Commit Graph

3036 Commits

Author SHA1 Message Date
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