This refactors the standard stream implementation in multiple ways:
- The streams are now `stream_data` structs, which contain all the data
required for a stream
- The windows mangling is generated via a macro instead of having magic
strings for the different streams. (i.e. it's now only partially magic)
This patch simplifies the implementation of `__construct_at_end` in
`vector<bool>`, which currently contains duplicate initialization logic
across its two overloads.
These symbols are never referenced directly outside the dylib, so we can
make them hidden instead. They are still in the dylib since can be
referenced through the `memory_resource*`, but dynamic linkers don't
have to do any work to deduplicate them.
This patch adds the following pieces to the locale base API:
- __setlocale (for std::setlocale)
- __lconv_t (for std::lconv)
- _LIBCPP_FOO_MASK and _LIBCPP_LC_ALL
This should be sufficient to implement all of the platform-agnostic
localization support in libc++ without relying directly on any public
API names from the C library. This makes it possible to port libc++ to
platforms that don't provide the usual locale APIs.
This changes the __output_buffer to a new structure. This improves the
performace of std::format, std::format_to, std::format_to_n, and
std::formatted_size.
The old and new implementation of `_And` are very close in terms of
performance according to my testing, but the new implementation can also
be used to implement `conjunction`, which make that ~50% faster.
The commit 24e70e3930724ce499ad05d669bfbc4423c542e0 changed internal
macros which were used in 0cd794d4860e376698bb4da24bcdf8cbf331835c.
This caused build failures on platforms without TZDB support
While implementing this feature and its associated LWG issues it turns
out
- LWG3316 Correctly define epoch for utc_clock / utc_timepoint only
added non-normative wording to the standard.
Implements parts of:
- P0355 Extending <chrono> to Calendars and Time Zones
- P1361 Integration of chrono with text formatting
- LWG3359 <chrono> leap second support should allow for negative leap
seconds
This is a continuation of what's been started in #89178.
As a drive-by, this also changes the PSTL macro to say `EXPERIMENTAL`
instead of `INCOMPLETE`.
This patch relands the following PRs:
* #111711
* #107350
* #111457
All of these patches were reverted due to an issue reported in
https://github.com/llvm/llvm-project/pull/111711#issuecomment-2406491485,
due to interdependencies.
---
[clang] Finish implementation of P0522
This finishes the clang implementation of P0522, getting rid
of the fallback to the old, pre-P0522 rules.
Before this patch, when partial ordering template template parameters,
we would perform, in order:
* If the old rules would match, we would accept it. Otherwise, don't
generate diagnostics yet.
* If the new rules would match, just accept it. Otherwise, don't
generate any diagnostics yet again.
* Apply the old rules again, this time with diagnostics.
This situation was far from ideal, as we would sometimes:
* Accept some things we shouldn't.
* Reject some things we shouldn't.
* Only diagnose rejection in terms of the old rules.
With this patch, we apply the P0522 rules throughout.
This needed to extend template argument deduction in order
to accept the historial rule for TTP matching pack parameter to non-pack
arguments.
This change also makes us accept some combinations of historical and P0522
allowances we wouldn't before.
It also fixes a bunch of bugs that were documented in the test suite,
which I am not sure there are issues already created for them.
This causes a lot of changes to the way these failures are diagnosed,
with related test suite churn.
The problem here is that the old rules were very simple and
non-recursive, making it easy to provide customized diagnostics,
and to keep them consistent with each other.
The new rules are a lot more complex and rely on template argument
deduction, substitutions, and they are recursive.
The approach taken here is to mostly rely on existing diagnostics,
and create a new instantiation context that keeps track of this context.
So for example when a substitution failure occurs, we use the error
produced there unmodified, and just attach notes to it explaining
that it occurred in the context of partial ordering this template
argument against that template parameter.
This diverges from the old diagnostics, which would lead with an
error pointing to the template argument, explain the problem
in subsequent notes, and produce a final note pointing to the parameter.
---
[clang] CWG2398: improve overload resolution backwards compat
With this change, we discriminate if the primary template and which partial
specializations would have participated in overload resolution prior to
P0522 changes.
We collect those in an initial set. If this set is not empty, or the
primary template would have matched, we proceed with this set as the
candidates for overload resolution.
Otherwise, we build a new overload set with everything else, and proceed
as usual.
---
[clang] Implement TTP 'reversed' pack matching for deduced function template calls.
Clang previously missed implementing P0522 pack matching
for deduced function template calls.
Some templates in the standard library are illegal to specialize for users
(even if the specialization contains user-defined types). The [[clang::no_specializations]]
attribute allows marking such base templates so that the compiler will
diagnose if users try adding a specialization.
This changes the implementation of `__copy_cvref_t` to only template the
implementation class on the `_From` parameter, avoiding instantiations
for every combination of `_From` and `_To`.
Changes:
- Carve out sized but input-only ranges for C++23.
- Call `std::move` for related functions when the iterator is possibly input-only.
Fixes#115727
By calling `std::move` for related functions when the iterator is
possibly input-only. Also slightly changes the conditions of branch for
contiguous iterators to avoid error.
Fixes#116502
This PR addresses an issue where the `shrink_to_fit` function in
`vector<bool>` is effectively a no-op, meaning it will never shrink the
capacity.
Fixes#122502
In #118710 we've added ``_LIBCPP_NODEBUG`` to all internal aliases, but
didn't actually document it. This patch adds documentation by adding the
new requirement and reasoning to the coding guidelines.
Currently we're using quite different internal names for the
`std::invoke` family of type traits. This adds a layer around the
current implementation to make it easier to understand when it is used
and makes it easier to define multiple implementations of it.
In https://reviews.llvm.org/D136765 / https://reviews.llvm.org/D144155,
the asan annotations for `std::vector` were modified to unpoison freed
backing memory on destruction, instead of leaving it poisoned. However,
calling `__clear()` instead of `clear()` skips informing the asan runtime
of this decrease in the accessible container size, which breaks the
invariant that the value of `old_mid` should match the value of `new_mid`
from the previous call to `__sanitizer_annotate_contiguous_container`, which
can trip the sanity checks for the partial poison between [d1, d2) and the
container redzone between [d2, c), if enabled. To fix this, ensure that
`clear()` is called instead, as is already done by `__vdeallocate()`.
Also remove `__clear()`, since it is no longer called.
Library feature-test macros added by P1353R0 are already implemented.
- `__cpp_lib_destroying_delete` was added by
ae02e8944807c7b611ca3645a983c62d464f27a4
(https://reviews.llvm.org/D55840) in LLVM 9.
- `__cpp_lib_three_way_comparison` was added by #91515 in LLVM 19.
https://github.com/llvm/llvm-project/pull/95498 implemented a libc++
extension where <stdatomic.h> would forward to <atomic> even before
C++23. Unfortunately, this was found to be a breaking change (with
fairly widespread impact) since that changes whether _Atomic(T) is a C
style atomic or std::atomic<T>. In principle, this can even be an ABI
break.
We generally don't implement extensions in libc++ because they cause so
many problems, and that extension had been accepted because it was
deemed pretty small and only a quality of life improvement. Since it has
widespread impact on valid C++20 (and before) code, this patch removes
the extension before we ship it in any public release.
`_LIBCPP_NODEBUG` has been disabled temporarily, since there were a few
problems when adding a bunch of annotations throughout the code base.
They have been resolved now, so we can enable all the annotations again.
Reverts llvm/llvm-project#122393
Missing information about begin and end pointers of std::vector can lead
to missed optimizations in LLVM.
This patch adds alignment assumptions at the point where the begin and
end pointers are loaded. If the pointers would not have the same
alignment, end might never get hit when incrementing begin.
See https://github.com/llvm/llvm-project/issues/101372 for a discussion
of missed range check optimizations in hardened mode.
Once https://github.com/llvm/llvm-project/pull/108958 lands, the created
`llvm.assume` calls for the alignment should be folded into the `load`
instructions, resulting in no extra instructions after InstCombine.
Co-authored-by: Louis Dionne <ldionne.2@gmail.com>
These functions weren't added until API 26 (Android 8.0), but libc++ is
supported for API 21 and up.
These APIs are undeclared as of r.android.com/3216959.
This adds a test for an issue reported downstream at
https://github.com/mstorsjo/llvm-mingw/issues/462; this is known to fail
on Windows right now, where the fseek/ftell calls end up truncated to 32
bits.
The test for this, unfortunately, requires temporarily creating a 4 GB
file.
