Moves:
* `std::move`, `std::forward`, `std::declval`, and `std::swap` into
`__utility/${FUNCTION_NAME}`.
* `std::swap_ranges` and `std::iter_swap` into
`__algorithm/${FUNCTION_NAME}`
Differential Revision: https://reviews.llvm.org/D103734
This is a fairly mechanical change, it just moves each algorithm into
its own header. This is intended to be a NFC.
This commit re-applies 7ed7d4ccb8, which was reverted in 692d7166f7
because the Modules build got broken. The modules build has now been
fixed, so we're re-committing this.
Differential Revision: https://reviews.llvm.org/D103583
Attribution note
----------------
I'm only committing this. This commit is a mix of D103583, D103330 and
D104171 authored by:
Co-authored-by: Christopher Di Bella <cjdb@google.com>
Co-authored-by: zoecarver <z.zoelec2@gmail.com>
This is a fairly mechanical change, it just moves each algorithm into its own header. This is a NFC.
Note: during this change, I burned down all the includes, so this follows "include only and exactly what you use."
Differential Revision: https://reviews.llvm.org/D103583
This reverts commit 924ea3bb53 *again*, this time because it broke the
LLDB build with modules. We need to figure out what's up with the libc++
modules build once and for all.
Differential Revision: https://reviews.llvm.org/D103369
- Quality-of-implementation: Avoid calling __unwrap_iter in constexpr contexts.
The user might conceivably write a contiguous iterator where normal iterator
arithmetic is constexpr-friendly but `std::to_address(it)` isn't.
- Bugfix: When you pass contiguous iterators to `std::copy`, you should get
back your contiguous iterator type, not a raw pointer. That means that
libc++ can't `__unwrap_iter` unless it also does `__rewrap_iter`.
Fortunately, this is implementable.
- Improve test coverage of the new `contiguous_iterator` test iterator.
This catches the bug described above.
- Tests: Stop testing that we can `std::copy` //into// an `input_iterator`.
Our test iterators may currently support that, but it seems nonsensical to me.
Differential Revision: https://reviews.llvm.org/D95983
This reverts commit b6ffece320.
The bug is now fixed (it was a stupid cut-and-paste kind of error),
and the regression test added. The new patch is also simpler than the old one!
Differential Revision: https://reviews.llvm.org/D96084
- 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
This patch is more than just adding the `constexpr` keyword, because
the old code relied on `goto`, and `goto` is not constexpr-friendly.
Refactor to eliminate `goto`, and then mark it as constexpr in C++20.
I freely admit that the name `__nth_element_partloop` is bad;
I couldn't find any better name because I don't really know
what this loop is doing, conceptually. Vice versa, I think
`__nth_element_find_guard` has a decent name.
Now the only one we're still missing from P0879 is `sort`.
Differential Revision: https://reviews.llvm.org/D93557
After this patch, the only parts of P0879 that remain missing will be
std::nth_element, std::sort, and the heap/partial_sort algorithms.
Differential Revision: https://reviews.llvm.org/D93443
Sometimes `_Compare` is an lvalue reference type, so letting it be
deduced is pretty much always wrong. (Well, less efficient than
it could be, anyway.)
Differential Revision: https://reviews.llvm.org/D93562
Everywhere, normalize the whitespace to `::new (EXPR) T`.
Everywhere, normalize the spelling of the cast to `(void*)EXPR`.
Without the cast to `(void*)`, the expression triggers ADL on GCC.
(I think this is a GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98249)
Even if it doesn't trigger ADL, it still seems incorrect to use any argument
that's not exactly `(void*)` because that opens the possibility of overload
resolution picking a user-defined overload of `operator new`, which would be
wrong.
Differential Revision: https://reviews.llvm.org/D93153
The interesting change here is that we no longer consider `__convert_to_integral`
an ADL customization point for the user's types. I think the new behavior
is defensible. The old behavior had come from D7449, where Marshall explicitly
said "people can't define their own [`__convert_to_integral` overloads]."
Differential Revision: https://reviews.llvm.org/D92814
The synopsis now reflects what's implemented. It does NOT reflect
all of what's specified in C++20. The "constexpr in C++20" markings
are still missing from these 12 algorithms, because they are still
unimplemented by libc++:
reverse partition sort nth_element next_permutation prev_permutation
push_heap pop_heap make_heap sort_heap partial_sort partial_sort_copy
All of the above algorithms were excluded from [P0202].
All of the above algorithms were made constexpr in [P0879] (along with
swap_ranges, iter_swap, and rotate — we've already implemented those three).
Differential Revision: https://reviews.llvm.org/D92255
These had been waiting on the ability to use `std::copy` from
constexpr code (which in turn had been waiting on the ability to
use `is_constant_evaluated()` to switch between `memmove` and non-`memmove`
implementations of `std::copy`). That work landed a while ago,
so these algorithms can all be constexpr in C++20 now.
Simultaneously, update the tests for the set algorithms.
- Use an element type with "equivalent but not identical" values.
- The custom-comparator tests now pass something different from `operator<`.
- Make the constexpr coverage match the non-constexpr coverage.
Differential Revision: https://reviews.llvm.org/D92255
previously, invocations of std::sort(T**, T**) casted the arguments to
(size_t *). this breaks sorting on systems for which pointers don't fit
in a size_t. change the cast to (uintptr_t *) and add a test.
Differential Revision: https://reviews.llvm.org/D92190
I used a lot of `git grep` to find places where `std::` was being used
outside of comments and assert-messages. There were three outcomes:
- Qualified function calls, e.g. `std::move` becomes `_VSTD::move`.
This is the most common case.
- Typenames that don't need qualification, e.g. `std::allocator` becomes `allocator`.
Leaving these as `_VSTD::allocator` would also be fine, but I decided
that removing the qualification is more consistent with existing practice.
- Names that specifically need un-versioned `std::` qualification,
or that I wasn't sure about. For example, I didn't touch any code in
<atomic>, <math.h>, <new>, or any ext/ or experimental/ headers;
and I didn't touch any instances of `std::type_info`.
In some deduction guides, we were accidentally using `class Alloc = typename std::allocator<T>`,
despite `std::allocator<T>`'s type-ness not being template-dependent.
Because `std::allocator` is a qualified name, this did parse as we intended;
but what we meant was simply `class Alloc = allocator<T>`.
Differential Revision: https://reviews.llvm.org/D92250
Zoe Carver says: "We decided that libc++ only supports C++20 constexpr algorithms
when `is_constant_evaluated` is also supported. Here's a link to the discussion."
https://reviews.llvm.org/D65721#inline-735682
Remove _LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED from tests, too.
See Louis's 5911e6a885 if needed to fix bots.
I've applied `UNSUPPORTED: clang-8` preemptively to the altered tests;
I don't know for sure that this was needed, because no clang-8 buildbots
are triggered on pull requests.
This patch makes `std::rotate` a constexpr. In doing so, this patch also
updates the internal `__move` and `__move_backward` funtions to be
constexpr.
This patch was previously reverted in ed653184ac because it was missing
some UNSUPPORTED markup for older compilers. This commit adds it.
Differential Revision: https://reviews.llvm.org/D65721
cppreference lists the support for this paper as partial.
I found 4 functions which the paper marks as `constexpr`,
but did not use the appropriate macro.
Differential Revision: https://reviews.llvm.org/D84275
This patch makes `std::rotate` a constexpr. In doing so, this patch also
updates the internal `__move` and `__move_backward` funtions to be
constexpr.
Reviewed By: ldionne
Differential Revision: https://reviews.llvm.org/D65721
With the upcoming introduction of iterator concepts in ranges,
the meaning of "__is_contiguous_iterator" changes drastically.
Currently we intend it to mean "does it have this iterator category",
but it could now also mean "does it meet the requirements of this
concept", and these can be different.
For the few (currently four) headers that make up the PSTL's interface
to other Standard Libraries, provide a stable uglified header file that
can be included by those Standard Libraries.
We can then more easily change the internal organization of the PSTL
without having to change the integration with Standard Libraries.
llvm-svn: 368088
Summary:
This commit allows specifying LIBCXX_ENABLE_PARALLEL_ALGORITHMS when
configuring libc++ in CMake. When that option is enabled, libc++ will
assume that the PSTL can be found somewhere on the CMake module path,
and it will provide the C++17 parallel algorithms based on the PSTL
(that is assumed to be available).
The commit also adds support for running the PSTL tests as part of
the libc++ test suite.
The first attempt to commit this failed because it exposed a bug in the
tests for modules. Now that this has been fixed, it should be safe to
commit this.
Reviewers: EricWF
Subscribers: mgorny, christof, jkorous, dexonsmith, libcxx-commits, mclow.lists, EricWF
Tags: #libc
Differential Revision: https://reviews.llvm.org/D60480
llvm-svn: 367903
This reverts r366593, which caused unforeseen breakage on the build bots.
I'm reverting until the problems have been figured out and fixed.
llvm-svn: 366603
Summary:
This commit allows specifying LIBCXX_ENABLE_PARALLEL_ALGORITHMS when
configuring libc++ in CMake. When that option is enabled, libc++ will
assume that the PSTL can be found somewhere on the CMake module path,
and it will provide the C++17 parallel algorithms based on the PSTL
(that is assumed to be available).
The commit also adds support for running the PSTL tests as part of
the libc++ test suite.
Reviewers: rodgert, EricWF
Subscribers: mgorny, christof, jkorous, dexonsmith, libcxx-commits, mclow.lists, EricWF
Tags: #libc
Differential Revision: https://reviews.llvm.org/D60480
llvm-svn: 366593
These functions are key to allowing the use of rvalues and variadics
in C++03 mode. Everything works the same as in C++11, except for one
tangentially related case:
struct T {
T(T &&) = default;
};
In C++11, T has a deleted copy constructor. But in C++03 Clang gives
it both a move and a copy constructor. This seems reasonable enough
given the extensions it's using.
The other changes in this patch were the minimal set required
to keep the tests passing after the move/forward change. Most notably
the removal of the `__rv<unique_ptr>` hack that was present
in an attempt to make unique_ptr move only without language support.
llvm-svn: 364063
Christopher Di Bella