# Overview
As a disclaimer, this is my first PR to LLVM and while I've tried to
ensure I've followed the LLVM and libc++ contributing guidelines,
there's probably a good chance I missed something. If I have, just let
me know and I'll try to correct it as soon as I can.
This PR implements `std::ranges::iota` and
`std::ranges::out_value_result` outlined in
[P2440r1](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2440r1.html).
As outlined in the paper above, I've:
- Implemented `out_value_result` and added to `<algorithm>`
- Added `out_value_result`, `iota_result`, and two overloads of `iota`
to `std::ranges` in `<numeric>`
- Updated the version macro `__cpp_lib_ranges_iota` in `<version>`
I've also added tests for `ranges::iota` and `ranges::out_value_result`.
Lastly, I added those structs to the appropriate module files.
Partially implements #105184
EDIT: Forgot to mention in the original post, thanks to @hawkinsw for
taking a look at a preliminary version of this PR!
# TODOs
- [x] Updating the range [status
doc](https://github.com/jamesETsmith/llvm-project/blob/main/libcxx/docs/Status/RangesMajorFeatures.csv)
- [x] Ensure all comments from https://reviews.llvm.org/D121436 are
addressed here
- [X] EDIT (I'll do this in a separate PR). ~~I'm open to implementing
the rest of P2440r1 (`ranges::shift_left` and `ranges::shift_right`) if
that's ok, I just wanted to get feedback on `ranges::iota` first~~
- [x] I've been having trouble building the modules locally and want to
make sure that's working properly
Closes: #134060
Completes:
- LWG3359 <chrono> leap second support should allow for negative leap
seconds
- P1361R2 Integration of chrono with text formatting
Implements parts of:
- P0355 Extending <chrono> to Calendars and Time Zones
Fixes: #100432Fixes: #100014
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
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`.
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
Currently, the library-internal feature test macros are only defined if
the feature is not available, and always have the prefix
`_LIBCPP_HAS_NO_`. This patch changes that, so that they are always
defined and have the prefix `_LIBCPP_HAS_` instead. This changes the
canonical use of these macros to `#if _LIBCPP_HAS_FEATURE`, which means
that using an undefined macro (e.g. due to a missing include) is
diagnosed now. While this is rather unlikely currently, a similar change
in `<__configuration/availability.h>` caught a few bugs. This also
improves readability, since it removes the double-negation of `#ifndef
_LIBCPP_HAS_NO_FEATURE`.
The current patch only touches the macros defined in `<__config>`. If
people are happy with this approach, I'll make a follow-up PR to also
change the macros defined in `<__config_site>`.
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.
The _LIBCPP_HAS_NO_THREADS carve-out does not result in hard errors
anymore, but the patch that changed that forgot to update the header
restrictions we use to auto-generate several files.
We can also remove the restrictions for the no-localization build and
no-wide-characters, but doing it is less straightforward so I'm leaving
it out of this patch.
This re-formats a few headers that had become out-of-sync with respect
to formatting since we ran clang-format on the whole codebase. There's
surprisingly few instances of it.
We always strive to test libc++ as close as possible to the way we are
actually shipping it. This was approximated reasonably well by setting
up the minimal driver flags when running the test suite, however we were
running the test suite against the library located in the build
directory.
This patch improves the situation by installing the library (the
headers, the built library, modules, etc) into a fake location and then
running the test suite against that fake "installation root".
This should open the door to getting rid of the temporary copy of the
headers we make during the build process, however this is left for a
future improvement.
Note that this adds quite a bit of verbosity whenever running the test
suite because we install the headers beforehand every time. We should be
able to override this to silence it, however CMake doesn't currently
give us a way to do that, see https://gitlab.kitware.com/cmake/cmake/-/issues/26085.
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.
This adds the new std::enable_nonlocking_formatter_optimization trait in
<format>. This trait will be used in std::print to implement the
performance benefits.
Implements parts of
- P3107R5 - Permit an efficient implementation of ``std::print``
Implementing the Hermite polynomials which are part of C++17's
mathematical special functions. The goal is to get early feedback which
will make implementing the other functions easier. Integration of
functions in chunks (e.g. `std::hermite` at first, then `std::laguerre`,
etc.) might make sense as well (also see note on boost.math below).
I started out from this abandoned merge request:
https://reviews.llvm.org/D58876 .
The C++23 standard defines them in-terms of `/* floating-point type */`
arguments. I have not looked into that.
Note, there is still an ongoing discussion on discourse whether
importing boost.math is an option.
Implements [P1223R5][] completely.
Includes an implementation of `find_last`, `find_last_if`, and
`find_last_if_not`.
[P1223R5]: https://wg21.link/p1223r5
41f7bb9975bcaffae0267fa87b63c90b83ffd551 claimed it implemented this
change but the code was not adjusted. The other spaceship operators in
the calendar code have been validated too.
Implements parts of
- P1614R2 The Mothership has Landed
This implements the class, its non-templated constructors and its
getters to verify the construction.
Completes
- LWG3224 zoned_time constructor from TimeZonePtr does not specify
initialization of tp_
Implements parts of:
- P0355 Extending chrono to Calendars and Time Zones
This PR addresses a problem that headers may not be able to be found if
`#include` is used with std modules.
Consider the following file:
#include <boost/json.hpp>
import std;
int main(int, const char **) { }
Boost will include something from libc++, but we are using -nostdinc++
at [1] so the compiler can not find any default std header. Therefore
the locally built header needs to be public.
[1]: 15fdd47c4b/libcxx/modules/CMakeLists.txt.in (L52)
This implements the throwing overload and the exception classes throw by
this overload.
Implements parts of:
- P0355 Extending chrono to Calendars and Time Zones
This patch reverts 9b832b72 (#87111):
- [libc++] Deprecated `shared_ptr` Atomic Access APIs as per P0718R2
- [libc++] Implemented P2869R3: Remove Deprecated `shared_ptr` Atomic Access APIs from C++26
As explained in [1], the suggested replacement in P2869R3 is `__cpp_lib_atomic_shared_ptr`,
which libc++ does not yet implement. Let's not deprecate the old way of doing things before
the new way of doing things exists.
[1]: https://github.com/llvm/llvm-project/pull/87111#issuecomment-2112740039
Instead of using FOO_TEST_DEPS global variables that don't get updated
properly from subdirectories, use targets to propagate the dependencies
across directories.
The patch does several things:
- fixes module exports
- disables clang-tidy with Clang-17 due to known issues
- disabled clang-tidy on older libstdc++ versions since it lacks C++20
features used
- fixes the CMake dependency
The issue why clang-tidy was not used in the CI was the last issue; the
plugin was not a
dependency of the tests. Without a plugin the tests disable clang-tidy.
This was noticed while investigating
https://github.com/llvm/llvm-project/issues/89898
This attribute is used in the headers. Not using this in the modules has
led to several issues. Add them to the modules to avoid these errors in
other placed.
This is missing e.g. on Windows. With this change, it's possible to make
the libcxx std module work on mingw-w64 (although that requires a few
fixes to those headers).
In the regular cstdlib header, we have _LIBCPP_USING_IF_EXISTS flagged
on every single reexported function (since
a9c9183ca42629fa83cdda297d1d30c7bc1d7c91), but the modules seem to only
have _LIBCPP_USING_IF_EXISTS set on a few individual functions, so far.
This adds the local_info type and its formatting options.
The usage of the local_info object will be done in separate patches.
Implements parts of:
- P0355 Extending to Calendars and Time Zones
- P1361 Integration of chrono with text formatting
Adds the sys_info class and time_zone::get_info(). The code still has a
few quirks and has not been optimized for performance yet.
The returned sys_info is compared against the output of the zdump tool
in the test giving confidence the implementation is correct.
Implements parts of:
- P0355 Extending <chrono> to Calendars and Time Zones
Implements:
- LWGXXXX The sys_info range should be affected by save
It adds the missing member functions of the tzdb class and adds the free
functions that use these member functions.
Implements parts of:
- P0355 Extending <chrono> to Calendars and Time Zones
This implements the loading of the leap-seconds.list file and store its
contents in the tzdb struct.
This adds the required `leap_seconds` member.
The class leap_seconds is fully implemented including its non-member
functions.
Implements parts of:
- P0355 Extending <chrono> to Calendars and Time Zones
- P1614 The Mothership has Landed
Implements:
- P1981 Rename leap to leap_second
- LWG3359 <chrono> leap second support should allow for negative leap
seconds
- LWG3383 §[time.zone.leap.nonmembers] sys_seconds should be replaced
with seconds
