The specification for std::ranges::iter_move apparently requires us to
handle types which do not satisfy std::indirectly_readable, for example
with overloaded operator* which behaves differently for different value
categories.

libstdc++-v3/ChangeLog:

	PR libstdc++/106612
	* include/bits/iterator_concepts.h (_IterMove::__iter_ref_t):
	New alias template.
	(_IterMove::__result): Use __iter_ref_t instead of
	std::iter_reference_t.
	(_IterMove::__type): Remove incorrect __dereferenceable
	constraint.
	(_IterMove::operator()): Likewise. Add correct constraints. Use
	__iter_ref_t instead of std::iter_reference_t. Forward parameter
	as correct value category.
	(iter_swap): Add comments.
	* testsuite/24_iterators/customization_points/iter_move.cc: Test
	that iter_move is found by ADL and that rvalue arguments are
	handled correctly.

Reviewed-by: Patrick Palka <ppalka@redhat.com>

The ranges::move and ranges::move_backward algorithms are supposed to
use ranges::iter_move(iter) instead of std::move(*iter), which matters
for an iterator type with an iter_move overload findable by ADL.

Currently those algorithms use std::__assign_one which uses std::move,
so define a new ranges::__detail::__assign_one helper function that uses
ranges::iter_move.

libstdc++-v3/ChangeLog:

	PR libstdc++/105609
	* include/bits/ranges_algobase.h (__detail::__assign_one): New
	helper function.
	(__copy_or_move, __copy_or_move_backward): Use new function
	instead of std::__assign_one.
	* testsuite/25_algorithms/move/constrained.cc: Check that
	ADL iter_move is used in preference to std::move.
	* testsuite/25_algorithms/move_backward/constrained.cc:
	Likewise.

The standard requires that we reject attempts to create a ranges::to
adaptor for cv-qualified types and non-class types. Currently we only
diagnose it once the adaptor is used in a pipeline.

This adds static assertions to diagnose it immediately.

libstdc++-v3/ChangeLog:

	PR libstdc++/112803
	* include/std/ranges (ranges::to): Add static assertions to
	enforce Mandates conditions.
	* testsuite/std/ranges/conv/112803.cc: New test.

Here for

  using RCI = reverse_iterator<basic_const_iterator<vector<int>::iterator>>
  static_assert(std::totally_ordered<RCI>);

we effectively need to check the requirement

  requires (RCI x) { x RELOP x; }  for each RELOP in {<, >, <=, >=}

which we expect to be straightforwardly satisfied by reverse_iterator's
namespace-scope relops.  But due to ADL we find ourselves also
considering the basic_const_iterator relop friends, which before CWG
2369 would be quickly discarded since RCI clearly isn't convertible to
basic_const_iterator.  After CWG 2369 though we must first check these
relops' constraints (with _It = vector<int>::iterator and _It2 = RCI),
which entails checking totally_ordered<RCI> recursively.

This patch fixes this by turning the problematic non-dependent function
parameters of type basic_const_iterator<_It> into dependent ones of
type basic_const_iterator<_It3> where _It3 is constrained to match _It.
Thus the basic_const_iterator relop friends now get quickly discarded
during deduction and before the constraint check if the second operand
isn't a specialization of basic_const_iterator (or derived from one)
like before CWG 2369.

	PR libstdc++/112490

libstdc++-v3/ChangeLog:

	* include/bits/stl_iterator.h (basic_const_iterator::operator<):
	Replace non-dependent basic_const_iterator function parameter with
	a dependent one of type basic_const_iterator<_It3> where _It3
	matches _It.
	(basic_const_iterator::operator>): Likewise.
	(basic_const_iterator::operator<=): Likewise.
	(basic_const_iterator::operator>=): Likewise.
	* testsuite/24_iterators/const_iterator/112490.cc: New test.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>

stable_sort has been made constexpr in C++26. Apart from plastering a
few functions with constexpr, there's an implementation challenge, that
is: stable_sort takes different codepaths in case extra memory can be
allocated. Rather than doing some major refactorings, simply use the
non-allocating path during constant evaluation. That's the same codepath
used when extra memory could not be allocated, as well as by
freestanding.

libstdc++-v3/ChangeLog:

	* include/bits/algorithmfwd.h (stable_sort): Add constexpr.
	* include/bits/ranges_algo.h (__stable_sort_fn): Add constexpr
	to the function call operators.
	* include/bits/stl_algo.h (__stable_sort): Add constexpr.
	During constant evaluation, always use the non-allocating path.
	(stable_sort): Add constexpr.
	(__inplace_stable_sort): Likewise.
	(__merge_without_buffer): Likewise.
	* include/bits/version.def (constexpr_algorithms): Bump value
	for C++26.
	* include/bits/version.h: Regnerate.
	* testsuite/25_algorithms/cpp_lib_constexpr.cc: Test the bumped
	feature-testing macro.
	* testsuite/25_algorithms/headers/algorithm/synopsis.cc: Adapt
	the test to constexpr stable_sort.
	* testsuite/25_algorithms/stable_sort/constexpr.cc: New test.

Signed-off-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

It is wrong to reuse a cached hash code from another container when this code depends
on the state of the container's Hash functor.

Add checks that Hash functor is stateless before reusing the cached hash code.

libstdc++-v3/ChangeLog:

	* include/bits/hashtable_policy.h
	(_Hash_code_base::_M_copy_code, _Hash_code_base::_M_store_code): Remove.
	* include/bits/hashtable.h (_M_hash_code_ext): New.
	(_M_merge_multi(_Hashtable&)): Use latter.
	(_M_copy_code): New.
	(_M_assign): Use latter.
	(_M_bucket_index_ex): New.
	(_M_equals): Use latter.
	(_M_store_code): New.
	(_M_src_hash_code): Remove key_type parameter.
	* testsuite/23_containers/unordered_map/modifiers/merge.cc (test10): New
	test case.

LWG 4027 effectively makes the const range access CPOs ranges::cfoo behave
more consistently across C++23 and C++20 (pre-P2278R4) and also more
consistently with the std::cfoo range accessors, as the below testcase
adjustments demonstrate (which mostly consist of reverting workarounds
added by r14-3771-gf12e26f3496275 and r13-7186-g0d94c6df183375).

In passing fix PR118083 which reports that the input_range constraint on
possibly-const-range is missing in our implementation.  A consequence of
this is that the const range access CPOs now consistently reject a non-range
argument, and so in some our of tests we need to introduce otherwise
unused begin/end members.

	PR libstdc++/118083

libstdc++-v3/ChangeLog:

	* include/bits/ranges_base.h
	(ranges::__access::__possibly_const_range): Adjust logic as per
	LWG 4027.  Add missing input_range constraint.
	* testsuite/std/ranges/access/cbegin.cc (test05): Verify LWG
	4027 testcases.
	* testsuite/std/ranges/access/cdata.cc: Adjust, simplify and
	consolidate some tests after the above.
	* testsuite/std/ranges/access/cend.cc: Likewise.
	* testsuite/std/ranges/access/crbegin.cc: Likewise.
	* testsuite/std/ranges/access/crend.cc: Likewise.
	* testsuite/std/ranges/adaptors/join.cc: Likewise.
	* testsuite/std/ranges/adaptors/take_while.cc: Likewise.
	* testsuite/std/ranges/adaptors/transform.cc: Likewise.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>

Turn test cases into UNSUPPORTED if running into 'sorry, unimplemented: dynamic stack allocation not supported'

In Subversion r217296 (Git commit e2acc079)
"Testsuite alloca fixes for ptx", effective-target 'alloca' was added to mark
up test cases that run into the nvptx back end's non-support of dynamic stack
allocation.  (Later, nvptx gained conditional support for that in
commit 3861d362
"nvptx: PTX 'alloca' for '-mptx=7.3'+, '-march=sm_52'+ [PR65181]", but on the
other hand, in commit f93a612f
"bpf: liberate R9 for general register allocation", the BPF back end joined
"the list of targets that do not support alloca in target-support.exp".

Manually maintaining the list of test cases requiring effective-target 'alloca'
is notoriously hard, gets out of date quickly: new test cases added to the test
suite may need to be analyzed and annotated, and over time annotations also may
need to be removed, in cases where the compiler learns to optimize out
'alloca'/VLA usage, for example.  This commit replaces (99 % of) the manual
annotations with an automatic scheme: turn test cases into UNSUPPORTED if
running into 'sorry, unimplemented: dynamic stack allocation not supported'.

	gcc/testsuite/
	* lib/target-supports.exp (check_effective_target_alloca):
	Gracefully handle the case that we've not be called (indirectly)
	from 'dg-test'.
	* lib/gcc-dg.exp (proc gcc-dg-prune): Turn
	'sorry, unimplemented: dynamic stack allocation not supported' into
	UNSUPPORTED.
	* c-c++-common/Walloca-larger-than.c: Don't
	'dg-require-effective-target alloca'.
	* c-c++-common/Warray-bounds-9.c: Likewise.
	* c-c++-common/Warray-bounds.c: Likewise.
	* c-c++-common/Wdangling-pointer-2.c: Likewise.
	* c-c++-common/Wdangling-pointer-4.c: Likewise.
	* c-c++-common/Wdangling-pointer-5.c: Likewise.
	* c-c++-common/Wdangling-pointer.c: Likewise.
	* c-c++-common/Wimplicit-fallthrough-7.c: Likewise.
	* c-c++-common/Wsizeof-pointer-memaccess1.c: Likewise.
	* c-c++-common/Wsizeof-pointer-memaccess2.c: Likewise.
	* c-c++-common/Wstringop-truncation.c: Likewise.
	* c-c++-common/Wunused-var-6.c: Likewise.
	* c-c++-common/Wunused-var-8.c: Likewise.
	* c-c++-common/analyzer/alloca-leak.c: Likewise.
	* c-c++-common/analyzer/allocation-size-multiline-2.c: Likewise.
	* c-c++-common/analyzer/allocation-size-multiline-3.c: Likewise.
	* c-c++-common/analyzer/capacity-1.c: Likewise.
	* c-c++-common/analyzer/capacity-3.c: Likewise.
	* c-c++-common/analyzer/imprecise-floating-point-1.c: Likewise.
	* c-c++-common/analyzer/infinite-recursion-alloca.c: Likewise.
	* c-c++-common/analyzer/malloc-callbacks.c: Likewise.
	* c-c++-common/analyzer/malloc-paths-8.c: Likewise.
	* c-c++-common/analyzer/out-of-bounds-5.c: Likewise.
	* c-c++-common/analyzer/out-of-bounds-diagram-11.c: Likewise.
	* c-c++-common/analyzer/uninit-alloca.c: Likewise.
	* c-c++-common/analyzer/write-to-string-literal-5.c: Likewise.
	* c-c++-common/asan/alloca_loop_unpoisoning.c: Likewise.
	* c-c++-common/auto-init-11.c: Likewise.
	* c-c++-common/auto-init-12.c: Likewise.
	* c-c++-common/auto-init-15.c: Likewise.
	* c-c++-common/auto-init-16.c: Likewise.
	* c-c++-common/builtins.c: Likewise.
	* c-c++-common/dwarf2/vla1.c: Likewise.
	* c-c++-common/gomp/pr61486-2.c: Likewise.
	* c-c++-common/torture/builtin-clear-padding-4.c: Likewise.
	* c-c++-common/torture/strub-run3.c: Likewise.
	* c-c++-common/torture/strub-run4.c: Likewise.
	* c-c++-common/torture/strub-run4c.c: Likewise.
	* c-c++-common/torture/strub-run4d.c: Likewise.
	* c-c++-common/torture/strub-run4i.c: Likewise.
	* g++.dg/Walloca1.C: Likewise.
	* g++.dg/Walloca2.C: Likewise.
	* g++.dg/cpp0x/pr70338.C: Likewise.
	* g++.dg/cpp1y/lambda-generic-vla1.C: Likewise.
	* g++.dg/cpp1y/vla10.C: Likewise.
	* g++.dg/cpp1y/vla2.C: Likewise.
	* g++.dg/cpp1y/vla6.C: Likewise.
	* g++.dg/cpp1y/vla8.C: Likewise.
	* g++.dg/debug/debug5.C: Likewise.
	* g++.dg/debug/debug6.C: Likewise.
	* g++.dg/debug/pr54828.C: Likewise.
	* g++.dg/diagnostic/pr70105.C: Likewise.
	* g++.dg/eh/cleanup5.C: Likewise.
	* g++.dg/eh/spbp.C: Likewise.
	* g++.dg/ext/builtin_alloca.C: Likewise.
	* g++.dg/ext/tmplattr9.C: Likewise.
	* g++.dg/ext/vla10.C: Likewise.
	* g++.dg/ext/vla11.C: Likewise.
	* g++.dg/ext/vla12.C: Likewise.
	* g++.dg/ext/vla15.C: Likewise.
	* g++.dg/ext/vla16.C: Likewise.
	* g++.dg/ext/vla17.C: Likewise.
	* g++.dg/ext/vla23.C: Likewise.
	* g++.dg/ext/vla3.C: Likewise.
	* g++.dg/ext/vla6.C: Likewise.
	* g++.dg/ext/vla7.C: Likewise.
	* g++.dg/init/array24.C: Likewise.
	* g++.dg/init/new47.C: Likewise.
	* g++.dg/init/pr55497.C: Likewise.
	* g++.dg/opt/pr78201.C: Likewise.
	* g++.dg/template/vla2.C: Likewise.
	* g++.dg/torture/Wsizeof-pointer-memaccess1.C: Likewise.
	* g++.dg/torture/Wsizeof-pointer-memaccess2.C: Likewise.
	* g++.dg/torture/pr62127.C: Likewise.
	* g++.dg/torture/pr67055.C: Likewise.
	* g++.dg/torture/stackalign/eh-alloca-1.C: Likewise.
	* g++.dg/torture/stackalign/eh-inline-2.C: Likewise.
	* g++.dg/torture/stackalign/eh-vararg-1.C: Likewise.
	* g++.dg/torture/stackalign/eh-vararg-2.C: Likewise.
	* g++.dg/warn/Wplacement-new-size-5.C: Likewise.
	* g++.dg/warn/Wsizeof-pointer-memaccess-1.C: Likewise.
	* g++.dg/warn/Wvla-1.C: Likewise.
	* g++.dg/warn/Wvla-3.C: Likewise.
	* g++.old-deja/g++.ext/array2.C: Likewise.
	* g++.old-deja/g++.ext/constructor.C: Likewise.
	* g++.old-deja/g++.law/builtin1.C: Likewise.
	* g++.old-deja/g++.other/crash12.C: Likewise.
	* g++.old-deja/g++.other/eh3.C: Likewise.
	* g++.old-deja/g++.pt/array6.C: Likewise.
	* g++.old-deja/g++.pt/dynarray.C: Likewise.
	* gcc.c-torture/compile/20000923-1.c: Likewise.
	* gcc.c-torture/compile/20030224-1.c: Likewise.
	* gcc.c-torture/compile/20071108-1.c: Likewise.
	* gcc.c-torture/compile/20071117-1.c: Likewise.
	* gcc.c-torture/compile/900313-1.c: Likewise.
	* gcc.c-torture/compile/parms.c: Likewise.
	* gcc.c-torture/compile/pr17397.c: Likewise.
	* gcc.c-torture/compile/pr35006.c: Likewise.
	* gcc.c-torture/compile/pr42956.c: Likewise.
	* gcc.c-torture/compile/pr51354.c: Likewise.
	* gcc.c-torture/compile/pr52714.c: Likewise.
	* gcc.c-torture/compile/pr55851.c: Likewise.
	* gcc.c-torture/compile/pr77754-1.c: Likewise.
	* gcc.c-torture/compile/pr77754-2.c: Likewise.
	* gcc.c-torture/compile/pr77754-3.c: Likewise.
	* gcc.c-torture/compile/pr77754-4.c: Likewise.
	* gcc.c-torture/compile/pr77754-5.c: Likewise.
	* gcc.c-torture/compile/pr77754-6.c: Likewise.
	* gcc.c-torture/compile/pr78439.c: Likewise.
	* gcc.c-torture/compile/pr79413.c: Likewise.
	* gcc.c-torture/compile/pr82564.c: Likewise.
	* gcc.c-torture/compile/pr87110.c: Likewise.
	* gcc.c-torture/compile/pr99787-1.c: Likewise.
	* gcc.c-torture/compile/vla-const-1.c: Likewise.
	* gcc.c-torture/compile/vla-const-2.c: Likewise.
	* gcc.c-torture/execute/20010209-1.c: Likewise.
	* gcc.c-torture/execute/20020314-1.c: Likewise.
	* gcc.c-torture/execute/20020412-1.c: Likewise.
	* gcc.c-torture/execute/20021113-1.c: Likewise.
	* gcc.c-torture/execute/20040223-1.c: Likewise.
	* gcc.c-torture/execute/20040308-1.c: Likewise.
	* gcc.c-torture/execute/20040811-1.c: Likewise.
	* gcc.c-torture/execute/20070824-1.c: Likewise.
	* gcc.c-torture/execute/20070919-1.c: Likewise.
	* gcc.c-torture/execute/built-in-setjmp.c: Likewise.
	* gcc.c-torture/execute/pr22061-1.c: Likewise.
	* gcc.c-torture/execute/pr43220.c: Likewise.
	* gcc.c-torture/execute/pr82210.c: Likewise.
	* gcc.c-torture/execute/pr86528.c: Likewise.
	* gcc.c-torture/execute/vla-dealloc-1.c: Likewise.
	* gcc.dg/20001012-2.c: Likewise.
	* gcc.dg/20020415-1.c: Likewise.
	* gcc.dg/20030331-2.c: Likewise.
	* gcc.dg/20101010-1.c: Likewise.
	* gcc.dg/Walloca-1.c: Likewise.
	* gcc.dg/Walloca-10.c: Likewise.
	* gcc.dg/Walloca-11.c: Likewise.
	* gcc.dg/Walloca-12.c: Likewise.
	* gcc.dg/Walloca-13.c: Likewise.
	* gcc.dg/Walloca-14.c: Likewise.
	* gcc.dg/Walloca-15.c: Likewise.
	* gcc.dg/Walloca-2.c: Likewise.
	* gcc.dg/Walloca-3.c: Likewise.
	* gcc.dg/Walloca-4.c: Likewise.
	* gcc.dg/Walloca-5.c: Likewise.
	* gcc.dg/Walloca-6.c: Likewise.
	* gcc.dg/Walloca-7.c: Likewise.
	* gcc.dg/Walloca-8.c: Likewise.
	* gcc.dg/Walloca-9.c: Likewise.
	* gcc.dg/Walloca-larger-than-2.c: Likewise.
	* gcc.dg/Walloca-larger-than-3.c: Likewise.
	* gcc.dg/Walloca-larger-than-4.c: Likewise.
	* gcc.dg/Walloca-larger-than.c: Likewise.
	* gcc.dg/Warray-bounds-22.c: Likewise.
	* gcc.dg/Warray-bounds-41.c: Likewise.
	* gcc.dg/Warray-bounds-46.c: Likewise.
	* gcc.dg/Warray-bounds-48-novec.c: Likewise.
	* gcc.dg/Warray-bounds-48.c: Likewise.
	* gcc.dg/Warray-bounds-50.c: Likewise.
	* gcc.dg/Warray-bounds-63.c: Likewise.
	* gcc.dg/Warray-bounds-66.c: Likewise.
	* gcc.dg/Wdangling-pointer.c: Likewise.
	* gcc.dg/Wfree-nonheap-object-2.c: Likewise.
	* gcc.dg/Wfree-nonheap-object.c: Likewise.
	* gcc.dg/Wrestrict-17.c: Likewise.
	* gcc.dg/Wrestrict.c: Likewise.
	* gcc.dg/Wreturn-local-addr-2.c: Likewise.
	* gcc.dg/Wreturn-local-addr-3.c: Likewise.
	* gcc.dg/Wreturn-local-addr-4.c: Likewise.
	* gcc.dg/Wreturn-local-addr-6.c: Likewise.
	* gcc.dg/Wsizeof-pointer-memaccess1.c: Likewise.
	* gcc.dg/Wstack-usage.c: Likewise.
	* gcc.dg/Wstrict-aliasing-bogus-vla-1.c: Likewise.
	* gcc.dg/Wstrict-overflow-27.c: Likewise.
	* gcc.dg/Wstringop-overflow-15.c: Likewise.
	* gcc.dg/Wstringop-overflow-23.c: Likewise.
	* gcc.dg/Wstringop-overflow-25.c: Likewise.
	* gcc.dg/Wstringop-overflow-27.c: Likewise.
	* gcc.dg/Wstringop-overflow-3.c: Likewise.
	* gcc.dg/Wstringop-overflow-39.c: Likewise.
	* gcc.dg/Wstringop-overflow-56.c: Likewise.
	* gcc.dg/Wstringop-overflow-57.c: Likewise.
	* gcc.dg/Wstringop-overflow-67.c: Likewise.
	* gcc.dg/Wstringop-overflow-71.c: Likewise.
	* gcc.dg/Wstringop-truncation-3.c: Likewise.
	* gcc.dg/Wvla-larger-than-1.c: Likewise.
	* gcc.dg/Wvla-larger-than-2.c: Likewise.
	* gcc.dg/Wvla-larger-than-3.c: Likewise.
	* gcc.dg/Wvla-larger-than-4.c: Likewise.
	* gcc.dg/Wvla-larger-than-5.c: Likewise.
	* gcc.dg/analyzer/boxed-malloc-1.c: Likewise.
	* gcc.dg/analyzer/call-summaries-2.c: Likewise.
	* gcc.dg/analyzer/malloc-1.c: Likewise.
	* gcc.dg/analyzer/malloc-reuse.c: Likewise.
	* gcc.dg/analyzer/out-of-bounds-diagram-12.c: Likewise.
	* gcc.dg/analyzer/pr93355-localealias.c: Likewise.
	* gcc.dg/analyzer/putenv-1.c: Likewise.
	* gcc.dg/analyzer/taint-alloc-1.c: Likewise.
	* gcc.dg/analyzer/torture/pr93373.c: Likewise.
	* gcc.dg/analyzer/torture/ubsan-1.c: Likewise.
	* gcc.dg/analyzer/vla-1.c: Likewise.
	* gcc.dg/atomic/stdatomic-vm.c: Likewise.
	* gcc.dg/attr-alloc_size-6.c: Likewise.
	* gcc.dg/attr-alloc_size-7.c: Likewise.
	* gcc.dg/attr-alloc_size-8.c: Likewise.
	* gcc.dg/attr-alloc_size-9.c: Likewise.
	* gcc.dg/attr-noipa.c: Likewise.
	* gcc.dg/auto-init-uninit-36.c: Likewise.
	* gcc.dg/auto-init-uninit-9.c: Likewise.
	* gcc.dg/auto-type-1.c: Likewise.
	* gcc.dg/builtin-alloc-size.c: Likewise.
	* gcc.dg/builtin-dynamic-alloc-size.c: Likewise.
	* gcc.dg/builtin-dynamic-object-size-1.c: Likewise.
	* gcc.dg/builtin-dynamic-object-size-2.c: Likewise.
	* gcc.dg/builtin-dynamic-object-size-3.c: Likewise.
	* gcc.dg/builtin-dynamic-object-size-4.c: Likewise.
	* gcc.dg/builtin-object-size-1.c: Likewise.
	* gcc.dg/builtin-object-size-2.c: Likewise.
	* gcc.dg/builtin-object-size-3.c: Likewise.
	* gcc.dg/builtin-object-size-4.c: Likewise.
	* gcc.dg/builtins-64.c: Likewise.
	* gcc.dg/builtins-68.c: Likewise.
	* gcc.dg/c23-auto-2.c: Likewise.
	* gcc.dg/c99-const-expr-13.c: Likewise.
	* gcc.dg/c99-vla-1.c: Likewise.
	* gcc.dg/fold-alloca-1.c: Likewise.
	* gcc.dg/gomp/pr30494.c: Likewise.
	* gcc.dg/gomp/vla-2.c: Likewise.
	* gcc.dg/gomp/vla-3.c: Likewise.
	* gcc.dg/gomp/vla-4.c: Likewise.
	* gcc.dg/gomp/vla-5.c: Likewise.
	* gcc.dg/graphite/pr99085.c: Likewise.
	* gcc.dg/guality/guality.c: Likewise.
	* gcc.dg/lto/pr80778_0.c: Likewise.
	* gcc.dg/nested-func-10.c: Likewise.
	* gcc.dg/nested-func-12.c: Likewise.
	* gcc.dg/nested-func-13.c: Likewise.
	* gcc.dg/nested-func-14.c: Likewise.
	* gcc.dg/nested-func-15.c: Likewise.
	* gcc.dg/nested-func-16.c: Likewise.
	* gcc.dg/nested-func-17.c: Likewise.
	* gcc.dg/nested-func-9.c: Likewise.
	* gcc.dg/packed-vla.c: Likewise.
	* gcc.dg/pr100225.c: Likewise.
	* gcc.dg/pr25682.c: Likewise.
	* gcc.dg/pr27301.c: Likewise.
	* gcc.dg/pr31507-1.c: Likewise.
	* gcc.dg/pr33238.c: Likewise.
	* gcc.dg/pr41470.c: Likewise.
	* gcc.dg/pr49120.c: Likewise.
	* gcc.dg/pr50764.c: Likewise.
	* gcc.dg/pr51491-2.c: Likewise.
	* gcc.dg/pr51990-2.c: Likewise.
	* gcc.dg/pr51990.c: Likewise.
	* gcc.dg/pr59011.c: Likewise.
	* gcc.dg/pr59523.c: Likewise.
	* gcc.dg/pr61561.c: Likewise.
	* gcc.dg/pr78468.c: Likewise.
	* gcc.dg/pr78902.c: Likewise.
	* gcc.dg/pr79972.c: Likewise.
	* gcc.dg/pr82875.c: Likewise.
	* gcc.dg/pr83844.c: Likewise.
	* gcc.dg/pr84131.c: Likewise.
	* gcc.dg/pr87099.c: Likewise.
	* gcc.dg/pr87320.c: Likewise.
	* gcc.dg/pr89045.c: Likewise.
	* gcc.dg/pr91014.c: Likewise.
	* gcc.dg/pr93986.c: Likewise.
	* gcc.dg/pr98721-1.c: Likewise.
	* gcc.dg/pr99122-2.c: Likewise.
	* gcc.dg/shrink-wrap-alloca.c: Likewise.
	* gcc.dg/sso-14.c: Likewise.
	* gcc.dg/strlenopt-62.c: Likewise.
	* gcc.dg/strlenopt-83.c: Likewise.
	* gcc.dg/strlenopt-84.c: Likewise.
	* gcc.dg/strlenopt-91.c: Likewise.
	* gcc.dg/torture/Wsizeof-pointer-memaccess1.c: Likewise.
	* gcc.dg/torture/calleesave-sse.c: Likewise.
	* gcc.dg/torture/pr48953.c: Likewise.
	* gcc.dg/torture/pr71881.c: Likewise.
	* gcc.dg/torture/pr71901.c: Likewise.
	* gcc.dg/torture/pr78742.c: Likewise.
	* gcc.dg/torture/pr92088-1.c: Likewise.
	* gcc.dg/torture/pr92088-2.c: Likewise.
	* gcc.dg/torture/pr93124.c: Likewise.
	* gcc.dg/torture/pr94479.c: Likewise.
	* gcc.dg/torture/stackalign/alloca-1.c: Likewise.
	* gcc.dg/torture/stackalign/inline-2.c: Likewise.
	* gcc.dg/torture/stackalign/nested-3.c: Likewise.
	* gcc.dg/torture/stackalign/vararg-1.c: Likewise.
	* gcc.dg/torture/stackalign/vararg-2.c: Likewise.
	* gcc.dg/tree-ssa/20030807-2.c: Likewise.
	* gcc.dg/tree-ssa/20080530.c: Likewise.
	* gcc.dg/tree-ssa/alias-37.c: Likewise.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-22.c: Likewise.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-25.c: Likewise.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-3.c: Likewise.
	* gcc.dg/tree-ssa/loop-interchange-15.c: Likewise.
	* gcc.dg/tree-ssa/pr23848-1.c: Likewise.
	* gcc.dg/tree-ssa/pr23848-2.c: Likewise.
	* gcc.dg/tree-ssa/pr23848-3.c: Likewise.
	* gcc.dg/tree-ssa/pr23848-4.c: Likewise.
	* gcc.dg/uninit-32.c: Likewise.
	* gcc.dg/uninit-36.c: Likewise.
	* gcc.dg/uninit-39.c: Likewise.
	* gcc.dg/uninit-41.c: Likewise.
	* gcc.dg/uninit-9-O0.c: Likewise.
	* gcc.dg/uninit-9.c: Likewise.
	* gcc.dg/uninit-pr100250.c: Likewise.
	* gcc.dg/uninit-pr101300.c: Likewise.
	* gcc.dg/uninit-pr101494.c: Likewise.
	* gcc.dg/uninit-pr98583.c: Likewise.
	* gcc.dg/vla-2.c: Likewise.
	* gcc.dg/vla-22.c: Likewise.
	* gcc.dg/vla-24.c: Likewise.
	* gcc.dg/vla-3.c: Likewise.
	* gcc.dg/vla-4.c: Likewise.
	* gcc.dg/vla-stexp-1.c: Likewise.
	* gcc.dg/vla-stexp-2.c: Likewise.
	* gcc.dg/vla-stexp-4.c: Likewise.
	* gcc.dg/vla-stexp-5.c: Likewise.
	* gcc.dg/winline-7.c: Likewise.
	* gcc.target/aarch64/stack-check-alloca-1.c: Likewise.
	* gcc.target/aarch64/stack-check-alloca-10.c: Likewise.
	* gcc.target/aarch64/stack-check-alloca-2.c: Likewise.
	* gcc.target/aarch64/stack-check-alloca-3.c: Likewise.
	* gcc.target/aarch64/stack-check-alloca-4.c: Likewise.
	* gcc.target/aarch64/stack-check-alloca-5.c: Likewise.
	* gcc.target/aarch64/stack-check-alloca-6.c: Likewise.
	* gcc.target/aarch64/stack-check-alloca-7.c: Likewise.
	* gcc.target/aarch64/stack-check-alloca-8.c: Likewise.
	* gcc.target/aarch64/stack-check-alloca-9.c: Likewise.
	* gcc.target/arc/interrupt-6.c: Likewise.
	* gcc.target/i386/pr80969-3.c: Likewise.
	* gcc.target/loongarch/stack-check-alloca-1.c: Likewise.
	* gcc.target/loongarch/stack-check-alloca-2.c: Likewise.
	* gcc.target/loongarch/stack-check-alloca-3.c: Likewise.
	* gcc.target/loongarch/stack-check-alloca-4.c: Likewise.
	* gcc.target/loongarch/stack-check-alloca-5.c: Likewise.
	* gcc.target/loongarch/stack-check-alloca-6.c: Likewise.
	* gcc.target/riscv/stack-check-alloca-1.c: Likewise.
	* gcc.target/riscv/stack-check-alloca-10.c: Likewise.
	* gcc.target/riscv/stack-check-alloca-2.c: Likewise.
	* gcc.target/riscv/stack-check-alloca-3.c: Likewise.
	* gcc.target/riscv/stack-check-alloca-4.c: Likewise.
	* gcc.target/riscv/stack-check-alloca-5.c: Likewise.
	* gcc.target/riscv/stack-check-alloca-6.c: Likewise.
	* gcc.target/riscv/stack-check-alloca-7.c: Likewise.
	* gcc.target/riscv/stack-check-alloca-8.c: Likewise.
	* gcc.target/riscv/stack-check-alloca-9.c: Likewise.
	* gcc.target/sparc/setjmp-1.c: Likewise.
	* gcc.target/x86_64/abi/ms-sysv/ms-sysv.c: Likewise.
	* gcc.c-torture/compile/20001221-1.c: Don't 'dg-skip-if'
	for '! alloca'.
	* gcc.c-torture/compile/20020807-1.c: Likewise.
	* gcc.c-torture/compile/20050801-2.c: Likewise.
	* gcc.c-torture/compile/920428-4.c: Likewise.
	* gcc.c-torture/compile/debugvlafunction-1.c: Likewise.
	* gcc.c-torture/compile/pr41469.c: Likewise.
	* gcc.c-torture/execute/920721-2.c: Likewise.
	* gcc.c-torture/execute/920929-1.c: Likewise.
	* gcc.c-torture/execute/921017-1.c: Likewise.
	* gcc.c-torture/execute/941202-1.c: Likewise.
	* gcc.c-torture/execute/align-nest.c: Likewise.
	* gcc.c-torture/execute/alloca-1.c: Likewise.
	* gcc.c-torture/execute/pr22061-4.c: Likewise.
	* gcc.c-torture/execute/pr36321.c: Likewise.
	* gcc.dg/torture/pr8081.c: Likewise.
	* gcc.dg/analyzer/data-model-1.c: Don't
	'dg-require-effective-target alloca'.  XFAIL relevant
	'dg-warning's for '! alloca'.
	* gcc.dg/uninit-38.c: Likewise.
	* gcc.dg/uninit-pr98578.c: Likewise.
	* gcc.dg/compat/struct-by-value-22_main.c: Comment on
	'dg-require-effective-target alloca'.
	libstdc++-v3/
	* testsuite/lib/prune.exp (proc libstdc++-dg-prune): Turn
	'sorry, unimplemented: dynamic stack allocation not supported' into
	UNSUPPORTED.

When linking statically to libstdc++.a (or to libstdc++_nonshared.a in
the RHEL devtoolset compiler) there's a static initialization order
problem where user code might be constructed before the
std::chrono::tzdb_list globals, and so might try to use them after
they've already been destroyed.

Use the init_priority attribute on those globals so that they are
initialized early. Since r15-7511-g4e7f74225116e7 we can disable the
warnings for using a reserved priority using a diagnostic pragma.

libstdc++-v3/ChangeLog:

	PR libstdc++/118811
	* src/c++20/tzdb.cc (tzdb_list::_Node): Use init_priority
	attribute on static data members.
	* testsuite/std/time/tzdb_list/pr118811.cc: New test.

Add conditional noexcept to the remaining range access functions that
were not changed in r15-5669-g8692cb10e82e72. This is now being proposed
for C++26 by P3623R0 (not published yet).

libstdc++-v3/ChangeLog:

	* include/bits/range_access.h (rbegin, rend, crbegin, crend):
	Add conditional noexcept, as per P3623R0.
	* testsuite/24_iterators/headers/iterator/range_access.cc: Add
	noexcept-specifier to rbegin, rend, crbegin and crend
	declarations.

Instead of a test with { target c++11_only } and another with
c++14_only and another with c++17 we can have a single test that uses
{ target c++11 }. This avoids needing to make edits to three very
similar tests.

Also fix the signatures for std::cbegin and std::cend which had the
wrong expression in the trailing-return-type and were missing their
constexpr and conditional noexcept (which were always present even in
C++14). That was wrong in two files, but now only needs to be fixed in
one place!

libstdc++-v3/ChangeLog:

	* testsuite/24_iterators/headers/iterator/range_access_c++11.cc:
	Removed.
	* testsuite/24_iterators/headers/iterator/range_access_c++14.cc:
	Removed.
	* testsuite/24_iterators/headers/iterator/range_access_c++17.cc:
	Removed.
	* testsuite/24_iterators/headers/iterator/range_access.cc:
	New test.

_Rb_tree::_M_equal_range calls make_pair unqualified, which means it
uses ADL. As the new testcase shows, this can find something other than
std::make_pair. Rather than just changing it to use a qualified call,
remove the use of make_pair entirely. We don't need to deduce any types
here, we know exactly what type of std::pair we want to construct, so do
that explicitly.

libstdc++-v3/ChangeLog:

	* include/bits/stl_tree.h (_Rb_tree::_M_equal_range): Replace
	unqualified call to make_pair with explicit construction of
	std::pair.
	* testsuite/23_containers/set/operations/equal_range_adl.cc:
	New test.

For GCN, this avoids ICEs further down the compilation pipeline.  For nvptx,
there's effectively no change: in presence of exception handling constructs,
instead of 'sorry, unimplemented: target cannot support nonlocal goto', we
now emit 'sorry, unimplemented: exception handling not supported'.

Additionally, turn test cases into UNSUPPORTED if running into
'sorry, unimplemented: exception handling not supported'.

	gcc/
	* config/gcn/gcn.md (exception_receiver): 'define_expand'.
	* config/nvptx/nvptx.md (exception_receiver): Likewise.
	gcc/testsuite/
	* lib/gcc-dg.exp (gcc-dg-prune): Turn
	'sorry, unimplemented: exception handling not supported' into
	UNSUPPORTED.
	* gcc.dg/pr104464.c: Remove GCN XFAIL.
	libstdc++-v3/
	* testsuite/lib/prune.exp (libstdc++-dg-prune): Turn
	'sorry, unimplemented: exception handling not supported' into
	UNSUPPORTED.

In Subversion r268025 (Git commit 3f21b8e3)
"Add dg-require-effective-target exceptions", effective-target 'exceptions'
was added, which "says that AMD GCN does not support [exception handling]".

In Subversion r279246 (Git commit a9046e98)
"MSP430: Add -fno-exceptions multilib", effective-target 'exceptions_enabled'
was added "to check if the testing configuration supports exceptions".  Testing
"if exceptions are unsupported or disabled (e.g. by passing -fno-exceptions)"
works as expected if exception handling is disabled at the front-end level
('-fno-exceptions'; the "exceptions are [...] disabled" case):

    exceptions_enabled2066068.cc: In function ‘void foo()’:
    exceptions_enabled2066068.cc:3:27: error: exception handling disabled, use ‘-fexceptions’ to enable

However, effective-target 'exceptions_enabled' additionally assumes that
"If exceptions aren't supported [by the target], then they're not enabled".
This is not correct: it's not unlikely that, in presence of explicit/implicit
'-fexceptions', exception handling code gets fully optimized away by the
compiler, and therefore effective-target 'exceptions_enabled' test cases may
PASS even for targets that don't support effective-target 'exceptions'; these
two effective-targets are orthogonal concepts.

(For completeness: code with trivial instances of C++ exception handling may
translate into simple '__cxa_allocate_exception', '__cxa_throw' function calls
without requiring any back end-level "exceptions magic", and then trigger
unresolved symbols at link time, if these functions are not available.)

This change only affects GCN, as that one currently is the only target declared
as not supporting effective-target 'exceptions'.

	gcc/
	* doc/sourcebuild.texi (Effective-Target Keywords): Clarify that
	effective-target 'exceptions' and 'exceptions_enabled' are
	orthogonal.
	gcc/testsuite/
	* lib/gcc-dg.exp (gcc-dg-prune): Clarify effective-target
	'exceptions_enabled'.
	* lib/target-supports.exp
	(check_effective_target_exceptions_enabled): Don't consider
	effective-target 'exceptions'.
	libstdc++-v3/
	* testsuite/lib/prune.exp (libstdc++-dg-prune): Clarify
	effective-target 'exceptions_enabled'.

The code was caching the result of `invoke(proj, *it)` in a local
`auto &&` variable. The problem is that this may create dangling
references, for instance in case `proj` is `std::identity` (the common
case) and `*it` produces a prvalue: lifetime extension does not
apply here due to the expressions involved.

Instead, store (and lifetime-extend) the result of `*it` in a separate
variable, then project that variable. While at it, also forward the
result of the projection to the predicate, so that the predicate can
act on the proper value category.

libstdc++-v3/ChangeLog:

	PR libstdc++/118160
	PR libstdc++/100249
	* include/bits/ranges_algo.h (__is_permutation_fn): Avoid a
	dangling reference by storing the result of the iterator
	dereference and the result of the projection in two distinct
	variables, in order to lifetime-extend each one.
	Forward the projected value to the predicate.
	* testsuite/25_algorithms/is_permutation/constrained.cc: Add a
	test with a range returning prvalues. Test it in a constexpr
	context, in order to rely on the compiler to catch UB.

Signed-off-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

Because basic_ostream::sentry::~sentry is implicitly noexcept, we can't
let any exceptions escape from it, or the program would terminate. If
the streambuf's sync() function throws, or if it returns an error and
setting badbit in the stream state throws, then the program would
terminate.

LWG 835 intended to prevent exceptions from being thrown by the
std::basic_ostream::sentry destructor, but failed to cover the case
where the streambuf's sync() member throws an exception. LWG 4188 is
needed to fix that part. In any case, LWG 835 was never implemented for
libstdc++ so this does that, as well as my proposed fix for 4188 (that
badbit should be set if pubsync() exits via an exception).

In order to avoid a second try-catch block to handle an exception that
might be thrown by setting badbit, this introduces an RAII helper class
that temporarily clears the stream's exceptions mask, then restores it
afterwards.

The try-catch block doesn't handle the forced_unwind exception
explicitly, because catching and rethrowing that would just terminate
when it reached the sentry's implicit noexcept(true) anyway.

libstdc++-v3/ChangeLog:

	* include/bits/ostream.h (basic_ostream::_Disable_exceptions):
	RAII helper type.
	(basic_ostream::sentry::~sentry): Use _Disable_exceptions. Add
	try-catch block around call to pubsync.
	* testsuite/27_io/basic_ostream/exceptions/char/lwg4188.cc: New
	test.
	* testsuite/27_io/basic_ostream/exceptions/wchar_t/lwg4188.cc:
	New test.

This patch

commit c6977f76
Author: Andreas Schwab <schwab@suse.de>
Date:   Tue Jan 21 23:50:15 2025 +0100

    libstdc++: correct symbol version of typeinfo for bfloat16_t on RISC-V

broke the libstdc++-abi/abi_check test on Solaris: the log shows

1 incompatible symbols
0
Argument "{CXXABI_1.3.15}" isn't numeric in numeric eq (==) at /vol/gcc/src/hg/master/local/libstdc++-v3/scripts/extract_symvers.pl line 129.
version status: incompatible
type: uncategorized
status: added

The problem has two parts:

* The patch above introduced a new version in libstdc++.so,
  CXXABI_1.3.16, which everywhere but on RISC-V contains no symbols (a
  weak version).  This is the first time this happened in libstdc++.

* Solaris uses scripts/extract_symvers.pl to determine the version info.
  The script currently chokes on the pvs output for weak versions:

  libstdc++.so.6.0.34 -	CXXABI_1.3.16 [WEAK]: {CXXABI_1.3.15};

  instead of

  libstdc++.so.6.0.34 -	CXXABI_1.3.16: {CXXABI_1.3.15};

While this patch hardens the script to cope with weak versions, there's
no reason to introduce them in the first place.  So the new version is
only created on __riscv.

Tested on i386-pc-solaris2.11, sparc-sun-solaris2.11, and
x86_64-pc-linux-gnu.

2025-01-29  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
	    Jonathan Wakely  <jwakely@redhat.com>

	libstdc++-v3:
	PR libstdc++/118701
	* config/abi/pre/gnu.ver (CXXABI_1.3.16): Move __riscv guard
	around version.
	* scripts/extract_symvers.pl: Allow for weak versions.
	* testsuite/util/testsuite_abi.cc (check_version): Wrap
	CXXABI_1.3.16 in __riscv.

This fixes flat_map/multimap::insert_range by just generalizing the
insert implementation to handle heterogenous iterator/sentinel pair.
I'm not sure we can do better than this, e.g. we can't implement it in
terms of the adapted containers' insert_range because that'd require two
passes over the range.

For flat_set/multiset, we can implement insert_range directly in terms
of the adapted container's insert_range.  A fallback implementation
is also provided if insert_range isn't available, as is the case for
std::deque currently.

	PR libstdc++/118156

libstdc++-v3/ChangeLog:

	* include/std/flat_map (_Flat_map_impl::_M_insert): Generalized
	version of insert taking heterogenous iterator/sentinel pair.
	(_Flat_map_impl::insert): Dispatch to _M_insert.
	(_Flat_map_impl::insert_range): Likewise.
	(flat_map): Export _Flat_map_impl::insert_range.
	(flat_multimap): Likewise.
	* include/std/flat_set (_Flat_set_impl::insert_range):
	Reimplement directly, not in terms of insert.
	(flat_set): Export _Flat_set_impl::insert_range.
	(flat_multiset): Likewise.
	* testsuite/23_containers/flat_map/1.cc (test06): New test.
	* testsuite/23_containers/flat_multimap/1.cc (test06): New test.
	* testsuite/23_containers/flat_multiset/1.cc (test06): New test.
	* testsuite/23_containers/flat_set/1.cc (test06): New test.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>

In some cases we're wrongly returning an iterator to (one past) the last
element inserted instead of to the first element inserted.

libstdc++-v3/ChangeLog:

	* include/bits/stl_bvector.h (vector<bool>::insert_range):
	Consistently return an iterator pointing to the first element
	inserted.
	* include/bits/vector.tcc (vector::insert_range): Likewise.
	* testsuite/23_containers/vector/bool/modifiers/insert/insert_range.cc:
	Verify insert_range return values.
	* testsuite/23_containers/vector/modifiers/insert/insert_range.cc:
	Likewise.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>

The std::latch::max() function assumes that the returned value can be
represented by ptrdiff_t, which is true when __platform_wait_t is int
(e.g. on Linux) but not when it's unsigned long, which is the case for
most other 64-bit targets. We should use the smaller of PTRDIFF_MAX and
std::numeric_limits<__platform_wait_t>::max(). Use std::cmp_less to do a
safe comparison that works for all types. We can also use std::cmp_less
and std::cmp_equal in std::latch::count_down so that we don't need to
deal with comparisons between signed and unsigned.

Also add a missing precondition check to constructor and fix the
existing check in count_down which was duplicated by mistake.

libstdc++-v3/ChangeLog:

	PR libstdc++/98749
	* include/std/latch (latch::max()): Ensure the return value is
	representable as the return type.
	(latch::latch(ptrdiff_t)): Add assertion.
	(latch::count_down): Fix copy & pasted duplicate assertion. Use
	std::cmp_equal to compare __platform_wait_t and ptrdiff_t
	values.
	(latch::_M_a): Use defined constant for alignment.
	* testsuite/30_threads/latch/1.cc: Check max(). Check constant
	initialization works for values in the valid range. Check
	alignment.

The range adaptor perfect forwarding simplification mechanism is currently
only enabled for trivially copyable bound arguments, to prevent undesirable
copies of complex objects.  But "trivially copyable" is the wrong property
to check for here, since a move-only type with a trivial move constructor
is considered trivially copyable, and after P2492R2 we can't assume copy
constructibility of the bound arguments.  This patch makes the mechanism
more specifically check for trivial copy constructibility instead so
that it's properly disabled for move-only bound arguments.

	PR libstdc++/118413

libstdc++-v3/ChangeLog:

	* include/std/ranges (views::__adaptor::_Partial): Adjust
	constraints on the "simple" partial specializations to require
	is_trivially_copy_constructible_v instead of
	is_trivially_copyable_v.
	* testsuite/std/ranges/adaptors/adjacent_transform/1.cc (test04):
	Extend P2494R2 test.
	* testsuite/std/ranges/adaptors/transform.cc (test09): Likewise.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>

RISC-V only gained support for bfloat16_t after gcc 14.  Passes
libstdc++/check_abi on {x86_64,aarch64,ppc64le,riscv64,s390x}-suse-linux.

	PR libstdc++/118563
	* testsuite/util/testsuite_abi.cc (check_version): Add
	CXXABI_1.3.16.
	* config/abi/pre/gnu.ver (CXXABI_1.3.14) [__riscv]: Exclude
	typeinfo for bfloat16_t.
	(CXXABI_1.3.16) [__riscv]: Add it here.

As reported in PR118185, std::ranges::clamp does not correctly forward
the projected value to the comparator. Add the missing forward.

libstdc++-v3/ChangeLog:

	PR libstdc++/118185
	PR libstdc++/100249
	* include/bits/ranges_algo.h (__clamp_fn): Correctly forward the
	projected value to the comparator.
	* testsuite/25_algorithms/clamp/118185.cc: New test.

Signed-off-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Patrick Palka <ppalka@redhat.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>

Do not report an error for (is_other(s1) && is_other(s2)) as the
standard originally said, nor for (is_other(s1) || is_other(s2)) as
libstdc++ was doing. We can compare inode numbers for special files and
so give sensible answers.

libstdc++-v3/ChangeLog:

	PR libstdc++/118158
	* src/c++17/fs_ops.cc (fs::equivalent): Remove error reporting
	for is_other(s1) && is_other(s2) case, as per LWG 2937.
	* testsuite/27_io/filesystem/operations/pr118158.cc: New test.

This test should use __cpp_lib_ios_noreplace rather than the internal
__glibcxx_ios_noreplace macro.

libstdc++-v3/ChangeLog:

	* testsuite/27_io/ios_base/types/openmode/case_label.cc: Use
	standard feature test macro not internal one.

The alloc_ptr.cc test for std::set tries to use C++17 features
unconditionally, and tries to use the C++23 range members which haven't
been implemented for std::set yet.

Some of the range checks are left in place but commented out, so they
can be added after the ranges members are implemented. Others (such as
prepend_range) are not valid for std::set at all.

Also fix uses of internal feature test macros in two other tests, which
should use the standard __cpp_lib_xxx macros.

libstdc++-v3/ChangeLog:

	* testsuite/23_containers/set/requirements/explicit_instantiation/alloc_ptr.cc:
	Guard node extraction checks with feature test macro. Remove
	calls to non-existent range members.
	* testsuite/23_containers/forward_list/requirements/explicit_instantiation/alloc_ptr.cc:
	Use standard macro not internal one.
	* testsuite/23_containers/list/requirements/explicit_instantiation/alloc_ptr.cc:
	Likewise.

libstdc++-v3/ChangeLog:

	* testsuite/28_regex/traits/char/transform_primary.cc: Fix
	subclause numbering in references to the standard.

c++: Delete defaulted operator <=> if std::strong_ordering::equal doesn't convert to its rettype [PR118387]

Note, the PR raises another problem.
If on the same testcase the B b; line is removed, we silently synthetize
operator<=> which will crash at runtime due to returning without a return
statement.  That is because the standard says that in that case
it should return static_cast<int>(std::strong_ordering::equal);
but I can't find anywhere wording which would say that if that isn't
valid, the function is deleted.
https://eel.is/c++draft/class.compare#class.spaceship-2.2
seems to talk just about cases where there are some members and their
comparison is invalid it is deleted, but here there are none and it
follows
https://eel.is/c++draft/class.compare#class.spaceship-3.sentence-2
So, we synthetize with tf_none, see the static_cast is invalid, don't
add error_mark_node statement silently, but as the function isn't deleted,
we just silently emit it.
Should the standard be amended to say that the operator should be deleted
even if it has no elements and the static cast from
https://eel.is/c++draft/class.compare#class.spaceship-3.sentence-2

On Fri, Jan 10, 2025 at 12:04:53PM -0500, Jason Merrill wrote:
> That seems pretty obviously what we want, and is what the other compilers
> implement.

This patch implements it then.

2025-01-15  Jakub Jelinek  <jakub@redhat.com>

	PR c++/118387
	* method.cc (build_comparison_op): Set bad if
	std::strong_ordering::equal doesn't convert to rettype.

	* g++.dg/cpp2a/spaceship-err6.C: Expect another error.
	* g++.dg/cpp2a/spaceship-synth17.C: Likewise.
	* g++.dg/cpp2a/spaceship-synth-neg6.C: Likewise.
	* g++.dg/cpp2a/spaceship-synth-neg7.C: New test.

	* testsuite/25_algorithms/default_template_value.cc
	(Input::operator<=>): Use auto as return type rather than bool.

When running tests using the "sim" config, the command is launched in
non-readonly mode and the text retrieved from the expect command will
then replace all LF with CRLF. (The problem can be found in sim_load
where it calls remote_spawn without an input file).

libstdc++-v3/ChangeLog:

	* testsuite/27_io/print/1.cc: Allow both LF and CRLF in test.
	* testsuite/27_io/print/3.cc: Likewise.

Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>

Test assumes libatomic.a is always available, but for some embedded
targets, there is no libatomic.a and the test thus fail.

libstdc++-v3/ChangeLog:

	* testsuite/29_atomics/atomic_float/compare_exchange_padding.cc:
	Use effective-target libatomic_available.

Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>

This commit implements P2447R6. The code is straightforward (just one
extra constructor, with constraints and conditional explicit).

I decided to suppress -Winit-list-lifetime because otherwise it would
give too many false positives. The new constructor is meant to be used
as a parameter-passing interface (this is a design choice, see
P2447R6/§2) and, as such, the initializer_list won't dangle despite
GCC's warnings.

The new constructor isn't 100% backwards compatible. A couple of
examples are included in Annex C, but I have also lifted some more
from R4. A new test checks for the old and the new behaviors.

libstdc++-v3/ChangeLog:

	* include/bits/version.def: Add the new feature-testing macro.
	* include/bits/version.h: Regenerate.
	* include/std/span: Add constructor from initializer_list.
	* testsuite/23_containers/span/init_list_cons.cc: New test.
	* testsuite/23_containers/span/init_list_cons_neg.cc: New test.

Signed-off-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

The current check for negative times (i.e. before the epoch) only checks
for a negative number of seconds. For a time 1ms before the epoch the
seconds part will be zero, but the futex syscall will still fail with an
EINVAL error. Extend the check to handle this case.

This change adds a redundant check in the headers too, so that we avoid
even calling into the library for negative times. Both checks can be
marked [[unlikely]]. The check in the headers avoids the cost of
splitting the time into seconds and nanoseconds and then making a PLT
call. The check inside the library matches where we were checking
already, and fixes existing binaries that were compiled against older
headers but use a newer libstdc++.so.6 at runtime.

libstdc++-v3/ChangeLog:

	PR libstdc++/118093
	* include/bits/atomic_futex.h (_M_load_and_test_until_impl):
	Return false for times before the epoch.
	* src/c++11/futex.cc (_M_futex_wait_until): Extend check for
	negative times to check for subsecond times. Add unlikely
	attribute.
	(_M_futex_wait_until_steady): Likewise.
	* testsuite/30_threads/future/members/118093.cc: New test.

We have several overloads of std::deque::_M_insert_aux, one of which is
variadic and called by std::deque::emplace. With a suitable set of
arguments to emplace, it's possible for one of the non-variadic
_M_insert_aux overloads to be selected by overload resolution, making
emplace ill-formed.

Rename the variadic _M_insert_aux to _M_emplace_aux so that calls to
emplace never select an _M_insert_aux overload. Also add an inline
_M_insert_aux for the const lvalue overload that is called from
insert(const_iterator, const value_type&).

libstdc++-v3/ChangeLog:

	PR libstdc++/90389
	* include/bits/deque.tcc (_M_insert_aux): Rename variadic
	overload to _M_emplace_aux.
	* include/bits/stl_deque.h (_M_insert_aux): Define inline.
	(_M_emplace_aux): Declare.
	* testsuite/23_containers/deque/modifiers/emplace/90389.cc: New
	test.

These two long-running tests happened to fail for me when
run in parallel (nprocs - 1) compared to a serial run, for
target mmix on my laptop.  The runtime is 3m40s for 3.cc
before this change, and 0.9s afterwards.

	* testsuite/std/time/year_month_day/3.cc (test01): Add ifdeffery to
	limit the tested dates.  For simulators, pass start and end dates
	limiting the tested range to 100000 days, centered on days (0).
	* testsuite/std/time/year_month_day/4.cc: Ditto.

The test used #include "<generator>", so FAILed everywhere with
fatal error: <generator>: No such file or directory

2024-12-28  Jakub Jelinek  <jakub@redhat.com>

	PR libstdc++/118196
	* testsuite/24_iterators/range_generators/pr118196.cc: Include
	<generator> rather than "<generator>".

libstdc++-v3/ChangeLog:

	PR libstdc++/118196
	* include/std/generator (generator::operator=(generator)): Add
	missing 'return *this;'.
	* testsuite/24_iterators/range_generators/pr118196.cc: New test.

This overload requires

  constructible_from<remove_cvref_t<yielded>,
                     const remove_reference_t<yielded>&>

... but then tries to construct remove_cvref_t<yielded> implicitly,
which means it imposes an additional constraint not in the standard.

libstdc++-v3/ChangeLog:

	PR libstdc++/118022
	* include/std/generator
	(_Promise_erased::yield_value(const _Yielded_deref&)): Don't
	implicit-constuct _Yielded_decvref.
	* testsuite/24_iterators/range_generators/pr118022.cc: New test.

The fancy allocator pointer type support is added to std::map,
std::multimap, std::multiset and std::set through the underlying
std::_Rb_tree class.

To respect ABI a new parralel hierarchy of node types has been added.
This change introduces new class template parameterized on the
allocator's void_pointer type, __rb_tree::_Node_base, and new class
templates parameterized on the allocator's pointer type, __rb_tree::_Node,
__rb_tree::_Iterator. The iterator class template is used for both
iterator and const_iterator. Whether std::_Rb_tree<K, V, KoV, C, A>
should use the old _Rb_tree_node<V> or new __rb_tree::_Node<A::pointer>
type family internally is controlled by a new __rb_tree::_Node_traits
traits template.

Because std::pointer_traits and std::__to_address are not defined for
C++98, there is no way to support fancy pointers in C++98. For C++98 the
_Node_traits traits always choose the old _Rb_tree_node family.

In case anybody is currently using std::_Rb_tree with an allocator that
has a fancy pointer, this change would be an ABI break, because their
std::_Rb_tree instantiations would start to (correctly) use the fancy
pointer type. If the fancy pointer just contains a single pointer and so
has the same size, layout, and object representation as a raw pointer,
the code might still work (despite being an ODR violation). But if their
fancy pointer has a different representation, they would need to
recompile all their code using that allocator with std::_Rb_tree. Because
std::_Rb_tree will never use fancy pointers in C++98 mode, recompiling
everything to use fancy pointers isn't even possible if mixing C++98 and
C++11 code that uses std::_Rb_tree. To alleviate this problem, compiling
with -D_GLIBCXX_USE_ALLOC_PTR_FOR_RB_TREE=0 will force std::_Rb_tree to
have the old, non-conforming behaviour and use raw pointers internally.
For testing purposes, compiling with -D_GLIBCXX_USE_ALLOC_PTR_FOR_RB_TREE=9001
will force std::_Rb_tree to always use the new node types. This macro is
currently undocumented, which needs to be fixed.

As _Rb_tree is using _Base_ptr to represent the tree this change also
simplifies the implementation by removing all the const pointer types
and associated methods.

libstdc++-v3/ChangeLog:

	PR libstdc++/57272
	* include/bits/stl_tree.h
	[_GLIBCXX_USE_ALLOC_PTR_FOR_RB_TREE]: New macro to control usage of the
	code required to support fancy allocator pointer type.
	(_Rb_tree_node_base::_Const_Base_ptr): Remove.
	(_Rb_tree_node_base::_S_minimum, _Rb_tree_node_base::_S_maximum): Remove
	overloads for _Const_Base_ptr.
	(_Rb_tree_node_base::_M_base_ptr()): New.
	(_Rb_tree_node::_Link_type): Remove.
	(_Rb_tree_node::_M_node_ptr()): New.
	(__rb_tree::_Node_base<>): New.
	(__rb_tree::_Header<>): New.
	(__rb_tree::_Node<>): New.
	(_Rb_tree_increment(const _Rb_tree_node_base*)): Remove declaration.
	(_Rb_tree_decrement(const _Rb_tree_node_base*)): Remove declaration.
	(_Rb_tree_iterator<>::_Self): Remove.
	(_Rb_tree_iterator<>::_Link_type): Rename into...
	(_Rb_tree_iterator<>::_Node_ptr): ...this.
	(_Rb_tree_const_iterator<>::_Link_type): Rename into...
	(_Rb_tree_const_iterator<>::_Node_ptr): ...this.
	(_Rb_tree_const_iterator<>::_M_const_cast): Remove.
	(_Rb_tree_const_iterator<>::_M_node): Change type into _Base_ptr.
	(__rb_tree::_Iterator<>): New.
	(__rb_tree::_Node_traits<>): New.
	(_Rb_tree<>::_Node_base, _Rb_tree::_Node): New.
	(_Rb_tree<>::_Link_type): Rename into...
	(_Rb_tree<>::_Node_ptr): ...this.
	(_Rb_tree<>::_Const_Base_ptr, _Rb_tree<>::_Const_Node_ptr): Remove.
	(_Rb_tree<>::_M_mbegin): Remove.
	(_Rb_tree<>::_M_begin_node()): New.
	(_S_key(const _Node&)): New.
	(_S_key(_Base_ptr)): New, call latter.
	(_S_key(_Node_ptr)): Likewise.
	(_Rb_tree<>::_S_left(_Const_Base_ptr)): Remove.
	(_Rb_tree<>::_S_right(_Const_Base_ptr)): Remove.
	(_Rb_tree<>::_S_maximum(_Const_Base_ptr)): Remove.
	(_Rb_tree<>::_S_minimum(_Const_Base_ptr)): Remove.
	* testsuite/23_containers/map/allocator/ext_ptr.cc: New test case.
	* testsuite/23_containers/multimap/allocator/ext_ptr.cc: New test case.
	* testsuite/23_containers/multiset/allocator/ext_ptr.cc: New test case.
	* testsuite/23_containers/set/allocator/ext_ptr.cc: New test case.
	* testsuite/23_containers/set/requirements/explicit_instantiation/alloc_ptr.cc:
	New test case.
	* testsuite/23_containers/set/requirements/explicit_instantiation/alloc_ptr_ignored.cc:
	New test case.

This implements the C++23 container adaptors std::flat_set and
std::flat_multiset from P1222R4.  The implementation is essentially
an simpler and pared down version of std::flat_map.

libstdc++-v3/ChangeLog:

	* include/Makefile.am: Add new header <flat_set>.
	* include/Makefile.in: Regenerate.
	* include/bits/version.def (__cpp_flat_set): Define.
	* include/bits/version.h: Regenerate
	* include/precompiled/stdc++.h: Include <flat_set>.
	* include/std/flat_set: New file.
	* src/c++23/std.cc.in: Export <flat_set>.
	* testsuite/23_containers/flat_multiset/1.cc: New test.
	* testsuite/23_containers/flat_set/1.cc: New test.

Co-authored-by: Jonathan Wakely <jwakely@redhat.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>