The changes are nearly pure simplifications, so I think it's OK to do
them together in the same PR.
Actual test coverages were already added in commit ad41d1e26b
(https://reviews.llvm.org/D141216). Thanks to Casey Carter!
Fixes#104975
Towards #105200
This patch hardens the "test iterators" we use to test algorithms by
ensuring that they don't get double-moved. As a result of this
hardening, the tests started reporting multiple failures where we would
double-move iterators, which are being fixed in this patch.
In particular:
- Fixed a double-move in pstl.partition
- Add coverage for begin()/end() in subrange tests
- Fix tests for ranges::ends_with and ranges::contains, which were
incorrectly calling begin() twice on the same subrange containing
non-copyable input iterators.
Fixes#100709
## Introduction
This patch implements LWG3564:
`transform_view::iterator<true>::value_type` and `iterator_category`
should use `const F&`.
`transform_view`'s iterator currently obtained from a `const
transform_view` invoke the transformation function as `const`, but the
`value_type` and `iterator_category` determination uses non-`const`
`F&`.
## Reference
-
[[range.transform.iterator]](https://eel.is/c++draft/range.transform.iterator)
- [LWG3564](https://cplusplus.github.io/LWG/issue3564)
## Introduction
This patch implements LWG3618: Unnecessary `iter_move` for
`transform_view::iterator`.
`transform_view`'s iterator currently specifies a customization point
for `iter_move`. This customization point does the same thing that the
default implementation would do, but its sole purpose is to ensure the
appropriate conditional `noexcept` specification.
## Reference
-
[[range.transform.iterator]](https://eel.is/c++draft/range.transform.iterator)
- [LWG3618](https://cplusplus.github.io/LWG/issue3618)
One-sided binary search, aka meta binary search, has been in the public
domain for decades, and has the general advantage of being constant time
in the best case, with the downside of executing at most 2*log(N)
comparisons vs classic binary search's exact log(N). There are two
scenarios in which it really shines: the first one is when operating
over non-random-access iterators, because the classic algorithm requires
knowing the container's size upfront, which adds N iterator increments
to the complexity. The second one is when traversing the container in
order, trying to fast-forward to the next value: in that case the
classic algorithm requires at least O(N*log(N)) comparisons and, for
non-random-access iterators, O(N^2) iterator increments, whereas the
one-sided version will yield O(N) operations on both counts, with a
best-case of O(log(N)) comparisons which is very common in practice.
This patch improves the preservation of qualifiers and loss of type
sugar in TemplateNames.
This problem is analogous to https://reviews.llvm.org/D112374 and this
patch takes a very similar approach to that patch, except the impact
here is much lesser.
When a TemplateName was written bare, without qualifications, we
wouldn't produce a QualifiedTemplate which could be used to disambiguate
it from a Canonical TemplateName. This had effects in the TemplateName
printer, which had workarounds to deal with this, and wouldn't print the
TemplateName as-written in most situations.
There are also some related fixes to help preserve this type sugar along
the way into diagnostics, so that this patch can be properly tested.
- Fix dropping the template keyword.
- Fix type deduction to preserve sugar in TST TemplateNames.
Implement
- LWG4053 Unary call to `std::views::repeat` does not decay the argument
- LWG4054 Repeating a `repeat_view` should repeat the view
Signed-off-by: yronglin <yronglin777@gmail.com>
This pull request implements LWG3984: ranges::to's recursion branch
may be ill-formed.
In the current implementation, ranges::to's recursion branch pipes the
range into a `views::transform(/* lambda */)`, which is a __range_adaptor_closure
object. In libc++, the pipe operator of __range_adaptor_closure requires a
viewable_range, so the following code won't compile, as the type of lvalue
`r` doesn't model viewable_range:
#include <ranges>
#include <vector>
#include <list>
int main() {
std::vector<std::vector<int>> v;
auto r = std::views::all(std::move(v));
auto l = std::ranges::to<std::list<std::list<int>>>(r);
}
Co-authored-by: A. Jiang <de34@live.cn>
This patch finalizes the std::ranges::range_adaptor_closure
class template from https://wg21.link/P2387R3.
// [range.adaptor.object], range adaptor objects
template<class D>
requires is_class_v<D> && same_as<D, remove_cv_t<D>>
class range_adaptor_closure { };
The current implementation of __range_adaptor_closure was introduced
in ee44dd8062 and has served as the
foundation for the range adaptors in libc++ for a while. This patch
keeps its implementation, with the exception of the following changes:
- __range_adaptor_closure now includes the missing constraints
`is_class_v<D> && same_as<D, remove_cv_t<D>>` to restrict the
type of class that can inherit from it. (https://eel.is/c++draft/ranges.syn)
- The operator| of __range_adaptor_closure no longer requires its
first argument to model viewable_range. (https://eel.is/c++draft/range.adaptor.object#1)
- The _RangeAdaptorClosure concept is refined to exclude cases where
T models range or where T has base classes of type range_adaptor_closure<U>
for another type U. (https://eel.is/c++draft/range.adaptor.object#2)
Previously, tests for whether comparison using == was supported by
iterators derived from ranges adaptors was spread throughout the testing
codebase. This PR centralizes the implementation of those tests.
This moves the definition of a `pair` constructor for `<tuple>` to
`<__utility/pair.h>` and uses the forward declaration of `pair` in
`<tuple>` instead of including the definition.
The exposition-only type trait `pair-like` includes `ranges::subrange`,
but in every single case excludes `ranges::subrange` from the list. This
patch introduces two new traits `__tuple_like_no_subrange` and
`__pair_like_no_subrange`, which exclude `ranges::subrange` from the
possible matches. `__pair_like` is no longer required, and thus removed.
`__tuple_like` is implemented as `__tuple_like_no_subrange` or a
`ranges::subrange` specialization.
## Abstract
This pull request implements LWG3715: `view_interface::empty` is
overconstrained. Here is an example similar to those described in the
report, which compiles with `-stdlib=libstdc++` but failed to compile
with `-stdlib=libc++`:
```cpp
// https://godbolt.org/z/EWEoTzah3
std::istringstream input("1 2 3 4 5");
auto i = std::views::istream<int>(input);
auto r = std::views::counted(i.begin(), 4) | std::views::take(2);
assert(!r.empty());
```
## Reference
- [Draft C++ Standard:
[view.interface.general]](https://eel.is/c++draft/view.interface.general)
- [LWG3715](https://wg21.link/LWG3715)
According to internally agreed upon best practices, type template
parameter names representing iterator types should be named `Iter`. For
type template parameters representing sentinel types, they should be
named `Sent`.
Signed-off-by: Will Hawkins <hawkinsw@obs.cr>
Instead of using a concept defined in the internal implementation, use a
definition of the simple_view ranges concept separately defined and
included in test code.
fixes#70506
The detailed problem description is in #70506
The original proposed fix was to remove `[[no_unique_address]]` except
when `_Tp` is empty.
Edit:
After the discussion in the comments below, the new fix here is to
remove the `[[no_unique_address]]` from `movable_box` in the cases where
we need to add our own assignment operator, which has contains the
problematic `construct_at`
As pointed out in #72883, the implementation only needs to return the
value of ranges::next and does not need to obtain the value through
ranges::advance, which causes it to have O(n) complexity in the case
of random-access-sized but non-common range.
Fixes#72883
Notable things in this commit:
* refactors `__indirect_binary_left_foldable`, making it slightly
different (but equivalent) to _`indirect-binary-left-foldable`_, which
improves readability (a [patch to the Working Paper][patch] was made)
* omits `__cpo` namespace, since it is not required for implementing
niebloids (a cleanup should happen in 2024)
* puts tests ensuring invocable robustness and dangling correctness
inside the correctness testing to ensure that the algorithms' results
are still correct
[patch]: https://github.com/cplusplus/draft/pull/6734
Currently, when libc++'s views::take specially handles an iota_view, the
addition is done after dereferencing the beginning iterator. However, in
[range.take.overview]/2.3, the addition is done before the dereferencing,
which means that the standard requires the returned iota_view to have
the same W and Bound type in such cases.
This patch fixes that, and also fixes a test that was testing the
incorrect behavior.
Fixes#75611
This is the last PR that's needed (for now) to get libc++'s tests
working with MSVC's STL.
The ADDITIONAL_COMPILE_FLAGS machinery is very useful, but also very
problematic for MSVC, as it doesn't understand most of Clang's compiler
options. We've been dealing with this by simply marking anything that
uses ADDITIONAL_COMPILE_FLAGS as FAIL or SKIPPED, but that creates
significant gaps in test coverage.
Fortunately, ADDITIONAL_COMPILE_FLAGS also supports "features", which
can be slightly enhanced to send Clang-compatible and MSVC-compatible
options to the right compilers.
This patch adds the gcc-style-warnings and cl-style-warnings Lit features,
and uses that to pass the appropriate warning flags to tests. It also uses
TEST_MEOW_DIAGNOSTIC_IGNORED for a few local suppressions of MSVC
warnings.
Fixes#75002. Found while running libc++'s tests with MSVC's STL.
This is a superset of #74961 that also fixes the product code
and adds a regression test. Thanks again, @cpplearner!
To summarize: `views::split` and `views::lazy_split` aren't unary,
aren't range adaptor **closure** objects, and can't be piped. However,
\[range.adaptor.object\]/8 says that `views::split(pattern)` and
`views::lazy_split(pattern)` produce unary, pipeable, range adaptor
closure objects.
This PR adjusts the test coverage accordingly, allowing it to portably
pass for libc++ and MSVC's STL.
Found while running libc++'s tests with MSVC's STL.
*
`libcxx/test/std/algorithms/alg.sorting/alg.heap.operations/sort.heap/ranges_sort_heap.pass.cpp`
+ Fix Clang `-Wunused-variable`, because `LIBCPP_ASSERT` expands to
nothing for MSVC's STL.
+ This is the same "always void-cast" change that #73437 applied to the
neighboring `complexity.pass.cpp`. I missed that
`ranges_sort_heap.pass.cpp` was also affected because we had disabled
this test.
*
`libcxx/test/std/input.output/file.streams/fstreams/ifstream.members/buffered_reads.pass.cpp`
*
`libcxx/test/std/input.output/file.streams/fstreams/ofstream.members/buffered_writes.pass.cpp`
+ Fix MSVC "warning C4244: '`=`': conversion from '`__int64`' to
'`_Ty`', possible loss of data".
+ This is a valid warning, possibly the best one that MSVC found in this
entire saga. We're accumulating a `std::vector<std::streamsize>` and
storing the result in `std::streamsize total_size` but we actually have
to start with `std::streamsize{0}` or we'll truncate.
*
`libcxx/test/std/input.output/filesystems/fs.enum/enum.path.format.pass.cpp`
+ Fix Clang `-Wunused-local-typedef` because the following usage is
libc++-only.
+ I'm just expanding it at the point of use, and using the dedicated
`LIBCPP_STATIC_ASSERT` to keep the line length down.
*
`libcxx/test/std/input.output/syncstream/syncbuf/syncstream.syncbuf.assign/swap.pass.cpp`
+ Fix MSVC "warning C4242: 'argument': conversion from '`int`' to
'`const _Elem`', possible loss of data".
+ This is a valid warning (possibly the second-best) as `sputc()`
returns `int_type`. If `sputc()` returns something unexpected, we want
to know, so we should separately say `expected.push_back(CharT('B'))`.
*
`libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new.size_align_nothrow.pass.cpp`
*
`libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new.size_nothrow.pass.cpp`
+ Fix MSVC "warning C6001: Using uninitialized memory '`x`'."
+ [N4964](https://wg21.link/N4964) \[new.delete.single\]/12:
> *Effects:* The deallocation functions
(\[basic.stc.dynamic.deallocation\]) called by a *delete-expression*
(\[expr.delete\]) to render the value of `ptr` invalid.
+ \[basic.stc.general\]/4:
> When the end of the duration of a region of storage is reached, the
values of all pointers representing the address of any part of that
region of storage become invalid pointer values (\[basic.compound\]).
Indirection through an invalid pointer value and passing an invalid
pointer value to a deallocation function have undefined behavior. Any
other use of an invalid pointer value has implementation-defined
behavior.
+ In certain configurations, after `delete x;` MSVC will consider `x` to
be radioactive (and in other configurations, it'll physically null out
`x` as a safety measure). We can copy it into `old_x` before deletion,
which the implementation finds acceptable.
*
`libcxx/test/std/ranges/range.adaptors/range.elements/general.pass.cpp`
*
`libcxx/test/std/ranges/range.adaptors/range.elements/iterator/deref.pass.cpp`
+ Fix MSVC "warning C4242: 'initializing': conversion from '`_Ty`' to
'`_Ty`', possible loss of data".
+ This was being emitted in `pair` and `tuple`'s perfect forwarding
constructors. Passing `short{1}` allows MSVC to see that no truncation
is happening.
*
`libcxx/test/std/ranges/range.adaptors/range.elements/iterator/member_types.compile.pass.cpp`
+ Fix MSVC "warning C4242: 'initializing': conversion from '`_Ty`' to
'`_Ty2`', possible loss of data".
+ Similarly, this was being emitted in `pair`'s perfect forwarding
constructor. After passing `short{1}`, I reduced repetition by relying
on CTAD. (I can undo that cleanup if it's stylistically undesirable.)
*
`libcxx/test/std/utilities/function.objects/refwrap/refwrap.const/type_conv_ctor.pass.cpp`
+ Fix MSVC "warning C4930: '`std::reference_wrapper<int> purr(void)`':
prototyped function not called (was a variable definition intended?)".
+ There's no reason for `purr()` to be locally declared (aside from
isolating it to a narrow scope, which has minimal benefits); it can be
declared like `meow()` above. 😸
*
`libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared_for_overwrite.pass.cpp`
*
`libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.create/make_unique_for_overwrite.default_init.pass.cpp`
+ Fix MSVC static analysis warnings when replacing `operator new`:
```
warning C28196: The requirement that '(_Param_(1)>0)?(return!=0):(1)' is
not satisfied. (The expression does not evaluate to true.)
warning C6387: 'return' could be '0': this does not adhere to the
specification for the function 'new'.
warning C6011: Dereferencing NULL pointer 'reinterpret_cast<char
*>ptr+i'.
```
+ All we need is a null check, which appears in other `operator new`
replacements:
b85f1f9b18/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new.size.replace.pass.cpp (L27-L28)
Found while running libc++'s tests with MSVC's STL.
*
`libcxx/test/std/algorithms/alg.modifying.operations/alg.unique/ranges_unique_copy.pass.cpp`
+ Fix MSVC "warning C4389: '`==`': signed/unsigned mismatch".
+ This was x86-specific for me. The LHS is `int` and the RHS is
`size_t`. We know the `array`'s size, so `static_cast<int>` is certainly
safe, and this matches the following `numberOfProj` comparisons.
*
`libcxx/test/std/containers/sequences/insert_range_sequence_containers.h`
+ Fix MSVC "warning C4267: 'argument': conversion from '`size_t`' to
'`const int`', possible loss of data".
+ `test_case.index` is `size_t`:
b85f1f9b18/libcxx/test/std/containers/insert_range_helpers.h (L65-L68)
+ But the container's `difference_type` is `int`:
b85f1f9b18/libcxx/test/support/test_allocator.h (L65-L76)
+ I introduced an alias `D` to make the long line more readable.
*
`libcxx/test/std/containers/unord/unord.map/eq.different_hash.pass.cpp`
*
`libcxx/test/std/containers/unord/unord.multimap/eq.different_hash.pass.cpp`
*
`libcxx/test/std/containers/unord/unord.multiset/eq.different_hash.pass.cpp`
*
`libcxx/test/std/containers/unord/unord.set/eq.different_hash.pass.cpp`
+ Fix MSVC "warning C6297: Arithmetic overflow. Results might not be an
expected value."
+ This warning is almost annoying enough to outright disable, but we use
similar `static_cast`s to deal with sign/truncation warnings elsewhere,
because there's some value in ensuring that product code is clean with
respect to these warnings. If there were many more occurrences, then
disabling the warning would be appropriate.
+ Cleanup: Change 2 inconsistently unqualified occurrences of `size_t`
to `std::size_t`.
*
`libcxx/test/std/containers/views/mdspan/layout_stride/index_operator.pass.cpp`
+ Fix MSVC "warning C4244: 'initializing': conversion from '`__int64`'
to '`size_t`', possible loss of data".
+ This was x86-specific for me. The `args` are indeed `int64_t`, and
we're storing the result in `size_t`, so we should cast.
* `libcxx/test/std/ranges/range.utility/range.utility.conv/container.h`
+ Fix MSVC "warning C4244: 'initializing': conversion from '`ptrdiff_t`'
to '`int`', possible loss of data".
+ Fix MSVC "warning C4267: 'initializing': conversion from '`size_t`' to
'`int`', possible loss of data".
+ We're initializing `int size_`, so we should explicitly cast from
pointer subtraction and `std::ranges::size`.
*
`libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/allocate_shared_for_overwrite.pass.cpp`
*
`libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared_for_overwrite.pass.cpp`
*
`libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.create/make_unique_for_overwrite.default_init.pass.cpp`
+ Fix MSVC "warning C4309: 'initializing': truncation of constant
value".
+ MSVC emits this warning because `0xDE` is outside the range of `char`
(signed by default in our implementation).
* `libcxx/test/support/concat_macros.h`
+ Fix MSVC "warning C4244: 'argument': conversion from '`char16_t`' to
'`const char`', possible loss of data".
+ Fix MSVC "warning C4244: 'argument': conversion from '`unsigned int`'
to '`const char`', possible loss of data".
+ This code was very recently introduced by @mordante in #73395.
Found while running libc++'s test suite with MSVC's STL.
* I've filed [LWG-4021](https://cplusplus.github.io/LWG/issue4021)
"`mdspan::is_always_meow()` should be `noexcept`" and implemented this
in libc++'s product and test code.
* Use `LIBCPP_STATIC_ASSERT` to avoid issues with `noexcept`
strengthening in MSVC's STL.
+ As permitted by the Standard, MSVC's STL conditionally strengthens
`mdspan` construction/`is_meow`/`stride` and `elements_view` iterator
`base() &&`, and always strengthens `basic_stringbuf` `swap`.
+ In `mdspan/properties.pass.cpp`, this also upgrades runtime `assert`s
to `static_assert`s.
* Improvement: Upgrade `assert` to `static_assert` when inspecting the
`noexcept`ness of `std::ranges::iter_move`. (These `!noexcept` tests
weren't causing issues for MSVC's STL, so I didn't change them to be
libc++-specific.)
Found while running libc++'s tests with MSVC's STL, where `std::array`
iterators are never pointers.
Most of these changes are reasonably self-explanatory (the `std::array`s
are right there, and the sometimes-slightly-wrapped raw pointer types
are a short distance away). A couple of changes are less obvious:
In `libcxx/test/std/containers/from_range_helpers.h`, `wrap_input()` is
called with `Iter` types that are constructible from raw pointers. It's
also sometimes called with an `array` as the `input`, so the first
overload was implicitly assuming that `array` iterators are pointers. We
can fix this assumption by providing a dedicated overload for `array`,
just like the one for `vector` immediately below. Finally,
`from_range_helpers.h` should explicitly include both `<array>` and
`<vector>`, even though they were apparently being dragged in already.
In `libcxx/test/std/containers/views/views.span/span.cons/iterator_sentinel.pass.cpp`,
fix `throw_operator_minus`. The error was pretty complicated, caused by
the concepts machinery noticing that `value_type` and `element_type`
were inconsistent. In the template instantiation context, you can see
the critical detail that `throw_operator_minus<std::_Array_iterator>` is
being formed.
Fortunately, the fix is extremely simple. To produce `element_type`
(which retains any cv-qualification, unlike `value_type`), we shouldn't
attempt to `remove_pointer` with the iterator type `It`. Instead, we've
already obtained the `reference` type, so we can `remove_reference_t`.
(This is modern code, where we have access to the alias templates, so I
saw no reason to use the older verbose form.)
I've structured this into a series of commits for even easier reviewing,
if that helps. I could easily split this up into separate PRs if
desired, but as this is low-risk with simple edits, I thought one PR
would be easiest.
* Drop unnecessary semicolons after function definitions.
* Cleanup comment typos.
* Cleanup `static_assert` typos.
* Cleanup test code typos.
+ There should be no functional changes, assuming I've changed all
occurrences.
* ~~Fix massive test code typos.~~
+ This was a real problem, but needed more surgery. I reverted those
changes here, and @philnik777 is fixing this properly with #73444.
* clang-formatting as requested by the CI.
This is to modify a list of libcxx tests written under the assumption
that iterators for std::array, std::string_view, and std::string are
pointers. The motivation for this PR is to make the tests more universal
and potentially being used to test other C++ standard library
implementations, for example
[microsoft/STL](https://github.com/microsoft/STL).
I can confirm that this patch makes a number of tests compatible with
microsoft STL:
`Failed : 204 (2.12%)` -> `Failed : 136 (1.42%)`
, and does not break any tests on `libcxx`.
This is not a complete list of such incompatibilities, but I am hoping
this will start a discussion about whether we are open to accepting such
changes.
Before this patch, we would fail to implicitly convert the result of
predicates to bool, which means we'd potentially perform a copy or move
construction of the boolean-testable, which isn't allowed. The same
holds true for comparing iterators against sentinels, which is allowed
to return a boolean-testable type.
We already had tests aiming to ensure correct handling of these types,
but they failed to provide appropriate coverage in several cases due to
guaranteed RVO. This patch fixes the tests, adds tests for missing
algorithms and views, and fixes the actual problems in the code.
Fixes#69074
We were incorrectly deducing the return type of size() because we were
not using ternary operators in the implementation (as the spec says).
Instead of deducing the common type of the expressions in the spec, we
would deduce potentially different return types and fail to compile.
Fixes#67551
Since LLVM 17 has been branched and is on the verge of being released,
we can drop the CI job that tests against Clang 15. I think the number
of cherry-picks to `release/17.x` will be a lot smaller now, so keeping
a Clang 15 job around for that purpose seems unnecessary.
As a fly-by, this patch also removes some Clang 15 workarounds and test
suite annotations as we usually do. It also removes some slightly older
gcc test suite annotations that were missed.
AppleClang 15 was released on September 18th and is now stable. Per our
policy, we're bumping the supported AppleClang compiler to the latest
release. This allows cleaning up the test suite, but most importantly
unblocking various other patches that are blocked on bumping the
compiler requirements.
