There are a lot of
```
#if _LIBCPP_DEBUG_LEVEL == 2
__get_db()->__insert_c(this);
#endif
```
This patch introduces `__debug_db_insert_c()` to put the `#if` in one central place.
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D116947
In D116873 I did this for libunwind prior to defining a new install path
variable. But I think the change is good on its own, and libc++{,abi}
could also use it.
libc++ needed the base header var defined above the conditional part to
use it for the prefi+ed headers in the non-target-specific case. For
consistency, I therefore put the unconditional ones above for all 3
libs, which is why I touched the libunwind code (seeing that it had the
core change already)
Reviewed By: phosek, #libunwind, #libc, #libc_abi, ldionne
Differential Revision: https://reviews.llvm.org/D116988
... even when `!defined(_LIBCPP_VERSION)`. (Note that the previous definition for this case - `((void)0);` - is ill-formed at namespace scope.) Ditto for `LIBCPP_ASSERT`, `LIBCPP_ASSERT_NOEXCEPT`, `LIBCPP_ASSERT_NOT_NOEXCEPT`, and `LIBCPP_ONLY`.
Differential Revision: https://reviews.llvm.org/D116880
That will make it easier to change the behavior of the arc4random()
based implementation. Note that in particular, the eval.pass.cpp test
used to work with non "/dev/random" based implementations because we'd
throw an exception upon constructing the random_device. This patch makes
the intent of the test clearer.
The NFC part of D116809. We still want to enforce this in CI,
but the mechanism for that is still to-be-determined.
Differential Revision: https://reviews.llvm.org/D116809
Use the zx_clock_get_monotonic system call directly rather than
going through the POSIX clock_gettime function. The libc function
is a trivial wrapper around the system call, and is not a standard C
function. Avoiding it reduces the Fuchsia libc ABI surface that
libc++ depends on.
Reviewed By: phosek, ldionne, #libc
Differential Revision: https://reviews.llvm.org/D116606
Before this patch, the user needed to specialize both of
`is_placeholder<MyType>` and `is_placeholder<const MyType>`.
After this patch, only the former is needed (although the
latter is harmless if provided).
The new tests don't actually fail unless return type deduction
is used, which is a C++14 feature. Specializing `is_placeholder`
is still allowed in C++11, though.
Fixes#51095.
Differential Revision: https://reviews.llvm.org/D116388
The documentation CI job is very cheap, so we can afford to keep it
around even with reduced capacity. This commit fixes the documentation
(which had an invalid reference in it) and re-enables that CI step.
Differential Revision: https://reviews.llvm.org/D116897
Casey Carter says, "We run std/thread/thread.mutex/thread.lock.algorithm/lock.pass.cpp
on every CI and it works fine with MSVC STL. I'm guessing this annotation predates
Billy's rewrite of std::lock in 2017-ish."
Differential Revision: https://reviews.llvm.org/D116712
The reason for those nested namespaces is explained in D115315:
> AIUI, this keeps the CPO's own type from ADL'ing into the `std::ranges`
> namespace; e.g. `foobar(std::ranges::uninitialized_default_construct)`
> should not consider `std::ranges::foobar` a candidate, even if
> `std::ranges::foobar` is not a CPO itself. Also, of course, consistency
> (Chesterton's Fence, the economist's hundred-dollar bill): if it were
> safe to omit the namespace, we'd certainly want to do it everywhere,
> not just here.
This makes these three niebloids more consistent with the other Ranges
niebloids we've already implemented, such as the `ranges::begin` group
and the `ranges::uninitialized_default_construct` group.
FWIW, we still have three different indentation-and-comment styles
among these three groups.
Differential Revision: https://reviews.llvm.org/D116569
When building libcxx, libcxxabi, and libunwind the build environment may
specify any number of sanitizers. For some build feature tests these
sanitizers must be disabled to prevent spurious linking errors. With
-fsanitize= this is straight forward with -fno-sanitize=all. With
-fsanitize-coverage= there is no -fno-sanitize-coverage=all, but there
is the equivalent undocumented but tested -fsanitize-coverage=0.
The current build rules fail to disable 'trace-pc-guard'. By disabling
all sanitize-coverage flags, including 'trace-pc-guard', possible
spurious linker errors are prevented. In particular, this allows libcxx,
libcxxabi, and libunwind to be built with HonggFuzz.
CMAKE_REQUIRED_FLAGS is extra compile flags when running CMake build
configuration steps (like check_cxx_compiler_flag). It does not affect
the compile flags for the actual build of the project (unless of course
these flags change whether or not a given source compiles and links or
not). So libcxx, libcxxabi, and libunwind will still be built with any
specified sanitize-coverage as before. The build configuration steps
(which are mostly checking to see if certain compiler flags are
available) will not try to compile and link "int main() { return 0;}"
(or other specified source) with sanitize-coverage (which can fail to
link at this stage in building, since the final compile flags required
are yet to be determined).
The change to LIBFUZZER_CFLAGS was done to keep it consistent with the
obvious intention of disabling all sanitize-coverage. This appears to
be intentional, preventing the fuzzer driver itself from showing up in
any coverage calculations.
Reviewed By: #libunwind, #libc, #libc_abi, ldionne, phosek
Differential Revision: https://reviews.llvm.org/D116050
In the test files, replace the old-style tests with a simple static_assert,
matching the current style as depicted in e.g.
`ranges_uninitialized_default_construct.pass.cpp`.
Preserve `is_function_like` (but renamed to `is_niebloid`) at
ldionne's request. The removal of this test helper will happen
in D116570 if at all.
Differential Revision: https://reviews.llvm.org/D116384
This should have been done in 6a6a80e88e, but buildkite was down so I
hadn't noticed. This brings this test file into line with several others
in this directory.
z/OS doesn't support fopen64() functions. Modify the preprocessor directive for z/OS to use fopen() instead.
Reviewed By: #libc, abhina.sreeskantharajan, muiez, ldionne
Differential Revision: https://reviews.llvm.org/D111226
Although we moved to Github Issues. The bug report message refers to
Bugzilla still. This patch tries to update these URLs.
Reviewed By: MaskRay, Quuxplusone, jhenderson, libunwind, libc++
Differential Revision: https://reviews.llvm.org/D116351
This reverts commit 640beb38e7.
That commit caused performance degradtion in Quicksilver test QS:sGPU and a functional test failure in (rocPRIM rocprim.device_segmented_radix_sort).
Reverting until we have a better solution to s_cselect_b64 codegen cleanup
Change-Id: Ibf8e397df94001f248fba609f072088a46abae08
Reviewed By: kzhuravl
Differential Revision: https://reviews.llvm.org/D115960
Change-Id: Id169459ce4dfffa857d5645a0af50b0063ce1105
The fix in D116381 makes an existing exception message wrong. This
improves the message and fixes the associated unit tests.
Note other message can be also be improved, but that will be done later.
Changing these messages may cause merge conflicts with other patches
that are under review or WIP.
Depends on D116381
Reviewed By: #libc, Quuxplusone, ldionne
Differential Revision: https://reviews.llvm.org/D116495
@CaseyCarter reported that the tests for the std-format-spec rejects leading
zeroes for precision, which the Standard does not require. The Standard allows
them. Only for precision, not for the width or an arg-id.
Fixes the precision parser and adds some test for the arg-id since they
were missing.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D116381
Remove duplicate header includes from `<algorithm>` and reorder the includes
Reviewed By: Quuxplusone, ldionne, Mordante, #libc, jloser
Spies: jloser, libcxx-commits
Differential Revision: https://reviews.llvm.org/D116507
`__cpp_lib_type_identity` was implemented way back in cf49ccd0 (Clang 8),
probably before the feature-test macro had been settled on.
`__cpp_lib_string_resize_and_overwrite` will be added by D113013 so I didn't add it here.
Fixes#46605.
Differential Revision: https://reviews.llvm.org/D116433
For example, `std::ranges::range<Holder<Incomplete>*>` should be
well-formed false, not a hard error at compile time.
Differential Revision: https://reviews.llvm.org/D116239
The big change here is that they now work as intended for rvalues,
e.g. `ranges::cbegin(std::string_view("hello"))`.
Also, add tests verifying their return types.
Differential Revision: https://reviews.llvm.org/D116199
If `__first == __middle`, then `partial_sort` is a no-op; don't
bother to iterate all the way from `__middle` to `__end`.
Fixes#49431.
Differential Revision: https://reviews.llvm.org/D116296
AFAICT, Cpp17InputIterators are not required to be default constructible,
since that requirement is added in Cpp17ForwardIterator. Hence, our
archetype for Cpp17InputIterator should not be default constructible.
Removing that constructor has a ripple effect on a couple of tests that
were making incorrect assumptions. Notably:
- Some tests were using cpp17_input_iterator as a sentinel for itself.
That is not valid, because a cpp17_input_iterator is not semiregular
anymore after the change (and hence it doesn't satisfy sentinel_for).
- Some tests were using a stride-counted cpp17_input_iterator as the
sentinel for a range. This doesn't work anymore because of the problem
above, so these tests were changed not to check stride counts for
input iterators.
- Some tests were default constructing cpp17_input_iterator when a simple
alternative was available -- those have been changed to use that alternative.
Differential Revision: https://reviews.llvm.org/D115806
Some headers which require the version header depend on other headers to
provide it. Include the version header in all top-level headers to make
sure a header cleanup can't remove the version header.
Note this doesn't add the version header to the c headers.
Reviewed By: #libc, Quuxplusone, ldionne
Differential Revision: https://reviews.llvm.org/D116172
Use the zx_cprng_draw system call directly rather than going
through the libc getentropy function. The libc function is a
trivial wrapper around the system call, and is not a standard C
function. Avoiding it reduces the Fuchsia libc ABI surface that
libc++ depends on.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D116498
In D116472 we created conditionally defined variables for the tools to
unbreak the legacy build where they are in `llvm/tools`.
The runtimes are not tools, so that flexibility doesn't matter. Still,
it might be nice to define (unconditionally) and use the variable for
the runtimes simply to make the code a bit clearer and document what is
going on.
Also, consistently put project dirs at the beginning, not end of `CMAKE_MODULE_PATH`. This ensures they will properly shadow similarly named stuff that happens to be later on the path.
Reviewed By: mstorsjo, #libunwind, #libc, #libc_abi, ldionne
Differential Revision: https://reviews.llvm.org/D116477
There is an ongoing CI outage with our Linux nodes, so I temporarily
set up a couple of nodes. These nodes will be much slower than the
usual ones and there's only a few of them, so I am temporarily disabling
most of our CI to keep things working.
Line 1140 is a duplicate of line 1119; it tests the two-argument version
of std::hypot, whereas all the lines in this section are supposed to be
testing the C++17 three-argument version. Remove the erroneous duplicated line.
Split out of D116295.
Some individual test files verify the CPO under test satisfies
`semiregular` concept. This is redundant since it is already part of the test
in verifying whether the entity is indeed a CPO in
`libcxx/test/std/library/description/conventions/customization.point.object/cpo.compile.pass.cpp`.
Differential Revision: https://reviews.llvm.org/D116173
We didn't support noop_coroutine for GCC in previous conforming patch.
So that GCC couldn't use noop_coroutine() defined in <coroutine>. And
after this patch, GCC should be able to compile the whole <coroutine>
header.
Reviewed By: Quuxplusone
Differential Revision: https://reviews.llvm.org/D116144
It was missing the cast to `bool` in `bool(__t.empty())`.
It was wrongly using `std::forward` in some places.
Differential Revision: https://reviews.llvm.org/D115312
During the review of D115991 @vitaut pointed out the enum shouldn't
depend on whether or not _LIBCPP_HAS_NO_INT128 is defined. The current
implementation lets the enum's ABI depend on this configuration option
without a good cause.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D116120
These headers have stabilized; we don't expect anyone to be
blindly clang-formatting them anymore.
Leave the comments in `__format/*.h` for Mark to remove at his leisure.
Clang is gaining `auto(x)` support in D113393; sadly there
seems to be no feature-test macro for it. Zhihao is opening
a core issue for that macro.
Use `_LIBCPP_AUTO_CAST` where C++20 specifies we should use `auto(x)`;
stop using `__decay_copy(x)` in those places.
In fact, remove `__decay_copy` entirely. As of C++20, it's purely
a paper specification tool signifying "Return just `x`, but it was
perfect-forwarded, so we understand you're going to have to call
its move-constructor sometimes." I believe there's no reason we'd
ever need to do its operation explicitly in code.
This heisenbugs away a test failure on MinGW; see D112214.
Differential Revision: https://reviews.llvm.org/D115686
As discussed with ldionne. The problem with this static_assert
is that it makes ranges::begin a pitfall for anyone ever to use
inside a constraint or decltype. Many Ranges things, such as ranges::size,
are specified as "Does X if X is well-formed, or else Y if Y is well-formed,
or else `ranges::end(t) - ranges::begin(t)` if that is well-formed, or else..."
And if there's a static_assert hidden inside `ranges::begin(t)`, then you get
a hard error as soon as you ask the question -- even if the answer would have
been "no, that's not well-formed"!
Constraining on `requires { t + 0; }` or `requires { t + N; }` is verboten
because of https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103700 . For ranges::begin,
we can just decay to a pointer even in the incomplete-type case. For ranges::end,
we can safely constrain on `sizeof(*t)`. Yes, this means that an array of incomplete
type has a `ranges::begin` but no `ranges::end`... just like an unbounded array of
complete type. This is a valid manifestation of IFNDR.
All of the new libcxx/test/std/ cases are mandatory behavior, as far as I'm aware.
Tests for the IFNDR cases in ranges::begin and ranges::end remain in `libcxx/test/libcxx/`.
The similar tests for ranges::empty and ranges::data were simply wrong, AFAIK.
Differential Revision: https://reviews.llvm.org/D115838
The paths to the compiler and to the python executable may need to
be quoted (if they're installed into e.g. C:\Program Files).
All testing commands that are executed expect a gcc compatible command
line interface, while clang-cl uses different command line options.
In the original testing config, if the chosen compiler was clang-cl, it
was replaced with clang++ by looking for such an executable in the path.
For the new from-scratch test configs, I instead chose to add
"--driver-mode=g++" to flags - invoking "clang-cl --driver-mode=g++"
has the same effect as invoking "clang++", without needing to run any
heuristics for picking a different compiler executable.
Differential Revision: https://reviews.llvm.org/D111202
While there's little value in polishing the old config system,
I ran into this function and was confused for a while, while grepping
around and trying to wrap my head around things.
Differential Revision: https://reviews.llvm.org/D116131
The test is currently marked XFAIL for mingw environments, but latest
mingw-w64 got support for timespec_get:
e62a0a987c
The CI environment will probably be upgraded to a state where this
test is passing only after 14.x is branched in the llvm-project monorepo.
If we'd just go from having an XFAIL to no marking at all (when CI is
passing), we'd have to update both main and 14.x branches in sync
exactly when the CI runners are updated to a newer version.
Instead, mark the test as temporarily unsupported (so it doesn't
cause failed builds when the CI environment is updated); after the
CI environments are upgraded to such a state, we can remove the
UNSUPPORTED marking to start requiring it to pass on the main branch,
without needing to synchronize that change to anything else.
Differential Revision: https://reviews.llvm.org/D116132
Eliminate a bogus operator== overload.
Also, check more intermediate steps in the logic we're checking here.
Some of this simplification is possible only now that we've implemented
more of <ranges>.
Differential Revision: https://reviews.llvm.org/D116002
If %{exec} sets "--env PATH=single-dir", the directory containing
bash and related shell utils is omitted from the path, which means
that most shell scripts would fail.
(Setting PATH is needed for DLL builds on Windows; PATH fills the same
role as e.g. LD_LIBRARY_PATH on Linux.)
This condition is missed in the current test, because the executor
run.py first resolves the executable to run using the original path,
then invokes that executable with an environment with a restricted
path. Thus the executor is able to run bash, but that bash is then
unable to run further shell commands (other than bash builtins).
Extend the test from "bash --version" to "bash -c 'bash --version'".
This correctly identifies the executor-has-no-bash condition in the
current Windows CI configs, allowing removing 6 cases of
LIBCXX-WINDOWS-FIXME.
Another longterm fix would be to extend run.py with an option like
"--env-prepend PATH=dir", to allow keeping the current path while
adding a directory to it.
Differential Revision: https://reviews.llvm.org/D116117
This is similar to the existing setting LIBCXX_ABI_DEFINES, with
the difference that this also allows setting other defines than
ones that start with "_LIBCPP_ABI_", and allows setting defines
to a specific value.
This allows avoiding using LIBCXX_TEST_COMPILER_FLAGS in two
CI configurations.
Differential Revision: https://reviews.llvm.org/D116109
This allows cross-testing (by setting LIBCXX_EXECUTOR to point
to ssh.py) without making an entirely new test config file.
Implicitly, this also fixes quoting of the python executable name
(which is quoted in test/CMakeLists.txt).
Differential Revision: https://reviews.llvm.org/D115398
We can't just memoize _supportsVerify in place in format.py, as it
previously was executed in each of the individual processes.
Instead use hasCompileFlag() and add a feature flag for it instead,
which can be used both by tests (that already have such a flag,
locally for one set of tests) and for the testing framework itself.
By using hasCompileFlag(), this also implicitly fixes two other issues:
Previously, _supportsVerify called subprocess.call() directly, which can
interpret command line quoting differently than lit.TestRunner.
(In particular, TestRunner handles arguments quoted by a single quote,
while launching Windows processes with subprocess.call() only supports
double quotes. This allows using shlex.quote(), which uses single quotes,
everywhere - as all commands now go through TestRunner. This should make
41d7909368 redundant.)
Secondly, the old _supportsVerify method didn't include %{flags) or
%{compile_flags}.
Differential Revision: https://reviews.llvm.org/D116010
Add test for various customization point object properties as defined by
the Standard. Test various CPOs from `<ranges>`, `<iterator>`,
`<concepts>`, etc.
The test is mostly from https://reviews.llvm.org/D107036 and split up
into this.
Differential Revision: https://reviews.llvm.org/D115588
Allow `__move_constexpr` to work with unrelated pointers and `_LIBCPP_ASSERT` that `__copy_constexpr`, `__move_constexpr` and `__assign_constexpr` are only run during constant evaluation
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D115986
When P0883R2 was initially implemented in D103769 #pragma clang deprecated didn't exist yet.
We also forgot to cleanup usages in libc++ itself.
This takes care of both.
Differential Revision: https://reviews.llvm.org/D115995
__transaction is a helper class that allows rolling back code in case an
exception is thrown. The main goal is to reduce the clutter when code
needs to be guarded with `#if _LIBCPP_NO_EXCEPTIONS`.
Differential Revision: https://reviews.llvm.org/D115730
Also:
- refactor out `__voidify`;
- use the `destroy` algorithm internally;
- refactor out helper classes used in tests for `uninitialized_*`
algorithms.
Differential Revision: https://reviews.llvm.org/D115626
When run in a git bash terminal, sys.stderr isn't flushed implicitly
after printing each line. Manually flush it after each printout,
to avoid getting broken/misordered output.
A similar fix had been done in the old libcxx test config, committed
as part of 7e3ee09ad2 / D28725; this
generalizes the fix, making it available in the new libcxx test
configs too, and for any other test that uses lit_config.note().
Differential Revision: https://reviews.llvm.org/D115761
The inline keyword is required on those functions because they are defined
in the headers, so we need them to be inline to avoid ODR violations.
While we're at it, slap _LIBCPP_HIDE_FROM_ABI on them because they are
implementation details and we don't want them to be part of our ABI under
any circumstances.
Differential Revision: https://reviews.llvm.org/D115906
There is no need to check the counters on `Counted` after destroying
elements in the range because these tests are not testing `destroy`.
Differential Revision: https://reviews.llvm.org/D115839
Remove `s.base()`; every test that wants to get the base of a "test sentinel"
should use the ADL `base(s)` from now on.
Differential Revision: https://reviews.llvm.org/D115766
GCC currently does not allow `__builtin_strlen()` during constant evaluation. This PR adds a workaround in `std::char_traits<char>::length()`
Reviewed By: Quuxplusone, ldionne, #libc, Mordante
Spies: Mordante, libcxx-commits
Differential Revision: https://reviews.llvm.org/D115795
However, there's a problem on both GCC and Clang: they can't mangle
`__is_same(T,U)` if it appears anywhere that affects mangling. That's
a hard error. And it turns out that GCC puts dependent return types
into the mangling more aggressively than Clang, so for GCC's benefit
we need to avoid using raw `_IsSame` in the return type of
`swap(tuple&, tuple&)`. Therefore, make `__all` into a named type
instead of an alias.
If we ever need to support a compiler without the __is_same builtin,
we can make this an alias template for `is_same<T,U>::type`.
Differential Revision: https://reviews.llvm.org/D115100
Use `_LIBCPP_DEBUG_ASSERT` instead of `_LIBCPP_ASSERT` and guarding it with `LIBCPP_DEBUG_LEVEL == 2`
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D115765
Defined in [`specialized.algorithms`](wg21.link/specialized.algorithms).
Also:
- refactor the existing non-range implementation so that most of it
can be shared between the range-based and non-range-based algorithms;
- remove an existing test for the non-range version of
`uninitialized_default_construct{,_n}` that likely triggered undefined
behavior (it read the values of built-ins after default-initializing
them, essentially reading uninitialized memory).
Reviewed By: #libc, Quuxplusone, ldionne
Differential Revision: https://reviews.llvm.org/D115315
A few tests in the test suite require support for Bash. For example,
tests that run a program and send data through stdin to it require some
way of piping the data in, and we use a Bash script for that.
However, some executors (e.g. an embedded systems simulator) do not
support Bash, so these tests will fail. This commit adds a Lit feature
that tries to detect whether Bash is available through conventional
means, and disables the tests that require it otherwise.
Differential Revision: https://reviews.llvm.org/D114612
The library is always build using C++20 so these guards are not needed.
Reviewed By: #libc, Quuxplusone, ldionne
Differential Revision: https://reviews.llvm.org/D115644
As explained in https://stackoverflow.com/a/70339311/627587, the fact
that shrink_to_fit wasn't defined as inline lead to issues when explicitly
instantiating basic_string. While explicit instantiations are always
somewhat brittle, this one was clearly a bug on our end.
Differential Revision: https://reviews.llvm.org/D115656
When `a` was an array type, `__decay_copy(a)` was incorrectly marking itself
noexcept(false), because it is false that `int[10]` is nothrow convertible to `int[10]`
(in fact it is not convertible at all).
We have no tests explicitly for `__decay_copy`, but the new ranges::begin
and ranges::end tests fail before this patch.
Differential Revision: https://reviews.llvm.org/D115658
We had previously been using a different workaround for pretending that
we were inside a system header, however it had some undesirable effects
on dependency parsing for build systems, as explained in [1].
This patch changes the workaround to use `#pragma GCC system_header`,
which shouldn't suffer from the same issue. Unfortunately, it is a lot
more verbose. The issue is that `#pragma GCC system_header` is ignored
when we are inside a source file, so we have to create a header just for
the sake of using it. IMO this seems like an artificial restriction
without much benefit, but investigating that is a different story.
For now, this should at least solve build system problems at the
cost of some readability.
[1]: https://reviews.llvm.org/D95972#3178968
Differential Revision: https://reviews.llvm.org/D115334
Just defensive CMake-ing. I pulled this from D115544 and D99484 which
are blocked on some lldb CI failures I don't yet understand. Hoping to land
something smaller in the meantime.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D115566
The aim of this patch is to fix the post processing that is happening on the temporary test directories upon scope exit. In particular, ~scoped_test_env aims to chmod and remove the temporary directories; however,
bad symlinks are followed and we get "No such file or directory". FIX: use find as alternative to chmod and avoid -follow option.
Attempting to remove read-only files on z/OS prompts a message asking for confirmation. FIX: use the -f option to delete read-only files immediately without asking for confirmation.
Some libcxx tests such as libcxx/test/std/input.output/filesystems/cl ass.directory_entry/directory_entry.cons/path.pass.cpp set the dir permissions to none. In turn, recursively doing chmod (-R) does not set the file permissions needed to be able to remove the dir on z/OS only. FIX: use find as alternative to chmod -R, which does not run into this issue on z/OS.
Differential Revision: https://reviews.llvm.org/D108326
Microsoft would like to contribute its implementation of floating-point to_chars to libc++. This uses the impossibly fast Ryu and Ryu Printf algorithms invented by Ulf Adams at Google. Upstream repos: https://github.com/microsoft/STL and https://github.com/ulfjack/ryu .
Licensing notes: MSVC's STL is available under the Apache License v2.0 with LLVM Exception, intentionally chosen to match libc++. We've used Ryu under the Boost Software License.
This patch contains minor changes from Jorg Brown at Google, to adapt the code to libc++. He verified that it works in Google's Linux-based environment, but then I applied more changes on top of his, so any compiler errors are my fault. (I haven't tried to build and test libc++ yet.) Please tell me if we need to do anything else in order to follow https://llvm.org/docs/DeveloperPolicy.html#attribution-of-changes .
Notes:
* libc++'s integer charconv is unchanged (except for a small refactoring). MSVC's integer charconv hasn't been tuned for performance yet, so you're not missing anything.
* Floating-point from_chars isn't part of this patch because Jorg found that MSVC's implementation (derived from our CRT's strtod) was slower than Abseil's. If you're unable to use Abseil or another implementation due to licensing or technical considerations, Microsoft would be delighted if you used MSVC's from_chars (and you can just take it, or ask us to provide a patch like this). Ulf is also working on a novel algorithm for from_chars.
* This assumes that float is IEEE 32-bit, double is IEEE 64-bit, and long double is also IEEE 64-bit.
* I have added MSVC's charconv tests (the whole thing: integer/floating from_chars/to_chars), but haven't adapted them to libcxx's harness at all. (These tests will be available in the microsoft/STL repo soon.)
* Jorg added int128 codepaths. These were originally present in upstream Ryu, and I removed them from microsoft/STL purely for performance reasons (MSVC doesn't support int128; Clang on Windows does, but I found that x64 intrinsics were slightly faster).
* The implementation is split into 3 headers. In MSVC's STL, charconv contains only Microsoft-written code. xcharconv_ryu.h contains code derived from Ryu (with significant modifications and additions). xcharconv_ryu_tables.h contains Ryu's large lookup tables (they were sufficiently large to make editing inconvenient, hence the separate file). The xmeow.h convention is MSVC's for internal headers; you may wish to rename them.
* You should consider separately compiling the lookup tables (see https://github.com/microsoft/STL/issues/172 ) for compiler throughput and reduced object file size.
* See https://github.com/StephanTLavavej/llvm-project/commits/charconv for fine-grained history. (If necessary, I can perform some rebase surgery to show you what Jorg changed relative to the microsoft/STL repo; currently that's all fused into the first commit.)
Differential Revision: https://reviews.llvm.org/D70631
Test that `nothrow-forward-iterator` subsumes `nothrow-input-iterator`,
`nothrow-forward-range` subsumes `nothrow-input-range`, and
`nothrow-sentinel-for` and `sentinel_for` subsume each other.
This is a follow-up to [D114761](https://reviews.llvm.org/D114761).
Differential Revision: https://reviews.llvm.org/D115422
Extending std::vector tests in vector.cons module:
- std::vector::assign when source range is bigger than destination
capacity
- construction of empty vector using copy ctor, initializer_list ctor and
others
Reviewed By: ldionne, rarutyun, #libc
Differential Revision: https://reviews.llvm.org/D114954
Add tests for std::set and std::multiset comparisons that were missed by
D111738 and D112424.
Reviewed By: ldionne, rarutyun, #libc
Differential Revision: https://reviews.llvm.org/D115136
This does mostly the same as D112126, but for the runtimes cmake files.
Most of that is straightforward, but the interdependency between
libcxx and libunwind is tricky:
Libunwind is built at the same time as libcxx, but libunwind is not
installed yet. LIBCXXABI_USE_LLVM_UNWINDER makes libcxx link directly
against the just-built libunwind, but the compiler implicit -lunwind
isn't found. This patch avoids that by adding --unwindlib=none if
supported, if we are going to link explicitly against a newly built
unwinder anyway.
Since the previous attempt, this no longer uses
llvm_enable_language_nolink (and thus doesn't set
CMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY during the compiler
sanity checks). Setting CMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY
during compiler sanity checks makes cmake not learn about some
aspects of the compiler, which can make further find_library or
find_package fail. This caused OpenMP to not detect libelf and libffi,
disabling some OpenMP target plugins.
Instead, require the caller to set CMAKE_{C,CXX}_COMPILER_WORKS=YES
when building in a configuration with an incomplete toolchain.
Differential Revision: https://reviews.llvm.org/D113253
This reverts commit 317dc31e53.
After that change, OpenMP doesn't find dependencies in the host
system (it fails do find e.g. /usr/lib/x86_64-linux-gnu/libelf.so
which it found before), which causes some OpenMP target offloading
plugins to not be found. This doesn't break the build, but just
causes the AMDGPU OpenMP target plugin to be omitted. See
https://reviews.llvm.org/D113253#3181934 for the report of this
issue.
No decrease in test coverage intended. The original goal here
was just to get rid of the global name `sentinel` so that we can
rename the `sentinel_wrapper` in "test_iterators.h" to `sentinel`;
but then I took a closer look at the offending tests and saw
that some of them probably weren't testing what they intended.
Also, add one `/*explicit*/` and one #if'ed out test indicating
bugs in the current ranges::empty (to be fixed by D115312 or
some equivalent patch).
Reviewed as part of D115272.
This follows up on my addition of base(cpp20_input_iterator) in D115177,
making all the ADL base() functions consistent.
Also align cpp20_input_iterator with the other test iterators' style.
Reviewed as part of D115272.
Use `= delete` for member functions that are marked with `// = delete;`
Reviewed By: ldionne, Quuxplusone, #libc
Spies: jloser, libcxx-commits
Differential Revision: https://reviews.llvm.org/D115291
There's a lot of history behind this, so here's a summary:
1. I stopped forcing -fPIC when building the runtimes in 30f305efe2,
before the LLVM 9 release back in 2019.
2. Someone complained that libc++.a couldn't be used in shared libraries
built without -fPIC (http://llvm.org/PR43604) since the LLVM 9 release.
This had been caused by my removal of -fPIC when building libc++.a in (1).
3. I suggested two ways of fixing the issue, the first being to force
-fPIC back unconditionally (http://llvm.org/D104328), and the second
being to specify that option explicitly when building the LLVM release
(http://llvm.org/D104327). We converged on the first solution.
4. I landed D104328, which forced building the runtimes with -fPIC.
This was included in the LLVM 13.0 release.
5. People complained about that and requested that we be able to
customize this setting (basically we should have done the second
solution).
This patch makes it such that the LLVM release script will specifically
ask for building with -fPIC using CMAKE_POSITION_INDEPENDENT_CODE,
however by default the runtimes will not force that option onto users.
This patch has the unintended effect that Clang and the LLVM libraries
(not only the runtime ones like libc++) will also be built with -fPIC
in the release. It would be better if we could specify that -fPIC is to
be used only when building the runtimes, however this is left as a
future improvement. The release should probably be using a bootstrapping
build and passing those options to the stage that builds the runtimes
only, see https://reviews.llvm.org/D112748 for that change.
Differential Revision: https://reviews.llvm.org/D110261
In addition to being more consistent with our approach for helpers, this
solves an actual issue where <cmath> was using numeric_limits but never
including the <limits> header directly. In a normal setup, this is not
an issue because the <math.h> header included by <cmath> does include
<limits>. However, I did stumble upon some code where that didn't work,
most likely because they were placing their own <math.h> header in front
of ours. I didn't bother investigating further.
Differential Revision: https://reviews.llvm.org/D115282
This does mostly the same as D112126, but for the runtimes cmake files.
Most of that is straightforward, but the interdependency between
libcxx and libunwind is tricky:
Libunwind is built at the same time as libcxx, but libunwind is not
installed yet. LIBCXXABI_USE_LLVM_UNWINDER makes libcxx link directly
against the just-built libunwind, but the compiler implicit -lunwind
isn't found. This patch avoids that by adding --unwindlib=none if
supported, if we are going to link explicitly against a newly built
unwinder anyway.
Reapplying this after
db32c4f456, which should fix the issues
that were reported last time this was applied.
Differential Revision: https://reviews.llvm.org/D113253
clang has `= default` as an extension in c++03, so just use it.
Reviewed By: ldionne, Quuxplusone, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D115275
Before this patch, the new test's `CountedInvocable<int*, int*>`
would hard-error instead of SFINAEing and cleanly returning false.
Notice that views::counted specifically does NOT work with pipes;
`counted(42)` is ill-formed. This is because `counted`'s first argument
is supposed to be an iterator, not a range.
Also, mark `views::counted(it, n)` as [[nodiscard]], and test that.
(We have a general policy now that range adaptors are consistently
marked [[nodiscard]], so that people don't accidentally think that
they have side effects. This matters mostly for `reverse` and
`transform`, arguably `drop`, and just generally let's be consistent.)
Differential Revision: https://reviews.llvm.org/D115177
In 6c75ab5f66, Clang deprecated _ExtInt in favor of _BitInt, which
made this test fail. This patch disables the test on older compilers
and uses the new _BitInt type instead.
Differential Revision: https://reviews.llvm.org/D115194
I assume nobody ever uses std::string_view::max_size() outside of
testing. However, we should still return a value that is based on
something with a reasonable rationale. Previously, we would forget
to take into account the size of the character type stored in the
string, and this patch takes that into account.
Thanks to @mclow.lists for pointing out this issue.
Differential Revision: https://reviews.llvm.org/D114395
Clang trunk rejects the new test case, but this is a Clang bug
(PR47414, 47509, 50864, 44833).
```
In module 'std' imported from /Users/aodwyer/llvm-project/libcxx/test/std/ranges/range.adaptors/range.transform/general.pass.cpp:17:
/Users/aodwyer/llvm-project/build2/include/c++/v1/__ranges/transform_view.h:85:44: error: constraints not satisfied for alias template 'range_reference_t' [with _Rp = const NonConstView]
regular_invocable<const _Fn&, range_reference_t<const _View>>
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/aodwyer/llvm-project/build2/include/c++/v1/__ranges/transform_view.h:416:25: note: in instantiation of template class 'std::ranges::transform_view<NonConstView, (lambda at /Users/aodwyer/llvm-project/libcxx/test/std/ranges/range.adaptors/range.transform/general.pass.cpp:73:71)>' requested here
-> decltype( transform_view(_VSTD::forward<_Range>(__range), _VSTD::forward<_Fn>(__f)))
^
```
We can work around this by adding a layer of indirection: put the
problematic constraint into a named concept and Clang becomes more
amenable to SFINAE'ing instead of hard-erroring.
Drive-by simplify `range.transform/general.pass.cpp` to make it clearer
what it's actually testing in this area.
Differential Revision: https://reviews.llvm.org/D115116
As discussed on the Discord, 2021-12-01 through 2021-12-05.
Our new consistent style for this is "don't align the right-braces"
(but still align the left-braces, as shown).
Microsoft would like to contribute its implementation of floating-point to_chars to libc++. This uses the impossibly fast Ryu and Ryu Printf algorithms invented by Ulf Adams at Google. Upstream repos: https://github.com/microsoft/STL and https://github.com/ulfjack/ryu .
Licensing notes: MSVC's STL is available under the Apache License v2.0 with LLVM Exception, intentionally chosen to match libc++. We've used Ryu under the Boost Software License.
This patch contains minor changes from Jorg Brown at Google, to adapt the code to libc++. He verified that it works in Google's Linux-based environment, but then I applied more changes on top of his, so any compiler errors are my fault. (I haven't tried to build and test libc++ yet.) Please tell me if we need to do anything else in order to follow https://llvm.org/docs/DeveloperPolicy.html#attribution-of-changes .
Notes:
* libc++'s integer charconv is unchanged (except for a small refactoring). MSVC's integer charconv hasn't been tuned for performance yet, so you're not missing anything.
* Floating-point from_chars isn't part of this patch because Jorg found that MSVC's implementation (derived from our CRT's strtod) was slower than Abseil's. If you're unable to use Abseil or another implementation due to licensing or technical considerations, Microsoft would be delighted if you used MSVC's from_chars (and you can just take it, or ask us to provide a patch like this). Ulf is also working on a novel algorithm for from_chars.
* This assumes that float is IEEE 32-bit, double is IEEE 64-bit, and long double is also IEEE 64-bit.
* I have added MSVC's charconv tests (the whole thing: integer/floating from_chars/to_chars), but haven't adapted them to libcxx's harness at all. (These tests will be available in the microsoft/STL repo soon.)
* Jorg added int128 codepaths. These were originally present in upstream Ryu, and I removed them from microsoft/STL purely for performance reasons (MSVC doesn't support int128; Clang on Windows does, but I found that x64 intrinsics were slightly faster).
* The implementation is split into 3 headers. In MSVC's STL, charconv contains only Microsoft-written code. xcharconv_ryu.h contains code derived from Ryu (with significant modifications and additions). xcharconv_ryu_tables.h contains Ryu's large lookup tables (they were sufficiently large to make editing inconvenient, hence the separate file). The xmeow.h convention is MSVC's for internal headers; you may wish to rename them.
* You should consider separately compiling the lookup tables (see https://github.com/microsoft/STL/issues/172 ) for compiler throughput and reduced object file size.
* See https://github.com/StephanTLavavej/llvm-project/commits/charconv for fine-grained history. (If necessary, I can perform some rebase surgery to show you what Jorg changed relative to the microsoft/STL repo; currently that's all fused into the first commit.)
Differential Revision: https://reviews.llvm.org/D70631
Implement the exposition-only concepts specified in
`[special.mem.concepts]`. These are all thin wrappers over other
concepts.
Reviewed By: #libc, Quuxplusone, ldionne
Differential Revision: https://reviews.llvm.org/D114761
This has been supported on gdb for something like ~10 years, so doesn't
seem necessary to carry a fallback.
Differential Revision: https://reviews.llvm.org/D114986
Seems better to rely on the existing formatting, makes the output
smaller/simpler - this is consistent with libstdc++'s std::string_view
pretty printing too.
Differential Revision: https://reviews.llvm.org/D113244
Implement P1989R2 which adds a range constructor for `string_view`.
Adjust `operator/=` in `path` to avoid atomic constraints caching issue
getting provoked from this PR.
Add defaulted template argument to `string_view`'s "sufficient
overloads" to avoid mangling issues in `clang-cl` builds. It is a
MSVC mangling bug that this works around.
Differential Revision: https://reviews.llvm.org/D113161
Add missing tests for std::vector funcionality to improve code coverage:
- Rewrote access tests to check modification of the container using
the reference returned by the non-const overload
- Added tests for reverse iterators: rbegin, rend, etc.
- Added exception test for vector::reserve
- Extended test cases for vector copy assignment
- Fixed insert_iter_value.pass.cpp to use insert overload with const
value_type& (not with value_type&& which is tested in
iter_rvalue.pass.cpp test)
Reviewed By: Quuxplusone, rarutyun, #libc
Differential Revision: https://reviews.llvm.org/D112438
`__wrap_iter` is currently only constexpr if it's not a debug built, but it isn't used in a constexpr context currently. Making it always constexpr and disabling the debugging utilities at constant evaluation is more usful since it has to be always constexpr to be used in a constexpr context.
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D114733
Reviewed as part of D114658.
Ultimately this will probably have to be flipped around and renamed
`TEST_IS_RUNTIME`, and extended with `TEST_IS_RUNTIME_OR_CXX20` (once
constexpr std::string support is added) and so on for every new C++
version. But we don't need that flexibility yet, so we're not adding it.
Disable the constructors taking `(size_type, const value_type&,
allocator_type)` if `allocator_type` is not a valid allocator.
Otherwise, these constructors are considered when resolving e.g.
`(int*, int*, NotAnAllocator())`, leading to a hard error during
instantiation. A hard error makes the Standard's requirement to not
consider deduction guides of the form `(Iterator, Iterator,
BadAllocator)` during overload resolution essentially non-functional.
The previous approach was to SFINAE away `allocator_traits`. This patch
SFINAEs away the specific constructors instead, for consistency with
`basic_string` -- see [LWG3076](wg21.link/lwg3076) which describes
a very similar problem for strings (note, however, that unlike LWG3076,
no valid constructor call is affected by the bad instantiation).
Differential Revision: https://reviews.llvm.org/D114311
This patch removes the ability to build the runtimes in the 32 bit
multilib configuration, i.e. using -m32. Instead of doing this, one
should cross-compile the runtimes for the appropriate target triple,
like we do for all other triples.
As it stands, -m32 has several issues, which all seem to be related to
the fact that it's not well supported by the operating systems that
libc++ support. The simplest path towards fixing this is to remove
support for the configuration, which is also the best course of action
if there is little interest for keeping that configuration. If there
is a desire to keep this configuration around, we'll need to do some
work to figure out the underlying issues and fix them.
Differential Revision: https://reviews.llvm.org/D114473
This removes the `format_args_t` from `<format>` and adjusts the type of
the `format_args` for the `vformat_to` overloads.
The `format_context` uses a `back_insert_iterator<string>` therefore the
new `output_iterator` function uses a `string` as its temporary storage
buffer. This isn't ideal. The next patches in this series will improve
this. These improvements make it easy to also improve `format_to_n` and
`formatted_size`.
This addresses P2216 `6. Binary size`.
P2216 `5. Compile-time checks` are not part of this change.
Implements parts of:
- P2216 std::format improvements
Depends on D103670
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D110494
Fixes https://llvm.org/PR51520. The problem is that `uniform_int_distribution`
currently uses an unsigned integer with at most 64 bits internally, which
is then casted to the desired result type. If the result type is `int64_t`,
this will produce a negative number if the most significant bit is set,
but if the result type is `__int128_t`, the value remains non-negative
and will be out of bounds for the example in PR#51520. (The reason why
it also seems to work if the upper or lower bound is changed is
because the branch at [1] will then no longer be taken, and proper
rejection sampling takes place.)
The bigger issue here is probably that `uniform_int_distribution` can be
instantiated with `__int128_t` but will silently produce incorrect results
(only the lowest 64 bits can ever be set). libstdc++ also supports `__int128_t`
as a result type, so I have simply extended the maximum width of the
internal intermediate result type.
[1]: https://github.com/llvm/llvm-project/blob/6d28dffb6/libcxx/include/__random/uniform_int_distribution.h#L266-L267
Differential Revision: https://reviews.llvm.org/D114129
We only support Clangs that implement nullptr as an extension in C++03 mode,
and we don't support GCC in C++03 mode. Hence, this patch disables the
use of the std::nullptr_t emulation in C++03 mode by default. Doing that
is technically an ABI break since it changes the mangling for std::nullptr_t.
However:
(1) The only affected users are those compiling in C++03 mode that have
std::nullptr_t as part of their ABI, which should be reasonably rare.
(2) Those users already have a lingering problem in that their code will
be incompatible in C++03 and C++11 modes because of that very ABI break.
Hence, the only users that could really be inconvenienced about this
change is those that planned on compiling in C++03 mode forever - for
other users, we're just breaking them now instead of letting them break
themselves later on when they try to upgrade to C++11.
(3) The ABI break will cause a linker error since the mangling changed,
and will not result in an obscure runtime error.
Furthermore, if anyone is broken by this, they can define the
_LIBCPP_ABI_USE_CXX03_NULLPTR_EMULATION macro to return to the
previous behavior. We will then remove that macro after shipping
this for one release if we haven't seen widespread issues.
Concretely, the motivation for making this change is to make our own ABI
consistent in C++03 and C++11 modes and to remove complexity around the
definition of nullptr.
Furthermore, we could investigate making nullptr a keyword in C++03 mode
as a Clang extension -- I don't think that would break anyone, since
libc++ already defines nullptr as a macro to something else. Only users
that do not use libc++ and compile in C++03 mode could potentially be
broken by that.
Differential Revision: https://reviews.llvm.org/D109459
The test doesn't depend specifically on the en_US.UTF-8 locale, instead
it depends on whether localization support exists, period.
Differential Revision: https://reviews.llvm.org/D114708
I encountered this while reviewing an unrelated patch. Will land after
the CI passes.
Reviewed By: #libc, Mordante
Differential Revision: https://reviews.llvm.org/D114673
These benchmarks will be used to test the performance inpact of the next
set of optimization patches.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D110501
Add missing tests to improve associative containers code coverage:
- Tests for key_comp() and value_comp() observers
- Tests for std::map and std::multimap value_compare member class
Reviewed by: ldionne, rarutyun, #libc
Differential Revision: https://reviews.llvm.org/D113998
Instead of silently swallowing errors that happen during Lit configuration
(for example trying to obtain compiler macros but compiling fails), raise
an exception with some amount of helpful information.
This should avoid the possibility of silently configuring Lit in a bogus
way, and also provides more helpful information when things fail.
Note that this requires a bit more finesse around how we handle some
failing configuration checks that we would previously return None for.
Differential Revision: https://reviews.llvm.org/D114010
-Wformat-nonliteral was turned on in https://reviews.llvm.org/D112927,
however we forgot to apply some __format__ attributes in Linux specific
code paths, which led to warnings when building on Linux. This patch
addresses that oversight.
Differential Revision: https://reviews.llvm.org/D113876
This patch implements operator<=> for std::reverse_iterator and
also adds a test that checks that three-way comparison of different
instantiations of std::reverse_iterator works as expected (related to
D113417).
Reviewed By: ldionne, Quuxplusone, #libc
Differential Revision: https://reviews.llvm.org/D113695
When testing with sanitizers enabled, we need to link against a plethora
of system libraries. Using `-nodefaultlibs` like we used to breaks this,
and we would have to add all these system libraries manually, which is
not portable and error prone. Instead, stop using `-nodefaultlibs` so
that we get the libraries added by default by the compiler.
The only caveat with this approach is that we are now relying on the
fact that `-L <path-to-local-libunwind>` will cause the just built
libunwind to be selected before the system implementation (either of
libunwind or libgcc_s.so), which is somewhat fragile.
This patch also turns the 32 bit multilib build into a soft failure
since we are in the process of removing it anyway, see D114473 for
details. This patch is incompatible with the 32 bit multilib build
because Ubuntu does not provide a proper libstdc++ for 32 bits, and
that is required when running with sanitizers enabled.
Differential Revision: https://reviews.llvm.org/D114385
On some platforms like armv7m, the size() method of containers returns
unsigned long, while ptrdiff_t is just int. Hence, std::ssize_t ends up
being long, which is not the same as ptrdiff_t. This is usually not an
issue because std::ptrdiff_t is long, so everything works out, but it
breaks on some more exotic architectures.
Differential Revision: https://reviews.llvm.org/D114563
Rework `std::filesystem::path::operator==` and friends to avoid overload
resolution and atomic constraint caching issues shown from
https://reviews.llvm.org/D113161.
Always call `__compare(string_view)` from the comparison operators which avoids
overload resolution.
Differential Revision: https://reviews.llvm.org/D114570
The `string_view` constructor taking an iterator/sentinel uses concepts
instead of type traits like the Standard states. Using `same_as` instead
of `is_same_v` should be harmless. Prefer `std::is_same_v` instead which is
cheaper to compile. Replace `convertible_to` with `is_convertible_v` as
well.
This observation came up while working on
https://reviews.llvm.org/D113161
Differential Revision: https://reviews.llvm.org/D114561
According to the C++ standard, the stored pointer and the stored deleter
should be value-initialized.
Differential Revision: https://reviews.llvm.org/D113612
In 1fa27f2a10, we made <filesystem>'s iterator types model concepts
from <ranges>, but we forgot to add the appropriate availability
annotations. This broke back-deployment to platforms that don't have
<filesystem> for which we have availability annotations.
For some reason, this wasn't caught by our back-deployment CI.
I believe this is due to the fact that we use a slightly older
compiler in the CI, and perhaps that compiler does not honour
our `#pragma clang attribute push` properly.
Differential Revision: https://reviews.llvm.org/D114456
Instead of having ad-hoc cleanup in various places, handle all creation
and removal of temporary files and directories inside _makeConfigTest.
As a fly-by, also remove testPrefix since we don't keep any source file
around anymore. Setting a prefix for the files is hence not useful anymore.
Differential Revision: https://reviews.llvm.org/D114390
This does not include `std::compare_*_fallback`; those are coming later.
There's still an open question of how to implement std::strong_order
for `long double`, which has 80 value bits and 48 padding bits on x86-64,
and which is presumably *not* IEEE 754-compliant on PPC64 and so on.
So that part is left unimplemented.
Differential Revision: https://reviews.llvm.org/D110738
Actually there's one functional change here, which is that users can
no longer depend on <random> to include all of C++20 <concepts>. That
inclusion is so new that we believe nobody should be depending on it
yet, even in the presence of Hyrum's Law. We keep the includes of <vector>,
<algorithm>, etc., so as not to break pre-C++20 Hyrum's Law users.
Differential Revision: https://reviews.llvm.org/D114281
Nikolas Klauser