Commit Graph

298 Commits

Author SHA1 Message Date
Eric Fiselier 0f8041b6e2 Remove unused try catch blocks from old debug tests
llvm-svn: 356429
2019-03-19 00:00:30 +00:00
Eric Fiselier cc703de62f Fix test failures after debug mode changes
llvm-svn: 356421
2019-03-18 22:12:09 +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
JF Bastien 2df59c5068 Support tests in freestanding
Summary:
Freestanding is *weird*. The standard allows it to differ in a bunch of odd
manners from regular C++, and the committee would like to improve that
situation. I'd like to make libc++ behave better with what freestanding should
be, so that it can be a tool we use in improving the standard. To do that we
need to try stuff out, both with "freestanding the language mode" and
"freestanding the library subset".

Let's start with the super basic: run the libc++ tests in freestanding, using
clang as the compiler, and see what works. The easiest hack to do this:

In utils/libcxx/test/config.py add:

  self.cxx.compile_flags += ['-ffreestanding']

Run the tests and they all fail.

Why? Because in freestanding `main` isn't special. This "not special" property
has two effects: main doesn't get mangled, and main isn't allowed to omit its
`return` statement. The first means main gets mangled and the linker can't
create a valid executable for us to test. The second means we spew out warnings
(ew) and the compiler doesn't insert the `return` we omitted, and main just
falls of the end and does whatever undefined behavior (if you're luck, ud2
leading to non-zero return code).

Let's start my work with the basics. This patch changes all libc++ tests to
declare `main` as `int main(int, char**` so it mangles consistently (enabling us
to declare another `extern "C"` main for freestanding which calls the mangled
one), and adds `return 0;` to all places where it was missing. This touches 6124
files, and I apologize.

The former was done with The Magic Of Sed.

The later was done with a (not quite correct but decent) clang tool:

  https://gist.github.com/jfbastien/793819ff360baa845483dde81170feed

This works for most tests, though I did have to adjust a few places when e.g.
the test runs with `-x c`, macros are used for main (such as for the filesystem
tests), etc.

Once this is in we can create a freestanding bot which will prevent further
regressions. After that, we can start the real work of supporting C++
freestanding fairly well in libc++.

<rdar://problem/47754795>

Reviewers: ldionne, mclow.lists, EricWF

Subscribers: christof, jkorous, dexonsmith, arphaman, miyuki, libcxx-commits

Differential Revision: https://reviews.llvm.org/D57624

llvm-svn: 353086
2019-02-04 20:31:13 +00:00
Thomas Anderson 7f50dfa6fc [libc++] Fix Windows build error in <functional>
On my Windows system, __allocator is defined to nothing.  This change fixes build errors of the below form:

    In file included from algorithm:644:
    functional(1492,31):  error: expected member name or ';' after declaration specifiers
        const _Alloc& __allocator() const { return __f_.second(); }

Differential Revision: https://reviews.llvm.org/D57355

llvm-svn: 352561
2019-01-29 23:19:45 +00:00
Casey Carter 1ecf6e55cd [test] Define _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST in msvc_stdlib_force_include.hpp
...so the tests under test/std/utilities/any continue to
compile with MSVC's standard library.

While we're here, let's test >C++17 features when _HAS_CXX20.

llvm-svn: 351991
2019-01-23 22:49:44 +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
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

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: 351636
2019-01-19 08:50:56 +00:00
Eric Fiselier efdac65f70 Attempt to make test_macros.h even more minimal
llvm-svn: 351292
2019-01-16 02:16:57 +00:00
Eric Fiselier d108bf85b0 Move internal usages of `alignof`/`__alignof` to use `_LIBCPP_ALIGNOF`.
Summary:
Starting in Clang 8.0 and GCC 8.0, `alignof` and `__alignof` return different values in same cases. Specifically `alignof` and `_Alignof` return the minimum alignment for a type, where as `__alignof` returns the preferred alignment. libc++ currently uses `__alignof` but means to use `alignof`. See  llvm.org/PR39713

This patch introduces the macro `_LIBCPP_ALIGNOF` so we can control which spelling gets used.

This patch does not introduce any ABI guard to provide the old behavior with newer compilers. However, if we decide that is needed, this patch makes it trivial to implement.

I think we should commit this change immediately, and decide what we want to do about the ABI afterwards. 

Reviewers: ldionne, EricWF

Reviewed By: ldionne, EricWF

Subscribers: jyknight, christof, libcxx-commits

Differential Revision: https://reviews.llvm.org/D54814

llvm-svn: 351289
2019-01-16 01:51:12 +00:00
Eric Fiselier 32784a740a Implement feature test macros using a script.
Summary:
This patch implements all the feature test macros libc++ currently supports, as specified by the standard or cppreference prior to C++2a.

The tests and `<version>` header are generated using a script. The script contains a table of each feature test macro, the headers it should be accessible from, and its values of each dialect of C++.
When a new feature test macro is added or needed, the table should be updated and the script re-run.



Reviewers: mclow.lists, jfb, serge-sans-paille

Reviewed By: mclow.lists

Subscribers: arphaman, jfb, ldionne, libcxx-commits

Differential Revision: https://reviews.llvm.org/D56750

llvm-svn: 351286
2019-01-16 01:37:43 +00:00
Dan Albert 5452d3f099 Add large file support to create_file for 32-bit.
Summary:
The tests need to create files larger than 2GB, but size_t is 32-bit
on a 32-bit system. Make use of explicit off64_t APIs so we can still
use a default off_t for the tests while enabling 64-bit file offsets
for create_file.

Reviewers: mclow.lists, EricWF

Reviewed By: EricWF

Subscribers: christof, ldionne, libcxx-commits

Differential Revision: https://reviews.llvm.org/D56619

llvm-svn: 351225
2019-01-15 19:14:15 +00:00
Casey Carter dcaaa1baed [test] Fix logic error in <compare> tests; enable for MSVC Dev16
Submitted upstream as https://reviews.llvm.org/D53763.

llvm-svn: 351148
2019-01-15 01:53:12 +00:00
Marshall Clow f3126c8bc5 Generalize the comparison test structure to support cross-type comparisons. NFC to the library
llvm-svn: 351140
2019-01-15 00:05:05 +00:00
Volodymyr Sapsai e7652f5c0d [libcxx] Use custom allocator's `construct` in C++03 when available.
Makes libc++ behavior consistent between C++03 and C++11.

Can use `decltype` in C++03 because `include/__config` defines a macro when
`decltype` is not available.

Reviewers: mclow.lists, EricWF, erik.pilkington, ldionne

Reviewed By: ldionne

Subscribers: dexonsmith, cfe-commits, howard.hinnant, ldionne, christof, jkorous, Quuxplusone

Differential Revision: https://reviews.llvm.org/D48753

llvm-svn: 349676
2018-12-19 20:08:43 +00:00
Eric Fiselier 2a58b11a8a Fix FP comparisons when SSE isn't available
llvm-svn: 349387
2018-12-17 20:17:43 +00:00
Michal Gorny 4ce222198c [test] [support] Use socket()+bind() to create unix sockets portably
Replace the mknod() call with socket() + bind() for creating unix
sockets.  The mknod() method is not portable and does not work
on NetBSD while binding the socket should work on all systems supporting
unix sockets.

Differential Revision: https://reviews.llvm.org/D55576

llvm-svn: 349305
2018-12-16 15:12:06 +00:00
Michal Gorny 97569391ea [test] Permit NetBSD in filesystem_dynamic_test_helper.py
llvm-svn: 348872
2018-12-11 18:29:35 +00:00
Louis Dionne 9f77b1a1de [pair] Mark constructors as conditionally noexcept
Summary:
std::tuple marks its constructors as noexcept when the corresponding
memberwise constructors are noexcept too -- this commit improves std::pair
so that it behaves the same.

This is a re-application of r348824, which broke the build in C++03 mode
because a test was marked as supported in C++03 when it shouldn't be.

Note:
I did not add support in the explicit and non-explicit `pair(_Tuple&& __p)`
constructors because those are non-standard extensions, and supporting them
properly is tedious (we have to copy the rvalue-referenceness of the deduced
_Tuple&& onto the result of tuple_element).

<rdar://problem/29537079>

Reviewers: mclow.lists, EricWF

Subscribers: christof, llvm-commits

Differential Revision: https://reviews.llvm.org/D48669

llvm-svn: 348847
2018-12-11 14:22:28 +00:00
Louis Dionne d5a20703c4 Revert "[pair] Mark constructors as conditionally noexcept"
This broke the tests on Linux. Reverting until I find out why the tests
are broken (tomorrow).

llvm-svn: 348825
2018-12-11 02:32:46 +00:00
Louis Dionne 76cce3b2bd [pair] Mark constructors as conditionally noexcept
Summary:
std::tuple marks its constructors as noexcept when the corresponding
memberwise constructors are noexcept too -- this commit improves std::pair
so that it behaves the same.

Note:
I did not add support in the explicit and non-explicit `pair(_Tuple&& __p)`
constructors because those are non-standard extensions, and supporting them
properly is tedious (we have to copy the rvalue-referenceness of the deduced
_Tuple&& onto the result of tuple_element).

<rdar://problem/29537079>

Reviewers: mclow.lists, EricWF

Subscribers: christof, llvm-commits

Differential Revision: https://reviews.llvm.org/D48669

llvm-svn: 348824
2018-12-11 02:17:23 +00:00
Eric Fiselier 9d25ada420 Revert "Move internal usages of `alignof`/`__alignof` to use `_LIBCPP_ALIGNOF`. "
This reverts commit 087f065cb0c7463f521a62599884493aaee2ea12.

The tests were failing on 32 bit builds, and I don't have time
to clean them up right now. I'll recommit tomorrow with fixed tests.

llvm-svn: 347816
2018-11-28 22:24:19 +00:00
Eric Fiselier 8a486dac25 Move internal usages of `alignof`/`__alignof` to use `_LIBCPP_ALIGNOF`.
Summary:
Starting in Clang 8.0 and GCC 8.0, `alignof` and `__alignof` return different values in same cases. Specifically `alignof` and `_Alignof` return the minimum alignment for a type, where as `__alignof` returns the preferred alignment. libc++ currently uses `__alignof` but means to use `alignof`. See  llvm.org/PR39713

This patch introduces the macro `_LIBCPP_ALIGNOF` so we can control which spelling gets used.

This patch does not introduce any ABI guard to provide the old behavior with newer compilers. However, if we decide that is needed, this patch makes it trivial to implement.

I think we should commit this change immediately, and decide what we want to do about the ABI afterwards. 

Reviewers: ldionne, EricWF

Reviewed By: EricWF

Subscribers: christof, libcxx-commits

Differential Revision: https://reviews.llvm.org/D54814

llvm-svn: 347787
2018-11-28 18:16:02 +00:00
Eric Fiselier 74fb163184 Fix missing includes in test header
llvm-svn: 347416
2018-11-21 20:39:24 +00:00
Louis Dionne cc870190d8 [NFC][libcxx] Fix incorrect comments
llvm-svn: 347267
2018-11-19 22:06:42 +00:00
Louis Dionne 8a063df194 [libcxx] Add availability markup for bad_optional_access, bad_variant_access and bad_any_cast
Reviewers: dexonsmith, EricWF

Subscribers: christof, arphaman, libcxx-commits

Differential Revision: https://reviews.llvm.org/D53256

llvm-svn: 347219
2018-11-19 15:37:04 +00:00
Eric Fiselier 22bdb33108 Get tests compiling with -Wunused-local-typedef
llvm-svn: 346914
2018-11-15 00:11:02 +00:00
Stephan T. Lavavej dec8905e13 [libcxx] [test] Strip trailing whitespace. NFC.
llvm-svn: 346826
2018-11-14 03:06:06 +00:00
Dan Albert d5d06a0763 Fix test assumption that Linux implies glibc.
Summary:
This fixes an regression when using bionic introduced in r345173.

I need to follow up and figure out what exactly is implied by
TEST_HAS_C11_FEATURES and see what the correct configuration is for
bionic (new versions should have everything the tests care about,
versions that predate C11 certainly don't), but this gets the tests
back to the old behavior.

Reviewers: EricWF

Reviewed By: EricWF

Subscribers: mclow.lists, christof, ldionne, libcxx-commits, cfe-commits

Differential Revision: https://reviews.llvm.org/D53956

llvm-svn: 345900
2018-11-01 22:35:51 +00:00
Louis Dionne 8df1d5a546 [libcxx] Fix usage of _C2, which is a "nasty macro" in some environments
The problem was pointed out in https://reviews.llvm.org/D48896#inline-475775.

llvm-svn: 345834
2018-11-01 14:41:37 +00:00
Eric Fiselier 5efe8ec4cd Fix use of libc++ specific macro in support/test_macros.h
llvm-svn: 345173
2018-10-24 18:37:42 +00:00
Eric Fiselier fca28db904 Add test macros for always_inline and noinline
llvm-svn: 344167
2018-10-10 18:22:23 +00:00
Marshall Clow 171c77b7da Selectively import timespec_get into namespace std, since some C libraries don't have it. Reviewed as https://reviews.llvm.org/D50799
llvm-svn: 339816
2018-08-15 21:19:08 +00:00
Dimitry Andric c7510aa2ac For FreeBSD, don't define _M in nasty_macros.hpp
Because FreeBSD uses _M in its <sys/types.h>, and it is hard to avoid
including that header, only define _M to NASTY_MACRO for other operating
systems.  This fixes almost 2000 unexpected test failures.

Discussed with Eric Fiselier.

llvm-svn: 339794
2018-08-15 17:30:32 +00:00
Louis Dionne 6513f375b1 [libc++] Fix incorrect definition of TEST_HAS_C11_FEATURES
Summary:
The macro was not defined in C++11 mode when it should have been, at least
according to how _LIBCPP_HAS_C11_FEATURES is defined.

Reviewers: mclow.lists, EricWF, jfb, dexonsmith

Subscribers: christof, dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D50719

llvm-svn: 339702
2018-08-14 18:16:56 +00:00
Marshall Clow 2fd30b4c87 Make my new test harness work w/c++03
llvm-svn: 338803
2018-08-03 02:58:16 +00:00
Zhihao Yuan 63ebd3bd24 [libc++] Fix build failures after merging <charconv>
Summary:
- fix a stupid unit test typo
- add <charconv> symbols to Linux abilist

Reviewers: EricWF

Subscribers: christof, ldionne, cfe-commits

Differential Revision: https://reviews.llvm.org/D50130

llvm-svn: 338486
2018-08-01 05:21:26 +00:00
Zhihao Yuan d27489645b [libc++][C++17] Elementary string conversions for integral types
Summary:
Major QoI considerations:

- The facility is backported to C++14, same as libstdc++.
- Efforts have been made to minimize the header dependencies.
- The design is friendly to the uses of MSVC intrinsics (`__emulu`, `_umul128`, `_BitScanForward`, `_BitScanForward64`) but not implemented; future contributions are welcome.

Thanks to Milo Yip for contributing the implementation of `__u64toa` and `__u32toa`.

References:
 https://wg21.link/p0067r5
 https://wg21.link/p0682r1

Reviewers: mclow.lists, EricWF

Reviewed By: mclow.lists

Subscribers: ldionne, Quuxplusone, christof, mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D41458

llvm-svn: 338479
2018-08-01 02:38:30 +00:00
Erik Pilkington b0386a515b First half of C++17's splicing maps and sets
This commit adds a node handle type, (located in __node_handle), and adds
extract() and insert() members to all map and set types, as well as their
implementations in __tree and __hash_table.

The second half of this feature is adding merge() members, which splice nodes
in bulk from one container into another. This will be committed in a follow-up.

Differential revision: https://reviews.llvm.org/D46845

llvm-svn: 338472
2018-08-01 01:33:38 +00:00
Marshall Clow 119f0a56d2 Introduce a new test macro TEST_HAS_C11_FEATURES which is set when the underlying C library has C11 features. In C++17, we use those features. <__config> defines a similar macro, _LIBCPP_HAS_C11_FEATURES, but we don't want to use that in the library-independent parts of the tests, so define the new one. Also add a libc++-specific test to make sure the two stay in sync.
llvm-svn: 338411
2018-07-31 18:23:57 +00:00
Eric Fiselier 998a5c8831 Implement <filesystem>
This patch implements the <filesystem> header and uses that
to provide <experimental/filesystem>.

Unlike other standard headers, the symbols needed for <filesystem>
have not yet been placed in libc++.so. Instead they live in the
new libc++fs.a library. Users of filesystem are required to link this
library. (Also note that libc++experimental no longer contains the
definition of <experimental/filesystem>, which now requires linking libc++fs).

The reason for keeping <filesystem> out of the dylib for now is that
it's still somewhat experimental, and the possibility of requiring an
ABI breaking change is very real. In the future the symbols will likely
be moved into the dylib, or the dylib will be made to link libc++fs automagically).

Note that moving the symbols out of libc++experimental may break user builds
until they update to -lc++fs. This should be OK, because the experimental
library provides no stability guarantees. However, I plan on looking into
ways we can force libc++experimental to automagically link libc++fs.

In order to use a single implementation and set of tests for <filesystem>, it
has been placed in a special `__fs` namespace. This namespace is inline in
C++17 onward, but not before that. As such implementation is available
in C++11 onward, but no filesystem namespace is present "directly", and
as such name conflicts shouldn't occur in C++11 or C++14.

llvm-svn: 338093
2018-07-27 03:07:09 +00:00
Eric Fiselier 3b3edcb0b7 Fix missing includes in format_string.hpp helper
llvm-svn: 337886
2018-07-25 04:21:59 +00:00
Marshall Clow c17628fb15 New test support for comparisons. Reviewed as https://reviews.llvm.org/D49773
llvm-svn: 337885
2018-07-25 04:21:21 +00:00
Alexander Richardson 2a6a3fc4a3 Stop wrapping __has_include in another macro
Summary:
This is not guaranteed to work since the characters after '__has_include('
have special lexing rules that can't possibly be applied when
__has_include is generated by a macro. It also breaks the crash reproducers
generated by -frewrite-includes (see https://llvm.org/pr37990).

Reviewers: EricWF, rsmith, mclow.lists
Reviewed By: mclow.lists
Differential Revision: https://reviews.llvm.org/D49067

llvm-svn: 337824
2018-07-24 12:40:56 +00:00
Eric Fiselier 8725bbdb1f Fix use of C++14 syntax in C++11 filesystem tests.
llvm-svn: 337666
2018-07-23 03:41:46 +00:00
Eric Fiselier 9158bfd32e Implement filesystem_error::what() and improve reporting.
This patch implements the `what()` for filesystem errors. The message
includes the 'what_arg', any paths that were specified, and the
error code message.

Additionally this patch refactors how errors are created, making it easier
to report them correctly.

llvm-svn: 337664
2018-07-23 02:00:52 +00:00
Eric Fiselier 7c0ed44db0 Implement a better copy_file.
This patch improves both the performance, and the safety of the
copy_file implementation.

The performance improvements are achieved by using sendfile on
Linux and copyfile on OS X when available.

The TOCTOU hardening is achieved by opening the source and
destination files and then using fstat to check their attributes to
see if we can copy them.

Unfortunately for the destination file, there is no way to open
it without accidentally creating it, so we first have to use
stat to determine if it exists, and if we should copy to it.
Then, once we're sure we should try to copy, we open the dest
file and ensure it names the same entity we previously stat'ed.

llvm-svn: 337649
2018-07-22 02:00:53 +00:00
Eric Fiselier c16998649e [libc++] Implement Directory Entry Caching -- Sort of.
Summary:
This patch implements directory_entry caching *almost* as specified in P0317r1. However, I explicitly chose to deviate from the standard as I'll explain below.

The approach I decided to take is a fully caching one. When `refresh()` is called, the cache is populated by calls to `stat` and `lstat` as needed.
During directory iteration the cache is only populated with the `file_type` as reported by `readdir`.
The cache can be in the following states:

* `_Empty`: There is nothing in the cache (likely due to an error)
* `_IterSymlink`: Created by directory iteration when we walk onto a symlink only the symlink file type is known.
* `_IterNonSymlink`: Created by directory iteration when we walk onto a non-symlink. Both the regular file type and symlink file type are known.
* `_RefreshSymlink` and `_RefreshNonSymlink`: A full cache created by `refresh()`.  This case includes dead symlinks.
* `_RefreshSymlinkUnresolved`: A partial cache created by refresh when we fail to resolve the file pointed to by a symlink (likely due to permissions). Symlink attributes are cached, but attributes about the linked entity are not.

As mentioned, this implementation purposefully deviates from the standard. According to some readings of the specification, and the Windows filesystem implementation, the constructors and modifiers which don't pass an `error_code` must throw when the `directory_entry` points to a entity which doesn't exist. or when attribute resolution fails for another reason. 

@BillyONeal  has proposed a more reasonable set of requirements, where modifiers other than refresh ignore errors. This is the behavior libc++ currently implements, with the expectation some form of the new language will be accepted into the standard.

Some additional semantics which differ from the Windows implementation:

1. `refresh` will not throw when the entry doesn't exist. In this case we can still meet the functions specification, so we don't treat it as an error.
2. We don't clear the path name when a constructor fails via refresh (this will hopefully be changed in the standard as well).

It should be noted that libstdc++'s current implementation has the same behavior as libc++, except for point (2).

If the changes to the specification don't get accepted, we'll be able to make the changes later.

[1] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0317r1.html

Reviewers: mclow.lists, gromer, ldionne, aaron.ballman

Subscribers: BillyONeal, christof, cfe-commits

Differential Revision: https://reviews.llvm.org/D49530

llvm-svn: 337516
2018-07-20 01:22:32 +00:00
Stephan T. Lavavej 896e499e38 [libcxx] [test] Update msvc_stdlib_force_include.hpp.
MSVC's STL removed _SCL_SECURE_NO_WARNINGS.

MSVC's STL implemented feature-test macros.

llvm-svn: 334675
2018-06-14 00:12:14 +00:00
Eric Fiselier 8cef7fd75a Fix PR37694 - std::vector doesn't correctly move construct allocators.
C++2a[container.requirements.general]p8 states that when move constructing
a container, the allocator is move constructed. Vector previously copy
constructed these allocators. This patch fixes that bug.

Additionally it cleans up some unnecessary allocator conversions
when copy constructing containers. Libc++ uses
__internal_allocator_traits::select_on_copy_construction to select
the correct allocator during copy construction, but it unnecessarily
converted the resulting allocator to the user specified allocator
type and back. After this patch list and forward_list no longer
do that.

Technically we're supposed to be using allocator_traits<allocator_type>::select_on_copy_construction,
but that should seemingly be addressed as a separate patch, if at all.

llvm-svn: 334053
2018-06-05 22:32:52 +00:00