This allows including once_flag directly from <__locale> instead of
depending on all of <mutex>, which requires threading. In turn, this
makes it easier to support locales on platforms without threading.
Drive-by change: clang-format once_flag.h and use _LIBCPP_HIDE_FROM_ABI
Differential Revision: https://reviews.llvm.org/D155487
These macros are always defined identically, so we can simplify the code a bit by merging them.
Reviewed By: ldionne, #libc
Spies: libcxx-commits, krytarowski, smeenai
Differential Revision: https://reviews.llvm.org/D152652
This patch makes global tag variables like std::allocator_arg
conform to C++17 by defining them as inline constexpr variables.
This is possible without creating an ODR violation now that we don't
define strong definitions of those variables in the shared library
anymore.
Differential Revision: https://reviews.llvm.org/D145589
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
We already have a clang-tidy check for making sure that `_LIBCPP_HIDE_FROM_ABI` is on free functions. This patch extends this to class members. The places where we don't check for `_LIBCPP_HIDE_FROM_ABI` are classes for which we have an instantiation in the library.
Reviewed By: ldionne, Mordante, #libc
Spies: jplehr, mikhail.ramalho, sstefan1, libcxx-commits, krytarowski, miyuki, smeenai
Differential Revision: https://reviews.llvm.org/D142332
This also updates the moved code to the current style. (i.e. `_VSTD` -> `std`, `_LIBCPP_INLINE_VISIBILITY` -> `_LIBCPP_HIDE_FROM_ABI`, clang-format).
Reviewed By: Mordante, #libc, EricWF
Spies: arichardson, libcxx-commits, mikhail.ramalho
Differential Revision: https://reviews.llvm.org/D146228
