Priorities below 101 are reserved for the implementation, so that's what
we should be using here. That is unfortunately only supported on more
recent versions of Clang. See https://reviews.llvm.org/D31413 for details.
Differential Revision: https://reviews.llvm.org/D95972
Implement P1391 (https://wg21.link/p1391) which allows
`std::string_view` to be constructible from any contiguous range of
characters.
Note that a different paper (http://wg21.link/P1989) handles the generic
range constructor for `std::string_view`.
Reviewed By: ldionne, Quuxplusone, Mordante, #libc
Differential Revision: https://reviews.llvm.org/D110718
In basic_string and vector, we've been encapsulating all exception
throwing code paths in helper functions of a base class, which are defined
in the compiled library. For example, __vector_base_common defines two
methods, __throw_length_error() and __throw_out_of_range(), and the class
is externally instantiated in the library. This was done a long time ago,
but after investigating, I believe the goal of the current design was to:
1. Encapsulate the code to throw an exception (which is non-trivial) in
an externally-defined function so that the important code paths that
call it (e.g. vector::at) are free from that code. Basically, the
intent is for the "hot" code path to contain a single conditional jump
(based on checking the error condition) to an externally-defined function,
which handles all the exception-throwing business.
2. Avoid defining this exception-throwing function once per instantiation
of the class template. In other words, we want a single copy of
__throw_length_error even if we have vector<int>, vector<char>, etc.
3. Encapsulate the passing of the container-specific string (i.e. "vector"
and "basic_string") to the underlying exception-throwing function
so that object files don't contain those duplicated string literals.
For example, we'd like to have a single "vector" string literal for
passing to `std::__throw_length_error` in the library, instead of
having one per translation unit.
However, the way this is achieved right now has two problems:
- Using a base class and exporting it is really weird - I've been confused
about this ever since I first saw it. It's just a really unusual way of
achieving the above goals. Also, it's made even worse by the fact that
the definitions of __throw_length_error and __throw_out_of_range appear
in the headers despite always being intended to be defined in the compiled
library (via the extern template instantiation).
- We end up exporting those functions as weak symbols, which isn't great
for load times. Instead, it would be better to export those as strong
symbols from the library.
This patch fixes those issues while retaining ABI compatibility (e.g. we
still export the exact same symbols as before). Note that we need to
keep the base classes as-is to avoid breaking the ABI of someone who
might inherit from std::basic_string or std::vector.
Differential Revision: https://reviews.llvm.org/D111173
e9ee517930 added support for using
winpthreads on Windows, enabled if `__WINPTHREADS_VERSION` was
defined (i.e. if winpthreads headers have been included before
including libcxx `__config`). This was fragile (libcxx changed
behaviour depending on what headers had been included externally
before), and was changed in a1bc823a59
to use pthreads on Windows whenever the pthread.h header was
available.
This is also fragile; pthread.h might be unavailable while building
libcxx but installed later, and available when users include the
libcxx headers.
In practice, in every modern setup for building libcxx for Windows
I've seen, users end up manually configuring it with
`LIBCXX_HAS_WIN32_THREAD_API=ON`, as the users may have winpthreads
installed (for other libraries/projects to use) while wanting to
build libcxx with the default win32 threading.
Don't automatically pick up pthreads on Windows even if the header
is available. Instead require the user to configure the libcxx
build with `LIBCXX_HAS_PTHREAD_API=ON` if that's desired.
Differential Revision: https://reviews.llvm.org/D110975
The existing tests for transform_view::iterator weren't quite right,
and can be simplified now that we have more of C++20 available to us.
Having done that, let's use the same pattern for iota_view::iterator
as well.
Differential Revision: https://reviews.llvm.org/D110774
This adds the width estimation functions to the std-format-spec.
Implements parts of:
- P0645 Text Formatting
- P1868 width: clarifying units of width and precision in std::format
Reviewed By: #libc, ldionne, vitaut
Differential Revision: https://reviews.llvm.org/D103413
This reverts part of commit b82683b2eb.
I hadn't intended to remove the `// -*- C++ -*-` comment line
from `libcxx/include/version`, only from the generated tests.
Thanks to Raul Tambre for the catch.
Even if these comments have a benefit in .h files (for editors that
care about language but can't be configured to treat .h as C++ code),
they certainly have no benefit for files with the .cpp extension.
Discussed in D110794.
Some of these were previously half-implemented in "ordering.h";
now they're all implemented, and tested.
Note that `constexpr` functions are implicitly `inline`, so the
standard wording omits `inline` on these; but Louis and I agree
that that's surprising and it's better to be explicit about it.
Differential Revision: https://reviews.llvm.org/D110515
Instead of using a base class to store the members and the optional
size, use [[no_unique_address]] to achieve the same thing without
needing a base class.
Also, as a fly-by:
- Change subrange from struct to class (per the standard)
- Improve the diagnostic for when one doesn't provide a size to the ctor of a sized subrange
- Replace this->member by just member since it's not in a dependent base anymore
This change would be an ABI break due to [[no_unique_address]], but we
haven't shipped ranges anywhere yet, so this shouldn't affect anyone.
Differential Revision: https://reviews.llvm.org/D110370
There's really no reason to even have two different enums here,
but *definitely* we shouldn't have *three*, and they don't need
so many synonymous enumerator values.
Differential Revision: https://reviews.llvm.org/D110516
In reaction to the issues raised by Richard in https://llvm.org/D109066,
this commit does not apply P1951 as a DR in previous standard modes,
since it breaks valid code.
I do believe it should be applied as a DR, however ideally we'd get some
sort of statement from the Committee to this effect (and all implementations
would behave consistently). In the meantime, only implement P1951 starting
with C++23 -- we can always come back and apply it as a DR if that's what
the Committee says.
Differential Revision: https://reviews.llvm.org/D110347
That macro was being defined but not used anywhere in libc++, so it
must be safe to remove it.
As a fly-by fix, also remove mentions of this macro in other places
in LLVM, to make sure they were not depending on the value defined in
libc++.
Differential Revision: https://reviews.llvm.org/D110289
Implements parts of P1614, including synth-three-way and three way comparison for std::pair.
Reviewed By: #libc, Quuxplusone, Mordante
Differential Revision: https://reviews.llvm.org/D107721
Instead of overloading `__to_address`, let's specialize `pointer_traits`.
Function overloads need to be in scope at the point where they're called,
whereas template specializations do not. (User code can provide pointer_traits
specializations to be used by already-included library code, so obviously
`__wrap_iter` can do the same.)
`pointer_traits<__wrap_iter<It>>` cannot provide `pointer_to`, because
you generally cannot create a `__wrap_iter` without also knowing the
identity of the container into which you're trying to create an iterator.
I believe this is OK; contiguous iterators are required to provide
`to_address` but *not* necessarily `pointer_to`.
Differential Revision: https://reviews.llvm.org/D110198
All supported compilers provide support for inline variables in C++17 now.
Also, as a fly-by fix, replace some uses of _LIBCPP_CONSTEXPR by just
constexpr.
The only exception in this patch is `std::ignore`, which is provided
prior to C++17. Since it is defined in an anonymous namespace, it always
has internal linkage anyway, so using an inline variable there doesn't
provide any benefit. Instead, `inline` was removed entirely on `std::ignore`.
Differential Revision: https://reviews.llvm.org/D110243
LWG 2447 is marked as `Complete`, but there is no `static_assert` to
reject volatile types in `std::allocator`. See the discussion at
https://reviews.llvm.org/D108856.
Add `static_assert` in `std::allocator` to disallow volatile types. Since this
is an implementation choice, mark the binding test as `libc++` only.
Remove tests that use containers backed by `std::allocator` that test
the container when used with a volatile type.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D109056
Also, as a fly-by fix, use `inline` directly to define inline variables
(all compilers support it).
Differential Revision: https://reviews.llvm.org/D110208
These routines were add years ago during initial porting attempts to AIX and are mostly build hacks for routines which we're missing at the time, but are available now on recent AIX OS levels.
Thus builds on modern AIX OS levels no longer need these and they cause problems if you try to build the library with a generic triple (i.e. powerpc-ibm-aix) as we'll pull them in and encounter duplicate definitions from the OS.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D110183
Neither the current C++2b draft, nor any revision of [p1135],
nor libstdc++, claims that `counting_semaphore` should be
default-constructible. I think this was just a copy-paste issue
somehow.
Also, `explicit` was missing from the constructor.
Also, `constexpr` remains missing; but that's probably more of a
technical limitation, since apparently there are some platforms
where we don't (can't??) use the atomic implementation and
have to rely on pthreads, which obviously isn't constexpr.
Differential Revision: https://reviews.llvm.org/D110042
This implements the generic std.format.spec framework for all types.
The Unicode support will be added in a separate patch.
Implements parts of:
- P0645 Text Formatting
Completes:
- LWG-3242 std::format: missing rules for arg-id in width and precision
- P1892 Extended locale-specific presentation specifiers for std::format
Reviewed By: #libc, ldionne, vitaut
Differential Revision: https://reviews.llvm.org/D103368
- Simplify the structure of the new tests.
- Test const containers as well as non-const containers,
since it's easy to do so.
- Remove redundant enable-iffing of helper structs' member functions.
(They're not instantiated unless they're called, and who would call them?)
- Fix indentation and use more consistent SFINAE method in <unordered_map>.
- Add _LIBCPP_INLINE_VISIBILITY on some swap functions.
Differential Revision: https://reviews.llvm.org/D109011
Now that __builtin_is_constant_evaluated() is present on all supported
compilers, we can use it to skip the UB-inducing assert in cases where
the computation might be happening at constexpr time.
Differential Revision: https://reviews.llvm.org/D101674
All supported compilers have supported `=delete` as an extension
in C++03 mode for many years at this point.
Differential Revision: https://reviews.llvm.org/D109942
The aim is to add the missing z/OS specific implementations for mbsnrtowcs and wcsnrtombs, as part of libc++.
Differential Revision: https://reviews.llvm.org/D98207
Summary:
AIX have 2 byte wchar in 32 bit mode and 4 byte wchar in 64 bit mode.
This patch add more missing short wchar handling under the existing _LIBCPP_SHORT_WCHAR macro.
Marked test case ctor_move.pass.cpp as XFAIL for 32-bit mode on AIX because UTF-8 constants used cannot be converted to 2-byte wchar (by xingxue).
Authored by: jasonliu
Reviewed by: ldionne, zibi, SeanP, libc++
Differential Revision: https://reviews.llvm.org/D100777
In other places in the code, we use lowercase spelling for things that
are not available in prior standards.
Differential Revision: https://reviews.llvm.org/D109435
Detected by evil-izing the widely used `MoveOnly` testing type.
I had to patch some tests that were themselves using its comma operator,
but I think that's a worthwhile cost in order to catch more places
in our headers that needed comma-proofing.
The trick here is that even `++ptr, SomeClass()` can find a comma operator
by ADL, if `ptr` is of type `Evil*`. (A comma between two operands
of non-class-or-enum type is always treated as the built-in
comma, without ADL. But if either operand is class-or-enum, then
ADL happens for _both_ operands' types.)
Differential Revision: https://reviews.llvm.org/D109414
I just ran into a compiler error involving __bind_back and some overloads
that were being disabled with _EnableIf. I noticed that the error message
was quite bad and did not mention the reason for the overload being
excluded. Specifically, the error looked like this:
candidate template ignored: substitution failure [with _Args =
<ContiguousView>]: no member named '_EnableIfImpl' in 'std::_MetaBase<false>'
Instead, when using enable_if or enable_if_t, the compiler is clever and
can produce better diagnostics, like so:
candidate template ignored: requirement 'is_invocable_v<
std::__bind_back_op<1, std::integer_sequence<unsigned long, 0>>,
std::ranges::views::__transform::__fn &, std::tuple<PlusOne> &,
ContiguousView>' was not satisfied [with _Args = <ContiguousView>]
Basically, it tries to do a poor man's implementation of concepts, which
is already a lot better than simply complaining about substitution failure.
Hence, this commit uses enable_if_t instead of _EnableIf whenever
possible. That is both more straightforward than using the internal
helper, and also leads to better error messages in those cases.
I understand the motivation for _EnableIf's implementation was to improve
compile-time performance, however I believe striving to improve error
messages is even more important for our QOI, hence this patch. Furthermore,
it is unclear that _EnableIf actually improved compile-time performance
in any noticeable way (see discussion in the review for details).
Differential Revision: https://reviews.llvm.org/D108216
These are specced as `inline constexpr auto`; the extra `const`
isn't doing anything except being inconsistent with the other CPOs.
Now all the implemented CPOs can be detected by
git grep 'inline constexpr auto.*fn' ../libcxx/include/
and I think that's beautiful.
There were basically two bugs here:
When C++20 `to_address` is called on `int arr[10]`, then `const _Ptr&` becomes
a reference to a const array, and then we dispatch to `__to_address<const int(&)[10]>`,
which, oops, gives us a `const int*` result instead of an `int*` result.
Solution: We need to provide the two standard-specified overloads of
`std::to_address` in exactly the same way that we provide two overloads
of `__to_address`.
When `__to_address` is called on a pointer type, `__to_address(const _Ptr&)`
is disabled so we successfully avoid trying to instantiate pointer_traits of
that pointer type. But when it's called on an array type, it's not disabled
for array types, so we go ahead and instantiate pointer_traits<int[10]>,
which goes boom. Solution: We need to disable `__to_address(const _Ptr&)`
for both pointer and array types. Also disable it for function types,
so that they get the nice error message; and put a test on it.
Differential Revision: https://reviews.llvm.org/D109331
Implementation of `three_way_comparable` and `three_way_comparable_with` concepts from <compare> header.
Please note that I have temporarily removed `<compare>` header from `<utility>` due to cyclic dependency that prevents using `<concepts>` header in `<compare>` one.
I tried to quickly resolve those issues including applying suggestions from @cjdb and dive deeper by myself but the problem seems more complicated that we thought initially.
I am in progress to prepare the patch with resolving this cyclic dependency between headers but for now I decided to put all that I have to the review to unblock people that depend on that functionality. At first glance the patch with resolving cyclic dependency is not so small (unless I find the way to make it smaller and cleaner) so I don't want to mix everything to one review.
Reviewed By: ldionne, cjdb, #libc, Quuxplusone
Differential Revision: https://reviews.llvm.org/D103478
This implements the initial version of the `std::formatter` class and its specializations. It also implements the following formatting functions:
- `format`
- `vformat`
- `format_to`
- `vformat_to`
- `format_to_n`
- `formatted_size`
All functions have a `char` and `wchar_t` version. Parsing the format-spec and
using the parsed format-spec hasn't been implemented. The code isn't optimized,
neither for speed, nor for size.
The goal is to have the rudimentary basics working, which can be used as a
basis to improve upon. The formatters used in this commit are simple stubs that
will be replaced by real formatters in later commits.
The formatters that are slated to be replaced in this patch series don't have
an availability macro to avoid merge conflicts.
Note the formatter for `bool` uses `0` and `1` instead of "false" and
"true". This will be fixed when the stub is replaced with a real
formatter.
Implements parts of:
- P0645 Text Formatting
Completes:
- LWG3539 format_to must not copy models of output_iterator<const charT&>
Reviewed By: ldionne, #libc, vitaut
Differential Revision: https://reviews.llvm.org/D96664
Those constructors are very easy to misuse -- one could easily think that
the size passed to the constructor is the size of the range to exhibit
from the subrange. Instead, it's a size hint and it's UB to get it wrong.
Hence, when it's cheap to compute the real size of the range, it's cheap
to make sure that the user didn't get it wrong.
Differential Revision: https://reviews.llvm.org/D108827
_LIBCPP_HAS_NO_LONG_LONG was only defined on FreeBSD. Instead, use the
using_if_exists attribute to skip over declarations that are not available
on the base system. Note that there's an annoying limitation that we can't
conditionally define a function based on whether the base system provides
a function, so for example we still need preprocessor logic to define the
abs() and div() overloads.
Differential Revision: https://reviews.llvm.org/D108630
The `insert_iterator::iter` member is defined as `Container::iterator` but
the standard requires `iter` to be defined in terms of `ranges::iterator_t` as
of C++20. So, if in C++20 or later, define the `iter` member as
`ranges::iterator_t`.
Original patch by Joe Loser!
Differential Revision: https://reviews.llvm.org/D108575
Louis Dionne