Commit Graph

3532 Commits

Author SHA1 Message Date
Christopher Di Bella fe31f11cc8 [libcxx] adds `std::incrementable_traits` to <iterator>
Implements parts of:
    - P0896R4 The One Ranges Proposal

Depends on D99041

Differential Revision: https://reviews.llvm.org/D99141
2021-04-13 05:01:45 +00:00
jasonliu 52e9d80d5d [libc++] add `inline` for __open's definition in ifstream and ofstream
Summary:

When building with gcc on AIX, it seems that gcc does not like the
`always_inline` without the `inline` keyword.
So adding the inline keywords in for __open in ifstream and ofstream.
That will also make it consistent with __open in basic_filebuf
(it seems we added `inline` there before for gcc build as well).

Differential Revision: https://reviews.llvm.org/D99422
2021-04-12 19:25:49 +00:00
Mara Sophie Grosch 8deaa4a147 [libc++] Move checks for newlib to actually work
The checks did not work in __config, since no header defining
`_NEWLIB_VERSION` was included before. This patch moves the two
checks for newlib to the headers that actually need it - and after
they already include relevant headers.

Differential Revision: https://reviews.llvm.org/D79888
2021-04-12 14:20:36 -04:00
Arthur O'Dwyer 4b7bad9eae [libc++] Implement D2351R0 "Mark all library static cast wrappers as [[nodiscard]]"
These [[nodiscard]] annotations are added as a conforming extension;
it's unclear whether the paper will actually be adopted and make them
mandatory, but they do seem like good ideas regardless.

https://isocpp.org/files/papers/D2351R0.pdf

This patch implements the paper's effect on:
- std::to_integer, std::to_underlying
- std::forward, std::move, std::move_if_noexcept
- std::as_const
- std::identity

The paper also affects (but libc++ does not yet have an implementation of):
- std::bit_cast

Differential Revision: https://reviews.llvm.org/D99895
2021-04-12 12:29:15 -04:00
Louis Dionne 344d381d9f [libc++] NFC: Remove duplicate synopsis from <__string> 2021-04-12 11:49:43 -04:00
Louis Dionne 6a1ac88fc1 [libc++] Split std::get_temporary_buffer out of <memory>
Differential Revision: https://reviews.llvm.org/D100216
2021-04-12 11:46:31 -04:00
Louis Dionne 0b439e4cc9 [libc++] Split std::allocator out of <memory>
Differential Revision: https://reviews.llvm.org/D100216
2021-04-12 11:46:29 -04:00
Louis Dionne 26beecfe47 [libc++] Split auto_ptr out of <memory>
Differential Revision: https://reviews.llvm.org/D100216
2021-04-12 11:46:25 -04:00
Louis Dionne b125392259 [libc++] NFC: Move unused include of <limits> to allocator_traits.h
The include should have been moved when I split allocator_traits.h out
of memory.
2021-04-09 15:31:55 -04:00
jasonliu f3d7536b24 [libc++] Fix abs and div overload issue for compilers on AIX
Summary:
AIX system's stdlib.h provide different overload of abs and div
depending on compiler versions.

For example, std::div(long, long) and std::abs(long) are not available
from OS's stdlib.h when building with clang, but they are available
when building with xlclang compiler.

Therefore, we need to provide those extra overloads in libc++'s stdlib.h
when OS's stdlib.h does not.

Differential Revision: https://reviews.llvm.org/D99767
2021-04-09 14:47:13 +00:00
zoecarver 097d77d611 [libcxx] Allow shared_ptr's unique_ptr converting constructor to support array types.
Refs: https://bugs.llvm.org/show_bug.cgi?id=32147

Differential Revision: https://reviews.llvm.org/D80882
2021-04-08 22:04:57 -07:00
Christopher Di Bella 920c0f7e09 [libcxx] adds __cpp_lib_concepts feature-test macro
Also adjusts C++20 status paper to indicate full concepts support.

Depends on D96477, D99817.

Differential Revision: https://reviews.llvm.org/D99805
2021-04-07 16:14:45 +00:00
Christopher Di Bella cedd07df51 [libcxx] fixes `common_reference` requirement for `swappable_with`
LWG3175 identifies that the `common_reference` requirement for
`swappable_with` is over-constraining and doesn't need to concern itself
with cv- or reference qualifiers.

Differential Revision: https://reviews.llvm.org/D99817
2021-04-07 05:51:36 +00:00
Arthur O'Dwyer 2d0f1fa472 [libc++] Header inclusion tests.
As mandated by the Standard's various synopses, e.g. [iterator.synopsis].
Searching the TeX source for '#include' is a good way to find all of these
mandates.

The new tests are all autogenerated by utils/generate_header_inclusion_tests.py.
I was SHOCKED by how many mandates there are, and how many of them
libc++ wasn't conforming with.

Differential Revision: https://reviews.llvm.org/D99309
2021-04-06 15:31:56 -04:00
Martin Storsjö 948dd664c3 [libcxx] Fix the type attribute for a couple templates
Use `_LIBCPP_TEMPLATE_VIS` instead of `_LIBCPP_TYPE_VIS` for a template
class.

This fixes the nodiscard_extensions.pass.cpp and a couple
func.search.default test cases when built in MSVC/DLL configurations.

Differential Revision: https://reviews.llvm.org/D99932
2021-04-06 19:54:34 +03:00
Christopher Di Bella 96dbdd753a [libcxx] adds remaining callable concepts
* `std::predicate`
* `std::relation`
* `std::equivalence_relation`
* `std::strict_weak_order`

Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Differential Revision: https://reviews.llvm.org/D96477
2021-04-06 16:35:57 +00:00
Zbigniew Sarbinowski 916093f49f [SystemZ][z/OS] correct rc and errno within nanosleep()
This patch fixes rc and errno within nanosleep(). It also updates __rem parameter as well it introduces cast to handle conversions from long into unsigned int to avoid warnings.

Reviewed By: Mordante

Differential Revision: https://reviews.llvm.org/D99373
2021-04-06 15:36:58 +00:00
Christopher Di Bella c25c22d5f9 [libcxx] moves `std::invoke` into `__functional_base`
Including `<concepts>` in other standard library headers (such as
`<iterator>`) creates circular dependencies due to `<functional>`.
Since `<concepts>` only needs `std::invoke` from `<functional>`, the
easiest, fastest, and cleanest way to eliminate the circular dep is to
move `std::invoke` into `__functional_base`.

This has the added advantage of `<concepts>` not transitively importing
`<functional>`.

Differential Revision: https://reviews.llvm.org/D99041
2021-04-06 01:25:15 +00:00
Arthur O'Dwyer 27e5bffbf6 [libc++] Fix the header guard from _LIBCPP_STEAMBUF to _LIBCPP_STREAMBUF. 2021-04-04 17:39:50 -04:00
Nico Weber d3b74dc1e4 Restore 8954fd436c after c06a8f9caa
Else, just-built clang can't build programs that include libc++ headers
on macOS if you build via the 'all' target.
2021-04-02 09:19:36 -04:00
Marek Kurdej 49e5a896d1 [libc++] Fix build on macOS older than 10.15.
* This was introduced in D99515 that added -Wundef flag. CI run on macOS 10.15 and this problem wasn't caught before.
2021-04-02 10:32:54 +02:00
Christopher Di Bella 7959d59028 [libcxx] adds concepts `std::totally_ordered` and `std::totally_ordered_with`
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Reviewed By: Mordante

Differential Revision: https://reviews.llvm.org/D98983
2021-04-02 06:00:21 +00:00
Louis Dionne 17095dc861 [libc++][NFC] Increase readability of typeinfo comparison of ARM64
We wasted a good deal of time trying to figure out whether our implementation
was correct. In the end, it was, but it wasn't so easy to determine. This
patch dumbs down the implementation and improves the documentation to make
it easier to validate.

See https://lists.llvm.org/pipermail/libcxx-dev/2020-December/001060.html.

Differential Revision: https://reviews.llvm.org/D97802
2021-04-01 16:38:34 -04:00
Petr Hosek 96d8c6b571 [CMake] Remove {LIBCXX,LIBCXXABI,LIBUNWIND}_INSTALL_PREFIX
These variables were introduced during early work on the runtimes build
but were obsoleted by {LIBCXX,LIBCXXABI,LIBUNWIND}_INSTALL_LIBRARY_DIR.

Differential Revision: https://reviews.llvm.org/D99697
2021-04-01 10:13:07 -07:00
Marek Kurdej 5c703f0fd8 [libc++] Build and test with -Wundef warning. NFC.
This will avoid typos like `_LIBCPP_STD_VERS` (<future>) or using `#if TEST_STD_VER > 17` without including "test_macros.h".

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D99515
2021-04-01 08:32:56 +02:00
Joerg Sonnenberger 9f4022ffeb [libc++] Avoid <climits> dependency in <thread>
The standard guarantees sleep durations of 2^63-1 nanoseconds to work.
Instead of depending on INT64_MAX or ULONGLONG_MAX to exist via the
header pollution, fold the constant directly. That has the additional
positive side effect that it avoids long double arithmetic bugs in GCC.

Differential Revision: https://reviews.llvm.org/D99516
2021-03-31 15:28:16 +02:00
Louis Dionne c06a8f9caa [libc++] Include <__config_site> from <__config>
Prior to this patch, we would generate a fancy <__config> header by
concatenating <__config_site> and <__config>. This complexifies the
build system and also increases the difference between what's tested
and what's actually installed.

This patch removes that complexity and instead simply installs <__config_site>
alongside the libc++ headers. <__config_site> is then included by <__config>,
which is much simpler. Doing this also opens the door to having different
<__config_site> headers depending on the target, which was impossible before.

It does change the workflow for testing header-only changes to libc++.
Previously, we would run `lit` against the headers in libcxx/include.
After this patch, we run it against a fake installation root of the
headers (containing a proper <__config_site> header). This makes use
closer to testing what we actually install, which is good, however it
does mean that we have to update that root before testing header changes.
Thus, we now need to run `ninja check-cxx-deps` before running `lit` by
hand.

Differential Revision: https://reviews.llvm.org/D97572
2021-03-30 14:06:11 -07:00
Christopher Di Bella 24c44c379f [libcxx] adds std::identity to <functional>
Implements parts of:
    - P0898R3 Standard Library Concepts

Differential Revision: https://reviews.llvm.org/D98151
2021-03-29 16:16:05 +00:00
Arthur O'Dwyer 199d2ebeed [libc++] Use _EnableIf and __iter_value_type consistently. NFCI.
Specifically, use these metafunctions consistently in areas that are
about to be affected by P1518R2's changes.

This is the NFCI part of https://reviews.llvm.org/D97742 .
The functional-change part is still waiting for P1518R2 to be
officially merged into the working draft.
2021-03-29 09:22:52 -04:00
Marek Kurdej 0324b46cd8 [libc++] [C++2b] [P2162] Allow inheritance from std::variant.
This patch changes the variant even in pre-C++2b.
It should not break anything, only allow use cases that didn't work previously.

Notes:
 `__as_variant` is used in `__visitation::__variant::__visit_alt`, but I haven't used it in `__visitation::__variant::__visit_alt_at`.
That's because it is used only in `__visit_value_at`, which in turn is always used on variant specializations (that's in comparison operators).

* https://wg21.link/P2162

Reviewed By: ldionne, #libc, Quuxplusone

Differential Revision: https://reviews.llvm.org/D97394
2021-03-25 18:20:50 +01:00
Arthur O'Dwyer e21ab31f45 [libc++] Eliminate <compare>'s dependency on <array>.
This refactor is not only a good idea, but is in fact required by the standard,
in the sense that <array> is mandated to include <compare>.
So <compare> shouldn't have a circular dependency on <array>!

Differential Revision: https://reviews.llvm.org/D99307
2021-03-25 10:34:35 -04:00
Arthur O'Dwyer 06e2b737aa [libc++] [P1032] Misc constexpr bits in <iterator>, <string_view>, <tuple>, <utility>.
This completes the implementation of P1032's changes to <iterator>,
<string_view>, <tuple>, and <utility> in C++20.
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1032r1.html

Drive-by fix a couple of unintended rvalues in "*iterators*/*.fail.cpp".

Differential Revision: https://reviews.llvm.org/D96385
2021-03-25 10:34:35 -04:00
jasonliu 09a84d3047 [libc++] Match declaration for non-member function std::swap(std::packaged_task) with what standard specify
Standard specifies:
```
template<class R, class... ArgTypes>
  void swap(packaged_task<R(ArgTypes...)>& x, packaged_task<R(ArgTypes...)>& y) noexcept;
```

Differential Revision: https://reviews.llvm.org/D99102
2021-03-24 22:33:32 +00:00
jasonliu 158026301b [libc++][AIX] Initial patch to unblock the libc++ build on AIX
This path would unblock the build of libc++ library on AIX:
1. Add _AIX guard for _LIBCPP_HAS_THREAD_API_PTHREAD
2. Use uselocale to actually take the locale setting
   into account.
3. extract_mtime and extract_atime mod needed for AIX. As stat
   structure on AIX uses internal structure st_timespec to store
   time for binary compatibility reason. So we need to convert it
   back to timespec here.
4. Do not build cxa_thread_atexit.cpp for libcxxabi on AIX.

Differential Revision: https://reviews.llvm.org/D97558
2021-03-24 22:13:20 +00:00
Martin Storsjö 675401e04c [libcxx] Avoid pulling in xlocinfo.h in public headers
Including xlocinfo.h is a bit of a layering violation; locale.h is
the C library header we should use, while xlocinfo.h is essentially
part of the MS C++ library. Including xlocinfo.h brings in yvals.h,
which brings in yvals_core.h, which defines the MS STL's version
support macros, overriding what libc++'s <version> had defined.

Instead just include locale.h, and provide the few defines we need
for locale categories manually.

Differential Revision: https://reviews.llvm.org/D99213
2021-03-24 23:29:59 +02:00
Marek Kurdej 28f82bec7f [libc++] [C++20] [P0482] Add missing tests and synopses for char8_t.
Left to finish P0482:
* <cuchar> header.
* Parts of <memory_resource> concerning char8_t. Also, tests for hash<pmr::*string>.

Reviewed By: ldionne, #libc, Quuxplusone

Differential Revision: https://reviews.llvm.org/D99184
2021-03-23 18:45:31 +01:00
Arthur O'Dwyer 43aaf87173 [libc++] Include <__config> first in all standard headers.
Mostly, *don't* include <experimental/__config> from C++17 <any>,
because that doesn't make any sense. I think it was just a cut-and-paste
typo when this header moved from experimental/.

Differential Revision: https://reviews.llvm.org/D99089
2021-03-22 19:01:18 -04:00
Louis Dionne 1e337b1dd9 [libc++] Revert "[SystemZ][z/OS] Missing wchar functions libc++"
This reverts commit febbf68b42 because it
added files that were not under the LLVM license.

See https://reviews.llvm.org/D98207 for details.
2021-03-22 17:35:43 -04:00
Arthur O'Dwyer 2ac6babcc0 [libc++] Move __libcpp_erase_if_container into <iterator>, and ADL-proof it.
The container headers don't need to include <functional> for any other reason
(or at least, they wouldn't if we moved `less` and `equal_to` out of <functional>),
so let's put `__libcpp_erase_if_container` somewhere that's common to the
containers but outside of <functional>.

Also, calling `std::erase_if(c, pred)` should not trigger ADL.

Differential Revision: https://reviews.llvm.org/D99043
2021-03-22 11:13:33 -04:00
Arthur O'Dwyer 72557476d4 [libc++] Consistency on _LIBCPP_CLANG_VER tests in <type_traits>.
This came out of my review comments on D97283.

This patch re-enables the use of `__is_fundamental`, `__is_signed`, etc.
on non-Clang compilers. Previously, when we found that a builtin didn't
work on old Clangs, we had been reacting by limiting its use to new Clangs
(i.e., we'd also stop using it on new GCCs and new MSVCs, just because of
the old Clang bug). I claim that this was unintentional.

Notice that on Apple Clang, `_LIBCPP_COMPILER_CLANG` is defined and
`_LIBCPP_CLANG_VER` is not defined (therefore `0` in arithmetic expressions).
We assume that Apple Clang has all the bugs of all the Clangs.

Differential Revision: https://reviews.llvm.org/D98720
2021-03-19 10:49:00 -04:00
Muiez Ahmed f6af5efcec [SystemZ][z/OS] vasprintf fix libc++
The aim is to use the correct vasprintf implementation for z/OS libc++, where a copy of va_list ap is needed. In particular, it avoids the potential that the initial internal call to vsnprintf will modify ap and the subsequent call to vsnprintf will use that modified ap.

Differential Revision: https://reviews.llvm.org/D97473
2021-03-18 15:00:57 -04:00
Christopher Di Bella 580416d573 [libcxx] updates the feature-test macro generator
D97015 didn't correctly update `generate_feature_test_macro_components.py`.

Reviewed By: ldionne, Quuxplusone, #libc, Mordante

Differential Revision: https://reviews.llvm.org/D97904
2021-03-18 17:08:10 +00:00
Arthur O'Dwyer 0aa637b203 [libc++] Improve src/filesystem's formatting of paths.
This is my attempt to merge D98077 (bugfix the format strings for
Windows paths, which use wchar_t not char)
and D96986 (replace C++ variadic templates with C-style varargs so that
`__attribute__((format(printf)))` can be applied, for better safety)
and D98065 (remove an unused function overload).

The one intentional functional change here is in `__create_what`.
It now prints path1 and path2 in square-brackets _and_ double-quotes,
rather than just square-brackets. Prior to this patch, it would
print either path double-quoted if-and-only-if it was the empty
string. Now the double-quotes are always present. I doubt anybody's
code is relying on the current format, right?

Differential Revision: https://reviews.llvm.org/D98097
2021-03-16 15:00:36 -04:00
Tomas Matheson 64595f9b84 [libcxx][type_traits] add tests for is_signed and is_unsigned
In previous versions of clang, __is_signed and __is_unsigned builtins did not
correspond to is_signed and is_unsigned behaviour for enums.  The builtins were
fixed in D67897 and D98104.

* Disable the fast path of is_unsigned for clang versions < 13

* Add more tests for is_signed, is_unsigned and is_arithmetic

Differential Revision: https://reviews.llvm.org/D97283
2021-03-16 16:36:10 +00:00
Muiez Ahmed febbf68b42 [SystemZ][z/OS] Missing wchar functions libc++
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
2021-03-12 15:39:31 -05:00
Christopher Di Bella 8d4af1b6e0 [libcxx] adds concept std::regular
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D97911

Reviewed By: EricWF, #libc, Quuxplusone

Differential Revision: https://reviews.llvm.org/D98154
2021-03-12 08:54:03 -08:00
Christopher Di Bella 154395536e [libcxx] adds concept std::semiregular
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D97443

Reviewed By: Quuxplusone, EricWF, #libc

Differential Revision: https://reviews.llvm.org/D97911
2021-03-11 22:40:07 -08:00
Christopher Di Bella 8ef69c66d5 [libcxx] adds concept std::copyable
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D97359

Reviewed By: EricWF, #libc, Quuxplusone, zoecarver

Differential Revision: https://reviews.llvm.org/D97443
2021-03-11 19:30:55 -08:00
Christopher Di Bella dc9f385722 [libcxx] adds concept std::movable
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D97162

Reviewed By: EricWF, #libc, Quuxplusone

Differential Revision: https://reviews.llvm.org/D97359
2021-03-11 19:27:43 -08:00
Martin Storsjö 49173ca4db [libcxx] Avoid intermediate string objects for substrings in windows operator/=
Check that appends with a path object doesn't do allocations, even
on windows.

Suggested by Marek in D98398. The patch might apply without D98398
(depending on how much of the diff context has to match), but doesn't
make much sense until after that patch has landed.

Differential Revision: https://reviews.llvm.org/D98412
2021-03-11 19:34:59 +02:00
Aditya Kumar 6976255faf Add noreturn attribute to non-returning functions
Differential Revision: https://reviews.llvm.org/D97308
2021-03-10 14:35:50 -08:00
Muiez Ahmed ebe6161c54 [SystemZ][z/OS] Missing locale functions libc++
The aim is to add the missing z/OS specific locale functions for libc++ (newlocale, freelocale and uselocale).

Reviewed By: ldionne, #libc, curdeius

Differential Revision: https://reviews.llvm.org/D98044
2021-03-08 19:32:33 +00:00
Martin Storsjö b9f169fb7d [libcxx] Document windows specifics regarding file_type and perms. NFC.
This was requested in the review of D98138.

Differential Revision: https://reviews.llvm.org/D98155
2021-03-08 15:27:07 +02:00
Arthur O'Dwyer ab49f50ad0 [libc++] Fix typos in the synopsis of bit_xor, bit_not, etc. NFC. 2021-03-07 20:22:50 -05:00
Christopher Di Bella c744332793 [libcxx] adds std::ranges::swap, std::swappable, and std::swappable_with
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D96742

Differential Revision: https://reviews.llvm.org/D97162
2021-03-05 19:03:57 -08:00
Marek Kurdej 43e4214173 [libc++] [C++2b] [P1682] Add to_underlying.
* https://wg21.link/P1682

Reviewed By: ldionne, Mordante, #libc

Differential Revision: https://reviews.llvm.org/D97365
2021-03-05 10:31:21 +01:00
Martin Storsjö 1773eec692 [libcxx] Implement semaphores for windows
Also add WIN32_LEAN_AND_MEAN before including windows.h, for consistency
with other sources.

Differential Revision: https://reviews.llvm.org/D97539
2021-03-05 10:48:59 +02:00
Christopher Di Bella 6eb5d55c55 [libcxx] fixes up some [concepts]-related code
* moves `std::copy_constructible` so it comes before
  `std::equality_comparable_with`
* replaces a few uses of `auto`
2021-03-04 22:09:43 -08:00
Christopher Di Bella e63ddcccf8 [libcxx] adds concepts std::equality_comparable[_with]
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D96660

Reviewed By: ldionne, #libc, Quuxplusone

Differential Revision: https://reviews.llvm.org/D97176
2021-03-04 18:24:04 -08:00
Muiez Ahmed 53c8587dcd [SystemZ][z/OS] Missing non-posix functions libc++
The aim is to add missing non-posix functions for z/OS libc++ (strtod_l and strtof_l).

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D97051
2021-03-04 15:23:21 +00:00
Martin Storsjö c793f68d9b [libcxx] Don't use dllimport for a static member in a template
This fixes clang warnings (that are treated as errors when running
the test suite):

libcxx/include/string:4409:59: error: definition of dllimport static field [-Werror,-Wdllimport-static-field-def]
               basic_string<_CharT, _Traits, _Allocator>::npos;

The warning is normally not visible as long as the libc++ headers
are treated as system headers.

The same construct is always an error in MSVC.

(One _LIBCPP_FUNC_VIS was added in
2d8f23f571, which broke DLL builds.
59919c4d6b fixed this by adding another
_LIBCPP_FUNC_VIS on the declaration for consistency, but the underlying
issue remained, that one can't use dllimport here.)

Differential Revision: https://reviews.llvm.org/D97168
2021-03-04 08:55:27 +02:00
Christopher Di Bella 647af31e74 [libcxx] adds concept `std::assignable_from`
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D96660

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D96742
2021-03-03 22:41:55 -08:00
Christopher Di Bella f893312c1a [libcxx] adds concept `std::common_with`
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D96660

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D96683
2021-03-03 20:01:11 -08:00
Arthur O'Dwyer 09fa1d0e50 [libc++] Introduce __identity_t<T>. NFCI.
This is just a shorter synonym for `__identity<T>::type`.
Use it consistently throughout, where possible.

There is still some metaprogramming in <memory> and <variant>
where `__identity` is being used _without_ immediately calling
`::type` on it; but this is the unusual case, and it will become
even less usual as we start deliberately protecting certain types
against deduction (e.g. D97742).

Differential Revision: https://reviews.llvm.org/D97862
2021-03-03 22:23:14 -05:00
Christopher Di Bella 3f5438c46c [libcxx] adds concept `std::common_reference_with`
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D96657

Reviewed By: ldionne, Mordante, #libc

Differential Revision: https://reviews.llvm.org/D96660
2021-03-03 17:52:41 -08:00
Louis Dionne 3c62198c61 [libc++] NFC: Normalize links to bug reports 2021-03-03 13:45:29 -05:00
zoecarver 84a50f5911 [libc++] Add bind_front function (P0356R5).
Implementes [[ http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0356r5.html | P0356R5 ]]. Adds `bind_front` to `functional`.

Reviewed By: ldionne, #libc, Quuxplusone

Differential Revision: https://reviews.llvm.org/D60368
2021-03-02 16:18:06 -08:00
Christopher Di Bella eadece333f [libcxx] adds common_reference to <type_traits>
Implements part of P0898R3 Standard Library Concepts

Reworks D74351 to use requires-clauses over SFINAE and so that it more
closely follows the wording.

Co-authored by: Michael Schellenberger Costa <mschellenbergercosta@googlemail.com>

(Michael did all the heavy lifting and I came in to polish it for
 submission, since Michael is focussing on `std::format` now.)

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D96657
2021-03-02 22:33:37 +00:00
Vitaly Buka 3744ba24dc [NFC][libc++] Suppress "warning: ignoring return value"
According to the comment on the next line
it's expected behaviour.
2021-02-26 14:32:54 -08:00
Christopher Di Bella e4dd614ae8 [libcxx] cleans up __cpp_concepts mess
libc++ was previously a bit confused by what the value of __cpp_concepts
should be. Also replaces `__floating_point` with `floating_point` now
that it exists.

Differential Revision: https://reviews.llvm.org/D97015
2021-02-26 18:43:40 +00:00
Louis Dionne 618862e89a [libc++] Fix incorrect forwarding in tuple's assignment operator
Also, add a bunch of tests for tuple and pair's assignment operators
involving reference types.

Differential Revision: https://reviews.llvm.org/D97419
2021-02-25 14:56:16 -05:00
Mark de Wever c61e511f38 [NFC][libc++] Fix _LIBCPP_HAS_BITSCAN64 usage.
Seems line was accidentally left in
llvm-svn: 290924 86eebc5b65

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D97211
2021-02-23 08:13:49 +01:00
Louis Dionne a0839b14df [libc++] Fix tuple assignment from types derived from a tuple-like
The implementation of tuple's constructors and assignment operators
currently diverges from the way the Standard specifies them, which leads
to subtle cases where the behavior is not as specified. In particular, a
class derived from a tuple-like type (e.g. pair) can't be assigned to a
tuple with corresponding members, when it should. This commit re-implements
the assignment operators (BUT NOT THE CONSTRUCTORS) in a way much closer
to the specification to get rid of this bug. Most of the tests have been
stolen from Eric's patch https://reviews.llvm.org/D27606.

As a fly-by improvement, tests for noexcept correctness have been added
to all overloads of operator=. We should tackle the same issue for the
tuple constructors in a future patch - I'm just trying to make progress
on fixing this long-standing bug.

PR17550
rdar://15837420

Differential Revision: https://reviews.llvm.org/D50106
2021-02-22 14:52:18 -05:00
Martin Storsjö 26005c788b [libcxx] Make path::format a non-class enum
The spec doesn't declare it as an enum class, and being declared
as an enum class breaks referring to the values as e.g.
path::auto_format.

Differential Revision: https://reviews.llvm.org/D97084
2021-02-21 00:25:54 +02:00
Mark de Wever 1a5c92f680 [libc++] Fixes _LIBCPP_HAS_NO_CONCEPTS
Before the define was in a GCC specific part. Now it's available for all
compilers. The patch had its CI run in D93593.
2021-02-20 09:13:16 +01:00
Martin Storsjö f4f5fb9151 [libcxx] Make generic_*string return paths with forward slashes on windows
This matches what MS STL returns; in std::filesystem, forward slashes
are considered generic dir separators that are valid on all platforms.

Differential Revision: https://reviews.llvm.org/D91181
2021-02-19 21:49:51 +02:00
zoecarver dbc89028d7 [libcxx] Fix LWG 2875: shared_ptr::shared_ptr(Y*, D, […]) constructors should be constrained.
Fixes LWG issue 2875.

Differential Revision: https://reviews.llvm.org/D81414
2021-02-19 11:11:39 -08:00
Marek Kurdej bcb5a124ae [libc++] Turn off clang-format for auto-generated version header. NFC. 2021-02-19 17:26:16 +01:00
zoecarver 6a328c66d3 [libc++] shared_ptr deleter requirements (LWG 2802).
This patch implements 2802. Requires _Deleter to have call operator and be move constructible. Based on D62233.

Refs PR37637.

Differential Revision: https://reviews.llvm.org/D62274
2021-02-18 21:31:07 -08:00
Christopher Di Bella 9f4f6ac94b [libcxx] adds concept `std::uniform_random_bit_generator`
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Differential Revision: https://reviews.llvm.org/D96577
2021-02-19 01:47:29 +00:00
Martin Storsjö 78d693faec [libcxx] Implement append and operator/ properly for windows
The root_path function has to be changed to return the parsed bit
as-is; otherwise a path like "//net" gets a root path of "//net/", as
the root name, "//net", gets the root directory (an empty string) appended,
forming "//net/". (The same doesn't happen for the root dir "c:" though.)

Differential Revision: https://reviews.llvm.org/D91178
2021-02-18 09:03:53 +02:00
Martin Storsjö 8a783e6845 [libcxx] Implement is_absolute properly for windows
Differential Revision: https://reviews.llvm.org/D91177
2021-02-17 19:33:05 +02:00
Arthur O'Dwyer 5f58374bbe [libc++] Change `std::numeric_limits` to just `numeric_limits` in <chrono>.
The namespace is unnecessary, and libc++ style is not to include it on type names.
(As opposed to function names, where qualification affects ADL; and in certain
function signatures where `std::` and `_VSTD::` might be mangled differently.
This is none of those situations.)
2021-02-15 16:12:10 -05:00
Louis Dionne 5d0d465ad4 [libc++] Mark __cpp_lib_constexpr_memory as being implemented 2021-02-15 15:26:53 -05:00
Zbigniew Sarbinowski 48fcce1aea [SystemZ][ZOS] Fix __libcpp_thrad_isnull()
Previous pthread revision https://reviews.llvm.org/D91875 missed a small change for `__libcpp_thrad_isnull()` required for z/OS.

Reviewed By: zibi

Differential Revision: https://reviews.llvm.org/D96302
2021-02-12 20:21:11 +00:00
Zbigniew Sarbinowski cb2d2ae56a [SystemZ][ZOS] Provide CLOCK_MONOTONIC alternative
We need CLOCK_MONOTONIC equivalent implementation for z/OS within libc++. The default implementation is asserting.

On z/OS the lack of  'clock_gettime()' and 'time_point()' force us to look for alternatives.
The current proposal is to use `gettimeofday()` for CLOCK_MONOTONIC  which is also used in CLOCK_REALTIME.  This will allow us to skip the assertion with compromised CLOCK_MONOTONIC implementation which will not guarantee to never go back in time because it will use `gettimeofday()` but only when it's set.

Is this a good compromise for platforms which does not support monotonic clock?
Hopefully this will spark the discussion and agreement how to proceed in this situation.

Reviewed By: #libc, ldionne, hubert.reinterpretcast

Differential Revision: https://reviews.llvm.org/D93542
2021-02-12 18:39:48 +00:00
Mark de Wever f8772da8cc [libc++][format] Enable format_error on older compilers.
It seems like modifying the header doesn't cause libc++ to be rebuild.
So the breakage of the previous commit didn't happen on my system.

This should fix the build of https://buildkite.com/mlir/mlir-core
2021-02-11 19:11:20 +01:00
Mark de Wever af83e89ae3 [libc++][format] Improve Add basic_format_parse_context.
Add an additional guard to prevent building on older clang versions.

This should fix the build of https://buildkite.com/mlir/mlir-core
2021-02-11 18:55:54 +01:00
Mark de Wever 38ddeade65 [libc++][format] Add basic_format_parse_context.
Implements parts of:
- P0645 Text Formatting

Depends on D92214

Reland with changes:
The format header will only be compiled if the compiler used has support
for concepts. This should fix the issues with the initial version.

Differential Revision: https://reviews.llvm.org/D93166
2021-02-11 17:57:54 +01:00
Ilya Tokar c81d52997a [libc++] Use builtins in more math.h functions.
Not using builtins doesn't always imply worse code,
but for e. g. isinf, this is 30%+ faster.

Before:
name        time/op
BM_isinf     2.14ns ± 2%

After:
name        time/op
BM_isinf     1.33ns ± 2%

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D88854
2021-02-10 15:17:42 -05:00
Christopher Di Bella 17db24a7a8 [libcxx] adds concepts `std::invocable` and `std::regular_invocable`
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Differential Revision: https://reviews.llvm.org/D96235
2021-02-10 19:35:53 +00:00
Christopher Di Bella c63de225fd [libcxx] adds concept std::derived_from
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D74292
2021-02-10 19:30:08 +00:00
Christopher Di Bella bee7b07f23 [libcxx] adds [concepts.arithmetic]
Implements parts of:
    * P0898R3 Standard Library Concepts
    * P1754 Rename concepts to standard_case for C++20, while we still can

Differential Revision: https://reviews.llvm.org/D88131
2021-02-10 19:04:57 +00:00
Christopher Di Bella 2193e8be3e [libcxx] adds concept `std::copy_constructible`
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D96230

Differential Revision: https://reviews.llvm.org/D96232
2021-02-10 17:56:42 +00:00
Christopher Di Bella 2b2f36a8b1 [libcxx] adds concept `std::move_constructible`
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D77961

Differential Revision: https://reviews.llvm.org/D96230
2021-02-10 17:33:35 +00:00
Colin Finck ebfadd82cb [libc++] Fix copy-paste mistake in __threading_support
Differential Revision: https://reviews.llvm.org/D96115
2021-02-10 11:00:32 -05:00
Christopher Di Bella 8caf835337 [libcxx] adds concept `std::convertible_to`
Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Differential Revision: https://reviews.llvm.org/D77961
2021-02-10 03:27:41 +00:00
Arthur O'Dwyer eec04092d6 [libc++] [LWG2993] reference_wrapper<T> conversion from U&&
Implement the resolution of LWG2993. Replace a deleted constructor
with a constructor that SFINAEs away in appropriate circumstances.
Also, now that the constructor is templated, we must have an
explicit deduction guide to make CTAD work.

Some tests have been merged in from Agustín Bergé's D40259.

Differential Revision: https://reviews.llvm.org/D92725
2021-02-09 15:50:25 -05:00
zoecarver dea74b2820 [libc++] Add `noexcept` to `string::find` and similar members.
Adds `noexcept` to `string_view`/`string::find` and similar members
(`rfind`, etc.). See discussion in D95251. Refs D95821.

Reviewed By: curdeius, ldionne

Differential Revision: https://reviews.llvm.org/D95848
2021-02-09 11:47:40 -08:00
Arthur O'Dwyer 85167fb7c2 [libc++] Further improve the contiguous-iterator story, and fix some bugs.
- Quality-of-implementation: Avoid calling __unwrap_iter in constexpr contexts.
    The user might conceivably write a contiguous iterator where normal iterator
    arithmetic is constexpr-friendly but `std::to_address(it)` isn't.

- Bugfix: When you pass contiguous iterators to `std::copy`, you should get
    back your contiguous iterator type, not a raw pointer. That means that
    libc++ can't `__unwrap_iter` unless it also does `__rewrap_iter`.
    Fortunately, this is implementable.

- Improve test coverage of the new `contiguous_iterator` test iterator.
    This catches the bug described above.

- Tests: Stop testing that we can `std::copy` //into// an `input_iterator`.
    Our test iterators may currently support that, but it seems nonsensical to me.

Differential Revision: https://reviews.llvm.org/D95983
2021-02-05 15:18:04 -05:00
Arthur O'Dwyer 5d9565634c Revert "Revert "[libc++] [P0879] constexpr std::nth_element, and rewrite its tests.""
This reverts commit b6ffece320.

The bug is now fixed (it was a stupid cut-and-paste kind of error),
and the regression test added. The new patch is also simpler than the old one!

Differential Revision: https://reviews.llvm.org/D96084
2021-02-05 12:02:43 -05:00
Jordan Rupprecht b6ffece320 Revert "[libc++] [P0879] constexpr std::nth_element, and rewrite its tests."
This reverts commit 207d4be4d9 due to returning incorrect results. Regression test case posted in D96074.
2021-02-04 14:03:49 -08:00
Louis Dionne 1700ea7302 [libc++] Remove the ability to use braced-init for filesystem paths
According to my reading of http://eel.is/c++draft/filesystems#fs.class.path,
the Standard doesn't actually mention that this should work. Since other
implementations don't allow it, allowing it in libc++ is just setting a
portability trap.

Supersedes https://reviews.llvm.org/D89865.

Differential Revision: https://reviews.llvm.org/D95975
2021-02-04 11:49:00 -05:00
Louis Dionne 76fc35752d [libc++] Make feature-test macros consistent with availability macros
Before this patch, feature-test macros didn't take special availability
markup into account, which means that feature-test macros can sometimes
appear to "lie". For example, if you compile in C++20 mode and target
macOS 10.13, the __cpp_lib_filesystem feature-test macro will be provided
even though the <filesystem> declarations are marked as unavailable.
This patch fixes that.

rdar://68142369

Differential Revision: https://reviews.llvm.org/D94983
2021-02-04 11:40:22 -05:00
Louis Dionne b51756819a [libc++] Rename include/support to include/__support
We do ship those headers, so the directory name should not be something
that can potentially conflict with user-defined directories.

Differential Revision: https://reviews.llvm.org/D95956
2021-02-04 10:16:33 -05:00
Arthur O'Dwyer 493f140792 [libc++] [P0879] constexpr std::sort
This completes libc++'s implementation of
P0879 "Constexpr for swap and swap related functions."
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0879r0.html

For the feature-macro adjustment, see
https://cplusplus.github.io/LWG/issue3256

Differential Revision: https://reviews.llvm.org/D93661
2021-02-03 18:57:05 -05:00
Arthur O'Dwyer d41c6d51cb [libc++] Rationalize our treatment of contiguous iterators and __unwrap_iter().
- Implement C++20's changes to `reverse_iterator`, so that it won't be
    accidentally counted as a contiguous iterator in C++20 mode.
- Implement C++20's changes to `move_iterator` as well.
- `move_iterator` should not be contiguous. This fixes a bug where
    we optimized `std::copy`-of-move-iterators in an observable way.
    Add a regression test for that bugfix.
- Add libcxx tests for `__is_cpp17_contiguous_iterator` of all relevant
    standard iterator types. Particularly check that vector::iterator
    is still considered contiguous in all C++ modes, even C++03.

After this patch, there continues to be no supported way to write your
own iterator type in C++17-and-earlier such that libc++ will consider it
"contiguous"; however, we now fully support the C++20 approach (in C++20
mode only). If you want user-defined contiguous iterators in C++17-and-earlier,
libc++'s position is "please upgrade to C++20."

Differential Revision: https://reviews.llvm.org/D94807
2021-02-03 16:28:38 -05:00
Reid Kleckner bab7486416 Disable CFI in __get_elem to allow casting a pointer to uninitialized memory
Fixes usage of shared_ptr with CFI enabled, which is llvm.org/pr48993.

Differential Revision: https://reviews.llvm.org/D95827
2021-02-02 12:39:24 -08:00
Mehdi Amini 68f66f37d7 Revert "[libc++][format] Add basic_format_parse_context."
This reverts commit 35a57f39b5.

A build is broken during clang bootstrap with:

In file included from ../libcxx/src/format.cpp:9:
/tmp/ci-nGNyLRM9V3/include/c++/v1/format:153:16: error: no member named 'is_constant_evaluated' in namespace 'std::__1'
    if (_VSTD::is_constant_evaluated() && __id >= __num_args_)
        ~~~~~~~^
1 error generated.
2021-02-01 21:18:11 +00:00
Mark de Wever 35a57f39b5 [libc++][format] Add basic_format_parse_context.
Implements parts of:
- P0645 Text Formatting

Depends on D92214

Reviewed By: ldionne, curdeius, #libc

Differential Revision: https://reviews.llvm.org/D93166
2021-02-01 20:19:20 +01:00
Mark de Wever 3ffc53ba16 [libc++] Implements concept default_initializable.
Implements:
- LWG3149 DefaultConstructible should require default initialization

Implements parts of:
 - P0898R3 Standard Library Concepts
 - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D91986

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D93461
2021-02-01 19:13:24 +01:00
Ruslan Arutyunyan c448ea948c [libc++] Fix for the Bug 41784
Add deleted volatile copy-assignment operator in the most derived atomic
to fix the Bug 41784. The root cause: there is an `operator=(T) volatile`
that has better match than the deleted copy-assignment operator of the base
class when `this` is `volatile`. The compiler sees that right operand of
the assignment operator can be converted to `T` and chooses that path
without taking into account the deleted copy-assignment operator of the
base class.

The current behavior on libstdc++ is different from what we have in libc++.
On the same test compilation fails with libstdc++. Proof: https://godbolt.org/z/nebPYd
(everything is the same except the -stdlib option).

I choose the way with explicit definition of copy-assignment for atomic
in the most derived class. But probably we can fix that by moving
`operator=(T)` overloads to the base class from both specializations.
At first glance, it shouldn't break anything.

Differential Revision: https://reviews.llvm.org/D90968
2021-02-01 10:14:22 -05:00
Mark de Wever 18fe3fe0e7 [libc++] Implements concept constructible_from
Implements parts of:
- P0898R3 Standard Library Concepts
- P1754 Rename concepts to standard_case for C++20, while we still can

Depends on: D91004

Reviewed By: ldionne, cjdb, #libc

Differential Revision: https://reviews.llvm.org/D91986
2021-01-28 18:32:47 +01:00
Mark de Wever 081c1db02d [libc++] Implement format_error.
This is the first step at implementing <format>. It adds the <format> header
and implements the `format_error`. class.

Implemnts parts of:
-P0645 Text Formatting

Reviewed By: ldionne, #libc, miscco, curdeius

Differential Revision: https://reviews.llvm.org/D92214
2021-01-28 18:02:53 +01:00
Arthur O'Dwyer 207d4be4d9 [libc++] [P0879] constexpr std::nth_element, and rewrite its tests.
This patch is more than just adding the `constexpr` keyword, because
the old code relied on `goto`, and `goto` is not constexpr-friendly.
Refactor to eliminate `goto`, and then mark it as constexpr in C++20.

I freely admit that the name `__nth_element_partloop` is bad;
I couldn't find any better name because I don't really know
what this loop is doing, conceptually. Vice versa, I think
`__nth_element_find_guard` has a decent name.

Now the only one we're still missing from P0879 is `sort`.

Differential Revision: https://reviews.llvm.org/D93557
2021-01-28 11:59:00 -05:00
Arthur O'Dwyer 5386aa2627 [libc++] [P0879] constexpr heap and partial_sort algorithms
Now the only ones we're still missing from P0879
are `sort` and `nth_element`.

Differential Revision: https://reviews.llvm.org/D93512
2021-01-27 10:26:06 -05:00
Simon Tatham 7b3ba8dd02 [libcxx] Update include/__libcpp_version to match include/__config
https://reviews.llvm.org/rG5369517d20dd362a178a1b2d6c398d8898ee4620
bumped the version number in __config to 13000, causing a test failure
in libcxx/test/libcxx/libcpp_version.pass.cpp because now the two
don't match.

This is the only part of the post-release TODO in
libcxx/docs/Contributing.rst that wasn't done by that commit.
2021-01-27 15:16:55 +00:00
Tom Stellard 5369517d20 Bump the trunk major version to 13
and clear the release notes.
2021-01-26 19:37:55 -08:00
Arthur O'Dwyer f9b6fd269b [libc++] Support immovable return types in std::function.
LWG reflector consensus is that this was a bug in libc++.
(In particular, MSVC also will fix it in their STL, soon.)
Bug originally discovered by Logan Smith.

Also fix `std::function<const void()>`, which should work
the same way as `std::function<void()>` in terms of allowing
"conversions" from non-void types.

Differential Revision: https://reviews.llvm.org/D94452
2021-01-25 19:34:41 -05:00
Nico Weber a206d991f9 libcxx: Try to fix build after D92044 2021-01-25 15:10:41 -05:00
Ruslan Arutyunyan 9d50958757 [libc++] Fix build after 51faba35fd
Differential Revision: https://reviews.llvm.org/D95372
2021-01-25 13:40:47 -05:00
Arthur O'Dwyer f851db3dae [libc++] [P0879] constexpr std::reverse, partition, *_permutation.
After this patch, the only parts of P0879 that remain missing will be
std::nth_element, std::sort, and the heap/partial_sort algorithms.

Differential Revision: https://reviews.llvm.org/D93443
2021-01-25 13:09:30 -05:00
Arthur O'Dwyer 3fbd3eaf28 [libc++] Implement [P0769] "Add shift to algorithm" (shift_left, shift_right)
I believe this is a complete implementation of std::shift_left and std::shift_right from
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0769r2.pdf

Some test cases copied-with-modification from D60027.

Differential Revision: https://reviews.llvm.org/D93819
2021-01-25 12:57:04 -05:00
Ruslan Arutyunyan 51faba35fd [libc++] Implement P0655R1 visit<R>: Explicit Return Type for visit
Differential Revision: https://reviews.llvm.org/D92044
2021-01-25 11:14:45 -05:00
Mark de Wever a8e06361dd [libc++] Implements concept destructible
Implements parts of:
- P0898R3 Standard Library Concepts
- P1754 Rename concepts to standard_case for C++20, while we still can

Reviewed By: ldionne, miscco, #libc

Differential Revision: https://reviews.llvm.org/D91004
2021-01-23 18:17:25 +01:00
Thorsten Schütt b973e2e2f2 [libc++] Introduce __bits
It has the low-level bit fiddling operations from bit. It eliminates a cyclic dependency between __bit_reference, bits, and vector. I want to exploit this in later patches.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D94908
2021-01-22 21:20:23 +01:00
Brad Smith 1be2524b7d [libcxx] Check return value for asprintf()
local __libcpp_asprintf_l() -> libc asprintf() was inspecting the pointer (with
indeterminate value) for failure, rather than the return value of -1.

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D94564
2021-01-21 19:43:11 -05:00
Wim Leflere 6ac9cb2a7c [libc++][P1679] add string contains
C++23 string contains implementation and tests

Paper: https://wg21.link/P1679R3
Standard (string): https://eel.is/c++draft/string.contains
Standard (string_view): https://eel.is/c++draft/string.view.ops#lib:contains,basic_string_view

Differential Revision: https://reviews.llvm.org/D93912
2021-01-19 14:35:07 -05:00
Louis Dionne 933518fff8 [libc++] Make LIBCXX_ENABLE_FILESYSTEM fully consistent
Previously, LIBCXX_ENABLE_FILESYSTEM controlled only whether the filesystem
support was compiled into libc++'s library. This commit promotes the
setting to a first-class option like LIBCXX_ENABLE_LOCALIZATION, where
the whole library is aware of the setting and features that depend on
<filesystem> won't be provided at all. The test suite is also properly
annotated such that tests that depend on <filesystem> are disabled when
the library doesn't support it.

This is an alternative to https://llvm.org/D94824, but also an improvement
along the lines of LIBCXX_ENABLE_LOCALIZATION that I had been wanting to
make for a while.

Differential Revision: https://reviews.llvm.org/D94921
2021-01-19 14:15:48 -05:00
Louis Dionne 68dba7eae1 [libc++] Unbreak the debug mode
When the Debug mode is enabled, we disable extern declarations because we
don't want to use the functions compiled in the library, which might not
have had the debug mode enabled when built. However, some extern declarations
need to be kept, because code correctness depends on it.

31e820378b removed those declarations, which had the unintended
consequence of breaking the debug build. This commit fixes that by
re-introducing a separate macro for the required extern declarations,
and adds a comment so that we don't fall into that trap in the future.

Differential Revision: https://reviews.llvm.org/D94718
2021-01-19 14:15:31 -05:00
Marek Kurdej a11f8b1ad6 [libc++] [P0935] [C++20] Eradicating unnecessarily explicit default constructors from the standard library.
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0935r0.html

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D91292
2021-01-19 08:22:06 +01:00
Louis Dionne 2cb4a96a99 [libc++] NFCI: Refactor allocator_traits
The implementation had a lot of boilerplate and was more complicated than
necessary. This NFC refactoring introduces a few macros to reduce code
duplication, and uses a consistent style and formatting for the whole file.

Differential Revision: https://reviews.llvm.org/D94544
2021-01-18 17:37:25 -05:00
Reid Kleckner 4f24d0dd53 Fix libc++ clang-cl build, swap attribute order
Clang insists that __attribute__ attributes precede __declspec
attributes. This is a longstanding known issue:
https://llvm.org/pr24559. Re-order the visibility and deprecation macros
to fix the build.

Differential Revision: https://reviews.llvm.org/D94788
2021-01-15 11:44:13 -08:00
Shoaib Meenai 0066a09579 [libc++] Give extern templates default visibility on gcc
Contrary to the current visibility macro documentation, it appears that
gcc does handle visibility attribute on extern templates correctly, e.g.
https://godbolt.org/g/EejuV7. We need this so that extern template
instantiations of classes not marked _LIBCPP_TEMPLATE_VIS (e.g.
__vector_base_common) are correctly exported with gcc when building with
hidden visibility.

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D35388
2021-01-12 18:30:56 -08:00
Brad Smith 79f99ba65d [libcxx] Port to OpenBSD
Add initial OpenBSD support.

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D94205
2021-01-12 14:21:11 -05:00
Arthur O'Dwyer eef4bdbb34 [libc++] Add a missing `<_Compare>` template argument.
Sometimes `_Compare` is an lvalue reference type, so letting it be
deduced is pretty much always wrong. (Well, less efficient than
it could be, anyway.)

Differential Revision: https://reviews.llvm.org/D93562
2021-01-12 14:18:24 -05:00
Marek Kurdej 1f1250151f [libc++] [C++2b] [P1048] Add is_scoped_enum and is_scoped_enum_v.
* https://wg21.link/p1048

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D94409
2021-01-12 17:08:20 +01:00
Arthur O'Dwyer ca1694b9d0 Re-enable __cpp_lib_constexpr_functional.
I accidentally disabled this feature-test macro in my D93830,
due to a rebasing conflict. It had been enabled by my D93815,
and should have remained enabled.
2021-01-08 17:30:04 -05:00
Louis Dionne 955dd7b7f3 [libc++] LWG2070: Use Allocator construction for objects created with allocate_shared
This patch updates `allocate_shared` to call `allocator_traits::construct`
when creating the object held inside the shared_pointer, and
`allocator_traits::destroy` when destroying it. This resolves
the part of P0674R1 that was originally filed as LWG2070.

This change is landed separately from the rest of P0674R1 because it is
incredibly tricky from an ABI perspective.

This is the reason why this change is so tricky is that we previously
used EBO in a compressed pair to store both the allocator and the object
type stored in the `shared_ptr`. However, starting in C++20, P0674
requires us to use Allocator construction for initializing the object type.
That requirement rules out the use of the EBO for the object type, since
using the EBO implies that the base will be initialized when the control
block is initialized (and hence we can't do it through Allocator construction).
Hence, supporting P0674 requires changing how we store the object type
inside the control block, which we do while being ABI compatible by using
some trickery with a properly aligned char buffer.

Fixes https://llvm.org/PR41900
Supersedes https://llvm.org/D62760

Differential Revision: https://reviews.llvm.org/D91201
2021-01-08 13:04:03 -05:00
Marek Kurdej 95729f95d8 [libc++] Add basic support for -std=c++2b.
* Add feature test macros.
* Add buildbot configuration generic-cxx2b that uses clang-tot.

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D94227
2021-01-08 19:02:41 +01:00
Arthur O'Dwyer 466df1718e [libc++] Update generate_feature_test_macro_components.py to match SD-6.
It's still a little confusing because in many cases C++17 and C++20
have different values, and libc++ implements the C++17 behavior but
not the C++20 behavior; 'unimplemented' can't represent that scenario.
Ultimately we probably ought to completely redesign the script to be
in terms of paper numbers, rather than language revisions, and make
it generate the CSV files like "Cxx2aStatusPaperStatus.csv" as well.

Most newly added macros are unimplemented. I've marked a few as implemented,
though, based on my reading of the code; for example I was pretty sure
`__cpp_lib_latch` is implemented since we have `<latch>`.

Differential Revision: https://reviews.llvm.org/D93830
2021-01-08 11:44:39 -05:00
Arthur O'Dwyer ff1b6f9ff2 [libc++] Alphabetize generate_feature_test_macro_components.py. NFCI.
For ease of comparing our list with the official SD-6 list, which is alphabetized.
https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations#library-feature-test-macros
This also alphabetizes the lists of headers in which the macros are
defined, which harmlessly alters many comments in <version>.
Also drive-by-fix some trivial flake8 warnings.
2021-01-07 18:11:46 -05:00
Marek Kurdej 044b892c79 [libc++] Use c++20 instead of c++2a consistently.
* The only exception is that the flag -std=c++2a is still used not to break compatibility with older compilers (clang <= 9, gcc <= 9).
* Bump _LIBCPP_STD_VER for C++20 to 20 and use 21 for the future standard (C++2b).

That's a preparation step to add c++2b support to libc++.

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D93383
2021-01-07 13:11:33 +01:00
Martin Storsjö f4485240a2 [libcxx] Handle backslash as path separator on windows
Differential Revision: https://reviews.llvm.org/D91138
2021-01-07 10:02:47 +02:00
Arthur O'Dwyer 781c476ce0 [libc++] ADL-proof vector<bool> by adding _VSTD:: qualification on calls.
This affects only vectors with weird/malicious allocators,
the same corner case covered in D91708, but for `vector<bool>` this time.

Also ADL-proof <__tree>, which affects only sets and maps with weird/malicious
allocators where the ADL trap is in the *fancy pointer type*.

Also drive-by _VSTD:: qualification in the guts of std::bind,
std::packaged_task, std::condition_variable.

Differential Revision: https://reviews.llvm.org/D93424
2021-01-06 18:23:50 -05:00
Arthur O'Dwyer 7b00e9fae3 [libc++] [P1065] Constexpr invoke, reference_wrapper, mem_fn, not_fn, default_searcher.
This completes the implementation of P1065 "constexpr INVOKE":
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1065r2.html

This doesn't yet complete the implementation of P1032 "Misc constexpr bits,"
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1032r1.html
but it does complete all of the <functional> bits, which means
that we can now set `__cpp_lib_constexpr_functional` for C++20.

This could use more constexpr tests for `std::reference_wrapper<T>`,
but the existing tests are extremely non-constexpr-friendly and
so I don't want to get into that rabbit-hole today.

Differential Revision: https://reviews.llvm.org/D93815
2020-12-28 13:24:07 -05:00
Martin Storsjö de698ae734 [libcxx] Convert paths to/from the right narrow code page for narrow strings on windows
On windows, the narrow, char based paths normally don't use utf8, but
can use many different native code pages, and this is what system
functions that operate on files, taking such paths/file names, interpret
them as.

Differential Revision: https://reviews.llvm.org/D91137
2020-12-18 11:24:52 +02:00
Martin Storsjö 48c6500b5b [libcxx] Reorder the two u8path functions, to make the following diff more readable. NFC.
Differential Revision: https://reviews.llvm.org/D91136
2020-12-18 11:24:52 +02:00
Martin Storsjö e83e0cac04 [libcxx] Make filesystem::path::value_type wchar_t on windows
Also set the preferred separator to backslash.

libc++ doesn't compile successfully for windows prior to this change,
and this change on its own isn't enough to make it compile successfully
either, but is the first stepping stone towards making it work correctly.

Most of operations.cpp will need to be touched, both for calling
functions that take wchar paths, but also for using other windows
specific functions instead of the posix functions used so far; that is
handled in later commits.

Changing parts of operations.cpp to generalize the string type handling
in code that doesn't touch system functions.

Differential Revision: https://reviews.llvm.org/D91135
2020-12-18 11:24:52 +02:00
Azat Khuzhin 6340f890bb [libc++] Fix extern C for __sanitizer_annotate_contiguous_container() (for gcc)
gcc supports it only at the beginning:

    $ g++ -o /dev/null -c /tmp/test_extern.cpp
    $ cat /tmp/test_extern.cpp
    extern "C" __attribute__ ((__visibility__("default"))) int foo();

Otherwise:

    $ g++ -o /dev/null -c /tmp/test_extern.cpp
    /tmp/test_extern.cpp:1:52: error: expected unqualified-id before string constant
        1 | __attribute__ ((__visibility__("default"))) extern "C" int foo();
          |                                                    ^~~
    $ cat /tmp/test_extern.cpp
    __attribute__ ((__visibility__("default"))) extern "C" int foo();

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D93316
2020-12-17 16:20:24 -05:00
Martin Storsjö 08a00c6f43 [libcxx] Remove ifdefs in the message to static_assert. NFC.
Differential Revision: https://reviews.llvm.org/D93283
2020-12-17 13:37:52 +02:00
Louis Dionne a00290ed10 [libc++] Fix allocate_shared when used with an explicitly convertible allocator
When the allocator is only explicitly convertible from other specializations
of itself, the new version of std::allocate_shared would not work because
it would try to do an implicit conversion. This patch fixes the problem
and adds a test so that we don't fall into the same trap in the future.
2020-12-15 11:50:06 -05:00
Louis Dionne b3d1d1f4ff [libc++] Remove unnecessary static assertion in allocate_shared
Checking that `T` is constructible from `Args...` is technically not
required by the Standard, although any implementation will obviously
error out if that's not satisfied. However, this check is incompatible
with using Allocator construction in the control block (upcoming change
as part of implementing P0674), so I'm removing it now to reduce the
upcoming diff as much as possible.

Differential Revision: https://reviews.llvm.org/D93246
2020-12-14 17:47:43 -05:00
Louis Dionne 3b7280f5e4 [libc++] NFCI: Return pointer instead of reference from __shared_ptr_emplace helper method
This makes __get_alloc consistent with __get_elem, and will reduce the
diff required to implement P0674R1.
2020-12-14 17:46:09 -05:00
Louis Dionne 19d57b5c42 [libc++] Refactor allocate_shared to use an allocation guard
This commit is a step towards making it easier to add support for arrays
in allocate_shared. Adding support for arrays will require writing multiple
functions, and the current complexity of writing allocate_shared is
prohibitive for understanding.

Differential Revision: https://reviews.llvm.org/D93130
2020-12-14 17:10:05 -05:00
Louis Dionne 7ad49aec12 [libc++] Split allocator_traits and pointer_traits out of <memory>
In addition to making the code a lot easier to grasp by localizing many
helper functions to the only file where they are actually needed, this
will allow creating helper functions that depend on allocator_traits
outside of <memory>.

This is done as part of implementing array support in allocate_shared,
which requires non-trivial array initialization algorithms that would be
better to keep out of <memory> for sanity. It's also a first step towards
splitting up our monolithic headers into finer grained ones, which will
make it easier to reuse functionality across the library. For example,
it's just weird that we had to define `addressof` inside <type_traits>
to avoid circular dependencies -- instead it's better to implement those
in true helper headers.

Differential Revision: https://reviews.llvm.org/D93074
2020-12-14 16:13:57 -05:00
Arthur O'Dwyer 3c8e31e17b [libc++] ADL-proof <functional> by adding _VSTD:: qualification on calls.
- std::reference_wrapper
- std::function
- std::mem_fn

While I'm here, remove _VSTD:: qualification from calls to `declval`
because it takes no arguments and thus isn't susceptible to ADL.

Differential Revision: https://reviews.llvm.org/D92884
2020-12-14 12:08:34 -05:00
Arthur O'Dwyer be4c657b01 [libc++] Consistently replace `::new(__p) T` with `::new ((void*)__p) T`. NFCI.
Everywhere, normalize the whitespace to `::new (EXPR) T`.
Everywhere, normalize the spelling of the cast to `(void*)EXPR`.

Without the cast to `(void*)`, the expression triggers ADL on GCC.
(I think this is a GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98249)
Even if it doesn't trigger ADL, it still seems incorrect to use any argument
that's not exactly `(void*)` because that opens the possibility of overload
resolution picking a user-defined overload of `operator new`, which would be
wrong.

Differential Revision: https://reviews.llvm.org/D93153
2020-12-14 12:08:34 -05:00
Arthur O'Dwyer b6f1917415 [libc++] Fix some one-off typos in comments. NFCI. 2020-12-14 09:54:58 -05:00
Arthur O'Dwyer ce9ac549c9 [libc++] Remove __is_construct::__nat. NFCI.
This type has been unused since commit 5b4cc84b87.
2020-12-14 09:54:58 -05:00
Arthur O'Dwyer e9eb99999f [libc++] s/insertible/insertable/g. NFCI. 2020-12-14 09:54:58 -05:00
Arthur O'Dwyer 1d7c39e14e [libc++] s/Birdirectional/Bidirectional/g. NFCI. 2020-12-14 09:54:57 -05:00
Louis Dionne ece3e5bb8b [libc++] NFCI: Implement make_shared as allocate_shared with std::allocator
This simplifies the implementation, and it appears to be equivalent since
make_shared was allocating memory with std::allocator anyway.

Differential Revision: https://reviews.llvm.org/D93071
2020-12-11 12:01:48 -05:00
Marek Kurdej da97d12cc0 [libc++] Remove invalid use of `#if _LIBCPP_STD_VER >= 11`, as `_LIBCPP_STD_VER` can never be less than 11.
The relevant part of `__config` is:
```
#ifndef _LIBCPP_STD_VER
#  if  __cplusplus <= 201103L
#    define _LIBCPP_STD_VER 11
```

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D93025
2020-12-11 08:31:59 +01:00
Arthur O'Dwyer 3696227c10 [libc++] ADL-proof by adding _VSTD:: qualifications to memmove etc.
Generally these calls aren't vulnerable to ADL because they involve only
primitive types. The ones in <list> and <vector> drag in namespace std
but that's OK; the ones in <fstream> and <strstream> are vulnerable
iff `CharT` is an enum type, which seems far-fetched.
But absolutely zero of them *need* ADL to happen; so in my opinion
they should all be consistently qualified, just like calls to any
other (non-user-customizable) functions in namespace std.

Also: Include <cstring> and <cwchar> in <__string>.
We seemed to be getting lucky that <memory> included <iterator>
included <iosfwd> included <wchar.h>. That gave us the
global-namespace `wmemmove`, but not `_VSTD::wmemmove`.
This is now fixed.

I didn't touch these headers:
<ext/__hash> uses strlen, safely
<support/ibm/locale_mgmt_aix.h> uses memcpy, safely
<string.h> uses memchr and strchr, safely
<wchar.h> uses wcschr, safely
<__bsd_locale_fallbacks.h> uses wcsnrtombs, safely

Differential Revision: https://reviews.llvm.org/D93061
2020-12-10 22:03:12 -05:00
Arthur O'Dwyer b12ea06521 [libc++] Include C++ headers, not C headers, in <charconv>.
This matches how libc++ does it in all other C++ headers
(that is, headers not ending in ".h").
We need to include <cstring> if we want to use `_VSTD::memmove`
instead of unqualified ADL `memmove`. Even though ADL doesn't
physically matter in <charconv>'s specific case, I'm trying
to migrate libc++ to using `_VSTD::memmove` for all cases
(because some of them do matter, and this way it's easier to
grep for outliers).

Differential Revision: https://reviews.llvm.org/D92875
2020-12-10 22:03:12 -05:00
Louis Dionne 092e8a7ea3 [libc++] NFCI: Refactor __shared_ptr_emplace
This is the first of a series of patches leading up to the implementation
of P0674r1, i.e. array support in allocate_shared. I am splitting this
up into multiple patches because the overall change is very tricky and
I want to isolate potential breakage.
2020-12-10 16:45:58 -05:00
Richard Smith 2a2c228c7a Add new 'preferred_name' attribute.
This attribute permits a typedef to be associated with a class template
specialization as a preferred way of naming that class template
specialization. This permits us to specify that (for example) the
preferred way to express 'std::basic_string<char>' is as 'std::string'.

The attribute is applied to the various class templates in libc++ that have
corresponding well-known typedef names.

This is a re-commit. The previous commit was reverted because it exposed
a pre-existing bug that has since been fixed / worked around; see
PR48434.

Differential Revision: https://reviews.llvm.org/D91311
2020-12-09 12:22:35 -08:00
Arthur O'Dwyer 1968804ac7 [libc++] Add _VSTD:: qualifications to ADL-proof <algorithm>.
Relevant blog post: https://quuxplusone.github.io/blog/2019/09/26/uglification-doesnt-stop-adl/

Differential Revision: https://reviews.llvm.org/D92776
2020-12-08 17:05:38 -05:00
Arthur O'Dwyer 35c3b53943 [libc++] ADL-proof __libcpp_is_nothrow_constructible.
The GCC C++20 buildbot hit this ADL call; Clang doesn't,
presumably because it uses a compiler builtin instead of
this codepath in <type_traits>.
https://buildkite.com/llvm-project/libcxx-ci/builds/674
2020-12-08 17:05:38 -05:00
Louis Dionne a65dc08d10 [libc++] Implement missing feature-test macro __cpp_lib_shared_ptr_arrays
This was forgotten when we implemented support for arrays in std::shared_ptr
in https://reviews.llvm.org/D62259.
2020-12-08 15:46:45 -05:00
Yuriy Chernyshov b526d87618 [libc++] Add std::hash<char8_t> specialization if char8_t is enabled
Differential Revision: https://reviews.llvm.org/D92325
2020-12-08 13:46:18 -05:00
Arthur O'Dwyer c0428b3c0c [libc++] ADL-proof <iterator>. `__convert_to_integral` is not a customization point.
The interesting change here is that we no longer consider `__convert_to_integral`
an ADL customization point for the user's types. I think the new behavior
is defensible. The old behavior had come from D7449, where Marshall explicitly
said "people can't define their own [`__convert_to_integral` overloads]."

Differential Revision: https://reviews.llvm.org/D92814
2020-12-08 11:19:16 -05:00
Richard Smith a1344779ab Revert "Add new 'preferred_name' attribute."
This change exposed a pre-existing issue with deserialization cycles
caused by a combination of attributes and template instantiations
violating the deserialization ordering restrictions; see PR48434 for
details.

A previous commit attempted to work around PR48434, but appears to have
only been a partial fix, and fixing this properly seems non-trivial.
Backing out for now to unblock things.

This reverts commit 98f76adf4e and
commit a64c26a47a.
2020-12-08 00:42:48 -08:00
Richard Smith 98f76adf4e Add new 'preferred_name' attribute.
This attribute permits a typedef to be associated with a class template
specialization as a preferred way of naming that class template
specialization. This permits us to specify that (for example) the
preferred way to express 'std::basic_string<char>' is as 'std::string'.

The attribute is applied to the various class templates in libc++ that have
corresponding well-known typedef names.

Differential Revision: https://reviews.llvm.org/D91311
2020-12-07 12:53:07 -08:00
Marek Kurdej bf8683adfa [libc++] [docs] Mark LWG3055 as complete. Use string_view instead of string in path::operator+=(ECharT).
The issue didn't change the behaviour which is tested in libcxx/test/std/input.output/filesystems/class.path/path.member/path.concat.pass.cpp.

The change to use string_view instead of string is not strictly necessary.

<filesystem> was added in commit 998a5c8831 (Implement <filesystem>).

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D92731
2020-12-07 20:18:09 +01:00
Marek Kurdej e2279c2350 [libc++] [docs] Mark P1865 as complete since 11.0 as it was implemented together with P1135. Fix synopses in <barrier> and <latch>.
It was implemented in commit 54fa9ecd30 ([libc++] Implementation of C++20's P1135R6 for libcxx).
2020-12-06 15:36:52 +01:00
Marek Kurdej f6326736ba [libc++] [LWG3374] Mark `to_address(const Ptr& p)` overload `constexpr`.
Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D92659
2020-12-06 15:26:26 +01:00
Zbigniew Sarbinowski e6c89a499d [SystemZ][ZOS] Fix the usage of pthread_t within libc++
This is the the minimal change introduced in [[ https://reviews.llvm.org/D88599 | D88599 ]]  to unblock the controversial change and discussion of proper separation between thread from thread id which will continue in D88599.

This patch will address the differences of definition of pthread_t on z/OS vs. Linux and other OS. Main trick to make the code work on z/OS relies on redefining libcpp_thread_id type and _LIBCPP_NULL_THREAD macro. This is necessary to separate initialization of libcxx_thread_id from the one of __libcxx_thread_t;

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D91875
2020-12-05 17:46:30 +00:00
Arthur O'Dwyer b8bc4e153f [libc++] Update the commented "synopsis" in <algorithm> to match current reality.
The synopsis now reflects what's implemented. It does NOT reflect
all of what's specified in C++20. The "constexpr in C++20" markings
are still missing from these 12 algorithms, because they are still
unimplemented by libc++:

    reverse partition sort nth_element next_permutation prev_permutation
    push_heap pop_heap make_heap sort_heap partial_sort partial_sort_copy

All of the above algorithms were excluded from [P0202].

All of the above algorithms were made constexpr in [P0879] (along with
swap_ranges, iter_swap, and rotate — we've already implemented those three).

Differential Revision: https://reviews.llvm.org/D92255
2020-12-04 17:53:54 -05:00
Arthur O'Dwyer 14098cf6c0 [libc++] [P0202] constexpr set_union, set_difference, set_symmetric_difference, merge
These had been waiting on the ability to use `std::copy` from
constexpr code (which in turn had been waiting on the ability to
use `is_constant_evaluated()` to switch between `memmove` and non-`memmove`
implementations of `std::copy`). That work landed a while ago,
so these algorithms can all be constexpr in C++20 now.

Simultaneously, update the tests for the set algorithms.

- Use an element type with "equivalent but not identical" values.
- The custom-comparator tests now pass something different from `operator<`.
- Make the constexpr coverage match the non-constexpr coverage.

Differential Revision: https://reviews.llvm.org/D92255
2020-12-04 17:53:54 -05:00
Brett Gutstein 297c839e2d [libc++] fix std::sort(T**, T**)
previously, invocations of std::sort(T**, T**) casted the arguments to
(size_t *). this breaks sorting on systems for which pointers don't fit
in a size_t. change the cast to (uintptr_t *) and add a test.

Differential Revision: https://reviews.llvm.org/D92190
2020-12-04 16:05:21 -05:00
Martin Storsjö 6be11e35d5 [libcxx] Implement c++2a char8_t input/output of std::filesystem::path
This implements the std::filesystem parts of P0482 (which is already
marked as in progress), and applies the actions that are suggested
in P1423.

Differential Revision: https://reviews.llvm.org/D90222
2020-12-04 11:37:05 +02:00
Arthur O'Dwyer d430330788 [libc++] Update and normalize the "all the headers" tests.
Some C++20 headers weren't added properly to all three of these
test files. Add them, and take the time to normalize the formatting
so that

    diff <(grep '#include' foo.cpp) <(grep '#include' bar.cpp)

shows no diffs (except that `no_assert_include` deliberately
excludes `<cassert>`).

- Add macro guards to <{barrier,latch,semaphore}>.
- Add macro guards to <experimental/simd>.
- Remove an include of <cassert> from <semaphore>.
- Instead, include <cassert> in the semaphore tests.

Differential Revision: https://reviews.llvm.org/D92525
2020-12-03 15:01:38 -05:00
zoecarver 644f68ed4d [libc++] Add slice_array operator= valarray overload.
Add the slice_array::operator=(const std::valarray<T>& val_arr) overload.

Fixes https://llvm.org/PR40792.

Differential Revision: https://reviews.llvm.org/D58735
2020-12-02 10:49:20 -08:00
Marek Kurdej a984dcaf7c [libc++] [P0482] [C++20] Implement missing bits for codecvt and codecvt_byname.
Add codecvt*<char16_t, char8_t> and codecvt*<char32_t, char8_t>.
Deprecate codecvt<char(16|32)_t, char>.
Enable disabled tests.
Update _LIBCPP_STD_VER to use 20 for C++20. Add _LIBCPP_DEPRECATED_IN_CXX20 macro.

Reviewed By: ldionne, #libc, #libc_abi

Differential Revision: https://reviews.llvm.org/D91517
2020-12-02 09:01:58 +01:00
Martin Storsjö 0d7bd72f5a [libcxx] Apply msvcrt specific exception for lgamma() to mingw configurations, too
This fixes linking code that uses some bits of the <random> header
on mingw targets.

Differential Revision: https://reviews.llvm.org/D92379
2020-12-02 09:55:16 +02:00
Arthur O'Dwyer e181a6aedd s/instantate/instantiate/ throughout. NFCI.
The static_assert in "libcxx/include/memory" was the main offender here,
but then I figured I might as well `git grep -i instantat` and fix all
the instances I found. One was in user-facing HTML documentation;
the rest were in comments or tests.
2020-12-01 22:13:40 -05:00
Arthur O'Dwyer d586f92c94 [libc++] Consistently replace `std::` qualification with `_VSTD::` or nothing. NFCI.
I used a lot of `git grep` to find places where `std::` was being used
outside of comments and assert-messages. There were three outcomes:

- Qualified function calls, e.g. `std::move` becomes `_VSTD::move`.
    This is the most common case.

- Typenames that don't need qualification, e.g. `std::allocator` becomes `allocator`.
    Leaving these as `_VSTD::allocator` would also be fine, but I decided
    that removing the qualification is more consistent with existing practice.

- Names that specifically need un-versioned `std::` qualification,
    or that I wasn't sure about. For example, I didn't touch any code in
    <atomic>, <math.h>, <new>, or any ext/ or experimental/ headers;
    and I didn't touch any instances of `std::type_info`.

In some deduction guides, we were accidentally using `class Alloc = typename std::allocator<T>`,
despite `std::allocator<T>`'s type-ness not being template-dependent.
Because `std::allocator` is a qualified name, this did parse as we intended;
but what we meant was simply `class Alloc = allocator<T>`.

Differential Revision: https://reviews.llvm.org/D92250
2020-12-01 22:13:39 -05:00
Arthur O'Dwyer 40950a44b9 [libc++] ADL-proof <thread>, and eliminate `using namespace chrono`.
Since we know exactly which identifiers we expect to find in `chrono`,
a using-directive seems like massive overkill. Remove the directives
and qualify the names as needed.

One subtle trick here: In two places I replaced `*__p` with `*__p.get()`.
The former is an unqualified call to `operator*` on a class type, which
triggers ADL and breaks the new test. The latter is a call to the
built-in `operator*` on pointers, which specifically
does NOT trigger ADL thanks to [over.match.oper]/1.

Differential Revision: https://reviews.llvm.org/D92243
2020-12-01 22:13:39 -05:00
Louis Dionne 2671fccf03 [libc++] NFC: Remove unused macros in <__config> 2020-12-01 16:51:25 -05:00
Louis Dionne c30d5101f1 [libc++] Optimize the number of assignments in std::exclusive_scan
Reported in https://twitter.com/blelbach/status/1169807347142676480

Differential Revision: https://reviews.llvm.org/D67273
2020-12-01 12:49:45 -05:00
Zequan Wu 871f96eed3 [libcxx] remove checks for __STDCPP_THREADS__ as it is defined by compiler
Differential Revision: https://reviews.llvm.org/D92349
2020-11-30 16:36:47 -08:00
Harald van Dijk fba0b65f72
[libc++] hash<long double>: adjust for x86-64 ILP32
x86-64 ILP32 mode (x32) uses 32-bit size_t, so share the code with ix86 to zero out padding bits, not with x86-64 LP64 mode.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D91349
2020-11-29 13:52:28 +00:00
Mark de Wever 67c88e47bd [libc++] P1645 constexpr for <numeric>
Implements P1645: constexpr for <numeric> algorithms

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D90569
2020-11-28 17:02:54 +01:00
Arthur O'Dwyer 03ee461276 [libc++] Consistently unparenthesize `numeric_limits<T>::max`. NFCI.
I think people were sometimes parenthesizing `(foo::max)()` out of
misplaced concern that an unparenthesized `foo::max()` would trip up
Windows' `max(a,b)` macro. However, this is not the case: `max(a,b)`
should be tripped up only by an unparenthesized call to `foo::max(a,b)`,
and in fact we already do `_VSTD::max(a,b)` all over the place anyway
without any guards.

However, in order to do it without guards, we must also
wrap the header in _LIBCPP_PUSH_MACROS, which <span> was not.

Differential Revision: https://reviews.llvm.org/D92240
2020-11-27 17:27:36 -05:00
zoecarver b2943765e7 [libc++] Use std::move in numeric algorithms (P0616R0).
This patch updates algorithms in <numeric> to use std::move
based on p0616r0. Moving values instead of copying them
creates huge speed improvements (see the paper for details).

Differential Revision: https://reviews.llvm.org/D61170
2020-11-27 11:09:44 -08:00
Bruce Mitchener 527a7fdfbd [libc++] Replace several uses of 0 by nullptr
Differential Revision: https://reviews.llvm.org/D43159
2020-11-27 10:00:21 -05:00
Marek Kurdej 841132efda [libc++] [P0966] [C++20] Fix bug PR45368 by correctly implementing P0966: string::reserve should not shrink.
This patch fixes the implementation as well as the tests that didn't actually test the wanted behaviour.
You'll find all the details in the bug report.
It adds as well deprecation warning for reserve() (without argument) and adds a test.

http://wg21.link/P0966R1
https://bugs.llvm.org/show_bug.cgi?id=45368
https://reviews.llvm.org/D54992

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D91778
2020-11-26 10:13:12 +01:00
Louis Dionne a78aaa1ad5 [libc++] Factor out common logic for calling aligned allocation
There were a couple of places where we needed to call the underlying
platform's aligned allocation/deallocation function. Instead of having
the same logic all over the place, extract the logic into a pair of
helper functions __libcpp_aligned_alloc and __libcpp_aligned_free.

The code in libcxxabi/src/fallback_malloc.cpp looks like it could be
simplified after this change -- I purposefully did not simplify it
further to keep this change as straightforward as possible, since it
is touching very important parts of the library.

Also, the changes in libcxx/src/new.cpp and libcxxabi/src/stdlib_new_delete.cpp
are basically the same -- I just kept both source files in sync.

The underlying reason for this refactoring is to make it easier to support
platforms that provide aligned allocation through C11's aligned_alloc
function instead of posix_memalign. After this change, we'll only have
to add support for that in a single place.

Differential Revision: https://reviews.llvm.org/D91379
2020-11-25 15:44:50 -05:00
Arthur O'Dwyer bbf8a9ca3f [libc++] ADL-proof <variant> by adding _VSTD:: qualification on calls.
Differential Revision: https://reviews.llvm.org/D92036
2020-11-25 09:19:37 -05:00
Mark de Wever ecabb39ca1 Revert "[libc++] P1645 constexpr for <numeric>"
This reverts commit eb9b063539.

The commit fails to build on build bots using LLVM 8.
2020-11-25 13:46:08 +01:00
Mark de Wever eb9b063539 [libc++] P1645 constexpr for <numeric>
Implements P1645: constexpr for <numeric> algorithms

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D90569
2020-11-25 13:19:32 +01:00
Marek Kurdej 9c97e4ef45 [libc++] [P0482] [C++20] Implement missing bits for atomic
Added: ATOMIC_CHAR8_T_LOCK_FREE, atomic<char8_t>, atomic_char8_t.
http://wg21.link/P0482

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D91706
2020-11-24 21:07:57 +01:00
Louis Dionne 0ec73a61cc [libc++] NFC: Fix confusing indentation in <numeric> 2020-11-24 12:30:31 -05:00
Mark de Wever 1a036e9cc8 [libcxx] Implement P1956 rename low-level bit functions
Implements P1956: On the names of low-level bit manipulation functions.

Users may use older versions of libc++ or other standard libraries with the old names. In order to keep compatibility the old functions are kept, but marked as deprecated.

The patch also adds a new config macro `_LIBCPP_DEPRECATED_MSG`. Do you prefer a this is a separate patch?

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D90551
2020-11-24 17:37:06 +01:00
Arthur O'Dwyer ee95c7020c [libc++] Remove _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED.
Zoe Carver says: "We decided that libc++ only supports C++20 constexpr algorithms
when `is_constant_evaluated` is also supported. Here's a link to the discussion."
https://reviews.llvm.org/D65721#inline-735682

Remove _LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED from tests, too.
See Louis's 5911e6a885 if needed to fix bots.
I've applied `UNSUPPORTED: clang-8` preemptively to the altered tests;
I don't know for sure that this was needed, because no clang-8 buildbots
are triggered on pull requests.
2020-11-24 11:04:21 -05:00
zoecarver 0a20660c8f [libcxx] Resolve LWG 2724 protected -> private.
Fixes LWG issue 2724: "The protected virtual member functions of memory_resource should be private."

Differential Revision: https://reviews.llvm.org/D66615
2020-11-23 14:27:22 -08:00
Arthur O'Dwyer 6e965df605 Revert "Revert "[libc++] ADL-proof <vector> by adding _VSTD:: qualification on calls.""
This reverts commit 620adacf87.

Fix: unsupport C++03 for the new test, define helpers before __swap_allocator

(1) Add _VSTD:: qualification to __swap_allocator.

(2) Add _VSTD:: qualification consistently to __to_address.

(3) Add some more missing _VSTD:: to <vector>, with a regression test.
This part is cleanup after d9a4f936d0.

Note that a vector whose allocator actually runs afoul of any of these ADL calls will
likely also run afoul of simple things like `v1 == v2` (which is also an ADL call).
But, still, libc++ should be consistent in qualifying function calls wherever possible.

Relevant blog post: https://quuxplusone.github.io/blog/2019/09/26/uglification-doesnt-stop-adl/

Differential Revision: https://reviews.llvm.org/D91708
2020-11-20 20:59:18 -05:00
Zbigniew Sarbinowski 2c7e24c4b6 Guard init_priority attribute within libc++
Not all platforms support priority attribute. I'm moving conditional definition of this attribute to `include/__config`.

Reviewed By: #libc, aaron.ballman

Differential Revision: https://reviews.llvm.org/D91565
2020-11-20 15:53:26 -05:00
Mikhail Goncharov 620adacf87 Revert "[libc++] ADL-proof <vector> by adding _VSTD:: qualification on calls."
This reverts commit 40267cc989.

Build fails, e.g. http://lab.llvm.org:8011/#/builders/23/builds/108
2020-11-19 15:36:49 +01:00
Arthur O'Dwyer 40267cc989 [libc++] ADL-proof <vector> by adding _VSTD:: qualification on calls.
(1) Add _VSTD:: qualification to __swap_allocator.

(2) Add _VSTD:: qualification consistently to __to_address.

(3) Add some more missing _VSTD:: to <vector>, with a regression test.
This part is cleanup after d9a4f936d0.

Note that a vector whose allocator actually runs afoul of any of these ADL calls will
likely also run afoul of simple things like `v1 == v2` (which is also an ADL call).
But, still, libc++ should be consistent in qualifying function calls wherever possible.

Relevant blog post: https://quuxplusone.github.io/blog/2019/09/26/uglification-doesnt-stop-adl/

Differential Revision: https://reviews.llvm.org/D91708
2020-11-19 09:19:16 -05:00
Louis Dionne be00e8893f [libc++] Clarify how we pick the typeinfo comparison
This commit makes it clear that the typeinfo comparison implementation
is automatically selected by default, and that the CMake option only
overrides the value. This has been a source of confusion and bugs ever
since we've introduced complexity in that area, so I'm trying to simplify
it while still allowing for some control on the implementation.

Differential Revision: https://reviews.llvm.org/D91574
2020-11-18 16:58:45 -05:00
Xiang Xiao f0785c1f7a [libcxx] Port to NuttX (https://nuttx.apache.org) RTOS
Since NuttX conform to POSIX standard, the code need to add is very simple.

Differential Revision: https://reviews.llvm.org/D88718
2020-11-18 16:20:56 -05:00
Mark de Wever 3abaf6cde7 [libc++] Implements multiline regex support.
This resolves LWG2503.
2020-11-18 18:17:36 +01:00
Martin Storsjö 83a03867da [libcxx] Add missing _LIBCPP_FUNC_VIS on a few win32 locale functions
These functions are called directly from the public installed
headers, and thus need to be exported in DLL builds, just like
some other functions in the same header (e.g. snprintf_l).

This fixes e.g. test/std/localization/locale.categories/category.numeric/locale.num.get/facet.num.get.members/get_float.pass.cpp
in mingw configurations.

Differential Revision: https://reviews.llvm.org/D91328
2020-11-18 11:04:55 +02:00
Eric Fiselier 9c09757bca [libc++] Revert switch-based std::variant implementation again.
These changes cause substantial binary size increases for non-opt builds.
For example, the visit.pass.cpp test grows from 20k to 420k.

Further work will be done to re-land this patch without the size increases,
but that work is proving too tricky to fix forward.

This patch fully reverts:

* 35d2269111

And it partially reverts:

* bb43a0cd4a

The latter of which added XFAIL's to new variant tests
because the new implementation needlessly makes non-throwing code
paths in variant invoke throwing code.

This means the reverted change also breaks source backwards compat
with code compiled on OS X targeting older system dylibs. There is no
need for this to be the case. We should fix it before recommitting.

Reviewed as:
https://reviews.llvm.org/D91662
2020-11-17 23:09:31 -05:00
Louis Dionne 48138e7338 [libc++] Do not error out when we don't know the file format
Erroring out prevents the library from working with other file formats
(e.g. in embedded). Since that error does not guard us from doing something
incorrect, it seems fine to just remove it.
2020-11-17 13:18:51 -05:00
Louis Dionne 121f27f3ac [libc++] Only include_next <wctype.h> if it exists
This allows building on platforms that don't provide that header.
2020-11-17 13:14:36 -05:00
Louis Dionne f1cf6b47e4 [libc++] Remove transitional #error message
It's been more than 4 years now, so anyone that was defining
_LIBCPP_TRIVIAL_PAIR_COPY_CTOR has had ample time to see that
error and fix their code.
2020-11-16 13:36:16 -05:00
Marek Kurdej d2acf22927 [gcc] Fix -Wempty-body warning. NFC. 2020-11-15 16:17:52 +01:00
Zbigniew Sarbinowski 6a8099e0f6 [libc++] Port the time functions to z/OS
This patch adds a shim for missing time functions on z/OS, and adds a
layer of indirection to account for differences in the timespec struct
on different systems.

This was originally committed as 173b51169b and reverted in 777ca48c9f
because the original commit also checked-in unrelated changes.

Differential Revision: https://reviews.llvm.org/D87940
2020-11-13 10:47:57 -05:00
Zbigniew Sarbinowski aa8a5b800d [SystemZ][ZOS] libcxx - no posix memalign
The unavailability of posix_memalign on z/OS forces us to define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION'. The use of posix_memalign is being used in libcxx/src/new.cpp.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D90178
2020-11-12 14:47:58 -05:00
Louis Dionne 997d41cdec [libc++] Instantiate additional <iostream> members in the dylib
This commit adds new explicit instantiations for some classes in <iostream>
in the library. This is done after noticing that many programs that use
streams end up containing weak definitions of these classes, which has a
negative impact on both code size and load times (due to the need to
resolve weak symbols at load time). Note that we are just adding the
additional explicit instantiations for the `char` specializations, since
the `wchar_t` specializations are not used as often, and as a result there
wouldn't be a clear benefit.

This change is not an ABI break, since we are just adding additional
symbols.

Differential Revision: https://reviews.llvm.org/D90677
2020-11-12 13:52:47 -05:00
Louis Dionne 777ca48c9f Revert "[SystemZ][ZOS] Porting the time functions within libc++ to z/OS"
This reverts commit 173b51169b. That commit was applied incorrectly,
and undid previous changes. That was clearly not intended.
2020-11-12 13:36:18 -05:00
Zbigniew Sarbinowski 173b51169b [SystemZ][ZOS] Porting the time functions within libc++ to z/OS
This patch is one part of many steps required to build libc++ and libc++abi libraries on z/OS.  This particular deals with time related functions and consists of the following 3 parts.

1) Initialization of :timeval within libc++ library need to be adjusted to work on z/OS.
The following is z/OS definition from time.h which includes additional aggregate member.
typedef signed int suseconds_t;
struct timeval {
time_t tv_sec;
char tv_usec_pad[4];
suseconds_t tv_usec;
};

In contracts the following is definition from time.h on Linux.

typedef long int __suseconds_t;
struct timeval
{
__time_t tv_sec;
__suseconds_t tv_usec;
};

2) In addition, retrieving ::timespec within libc++ library needs to be adjusted to compensate the difference of some of the members of ::stat depending of the target host.
Here are the 2 members in conflict on z/OS extracted from stat.h.
struct stat {
...
time_t st_atime;
time_t st_mtime;
...
};
In contract here is Linux equivalent from stat.h.
struct stat
{
...
struct timespec st_atim;
struct timespec st_mtim;
...
};

3) On Linux both members are of type timespec whereas on z/OS an object of type timespec need to be constructed first before retrieving it within libc++ library.

The libc++ header file __threading_support calls nanosleep, which is not available on z/OS.
The equivalent functionality will be implemented by using both sleep() and usleep().

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D87940
2020-11-12 11:29:13 -05:00
Ruslan Arutyunyan e5ec94a1a0 [libc++] Implement P0919R3: heterogenous lookup for unordered containers
Implement heterogenous lookup for unordered containers, including the
refinement from P1690R1.

Differential Revision: https://reviews.llvm.org/D87171
2020-11-11 17:44:42 -05:00
Louis Dionne 69ca17a92c [libc++] NFC: Simplify incude of <cstdlib>
We include <exception>, which includes <cstdlib> unconditionally anyway.
2020-11-11 17:04:32 -05:00
Xiang Xiao 20acf6d588 [libcxx] Check _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE first in __locale
This is consistent with what's done in locale.cpp, and it ensures that
we get the default rune table whenever _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
is defined, regardless of the actual platform.

Differential Revision: https://reviews.llvm.org/D91074
2020-11-11 15:32:59 -05:00
zoecarver 31dfaff3b3 [libc++] Change requirements on linear_congruential_engine.
This patch changes how linear_congruential_engine picks its randomization
algorithm. It adds two restrictions, `_OverflowOK` and `_SchrageOK`.
`_OverflowOK` means that m is a power of two so using the classic
`(a * x + c) % m` will create a meaningless overflow. The second checks
that Schrage's algorithm will produce results that are in bounds of min
and max. This patch fixes https://llvm.org/PR27839.

Differential Revision: D65041
2020-11-10 18:23:22 -08:00
Louis Dionne 02af11094f [libc++] NFC: Add helper methods to simplify __shared_ptr_emplace
The previous implementation was really difficult to follow, especially
with the get() method sharing the same name as std::unique_ptr::get().
2020-11-10 12:49:19 -05:00
Muiez Ahmed e72e785d47 [SystemZ][z/OS] Enable POSIX_l functions for z/OS
The aim of this patch is to enable POSIX _l functions for z/OS. In particular, the functions are provided with libc++ and this patch resorts to the fallback functions. Nonetheless, the functions are being added so the implementation of the ctype<> member functions can call them. The following changes were needed to allow for a successful build when using the libc++ library for z/OS.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D90319
2020-11-10 09:57:11 -05:00
Louis Dionne bb43a0cd4a [libc++] Add a Buildkite job that tests back-deployment on Apple
The current way we test this is pretty cheap, i.e. we download previously
released macOS dylibs and run against that. Ideally, we would require a
full host running the appropriate version of macOS, and we'd execute the
tests using SSH on that host. But since we don't have such hosts available
easily for now, this is better than nothing.

At the same time, also fix some tests that were failing when back
deploying.

Differential Revision: https://reviews.llvm.org/D90869
2020-11-05 18:26:08 -05:00
Louis Dionne 2eadbc8614 [libc++] Rework the whole availability markup implementation
Currently, vendor-specific availability markup is enabled by default.
This means that even when building against trunk libc++, the headers
will by default prevent you from using some features that were not
released in the dylib on your target platform. This is a source of
frustration since people building libc++ from sources are usually not
trying to use some vendor's released dylib.

For that reason, I've been thinking for a long time that availability
annotations should be off by default, which is the primary change that
this commit enables.

In addition, it reworks the implementation to make it easier for new
vendors to add availability annotations for their platform, and it
refreshes the documentation to reflect the current state of the codebase.

Finally, a CMake configuration option is added to control whether
availability annotations should be turned on for the flavor of libc++
being created. The intent is for vendors like Apple to turn it on, and
for the upstream libc++ to leave it off (the default).

Differential Revision: https://reviews.llvm.org/D90843
2020-11-05 12:28:52 -05:00
Louis Dionne 0df0d0fe2d [libc++] NFC: Remove trailing whitespace 2020-11-04 14:08:06 -05:00
Louis Dionne 6706342f48 [libc++] Remove the ability to not install the support headers
Those are part of the library, and shipping them just adds a tiny bit of
size to the distribution. This was originally added in b422ecc7de to
make it possible to match the Makefile build, which doesn't exist anymore.

The upside is build system simplification.
2020-11-04 11:45:34 -05:00
Louis Dionne d9a4f936d0 [libc++] Move <memory> helpers outside of std::allocator_traits
They don't really belong as members of allocator_traits.
2020-11-03 12:27:26 -05:00
Nico Weber 8954fd436c [libcxx] Fix regression where `ninja all` doesn't copy libcxx headers
Before 6db314e86b, when running cmake with clang, libcxx, and
compiler-rt enabled, building `ninja all` would run the
generate-cxx-headers target, due to the sanitizers depending on it.

After 6db314e86b, if LIBCXX_ENABLE_SHARED and LIBCXX_ENABLE_STATIC
and LIBCXX_INCLUDE_TESTS and LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY are
disabled (https://reviews.llvm.org/D82702#2153627), `ninja all`
no longer copies the libcxx headers, which means clang can't compile
programs like `#include <string>` on macOS.

Explicitly add the copy target to the all target to restore the old
behavior.
2020-11-01 21:34:51 -05:00
Michael Park 35d2269111 [libc++] Re-apply the switch-based std::variant implementation
This commit is a mass re-application of the following commits:

  7d15ece79c
  e0ec7a0206
  02197f7e50
  a175a96517

Those were temporarily reverted in 057028ed39, and never re-applied.
Re-committed by @ldionne (author edited for credit).

Differential Revision: https://reviews.llvm.org/D90168
2020-10-28 17:09:11 -04:00
Louis Dionne 91336a0c61 [libc++] Move the #error message for no localization to <locale.h>
<locale.h> is lower level than <__locale>, so that's where we want the
error to live for systems that don't provide localization support.
2020-10-28 09:49:37 -04:00
Martin Storsjö 70bba9ef35 [libcxx] Don't truncate intermediates to wchar_t when widening
On windows, wchar_t is 16 bit, while we might be widening chars to
char32_t.

This cast had been present since the initial commit, and removing it
doesn't seem to make any tests fail.

Differential Revision: https://reviews.llvm.org/D90228
2020-10-27 23:58:27 +02:00
Louis Dionne 88ffc72717 [libc++] Add a libc++ configuration that does not support localization
When porting libc++ to embedded systems, it can be useful to drop support
for localization, which these systems don't implement or care about.

Differential Revision: https://reviews.llvm.org/D90072
2020-10-27 14:56:30 -04:00
Martin Storsjö 0be27302d4 [libcxx] Fix typo in spelling of 'sentinel'. NFC.
Differential Revision: https://reviews.llvm.org/D90220
2020-10-27 20:38:32 +02:00
Louis Dionne 48e4b0fd3a [runtimes] Revert the libc++ __config_site change
This is a massive revert of the following commits (from most revent to oldest):

	2b9b7b5775.
	529ac33197
	28270234f1
	69c2087283
	b5aa67446e
	5d796645d6

After checking-in the __config_site change, a lot of things started breaking
due to widespread reliance on various aspects of libc++'s build, notably the
fact that we can include the headers from the source tree, but also reliance
on various "internal" CMake variables used by the runtimes build and compiler-rt.

These were unintended consequences of the change, and after two days, we
still haven't restored all the bots to being green. Instead, now that I
understand what specific areas this will blow up in, I should be able to
chop up the patch into smaller ones that are easier to digest.

See https://reviews.llvm.org/D89041 for more details on this adventure.
2020-10-23 09:41:48 -04:00
Louis Dionne ce565861c7 [libc++] Drop old workaround for iostreams instantiations missing from the dylib
On old Apple platforms (pre 10.9), we couldn't rely on the iostreams
explicit instantiations being part of the dylib. However, we don't
support back-deploying to such old deployment targets anymore, so the
workaround can be dropped.
2020-10-22 14:51:25 -04:00
Louis Dionne 69c2087283 [libc++] Fix compiler-rt build by copying libc++ headers to <build>/include
This commit should really be named "Workaround external projects depending
on libc++ build system implementation details". It seems that the compiler-rt
build (and perhaps other projects) is relying on the fact that we copy libc++
and libc++abi headers to `<build-root>/include/c++/v1`. This was changed
by 5d796645, which moved the headers to `<build-root>/projects/libcxx/include/c++/v1`
and broke the compiler-rt build.

I'm committing this workaround to fix the compiler-rt build, but we should
remove reliance on implementation details like that. The correct way to
setup the compiler-rt build would be to "link" against the `cxx-headers`
target in CMake, or to run `install-cxx-headers` using an appropriate
installation prefix, and then manually add a `-I` path to that location.
2020-10-21 16:56:33 -04:00
Louis Dionne b5aa67446e [libc++] Fix the installation of libc++ headers since the __config_site change 2020-10-21 12:54:42 -04:00
Louis Dionne 5d796645d6 [take 2] [libc++] Include <__config_site> from <__config>
Prior to this patch, we would generate a fancy <__config> header by
concatenating <__config_site> and <__config>. This complexifies the
build system and also increases the difference between what's tested
and what's actually installed.

This patch removes that complexity and instead simply installs <__config_site>
alongside the libc++ headers. <__config_site> is then included by <__config>,
which is much simpler. Doing this also opens the door to having different
<__config_site> headers depending on the target, which was impossible before.

It does change the workflow for testing header-only changes to libc++.
Previously, we would run `lit` against the headers in libcxx/include.
After this patch, we run it against a fake installation root of the
headers (containing a proper <__config_site> header). This makes use
closer to testing what we actually install, which is good, however it
does mean that we have to update that root before testing header changes.
Thus, we now need to run `ninja check-cxx-deps` before running `lit` by
hand.

This commit was originally applied in 1e46d1aa3 and reverted in eb60c487
because it broke the libc++abi and libunwind test suites. This has now
been fixed.

Differential Revision: https://reviews.llvm.org/D89041
2020-10-21 10:40:33 -04:00
Louis Dionne eb60c48744 [libc++] Revert "Include <__config_site> from <__config>"
This temporarily reverts commit 1e46d1aa until I find a solution to fix
the libc++abi and libunwind test suites with that change.
2020-10-21 09:18:29 -04:00
Louis Dionne 1e46d1aa3f [libc++] Include <__config_site> from <__config>
Prior to this patch, we would generate a fancy <__config> header by
concatenating <__config_site> and <__config>. This complexifies the
build system and also increases the difference between what's tested
and what's actually installed.

This patch removes that complexity and instead simply installs <__config_site>
alongside the libc++ headers. <__config_site> is then included by <__config>,
which is much simpler. Doing this also opens the door to having different
<__config_site> headers depending on the target, which was impossible before.

It does change the workflow for testing header-only changes to libc++.
Previously, we would run `lit` against the headers in libcxx/include.
After this patch, we run it against a fake installation root of the
headers (containing a proper <__config_site> header). This makes use
closer to testing what we actually install, which is good, however it
does mean that we have to update that root before testing header changes.
Thus, we now need to run `ninja check-cxx-deps` before running `lit` by
hand.

Differential Revision: https://reviews.llvm.org/D89041
2020-10-21 08:46:57 -04:00
Eric Fiselier 229db36474 [libc++] Make __shared_weak_count vtable consistent across all build configurations
This patch ensures that __shared_weak_count provides a consistent vtable
regardless of if RTTI is enabled or if we are targeting a static or shared
libc++ build.

This patch is technically ABI breaking, but only for a very specific
configuration that no vendor should be shipping.

Note that _LIBCPP_BUILD_STATIC is not normally defined when building
libc++.a, but instead it must be manually provided by the user or the
__config_site.

Differential Revision: https://reviews.llvm.org/D32838
2020-10-20 08:19:43 -04:00
Louis Dionne ec0dc70efc [libc++] Add more tests for operator<< on std::complex 2020-10-19 13:23:59 -04:00
Louis Dionne 6abc15ae3c [libc++] Reduce dependencies on <iostream> from <random>
We included <istream> and <ostream> from <random>, but really it is
sufficient to include <iosfwd> if we make sure we access ios_base
members through a dependent type. This allows us to break a hard
dependency of <random> on locales.
2020-10-15 13:40:18 -04:00
Louis Dionne e0d01294bc [libc++] Allow building libc++ on platforms without a random device
Some platforms, like several embedded platforms, do not provide a source
of randomness through a random device. This commit makes it possible to
build and test libc++ for such platforms, i.e. without std::random_device.

Surprisingly, the only functionality that doesn't work on such platforms
is std::random_device itself -- everything else in <random> still works,
one just has to find alternative ways to seed the PRNGs.
2020-10-15 12:20:29 -04:00
Louis Dionne 4abb519619 [libc++] NFCI: Define small methods of basic_stringstream inline
It greatly increases readability because defining the methods out-of-line
involves a ton of boilerplate template declarations.
2020-10-09 14:33:49 -04:00
Louis Dionne c778f6c4f9 [libc++] Clean up logic around aligned/sized allocation and deallocation
Due to the need to support compilers that implement builtin operator
new/delete but not their align_val_t overloaded versions, there was a
lot of complexity. By assuming that a compiler that supports the builtin
new/delete operators also supports their align_val_t overloads, the code
can be simplified quite a bit.

Differential Revision: https://reviews.llvm.org/D88301
2020-10-09 12:43:28 -04:00
Louis Dionne 12805513a6 [libc++] Remove some workarounds for C++03
We don't support any compiler that doesn't support variadics and rvalue
references in C++03 mode, so these workarounds can be dropped. There's
still *a lot* of cruft related to these workarounds, but I try to tackle
a bit of it here and there.
2020-10-09 12:35:13 -04:00
Louis Dionne 8da0df3d6d [libc++] Remove unused includes of Availability.h
Since ebaf1d5e2b, the macros defined in <Availability.h> are not used
anymore.
2020-10-07 18:03:40 -04:00
Louis Dionne 602c193e2a [libc++] Make sure __clear_and_shrink() maintains string invariants
__clear_and_shrink() was added in D41976, and a test was added alongside
it to make sure that the string invariants were maintained. However, it
appears that the test never ran under UBSan before, which would have
highlighted the fact that it doesn't actually maintain the string
invariants.

Differential Revision: https://reviews.llvm.org/D88849
2020-10-07 09:16:59 -04:00
Chris Palmer 9eff07a746 [libc++] Add assert to check bounds in `constexpr string_view::operator[]`
Differential Revision: https://reviews.llvm.org/D88864
2020-10-06 16:57:41 -04:00
Louis Dionne fe7245b772 [libc++] NFC: Rename variant helpers to avoid name clashes
Some system headers define __constructor and __destructor macros (for
Clang attributes constructor and destructor). While this is badly
behaved, it is easy for libc++ to work around this issue.
2020-10-05 16:41:25 -04:00
Louis Dionne 04fce1515b [libc++] Fix the build with GCC < 10
For now, we still need to support older GCCs, so work around the lack of
__is_constructible on older GCCs.
2020-10-02 18:01:48 -04:00
Louis Dionne 870827f652 [libc++] NFCI: Remove the _LIBCPP_DEBUG_MODE helper macro
It was used inconsistently and the name was pretty confusing, so we might
as well use `#if _LIBCPP_DEBUG_LEVEL == 2` consistently everywhere.
2020-10-02 15:11:23 -04:00
Louis Dionne 31e820378b [libc++] NFCI: Simplify macro definitions for the debug mode
The debug mode always had three possibilities:
- _LIBCPP_DEBUG is undefined => no assertions
- _LIBCPP_DEBUG == 0         => some assertions
- _LIBCPP_DEBUG == 1         => some assertions + iterator checks

This was documented that way, however the code did not make this clear
at all. The discrepancy between _LIBCPP_DEBUG and _LIBCPP_DEBUG_LEVEL
was especially confusing. I reworked how the various macros are defined
without changing anything else to make the code clearer.
2020-10-02 15:11:23 -04:00
Louis Dionne 1a92de0064 [libc++] NFCI: Remove _LIBCPP_EXTERN_TEMPLATE2
This seems to have been added a long time ago as a temporary help
for debugging some <regex> issue, but it's really the same as
_LIBCPP_EXTERN_TEMPLATE.
2020-10-02 14:31:43 -04:00
Petr Hosek 8d26760a95 [CMake] Use -isystem flag to access libc++ headers
This is a partial revert of D62155. Rather than copying libc++ headers
into the build directory to be later overwritten by the final headers,
use -isystem flag to access libc++ headers during CMake checks. This
should address the occasional flake we've seen, especially on Windows
builders where CMake fails to overwrite __config with the final version.

Differential Revision: https://reviews.llvm.org/D88454
2020-10-01 12:09:27 -07:00
Richard Smith afcf9c47c5 Fix test failures with trunk clang
- Make the consteval constructor for the zero type be noexcept
- Don't expect three-way comparison of 0 against a comparison category
  to fail
2020-09-29 17:10:07 -07:00
Richard Smith bf434a5f17 Improve the representation of <compare>'s zero-only type.
* Use an empty struct instead of a member pointer to represent this
  type, so that we don't actually pass a zero member pointer at runtime.

* Mark the constructor as consteval to ensure that no code is emitted
  for it whenever possible.

* Add a honeypot constructor to reject all non-int arguments, so that
  the only argument that can arrive at the real constructor is the
  literal 0.

This results in better generated code, and rejecting invalid comparisons
against nullptr, 0L, and so on, while also rejecting invalid comparisons
against (1-1) and similar that would be allowed if we required an
integer constant expression with value 0.

Differential Revision: https://reviews.llvm.org/D85051
2020-09-29 15:44:05 -07:00
Louis Dionne 3e5f9dacb0 [libc++] Fix tests on GCC 10
Also, remove workarounds for ancient Clangs from is_constructible tests.
2020-09-29 12:08:33 -04:00
Louis Dionne d092c91288 [libc++] Fix constexpr dynamic allocation on GCC 10
We're technically not allowed by the Standard to call ::operator new in
constexpr functions like __libcpp_allocate. Clang doesn't seem to complain
about it, but GCC does.
2020-09-28 17:44:31 -04:00
Louis Dionne 59f8ac3eb4 [libc++] Replace uses of __libcpp_allocate by std::allocator<>
Both are equivalent, however std::allocator can appear in constant
expressions and is higher level.
2020-09-28 16:09:42 -04:00
Louis Dionne c90dee1e90 [libc++] Re-apply fdc41e11f (LWG1203) without breaking the C++11 build
fdc41e11f was reverted in e46c1def5 because it broke the C++11 build.
We shouldn't be using enable_if_t in C++11, instead we must use
enable_if<...>::type.
2020-09-23 08:56:00 -04:00
Raphael Isemann e46c1def52 Revert "[libc++] Implement LWG1203"
This reverts commit fdc41e11f9. It causes the
libcxx/modules/stds_include.sh.cpp test to fail with:
libcxx/include/ostream:1039:45: error: no template named 'enable_if_t'; did you mean 'enable_if'?
template <class _Stream, class _Tp, class = enable_if_t<

Still investigating what's causing this and reverting in the meantime to get
the bots green again.
2020-09-23 10:13:38 +02:00
Louis Dionne 2404ed0202 [libc++] NFC: Collocate C++20 removed members of std::allocator 2020-09-22 17:40:14 -04:00
Louis Dionne fdc41e11f9 [libc++] Implement LWG1203
Libc++ had an issue where nonsensical code like

  decltype(std::stringstream{} << std::vector<int>{});

would compile, as long as you kept the expression inside decltype in
an unevaluated operand. This turned out to be that we didn't implement
LWG1203, which clarifies what we should do in that case.

rdar://58769296
2020-09-22 17:15:31 -04:00
Louis Dionne 0724f8bf47 [libc++] Implement C++20's P0784 (More constexpr containers)
This commit adds std::construct_at, and marks various members of
std::allocator_traits and std::allocator as constexpr. It also adds
tests and turns the existing tests into hybrid constexpr/runtime tests.

Thanks to Richard Smith for initial work on this, and to Michael Park
for D69803, D69132 and D69134, which are superseded by this patch.

Differential Revision: https://reviews.llvm.org/D68364
2020-09-22 11:20:33 -04:00
Louis Dionne bb09ef9598 [libc++] Fix failures when running the test suite without RTTI 2020-09-21 20:17:24 -04:00
Mark de Wever d4dd961300 Fixes complexity of map insert_or_assign with a hint.
Mitsuru Kariya reported the map operations insert_or_assign with a hint
violates the complexity requirement. The function no longer uses a lower_bound,
which caused the wrong complexity.

Fixes PR38722: [C++17] std::map::insert_or_assign w/ hint violate complexity requirements

Differential Revision: https://reviews.llvm.org/D62779
2020-09-19 16:28:55 +02:00
Louis Dionne a3c28ccd49 [libc++] Remove some workarounds for missing variadic templates
We don't support GCC in C++03 mode, and Clang provides variadic templates
even in C++03 mode. So there's effectively no supported compiler that
doesn't support variadic templates.

This effectively gets rid of all uses of _LIBCPP_HAS_NO_VARIADICS, but
some workarounds for the lack of variadics remain.
2020-09-17 11:05:39 -04:00
Louis Dionne d9c9a74d0d [libc++] Add missing friend keyword
Otherwise, we're declaring a non-static member function, and that
gives errors in C++11 because of the change of semantics between
C++11 and C++14 for non-const constexpr member functions.

This was always intended to be a friend declaration.
2020-09-15 14:21:05 -04:00
Marshall Clow 39c8795141 [libc++] Use allocator_traits to consistently allocate/deallocate/construct/destroy objects in std::any
https://llvm.org/PR45099 notes (correctly) that we're inconsistent in memory
allocation in `std::any`. We allocate memory with `std::allocator<T>::allocate`,
construct with placement new, destroy by calling the destructor directly, and
deallocate by calling `delete`. Most of those are customizable by the user,
but in different ways.

The standard is silent on how these things are to be accomplished.
This patch makes it so we use `allocator_traits<allocator<T>>` for all
of these operations (allocate, construct, destruct, deallocate).
This is, at least, consistent.

Fixes https://llvm.org/PR45099.

Differential Revision: https://reviews.llvm.org/D81133
2020-09-15 11:04:59 -04:00
zoecarver 3ed89b51da [Take 2] [libc++] Make rotate a constexpr.
This patch makes `std::rotate` a constexpr. In doing so, this patch also
updates the internal `__move` and `__move_backward` funtions to be
constexpr.

This patch was previously reverted in ed653184ac because it was missing
some UNSUPPORTED markup for older compilers. This commit adds it.

Differential Revision: https://reviews.llvm.org/D65721
2020-09-14 18:14:46 -04:00
zoecarver ed653184ac Revert "[libc++] Make rotate a constexpr."
This reverts commit 1ec02efee9.
2020-09-14 14:53:17 -07:00
Nicholas-Baron b552a30283 [libc++] Finish implementing P0202R3
cppreference lists the support for this paper as partial.
I found 4 functions which the paper marks as `constexpr`,
but did not use the appropriate macro.

Differential Revision: https://reviews.llvm.org/D84275
2020-09-14 16:58:49 -04:00
zoecarver 1ec02efee9 [libc++] Make rotate a constexpr.
This patch makes `std::rotate` a constexpr. In doing so, this patch also
updates the internal `__move` and `__move_backward` funtions to be
constexpr.

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D65721
2020-09-14 13:56:48 -07:00
Louis Dionne 71a16e40f7 [libcxx] ostream{,buf}_iterator::difference_type changes in C++20
In C++20, since P0896R4, std::ostream_iterator and std::ostreambuf_iterator
must have std::ptrdiff_t instead of void as a difference_type.

Tests by Casey Carter (thanks!).

Differential Revision: https://reviews.llvm.org/D87459
2020-09-14 11:08:09 -04:00
Olivier Giroux 59fc867790 Re-split integral & pointer overloads. Add tests. 2020-09-11 12:13:35 -07:00
Olivier Giroux fc4bff0cd3 Update atomic feature macros, synopsis, signatures to match C++20. Improve test coverage for non-lock-free atomics. 2020-09-09 10:00:09 -07:00
Louis Dionne 5571467879 [libc++] Avoid including <sys/cdefs.h> on non-Apple platforms in <ctime> 2020-09-02 18:11:26 -04:00
Michael Schellenberger Costa 737a4501e8 Add constexpr to pair
Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D80558
2020-09-02 21:21:24 +02:00
Louis Dionne 4f57a126c4 [libc++] Remove definition of _LIBCPP_ALIGNOF for GCC in C++03 mode
That definition is known to be potentially incorrect, and we don't support
GCC in C++03 mode anyway.
2020-09-02 12:29:42 -04:00
hyd-dev 44cc78da05 [libc++] Fix incorrect usage of __STDC_HOSTED__
D56913 introduced the _LIBCPP_FREESTANDING macro and guarded its
definition by:

	#ifndef __STDC_HOSTED__
	#  define _LIBCPP_FREESTANDING
	#endif

However, __STDC_HOSTED__ is defined as 0 in freestanding implementations
instead of undefined, which means that _LIBCPP_FREESTANDING would never
get defined. This patch corrects the above as:

	#if __STDC_HOSTED__ == 0
	#  define _LIBCPP_FREESTANDING
	#endif

Differential Revision: https://reviews.llvm.org/D86055
2020-09-02 12:26:37 -04:00
Louis Dionne 5201b962e8 [libc++] Re-apply the workaround for timespec_get not always being available in Apple SDKs
This commit re-applies 99f3b231cb, which was reverted in 8142425727
because it broke the modules build. The modules failure was a circular
dependency between the Darwin module and __config. Specifically, the
issue was that if <__config> includes a system header, the std_config
module depends on the Darwin module. However, the Darwin module already
depends on the std_config header because some of its headers include
libc++ headers like <ctype.h> (they mean to include the C <ctype.h>,
but libc++ headers are first in the header search path).

This is fixed by moving the workaround to <ctime> only.

https://llvm.org/PR47208
rdar://68157284
2020-09-02 12:20:32 -04:00
Raphael Isemann 8142425727 Revert "[libc++] Workaround timespec_get not always being available in Apple SDKs"
This reverts commit 99f3b231cb. It breaks
libcxx/modules/stds_include.sh.cpp on macOS as the new include to sys/cdefs.h
causes a dependency from __config to the Darwin module (which already has
a dependency on __config). This cyclic dependency breaks compiling the std
module which breaks compiling pretty much every program with ToT libc++ and
enabled modules.

I'll revert for now to get the bots green again. Sorry for the inconvenience.
2020-09-02 09:45:35 +02:00
Eric Fiselier 057028ed39 Revert switch based variant temporarily.
There are currently some failures caused by this change internally. I'm working
to debug them and hopefully these series of patches should be recommitted by
the end of the week.

Thank you to Micheal Park for the contributions, and for allowing the temporary
rollback.

The commits reverted by this change are:

7d15ece79c
e0ec7a0206
02197f7e50
a175a96517
2020-09-01 22:15:33 -04:00
Louis Dionne 99f3b231cb [libc++] Workaround timespec_get not always being available in Apple SDKs
timespec_get is not available in Apple SDKs when (__DARWIN_C_LEVEL >= __DARWIN_C_FULL)
isn't true, which leads to libc++ trying to import ::timespec_get into
namespace std when it's not available. This issue has been reported to
Apple's libc, but we need a workaround in the meantime.

https://llvm.org/PR47208
rdar://68157284
2020-09-01 15:10:50 -04:00
Michael Park 7d15ece79c [libcxx/variant] Implement workaround for GCC bug.
A parameter pack is deemed to be uncaptured, which is bogus... but it seems to
be because it's within an expression that involves `decltype` of an uncaptured
pack or something: https://godbolt.org/z/b8z3sh

Drive-by fix for uglified name.

Differential Revision: https://reviews.llvm.org/D86827
2020-08-30 12:43:14 -04:00
Louis Dionne 316d336dca [libc++] Un-deprecate and un-remove some members of std::allocator
This implements the part of P0619R4 related to the default allocator.
This is incredibly important, since otherwise there is an ABI break
between C++17 and C++20 w.r.t. the default allocator's size_type on
platforms where std::size_t is not the same as std::make_unsigned<std::ptrdiff_t>.
2020-08-28 12:51:51 -04:00
Louis Dionne 21a1a263a6 [libc++][NFC] Define functor's call operator inline
This fixes a mismatched visibility attribute on the call operator in
addition to making the code clearer. Given this is a simple lambda
in essence, the intent has always been to give it inline visibility.
2020-08-27 14:20:34 -04:00
Mikhail Maltsev a19fd1aab5 Revert "[libcxx] Fix compile for BUILD_EXTERNAL_THREAD_LIBRARY"
This reverts commit 3b71f91558.

The commit is breaking some build bots.
2020-08-27 16:48:10 +01:00
David Nicuesa 3b71f91558 [libcxx] Fix compile for BUILD_EXTERNAL_THREAD_LIBRARY
Fix compilation with -DLIBCXX_BUILD_EXTERNAL_THREAD_LIBRARY when using clang. Now linking target  'cxx_external_threads' with 'cxx-headers'. Fix mismatching visibility for `libcpp_timed_backoff_policy` function in file <__threading_support>.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D86598
2020-08-27 16:24:19 +01:00
Michael Park e0ec7a0206
[libcxx/variant] Correctly propagate return type of the visitor.
The tests for it were missing so I've added them.

Reviewed By: #libc, EricWF

Differential Revision: https://reviews.llvm.org/D86006
2020-08-17 10:53:59 -07:00
Michael Park 02197f7e50
[libcxx/variant] Avoided variable name shadowing. 2020-08-14 16:30:27 -07:00
Michael Park a175a96517
[libcxx/variant] Introduce `switch`-based mechanism for `std::visit`.
This patch introduces mechanism for `std::visit` backed by `switch`.
The `switch` is structured such that it's a flattened manual vtable (an n-ary array).
The `switch` mechanism is enabled if `(1 * ... * vs.size()) < 1024`.

The following are performance numbers from the benchmarks added in D85419, tested on my 2017 Macbook Pro.

```
$ ./projects/libcxx/benchmarks/variant_visit_1.libcxx.out
2020-08-09 23:55:14
Running ./projects/libcxx/benchmarks/variant_visit_1.libcxx.out
Run on (8 X 3100 MHz CPU s)
CPU Caches:
  L1 Data 32K (x4)
  L1 Instruction 32K (x4)
  L2 Unified 262K (x4)
  L3 Unified 8388K (x1)
Load Average: 2.03, 2.36, 2.43
------------------------------------------------------------
Benchmark                 Time             CPU   Iterations
------------------------------------------------------------
BM_Visit<1, 1>        0.260 ns        0.260 ns   1000000000
BM_Visit<1, 2>         1.56 ns         1.56 ns    435925220
BM_Visit<1, 3>         1.55 ns         1.55 ns    444416228
BM_Visit<1, 4>         1.57 ns         1.57 ns    427951336
BM_Visit<1, 5>         1.57 ns         1.56 ns    444766371
BM_Visit<1, 6>         1.70 ns         1.68 ns    446639358
BM_Visit<1, 7>         1.64 ns         1.64 ns    400441630
BM_Visit<1, 8>         1.56 ns         1.56 ns    430729471
BM_Visit<1, 9>         1.58 ns         1.58 ns    449894596
BM_Visit<1, 10>        1.54 ns         1.54 ns    449660506
BM_Visit<1, 20>        1.56 ns         1.56 ns    450813074
BM_Visit<1, 30>        1.59 ns         1.59 ns    440032940
BM_Visit<1, 40>        1.59 ns         1.59 ns    443731656
BM_Visit<1, 50>        1.56 ns         1.56 ns    444709859
BM_Visit<1, 60>        1.59 ns         1.58 ns    439527320
BM_Visit<1, 70>        1.57 ns         1.57 ns    438450890
BM_Visit<1, 80>        1.58 ns         1.58 ns    443001525
BM_Visit<1, 90>        1.63 ns         1.62 ns    448456349
BM_Visit<1, 100>       1.57 ns         1.57 ns    445740630

$ ./projects/libcxx/benchmarks/variant_visit_2.libcxx.out
2020-08-09 23:59:35
Running ./projects/libcxx/benchmarks/variant_visit_2.libcxx.out
Run on (8 X 3100 MHz CPU s)
CPU Caches:
  L1 Data 32K (x4)
  L1 Instruction 32K (x4)
  L2 Unified 262K (x4)
  L3 Unified 8388K (x1)
Load Average: 1.40, 1.94, 2.22
-----------------------------------------------------------
Benchmark                Time             CPU   Iterations
-----------------------------------------------------------
BM_Visit<2, 1>       0.261 ns        0.260 ns   1000000000
BM_Visit<2, 2>        1.55 ns         1.54 ns    432844219
BM_Visit<2, 3>        1.30 ns         1.30 ns    532529974
BM_Visit<2, 4>        1.54 ns         1.54 ns    446055910
BM_Visit<2, 5>        1.31 ns         1.31 ns    531099680
BM_Visit<2, 6>        1.56 ns         1.56 ns    443203475
BM_Visit<2, 7>        1.29 ns         1.29 ns    526478087
BM_Visit<2, 8>        1.56 ns         1.56 ns    439000834
BM_Visit<2, 9>        1.30 ns         1.30 ns    528756817
BM_Visit<2, 10>       1.56 ns         1.55 ns    442923039
BM_Visit<2, 20>       1.35 ns         1.35 ns    517021072
BM_Visit<2, 30>       1.60 ns         1.59 ns    419724661
BM_Visit<2, 40>       1.45 ns         1.44 ns    472137163
BM_Visit<2, 50>       1.65 ns         1.65 ns    421389743

$ ./projects/libcxx/benchmarks/variant_visit_3.libcxx.out
2020-08-10 00:01:32
Running ./projects/libcxx/benchmarks/variant_visit_3.libcxx.out
Run on (8 X 3100 MHz CPU s)
CPU Caches:
  L1 Data 32K (x4)
  L1 Instruction 32K (x4)
  L2 Unified 262K (x4)
  L3 Unified 8388K (x1)
Load Average: 2.20, 2.01, 2.21
-----------------------------------------------------------
Benchmark                Time             CPU   Iterations
-----------------------------------------------------------
BM_Visit<3, 1>       0.272 ns        0.271 ns   1000000000
BM_Visit<3, 2>        1.87 ns         1.86 ns    361858090
BM_Visit<3, 3>        1.77 ns         1.77 ns    391192579
BM_Visit<3, 4>        1.84 ns         1.84 ns    374694223
BM_Visit<3, 5>        1.75 ns         1.75 ns    408270392
BM_Visit<3, 6>        1.88 ns         1.88 ns    378759185
BM_Visit<3, 7>        1.79 ns         1.79 ns    395498102
BM_Visit<3, 8>        1.85 ns         1.85 ns    371660366
BM_Visit<3, 9>        1.80 ns         1.80 ns    386872851
BM_Visit<3, 10>       1.84 ns         1.84 ns    362367606
BM_Visit<3, 15>       1.77 ns         1.77 ns    392060220
BM_Visit<3, 20>       1.85 ns         1.85 ns    379157188
```

```
$ ./projects/libcxx/benchmarks/variant_visit_1.libcxx.out
2020-08-10 00:05:57
Running ./projects/libcxx/benchmarks/variant_visit_1.libcxx.out
Run on (8 X 3100 MHz CPU s)
CPU Caches:
  L1 Data 32K (x4)
  L1 Instruction 32K (x4)
  L2 Unified 262K (x4)
  L3 Unified 8388K (x1)
Load Average: 2.27, 2.36, 2.34
------------------------------------------------------------
Benchmark                 Time             CPU   Iterations
------------------------------------------------------------
BM_Visit<1, 1>        0.271 ns        0.271 ns   1000000000
BM_Visit<1, 2>        0.269 ns        0.269 ns   1000000000
BM_Visit<1, 3>        0.271 ns        0.271 ns   1000000000
BM_Visit<1, 4>        0.270 ns        0.270 ns   1000000000
BM_Visit<1, 5>        0.269 ns        0.269 ns   1000000000
BM_Visit<1, 6>        0.270 ns        0.269 ns   1000000000
BM_Visit<1, 7>        0.265 ns        0.265 ns   1000000000
BM_Visit<1, 8>        0.269 ns        0.269 ns   1000000000
BM_Visit<1, 9>        0.268 ns        0.268 ns   1000000000
BM_Visit<1, 10>       0.269 ns        0.269 ns   1000000000
BM_Visit<1, 20>       0.267 ns        0.267 ns   1000000000
BM_Visit<1, 30>       0.272 ns        0.272 ns   1000000000
BM_Visit<1, 40>       0.268 ns        0.268 ns   1000000000
BM_Visit<1, 50>       0.268 ns        0.268 ns   1000000000
BM_Visit<1, 60>       0.268 ns        0.268 ns   1000000000
BM_Visit<1, 70>       0.269 ns        0.269 ns   1000000000
BM_Visit<1, 80>       0.266 ns        0.266 ns   1000000000
BM_Visit<1, 90>       0.268 ns        0.268 ns   1000000000
BM_Visit<1, 100>      0.267 ns        0.267 ns   1000000000

$ ./projects/libcxx/benchmarks/variant_visit_2.libcxx.out
2020-08-12 04:09:59
Running ./projects/libcxx/benchmarks/variant_visit_2.libcxx.out
Run on (8 X 3100 MHz CPU s)
CPU Caches:
  L1 Data 32K (x4)
  L1 Instruction 32K (x4)
  L2 Unified 262K (x4)
  L3 Unified 8388K (x1)
Load Average: 2.17, 4.20, 4.78
-----------------------------------------------------------
Benchmark                Time             CPU   Iterations
-----------------------------------------------------------
BM_Visit<2, 1>       0.302 ns        0.301 ns   1000000000
BM_Visit<2, 2>       0.297 ns        0.295 ns   1000000000
BM_Visit<2, 3>       0.353 ns        0.351 ns   1000000000
BM_Visit<2, 4>       0.276 ns        0.276 ns   1000000000
BM_Visit<2, 5>       0.285 ns        0.283 ns   1000000000
BM_Visit<2, 6>       0.290 ns        0.287 ns   1000000000
BM_Visit<2, 7>       0.282 ns        0.280 ns   1000000000
BM_Visit<2, 8>       0.290 ns        0.287 ns   1000000000
BM_Visit<2, 9>       0.291 ns        0.285 ns   1000000000
BM_Visit<2, 10>      0.293 ns        0.287 ns   1000000000
BM_Visit<2, 20>       1.70 ns         1.68 ns    391400375
BM_Visit<2, 30>       1.64 ns         1.63 ns    418925874
BM_Visit<2, 40>       1.63 ns         1.62 ns    423623677
BM_Visit<2, 50>       1.68 ns         1.67 ns    411687212

$ ./projects/libcxx/benchmarks/variant_visit_3.libcxx.out
2020-08-12 04:10:43
Running ./projects/libcxx/benchmarks/variant_visit_3.libcxx.out
Run on (8 X 3100 MHz CPU s)
CPU Caches:
  L1 Data 32K (x4)
  L1 Instruction 32K (x4)
  L2 Unified 262K (x4)
  L3 Unified 8388K (x1)
Load Average: 1.57, 3.76, 4.59
-----------------------------------------------------------
Benchmark                Time             CPU   Iterations
-----------------------------------------------------------
BM_Visit<3, 1>       0.271 ns        0.270 ns   1000000000
BM_Visit<3, 2>       0.344 ns        0.334 ns   1000000000
BM_Visit<3, 3>       0.347 ns        0.336 ns   1000000000
BM_Visit<3, 4>       0.300 ns        0.296 ns   1000000000
BM_Visit<3, 5>       0.290 ns        0.286 ns   1000000000
BM_Visit<3, 6>       0.272 ns        0.271 ns   1000000000
BM_Visit<3, 7>        1.72 ns         1.71 ns    415765841
BM_Visit<3, 8>        1.73 ns         1.72 ns    408909555
BM_Visit<3, 9>        2.16 ns         2.04 ns    380898485
BM_Visit<3, 10>       2.45 ns         2.40 ns    295714256
BM_Visit<3, 15>       1.92 ns         1.85 ns    375990332
BM_Visit<3, 20>       1.66 ns         1.65 ns    414456233
```

Differential Revision: https://reviews.llvm.org/D85420
2020-08-14 12:54:58 -07:00
Louis Dionne 8d4860aa9e [libc++] Remove workarounds for missing rvalue references
We don't support GCC in C++03 mode, and Clang provides rvalue references
even in C++03 mode. So there's effectively no supported compiler that
doesn't support rvalue references.

Differential Revision: https://reviews.llvm.org/D84943
2020-08-12 12:02:28 -04:00
Evgenii Stepanov 189ba3db86 Fix CFI issues in <future>
This change fixes errors reported by Control Flow Integrity (CFI) checking when using `std::packaged_task`.  The errors mostly stem from casting the underlying storage (`__buf_`) to `__base*`, even if it is uninitialized.  The solution is to wrap `__base*` access to `__buf_` behind a getter marked with _LIBCPP_NO_CFI.

Differential Revision: https://reviews.llvm.org/D82627
2020-08-06 12:05:22 -07:00
Louis Dionne 19bc9ea480 [libc++] Avoid including <Block.h> from <functional>
Block.h is a pretty common name, which can lead to nasty collisions with
user provided headers. Since we're only getting a few simple declarations
from the header, it's better to declare them manually than to include the
header.

rdar://66384326

Differential Revision: https://reviews.llvm.org/D85035
2020-07-31 14:22:28 -04:00
Louis Dionne 67dfba9629 [libc++] Provide std::aligned_alloc and std::timespec_get on Apple platforms
rdar://66113878
2020-07-28 15:13:05 -04:00
Louis Dionne 1bd7c02233 [libc++] Clean up tests for "optional" C11 features
First, add a TEST_HAS_QUICK_EXIT macro to mirror other C11 features like
TEST_HAS_ALIGNED_ALLOC, and update the tests for that.

Second, get rid of TEST_HAS_C11_FEATURES and _LIBCPP_HAS_C11_FEATURES,
which were only used to ensure that feature macros don't get out of
sync between <__config> and "test_macros.h". This is not necessary
anymore, since we have tests for each individual macro now.
2020-07-28 15:13:05 -04:00
Louis Dionne 9798b2311f [libc++] Make sure we only consider _GNUC_VER_NEW when the compiler is GCC
When the compiler is Clang, _GNUC_VER_NEW is 0, which messes up the logic.
2020-07-22 16:08:19 -04:00
Louis Dionne e9748a7255 [libc++] Workaround broken support for C++17 in GCC 5 2020-07-22 15:38:58 -04:00
Vy Nguyen 76887bc4c1 Reland [libcxx]Put clang::trivial_abi on smart pointers
Reviewed By: ldionne,EricWF

    Tags: #libcxx

    Differential Revision: https://reviews.llvm.org/D82490
2020-07-20 11:54:34 -04:00
Hans Wennborg 7ab7b979d2 Bump the trunk major version to 12
and clear the release notes.
2020-07-15 12:05:05 +02:00
Louis Dionne eaca1e4e54 [libc++] Automatically detect whether RTTI is enabled
Instead of detecting it automatically but also allowing for the setting
to be specified explicitly, always detect whether exceptions are enabled
based on whether -fno-rtti (or equivalent) is used. It's less confusing
to have a single way of tweaking that knob.

This change follows the lead of 71d88cebfb.
2020-07-14 16:51:37 -04:00
Louis Dionne efa40eb194 [libc++] Use a proper CMake target to represent libc++ headers
Instead of having complex logic around how to include the libc++ headers
and __config_site, handle that by defining cxx-headers as an INTERFACE
library and linking against it. After this patch, linking against cxx-headers
is sufficient to get the right __config_site include and include paths
for libc++.

Differential Revision: https://reviews.llvm.org/D82702
2020-07-14 09:52:58 -04:00
Louis Dionne 2d3b8cc83f [libc++] Implement P0551
Make sure we satisfy the requirements added by P0551, and add tests to
enforce that.
2020-07-13 13:42:26 -04:00
Michael Park 6ab3208d77
Remove the unnecessary `is_nothrow_swappable` condition in `swap`.
Thanks to @lewissbaker who pointed out the unnecessary condition in
https://reviews.llvm.org/D81954#inline-756872. Since this codepath does not
make use of `swap` anyway (that codepath is a different branch), we can safely
remove this condition and produce better codegen when all types are nothrow
movable but are potentially-throwing swappable.

See codegen in https://gcc.godbolt.org/z/uDFZjz

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D83274
2020-07-08 10:46:38 -07:00
Stephan Herhut 3341d470fc Revert "Revert "Revert "[libcxx] Put clang::trivial_abi on std::unique_ptr, std::shared_ptr, and std::weak_ptr"""
This reverts commit f706b01a00.
2020-07-06 12:18:17 +02:00
Vy Nguyen f706b01a00 Revert "Revert "[libcxx] Put clang::trivial_abi on std::unique_ptr, std::shared_ptr, and std::weak_ptr""
This reverts commit dc13ac0280.

Rolling forward + fix typos and unused variables in tests

    Differential Revision: https://reviews.llvm.org/D82490
2020-07-05 13:44:42 -04:00
Vy Nguyen dc13ac0280 Revert "[libcxx] Put clang::trivial_abi on std::unique_ptr, std::shared_ptr, and std::weak_ptr"
This reverts commit 5cde3c9633.

The tests were reported failing on clang10
2020-07-04 11:29:08 -04:00
Vy Nguyen 5cde3c9633 [libcxx] Put clang::trivial_abi on std::unique_ptr, std::shared_ptr, and std::weak_ptr
Reviewers: jyknight, EricWF, #libc!

Subscribers: arphaman, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D82490
2020-07-03 17:23:13 -04:00
Louis Dionne 71d88cebfb [libc++/libc++abi] Automatically detect whether exceptions are enabled
Instead of detecting it automatically (in libc++) and relying on
_LIBCXXABI_NO_EXCEPTIONS being set explicitly (in libc++abi), always
detect whether exceptions are enabled automatically.

This commit also removes support for specifying -D_LIBCPP_NO_EXCEPTIONS
and -D_LIBCXXABI_NO_EXCEPTIONS explicitly -- those should just be inferred
from using -fno-exceptions (or an equivalent flag).

Allowing both -D_FOO_NO_EXCEPTIONS to be provided explicitly and trying
to detect it automatically is just confusing, especially since we did
specify it explicitly when building libc++abi. We should have only one
way to detect whether exceptions are enabled, but it should be robust.
2020-07-03 14:58:09 -04:00
Martijn Vels 2bad222680 Add optimization to basic_string::assign for compile-time known constant values.
Summary:
This change optimizes the assign() methods for string where either the contents or lengths are compile time known constants. For small strings (< min_cap) we can execute the assignment entirely inline. For strings up to 128 bytes we allow the compiler to efficiently inline the copy operation after we call the offline __resize<>() method. Short / long branches are taken at the call site for better branch prediction and allowing FDO optimizations.

Benchmarks (unstable / google perflab):
```
name                                                old time/op             new time/op             delta
BM_StringAssignAsciiz_Empty_Opaque                  5.69ns ± 7%             5.97ns ± 7%     ~             (p=0.056 n=5+5)
BM_StringAssignAsciiz_Empty_Transparent             5.39ns ± 7%             0.79ns ± 8%  -85.36%          (p=0.008 n=5+5)
BM_StringAssignAsciiz_Small_Opaque                  11.2ns ± 5%             11.0ns ± 6%     ~             (p=0.548 n=5+5)
BM_StringAssignAsciiz_Small_Transparent             10.1ns ± 7%              1.0ns ± 8%  -89.76%          (p=0.008 n=5+5)
BM_StringAssignAsciiz_Large_Opaque                  23.5ns ± 7%             23.8ns ± 7%     ~             (p=0.841 n=5+5)
BM_StringAssignAsciiz_Large_Transparent             21.4ns ± 7%             12.7ns ± 7%  -40.83%          (p=0.008 n=5+5)
BM_StringAssignAsciiz_Huge_Opaque                    336ns ± 4%              327ns ± 7%     ~             (p=0.421 n=5+5)
BM_StringAssignAsciiz_Huge_Transparent               331ns ± 5%              324ns ± 7%     ~             (p=0.548 n=5+5)
BM_StringAssignAsciizMix_Opaque                     13.6ns ±10%             13.7ns ± 9%     ~             (p=0.690 n=5+5)
BM_StringAssignAsciizMix_Transparent                12.9ns ± 8%              3.6ns ± 8%  -71.82%          (p=0.008 n=5+5)
```

Reviewers: EricWF, #libc!

Subscribers: jfb, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D82221
2020-06-29 14:34:34 -04:00
Louis Dionne 8bc62db272 [libc++] Remove support for building through llvm-config
We've decided to move away from that by requiring that libc++ is built
as part of the monorepo a while ago. This commit removes code pertaining
to that unsupported use case and produces a clear error when the user
violates that.

In fact, building outside of the monorepo will still work as long as
LLVM_PATH is pointing to the root of the LLVM project, although that
is not officially supported.
2020-06-26 15:13:04 -04:00
Louis Dionne 05c552ad05 [libc++] Fix the runtimes build after making __config_site mandatory
The runtimes build includes libcxx/include/CMakeLists.txt directly instead
of going through the top-level CMake file. This not-very-hygienic inclusion
caused some variables like LIBCXX_BINARY_DIR not to be defined properly,
and the config_site generation logic to fail after landing 53623d4aa7.

This patch works around this issue by defining the missing variables.
However, the proper fix for this would be for the runtimes build to
always go through libc++'s top-level CMakeLists.txt. Doing otherwise
is unsupported.
2020-06-26 01:26:34 -04:00
Louis Dionne 53623d4aa7 [libc++] Always generate a __config_site header
Before this patch, the __config_site header was only generated when at
least one __config_site macro needed to be defined. This lead to two
different code paths in how libc++ is configured, depending on whether
a __config_site header was generated or not. After this patch, the
__config_site is always generated, but it can be empty in case there
are no macros to define in it.

More context on why this change is important
--------------------------------------------
In addition to being confusing, this double-code-path situation lead to
broken code being checked in undetected in 2405bd6898, which introduced
the LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT CMake setting. Specifically,
the _LIBCPP_HAS_MERGED_TYPEINFO_NAMES_DEFAULT <__config_site> macro was
supposed NOT to be defined unless LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT
was specified explicitly on the CMake command line. Instead, what happened
is that it was defined to 0 if it wasn't specified explicitly and a
<__config_site> header was generated. And defining that macro to 0 had
the important effect of using the non-unique RTTI comparison implementation,
which changes the ABI.

This change in behavior wasn't noticed because the <__config_site> header
is not generated by default. However, the Apple configuration does cause
a <__config_site> header to be generated, which lead to the wrong RTTI
implementation being used, and to https://llvm.org/PR45549. We came close
to an ABI break in the dylib, but were saved due to a downstream-only
change that overrode the decision of the <__config_site> for the purpose
of RTTI comparisons in libc++abi. This is an incredible luck that we should
not rely on ever again.

While the problem itself was fixed with 2464d8135e by setting
LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT explicitly in the Apple
CMake cache and then in d0fcdcd28f by making the setting less
brittle, the point still is that we should have had a single code
path from the beginning. Unlike most normal libraries, the macros
that configure libc++ are really complex, there's a lot of them and
they control important properties of the C++ runtime. There must be
a single code path for that, and it must be simple and robust.

Differential Revision: https://reviews.llvm.org/D80927
2020-06-26 00:47:48 -04:00
Louis Dionne 8808574e74 [libc++] Add missing <stddef.h> include to <wchar.h>
It is needed because <wchar.h> uses size_t.
2020-06-25 19:27:32 -04:00
Louis Dionne 06be4bb5e6 [libc++] Remove deprecated _LIBCPP_ALTERNATE_STRING_LAYOUT macro
We use the _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT macro for that now instead.
I did leave a check behind to make sure that nobody was still using the old
macro name. I'll remove it a couple of months down the road.
2020-06-25 16:33:30 -04:00
Arthur O'Dwyer d8e3e55857 [libc++] Fix some typos in the comment header for <regex>
No functional change because all the changed "code" is actually inside
comments.

Differential Revision: https://reviews.llvm.org/D82589
2020-06-25 15:34:51 -04:00
Raul Tambre 98eb1457ff [libc++] Require concepts support for <numbers>
Similar to <concepts>, we need to protect the header and test against
inclusion and being run if concepts aren't supported by the compiler.

Differential Revision: https://reviews.llvm.org/D82171
2020-06-19 10:49:44 -04:00
Raul Tambre 4f6c4b473c [libc++] Implement <numbers>
Summary: Constants have 33 significant decimal digits for IEEE 754 128-bit floating-point numbers.

Reviewers: ldionne, #libc, EricWF, zoecarver, curdeius

Reviewed By: ldionne, #libc, curdeius

Differential Revision: https://reviews.llvm.org/D77505
2020-06-19 14:25:02 +05:30
Martijn Vels d96aac4354 Optimize 'construct at end' loops in vector
Summary:
This change adds local 'end' and 'pos' variables for the main loop inmstead of using the ConstructTransaction variables directly.

We observed that not all vector initialization and resize operations got properly vectorized, i.e., (partially) unrolled into XMM stores for floats.

For example, `vector<int32_t> v(n, 1)` gets vectorized, but `vector<float> v(n, 1)`. It looks like the compiler assumes the state is leaked / aliased in the latter case (unclear how/why for float, but not for int32), and because of this fails to see vectorization optimization?

See https://gcc.godbolt.org/z/UWhiie

By using a local `__new_end_` (fixed), and local `__pos` (copied into __tx.__pos_ per iteration), we offer the compiler a clean loop for unrolling.

A demonstration can be seen in the isolated logic in https://gcc.godbolt.org/z/KoCNWv

The com

Reviewers: EricWF, #libc!

Subscribers: libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D82111
2020-06-18 13:51:12 -04:00
Christopher Di Bella ec789a41e2 [libc++] Add equality for spaceship types for themselves
- Adds operator==(partial_ordering, partial_ordering)
- Adds operator==(weak_ordering, weak_ordering)
- Adds operator==(strong_ordering, strong_ordering)

Differential Revision: https://reviews.llvm.org/D81823
2020-06-18 10:22:50 -04:00
Michael Park 8fbd6d99a0
[libcxx/variant] Fix build error for when exceptions disabled.
Reviewers: #libc!

Subscribers: libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D81973
2020-06-18 07:21:42 -07:00
Michael Park ada2a8ea4a
Remove the try/catch codepath if `swap` is `noexcept`.
Summary:
In the case where `swap` is `noexcept`, we should avoid the extension to provide strong-exception guarantee.

Fixes https://bugs.llvm.org/show_bug.cgi?id=46342

Reviewers: #libc, ldionne

Reviewed By: #libc, ldionne

Subscribers: dexonsmith, mclow.lists, miscco, ldionne, zoecarver, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D81954
2020-06-16 14:51:22 -07:00
Louis Dionne 12b01ab7fa [libc++] Don't trigger unsigned conversion warnings in std::advance
The Standard documents the signature of std::advance as

    template <class Iter, class Distance>
    constexpr void advance(Iter& i, Distance n);

Furthermore, it does not appear to put any restriction on what the type
of Distance should be. While it is understood that it should usually
be std::iterator_traits::difference_type, I couldn't find any wording
that mandates that. Similarly, I couldn't find wording that forces the
distance to be a signed type.

This patch changes std::advance to accept any type in the second argument,
which appears to be what the Standard mandates. We then coerce it to the
iterator's difference type, but that's an implementation detail.

Differential Revision: https://reviews.llvm.org/D81425
2020-06-16 13:47:47 -04:00
Joel E. Denny d9a42ec98a [libc++] Work around gcc/Power9 bug in `include/thread`
This fixes PR39696, which breaks the libcxx build with gcc (I tested
7.5.0) on Power9.  This fix was suggested at

https://bugs.llvm.org/show_bug.cgi?id=39696#c38

but never applied.  It just reverts 0583d9ea8d, which reverses
components of the original fix in 3bf63cf3b3, which is correct.

Fixes https://llvm.org/PR39696

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D81438
2020-06-10 12:40:43 -04:00
Louis Dionne 7fb40e1569 [libc++] Fix too stringent availability markup for bad_optional_access
The availability markup for bad_optional_access marked it as being added
in MacOS 10.14 and aligned releases, however it appears to have been added
in Mac OS 10.13 and aligned releases.
2020-06-09 14:39:51 -04:00
Louis Dionne 1f48f8f6e2 [libc++] Avoid UB in year_month_day_last::day() for incorrect months
This effectively implements the resolution of LWG3231, which mandates
that calling year_month_day_last::day() on an invalid year_month_day_last
is unspecified behavior. Before this change, it was undefined behavior.

Differential Revision: https://reviews.llvm.org/D81477
2020-06-09 13:43:13 -04:00
Louis Dionne cb347a1106 [libc++] Remove assertion in year_month_day_last::day()
This reverts commit 0c148430cf, which added an assertion in day().
The Standard doesn't allow day() to crash -- instead it says that the
result is unspecified.

Differential Revision: https://reviews.llvm.org/D70346
2020-06-09 10:46:13 -04:00
zoecarver b1b64dbef1 [NFC] [libcxx] Remove shared_ptr's no-rvalue unique_ptr converting constructor.
All compilers supported by libc++ have rvalues in C++03 mode so, there is no need for this non-rvalue overload.

Differential Revision: https://reviews.llvm.org/D80881
2020-06-08 09:49:21 -07:00
Louis Dionne 62cfa3a0b5 [libc++] Support move construction and assignment in <thread> in C++03
Libc++ provides support for <thread> in C++03 as an extension. Furthermore,
it does not support any compiler that doesn't have rvalue references. It
is hence possible to provide the move constructor and move assignment
operator in C++03.
2020-06-03 12:16:27 -04:00
Olivier Giroux 06aaf0b343 Updated synopsis of <atomic> to match what is implemented 2020-06-01 14:30:13 -07:00
Louis Dionne 23776a178f [libc++] Add assertions on OOB accesses in std::array when the debug mode is enabled
Like we do for empty std::array, make sure we have assertions in place
for obvious out-of-bounds issues in std::array when the debug mode is
enabled (which isn't by default).
2020-06-01 16:37:39 -04:00
Louis Dionne 66a14d151e [libc++] NFC: Minor refactoring in std::array 2020-06-01 16:28:44 -04:00
Louis Dionne 7265ff928a [libc++] Fix issues with the triviality of std::array
The Standard is currently unimplementable. We have to pick between:

1. Not implementing constexpr support properly in std::array<T, 0>
2. Making std::array<T, 0> non-trivial even when T is trivial
3. Returning nullptr from std::array<T, 0>::begin()

Libc++ initially picked (1). In 77b9abfc8e, we started implementing constexpr properly, but lost the guarantee of triviality. Since it seems like both (1) and (2) are really important, it seems like (3) is the only viable option for libc++, after all. This is also what other implementations are doing.

This patch moves libc++ from (1) to (3).

It also:
- Improves the test coverage for the various ways of initializing std::array
- Adds tests for the triviality of std::array
- Adds tests for the aggregate-ness of std::array

Reviewed By: #libc, miscco, EricWF, zoecarver

Differential Revision: https://reviews.llvm.org/D80821
2020-05-29 16:32:55 -07:00
Louis Dionne d0fcdcd28f [libc++] Fix the LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT setting
When the __config_site header is generated, but LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT
wasn't specified, _LIBCPP_HAS_MERGED_TYPEINFO_NAMES_DEFAULT would be defined
to 0, which was the NonUnique RTTI comparison implementation. The intent
was to use the Unique RTTI comparison implementation in that case, which
caused https://llvm.org/PR45549.

Instead, use a proper "switch" to select the RTTI comparison implementation.
Note that 0 can't be used as a value, because that is treated the same
by CMake as a variable that is just not defined.

Differential Revision: https://reviews.llvm.org/D80037
2020-05-29 06:14:30 -04:00
Louis Dionne ebddf90a4e [libc++] NFC: Remove outdated numbering in <bit> synopsis 2020-05-28 14:31:21 -04:00
Louis Dionne 77b9abfc8e [libc++] Complete overhaul of constexpr support in std::array
This commit adds missing support for constexpr in std::array under all
standard modes up to and including C++20. It also transforms the <array>
tests to check for constexpr-friendliness under the right standard modes.

Fixes https://llvm.org/PR40124
Fixes rdar://57522096
Supersedes https://reviews.llvm.org/D60666

Differential Revision: https://reviews.llvm.org/D80452
2020-05-28 12:31:06 -04:00
Marek Kurdej d1dbda10ce [libc++] [LWG3201] Update status page: lerp should be marked noexcept.
Summary: Update status page and test synopsis. Add synopsis in <cmath>.

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D80456
2020-05-25 22:28:21 +02:00
zoecarver 6e48a6e407 [libcxx] Fix deprecation warning by suppressing deprecated around
__test_has_construct.

In C++17 some tests started failing after a521532aa1. This fixes those errors by suppressing the deprecation warning when calling `construct` in `__test_has_construct`. This is the same solution as `__has_destroy_test` already uses.

Reviewers: ldionne, #libc!

Subscribers: dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D80481
2020-05-23 14:33:10 -07:00
zoecarver a521532aa1 [NFC] Remove non-variadic overloads of allocator_traits::construct.
Summary:
Libcxx only supports compilers with variadics. We can safely remove all "fake" variadic overloads of allocator_traits::construct.

This also provides the correct behavior if anything other than exactly one argument is supplied to allocator_traits::construct in C++03 mode.

Reviewers: ldionne, #libc!

Subscribers: dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D80067
2020-05-23 14:03:47 -07:00
Marek Kurdej 174322c273 [libc++] Mark __cpp_lib_hardware_interference_size as unimplemented. This fxes bug PR41423.
Summary:
As described in the bug report:
The commit a8b9f59e8caf378d56e8bfcecdb22184cdabf42d "Implement feature test macros using a script" added test features macros for libc++. Among others, it added `__cpp_lib_hardware_interference_size`. However, there is nothing like std::hardware_constructive_interference_size nor std::hardware_destructive_interference_size, that should be in header <new>.

* https://bugs.llvm.org/show_bug.cgi?id=41423

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D80431
2020-05-23 14:33:50 +02:00
Louis Dionne 485b9083fe [libc++] Mark __u64toa and __u32toa as noexcept
The two functions don't throw, and the generated code is better when
we explicitly tell the compiler that the functions are noexcept. This
isn't an ABI break because the signatures of the functions stay the
same with or without noexcept.

Fixes https://llvm.org/PR46016

Differential Revision: https://reviews.llvm.org/D80379
2020-05-22 16:11:44 -04:00
Louis Dionne 0161874c04 [libc++] NFC: Inline array<T,N>::at methods inside the class
All other methods are defined in the class, so this increases consistency.
2020-05-22 09:24:07 -04:00
Marek Kurdej 0c148430cf Reland [libc++] [LWG3321] Mark "year_month_day_last::day() specification does not cover !ok() values" issue as "Nothing to do", but add assertion.
Summary:
This LWG issue states that the result of `year_month_day_last::day()` is implementation defined if `ok()` is `false`.
However, from user perspective, calling `day()` in this situation will lead to a (possibly difficult to find) crash.
Hence, I have added an assertion to warn user at least when assertions are enabled.

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D70346
2020-05-21 21:55:38 +02:00
David Nicuesa 3411a1a920 Fix compile for -DLIBCXX_BUILD_EXTERNAL_THREAD_LIBRARY
Summary: Compilation with  -DLIBCXX_BUILD_EXTERNAL_THREAD_LIBRARY was failing due to missing declarations of functions used in libcxx/include/atomic. The lines this commit affects are the places where those functions are defined, now moved to be always defined.

Reviewers: #libc, ldionne

Reviewed By: #libc, ldionne

Subscribers: miyuki, dexonsmith, ldionne, jfb, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D80372
2020-05-21 13:48:59 +01:00
Jan Wilken Dörrie 416b1560c5 [libcxx] Remove swap for std::span
This change removes both the member function swap and the free function
overload of swap for std::span. While swap is a member and overloaded
for every other container in the standard library [1], it is neither a
member function nor a free function overload for std::span [2].
Thus the corresponding implementation should be removed.

[1] https://eel.is/c++draft/libraryindex#:swap
[2] https://eel.is/c++draft/span.overview

Differential Revision: https://reviews.llvm.org/D69827
2020-05-20 14:34:21 -04:00
zoecarver ca5bff18fc [NFC] Remove non-rvlaue non-variadic allocator::construct overloads.
Summary: All supported compilers have rvalues and variadics so we can safely remove the overloads of allocator::construct which are only enabled on compilers without rvalues and variadics.

Reviewers: ldionne, #libc!

Subscribers: dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D80068
2020-05-19 17:25:00 -07:00
zoecarver b8998ab9c2 [NFC] Remove non-rvlaue non-variadic allocator::construct overloads.
Summary: All supported compilers have rvalues and variadics so we can safely remove the overloads of allocator::construct which are only enabled on compilers without rvalues and variadics.

Reviewers: ldionne, #libc!

Subscribers: dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D80068
2020-05-19 17:21:35 -07:00
zoecarver 21d4050e2c Mark shared_ptr::__create_with_control_block as noexcept.
Summary: The default constructor for shared_ptr and shared_ptr::__enable_weak_this are both noexcept so, shared_ptr::__create_with_control_block can also be marked noexcept.

Reviewers: ldionne, #libc!

Subscribers: dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D80070
2020-05-19 17:17:16 -07:00
zoecarver c98648a175 [NFC] Add _EnableIfLValueCallable and move reference out of __callable.
Summary: In std::functional moves the reference out of the `__callable` implementation and replaces `_EnableIfCallable` with `_EnableIfLValueCallable` (`_EnableIfLValueCallable` passes `__callable` an lvalue reference type).

    Reviewers: ldionne, #libc!

    Subscribers: dexonsmith, libcxx-commits

    Tags: #libc

    Differential Revision: https://reviews.llvm.org/D80071
2020-05-19 17:15:28 -07:00
Michael Schellenberger Costa c579ab9962 [libcxx][type_traits] Add C++20 changes to common_type
Summary: This already implements the expected changes for LWG-3205

Reviewers: mclow.lists, EricWF, CaseyCarter, cjdb, #libc, ldionne

Reviewed By: #libc, ldionne

Subscribers: dexonsmith, broadwaylamb, christof, ldionne, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D74350
2020-05-18 14:06:32 +02:00
Michael Schellenberger Costa ab9f11168f [libcxx][span] Implement solution to LWG-3255
This implements the relaxed requirements on the std::array constructors of span,
where the type only needs to be convertible to the element type of the span.

Note that the previous tests were not sufficient, as the const array<T, n> constructor
was only tested for compile time and the array<T, N> only during runtime.

Restructure the tests so that we can test conversions as well as both constructors.

Differential Revision: https://reviews.llvm.org/D75706
2020-05-14 10:50:44 -04:00
Michael Schellenberger Costa 79941086fb [libc++][span] SFINAE span default constructor on Extent == 0
The default constructor of a static span requires _Extent == 0 so
SFINAE it out rather than using a static_assert

Differential Revision: https://reviews.llvm.org/D71994
2020-05-14 09:35:07 -04:00
Michael Schellenberger Costa c5ff4031c6 [libcxx][span] Remove const_iterator from std::span
This implements the resolution to LWG-3320.

Differential Revision: https://reviews.llvm.org/D75642
2020-05-14 08:34:32 -04:00
Michael Schellenberger Costa c73a491d10 [libcxx][span] Remove tuple interface
This implements P2116 by removing the tuple interface from std::span.

Differential Revision: https://reviews.llvm.org/D75640
2020-05-14 08:25:49 -04:00
Michael Schellenberger Costa 6d2599e4f7 [libcxx][span] Implement P1976R2
This resolves the NB comment about the construction of a fixed-size span
from a dynamic range.

Differential Revision: https://reviews.llvm.org/D74577
2020-05-13 09:52:47 -04:00
Marek Kurdej ab61fe4150 Revert "[libc++] [LWG3321] Mark "year_month_day_last::day() specification does not cover !ok() values" issue as "Nothing to do", but add assertion."
This reverts commit e25a2601aa.
It was failing due to _LIBCPP_ASSERT throwing in a method marked noexcept.
2020-05-13 13:16:43 +02:00
Marek Kurdej e25a2601aa [libc++] [LWG3321] Mark "year_month_day_last::day() specification does not cover !ok() values" issue as "Nothing to do", but add assertion.
Summary:
This LWG issue states that the result of `year_month_day_last::day()` is implementation defined if `ok()` is `false`.
However, from user perspective, calling `day()` in this situation will lead to a (possibly difficult to find) crash.
Hence, I have added an assertion to warn user at least when assertions are enabled.
I am however not aware of the libc++ stand on the desired behaviour.

Reviewers: ldionne, mclow.lists, EricWF, #libc

Reviewed By: ldionne, #libc

Subscribers: christof, dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D70346
2020-05-13 11:45:55 +02:00
zoecarver 8aa2266fd8 [libcxx] Constrain function assignment operator (2574).
This patch fixes LWG issue 2574.

Differential Review: https://reviews.llvm.org/D62928
2020-05-12 18:57:50 -07:00
zoecarver ce195fb22b [libcxx] Re-commit: shared_ptr changes from library fundamentals (P0414R2).
Implements P0414R2:
  * Adds support for array types in std::shared_ptr.
  * Adds reinterpret_pointer_cast for shared_ptr.

Re-committing now that the leaking tests are fixed.

Differential Revision: https://reviews.llvm.org/D62259
2020-05-12 11:23:18 -07:00
zoecarver 5eb55483eb Revert "[libcxx] shared_ptr changes from library fundamentals (P0414R2)."
This reverts commit e8c13c182a.
2020-05-11 22:43:17 -07:00
zoecarver e8c13c182a [libcxx] shared_ptr changes from library fundamentals (P0414R2).
Implements P0414R2:
  * Adds support for array types in std::shared_ptr.
  * Adds reinterpret_pointer_cast for shared_ptr.

Differential Revision: https://reviews.llvm.org/D62259
2020-05-11 18:46:29 -07:00
Eric Fiselier c490c5e81a Reland [libc++] Move abs and div into stdlib.h to fix header cycle.
This commit should will break libc++ without local submodule visibility, but
the LLVM+modules bots are now all using this mode. Before the Green Dragon
LLDB bot was failing to compile with a libc++ built with this commit as LSV
was disabled on macOS.

Original summary:

libc++ is careful to not fracture overload sets. When one overload
is visible to a user, all of them should be. Anything less causes
subtle bugs and ODR violations.

Previously, in order to support ::abs and ::div being supplied by
both <cmath> and <cstdlib> we had to do awful things that make
<math.h> and <stdlib.h> have header cycles and be non-modular.
This really breaks with modules.

Specifically the problem was that in C++ ::abs introduces overloads
for floating point numbers, these overloads forward to ::fabs,
which are defined in math.h. Therefore ::abs needed to be in math.h
too. But this required stdlib.h to include math.h and math.h to
include stdlib.h.

To avoid these problems the definitions have been moved to stddef.h
(which math includes), and the floating point overloads of ::abs
have been changed to call __builtin_fabs, which both Clang and GCC
support.
2020-05-08 21:52:27 +02:00
zoecarver 26466efe08 Revert "[libc++] ECMAScript IdentityEscape is ambiguous (2584)"
This reverts commit 6d2a66b10d.

The regex expressions in some lld tests need to be fixed. Reverting
until those are fixed.
2020-05-08 10:37:04 -07:00
zoecarver 6d2a66b10d [libc++] ECMAScript IdentityEscape is ambiguous (2584)
This patch fixes [[ https://cplusplus.github.io/LWG/issue2584 | 2584 ]]. Now the following works:
    const std::regex r1("\\z");
    assert(std::regex_match("z", r1));

Differential Revision: https://reviews.llvm.org/D66610
2020-05-07 14:26:25 -07:00
Marcel Hlopko c9e6519d15 Remove unused _LIBCPP_RAW_ITERATORS
Summary: This change removes seemingly unused _LIBCPP_RAW_ITERATORS.

Reviewers: #libc, EricWF, ldionne

Reviewed By: #libc, EricWF, ldionne

Subscribers: dexonsmith, ldionne, gribozavr2, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D79323
2020-05-07 22:26:15 +02:00
Antonio Sanchez aa0b991dcf [libc++] Fix ostream for complex numbers with fixed field width
The ostream operator<< is currently broken for std::complex with
specified field widths.

This patch a partial revert of c3478eff7a (reviewed as D71214),
restoring the correct behavior.

Differential Revision: https://reviews.llvm.org/D78816
2020-05-07 13:51:07 -04:00
Louis Dionne 31d41e3879 [libc++] Add tests for _LIBCPP_HAS_MERGED_TYPEINFO_NAMES_DEFAULT
The issue on Apple platforms was fixed in 2464d8135e, but this commit
adds some tests to make sure we don't regress.

See https://llvm.org/PR45549.

Differential Revision: https://reviews.llvm.org/D78963
2020-05-07 12:40:02 -04:00
Logan Smith 83564056d4 [libcxx] Add deduction guides for shared_ptr and weak_ptr
This patch adds deduction guides to <memory> to allow deducing
construction of shared_ptrs from unique_ptrs, and from weak_ptrs
and vice versa, as specified by C++17.

Differential Revision: https://reviews.llvm.org/D69603
2020-05-07 12:07:48 -04:00
Logan Smith 5b4a98eb58 [libcxx] Qualify make_pair in searcher implementations to prevent ADL
This patch adds `_VSTD::` to some calls to `make_pair` inside the
implementations of searchers, to prevent things exploding if there is
a make_pair in an associated namespace of a user-defined type.
https://godbolt.org/z/xAFG98

Differential Revision: https://reviews.llvm.org/D72640
2020-05-07 11:57:10 -04:00
Marek Kurdej 3e895085de [libc++][P1115][C++20] Improving the Return Value of Erase-Like Algorithms II: Free erase/erase if.
Summary:
This patch adds return type to std::erase and std::erase_if functions.

Also:
* Update __cpp_lib_erase_if to 202002L.
* Fix synopsis in unordered_map.
* Fix generate_feature_test_macro_components.py script.

Reviewers: EricWF, mclow.lists, ldionne, #libc

Reviewed By: ldionne, #libc

Subscribers: broadwaylamb, zoecarver, dexonsmith, ldionne, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D75905
2020-05-02 14:04:50 +02:00
Diogo Sampaio c14ac8043e [FIX][libc++][Regex] Using regex_constants match_prev_avail | match_not_bol | match_not_bow
Summary:
pr42199
When using regex_constants::match_prev_avail, it is defined that
--first is valid, and match_not_bol and match_not_bow should be
ignored. At the moment these flags are not ignored. This fixis that.

Reviewers: ldionne, miyuki, EricWF, mclow.lists, #libc

Reviewed By: ldionne, miyuki, #libc

Subscribers: broadwaylamb, dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D75622
2020-04-30 23:36:25 +01:00
Saleem Abdulrasool 88af3ddb1e build: update libc++ as there are some bots with integrated build
Some of the builders are building with C++ in the unified build.  Merge
this without review to try to restore the builder.
2020-04-28 20:07:28 +00:00
Raphael Isemann bd2965c9db Revert "Recommit [libc++] Move abs and div into stdlib.h to fix header cycle."
It seems that D74892 still hasn't fixed the issue on the bot. Currently
investigating the bot breakage and meanwhile (again) reverting this...
2020-04-28 20:23:22 +02:00
Eric Fiselier d0846b432c Recommit [libc++] Move abs and div into stdlib.h to fix header cycle.
This relands this commit as it broke the LLDB bot the first time it landed.
See also the discussion on https://reviews.llvm.org/rG82b47b2978405f802a33b00d046e6f18ef6a47be

Since D74892 this code should now also work on macOS.

Original description:

libc++ is careful to not fracture overload sets. When one overload
is visible to a user, all of them should be. Anything less causes
subtle bugs and ODR violations.

Previously, in order to support ::abs and ::div being supplied by
both <cmath> and <cstdlib> we had to do awful things that make
<math.h> and <stdlib.h> have header cycles and be non-modular.
This really breaks with modules.

Specifically the problem was that in C++ ::abs introduces overloads
for floating point numbers, these overloads forward to ::fabs,
which are defined in math.h. Therefore ::abs needed to be in math.h
too. But this required stdlib.h to include math.h and math.h to
include stdlib.h.

To avoid these problems the definitions have been moved to stddef.h
(which math includes), and the floating point overloads of ::abs
have been changed to call __builtin_fabs, which both Clang and GCC
support.
2020-04-28 15:42:36 +02:00
Louis Dionne f76c42416c [libc++] Improve the detection of whether the blocks runtime is available
The runtime for Blocks may not be available even though the Blocks
language extension _is_ available. Instead of potentially failing,
this commit is much more conservative and assumes the runtime for
Blocks is only provided on Apple platforms.

Differential Revision: https://reviews.llvm.org/D78757
2020-04-24 07:02:21 -04:00
Louis Dionne cd66970b37 [libc++] Don't try to include <Block.h> when not available 2020-04-22 15:22:12 -04:00
Louis Dionne 430b00954c [libc++] Add support for blocks in std::function
rdar://14390808
2020-04-22 14:58:02 -04:00
Dan Albert 75c4408653 Reland: Don't expose unavailable cstdio functions.
Marked unsupported for C++03 and C++11 since this test uses alias
declarations, and at least one C++03 bot was failing with
-Wc++11-extensions.

Change-Id: I8c3a579edd7eb83e0bc74e85d116b68f22400161
2020-04-16 12:51:08 -07:00
Louis Dionne 548d501082 [libc++] NFC: Reindent impossible to read conditional in __config 2020-04-16 15:02:03 -04:00
Louis Dionne 8079f8a7e8 [libc++] Simplify conditional in __config for _LIBCPP_NO_RTTI
We don't support GCC's older than 5.x anymore.
2020-04-16 12:51:30 -04:00
Martijn Vels 7ba045a430 Make basic_string::operator=() tail call properly
Summary: We discovered that the compiler may chose not to inline the operator=, which leads to an expensive extra stack frame. This change makes __assign_no_alias always tail called.

Reviewers: EricWF, #libc!

Subscribers: libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D77913
2020-04-10 19:41:46 -04:00
Eric Fiselier c6eb584c64 [libc++] Fix recursive instantiation in std::array.
The use of the `&& ...` fold expression in std::array's deduction guides
recursively builds a set of binary operator expressions of depth N where
`N` is the number of elements in the initializer.

This is problematic because arrays may be large, and instantiation
depth is limited.

This patch addresses the issue by flattening the SFINAE using
the existing `__all` type trait.
2020-04-09 17:42:10 -04:00
Eric Fiselier 601f763182 [libcxx] Adds [concept.same]
Patch from Christopher Di Bella (cjdb@google.com)
Reviewed as https://reviews.llvm.org/D74291

Adds `std::same_as` to libc++. Since there aren't clang-format rules for
//requires-expressions//, I'll need to disable the formatter in certain areas.
2020-04-08 18:00:13 -04:00
zoecarver b25ec45809 Fix __is_pointer builtin type trait to work with Objective-C pointer types.
Summary: 5ade17e broke __is_pointer for Objective-C pointer types. This patch fixes the builtin and re-applies the change to type_traits.

Tags: #clang, #libc

Differential Revision: https://reviews.llvm.org/D77519
2020-04-08 10:02:53 -07:00
Dan Albert 50280c1895 Revert "Don't expose unavailable cstdio functions."
Broke builders that emit different diagnostics. e.g.:

error: 'warning' diagnostics seen but not expected:
  Line 13: alias declarations are a C++11 extension
  Line 20: alias declarations are a C++11 extension

This reverts commit ff87813715.
2020-04-07 15:36:44 -07:00
Dan Albert ff87813715 Don't expose unavailable cstdio functions.
Summary: These aren't available on Android in all configurations.

Reviewers: EricWF, mclow.lists, #libc, ldionne

Reviewed By: EricWF, #libc, ldionne

Subscribers: broadwaylamb, dexonsmith, ldionne, krytarowski, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D76093
2020-04-07 15:02:30 -07:00
Louis Dionne 46c3876188 [libc++] Add availability markup for the C++20 Synchronization Library on Apple 2020-04-06 18:07:26 -04:00