Instead of using `reverse_iterator`, share the optimization between the 4 algorithms. The key observation here that `memmove` applies to both `copy` and `move` identically, and to their `_backward` versions very similarly. All algorithms now follow the same pattern along the lines of:
```
if constexpr (can_memmove<InIter, OutIter>) {
memmove(first, last, out);
} else {
naive_implementation(first, last, out);
}
```
A follow-up will delete `unconstrained_reverse_iterator`.
This patch removes duplication and divergence between `std::copy`, `std::move` and `std::move_backward`. It also improves testing:
- the test for whether the optimization is used only applied to `std::copy` and, more importantly, was essentially a no-op because it would still pass if the optimization was not used;
- there were no tests to make sure the optimization is not used when the effect would be visible.
Differential Revision: https://reviews.llvm.org/D130695
Implement LWG 3629, by making lookup for make_error_code and
make_error_condition only consider names found by ADL. This is achieved
by adding a block scope using-declaration for a function that will be
found by unqualified lookup, preventing unqualified lookup from
continuing to enclosing scopes (the class scope, then enclosing
namespaces). The function named by the using declaration is not
viable, so overload resolution must select a candidate found by ADL.
This fixes https://github.com/llvm/llvm-project/issues/57614
Differential Revision: https://reviews.llvm.org/D134943
Noticed this while working on D133326. Let's see whehter all compilers
now support this feature.
Reviewed By: #libc, philnik, ldionne
Differential Revision: https://reviews.llvm.org/D134818
We should strive to have our own tests, except when there is overwhelming
value in using another standard library's existing tests. The reason is
that it ensures that implementations don't all start relying on the same
interpretation of the Standard.
The unique_ptr tests did not add any test coverage AFAICT, and the
forward_like tests were moved to the style used everywhere in the
libc++ test suite.
Note that I got to this because this actually broke a downstream
configuration where we use -ffreestanding. The signature of main()
was not consistent with the signature we (need to) use everywhere
in the test suite.
Differential Revision: https://reviews.llvm.org/D134767
In the implementation of `std::views::take`, it uses `subrange<Iter>` as part of the return type. But in case of input iterator, `subrange<Iter>` can be ill-formed
Differential Revision: https://reviews.llvm.org/D133220
While testing a test failure of C++17 with Clang ToT it was noticed the
paper
P0602R4 variant and optional should propagate copy/move triviality
was not applied as a DR in libc++.
This was discovered while investigating the issue "caused by" D131479.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D133326
Update the formatter day tests to the new style.
Other test will be done separately.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D134031
In https://llvm.org/D56913, we added an emulation for the __atomic_always_lock_free
compiler builtin when compiling in Freestanding mode. However, the emulation
did (and could not) give exactly the same answer as the compiler builtin,
which led to a potential ABI break for e.g. enum classes.
After speaking to the original author of D56913, we agree that the correct
behavior is to instead always use the compiler builtin, since that provides
a more accurate answer, and __atomic_always_lock_free is a purely front-end
builtin which doesn't require any runtime support. Furthermore, it is
available regardless of the Standard mode (see https://godbolt.org/z/cazf3ssYY).
However, this patch does constitute an ABI break. As shown by https://godbolt.org/z/1eoex6zdK:
- In LLVM <= 11.0.1, an atomic<enum class with 1 byte> would not contain a lock byte.
- In LLVM >= 12.0.0, an atomic<enum class with 1 byte> would contain a lock byte.
This patch breaks the ABI again to bring it back to 1 byte, which seems
like the correct thing to do.
Fixes#57440
Differential Revision: https://reviews.llvm.org/D133377
compressed_pair is widely used in the library, but most of the uses don't use the tuple parts. To avoid including <tuple> everywhere, use the forward declaration instead in compressed_pair.h
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D133331
Summary:
This patch enables libc++ LIT test case last_write_time.pass.cpp for AIX. Because system call utimensat() of AIX which is used in the libc++ implementation of last_write_time() does not accept the times parameter with a negative tv_sec or tv_nsec field, testing of setting file time to before epoch time is excluded for AIX.
Reviewed by: ldionne, libc++
Differential Revision: https://reviews.llvm.org/D133124
Replaces std::__format_context_create with the public wrapper
test_format_context_create.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D133781
It seems these includes are still provided by the sub headers, so it only
removes the duplicates.
There is no change in the list of includes, but the change affects the
modular build. By not having the includes in the top-level header the
module map has changed. This uncovers missing includes in the tests
and missing exports in the module map. This causes the huge amount of
changes in the patch.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D133252
This change implements the C library dependent portions of P0482R6
(char8_t: A type for UTF-8 characters and strings (Revision 6)) by
declaring std::c8rtomb() and std::mbrtoc8() in the <cuchar> header
when implementations are provided by the C library as specified by
WG14 N2653 (char8_t: A type for UTF-8 characters and strings
(Revision 1)) as adopted for C23.
A _LIBCPP_HAS_NO_C8RTOMB_MBRTOC8 macro is defined by the libc++ __config
header unless it is known that the C library provides these functions
in the current compilation mode. This macro is used for testing purposes
and may be of use to libc++ users. At present, the only C library known
to implement these functions is GNU libc as of its 2.36 release.
Reviewed By: ldionne
Differential Revision: https://reviews.llvm.org/D130946
Instead of mentioning tm directly in the definition of __convert_to_tm,
take it as a template argument. As a fly-by also fix incorrect Lit feature
(should have been no-localization instead of libcpp-has-no-localization).
Differential Revision: https://reviews.llvm.org/D133490
During the discussion on the SG-10 mailinglist regarding the format
feature-test macros voted in during the last plenary it turns out libc++
can't mark the format feature-test macro as implemented.
According to
https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations#__cpp_lib_format
the not yet implemented paper
P1361R2 Integration of chrono with text formatting
affects the feature test macro.
Note that P1361R2 doesn't mention the feature-test macro nor is there an
LWG-issue to address the issue. The reporter of the issue didn't recall
where this requirement exactly has been decided.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D133271
We require rvalue support anyways, so let's use it.
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D133013
For some reason `operator""s(const char8_t*, size_t)` was marked `noexcept`. Remove it and add regression tests.
Reviewed By: ldionne, huixie90, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D132340
Adding `[[nodiscard]]` to functions is a conforming extension and done extensively in the MSVC STL.
Reviewed By: ldionne, EricWF, #libc
Spies: #libc_vendors, cjdb, mgrang, jloser, libcxx-commits
Differential Revision: https://reviews.llvm.org/D128267
Formatting the alternate form for the general categories should keep the
trailing zeros. This was reported by @fsb4000 in D131336.
The default format uses general formatting but this should not keep the
trailing zeros so the default format is not passed to the formatter.
While testing I found an off by one error; finding the exponent character
`e` in 1e+03 will start at after the `1` so a size of `4` can contain an
exponent.
Reviewed By: fsb4000, ldionne, #libc
Differential Revision: https://reviews.llvm.org/D131417
Implements:
- LWG3721 Allow an arg-id with a value of zero for width in std-format-spec
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D130649
This was discovered as an issue in D131317.
Depends on D131835
Reviewed By: #libc, var-const, ldionne, philnik
Differential Revision: https://reviews.llvm.org/D131836
This patch simplifies the implementation of `deque` by removing the `__deque_base` class which results in a lot less indirections and removes the need for `__base::`.
Reviewed By: ldionne, #libc
Spies: AdvenamTacet, libcxx-commits
Differential Revision: https://reviews.llvm.org/D132081
Many tests in `libcxx/test/std/strings` use
`#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L`
which can be replaced with the more terse `#ifndef TEST_HAS_NO_CHAR8_T`.
Differential Revision: https://reviews.llvm.org/D132626
Increase the timeout tolerance if TEST_IS_EXECUTED_IN_A_SLOW_ENVIRONMENT
is set, similarly to how it's done in a couple other tests.
Use `std::this_thread::yield();` instead of busylooping. When multiple
threads are busylooping, it's plausible that not all threads even get
started running before the timeout runs out.
This makes the threading tests succeed if run in Windows runners on
Github Actions.
Differential Revision: https://reviews.llvm.org/D131483
Vitaly Buka