This patch introduces a new kind of bounded iterator that knows the size
of its valid range at compile-time, as in std::array. This allows computing
the end of the range from the start of the range and the size, which requires
storing only the start of the range in the iterator instead of both the start
and the size (or start and end). The iterator wrapper is otherwise identical
in design to the existing __bounded_iter.
Since this requires changing the type of the iterators returned by
std::array, this new bounded iterator is controlled by an ABI flag.
As a drive-by, centralize the tests for std::array::operator[] and add
missing tests for OOB operator[] on non-empty arrays.
Fixes#70864
Instead of building the benchmarks separately via CMake and running them
separately from the test suite, this patch merges the benchmarks into
the test suite and handles both uniformly.
As a result:
- It is now possible to run individual benchmarks like we run tests
(e.g. using libcxx-lit), which is a huge quality-of-life improvement.
- The benchmarks will be run under exactly the same configuration as
the rest of the tests, which is a nice simplification. This does
mean that one has to be careful to enable the desired optimization
flags when running benchmarks, but that is easy with e.g.
`libcxx-lit <...> --param optimization=speed`.
- Benchmarks can use the same annotations as the rest of the test
suite, such as `// UNSUPPORTED` & friends.
When running the tests via `check-cxx`, we only compile the benchmarks
because running them would be too time consuming. This introduces a bit
of complexity in the testing setup, and instead it would be better to
allow passing a --dry-run flag to GoogleBenchmark executables, which is
the topic of https://github.com/google/benchmark/issues/1827.
I am not really satisfied with the layering violation of adding the
%{benchmark_flags} substitution to cmake-bridge, however I believe
this can be improved in the future.
Minor version of releases starts at `N.1.0` for all releases since 4532617ae42005.
The current status pages are not terribly wrong (the version during
development can be considered `N.0`), but still it's kinda weird to use
versions that never get released as the lower bound.
This PR deprecates `<ccomplex>`, `<cstdbool>`, `<ctgmath>`, and
`<ciso646>` in C++17 and "removes" them in C++20 by special deprecation
warnings.
`<cstdalign>` is previously missing. This PR also tries to add them, and
then deprecates and "removes" `<cstdalign>`.
Papers:
- https://wg21.link/P0063R3
- https://wg21.link/P0619R4Closes#99985.
---------
Co-authored-by: Louis Dionne <ldionne.2@gmail.com>
Around half of the tests are based on the tests Arthur O'Dwyer's
original implementation of std::flat_map, with modifications and
removals.
partially implement #105190
In C++20 mode, `__cpp_lib_optional` and `__cpp_lib_variant` should be
`202106L` due to DR P2231R1.
In C++26 mode, `__cpp_lib_variant` should be bumped to `202306L` due to
P2637R3.
- Clang 16/17 shouldn't get this bumping (as member `visit` requires
explicit object parameters), but it's very tricky to make the bumping
conditionally enabled. I _hope_ unconditionally bumping in C++26 will be
OK for LLVM 20 when the support for Clang 17 is dropped.
Related PRs:
- https://reviews.llvm.org/D102119
- #83335
- #76447
Implements std::from_chars for float and double.
The implementation uses LLVM-libc to do the real parsing. Since this is
the first time libc++
uses LLVM-libc there is a bit of additional infrastructure code. The
patch is based on the
[RFC] Project Hand In Hand (LLVM-libc/libc++ code sharing)
https://discourse.llvm.org/t/rfc-project-hand-in-hand-llvm-libc-libc-code-sharing/77701
Currently, libc++'s `bitset`, `forward_list`, and `list` have
non-conforming member typedef name `base`. The typedef is private, but
can cause ambiguity in name lookup.
Some other classes in libc++ that are either implementation details or
not precisely specified by the standard also have member typdef `base`.
I think this can still be conforming.
Follows up #80706 and #111127.
Make __libcpp_verbose_abort() noexcept (it is already noreturn), to
match std::terminate(). Clang's function effect analysis can use this to
ignore such functions as being beyond its scope. (See
https://github.com/llvm/llvm-project/pull/99656).
The changes are nearly pure simplifications, so I think it's OK to do
them together in the same PR.
Actual test coverages were already added in commit ad41d1e26b12
(https://reviews.llvm.org/D141216). Thanks to Casey Carter!
Fixes#104975
Towards #105200
This commit changes the libc++ frame recognizer to hide implementation
details of libc++ more aggressively. The applied heuristic is rather
straightforward: We consider every function name starting with `__` as
an implementation detail.
This works pretty neatly for `std::invoke`, `std::function`,
`std::sort`, `std::map::emplace` and many others. Also, this should
align quite nicely with libc++'s general coding convention of using the
`__` for their implementation details, thereby keeping the future
maintenance effort low.
However, this heuristic by itself does not work in 100% of the cases:
E.g., `std::ranges::sort` is not a function, but an object with an
overloaded `operator()`, which means that there is no actual call
`std::ranges::sort` in the call stack. Instead, there is a
`std::ranges::__sort::operator()` call. To make sure that we don't hide
this stack frame, we never hide the frame which represents the entry
point from user code into libc++ code
[template.bitset.general] indicates that `bitset` shouldn't have member
typedef-names `iterator` and `const_iterator`. Currently libc++'s
typedef-names are causing ambiguity in name lookup, which isn't
conforming.
As these iterator types are themselves useful, I think we should just
use __uglified member typedef-names for them.
Fixes#111125
Only the [cmp.alg] part (for `comparison_meow_fallback` CPOs) in the
paper required changes. Other parts merely fixed preconditions of some
standard library functions.
I strongly feel that P2167R3 should be a DR despite that it is not a DR
officially: CPOs -> C++20; remain parts -> C++98/11 (except that
_`boolean-testable`_ should be transformed into the original
_BooleanTestable_ requirements in the old resolution of LWG2114).
Note that P2167R3 damaged the resolution of LWG3465: the type of `F < E`
was left underconstrained. I've tried to submit an LWG issue for this,
which is now LWG4157.
Drive-by change:
- enable some test coverages in `compare_strong_order_fallback.pass.cpp`
when `TEST_LONG_DOUBLE_IS_DOUBLE`, following up #106742Closes#105241.
This reverts commit 78f9a8b82d772ff04a12ef95f2c9d31ee8f3e409.
This caused the LLDB test `TestDataFormatterGenericOptional.py` to fail, and we need
a bit more time to look into it.
Instead of changing the cast sequence to implicit conversion in
_`voidify`_, I think it is better to totally remove `__voidify` and use
`static_cast` to `void*`, which has equivalent effects.
Test coverage for const iterators are removed.
Now most affected algorithms are underconstrained, for which I submitted
[LWG3888](https://cplusplus.github.io/LWG/issue3888). I'm not sure
whether we should speculatively implement it at this moment, and thus
haven't added any `*.verify.cpp`.
In some control block types and `optional`, the stored objects are
changed to have cv-unqualified type.
Fixes#105119.
The paper was implemented by commit b0386a515b60c
(https://reviews.llvm.org/D46845) in LLVM 7.0. But it would be nice to
have test coverage for desired properties of `insert_return_type`.
Closes#99944
This ABI break only affects fancy pointer which have a different value
representation when pointing to a base of T instead of T itself. This
seems like a rather small set of fancy pointers, which themselves
already represent a very small niche. This patch swaps a pointer to T
with a pointer to base of T in a few library-internal types.
Works towards P0619R4 / #99985.
The use of `std::get_temporary_buffer` and `std::return_temporary_buffer`
are replaced with `unique_ptr`-based RAII buffer holder.
Escape hatches:
- `_LIBCPP_ENABLE_CXX20_REMOVED_TEMPORARY_BUFFER` restores
`std::get_temporary_buffer` and `std::return_temporary_buffer`.
Drive-by changes:
- In `<syncstream>`, states that `get_temporary_buffer` is now removed,
because `<syncstream>` is added in C++20.
This significantly simplifies the code, improves compile times and
improves the object layout of types using `__compressed_pair` in the
unstable ABI. The only downside is that this is extremely ABI sensitive
and pedantically breaks the ABI for empty final types, since the address
of the subobject may change. The ABI of the whole object should not be
affected.
Fixes#91266Fixes#93069
There are a few lines in the release notes which are much wider than the
120 columns we usually use. This reflows the text to keep it below the
threshold.
We waited before supporting std::jthread fully because we wanted to
investigate other implementation strategies (in particular one involving
std::mutex). Since then, we did some benchmarking and decided that we
wouldn't be moving forward with std::mutex. Hence, there is no real
reason to punt on making std::jthread & friends non-experimental.
They were originally implemented in d42db7e083ee0 but reverted later in
a2f3c63282330be0.
This PR implement both LWG issues again, guarding the removed functions
with `_LIBCPP_STD_VER <= 14`, because they should be treated as patches
for P0302R1 which was adopted for C++17.
Fixes#103598Fixes#103755
The resolution of LWG2593 didn't require the standard library
implementation to change. It merely strengthened requirements on
user-defined allocator types and allowed the implementation to make
stronger assumptions. The status is tentatively set to Nothing To Do.
However, `test_allocator` in libc++'s test suit needs to be fixed to
conform to the strengthened requirements.
Closes#100220.
This patch replaces 'tags' in the CSV status pages by inline notes
that optionally describe more details about the paper/LWG issue.
Tags were not really useful anymore because we have a vastly superior
tagging system via Github issues, and keeping the tags up-to-date
between CSV files and Github is going to be really challenging.
This patch also adds support for encoding custom notes in the CSV
files via Github issues. To encode a note in the CSV file, the
body (initial description) of a Github issue can be edited to contain
the following markers:
BEGIN-RST-NOTES
text that will be added as a note in the RST
END-RST-NOTES
Amongst other things, this solves the problem of conveying that a
paper has been implemented as a DR, and it gives a unified way to
add notes to the status pages from Github.
Please refer to the Github issues for details on why those are marked
as resolved. Huge thanks to @frederick-vs-ja for the analysis.
Closes#104336Closes#100042Closes#100615
This patch implements https://wg21.link/P2747R2.
The library changes affect direct `operator new` and `operator new[]`
calls even when the core language changes are absent.
The changes are not available for MS ABI because the `operator new` and
`operator new[]` are from VCRuntime's `<vcruntime_new.h>`. A feature
request was submitted for that [1].
As a drive-by change, the patch reformatted the whole `new.pass.cpp` and
`new_array.pass.cpp` tests.
Closes#105427
[1]: https://developercommunity.visualstudio.com/t/constexpr-for-placement-operator-newope/10730304.
This patch implements https://wg21.link/p2609r3.
The test code was originally authored by JMazurkiewicz.
Notes:
- P2609R3 is not officially a Defect Report, but MSVC STL
implements it in C++20 mode.
Moreover, P2609R3 and P2997R1 touch exactly the same set of
concepts, and MSVC STL and libc++ have already treated P2997R1
as a DR.
- This patch also adjusted feature-test macros.
+ In C++20 mode, the value of __cpp_lib_ranges should be `202110L` because
- `202202L` covers `range_adaptor_closure` (P2387R3), and
- `202207L` covers move-only types in range adaptors (P2494R2).
And all of these changes are only available since C++23 mode.
+ In C++23 mode, the value should be `202406L` because
- `202211L` covers removing poison overloads (P2602R2),
- `202302L` covers relaxing projected value types (P2609R3), and
- `202406L` covers removing requirements on `iter_common_reference_t` (P2997R1).
And all of these changes are already or being implemented.
Fixes#105253.
Co-authored-by: Jakub Mazurkiewicz <mazkuba3@gmail.com>
Works towards P0619R4/#99985.
- std::uncaught_exception was not previously deprecated. This patch
deprecates it since C++17 as per N4259. std::uncaught_exceptions is
used instead as libc++ unconditionally provides this function.
- _LIBCPP_ENABLE_CXX20_REMOVED_UNCAUGHT_EXCEPTION restores
std::uncaught_exception.
- As a drive-by, this patch updates the C++20 status page to
explain that D.11 is already done, since it was done in
578d09c1b195d859ca7e62840ff6bb83421a77b5.
