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
This commit re-adds transitive includes that had been removed by
4cd04d1687, c36870c8e7, a83f4b9cda, 1458458b55, 2e2f3158c6,
and 489637e66d. This should cover almost all the includes that had
been removed since LLVM 14 and that would contribute to breaking user
code when releasing LLVM 15.
It is possible to disable the inclusion of these headers by defining
_LIBCPP_REMOVE_TRANSITIVE_INCLUDES. The intent is that vendors will
enable that macro and start fixing downstream issues immediately. We
can then remove the macro (and the transitive includes) by default in
a future release. That way, we will break users only once by removing
transitive includes in bulk instead of doing it bit by bit a every
release, which is more disruptive for users.
Note 1: The set of headers to re-add was found by re-generating the
transitive include test on a checkout of release/14.x, which
provided the list of all transitive includes we used to provide.
Note 2: Several includes of <vector>, <optional>, <array> and <unordered_map>
have been added in this commit. These transitive inclusions were
added when we implemented boyer_moore_searcher in <functional>.
Note 3: This is a best effort patch to try and resolve downstream breakage
caused since branching LLVM 14. I wasn't able to perfectly mirror
transitive includes in LLVM 14 for a few headers, so I added a
release note explaining it. To summarize, adding boyer_moore_searcher
created a bunch of circular dependencies, so we have to break
backwards compatibility in a few cases.
Differential Revision: https://reviews.llvm.org/D128661
`__GCC_CONSTRUCTIVE_SIZE` and `__GCC_DESTRUCTIVE_SIZE` are available since GCC 12. I'm assuming clang will also implement these for compatability with libstdc++.
Reviewed By: ldionne, #libc
Spies: h-vetinari, libcxx-commits, arichardson
Differential Revision: https://reviews.llvm.org/D122276
`std::function` has been deprecated for a few releases now. Remove it with an option to opt-back-in with a note that this option will be removed in LLVM 16.
Reviewed By: ldionne, #libc
Spies: #libc_vendors, EricWF, jloser, libcxx-commits
Differential Revision: https://reviews.llvm.org/D127908
This mostly copys the `<experimental/functional>` stuff and updates the code to current libc++ style.
Reviewed By: ldionne, #libc
Spies: nlopes, adamdebreceni, arichardson, libcxx-commits, mgorny
Differential Revision: https://reviews.llvm.org/D121074
When compiled with `-D_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS`
uses of `allocator<void>::pointer` resulted in compiler errors after D104323.
If we instantiate the primary template, `allocator<void>::reference` produces
an error 'cannot form references to void'.
To workaround this, allow to bring back the `allocator<void>` specialization by defining the new `_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_VOID_SPECIALIZATION` macro.
To make sure the code that uses `allocator<void>` and the removed members does not break,
both `_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS` and `_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS` have to be defined.
Reviewed By: ldionne, #libc, philnik
Differential Revision: https://reviews.llvm.org/D126210
This removes all "TODO: remove these headers" comments from our headers.
Note there seem to be more headers that can be removed, that will be
done in separate commits.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D127592
The flexibility around extern template instantiation declarations in
libc++ result in a very complicated model, especially when support for
slightly different configurations (like the debug mode or assertions
in the dylib) are taken into account. That results in unexpected bugs
like http://llvm.org/PR50534 (and there have been multiple similar
bugs in the past, notably around the debug mode).
This patch gets rid of the _LIBCPP_DISABLE_EXTERN_TEMPLATE knob, which
I don't think is fundamental. Indeed, the motivation for that knob was to
avoid taking a dependency on the library, however that can be done better
by linking against the static library instead. And in fact, some parts of
the headers will always depend on things defined in the library, which
defeats the original goal of _LIBCPP_DISABLE_EXTERN_TEMPLATE.
Differential Revision: https://reviews.llvm.org/D103960
The debug mode has been broken pretty much ever since it was shipped
because it was possible to enable the debug mode in user code without
actually enabling it in the dylib, leading to ODR violations that
caused various kinds of failures.
This commit makes the debug mode a knob that is configured when
building the library and which can't be changed afterwards. This is
less flexible for users, however it will actually work as intended
and it will allow us, in the future, to add various kinds of checks
that do not assume the same ABI as the normal library. Furthermore,
this will make the debug mode more robust, which means that vendors
might be more tempted to support it properly, which hasn't been the
case with the current debug mode.
This patch shouldn't break any user code, except folks who are building
against a library that doesn't have the debug mode enabled and who try
to enable the debug mode in their code. Such users will get a compile-time
error explaining that this configuration isn't supported anymore.
In the future, we should further increase the granularity of the debug
mode checks so that we can cherry-pick which checks to enable, like we
do for unspecified behavior randomization.
Differential Revision: https://reviews.llvm.org/D122941
After moving the std::to_chars base 10 implementation from the dylib to
the header the integral overloads of std::to_chars are available on all
platforms.
Remove the _LIBCPP_AVAILABILITY_TO_CHARS availability macro and update
the tests.
Depends on D125704
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D125745
Currently, unary expressions involving valarray will create a temporary.
This leads to dangling references in expressions like `-a * b`, because
`-a` is a temporary and the resulting expression will refer to it. This
patch fixes the problem by creating a lazy expression to perform the unary
operation instead of eagerly creating a temporary valarray. This is
permitted by the Standard, which does not specify the exact type of
most expressions involving valarrays.
This is technically an ABI break, however I believe the actual potential
for breakage is very low.
rdar://90152242
Differential Revision: https://reviews.llvm.org/D125019
Add a warning and tweak the release note to explain that the deprecation
targets libc++, libc++abi and libuwnind as well.
Also, as a fly-by, ensure that our CI runs the legacy testing configuration
for libc++, libc++abi and libunwind. This doesn't matter too much since
it's deprecated, but we might as well test it properly.
Differential Revision: https://reviews.llvm.org/D126478
Quite a few C++20 LWG issues/papers related to the One Ranges Proposal
were already effectively implemented (or contain semantic-only wording
changes that don't affect the implementation), mark them as such.
Differential Revision: https://reviews.llvm.org/D125065
Louis Dionne