On Windows, the underlying file descriptors for stdout/stdin/stderr
can be reconfigured to wide mode. In the default (narrow) mode, the
charset usually isn't utf8 (as libcxx assumes), but normally a locale
specific codepage (where each codepage only can represent a small
subset of unicode characters).
By configuring the stdout file descriptor to wide mode, the user can
output wchar_t based strings without convesion to the narrow charset.
Within libcxx, don't try to use codecvt to convert this to a narrow
character encoding, but output these strings as such with fputwc.
In wide mode, such strings could be output directly with fwrite too,
but if the file descriptor hasn't been configured in wide mode, that
breaks the output (which currently works reasonably). By always
outputting one character at a time with fputwc, it works regardless
of mode of the stdout file descriptor.
For the narrow output stream, std::cout, outputting (via fwrite)
does fail when the file descriptor is set to wide mode. This matches
how it behaves with both MS STL and GNU libstdc++ too, so this is
probably acceptable.
This fixes https://github.com/llvm/llvm-project/issues/46646, and
the downstream bugs https://github.com/mstorsjo/llvm-mingw/issues/145
and https://github.com/mstorsjo/llvm-mingw/issues/222.
Differential Revision: https://reviews.llvm.org/D146398
This allows removing a bunch of boilerplate from the test suite and
reducing the amount of manual stuff contributors have to do when they
add a new public header.
Differential Revision: https://reviews.llvm.org/D151830
This removes the need for contributors to do some manual steps
when adding a new public header.
Differential Revision: https://reviews.llvm.org/D151831
These have been deprecated since their initial version in libc++. It
seems they were never properly marked as deprecated.
Discovered while working on D151223.
Reviewed By: #libc, ldionne, philnik
Differential Revision: https://reviews.llvm.org/D151474
This is an ongoing series of commits that are reformatting our
Python code.
Reformatting is done with `black`.
If you end up having problems merging this commit because you
have made changes to a python file, the best way to handle that
is to run git checkout --ours <yourfile> and then reformat it
with black.
If you run into any problems, post to discourse about it and
we will try to help.
RFC Thread below:
https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style
Reviewed By: #libc, kwk, Mordante
Differential Revision: https://reviews.llvm.org/D150763
The code has been quite ready for a while now and there are no more ABI
breaking papers. So this is a good time to mark the feature as stable.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D150802
Clang has been updated to support C++26, this adds the same support for
libc++. At the moment C++23 and C++26 are identical. During the next
plenary in June the first C++26 papers will be voted on.
Note like Clang this patch uses C++26 is the internal part and C++2c in
the user visible part.
Depends on D150795
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D151026
During the ISO C++ Committee meeting plenary session the C++23 Standard
has been voted as technical complete.
This updates the reference to c++2b to c++23 and updates the __cplusplus
macro.
Note since we use clang-tidy 16 a small work-around is needed. Clang
knows -std=c++23 but clang-tidy not so for now force the lit compiler
flag to use -std=c++2b instead of -std=c++23.
Reviewed By: #libc, philnik, jloser, ldionne
Differential Revision: https://reviews.llvm.org/D150795
The main change is to allow a UCS scalar value as fill character.
Especially for char based formatting this increase the number of valid
characters. Originally this was to be expected ABI breaking, however the
current change does not seem to break the ABI.
Implements
- P2572 std::format() fill character allowances
Depends on D144499
Reviewed By: ldionne, tahonermann, #libc
Differential Revision: https://reviews.llvm.org/D144742
This reverts commit ebc111b08bddca55d5f7e560a20bdb2c913d80cb.
Sorry, I forgot to append Phabricator reversion when land D140911, I try to revert this change and reland.
Reviewed By: #libc, ldionne, EricWF
Differential Revision: https://reviews.llvm.org/D150793
This patch adds std::extents. extents is one of the core classes used by std::mdspan. It describes a multi-dimensional index space with a mix of compile time and runtime sizes. Furthermore, it is templated on the index type used to describe the multi-dimensional index space.
The class is designed to be highly optimizable in performance critical code sections, and is fully useable in constant expressions contexts.
Testing of this class tends to be somewhat combinatorical, due to the large number of possible corner cases involved in situations where we have both runtime and compile time extents. To add to this, the class is designed to be interoperable (in particular constructible) from arguments which only need to be convertible to the index_type, but are otherwise arbitrary user types. For a larger discussion on the design of this class refer to: https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p0009r18.html
Co-authored-by: Damien L-G <dalg24@gmail.com>
Reviewed By: ldionne, #libc
Spies: libcxx-commits, H-G-Hristov, tschuett, philnik, arichardson, Mordante, crtrott
Differential Revision: https://reviews.llvm.org/D148067
We introduced an optimization to std::sort in 4eddbf9f10a6. However,
that optimization led to issues where users that were passing invalid
comparators to std::sort could start seeing OOB reads. This led to
the revert of the std::sort optimization from the LLVM 16 release
(see https://llvm.org/D146421).
This patch introduces _LIBCPP_ASSERTs to the places in the algorithm
where we make an assumption that the comparator will be consistent and
hence avoid a bounds check based on that. If the comparator happens not
to be consistent with itself, these are the places where we would
incorrectly go out of bounds. This allows users that enable libc++
assertions to catch such misuse at the cost of basically a bounds
check. For users that do not enable libc++ assertions (which is 99.9%
of users since assertions are off by default), this is basically a
no-op, and in fact the assertion will turn into a __builtin_assume,
making it explicit to the compiler that it can rely on the fact that
we're not going out of bounds.
I think this patch strikes the right balance. Folks that want absolute
performance will get what they want, since it is a precondition for the
comparator to be consistent, so the bounds checks are technically not
mandatory. Folks who want more safety *already* need to be enabling
libc++ assertions to catch other types of bugs (like operator[] OOB),
so this solution should also work for them.
I do think we have a lot of work towards popularizing the use of libc++
assertions and integrating it better so that users don't have to know
about the obscure _LIBCPP_ENABLE_ASSERTIONS macro to enable them, but
that's a separate concern.
rdar://106897934
Differential Revision: https://reviews.llvm.org/D147089
- add the `from_range_t` constructors and the related deduction guides;
- add the `insert_range`/`assign_range`/etc. member functions.
(Note: this patch is split from https://reviews.llvm.org/D142335)
Differential Revision: https://reviews.llvm.org/D149826
LWG3759 ranges::rotate_copy should use std::move
This has been one in the initial version (D127211).
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D142813
Makes sure the formatter for the vector<bool>::reference is enabled
when only the header <vector> is included. Before this change it
required <vector> and <format> to be included. This violated the
requirements in the Standard.
Fixes: https://llvm.org/PR61314
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D149543
This revision is part of our efforts to support container annotations with (almost) every allocator.
That patch is necessary to enable support for most annotations (D136765). Without a way to turn off annotations, it's hard to use ASan with area allocators (no calls to destructors).
This is an answer to a request about it. This patch provides a solution to the aforementioned issue by introducing a new template structure `__asan_annotate_container_with_allocator`, which allows the disabling of container annotations for a specific allocator.
This patch also introduces `_LIBCPP_HAS_ASAN_CONTAINER_ANNOTATIONS_FOR_ALL_ALLOCATORS` FTM.
To turn off annotations, it is sufficient to create a template specialization with a false value using a [Unary Type Trait](https://en.cppreference.com/w/cpp/types/integral_constant).
The proposed structure is being used in the code enabling annotations for all allocators in `std::vector`, `std::basic_string`, and `std::deque`. (D136765 D146214 D146815)
Possibility to do it was added to ASan API in rGdd1b7b797a116eed588fd752fbe61d34deeb24e4 commit.
For context on not calling a destructor, look at https://eel.is/c++draft/basic.life#5 and notes there, you may also read a discussion in D136765.
Reviewed By: ldionne, philnik, #libc, hans
Spies: EricWF, mikhail.ramalho, #sanitizers, libcxx-commits, hans, vitalybuka
Differential Revision: https://reviews.llvm.org/D145628
Committing on behalf of davidben. Reviewed as D146190
Patch originally by Jan Dörrie in https://reviews.llvm.org/D120064. I've just updated it to include tests, and update documentation that MSVC ABI is not stable.
In the current implementation both `std::optional` and `std::variant` don't perform the EBO on MSVC's ABI. This is because both classes inherit from multiple empty base classes, which breaks the EBO for MSVC. This patch fixes this issue by applying the `empty_bases` declspec attribute, which is already used to fix a similar issue for `std::tuple`.
See https://reviews.llvm.org/D120064 for discussion on MSVC ABI stability. From the discussion, libc++ doesn't have users that expect a stable ABI on MSVC. The fix is thus applied unconditionally to benefit more users. Documentation has been updated to reflect this.
Fixes https://github.com/llvm/llvm-project/issues/61095.
algorithm's include of chrono causes include cycles:
```
algorithm -> chrono -> __chrono/convert_to_tm.h -> __chrono/statically_widen.h -> __format/concepts.h -> __format/format_parse_context.h -> string_view -> algorithm
algorithm -> chrono -> __chrono/convert_to_tm.h -> __chrono/statically_widen.h -> __format/concepts.h -> __format/format_parse_context.h -> string_view -> functional -> __functional/boyer_moore_searcher.h -> array -> algorithm
algorithm -> chrono -> __chrono/convert_to_tm.h -> __chrono/statically_widen.h -> __format/concepts.h -> __format/format_parse_context.h -> string_view -> functional -> __functional/boyer_moore_searcher.h -> unordered_map -> algorithm
algorithm -> chrono -> __chrono/convert_to_tm.h -> __chrono/statically_widen.h -> __format/concepts.h -> __format/format_parse_context.h -> string_view -> functional -> __functional/boyer_moore_searcher.h -> vector -> algorithm
```
This is a problem for clang modules after the std mega module is broken up, because it becomes a module cycle which is a hard error.
All of the includes in the `__chrono` and `__format` headers are being used and so can't be removed. algorithm's include of chrono is already removed in C++20, whereas the array, string_view, unordered_map, vector includes of algorithm aren't removed until C++23 (and it's 4x the includes that would need removing). Unconditionally remove the chrono include from algorithm in all versions, so that the module breakup can happen (the module has to apply to all C++ versions).
Reviewed By: Mordante, #libc
Differential Revision: https://reviews.llvm.org/D148405
The removal of operator!= in this header will be done in a separate
commit.
Note in the synopsis of P1614R2 there is a constexpr
template<class BiIter>
constexpr auto operator<=>(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);
In the implementation of P1614R2 there isn't a constexpr
template<class BiIter>
auto operator<=>(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);
There doesn't seem to be an LWG-issue, but it was fixed in the Standard
by removing the constexpr in b050fd474f11441942c88ef69b8622c8036656ac.
Implements part of:
- P1614R2 The Mothership has Landed
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D132310
As obvious from the paper's title this is an LWG issue and thus retroactively
applied to C++20. This change may the output for certain code points:
1 Considers 8477 extra codepoints as having a width 2 (as of Unicode 15)
(mostly Tangut Ideographs)
2 Change the width of 85 unassigned code points from 2 to 1
3 Change the width of 8 codepoints (in the range U+3248 CIRCLED NUMBER
TEN ON BLACK SQUARE ... U+324F CIRCLED NUMBER EIGHTY ON BLACK
SQUARE) from 2 to 1, because it seems questionable to make an exception
for those without input from Unicode
Note that libc++ already uses Unicode 15, while the Standard requires Unicode 12.
(The last time I checked MSVC STL used Unicode 14.)
So in practice the only notable change is item 3.
Implements
P2675 LWG3780: The Paper
format's width estimation is too approximate and not forward compatible
Benchmark before these changes
--------------------------------------------------------------------
Benchmark Time CPU Iterations
--------------------------------------------------------------------
BM_ascii_text<char> 3928 ns 3928 ns 178131
BM_unicode_text<char> 75231 ns 75230 ns 9158
BM_cyrillic_text<char> 59837 ns 59834 ns 11529
BM_japanese_text<char> 39842 ns 39832 ns 17501
BM_emoji_text<char> 3931 ns 3930 ns 177750
BM_ascii_text<wchar_t> 4024 ns 4024 ns 174190
BM_unicode_text<wchar_t> 63756 ns 63751 ns 11136
BM_cyrillic_text<wchar_t> 44639 ns 44638 ns 15597
BM_japanese_text<wchar_t> 34425 ns 34424 ns 20283
BM_emoji_text<wchar_t> 3937 ns 3937 ns 177684
Benchmark after these changes
--------------------------------------------------------------------
Benchmark Time CPU Iterations
--------------------------------------------------------------------
BM_ascii_text<char> 3914 ns 3913 ns 178814
BM_unicode_text<char> 70380 ns 70378 ns 9694
BM_cyrillic_text<char> 51889 ns 51877 ns 13488
BM_japanese_text<char> 41707 ns 41705 ns 16723
BM_emoji_text<char> 3908 ns 3907 ns 177912
BM_ascii_text<wchar_t> 3949 ns 3948 ns 177525
BM_unicode_text<wchar_t> 64591 ns 64587 ns 10649
BM_cyrillic_text<wchar_t> 44089 ns 44078 ns 15721
BM_japanese_text<wchar_t> 39369 ns 39367 ns 17779
BM_emoji_text<wchar_t> 3936 ns 3934 ns 177821
Benchmarks without "if(__code_point < (__entries[0] >> 14))"
--------------------------------------------------------------------
Benchmark Time CPU Iterations
--------------------------------------------------------------------
BM_ascii_text<char> 3922 ns 3922 ns 178587
BM_unicode_text<char> 94474 ns 94474 ns 7351
BM_cyrillic_text<char> 69202 ns 69200 ns 10157
BM_japanese_text<char> 42735 ns 42692 ns 16382
BM_emoji_text<char> 3920 ns 3919 ns 178704
BM_ascii_text<wchar_t> 3951 ns 3950 ns 177224
BM_unicode_text<wchar_t> 81003 ns 80988 ns 8668
BM_cyrillic_text<wchar_t> 57020 ns 57018 ns 12048
BM_japanese_text<wchar_t> 39695 ns 39687 ns 17582
BM_emoji_text<wchar_t> 3977 ns 3976 ns 176479
This optimization does carry its weight for the Unicode and Cyrillic
test. For the Japanese tests the gains are minor and for emoji it seems
to have no effect.
Reviewed By: ldionne, tahonermann, #libc
Differential Revision: https://reviews.llvm.org/D144499
This patch removes the symbols defined in the library for std::allocator_arg,
std::defer_lock, std::try_to_lock, std::adopt_lock, and std::piecewise_construct.
Those were defined in the library because we provided them in C++03 as an
extension, and in C++03 it was impossible to define them as `constexpr`
variables, like in the spec.
This is technically an ABI break since we are removing symbols from the
library. However, in practice, only programs compiled in C++03 mode who
take the address of those objects (or pass them as a reference) will have
an undefined ref to those symbols. In practice, this is expected to be
rare. First, those are C++11 features that we happen to provide in C++03,
and only the C++03 definition can potentially lead to code referencing
the dylib definition. So any code that is using these objects but compiling
in C++11 mode (as they should) is not at risk. Second, all uses of these
types in the library is done by passing those types by value to a function
that can get inlined. Since they are empty types, the compiler won't
generate an undefined reference if passed by value, since there's nothing
to pass anyway.
Long story short, the risk for code actually containing an undefined
reference to one of these types is rather small (but non-zero). I also
couldn't find any app on the App Store that referenced these symbols,
which supports my impression that this won't be an issue in practice.
Differential Revision: https://reviews.llvm.org/D145587
The __cpp_lib_format_ranges feature-test macro only depends on P2286R8
and P2585R0. Note since LWG3750 only affects these two C++23 papers
there is nothing to do for older language versions.
(The __cpp_lib_format feature-test macro depends on the incomplete
formatting for chrono. So this part can't be marked as complete yet.)
This completes
- P2286R8 Formatting ranges
- P2585R0 Improving default container formatting
This partly implements
- LWG3750 Too many papers bump __cpp_lib_format
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D147880
LWG3720 Restrict the valid types of arg-id for width and precision in
std-format-spec
Depends on D144325
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D144326
Since stacktrace header is WIP and it's not sure that will be done
before LLVM17 update the documentation. When the header is implemented
implementing the formatter is trivial, so that can be done quickly
afterwards.
Implements parts of:
- P2693R1 Formatting thread::id and stacktrace
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D144331
