181 Commits

Author SHA1 Message Date
Peng Liu
f1ecff8f88
[libc++] Improve test coverage and readability for swap_ranges (#133752)
This patch enhances the test coverage of `{std,ranges}::swap_ranges` by
adding larger test cases with 100 elements across different containers.
It also inlines standalone tests for better readability, avoiding
unnecessary navigation.

This patch addresses a follow-up suggestion from PR #121138 to extend
test coverage beyond 3 elements.
2025-05-14 13:02:01 -04:00
Peng Liu
7087ee6bc7
[libc++][NFC] Improve test readability for std::fill_n (#133771)
This patch enhances test readability by inlining standalone tests,
eliminating unnecessary navigation. Additionally, several classes with
ad-hoc names have been renamed for better clarity:
- `A` -> `CharWrapper` as it wraps a char
- `B -> CharTransformer` as it accepts a char `xc` but stores `xc + 1`
- `Storage -> CharUnionStorage` as it stores a union of 2 `char`s.  

This patch addresses a follow-up comment from #120909 to inline tests.
2025-05-06 16:17:18 -04:00
Stephan T. Lavavej
bf5cdd6358
[libc++][test] Fix issues found by MSVC's STL (#131787)
* libcxx/test/support/min_allocator.h
+ Fix `tiny_size_allocator::rebind` which mistakenly said `T` instead of
`U`.
*
libcxx/test/std/algorithms/alg.modifying.operations/alg.partitions/stable_partition.pass.cpp
  + `std::stable_partition` requires bidirectional iterators.
* libcxx/test/std/containers/sequences/vector.bool/max_size.pass.cpp
+ Fix allocator type given to `std::vector<bool>`. The element types are
required to match, [N5008](https://isocpp.org/files/papers/N5008.pdf)
\[container.alloc.reqmts\]/5: "*Mandates:* `allocator_type::value_type`
is the same as `X::value_type`."
* libcxx/test/std/time/time.clock/time.clock.utc/types.compile.pass.cpp
+ Mark `is_steady` as `[[maybe_unused]]`, as it appears within
`LIBCPP_STATIC_ASSERT` only.
*
libcxx/test/std/algorithms/alg.modifying.operations/alg.rotate/rotate.pass.cpp
*
libcxx/test/std/algorithms/alg.modifying.operations/alg.swap/swap_ranges.pass.cpp
* libcxx/test/std/utilities/utility/utility.swap/swap_array.pass.cpp
+ Fix MSVC warning C4127 "conditional expression is constant".
`TEST_STD_AT_LEAST_23_OR_RUNTIME_EVALUATED` was introduced for this
purpose, so it should be used consistently.
* libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp
+ Fix `gcd()` precondition violation for `signed char`. This test case
was causing `-128` to be passed as a `signed char` to `gcd()`, which is
forbidden.
* libcxx/test/std/containers/sequences/array/assert.iterators.pass.cpp
*
libcxx/test/std/containers/sequences/vector/vector.modifiers/assert.push_back.invalidation.pass.cpp
*
libcxx/test/std/input.output/iostream.format/print.fun/no_file_description.pass.cpp
+ Split some REQUIRES and XFAIL lines. This is a "nice to have" for
MSVC's internal test harness, which is extremely simple and looks for
exact comment matches to skip tests. We can recognize the specific lines
"REQUIRES: has-unix-headers" and "XFAIL: msvc", but it's a headache to
maintain if they're chained with other conditions.
* libcxx/test/support/sized_allocator.h
+ Fix x86 truncation warnings. `std::allocator` takes `std::size_t`, so
we need to `static_cast`.
*
libcxx/test/std/input.output/file.streams/fstreams/ifstream.members/offset_range.pass.cpp
+ Fix x86 truncation warning. `std::min()` is returning
`std::streamoff`, which was being unnecessarily narrowed to
`std::size_t`.
*
libcxx/test/std/algorithms/alg.sorting/alg.merge/inplace_merge_comp.pass.cpp
+ Fix MSVC warning C4127 "conditional expression is constant" for an
always-true branch. This was very recently introduced by #129008 making
`N` constexpr. As it's a local constant just nine lines above, we don't
need to test whether 100 is greater than 0.
2025-03-20 15:53:25 +08:00
Peng Liu
029cb8aff1
[libc++] Fix copy_backward for vector<bool> with small storage types (#131560)
This patch fixes an issue in libc++ where `std::copy_backward` and
`ranges::copy_backward` incorrectly copy `std::vector<bool>` with small
storage types (e.g., `uint8_t`, `uint16_t`). The problem arises from
flawed bit mask computations involving integral promotions and sign-bit
extension, leading to unintended zeroing of bits. This patch corrects
the bitwise operations to ensure correct bit-level copying.

Fixes #131718.
2025-03-19 11:58:02 -04:00
Peng Liu
a5b3d3a03f
[libc++] Fix {std, ranges}::copy for vector<bool> with small storage types (#131545)
The current implementation of `{std, ranges}::copy` fails to copy
`vector<bool>` correctly when the underlying storage type
(`__storage_type`) is smaller than `int`, such as `unsigned char`,
`unsigned short`, `uint8_t` and `uint16_t`. The root cause is that the
unsigned small storage type undergoes integer promotion to (signed)
`int`, which is then left and right shifted, leading to UB (before
C++20) and sign-bit extension (since C++20) respectively. As a result,
the underlying bit mask evaluations become incorrect, causing erroneous
copying behavior.

This patch resolves the issue by correcting the internal bitwise
operations, ensuring that `{std, ranges}::copy` operates correctly for
`vector<bool>` with any custom (unsigned) storage types.

Fixes #131692.
2025-03-19 11:55:51 -04:00
Peng Liu
4baf1c03fa
[libc++] Optimize ranges::rotate for vector<bool>::iterator (#121168)
This PR optimizes the performance of `std::ranges::rotate` for
`vector<bool>::iterator`. The optimization yields a performance
improvement of up to 2096x.

Closes #64038.
2025-03-13 14:07:23 -04:00
A. Jiang
c28c508962
[libc++] Implement part of P2562R1: constexpr ranges::stable_partition (#129839) 2025-03-06 09:23:55 +08:00
Peng Liu
a12744ff05
[libc++] Optimize ranges::swap_ranges for vector<bool>::iterator (#121150)
This PR optimizes the performance of `std::ranges::swap_ranges` for
`vector<bool>::iterator`, addressing a subtask outlined in issue #64038.
The optimizations yield performance improvements of up to **611x** for
aligned range swap and **78x** for unaligned range swap comparison.
Additionally, comprehensive tests covering up to 4 storage words (256
bytes) with odd and even bit sizes are provided, which validate the
proposed optimizations in this patch.
2025-03-04 17:15:36 -05:00
A. Jiang
bf9bf291a3
[libc++] Implement part of P2562R1: constexpr std::stable_partition (#128868)
Drive-by changes:
- Enables no-memory case for Clang.
- Enables `robust_re_difference_type.compile.pass.cpp` and
`robust_against_proxy_iterators_lifetime_bugs.pass.cpp` test coverage
for `std::stable_sort` in constant evaluation since C++26. The changes
were missing in the PR making `std::stable_sort` `constexpr`.
2025-03-04 09:23:29 +08:00
Peng Liu
f161b1b526
[libc++][test] Refactor tests for rotate and rotate_copy (#126458)
This PR refactors the tests and fix some problems:  
- Refactor similar tests using `types::for_each` to remove redundant code;
- Explicitly include the missing header `type_algorithms.h` instead of relying
  on a transitive include;
- Fix the incorrect constexpr declaration in `rotate.pass.cpp`, where
  the `test()` function is incorrectly defined as `TEST_CONSTEXPR_CXX17`,
  which is wrong since `std::rotate()` becomes constexpr only since C++20.
2025-02-26 11:57:57 -05:00
Peng Liu
ffc5d2b5d4
[libc++][test] Refactor tests for ranges::swap_range algorithms (#121138)
This PR refactors tests for `ranges::swap_range`, `std::{swap_range,
iter_swap, swap}` algorithms to eliminate redundant code.
2025-02-26 11:49:19 -05:00
Peng Liu
1d583ed2fb
[libc++][test] Augment ranges::{fill, fill_n, find} with missing tests (#121209)
libc++ currently has very limited test coverage for `std::ranges{fill, fill_n, find}`
with `vector<bool>::iterator` optimizations. Specifically, the existing tests for
`std::ranges::fill` only covers cases of 1 - 2 bytes, which is merely 1/8 to 1/4
of the `__storage_type` word size. This renders the tests insufficient to validate
functionality for whole words, with or without partial words (which necessitates at
least 8 bytes of data). Moreover, no tests were provided for `ranges::{find, fill_n}`
with `vector<bool>::iterator` optimizations. This PR fills in the gap.
2025-02-26 11:38:15 -05:00
Peng Liu
ad87d5f23d
[libc++][test] Refactor tests for std::{copy, move, fill} algorithms (#120909)
This refactor includes the following changes:
- Refactor similar tests using `types::for_each` to remove redundant code;
- Explicitly include the missing header `type_algorithms.h` in some test files;
- Some tests scattered in different test functions with ad-hoc names
  (e.g., `test5()`, `test6()`) but belong to the same kind are now grouped
  into one function (`test_struct_array()`).
2025-02-19 12:44:44 -05:00
Peng Liu
ab3d793982
[libc++] Optimize ranges::move{,_backward} for vector<bool>::iterator (#121109)
As a follow-up to #121013 (which optimized `ranges::copy`) and #121026
(which optimized `ranges::copy_backward`), this PR enhances the
performance of `std::ranges::{move, move_backward}` for
`vector<bool>::iterator`, addressing a subtask outlined in issue #64038.

The optimizations bring performance improvements analogous to those
achieved for the `{copy, copy_backward}` algorithms: up to 2000x for
aligned moves and 60x for unaligned moves. Moreover, comprehensive
tests covering up to 4 storage words (256 bytes) with odd and even bit
sizes are provided, which validate the proposed optimizations in this
patch.
2025-02-19 11:36:45 -05:00
Peng Liu
cf9806eb4d
[libc++] Fix UB in bitwise logic of {std, ranges}::{fill, fill_n} algorithms (#122410)
This PR addresses an undefined behavior that arises when using the
`std::fill` and `std::fill_n` algorithms, as well as their ranges
counterparts `ranges::fill` and `ranges::fill_n`, with `vector<bool, Alloc>`
that utilizes a custom-sized allocator with small integral types.
2025-02-05 11:39:49 -05:00
Peng Liu
edc3dc6abd
[libc++] Optimize ranges::copy_backward for vector<bool>::iterator (#121026)
As a follow-up to #121013 (which focused on `std::ranges::copy`), this
PR optimizes the performance of `std::ranges::copy_backward` for
`vector<bool>::iterator`, addressing a subtask outlined in issue #64038.
The optimizations yield performance improvements of up to 2000x for
aligned copies and 60x for unaligned copies.
2025-01-30 14:55:05 -05:00
Peng Liu
5b65896ad6
[libc++] Optimize ranges::copy{, _n} for vector<bool>::iterator (#121013)
This PR optimizes the performance of `std::ranges::copy` and
`std::ranges::copy_n` specifically for `vector<bool>::iterator`,
addressing a subtask outlined in issue #64038. The optimizations yield
performance improvements of up to **2000x** for aligned copies and
**60x** for unaligned copies. Additionally, new tests have been added to
validate these enhancements.


- Aligned source-destination bits

ranges::copy
```
--------------------------------------------------------------------------
Benchmark                                Before        After   Improvement
--------------------------------------------------------------------------
bm_ranges_copy_vb_aligned/8              10.8 ns      1.42 ns           8x
bm_ranges_copy_vb_aligned/64             88.5 ns      2.28 ns          39x
bm_ranges_copy_vb_aligned/512             709 ns      1.95 ns         364x
bm_ranges_copy_vb_aligned/4096           5568 ns      5.01 ns        1111x
bm_ranges_copy_vb_aligned/32768         44754 ns      38.7 ns        1156x
bm_ranges_copy_vb_aligned/65536         91092 ns      73.2 ns        1244x
bm_ranges_copy_vb_aligned/102400       139473 ns       127 ns        1098x
bm_ranges_copy_vb_aligned/106496       189004 ns      81.5 ns        2319x
bm_ranges_copy_vb_aligned/110592       153647 ns      71.1 ns        2161x
bm_ranges_copy_vb_aligned/114688       159261 ns      70.2 ns        2269x
bm_ranges_copy_vb_aligned/118784       181910 ns      73.5 ns        2475x
bm_ranges_copy_vb_aligned/122880       174117 ns      76.5 ns        2276x
bm_ranges_copy_vb_aligned/126976       176020 ns      82.0 ns        2147x
bm_ranges_copy_vb_aligned/131072       180757 ns       137 ns        1319x
bm_ranges_copy_vb_aligned/135168       190342 ns       158 ns        1205x
bm_ranges_copy_vb_aligned/139264       192831 ns       103 ns        1872x
bm_ranges_copy_vb_aligned/143360       199627 ns      89.4 ns        2233x
bm_ranges_copy_vb_aligned/147456       203881 ns      88.6 ns        2301x
bm_ranges_copy_vb_aligned/151552       213345 ns      88.4 ns        2413x
bm_ranges_copy_vb_aligned/155648       216892 ns      92.9 ns        2335x
bm_ranges_copy_vb_aligned/159744       222751 ns      96.4 ns        2311x
bm_ranges_copy_vb_aligned/163840       225995 ns       173 ns        1306x
bm_ranges_copy_vb_aligned/167936       235230 ns       202 ns        1165x
bm_ranges_copy_vb_aligned/172032       244093 ns       131 ns        1863x
bm_ranges_copy_vb_aligned/176128       244434 ns       111 ns        2202x
bm_ranges_copy_vb_aligned/180224       249570 ns       108 ns        2311x
bm_ranges_copy_vb_aligned/184320       254538 ns       108 ns        2357x
bm_ranges_copy_vb_aligned/188416       261817 ns       113 ns        2317x
bm_ranges_copy_vb_aligned/192512       269923 ns       125 ns        2159x
bm_ranges_copy_vb_aligned/196608       273494 ns       210 ns        1302x
bm_ranges_copy_vb_aligned/200704       280035 ns       269 ns        1041x
bm_ranges_copy_vb_aligned/204800       293102 ns       231 ns        1269x
```

ranges::copy_n
```
--------------------------------------------------------------------------
Benchmark                                Before        After   Improvement
--------------------------------------------------------------------------
bm_ranges_copy_n_vb_aligned/8            11.8 ns       0.89 ns         13x
bm_ranges_copy_n_vb_aligned/64           91.6 ns       2.06 ns         44x
bm_ranges_copy_n_vb_aligned/512           718 ns       2.45 ns        293x
bm_ranges_copy_n_vb_aligned/4096         5750 ns       5.02 ns       1145x
bm_ranges_copy_n_vb_aligned/32768       45824 ns       40.9 ns       1120x
bm_ranges_copy_n_vb_aligned/65536       92267 ns       73.8 ns       1250x
bm_ranges_copy_n_vb_aligned/102400     143267 ns       125 ns        1146x
bm_ranges_copy_n_vb_aligned/106496     148625 ns      82.4 ns        1804x
bm_ranges_copy_n_vb_aligned/110592     154817 ns      72.0 ns        2150x
bm_ranges_copy_n_vb_aligned/114688     157953 ns      70.4 ns        2244x
bm_ranges_copy_n_vb_aligned/118784     162374 ns      71.5 ns        2270x
bm_ranges_copy_n_vb_aligned/122880     168638 ns      72.9 ns        2313x
bm_ranges_copy_n_vb_aligned/126976     175596 ns      76.6 ns        2292x
bm_ranges_copy_n_vb_aligned/131072     181164 ns       135 ns        1342x
bm_ranges_copy_n_vb_aligned/135168     184697 ns       157 ns        1176x
bm_ranges_copy_n_vb_aligned/139264     191395 ns       104 ns        1840x
bm_ranges_copy_n_vb_aligned/143360     194954 ns      88.3 ns        2208x
bm_ranges_copy_n_vb_aligned/147456     208917 ns      86.1 ns        2426x
bm_ranges_copy_n_vb_aligned/151552     211101 ns      87.2 ns        2421x
bm_ranges_copy_n_vb_aligned/155648     213175 ns      89.0 ns        2395x
bm_ranges_copy_n_vb_aligned/159744     218988 ns      86.7 ns        2526x
bm_ranges_copy_n_vb_aligned/163840     225263 ns       156 ns        1444x
bm_ranges_copy_n_vb_aligned/167936     230725 ns       184 ns        1254x
bm_ranges_copy_n_vb_aligned/172032     235795 ns       119 ns        1981x
bm_ranges_copy_n_vb_aligned/176128     241145 ns       101 ns        2388x
bm_ranges_copy_n_vb_aligned/180224     250680 ns      99.5 ns        2519x
bm_ranges_copy_n_vb_aligned/184320     262954 ns      99.7 ns        2637x
bm_ranges_copy_n_vb_aligned/188416     258584 ns       103 ns        2510x
bm_ranges_copy_n_vb_aligned/192512     267190 ns       125 ns        2138x
bm_ranges_copy_n_vb_aligned/196608     270821 ns       213 ns        1271x
bm_ranges_copy_n_vb_aligned/200704     279532 ns       262 ns        1067x
bm_ranges_copy_n_vb_aligned/204800     283412 ns       222 ns        1277x
```

- Unaligned source-destination bits
```
--------------------------------------------------------------------------------
Benchmark                                    Before           After  Improvement
--------------------------------------------------------------------------------
bm_ranges_copy_vb_unaligned/8               12.8 ns         8.59 ns         1.5x
bm_ranges_copy_vb_unaligned/64              98.2 ns         8.24 ns          12x
bm_ranges_copy_vb_unaligned/512              755 ns         18.1 ns          42x
bm_ranges_copy_vb_unaligned/4096            6027 ns          102 ns          59x
bm_ranges_copy_vb_unaligned/32768          47663 ns          774 ns          62x
bm_ranges_copy_vb_unaligned/262144        378981 ns         6455 ns          59x
bm_ranges_copy_vb_unaligned/1048576      1520486 ns        25942 ns          59x
bm_ranges_copy_n_vb_unaligned/8             11.3 ns         8.22 ns         1.4x
bm_ranges_copy_n_vb_unaligned/64            97.3 ns         7.89 ns          12x
bm_ranges_copy_n_vb_unaligned/512            747 ns         18.1 ns          41x
bm_ranges_copy_n_vb_unaligned/4096          5932 ns         99.0 ns          60x
bm_ranges_copy_n_vb_unaligned/32768        47776 ns         749 ns           64x
bm_ranges_copy_n_vb_unaligned/262144      378802 ns        6576 ns           58x
bm_ranges_copy_n_vb_unaligned/1048576    1547234 ns       26229 ns           59x
```
2025-01-30 17:26:26 +01:00
Nikolas Klauser
e99c4906e4
[libc++] Granularize <cstddef> includes (#108696) 2024-10-31 02:20:10 +01:00
Louis Dionne
09e3a36058
[libc++][modules] Fix missing and incorrect includes (#108850)
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.
2024-09-16 15:06:20 -04:00
A. Jiang
94e7c0b051
[libc++] Remove get_temporary_buffer and return_temporary_buffer (#100914)
Works towards P0619R4 / #99985.

The use of `std::get_temporary_buffer` and `std::return_temporary_buffer`
are replaced with `unique_ptr`-based RAII buffer holder.

Escape hatches:
- `_LIBCPP_ENABLE_CXX20_REMOVED_TEMPORARY_BUFFER` restores
`std::get_temporary_buffer` and `std::return_temporary_buffer`.

Drive-by changes:
- In `<syncstream>`, states that `get_temporary_buffer` is now removed,
because `<syncstream>` is added in C++20.
2024-09-16 11:53:05 -04:00
Louis Dionne
f73050e722
[libc++] Fix several double-moves in the code base (#104616)
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
2024-08-20 14:36:11 -04:00
Louis Dionne
bd3f5a4bd3
[libc++][pstl] Improve exception handling (#88998)
There were various places where we incorrectly handled exceptions in the
PSTL. Typical issues were missing `noexcept` and taking iterators by
value instead of by reference.

This patch fixes those inconsistent and incorrect instances, and adds
proper tests for all of those. Note that the previous tests were often
incorrectly turned into no-ops by the compiler due to copy ellision,
which doesn't happen with these new tests.
2024-05-22 12:39:21 -07:00
Nikolas Klauser
07b18c5e1b
[libc++] Optimize ranges::fill{,_n} for vector<bool>::iterator (#84642)
```
------------------------------------------------------
Benchmark                          old             new
------------------------------------------------------
bm_ranges_fill_n/1             1.64 ns         3.06 ns
bm_ranges_fill_n/2             3.45 ns         3.06 ns
bm_ranges_fill_n/3             4.88 ns         3.06 ns
bm_ranges_fill_n/4             6.46 ns         3.06 ns
bm_ranges_fill_n/5             8.03 ns         3.06 ns
bm_ranges_fill_n/6             9.65 ns         3.07 ns
bm_ranges_fill_n/7             11.5 ns         3.06 ns
bm_ranges_fill_n/8             13.0 ns         3.06 ns
bm_ranges_fill_n/16            25.9 ns         3.06 ns
bm_ranges_fill_n/64             103 ns         4.62 ns
bm_ranges_fill_n/512            711 ns         4.40 ns
bm_ranges_fill_n/4096          5642 ns         9.86 ns
bm_ranges_fill_n/32768        45135 ns         33.6 ns
bm_ranges_fill_n/262144      360818 ns          243 ns
bm_ranges_fill_n/1048576    1442828 ns          982 ns
bm_ranges_fill/1               1.63 ns         3.17 ns
bm_ranges_fill/2               3.43 ns         3.28 ns
bm_ranges_fill/3               4.97 ns         3.31 ns
bm_ranges_fill/4               6.53 ns         3.27 ns
bm_ranges_fill/5               8.12 ns         3.33 ns
bm_ranges_fill/6               9.76 ns         3.32 ns
bm_ranges_fill/7               11.6 ns         3.29 ns
bm_ranges_fill/8               13.2 ns         3.26 ns
bm_ranges_fill/16              26.3 ns         3.26 ns
bm_ranges_fill/64               104 ns         4.92 ns
bm_ranges_fill/512              716 ns         4.47 ns
bm_ranges_fill/4096            5772 ns         8.21 ns
bm_ranges_fill/32768          45778 ns         33.1 ns
bm_ranges_fill/262144        351422 ns          241 ns
bm_ranges_fill/1048576      1404710 ns          965 ns
```
2024-03-17 20:00:54 +01:00
Konstantin Varlamov
8dfc67d672
[libc++][hardening] Rework how the assertion handler can be overridden. (#77883)
Previously there were two ways to override the verbose abort function
which gets called when a hardening assertion is triggered:
- compile-time: define the `_LIBCPP_VERBOSE_ABORT` macro;
- link-time: provide a definition of `__libcpp_verbose_abort` function.

This patch adds a new configure-time approach: the vendor can provide
a path to a custom header file which will get copied into the build by
CMake and included by the library. The header must provide a definition
of the
`_LIBCPP_ASSERTION_HANDLER` macro which is what will get called should
a hardening assertion fail. As of this patch, overriding
`_LIBCPP_VERBOSE_ABORT` will still work, but the previous mechanisms
will be effectively removed in a follow-up patch, making the
configure-time mechanism the sole way of overriding the default handler.

Note that `_LIBCPP_ASSERTION_HANDLER` only gets invoked when a hardening
assertion fails. It does not affect other cases where
`_LIBCPP_VERBOSE_ABORT` is currently used (e.g. when an exception is
thrown in the `-fno-exceptions` mode).

The library provides a default version of the custom header file that
will get used if it's not overridden by the vendor. That allows us to
always test the override mechanism and reduces the difference in
configuration between the pristine version of the library and
a platform-specific version.
2024-01-17 18:56:07 -08:00
Stephan T. Lavavej
64addd6521
[libc++][test] Enhance ADDITIONAL_COMPILE_FLAGS, use TEST_MEOW_DIAGNOSTIC_IGNORED sparingly (#75317)
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.
2023-12-14 17:38:27 -05:00
Jakub Mazurkiewicz
6a66467499
[libc++] P2770R0: Stashing stashing iterators for proper flattening (#66033)
- Partially implements P2770R0 (http://wg21.link/p2770)
- Fixes https://wg21.link/LWG3698, https://wg21.link/LWG3700, and https://wg21.link/LWG3791
- join_with_view hasn't been done yet since this type isn't implemented yet
- Rename tuple test directory to match the standard (which changed in P2770R0)
- Rename join_view test directory to match the standard
2023-12-12 09:45:14 -05:00
Stephan T. Lavavej
774295ca1d
[libc++][test] Fix MSVC warnings with static_casts (#74962)
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.
2023-12-10 13:41:30 -08:00
Stephan T. Lavavej
bfdc562d0c
[libc++] Fix copy-paste damage in ranges::rotate_copy and its test (#74544)
Found while running libc++'s tests with MSVC's STL.

`ranges::rotate_copy` takes `forward_iterator`s as this test's comment
banner correctly depicts. However, this test had bogus assertions
expecting that `ranges::rotate_copy` would be constrained away for
not-quite-**bidi** iterators. @philnik777 confirmed that these were
copy-paste relics from the `ranges::reverse_copy` test.

I fixed this by replacing the assertions with the test types that aren't
quite **forward** iterators/ranges. Additionally, I noticed that the
top-level `test()` function was missing coverage with the weakest
possible `forward_iterator<int*>`.

This revealed that the product code in `ranges_rotate_copy.h` was
similarly damaged. In addition to fixing it by taking `forward_iterator`
and `forward_range` as depicted in the Standard, this drops the
inclusion of `<__iterator/reverse_iterator.h>` as this algorithm doesn't
need `std::__reverse_range`.
2023-12-06 02:29:09 -08:00
Stephan T. Lavavej
f1db578f0d
[libc++][test] Fix assumptions that std::array iterators are pointers (#74430)
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.)
2023-12-05 11:25:42 -05:00
Stephan T. Lavavej
164c204a19
[libc++][test] Fix simple warnings (#74186)
Found while running libc++'s tests with MSVC's STL. This fixes 3 kinds of warnings:

- Add void-casts to fix `-Wunused-variable` warnings.
- Avoid sign/truncation warnings in `ConvertibleToIntegral.h`.
- Add `TEST_STD_AT_LEAST_23_OR_RUNTIME_EVALUATED` to avoid mixing preprocessor 
  and runtime tests.
- Cleanup: Add `TEST_STD_AT_LEAST_20_OR_RUNTIME_EVALUATED` for
  consistency.
2023-12-05 09:46:41 -05:00
Stephan T. Lavavej
c000f754bf
[libc++][test] Avoid non-Standard zero-length arrays (#74183)
Found while running libc++'s test suite with MSVC's STL, where we use
both MSVC's compiler and Clang/LLVM.

MSVC's compiler rejects the non-Standard extension of zero-length
arrays. For conformance, I'm changing these occurrences to
`std::array<int, 0>`.

Many of these files already had `#include <array>`; I'm adding it to the
rest.

I wanted to add `-Wzero-length-array` to
`libcxx/utils/libcxx/test/params.py` to prevent future occurrences, but
it complained about product code 😿 :

```
In file included from /home/runner/_work/llvm-project/llvm-project/libcxx/test/std/input.output/iostream.format/input.streams/istream.formatted/istream.formatted.arithmetic/long.pass.cpp:18:
In file included from /home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/istream:170:
In file included from /home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/ostream:172:
In file included from /home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/__system_error/error_code.h:18:
In file included from /home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/__system_error/error_category.h:15:
/home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/string:811:25: error: zero size arrays are an extension [-Werror,-Wzero-length-array]
  811 |         char __padding_[sizeof(value_type) - 1];
      |                         ^~~~~~~~~~~~~~~~~~~~~~
/home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/string:817:19: note: in instantiation of member class 'std::basic_string<char>::__short' requested here
  817 |     static_assert(sizeof(__short) == (sizeof(value_type) * (__min_cap + 1)), "__short has an unexpected size.");
      |                   ^
/home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/string:2069:5: note: in instantiation of template class 'std::basic_string<char>' requested here
 2069 |     _LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST(_LIBCPP_DECLARE, char)
      |     ^
/home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/__string/extern_template_lists.h:31:60: note: expanded from macro '_LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST'
   31 |   _Func(_LIBCPP_EXPORTED_FROM_ABI basic_string<_CharType>& basic_string<_CharType>::replace(size_type, size_type, value_type const*, size_type)) \
      |                                                            ^
```

I pushed a tiny commit to fix unrelated comment typos, in an attempt to
clear out spurious CI failures.
2023-12-03 10:47:09 +01:00
Stephan T. Lavavej
f5832bab6f
[libc++][test] Cleanup typos and unnecessary semicolons (#73435)
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.
2023-11-27 02:11:24 +01:00
Duo Wang
d05bada592
[libcxx][test] std::array::iterator are not pointers by C++ standard (#70729)
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.
2023-11-12 17:30:15 +01:00
Louis Dionne
02540b2f6d
[libc++] Make sure ranges algorithms and views handle boolean-testable correctly (#69378)
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
2023-11-06 21:19:49 -10:00
Rajveer Singh Bharadwaj
dd4891318c
[libc++] Fix _CopySegment helper in ranges::copy(join_view, out) when called in a static assertion context (#69593)
Resolves Issue #69083

The `_CopySegment` helper for `ranges::copy(join_view, out)` is not
`constexpr` causing rejection in `libc++` in a static assertion context
as in the issue snippet.
2023-10-27 11:07:12 +02:00
Nikolas Klauser
5d7f346bd3 [libc++][PSTL] Implement std::rotate_copy
Reviewed By: #libc, ldionne

Spies: ldionne, libcxx-commits

Differential Revision: https://reviews.llvm.org/D155025
2023-10-24 14:02:37 +02:00
Nikolas Klauser
d2a46e6480 [libc++][PSTL] Implement std::move
Reviewed By: #libc, ldionne

Spies: ldionne, libcxx-commits

Differential Revision: https://reviews.llvm.org/D155330
2023-10-22 10:25:49 +02:00
Nikolas Klauser
aade74675c [libc++][PSTL] Overhaul exceptions handling
This makes exception handling a lot simpler, since we don't have to convert any exceptions this way. Is also properly handles all the user-thrown exceptions.

Reviewed By: ldionne, #libc

Spies: arichardson, mstorsjo, libcxx-commits

Differential Revision: https://reviews.llvm.org/D154238
2023-10-06 23:01:30 +02:00
Louis Dionne
6b03d8aa94 [libc++][NFC] Remove spurious check for is-constant-evaluated
This NFC change was reverted as part of 880fa7faa97, but the change is
really good regardless of the associated Clang patch.
2023-09-28 14:21:35 -04:00
Louis Dionne
9bb9ec380a
[libc++][NFC] Simplify checks for static assertions in .verify.cpp tests (#67559)
We don't neeed to handle both spellings anymore since we don't support
Clang 15 anymore.
2023-09-28 09:07:08 -04:00
Sam McCall
880fa7faa9 Revert "[clang][SemaCXX] Diagnose tautological uses of consteval if and is_constant_evaluated"
This reverts commit 491b2810fb7fe5f080fa9c4f5945ed0a6909dc92.

This change broke valid code and generated incorrect diagnostics, see
https://reviews.llvm.org/D155064
2023-09-27 18:58:01 +02:00
Takuya Shimizu
491b2810fb [clang][SemaCXX] Diagnose tautological uses of consteval if and is_constant_evaluated
This patch makes clang diagnose extensive cases of consteval if and is_constant_evaluated usage that are tautologically true or false.
This introduces a new IsRuntimeEvaluated boolean flag to Sema::ExpressionEvaluationContextRecord that means the immediate appearance of if consteval or is_constant_evaluated are tautologically false(e.g. inside if !consteval {} block or non-constexpr-qualified function definition body)
This patch also pushes new expression evaluation context when parsing the condition of if constexpr and initializer of constexpr variables so that Sema can be aware that the use of consteval if and is_consteval are tautologically true in if constexpr condition and constexpr variable initializers.
BEFORE this patch, the warning for is_constant_evaluated was emitted from constant evaluator. This patch moves the warning logic to Sema in order to diagnose tautological use of is_constant_evaluated in the same way as consteval if.

This patch separates initializer evaluation context from InitializerScopeRAII.
This fixes a bug that was happening when user takes address of function address in initializers of non-local variables.

Fixes https://github.com/llvm/llvm-project/issues/43760
Fixes https://github.com/llvm/llvm-project/issues/51567

Reviewed By: cor3ntin, ldionne
Differential Revision: https://reviews.llvm.org/D155064
2023-09-27 09:26:06 +09:00
Louis Dionne
6f36ead577 [libc++] Fix std::move algorithm with trivial move-only types
As reported in https://reviews.llvm.org/D151953#4472195, the std::move
algorithm (and various other functions that relied on it) stopped working
after starting to use `__constexpr_memmove` in its implementation. This
patch fixes the underlying issue in `__constexpr_memmove` and adds tests
for various related algorithms and functions that were not exercising
trivial move-only types.

Differential Revision: https://reviews.llvm.org/D154613
2023-07-10 11:50:09 -04:00
Louis Dionne
b82dcb624e [libc++] Move all the remaining .fail.cpp tests to .verify.cpp
I made sure they all had some expected-error output in them. Many of
these tests would be better implemented as a positive test using SFINAE,
but this is beyond the scope of this patch.

Differential Revision: https://reviews.llvm.org/D153980
2023-07-03 09:41:03 -04:00
Nikolas Klauser
c4e98722ca [libc++] Fix std::copy and std::move for ranges with potentially overlapping tail padding
This fixes thr bug reported in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108846.

Reviewed By: ldionne, #libc

Spies: mstorsjo, libcxx-commits

Differential Revision: https://reviews.llvm.org/D151953
2023-06-30 13:48:16 -07:00
Louis Dionne
f13e1a65ca [libc++] Revert __uninitialized_buffer changes
This patch reverts the following commits:

    015cd317eaed28a923d14a33c9d6739012a688be (add missing HIDE_FROM_ABI)
    420a204d52205f1277a8d5df3dbafac6082e02e2 (add _LIBCPP_NO_CFI)
    31eeba3f7c0e2ef4a21c07da9326a4ae1a8de7e2 (add __uninitialized_buffer)

It also reverts a small part of b935ab8e747cf52ff12471879460206a9f433eea
which is required to make the stable_partition.pass.cpp test pass on GCC.

Some issues were pointed out in https://reviews.llvm.org/D152208 and
in https://reviews.llvm.org/D154017, so I am reverting this patch
until we have time to weigh the various solutions and get consensus
on the design of the API.

Differential Revision: https://reviews.llvm.org/D154161
2023-06-30 09:17:24 -04:00
Nikolas Klauser
b935ab8e74 [libc++] Add tests to make sure that stable algorithms work without memory available
Reviewed By: #libc, ldionne

Spies: power-llvm-team, ldionne, libcxx-commits, arichardson, mstorsjo

Differential Revision: https://reviews.llvm.org/D152939
2023-06-15 10:59:34 -07:00
Louis Dionne
520c7fbbd0 [libc++] Mark slow tests as unsupported on GCC
Some tests in our test suite are unbelievably slow on GCC due to the
use of the always_inline attribute. See [1] for more details.

This patch introduces the GCC-ALWAYS_INLINE-FIXME lit feature to
disable tests that are plagued by that issue. At the same time, it
moves several existing tests from ad-hoc `UNSUPPORTED: gcc-12` markup
to the new GCC-ALWAYS_INLINE-FIXME feature, and marks the slowest tests
reported by the CI as `UNSUPPORTED: GCC-ALWAYS_INLINE-FIXME`.

[1]: https://discourse.llvm.org/t/rfc-stop-supporting-extern-instantiations-with-gcc/71277/1

Differential Revision: https://reviews.llvm.org/D152736
2023-06-13 10:20:30 -07:00
Nikolas Klauser
cd916108b4 [libc++][PSTL] Implement std::generate{,_n}
Reviewed By: #libc, ldionne

Spies: ldionne, libcxx-commits

Differential Revision: https://reviews.llvm.org/D152581
2023-06-13 07:55:06 -07:00
Nikolas Klauser
51131edf83 [libc++][PSTL] Implement std::replace{,_if,_copy,_copy_if}
Reviewed By: #libc, ldionne

Spies: ldionne, libcxx-commits

Differential Revision: https://reviews.llvm.org/D151841
2023-06-06 08:44:53 -07:00