This patch adds a large number of missing includes in the libc++ headers
and the test suite. Those were found as part of the effort to move
towards a mostly monolithic top-level std module.
Many headers include `<cstddef>` just for size_t, and pulling in
additional content (e.g. the traits used for std::byte) is unnecessary.
To solve this problem, this patch splits up `<cstddef>` into
subcomponents so that headers can include only the parts that they
actually require.
This has the added benefit of making the modules build a lot stricter
with respect to IWYU, and also providing a canonical location where we
define `std::size_t` and friends (which were previously defined in
multiple headers like `<cstddef>` and `<ctime>`).
After this patch, there's still many places in the codebase where we
include `<cstddef>` when `<__cstddef/size_t.h>` would be sufficient.
This patch focuses on removing `<cstddef>` includes from __type_traits
to make these headers non-circular with `<cstddef>`. Additional
refactorings can be tackled separately.
As time went by, a few files have become mis-formatted w.r.t.
clang-format. This was made worse by the fact that formatting was not
being enforced in extensionless headers. This commit simply brings all
of libcxx/include in-line with clang-format again.
We might have to do this from time to time as we update our clang-format
version, but frankly this is really low effort now that we've formatted
everything once.
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
In preparation for running clang-format on the whole code base, we are
also removing mentions of the legacy _LIBCPP_INLINE_VISIBILITY macro in
favor of the newer _LIBCPP_HIDE_FROM_ABI.
We're still leaving the definition of _LIBCPP_INLINE_VISIBILITY to avoid
creating needless breakage in case some older patches are checked-in
with mentions of the old macro. After we branch for LLVM 18, we can do
another pass to clean up remaining uses of the macro that might have
gotten introduced by mistake (if any) and remove the macro itself at the
same time. This is just a minor convenience to smooth out the transition
as much as possible.
See
https://discourse.llvm.org/t/rfc-clang-formatting-all-of-libc-once-and-for-all
for the clang-format proposal.
This change is almost fully mechanical. The only interesting change is in `generate_feature_test_macro_components.py` to generate `_LIBCPP_STD_VER >=` instead. To avoid churn in the git-blame this commit should be added to the `.git-blame-ignore-revs` once committed.
Reviewed By: ldionne, var-const, #libc
Spies: jloser, libcxx-commits, arichardson, arphaman, wenlei
Differential Revision: https://reviews.llvm.org/D143962
While it's not necessary to qualify calls to `declval` it makes error messages very crypric if the declaration isn't reachable anymore
For example:
```
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:53:66: error: no type named 'type' in 'std::common_type<long, long>'
typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:107:14: note: in instantiation of template class 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>, std::chrono::duration<long, std::ratio<3600, 1>>>' requested here
: public common_type<_Tp, _Tp> {};
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:279:58: note: in instantiation of template class 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>>' requested here
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:308:54: note: in instantiation of template class 'std::chrono::duration<long, std::ratio<3600, 1>>' requested here
typedef duration< int, ratio_multiply<ratio<24>, hours::period>> days;
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:280:81: error: no type named 'type' in 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>>'
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator-() const {return typename common_type<duration>::type(-__rep_);}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:308:54: note: in instantiation of template class 'std::chrono::duration<long, std::ratio<3600, 1>>' requested here
typedef duration< int, ratio_multiply<ratio<24>, hours::period>> days;
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:53:66: error: no type named 'type' in 'std::common_type<int, int>'
typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:107:14: note: in instantiation of template class 'std::common_type<std::chrono::duration<int, std::ratio<86400, 1>>, std::chrono::duration<int, std::ratio<86400, 1>>>' requested here
: public common_type<_Tp, _Tp> {};
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:279:58: note: in instantiation of template class 'std::common_type<std::chrono::duration<int, std::ratio<86400, 1>>>' requested here
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:309:55: note: in instantiation of template class 'std::chrono::duration<int, std::ratio<86400, 1>>' requested here
typedef duration< int, ratio_multiply<ratio<7>, days::period>> weeks;
^
19 similar errors omitted
```
changes with qualification added to:
```
While building module 'std' imported from /home/nikolask/llvm-projects/libcxx/libcxx/test/std/utilities/meta/meta.trans/meta.trans.other/common_type.pass.cpp:13:
In file included from <module-includes>:17:
In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/math.h:309:
In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/limits:107:
In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/type_traits:432:
In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_reference.h:13:
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:28:43: error: declaration of 'declval' must be imported from module 'std.utility.__utility.declval' before it is required
using __cond_type = decltype(false ? std::declval<_Tp>() : std::declval<_Up>());
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__utility/declval.h:30:34: note: declaration here is not visible
decltype(std::__declval<_Tp>(0)) declval() _NOEXCEPT;
^
/home/nikolask/llvm-projects/libcxx/libcxx/test/std/utilities/meta/meta.trans/meta.trans.other/common_type.pass.cpp:13:10: fatal error: could not build module 'std'
#include <functional>
~~~~~~~~^
2 errors generated.
```
Reviewed By: ldionne, Mordante, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D130854
This was discussed on Discord with the consensus that we should rename the macros.
Reviewed By: ldionne, Mordante, var-const, avogelsgesang, jloser, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D131498
Evaluating `contiguous_iterator` on an iterator that satisfies all the
constraints except the `to_address` constraint and doesn't have
`operator->` defined results in a hard error. This is because
instantiating `to_address` ends up instantiating templates
dependent on the given type which might lead to a hard error even
in a SFINAE context.
Differential Revision: https://reviews.llvm.org/D130835
This commit reverts 5aaefa51 (and also partly 7f285f48e77 and b6d75682f9,
which were related to the original commit). As landed, 5aaefa51 had
unintended consequences on some downstream bots and didn't have proper
coverage upstream due to a few subtle things. Implementing this is
something we should do in libc++, however we'll first need to address
a few issues listed in https://reviews.llvm.org/D106124#3349710.
Differential Revision: https://reviews.llvm.org/D120683
libc++ has started splicing standard library headers into much more
fine-grained content for maintainability. It's very likely that outdated
and naive tooling (some of which is outside of LLVM's scope) will
suggest users include things such as <__ranges/access.h> instead of
<ranges>, and Hyrum's law suggests that users will eventually begin to
rely on this without the help of tooling. As such, this commit
intends to protect users from themselves, by making it a hard error for
anyone outside of the standard library to include libc++ detail headers.
Differential Revision: https://reviews.llvm.org/D106124
In other places in the code, we use lowercase spelling for things that
are not available in prior standards.
Differential Revision: https://reviews.llvm.org/D109435
There were basically two bugs here:
When C++20 `to_address` is called on `int arr[10]`, then `const _Ptr&` becomes
a reference to a const array, and then we dispatch to `__to_address<const int(&)[10]>`,
which, oops, gives us a `const int*` result instead of an `int*` result.
Solution: We need to provide the two standard-specified overloads of
`std::to_address` in exactly the same way that we provide two overloads
of `__to_address`.
When `__to_address` is called on a pointer type, `__to_address(const _Ptr&)`
is disabled so we successfully avoid trying to instantiate pointer_traits of
that pointer type. But when it's called on an array type, it's not disabled
for array types, so we go ahead and instantiate pointer_traits<int[10]>,
which goes boom. Solution: We need to disable `__to_address(const _Ptr&)`
for both pointer and array types. Also disable it for function types,
so that they get the nice error message; and put a test on it.
Differential Revision: https://reviews.llvm.org/D109331
Clang used to support [[nodebug]] everywhere except on typedefs. Since
we don't support such old Clangs anymore, we can get rid of _LIBCPP_NODEBUG_TYPE
in favour of always using _LIBCPP_NODEBUG.
Differential Revision: https://reviews.llvm.org/D108996
This has been broken out of D104170 since it should be merged whether or
not we go ahead with the module map changes.
Differential Revision: https://reviews.llvm.org/D104175
Most of our private headers need to be treated as submodules so that
Clang modules can export things correctly. Previous commits that split
monolithic headers into smaller chunks were unaware of this requirement,
and so this is being addressed in one fell swoop. Moving forward, most
new headers will need to have their own submodule (anything that's
conditionally included is exempt from this rule, which means `__support`
headers aren't made into submodules).
This hasn't been marked NFC, since I'm not 100% sure that's the case.
Differential Revision: https://reviews.llvm.org/D103551
This is a rough reapplication of the change that fixed std::to_address
to avoid relying on element_type (da456167). It is somewhat different
because the fix to avoid breaking Clang (which caused it to be reverted
in 347f69c55) was a bit more involved.
Differential Revision: https://reviews.llvm.org/D101638
This reverts commit da456167, which broke the Clang build. I'm able to
reproduce it but I want to give myself a bit more time to investigate.
Differential Revision: https://reviews.llvm.org/D101638
- Implement C++20's changes to `reverse_iterator`, so that it won't be
accidentally counted as a contiguous iterator in C++20 mode.
- Implement C++20's changes to `move_iterator` as well.
- `move_iterator` should not be contiguous. This fixes a bug where
we optimized `std::copy`-of-move-iterators in an observable way.
Add a regression test for that bugfix.
- Add libcxx tests for `__is_cpp17_contiguous_iterator` of all relevant
standard iterator types. Particularly check that vector::iterator
is still considered contiguous in all C++ modes, even C++03.
After this patch, there continues to be no supported way to write your
own iterator type in C++17-and-earlier such that libc++ will consider it
"contiguous"; however, we now fully support the C++20 approach (in C++20
mode only). If you want user-defined contiguous iterators in C++17-and-earlier,
libc++'s position is "please upgrade to C++20."
Differential Revision: https://reviews.llvm.org/D94807
In addition to making the code a lot easier to grasp by localizing many
helper functions to the only file where they are actually needed, this
will allow creating helper functions that depend on allocator_traits
outside of <memory>.
This is done as part of implementing array support in allocate_shared,
which requires non-trivial array initialization algorithms that would be
better to keep out of <memory> for sanity. It's also a first step towards
splitting up our monolithic headers into finer grained ones, which will
make it easier to reuse functionality across the library. For example,
it's just weird that we had to define `addressof` inside <type_traits>
to avoid circular dependencies -- instead it's better to implement those
in true helper headers.
Differential Revision: https://reviews.llvm.org/D93074
