Commit Graph

122 Commits

Author SHA1 Message Date
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
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 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
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 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
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
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
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 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 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
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
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
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
Eric Fiselier f82dba0192 Rename __is_foo_iterator traits to reflect their Cpp17 nature.
With the upcoming introduction of iterator concepts in ranges,
the meaning of "__is_contiguous_iterator" changes drastically.

Currently we intend it to mean "does it have this iterator category",
but it could now also mean "does it meet the requirements of this
concept", and these can be different.
2019-11-18 01:49:32 -05:00
Eric Fiselier 6624fcba43 [libc++] Add _ITER_CONCEPT and _ITER_TRAITS implementations from C++20
These traits are currently unused because we don't implement ranges.
However, their addition is part of ongoing work to allow libc++
to optimize on user-provided contiguous iterators.
2019-11-16 20:26:35 -05:00
Eric Fiselier 45d048c204 [libc++] Add C++20 contiguous_iterator_tag.
This work is part of an ongoing effort to allow libc++ to
optimize user provided contiguous iterators.
2019-11-16 20:14:44 -05:00
Louis Dionne 13c90a5716 [libc++][P0202] Marked algorithms copy/copy_n/copy_if/copy_backward constexpr
Thanks to Michael Park for the patch.

Differential Revision: https://reviews.llvm.org/D68837
2019-11-06 12:02:41 +00:00
Eric Fiselier 278d593014 Revert "Suppress -Wctad-maybe-unsupported on types w/o deduction guides."
Some modules builds are issuing buggy diagnostics. The cause of which is
TBD.

This reverts commit r@367770.

llvm-svn: 367777
2019-08-04 07:13:43 +00:00
Eric Fiselier fcd549a7d8 Suppress -Wctad-maybe-unsupported on types w/o deduction guides.
There are a handful of standard library types that are intended
to support CTAD but don't need any explicit deduction guides to
do so.

This patch adds a dummy deduction guide to those types to suppress
-Wctad-maybe-unsupported (which gets emitted in user code).

llvm-svn: 367770
2019-08-03 23:54:29 +00:00
Louis Dionne f2f7d72f00 [libc++] Take 2: Implement CTAD for map and multimap
This is a re-application of r362986 (which was reverted in r363688) with fixes
for the issue that caused it to be reverted.

Thanks to Arthur O'Dwyer for the patch.

Differential Revision: https://reviews.llvm.org/D58587

llvm-svn: 363968
2019-06-20 19:32:00 +00:00
Louis Dionne 1fab01f92b [libc++] Revert the addition of map/multimap CTAD
This was found to be broken on Clang trunk. This is a revert of the
following commits (the subsequent commits added XFAILs to the tests
that were missing from the original submission):

    r362986: Implement deduction guides for map/multimap.
    r363014: Add some XFAILs
    r363097: Add more XFAILs
    r363197: Add even more XFAILs

llvm-svn: 363688
2019-06-18 14:40:15 +00:00
Marshall Clow edfe8525de Implement deduction guides for map/multimap. Reviewed as https://reviews.llvm.org/D58587. Thanks to Quuxplusone for the submission.
llvm-svn: 362986
2019-06-10 21:28:23 +00:00
Louis Dionne a2a1ec27d0 [NFC][libcxx] Remove trailing whitespace
It's incredibly annoying when trying to create diffs

llvm-svn: 361981
2019-05-29 16:01:36 +00:00
Louis Dionne ebaf1d5e2b [libc++] Unconditionally enable the __pad_and_output optimization
This used to be guarded on whether the deployment target was greater
than macosx10.8, however testing against the dylibs for 10.8 and earlier
with the function enabled works too. The revision that introduced
__pad_and_output is r164241 and it does not mention a reason for the
guard.

llvm-svn: 358677
2019-04-18 15:19:35 +00:00
Marshall Clow e1cd11d80f Fix a minor bug with std::next and prev not and negative numbers. In particular, std::prev cannot require Bidirectional Iterators, because you might 'go back' -1 places, which goes forward. Thanks to Ville and Jonathan for the bug report.
llvm-svn: 356818
2019-03-22 22:32:20 +00:00
Eric Fiselier 61b302f94f Remove exception throwing debug mode handler support.
Summary:
The reason libc++ implemented a throwing debug mode handler was for ease of testing. Specifically,
I thought that if a debug violation aborted, we could only test one violation per file. This made
it impossible to test debug mode. Which throwing behavior we could test more!

However, the throwing approach didn't work either, since there are debug violations underneath noexcept
functions. This lead to the introduction of `_NOEXCEPT_DEBUG`, which was only noexcept when debug
mode was off.

Having thought more and having grown wiser, `_NOEXCEPT_DEBUG` was a horrible decision. It was
viral, it didn't cover all the cases it needed to, and it was observable to the user -- at worst
changing the behavior of their program.

  This patch removes the throwing debug handler, and rewrites the debug tests using 'fork-ing' style
  death tests.

Reviewers: mclow.lists, ldionne, thomasanderson

Reviewed By: ldionne

Subscribers: christof, arphaman, libcxx-commits, #libc

Differential Revision: https://reviews.llvm.org/D59166

llvm-svn: 356417
2019-03-18 21:50:12 +00:00
Marshall Clow 2ffa170515 In the review of D58642, Louis asked: 'Is there a reason for making this inline? Templates are already inline by default'. I told him that I didn't want to change the one call (ssize) that I was adding, but would come back later and clean them all (data/empty/begin/end/cbegin/cend/rbegin/rend/crbegin/crend/size/ssize) up later. Now it is later. Remove the unnecessary 'inline' modifiers from all these calls.
llvm-svn: 354952
2019-02-27 03:25:43 +00:00
Marshall Clow 7d3986ea30 Implement the second part of P1227R2 - Signed ssize() functions. Reviewed as https://reviews.llvm.org/D58642
llvm-svn: 354950
2019-02-27 02:58:56 +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
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 d4fa0381e3 Fix PR39619 - iterator_traits isn't SFINAE-friendly enough. Thanks to Eric for the report
llvm-svn: 346738
2018-11-13 05:33:31 +00:00
Marshall Clow f56972e224 Implement the infrastructure for feature-test macros. Very few actual feature test macros, though. Reviewed as: https://reviews.llvm.org/D51955
llvm-svn: 342073
2018-09-12 19:41:40 +00:00
Marshall Clow 4ce0a916f0 Mark one more __wrap_iter operation as constexpr.
llvm-svn: 337085
2018-07-14 03:06:11 +00:00
Marshall Clow 9cad502555 Make internal class __wrap_iter constexpr when not using libc++'s debugging mode. Introduce a new macro _LIBCPP_CONSTEXPR_IF_NODEBUG to mark this.
llvm-svn: 337019
2018-07-13 16:35:26 +00:00
Roger Ferrer Ibanez 6f56d3eee8 [libcxx] Define istream_iterator equality comparison operators out-of-line
Currently libc++ defines operator== and operator!= as friend functions in the
definition of the istream_iterator class template. Such definition has a subtle
difference from an out-of-line definition required by the C++ Standard: these
functions can only be found by argument-dependent lookup, but not by qualified
lookup.

This patch changes the definition, so that it conforms to the C++ Standard and
adds a check involving qualified lookup to the test suite.

Patch contributed by Mikhail Maltsev.

Differential Revision: https://reviews.llvm.org/D40415

llvm-svn: 320363
2017-12-11 13:54:58 +00:00
Marshall Clow d1dcda1969 Mark free functions size/empty/data conditionally noexcept.
llvm-svn: 318432
2017-11-16 17:55:41 +00:00
Marshall Clow 25a7ba4524 More of P0600 - '[[nodiscard]] in the Library' mark empty() as nodiscard in string, string_view, and the free function std::empty(). Removed tabs from <string_view>, which is why the diff is so big.
llvm-svn: 318328
2017-11-15 20:02:27 +00:00
Marshall Clow ffcfd923d7 Implement LWG2952: iterator_traits should work for pointers to cv T
llvm-svn: 318119
2017-11-14 00:03:10 +00:00
Rachel Craik 3e2ef40812 Remove addtional parameters in function std::next() and std::prev()
Creating a function pointer with proper parameters pointing to std::next() or std::prev() should work.
This change moves the invented paramater for enable_if over to the return type to resolve this QoI issue.

Patch by Jason Liu.

Differential Revision: https://reviews.llvm.org/D34649

llvm-svn: 308932
2017-07-24 22:17:05 +00:00
Marshall Clow c44a727ee4 Implement LWG#2790: Remove istreambuf_iterator::operator->. It never did anything useful.
llvm-svn: 303675
2017-05-23 18:55:32 +00:00
Marshall Clow f51ee63247 Make next/prev/advance/distance operations on iterators be constexpr. I missed this when I implemented the rest of P0031R0
llvm-svn: 303281
2017-05-17 18:51:36 +00:00
Eric Fiselier 046492b932 Cleanup usages of _LIBCPP_HAS_NO_<c++11-feature> in <bitset>, <ios>, <locale>, and <iterator>
llvm-svn: 300648
2017-04-19 01:34:08 +00:00
Eric Fiselier e02ed1c255 Diagnose when reverse_iterator is used on path::iterator.
path::iterator isn't a strictly conforming iterator. Specifically
it stashes the current element inside the iterator. This leads to
UB when used with reverse_iterator since it requires the element
to outlive the lifetime of the iterator.

This patch adds a static_assert inside reverse_iterator to disallow
"stashing iterator types", and it tags path::iterator as such a type.

Additionally this patch removes all uses of reverse_iterator<path::iterator>
within the tests.

llvm-svn: 300164
2017-04-13 02:54:13 +00:00
Eric Fiselier e2f2d1edef [NFC] Rename _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS
The name _LIBCPP_TYPE_VIS_ONLY is no longer accurate because both
_LIBCPP_TYPE_VIS and _LIBCPP_TYPE_VIS_ONLY expand to
__attribute__((__type_visibility__)) with Clang. The only remaining difference
is that _LIBCPP_TYPE_VIS_ONLY can be applied to templates whereas
_LIBCPP_TYPE_VIS cannot (due to dllimport/dllexport not being allowed on
templates).

This patch renames _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS.

llvm-svn: 291035
2017-01-04 23:56:00 +00:00
Marshall Clow 020b623a3b Implement the last bit of P0031: 'A Proposal to Add Constexpr Modifiers to reverse_iterator, move_iterator, array and Range Access' for C++17
llvm-svn: 290976
2017-01-04 17:58:17 +00:00
Eric Fiselier 14bd0bf008 Fix __wrap_iter in debug mode and apply _NOEXCEPT_DEBUG to it
llvm-svn: 290654
2016-12-28 05:35:32 +00:00
Eric Fiselier fd83822741 Fix unused parameters and variables
llvm-svn: 290459
2016-12-23 23:37:52 +00:00
Marshall Clow 720ef47200 Implement another part of P0031; adding constexpr to move_iterator
llvm-svn: 285818
2016-11-02 15:30:26 +00:00