Commit Graph

2169 Commits

Author SHA1 Message Date
Eric Fiselier
b6a95e7ae7 Work around missing braces in init warning
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329474 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-07 01:28:54 +00:00
Eric Fiselier
24258c4417 Implement P0768r1: Library support for the Spaceship Operator.
this patch adds the <compare> header and implements all of it
except for [comp.alg].

As I understand it, the header is needed by the compiler in
when implementing the semantics of operator<=>. For that reason
I feel it's important to land this header early, despite
all compilers lacking support.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329460 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-06 21:37:23 +00:00
Gor Nishanov
b431c5a9ec [coroutines] libcxx, noop_coroutine, make bots even more happy
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329245 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-05 00:18:37 +00:00
Gor Nishanov
827c4ff600 [coroutines] Allow compilation under c++03
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329239 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-04 22:51:57 +00:00
Gor Nishanov
81e07a9315 [coroutines] Add noop_coroutine to <experimental/coroutine>
A recent addition to Coroutines TS (https://wg21.link/p0913) adds a pre-defined
coroutine noop_coroutine that does nothing.

This patch implements require library types in <experimental/coroutine>

Related clang and llvm patches:

https://reviews.llvm.org/D45114
https://reviews.llvm.org/D45120

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329237 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-04 22:18:03 +00:00
Eric Fiselier
576717d499 Touch up tests for new <version> header; fix module.modulemap.
This patch does some housekeeping for the new <version> header.
It adds it to the module.modulemap, and the double_include.sh.cpp test.

Additionally it corrects the // UNSUPPORTED options for the libc++
specific test. The header needs to compile under C++03 to support
modules, and it should compile under all available compilers.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329144 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-04 04:21:54 +00:00
Marshall Clow
0b261846c9 Implement P0754R2: The <version> header.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329075 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-03 15:48:24 +00:00
Eric Fiselier
e96d6a1fb7 Implement P0430R2 - File system library on non-POSIX systems.
This patch implements P0430R2, who's largest change is adding the path::format
enumeration for supporting path format conversions in path constructors.

However, since libc++'s filesystem only really supports POSIX like systems,
there are no real changes needed. This patch simply adds the format enum
and then ignores it when it's passed to constructors.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329031 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-02 23:35:24 +00:00
Eric Fiselier
1e34c76d33 Implement filesystem NB comments, relative paths, and related issues.
This is a fairly large patch that implements all of the filesystem NB comments
and the relative paths changes (ex. adding weakly_canonical). These issues
and papers are all interrelated so their implementation couldn't be split up
nicely.

This patch upgrades <experimental/filesystem> to match the C++17 spec and not
the published experimental TS spec. Some of the changes in this patch are both
API and ABI breaking, however libc++ makes no guarantee about stability for
experimental implementations.

The major changes in this patch are:

* Implement NB comments for filesystem (P0492R2), including:
  * Implement `perm_options` enum as part of NB comments, and update the
    `permissions` function to match.
  * Implement changes to `remove_filename` and `replace_filename`
  * Implement changes to `path::stem()` and `path::extension()` which support
    splitting examples like `.profile`.
  * Change path iteration to return an empty path instead of '.' for trailing
    separators.
  * Change `operator/=` to handle absolute paths on the RHS.
  * Change `absolute` to no longer accept a current path argument.

* Implement relative paths according to NB comments (P0219r1)

* Combine `path.cpp` and `operations.cpp` since some path functions require
  access to the operations internals, and some fs operations require access
  to the path parser.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329028 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-02 23:03:41 +00:00
Eric Fiselier
f382e53015 Fix PR36914 - num_get::get(unsigned) incorrectly handles negative numbers.
This patch corrects num_get for unsigned types to support strings
with a leading `-` character. According to the standard the
number should be parsed as an unsigned integer and then
negated.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@328751 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-29 01:18:53 +00:00
Eric Fiselier
f2c93738b8 Implement filesystem::perm_options specified in NB comments.
The NB comments for filesystem changed permissions and added
a new enum `perm_options` which control how the permissions
are applied.

This implements than NB resolution

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@328476 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-26 06:23:55 +00:00
Eric Fiselier
5a424a9856 Partially Revert "Workaround GCC bug PR78489 - SFINAE order is not respected."
This partially reverts commit r328261. The GCC bug has been fixed in
trunk and has never existed in a released version. Therefore the changes
to variant are unneeded.

However, the additional tests have been left in place.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@328388 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-23 23:42:30 +00:00
Eric Fiselier
493b609b27 Workaround GCC bug PR78489 - SFINAE order is not respected.
This patch works around variant test failures which are new to
GCC 8. GCC 8 either doesn't perform SFINAE in lexical order, or
it doesn't halt after encountering the first failure. This
causes hard error to occur instead of substitution failure.

See gcc.gnu.org/PR78489

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@328261 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-22 22:32:55 +00:00
Marshall Clow
e9e128b0a6 Fix improperly failing test - and the code it was testing. Thanks to Stephan Lavavej for the catch.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@328225 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-22 18:27:28 +00:00
Eric Fiselier
f4f3025362 Fix dynarray test failures after changing __libcpp_allocate/deallocate
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@328182 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-22 05:44:48 +00:00
Eric Fiselier
a831287399 Fix PR22634 - std::allocator doesn't respect over-aligned types.
This patch fixes std::allocator, and more specifically, all users
of __libcpp_allocate and __libcpp_deallocate, to support over-aligned
types.

__libcpp_allocate/deallocate now take an alignment parameter, and when
the specified alignment is greater than that supported by malloc/new,
the aligned version of operator new is called (assuming it's available).

When aligned new isn't available, the old behavior has been kept, and the
alignment parameter is ignored.

This patch depends on recent changes to __builtin_operator_new/delete which
allow them to be used to call any regular new/delete operator. By using
__builtin_operator_new/delete when possible, the new/delete erasure optimization
is maintained.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@328180 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-22 04:42:56 +00:00
Marshall Clow
256f187bc6 Implement LWG3034: P0767R1 breaks previously-standard-layout types
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@328064 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-21 00:36:05 +00:00
Marshall Clow
dfeb9b2af7 Implement LWG3035: std::allocator's constructors should be constexpr.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@328059 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-20 23:02:53 +00:00
Marshall Clow
483bc7c64a Implement LWG 3039 and 3041 - 'Treating Unnecessary decay'.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@328054 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-20 22:37:37 +00:00
Petr Hosek
698b695147 [CMake] Copy the generated __config header into build directory
When the generated __config file is being used, it is currently only
copied during installation process. However, that means that the file
that gets copied into LLVM build directory is the vanilla __config file,
and any parts of the build that depend on the just built toolchain like
sanitizers will get that instead of the generated version. To avoid this
issue, we need to copy the generated header into the LLVM build
directory as well.

Differential Revision: https://reviews.llvm.org/D43797

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@327194 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-10 01:20:11 +00:00
Vedant Kumar
2b588cbf15 Low-hanging fruit optimization in string::__move_assign().
shrink_to_fit() ends up doing a lot work to get information that we
already know since we just called clear(). This change seems concise
enough to be worth the couple extra lines and my benchmarks show that it
is indeed a pretty decent win. It looks like the same thing is going on
twice in __copy_assign_alloc(), but I didn't want to go overboard since
this is my first contribution to llvm/libc++.

Patch by Timothy VanSlyke!

Differential Revision: https://reviews.llvm.org/D41976

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@327064 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-08 21:15:26 +00:00
Marshall Clow
46b8a51b49 Implement LWG#2518 - Non-member swap for propagate_const should call member swap
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@327005 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-08 15:01:50 +00:00
Logan Chien
7102892bf3 Cleanup __config indention NFC
This commit indents each level by two space characters, e.g.

#if defined(CONDITION)
#  define _LIBCPP_NAME VALUE
#else
#  define _LIBCPP_NAME VALUE
#endif

The simple #ifndef, #define, and #endif sequences are not indented, e.g.

#ifndef _LIBCPP_NAME
#define _LIBCPP_NAME ...
#endif


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@326027 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-24 07:57:32 +00:00
Mikhail Maltsev
df7a35ce32 [libcxx] Do not include the C math.h header before __config
Summary:
Certain C libraries require configuration macros defined in __config
to provide the correct functionality for libc++. This patch ensures
that the C header math.h is always included after the __config
header. It also adds a Windows-specific #if guard for the case when
the C math.h file is included the second time, as suggested by
Marshall in https://reviews.llvm.org/rL323490.

Fixes PR36382.

Reviewers: mclow.lists, EricWF

Reviewed By: mclow.lists

Subscribers: cfe-commits, pcc, christof, rogfer01

Differential Revision: https://reviews.llvm.org/D43579

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@325760 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-22 09:34:08 +00:00
Peter Collingbourne
61494b519c libcxx: Unbreak external thread library configuration.
Differential Revision: https://reviews.llvm.org/D42503

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@325723 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-21 21:36:18 +00:00
Mikhail Maltsev
c4658abe60 [libcxx] Improve accuracy of complex asinh and acosh
Summary:
Currently std::asinh and std::acosh use std::pow to compute x^2. This
results in a significant error when computing e.g. asinh(i) or
acosh(-1).

This patch expresses x^2 directly via x.real() and x.imag(), like it
is done in libstdc++/glibc, and adds tests that checks the accuracy.

Reviewers: EricWF, mclow.lists

Reviewed By: mclow.lists

Subscribers: christof, cfe-commits

Differential Revision: https://reviews.llvm.org/D41629

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@325510 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-19 15:41:36 +00:00
Bruce Mitchener
26a02748eb Fix incorrect indentation.
Reviewers: mclow.lists

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D43167

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@325087 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-14 00:29:38 +00:00
Dimitry Andric
52474820e4 Put type attributes after class keyword
Summary:
Compiling `<functional>` in C++17 or higher mode results in:

```
functional:2500:1: warning: attribute '__visibility__' is ignored, place it after "class" to apply attribute to type declaration [-Wignored-attributes]
_LIBCPP_TYPE_VIS
^
__config:701:46: note: expanded from macro '_LIBCPP_TYPE_VIS'
#    define _LIBCPP_TYPE_VIS __attribute__ ((__visibility__("default")))
                                             ^
1 warning generated.
```

Fix it by putting the attribute after the `class` keyword.

Reviewers: EricWF, mclow.lists

Reviewed By: EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D43209

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@325027 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-13 17:40:59 +00:00
Marshall Clow
806a6ec645 Implement LWG 2835 - fix <tgmath.h>
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324923 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-12 19:13:24 +00:00
Marshall Clow
f72f21907c Implement LWG#2908 - The less-than operator for shared pointers could do more, and mark 2878 as complete as well (we already do that)
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324911 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-12 17:26:40 +00:00
Marshall Clow
b8cb776511 While implementing P0777 - preventing unnecessary decay, I found some non-public uses of decay that could be replaced by __uncvref. NFC intented
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324895 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-12 15:41:25 +00:00
Eric Fiselier
22a291c94e Fix libcxx MSVC C++17 redefinition of 'align_val_t'
Patch from 	charlieio@outlook.com

Reviewed as https://reviews.llvm.org/D42354

When the following command is used:

> clang-cl -std:c++17 -Iinclude\c++\v1 hello.cc c++.lib

An error occurred:

In file included from hello.cc:1:
In file included from include\c++\v1\iostream:38:
In file included from include\c++\v1\ios:216:
In file included from include\c++\v1\__locale:15:
In file included from include\c++\v1\string:477:
In file included from include\c++\v1\string_view:176:
In file included from include\c++\v1\__string:56:
In file included from include\c++\v1\algorithm:643:
In file included from include\c++\v1\memory:656:
include\c++\v1\new(165,29):  error: redefinition of 'align_val_t'
enum class _LIBCPP_ENUM_VIS align_val_t : size_t { };
                            ^
C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.12.25827\include\vcruntime_new.h(43,16):  note:
      previous definition is here
    enum class align_val_t : size_t {};
               ^
1 error generated.
vcruntime_new.h has defined align_val_t, libcxx need hide align_val_t.

This patch fixes that error.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324853 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-11 22:00:19 +00:00
Marshall Clow
a8de063568 Fix a typo in the synopsis comment. NFC. Thanks to K-ballo for the catch
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324851 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-11 21:51:49 +00:00
Eric Fiselier
9e6ac074ee Use multi-key tree search for {map, set}::{count, equal_range}
Patch from ngolovliov@gmail.com
Reviewed as: https://reviews.llvm.org/D42344

As described in llvm.org/PR30959, the current
implementation of std::{map, key}::{count, equal_range} in libcxx is
non-conforming. Quoting the C++14 standard [associative.reqmts]p3

> The phrase “equivalence of keys” means the equivalence relation imposed by
> the comparison and not the operator== on keys. That is, two keys k1 and k2 are
> considered to be equivalent if for the comparison object comp,
> comp(k1, k2) == false && comp(k2, k1) == false.

In the same section, the requirements table states the following:

> a.equal_range(k) equivalent to make_pair(a.lower_bound(k), a.upper_bound(k))
> a.count(k) returns the number of elements with key equivalent to k

The behaviour of libstdc++ seems to conform to the standard here.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324799 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-10 02:53:47 +00:00
Mikhail Maltsev
171ed2198d [libcxx] Avoid spurious construction of valarray elements
Summary:
Currently libc++ implements some operations on valarray by using the
resize method. This method has a parameter with a default value.
Because of this, valarray may spuriously construct and destruct
objects of valarray's element type.
    
This patch fixes this issue and adds corresponding test cases.


Reviewers: EricWF, mclow.lists

Reviewed By: mclow.lists

Subscribers: rogfer01, cfe-commits

Differential Revision: https://reviews.llvm.org/D41992

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324596 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-08 11:33:48 +00:00
Marshall Clow
5b1e87e52d Implement deduction guide for basic_string as described in P0433
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324569 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-08 06:34:03 +00:00
Eric Fiselier
c0acd34e9a Fix size and alignment of array<T, 0>.
An array T[1] isn't necessarily the same say when it's
a member of a struct. This patch addresses that problem and corrects
the tests to deal with it.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324545 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-07 23:50:25 +00:00
Dan Albert
73660f725a Stop using __strtonum_fallback on Android.
Fallback implementations are now provided by bionic when necessary,
which these may conflict with.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324534 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-07 21:58:48 +00:00
Marshall Clow
088e6015b2 Fix PR#31454 - 'basic_string<T>::push_back() crashes if sizeof(T)>sizeof(long long)'. We were mishandling the small-string optimization calculations for very large 'characters'. This may be an ABI change (change the size of) strings of very large 'characters', but since they never worked, I'm not too concerned.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324531 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-07 21:30:17 +00:00
Eric Fiselier
6cb35ede81 [libc++] Fix PR35491 - std::array of zero-size doesn't work with non-default constructible types.
Summary:
This patch fixes llvm.org/PR35491 and LWG2157  (https://cplusplus.github.io/LWG/issue2157)

The fix attempts to maintain ABI compatibility by replacing the array with a instance of `aligned_storage`.

Reviewers: mclow.lists, EricWF

Reviewed By: EricWF

Subscribers: lichray, cfe-commits

Differential Revision: https://reviews.llvm.org/D41223

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324526 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-07 21:06:13 +00:00
Marshall Clow
31810d9c0b Remove more of the std::experimental bits that are now in std::. All the _v type aliases, conjunction/disjunction, apply, etc. See https://libcxx.llvm.org/TS_deprecation.html
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324423 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-06 23:13:48 +00:00
Marshall Clow
52f9ca28a3 Implement P0777: Treating unnecessay decay
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324398 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-06 20:56:55 +00:00
Marshall Clow
f477af5fda Fix misleading indentation; replace a couple of NULLs with nullptr. Resolves https://reviews.llvm.org/D42945 ; thanks to Bruce Mitchener for the patch.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324378 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-06 18:58:05 +00:00
Nirav Dave
610fc67809 Revert "[libc++] Fix PR35491 - std::array of zero-size doesn't work with non-default constructible types."
Revert "Fix initialization of array<const T, 0> with GCC."
Revert "Make array<const T, 0> non-CopyAssignable and make swap and fill ill-formed."

This reverts commit r324182, r324185, and r324194 which were causing issues with zero-length std::arrays.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324309 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-06 03:03:37 +00:00
Marshall Clow
b50d2443d5 Remove <experimental/string_view>; use <string_view> instead. See https://libcxx.llvm.org/TS_deprecation.html
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324290 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-05 23:43:34 +00:00
Eric Fiselier
13177172d0 Fix initialization of array<const T, 0> with GCC.
Previously, when handling zero-sized array of const objects we
used a const version of aligned_storage_t, which is not an array type.
However, GCC complains about initialization of the form: array<const T, 0> arr = {};

This patch fixes that bug by making the dummy object used to represent
the zero-sized array an array itself. This avoids GCC's complaints
about the uninitialized const member.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324194 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-04 08:02:35 +00:00
Eric Fiselier
4d0f42850b Implement LWG 3014 - Fix more noexcept issues in filesystem.
This patch removes the noexcept declaration from filesystem
operations which require creating temporary paths or
creating a directory iterator. Either of these operations
can throw.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324192 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-04 07:35:36 +00:00
Eric Fiselier
0b47a655ac Implement LWG2989: path's streaming operators allow everything under the sun.
Because path can be constructed from a ton of different types, including string
and wide strings, this caused it's streaming operators to suck up all sorts
of silly types via silly conversions. For example:

using namespace std::experimental::filesystem::v1;
std::wstring w(L"wide");
std::cout << w; // converts to path.

This patch tentatively adopts the resolution to LWG2989 and fixes the issue
by making the streaming operators friends of path.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324189 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-04 03:10:53 +00:00
Eric Fiselier
122c064a76 Make array<const T, 0> non-CopyAssignable and make swap and fill ill-formed.
The standard isn't exactly clear how std::array should handle zero-sized arrays
with const element types. In particular W.R.T. copy assignment, swap, and fill.

This patch takes the position that those operations should be ill-formed,
and makes changes to libc++ to make it so.

This follows up on commit r324182.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324185 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-04 02:17:02 +00:00
Eric Fiselier
f3224ac007 [libc++] Fix PR35491 - std::array of zero-size doesn't work with non-default constructible types.
Summary:
This patch fixes llvm.org/PR35491 and LWG2157  (https://cplusplus.github.io/LWG/issue2157)

The fix attempts to maintain ABI compatibility by replacing the array with a instance of `aligned_storage`.

Reviewers: mclow.lists, EricWF

Reviewed By: EricWF

Subscribers: lichray, cfe-commits

Differential Revision: https://reviews.llvm.org/D41223

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324182 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-04 01:03:08 +00:00