The standard requires overloads of std::to_chars for char and (un)signed
integer types. This means that our constrained function template is
non-conforming, because the difference is observable when using types
that convert to an integer (e.g. wchar_t, which promotes).
As well as defining the deleted bool overload for LWG 3266, replace the
constrained function template with overloads for each type.
* include/std/charconv (to_chars): Rename to __to_chars_i. Define
non-template overloads for each signed and unsigned integer type and
char. Define deleted overload for bool (LWG 3266).
* testsuite/20_util/to_chars/1_neg.cc: Remove.
* testsuite/20_util/to_chars/3.cc: New test.
* testsuite/20_util/to_chars/lwg3266.cc: New test.
From-SVN: r275588
The main difference with existing support is that function addresses
are function descriptor addresses instead. This means that all code
dealing with function pointers now has to cope with function
descriptors instead.
For the same reason, Linux kernel helpers can no longer be called by
dereferencing their address, so we implement wrappers that directly
call the kernel helpers.
When restoring a function address, we also have to restore the FDPIC
register value (r9).
2019-09-10 Christophe Lyon <christophe.lyon@st.com>
Mickaël Guêné <mickael.guene@st.com>
gcc/
* ginclude/unwind-arm-common.h (unwinder_cache): Add reserved5
field.
libgcc/
* config/arm/linux-atomic.c (__kernel_cmpxchg): Add FDPIC support.
(__kernel_dmb): Likewise.
(__fdpic_cmpxchg): New function.
(__fdpic_dmb): New function.
* config/arm/unwind-arm.h (FDPIC_REGNUM): New define.
(gnu_Unwind_Find_got): New function.
(_Unwind_decode_typeinfo_ptr): Add FDPIC support.
* unwind-arm-common.inc (UCB_PR_GOT): New.
(funcdesc_t): New struct.
(get_eit_entry): Add FDPIC support.
(unwind_phase2): Likewise.
(unwind_phase2_forced): Likewise.
(__gnu_Unwind_RaiseException): Likewise.
(__gnu_Unwind_Resume): Likewise.
(__gnu_Unwind_Backtrace): Likewise.
* unwind-pe.h (read_encoded_value_with_base): Likewise.
libstdc++/
* libsupc++/eh_personality.cc (get_ttype_entry): Add FDPIC
support.
Co-Authored-By: Mickaël Guêné <mickael.guene@st.com>
From-SVN: r275568
Define partial specializations for std::remove_cv so that
std::remove_const and std::remove_volatile don't need to be
instantiated.
* include/std/type_traits (__remove_cv_t): New alias template.
(is_void, is_integral, is_floating_point, is_pointer)
(is_member_object_pointer, is_member_function_pointer, is_null_pointer)
(is_member_point), __is_signed_integer, __is_unsigned_integer)
(__make_unsigned_selector, __make_signed_selector, remove_pointer)
(__decay_selector): Use __remove_cv_t.
(remove_cv): Add partial specializations for cv-qualified types.
(__decay_t): New alias template.
(__decay_and_strip, __common_type_impl, __result_of_impl): Use
__decay_t.
(__enable_if_t): Move earlier in the file.
(_Require): Use __enable_if_t.
(swap(T&, T&)): Use _Require.
(swap(T(&)[N])): Use __enable_if_t.
From-SVN: r275562
__to_chars_10_impl is quite fast. According to the IACA the main loop
takes only 6.0 cycles, the whole function with one iteration takes
10.0 cycles. Replacing the __first[pos] and __first[pos - 1] with
__first[0] and __first[1] drops the function time to 7.53 cycles.
2019-09-09 Antony Polukhin <antoshkka@gmail.com>
* include/bits/charconv.h (__detail::__to_chars_10_impl): Replace
final offsets with constants.
From-SVN: r275514
This patch simplifies the constraints on the constructors from arrays by
removing the redundant checks that element_type and value_type are
convertible to element_type. The incorrect uses of __adl_data in those
constructors are removed as well (they should use std::data not
std::ranges::data, and the former doesn't use ADL).
The range/container constructors are now constrained to exclude all
specializations of std::span, not just the current instantiation. The
range constructor now also checks s subset of the contiguous_range
requirements.
All relevant constructor constraints now use the _Require helper in
order to short circuit and avoid unnecessary instantiations after the
first failed constraint.
A new constructor supports initialization from different specializations
of std::span<OtherType, OtherExtent>, as specified in the C++20 draft.
* include/bits/range_access.h (__adl_to_address): Remove.
* include/std/span (__is_base_derived_safe_convertible_v): Replace
with span::__is_compatible.
(__is_std_array_v): Replace with __is_std_array class template and
partial specializations.
(__is_std_array, __is_std_span): New class templates and partial
specializations.
(span::__is_compatible): New alias template for SFINAE constraints.
(span::span(element_type (&)[N])): Remove redundant constraints. Do
not use __adl_data to obtain a pointer.
(span::span(array<value_type, N>&)): Likewise.
(span::span(const array<value_type, N>&)): Likewise.
[_GLIBCXX_P1394] (span::iter_reference_t, span::iterator_t)
(span::iter_value_t, span::derived_from): New alias templates for
SFINAE constraints, until the equivalents are supported in <concepts>
and <iterator>.
[_GLIBCXX_P1394] (span::__is_compatible_iterator): New alias template
for SFINAE constraints.
[_GLIBCXX_P1394] (span::is_compatible_range): New class template for
SFINAE constraints.
[_GLIBCXX_P1394] (span::span(Range&&)): Improve constraints.
[_GLIBCXX_P1394] (span::span(ContiguousIterator, Sentinel)): Likewise.
Use std::to_address instead of __adl_to_address.
[_GLIBCXX_P1394] (span::span(ContiguousIterator, size_type)): Likewise.
[!_GLIBCXX_P1394] (span::__is_compatible_container): New alias
template for SFINAE constraints.
[!_GLIBCXX_P1394] (span::span(Container&))
(span::span(const Container&)): Improve constraints.
[!_GLIBCXX_P1394] (span::span(pointer, size_type))
(span::span(pointer, pointer)): Remove redundant cast of pointer.
(span(const span<OType, OExtent>&)): New constructor.
From-SVN: r275513
The URL for the "What Are Allocators Good For?" article has been a
recurring source of problems. It moved from the C/C++ Users Journal
website to the Dr Dobbs site after CUJ shut down, and the original
domain changed hands, leaving old links pointing to nefarious sites.
Now the URL to the copy on drdobbs.com no longer works either and I
can't find a (legal) copy of the article online. The simplest solution
is to remove the URL.
* doc/xml/manual/allocator.xml: Remove URL for bibliography entry.
* doc/html/*: Regenerate.
From-SVN: r275398
The pthread_cond_clockwait function is available in glibc since the 2.30
release. If this function is available in the C library it can be used
to fix PR libstdc++/41861 by supporting std::chrono::steady_clock
properly with std::condition_variable.
This means that code using std::condition_variable::wait_for or
std::condition_variable::wait_until with std::chrono::steady_clock is no
longer subject to timing out early or potentially waiting for much
longer if the system clock is warped at an inopportune moment.
If pthread_cond_clockwait is available then std::chrono::steady_clock is
deemed to be the "best" clock available which means that it is used for
the relative wait_for calls and absolute wait_until calls using
user-defined clocks. Calls explicitly using std::chrono::system_clock
continue to use CLOCK_REALTIME via __gthread_cond_timedwait.
If pthread_cond_clockwait is not available then
std::chrono::system_clock is deemed to be the "best" clock available
which means that the previous suboptimal behaviour remains.
2019-09-04 Mike Crowe <mac@mcrowe.com>
PR libstdc++/41861
* acinclude.m4 (GLIBCXX_CHECK_PTHREAD_COND_CLOCKWAIT): Check for new
pthread_cond_clockwait function.
* configure.ac: Use GLIBCXX_CHECK_PTHREAD_COND_CLOCKWAIT.
* configure: Regenerate.
* config.h.in: Regenerate.
* include/std/condition_variable: (condition_variable): Rename
__steady_clock_t typedef and add system_clock. Change __clock_t to be
a typedef for the preferred clock to convert arbitrary other clocks to.
[_GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT] (wait_until): Add a steady_clock
overload.
(wait_until): Change __clock_t overload to use system_clock.
[_GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT] (__wait_until_impl): Add
steady_clock overload that calls pthread_cond_clockwait.
(__wait_until_impl): Change __clock_t overload to use system_clock.
(condition_variable_any) [_GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT]: Use
steady_clock for __clock_t if pthread_cond_clockwait is available.
From-SVN: r275390
2019-09-04 Mike Crowe <mac@mcrowe.com>
* testsuite/30_threads/condition_variable/members/2.cc (test01):
Parameterise so that test can be run against an arbitrary clock.
(main): Test using std::chrono::steady_clock and a user-defined
clock in addition to the previous std::chrono::system_clock.
* testsuite/30_threads/condition_variable_any/members/2.cc: Likewise.
From-SVN: r275389
2019-09-03 Chung-Lin Tang <cltang@codesourcery.com>
libatomic/
PR other/79543
* acinclude.m4 (LIBAT_CHECK_LINKER_FEATURES): Fix GNU ld --version
scanning to conform to the GNU Coding Standards.
* configure: Regenerate.
libffi/
PR other/79543
* acinclude.m4 (LIBAT_CHECK_LINKER_FEATURES): Fix GNU ld --version
scanning to conform to the GNU Coding Standards.
* configure: Regenerate.
libgomp/
PR other/79543
* acinclude.m4 (LIBGOMP_CHECK_LINKER_FEATURES): Fix GNU ld --version
scanning to conform to the GNU Coding Standards.
* configure: Regenerate.
libitm/
PR other/79543
* acinclude.m4 (LIBITM_CHECK_LINKER_FEATURES): Fix GNU ld --version
scanning to conform to the GNU Coding Standards.
* configure: Regenerate.
libstdc++-v3/
PR other/79543
* acinclude.m4 (GLIBCXX_CHECK_LINKER_FEATURES): Fix GNU ld --version
scanning to conform to the GNU Coding Standards.
* configure: Regenerate.
From-SVN: r275341
Bunch of micro optimizations for std::to_chars:
* For base == 8 replacing the lookup in __digits table with arithmetic
computations leads to a same CPU cycles for a loop (exchanges two movzx
with 3 bit ops). However this saves 129 bytes of data and totally avoids
a chance of cache misses on __digits.
* For base == 16 replacing the lookup in __digits table with
arithmetic computations leads to a few additional instructions, but
totally avoids a chance of cache misses on __digits (- ~9 cache misses
for worst case) and saves 513 bytes of const data.
* Replacing __first[pos] and __first[pos - 1] with __first[1] and
__first[0] on final iterations saves ~2% of code size.
* Removing trailing '\0' from arrays of digits allows the linker to
merge the symbols (so that "0123456789abcdefghijklmnopqrstuvwxyz" and
"0123456789abcdef" could share the same address). This improves data
locality and reduces binary sizes.
* Using __detail::__to_chars_len_2 instead of a generic
__detail::__to_chars_len makes the operation O(1) instead of O(N). It
also makes the code two times shorter.
In sum: this significantly reduces the size of a binary (for about 4KBs
only for base-8 conversion), deals with latency (CPU cache misses)
without changing the iterations count and without adding costly
instructions into the loops.
2019-08-30 Antony Polukhin <antoshkka@gmail.com>
* include/std/charconv (__detail::__to_chars_8)
__detail::__to_chars_16): Replace array of precomputed digits with
arithmetic operations to avoid CPU cache misses. Remove zero
termination from array of digits to allow symbol merge with generic
implementation of __detail::__to_chars. Replace final offsets with
constants. Use __detail::__to_chars_len_2 instead of a generic
__detail::__to_chars_len.
(__detail::__to_chars): Remove zero termination from array of digits.
(__detail::__to_chars_2): Leading digit is always '1'.
From-SVN: r275205
The memmove optimizations for std::uninitialized_copy/fill/_n will
compile even if the type is not copy constructible, because std::copy
doesn't require copy construction to work. But the uninitialized
algorithms do require it.
This adds explicit static assertions to ensure we don't allow ill-formed
initializations.
PR libstdc++/89164
* include/bits/stl_algobase.h (__copy_move): Give descriptive names
to template parameters.
* include/bits/stl_uninitialized.h (uninitialized_copy)
(uninitialized_fill, uninitialized_fill_n): Add static assertions to
diagnose invalid uses.
* testsuite/20_util/specialized_algorithms/uninitialized_copy/1.cc:
Adjust expected error.
* testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_copy_n/
89164.cc: New test.
* testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_fill_n/
89164.cc: New test.
* testsuite/23_containers/vector/cons/89164.cc: New test.
* testsuite/23_containers/vector/cons/89164_c++17.cc: New test.
From-SVN: r275177
Building for i686-mingw32 target (with some local changes) produced an
error
error: ISO C++ forbids declaration of 'lstat' with no type [-fpermissive]
in libstdc++-v3/src/filesystem/ops-common.h. This patch adds the
missing return type. OK to commit (trunk and GCC 9 branch)?
Note 1: I haven't run the testsuite with this patch, but it fixes the
build failure I see (in sources with other local changes).
Note 2: I don't know why this hasn't produced build failures for other
people, but the missing return type looks wrong in any case even if
other local changes are for some reason needed for it to produce an
error.
* src/filesystem/ops-common.h [_GLIBCXX_FILESYSTEM_IS_WINDOWS]
(std::filesystem::__gnu_posix::lstat): Add return type.
From-SVN: r274885
The x86 attributes such as ms_abi, stdcall, fastcall etc. alter the
function type, which means that functions with one of those attributes
do not match any of the partial specializations of std::is_function.
Rather than duplicating the list for every calling convention, use a
much simpler definition of std::is_function.
Also redefine __is_referenceable to not rely on partial specializations
for each type of referenceable function.
PR libstdc++/91371
* include/std/type_traits (is_function): Simplify definition. Remove
partial specializations for function types.
(__is_referenceable): Simplify definition.
* testsuite/20_util/bind/91371.cc: New test.
* testsuite/20_util/is_function/91371.cc: New test.
* testsuite/20_util/is_function/value.cc: Check more pointer types.
* testsuite/20_util/is_member_function_pointer/91371.cc: New test.
* testsuite/20_util/is_object/91371.cc: New test.
From-SVN: r274756
In C++17 a function can return a prvalue of a type that cannot be moved
or copied. The current implementation of std::is_invocable_r uses
std::is_convertible to test the conversion to R required by INVOKE<R>.
That fails for non-copyable prvalues, because std::is_convertible is
defined in terms of std::declval which uses std::add_rvalue_reference.
In C++17 conversion from R to R involves no copies and so is not the
same as conversion from R&& to R.
This commit changes std::is_invocable_r to check the conversion without
using std::is_convertible.
std::function also contains a similar check using std::is_convertible,
which can be fixed by simply reusing std::is_invocable_r (but because
std::is_invocable_r is not defined for C++11 it uses the underlying
std::__is_invocable_impl trait directly).
PR libstdc++/91456
* include/bits/std_function.h (__check_func_return_type): Remove.
(function::_Callable): Use std::__is_invocable_impl instead of
__check_func_return_type.
* include/std/type_traits (__is_invocable_impl): Add another defaulted
template parameter. Define a separate partial specialization for
INVOKE and INVOKE<void>. For INVOKE<R> replace is_convertible check
with a check that models delayed temporary materialization.
* testsuite/20_util/function/91456.cc: New test.
* testsuite/20_util/is_invocable/91456.cc: New test.
From-SVN: r274542
This non-standard extension is redundant and unused by the library.
* include/std/type_traits (__is_nullptr_t): Add deprecated attribute.
From-SVN: r274491
The src/c++17/string-inst.cc file needs to override the default string
ABI so that it still contains the expected symbols even when the library
is configured with --with-default-libstdcxx-abi=gcc4-compatible.
PR libstdc++/90361
* src/c++17/string-inst.cc: Use _GLIBCXX_USE_CXX11_ABI=1 by default.
From-SVN: r274314
When unpacking a std::tuple we know that the std::get calls are
noexcept, so only the invocation (for std::apply) and construction (for
std::make_from_tuple) can throw.
We also know the std::get calls won't throw for a std::array, but this
patch doesn't specialize the variable template for std::array. For an
arbitrary tuple-like type we don't know if the std::get calls will
throw, and so just use a potentially-throwing noexcept-specifier.
* include/std/tuple (__unpack_std_tuple): New variable template and
partial specializations.
(apply, make_from_tuple): Add noexcept-specifier.
* testsuite/20_util/tuple/apply/2.cc: New test.
* testsuite/20_util/tuple/make_from_tuple/2.cc: New test.
From-SVN: r274312
normal_mv_distribution maintains the variance-covariance matrix param
in Cholesky-decomposed form. Existing param_type constructors, when
taking a full or lower-triangle varcov matrix, perform Cholesky
decomposition to convert it to the internal representation. This
internal representation is visible both in the varcov() result, and in
the streamed-out representation of a normal_mv_distribution object.
The problem is that when that representation is streamed back in, the
read-back decomposed varcov matrix is used as a lower-triangle
non-decomposed varcov matrix, and it undergoes Cholesky decomposition
again. So, each cycle of stream-out/stream-in changes the varcov
matrix to its "square root", instead of restoring the original
params.
This patch includes Corentin's changes that introduce verification in
testsuite/ext/random/normal_mv_distribution/operators/serialize.cc and
other similar tests that the object read back in compares equal to the
written-out object: the modified tests pass only if (u == v).
This patch also fixes the error exposed by his change, introducing an
alternate private constructor for param_type, used only by operator>>.
for libstdc++-v3/ChangeLog
* include/ext/random
(normal_mv_distribution::param_type::param_type): New private
ctor taking a decomposed varcov matrix, for use by...
(operator>>): ... this, befriended.
* include/ext/random.tcc (operator>>): Use it.
(normal_mv_distribution::param_type::_M_init_lower): Adjust
member function name in exception message.
for libstdc++-v3/ChangeLog
from Corentin Gay <gay@adacore.com>
* testsuite/ext/random/beta_distribution/operators/serialize.cc,
testsuite/ext/random/hypergeometric_distribution/operators/serialize.cc,
testsuite/ext/random/normal_mv_distribution/operators/serialize.cc,
testsuite/ext/random/triangular_distribution/operators/serialize.cc,
testsuite/ext/random/von_mises_distribution/operators/serialize.cc:
Add call to `VERIFY`.
From-SVN: r274233
As an extension to what the standard requires, this also adds
conditional noexcept-specifiers to the std::to_array functions.
P0325R4 to_array from LFTS with updates
* include/experimental/array (to_array): Qualify call to __to_array.
* include/std/array (__cpp_lib_to_array, to_array): Define for C++20.
* include/std/version (__cpp_lib_to_array): Likewise.
* testsuite/23_containers/array/creation/1.cc: New test.
* testsuite/23_containers/array/creation/2.cc: New test.
* testsuite/23_containers/array/creation/3_neg.cc: New test.
* testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc:
Use zero for dg-error line number.
From-SVN: r274209
