Commit Graph

51 Commits

Author SHA1 Message Date
Konstantin Varlamov 9924d8d66a [libc++][ranges] Implement `views::take`.
The view itself has been implemented previously -- this patch only adds
the ability to pipe it.

Also implements [P1739](https://wg21.link/p1739) (partially) and [LWG3407](https://wg21.link/lwg3407).

Differential Revision: https://reviews.llvm.org/D123600
2022-05-06 14:16:13 -07:00
Louis Dionne 385cc25a53 [libc++] Ensure that all public C++ headers include <__assert>
This patch changes the requirement for getting the declaration of the
assertion handler from including <__assert> to including any public
C++ header of the library. Note that C compatibility headers are
excluded because we don't implement all the C headers ourselves --
some of them are taken straight from the C library, like assert.h.

It also adds a generated test to check it. Furthermore, this new
generated test is designed in a way that will make it possible to
replace almost all the existing test-generation scripts with this
system in upcoming patches.

Differential Revision: https://reviews.llvm.org/D122506
2022-03-30 15:05:31 -04:00
Louis Dionne 6a7f055117 [libc++] Re-enable workaround for pre-ranges CTAD in std::span
See https://reviews.llvm.org/D121626 for details -- this re-enables the
CTAD we removed, since it does break some stuff as well (even though it's
not nearly as bad as the removed constructors fixed by D121626).

Differential Revision: https://reviews.llvm.org/D122184
2022-03-21 21:56:42 -04:00
Louis Dionne d4c39f1ab9 [libc++] Add workaround to avoid breaking users of <span> when <ranges> are disabled
Back in 3a208c6894, we implemented the range-based constructor for <span>.
However, in doing so, we removed a previous non-standard constructor that
we provided before shipping <ranges>. Unfortunately, that breaks code that
was relying on a range-based constructor until we ship all of <ranges>.

This patch reintroduces the old non-conforming constructors and tests
that were removed in 3a208c6894 and uses them whenever <ranges> is
not provided (e.g. in LLVM 14). This is only a temporary workaround
until we enable <ranges> by default in C++20, which should hopefully
happen by LLVM 15.

The goal is to cherry-pick this workaround back to the LLVM 14 release
branch, since I suspect the constructor removal may otherwise cause
breakage out there, like the breakage I saw internally.

We could have avoided this situation by waiting for C++20 to be finalized
before shipping std::span. For example, we could have guarded it with
something like _LIBCPP_HAS_NO_INCOMPLETE_RANGES to prevent users from
accidentally starting to depend on it before it is stable. We did not
have these mechanisms when std::span was first implemented, though.

Differential Revision: https://reviews.llvm.org/D121626
2022-03-15 16:36:33 -04:00
Louis Dionne 849e749d7f [libc++][NFC] Remove several redundant #if _LIBCPP_STD_VER > 17 in <span>
It turns out that the whole header is only enabled in C++20 and above,
so these checks were redundant (and always true).

Differential Revision: https://reviews.llvm.org/D121604
2022-03-14 13:53:30 -04:00
Joe Loser d2baefae68
[libc++] Replace _LIBCPP_HAS_NO_CONCEPTS with _LIBCPP_STD_VER > 17. NFCI.
All supported compilers that support C++20 now support concepts. So, remove
`_LIB_LIBCPP_HAS_NO_CONCEPTS` in favor of `_LIBCPP_STD_VER > 17`. Similarly in
the tests, remove `// UNSUPPORTED: libcpp-no-concepts`.

Differential Revision: https://reviews.llvm.org/D121528
2022-03-13 12:32:06 -04:00
Louis Dionne f87aa19be6 [libc++] Move everything related solely to _LIBCPP_ASSERT to its own file
This is the first step towards disentangling the debug mode and assertions
in libc++. This patch doesn't make any functional change: it simply moves
_LIBCPP_ASSERT-related stuff to its own file so as to make it clear that
libc++ assertions and the debug mode are different things. Future patches
will make it possible to enable assertions without enabling the debug
mode.

Differential Revision: https://reviews.llvm.org/D119769
2022-02-16 12:49:50 -05:00
Arthur O'Dwyer 53406fb691 [libc++] Guard much of std::ranges under _LIBCPP_HAS_NO_INCOMPLETE_RANGES.
The logic here is that we are disabling *only* things in `std::ranges::`.
Everything in `std::` is permitted, including `default_sentinel`, `contiguous_iterator`,
`common_iterator`, `projected`, `swappable`, and so on. Then, we include
anything from `std::ranges::` that is required in order to make those things
work: `ranges::swap`, `ranges::swap_ranges`, `input_range`, `ranges::begin`,
`ranges::iter_move`, and so on. But then that's all. Everything else (including
notably all of the "views" and the `std::views` namespace itself) is still
locked up behind `_LIBCPP_HAS_NO_INCOMPLETE_RANGES`.

Differential Revision: https://reviews.llvm.org/D118736
2022-02-15 10:38:21 -05:00
Arthur O'Dwyer fa6b9e4010 [libc++] Normalize all our '#pragma GCC system_header', and regression-test.
Now we'll notice if a header forgets to include this magic phrase.

Differential Revision: https://reviews.llvm.org/D118800
2022-02-04 12:27:19 -05:00
Arthur O'Dwyer 2eb2ff2a02 [libc++] Merge _LIBCPP_HAS_NO_RANGES into _LIBCPP_HAS_NO_CONCEPTS. NFC.
The macro that opts out of `std::ranges::` functionality is called
`_LIBCPP_HAS_NO_INCOMPLETE_RANGES`, and is unrelated to this macro
which is specifically about _compiler_ support for the _syntax_.

The only non-mechanical diff here is in `<__config>`.

Differential Revision: https://reviews.llvm.org/D118507
2022-01-31 12:10:22 -05:00
Louis Dionne eb8650a757 [runtimes][NFC] Remove filenames at the top of the license notice
We've stopped doing it in libc++ for a while now because these names
would end up rotting as we move things around and copy/paste stuff.
This cleans up all the existing files so as to stop the spreading
as people copy-paste headers around.
2021-11-17 16:30:52 -05:00
Arthur O'Dwyer 0412c007e3 [libc++] Implement LWG3369, tweak CTAD for std::span.
The original bug doesn't reproduce on Clang, allegedly because of
https://bugs.llvm.org/show_bug.cgi?id=44484
We already test STL's exact test case, in "span.cons/deduct.pass.cpp",
which I'm touching just for the heck of it.

Differential Revision: https://reviews.llvm.org/D111838
2021-10-29 14:15:41 -06:00
Joe Loser 8e92410ecc
[libc++][docs] Mark LWG3274 as complete
Mark LWG3274 as complete. The feature test macro `__cpp_lib_span` was added in
`6d2599e4f776d0cd88438cb82a00c4fc25cc3f67`.

https://wg21.link/p1024 mentions marking `span:::empty()` with
`[[nodiscard]]` which is not done yet. So, do that and add tests.

Reviewed By: ldionne, Quuxplusone, Mordante, #libc

Differential Revision: https://reviews.llvm.org/D111516
2021-10-12 22:31:32 -04:00
Joe Loser 3a208c6894
[libc++] Implement P1394r4 for span: range constructor
Implement https://wg21.link/p1394 which allows span to be constructible
from any contiguous forwarding-range that has a compatible element type.

Fixes https://bugs.llvm.org/show_bug.cgi?id=51443

Reviewed By: ldionne, Quuxplusone, #libc

Differential Revision: https://reviews.llvm.org/D110503
2021-10-08 17:00:39 -04:00
Joe Loser 9451d9da95
[libc++][NFC] s/enable_if<...>::type/enable_if_t<...> in span
There is some use of `enable_if<...>::type` when the rest of the file
uses `enable_if_t`. So, use `enable_if_t` consistently throughout.
2021-09-27 19:21:07 -04:00
Christopher Di Bella e37bbfe59c [libcxx][modules] protects users from relying on libc++ detail headers (1/n)
libc++ has started splicing standard library headers into much more
fine-grained content for maintainability. It's very likely that outdated
and naive tooling (some of which is outside of LLVM's scope) will
suggest users include things such as `<__algorithm/find.h>` instead of
`<algorithm>`, and Hyrum's law suggests that users will eventually begin
to rely on this without the help of tooling. As such, this commit
intends to protect users from themselves, by making it a hard error for
anyone outside of the standard library to include libc++ detail headers.

This is the first of four patches. Patch #2 will solve the problem for
pre-processor `#include`s; patches #3 and #4 will solve the problem for
`<__tree>` and `<__hash_table>` (since I've never touched the test cases
that are failing for these two, I want to split them out into their own
commits to be extra careful). Patch #5 will concern itself with
`<__threading_support>`, which intersects with libcxxabi (which I know
even less about).

Differential Revision: https://reviews.llvm.org/D105932
2021-07-16 22:39:18 +00:00
Louis Dionne f32f3db9fc [libc++] Split the various iterator types out of <iterator>
Differential Revision: https://reviews.llvm.org/D104669
2021-06-28 12:25:40 -04:00
Christopher Di Bella 69d5a66621 [libcxx][modularisation] splits `<utility>` into self-contained headers
* moves `std::hash` and `std::unary_function` into `__functional`
* Everything else goes into `__utility/${NAME}.h`

Differential Revision: https://reviews.llvm.org/D104002
2021-06-25 00:29:01 +00:00
Christopher Di Bella 462f8f0611 [libcxx][ranges] removes default_initializable from weakly_incrementable and view
also:

* removes default constructors from predefined iterators
* makes span and string_view views

Partially implements P2325.
Partially resolves LWG3326.

Differential Revision: https://reviews.llvm.org/D102468
2021-06-10 22:45:36 +00:00
Arthur O'Dwyer 06b40e80ae [libc++] Alphabetize header inclusions and include-what-you-use <__debug>. NFCI. 2021-05-18 19:56:30 -04:00
Arthur O'Dwyer 6946f0ecca [libc++] [LIBCXX-DEBUG-FIXME] <span>, like <string_view>, has no use for debug iterators.
A span has no idea what container (if any) "owns" its iterators, nor
under what circumstances they might become invalidated.

However, continue to use `__wrap_iter<T*>` instead of raw `T*` outside
of debug mode, because we've been shipping `std::span` since Clang 7
and ldionne doesn't want to break ABI. (Namely, the mangling of functions
taking `span::iterator` as a parameter.) Permit using raw `T*` there,
but only under an ABI macro: `_LIBCPP_ABI_SPAN_POINTER_ITERATORS`.

Differential Revision: https://reviews.llvm.org/D101003
2021-04-30 23:06:45 -04:00
Mark de Wever 01ace074fc [libc++] Implements ranges::enable_borrowed_range
This is the initial patch to implement ranges in libc++.

Implements parts of:
- P0896R4 One Ranges Proposal
- P1870 forwarding-range is too subtle
- LWG3379 in several library names is misleading

Reviewed By: ldionne, #libc, cjdb, zoecarver, Quuxplusone

Differential Revision: https://reviews.llvm.org/D90999
2021-04-18 13:35:08 +02:00
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
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
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
Louis Dionne 0a0e0afaa0 [libc++] span: Fix incorrect static asserts
The static asserts in span<T, N>::front() and span<T, N>::back() are
incorrect as they may be triggered from valid code due to evaluation
of a never taken branch:

    span<int, 0> foo;
    if (!foo.empty()) {
        auto x = foo.front();
    }

The problem is that the branch is always evaluated by the compiler,
creating invalid compile errors for span<T, 0>.

Thanks to Michael Schellenberger Costa for the patch.

Differential Revision: https://reviews.llvm.org/D71995
2020-02-14 14:32:41 +01:00
Louis Dionne b5abd50f06 [libc++] span: Guard against overflow in span::subspan
The calculation _Offset + _Count <= size() may overflow, so use
_Count <= size() - _Offset instead. Note that this is safe due to
the previous constraint that _Offset <= size().

Patch by Michael Schellenberger Costa.

Differential Revision: https://reviews.llvm.org/D71998
2020-02-12 16:21:46 +01:00
Louis Dionne 92a1f65f17 [libc++] span: Fix incorrect return type of span::subspan
The extent of the returned span was always std::dynamic_extent, which
is incorrect.

Thanks to Michael Schellenberger Costa for the patch.

Differential Revision: https://reviews.llvm.org/D71997
2020-02-11 11:58:45 +01:00
Louis Dionne b4a3e6b664 [libcxx] span: Remove unneeded comparison
size_t is always greater than 0, so remove the artifact from the old
index_type.

Patch by Michael Schellenberger Costa.

Differential Revision: https://reviews.llvm.org/D71996
2020-02-11 11:39:12 +01:00
Louis Dionne edbaa7fc04 [libc++] span: Cleanup includes
Thanks to Michael Schellenberger Costa for the patch.

Differential Revision: https://reviews.llvm.org/D72036
2020-02-11 11:17:30 +01:00
Louis Dionne 1ac44d9fd1 [libc++] Protect <span> against min/max macro
Patch by Corentin Jabot
Differential Revision: https://reviews.llvm.org/D73855
2020-02-10 13:41:34 +01:00
Louis Dionne 1466335cf4 [libc++][P1872] span should have size_type, not index_type.
Thanks to Marek Kurdej for the patch.

Differential Revision: https://reviews.llvm.org/D70206
2019-11-14 09:07:05 -05:00
Louis Dionne 2b0c7abba3 [libc++] Declare std::tuple_element as struct instead of class
Similarly to https://reviews.llvm.org/rL350972, this revision changes
std::tuple_element from class to struct.

Fixes PR41331.
Thanks to Jan Wilken Dörrie for the patch.

Differential Revision: https://reviews.llvm.org/D60069

llvm-svn: 357411
2019-04-01 16:39:34 +00:00
Louis Dionne 7cd0dad834 [libc++] Rename span's as_writeable_bytes to as_writable_bytes
Summary: The Standard says as_writable_bytes.

Reviewers: mclow.lists, EricWF

Subscribers: christof, jkorous, dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59882

llvm-svn: 357139
2019-03-28 01:27:52 +00:00
Marshall Clow 8eda3ad29d Eradicate all the ptrdiff_ts in span left over from applying P1227. A couple of other minor cleanups. NFC
llvm-svn: 355481
2019-03-06 03:59:44 +00:00
Marshall Clow 5c814099c7 I changed a 'enable_if<...>::type to' 'enable_if_t<...>' but forgot to remove the preceding 'typename'
llvm-svn: 354995
2019-02-27 16:09:35 +00:00
Marshall Clow 02e1651c1f Implment the last part of P1024: tuple-like interface to span. Reviewed as https://reviews.llvm.org/D58706.
llvm-svn: 354988
2019-02-27 15:41:37 +00:00
Marshall Clow 7ad06a9319 First part of P1227R2 - change span over to use 'size_t' instead of 'ptrdiff_t'. Reviewed as https://reviews.llvm.org/D58639.
llvm-svn: 354936
2019-02-27 00:32:16 +00:00
Marshall Clow 310b75e519 LWG3101 - span's Container constructors need another constraint. Reviewed as https://reviews.llvm.org/D57058.
llvm-svn: 354805
2019-02-25 18:32:57 +00:00
Marshall Clow 4fd0395477 Commit LWG3144 - span does not have a const_pointer typedef. Reviewed as D57039.
llvm-svn: 354802
2019-02-25 17:58:03 +00:00
Marshall Clow 9ab85a69dc First part of P1024: Usability Enhancements for std::span. Remove operator() for indexing, and add 'front' and 'back' calls.
llvm-svn: 354801
2019-02-25 17:54:08 +00:00
Chandler Carruth 57b08b0944 Update more file headers across all of the LLVM projects in the monorepo
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351648
2019-01-19 10:56:40 +00:00
Marshall Clow 44d247d280 Implement P1085R2 - Should Span be Regular?. This consists entirely of deletions
llvm-svn: 347672
2018-11-27 16:35:41 +00:00
Louis Dionne 98faa3976d [libc++][NFC] Add error messages to a couple of static_asserts in span
Summary:
Add error messages to a couple of static_asserts in span to match the
style used in the rest of the file. Also fix an extra paren typo in a
assert error message.

Committed on behalf of Jason Lovett.

Reviewers: ldionne

Subscribers: libcxx-commits

Differential Revision: https://reviews.llvm.org/D52841

llvm-svn: 343725
2018-10-03 21:36:16 +00:00
Louis Dionne 7c3492b00d [NFC][libc++] Consistently use spaces to indent
rdar://problem/19988944

llvm-svn: 338933
2018-08-03 22:36:53 +00:00
Marshall Clow 35773f5517 fix nesting of namespace and standard-version check. Also include <__config>
llvm-svn: 337809
2018-07-24 03:56:38 +00:00