50:03 +02:00
Jonathan Wakely
9b6b7fed78 libstdc++: Correct value of __cpp_lib_constexpr_exceptions [PR117785] 
Only P3068R6 (Allowing exception throwing in constant-evaluation) is
implemented in the library so far, so the value of the
constexpr_exceptions feature test macro should be 202411L. Once we
support the library changes in P3378R2 (constexpr exception types) then
we can set the value to 202502L again.

libstdc++-v3/ChangeLog:

	PR libstdc++/117785
	* include/bits/version.def (constexpr_exceptions): Define
	correct value.
	* include/bits/version.h: Regenerate.
	* libsupc++/exception: Check correct value.
	* testsuite/18_support/exception/version.cc: New test.
 2025-07-14 12:53:22 +01:00
Jakub Jelinek
baaee10123 c++, libstdc++: Implement C++26 P3068R5 - constexpr exceptions [PR117785] 
The following patch implements the C++26 P3068R5 - constexpr exceptions
paper.

As the IL cxx_eval_constant* functions process already contains the low
level calls like __cxa_{allocate,free}_exception, __cxa_{,re}throw etc.,
the patch just makes 10 extern "C" __cxa_* functions magic builtins which
during constant evaluation pretend to be constexpr even when not declared
so and handle them directly, plus does the same for 3 std namespace
functions - std::uncaught_exceptions, std::current_exception and
std::rethrow_exception and adds one new FE builtin -
__builtin_eh_ptr_adjust_ref which the library can use instead of the
_M_addref and _M_release out of line methods (this one instead of
recognizing _M_* as magic too because those are clearly specific to
libstdc++ and e.g. libc++ could use something else).

The patch uses magic VAR_DECLs with heap_{uninit_,,deleted_}identifier
DECL_NAME like for operator new/delete for objects allocated with
__cxa_allocate_exception, just sets their DECL_LANG_SPECIFIC so that
we can track their reference count as well (with std::exception_ptr
the same exception object can be referenced multiple times and we want
to destruct and free only when it reaches zero refcount).

For uncaught exceptions being propagated, the patch uses new kind of
*jump_target, which is that magic VAR_DECL described above.
The largest change in the patch is making jump_target argument non-optional
in cxa_eval_constant_exception and all functions it calls that need it.
This is because exceptions can be thrown from pretty much everywhere, e.g.
binary expression can throw in either operand.  And the patch also adds
if (*jump_target) return NULL_TREE; or similar in many spots, so that we
don't crash because cxx_eval_constant_expression returned NULL_TREE
somewhere before actually trying to use it and so that we don't uselessly
dive into other operands etc.
Note, with statement expressions actually this was something we just didn't
handle correctly before, one can validly have:
  a = ({ if (x) return 42; 12; }) + b;
or in the other operand, or break/continue instead of return if it is
somewhere in a loop/switch; and it isn't ok to branch from one operand to
another one through some kind of goto.

On the potential_constant_expression_1 side, important change was to
set *jump_target conservatively on calls that could throw for C++26 (the
patch uses magic void_node for potential_constant_expression* instead of
VAR_DECL, so that we don't have to create new VAR_DECLs there uselessly).
Without that change, several methods in libstdc++ wouldn't work correctly.
I'm not sure what exactly potential_constant_expression_1 maps to in the
C++26 standard wording now and whether doing that is ok, because basically
after the first call to non-noexcept function it stops checking stuff.

And, in some spots where I know potential_constant_expression_1 didn't
check some subexpressions (e.g. the EH only cleanups or TRY_BLOCK handlers)
I've added *potential_constant_expression* calls during cxx_eval_constant*,
not sure if I need to do that because potential_constant_expression_1 is
very conservative and just doesn't recurse on subexpressions in many cases.

2025-07-10  Jakub Jelinek  <jakub@redhat.com>

	PR c++/117785
gcc/c-family/
	* c-cppbuiltin.cc (c_cpp_builtins): Predefine
	__cpp_constexpr_exceptions=202411L for C++26.
gcc/cp/
	* constexpr.cc: Implement C++26 P3068R5 - constexpr exceptions.
	(class constexpr_global_ctx): Add caught_exceptions and
	uncaught_exceptions members.
	(constexpr_global_ctx::constexpr_global_ctx): Initialize
	uncaught_exceptions.
	(returns, breaks, continues, switches): Move earlier.
	(throws): New function.
	(exception_what_str, diagnose_std_terminate,
	diagnose_uncaught_exception): New functions.
	(enum cxa_builtin): New type.
	(cxx_cxa_builtin_fn_p, cxx_eval_cxa_builtin_fn): New functions.
	(cxx_eval_builtin_function_call): Add jump_target argument.  Call
	cxx_eval_cxa_builtin_fn for __builtin_eh_ptr_adjust_ref.  Adjust
	cxx_eval_constant_expression calls, if it results in jmp_target,
	set *jump_target to it and return.
	(cxx_bind_parameters_in_call): Add jump_target argument.  Pass
	it through to cxx_eval_constant_expression.  If it sets *jump_target,
	break.
	(fold_operand): Adjust cxx_eval_constant_expression caller.
	(cxx_eval_assert): Likewise.  If it set jmp_target, return true.
	(cxx_eval_internal_function): Add jump_target argument.  Pass it
	through to cxx_eval_constant_expression.  Return early if *jump_target
	after recursing on args.
	(cxx_eval_dynamic_cast_fn): Likewise.  Don't set reference_p for
	C++26 with -fexceptions.
	(cxx_eval_thunk_call): Add jump_target argument.  Pass it through
	to cxx_eval_constant_expression.
	(cxx_set_object_constness): Likewise.  Don't set TREE_READONLY if
	throws (jump_target).
	(cxx_eval_call_expression): Add jump_target argument.  Pass it
	through to cxx_eval_internal_function, cxx_eval_builtin_function_call,
	cxx_eval_thunk_call, cxx_eval_dynamic_cast_fn and
	cxx_set_object_constness.  Pass it through also
	cxx_eval_constant_expression on arguments, cxx_bind_parameters_in_call
	and cxx_fold_indirect_ref and for those cases return early
	if *jump_target.  Call cxx_eval_cxa_builtin_fn for cxx_cxa_builtin_fn_p
	functions.  For cxx_eval_constant_expression on body, pass address of
	cleared jmp_target automatic variable, if it throws propagate
	to *jump_target and make it non-cacheable.  For C++26 don't diagnose
	calls to non-constexpr functions before cxx_bind_parameters_in_call
	could report some argument throwing an exception.
	(cxx_eval_unary_expression): Add jump_target argument.  Pass it
	through to cxx_eval_constant_expression and return early
	if *jump_target after the call.
	(cxx_fold_pointer_plus_expression): Likewise.
	(cxx_eval_binary_expression): Likewise and similarly for
	cxx_fold_pointer_plus_expression call.
	(cxx_eval_conditional_expression): Pass jump_target to
	cxx_eval_constant_expression on first operand and return early
	if *jump_target after the call.
	(cxx_eval_vector_conditional_expression): Add jump_target argument.
	Pass it through to cxx_eval_constant_expression for all 3 arguments
	and return early if *jump_target after any of those calls.
	(get_array_or_vector_nelts): Add jump_target argument.  Pass it
	through to cxx_eval_constant_expression.
	(eval_and_check_array_index): Add jump_target argument.  Pass it
	through to cxx_eval_constant_expression calls and return early after
	each of them if *jump_target.
	(cxx_eval_array_reference): Likewise.
	(cxx_eval_component_reference): Likewise.
	(cxx_eval_bit_field_ref): Likewise.
	(cxx_eval_bit_cast): Likewise.  Assert CHECKING_P call doesn't
	throw or return.
	(cxx_eval_logical_expression): Add jump_target argument.  Pass it
	through to cxx_eval_constant_expression calls and return early after
	each of them if *jump_target.
	(cxx_eval_bare_aggregate): Likewise.
	(cxx_eval_vec_init_1): Add jump_target argument.  Pass it through
	to cxx_eval_bare_aggregate and recursive call.  Pass it through
	to get_array_or_vector_nelts and cxx_eval_constant_expression
	and return early after it if *jump_target.
	(cxx_eval_vec_init): Add jump_target argument.  Pass it through
	to cxx_eval_constant_expression and cxx_eval_vec_init_1.
	(cxx_union_active_member): Add jump_target argument.  Pass it
	through to cxx_eval_constant_expression and return early after it
	if *jump_target.
	(cxx_fold_indirect_ref_1): Add jump_target argument.  Pass it
	through to cxx_union_active_member and recursive calls.
	(cxx_eval_indirect_ref): Add jump_target argument.  Pass it through
	to cxx_fold_indirect_ref_1 calls and to recursive call, in which
	case return early after it if *jump_target.
	(cxx_fold_indirect_ref): Add jump_target argument.  Pass it through
	to cxx_fold_indirect_ref and cxx_eval_constant_expression calls and
	return early after those if *jump_target.
	(cxx_eval_trinary_expression): Add jump_target argument.  Pass it
	through to cxx_eval_constant_expression calls and return early after
	those if *jump_target.
	(cxx_eval_store_expression): Add jump_target argument.  Pass it
	through to cxx_eval_constant_expression and eval_and_check_array_index
	calls and return early after those if *jump_target.
	(cxx_eval_increment_expression): Add jump_target argument.  Pass it
	through to cxx_eval_constant_expression calls and return early after
	those if *jump_target.
	(label_matches): Handle VAR_DECL case.
	(cxx_eval_statement_list): Remove local_target variable and
	!jump_target handling.  Handle throws (jump_target) like returns or
	breaks.
	(cxx_eval_loop_expr): Remove local_target variable and !jump_target
	handling.  Pass it through to cxx_eval_constant_expression.  Handle
	throws (jump_target) like returns.
	(cxx_eval_switch_expr): Pass jump_target through to
	cxx_eval_constant_expression on cond, return early after it
	if *jump_target.
	(build_new_constexpr_heap_type): Add jump_target argument.  Pass it
	through to cxx_eval_constant_expression calls, return early after
	those if *jump_target.
	(merge_jump_target): New function.
	(cxx_eval_constant_expression): Make jump_target argument no longer
	defaulted, don't test jump_target for NULL.  Pass jump_target
	through to recursive calls, cxx_eval_call_expression,
	cxx_eval_store_expression, cxx_eval_indirect_ref,
	cxx_eval_unary_expression, cxx_eval_binary_expression,
	cxx_eval_logical_expression, cxx_eval_array_reference,
	cxx_eval_component_reference, cxx_eval_bit_field_ref,
	cxx_eval_vector_conditional_expression, cxx_eval_bare_aggregate,
	cxx_eval_vec_init, cxx_eval_trinary_expression, cxx_fold_indirect_ref,
	build_new_constexpr_heap_type, cxx_eval_increment_expression,
	cxx_eval_bit_cast and return earlyu after some of those
	if *jump_target as needed.
	(cxx_eval_constant_expression) <case TARGET_EXPR>: For C++26 push
	also CLEANUP_EH_ONLY cleanups, with NULL_TREE marker after them.
	(cxx_eval_constant_expression) <case RETURN_EXPR>: Don't
	override *jump_target if throws (jump_target).
	(cxx_eval_constant_expression) <case TRY_CATCH_EXPR, case TRY_BLOCK,
	case MUST_NOT_THROW_EXPR, case TRY_FINALLY_EXPR, case CLEANUP_STMT>:
	Handle C++26 constant expressions.
	(cxx_eval_constant_expression) <case CLEANUP_POINT_EXPR>: For C++26
	with throws (jump_target) evaluate the CLEANUP_EH_ONLY cleanups as
	well, and if not throws (jump_target) skip those.  Set *jump_target
	if some of the cleanups threw.
	(cxx_eval_constant_expression) <case THROW_EXPR>: Recurse on operand
	for C++26.
	(cxx_eval_outermost_constant_expr): Diagnose uncaught exceptions both
	from main expression and cleanups, diagnose also
	break/continue/returns from the main expression.  Handle
	CLEANUP_EH_ONLY cleanup markers.  Don't diagnose mutable poison stuff
	if non_constant_p.  Use different diagnostics for non-deleted heap
	allocations if they were allocated by __cxa_allocate_exception.
	(callee_might_throw): New function.
	(struct check_for_return_continue_data): Add could_throw field.
	(check_for_return_continue): Handle AGGR_INIT_EXPR and CALL_EXPR and
	set d->could_throw if they could throw.
	(potential_constant_expression_1): For CALL_EXPR allow
	cxx_dynamic_cast_fn_p calls.  For C++26 set *jump_target to void_node
	for calls that could throw.  For C++26 if call to non-constexpr call
	is seen, try to evaluate arguments first and if they could throw,
	don't diagnose call to non-constexpr function nor return false.
	Adjust check_for_return_continue_data initializers and
	set *jump_target to void_node if data.could_throw_p.  For C++26
	recurse on THROW_EXPR argument.  Add comment explaining TRY_BLOCK
	handling with C++26 exceptions.  Handle throws like returns in some
	cases.
	* cp-tree.h (MUST_NOT_THROW_NOEXCEPT_P, MUST_NOT_THROW_THROW_P,
	MUST_NOT_THROW_CATCH_P, DECL_EXCEPTION_REFCOUNT): Define.
	(DECL_LOCAL_DECL_P): Fix comment typo, VARIABLE_DECL -> VAR_DECL.
	(enum cp_built_in_function): Add CP_BUILT_IN_EH_PTR_ADJUST_REF,
	(handler_match_for_exception_type): Declare.
	* call.cc (handler_match_for_exception_type): New function.
	* except.cc (initialize_handler_parm): Set MUST_NOT_THROW_CATCH_P
	on newly created MUST_NOT_THROW_EXPR.
	(begin_eh_spec_block): Set MUST_NOT_THROW_NOEXCEPT_P.
	(wrap_cleanups_r): Set MUST_NOT_THROW_THROW_P.
	(build_throw): Add another TARGET_EXPR whose scope spans
	until after the __cxa_throw call and copy pointer value from ptr
	to it and use it in __cxa_throw argument.
	* tree.cc (builtin_valid_in_constant_expr_p): Handle
	CP_BUILT_IN_EH_PTR_ADJUST_REF.
	* decl.cc (cxx_init_decl_processing): Initialize
	__builtin_eh_ptr_adjust_ref FE builtin.
	* pt.cc (tsubst_stmt) <case MUST_NOT_THROW_EXPR>: Copy the
	MUST_NOT_THROW_NOEXCEPT_P, MUST_NOT_THROW_THROW_P and
	MUST_NOT_THROW_CATCH_P flags.
	* cp-gimplify.cc (cp_gimplify_expr) <case CALL_EXPR>: Error on
	non-folded CP_BUILT_IN_EH_PTR_ADJUST_REF calls.
gcc/testsuite/
	* g++.dg/cpp0x/constexpr-ellipsis2.C: Expect different diagnostics for
	C++26.
	* g++.dg/cpp0x/constexpr-throw.C: Likewise.
	* g++.dg/cpp1y/constexpr-84192.C: Expect different diagnostics.
	* g++.dg/cpp1y/constexpr-throw.C: Expect different diagnostics for
	C++26.
	* g++.dg/cpp1z/constexpr-asm-5.C: Likewise.
	* g++.dg/cpp26/constexpr-eh1.C: New test.
	* g++.dg/cpp26/constexpr-eh2.C: New test.
	* g++.dg/cpp26/constexpr-eh3.C: New test.
	* g++.dg/cpp26/constexpr-eh4.C: New test.
	* g++.dg/cpp26/constexpr-eh5.C: New test.
	* g++.dg/cpp26/constexpr-eh6.C: New test.
	* g++.dg/cpp26/constexpr-eh7.C: New test.
	* g++.dg/cpp26/constexpr-eh8.C: New test.
	* g++.dg/cpp26/constexpr-eh9.C: New test.
	* g++.dg/cpp26/constexpr-eh10.C: New test.
	* g++.dg/cpp26/constexpr-eh11.C: New test.
	* g++.dg/cpp26/constexpr-eh12.C: New test.
	* g++.dg/cpp26/constexpr-eh13.C: New test.
	* g++.dg/cpp26/constexpr-eh14.C: New test.
	* g++.dg/cpp26/constexpr-eh15.C: New test.
	* g++.dg/cpp26/feat-cxx26.C: Change formatting in __cpp_pack_indexing
	and __cpp_pp_embed test.  Add __cpp_constexpr_exceptions test.
	* g++.dg/cpp26/static_assert1.C: Expect different diagnostics for
	C++26.
	* g++.dg/cpp2a/consteval34.C: Likewise.
	* g++.dg/cpp2a/consteval-memfn1.C: Likewise.
	* g++.dg/cpp2a/constexpr-dynamic4.C: For C++26 add std::exception and
	std::bad_cast definitions and expect different diagnostics.
	* g++.dg/cpp2a/constexpr-dynamic6.C: Likewise.
	* g++.dg/cpp2a/constexpr-dynamic7.C: Likewise.
	* g++.dg/cpp2a/constexpr-dynamic8.C: Likewise.
	* g++.dg/cpp2a/constexpr-dynamic9.C: Likewise.
	* g++.dg/cpp2a/constexpr-dynamic11.C: Likewise.
	* g++.dg/cpp2a/constexpr-dynamic14.C: Likewise.
	* g++.dg/cpp2a/constexpr-dynamic18.C: Likewise.
	* g++.dg/cpp2a/constexpr-new27.C: New test.
	* g++.dg/cpp2a/constexpr-typeid5.C: New test.
libstdc++-v3/
	* include/bits/version.def (constexpr_exceptions): New.
	* include/bits/version.h: Regenerate.
	* libsupc++/exception (std::bad_exception::bad_exception): Add
	_GLIBCXX26_CONSTEXPR.
	(std::bad_exception::~bad_exception, std::bad_exception::what): For
	C++26 add constexpr and define inline.
	* libsupc++/exception.h (std::exception::exception,
	std::exception::operator=): Add _GLIBCXX26_CONSTEXPR.
	(std::exception::~exception, std::exception::what): For C++26 add
	constexpr and define inline.
	* libsupc++/exception_ptr.h (std::make_exception_ptr): Add
	_GLIBCXX26_CONSTEXPR.  For if consteval use just throw with
	current_exception() in catch.
	(std::exception_ptr::exception_ptr(void*)): For C++26 add constexpr
	and define inline.
	(std::exception_ptr::exception_ptr()): Add _GLIBCXX26_CONSTEXPR.
	(std::exception_ptr::exception_ptr(const exception_ptr&)): Likewise.
	Use __builtin_eh_ptr_adjust_ref if consteval and compiler has it
	instead of _M_addref.
	(std::exception_ptr::exception_ptr(nullptr_t)): Add
	_GLIBCXX26_CONSTEXPR.
	(std::exception_ptr::exception_ptr(exception_ptr&&)): Likewise.
	(std::exception_ptr::operator=): Likewise.
	(std::exception_ptr::~exception_ptr): Likewise.  Use
	__builtin_eh_ptr_adjust_ref if consteval and compiler has it
	instead of _M_release.
	(std::exception_ptr::swap): Add _GLIBCXX26_CONSTEXPR.
	(std::exception_ptr::operator bool): Likewise.
	(std::exception_ptr::operator==): Likewise.
	* libsupc++/nested_exception.h
	(std::nested_exception::nested_exception): Add _GLIBCXX26_CONSTEXPR.
	(std::nested_exception::operator=): Likewise.
	(std::nested_exception::~nested_exception): For C++26 add constexpr
	and define inline.
	(std::nested_exception::rethrow_if_nested): Add _GLIBCXX26_CONSTEXPR.
	(std::nested_exception::nested_ptr): Likewise.
	(std::_Nested_exception::_Nested_exception): Likewise.
	(std::throw_with_nested, std::rethrow_if_nested): Likewise.
	* libsupc++/new (std::bad_alloc::bad_alloc): Likewise.
	(std::bad_alloc::operator=): Likewise.
	(std::bad_alloc::~bad_alloc): For C++26 add constexpr and define
	inline.
	(std::bad_alloc::what): Likewise.
	(std::bad_array_new_length::bad_array_new_length): Add
	_GLIBCXX26_CONSTEXPR.
	(std::bad_array_new_length::~bad_array_new_length): For C++26 add
	constexpr and define inline.
	(std::bad_array_new_length::what): Likewise.
	* libsupc++/typeinfo (std::bad_cast::bad_cast): Add
	_GLIBCXX26_CONSTEXPR.
	(std::bad_cast::~bad_cast): For C++26 add constexpr and define inline.
	(std::bad_cast::what): Likewise.
	(std::bad_typeid::bad_typeid): Add _GLIBCXX26_CONSTEXPR.
	(std::bad_typeid::~bad_typeid): For C++26 add constexpr and define
	inline.
	(std::bad_typeid::what): Likewise.
 2025-07-10 23:32:06 +02:00
Paul Keir
10b8379252 libstdc++: Add smart ptr owner_equals and owner_hash [PR117403] 
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>
 2025-07-09 12:14:40 +01:00
Luc Grosheintz
7b3b315e48 libstdc++: Set feature test macro for complete C++23 mdspan [PR107761]. 
PR libstdc++/107761

libstdc++-v3/ChangeLog:

	* include/bits/version.def (mdspan): Set to 202207 and remove
	no_stdname.
	* include/bits/version.h: Regenerate.
	* testsuite/23_containers/mdspan/version.cc: Test presence
	of feature test macro.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Signed-off-by: Luc Grosheintz <luc.grosheintz@gmail.com>
 2025-07-08 15:35:41 +02:00
Patrick Palka
2a56f3c539 libstdc++: Implement ranges::shift_left/right from P2440R1 
The implementation is just a copy of std::shift_left/right with the
following changes:

 - check bidirectional_iterator instead of iterator_category
 - cope with __last being a distinct sentinel type
 - for shift_left, return the subrange {__first, X} instead of X
 - for shift_right, return the subrange {X, ranges::next(__first, __last)}
   instead of X
 - use the ranges:: versions of move_backward, move and iter_swap
 - don't bother std::move'ing any iterators, it's unnecessary since all
   iterators are forward, it's visually noisy, and in earlier versions
   of this patch it introduced subtle use-after-move bugs

In passing also use the __glibcxx_shift macro to guard the
std::shift_left/right implementations.

libstdc++-v3/ChangeLog:

	* include/bits/ranges_algo.h (shift_left, shift_right): Guard
	with __glibcxx_shift >= 201806L.
	(ranges::__shift_left_fn, ranges::shift_left): Define for C++23.
	(ranges::__shift_right_fn, ranges::shift_right): Likewise.
	* include/bits/version.def (shift): Update for C++23.
	* include/bits/version.h: Regenerate.
	* src/c++23/std.cc.in: Add ranges::shift_left/right.
	* testsuite/25_algorithms/shift_left/constrained.cc: New test,
	based off of 1.cc.
	* testsuite/25_algorithms/shift_right/constrained.cc: New test,
	based off of 1.cc.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
 2025-07-06 14:49:34 -04:00
Nathan Myers
062f217f41 libstdc++: fix bits/version.def typo 
bits/version.def was missing a ';'.

libstdc++-v3/Changelog:
	* include/bits/version.def: Fix typo.
	* include/bits/version.h: Rebuilt.
 2025-07-03 19:54:28 -04:00