This patch removes the base template implementation for std::char_traits.
If my reading of http://eel.is/c++draft/char.traits is correct, the
Standard mandates that the library provides specializations for several
types like char and wchar_t, but not any implementation in the base
template. Indeed, such an implementation is bound to be incorrect for
most types anyways, since things like `eof()` and `int_type` will definitely
have to be customized.
Since the base template implementation should not have worked for anyone,
this shouldn't be a breaking change (I expect that anyone defining a
custom character type today will already have to provide their own
specialization of char_traits). However, since we're aware of some users
of char_traits for unsigned char and signed char, we're keeping those two
specializations around for two releases to give people some time to migrate.
Differential Revision: https://reviews.llvm.org/D138307
The ctype mask for newlib/picolibc is fully saturated, so __regex_word
has to overlap with one of the values. This commit uses the same workaround
as bionic did (uint16_t for char_class_type inside regex_traits). It
should be possible to have libc++ provide the default rune table instead,
but that will require a new mechanism to detect newlib inside __config
since the header defining the newlib/picolibc macros has not been included
yet inside __config. Doing it this way also avoids duplicating the ctype
table for newlib, reducing the global data size.
Differential Revision: https://reviews.llvm.org/D138195
This doesn't affect our ABI because `std::string::substr()` isn't in the dylib and the mangling of `substr() const` and `substr() const&` are different.
Reviewed By: ldionne, Mordante, var-const, avogelsgesang, #libc
Spies: arphaman, huixie90, libcxx-commits
Differential Revision: https://reviews.llvm.org/D131668
This commit deprecates <experimental/memory_resource> since we now ship the non-experimental
version of it. Per the libc++ policy [1], we are deprecating the experimental feature in
upcoming LLVM 16 and will remove it entirely in LLVM 18.
[1]: https://libcxx.llvm.org/DesignDocs/ExperimentalFeatures.html#id4
Reviewed By: ldionne, #libc
Spies: EricWF, libcxx-commits
Differential Revision: https://reviews.llvm.org/D136245
We've said that we'll remove `std::function` from C++03 in LLVM 16, so we might as well do it now before we forget.
Reviewed By: ldionne, #libc, Mordante
Spies: jloser, Mordante, libcxx-commits
Differential Revision: https://reviews.llvm.org/D135868
Implements:
- P2291R3 Add Constexpr Modifiers to Functions to_chars and from_chars for
Integral Types in <charconv> Header
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D131317
This patch is the rebase and squash of three earlier patches.
It supersedes all three of them.
- D47111: experimental monotonic_buffer_resource.
- D47358: experimental pool resources.
- D47360: Copy std::experimental::pmr to std::pmr.
The significant difference between this patch and the-sum-of-those-three
is that this patch does not add `std::experimental::pmr::monotonic_buffer_resource`
and so on. This patch simply adds the C++17 standard facilities, and
leaves the `std::experimental` namespace entirely alone.
Differential Revision: https://reviews.llvm.org/D89057
Implementing the paper
P2291R3 Add Constexpr Modifiers to Functions to_chars and from_chars for
Integral Types in <charconv> Header
Gives issues in language versions prior to C++17. As suggested in
D131855 disable the code prior to C++17. This removes libc++'s
extension.
Reviewed By: ldionne, #libc_vendors, #libc, philnik
Differential Revision: https://reviews.llvm.org/D133216
This is a breaking change. If you were passing one of those three runtimes
in LLVM_ENABLE_PROJECTS, you need to start passing them in LLVM_ENABLE_RUNTIMES
instead. The runtimes in LLVM_ENABLE_RUNTIMES will start being built using
the "bootstrapping build" instead, which means that they will be built
using the just-built Clang. This is usually what you wanted anyway.
If you were using LLVM_ENABLE_PROJECTS=all with the explicit goal of
building these three runtimes, you can now use LLVM_ENABLE_RUNTIMES=all
and these runtimes will be built using the bootstrapping build.
NOTE: This is a re-application of 887b8bd733 which had been reverted
in 6b03a4fea0 because it broke the Sphinx documentation publishers.
The Sphinx documentation publishers have now been moved to using
the runtimes build, so this should not be an issue anymore.
Differential Revision: https://reviews.llvm.org/D132480
Now that all jobs have moved over to the new style of Lit configuration,
we can remove all traces of the legacy testing configuration system.
This includes:
- Cache settings that are not honored or useful anymore
- Several CMake options that were only useful in the context of the
legacy Lit configuration system
- A bunch of Python support code that is not used anymore
- The legacy lit.cfg.in files themselves
Differential Revision: https://reviews.llvm.org/D134650
This is a breaking change. If you were passing one of those three runtimes
in LLVM_ENABLE_PROJECTS, you need to start passing them in LLVM_ENABLE_RUNTIMES
instead. The runtimes in LLVM_ENABLE_RUNTIMES will start being built using
the "bootstrapping build" instead, which means that they will be built
using the just-built Clang. This is usually what you wanted anyway.
If you were using LLVM_ENABLE_PROJECTS=all with the explicit goal of
building these three runtimes, you can now use LLVM_ENABLE_RUNTIMES=all
and these runtimes will be built using the bootstrapping build.
Differential Revision: https://reviews.llvm.org/D132480
In https://llvm.org/D56913, we added an emulation for the __atomic_always_lock_free
compiler builtin when compiling in Freestanding mode. However, the emulation
did (and could not) give exactly the same answer as the compiler builtin,
which led to a potential ABI break for e.g. enum classes.
After speaking to the original author of D56913, we agree that the correct
behavior is to instead always use the compiler builtin, since that provides
a more accurate answer, and __atomic_always_lock_free is a purely front-end
builtin which doesn't require any runtime support. Furthermore, it is
available regardless of the Standard mode (see https://godbolt.org/z/cazf3ssYY).
However, this patch does constitute an ABI break. As shown by https://godbolt.org/z/1eoex6zdK:
- In LLVM <= 11.0.1, an atomic<enum class with 1 byte> would not contain a lock byte.
- In LLVM >= 12.0.0, an atomic<enum class with 1 byte> would contain a lock byte.
This patch breaks the ABI again to bring it back to 1 byte, which seems
like the correct thing to do.
Fixes#57440
Differential Revision: https://reviews.llvm.org/D133377
It seems these includes are still provided by the sub headers, so it only
removes the duplicates.
There is no change in the list of includes, but the change affects the
modular build. By not having the includes in the top-level header the
module map has changed. This uncovers missing includes in the tests
and missing exports in the module map. This causes the huge amount of
changes in the patch.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D133252
This change implements the C library dependent portions of P0482R6
(char8_t: A type for UTF-8 characters and strings (Revision 6)) by
declaring std::c8rtomb() and std::mbrtoc8() in the <cuchar> header
when implementations are provided by the C library as specified by
WG14 N2653 (char8_t: A type for UTF-8 characters and strings
(Revision 1)) as adopted for C23.
A _LIBCPP_HAS_NO_C8RTOMB_MBRTOC8 macro is defined by the libc++ __config
header unless it is known that the C library provides these functions
in the current compilation mode. This macro is used for testing purposes
and may be of use to libc++ users. At present, the only C library known
to implement these functions is GNU libc as of its 2.36 release.
Reviewed By: ldionne
Differential Revision: https://reviews.llvm.org/D130946
Adding `[[nodiscard]]` to functions is a conforming extension and done extensively in the MSVC STL.
Reviewed By: ldionne, EricWF, #libc
Spies: #libc_vendors, cjdb, mgrang, jloser, libcxx-commits
Differential Revision: https://reviews.llvm.org/D128267
This defines a new policy for removal of transitive includes.
The goal of the policy it to make it relatively easy to remove
headers when needed, but avoid breaking developers using and
vendors shipping libc++.
The method used is to guard transitive includes based on the
C++ language version. For the upcoming C++23 we can remove
headers when we want, but for other language versions we try
to keep it to a minimum.
In this code the transitive include of `<chrono>` is removed
since D128577 introduces a header cycle between `<format>`
and `<chrono>`. This cycle is indirectly required by the
Standard. Our cycle dependency tool basically is a grep based
tool, so it needs some hints to ignore cycles. With the input
of our transitive include tests we can create a better tool.
However that's out of the scope of this patch.
Note the flag `_LIBCPP_REMOVE_TRANSITIVE_INCLUDES` remains
unchanged. So users can still opt-out of transitives includes
entirely.
Reviewed By: #libc, ldionne, philnik
Differential Revision: https://reviews.llvm.org/D132284
When -fexperimental-library is passed, libc++ will now pick up the
appropriate __has_feature flag defined by Clang to enable the
experimental library features.
As a fly-by, also update the documentation for the various TSes.
Differential Revision: https://reviews.llvm.org/D130176
In D125283, we ensured that integer distributions would not compile when
used with arbitrary unsupported types. This effectively enforced what
the Standard mentions here: http://eel.is/c++draft/rand#req.genl-1.5.
However, this also had the effect of breaking some users that were
using integer distributions with unsupported types like int8_t. Since we
already support using __int128_t in those distributions, it is reasonable
to also support smaller types like int8_t and its unsigned variant. This
commit implements that, adds tests and documents the extension. Note that
we voluntarily don't add support for instantiating these distributions
with bool and char, since those are not integer types. However, it is
trivial to replace uses of these random distributions on char using int8_t.
It is also interesting to note that in the process of adding tests
for smaller types, I discovered that our distributions sometimes don't
provide as faithful a distribution when instantiated with smaller types,
so I had to relax a couple of tests. In particular, we do a really bad
job at implementing the negative binomial, geometric and poisson distributions
for small types. I think this all boils down to the algorithm we use in
std::poisson_distribution, however I am running out of time to investigate
that and changing the algorithm would be an ABI break (which might be
reasonable).
As part of this patch, I also added a mitigation for a very likely
integer overflow bug we were hitting in our tests in negative_binomial_distribution.
I also filed http://llvm.org/PR56656 to track fixing the problematic
distributions with int8_t and uint8_t.
Supersedes D125283.
Differential Revision: https://reviews.llvm.org/D126823
Leave the escape hatch in place with a note, but don't include the
debug mode symbols by default since we don't support the debug mode
in the normal library anymore.
This is technically an ABI break for users who were depending on
those debug mode symbols in the dylib, however those users will
already be broken at compile-time because they must have been using
_LIBCPP_DEBUG=2, which is now an error.
Differential Revision: https://reviews.llvm.org/D127360
According to @aaron.ballman this was marked Tentatively Ready as of 2022-07-07.
D129362 implemented the C counterpart.
Reviewed By: ldionne, #libc, Mordante
Differential Revision: https://reviews.llvm.org/D129380
This implements a not accepted LWG issue. Not doing so would require
integral types to use the handle class instead of being directly stored
in the basic_format_arg.
The previous code used `std::forward` in places where it wasn't required
by the Standard. These are now removed.
Implements:
- P2418R2 Add support for std::generator-like types to std::format
- LWG 3631 basic_format_arg(T&&) should use remove_cvref_t<T> throughout
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D127570
This commit re-applies 9ee97ce3b8, which was reverted by 61d417ce
because it broke the LLDB data formatter tests. It also re-applies
6148c79a (the manual GN change associated to it).
Differential Revision: https://reviews.llvm.org/D127444
Instead of marking private symbols with internal_linkage (which leads to
one copy per translation unit -- rather wasteful), use an ABI tag that
gets rev'd with each libc++ version. That way, we know that we can't have
name collisions between implementation-detail functions across libc++
versions, so we'll never violate the ODR. However, within a single program,
each symbol still has a proper name with external linkage, which means
that the linker is free to deduplicate symbols even across TUs.
This actually means that we can guarantee that versions of libc++ can
be mixed within the same program without ever having to take a code size
hit, and without having to manually opt-in -- it should just work out of
the box.
Differential Revision: https://reviews.llvm.org/D127444
Nikolas Klauser