Commit Graph

7633 Commits

Author SHA1 Message Date
Jonathan Wakely
5a4e208022 libstdc++: Ensure that std::from_chars is declared when supported
This adjusts the declarations in <charconv> to match when the definition
is present. This solves the issue that std::from_chars is present on
Solaris 11.3 (using fast_float) but was not declared in the header
(because the declarations were guarded by _GLIBCXX_HAVE_USELOCALE).

Additionally, do not define __cpp_lib_to_chars unless both from_chars
and to_chars are supported (which is only true for IEEE float and
double). We might still provide from_chars (via strtold) but if to_chars
isn't provided, we shouldn't define the feature test macro.

Finally, this simplifies some of the preprocessor checks in the bodies
of std::from_chars in src/c++17/floating_from_chars.cc and hoists the
repeated code for the strtod version into a new function template.

N.B. the long double overload of std::from_chars will always be defined
if the float and double overloads are defined. We can always use one of
strtold or fast_float's binary64 routines (although the latter might
produce errors for some long double values if they are not representable
as binary64).

libstdc++-v3/ChangeLog:

	* include/std/charconv (__cpp_lib_to_chars): Only define when
	both from_chars and to_chars are supported for floating-point
	types.
	(from_chars, to_chars): Adjust preprocessor conditions guarding
	declarations.
	* include/std/version (__cpp_lib_to_chars): Adjust condition to
	match <charconv> definition.
	* src/c++17/floating_from_chars.cc (from_chars_strtod): New
	function template.
	(from_chars): Simplify preprocessor checks and use
	from_chars_strtod when appropriate.
2022-03-16 16:06:29 +00:00
Detlef Vollmann
b5417a0ba7 libstdc++: Move closing brace outside #endif [PR104866]
libstdc++-v3/ChangeLog:

	PR libstdc++/104866
	* include/bits/this_thread_sleep.h: Fix order of #endif and
	closing brace of namespace.
2022-03-10 21:04:01 +00:00
Jonathan Wakely
7cce7b1c3d libstdc++: Remove incorrect copyright notice from header
This file has the SGI copyright notice, but contains no code from
the SGI STL. It was entirely written by me in 2019, originally as part
of the <memory> header. When I extracted it into a new header I
accidentally copied across the SGI copyright, but that only applies to
some much older parts of <memory>.

libstdc++-v3/ChangeLog:

	* include/bits/uses_allocator_args.h: Remove incorrect copyright
	notice.
2022-03-08 12:53:04 +00:00
Jonathan Wakely
4cb935cb69 libstdc++: Use visibility pragmas instead of attributes [PR104807]
The _GLIBCXX_PSEUDO_VISIBILITY macro isn't defined until after including
os_defines.h, so we can't use _GLIBCXX_VISIBILITY early in c++config.
Replace the uses of that macro with #pragma visibility push(default)
instead.

libstdc++-v3/ChangeLog:

	PR libstdc++/104807
	* include/bits/c++config (__terminate, __glibcxx_assert_fail):
	Replace _GLIBCXX_VISIBILITY on function with visibility pragma.
	(__is_constant_evaluated): Add visibility pragma.
2022-03-07 15:10:29 +00:00
Jonathan Wakely
d3a757af21 libstdc++: Ensure __glibcxx_assert_fail has default visibility
This ensures there's no linker error if libstdc++ headers are included
following a pragma that sets hidden visibility.

Similarly for std::__terminate, which is always-inline so shouldn't
matter, but it's not wrong to do this anyway.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (__glibcxx_assert_fail): Add visibility
	attribute.
	(__terminate): Likewise.
2022-03-05 20:33:36 +00:00
Jonathan Wakely
ad66b03b3c libstdc++: Fix -Wmaybe-uninitialized false positive [PR103984]
This fixes a false positive warning seen with LTO:

12/bits/regex_compiler.tcc:443:32: error: '__last_char._M_char' may be used uninitialized [-Werror=maybe-uninitialized]

Given that the std::regex code is not very efficient anyway, the
overhead of initializing this byte should be minimal.

libstdc++-v3/ChangeLog:

	PR middle-end/103984
	* include/bits/regex_compiler.h (_BracketMatcher::_M_char): Use
	default member initializer.
2022-03-01 15:25:39 +00:00
Jonathan Wakely
41cbcf53dc libstdc++: Fix cast in source_location::current() [PR104602]
This fixes a problem for Clang, which is going to return a non-void
pointer from __builtin_source_location(). The current definition of
std::source_location::current() converts that to void* and then has to
cast it back again in the body (which makes it invalid in a constant
expression). By using the actual type of the returned pointer, we avoid
the problematic cast for Clang.

libstdc++-v3/ChangeLog:

	PR libstdc++/104602
	* include/std/source_location (source_location::current): Use
	deduced type of __builtin_source_location().
2022-02-24 23:42:41 +00:00
Patrick Palka
5e1b17f038 libstdc++: Implement P2415R2 changes to viewable_range / views::all
This implements the wording changes in P2415R2 "What is a view?", which
is a DR for C++20.

libstdc++-v3/ChangeLog:

	* include/bits/ranges_base.h (__detail::__is_initializer_list):
	Define.
	(viewable_range): Adjust as per P2415R2.
	* include/bits/ranges_cmp.h (__cpp_lib_ranges): Adjust value.
	* include/std/ranges (owning_view): Define as per P2415R2.
	(enable_borrowed_range<owning_view>): Likewise.
	(views::__detail::__can_subrange): Replace with ...
	(views::__detail::__can_owning_view): ... this.
	(views::_All::_S_noexcept): Sync with operator().
	(views::_All::operator()): Use owning_view instead of subrange
	as per P2415R2.
	* include/std/version (__cpp_lib_ranges): Adjust value.
	* testsuite/std/ranges/adaptors/all.cc (test06): Adjust now that
	views::all uses owning_view instead of subrange.
	(test08): New test.
	* testsuite/std/ranges/adaptors/lazy_split.cc (test09): Adjust
	now that rvalue non-view non-borrowed ranges are viewable.
	* testsuite/std/ranges/adaptors/split.cc (test06): Likewise.
2022-02-22 09:37:58 -05:00
Jonathan Wakely
12a88e6e20 libstdc++: Deprecate non-standard std::vector<bool>::insert(pos) [PR104559]
The SGI STL and pre-1998 drafts of the C++ standard had a default
argument for vector<bool>::insert(iterator, const bool&) which was
remove by N1051. The default argument is still present in libstdc++ for
some reason. There are no tests verifying it as an extension, so I don't
think it has been kept intentionally.

This removes the default argument but adds an overload without the
second parameter, and adds the deprecated attribute to it. This allows
any code using it to keep working (for now) but with a warning.

libstdc++-v3/ChangeLog:

	PR libstdc++/104559
	* doc/xml/manual/evolution.xml: Document deprecation.
	* doc/html/manual/api.html: Regenerate.
	* include/bits/stl_bvector.h (insert(const_iterator, const bool&)):
	Remove default argument.
	(insert(const_iterator)): New overload with deprecated attribute.
	* testsuite/23_containers/vector/bool/modifiers/insert/104559.cc:
	New test.
2022-02-17 23:44:25 +00:00
Jonathan Wakely
6cfb7ffb65 libstdc++: Add missing constexpr to uses-allocator construction utilities [PR104542]
libstdc++-v3/ChangeLog:

	PR libstdc++/104542
	* include/bits/uses_allocator_args.h (make_obj_using_allocator)
	(uninitialized_construct_using_allocator): Add constexpr.
	* testsuite/20_util/uses_allocator/make_obj.cc: Check constexpr.
	* testsuite/20_util/uses_allocator/uninitialized_construct.cc: New test.
2022-02-15 12:49:34 +00:00
Jonathan Wakely
3d50dede07 libstdc++: Fix stream extraction of IEEE128 long double [PR100912]
The std::__convert_from_v helper that formats double and long double
values into a char buffer was not being duplicated for the two long
double ABIs. This resulted in an ODR violation inside the library, where
some callers needed it to use snprintf to format __ibm128 values and
other callers needed it to use __snprintfieee128 to format __ieee128
values. The linker discarded one of the definitions, leaving one set of
callers using the wrong code.

This puts __convert_from_v in the __gnu_cxx_ieee128 inline namespace
when long double is __ieee128, so that there are two different
definitions of the function.

The std::money_put::__do_put overload for __ibm128 values needs a
different fix, because that is defined when long double is __ieee128 and
so would call the one in the inline namespace. That can be fixed by just
inlining the code directly into the function and using an asm alias to
call the right version of snprintf for the __ibm128 format. The code to
do that can be simpler than __convert_from_v because if we're defining
the ALT128_COMPAT symbols we know that we have a recent glibc and so we
can assume that uselocale and snprintf are supported.

libstdc++-v3/ChangeLog:

	PR libstdc++/100912
	* config/locale/gnu/c_locale.h (__convert_from_v): Use inline
	namespace for IEEE128 long double mode.
	* config/os/gnu-linux/ldbl-ieee128-extra.ver: Add new symbol
	version and export __gnu_cxx_ieee128::__convert_from_v.
	* include/bits/locale_facets_nonio.tcc (money_put::__do_put):
	Make __ibm128 overload use snprintf directly
	* testsuite/util/testsuite_abi.cc: Add new symbol version.
	Remove stable IEEE128/LDBL versions.
2022-02-14 17:19:08 +00:00
Jonathan Wakely
164a761a9f libstdc++: Use __cpp_concepts instead of custom macro [PR103891]
With the new value of __cpp_concepts required by P2493, we can test
whether the compiler supports conditionally trivial special members.
This allows us to remove the workaround that disables fully-constexpr
std::variant for Clang. Now it should work for non-GCC compilers (such
as future releases of Clang) that support conditionally trivial
destructors and define the new value of __cpp_concepts.

libstdc++-v3/ChangeLog:

	PR libstdc++/103891
	* include/bits/c++config (_GLIBCXX_HAVE_COND_TRIVIAL_SPECIAL_MEMBERS):
	Remove.
	* include/std/variant: Check feature test macros instead.
	* include/std/version: Likewise.
2022-02-14 13:03:31 +00:00
Thomas Rodgers
b25a7c05f1 libstdc++: Strengthen memory order for atomic<T>::wait/notify
This changes the memory order used in the spin wait code to match
that of libc++.

libstdc++-v3/ChangeLog:
	* include/bits/atomic_wait.h (__waiter_base::_S_do_spin,
	__waiter_base::_S_do_spin_v): Change memory order from relaxed
	to acquire.
2022-02-10 10:14:36 -08:00
Jonathan Wakely
3e539985cc libstdc++: Add atomic_fetch_xor to <stdatomic.h>
This function (and the explicit memory over version) are present in both
C++ <atomic> and C <stdatomic.h>, so should be in C++ <stdatomic.h> too.
There is a library issue incoming for this, but the resolution is
obvious.

libstdc++-v3/ChangeLog:

	* include/c_compatibility/stdatomic.h (atomic_fetch_xor): Add
	using-declaration.
	(atomic_fetch_xor_explicit): Likewise.
	* testsuite/29_atomics/headers/stdatomic.h/c_compat.cc: Check
	arithmetic and logical operations for atomic_int.
2022-02-10 13:01:10 +00:00
Thomas Rodgers
4cf3c33981 libstdc++: Fix deadlock in atomic wait [PR104442]
This issue was observed as a deadlock in
29_atomics/atomic/wait_notify/100334.cc on vxworks. When a wait is
"laundered" (e.g. type T* does not suffice as a waitable address for the
platform's native waiting primitive), the address waited is that of the
_M_ver member of __waiter_pool_base, so several threads may wait on the
same address for unrelated atomic<T> objects. As noted in the PR, the
implementation correctly exits the wait for the thread whose data
changed, but not for any other threads waiting on the same address.

As noted in the PR the __waiter::_M_do_wait_v member was correctly exiting
but the other waiters were not reloading the value of _M_ver before
re-entering the wait.

Moving the spin call inside the loop accomplishes this, and is
consistent with the predicate accepting version of __waiter::_M_do_wait.

libstdc++-v3/ChangeLog:

	PR libstdc++/104442
	* include/bits/atomic_wait.h (__waiter::_M_do_wait_v): Move spin
	 loop inside do loop so that threads failing the wait, reload
	 _M_ver.
2022-02-09 12:30:51 -08:00
Jonathan Wakely
0d1aabb60e libstdc++: Allow Clang to use <stdatomic.h> before C++23
There is code that only expects to be compiled with clang++ and uses its
<stdatomic.h>, which works because Clang supports the _Atomic specifier
in C++. The addition  of <stdatomic.h> to libstdc++ broke this code, as
now it finds the C++ header instead, which is empty for any standard
mode before C++23.

This change allows that code to keep working as before, by forwarding to
clang's <stdatomic.h>.

libstdc++-v3/ChangeLog:

	* include/c_compatibility/stdatomic.h [__clang__]: Use
	#include_next <stdatomic.h>.
2022-02-04 19:51:26 +00:00
Jonathan Wakely
da72e0fd20 libstdc++: Remove un-implementable noexcept from Filesystem TS operations
LWG 3014 removed these incorrect noexcept specifications from the C++17
std::filesystem operations. They are also incorrect on the experimental
TS versions and should be removed from them too.

libstdc++-v3/ChangeLog:

	* include/experimental/bits/fs_ops.h (fs::copy_file): Remove
	noexcept.
	(fs::create_directories): Likewise.
	(fs::remove_all): Likewise.
	* src/filesystem/ops.cc (fs::copy_file): Remove noexcept.
	(fs::create_directories): Likewise.
	(fs::remove_all): Likewise.
2022-02-04 19:51:26 +00:00
Jonathan Wakely
ebf6175464 libstdc++: Fix filesystem::remove_all races [PR104161]
This fixes the remaining filesystem::remove_all race condition by using
POSIX openat to recurse into sub-directories and using POSIX unlinkat to
remove files. This avoids the remaining race where the directory being
removed is replaced with a symlink after the directory has been opened,
so that the filesystem::remove("subdir/file") resolves to "target/file"
instead, because "subdir" has been removed and replaced with a symlink.
The previous patch only fixed the case where the directory was replaced
with a symlink before we tried to open it, but it still used the full
(potentially compromised) path as an argument to filesystem::remove.

The first part of the fix is to use openat when recursing into a
sub-directory with recursive_directory_iterator. This means that opening
"dir/subdir" uses the file descriptor for "dir", and so is sure to open
"dir/subdir" and not "symlink/subdir". (The previous patch to use
O_NOFOLLOW already ensured we won't open "dir/symlink/" here.)

The second part of the fix is to use unlinkat for the remove_all
operation. Previously we used a directory_iterator to get the name of
each file in a directory and then used filesystem::remove(iter->path())
on that name. This meant that any checks (e.g. O_NOFOLLOW) done by the
iterator could be invalidated before the remove operation on that
pathname. The directory iterator contains an open DIR stream, which we
can use to obtain a file descriptor to pass to unlinkat. This ensures
that the file being deleted really is contained within the directory
we're iterating over, rather than using a pathname that could resolve to
some other file.

The filesystem::remove_all function previously used a (non-recursive)
filesystem::directory_iterator for each directory, and called itself
recursively for sub-directories. The new implementation uses a single
filesystem::recursive_directory_iterator object, and calls a new __erase
member function on that iterator. That new __erase member function does
the actual work of removing a file (or a directory after its contents
have been iterated over and removed) using unlinkat. That means we don't
need to expose the DIR stream or its file descriptor to the remove_all
function, it's still encapuslated by the iterator class.

It would be possible to add a __rewind member to directory iterators
too, to call rewinddir after each modification to the directory. That
would make it more likely for filesystem::remove_all to successfully
remove everything even if files are being written to the directory tree
while removing it. It's unclear if that is actually prefereable, or if
it's better to fail and report an error at the first opportunity.

The necessary APIs (openat, unlinkat, fdopendir, dirfd) are defined in
POSIX.1-2008, and in Glibc since 2.10. But if the target doesn't provide
them, the original code (with race conditions) is still used.

This also reduces the number of small memory allocations needed for
std::filesystem::remove_all, because we do not store the full path to
every directory entry that is iterated over. The new filename_only
option means we only store the filename in the directory entry, as that
is all we need in order to use openat or unlinkat.

Finally, rather than duplicating everything for the Filesystem TS, the
std::experimental::filesystem::remove_all implementation now just calls
std::filesystem::remove_all to do the work.

libstdc++-v3/ChangeLog:

	PR libstdc++/104161
	* acinclude.m4 (GLIBCXX_CHECK_FILESYSTEM_DEPS): Check for dirfd
	and unlinkat.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* include/bits/fs_dir.h (recursive_directory_iterator): Declare
	remove_all overloads as friends.
	(recursive_directory_iterator::__erase): Declare new member
	function.
	* include/bits/fs_fwd.h (remove, remove_all): Declare.
	* src/c++17/fs_dir.cc (_Dir): Add filename_only parameter to
	constructor. Pass file descriptor argument to base constructor.
	(_Dir::dir_and_pathname, _Dir::open_subdir, _Dir::do_unlink)
	(_Dir::unlink, _Dir::rmdir): Define new member functions.
	(directory_iterator): Pass filename_only argument to _Dir
	constructor.
	(recursive_directory_iterator::_Dir_stack): Adjust constructor
	parameters to take a _Dir rvalue instead of creating one.
	(_Dir_stack::orig): Add data member for storing original path.
	(_Dir_stack::report_error): Define new member function.
	(__directory_iterator_nofollow): Move here from dir-common.h and
	fix value to be a power of two.
	(__directory_iterator_filename_only): Define new constant.
	(recursive_directory_iterator): Construct _Dir object and move
	into _M_dirs stack. Pass skip_permission_denied argument to first
	advance call.
	(recursive_directory_iterator::increment): Use _Dir::open_subdir.
	(recursive_directory_iterator::__erase): Define new member
	function.
	* src/c++17/fs_ops.cc (ErrorReporter, do_remove_all): Remove.
	(fs::remove_all): Use new recursive_directory_iterator::__erase
	member function.
	* src/filesystem/dir-common.h (_Dir_base): Add int parameter to
	constructor and use openat to implement nofollow semantics.
	(_Dir_base::fdcwd, _Dir_base::set_close_on_exec, _Dir_base::openat):
	Define new member functions.
	(__directory_iterator_nofollow): Move to fs_dir.cc.
	* src/filesystem/dir.cc (_Dir): Pass file descriptor argument to
	base constructor.
	(_Dir::dir_and_pathname, _Dir::open_subdir): Define new member
	functions.
	(recursive_directory_iterator::_Dir_stack): Adjust constructor
	parameters to take a _Dir rvalue instead of creating one.
	(recursive_directory_iterator): Check for new nofollow option.
	Construct _Dir object and move into _M_dirs stack. Pass
	skip_permission_denied argument to first advance call.
	(recursive_directory_iterator::increment): Use _Dir::open_subdir.
	* src/filesystem/ops.cc (fs::remove_all): Use C++17 remove_all.
2022-02-04 19:51:26 +00:00
Jonathan Wakely
27ba40559c libstdc++: Add suggestion to std::uncaught_exception() warning
We should use the SUGGEST macro for std::uncaught_exception()
deprecation warnings.

libstdc++-v3/ChangeLog:

	* include/bits/allocator.h: Qualify std::allocator_traits in
	deprecated warnings.
	* libsupc++/exception (uncaught_exception): Add suggestion to
	deprecated warning.
2022-02-04 15:26:59 +00:00
Jonathan Wakely
b229c51860 libstdc++: Fix link failure in _OutputIteratorConcept
The C++98-style concept check for output iterators causes a link
failure on mingw-w64, because the __val() member function isn't defined.
Change it to use a function pointer instead. That pointer is never set
to anything meaningful, but it doesn't matter as the __constraints()
function only has to be instantiated, it's never called.

We could refactor all of these to use unevaluated contexts (e.g. sizeof
of __decltype) so that we only check the expressions are well-formed,
without any codegen at all. Any improvements to these are very low
priority though.

libstdc++-v3/ChangeLog:

	* include/bits/boost_concept_check.h (_OutputIteratorConcept):
	Change member function to data member of function pointer type.
2022-02-02 16:30:51 +00:00
Martin Sebor
756eabacfc Declare std::array members with attribute const [PR101831].
Resolves:
PR libstdc++/101831 - Spurious maybe-uninitialized warning on std::array::size

libstdc++-v3/ChangeLog:

	PR libstdc++/101831
	* include/std/array (begin): Declare const member function attribute
	const.
	(end, rbegin, rend, size, max_size, empty, data): Same.
	* testsuite/23_containers/array/capacity/empty.cc: Add test cases.
	* testsuite/23_containers/array/capacity/max_size.cc: Same.
	* testsuite/23_containers/array/capacity/size.cc: Same.
	* testsuite/23_containers/array/iterators/begin_end.cc: New test.
2022-02-01 17:21:49 -07:00
Jonathan Wakely
90263a4830 libstdc++: Fix doxygen comment for filesystem::perms operators
libstdc++-v3/ChangeLog:

	* include/bits/fs_fwd.h (filesystem::perms): Fix comment.
2022-02-01 21:53:15 +00:00
Thomas Rodgers
07a971b28c Strengthen memory order for atomic<T>::wait/notify
This matches the memory order in libc++.

libstdc++-v3/ChangeLog:
	* include/bits/atomic_wait.h: Change memory order from
	Acquire/Release with relaxed loads to SeqCst+Release for
	accesses to the waiter's count.
2022-02-01 09:04:10 -08:00
Jonathan Wakely
eae41b4d2c libstdc++: Prevent -Wstringop-overread warning in std::deque [PR100516]
The compiler warns about the loop in deque::_M_range_initialize because
it doesn't know that the number of nodes has already been correctly
sized to match the size of the input. Use __builtin_unreachable to tell
it that the loop will never be entered if the number of elements is
smaller than a single node.

libstdc++-v3/ChangeLog:

	PR libstdc++/100516
	* include/bits/deque.tcc (_M_range_initialize<ForwardIterator>):
	Add __builtin_unreachable to loop.
	* testsuite/23_containers/deque/100516.cc: New test.
2022-01-27 23:31:03 +00:00
Jonathan Wakely
f21f22d1ba libstdc++: Avoid overflow in ranges::advance(i, n, bound)
When (bound - i) or n is the most negative value of its type, the
negative of the value will overflow. Instead of abs(n) >= abs(bound - i)
use n >= (bound - i) when positive and n <= (bound - i) when negative.
The function has a precondition that they must have the same sign, so
this works correctly. The precondition check can be moved into the else
branch, and simplified.

The standard requires calling ranges::advance(i, bound) even if i==bound
is already true, which is technically observable, but that's pointless.
We can just return n in that case. Similarly, for i!=bound but n==0 we
are supposed to call ranges::advance(i, n), but that's pointless. An LWG
issue to allow omitting the pointless calls is expected to be filed.

libstdc++-v3/ChangeLog:

	* include/bits/ranges_base.h (ranges::advance): Avoid signed
	overflow. Do nothing if already equal to desired result.
	* testsuite/24_iterators/range_operations/advance_overflow.cc:
	New test.
2022-01-27 22:24:29 +00:00
Jonathan Wakely
5c1f274e3e libstdc++: Avoid some more warnings [PR104019]
With -fno-exceptions we get a -Wmisleading-indentation warning for:

  if (cond)
    __try {}
    __catch (...) {}

This is because the __catch(...) expands to if (false), but is indented
as though it is controlled by the preceding 'if'. Surround it in braces.

The new make_shared<T[]> code triggers a bogus warning due to PR 61596,
which can be disabled with a pragma.

libstdc++-v3/ChangeLog:

	PR libstdc++/104019
	* include/bits/istream.tcc (basic_istream::sentry): Add braces
	around try-block.
	* include/bits/shared_ptr_base.h (_Sp_counted_array_base::_M_init):
	Add pragmas to disable bogus warnings from PR 61596.
2022-01-25 21:05:16 +00:00
Jonathan Wakely
51631875a2 libstdc++: Fix std::spanstream move assignment [PR104032]
libstdc++-v3/ChangeLog:

	PR libstdc++/104032
	* include/std/spanstream (basic_spanbuf(basic_spanbuf&&)): Use
	mem-initializer for _M_buf.
	(basic_spanbuf::Operator=(basic_spanbuf&&)): Fix ill-formed
	member access.
	* testsuite/27_io/spanstream/2.cc: New test.
2022-01-23 22:48:33 +00:00
Jonathan Wakely
084680db9a libstdc++: Restore support for unordered_map<const T, ...> [PR104174]
I broke this unintentionally in r12-4259.

libstdc++-v3/ChangeLog:

	PR libstdc++/104174
	* include/bits/hashtable_policy.h (_Map_base): Add partial
	specialization for maps with const key types.
	* testsuite/23_containers/unordered_map/104174.cc: New test.
2022-01-23 22:47:00 +00:00
Jonathan Wakely
2d8a9ad4a9 libstdc++: Fix aliasing violation in std::shared_ptr [PR104019]
The non-atomic store that sets both reference counts to zero uses a
type-punned pointer, which has undefined behaviour. We could use memset
to write 8 bytes, but we don't actually need it to be a single store
anyway. No other thread can observe the values, that's why it's safe to
use non-atomic stores in the first place. So we can just set each count
to zero.

With -fstore-merging (which is enabled by default at -O2) GCC produces
the same code for this as for memset or the type punned store. Clang
does that store merging even at -O1.

libstdc++-v3/ChangeLog:

	PR libstdc++/104019
	* include/bits/shared_ptr_base.h (_Sp_counted_base<>::_M_release):
	Set members to zero without type punning.
2022-01-23 22:47:00 +00:00
Jonathan Wakely
b8806796ec libstdc++: Ensure all feature test macros have type long [PR87193]
This defines all the __cpp_lib_xxx macros as type long, as required by
the standard. We had an inconsistent mix of int and long, sometimes even
for the same macro name.

The __cpp_lib_experimental_xxx macros are left as type int, because
that's what it says in the relevant TS specs.

libstdc++-v3/ChangeLog:

	PR libstdc++/87193
	PR libstdc++/104019
	* include/bits/alloc_traits.h (__cpp_lib_allocator_traits_is_always_equal):
	Define as type long.
	* include/bits/allocator.h (__cpp_lib_incomplete_container_elements):
	Likewise.
	* include/bits/basic_string.h (__cpp_lib_string_udls): Likewise.
	* include/bits/chrono.h (__cpp_lib_chrono): Likewise.
	(__cpp_lib_chrono_udls): Likewise.
	* include/bits/move.h (__cpp_lib_addressof_constexpr): Likewise.
	* include/bits/node_handle.h (__cpp_lib_node_extract): Likewise.
	* include/bits/range_access.h (__cpp_lib_nonmember_container_access):
	Likewise.
	* include/bits/shared_ptr.h (__cpp_lib_enable_shared_from_this):
	Likewise.
	* include/bits/stl_algo.h (__cpp_lib_clamp): Likewise.
	(__cpp_lib_sample): Likewise.
	* include/bits/stl_algobase.h (__cpp_lib_robust_nonmodifying_seq_ops):
	Likewise.
	* include/bits/stl_function.h (__cpp_lib_transparent_operators):
	Likewise.
	* include/bits/stl_iterator.h (__cpp_lib_make_reverse_iterator):
	Likewise.
	* include/bits/stl_map.h (__cpp_lib_map_try_emplace):
	Likewise.
	* include/bits/stl_tree.h (__cpp_lib_generic_associative_lookup):
	Likewise.
	* include/bits/unique_ptr.h (__cpp_lib_make_unique):
	Likewise.
	* include/bits/unordered_map.h (__cpp_lib_unordered_map_try_emplace):
	Likewise.
	* include/c_global/cmath (__cpp_lib_hypot): Likewise.
	* include/c_global/cstddef (__cpp_lib_byte): Likewise.
	* include/std/atomic (__cpp_lib_atomic_is_always_lock_free):
	Likewise.
	* include/std/complex (__cpp_lib_complex_udls): Likewise.
	* include/std/filesystem (__cpp_lib_filesystem): Likewise.
	* include/std/functional (__cpp_lib_not_fn): Likewise.
	(__cpp_lib_boyer_moore_searcher): Likewise.
	* include/std/iomanip (__cpp_lib_quoted_string_io): Likewise.
	* include/std/mutex (__cpp_lib_scoped_lock): Likewise.
	* include/std/numeric (__cpp_lib_gcd_lcm): Likewise.
	(__cpp_lib_gcd, __cpp_lib_lcm): Likewise.
	* include/std/tuple (__cpp_lib_apply): Likewise.
	(__cpp_lib_make_from_tuple): Likewise.
	* include/std/type_traits (__cpp_lib_integral_constant_callable)
	(__cpp_lib_bool_constant, __cpp_lib_logical_traits)
	(__cpp_lib_is_null_pointer, __cpp_lib_transformation_trait_aliases)
	(__cpp_lib_result_of_sfinae, __cpp_lib_void_t)
	(__cpp_lib_is_swappable, __cpp_lib_is_invocable)
	(__cpp_lib_has_unique_object_representations)
	(__cpp_lib_is_aggregate): Likewise.
	* include/std/version: Likewise.
	* libsupc++/new (__cpp_lib_launder): Likewise.
2022-01-21 16:07:34 +00:00
Jonathan Wakely
2da1ef06ff libstdc++: Fix condition for __cpp_lib_shared_ptr_arrays
I changed the preprocessor condition from <= to < in r12-6574 which
meant the macro was not defined by <version> for C++17.

libstdc++-v3/ChangeLog:

	* include/std/version (__cpp_lib_shared_ptr_arrays): Fix
	condition for C++17 definition.
2022-01-21 16:07:33 +00:00
Jonathan Wakely
7d47aae7cd libstdc++: Fix constexpr constructor for atomic<shared_ptr<T>>
libstdc++-v3/ChangeLog:

	* include/bits/shared_ptr_atomic.h (_Sp_atomic::_Atomic_count):
	Add constexpr.
	(_Sp_atomic::_M_ptr): Add default member-initializer.
	* testsuite/20_util/shared_ptr/atomic/atomic_shared_ptr.cc:
	Check constant initialization.
	* testsuite/20_util/weak_ptr/atomic_weak_ptr.cc: Likewise.
2022-01-21 13:21:27 +00:00
Matthias Kretz
39f581028c libstdc++: Fix for non-constexpr math_errhandling
Use SFINAE magic to support: "It is unspecified whether math_errhandling
is a macro or an identifier with external linkage." [C Standard]

Signed-off-by: Matthias Kretz <m.kretz@gsi.de>

libstdc++-v3/ChangeLog:

	* include/experimental/bits/simd.h (__floating_point_flags): Do
	not rely on math_errhandling to expand to a constant expression.
2022-01-19 13:45:58 +01:00
Jonathan Wakely
a68080a121 libstdc++: Fix deprecated attribute for std::get_temporary_buffer
This was deprecated in C++17, not C++14.

libstdc++-v3/ChangeLog:

	* include/bits/stl_tempbuf.h (get_temporary_buffer): Change
	_GLIBCXX14_DEPRECATED to _GLIBCXX17_DEPRECATED.
2022-01-19 00:58:25 +00:00
Jonathan Wakely
72ce3fd2c7 libstdc++: Remove unused std::pair helper function
This function is no longer used since r12-6691 and can be removed.

libstdc++-v3/ChangeLog:

	* include/bits/stl_pair.h (_PCC::_DeprConsPair): Remove unused
	function.
2022-01-19 00:58:25 +00:00
Jonathan Wakely
c3861f7985 libstdc++: Fix std::atomic<std::shared_ptr<T>> for AIX [PR104101]
This fixes an on AIX.

The lock function currently just spins, which should be changed to use
back-off, and maybe then _M_val.wait(__current) when supported.

libstdc++-v3/ChangeLog:

	PR libstdc++/104101
	* include/bits/shared_ptr_atomic.h (_Sp_atomic::_Atomic_count::lock):
	Only use __thread_relax if __cpp_lib_atomic_wait is defined.
2022-01-19 00:58:21 +00:00
Jonathan Wakely
fe3ed885cd libstdc++: Limit new basic_string(nullptr_t) constructor to C++23 [PR104099]
The new deleted constructors added by P2166R1 are a breaking change,
making previously valid code ill-formed in C++23. As a result, they
should only be defined for C++23 and not for C++11 and up.

libstdc++-v3/ChangeLog:

	PR libstdc++/104099
	* include/bits/basic_string.h (basic_string(nullptr_t)): Only
	define for C++23.
	(operator=(nullptr_t)): Likewise.
	* include/bits/cow_string.h: Likewise.
	* include/std/string_view (basic_string_view(nullptr_t)):
	Likewise.
	* testsuite/21_strings/basic_string/cons/char/nullptr.cc: Adjust
	expected error. Add examples that become ill-formed in C++23.
	* testsuite/21_strings/basic_string_view/cons/char/nonnull.cc:
	Adjust expected errors.
	* testsuite/21_strings/basic_string_view/cons/wchar_t/nonnull.cc:
	Likewise.
2022-01-18 20:41:46 +00:00
Jonathan Wakely
e13e95bd27 libstdc++: Use __cpp_lib_concepts in std::reverse_iterator [PR104098]
We should not assume that std::iter_value_t etc. are defined
unconditionally for C++20 mode.

libstdc++-v3/ChangeLog:

	PR libstdc++/104098
	* include/bits/stl_iterator.h (reverse_iterator): Check
	__cpp_lib_concepts instead of __cplusplus.
2022-01-18 16:31:03 +00:00
Jonathan Wakely
302343d8dd libstdc++: Fix ambiguous std::pair constructors [PR101124]
The deprecated non-standard std::pair constructors that allow
constructing std::pair<move-only-type, pointer-type> from an rvalue and
a literal zero where not sufficiently constrained. They were viable when
constructing std::pair<copyable-type, pointer-type>, and that case
should work fine using the standard constructors.

Replace the constraints on the non-standard constructors so they are
only viable in cases that should actually be ill-formed according to the
standard.

Also rename __null_ptr_constant to __zero_as_null_pointer_constant so it
matches the name of the -Wzero-as-null-pointer-constant warning. Also
make the text of the deprecated warning describe the problem in more
detail.

libstdc++-v3/ChangeLog:

	PR libstdc++/101124
	* include/bits/stl_pair.h (pair): Adjust constraints on
	deprecated constructors accepting literal zero as null pointer
	constant. Improve wording of deprecated attribute.
	* testsuite/20_util/pair/cons/99957.cc: Check that deprecated
	constructors do not cause ambiguities for copyable types.
2022-01-18 16:31:03 +00:00
Jonathan Wakely
50bc6e463b libstdc++: Fix suggested alternative to std::ptr_fun
libstdc++-v3/ChangeLog:

	* include/bits/stl_function.h (ptr_fun): Fix suggestion for
	non-deprecated alternative.
2022-01-18 16:31:02 +00:00
Tom Honermann
0e4e4b37d9 libstdc++: Declare std::c8rtomb and std::mbrtoc8 if provided by the C library
This patch completes implementation of the C++20 proposal P0482R6 [1] by
adding declarations of std::c8rtomb() and std::mbrtoc8() in <cuchar> if
provided by the C library in <uchar.h>.

This patch addresses feedback provided in response to a previous patch
submission [2].

Autoconf changes determine if the C library declares c8rtomb and mbrtoc8
at global scope when uchar.h is included and compiled with either
-fchar8_t or -std=c++20. New _GLIBCXX_USE_UCHAR_C8RTOMB_MBRTOC8_FCHAR8_T
and _GLIBCXX_USE_UCHAR_C8RTOMB_MBRTOC8_CXX20 configuration macros
reflect the probe results. The <cuchar> header declares these functions
in the std namespace only if available and the _GLIBCXX_USE_CHAR8_T
configuration macro is defined (by default it is defined if the C++20
__cpp_char8_t feature test macro is defined)

Patches to glibc to implement c8rtomb and mbrtoc8 have been submitted [3].

New tests validate the presence of these declarations. The tests pass
trivially if the C library does not provide these functions. Otherwise
they ensure that the functions are declared when <cuchar> is included
and either -fchar8_t or -std=c++20 is enabled.

1]: WG21 P0482R6
      "char8_t: A type for UTF-8 characters and strings (Revision 6)"
      https://wg21.link/p0482r6

[2]: [PATCH] C++ P0482R6 char8_t: declare std::c8rtomb and std::mbrtoc8
if provided by the C library
      https://gcc.gnu.org/pipermail/libstdc++/2021-June/052685.html

[3]: "C++20 P0482R6 and C2X N2653"
      [Patch 0/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135061.html
      [Patch 1/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135062.html
      [Patch 2/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135063.html
      [Patch 3/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135064.html

libstdc++-v3/ChangeLog:

	* acinclude.m4: Define config macros if uchar.h provides
	c8rtomb() and mbrtoc8().
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* include/c_compatibility/uchar.h (c8rtomb, mbrtoc8): Define.
	* include/c_global/cuchar (c8rtomb, mbrtoc8): Likewise.
	* include/c_std/cuchar (c8rtomb, mbrtoc8): Likewise.
	* testsuite/21_strings/headers/cuchar/functions_std_cxx20.cc:
	New test.
	* testsuite/21_strings/headers/cuchar/functions_std_fchar8_t.cc:
	New test.
2022-01-18 16:31:02 +00:00
Jonathan Wakely
d7f2a09e98 libstdc++: Define <stdatomic.h> for C++23
This adds the C++23 <stdatomic.h> header, as proposed by P0943R6, for
compatibility with C code.

There are still some ABI differences between atomic_xxx in C and C++
std::atomic_xxx in C++, so this only provides source compatibility, not
binary compatibility.

libstdc++-v3/ChangeLog:

	* include/Makefile.am: Install new header.
	* include/Makefile.in: Regenerate.
	* include/c_compatibility/stdatomic.h: New file.
	* testsuite/29_atomics/headers/stdatomic.h/c_compat.cc: New test.
2022-01-18 16:31:02 +00:00
Jonathan Wakely
3acb929cc0 libstdc++: Define <stacktrace> header for C++23
Add the <stacktrace> header and a new libstdc++_libbacktrace.a library
that provides the implementation. For now, the new library is only built
if --enable-libstdcxx-backtrace=yes is used. As with the Filesystem TS,
the new library is only provided as a static archive.

libstdc++-v3/ChangeLog:

	* acinclude.m4 (GLIBCXX_ENABLE_BACKTRACE): New macro.
	* configure.ac: Use GLIBCXX_ENABLE_BACKTRACE.
	* include/Makefile.am: Add new header.
	* include/Makefile.in: Regenerate.
	* include/std/stacktrace: New header.
	* include/std/version (__cpp_lib_stacktrace): Define.
	* Makefile.in: Regenerate.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* doc/Makefile.in: Regenerate.
	* libsupc++/Makefile.in: Regenerate.
	* po/Makefile.in: Regenerate.
	* python/Makefile.in: Regenerate.
	* src/Makefile.am: Regenerate.
	* src/Makefile.in: Regenerate.
	* src/c++11/Makefile.in: Regenerate.
	* src/c++17/Makefile.in: Regenerate.
	* src/c++20/Makefile.in: Regenerate.
	* src/c++98/Makefile.in: Regenerate.
	* src/filesystem/Makefile.in: Regenerate.
	* testsuite/Makefile.in: Regenerate.
	* src/libbacktrace/Makefile.am: New file.
	* src/libbacktrace/Makefile.in: New file.
	* src/libbacktrace/backtrace-rename.h: New file.
	* src/libbacktrace/backtrace-supported.h.in: New file.
	* src/libbacktrace/config.h.in: New file.
	* testsuite/lib/libstdc++.exp (check_effective_target_stacktrace):
	New proc.
	* testsuite/20_util/stacktrace/entry.cc: New test.
	* testsuite/20_util/stacktrace/synopsis.cc: New test.
	* testsuite/20_util/stacktrace/version.cc: New test.
2022-01-17 12:13:02 +00:00
Jonathan Wakely
fa092570fb libstdc++: Rename non-reserved macros in config header [PR103650]
libstdc++-v3/ChangeLog:

	PR libstdc++/103650
	* include/Makefile.am: Rename LT_OBJDIR and STDC_HEADERS.
	* include/Makefile.in: Regenerate.
	* testsuite/17_intro/headers/c++1998/103650.cc: New test.
2022-01-17 12:08:26 +00:00
Matthias Kretz
84eb13b9d6 libstdc++: Don't fail if math_errhandling is not defined
Older glibc does not define math_errhandling with -ffast-math, in which
case floating-point exceptions are not used.

Signed-off-by: Matthias Kretz <m.kretz@gsi.de>

libstdc++-v3/ChangeLog:

	* include/experimental/bits/simd.h (__floating_point_flags): Do
	not rely on the presence of the math_errhandling macro.
2022-01-17 11:27:32 +01:00
Jonathan Wakely
a923345c72 libstdc++: Add 'typename' to dependent types in atomic<shared_ptr<T>>
libstdc++-v3/ChangeLog:

	* include/bits/shared_ptr_atomic.h (_Sp_atomic): Add typename
	to qualified-id for dependent type.
2022-01-17 09:48:09 +00:00
Jonathan Wakely
2ac0649d7b libstdc++: Implement C++20 atomic<shared_ptr> and atomic<weak_ptr>
This adds another piece of C++20, the std::atomic specializations for
std::shared_ptr and std::weak_ptr.

The new _Sp_atomic type mimics the structure of shared_ptr<T> and
weak_ptr<T>, holding a T* pointer (the one returned by get() on a
shared_ptr/weak ptr) and a _Sp_counted_base<>* pointer to the
ref-counted control block. For _Sp_atomic the low bit of the control
block pointer is used as a lock bit, to ensure only one thread will
access the object at a time.  The pointer is actually stored as a
uintptr_t to avoid accidental dereferences of the pointer when unlocked
(which would be a race) or when locked (which would dereference the
wrong pointer value due to the low bit being set). To get a raw pointer
to the control block, the lock must be acquired. Converting between a
_Sp_atomic and a shared_ptr or weak_ptr requires manually adjusting the
T* and _Sp_counted_base<>* members of the shared/weak ptr, instead of
going through the public API. This must be done carefully to ensure that
any change in the number of owners is reflected in a ref-count update.

Co-authored-by: Thomas Rodgers <trodgers@redhat.com>
Signed-off-by: Thomas Rodgers <trodgers@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/shared_ptr_atomic.h (__cpp_lib_atomic_shared_ptr):
	New macro.
	(_Sp_atomic): New class template.
	(atomic<shared_ptr<T>>, atomic<weak_ptr<T>>): New partial
	specializations.
	* include/bits/shared_ptr_base.h (__shared_count, __weak_count)
	(__shared_ptr, __weak_ptr): Declare _Sp_atomic as a friend.
	* include/std/version (__cpp_lib_atomic_shared_ptr): New macro.
	* testsuite/20_util/shared_ptr/atomic/atomic_shared_ptr.cc: New
	test.
	* testsuite/20_util/weak_ptr/atomic_weak_ptr.cc: New test.
2022-01-17 00:06:28 +00:00
Matthias Kretz
52d2821038 libstdc++: Fix ODR issues with different -m flags
Explicitly support use of the stdx::simd implementation in situations
where the user links TUs that were compiled with different -m flags. In
general, this is always a (quasi) ODR violation for inline functions
because at least codegen may differ in important ways. However, in the
resulting executable only one (unspecified which one) of them might be
used. For simd we want to support users to compile code multiple times,
with different -m flags and have a runtime dispatch to the TU matching
the target CPU. But if internal functions are not inlined this may lead
to unexpected performance loss or execution of illegal instructions.
Therefore, inline functions that are not marked as always_inline must
use an additional template parameter somewhere in their name, to
disambiguate between the different -m translations.

Signed-off-by: Matthias Kretz <m.kretz@gsi.de>

libstdc++-v3/ChangeLog:

	* include/experimental/bits/simd.h: Move feature detection bools
	and add __have_avx512bitalg, __have_avx512vbmi2,
	__have_avx512vbmi, __have_avx512ifma, __have_avx512cd,
	__have_avx512vnni, __have_avx512vpopcntdq.
	(__detail::__machine_flags): New function which returns a unique
	uint64 depending on relevant -m and -f flags.
	(__detail::__odr_helper): New type alias for either an anonymous
	type or a type specialized with the __machine_flags number.
	(_SimdIntOperators): Change template parameters from _Impl to
	_Tp, _Abi because _Impl now has an __odr_helper parameter which
	may be _OdrEnforcer from the anonymous namespace, which makes
	for a bad base class.
	(many): Either add __odr_helper template parameter or mark as
	always_inline.
	* include/experimental/bits/simd_detail.h: Add defines for
	AVX512BITALG, AVX512VBMI2, AVX512VBMI, AVX512IFMA, AVX512CD,
	AVX512VNNI, AVX512VPOPCNTDQ, and AVX512VP2INTERSECT.
	* include/experimental/bits/simd_builtin.h: Add __odr_helper
	template parameter or mark as always_inline.
	* include/experimental/bits/simd_fixed_size.h: Ditto.
	* include/experimental/bits/simd_math.h: Ditto.
	* include/experimental/bits/simd_scalar.h: Ditto.
	* include/experimental/bits/simd_neon.h: Add __odr_helper
	template parameter.
	* include/experimental/bits/simd_ppc.h: Ditto.
	* include/experimental/bits/simd_x86.h: Ditto.
2022-01-15 21:05:17 +01:00
Jonathan Wakely
de196e5dd8 libstdc++: Add attribute to features deprecated in C++17 [PR91260]
There are a lot of things in the C++ standard library which were
deprecated in C++11, and more in C++17.  Some of them were removed after
deprecation and are no longer present in the standard at all. We have
not removed these from libstdc++ because keeping them as non-standard
extensions is conforming, and avoids gratuitously breaking user code,
and in some cases we need to keep using them to avoid ABI changes. But
we should at least give a warning for using them. That has not been done
previously because of the library's own uses of them (e.g. the
std::iterator class template used as a base class).

This adds deprecated attributes to the relevant components, and then
goes through the whole library to add diagnostic pragmas where needed to
suppress warnings about our internal uses of them. The tests are updated
to either expect the additional warnings, or to suppress them where we
aren't interested in them.

libstdc++-v3/ChangeLog:

	PR libstdc++/91260
	PR libstdc++/91383
	PR libstdc++/95065
	* include/backward/binders.h (bind1st, bind2nd): Add deprecated
	attribute.
	* include/bits/refwrap.h (_Maybe_unary_or_binary_function):
	Disable deprecated warnings for base classes.
	(_Reference_wrapper_base): Likewise.
	* include/bits/shared_ptr_base.h (_Sp_owner_less): Likewise.
	* include/bits/stl_bvector.h (_Bit_iterator_base): Likewise.
	* include/bits/stl_function.h (unary_function, binary_function):
	Add deprecated attribute.
	(unary_negate, not1, binary_negate, not2, ptr_fun)
	(pointer_to_unary_function, pointer_to_binary_function)
	(mem_fun_t, const_mem_fun_t, mem_fun_ref_t, const_mem_fun_ref_t)
	(mem_fun1_t, const_mem_fun1_t, mem_fun_ref1_t)
	(const_mem_fun1_ref_t, mem_fun, mem_fun_ref): Add deprecated
	attributes.
	* include/bits/stl_iterator.h: Disable deprecated warnings for
	std::iterator base classes.
	* include/bits/stl_iterator_base_types.h (iterator): Add
	deprecated attribute.
	* include/bits/stl_map.h (map::value_compare): Disable
	deprecated warnings for base class.
	* include/bits/stl_multimap.h (multimap::value_compare):
	Likewise.
	* include/bits/stl_raw_storage_iter.h (raw_storage_iterator):
	Add deprecated attribute.
	* include/bits/stl_tempbuf.h (get_temporary_buffer): Likewise.
	* include/bits/stream_iterator.h: Disable deprecated warnings.
	* include/bits/streambuf_iterator.h: Likewise.
	* include/ext/bitmap_allocator.h: Remove unary_function base
	classes.
	* include/ext/functional: Disable deprecated warnings.
	* include/ext/rope: Likewise.
	* include/ext/throw_allocator.h: Likewise.
	* include/std/type_traits (result_of): Add deprecated attribute.
	* include/tr1/functional: Disable deprecated warnings.
	* include/tr1/functional_hash.h: Likewise.
	* testsuite/20_util/function_objects/binders/1.cc: Add
	-Wno-disable-deprecations.
	* testsuite/20_util/function_objects/binders/3113.cc: Likewise.
	* testsuite/20_util/function_objects/constexpr.cc: Add
	dg-warning.
	* testsuite/20_util/raw_storage_iterator/base.cc: Likewise.
	* testsuite/20_util/raw_storage_iterator/dr2127.cc: Likewise.
	* testsuite/20_util/raw_storage_iterator/requirements/base_classes.cc:
	Likewise.
	* testsuite/20_util/raw_storage_iterator/requirements/explicit_instantiation/1.cc:
	Likewise.
	* testsuite/20_util/raw_storage_iterator/requirements/typedefs.cc:
	Likewise.
	* testsuite/20_util/reference_wrapper/24803.cc:
	Likewise.
	* testsuite/20_util/reference_wrapper/typedefs.cc: Enable for
	C++20 and check for absence of nested types.
	* testsuite/20_util/shared_ptr/comparison/less.cc: Remove
	std::binary_function base class.
	* testsuite/20_util/temporary_buffer.cc: Add dg-warning.
	* testsuite/21_strings/basic_string/cons/char/69092.cc: Remove
	std::iterator base class.
	* testsuite/24_iterators/back_insert_iterator/requirements/base_classes.cc:
	Likewise.
	* testsuite/24_iterators/front_insert_iterator/requirements/base_classes.cc:
	Likewise.
	* testsuite/24_iterators/insert_iterator/requirements/base_classes.cc:
	Likewise.
	* testsuite/24_iterators/istream_iterator/requirements/base_classes.cc:
	Likewise.
	* testsuite/24_iterators/istreambuf_iterator/92285.cc:
	Likewise.
	* testsuite/24_iterators/istreambuf_iterator/requirements/base_classes.cc:
	Likewise.
	* testsuite/24_iterators/ostream_iterator/requirements/base_classes.cc:
	Likewise.
	* testsuite/24_iterators/ostreambuf_iterator/requirements/base_classes.cc:
	Likewise.
	* testsuite/24_iterators/reverse_iterator/requirements/base_classes.cc:
	Likewise.
	* testsuite/25_algorithms/copy/34595.cc:
	Likewise.
	* testsuite/25_algorithms/minmax/3.cc: Remove std::binary_function
	base class.
	* testsuite/25_algorithms/all_of/requirements/explicit_instantiation/2.cc:
	Disable deprecated warnings.
	* testsuite/25_algorithms/all_of/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/any_of/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/any_of/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/copy_if/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/copy_if/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/count_if/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/count_if/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/find_end/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/find_end/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/find_first_of/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/find_first_of/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/find_if/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/find_if/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/find_if_not/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/find_if_not/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/for_each/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/for_each/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/is_partitioned/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/is_partitioned/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/is_permutation/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/is_permutation/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/none_of/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/none_of/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/partition/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/partition/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/partition_copy/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/partition_copy/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/partition_point/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/partition_point/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/random_shuffle/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/random_shuffle/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/remove_copy_if/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/remove_copy_if/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/remove_if/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/remove_if/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/replace_copy_if/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/replace_copy_if/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/replace_if/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/replace_if/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/search/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/search/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/search_n/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/search_n/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/stable_partition/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/stable_partition/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/25_algorithms/transform/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/transform/requirements/explicit_instantiation/pod.cc:
	Likewise.
	* testsuite/27_io/basic_filebuf/underflow/wchar_t/9178.cc: Add
	dg-warning.
	* testsuite/ext/pb_ds/example/priority_queue_erase_if.cc:
	Likewise.
	* testsuite/ext/pb_ds/example/priority_queue_split_join.cc:
	Likewise.
	* testsuite/tr1/3_function_objects/reference_wrapper/typedefs.cc:
	Disable deprecated warnings.
	* testsuite/tr1/6_containers/hash/requirements/base_classes.cc:
	Likewise.
	* testsuite/util/regression/trait/erase_if_fn.hpp: Remove
	std::unary_function base classes.
	* testsuite/util/testsuite_iterators.h (output_iterator_wrapper):
	Remove std::iterator base classes.
2022-01-14 11:27:50 +00:00
Jonathan Wakely
9a0b518a82 libstdc++: Add C++20 std::make_shared enhancements (P0674R1)
This adds the overloads of std::make_shared and std::allocate_shared for
creating arrays, added to C++20 by P0674R1.

It also adds std::make_shared_for_overwrite, added to C++20 by P1020R1
(and renamed by P1973R1). The std::make_unique_for_overwite overloads
are already supported.

The original std::make_shared overload is changed to construct a
shared_ptr directly instead of calling std::allocate_shared. This
removes a function call at runtime, and avoids having to do overload
resolution for std::allocate_shared, now that there are five overloads
of it.

Allocating a shared array is done by a new __shared_count constructor.
An array is allocated with space for additional elements at the end and
an instance of new _Sp_counted_array class template is constructed in
that unused capacity.

The non-array form of std::make_shared_for_overwrite uses the same
__shared_count constructor as the original std::make_shared overload,
but a new partial specialization of _Sp_counted_ptr_inplace is selected
when the allocator's value_type is the new _Sp_overwrite_tag type. That
new partial specialization default-initializes its contained object and
destroys it with a destructor call rather than using the allocator.

Despite being C++20 features, this implementation only uses concepts
conditionally, with workarounds when they are not supported. This allows
it to work with older non-GCC compilers (Clang 9 and icc 2021). At some
point we can simplify the code by removing the workarounds.

libstdc++-v3/ChangeLog:

	* include/bits/shared_ptr.h (__cpp_lib_shared_ptr_weak_type):
	Correct type of macro value.
	(shared_ptr): Add additional friend declarations.
	(make_shared, allocate_shared): Constrain existing overloads and
	remove static_assert.
	* include/bits/shared_ptr_base.h (__cpp_lib_smart_ptr_for_overwrite):
	New macro.
	(_Sp_counted_ptr_inplace<T, Alloc, Lp>): New partial
	specialization for use with make_shared_for_overwrite.
	(__cpp_lib_shared_ptr_arrays): Update value for C++20.
	(_Sp_counted_array_base): New class template.
	(_Sp_counted_array): New class template.
	(__shared_count(_Tp*&, const _Sp_counted_array_base&, _Init)):
	New constructor for allocating shared arrays.
	(__shared_ptr(const _Sp_counted_array_base&, _Init)): Likewise.
	* include/std/version (__cpp_lib_shared_ptr_weak_type): Correct
	type.
	(__cpp_lib_shared_ptr_arrays): Update value for C++20.
	(__cpp_lib_smart_ptr_for_overwrite): New macro.
	* testsuite/20_util/shared_ptr/creation/99006.cc: Adjust
	expected errors.
	* testsuite/20_util/shared_ptr/creation/array.cc: New test.
	* testsuite/20_util/shared_ptr/creation/overwrite.cc: New test.
	* testsuite/20_util/shared_ptr/creation/version.cc: New test.
	* testsuite/20_util/unique_ptr/creation/for_overwrite.cc: Check
	feature test macro. Test non-trivial default-initialization.
2022-01-14 10:14:25 +00:00