Commit Graph

3723 Commits

Author SHA1 Message Date
Arthur O'Dwyer 3042091168 [libc++] [ranges] Whitespace and namespace-style adjustments. NFC.
Largely split out of D116199 to keep that PR smaller.
2021-12-23 14:56:23 -05:00
Arthur O'Dwyer a2a9a5c7d3 [libc++] [ranges] Fix bugs in ranges::empty().
It was missing the cast to `bool` in `bool(__t.empty())`.
It was wrongly using `std::forward` in some places.

Differential Revision: https://reviews.llvm.org/D115312
2021-12-23 14:56:23 -05:00
Mark de Wever e8b24ee115 [libc++][format][NFC] Remove some unneeded headers.
Reviewed By: #libc, Quuxplusone, Mordante

Differential Revision: https://reviews.llvm.org/D116175
2021-12-23 17:38:21 +01:00
Mark de Wever dfb20d4d19 [libc++][format] Improve ABI stability.
During the review of D115991 @vitaut pointed out the enum shouldn't
depend on whether or not _LIBCPP_HAS_NO_INT128 is defined. The current
implementation lets the enum's ABI depend on this configuration option
without a good cause.

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D116120
2021-12-23 17:37:12 +01:00
Nikolas Klauser 23f1cd9e63 [libc++] Remove unused headers from <filesystem>
Remove unused headers from `<filesystem>`

Reviewed By: Quuxplusone, #libc, Mordante

Spies: Mordante, libcxx-commits

Differential Revision: https://reviews.llvm.org/D116146
2021-12-23 13:32:49 +01:00
Nikolas Klauser fcc0964ed4 Revert "[libc++] Remove unused headers from <filesystem>"
This reverts commit 352945dd36.
2021-12-23 11:55:38 +01:00
Nikolas Klauser 352945dd36 [libc++] Remove unused headers from <filesystem>
Remove unused headers from `<filesystem>`

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D116146
2021-12-23 02:07:47 +01:00
Arthur O'Dwyer caf940bac6 [libc++] Remove "clang-format off/on" comments. NFC.
These headers have stabilized; we don't expect anyone to be
blindly clang-formatting them anymore.
Leave the comments in `__format/*.h` for Mark to remove at his leisure.
2021-12-22 17:56:03 -05:00
Arthur O'Dwyer cb8a0b0797 [libc++] [ranges] Introduce _LIBCPP_AUTO_CAST(x) for auto(x).
Clang is gaining `auto(x)` support in D113393; sadly there
seems to be no feature-test macro for it. Zhihao is opening
a core issue for that macro.

Use `_LIBCPP_AUTO_CAST` where C++20 specifies we should use `auto(x)`;
stop using `__decay_copy(x)` in those places.
In fact, remove `__decay_copy` entirely. As of C++20, it's purely
a paper specification tool signifying "Return just `x`, but it was
perfect-forwarded, so we understand you're going to have to call
its move-constructor sometimes." I believe there's no reason we'd
ever need to do its operation explicitly in code.

This heisenbugs away a test failure on MinGW; see D112214.

Differential Revision: https://reviews.llvm.org/D115686
2021-12-22 12:29:42 -05:00
Arthur O'Dwyer 8ad364ad21 [libc++] [ranges] Remove the static_assert from ranges::begin and ranges::end.
As discussed with ldionne. The problem with this static_assert
is that it makes ranges::begin a pitfall for anyone ever to use
inside a constraint or decltype. Many Ranges things, such as ranges::size,
are specified as "Does X if X is well-formed, or else Y if Y is well-formed,
or else `ranges::end(t) - ranges::begin(t)` if that is well-formed, or else..."
And if there's a static_assert hidden inside `ranges::begin(t)`, then you get
a hard error as soon as you ask the question -- even if the answer would have
been "no, that's not well-formed"!

Constraining on `requires { t + 0; }` or `requires { t + N; }` is verboten
because of https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103700 . For ranges::begin,
we can just decay to a pointer even in the incomplete-type case. For ranges::end,
we can safely constrain on `sizeof(*t)`. Yes, this means that an array of incomplete
type has a `ranges::begin` but no `ranges::end`... just like an unbounded array of
complete type. This is a valid manifestation of IFNDR.

All of the new libcxx/test/std/ cases are mandatory behavior, as far as I'm aware.
Tests for the IFNDR cases in ranges::begin and ranges::end remain in `libcxx/test/libcxx/`.
The similar tests for ranges::empty and ranges::data were simply wrong, AFAIK.

Differential Revision: https://reviews.llvm.org/D115838
2021-12-22 10:33:17 -05:00
Nikolas Klauser 7056250f51 [libc++][NFC] Granularize <filesystem>
Granularize the `<filesystem>` header

Reviewed By: Quuxplusone, ldionne, #libc

Spies: libcxx-commits, mgorny

Differential Revision: https://reviews.llvm.org/D115578
2021-12-22 02:31:17 +01:00
Martin Storsjö f68e89044a [libcxx] Add LIBCXX_EXTRA_SITE_DEFINES for adding extra defines in __config_site
This is similar to the existing setting LIBCXX_ABI_DEFINES, with
the difference that this also allows setting other defines than
ones that start with "_LIBCPP_ABI_", and allows setting defines
to a specific value.

This allows avoiding using LIBCXX_TEST_COMPILER_FLAGS in two
CI configurations.

Differential Revision: https://reviews.llvm.org/D116109
2021-12-22 00:43:29 +02:00
Louis Dionne beff71520b [libc++] Partially revert 346ef5e587
This moves the macro definitions back to __config, but keeps the
improved documentation. 346ef5e587 had broken the MinGW build.
2021-12-21 23:58:17 +02:00
Louis Dionne 346ef5e587 [libc++][NFC] Improve documentation of the various random_device implementations
Also, move the setting of the macro closer to its point of use, which
also has the benefit of uncluttering `__config`.
2021-12-21 15:32:09 -05:00
Louis Dionne e03ce65190 [libc++][NFC] Reformatting in random_device.h and random.cpp 2021-12-21 13:32:56 -05:00
Arthur O'Dwyer 9233675466 [libc++] Rename __s1/__s2 to __dest/__source in __copy_constexpr. NFC.
This consistently completes the renaming started in D115986.
2021-12-21 08:36:44 -05:00
Nikolas Klauser edb4698008 [libc++] Allow __move_constexpr to work with unrelated pointers
Allow `__move_constexpr` to work with unrelated pointers and `_LIBCPP_ASSERT` that `__copy_constexpr`, `__move_constexpr` and `__assign_constexpr` are only run during constant evaluation

Reviewed By: ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D115986
2021-12-21 14:03:39 +01:00
Raul Tambre 4e730aeb73 [libcxx] Add deprecation notices to macros deprecated in P0883R2
When P0883R2 was initially implemented in D103769 #pragma clang deprecated didn't exist yet.
We also forgot to cleanup usages in libc++ itself.

This takes care of both.

Differential Revision: https://reviews.llvm.org/D115995
2021-12-20 20:30:00 +02:00
Louis Dionne 37e6bd8bc8 [libc++] Add a helper class to write code with the strong exception guarantee
__transaction is a helper class that allows rolling back code in case an
exception is thrown. The main goal is to reduce the clutter when code
needs to be guarded with `#if _LIBCPP_NO_EXCEPTIONS`.

Differential Revision: https://reviews.llvm.org/D115730
2021-12-20 11:17:29 -05:00
Konstantin Varlamov 754ea6fd4d [libc++][ranges] Implement `uninitialized_value_construct{,_n}` and `uninitialized_fill{,_n}`.
Also:
- refactor out `__voidify`;
- use the `destroy` algorithm internally;
- refactor out helper classes used in tests for `uninitialized_*`
  algorithms.

Differential Revision: https://reviews.llvm.org/D115626
2021-12-20 00:24:27 -08:00
Louis Dionne 2722ac65f6 [libc++] Add a bunch of missing inline and _LIBCPP_HIDE_FROM_ABI in __threading_support
The inline keyword is required on those functions because they are defined
in the headers, so we need them to be inline to avoid ODR violations.
While we're at it, slap _LIBCPP_HIDE_FROM_ABI on them because they are
implementation details and we don't want them to be part of our ABI under
any circumstances.

Differential Revision: https://reviews.llvm.org/D115906
2021-12-17 12:02:32 -05:00
Nikolas Klauser 5675b6112a [libc++] Disable _LIBCPP_DEBUG_ASSERT during constant evaluation
Disable `_LIBCPP_DEBUG_ASSERT` and debug iterators in <string> during constant evaluation

Reviewed By: ldionne, #libc

Spies: goncharov, libcxx-commits

Differential Revision: https://reviews.llvm.org/D115788
2021-12-17 11:15:53 +01:00
Nikolas Klauser 148ef80f89 [libc++] Add GCC workaround in std::char_traits<char>::length()
GCC currently does not allow `__builtin_strlen()` during constant evaluation. This PR adds a workaround in `std::char_traits<char>::length()`

Reviewed By: Quuxplusone, ldionne, #libc, Mordante

Spies: Mordante, libcxx-commits

Differential Revision: https://reviews.llvm.org/D115795
2021-12-16 14:27:51 +01:00
Arthur O'Dwyer 5c0ea7488b [libc++] Enable the optimized _IsSame on GCC as well as Clang.
However, there's a problem on both GCC and Clang: they can't mangle
`__is_same(T,U)` if it appears anywhere that affects mangling. That's
a hard error. And it turns out that GCC puts dependent return types
into the mangling more aggressively than Clang, so for GCC's benefit
we need to avoid using raw `_IsSame` in the return type of
`swap(tuple&, tuple&)`. Therefore, make `__all` into a named type
instead of an alias.

If we ever need to support a compiler without the __is_same builtin,
we can make this an alias template for `is_same<T,U>::type`.

Differential Revision: https://reviews.llvm.org/D115100
2021-12-15 20:19:56 -05:00
Arthur O'Dwyer 5e86f8abd1 [libc++] Reorder a comment pertaining to `struct __two`. NFC. 2021-12-15 19:21:51 -05:00
Nikolas Klauser 17cfc57d14 [libc++] Implement P0798R8 (Monadic operations for std::optional)
Implement P0798R8

Reviewed By: #libc, ldionne, Quuxplusone

Spies: tcanens, Quuxplusone, ldionne, Wmbat, arichardson, Mordante, libcxx-commits

Differential Revision: https://reviews.llvm.org/D113408
2021-12-15 22:49:03 +01:00
Nikolas Klauser af88bc153d [libc++][NFC] Use _LIBCPP_DEBUG_ASSERT in <string>
Use `_LIBCPP_DEBUG_ASSERT` instead of `_LIBCPP_ASSERT` and guarding it with `LIBCPP_DEBUG_LEVEL == 2`

Reviewed By: ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D115765
2021-12-15 08:39:42 +01:00
Konstantin Varlamov 3f630cff65 [libc++][ranges] Implement ranges::uninitialized_default_construct{,_n}.
Defined in [`specialized.algorithms`](wg21.link/specialized.algorithms).

Also:
- refactor the existing non-range implementation so that most of it
  can be shared between the range-based and non-range-based algorithms;
- remove an existing test for the non-range version of
  `uninitialized_default_construct{,_n}` that likely triggered undefined
  behavior (it read the values of built-ins after default-initializing
  them, essentially reading uninitialized memory).

Reviewed By: #libc, Quuxplusone, ldionne

Differential Revision: https://reviews.llvm.org/D115315
2021-12-14 14:11:46 -08:00
Louis Dionne bf39e7dc6c [libc++] Fix wrongly non-inline basic_string::shrink_to_fit
As explained in https://stackoverflow.com/a/70339311/627587, the fact
that shrink_to_fit wasn't defined as inline lead to issues when explicitly
instantiating basic_string. While explicit instantiations are always
somewhat brittle, this one was clearly a bug on our end.

Differential Revision: https://reviews.llvm.org/D115656
2021-12-14 11:12:04 -05:00
Nikolas Klauser 10a356c47a [libc++] Make __swap_allocator constexpr
Make `__swap_allocator` constexpr

Reviewed By: Quuxplusone, ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D115719
2021-12-14 15:41:56 +01:00
Nikolas Klauser a376a3f354 [libc++] Make __compressed_pair fully constexpr
Make `__compressed_pair` fully constexpr

Reviewed By: ldionne, #libc, nilayvaish

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D115687
2021-12-14 15:39:46 +01:00
Nikolas Klauser f2eab339b9 [libc++][NFC] Remove goto from std::string
Remove `goto` from `std::string`

Reviewed By: Quuxplusone, ldionne, #libc, nilayvaish

Spies: nilayvaish, libcxx-commits

Differential Revision: https://reviews.llvm.org/D115598
2021-12-14 12:35:02 +01:00
Arthur O'Dwyer 4dd901f4d3 [libc++] Fix the noexceptness of __decay_copy.
When `a` was an array type, `__decay_copy(a)` was incorrectly marking itself
noexcept(false), because it is false that `int[10]` is nothrow convertible to `int[10]`
(in fact it is not convertible at all).

We have no tests explicitly for `__decay_copy`, but the new ranges::begin
and ranges::end tests fail before this patch.

Differential Revision: https://reviews.llvm.org/D115658
2021-12-13 17:55:38 -05:00
John Ericson ddcc02dbcc Quote some more destination paths with variables
Just defensive CMake-ing. I pulled this from D115544 and D99484 which
are blocked on some lldb CI failures I don't yet understand. Hoping to land
something smaller in the meantime.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D115566
2021-12-13 17:29:08 +00:00
Mark de Wever abb5dd6e99 Microsoft's floating-point to_chars powered by Ryu and Ryu Printf
Microsoft would like to contribute its implementation of floating-point to_chars to libc++. This uses the impossibly fast Ryu and Ryu Printf algorithms invented by Ulf Adams at Google. Upstream repos: https://github.com/microsoft/STL and https://github.com/ulfjack/ryu .

Licensing notes: MSVC's STL is available under the Apache License v2.0 with LLVM Exception, intentionally chosen to match libc++. We've used Ryu under the Boost Software License.

This patch contains minor changes from Jorg Brown at Google, to adapt the code to libc++. He verified that it works in Google's Linux-based environment, but then I applied more changes on top of his, so any compiler errors are my fault. (I haven't tried to build and test libc++ yet.) Please tell me if we need to do anything else in order to follow https://llvm.org/docs/DeveloperPolicy.html#attribution-of-changes .

Notes:

* libc++'s integer charconv is unchanged (except for a small refactoring). MSVC's integer charconv hasn't been tuned for performance yet, so you're not missing anything.
* Floating-point from_chars isn't part of this patch because Jorg found that MSVC's implementation (derived from our CRT's strtod) was slower than Abseil's. If you're unable to use Abseil or another implementation due to licensing or technical considerations, Microsoft would be delighted if you used MSVC's from_chars (and you can just take it, or ask us to provide a patch like this). Ulf is also working on a novel algorithm for from_chars.
* This assumes that float is IEEE 32-bit, double is IEEE 64-bit, and long double is also IEEE 64-bit.
* I have added MSVC's charconv tests (the whole thing: integer/floating from_chars/to_chars), but haven't adapted them to libcxx's harness at all. (These tests will be available in the microsoft/STL repo soon.)
* Jorg added int128 codepaths. These were originally present in upstream Ryu, and I removed them from microsoft/STL purely for performance reasons (MSVC doesn't support int128; Clang on Windows does, but I found that x64 intrinsics were slightly faster).
* The implementation is split into 3 headers. In MSVC's STL, charconv contains only Microsoft-written code. xcharconv_ryu.h contains code derived from Ryu (with significant modifications and additions). xcharconv_ryu_tables.h contains Ryu's large lookup tables (they were sufficiently large to make editing inconvenient, hence the separate file). The xmeow.h convention is MSVC's for internal headers; you may wish to rename them.
* You should consider separately compiling the lookup tables (see https://github.com/microsoft/STL/issues/172 ) for compiler throughput and reduced object file size.
* See https://github.com/StephanTLavavej/llvm-project/commits/charconv for fine-grained history. (If necessary, I can perform some rebase surgery to show you what Jorg changed relative to the microsoft/STL repo; currently that's all fused into the first commit.)

Differential Revision: https://reviews.llvm.org/D70631
2021-12-12 16:34:50 +01:00
Nikolas Klauser feb80aa96b [libc++] `= delete` member functions with // = delete;
Use `= delete` for member functions that are marked with `// = delete;`

Reviewed By: ldionne, Quuxplusone, #libc

Spies: jloser, libcxx-commits

Differential Revision: https://reviews.llvm.org/D115291
2021-12-08 19:29:44 +01:00
Louis Dionne 81eda008e9 [libc++] Extract __clamp_to_integral to its own header
In addition to being more consistent with our approach for helpers, this
solves an actual issue where <cmath> was using numeric_limits but never
including the <limits> header directly. In a normal setup, this is not
an issue because the <math.h> header included by <cmath> does include
<limits>. However, I did stumble upon some code where that didn't work,
most likely because they were placing their own <math.h> header in front
of ours. I didn't bother investigating further.

Differential Revision: https://reviews.llvm.org/D115282
2021-12-08 08:33:37 -05:00
Nikolas Klauser 4955095fe6 [libc++] Remove _LIBCPP_DEFAULT
clang has `= default` as an extension in c++03, so just use it.

Reviewed By: ldionne, Quuxplusone, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D115275
2021-12-07 22:18:38 +01:00
Arthur O'Dwyer bd0c0e5b8c [libc++] [ranges] SFINAE-friendly "write it three times" in views::counted.
Before this patch, the new test's `CountedInvocable<int*, int*>`
would hard-error instead of SFINAEing and cleanly returning false.

Notice that views::counted specifically does NOT work with pipes;
`counted(42)` is ill-formed. This is because `counted`'s first argument
is supposed to be an iterator, not a range.

Also, mark `views::counted(it, n)` as [[nodiscard]], and test that.
(We have a general policy now that range adaptors are consistently
marked [[nodiscard]], so that people don't accidentally think that
they have side effects. This matters mostly for `reverse` and
`transform`, arguably `drop`, and just generally let's be consistent.)

Differential Revision: https://reviews.llvm.org/D115177
2021-12-07 13:59:41 -05:00
Arthur O'Dwyer 7a06a14f62 [libc++] Remove unneeded `std::` qualifications from <compare>. NFCI.
Reviewed as part of D115177.
2021-12-07 13:59:41 -05:00
Arthur O'Dwyer 04d74aaff9 [libc++] std::move should be _VSTD::move in one place. NFCI.
Reviewed as part of D115177.
2021-12-07 13:59:41 -05:00
Petr Hosek ae53d02f55 Revert "Microsoft's floating-point to_chars powered by Ryu and Ryu Printf"
This reverts commit a8025e06fc since
it triggers PR52584 with debug info enabled.
2021-12-07 00:10:14 -08:00
Louis Dionne 2db67e9771 [libc++] Fix the return value of max_size()
I assume nobody ever uses std::string_view::max_size() outside of
testing. However, we should still return a value that is based on
something with a reasonable rationale. Previously, we would forget
to take into account the size of the character type stored in the
string, and this patch takes that into account.

Thanks to @mclow.lists for pointing out this issue.

Differential Revision: https://reviews.llvm.org/D114395
2021-12-06 13:53:25 -05:00
Arthur O'Dwyer dcdb07abce [libc++] Work around a Clang bug in transform_view, and regression-test.
Clang trunk rejects the new test case, but this is a Clang bug
(PR47414, 47509, 50864, 44833).

```
In module 'std' imported from /Users/aodwyer/llvm-project/libcxx/test/std/ranges/range.adaptors/range.transform/general.pass.cpp:17:
/Users/aodwyer/llvm-project/build2/include/c++/v1/__ranges/transform_view.h:85:44: error: constraints not satisfied for alias template 'range_reference_t' [with _Rp = const NonConstView]
             regular_invocable<const _Fn&, range_reference_t<const _View>>
                                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/aodwyer/llvm-project/build2/include/c++/v1/__ranges/transform_view.h:416:25: note: in instantiation of template class 'std::ranges::transform_view<NonConstView, (lambda at /Users/aodwyer/llvm-project/libcxx/test/std/ranges/range.adaptors/range.transform/general.pass.cpp:73:71)>' requested here
      -> decltype(      transform_view(_VSTD::forward<_Range>(__range), _VSTD::forward<_Fn>(__f)))
                        ^
```

We can work around this by adding a layer of indirection: put the
problematic constraint into a named concept and Clang becomes more
amenable to SFINAE'ing instead of hard-erroring.

Drive-by simplify `range.transform/general.pass.cpp` to make it clearer
what it's actually testing in this area.

Differential Revision: https://reviews.llvm.org/D115116
2021-12-06 11:20:08 -05:00
Arthur O'Dwyer 2f16b87b4b [libc++] Remove space-alignment of trailing braces in module.modulemap. NFC.
As discussed on the Discord, 2021-12-01 through 2021-12-05.
Our new consistent style for this is "don't align the right-braces"
(but still align the left-braces, as shown).
2021-12-05 18:56:58 -05:00
Arthur O'Dwyer 4c2fef74dd [libc++] Adjust space-alignment in module.modulemap. NFC. 2021-12-05 13:22:19 -05:00
Arthur O'Dwyer 413c3c4f81 [libc++] Add missing `#pragma GCC system_header` in a few headers. NFCI. 2021-12-05 13:22:19 -05:00
Arthur O'Dwyer 0b609efd4f [libc++] Fix an include-guard comment. NFC. 2021-12-05 13:22:19 -05:00
Nilay Vaish 3536e18a6c Remove duplicate comment
The same comment appears in the very next line.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D115018
2021-12-05 14:03:44 +01:00
Mark de Wever a8025e06fc Microsoft's floating-point to_chars powered by Ryu and Ryu Printf
Microsoft would like to contribute its implementation of floating-point to_chars to libc++. This uses the impossibly fast Ryu and Ryu Printf algorithms invented by Ulf Adams at Google. Upstream repos: https://github.com/microsoft/STL and https://github.com/ulfjack/ryu .

Licensing notes: MSVC's STL is available under the Apache License v2.0 with LLVM Exception, intentionally chosen to match libc++. We've used Ryu under the Boost Software License.

This patch contains minor changes from Jorg Brown at Google, to adapt the code to libc++. He verified that it works in Google's Linux-based environment, but then I applied more changes on top of his, so any compiler errors are my fault. (I haven't tried to build and test libc++ yet.) Please tell me if we need to do anything else in order to follow https://llvm.org/docs/DeveloperPolicy.html#attribution-of-changes .

Notes:

* libc++'s integer charconv is unchanged (except for a small refactoring). MSVC's integer charconv hasn't been tuned for performance yet, so you're not missing anything.
* Floating-point from_chars isn't part of this patch because Jorg found that MSVC's implementation (derived from our CRT's strtod) was slower than Abseil's. If you're unable to use Abseil or another implementation due to licensing or technical considerations, Microsoft would be delighted if you used MSVC's from_chars (and you can just take it, or ask us to provide a patch like this). Ulf is also working on a novel algorithm for from_chars.
* This assumes that float is IEEE 32-bit, double is IEEE 64-bit, and long double is also IEEE 64-bit.
* I have added MSVC's charconv tests (the whole thing: integer/floating from_chars/to_chars), but haven't adapted them to libcxx's harness at all. (These tests will be available in the microsoft/STL repo soon.)
* Jorg added int128 codepaths. These were originally present in upstream Ryu, and I removed them from microsoft/STL purely for performance reasons (MSVC doesn't support int128; Clang on Windows does, but I found that x64 intrinsics were slightly faster).
* The implementation is split into 3 headers. In MSVC's STL, charconv contains only Microsoft-written code. xcharconv_ryu.h contains code derived from Ryu (with significant modifications and additions). xcharconv_ryu_tables.h contains Ryu's large lookup tables (they were sufficiently large to make editing inconvenient, hence the separate file). The xmeow.h convention is MSVC's for internal headers; you may wish to rename them.
* You should consider separately compiling the lookup tables (see https://github.com/microsoft/STL/issues/172 ) for compiler throughput and reduced object file size.
* See https://github.com/StephanTLavavej/llvm-project/commits/charconv for fine-grained history. (If necessary, I can perform some rebase surgery to show you what Jorg changed relative to the microsoft/STL repo; currently that's all fused into the first commit.)

Differential Revision: https://reviews.llvm.org/D70631
2021-12-05 13:25:33 +01:00
Konstantin Varlamov 2d9efcfeec [libc++][ranges] Implement [special.mem.concepts].
Implement the exposition-only concepts specified in
`[special.mem.concepts]`. These are all thin wrappers over other
concepts.

Reviewed By: #libc, Quuxplusone, ldionne

Differential Revision: https://reviews.llvm.org/D114761
2021-12-02 17:58:04 -08:00
Nikolas Klauser d2b0df35af [libc++][NFC] Update namespace comments in include/
update the namspace comments in include/

Reviewed By: ldionne, #libc

Spies: smeenai, libcxx-commits

Differential Revision: https://reviews.llvm.org/D114947
2021-12-02 21:06:59 +01:00
Joe Loser c16b13ebf9
[libc++] Implement P1989R2: range constructor for string_view
Implement P1989R2 which adds a range constructor for `string_view`.

Adjust `operator/=` in `path` to avoid atomic constraints caching issue
getting provoked from this PR.

Add defaulted template argument to `string_view`'s "sufficient
overloads" to avoid mangling issues in `clang-cl` builds. It is a
MSVC mangling bug that this works around.

Differential Revision: https://reviews.llvm.org/D113161
2021-12-01 23:16:36 -05:00
Nikolas Klauser 6146e4cf89 [libc++] Make __wrap_iter constexpr
`__wrap_iter` is currently only constexpr if it's not a debug built, but it isn't used in a constexpr context currently. Making it always constexpr and disabling the debugging utilities at constant evaluation is more usful since it has to be always constexpr to be used in a constexpr context.

Reviewed By: ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D114733
2021-12-01 23:29:22 +01:00
Christopher Di Bella a0efb17500 [libcxx][modularisation] modularises <numeric> header
Differential Revision: https://reviews.llvm.org/D114836
2021-12-01 20:40:21 +00:00
Konstantin Varlamov 7da4ee6f23 [libcxx][NFC] Make sequence containers slightly more SFINAE-friendly during CTAD.
Disable the constructors taking `(size_type, const value_type&,
allocator_type)` if `allocator_type` is not a valid allocator.
Otherwise, these constructors are considered when resolving e.g.
`(int*, int*, NotAnAllocator())`, leading to a hard error during
instantiation. A hard error makes the Standard's requirement to not
consider deduction guides of the form `(Iterator, Iterator,
BadAllocator)` during overload resolution essentially non-functional.

The previous approach was to SFINAE away `allocator_traits`. This patch
SFINAEs away the specific constructors instead, for consistency with
`basic_string` -- see [LWG3076](wg21.link/lwg3076) which describes
a very similar problem for strings (note, however, that unlike LWG3076,
no valid constructor call is affected by the bad instantiation).

Differential Revision: https://reviews.llvm.org/D114311
2021-12-01 11:56:51 -08:00
Mark de Wever 0e9979affe [libc++][format][1/6] Reduce binary size.
This removes the `format_args_t` from `<format>` and adjusts the type of
the `format_args` for the `vformat_to` overloads.

The `format_context` uses a `back_insert_iterator<string>` therefore the
new `output_iterator` function uses a `string` as its temporary storage
buffer. This isn't ideal. The next patches in this series will improve
this. These improvements make it easy to also improve `format_to_n` and
`formatted_size`.

This addresses P2216 `6. Binary size`.
P2216 `5. Compile-time checks` are not part of this change.

Implements parts of:
- P2216 std::format improvements

Depends on D103670

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D110494
2021-12-01 17:50:17 +01:00
Fabian Wolff b254c2e2c4 [libc++] Fix `uniform_int_distribution` for 128-bit result type
Fixes https://llvm.org/PR51520. The problem is that `uniform_int_distribution`
currently uses an unsigned integer with at most 64 bits internally, which
is then casted to the desired result type. If the result type is `int64_t`,
this will produce a negative number if the most significant bit is set,
but if the result type is `__int128_t`, the value remains non-negative
and will be out of bounds for the example in PR#51520. (The reason why
it also seems to work if the upper or lower bound is changed is
because the branch at [1] will then no longer be taken, and proper
rejection sampling takes place.)

The bigger issue here is probably that `uniform_int_distribution` can be
instantiated with `__int128_t` but will silently produce incorrect results
(only the lowest 64 bits can ever be set). libstdc++ also supports `__int128_t`
as a result type, so I have simply extended the maximum width of the
internal intermediate result type.

[1]: https://github.com/llvm/llvm-project/blob/6d28dffb6/libcxx/include/__random/uniform_int_distribution.h#L266-L267

Differential Revision: https://reviews.llvm.org/D114129
2021-12-01 11:03:29 -05:00
Louis Dionne a34f246899 [libc++][ABI BREAK] Do not use the C++03 emulation for std::nullptr_t by default
We only support Clangs that implement nullptr as an extension in C++03 mode,
and we don't support GCC in C++03 mode. Hence, this patch disables the
use of the std::nullptr_t emulation in C++03 mode by default. Doing that
is technically an ABI break since it changes the mangling for std::nullptr_t.
However:

(1) The only affected users are those compiling in C++03 mode that have
    std::nullptr_t as part of their ABI, which should be reasonably rare.

(2) Those users already have a lingering problem in that their code will
    be incompatible in C++03 and C++11 modes because of that very ABI break.
    Hence, the only users that could really be inconvenienced about this
    change is those that planned on compiling in C++03 mode forever - for
    other users, we're just breaking them now instead of letting them break
    themselves later on when they try to upgrade to C++11.

(3) The ABI break will cause a linker error since the mangling changed,
    and will not result in an obscure runtime error.

Furthermore, if anyone is broken by this, they can define the
_LIBCPP_ABI_USE_CXX03_NULLPTR_EMULATION macro to return to the
previous behavior. We will then remove that macro after shipping
this for one release if we haven't seen widespread issues.

Concretely, the motivation for making this change is to make our own ABI
consistent in C++03 and C++11 modes and to remove complexity around the
definition of nullptr.

Furthermore, we could investigate making nullptr a keyword in C++03 mode
as a Clang extension -- I don't think that would break anyone, since
libc++ already defines nullptr as a macro to something else. Only users
that do not use libc++ and compile in C++03 mode could potentially be
broken by that.

Differential Revision: https://reviews.llvm.org/D109459
2021-11-30 06:01:45 -05:00
Mark de Wever 730dccb986 [libc++] Remove support for Clang 9 and older.
I encountered this while reviewing an unrelated patch. Will land after
the CI passes.

Reviewed By: #libc, Mordante

Differential Revision: https://reviews.llvm.org/D114673
2021-11-28 15:17:05 +01:00
Louis Dionne 7dc9a03cfd [libc++] Add missing __format__ attributes
-Wformat-nonliteral was turned on in https://reviews.llvm.org/D112927,
however we forgot to apply some __format__ attributes in Linux specific
code paths, which led to warnings when building on Linux. This patch
addresses that oversight.

Differential Revision: https://reviews.llvm.org/D113876
2021-11-26 11:03:14 -05:00
Mikhail Maltsev d8f3cdfed0 [libcxx] Implement three-way comparison for std::reverse_iterator
This patch implements operator<=> for std::reverse_iterator and
also adds a test that checks that three-way comparison of different
instantiations of std::reverse_iterator works as expected (related to
D113417).

Reviewed By: ldionne, Quuxplusone, #libc

Differential Revision: https://reviews.llvm.org/D113695
2021-11-26 10:12:19 +00:00
Joe Loser 3e7452a812
[libc++] Avoid overload resolution in path comparison operators
Rework `std::filesystem::path::operator==` and friends to avoid overload
resolution and atomic constraint caching issues shown from
https://reviews.llvm.org/D113161.

Always call `__compare(string_view)` from the comparison operators which avoids
overload resolution.

Differential Revision: https://reviews.llvm.org/D114570
2021-11-25 11:40:55 -05:00
Joe Loser 68e7e76a9b
[libc++] Fix constraints for string_view's iterator/sentinel constructor
The `string_view` constructor taking an iterator/sentinel uses concepts
instead of type traits like the Standard states. Using `same_as` instead
of `is_same_v` should be harmless. Prefer `std::is_same_v` instead which is
cheaper to compile. Replace `convertible_to` with `is_convertible_v` as
well.

This observation came up while working on
https://reviews.llvm.org/D113161

Differential Revision: https://reviews.llvm.org/D114561
2021-11-25 11:39:59 -05:00
Johan Berg 68e2231f87 [libc++] Value-initialize unique_ptr's deleter_type
According to the C++ standard, the stored pointer and the stored deleter
should be value-initialized.

Differential Revision: https://reviews.llvm.org/D113612
2021-11-24 17:31:34 -05:00
Louis Dionne 7a0584fe3f [libc++] Fix backdeployment annotations for std::filesystem
In 1fa27f2a10, we made <filesystem>'s iterator types model concepts
from <ranges>, but we forgot to add the appropriate availability
annotations. This broke back-deployment to platforms that don't have
<filesystem> for which we have availability annotations.

For some reason, this wasn't caught by our back-deployment CI.
I believe this is due to the fact that we use a slightly older
compiler in the CI, and perhaps that compiler does not honour
our `#pragma clang attribute push` properly.

Differential Revision: https://reviews.llvm.org/D114456
2021-11-24 16:58:15 -05:00
Arthur O'Dwyer d8380ad977 [libc++] [P1614] Implement [cmp.alg]'s std::{strong,weak,partial}_order.
This does not include `std::compare_*_fallback`; those are coming later.

There's still an open question of how to implement std::strong_order
for `long double`, which has 80 value bits and 48 padding bits on x86-64,
and which is presumably *not* IEEE 754-compliant on PPC64 and so on.
So that part is left unimplemented.

Differential Revision: https://reviews.llvm.org/D110738
2021-11-22 13:24:28 -05:00
Arthur O'Dwyer 344cef6695 [libc++] Granularize the <random> header. NFCI.
Actually there's one functional change here, which is that users can
no longer depend on <random> to include all of C++20 <concepts>. That
inclusion is so new that we believe nobody should be depending on it
yet, even in the presence of Hyrum's Law. We keep the includes of <vector>,
<algorithm>, etc., so as not to break pre-C++20 Hyrum's Law users.

Differential Revision: https://reviews.llvm.org/D114281
2021-11-22 13:24:27 -05:00
Joe Loser a60b63940a
[libc++][NFC] Sort includes in __ranges/concepts.h
Differential Revision: https://reviews.llvm.org/D114328
2021-11-21 19:34:02 -05:00
Nikolas Klauser 1dc62f2653 [libc++] Implement P1272R4 (std::byteswap)
Implement P1274R4

Reviewed By: Quuxplusone, Mordante, #libc

Spies: jloser, lebedev.ri, mgorny, libcxx-commits, arichardson

Differential Revision: https://reviews.llvm.org/D114074
2021-11-22 01:28:18 +01:00
Joe Loser dca681fee9
[libc++][NFC] Fix typo in ranges::iterator_t synopsis
The `iterator_t` alias template is on `T` not a `R` like the other
neighboring alias templates. Fix the typo.
2021-11-20 19:15:00 -05:00
Arthur O'Dwyer b07b5bd727 [libc++] Test that our algorithms never copy a user-provided comparator.
This is not mandated by the standard, so it goes in libcxx/test/libcxx/.
It's certainly arguable that the algorithms changed here
(`is_heap`, `is_sorted`, `min`, `max`) are harmless and we should
just let them copy their comparators once. But at the same time,
it's nice to have all our algorithms be 100% consistent and never
copy a comparator, not even once.

Differential Revision: https://reviews.llvm.org/D114136
2021-11-19 15:03:24 -05:00
Louis Dionne e0f58444e1 [libc++] Fix feature test macro for __cpp_lib_to_chars
We would have been defining it in <utility> instead of <charconv>. For
the time being, this doesn't change anything since we don't implement
the feature test macro anyways.

Also, as a fly-by, this removes obsolete feature test macro tests. There
was a brief time back in the days when we wrote feature test macro tests
manually. In particular, we had test files for __cpp_lib_to_chars and
__cpp_lib_memory_resource. Since we now have a principled way of generating
these tests with scripts, this commit removes the obsolete (and empty)
tests for these two feature test macros.

Differential Revision: https://reviews.llvm.org/D114243
2021-11-19 14:26:34 -05:00
Mark de Wever ed86610c7b [libc++][nfc] Move functions to a generic place.
This allows the floating-point formatter to use the same functions as
the integral formatter. This was tested in D114001.
2021-11-19 16:38:35 +01:00
Mark de Wever 3624c4d845 [libc++] Adds (to|from)_chars_result operator==.
Implements part of P1614 The Mothership has Landed.

Reviewed By: #libc, Quuxplusone, Mordante

Differential Revision: https://reviews.llvm.org/D112366
2021-11-19 16:29:33 +01:00
Fabian Wolff dc1c27149f [libc++] Cast to the right `difference_type` in various algorithms
Differential Revision: https://reviews.llvm.org/D113868
2021-11-18 17:07:36 -05:00
Arthur O'Dwyer 1ce516d43f [libc++] Minor fixups in the new introsort code.
Differential Revision: https://reviews.llvm.org/D114133
2021-11-18 11:01:41 -05:00
Louis Dionne 92832e4889 [libc++] Enable <atomic> when threads are disabled
std::atomic is, for the most part, just a thin veneer on top of compiler
builtins. Hence, it should be available even when threads are not available
on the system, and in fact there has been requests for such support.

This patch:
- Moves __libcpp_thread_poll_with_backoff to its own header so it can
  be used in <atomic> when threads are disabled.
- Adds a dummy backoff policy for atomic polling that doesn't know about
  threads.
- Adjusts the <atomic> feature-test macros so they are provided even when
  threads are disabled.
- Runs the <atomic> tests when threads are disabled.

rdar://77873569

Differential Revision: https://reviews.llvm.org/D114109
2021-11-17 23:02:58 -05:00
Louis Dionne eb8650a757 [runtimes][NFC] Remove filenames at the top of the license notice
We've stopped doing it in libc++ for a while now because these names
would end up rotting as we move things around and copy/paste stuff.
This cleans up all the existing files so as to stop the spreading
as people copy-paste headers around.
2021-11-17 16:30:52 -05:00
Louis Dionne 3e957e5d66 [libc++] Refactor tests for trivially copyable atomics
- Replace irrelevant synopsis by a comment
- Use a .verify.cpp test instead of .compile.fail.cpp
- Remove unnecessary includes in one of the tests (was a copy-paste error)

Differential Revision: https://reviews.llvm.org/D114094
2021-11-17 13:32:12 -05:00
Louis Dionne c0f87e8382 [libc++] Remove _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
All supported compilers support spaceship in C++20 nowadays.

Differential Revision: https://reviews.llvm.org/D113938
2021-11-17 10:59:57 -05:00
Danila Kutenin a45d2287ad [libc++] Unspecified behavior randomization in libc++
This effort is dedicated to deflake the tests of the users which depend
on the unspecified behavior of algorithms and containers. This also
might help updating the sorting algorithm in libcxx which has the
quadratic worst case in the future or at least create a new one under
flag.

For detailed design, please see the design doc I provide in the patch.

Differential Revision: https://reviews.llvm.org/D96946
2021-11-16 15:55:33 -05:00
Konstantin Varlamov 434dc0a5bc [libc++] Always define a key function for std::bad_function_call in the dylib
However, whether applications rely on the std::bad_function_call vtable
being in the dylib is still controlled by the ABI macro, since changing
that would be an ABI break.

Also separate preprocessor definitions for whether to use a key function
and whether to use a `bad_function_call`-specific `what` message
(`what` message is mandated by [LWG2233](http://wg21.link/LWG2233)).

Differential Revision: https://reviews.llvm.org/D92397
2021-11-16 11:23:27 -08:00
Nilay Vaish 7f287390d7 [libc++] Add introsort to avoid O(n^2) behavior
This commit adds a benchmark that tests std::sort on an adversarial inputs,
and uses introsort in std::sort to avoid O(n^2) behavior on adversarial
inputs.

Inputs where partitions are unbalanced even after 2 log(n) pivots have
been selected, the algorithm switches to heap sort to avoid the
possibility of spending O(n^2) time on sorting the input.
Benchmark results show that the intro sort implementation does
significantly better.

Benchmarking results before this change. Time represents the sorting
time required per element:

----------------------------------------------------------------------------------------------------------
Benchmark                                                                Time             CPU   Iterations
----------------------------------------------------------------------------------------------------------
BM_Sort_uint32_QuickSortAdversary_1                                   3.75 ns         3.74 ns    187432960
BM_Sort_uint32_QuickSortAdversary_4                                   3.05 ns         3.05 ns    231211008
BM_Sort_uint32_QuickSortAdversary_16                                  2.45 ns         2.45 ns    288096256
BM_Sort_uint32_QuickSortAdversary_64                                  32.8 ns         32.8 ns     21495808
BM_Sort_uint32_QuickSortAdversary_256                                  132 ns          132 ns      5505024
BM_Sort_uint32_QuickSortAdversary_1024                                 498 ns          497 ns      1572864
BM_Sort_uint32_QuickSortAdversary_16384                               3846 ns         3845 ns       262144
BM_Sort_uint32_QuickSortAdversary_262144                             61431 ns        61400 ns       262144
BM_Sort_uint64_QuickSortAdversary_1                                   3.93 ns         3.92 ns    181141504
BM_Sort_uint64_QuickSortAdversary_4                                   3.10 ns         3.09 ns    222560256
BM_Sort_uint64_QuickSortAdversary_16                                  2.50 ns         2.50 ns    283639808
BM_Sort_uint64_QuickSortAdversary_64                                  33.2 ns         33.2 ns     21757952
BM_Sort_uint64_QuickSortAdversary_256                                  132 ns          132 ns      5505024
BM_Sort_uint64_QuickSortAdversary_1024                                 478 ns          477 ns      1572864
BM_Sort_uint64_QuickSortAdversary_16384                               3932 ns         3930 ns       262144
BM_Sort_uint64_QuickSortAdversary_262144                             61646 ns        61615 ns       262144

Benchmarking results after this change:

----------------------------------------------------------------------------------------------------------
Benchmark                                                                Time             CPU   Iterations
----------------------------------------------------------------------------------------------------------
BM_Sort_uint32_QuickSortAdversary_1                                   6.31 ns         6.30 ns    107741184
BM_Sort_uint32_QuickSortAdversary_4                                   4.51 ns         4.50 ns    158859264
BM_Sort_uint32_QuickSortAdversary_16                                  3.00 ns         3.00 ns    223608832
BM_Sort_uint32_QuickSortAdversary_64                                  44.8 ns         44.8 ns     15990784
BM_Sort_uint32_QuickSortAdversary_256                                 69.0 ns         68.9 ns      9961472
BM_Sort_uint32_QuickSortAdversary_1024                                 118 ns          118 ns      6029312
BM_Sort_uint32_QuickSortAdversary_16384                                175 ns          175 ns      4194304
BM_Sort_uint32_QuickSortAdversary_262144                               210 ns          210 ns      3407872
BM_Sort_uint64_QuickSortAdversary_1                                   6.75 ns         6.73 ns    103809024
BM_Sort_uint64_QuickSortAdversary_4                                   4.53 ns         4.53 ns    160432128
BM_Sort_uint64_QuickSortAdversary_16                                  2.98 ns         2.97 ns    234356736
BM_Sort_uint64_QuickSortAdversary_64                                  44.3 ns         44.3 ns     15990784
BM_Sort_uint64_QuickSortAdversary_256                                 69.2 ns         69.2 ns     10223616
BM_Sort_uint64_QuickSortAdversary_1024                                 119 ns          119 ns      6029312
BM_Sort_uint64_QuickSortAdversary_16384                                173 ns          173 ns      4194304
BM_Sort_uint64_QuickSortAdversary_262144                               212 ns          212 ns      3407872

Differential Revision: https://reviews.llvm.org/D113413
2021-11-16 11:38:46 -05:00
Louis Dionne 4eda928660 [libc++] Add missed comment in https://reviews.llvm.org/D113910 2021-11-16 11:36:06 -05:00
Mark de Wever bfc253c000 [libc++][nfc] Improve standard conformance.
The return type of the deleted functions doesn't match the synopsis in
the standard.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D114000
2021-11-16 17:30:35 +01:00
Nilay Vaish d17d89f4eb [libc++] Remove not needed call to __is_long()
The string is known to be long since __grow_by unconditionally calls
__set_long_cap().

Differential Revision: https://reviews.llvm.org/D113910
2021-11-16 11:26:13 -05:00
Mark de Wever 0e50216f22 [libc++][format][nfc] Remove dead code.
This was an early part of the prototype. This has never been shipped
enabled and the final version of this code looks completely different.
2021-11-16 16:02:26 +01:00
Mark de Wever f0bb6c760c [libc++][doc] Add a todo.
As suggested in D113831.
2021-11-16 15:56:29 +01:00
Mark de Wever 5baa4ee30b [libc++][NFC] Move format_to_n_result.
Places `format_to_n_result` to its own file. While working on D112361 it
turns out the type will be used outside the format header.

Reviewed By: #libc, Quuxplusone, Mordante

Differential Revision: https://reviews.llvm.org/D113831
2021-11-16 15:51:49 +01:00
Zbigniew Sarbinowski 422cf2b506 [SystemZ][z/OS] Fix warnings from unsigned int to long in 32-bit mode
This patch fixes the warnings which shows up when libcxx library started to be compiled in 32-bit mode on z/OS.
More specifically, the assignment from unsigned int to time_t aka long was flags as follows:
 ```
libcxx/include/c++/v1/__support/ibm/nanosleep.h:31:11: warning: implicit conversion changes signedness: 'unsigned int' to 'time_t' (aka 'long') [-Wsign-conversion]
  __sec = sleep(static_cast<unsigned int>(__sec));
        ~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
libcxx/include/c++/v1/__support/ibm/nanosleep.h:36:36: warning: implicit conversion changes signedness: 'unsigned int' to 'long' [-Wsign-conversion]
      __rem->tv_nsec = __micro_sec * 1000;
                     ~ ~~~~~~~~~~~~^~~~~~
libcxx/include/c++/v1/__support/ibm/nanosleep.h:47:36: warning: implicit conversion changes signedness: 'unsigned int' to 'long' [-Wsign-conversion]
      __rem->tv_nsec = __micro_sec * 1000;
                     ~ ~~~~~~~~~~~~^~~~~~
3 warnings generated.
```

Here is a small test case illustrating the issue:

```
typedef long    time_t ;
unsigned int sleep(unsigned int );
int main() {
  time_t sec = 0;
#ifdef FIX
  sec = static_cast<time_t>(sleep(static_cast<unsigned int>(sec)));
#else
  sec = sleep(static_cast<unsigned int>(sec));
#endif
}
```
clang++ -c -Wsign-conversion -m32 t.C
```
t.C:8:9: warning: implicit conversion changes signedness: 'unsigned int' to 'time_t' (aka 'long') [-Wsign-conversion]
  sec = sleep(static_cast<unsigned int>(sec));
      ~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Reviewed By: ldionne, #libc, Quuxplusone, Mordante

Differential Revision: https://reviews.llvm.org/D112837
2021-11-16 13:51:35 +00:00
Chuanqi Xu 2e6ae1d3f2 [libcxx] [Coroutine] Conform Coroutine Implementation
Since coroutine is merged in C++ standard and the support for coroutine
seems relatively stable. It's the time to move the implementation of
coroutine out of the experimental directory and the std::experimental
namespace. This patch creates header <coroutine> with conformed
implementation with C++ standard. To avoid breaking user's code too
fast, the <experimental/coroutine> header is remained. Note that
<experimental/coroutine> is deprecated and it would be removed in
LLVM15.

Reviewed By: Quuxplusone, ldionne

Differential Revision: https://reviews.llvm.org/D109433
2021-11-16 14:13:13 +08:00
Louis Dionne 855a419b92 [libc++] Add missing _LIBCPP_HIDE_FROM_ABI to __rewrap_iter 2021-11-15 10:10:33 -05:00
Mikhail Maltsev 6938270fa6 [libcxx] Fix enable_if condition of std::reverse_iterator::operator=
The template std::is_assignable<T, U> checks that T is assignable from
U. Hence, the order of operands in the instantiation of
std::is_assignable in the std::reverse_iterator::operator= condition
should be reversed.

This issue remained unnoticed because std::reverse_iterator has an
implicit conversion constructor. This patch adds a test to check that
the assignment operator is used directly, without any implicit
conversions. The patch also adds a similar test for
std::move_iterator.

Reviewed By: Quuxplusone, ldionne, #libc

Differential Revision: https://reviews.llvm.org/D113417
2021-11-15 13:08:36 +00:00
Mark de Wever b19e823ff9 [libc++][NFC] Fixes code alignment.
D112904 fixed some code alignment issues, but it seems only line was
omitted. (Found while resolving merge conflicts for my own patches.)
2021-11-13 19:11:24 +01:00
Brian Cain 2d0aede515 [libcxx] Change the type of __size to correspond
__size was declared as unsigned which was compatible with
2021-11-12 08:30:38 -08:00
Daniel McIntosh 75ecd1f38c [libcxx][format] Fix how we handle char traits in formatter<string> and formatter<string_view>
Right now we drop the char_traits template argument, which presumes that
string<_CharT, _Traits> and string<_CharT> are interchangeable.

Reviewed By: Mordante, #libc, Quuxplusone

Differential Revision: https://reviews.llvm.org/D112017
2021-11-11 14:49:40 -05:00
Louis Dionne dce5fc56b6 [libc++] Implement file_clock::{to,from}_sys
This is part of https://wg21.link/P0355R7. I am adding these methods
to provide an alternative for the {from,to}_time_t methods that were
removed in https://llvm.org/D113027.

Differential Revision: https://reviews.llvm.org/D113430
2021-11-11 14:17:02 -05:00
Nikolas Klauser b57c22ade8 [libc++] Implement P2186R2 (Remove Garbage Collection)
Reviewed By: Quuxplusone, #libc, ldionne

Differential Revision: https://reviews.llvm.org/D112869
2021-11-11 19:03:00 +01:00
Mark de Wever 4732dd3010 [libc++] Use addressof in list.
This addresses the usage of `operator&` in `<list>`.

(Note there are still more headers with the same issue.)

Reviewed By: #libc, Quuxplusone, ldionne

Differential Revision: https://reviews.llvm.org/D112654
2021-11-11 18:56:08 +01:00