Recent Clang-21 builds improved the deprecated diagnotics. This
uncovered missing guards in libc++ internally.
Note: This patch should be a separate commit and not merged.
For testing purposes they are combined.
Reviewed as part of #130497.
It seems that Apple Clang 17 starts to be used for CI, while it hasn't
supported `__builtin_is_virtual_base_of` yet. And thus we need to skip
the test for `is_virtual_base_of`.
Follows up #131302.
The skipping was present before but dropped. At the time it was dropped
in #128649, apple-clang-17 wasn't used for CI. But today it is used at
least for the "macos (generic-cxx23, macos-15)" configuration. So I
think we need to skip apple-clang-17 again.
This PR fixes an ambiguous call encountered when using the `std::ranges::find` or `std::find`
algorithms with `vector<bool>` with small `allocator_traits::size_type`s, an issue reported
in #122528. The ambiguity arises from integral promotions during the internal bitwise
arithmetic of the `find` algorithms when applied to `vector<bool>` with small integral
`size_type`s. This leads to multiple viable candidates for small integral types:
__libcpp_ctz(unsigned), __libcpp_ctz(unsigned long), and __libcpp_ctz(unsigned long long),
none of which represent a single best viable match, resulting in an ambiguous call error.
To resolve this, we propose invoking an internal function __countr_zero as a dispatcher
that directs the call to the appropriate overload of __libcpp_ctz. Necessary amendments
have also been made to __countr_zero.
Previously, commit 042f07eed8c1acba19ea04310137bee12b18045a claimed that
P0767R1 was implemented in LLVM 7.0, but no deprecation warning was
implemented. This patch adds the missing warnings.
According to the commit history, the constructors removed by LWG4140
have never been added to libc++.
Existence of non-public or deleted default constructor is observable,
this patch tests that there's no such default constructor at all.
These member types were deprecated in C++17 by P0174R2 and removed in
C++20 by P0619R4, but the changes in `<variant>` seem missing.
Drive-by: Replace one `_NOEXCEPT` with `noexcept` as the `hash`
specialization is C++17-and-later only.
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.
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 PR fixes the ambiguities in name lookup caused by non-standard
member typedefs `size_type` and `difference_type` in `std::bitset`.
Follows up #121620.
Closes#121618.
Currently, when the result type is 1-`tuple`, `tuple_cat` possibly tests
an undesired constructor of the element, due to conversion from the
reference tuple to the result type. If the element type has an
unconstrained constructor template, there can be extraneous hard error
which shouldn't happen.
This patch introduces a helper function template to select the element-wise
constructor template of `tuple`, which can avoid such error.
Fixes#41034.
According to
[[template.bitset.general]](https://eel.is/c++draft/template.bitset.general),
`std::bitset` is supposed to have only
one (public) member typedef, `reference`. However, libc++'s
implementation of `std::bitset` offers more that that. Specifically, it
offers a public typedef `const_reference` and two private typedefs
`size_type` and `difference_type`. These non-standard member typedefs,
despite being private, can cause potential ambiguities in name lookup in
user-defined classes, as demonstrated in issue #121618.
Fixing the public member typedef `const_reference` is straightforward:
we can simply replace it with an `__ugly_name` such as
`__const_reference`. However, fixing the private member typedefs
`size_type` and `difference_type` is not so straightforward as they are
required by the `__bit_iterator` class and the corresponding algorithms
optimized for `__bit_iterator`s (e.g., `ranges::fill`).
This PR fixes the member typedef `const_reference` by using uglified
name for it. Further work will be undertaken to address `size_type` and
`difference_type`.
Follows up #80706, #111127, and #112843,
This patch implements the forwarding to frozen C++03 headers as
discussed in
https://discourse.llvm.org/t/rfc-freezing-c-03-headers-in-libc. In the
RFC, we initially proposed selecting the right headers from the Clang
driver, however consensus seemed to steer towards handling this in the
library itself. This patch implements that direction.
At a high level, the changes basically amount to making each public
header look like this:
```
// inside <vector>
#ifdef _LIBCPP_CXX03_LANG
# include <__cxx03/vector>
#else
// normal <vector> content
#endif
```
In most cases, public headers are simple umbrella headers so there isn't
much code in the #else branch. In other cases, the #else branch contains
the actual implementation of the header.
This commit reverts c3276a96d9 and 1901da32, which added a test to
ensure that type traits are derived from integral_constant. While that
is a fine test to add, the commit didn't go through a PR and as a result
it looks like some of our CI has been broken by it.
This should be an uncontroversial change, but let's re-land it via a PR
to get our usual CI coverage.
This disentangles the code which previously had a mix of many #ifdefs, a
non-versioned namespace and a versioned namespace. It also makes it
clearer which parts of <new> are implemented on Windows by including <new.h>.
I'm exploring marking microsoft/STL's std::expected as [[nodiscard]],
which affects all functions returning std::expected, including its
own monadic member functions.
As usual, libc++'s test suite contains calls to these member functions
to make sure they compile, but it's discarding the returns. I'm adding
void casts to silence the [[nodiscard]] warnings without altering
what the test is covering.
The Android clang-r536225 compiler identifies as Clang 19, but it is
based on commit fc57f88f007497a4ead0ec8607ac66e1847b02d6, which predates
the official LLVM 19.0.0 release.
Some tests need fixes:
* The sized delete tests fail because clang-r536225 leaves sized
deallocation off by default.
* std::array<T[0]> is true when this Android Clang version is used with
a trunk libc++, but we expect it to be false in the test. In practice,
Clang and libc++ usually come from the same commit on Android.
Currently, libc++ incorrectly rejects heterogeneous comparison of
`unexpected`, because the `operator==` is only a hidden friend of
`unexpected<_Err>` but not of `unexpected<_Err2>`. We need to call the
`error()` member function on `__y`.
Fixes#115326
We can define some of these aliases without having to include the system
<stddef.h> and there doesn't seem to be much of a reason we shouldn't do
it this way.
This implements a warning that's similar to what GCC does in that
context: both memcpy and memset require their first and second operand
to be trivially copyable, let's warn if that's not the case.
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.
`overload_compare_iterator` only supports operations required for
forward iterators. On the other hand, it is used for output iterators of
uninitialized memory algorithms, which requires it to be forward
iterator.
As a result, `overload_compare_iterator<I>::iterator_category` should
always be `std::forward_iterator_tag` if we don't extend its ability.
The correct `iterator_category` can prevent standard library
implementations like MSVC STL attempting random access operations on
`overload_compare_iterator`.
Fixes#74756.
Previously, SFINAE constraints and exception specification propagation
were missing in the return type of libc++'s `std::mem_fn`. The
requirements on expression-equivalence (or even plain "equivalent" in
pre-C++20 specification) in [func.memfn] are actually requiring them.
This PR adds the missed stuffs. Fixes#86043.
Drive-by changes:
- removing no longer used `__invoke_return`,
- updating synopsis comments in several files, and
- merging several test files for `mem_fn` into one.
[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
It turns out that we can never do bounds-checking for unique_ptrs with
custom deleters, except when converting from a unique_ptr with a default
deleter to one with a custom deleter.
If we had an API like `std::make_unique` that allowed passing a custom
deleter, we could at least get bounds checking when the unique_ptr is
created through those APIs, but for now that is not possible.
Fixes#110683
