This is a workaround to provide a grace period for folks that were
broken by D147089. As a fly-by, also apply comments by Mark I had
somehow missed in the review.
Differential Revision: https://reviews.llvm.org/D150779
Several PSTL headers included by <algorithm> are missing includes for things they use.
Switch some quoted includes to angle includes.
(Issues found from running `check-cxx` with https://reviews.llvm.org/D144322)
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D150085
We introduced an optimization to std::sort in 4eddbf9f10a6. However,
that optimization led to issues where users that were passing invalid
comparators to std::sort could start seeing OOB reads. This led to
the revert of the std::sort optimization from the LLVM 16 release
(see https://llvm.org/D146421).
This patch introduces _LIBCPP_ASSERTs to the places in the algorithm
where we make an assumption that the comparator will be consistent and
hence avoid a bounds check based on that. If the comparator happens not
to be consistent with itself, these are the places where we would
incorrectly go out of bounds. This allows users that enable libc++
assertions to catch such misuse at the cost of basically a bounds
check. For users that do not enable libc++ assertions (which is 99.9%
of users since assertions are off by default), this is basically a
no-op, and in fact the assertion will turn into a __builtin_assume,
making it explicit to the compiler that it can rely on the fact that
we're not going out of bounds.
I think this patch strikes the right balance. Folks that want absolute
performance will get what they want, since it is a precondition for the
comparator to be consistent, so the bounds checks are technically not
mandatory. Folks who want more safety *already* need to be enabling
libc++ assertions to catch other types of bugs (like operator[] OOB),
so this solution should also work for them.
I do think we have a lot of work towards popularizing the use of libc++
assertions and integrating it better so that users don't have to know
about the obscure _LIBCPP_ENABLE_ASSERTIONS macro to enable them, but
that's a separate concern.
rdar://106897934
Differential Revision: https://reviews.llvm.org/D147089
Several headers are missing includes for things they use.
type_traits.is_enum needs to export type_traits.integral_constant so that clients can access its `value` member without explicitly including __type_traits/integral_constant.h themselves.
Make `subrange_fwd` a peer submodule to `subrange` rather than a submodule of it, and have `subrange` export `subrange_fwd`. That will make it easier to programmatically generate modules for the private detail headers, and it will accomplish the same effect that __ranges/subrange.h will make subrange_kind visible.
Reviewed By: Mordante, #libc
Differential Revision: https://reviews.llvm.org/D150055
This removes the need for a custom libc++ build to have a basic set of PSTL algorithms.
Reviewed By: ldionne, #libc
Spies: miyuki, libcxx-commits, arichardson
Differential Revision: https://reviews.llvm.org/D149624
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
The __insertion_sort_move helper function is only used in partial_sort.h,
so it makes sense to define it there.
Differential Revision: https://reviews.llvm.org/D147080
Internal linkages fails when building libc++ with modules. Using
internal linkage is headers seems questionable to change the linkage.
Reviewed By: #libc, philnik
Differential Revision: https://reviews.llvm.org/D146384
Don't forward to `min_element` for small types that are trivially copyable, and instead use a naive loop that keeps track of the smallest element (as opposed to an iterator to the smallest element). This allows the compiler to vectorize the loop in some cases.
Reviewed By: #libc, ldionne
Spies: ldionne, libcxx-commits
Differential Revision: https://reviews.llvm.org/D143596
Clang wants to enable this flag by default, but libc++ isn't working with it yet.
Reviewed By: Mordante, #libc, #libc_abi, EricWF
Spies: libcxx-commits, arichardson
Differential Revision: https://reviews.llvm.org/D144667
Don't return the number of swaps; it's not used anywhere.
Reviewed By: Mordante, #libc, avogelsgesang
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D144478
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
The implementation makes use of the freedom added by LWG 3410. We have
two variants of this algorithm:
* a fast path for random access iterators: This fast path computes the
maximum number of loop iterations up-front and does not compare the
iterators against their limits on every loop iteration.
* A basic implementation for all other iterators: This implementation
compares the iterators against their limits in every loop iteration.
However, it still takes advantage of the freedom added by LWG 3410 to
avoid unnecessary additional iterator comparisons, as originally
specified by P1614R2.
https://godbolt.org/z/7xbMEen5e shows the benefit of the fast path:
The hot loop generated of `lexicographical_compare_three_way3` is
more tight than for `lexicographical_compare_three_way1`. The added
benchmark illustrates how this leads to a 30% - 50% performance
improvement on integer vectors.
Implements part of P1614R2 "The Mothership has Landed"
Fixes LWG 3410 and LWG 3350
Differential Revision: https://reviews.llvm.org/D131395
This patch removes `_WrapAlgPolicy` and related functionality. Instead, we explicitly forward to `__sort` now if we have an instantiation inside the dylib. If we don't we just call `__introsort`.
Reviewed By: ldionne, #libc
Spies: sstefan1, libcxx-commits
Differential Revision: https://reviews.llvm.org/D140824
These instantiations were never visible, because they are only used in `__sort`, which is also explicitly instantiated in the dylib.
Reviewed By: ldionne, #libc
Spies: #libc_vendors, emaste, nemanjai, libcxx-commits
Differential Revision: https://reviews.llvm.org/D142185
This has multiple benefits:
- The optimizations are also performed for the `ranges::` versions of the algorithms
- Code duplication is reduced
- it is simpler to add this optimization for other segmented iterators,
like `ranges::join_view::iterator`
- Algorithm code is removed from `<deque>`
Reviewed By: ldionne, huixie90, #libc
Spies: mstorsjo, sstefan1, EricWF, libcxx-commits, mgorny
Differential Revision: https://reviews.llvm.org/D132505
This reverts commit a6e1080b87db8fbe0e1afadd96af5a3c0bd5e279.
Fix the conditions when the `memmove` optimization can be applied and refactor them out into a reusable type trait, fix and significantly expand the tests.
Differential Revision: https://reviews.llvm.org/D139235
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
