Commit Graph

585 Commits

Author SHA1 Message Date
Dan Albert 5e37d7f9ff Implement std::condition_variable via pthread_cond_clockwait() where available
std::condition_variable is currently implemented via
pthread_cond_timedwait() on systems that use pthread. This is
problematic, since that function waits by default on CLOCK_REALTIME
and libc++ does not provide any mechanism to change from this
default.

Due to this, regardless of if condition_variable::wait_until() is
called with a chrono::system_clock or chrono::steady_clock parameter,
condition_variable::wait_until() will wait using CLOCK_REALTIME. This
is not accurate to the C++ standard as calling
condition_variable::wait_until() with a chrono::steady_clock parameter
should use CLOCK_MONOTONIC.

This is particularly problematic because CLOCK_REALTIME is a bad
choice as it is subject to discontinuous time adjustments, that may
cause condition_variable::wait_until() to immediately timeout or wait
indefinitely.

This change fixes this issue with a new POSIX function,
pthread_cond_clockwait() proposed on
http://austingroupbugs.net/view.php?id=1216. The new function is
similar to pthread_cond_timedwait() with the addition of a clock
parameter that allows it to wait using either CLOCK_REALTIME or
CLOCK_MONOTONIC, thus allowing condition_variable::wait_until() to
wait using CLOCK_REALTIME for chrono::system_clock and CLOCK_MONOTONIC
for chrono::steady_clock.

pthread_cond_clockwait() is implemented in glibc (2.30 and later) and
Android's bionic (Android API version 30 and later).

This change additionally makes wait_for() and wait_until() with clocks
other than chrono::system_clock use CLOCK_MONOTONIC.<Paste>

llvm-svn: 372016
2019-09-16 17:57:48 +00:00
Dimitry Andric 5bd4a4806a Remove ::gets for FreeBSD 13 and later
Summary:
In https://svnweb.freebsd.org/changeset/base/351659 @emaste removed gets() from
FreeBSD 13's libc, and our copies of libc++ and libstdc++.  In that change, the
declarations were simply deleted, but I would like to propose this conditional
test instead.

Reviewers: EricWF, mclow.lists, emaste

Reviewed By: mclow.lists

Subscribers: krytarowski, christof, ldionne, emaste, libcxx-commits

Differential Revision: https://reviews.llvm.org/D67316

llvm-svn: 371324
2019-09-07 22:18:20 +00:00
Louis Dionne 801f6a495c [libc++] Use __extension__ in a portable manner
llvm-svn: 370889
2019-09-04 12:44:19 +00:00
Louis Dionne 619172a818 [libc++] Enable <chrono> ""d and ""y literals for AppleClang 10 and up
AppleClang supports those literals starting in version 10.0.1.

llvm-svn: 368882
2019-08-14 17:04:31 +00:00
Louis Dionne 3555af7120 [libc++] Do not define _LIBCPP_CLANG_VER for non-LLVM Clang
In r292833, we started defining _LIBCPP_CLANG_VER to 0 for Apple Clang.
The result is that AppleClang is detected as being a very old version
of LLVM Clang (version 0), which is obviously incorrect.

I believe this was added so that we don't have to check whether
_LIBCPP_CLANG_VER is defined prior to comparing it with a number
(which can trigger a warning). This commit also fixes the two
places that use the macro correspondingly.

llvm-svn: 368880
2019-08-14 17:01:08 +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
Nico Weber 9aae539d4c libcxx: Define __STDCPP_THREADS__ to 1, not to __cplusplus.
[cpp.predefined]p2:

   __STDCPP_THREADS__
    Defined, and has the value integer literal 1, if and only if a program
    can have more than one thread of execution .

Also define it only if it's not defined already, since it's supposed
to be defined by the compiler.

Also move it from thread to __config (which requires setting it only
if _LIBCPP_HAS_NO_THREADS is not defined).

Part of PR33230. The intent is to eventually make the compiler define
this instead.

llvm-svn: 367316
2019-07-30 14:32:47 +00:00
Louis Dionne 568bb7eeb6 [NFC][libcxx] Add comments about making mutex/condition_variable trivial on Apple platforms
Leaving some comments behind so that we avoid re-having that discussion
in the future.

llvm-svn: 367048
2019-07-25 20:29:20 +00:00
Hans Wennborg 8f5b44aead Bump the trunk version to 10.0.0svn
and clear the release notes.

llvm-svn: 366427
2019-07-18 11:51:05 +00:00
Eric Fiselier 8cedf04a6c Make ~mutex and ~condition_variable trivial on Windows.
The implementations of __libcpp_mutex_destroy and __libcpp_condvar_destroy
are already NOPs, so this optimization is safe to perform.

See r365273 and PR27658 for more information.

llvm-svn: 365281
2019-07-07 17:24:03 +00:00
Eric Fiselier 8baf83839e Fix PR27658 - Make ~mutex trivial when possible.
Currently std::mutex has a constexpr constructor, but a non-trivial
destruction.

The constexpr constructor is required to ensure the construction of a
mutex with static storage duration happens at compile time, during
constant initialization, and not during dynamic initialization.
This means that static mutex's are always initialized and can be used
safely during dynamic initialization without the "static initialization
order fiasco".

A trivial destructor is important for similar reasons. If a mutex is
used during dynamic initialization it might also be used during program
termination. If a static mutex has a non-trivial destructor it will be
invoked during termination. This can introduce the "static
deinitialization order fiasco".

Additionally, function-local statics emit a guard variable around
non-trivially destructible types. This results in horrible codegen and
adds a runtime cost to every call to that function. non-local static's
also result in slightly worse codegen but it's not as big of a problem.

Example codegen can be found here: https://goo.gl/3CSzbM

Note: This optimization is not safe with every pthread implementation.
Some implementations allocate on the first call to pthread_mutex_lock
and free the allocation in pthread_mutex_destroy.

Also, changing the triviality of the destructor is not an ABI break.
At least to the best of my knowledge :-)

llvm-svn: 365273
2019-07-07 01:20:54 +00:00
Louis Dionne 1c478d6e85 [libc++] Update availability markup for Filesystem on Apple platforms
llvm-svn: 365068
2019-07-03 18:29:02 +00:00
Eric Fiselier ae9e42f614 Revert "Change the ABI version and ABI namespace to be `_LIBCPP_VERSION`"
There are some suspicious bot failures that I want to ensure aren't
caused by this patch.

I'll recommit tomorrow.

llvm-svn: 364363
2019-06-26 00:05:14 +00:00
Eric Fiselier 1fa0f4b942 Change the ABI version and ABI namespace to be `_LIBCPP_VERSION`
when _LIBCPP_ABI_UNSTABLE is defined.

User defined _LIBCPP_ABI_NAMESPACE will still be respected,
but the default version namespace in unstable mode will be the libc++ version
(Currently '__9000').

Previously  `_LIBCPP_ABI_VERSION` and `_LIBCPP_ABI_NAMESPACE` were
`1` and `__1` respectively, whuch conflicted with the stable ABI

llvm-svn: 364354
2019-06-25 22:13:39 +00:00
Eric Fiselier 5b4cc84b87 Remove even more dead code.
llvm-svn: 364050
2019-06-21 14:09:32 +00:00
Eric Fiselier 395c7330e4 Assume __is_final, __is_base_of, and friends.
All the compilers we support provide these builtins. We don't
need to do a configuration dance anymore.

This patch also cleans up some dead or almost dead
C++11 feature detection macros.

llvm-svn: 364047
2019-06-21 13:56:13 +00:00
Eric Fiselier 8d30a6e40c Remove dead config now that C++03 requires Clang.
llvm-svn: 364031
2019-06-21 11:32:43 +00:00
Eric Fiselier 5c739665a8 Remove GCC C++03 fallbacks for decltype and static_assert.
This means libc++ no longer needs to write extra braces in
static asserts: Ex `static_assert((is_same_v<T, V>), "msg")`.

llvm-svn: 363738
2019-06-18 20:50:25 +00:00
Eric Fiselier 5de7cacf07 Make GCC in C++03 Unsupported
Summary:
This patch make G++03 explicitly unsupported with libc++, as discussed on the mailing lists.


Below is the rational for this decision.
----------------------------------------------------------------------------------------------------

libc++ claims to support GCC with C++03 ("G++03"), and this is a problem for our users.

Our C++03 users are all using Clang. They must be.  Less than 9% of the C++03 tests pass with GCC [1][2]. No non-trivial C++ program could work.

Attempting to support G++03 impacts our QoI considerably. Unlike Clang, G++03 offers almost no C++11 extensions. If we could remove all the fallbacks for G++03, it would mean libc++ could::

* Improve Correctness:

Every `#ifdef _LIBCPP_HAS_NO_<C++11-feature>` is a bug manifest. It exists to admit for deviant semantics.

* Achieve ABI stability between C++03 and C++11

Differences between our C++03 and C++Rest branches contain ABI bugs. For example `std::nullptr_t` and `std::function::operator()(...)` are currently incompatible between C++11 and C++03, but could be fixed.

* Decrease Compile Times and Memory Usage:

Writing efficient SFINAE requires C++11. Using alias templates, libc++ could reduce the number of instantiations it produces substantially.

* Decrease Binary Size

Similar to the last point, G++03 forces metaprogramming techniques that emit more debug information [3] [4]. Compared to libstdc++, debug information size increases of +10% are not uncommon.

Reviewers: ldionne, mclow.lists, EricWF

Reviewed By: ldionne, EricWF

Subscribers: zoecarver, aprantl, dexonsmith, arphaman, libcxx-commits, #libc

Differential Revision: https://reviews.llvm.org/D63154

llvm-svn: 363219
2019-06-13 00:37:25 +00:00
Eric Fiselier 14d4869209 Apply [[nodebug]] to typedefs throughout the STL.
When applied to a typedef or alias template, the [[nodebug]] attribute
makes the typedef transparent to the debugger, so instead of seeing
`std::__function::__alloc_func<remove_reference<void(&)()>::type,
allocator<remove_reference<void(&)()>, void()>::_Target` you see
`void(&)()` as the type of the variable in your debugger.

Removing all this SFINAE noise from debug info has huge binary size
wins, in addition to improving the readability.

For now this change is on by default. Users can override it by
specifying -D_LIBCPP_NODEBUG_TYPE=

llvm-svn: 363117
2019-06-12 02:03:31 +00:00
Eric Fiselier d63dd874ec Substantially reduce instantiations and debug size of std::function
std::function uses a standard allocator to manage its memory, however
standard allocators are templates and using them correctly requires
a stupid amount of instantiations. This leads to a substantial increase
in debug info and object sizes.

This patch addresses the issue by dropping the allocator when possible
and using raw new and delete to get memory.

This change decreases the object file size for the test func.wrap.func.con/F.pass.cpp by 33% and the final binary by 29% (when compiled with -g -ggnu-pubnames -gpubnames).

It also roughly halfs the number of entries in the pubnames and pubtype
sections.

llvm-svn: 362865
2019-06-08 01:31:19 +00:00
Eric Fiselier 2405bd6898 Rework std::type_info definition to support systems without fully
merged type info names.

Previously std::type_info always expected type info string to be unique.
But this isn't always the case. Like when -Bsymbolic is passed to the
linker or due to llvm.org/PR37398.

This patch adds the LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT CMake
option which, when specified, overrides the default configuration for
the library.

The current defaults still assume unique names even though this isn't
strictly correct for ELF binaries. We should consider changing the
default in a follow up commit.

llvm-svn: 361913
2019-05-29 02:21:37 +00:00
Dan Gohman 3efd6e37e4 [WebAssembly] WASI support for libcxx
This adds explicit support for the WASI platform to libcxx.

WASI libc uses some components from musl, however it's not fully compatible
with musl, so we're planning to stop using _LIBCPP_HAS_MUSL_LIBC and
customize for WASI libc specifically.

Differential Revision: https://reviews.llvm.org/D61336

Reviewers: sbc100, ldionne
llvm-svn: 359703
2019-05-01 16:47:30 +00:00
Richard Smith ae62727a28 Remove libc++ checks and workarounds for unsupported old versions of GCC (<4.9).
Differential Revision: https://reviews.llvm.org/D61107

llvm-svn: 359232
2019-04-25 20:02:10 +00:00
Martin Storsjo 2bbb7feda8 Set _LIBCPP_DLL_VIS on _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS in MinGW mode
Contrary to MSVC, MinGW compilers wants the dllexport attribute on
the declaration of an explicit template instantiation, not on the
definition.

Differential Revision: https://reviews.llvm.org/D61123

llvm-svn: 359227
2019-04-25 19:46:28 +00:00
Eric Fiselier 2fc5a786be Add std::is_constant_evaluated.
Clang recently added __builtin_is_constant_evaluated() and GCC 9.0
has it as well.

This patch adds support for it in libc++.

llvm-svn: 359119
2019-04-24 17:54:25 +00:00
Louis Dionne 81875a67b0 [libc++] Use the no_destroy attribute to avoid destroying debug DB statics
Summary:
Otherwise, we can run into problems when the program has static variables
that need to use the debug database during their deinitialization, if
the debug DB has already been deinitialized.

Reviewers: EricWF

Subscribers: christof, jkorous, dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D60830

llvm-svn: 358602
2019-04-17 18:20:19 +00:00
Marshall Clow 1931c4306a Fix PR#35967: '<regex> syntax_option_type is not a proper bitmask' Sadly, this is an ABI break, so it's only available if you define either '_LIBCPP_ABI_VERSION > 2' or '_LIBCPP_ABI_UNSTABLE' or '_LIBCPP_ABI_REGEX_CONSTANTS_NONZERO' and rebuild your dylib.
llvm-svn: 357190
2019-03-28 17:30:23 +00:00
Louis Dionne fa0573027f [libc++] Mark <filesystem> as unavailable on Apple platforms using pragmas
Summary:
Also add the corresponding XFAILs to tests that require filesystem.
The approach taken to mark <filesystem> as unavailable in this patch
is to mark all the header as unavailable using #pragma clang attribute.
Marking each declaration using the attribute is more intrusive and
does not provide a lot of value right now because pretty much everything
in <filesystem> requires dylib support, often transitively.

This is an alternative to https://reviews.llvm.org/D59093.
A similar (but partial) patch was already applied in r356558.

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

Subscribers: christof, jkorous, dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59224

llvm-svn: 356616
2019-03-20 21:18:14 +00:00
Louis Dionne 77bca6d296 [NFC] Fix a couple of typos in libc++'s __config
llvm-svn: 356574
2019-03-20 17:05:52 +00:00
Louis Dionne b38c08ac02 [libc++] Mark <filesystem> tests as failing when the dylib doesn't support filesystem
This fixes CI for back-deployment testers on platforms that don't have
<filesystem> support in the dylib.

This is effectively half of https://reviews.llvm.org/D59224. The other
half requires fixes in Clang.

llvm-svn: 356558
2019-03-20 14:34:00 +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
Louis Dionne a470a13a70 [libc++] Enable deprecation warnings by default
Summary:
In r342843, I added deprecation warnings to some facilities that were
deprectated in C++14 and C++17. However, those deprecation warnings
were not enabled by default.

After discussing this on IRC, we had finally gotten consensus to enable
those warnings by default, and I'm getting around to doing that only
now.

Reviewers: mclow.lists, EricWF

Subscribers: christof, jkorous, dexonsmith, jdoerfert, libcxx-commits

Differential Revision: https://reviews.llvm.org/D58140

llvm-svn: 355961
2019-03-12 20:10:06 +00:00
Davide Italiano 6de760ac4e Reinstate libc++ patches now that the lldb formatter has been updated.
"[libc++] Fix <atomic> failures on GCC"
"[libc++] Change memory_order to an enum class"
"[libc++] decoupling Freestanding atomic<T> from libatomic.a"

llvm-svn: 355427
2019-03-05 18:40:49 +00:00
Davide Italiano 1061cb6a93 [libcxx] Revert set of atomic patches that broke lldb.
Revert "[libc++] Fix <atomic> failures on GCC"
Revert "[libc++] Change memory_order to an enum class"
Revert "[libc++] decoupling Freestanding atomic<T> from libatomic.a"

The lldb formatter nededs to be updated. Shafik and Louis will
coordinate to do so.

llvm-svn: 355417
2019-03-05 17:38:33 +00:00
Eric Fiselier e69290dc7f Make VCRuntime ABI configuration a first-class option.
Summary:
On Windows we currently provide two separate ABI configurations. One which defers to `vcruntime` to provide the C++ runtime and another which doesn't.
Using `vcruntime` allows interoperability which programs compiled against the MSVC STL, and should be preferred whenever possible.

When deferring to `vcruntime` much of the ABI we provide changes. Including the layout of `<stdexcept>` types, their vtables, and how the linkage of their members.

This patch introduces the `_LIBCPP_ABI_VCRUNTIME` macro to denote this configuration. It also cleans up the existing configuration for using `vcruntime`.

This cleanup lays the groundwork for fixing a number of ABI and interoperability bugs in  `<stdexcept>`.


Reviewers: thomasanderson, ldionne, smeenai

Reviewed By: smeenai

Subscribers: jdoerfert, libcxx-commits, #libc

Differential Revision: https://reviews.llvm.org/D58942

llvm-svn: 355366
2019-03-05 01:57:01 +00:00
Louis Dionne 21450545d1 [libc++] decoupling Freestanding atomic<T> from libatomic.a
This patch introduces non-lockfree atomics that do not require using
an external libatomic. This work is done with the long-term goal of
allowing the use of <atomic> in freestanding environments.

Thanks to Olivier Giroux for the patch.
Differential Revision: https://reviews.llvm.org/D56913

llvm-svn: 355318
2019-03-04 15:26:27 +00:00
Louis Dionne 5d79eaa82f [libc++] Rename _NOALIAS macro to _LIBCPP_NOALIAS
Summary:
For consistency, libc++ macros always start with _LIBCPP. This should
have no functionality change.

Reviewers: EricWF, mclow.lists

Subscribers: christof, jkorous, dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D58558

llvm-svn: 354848
2019-02-26 06:34:42 +00:00
Thomas Anderson 13447450bc [libc++] Don't define operator new/delete when using vcruntime
Fixes build errors on Windows without libc++abi of the form:

    new(173,36):  error: redeclaration of 'operator delete' cannot add 'dllexport' attribute
    _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p) _NOEXCEPT;
    vcruntime_new.h(87,16):  note: previous declaration is here
    void __CRTDECL operator delete(
    new(205,70):  error: redefinition of 'operator new'
    _LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new  (std::size_t, void* __p) _NOEXCEPT {return __p;}
    vcruntime_new.h(184,28):  note: previous definition is here
        inline void* __CRTDECL operator new(size_t _Size, _Writable_bytes_(_Size) void* _Where) noexcept
    new(206,70):  error: redefinition of 'operator new[]'
    _LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new[](std::size_t, void* __p) _NOEXCEPT {return __p;}
    vcruntime_new.h(199,28):  note: previous definition is here
        inline void* __CRTDECL operator new[](size_t _Size,
    new(207,40):  error: redefinition of 'operator delete'
    inline _LIBCPP_INLINE_VISIBILITY void  operator delete  (void*, void*) _NOEXCEPT {}
    vcruntime_new.h(190,27):  note: previous definition is here
        inline void __CRTDECL operator delete(void*, void*) noexcept
    new(208,40):  error: redefinition of 'operator delete[]'
    inline _LIBCPP_INLINE_VISIBILITY void  operator delete[](void*, void*) _NOEXCEPT {}
    vcruntime_new.h(206,27):  note: previous definition is here
        inline void __CRTDECL operator delete[](void*, void*) noexcept

Differential Revision: https://reviews.llvm.org/D57362

llvm-svn: 352647
2019-01-30 19:08:32 +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
Hans Wennborg 1fe469ae6c Bump the trunk version to 9.0.0svn
llvm-svn: 351320
2019-01-16 10:57:02 +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
Petr Hosek 2fefe153dd [libcxx] Mark do_open, do_get and do_close parameters unused when catopen is missing
When catopen is missing, do_open, do_get and do_close end up being
no-op, and as such their parameters will be unused which triggers a
warning/error when building with -Wunused-parameter.

Differential Revision: https://reviews.llvm.org/D56023

llvm-svn: 351027
2019-01-13 22:15:37 +00:00
Louis Dionne c8ca4d8cc1 [libcxx][NFC] Properly indent nested #ifdefs and #defines
I just realized I had always been reading this wrong because of the lack
of indentation, so I'm re-indenting this properly.

llvm-svn: 349408
2018-12-17 22:22:44 +00:00
Thomas Anderson 1cffc38485 [libc++] Fix _LIBCPP_EXPORTED_FROM_ABI when visibility annotations are disabled
Fixes a bug where functions would get exported when building with
-fvisibility=hidden and defining _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS. No
visibility annotations should be added in this case.

The new logic for _LIBCPP_EXPORTED_FROM_ABI matches that of the other visibility
annotations around it.

Differential Revision: https://reviews.llvm.org/D55664

llvm-svn: 349080
2018-12-13 20:06:14 +00:00
Marshall Clow 7dad0bd68b Second part of P0482 - char8_t. Reviewed as https://reviews.llvm.org/D55308
llvm-svn: 348828
2018-12-11 04:35:44 +00:00
Eric Fiselier 08e231dd9c Add a version of std::function that includes a few optimizations in ABI V2.
Patch by Jordan Soyke (jsoyke@google.com)
Reviewed as D55045

The result of running the benchmarks and comparing them can be found
here: https://gist.github.com/EricWF/a77fd42ec87fc98da8039e26d0349498

llvm-svn: 348812
2018-12-11 00:14:34 +00:00
Louis Dionne f7f5a1f778 [libcxx] Don't depend on availability markup to provide the streams in the dylib
Whether an explicit instantiation declaration should be provided is not
a matter of availability markup.

This problem is exemplified by the fact that some tests were incorrectly
marked as XFAIL when they should instead have been using the definition
of streams from the headers, and hence passing, and that, regardless of
whether visibility annotations are enabled.

llvm-svn: 348436
2018-12-06 00:24:58 +00:00
Louis Dionne e823b6d7e6 [libcxx] Remove bad_array_length
Summary:
std::bad_array_length was added by n3467, but this never made it into C++.
This commit removes the definition of std::bad_array_length from the headers
AND from the shared library. See the comments in the ABI changelog for details
about the ABI implications of this change.

Reviewers: mclow.lists, dexonsmith, howard.hinnant, EricWF

Subscribers: christof, jkorous, libcxx-commits

Differential Revision: https://reviews.llvm.org/D54804

llvm-svn: 347903
2018-11-29 19:44:57 +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
Louis Dionne 9a494eacba [libcxx] Remove dynarray
Summary:
std::dynarray had been proposed for C++14, but it was pulled out from C++14
and there are no plans to standardize it anymore.

Reviewers: mclow.lists, EricWF

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

Differential Revision: https://reviews.llvm.org/D54801

llvm-svn: 347783
2018-11-28 18:02:00 +00:00
Louis Dionne 2804508ffe [libcxx] Remove unused definition of aligned allocation macro on old OS X
We don't support mac OS 10.6 and older anymore, so this macro can never
be defined. This bit of code had been added in D28931 as a fix for
PR31448, but it doesn't seem necessary anymore.

llvm-svn: 347427
2018-11-21 21:22:08 +00:00
Louis Dionne 8eb65cb25e [NFC] Reformat availability #defines in __config
Aligning everything makes what we're doing more obvious.

llvm-svn: 347363
2018-11-20 23:18:25 +00:00
Louis Dionne c2b375ad60 [libcxx] Fix threads detection on GNU/Hurd
GNU/Hurd provides standard Posix threads

Reviewed as https://reviews.llvm.org/D54339.
Thanks to Samuel Thibault for the patch.

llvm-svn: 347347
2018-11-20 21:14:05 +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
Reid Kleckner 60cce5c782 Use C++11 fallthrough attribute syntax when available and add a break
Summary:
This silences the two -Wimplicit-fallthrough warnings clang finds in
ItaniumDemangle.h in libc++abi.

Clang does not have a GNU attribute spelling for this attribute, so this
is necessary.

I will commit the same change to the LLVM demangler soon.

Reviewers: EricWF, ldionne

Subscribers: christof, erik.pilkington, cfe-commits

Differential Revision: https://reviews.llvm.org/D53985

llvm-svn: 345870
2018-11-01 18:24:03 +00:00
Eric Fiselier fe13c13cc2 Make libc++'s versioning namespace customizable
Summary:
This patch makes the versioning namespace libc++ uses customizable by the user using `-DLIBCXX_ABI_NAMESPACE=__foo`. 

This allows users to build custom versions of libc++ which can be linked into binaries with other libc++ versions without causing symbol conflicts or ODR issues. 

Reviewers: mclow.lists, ldionne

Reviewed By: ldionne

Subscribers: kristina, smeenai, mgorny, phosek, libcxx-commits

Differential Revision: https://reviews.llvm.org/D53879

llvm-svn: 345657
2018-10-30 21:44:53 +00:00
Eric Fiselier 2f3e8b3d2e Unify definition of _LIBCPP_BEGIN/END_NAMESPACE_STD
llvm-svn: 345561
2018-10-30 02:02:00 +00:00
Louis Dionne e9d85264ac [libc++] Use exclude_from_explicit_instantiation instead of always_inline
Summary:
This commit adopts the exclude_from_explicit_instantiation attribute discussed
at [1] and reviewed in [2] in libc++ to supplant the use of __always_inline__
for visibility purposes.

This change means that users wanting to link together translation units built
with different versions of libc++'s headers into the same final linked image
MUST define the _LIBCPP_HIDE_FROM_ABI_PER_TU macro to 1 when building those
TUs. Doing otherwise will lead to ODR violations and ABI issues.

[1]: http://lists.llvm.org/pipermail/cfe-dev/2018-August/059024.html
[2]: https://reviews.llvm.org/D51789

Reviewers: rsmith, EricWF

Subscribers: dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D52405

llvm-svn: 345516
2018-10-29 17:30:04 +00:00
Louis Dionne 9b3222f613 [libc++] Make sure we can build libc++ with -fvisibility=hidden
Summary:
When building with -fvisibility=hidden, some symbols do not get exported from
libc++.dylib. This means that some entities are not explicitly given default
visibility in the source code, and that we rely on the fact -fvisibility=default
is the default. This commit explicitly gives default visibility to those
symbols to avoid being dependent on the command line flags used.

The commit also remove symbols from the dylib -- those symbols do not
actually need to be exported from the dylib and this should not be an
ABI break.

Finally, in the future, we may want to mark the whole std:: namespace as
having hidden visibility (to switch from opt-out to opt-in), in which
case the changes done in this commit will be required.

Reviewers: EricWF

Subscribers: mgorny, christof, dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D52662

llvm-svn: 345260
2018-10-25 12:13:43 +00:00
Louis Dionne 4084df0040 [libcxx] Avoid repeating the definition of std:: namespaces
This reduces code duplication a tiny bit.

llvm-svn: 344642
2018-10-16 20:02:59 +00:00
Louis Dionne 7833b88ad8 [libcxx] Remove _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY
That macro has been defined to _LIBCPP_HIDE_FROM_ABI_AFTER_V1 for many
weeks now, so we're actually replacing uses of it for uses of
_LIBCPP_HIDE_FROM_ABI_AFTER_V1 directly.

This should not change or break anything since the two macros are
100% equivalent, unless somebody is (incorrectly!) relying on
_LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY being defined.

llvm-svn: 344641
2018-10-16 19:26:23 +00:00
Marshall Clow 5b08c1742a Recommit <chrono> changes with a couple xtra tests marked to fail on apple's clang. Reviewed as D51762
llvm-svn: 344627
2018-10-16 17:27:54 +00:00
Artem Dergachev a9bc0face5 Revert r344529 "Implement the first part of the calendar support for C++20"
Revert r344535 "Wrap up the new chrono literals in an #ifdef..."
Revert r344546 "Mark a couple of test cases as 'C++17-only'..."

Some of the buildbot failures were masked by another error,
and this one was probably missed.

llvm-svn: 344580
2018-10-16 02:40:42 +00:00
Marshall Clow 323e01d46f Wrap up the new chrono literals in an #ifdef so that old versions of clang don't complain. I'm looking at you, clang 5.0.1
llvm-svn: 344535
2018-10-15 17:33:20 +00:00
Eric Fiselier 42f9868cd8 Distinguish between library and language support for aligned allocation.
There are two cases:
1. The library has all it needs to provide align_val_t and the
new/delete overloads needed to support aligned allocation.
2. The compiler has actually turned the language feature on.

There are times where libc++ needs to distinguish between the two.

This patch adds the additional macro
_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION which denotes when case (1)
does not hold. _LIBCPP_HAS_NO_ALIGNED_ALLOCATION is defined whenever
_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION is defined, or when the
compiler has not enabled the language feature.

Additionally this patch cleans up a number of other macros related
to detection of aligned allocation machinery.

llvm-svn: 344207
2018-10-11 00:17:24 +00:00
Louis Dionne f9a52903ef [libc++] Remove Fuchsia-specific knowledge to pick the ABI version
Summary:
The ABI version used by libc++ is a configuration option just like any other
configuration option. It is a knob that can be used by vendors to customize
the libc++ that they ship. As such, we should not be hardcoding vendor-specific
configuration choices in libc++.

When building libc++ for Fuchsia, Fuchsia's build scripts should simply define
the libc++ ABI version to 2 -- this will result in the _LIBCPP_ABI_VERSION
macro being defined in the __config header that is generated when libc++ is
built and installed, which is the correct way to customize libc++'s behavior
for specific vendors.

Reviewers: phosek, EricWF

Subscribers: mgorny, christof, dexonsmith, cfe-commits, libcxx-commits

Differential Revision: https://reviews.llvm.org/D52397

llvm-svn: 343079
2018-09-26 08:24:51 +00:00
Louis Dionne ea5cd3b476 [libc++] Add deprecated attributes to many deprecated components
Summary:
These deprecation warnings are opt-in: they are only enabled when the
_LIBCXX_DEPRECATION_WARNINGS macro is defined, which is not the case
by default. Note that this is a first step in the right direction, but
I wasn't able to get an exhaustive list of all deprecated components
per standard, so there's certainly stuff that's missing. The list of
components this commit marks as deprecated is:

in C++11:
- auto_ptr, auto_ptr_ref
- binder1st, binder2nd, bind1st(), bind2nd()
- pointer_to_unary_function, pointer_to_binary_function, ptr_fun()
- mem_fun_t, mem_fun1_t, const_mem_fun_t, const_mem_fun1_t, mem_fun()
- mem_fun_ref_t, mem_fun1_ref_t, const_mem_fun_ref_t, const_mem_fun1_ref_t, mem_fun_ref()

in C++14:
- random_shuffle()

in C++17:
- unary_negate, binary_negate, not1(), not2()

<rdar://problem/18168350>

Reviewers: mclow.lists, EricWF

Subscribers: christof, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D48912

llvm-svn: 342843
2018-09-23 18:35:00 +00:00
Roman Lebedev c65d39a464 [libc++] Add _LIBCPP_ENABLE_NODISCARD and _LIBCPP_NODISCARD_EXT to allow pre-C++2a [[nodiscard]]
Summary:
The `[[nodiscard]]` attribute is intended to help users find bugs where
function return values are ignored when they shouldn't be. After C++17 the
C++ standard has started to declared such library functions as `[[nodiscard]]`.
However, this application is limited and applies only to dialects after C++17.
Users who want help diagnosing misuses of STL functions may desire a more
liberal application of `[[nodiscard]]`.

For this reason libc++ provides an extension that does just that! The
extension must be enabled by defining `_LIBCPP_ENABLE_NODISCARD`. The extended
applications of `[[nodiscard]]` takes two forms:

1. Backporting `[[nodiscard]]` to entities declared as such by the
   standard in newer dialects, but not in the present one.

2. Extended applications of `[[nodiscard]]`, at the libraries discretion,
   applied to entities never declared as such by the standard.

Users may also opt-out of additional applications `[[nodiscard]]` using
additional macros.

Applications of the first form, which backport `[[nodiscard]]` from a newer
dialect may be disabled using macros specific to the dialect it was added. For
example `_LIBCPP_DISABLE_NODISCARD_AFTER_CXX17`.

Applications of the second form, which are pure extensions, may be disabled
by defining `_LIBCPP_DISABLE_NODISCARD_EXT`.

This patch was originally written by me (Roman Lebedev),
then but then reworked by Eric Fiselier.

Reviewers: mclow.lists, thakis, EricWF

Reviewed By: thakis, EricWF

Subscribers: llvm-commits, mclow.lists, lebedev.ri, EricWF, rjmccall, Quuxplusone, cfe-commits, christof

Differential Revision: https://reviews.llvm.org/D45179

llvm-svn: 342808
2018-09-22 17:54:48 +00:00
Louis Dionne 61cd687009 [libcxx] By default, do not use internal_linkage to hide symbols from the ABI
Summary:
https://reviews.llvm.org/D49240 led to symbol size problems in Chromium, and
we expect this may be the case in other projects built in debug mode too.
Instead, unless users explicitly ask for internal_linkage, we use always_inline
like we used to.

In the future, when we have a solution that allows us to drop always_inline
without falling back on internal_linkage, we can replace always_inline by
that.

Note that this commit introduces a change in contract for existing libc++
users: by default, libc++ used to guarantee that TUs built with different
versions of libc++ could be linked together. With the introduction of the
_LIBCPP_HIDE_FROM_ABI_PER_TU macro, the default behavior is that TUs built
with different libc++ versions are not guaranteed to link. This is a change
in contract but not a change in behavior, since the current implementation
still allows linking TUs built with different libc++ versions together.

Reviewers: EricWF, mclow.lists, dexonsmith, hans, rnk

Subscribers: christof, cfe-commits

Differential Revision: https://reviews.llvm.org/D50652

llvm-svn: 339874
2018-08-16 12:44:28 +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
Louis Dionne 894ffdd82f [libc++] Detect C11 features on non-Clang compilers
Summary:
The macros were inside `#if defined(_LIBCPP_COMPILER_CLANG)`, which means
we would never detect C11 features on non-Clang compilers. According to
Marshall Clow, this is not the intended behavior.

Reviewers: mclow.lists, EricWF

Subscribers: krytarowski, christof, dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D50748

llvm-svn: 339741
2018-08-15 00:16:41 +00:00
Louis Dionne 53ac1776f3 [libc++] Enable aligned allocation based on feature test macro, irrespective of standard
Summary:
The current code enables aligned allocation functions when compiling in C++17
and later. This is a problem because aligned allocation functions might not
be supported on the target platform, which leads to an error at link time.

Since r338934, Clang knows not to define __cpp_aligned_new when it's not
available on the target platform -- this commit takes advantage of that to
only use aligned allocation functions when they are available.

Reviewers: vsapsai, EricWF

Subscribers: christof, dexonsmith, cfe-commits, EricWF, mclow.lists

Differential Revision: https://reviews.llvm.org/D50344

llvm-svn: 339431
2018-08-10 13:24:56 +00:00
Louis Dionne ba71bd7c55 [libc++] Add the _LIBCPP_HIDE_FROM_ABI_AFTER_V1 macro
Summary:
This macro allows hiding symbols from the ABI when the library is built
with an ABI version after ABI v1, which is currently the only stable ABI.
This commit defines `_LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY` to be
`_LIBCPP_HIDE_FROM_ABI_AFTER_V1`, meaning that symbols that were only
exported by the library for historical reasons are not exported anymore
in the unstable ABI.

Because of that, this commit is an ABI break for ABI v2. This ABI version
is not stable, however, so this should not be a problem.

Reviewers: EricWF, mclow.lists

Subscribers: christof, dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D49914

llvm-svn: 339012
2018-08-06 14:11:50 +00:00
Hans Wennborg 25977548aa Update version to 8.0.0svn: cmake, includes files and docs
llvm-svn: 338555
2018-08-01 13:54:28 +00:00
Louis Dionne 306b73e35b [libc++] Fix GCC 7.2.0 macro redefinition warning
The warning happens when LIBCXX_ENABLE_EXCEPTIONS cmake option is not set,
and it fires every time __config is included, 33 in total.

Patch by Jason Lovett
Reviewed as https://reviews.llvm.org/D49997

llvm-svn: 338531
2018-08-01 13:13:14 +00:00
Tim Shen 38cd7de5ac Re-apply "[libcxx] implement <simd> ABI for Clang/GCC vector extension, constructors, copy_from and copy_to."
...with proper guarding #ifdefs for unsupported C++11.

llvm-svn: 338318
2018-07-30 22:27:38 +00:00
Tim Shen 6f33ea4ef6 Revert "[libcxx] implement <simd> ABI for Clang/GCC vector extension, constructors, copy_from and copy_to."
This reverts commit r338309.

llvm-svn: 338316
2018-07-30 22:21:22 +00:00
Tim Shen 47ad09b339 [libcxx] implement <simd> ABI for Clang/GCC vector extension, constructors, copy_from and copy_to.
Summary:
This patch adds a new macro _LIBCPP_HAS_NO_VECTOR_EXTENSION for detecting
whether a vector extension (\_\_attribute\_\_((vector_size(num_bytes)))) is
available.

On the top of that, this patch implements the following API:
* all constructors
* operator[]
* copy_from
* copy_to

It also defines simd_abi::native to use vector extension, if available.
In GCC and Clang, certain values with vector extension are passed by registers,
instead of memory.

Based on D41148.

Reviewers: mclow.lists, EricWF

Subscribers: cfe-commits, MaskRay, lichray, sanjoy

Differential Revision: https://reviews.llvm.org/D41376

llvm-svn: 338309
2018-07-30 21:23:13 +00:00
Louis Dionne cb3eb30636 [libc++] Introduce _LIBCPP_HIDE_FROM_ABI to replace _LIBCPP_INLINE_VISIBILITY
Summary:
This commit introduces a new macro, _LIBCPP_HIDE_FROM_ABI, whose goal is to
mark functions that shouldn't be part of libc++'s ABI. It marks the functions
as being hidden for dylib visibility purposes, and as having internal linkage
using Clang's __attribute__((internal_linkage)) when available, and
__always_inline__ otherwise.

It replaces _LIBCPP_INLINE_VISIBILITY, which was always using __always_inline__
to achieve similar goals, but suffered from debuggability and code size problems.
The full proposal, along with more background information, can be found here:

    http://lists.llvm.org/pipermail/cfe-dev/2018-July/058419.html

This commit does not rename uses of _LIBCPP_INLINE_VISIBILITY to
_LIBCPP_HIDE_FROM_ABI: this wide reaching but mechanical change can
be done later when we've confirmed we're happy with the new macro.

In the future, it would be nice if we could optionally allow dropping
any internal_linkage or __always_inline__ attribute, which could result
in code size improvements. However, this is currently impossible for
reasons explained here: http://lists.llvm.org/pipermail/cfe-dev/2018-July/058450.html

Reviewers: EricWF, dexonsmith, mclow.lists

Subscribers: christof, dexonsmith, llvm-commits, mclow.lists

Differential Revision: https://reviews.llvm.org/D49240

llvm-svn: 338122
2018-07-27 12:46:03 +00:00
Eric Fiselier 8e4a1690bf Move Filesystem namespace definition out of a clang specific ifdef block.
llvm-svn: 338103
2018-07-27 06:12:46 +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
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
Marshall Clow 75c4f5552e wrap _LIBCPP_HAS_NO_CXX14_CONSTEXPR in defined(...)
llvm-svn: 337028
2018-07-13 17:31:36 +00:00
Marshall Clow 2d1d690863 Shot in the dark to fix gcc 4.9 / c++11 build
llvm-svn: 337027
2018-07-13 17:24:59 +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
Louis Dionne dc7200b486 [libc++] Take 2: Replace uses of _LIBCPP_ALWAYS_INLINE by _LIBCPP_INLINE_VISIBILITY
Summary:
We never actually mean to always inline a function -- all the uses of
the macro I could find are actually attempts to control the visibility
of symbols. This is better described by _LIBCPP_INLINE_VISIBILITY, which
is actually always defined the same.

This change is orthogonal to the decision of what we're actually going
to do with _LIBCPP_INLINE_VISIBILITY -- it just simplifies things by
having one canonical way of doing things.

Note that this commit had originally been applied in r336369 and then
reverted in r336382 because of unforeseen problems. Both of these problems
have now been fixed.

Reviewers: EricWF, mclow.lists

Subscribers: christof, dexonsmith, erikvanderpoel

Differential Revision: https://reviews.llvm.org/D48892

llvm-svn: 336866
2018-07-11 23:14:33 +00:00
Louis Dionne 195a499d63 Revert "[libc++] Replace uses of _LIBCPP_ALWAYS_INLINE by _LIBCPP_INLINE_VISIBILITY"
This reverts commit r336369. The commit had two problems:
1. __pbump was marked as _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY instead of
   _LIBCPP_INLINE_VISIBILITY, which lead to two symbols being added in the
   dylib and the check-cxx-abilist failing.

2. The LLDB tests started failing because they undefine
   `_LIBCPP_INLINE_VISIBILITY`. I need to figure out why they do that and
   fix the tests before we can go forward with this change.

llvm-svn: 336382
2018-07-05 18:41:50 +00:00
Louis Dionne 4a8f3f9948 [libc++] Replace uses of _LIBCPP_ALWAYS_INLINE by _LIBCPP_INLINE_VISIBILITY
Summary:
We never actually mean to always inline a function -- all the uses of
the macro I could find are actually attempts to control the visibility
of symbols. This is better described by _LIBCPP_INLINE_VISIBILITY, which
is actually always defined the same.

This change is orthogonal to the decision of what we're actually going
to do with _LIBCPP_INLINE_VISIBILITY -- it just simplifies things by
having one canonical way of doing things.

Reviewers: EricWF

Subscribers: christof, llvm-commits, dexonsmith, erikvanderpoel, mclow.lists

Differential Revision: https://reviews.llvm.org/D48892

llvm-svn: 336369
2018-07-05 16:49:38 +00:00
JF Bastien f764dbd023 Revert "Add nonnull; use it for atomics"
That's r333325, as well as follow-up "Fix GCC handling of ATOMIC_VAR_INIT"
r333327.

Marshall asked to revert:

Let's have a discussion about how to implement this so that it is more friendly
to people with installed code bases. We've had *extremely* loud responses to
unilaterally adding warnings - especially ones that can't be easily disabled -
to the libc++ code base in the past.

llvm-svn: 333351
2018-05-26 19:44:45 +00:00
JF Bastien 1be7517aa9 Add nonnull; use it for atomics
Summary:
The atomic non-member functions accept pointers to std::atomic / std::atomic_flag as well as to the non-atomic value. These are all dereferenced unconditionally when lowered, and therefore will fault if null. It's a tiny gotcha for new users, especially when they pass in NULL as expected value (instead of passing a pointer to a NULL value). We can therefore use the nonnull attribute to denote that:

  - A warning should be generated if the argument is null
  - It is undefined behavior if the argument is null (because a dereference will segfault)

This patch adds support for this attribute for clang and GCC, and sticks to the subset of the syntax both supports. In particular, work around this GCC oddity:
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60625

The attributes are documented:

  - https://gcc.gnu.org/onlinedocs/gcc-4.0.0/gcc/Function-Attributes.html
  - https://clang.llvm.org/docs/AttributeReference.html#nullability-attributes

I'm authoring a companion clang patch for the __c11_* and __atomic_* builtins, which currently only warn on a subset of the pointer parameters.

In all cases the check needs to be explicit and not use the empty nonnull list, because some of the overloads are for atomic<T*> and the values themselves are allowed to be null.

<rdar://problem/18473124>

Reviewers: arphaman, EricWF

Subscribers: aheejin, christof, cfe-commits

Differential Revision: https://reviews.llvm.org/D47225

llvm-svn: 333325
2018-05-25 23:43:53 +00:00
Reid Kleckner 6a2a5e0abb Don't do aligned allocations on MSVCRT before 19.12 (update 15.3)
Reviewers: EricWF, pcc

Subscribers: christof, cfe-commits

Differential Revision: https://reviews.llvm.org/D45836

llvm-svn: 330372
2018-04-19 22:12:10 +00:00
Reid Kleckner 317a6ddea7 Remove impossible _MSC_VER check
Summary:
It is immediately preceded by this check:
  #if _MSC_VER < 1900
  #error "MSVC versions prior to Visual Studio 2015 are not supported"
  #endif

Reviewers: EricWF

Subscribers: christof, cfe-commits

Differential Revision: https://reviews.llvm.org/D45829

llvm-svn: 330360
2018-04-19 19:40:12 +00:00
Petr Hosek 2b3846306d [libcxx] Set ABI version 2 as default for Fuchsia
This avoids the need for a custom generated config file which is desired
because the custom config files differs per-target which means we cannot
reuse headers across different targets.

Differential Revision: https://reviews.llvm.org/D45304

llvm-svn: 329770
2018-04-11 01:06:28 +00:00
Eric Fiselier 0913ca1978 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.

llvm-svn: 329460
2018-04-06 21:37:23 +00:00
Eric Fiselier f2918d1c24 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.

llvm-svn: 328180
2018-03-22 04:42:56 +00:00
Logan Chien 2b772b930e 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

llvm-svn: 326027
2018-02-24 07:57:32 +00:00
Eric Fiselier 1a78ae3c89 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.

llvm-svn: 324545
2018-02-07 23:50:25 +00:00
Eric Fiselier 59cdf90ac8 [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

llvm-svn: 324526
2018-02-07 21:06:13 +00:00
Peter Collingbourne fcac3c9642 libcxx: Allow auto-linking to be disabled with a macro.
Some users may have a custom build system which gives a different
name to the libc++ archive (or does not create an archive at all,
instead passing the object files directly to the linker). Give those
users a way to disable auto-linking.

Differential Revision: https://reviews.llvm.org/D42436

llvm-svn: 323300
2018-01-24 04:30:19 +00:00
Peter Collingbourne 4801624ee3 libcxx: Provide overloads for basic_filebuf::open() et al that take wchar_t* filenames on Windows.
This is an MSVC standard library extension. It seems like a reasonable
enough extension to me because wchar_t* is the native format for
filenames on that platform.

Differential Revision: https://reviews.llvm.org/D42225

llvm-svn: 323170
2018-01-23 02:07:27 +00:00
Peter Collingbourne 4bdb80faf2 libcxx: Stop using private MSVC macros in the exception implementation.
Inline the provided "fallback" definitions (which seem to always be
taken) that expand to __cdecl into users. The fallback definitions
for the *CRTIMP* macros were wrong in the case where the CRT is being
linked statically, so define our own macro as a replacement.

Differential Revision: https://reviews.llvm.org/D42158

llvm-svn: 322617
2018-01-17 04:37:04 +00:00
Peter Collingbourne 4566d827a1 libcxx: Stop providing a definition of __GLIBC_PREREQ.
An application may determine whether the C standard library is glibc
by testing whether __GLIBC_PREREQ is defined. This breaks if libc++
provides its own definition. Instead, define our own macro in our
namespace with the desired semantics.

Differential Revision: https://reviews.llvm.org/D41892

llvm-svn: 322201
2018-01-10 18:16:58 +00:00
Saleem Abdulrasool ae20590c17 Correct mistake in pragma usage for Windows
The autolink pragma was missing the pragma name itself.  This would
result in the pragma being silently dropped.

llvm-svn: 321937
2018-01-06 18:47:03 +00:00
Hans Wennborg 6be97eca93 Update version to 7.0.0svn: cmake, include files and docs
llvm-svn: 321725
2018-01-03 15:40:29 +00:00
Marshall Clow dd74d83f84 Implement p0258r2: has_unique_object_representations
llvm-svn: 321685
2018-01-03 02:32:28 +00:00
Marshall Clow 40a01d5314 Implement most of P0607: Inline Variables for the Standard Library. This involved marking a lot of variables as inline (but only for C++17 and later).
llvm-svn: 321658
2018-01-02 17:17:01 +00:00
Sam Clegg 5029d676f8 [libcxx] Add WebAssembly support
It turns out that this is the only change required in libcxx
for it to compile with the new `wasm32-unknown-unknown-wasm`
target recently added to Clang.

Patch by Nicholas Wilson!

Differential Revision: https://reviews.llvm.org/D41073

llvm-svn: 320925
2017-12-16 18:59:50 +00:00
Saleem Abdulrasool 74f41817a5 Enable auto-linking on Windows
The MSVC driver and clang do not link against the C++ runtime
explicitly.  Instead, they rely on the auto-linking via the pragma
(through `use_ansi.h`) to link against the correct version of the C++
runtime.  Attempt to do something similar here so that linking real C++
code on Windows does not require the user to explicitly specify
`c++.lib` when using libc++ as a C++ runtime on windows.

llvm-svn: 319816
2017-12-05 19:32:49 +00:00
Petr Hosek 5c70428176 [libcxx] Support getentropy as a source of randomness for std::random_device
Use this source use on Fuchsia where this is the oficially way
to obtain randomness. This could be also used on other platforms
that already support getentropy such as *BSD or Linux.

Differential Revision: https://reviews.llvm.org/D40319

llvm-svn: 319523
2017-12-01 06:34:33 +00:00
Martin Storsjo 771edc7949 Allow to set locale on Windows.
Fix the problem PR31516 with setting locale on Windows by wrapping
_locale_t with a pointer-like class.

Reduces 74 test failures in std/localization test suite to 47 test
failures (on llvm clang, Visual Studio 2015). Number of test failures
doesn't depend on the platform (x86 or x64).

Patch by Andrey Khalyavin.

Differential Revision: https://reviews.llvm.org/D40181

llvm-svn: 318902
2017-11-23 10:38:18 +00:00
Marshall Clow 9180eb1f4a Implement p0137r1 - std::launder. Reviewed as https://reviews.llvm.org/D40144
llvm-svn: 318864
2017-11-22 19:49:03 +00:00
Eric Fiselier 0ed525382f [libc++] Shrink variant's index type when possible
Summary:
Currently `std::variant` always uses an unsigned int to store the variant index. However this isn't nessesary and causes `std::variant` to be larger than it needs to be in most cases.

This patch changes the index type to be `unsigned char` when possible, and `unsigned short` or `unsigned int` otherwise, depending on the size (Although it's questionable if it's even possible to create a variant with 65535 elements.

Unfortunately this change is an ABI break, and as such is only enabled in ABI v2.

Reviewers: mpark

Reviewed By: mpark

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D40210

llvm-svn: 318621
2017-11-19 04:19:44 +00:00
Marshall Clow 1644c12ef8 Add two new macros: _LIBCPP_NODISCARD_AFTER_CXX17 and _LIBCPP_CONSTEXPR_AFTER_CXX17, along with a way to turn off the NODISCARD one: _LIBCPP_DISABLE_NODISCARD_AFTER_CXX17. No one is using these yet, but we will be ... soon
llvm-svn: 318208
2017-11-14 22:26:50 +00:00
Dan Albert f33558b224 Revert "[libc++] Don't alias quick_exit if __ANDROID_API__ < 21"
Broke the Darwin build bots.

This reverts commit f56f1bba1ade4a408d403ff050d50e837bae47df.

llvm-svn: 317142
2017-11-01 23:43:07 +00:00
Dan Albert 5a4e27dfa6 [libc++] Don't alias quick_exit if __ANDROID_API__ < 21
Summary:
quick_exit() and at_quick_exit() were introduced in android NDK 21:
https://android.googlesource.com/platform/prebuilts/ndk/+/dev/platform/sysroot/usr/include/stdlib.h#55

This CL conditions `_LIBCPP_HAS_QUICK_EXIT` on `__ANDROID_API__ >= 21`.  The only place this macro is used is in some using declarations: `using ::quick_exit`, `using ::at_quick_exit`.

Also, add a missing include to sys/cdefs.h which is what defines `__BIONIC__`.

Reviewers: thakis, danalbert, EricWF

Reviewed By: danalbert

Subscribers: srhines, krytarowski

Differential Revision: https://reviews.llvm.org/D39479

llvm-svn: 317124
2017-11-01 21:17:56 +00:00
Eric Fiselier da0183947f Refactor _LIBCPP_<LITTLE|BIG>_ENDIAN
Previously this macro used 0/1 to indicate if it was set.
This is unlike all other libc++ configuration macros which
use ifdef/ifndef.

This patch makes this macro consistent with everything else.

llvm-svn: 315995
2017-10-17 13:16:01 +00:00
Shoaib Meenai a4a3d40eb6 [libc++] Clarify names of ABI forcing macros
Make it clear that these are intended only to force a specific ABI when
the autodetection would give the wrong result by renaming the cmake
options and adding separate forcing macros, as suggested by EricWF in
the post-commit review of r314949 and further discussed on IRC.

llvm-svn: 314965
2017-10-05 02:18:08 +00:00
Shoaib Meenai d456385043 [libc++] Allow users to explicitly specify ABI
libc++'s current heuristic for detecting Itanium vs. Microsoft ABI falls
short in some cases. For example, it will detect windows-itanium targets
as using the Microsoft ABI, since they set `_MSC_VER` (for compatibility
with Microsoft headers). Leave the current heuristic in place by default
but also allow users to explicitly specify the ABI if need be.

llvm-svn: 314949
2017-10-04 23:44:38 +00:00
Nico Weber 7fa845e713 Fix grammar-o in comment.
llvm-svn: 308827
2017-07-22 15:16:42 +00:00
Hans Wennborg 9e82a506ae Update _LIBCPP_VERSION and the version in CMakeLists to 6.0
llvm-svn: 308468
2017-07-19 13:57:10 +00:00
Bruno Cardoso Lopes e59dd00038 Check for _MSC_VER before defining _LIBCPP_MSVCRT
Some targets (e.g. Darwin) might have the Win32 API available, but they
do not use MSVC CRT. Assume _LIBCPP_MSVCRT only when _MSC_VER is available
and __MINGW32__ isn't defined.

Differential Revision: https://reviews.llvm.org/D34588

rdar://problem/32628786

llvm-svn: 308225
2017-07-17 21:52:31 +00:00
Marshall Clow 33116350ad Add case for c++2a to libc++ and test macros
llvm-svn: 308159
2017-07-17 03:02:27 +00:00
Shoaib Meenai c44edbcc94 [libc++] Remove unused _LIBCPP_FUNC_VIS_ONLY
This has been unused since r282644.

llvm-svn: 307965
2017-07-13 21:28:17 +00:00
Akira Hatanaka 539cb66bea Revert "[libcxx] Annotate c++17 aligned new/delete operators with availability"
This reverts commit r306310.

r306310 causes clang to reject a call to an aligned allocation or
deallocation function if it is not implemented in the standard library
of the deployment target. This is not the desired behavior when users
have defined their own aligned functions.

rdar://problem/32664169

llvm-svn: 306859
2017-06-30 18:50:23 +00:00
Akira Hatanaka 393b55ffe2 [libcxx] Annotate c++17 aligned new/delete operators with availability
attribute.

This is needed because older versions of libc++ do not have these
operators. If users target an older deployment target and try to compile
programs in which these operators are explicitly called, the compiler
will complain.

The following is the list of minimum deployment targets for the four
OSes:

macosx: 10.13
ios: 11.0
tvos: 11.0
watchos: 4.0

rdar://problem/32664169

Differential Revision: https://reviews.llvm.org/D34556

llvm-svn: 306310
2017-06-26 17:39:48 +00:00
Duncan P. N. Exon Smith 878cf8fbd4 iostreams: Fix deployment target for streams dylib support
Fix an off-by-one in r302172, which triggered building local versions of
the iostreams when deploying to `<= macOS 10.9`, when it should have
been `< macOS 10.9`.  10.9 had the dylib support.

This defines `_LIBCPP_AVAILABILITY_NO_STREAMS_EXTERN_TEMPLATE` less
often, reducing code size for users with deployment targets of exactly
macOS 10.9 or iOS 7.0.

rdar://problem/32233981

llvm-svn: 305649
2017-06-18 16:50:23 +00:00
Duncan P. N. Exon Smith b1cb279014 any: Add availability for experimental::bad_any_cast
As a follow up to r302172, add missing availability for bad_any_cast.

rdar://problem/32161524

llvm-svn: 305647
2017-06-18 14:52:26 +00:00
Eric Fiselier 56312f5ad5 Allow the libc++ C header wrappers to be included when compiling C.
C99 at least. C89 still fails due to the use of block comments.

NOTE: Having libc++ on the include path when compiling C is not
recommended or ever really supported. However it happens often
enough that this change is warrented.

llvm-svn: 305539
2017-06-16 01:57:41 +00:00
Eric Fiselier b4f962cdcc attempt to fix GCC ToT build failures
llvm-svn: 305451
2017-06-15 03:50:02 +00:00
Aditya Kumar 38bc3df8a3 [locale] Avoid copy of __atoms when char_type is char
The function num_get<_CharT>::stage2_int_prep makes unnecessary copy of src
into atoms when char_type is char. This can be avoided by creating
a switch on type and just returning __src when char_type is char.

Added the test case to demonstrate performance improvement.
In order to avoid ABI incompatibilities, the changes are guarded
with a macro _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET

Differential Revision: https://reviews.llvm.org/D30268
Reviewed by: EricWF

llvm-svn: 305427
2017-06-14 23:17:45 +00:00
Eric Fiselier 1ec026252b Fix Libc++ build with MinGW64
Summary: This patch corrects the build errors I encountered when building on MinGW64.

Reviewers: mati865, rnk, compnerd, smeenai, bcraig

Reviewed By: mati865, smeenai

Subscribers: martell, chapuni, cfe-commits

Differential Revision: https://reviews.llvm.org/D33082

llvm-svn: 304360
2017-05-31 22:14:05 +00:00
Eric Fiselier a016efb1dc [Libc++] Use #pragma push_macro/pop_macro to better handle min/max on Windows
Summary:
This patch improves how libc++ handles min/max macros within the headers. Previously libc++ would undef them and emit a warning.
This patch changes libc++ to use `#pragma push_macro`  to save the macro before undefining it, and `#pragma pop_macro` to restore the macros and the end of the header.

Reviewers: mclow.lists, bcraig, compnerd, EricWF

Reviewed By: EricWF

Subscribers: cfe-commits, krytarowski

Differential Revision: https://reviews.llvm.org/D33080

llvm-svn: 304357
2017-05-31 22:07:49 +00:00
Eric Fiselier eb04c8cae2 Guard <experimental/coroutine> against older Clang versions.
Clang started providing -fcoroutines and defining __cpp_coroutines
way before it implemented the __builtin_coro_foo functions. This
means that simply checking if __cpp_coroutines is not a sufficient
way of detecting the actual feature.

This patch implements _LIBCPP_HAS_NO_COROUTINES which implements
a slightly more complex feature check. Specifically it requires
__cpp_coroutines >= 201703L, which only holds for Clang 5.0 built
after 2017/05/24.

llvm-svn: 303956
2017-05-26 01:52:59 +00:00
Eric Fiselier 0c6e7ae4cc Remove usages of _LIBCPP_MSVC which is never defined
llvm-svn: 302736
2017-05-10 21:40:58 +00:00
Eric Fiselier a1bc823a59 Fix MinGW build to use Pthread when the header is available.
Some MinGW configurations use WinPThread instead of the native
threading interfaces. When this happens libc++ doesn't build because
it tries to use the wrong threading API.

This patch attempts to correctly detect and enable pthreads; Selecting
them when __MINGW32__ is defined and __has_include(<pthread.h>) is true.
I'm not sure if this works correctly 100% of the time but it seemed
like the most correct approach available.

llvm-svn: 302734
2017-05-10 21:34:58 +00:00
Eric Fiselier e9ee517930 Support using MinGW POSIX threads on Windows
llvm-svn: 302617
2017-05-10 02:36:48 +00:00
Eric Fiselier 1a5733af6a Fix detection for [[fallthrough]] with GCC
llvm-svn: 302285
2017-05-05 20:50:24 +00:00
Eric Fiselier 807790a09b Fix new warnings emitted by GCC 7
llvm-svn: 302280
2017-05-05 20:32:26 +00:00
Mehdi Amini e9c66ad9fa Add markup for libc++ dylib availability
Libc++ is used as a system library on macOS and iOS (amongst others). In order
for users to be able to compile a binary that is intended to be deployed to an
older version of the platform, clang provides the
availability attribute <https://clang.llvm.org/docs/AttributeReference.html#availability>_
that can be placed on declarations to describe the lifecycle of a symbol in the
library.

See docs/DesignDocs/AvailabilityMarkup.rst for more information.

Differential Revision: https://reviews.llvm.org/D31739

llvm-svn: 302172
2017-05-04 17:08:54 +00:00
Eric Fiselier 6b88dae046 Fix macro redefinition warnings for _LIBCPP_NO_RTTI
llvm-svn: 302099
2017-05-04 01:06:54 +00:00
Petr Hosek d0e9481c55 [libcxx] Direct support for Fuchsia
Fuchsia's libc was forked from musl, but has evolved sufficiently
since then so it no longer makes sense to pretend it's musl. This
change implements direct support for Fuchsia rather than
piggybacking on musl support.

Differential Revision: https://reviews.llvm.org/D31970

llvm-svn: 300261
2017-04-13 21:29:21 +00:00
Shoaib Meenai 461764de0d [libc++] Add _LIBCPP_DISABLE_EXTERN_TEMPLATE config option
When the libc++ extern template macros were added, the intent was for it
to be possible for consumers of the headers to disable extern templates
(via `-D_LIBCPP_EXTERN_TEMPLATE(...)=`). Unfortunately, support for
specifying function-like macros varies on the command line varies across
compilers (e.g. MSVC doesn't support it at all), and cmake doesn't allow
it for the same reason. Add a non-function macro for this purpose.

The intended use is for libraries which want to use the libc++ headers
without taking a dependency on the libc++ library itself. I can name the
macro something which reflects its intent rather than its behavior (e.g.
`_LIBCPP_HEADER_ONLY`) if desired.

Differential Revision: https://reviews.llvm.org/D31725

llvm-svn: 300246
2017-04-13 20:13:32 +00:00
Marshall Clow 7d210c787e Remove the binders from C++17. Reviewed as https://reviews.llvm.org/D31769
llvm-svn: 300232
2017-04-13 18:25:32 +00:00
Eric Fiselier da04d79a1f [libc++] Implement LWG 2911 - add an is_aggregate type-trait
Summary:
This patch implements http://cplusplus.github.io/LWG/lwg-defects.html#2911.

I'm putting this up for review until __is_aggregate is added to clang (See D31513)

Reviewers: mclow.lists

Reviewed By: mclow.lists

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D31515

llvm-svn: 300126
2017-04-12 23:08:46 +00:00
Shoaib Meenai 538b3f4198 [libc++] Use more appropriate conditional for ABI macro definition
The inline function definition ABI macro is gated on COFF dllexport
semantics, so it's more appropriate to mark it with the object file
format macro rather than the generic _WIN32 macro. We now have no uses
of _WIN32 apart from those used to define the other Windows macros :)

Clarify the ABI macro comment and make the object file format check
exhaustive while I'm here.

llvm-svn: 300097
2017-04-12 19:56:37 +00:00
Shoaib Meenai 5dc5a8e5be [libc++] Respect Windows Store app CRT restrictions
Some CRT APIs are unavailable for Windows Store apps [1]. Detect when
we're targeting the Windows Store and don't try to refer to non-existent
CRT functions in that case. (This would otherwise lead to a compile
error when using the libc++ headers and compiling for Windows Store.)

[1] https://docs.microsoft.com/en-us/cpp/cppcx/crt-functions-not-supported-in-universal-windows-platform-apps

Differential Revision: https://reviews.llvm.org/D31737

llvm-svn: 299625
2017-04-06 04:47:49 +00:00
Mehdi Amini 605d1eb9f4 Use alternate string layout for ARMv7k
llvm-svn: 299606
2017-04-06 01:10:22 +00:00
Duncan P. N. Exon Smith 64ea46f82a Use strong enums independently of -fobjc-arc
r145698 introduced _LIBCPP_HAS_NO_STRONG_ENUMS by copy-pasting the
__has_feature check from objc_arc_weak/_LIBCPP_HAS_OBJC_ARC_WEAK, and
accidentally started defining _LIBCPP_HAS_NO_STRONG_ENUMS whenever
__has_feature(objc_arc_weak).  This is totally bogus, and means that
Libc++ thinks Objective-C++ compilations with -fobjc-arc don't have
strong enums.

Delete the accidental line.

I thought about adding a test, but it would be entirely duplicative of
the patch (if has-feature strong enums, check that has-no-strong-enums
is not defined).

llvm-svn: 299236
2017-03-31 17:39:56 +00:00
Shoaib Meenai c7cd73e8b8 [libc++] Add a key function for bad_function_call
Summary:
bad_function_call is currently an empty class, so any object files using
that class will end up with their own copy of its typeinfo, typeinfo
name and vtable, leading to unnecessary duplication that has to be
resolved by the dynamic linker. Instead, give bad_function_call a key
function and put a definition for that key function in libc++ itself, to
centralize the typeinfo and vtable.

This is consistent with the behavior for other exception classes. The
key functions are defined in libc++ rather than libc++abi since the
class is defined in the libc++ versioning namespace, so ABI
compatibility with libstdc++ is not a concern.

Guard this change behind an ABI macro, since it isn't backwards
compatible (i.e., clients built against the new libc++ headers wouldn't
be able to run against an older libc++ library).

Reviewers: mclow.lists, EricWF

Subscribers: mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D27387

llvm-svn: 298937
2017-03-28 19:33:31 +00:00
Marshall Clow 6015dd11c8 Implement Pp0156r2: 'Variadic Lock Guard, version 5' Reviewed as https://reviews.llvm.org/D31163.
llvm-svn: 298681
2017-03-24 03:40:36 +00:00
Marshall Clow c53faf7bca One more file for the random_shuffle removal
llvm-svn: 298598
2017-03-23 13:44:06 +00:00
Shoaib Meenai 5e5d8672a7 [libc++] Avoid double defining macro on Windows
Put proper guards around _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS.
No functional change on non-Windows. Avoids incorrect macro redefinition
on Windows.

llvm-svn: 297330
2017-03-09 00:18:00 +00:00
Shoaib Meenai bda3c7df78 [libc++] Make _LIBCPP_TYPE_VIS export members
Summary:
Most classes annotated with _LIBCPP_TYPE_VIS need to have at least some
of their members exported, otherwise we have a lot of link errors when
linking against a libc++ built with hidden visibility. This also makes
_LIBCPP_TYPE_VIS be consistent across platforms, since on Windows it
already exports members.

With this change made, any template methods of a class marked
_LIBCPP_TYPE_VIS will also get default visibility when instantiatied,
which is not desirable for clients of libc++ headers who wish to control
their visibility; this is the same issue as PR30642. Annotate all
problematic methods with an explicit visibility specifier to avoid this.

The problematic methods were found by running bad-visibility-finder [1]
against the libc++ headers after making the _LIBCPP_TYPE_VIS change. The
small methods were marked for inlining; the larger ones hidden.

[1] https://github.com/smeenai/bad-visibility-finder

Reviewers: mclow.lists, EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D25208

llvm-svn: 296732
2017-03-02 03:22:18 +00:00
Shoaib Meenai bad28c44eb [libc++] Make _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS export members
When building libc++ with hidden visibility, we want explicit template
instantiations to export members. This is consistent with existing
Windows behavior, and is necessary for clients to be able to link
against a hidden visibility built libc++ without running into lots of
missing symbols.

An unfortunate side effect, however, is that any template methods of a
class with an explicit instantiation will get default visibility when
instantiated, unless the methods are explicitly marked inline or hidden
visibility. This is not desirable for clients of libc++ headers who wish
to control their visibility, and led to PR30642.

Annotate all problematic methods with an explicit visibility specifier
to avoid this. The problematic methods were found by running
https://github.com/smeenai/bad-visibility-finder against the libc++
headers after making the _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS change. The
methods were marked with the new _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
macro, which was created for this purpose.

It should be noted that _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS was originally
intended to expand to default visibility, and was changed to expanding
to default type visibility to fix PR30642. The visibility macro
documentation was not updated accordingly, however, so this change makes
the macro consistent with its documentation again, while explicitly
fixing the methods which resulted in that PR.

Differential Revision: https://reviews.llvm.org/D29157

llvm-svn: 296731
2017-03-02 03:02:50 +00:00
Asiri Rathnayake 68050fd694 Fix LIBCXX_HAS_EXTERNAL_THREAD_API builds. NFC.
Add the missing check in the __config header.

llvm-svn: 296351
2017-02-27 16:10:57 +00:00
Asiri Rathnayake 01eb47800b Fix typo in error message. NFC.
llvm-svn: 296346
2017-02-27 15:49:51 +00:00
Eric Fiselier 7f1604aae6 Use inline namespaces with GCC instead of __attribute__((__strong__)).
GCC 7.0.1 started warning that __attribute__((__strong__)) is depricated.
This patch switches to using inline namespace with GCC instead. I believe
this wasn't done originally in order to support older GCC versions w/o
support for inline namespaces, or because earlier versions of GCC warned
users that the STL was using an inline namespace (even though it shouldn't affect users).

However I believe all of the above problems are gone for GCC 4.9 and greater.
Therefore switching to using inline namespaces instead of using __strong__
is the most correct behavior.

llvm-svn: 295428
2017-02-17 07:31:38 +00:00
Eric Fiselier 07e93d3b00 Add doc for _LIBCPP_ENABLE_CXX17_DISABLED_AUTO_PTR and make it work under _LIBCPP_ENABLE_CXX17_REMOVED_FEATURES
llvm-svn: 295407
2017-02-17 03:30:25 +00:00
Eric Fiselier 2a1bfa98d1 [libcxx] Remove unexpected handlers in C++17
Summary:
This patch implements [P0003R5](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0003r5.html) which removes exception specifications from C++17.

The only changes to the library are removing `set_unexpected`, `get_unexpected`, `unexpected`, and `unexpected_handler`. These functions can be re-enabled in C++17 using `_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS`.

@mclow.lists what do you think about removing stuff is this way?

Reviewers: mclow.lists

Reviewed By: mclow.lists

Subscribers: mclow.lists, cfe-commits

Differential Revision: https://reviews.llvm.org/D28172

llvm-svn: 295406
2017-02-17 03:25:08 +00:00
Saleem Abdulrasool 3444e9fa15 config: disable thread safety analysis on COFF
clang cannot properly handle __declspec and __attribute__ on classes
right now.  This prevents the shared_mutex tests from working.  Disable
the use of the annotation on COFF targets.

llvm-svn: 294958
2017-02-13 15:26:51 +00:00
Saleem Abdulrasool bcc85cbcde Refer to _LIBCPP_MSVC macro where applicable
Replace preprocess conditions of defined(_MSC_VER) &&
!defined(__clang__) with defined(_LIBCPP_MSVC).  NFC.

Patch by Dave Lee!

llvm-svn: 294171
2017-02-06 05:26:49 +00:00
Eric Fiselier e49cdfbeea Recommit [libcxx] Never use <cassert> within libc++
It is my opinion that libc++ should never use `<cassert>`, including in the `dylib`.
This patch remove all uses of `assert` from within libc++ and replaces most of them with `_LIBCPP_ASSERT` instead.

Additionally this patch turn `LIBCXX_ENABLE_ASSERTIONS`  off by default,
because the standard library should not be aborting user programs unless explicitly asked to.

llvm-svn: 294107
2017-02-04 23:22:28 +00:00
Saleem Abdulrasool 87996f906a config: prevent the re-definition of a macro
This causes unnecessary warnings when building with `cl`.  Newer
versions of the C standard permit the redefinition of the macro to the
same value (which is the case here), unfortunately, `cl` does not yet
implement this.  Add a check to prevent the redefinition.

llvm-svn: 293439
2017-01-29 18:16:33 +00:00
Marshall Clow 3a3c09c5dd Use the new __has_feature(cxx_constexpr_string_builtins) for detection of the C-string intrinsics for constexpr support in std::char_traits. Thanks to Richard for the intrisic support.
llvm-svn: 293154
2017-01-26 06:58:29 +00:00
Eric Fiselier f9e7bf3a43 Revert "[libcxx] Never use <cassert> within libc++"
This reverts commit r292883. Unfortunately <string_view> uses
_LIBCPP_ASSERT in a way which is not compatible with the C++11 dylib
build. I'll investigate more tomorrow.

llvm-svn: 292923
2017-01-24 12:26:01 +00:00
Eric Fiselier d5fd7d7ea1 [libcxx] Never use <cassert> within libc++
Summary:
It is my opinion that libc++ should never use `<cassert>`, including in the `dylib`. This patch remove all uses of `assert` from within libc++ and replaces most of them with `_LIBCPP_ASSERT` instead.

Additionally this patch turn `LIBCXX_ENABLE_ASSERTIONS`  off by default, because the standard library should not be aborting user programs unless explicitly asked to.

Reviewers: mclow.lists, compnerd, smeenai

Reviewed By: mclow.lists

Subscribers: mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D29063

llvm-svn: 292883
2017-01-24 04:57:33 +00:00
Eric Fiselier 014d9491ff Manually force the use of __decltype in C++03 with Clang 3.4.
<string> uses `decltype` in a way incompatible with `__typeof__`.
This is problematic when compiling <string> with Clang 3.4 because
even though it provides `__decltype` libc++ still used `__typeof__`
because clang 3.4 doesn't provide __is_identifier which libc++
uses to detect __decltype.

This patch manually detects Clang 3.4 and properly configures
for it.

llvm-svn: 292833
2017-01-23 21:41:13 +00:00
Marshall Clow c68c62c97f Fixed a typo in __config that prevented the aligned new/delete tests from passing on Mac OS.
llvm-svn: 292822
2017-01-23 19:51:54 +00:00
Eric Fiselier efea04512c Disable aligned new/delete on Apple platforms without posix_memalign
Summary:
This patch disables the aligned new/delet overloads on Apple platforms without `posix_memalign`. This fixes libc++.dylib build regressions on such platforms.
This fixes http://llvm.org/PR31448.

This patch should also be merged into the 4.0 release branch


Reviewers: mclow.lists, rsmith, dexonsmith, jeremyhu

Reviewed By: mclow.lists

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D28931

llvm-svn: 292564
2017-01-20 01:47:26 +00:00
Eric Fiselier b8c2a52266 Adjust msvc_stdlib_force_include.hpp to handle clang++
Summary: This patch adjusts the newly added `msvc_stdlib_force_include.hpp` so that it also works when used with `clang++`.

Reviewers: STL_MSFT

Reviewed By: STL_MSFT

Differential Revision: https://reviews.llvm.org/D28917

llvm-svn: 292539
2017-01-19 23:48:05 +00:00
Eric Fiselier 11f6045379 Add ABI option to remove recently inlined __shared_count functions from the library.
In order to allow inlining of previously out-of-line functions without an ABI break
libc++ provides legacy definitions in the dylib that old programs can
continue to use. Unfortunatly Windows link.exe detects this hack and diagnoses the duplicate
definitions.

This patch disable the duplicate definitions on Windows by adding an ABI option
which disables all "legacy out-of-line symbols"

llvm-svn: 292190
2017-01-17 03:16:26 +00:00
Eric Fiselier b43f17c835 Fix std::tuples EBO when targeting the MSVC ABI.
MSVC/clang-cl doesn't do a full EBO unless __declspec(empty_bases)
is applied to the derived type. This causes certain tuple tests
to fail.

This patch adds the empty_bases attribute to __tuple_impl in order
for tuple to fully provide the EBO.

llvm-svn: 292159
2017-01-16 21:15:08 +00:00
Eric Fiselier fc26379a84 [libc++] Introduce _LIBCPP_EXTERN_VIS to fix __libcpp_debug_function link errors
Summary: On Windows tests that use `_LIBCPP_ASSERT` fail to link because the assertion handler function isn't correctly exported from the libc++ dylib. This patch fixes the dll import/export issues by introducing a new visibility macro `_LIBCPP_EXTERN_VIS` for use on external variables.

Reviewers: compnerd, smeenai, EricWF

Reviewed By: EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D28728

llvm-svn: 292158
2017-01-16 21:01:00 +00:00
Eric Fiselier 1e33f12a7c Use __is_identifier to detect Clang extensions instead of __has_extension.
When -pedantic-errors is specified `__has_extension(<feature>)` is always
false when it would otherwise be true. This causes C++03 <atomic> to break
along with other issues.

This patch avoids the above problem by using __is_identifier(...) instead since
it is not affected by -pedantic-errors. For example instead of checking for
__has_extension(c_atomics) we now check `!__is_identifier(_Atomic)`, which
is only true when _Atomic is not a keyword provided by the compiler.

This patch applies similar changes to the detection logic for __decltype and
__nullptr as well.

Note that it does not apply this change to the C++03
`static_assert` macro since -Wc11-extensions warnings generated by expanding
that macro will appear in user code, and will not be suppressed as part of a
system header.

llvm-svn: 291995
2017-01-14 04:27:58 +00:00
Eric Fiselier faf2a81380 Diagnose invalid memory orderings in <atomic>
llvm-svn: 291976
2017-01-13 23:45:39 +00:00
Eric Fiselier b1e7a12ee8 Add _LIBCPP_DIAGNOSE_WARNING and _LIBCPP_DIAGNOSE_ERROR macros.
Clang recently added a `diagnose_if(cond, msg, type)` attribute
which can be used to generate diagnostics when `cond` is a constant
expression that evaluates to true. Otherwise no attribute has no
effect.

This patch adds _LIBCPP_DIAGNOSE_ERROR/WARNING macros which
use this new attribute. Additionally this patch implements
a diagnostic message when a non-const-callable comparator is
given to a container.

Note: For now the warning version of the diagnostic is useless
within libc++ since warning diagnostics are suppressed by the
system header pragma. I'm going to work on fixing this.

llvm-svn: 291961
2017-01-13 22:02:08 +00:00
Eric Fiselier d066f3af61 Update version to 5.0
llvm-svn: 291928
2017-01-13 18:29:56 +00:00
Eric Fiselier c8bd38a15d Revert "Rework fix for PR19460 - Use explicit bool as an extension instead."
This reverts commit 3a1b90a866b6d5d62a5f37fbfb3a1ee36cc70dd1.

llvm-svn: 291921
2017-01-13 18:03:46 +00:00
Marshall Clow 3d4cc68b8b Add new macro _LIBCPP_BUILTIN_MEMCMP_ISCONSTEXPR to use in std::char_traits.
This tells whether or not the builtin function __builtin_memcmp is constexpr.
Only defined for clang 4.0 and later, and not true for any shipping version of Apple's clang.

llvm-svn: 291773
2017-01-12 16:25:07 +00:00
Saleem Abdulrasool 6d7d0bec10 provide Win32 native threading
Add an implementation for the Win32 threading model as a backing API for
the internal c++ threading interfaces.  This uses the Fls* family for
the TLS (which has the support for adding termination callbacks),
CRITICAL_SECTIONs for the recursive mutex, and Slim Reader/Writer locks
(SRW locks) for non-recursive mutexes.  These APIs should all be
available on Vista or newer.

llvm-svn: 291333
2017-01-07 03:07:45 +00:00
Eric Fiselier 330fe0170f Add _LIBCPP_ABI_[ITANIUM|MICROSOFT] macros.
This patch adds a libc++ configuration macro for the ABI we
are targeting, either Itanium or Microsoft. For now we configure
for the Microsoft ABI when on Windows with a compiler that defines
_MSC_VER. However this is only temporary until Clang implements
builtin macros we can use.

llvm-svn: 291329
2017-01-07 02:43:58 +00:00
Eric Fiselier 72cffa5583 Fix breakage caused when _LIBCPP_HAS_THREAD_API_PTHREAD is manually defined
llvm-svn: 291298
2017-01-06 23:15:16 +00:00
Eric Fiselier 541f9e2830 Add _LIBCPP_COMPILER_[CLANG|GCC|MSVC|IBM] macros.
This patch refactors the compiler detection done in `__config` by creating a
set of `_LIBCPP_COMPILER_<TYPE>` macros. The goal of this patch is to make
it easier to detect what compiler is being used outside of `__config`.

Additionally this patch removes workarounds for GCC in `__bit_reference`. I
tested GCC 4.8 and 4.9 without the workaround and neither seemed to need it
anymore.

llvm-svn: 291286
2017-01-06 21:42:58 +00:00
Eric Fiselier 8f56dedb5f Replace _LIBCPP_HAS_NO_DELETED_FUNCTIONS with _LIBCPP_CXX03_LANG
llvm-svn: 291278
2017-01-06 20:58:25 +00:00
Eric Fiselier 00f6beaed4 [libc++] Cleanup and document <__threading_support>
Summary:
This patch attempts to clean up the macro configuration mess in `<__threading_support>`, specifically the mess involving external threading variants. Additionally this patch adds design documentation for `<__threading_support>` and the configuration macros it uses.

The primary change in this patch is separating the idea of an "external API" provided by `<__external_threading>` and the idea of having an external threading library. Now `_LIBCPP_HAS_THREAD_API_EXTERNAL` means that libc++ should use `<__external_threading>` and that the header is expected to exist.  Additionally the new macro `_LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL` is now used to configure for using an "external library"  with the default threading API.

Reviewers: compnerd, rmaprath

Subscribers: smeenai, cfe-commits, mgorny

Differential Revision: https://reviews.llvm.org/D28316

llvm-svn: 291275
2017-01-06 20:05:40 +00:00
Eric Fiselier 528600c41f Fix std::pointer_safety type in ABI v2
In the C++ standard `std::pointer_safety` is defined
as a C++11 strongly typed enum. However libc++ currently defines
it as a class type which simulates a C++11 enumeration. This
can be detected in valid C++ code.

This patch introduces an the _LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE ABI option.
When defined `std::pointer_safety` is implemented as an enum type.
Unfortunatly this also means it can no longer be provided as an extension
in C++03.

Additionally this patch moves the definition for `get_pointer_safety()`
out of the dylib, and into the headers. New usages of `get_pointer_safety()`
will now use the inline version instead of the dylib version. However in
order to keep the dylib ABI compatible the old definition is explicitly
compiled into it.

llvm-svn: 291046
2017-01-05 01:15:42 +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
Saleem Abdulrasool 07b65ed040 config: MSVC 19+ has unicode chars
MSVC 19+ and clang-cl with emulation version >= 19.00 will provide
char{16,32}_t as builtin types.  Adjust the configuration accordingly.

llvm-svn: 290940
2017-01-04 05:49:59 +00:00
Saleem Abdulrasool 86eebc5b65 Refactor bitscan64 check
Introduce a `_LIBCPP_HAS_BITSCAN64` macro to specify if the 64-bit
variant of the bitscan family of APIs is available.  This avoids
duplicating the check in the support header.

llvm-svn: 290924
2017-01-04 01:53:24 +00:00
Saleem Abdulrasool b2826a1ddc clean up use of _WIN32
Replace the use of _WIN32 in libc++. Replace most use with a C runtime
check _LIBCPP_MSVCRT or the new _LIBCPP_WIN32 to indicate that we are
using the Win32 API. Use a new _LIBCPP_WCHAR_IS_UCS2 to indicate that we
are on an environment that has a short wchar_t.

llvm-svn: 290910
2017-01-03 21:53:51 +00:00
Eric Fiselier 9aca97d6f9 Introduce _LIBCPP_DEPRECATED_ABI_EXTERNAL_ERROR_CATEGORY_CONSTRUCTOR ABI option.
Currently libc++ compiles a special version of error_category()
into the dylib. This definition is no longer needed, and doesn't
work on Windows due to dllimport/dllexport semantics.

For those reasons this patch introduces an option to
disable/enable this definition. By default the definition
is provided in ABI v1 except on windows. This patch
also addresses D28210.

llvm-svn: 290840
2017-01-02 22:17:51 +00:00
Eric Fiselier e9735f17e0 Rework fix for PR19460 - Use explicit bool as an extension instead.
In the previous fix I used a PMF type as a semi-safe bool type in C++03.
However immediately after committing I realized clang offered explicit
conversion operators as an extension. This patch removes the old fix and
enables _LIBCPP_EXPLICIT using __has_extension instead.

This change also affects the following other classes, which have
'_LIBCPP_EXPLICIT operator bool()'.

* shared_ptr
* unique_ptr
* error_condition
* basic_ios
* function (already C++11 only)
* istream::sentry
* experimental::string_view.

In all of the above cases I believe it is safe to enable the extension, except
in the experimental::string_view case. There seem to be some Clang bugs
affecting the experimental::string_view conversion to std::basic_string. To
work around that I manually disabled _LIBCPP_EXPLICIT in that case.

llvm-svn: 290831
2017-01-02 20:15:33 +00:00
Eric Fiselier 1b06dfe7b7 Recommit r290750: Fix PR19460 - std::ios is convertible to int.
There were two problems with the initial fix.

1. The added tests flushed out that we misconfigured _LIBCPP_EXPLICIT with GCC.

2. Because the boolean type was a member function template it caused weird link
   errors. I'm assuming due to the vague linkage rules. This time the bool type
   is a non-template member function pointer. That seems to have fixed the
   failing tests. Plus it will end up generating less symbols overall, since
   the bool type is no longer per instantiation.

original commit message below
-----------------------------

std::basic_ios has an operator bool(). In C++11 and later
it is explicit, and only allows contextual implicit conversions.

However explicit isn't available in C++03 which causes std::istream (et al)
to have an implicit conversion to int. This can easily cause ambiguities
when calling operator<< and operator>>.

This patch uses a "bool-like" type in C++03 to work around this. The
"bool-like" type is an arbitrary pointer to member function type. It
will not convert to either int or void*, but will convert to bool.

llvm-svn: 290754
2016-12-30 14:05:52 +00:00
Ed Schouten 0a92402436 Remove mblen(), mbtowc() and wctomb() from the thread-unsafe functions.
Back in r240527 I added a knob to prevent thread-unsafe functions from
being exposed. mblen(), mbtowc() and wctomb() were also added to this
list, as the latest issue of POSIX doesn't require these functions to be
thread-safe.

It turns out that the only circumstance in which these functions are not
thread-safe is in case they are used in combination with state-dependent
character sets (e.g., Shift-JIS). According to Austin Group Bug 708,
these character sets "[...] are mostly a relic of the past and which
were never supported on most POSIX systems".

Though in many cases the use of these functions can be prevented by
using the reentrant counterparts, they are the only functions that allow
you to query whether the locale's character set is state-dependent. This
means that omitting these functions removes actual functionality.

Let's be a bit less pedantic and drop the guards around these functions.

Links:
http://austingroupbugs.net/view.php?id=708
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2037.htm

Reviewed by:	ericwf
Differential Revision:	https://reviews.llvm.org/D21436

llvm-svn: 290748
2016-12-30 10:44:00 +00:00
Eric Fiselier 99940720c8 Fix typo in comment
llvm-svn: 290666
2016-12-28 11:09:18 +00:00
Eric Fiselier b9565705bd Fix ABI incompatible C++03 nullptr_t
In C++03 libc++ emulates nullptr_t using a class, and #define's nullptr.
However this makes nullptr_t mangle differently between C++03 and C++11.
This breaks any function ABI which takes nullptr_t.

Thanfully Clang provides __nullptr in all dialects. This patch adds
an ABI option to switch to using __nullptr in C++03. In a perfect world
I would like to turn this on by default, since it's just ABI breaking fix
to an ABI breaking bug.

llvm-svn: 290662
2016-12-28 09:50:23 +00:00
Eric Fiselier 687d3213f0 Implement a throwing version of _LIBCPP_ASSERT.
This patch implements changes to allow _LIBCPP_ASSERT to throw on failure
instead of aborting. The main changes needed to do this are:

1. Change _LIBCPP_ASSERT to call a handler via a replacable function pointer
   instead of calling abort directly. Additionally this patch implements two
   handler functions, one which aborts and another that throws an exception.

2. Add _NOEXCEPT_DEBUG macro for disabling noexcept spec on function which
   contain _LIBCPP_ASSERT. This is required in order to prevent assertion
   failures throwing through a noexcept function. This macro has no effect
   unless _LIBCPP_DEBUG_USE_EXCEPTIONS is defined.

Having a non-aborting _LIBCPP_ASSERT is very important to allow sane testing of
debug mode. Currently we can only have one test case per file, since the test
case will cause the program to abort. Testing debug mode this way would require
thousands of test files, most of which would be 95% boiler plate. I don't think
this is a feasible strategy. Fortunately using a throwing debug handler solves
these issues.

Additionally this patch rewrites the documentation for debug mode.

llvm-svn: 290651
2016-12-28 04:58:52 +00:00