Summary:
Android added quick_exit()/at_quick_exit() in API level 21,
aligned_alloc() in API level 28, and timespec_get() in API level 29,
but has the other C11 features at all API levels (since they're basically
just coming from clang directly).
_LIBCPP_HAS_QUICK_EXIT and _LIBCPP_HAS_TIMESPEC_GET already existed,
so we can reuse them. (And use _LIBCPP_HAS_TIMESPEC_GET in a few more
places where _LIBCPP_HAS_C11_FEATURES has been used as a proxy. This
isn't correct for Android.)
_LIBCPP_HAS_ALIGNED_ALLOC is added, to cover aligned_alloc() (obviously).
Add a missing std:: before aligned_alloc in a cstdlib test, and remove a
couple of !defined(_WIN32)s now that we're explicitly testing
TEST_HAS_ALIGNED_ALLOC rather than TEST_HAS_C11_FEATURES.
Reviewers: danalbert, EricWF, mclow.lists
Reviewed By: danalbert
Subscribers: srhines, christof, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D69929
Summary:
In D67316 we added `_LIBCPP_C_HAS_NO_GETS` to signal that the C library
does not provide `gets()`, and added a test for FreeBSD 13 or higher,
using the compiler-defined `__FreeBSD__` macro.
Unfortunately this did not work that well for FreeBSD's own CI process,
since the gcc compilers used for some architectures define `__FreeBSD__`
to match the build host, not the target.
Instead, we should use the `__FreeBSD_version` macro from the userland
header `<osreldate.h>`, which is more fine-grained. See also
<https://reviews.freebsd.org/D22034>.
Reviewers: EricWF, mclow.lists, emaste, ldionne
Reviewed By: emaste, ldionne
Subscribers: dexonsmith, bsdjhb, krytarowski, christof, ldionne, libcxx-commits
Differential Revision: https://reviews.llvm.org/D69174
llvm-svn: 375340
Summary: The implementation of P1152R4 in Clang has resulted in some deprecation warnings appearing in the libc++ and libc++abi test suite. Fix or suppress these warnings.
Reviewers: mclow.lists, EricWF
Subscribers: christof, ldionne, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D68879
llvm-svn: 375307
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
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
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
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
[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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Dan Albert