[libc++][hardening] Classify assertions related to leaks and syscalls. (#77164)

Introduce two new categories:
- `_LIBCPP_ASSERT_VALID_DEALLOCATION`;
- `_LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL`.

[libc++] Format the code base (#74334)

This patch runs clang-format on all of libcxx/include and libcxx/src, in
accordance with the RFC discussed at [1]. Follow-up patches will format
the benchmar

[libc++] Format the code base (#74334)

This patch runs clang-format on all of libcxx/include and libcxx/src, in
accordance with the RFC discussed at [1]. Follow-up patches will format
the benchmarks, the test suite and remaining parts of the code. I'm
splitting this one into its own patch so the diff is a bit easier to
review.

This patch was generated with:

find libcxx/include libcxx/src -type f \
| grep -v 'module.modulemap.in' \
| grep -v 'CMakeLists.txt' \
| grep -v 'README.txt' \
| grep -v 'libcxx.imp' \
| grep -v '__config_site.in' \
| xargs clang-format -i

A Git merge driver is available in libcxx/utils/clang-format-merge-driver.sh
to help resolve merge and rebase issues across these formatting changes.

[1]: https://discourse.llvm.org/t/rfc-clang-formatting-all-of-libc-once-and-for-all

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[libc++] Handle threads-related .cpp files like we do all other source files (#71100)

Source files in libc++ are added to the CMake targets only if they are
required by the configuration. We do thi

[libc++] Handle threads-related .cpp files like we do all other source files (#71100)

Source files in libc++ are added to the CMake targets only if they are
required by the configuration. We do this pretty consistently for all
configurations like no-filesystem, no-random-device, etc. but we didn't
do it for no-threads. This patch makes this consistent for no-threads,
which is helpful in reducing the amount of work required to port libc++
to some platforms without threads.

Indeed, with the previous approach, several threads-related source files
would end up including headers that might fail to compile properly on
some platforms. This issue is sidestepped entirely by making the
approach for no-threads consistent with the other configurations.

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[libc++][NFC] Clean up std::__call_once

__call_once is large and cluttered with #ifdef preprocessor guards. This
cleans it up a bit by using an exception guard instead of try-catch.

Differential Re

[libc++][NFC] Clean up std::__call_once

__call_once is large and cluttered with #ifdef preprocessor guards. This
cleans it up a bit by using an exception guard instead of try-catch.

Differential Revision: https://reviews.llvm.org/D112319
Co-authored-by: Louis Dionne <ldionne.2@gmail.com>

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[libc++][NFC] Introduce named states in std::call_once (#66289)

This idea is extracted from https://reviews.llvm.org/D112319. It makes
the code easier to read but doesn't otherwise change any funct

[libc++][NFC] Introduce named states in std::call_once (#66289)

This idea is extracted from https://reviews.llvm.org/D112319. It makes
the code easier to read but doesn't otherwise change any functionality.

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[libc++] Move __thread_id out of <__threading_support>

This makes <__threading_support> closer to handling only the bridge
between the system's implementation of threading and the rest of libc++.

D

[libc++] Move __thread_id out of <__threading_support>

This makes <__threading_support> closer to handling only the bridge
between the system's implementation of threading and the rest of libc++.

Differential Revision: https://reviews.llvm.org/D154464

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[libc++][hardening][NFC] Introduce `_LIBCPP_ASSERT_UNCATEGORIZED`.

Replace most uses of `_LIBCPP_ASSERT` with
`_LIBCPP_ASSERT_UNCATEGORIZED`.

This is done as a prerequisite to introducing hardened

[libc++][hardening][NFC] Introduce `_LIBCPP_ASSERT_UNCATEGORIZED`.

Replace most uses of `_LIBCPP_ASSERT` with
`_LIBCPP_ASSERT_UNCATEGORIZED`.

This is done as a prerequisite to introducing hardened mode to libc++.
The idea is to make enabling assertions an opt-in with (somewhat)
fine-grained controls over which categories of assertions are enabled.
The vast majority of assertions are currently uncategorized; the new
macro will allow turning on `_LIBCPP_ASSERT` (the underlying mechanism
for all kinds of assertions) without enabling all the uncategorized
assertions (in the future; this patch preserves the current behavior).

Differential Revision: https://reviews.llvm.org/D153816

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[libc++] Remove symbols for a std::allocator_arg & friends from the dylib

This patch removes the symbols defined in the library for std::allocator_arg,
std::defer_lock, std::try_to_lock, std::adopt_

[libc++] Remove symbols for a std::allocator_arg & friends from the dylib

This patch removes the symbols defined in the library for std::allocator_arg,
std::defer_lock, std::try_to_lock, std::adopt_lock, and std::piecewise_construct.
Those were defined in the library because we provided them in C++03 as an
extension, and in C++03 it was impossible to define them as `constexpr`
variables, like in the spec.

This is technically an ABI break since we are removing symbols from the
library. However, in practice, only programs compiled in C++03 mode who
take the address of those objects (or pass them as a reference) will have
an undefined ref to those symbols. In practice, this is expected to be
rare. First, those are C++11 features that we happen to provide in C++03,
and only the C++03 definition can potentially lead to code referencing
the dylib definition. So any code that is using these objects but compiling
in C++11 mode (as they should) is not at risk. Second, all uses of these
types in the library is done by passing those types by value to a function
that can get inlined. Since they are empty types, the compiler won't
generate an undefined reference if passed by value, since there's nothing
to pass anyway.

Long story short, the risk for code actually containing an undefined
reference to one of these types is rather small (but non-zero). I also
couldn't find any app on the App Store that referenced these symbols,
which supports my impression that this won't be an issue in practice.

Differential Revision: https://reviews.llvm.org/D145587

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[libc++] Granularize system_error.

Reviewed By: #libc, philnik

Differential Revision: https://reviews.llvm.org/D147853

[libc++][NFC] Rename _LIBCPP_NO_EXCEPTIONS to _LIBCPP_HAS_NO_EXCEPTIONS

Other macros that disable parts of the library are named `_LIBCPP_HAS_NO_WHATEVER`.

Reviewed By: ldionne, Mordante, #libc

Sp

[libc++][NFC] Rename _LIBCPP_NO_EXCEPTIONS to _LIBCPP_HAS_NO_EXCEPTIONS

Other macros that disable parts of the library are named `_LIBCPP_HAS_NO_WHATEVER`.

Reviewed By: ldionne, Mordante, #libc

Spies: libcxx-commits, smeenai

Differential Revision: https://reviews.llvm.org/D143163

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[libc++] Move everything related solely to _LIBCPP_ASSERT to its own file

This is the first step towards disentangling the debug mode and assertions
in libc++. This patch doesn't make any functional

[libc++] Move everything related solely to _LIBCPP_ASSERT to its own file

This is the first step towards disentangling the debug mode and assertions
in libc++. This patch doesn't make any functional change: it simply moves
_LIBCPP_ASSERT-related stuff to its own file so as to make it clear that
libc++ assertions and the debug mode are different things. Future patches
will make it possible to enable assertions without enabling the debug
mode.

Differential Revision: https://reviews.llvm.org/D119769

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[libc++] Replace `#include ""` with `<>` in libcxx/src/. NFCI.

Our best guess is that the two syntaxes should have exactly equivalent
effects, so, let's be consistent with what we do in libcxx/inclu

[libc++] Replace `#include ""` with `<>` in libcxx/src/. NFCI.

Our best guess is that the two syntaxes should have exactly equivalent
effects, so, let's be consistent with what we do in libcxx/include/.

I've left `#include "include/x.h"` and `#include "../y.h"` alone
because I'm less sure that they're interchangeable, and they aren't
inconsistent with libcxx/include/ because libcxx/include/ never
does that kind of thing.

Also, use the `_LIBCPP_PUSH_MACROS/POP_MACROS` dance for `<__undef_macros>`,
even though it's technically unnecessary in a standalone .cpp file,
just so we have consistently one way to do it.

Differential Revision: https://reviews.llvm.org/D119561

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[libc++] Rename *SAFE_STATIC to *CONSTINIT, and normalize its uses.

In src/, most files can use `constinit` directly because they're always
compiled with C++20. But some files, like "libcxxabi/src/f

[libc++] Rename *SAFE_STATIC to *CONSTINIT, and normalize its uses.

In src/, most files can use `constinit` directly because they're always
compiled with C++20. But some files, like "libcxxabi/src/fallback_malloc.cpp",
can't, because they're `#include`d directly from test cases in libcxxabi/test/
and therefore must (currently) compile as C++03. We might consider refactoring
those offending tests, or at least marking them `UNSUPPORTED: c++03`.

Differential Revision: https://reviews.llvm.org/D119264

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[runtimes][NFC] Remove filenames at the top of the license notice

We've stopped doing it in libc++ for a while now because these names
would end up rotting as we move things around and copy/paste st

[runtimes][NFC] Remove filenames at the top of the license notice

We've stopped doing it in libc++ for a while now because these names
would end up rotting as we move things around and copy/paste stuff.
This cleans up all the existing files so as to stop the spreading
as people copy-paste headers around.

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[libc++] NFC: Normalize `#endif //` comment indentation

[libc++/abi] Replace uses of _NOEXCEPT in src/ by noexcept

We always build the libraries in a Standard mode that supports noexcept,
so there's no need to use the _NOEXCEPT macro.

Differential Revis

[libc++/abi] Replace uses of _NOEXCEPT in src/ by noexcept

We always build the libraries in a Standard mode that supports noexcept,
so there's no need to use the _NOEXCEPT macro.

Differential Revision: https://reviews.llvm.org/D97700

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[libcxx{,abi}] Emit deplibs only when detected by CMake

This is a followup to 35bc5276ca3. It fixes the dependent libs usage
in libcxx and libcxxabi to link pthread and rt libraries only if CMake
d

[libcxx{,abi}] Emit deplibs only when detected by CMake

This is a followup to 35bc5276ca3. It fixes the dependent libs usage
in libcxx and libcxxabi to link pthread and rt libraries only if CMake
detects them, rather than based on explicit platform blacklist.

Differential Revision: https://reviews.llvm.org/D70888

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[libc++] Take 2: Implement LWG 2510

Summary:
LWG2510 makes tag types like allocator_arg_t explicitly default
constructible instead of implicitly default constructible. It also
makes the constructors

[libc++] Take 2: Implement LWG 2510

Summary:
LWG2510 makes tag types like allocator_arg_t explicitly default
constructible instead of implicitly default constructible. It also
makes the constructors for std::pair and std::tuple conditionally
explicit based on the explicit-ness of the default constructibility
for the pair/tuple's elements.

This was previously committed as r372777 and reverted in r372832 due to
the commit breaking LLVM's build in C++14 mode. This issue has now been
addressed.

Reviewers: mclow.lists

Subscribers: christof, jkorous, dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D65161

llvm-svn: 372983

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Revert r372777: [libc++] Implement LWG 2510 and its follow-ups

This also reverts:
- r372778: [libc++] Implement LWG 3158
- r372782: [libc++] Try fixing tests that fail on GCC 5 and older
- r37278

Revert r372777: [libc++] Implement LWG 2510 and its follow-ups

This also reverts:
- r372778: [libc++] Implement LWG 3158
- r372782: [libc++] Try fixing tests that fail on GCC 5 and older
- r372787: Purge mentions of GCC 4 from the test suite

Reason: the change breaks compilation of LLVM with libc++, for details see
http://lists.llvm.org/pipermail/libcxx-dev/2019-September/000599.html

llvm-svn: 372832

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[libc++] Implement LWG 2510

Summary:
LWG2510 makes tag types like allocator_arg_t explicitly default
constructible instead of implicitly default constructible. It also
makes the constructors for std

[libc++] Implement LWG 2510

Summary:
LWG2510 makes tag types like allocator_arg_t explicitly default
constructible instead of implicitly default constructible. It also
makes the constructors for std::pair and std::tuple conditionally
explicit based on the explicit-ness of the default constructibility
for the pair/tuple's elements.

Reviewers: mclow.lists, EricWF

Subscribers: christof, jkorous, dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D65161

llvm-svn: 372777

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Fix thread comparison by making sure we never pass our special 'not a thread' value to the underlying implementation. Fixes PR#42918.

llvm-svn: 368916

Rework recursive_timed_mutex so that it uses __thread_id instead of using the lower-level __libcpp_thread_id. This is prep for fixing PR42918. Reviewed as https://reviews.llvm.org/D65895

llvm-svn: 3

Rework recursive_timed_mutex so that it uses __thread_id instead of using the lower-level __libcpp_thread_id. This is prep for fixing PR42918. Reviewed as https://reviews.llvm.org/D65895

llvm-svn: 368867

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[runtimes] Don't depend on libpthread on Android

r362048 added support for ELF dependent libraries, but broke Android
build since Android does not have libpthread. Remove the dependency on
the Andro

[runtimes] Don't depend on libpthread on Android

r362048 added support for ELF dependent libraries, but broke Android
build since Android does not have libpthread. Remove the dependency on
the Android build.

Differential Revision: https://reviews.llvm.org/D65098

llvm-svn: 366734

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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

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

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[runtimes] Check if pragma comment(lib, ...) is supported first

This fixes the issue introduced by r362048 where we always use
pragma comment(lib, ...) for dependent libraries when the compiler
is C

[runtimes] Check if pragma comment(lib, ...) is supported first

This fixes the issue introduced by r362048 where we always use
pragma comment(lib, ...) for dependent libraries when the compiler
is Clang, but older Clang versions don't support this pragma so
we need to check first if it's supported before using it.

llvm-svn: 362055

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