Commit graph

1573 commits

Author SHA1 Message Date
Ken Matsui
41a6d25605
libstdc++: Use _GLIBCXX_USE_BUILTIN_TRAIT for is_same
Since is_same has a fallback native implementation, and
_GLIBCXX_HAVE_BUILTIN_IS_SAME does not support toggling which
implementation to use, we remove the _GLIBCXX_HAVE_BUILTIN_IS_SAME
definition and use _GLIBCXX_USE_BUILTIN_TRAIT instead.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_HAVE_BUILTIN_IS_SAME):
	Removed.
	* include/std/type_traits (is_same): Use
	_GLIBCXX_USE_BUILTIN_TRAIT instead of
	_GLIBCXX_HAVE_BUILTIN_IS_SAME.
	(is_same_v): Likewise.

Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
Reviewed-by: Patrick Palka <ppalka@redhat.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
2024-02-09 10:11:47 -08:00
Jakub Jelinek
a945c346f5 Update copyright years. 2024-01-03 12:19:35 +01:00
Jonathan Wakely
7d00a59229 libstdc++: Make __gnu_debug::vector usable in constant expressions [PR109536]
This makes constexpr std::vector (mostly) work in Debug Mode. All safe
iterator instrumentation and checking is disabled during constant
evaluation, because it requires mutex locks and calls to non-inline
functions defined in libstdc++.so. It should be OK to disable the safety
checks, because most UB should be detected during constant evaluation
anyway.

We could try to enable the full checking in constexpr, but it would mean
wrapping all the non-inline functions like _M_attach with an inline
_M_constexpr_attach that does the iterator housekeeping inline without
mutex locks when called for constant evaluation, and calls the
non-inline function at runtime. That could be done in future if we find
that we've lost safety or useful checking by disabling the safe
iterators.

There are a few test failures in C++20 mode, which I'm unable to
explain. The _Safe_iterator::operator++() member gives errors for using
non-constexpr functions during constant evaluation, even though those
functions are guarded by std::is_constant_evaluated() checks. The same
code works fine for C++23 and up.

libstdc++-v3/ChangeLog:

	PR libstdc++/109536
	* include/bits/c++config (__glibcxx_constexpr_assert): Remove
	macro.
	* include/bits/stl_algobase.h (__niter_base, __copy_move_a)
	(__copy_move_backward_a, __fill_a, __fill_n_a, __equal_aux)
	(__lexicographical_compare_aux): Add constexpr to overloads for
	debug mode iterators.
	* include/debug/helper_functions.h (__unsafe): Add constexpr.
	* include/debug/macros.h (_GLIBCXX_DEBUG_VERIFY_COND_AT): Remove
	macro, folding it into ...
	(_GLIBCXX_DEBUG_VERIFY_AT_F): ... here. Do not use
	__glibcxx_constexpr_assert.
	* include/debug/safe_base.h (_Safe_iterator_base): Add constexpr
	to some member functions. Omit attaching, detaching and checking
	operations during constant evaluation.
	* include/debug/safe_container.h (_Safe_container): Likewise.
	* include/debug/safe_iterator.h (_Safe_iterator): Likewise.
	* include/debug/safe_iterator.tcc (__niter_base, __copy_move_a)
	(__copy_move_backward_a, __fill_a, __fill_n_a, __equal_aux)
	(__lexicographical_compare_aux): Add constexpr.
	* include/debug/vector (_Safe_vector, vector): Add constexpr.
	Omit safe iterator operations during constant evaluation.
	* testsuite/23_containers/vector/bool/capacity/constexpr.cc:
	Remove dg-xfail-if for debug mode.
	* testsuite/23_containers/vector/bool/cmp_c++20.cc: Likewise.
	* testsuite/23_containers/vector/bool/cons/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/bool/element_access/1.cc:
	Likewise.
	* testsuite/23_containers/vector/bool/element_access/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/bool/modifiers/assign/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/bool/modifiers/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/bool/modifiers/swap/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/capacity/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/cmp_c++20.cc: Likewise.
	* testsuite/23_containers/vector/cons/constexpr.cc: Likewise.
	* testsuite/23_containers/vector/data_access/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/element_access/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/modifiers/assign/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/modifiers/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/modifiers/swap/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/cons/destructible_debug_neg.cc:
	Adjust dg-error line number.
2023-12-14 16:07:48 +00:00
Jonathan Wakely
1395c573c5 libstdc++: Fix recent changes to __glibcxx_assert [PR112882]
The changes in r14-6198-g5e8a30d8b8f4d7 were broken, as I used
_GLIBCXX17_CONSTEXPR for the 'if _GLIBCXX17_CONSTEXPR (true)' condition,
forgetting that it would also be used for the is_constant_evaluated()
check. Using 'if constexpr (std::is_constant_evaluated())' is a bug.

Additionally, relying on __glibcxx_assert_fail to give a "not a constant
expression" error is a problem because at -O0 an undefined reference to
__glibcxx_assert_fail is present in the compiled code. This means you
can't use libstdc++ headers without also linking to libstdc++ for the
symbol definition.

This fix rewrites the __glibcxx_assert macro again. This still avoids
doing the duplicate checks, once for constexpr and once at runtime (if
_GLIBCXX_ASSERTIONS is defined). When _GLIBCXX_ASSERTIONS is defined we
still rely on __glibcxx_assert_fail to give a "not a constant
expression" error during constant evaluation (because when assertions
are defined it's not a problem to emit a reference to the symbol). But
when that macro is not defined, we use a new inline (but not constexpr)
overload of __glibcxx_assert_fail to cause compilation to fail. That
inline function doesn't cause an undefined reference to a symbol in the
library (and will be optimized away anyway).

We can also add always_inline to the __is_constant_evaluated function,
although this doesn't actually matter for -O0 and it's always inlined
with any optimization enabled.

libstdc++-v3/ChangeLog:

	PR libstdc++/112882
	* include/bits/c++config (__is_constant_evaluated): Add
	always_inline attribute.
	(_GLIBCXX_DO_ASSERT): Remove macro.
	(__glibcxx_assert): Define separately for assertions-enabled and
	constexpr-only cases.
2023-12-07 20:54:11 +00:00
Jonathan Wakely
5e8a30d8b8 libstdc++: Redefine __glibcxx_assert to work in C++23 constexpr
The changes in r14-5979 to support unknown references in constant
expressions caused some test regressions. The way that __glibcxx_assert
is defined for constant evaluation no longer works when
_GLIBCXX_ASSERTIONS is defined.

This change simplifies __glibcxx_assert so that there is only one check,
rather than a constexpr one and a conditionally-enabled runtime one. The
constexpr one does not need to use __builtin_unreachable to cause a
compilation failure, because __glibcxx_assert_fail is not usable in
constant expressions, so that will cause a failure too.

As well as fixing the regressions, this makes the code for the
assertions shorter and simpler, so should be quicker to compile, and
might inline better too.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (__glibcxx_assert_fail): Declare even
	when assertions are not enabled.
	(__glibcxx_constexpr_assert): Remove macro.
	(__glibcxx_assert_impl): Remove macro.
	(_GLIBCXX_ASSERT_FAIL): New macro.
	(_GLIBCXX_DO_ASSERT): New macro.
	(__glibcxx_assert): Simplify to a single definition that works
	at runtime and during constant evaluation.
	* testsuite/21_strings/basic_string_view/element_access/char/back_constexpr_neg.cc:
	Adjust expected errors.
	* testsuite/21_strings/basic_string_view/element_access/char/constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/char/front_constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/back_constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/front_constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/modifiers/remove_prefix/debug.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/modifiers/remove_suffix/debug.cc:
	Likewise.
	* testsuite/23_containers/span/back_neg.cc: Likewise.
	* testsuite/23_containers/span/front_neg.cc: Likewise.
	* testsuite/23_containers/span/index_op_neg.cc: Likewise.
	* testsuite/26_numerics/lcm/105844.cc: Likewise.
2023-12-05 23:33:22 +00:00
Ken Matsui
286655d046
libstdc++: Define _GLIBCXX_USE_BUILTIN_TRAIT
This patch defines _GLIBCXX_USE_BUILTIN_TRAIT macro, which will be used
as a flag to toggle the use of built-in traits in the type_traits header
through _GLIBCXX_DO_NOT_USE_BUILTIN_TRAITS macro, without needing to modify
the source code.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_HAS_BUILTIN): Do not undef.
	(_GLIBCXX_USE_BUILTIN_TRAIT): Define.

Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
Reviewed-by: Patrick Palka <ppalka@redhat.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
2023-09-11 08:11:24 -07:00
Jonathan Wakely
1a566fddea libstdc++: Define std::numeric_limits<_FloatNN> before C++23
The extended floating-point types such as _Float32 are supported by GCC
prior to C++23, you just can't use the standard-conforming names from
<stdfloat> to refer to them. This change defines the specializations of
std::numeric_limits for those types for older dialects, not only for
C++23.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (__gnu_cxx::__bfloat16_t): Define
	whenever __BFLT16_DIG__ is defined, not only for C++23.
	* include/std/limits (numeric_limits<bfloat16_t>): Likewise.
	(numeric_limits<_Float16>, numeric_limits<_Float32>)
	(numeric_limits<_Float64>): Likewise for other extended
	floating-point types.
2023-08-17 20:24:18 +01:00
Jan Hubicka
45c53768b6 Add cold attribute to throw wrappers and terminate
PR middle-end/109849
	* include/bits/c++config (std::__terminate): Mark cold.
	* include/bits/functexcept.h: Mark everything as cold.
	* libsupc++/exception: Mark terminate and unexpected as cold.
2023-06-28 11:47:11 +02:00
Jonathan Wakely
98827c53ed libstdc++: Add system_header pragma to <bits/c++config.h>
Without this change many tests that depend on an effective-target will
fail when compiled with -pedantic -std=c++98. This happens because the
preprocessor check done by v3_check_preprocessor_condition uses -Werror
and includes <bits/c++config.h> directly (rather than via another header
like <string>). If <bits/c++config.h> is not a system header then this
pedwarn is not suppressed, and the effective-target check fails:

bits/c++config.h:220: error: anonymous variadic macros were introduced in C++11 [-Werror=variadic-macros]
cc1plus: all warnings being treated as errors
compiler exited with status 1
UNSUPPORTED: 18_support/headers/limits/synopsis.cc

We could consider also changing proc v3_check_preprocessor_condition so
that it includes a real header, rather than just <bits/c++config.h>, but
that's not necessary for now.

libstdc++-v3/ChangeLog:

	* include/bits/c++config: Add system_header pragma.
2023-05-17 20:01:49 +01:00
Arsen Arsenović
bff26ac162
libstdc++: Downgrade DEBUG to ASSERTIONS when !HOSTED
Supporting the debug mode in freestanding is a non-trivial job, so
instead, as a best-effort, enable assertions, which are light and easy.

libstdc++-v3/ChangeLog:

	* include/bits/c++config: When __STDC_HOSTED__ is zero,
	disable _GLIBCXX_DEBUG and, if it was set, enable
	_GLIBCXX_ASSERTIONS.
	* testsuite/lib/libstdc++.exp (check_v3_target_debug_mode):
	Include <bits/c++config.h> when determining whether debug is
	set, in order to inherit the logic from above
2023-04-05 18:45:14 +02:00
Nathaniel Shead
aa02a69e15 libstdc++: Implement P1413R3 'deprecate aligned_storage and aligned_union'
Adds deprecated attributes for C++23, and makes use of it for
std::aligned_storage, std::aligned_storage_t, std::aligned_union, and
std::aligned_union_t.

libstdc++-v3/ChangeLog:

	* doc/doxygen/user.cfg.in (PREDEFINED): Add new macros.
	* include/bits/c++config (_GLIBCXX23_DEPRECATED)
	(_GLIBCXX23_DEPRECATED_SUGGEST): New macros.
	* include/std/type_traits (aligned_storage, aligned_union)
	(aligned_storage_t, aligned_union_t): Deprecate for C++23.
	* testsuite/20_util/aligned_storage/deprecated-2b.cc: New test.
	* testsuite/20_util/aligned_union/deprecated-2b.cc: New test.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
2023-02-06 14:23:47 +00:00
Nathaniel Shead
4f49ae607c libstdc++: Normalise _GLIBCXX20_DEPRECATED macro
Updates _GLIBCXX20_DEPRECATED to be defined and behave the same as the
versions for other standards (e.g. _GLIBCXX17_DEPRECATED).

libstdc++-v3/ChangeLog:

	* doc/doxygen/user.cfg.in (PREDEFINED): Update macros.
	* include/bits/c++config (_GLIBCXX20_DEPRECATED): Make
	consistent with other 'deprecated' macros.
	* include/std/type_traits (is_pod, is_pod_v): Use
	_GLIBCXX20_DEPRECATED_SUGGEST instead.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
2023-02-06 14:23:46 +00:00
Jakub Jelinek
83ffe9cde7 Update copyright years. 2023-01-16 11:52:17 +01:00
Jakub Jelinek
a23225fb4f libstdc++: Partial library support for std::float{16,32,64,128}_t and std::bfloat16_t
The following patch is partial support for std::float{16,32,64,128}_t
and std::bfloat16_t in libstdc++.
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p1467r9.html
says that <ostream>, <istream>, <charconv> and <complex>
need changes toom, but that isn't implemented so far.
In <cmath> the only thing missing I'm aware of is
std::nextafter std::float16_t and std::bfloat16_t overloads (I think
we probably need to implement that out of line somewhere, or inline? - might
need inline asm barriers) and std::nexttoward overloads (those are
intentional, you said there is a LWG issue about that).
Also, this patch has the glibc 2.26+ std::float128_t support for platforms
where long double isn't IEEE quad format temporarily disabled
because it depends on
https://gcc.gnu.org/pipermail/gcc-patches/2022-October/603665.html
changes which aren't in yet.

The patch also doesn't include any testcases to cover the <type_traits>
changes, it isn't clear to me where to put that.

2022-10-18  Jakub Jelinek  <jakub@redhat.com>

	PR c++/106652
	* include/std/stdfloat: New file.
	* include/std/numbers (__glibcxx_numbers): Define and use it
	for __float128 explicit instantiations as well as
	_Float{16,32,64,128} and __gnu_cxx::__bfloat16_t.
	* include/std/atomic (atomic<_Float16>, atomic<_Float32>,
	atomic<_Float64>, atomic<_Float128>, atomic<__gnu_cxx::__bfloat16_t>):
	New explicit instantiations.
	* include/std/type_traits (__is_floating_point_helper<_Float16>,
	__is_floating_point_helper<_Float32>,
	__is_floating_point_helper<_Float64>,
	__is_floating_point_helper<_Float128>,
	__is_floating_point_helper<__gnu_cxx::__bfloat16_t>): Likewise.
	* include/std/limits (__glibcxx_concat3_, __glibcxx_concat3,
	__glibcxx_float_n): Define.
	(numeric_limits<_Float16>, numeric_limits<_Float32>,
	numeric_limits<_Float64>, numeric_limits<_Float128>,
	numeric_limits<__gnu_cxx::__bfloat16_t>): New explicit instantiations.
	* include/bits/std_abs.h (abs): New overloads for
	_Float{16,32,64,128} and __gnu_cxx::__bfloat16_t.
	* include/bits/c++config (_GLIBCXX_LDOUBLE_IS_IEEE_BINARY128): Define
	if long double is IEEE quad.
	(__gnu_cxx::__bfloat16_t): New using.
	* include/c_global/cmath (acos, asin, atan, atan2, ceil, cos, cosh,
	exp, fabs, floor, fmod, frexp, ldexp, log, log10, modf, pow, sin,
	sinh, sqrt, tan, tanh, fpclassify, isfinite, isinf, isnan, isnormal,
	signbit, isgreater, isgreaterequal, isless, islessequal,
	islessgreater, isunordered, acosh, asinh, atanh, cbrt, copysign, erf,
	erfc, exp2, expm1, fdim, fma, fmax, fmin, hypot, ilogb, lgamma,
	llrint, llround, log1p, log2, logb, lrint, lround, nearbyint,
	nextafter, remainder, rint, round, scalbln, scalbn, tgamma, trunc,
	lerp): New overloads with _Float{16,32,64,128} or
	__gnu_cxx::__bfloat16_t types.
	* config/os/gnu-linux/os_defines.h (_GLIBCXX_HAVE_FLOAT128_MATH):
	Prepare for definition if glibc 2.26 and later implements *f128 APIs
	but comment out the actual definition for now.
	* include/ext/type_traits.h (__promote<_Float16>, __promote<_Float32>,
	__promote<_Float64>, __promote<_Float128>,
	__promote<__gnu_cxx::__bfloat16_t>): New specializations.
	* include/Makefile.am (std_headers): Add stdfloat.
	* include/Makefile.in: Regenerated.
	* include/precompiled/stdc++.h: Include stdfloat.
	* testsuite/18_support/headers/stdfloat/types_std.cc: New test.
	* testsuite/18_support/headers/limits/synopsis_cxx23.cc: New test.
	* testsuite/26_numerics/headers/cmath/c99_classification_macros_c++23.cc:
	New test.
	* testsuite/26_numerics/headers/cmath/functions_std_c++23.cc: New test.
	* testsuite/26_numerics/numbers/4.cc: New test.
	* testsuite/29_atomics/atomic_float/requirements_cxx23.cc: New test.
2022-10-18 11:37:13 +02:00
Jonathan Wakely
1b01963a4e libstdc++: Improve doxygen docs for <regex>
Add @headerfile and @since tags. Improve grouping of non-member
functions via @relates tags.

Mark the std::pair base class of std::sub_match as undocumented, so that
the docs don't show all the related non-member functions are part of the
sub_match API. Use a new macro to re-add the data members for Doxygen
only.

libstdc++-v3/ChangeLog:

	* doc/doxygen/user.cfg.in (PREDEFINED): Define macro
	_GLIBCXX_DOXYGEN_ONLY to expand its argument.
	* include/bits/c++config (_GLIBCXX_DOXYGEN_ONLY): Define.
	* include/bits/regex.h: Improve doxygen docs.
	* include/bits/regex_constants.h: Likewise.
	* include/bits/regex_error.h: Likewise.
2022-05-13 13:32:22 +01:00
Jonathan Wakely
e4905f1185 libstdc++: Add macros for the inline namespace std::_V2
Use macros to open and close the inline namespace _V2 that is used for
ABI versioning of individual components such as chrono::system_clock.

This allows the namespace to be hidden in the docs generated by Doxygen,
so that we document std::foo instead of std::_V2::foo.

This also makes it easy to remove that namespace entirely for the
gnu-versioned-namespace build, where everything is already versioned as
std::__8 and there are no backwards compatibility guarantees.

libstdc++-v3/ChangeLog:

	* doc/doxygen/user.cfg.in (PREDEFINED): Expand new macros to
	nothing.
	* include/bits/c++config (_GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE)
	(_GLIBCXX_END_INLINE_ABI_NAMESPACE): Define new macros.
	* include/bits/algorithmfwd.h (_V2::__rotate): Use new macros
	for the namespace.
	* include/bits/chrono.h (chrono::_V2::system_clock): Likewise.
	* include/bits/stl_algo.h (_V2::__rotate): Likewise.
	* include/std/condition_variable (_V2::condition_variable_any):
	Likewise.
	* include/std/system_error (_V2::error_category): Likewise.
2022-05-13 13:32:22 +01:00
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
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
Jonathan Wakely
5b417b3582 libstdc++: Make std::variant work with Clang in C++20 mode [PR103891]
Clang has some bugs with destructors that use constraints to be
conditionally trivial, so disable the P2231R1 constexpr changes to
std::variant unless the compiler is GCC 12 or later.

If/when P2493R0 gets accepted and implemented by G++ we can remove the
__GNUC__ check and use __cpp_concepts >= 202002 instead.

libstdc++-v3/ChangeLog:

	PR libstdc++/103891
	* include/bits/c++config (_GLIBCXX_HAVE_COND_TRIVIAL_SPECIAL_MEMBERS):
	Define.
	* include/std/variant (__cpp_lib_variant): Only define C++20
	value when the compiler is known to support conditionally
	trivial destructors.
	* include/std/version (__cpp_lib_variant): Likewise.
2022-01-11 13:22:35 +00:00
Jonathan Wakely
3633cc5428 libstdc++: Implement P1328 "Making std::type_info::operator== constexpr"
This feature is present in the C++23 draft.

With Jakub's recent front-end changes we can implement constexpr
equality by comparing the addresses of std::type_info objects. We do not
need string comparisons, because for constant evaluation cases we know
we aren't dealing with std::type_info objects defined in other
translation units.

The ARM EABI requires that the type_info::operator== function can be
defined out-of-line (and suggests that should be the default), but to be
a constexpr function it must be defined inline (at least for C++23
mode). To meet these conflicting requirements we make the inline version
of operator== call a new __equal function when called at runtime. That
is an alias for the non-inline definition of operator== defined in
libsupc++.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver (GLIBCXX_3.4.30): Export new symbol for
	ARM EABI.
	* include/bits/c++config (_GLIBCXX23_CONSTEXPR): Define.
	* include/std/version (__cpp_lib_constexpr_typeinfo): Define.
	* libsupc++/tinfo.cc: Add #error to ensure non-inline definition
	is emitted.
	(type_info::__equal): Define alias symbol.
	* libsupc++/typeinfo (type_info::before): Combine different
	implementations into one.
	(type_info::operator==): Likewise. Use address equality for
	constant evaluation. Call __equal for targets that require the
	definition to be non-inline.
	* testsuite/18_support/type_info/constexpr.cc: New test.
2022-01-05 14:43:01 +00:00
Jakub Jelinek
7adcbafe45 Update copyright years. 2022-01-03 10:42:10 +01:00
Maged Michael
dbf8bd3c2f libstdc++: Skip atomic instructions in shared_ptr when both counts are 1
This rewrites _Sp_counted_base::_M_release to skip the two atomic
instructions that decrement each of the use count and the weak count
when both are 1.

Benefits: Save the cost of the last atomic decrements of each of the use
count and the weak count in _Sp_counted_base. Atomic instructions are
significantly slower than regular loads and stores across major
architectures.

How current code works: _M_release() atomically decrements the use
count, checks if it was 1, if so calls _M_dispose(), atomically
decrements the weak count, checks if it was 1, and if so calls
_M_destroy().

How the proposed algorithm works: _M_release() loads both use count and
weak count together atomically (assuming suitable alignment, discussed
later), checks if the value corresponds to a 0x1 value in the individual
count members, and if so calls _M_dispose() and _M_destroy().
Otherwise, it follows the original algorithm.

Why it works: When the current thread executing _M_release() finds each
of the counts is equal to 1, then no other threads could possibly hold
use or weak references to this control block. That is, no other threads
could possibly access the counts or the protected object.

There are two crucial high-level issues that I'd like to point out first:
- Atomicity of access to the counts together
- Proper alignment of the counts together

The patch is intended to apply the proposed algorithm only to the case of
64-bit mode, 4-byte counts, and 8-byte aligned _Sp_counted_base.

** Atomicity **
- The proposed algorithm depends on the mutual atomicity among 8-byte
atomic operations and 4-byte atomic operations on each of the 4-byte halves
of the 8-byte aligned 8-byte block.
- The standard does not guarantee atomicity of 8-byte operations on a pair
of 8-byte aligned 4-byte objects.
- To my knowledge this works in practice on systems that guarantee native
implementation of 4-byte and 8-byte atomic operations.
- __atomic_always_lock_free is used to check for native atomic operations.

** Alignment **
- _Sp_counted_base is an internal base class, with a virtual destructor,
so it has a vptr at the beginning of the class, and will be aligned to
alignof(void*) i.e. 8 bytes.
- The first members of the class are the 4-byte use count and 4-byte
weak count, which will occupy 8 contiguous bytes immediately after the
vptr, i.e. they form an 8-byte aligned 8 byte range.

Other points:
- The proposed algorithm can interact correctly with the current algorithm.
That is, multiple threads using different versions of the code with and
without the patch operating on the same objects should always interact
correctly. The intent for the patch is to be ABI compatible with the
current implementation.
- The proposed patch involves a performance trade-off between saving the
costs of atomic instructions when the counts are both 1 vs adding the cost
of loading the 8-byte combined counts and comparison with {0x1, 0x1}.
- I noticed a big difference between the code generated by GCC vs LLVM. GCC
seems to generate noticeably more code and what seems to be redundant null
checks and branches.
- The patch has been in use (built using LLVM) in a large environment for
many months. The performance gains outweigh the losses (roughly 10 to 1)
across a large variety of workloads.

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

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

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_TSAN): Define macro
	indicating that TSan is in use.
	* include/bits/shared_ptr_base.h (_Sp_counted_base::_M_release):
	Replace definition in primary template with explicit
	specializations for _S_mutex and _S_atomic policies.
	(_Sp_counted_base<_S_mutex>::_M_release): New specialization.
	(_Sp_counted_base<_S_atomic>::_M_release): New specialization,
	using a single atomic load to access both reference counts at
	once.
	(_Sp_counted_base::_M_release_last_use): New member function.
2021-12-08 11:39:34 +00:00
Jonathan Wakely
74d14778e7 libstdc++: Define std::__is_constant_evaluated() for internal use
This adds std::__is_constant_evaluated() as a C++11 wrapper for
__builtin_is_constant_evaluated, but just returning false if the
built-in isn't supported by the compiler. This allows us to use it
throughout the library without checking __has_builtin every time.

Some uses in std::vector and std::string can only be constexpr when the
std::is_constant_evaluated() function actually works, so we might as
well guard them with a relevant macro and call that function directly,
rather than the built-in or std::__is_constant_evaluated().

The remaining checks of the __cpp_lib_is_constant_evaluated macro could
now be replaced by checking __cplusplus >= 202002 instead, but there's
no practical difference. We still need some kind of preprocessor check
there anyway.

libstdc++-v3/ChangeLog:

	* doc/doxygen/user.cfg.in (PREDEFINED): Change macro name.
	* include/bits/allocator.h (allocate, deallocate): Use
	std::__is_constant_evaluated() unconditionally, instead of
	checking whether std::is_constant_evaluated() (or the built-in)
	can be used.
	* include/bits/basic_string.h: Check new macro. call
	std::is_constant_evaluated() directly in C++20-only code that is
	guarded by a suitable macro.
	* include/bits/basic_string.tcc: Likewise.
	* include/bits/c++config (__is_constant_evaluated): Define.
	(_GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED): Replace with ...
	(_GLIBCXX_HAVE_IS_CONSTANT_EVALUATED): New macro.
	* include/bits/char_traits.h (char_traits): Replace conditional
	calls to std::is_constant_evaluated with unconditional calls to
	std::__is_constant_evaluated.
	* include/bits/cow_string.h: Use new macro.
	* include/bits/ranges_algobase.h (__copy_or_move): Replace
	conditional calls to std::is_constant_evaluated with unconditional
	calls to std::__is_constant_evaluated.
	(__copy_or_move_backward, __fill_n_fn): Likewise.
	* include/bits/ranges_cmp.h (ranges::less): Likewise.
	* include/bits/stl_algobase.h (lexicographical_compare_three_way):
	Likewise.
	* include/bits/stl_bvector.h: Call std::is_constant_evaluated
	directly in C++20-only code that is guarded by a suitable macro.
	* include/bits/stl_construct.h (_Construct, _Destroy, _Destroy_n):
	Replace is_constant_evaluated with __is_constant_evaluated.
	* include/bits/stl_function.h (greater, less, greater_equal)
	(less_equal): Replace __builtin_is_constant_evaluated and
	__builtin_constant_p with __is_constant_evaluated.
	* include/bits/stl_vector.h: Call std::is_constant_evaluated()
	in C++20-only code.
	* include/debug/helper_functions.h (__check_singular): Use
	__is_constant_evaluated instead of built-in, or remove check
	entirely.
	* include/std/array (operator<=>): Use __is_constant_evaluated
	unconditionally.
	* include/std/bit (__bit_ceil): Likewise.
	* include/std/type_traits (is_constant_evaluated): Define using
	'if consteval' if possible.
	* include/std/version: Use new macro.
	* libsupc++/compare: Use __is_constant_evaluated instead of
	__builtin_is_constant_evaluated.
	* testsuite/23_containers/array/tuple_interface/get_neg.cc:
	Adjust dg-error lines.
2021-12-01 15:00:33 +00:00
Jonathan Wakely
d7376862b6 libstdc++: Fix condition for definition of _GLIBCXX14_DEPRECATED
The check for C++14 was using the wrong date.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX14_DEPRECATED): Fix condition
	checking for C++14.
2021-11-22 14:57:17 +00:00
Jonathan Wakely
a54ce8865a libstdc++: Print assertion messages to stderr [PR59675]
This replaces the printf used by failed debug assertions with fprintf,
so we can write to stderr.

To avoid including <stdio.h> the assert function is moved into the
library. To avoid programs using a vague linkage definition of the old
inline function, the function is renamed. Code compiled with old
versions of GCC might still call the old function, but code compiled
with the newer GCC will call the new function and write to stderr.

libstdc++-v3/ChangeLog:

	PR libstdc++/59675
	* acinclude.m4 (libtool_VERSION): Bump version.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.30): Add version and
	export new symbol.
	* configure: Regenerate.
	* include/bits/c++config (__replacement_assert): Remove, declare
	__glibcxx_assert_fail instead.
	* src/c++11/debug.cc (__glibcxx_assert_fail): New function to
	replace __replacement_assert, writing to stderr instead of
	stdout.
	* testsuite/util/testsuite_abi.cc: Update latest version.
2021-11-12 12:23:10 +00:00
Jonathan Wakely
c1b6c360fc libstdc++: Ensure language linkage of std::__terminate()
This is needed because people still find it necessary to do:

  extern "C" {
  #include <stdlib.h>
  }

libstdc++-v3/ChangeLog:

	* include/bits/c++config (__terminate): Add extern "C++".
2021-10-13 10:42:45 +01:00
Jonathan Wakely
250ddf4c0b libstdc++: Add wrapper for internal uses of std::terminate
This adds an inline wrapper for std::terminate that doesn't add the
declaration of std::terminate to namespace std. This allows the
library to terminate without including all of <exception>.

libstdc++-v3/ChangeLog:

	* include/bits/atomic_timed_wait.h: Remove unused header.
	* include/bits/c++config (std:__terminate): Define.
	* include/bits/semaphore_base.h: Remove <exception> and use
	__terminate instead of terminate.
	* include/bits/std_thread.h: Likewise.
	* libsupc++/eh_terminate.cc (std::terminate): Use qualified-id
	to call __cxxabiv1::__terminate.
2021-10-11 20:35:51 +01:00
Jonathan Wakely
92936be474 libstdc++: Restore printing of assertion messages [PR102100]
My changes for PR 101429 broke the _-replacement_assert function,
because we now always just abort without printing anything. That's
because I added checks for _GLIBCXX_HOSTED and _GLIBCXX_VERBOSE, but the
checks are done before those get defined.

This adds a new macro which is set
by the sed command in include/Makefile, once the HOSTED and VERBOSE
macros have been set by the configure script.

libstdc++-v3/ChangeLog:

	PR libstdc++/102100
	* include/Makefile.am (c++config.h): Define
	_GLIBCXX_VERBOSE_ASSERT based on configure output.
	* include/Makefile.in: Regenerate.
	* include/bits/c++config: Fix condition for verbose assertions.
2021-10-01 21:06:26 +01:00
Jonathan Wakely
7f2f4b8791 libstdc++: Deprecate std::random_shuffle for C++14
The std::random_shuffle algorithm was removed in C++14 (without
deprecation). This adds the deprecated attribute for C++14 and later, so
that users are warned they should not be using it in those dialects.

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

libstdc++-v3/ChangeLog:

	* doc/xml/manual/evolution.xml: Document deprecation.
	* doc/html/*: Regenerate.
	* include/bits/c++config (_GLIBCXX14_DEPRECATED): Define.
	(_GLIBCXX14_DEPRECATED_SUGGEST): Define.
	* include/bits/stl_algo.h (random_shuffle): Deprecate for C++14
	and later.
	* testsuite/25_algorithms/headers/algorithm/synopsis.cc: Adjust
	for C++11 and C++14 changes to std::random_shuffle and
	std::shuffle.
	* testsuite/25_algorithms/random_shuffle/1.cc: Add options to
	use deprecated algorithms.
	* testsuite/25_algorithms/random_shuffle/59603.cc: Likewise.
	* testsuite/25_algorithms/random_shuffle/moveable.cc: Likewise.
	* testsuite/25_algorithms/random_shuffle/requirements/explicit_instantiation/2.cc:
	Likewise.
	* testsuite/25_algorithms/random_shuffle/requirements/explicit_instantiation/pod.cc:
	Likewise.
2021-08-03 15:30:35 +01:00
Jonathan Wakely
1f7182d68c libstdc++: Add noexcept to __replacement_assert [PR101429]
This results in slightly smaller code when assertions are enabled when
either using Clang (because it adds code to call std::terminate when
potentially-throwing functions are called in a noexcept function) or a
freestanding or non-verbose build (because it doesn't use printf).

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

libstdc++-v3/ChangeLog:

	PR libstdc++/101429
	* include/bits/c++config (__replacement_assert): Add noexcept.
	[!_GLIBCXX_VERBOSE] (__glibcxx_assert_impl): Use __builtin_trap
	instead of __replacement_assert.
2021-07-15 16:25:42 +01:00
Jonathan Wakely
6b42b5a8a2 libstdc++: Use __builtin_unreachable for constexpr assertions [PR 100676]
The current implementation of compile-time precondition checks causes
compilation to fail by calling a non-constexpr function declared at
block scope. This breaks the CUDA compiler, which wraps some libstdc++
headers in a pragma that declares everything as a __host__ __device__
function, but others are not wrapped and so everything is a __host__
function. The local declaration thus gets redeclared as two different
types of function, which doesn't work.

Just use __builtin_unreachable to make constant evaluation fail, instead
of the local function declaration. Also simplify the assertion macros,
which has the side effect of giving simpler compilation errors when
using Clang.

libstdc++-v3/ChangeLog:

	PR libstdc++/100676
	* include/bits/c++config (__glibcxx_assert_1): Rename to ...
	(__glibcxx_constexpr_assert): ... this.
	(__glibcxx_assert_impl): Use __glibcxx_constexpr_assert.
	(__glibcxx_assert): Define as either __glibcxx_constexpr_assert
	or __glibcxx_assert_impl.
	(__glibcxx_assert_2): Remove
	* include/debug/macros.h (_GLIBCXX_DEBUG_VERIFY_AT_F): Use
	__glibcxx_constexpr_assert instead of __glibcxx_assert_1.
	* testsuite/21_strings/basic_string_view/element_access/char/back_constexpr_neg.cc:
	Adjust expected error.
	* testsuite/21_strings/basic_string_view/element_access/char/constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/char/front_constexpr_neg.cc:
	Likewise.
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/back_constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/front_constexpr_neg.cc:
	Likewise.
	* testsuite/23_containers/span/back_neg.cc: Likewise.
	* testsuite/23_containers/span/front_neg.cc: Likewise.
	* testsuite/23_containers/span/index_op_neg.cc: Likewise.
2021-05-20 20:49:57 +01:00
Jonathan Wakely
baef0cffb5 libstdc++: Disable "ALT128" long double support for Clang
Clang does not currently support the __ibm128 type [1] and only supports
the __ieee128 type in the unreleased 12.0.0 version [2]. That means it
is not possible to provide support for -mabi=ieeelongdouble with Clang
in an ABI compatible way (as we do for GCC by defining new facets and
other types in the __gnu_cxx_ldbl128 namespace).

By preventing the definition of _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT when
compiling with Clang, all uses of __ibm128 and __ieee128 types will be
disabled. This can be revisited in future when Clang supports the types
(and provides a way to detect that support using the preprocessor).

[1] https://reviews.llvm.org/D93377
[2] https://reviews.llvm.org/D97846

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT):
	Do not define when compiling with Clang.
2021-03-23 15:00:43 +00:00
Jakub Jelinek
99dee82307 Update copyright years. 2021-01-04 10:26:59 +01:00
Patrick Palka
6a31d47e27 libstdc++: Disable floating-point std::to_chars on unsupported targets
This patch conditionally disables the floating-point std::to_chars
implementation on targets whose float and double aren't IEEE binary32
and binary64, until a proper fallback can be added for such targets.
This fixes a bootstrap failure on non-IEEE-754 FP targets such as
vax-netbsdelf.

The new preprocessor tests in c++config that detect the binary32 and
binary64 formats were copied from gcc/testsuite/gcc.dg/float-exact-1.c.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_FLOAT_IS_IEEE_BINARY_32):
	Define this macro.
	(_GLIBCXX_DOUBLE_IS_IEEE_BINARY_64): Likewise.
	* include/std/charconv (to_chars): Use these macros to
	conditionally hide the overloads for floating-point types.
	* src/c++17/floating_to_chars.cc: Use the macros to
	conditionally disable this file.
	(floating_type_traits<float>): Remove redundant static assert.
	(floating_type_traits<double>): Likewise.
	* testsuite/20_util/to_chars/double.cc: Run this test only on
	ieee-floats effective targets.
	* testsuite/20_util/to_chars/float.cc: Likewise.
	* testsuite/20_util/to_chars/long_double.cc: Likewise.
	* testsuite/lib/libstdc++.exp
	(check_effective_target_ieee-floats): Define new proc for
	detecting whether float and double have the IEEE binary32 and
	binary64 formats.
2020-12-21 15:15:36 -05:00
Jonathan Wakely
7c1e7eed89 libstdc++: Add C++ runtime support for new 128-bit long double format
This adds support for the new __ieee128 long double format on
powerpc64le targets.

Most of the complexity comes from wanting a single libstdc++.so library
that contains the symbols needed by code compiled with both
-mabi=ibmlongdouble and -mabi=ieeelongdouble (and not forgetting
-mlong-double-64 as well!)

In a few places this just requires an extra overload, for example
std::from_chars has to be overloaded for both forms of long double.
That can be done in a single translation unit that defines overloads
for 'long double' and also '__ieee128', so that user code including
<charconv> will be able to link to a definition for either type of long
double. Those are the easy cases.

The difficult parts are (as for the std::string ABI transition) the I/O
and locale facets. In order to be able to write either form of long
double to an ostream such as std::cout we need the locale to contain a
std::num_put facet that can handle both forms. The same approach is
taken as was already done for supporting 64-bit long double and 128-bit
long double: adding extra overloads of do_put to the facet class. On
targets where the new long double code is enabled, the facets that are
registered in the locale at program startup have additional overloads so
that they can work with any long double type. Where this fails to work
is if user code installs its own facet, which will probably not have the
additional overloads and so will only be able to output one or the other
type. In practice the number of users expecting to be able to use their
own locale facets in code using a mix of -mabi=ibmlongdouble and
-mabi=ieeelongdouble is probably close to zero.

libstdc++-v3/ChangeLog:

	* Makefile.in: Regenerate.
	* config.h.in: Regenerate.
	* config/abi/pre/gnu.ver: Make patterns less greedy.
	* config/os/gnu-linux/ldbl-ieee128-extra.ver: New file with patterns
	for IEEE128 long double symbols.
	* configure: Regenerate.
	* configure.ac: Enable alternative 128-bit long double format on
	powerpc64*-*-linux*.
	* doc/Makefile.in: Regenerate.
	* fragment.am: Regenerate.
	* include/Makefile.am: Set _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT.
	* include/Makefile.in: Regenerate.
	* include/bits/c++config: Define inline namespace for new long
	double symbols. Don't define _GLIBCXX_USE_FLOAT128 when it's the
	same type as long double.
	* include/bits/locale_classes.h [_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT]
	(locale::_Impl::_M_init_extra_ldbl128): Declare new member function.
	* include/bits/locale_facets.h (_GLIBCXX_NUM_FACETS): Simplify by
	only counting narrow character facets.
	(_GLIBCXX_NUM_CXX11_FACETS): Likewise.
	(_GLIBCXX_NUM_LBDL_ALT128_FACETS): New.
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT] (num_get::__do_get): Define
	vtable placeholder for __ibm128 long double type.
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(num_get::__do_get): Declare vtable placeholder for __ibm128 long
	double type.
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(num_put::__do_put): Likewise.
	* include/bits/locale_facets.tcc
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(num_get::__do_get, num_put::__do_put): Define.
	* include/bits/locale_facets_nonio.h
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(money_get::__do_get): Declare vtable placeholder for __ibm128 long
	double type.
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(money_put::__do_put): Likewise.
	* include/bits/locale_facets_nonio.tcc
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(money_get::__do_get, money_put::__do_put): Define.
	* include/ext/numeric_traits.h [_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT]
	(__numeric_traits<__ibm128>, __numeric_traits<__ieee128>): Define.
	* libsupc++/Makefile.in: Regenerate.
	* po/Makefile.in: Regenerate.
	* python/Makefile.in: Regenerate.
	* src/Makefile.am: Add compatibility-ldbl-alt128.cc and
	compatibility-ldbl-alt128-cxx11.cc sources and recipes for objects.
	* src/Makefile.in: Regenerate.
	* src/c++11/Makefile.in: Regenerate.
	* src/c++11/compatibility-ldbl-alt128-cxx11.cc: New file defining
	symbols using the old 128-bit long double format, for the cxx11 ABI.
	* src/c++11/compatibility-ldbl-alt128.cc: Likewise, for the
	gcc4-compatible ABI.
	* src/c++11/compatibility-ldbl-facets-aliases.h: New header for long
	double compat aliases.
	* src/c++11/cow-locale_init.cc: Add comment.
	* src/c++11/cxx11-locale-inst.cc: Define C and C_is_char
	unconditionally.
	* src/c++11/cxx11-wlocale-inst.cc: Add sanity check. Include
	locale-inst.cc directly, not via cxx11-locale-inst.cc.
	* src/c++11/locale-inst-monetary.h: New header for monetary
	category instantiations.
	* src/c++11/locale-inst-numeric.h: New header for numeric category
	instantiations.
	* src/c++11/locale-inst.cc: Include new headers for monetary,
	numeric, and long double definitions.
	* src/c++11/wlocale-inst.cc: Remove long double compat aliases that
	are defined in new header now.
	* src/c++17/Makefile.am: Use -mabi=ibmlongdouble for
	floating_from_chars.cc.
	* src/c++17/Makefile.in: Regenerate.
	* src/c++17/floating_from_chars.cc (from_chars_impl): Add
	if-constexpr branch for __ieee128.
	(from_chars): Overload for __ieee128.
	* src/c++20/Makefile.in: Regenerate.
	* src/c++98/Makefile.in: Regenerate.
	* src/c++98/locale_init.cc (num_facets): Adjust calculation.
	(locale::_Impl::_Impl(size_t)): Call _M_init_extra_ldbl128.
	* src/c++98/localename.cc (num_facets): Adjust calculation.
	(locale::_Impl::_Impl(const char*, size_t)): Call
	_M_init_extra_ldbl128.
	* src/filesystem/Makefile.in: Regenerate.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/util/testsuite_abi.cc: Add new symbol versions.
	Allow new symbols to be added to GLIBCXX_IEEE128_3.4.29 and
	CXXABI_IEEE128_1.3.13 too.
	* testsuite/26_numerics/complex/abi_tag.cc: Add u9__ieee128 to
	regex matching expected symbols.
2020-12-16 23:25:01 +00:00
Jonathan Wakely
767537a8b0 libstdc++: Warn if __STRICT_ANSI has been undefined
Recent changes to use __int128 as an integer-like type in <ranges> and
to optimize std::uniform_int_distribution mean that the library relies
on __int128 more heavily than in the past.

The library expects that if __int128 is supported then either
__GLIBCXX_TYPE_INT_N_0 is defined (and we treat is like the standard
integer types), or __STRICT_ANSI__ is defined (and we need to add
special handling for __int128 as a non-standard integer type).

If users compile with -std=c++NN -U__STRICT_ANSI__ then it puts the
library into a broken and inconsistent state, where the compiler doesn't
define the __GLIBCXX_TYPE_INT_N_0 macro, but the library thinks it
doesn't need special handling for __int128. What the user should do is
compile with -std=gnu++NN instead.

This adds a warning if it appears that __int128 is supported but neither
__GLIBCXX_TYPE_INT_N_0 nor __STRICT_ANSI__ is defined.

libstdc++-v3/ChangeLog:

	* include/bits/c++config: Warn if __STRICT_ANSI__ state is
	inconsistent with __GLIBCXX_TYPE_INT_N_0.
2020-12-16 19:25:09 +00:00
Jonathan Wakely
f072d1021e libstdc++: Do not define constexpr assertions for C++11
There's no point even checking is_constant_evaluated() in C++11 mode,
because the 'if' statement used for the assertion wouldn't be valid in a
C++11 constexpr function anyway.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (__glibcxx_assert_1): Define as empty
	for C++11.
2020-12-15 15:39:58 +00:00
Jonathan Wakely
6aa1227400 libstdc++: Simplify detection of built-in functions
This fixes a regression affecting the Intel compiler. Because that
compiler defines __GNUC__ to match whatever version of GCC it finds on
the host system, it might claim to be a brand new GCC despite not
actually supporting all the built-ins that the latest GCC supports. This
means the config checks for __GNUC__ don't work. Most recently this
broke when r11-3569-g73ae6eb572515ad627b575a7fbdfdd47a4368e1c switched
us from using __is_same_as to __is_same when __GNUC__ >= 11.

Because __has_builtin is supported by all of GCC, Clang, and Intel we can
use that to reliably detect whether a given built-in is supported,
instead of hardcoding anything based on __GNUC__. The big caveat is
that for versions of Clang <= 9.0.0 and for (as far as I can tell) all
released versions of Intel icc, __has_builtin only evaluates to true for
built-ins with a name starting "__builtin_". For __is_aggregate,
__is_same, and __has_unique_object_representations it's necessary to use
__is_identifier to check if it's a valid identifeir token instead.

The solution used in this patch is to define _GLIBCXX_HAS_BUILTIN and
use that instead of using __has_builtin directly. For compilers that
define __is_identifier as well as __has_builtin we use both, so that if
__has_builtin evaluates to false we try again using !__is_identifier.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_HAS_BUILTIN): Define macro to
	work around different implementations of __has_builtin.
	(_GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP)
	(_GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE)
	(_GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED)
	(_GLIBCXX_HAVE_BUILTIN_IS_SAME, _GLIBCXX_HAVE_BUILTIN_LAUNDER):
	Define using _GLIBCXX_HAS_BUILTIN.
2020-12-01 14:14:18 +00:00
Jonathan Wakely
73ae6eb572 libstdc++: Use __is_same instead of __is_same_as
PR 92271 added __is_same as another spelling of __is_same_as. Since
Clang also spells it __is_same, let's just use that consistently.

It appears that Intel icc sets __GNUC__ to 10, but only supports
__is_same_as. If we only use __is_same for __GNUC__ >= 11 then we won't
break icc again (it looks like we broke previous versions of icc when we
started using __is_same_as).

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_HAVE_BUILTIN_IS_SAME):
	Define for GCC 11 or when !__is_identifier(__is_same).
	(_GLIBCXX_BUILTIN_IS_SAME_AS): Remove.
	* include/std/type_traits (is_same, is_same_v): Replace uses
	of _GLIBCXX_BUILTIN_IS_SAME_AS.
2020-09-30 18:41:12 +01:00
Jonathan Wakely
7db5967f10 libstdc++: Use __builtin_expect in __glibcxx_assert
libstdc++-v3/ChangeLog:

	* include/bits/c++config (__replacement_assert): Add noreturn
	attribute.
	(__glibcxx_assert_impl): Use __builtin_expect to hint that the
	assertion is expected to pass.
2020-09-21 23:43:25 +01:00
Jonathan Wakely
10f51543bb libstdc++: Add compile-time checks to__glibcxx_assert [PR 71960]
This change evaluates __glibcxx_assert checks unconditionally when a
function is being constant evaluated (when std::is_constant_evaluated()
is true). If the check fails, compilation will fail with an error.

If the function isn't being constant evaluated, the normal runtime check
will be done if enabled by _GLIBCXX_ASSERTIONS or _GLIBCXX_DEBUG, the
same as before.

Tangentially, the __glibcxx_assert and _GLIBCXX_PARALLEL_ASSERT macros
are changed to expand to 'do { } while (false)' when assertions are
disabled, instead of expanding to nothing. This avoids -Wempty-body
warnings when a disabled assertion is used in an 'if' or 'else'
statement e.g.

  if constexpr (/* precondition is testable */)
    __glibcxx_assert(precondition);

a.C:9:27: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
    9 |     __glibcxx_assert(precondition);
      |                                  ^

libstdc++-v3/ChangeLog:

	PR libstdc++/71960
	* include/bits/c++config (__glibcxx_assert_impl): Remove
	do-while so that uses of the macro need to add it.
	(__glibcxx_assert): Rename macro for runtime assertions
	to __glibcxx_assert_2.
	(__glibcxx_assert_1): Define macro for constexpr assertions.
	(__glibcxx_assert): Define macro for constexpr and runtime
	assertions.
	* include/bits/range_access.h (ranges::advance): Remove
	redundant precondition checks during constant evaluation.
	* include/parallel/base.h (_GLIBCXX_PARALLEL_ASSERT): Always
	use do-while in macro expansion.
	* include/std/ranges (iota_view::iota_view(W, B)): Remove
	redundant braces.
2020-09-01 20:52:26 +01:00
Jonathan Wakely
1e235788bb libstdc++: Mention new macros in comments
libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_DEPRECATED_SUGGEST)
	(_GLIBCXX11_DEPRECATED, _GLIBCXX11_DEPRECATED_SUGGEST)
	(_GLIBCXX17_DEPRECATED_SUGGEST, _GLIBCXX20_DEPRECATED_SUGGEST):
	Add new macros to comment.
2020-08-19 14:51:32 +01:00
Jonathan Wakely
eef9bf4ca8 libstdc++: Add deprecated attributes to old iostream members
Back in 2017 I removed these prehistoric members (which were deprecated
since C++98) for C++17 mode. But I didn't add deprecated attributes to
most of them, so users didn't get any warning they would be going away.
Apparently some poor souls do actually use some of these names, and so
now that GCC 11 defaults to -std=gnu++17 some code has stopped
compiling.

This adds deprecated attributes to them, so that C++98/03/11/14 code
will get a warning if it uses them. I'll also backport this to the
release branches so that users can find out about the deprecation before
they start using C++17.

In order to give deprecated warnings even in C++98 mode this patch makes
_GLIBCXX_DEPRECATED work even for C++98, adds _GLIBCXX11_DEPRECATED for
the old meaning of _GLIBCXX_DEPRECATED, and adds new macros such as
_GLIBCXX_DEPRECATED_SUGGEST for suggesting alternatives to deprecated
features.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_DEPRECATED): Define for all
	standard modes.
	(_GLIBCXX_DEPRECATED_SUGGEST): New macro for "use 'foo' instead"
	message in deprecated warnings.
	(_GLIBCXX11_DEPRECATED, _GLIBCXX11_DEPRECATED_SUGGEST): New
	macros for marking features derpecated in C++11.
	(_GLIBCXX17_DEPRECATED_SUGGEST, _GLIBCXX20_DEPRECATED_SUGGEST):
	New macros.
	* include/backward/auto_ptr.h (auto_ptr_ref, auto_ptr<void>):
	Use _GLIBCXX11_DEPRECATED instead of _GLIBCXX_DEPRECATED.
	(auto_ptr): Use _GLIBCXX11_DEPRECATED_SUGGEST.
	* include/backward/binders.h (binder1st, binder2nd): Likewise.
	* include/bits/ios_base.h (io_state, open_mode, seek_dir)
	(streampos, streamoff): Use _GLIBCXX_DEPRECATED_SUGGEST.
	* include/std/streambuf (stossc): Replace C++11 attribute
	with _GLIBCXX_DEPRECATED_SUGGEST.
	* include/std/type_traits (__is_nullptr_t): Use
	_GLIBCXX_DEPRECATED_SUGGEST instead of _GLIBCXX_DEPRECATED.
	* testsuite/27_io/types/1.cc: Check for deprecated warnings.
	Also check for io_state, open_mode and seek_dir typedefs.
2020-08-19 12:13:23 +01:00
Jonathan Wakely
0ba6a850b5 libstdc++: Fix freestanding build PR 92376)
In a freestanding library we don't install the <pstl/pstl_config.h>
header, so don't try to include it unless it exists.

Explicitly declare aligned alloc functions for freestanding, because
<cstdlib> doesn't declare them.

	PR libstdc++/92376
	* include/bits/c++config: Only do PSTL config when the header is
	present, to fix freestanding.
	* libsupc++/new_opa.cc [!_GLIBCXX_HOSTED]: Declare allocation
	functions if they were detected by configure.
2020-01-17 17:03:46 +00:00
JeanHeyd "ThePhD" Meneide
1a6c5064f9 libstdc++: Implementing P0767 - deprecate POD
This adds the deprecated attribute to std::is_pod and std::is_pod_v for
C++20.

2019-12-05  JeanHeyd "ThePhD" Meneide  <phdofthehouse@gmail.com>

	* include/bits/c++config (_GLIBCXX20_DEPRECATED): Add new macro.
	* include/std/type_traits (is_pod, is_pod_v): Deprecate for C++20.
	* testuite/20_util/is_pod/deprecated-2a.cc: New test.

From-SVN: r280065
2020-01-09 21:31:43 +00:00
Jakub Jelinek
8d9254fc8a Update copyright years.
From-SVN: r279813
2020-01-01 12:51:42 +01:00
Tom Honermann
2b4e2c93d9 libstdc++: P1423R3 char8_t remediation (2/4)
Update feature test macro, add deleted operators, update u8path

This patch increments the __cpp_lib_char8_t feature test macro, adds deleted
operator<< overloads for basic_ostream, and modifies u8path to accept
sequences of char8_t for both the C++17 implementation of std::filesystem, and
the filesystem TS implementation.

The implementation mechanism used for u8path differs between the C++17 and
filesystem TS implementations.  The changes to the former take advantage of
C++17 'if constexpr'.  The changes to the latter retain C++11 compatibility
and rely on tag dispatching.

2019-11-29  Tom Honermann  <tom@honermann.net>

	Update feature test macro, add deleted operators, update u8path
	* include/bits/c++config: Bumped the value of the __cpp_lib_char8_t
	feature test macro.
	* include/bits/fs_path.h (u8path): Modified u8path to accept sequences
	of char8_t.
	* include/experimental/bits/fs_path.h (u8path): Modified u8path to
	accept sequences of char8_t.
	* include/std/ostream: Added deleted overloads of wchar_t, char8_t,
	char16_t, and char32_t for ordinary and wide formatted character and
	string inserters.

From-SVN: r278856
2019-11-29 17:43:42 +00:00
Jonathan Wakely
44af818f00 Only use GCC-specific __is_same_as built-in conditionally
Clang doesn't support __is_same_as but provides __is_same instead.
Restore the original implementation (pre r276891) when neither of those
built-ins is available.

	* include/bits/c++config (_GLIBCXX_BUILTIN_IS_SAME_AS): Define to
	one of __is_same_as or __is_same when available.
	* include/std/concepts (__detail::__same_as): Use std::is_same_v.
	* include/std/type_traits (is_same) [_GLIBCXX_BUILTIN_IS_SAME_AS]:
	Use new macro instead of __is_same_as.
	(is_same) [!_GLIBCXX_BUILTIN_IS_SAME_AS]: Restore partial
	specialization.
	(is_same_v) [_GLIBCXX_BUILTIN_IS_SAME_AS]: Use new macro.
	(is_same_v) [!_GLIBCXX_BUILTIN_IS_SAME_AS]: Use std::is_same.

From-SVN: r277058
2019-10-16 11:26:05 +01:00
Jonathan Wakely
4887c9e808 Fix preprocessor checks for Clang builtins
Clang seems to define built-ins that start with "__builtin_" as
non-keywords, which means that we need to use __has_builtin to detect
them, not __is_identifier. The built-ins that don't start with
"__builtin_" are keywords, and can only be detected using
__is_identifier and not by __has_builtin.

	* include/bits/c++config (_GLIBCXX_HAVE_BUILTIN_LAUNDER)
	(_GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED): Use __has_builtin
	instead of __is_identifier to detect Clang support.

From-SVN: r272931
2019-07-02 12:50:27 +01:00