Thanks to @lewissbaker who pointed out the unnecessary condition in
https://reviews.llvm.org/D81954#inline-756872. Since this codepath does not
make use of `swap` anyway (that codepath is a different branch), we can safely
remove this condition and produce better codegen when all types are nothrow
movable but are potentially-throwing swappable.
See codegen in https://gcc.godbolt.org/z/uDFZjz
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D83274
There used to be a workaround where we'd pretend that GCC 5 didn't support
C++14 because it doesn't implement it properly. Since that workaround has
been removed (in 1eb211ada1), we need to mark a few individual tests as
failing with GCC 5.
Summary:
Modifies the algorithm sort bench:
- shows sorting time per element, instead of sorting time per array.
This would make comparison between different sizes of arrays easier.
- adds std::pair benchmark cases.
- uses a large number of arrays to benchmark, instead of repeatedly sorting the same array.
* sorting the same array again and again would not show actual sorting performance over randomized data sets.
Reviewers: EricWF, #libc, mvels
Reviewed By: EricWF, #libc, mvels
Subscribers: mgrang, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D81770
Instead of detecting it automatically (in libc++) and relying on
_LIBCXXABI_NO_EXCEPTIONS being set explicitly (in libc++abi), always
detect whether exceptions are enabled automatically.
This commit also removes support for specifying -D_LIBCPP_NO_EXCEPTIONS
and -D_LIBCXXABI_NO_EXCEPTIONS explicitly -- those should just be inferred
from using -fno-exceptions (or an equivalent flag).
Allowing both -D_FOO_NO_EXCEPTIONS to be provided explicitly and trying
to detect it automatically is just confusing, especially since we did
specify it explicitly when building libc++abi. We should have only one
way to detect whether exceptions are enabled, but it should be robust.
As announced on libcxx-dev at [1], the old libc++ testing format is being
removed in favour of the new one. Follow-up commits will clean up the
code that is dead after the removal of this option.
[1]: http://lists.llvm.org/pipermail/libcxx-dev/2020-June/000885.html
Since we can always find the rest of the LLVM tree, we can always run the
tests in the standalone mode. Do it so that the default behavior is the
same in the standalone and non-standalone modes.
Since we require that libc++ is built as part of the monorepo layout, we
can assume the path of the rest of LLVM and avoid requiring that LLVM_PATH
be set explicitly.
Doing so doesn't work reliably, since it relies on LLVM_* implementation
detail variables being set. Furthermore, since we rely on the lit.site.cfg
being generated, running the tests requires LIBCXX_INCLUDE_TESTS=ON anyway.
We've decided to move away from that by requiring that libc++ is built
as part of the monorepo a while ago. This commit removes code pertaining
to that unsupported use case and produces a clear error when the user
violates that.
In fact, building outside of the monorepo will still work as long as
LLVM_PATH is pointing to the root of the LLVM project, although that
is not officially supported.
The runtimes build includes libcxx/include/CMakeLists.txt directly instead
of going through the top-level CMake file. This not-very-hygienic inclusion
caused some variables like LIBCXX_BINARY_DIR not to be defined properly,
and the config_site generation logic to fail after landing 53623d4aa7.
This patch works around this issue by defining the missing variables.
However, the proper fix for this would be for the runtimes build to
always go through libc++'s top-level CMakeLists.txt. Doing otherwise
is unsupported.
Before this patch, the __config_site header was only generated when at
least one __config_site macro needed to be defined. This lead to two
different code paths in how libc++ is configured, depending on whether
a __config_site header was generated or not. After this patch, the
__config_site is always generated, but it can be empty in case there
are no macros to define in it.
More context on why this change is important
--------------------------------------------
In addition to being confusing, this double-code-path situation lead to
broken code being checked in undetected in 2405bd6898, which introduced
the LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT CMake setting. Specifically,
the _LIBCPP_HAS_MERGED_TYPEINFO_NAMES_DEFAULT <__config_site> macro was
supposed NOT to be defined unless LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT
was specified explicitly on the CMake command line. Instead, what happened
is that it was defined to 0 if it wasn't specified explicitly and a
<__config_site> header was generated. And defining that macro to 0 had
the important effect of using the non-unique RTTI comparison implementation,
which changes the ABI.
This change in behavior wasn't noticed because the <__config_site> header
is not generated by default. However, the Apple configuration does cause
a <__config_site> header to be generated, which lead to the wrong RTTI
implementation being used, and to https://llvm.org/PR45549. We came close
to an ABI break in the dylib, but were saved due to a downstream-only
change that overrode the decision of the <__config_site> for the purpose
of RTTI comparisons in libc++abi. This is an incredible luck that we should
not rely on ever again.
While the problem itself was fixed with 2464d8135e by setting
LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT explicitly in the Apple
CMake cache and then in d0fcdcd28f by making the setting less
brittle, the point still is that we should have had a single code
path from the beginning. Unlike most normal libraries, the macros
that configure libc++ are really complex, there's a lot of them and
they control important properties of the C++ runtime. There must be
a single code path for that, and it must be simple and robust.
Differential Revision: https://reviews.llvm.org/D80927
Since we're using an empty top-level CMakeLists.txt instead of the CMakeLists.txt
inside llvm/, we don't need to specify LLVM_INCLUDE_BENCHMARKS anymore.
We use the _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT macro for that now instead.
I did leave a check behind to make sure that nobody was still using the old
macro name. I'll remove it a couple of months down the road.
Summary:
https://reviews.llvm.org/D82029 introduced the non-throw check for final_suspend(). There are a few tests I missed in that patch.
Fixing them here.
Reviewers: #libc, lewissbaker, modocache, ldionne
Reviewed By: #libc, ldionne
Subscribers: dexonsmith, modocache, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D82338
Similar to <concepts>, we need to protect the header and test against
inclusion and being run if concepts aren't supported by the compiler.
Differential Revision: https://reviews.llvm.org/D82171
Summary:
This change adds local 'end' and 'pos' variables for the main loop inmstead of using the ConstructTransaction variables directly.
We observed that not all vector initialization and resize operations got properly vectorized, i.e., (partially) unrolled into XMM stores for floats.
For example, `vector<int32_t> v(n, 1)` gets vectorized, but `vector<float> v(n, 1)`. It looks like the compiler assumes the state is leaked / aliased in the latter case (unclear how/why for float, but not for int32), and because of this fails to see vectorization optimization?
See https://gcc.godbolt.org/z/UWhiie
By using a local `__new_end_` (fixed), and local `__pos` (copied into __tx.__pos_ per iteration), we offer the compiler a clean loop for unrolling.
A demonstration can be seen in the isolated logic in https://gcc.godbolt.org/z/KoCNWv
The com
Reviewers: EricWF, #libc!
Subscribers: libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D82111
When testing libc++ for our cross-compiled CheriBSD target we specify an
explicit LIBCXX_CXX_ABI_INCLUDE_PATHS for libcxxrt. The hardcoded path
/usr/include/c++/v1 was introduced in 61e89737c5
and overrides any value passed on the CMake command line. Fix this by using
it as a fallback rather than a fixed default value.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D82095
Before this patch, the libc++ test suite first loads lit.site.cfg
(generated by CMake), and then lit.cfg. It's also possible to load
lit.cfg before lit.site.cfg and to point to a custom lit.site.cfg
file using '--param=libcxx_site_config'. However, in that case, lit.cfg
still relies on the site configuration filling up the 'config' object
like the default lit.site.cfg file does, which isn't flexible enough.
This commit simplifies the setup by having just a single Lit site config
file per CMake configuration, and always loading exactly that config file.
However, the config file to use can be selected when setting up CMake via
the LIBCXX_TEST_CONFIG setting. Furthermore, the site configs are entirely
standalone, which means that a new site config can be added that doesn't
need to conform what's expected by config.py.
Differential Revision: https://reviews.llvm.org/D81846
Summary:
In the case where `swap` is `noexcept`, we should avoid the extension to provide strong-exception guarantee.
Fixes https://bugs.llvm.org/show_bug.cgi?id=46342
Reviewers: #libc, ldionne
Reviewed By: #libc, ldionne
Subscribers: dexonsmith, mclow.lists, miscco, ldionne, zoecarver, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D81954
The Standard documents the signature of std::advance as
template <class Iter, class Distance>
constexpr void advance(Iter& i, Distance n);
Furthermore, it does not appear to put any restriction on what the type
of Distance should be. While it is understood that it should usually
be std::iterator_traits::difference_type, I couldn't find any wording
that mandates that. Similarly, I couldn't find wording that forces the
distance to be a signed type.
This patch changes std::advance to accept any type in the second argument,
which appears to be what the Standard mandates. We then coerce it to the
iterator's difference type, but that's an implementation detail.
Differential Revision: https://reviews.llvm.org/D81425
The commit was reverted in 43c4afb56f because it broke the Windows to
Linux cross-compilation build bots. The issue turned out to be that the
bots were setting the LIBCXX_EXECUTOR incorrectly. This has been fixed
now and verified with the bot owners.
Note that this is only a partial re-application of the commit, since
non-problematic parts of the commits have already been re-applied earlier.
This is useful for checking runtime properties of the target system.
This is a partial re-application of 3ea9450bda. This part was tested
to work on a Windows host with a SSH executor.
That test is already only enabled if LIBCXX_TEST_GDB_PRETTY_PRINTERS is
enabled, which isn't the default. If someone turns on that option on
Windows, they should be able to run the test and see whatever failure
happens.
The integration between CMake and executor selection in the new format
wasn't very flexible -- only the default executor and SSH executors were
supported.
This patch makes it possible to specify arbitrary executors with the new
format. With the new testing format, a custom executor is just a script
that gets called with a command-line to execute, and some arguments like
--env, --codesign_identity and --execdir. As such, the default executor
is just run.py.
Remote execution with the SSH executor can be achived by specifying
LIBCXX_EXECUTOR="<path-to-ssh.py> --host <host>". Similarly, arbitrary
scripts can be provided.
Instead of passing file dependencies individually, assume that the
whole content of the unique test directory is a dependency. This
simplifies the test harness significantly, by making %T the directory
that contains everything required to run a test. This also removes the
need for the %{file_dependencies} substitution, which is removed by this
patch.
Furthermore, this patch also changes the harness to execute tests locally
inside %T, so as to avoid creating a separate directory for no purpose.
This will allow simplifying executors by always just copying the whole
%T, and assuming that all file dependencies are contained in it.
Superseeds https://reviews.llvm.org/D78245, which tried to make %T unique
in Lit, but which encountered push back.
The test is failing on 32-bit targets in C++03 mode. Clang produces
the following warning: 'integer literal is too large to be represented
in type 'long' and is subject to undefined behavior under C++98,
interpreting as 'unsigned long'; this literal will have type 'long
long' in C++11 onwards [-Wc++11-compat]' which is promoted to an error
and causes the test to fail.
There have been no changes in the test itself since 2019, so it looks
like the diagnostic has been updated.
Differential Revision: https://reviews.llvm.org/D81559
Unlike parameters in litConfig.params, the config isn't shared across
all test suites. For example, if we want to enable exceptions in the
tests for libcxxabi, but not in the tests for libcxx, we can't set the
enable_exceptions parameter in the litConfig object, cause it will be
used by both. Instead, setting it inside the config object solves that
problem.
This commit adds CMake caches for the various configurations of libc++
that are tested by our build bots.
Differential Revision: https://reviews.llvm.org/D81293
The availability markup for bad_optional_access marked it as being added
in MacOS 10.14 and aligned releases, however it appears to have been added
in Mac OS 10.13 and aligned releases.
This effectively implements the resolution of LWG3231, which mandates
that calling year_month_day_last::day() on an invalid year_month_day_last
is unspecified behavior. Before this change, it was undefined behavior.
Differential Revision: https://reviews.llvm.org/D81477
This increases the Mac OS requirement for building libc++ to 10.12.
Note that it doesn't change whether the *headers* still support older
platforms -- it's only that macOS >= 10.12 is required to build the
dylib from sources.
Differential Revision: https://reviews.llvm.org/D74489
This reverts commit 0c148430cf, which added an assertion in day().
The Standard doesn't allow day() to crash -- instead it says that the
result is unspecified.
Differential Revision: https://reviews.llvm.org/D70346
All compilers supported by libc++ have rvalues in C++03 mode so, there is no need for this non-rvalue overload.
Differential Revision: https://reviews.llvm.org/D80881
Otherwise, if %{flags} contain other files like static libraries, those
files are treated as C++ source files instead of object files, and the
compiler gets all confused.
Before this patch, we tried detecting whether small atomics were available
without linking against libatomic. However, that's not really what we want
to know -- instead, we want to know what's required in order to support
atomics fully, which is to link against libatomic when it's provided.
That is both much simpler, and it doesn't suffer the problem that we would
not link against libatomic when small atomics didn't require it, which
lead to non-lockfree atomics never working.
Furthermore, because we understand that some platforms might not want to
(or be able to) ship non-lockfree atomics, we add that notion to the test
suite, independently of a potential extern library.
After this patch, we therefore:
(1) Link against libatomic when it is provided
(2) Independently detect whether non-lockfree atomics are supported in
the test suite, regardless of whether that means we're linking against
an external library or not (which is an implementation detail).
Differential Revision: https://reviews.llvm.org/D81190
It is legitimate for the test suite to use types that are slow to use
with std::atomic, since we need coverage for those too. If we don't
disable the warning, it is promoted to an error, which prevents us
from testing such types.
Libc++ provides support for <thread> in C++03 as an extension. Furthermore,
it does not support any compiler that doesn't have rvalue references. It
is hence possible to provide the move constructor and move assignment
operator in C++03.
C++98 and C++03 are effectively aliases as far as Clang is concerned.
As such, allowing both std=c++98 and std=c++03 as Lit parameters is
just slightly confusing, but provides no value. It's similar to allowing
both std=c++17 and std=c++1z, which we don't do.
This was discovered because we had an internal bot that ran the test
suite under both c++98 AND c++03 -- one of which is redundant.
Differential Revision: https://reviews.llvm.org/D80926
This test is arguably fatally flawed, at least as long as C++ condition
variables are just trivial wrappers around POSIX. I've added some notes
to the test for future authors to consider.
Like we do for empty std::array, make sure we have assertions in place
for obvious out-of-bounds issues in std::array when the debug mode is
enabled (which isn't by default).
The Standard is currently unimplementable. We have to pick between:
1. Not implementing constexpr support properly in std::array<T, 0>
2. Making std::array<T, 0> non-trivial even when T is trivial
3. Returning nullptr from std::array<T, 0>::begin()
Libc++ initially picked (1). In 77b9abfc8e, we started implementing constexpr properly, but lost the guarantee of triviality. Since it seems like both (1) and (2) are really important, it seems like (3) is the only viable option for libc++, after all. This is also what other implementations are doing.
This patch moves libc++ from (1) to (3).
It also:
- Improves the test coverage for the various ways of initializing std::array
- Adds tests for the triviality of std::array
- Adds tests for the aggregate-ness of std::array
Reviewed By: #libc, miscco, EricWF, zoecarver
Differential Revision: https://reviews.llvm.org/D80821
When the __config_site header is generated, but LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT
wasn't specified, _LIBCPP_HAS_MERGED_TYPEINFO_NAMES_DEFAULT would be defined
to 0, which was the NonUnique RTTI comparison implementation. The intent
was to use the Unique RTTI comparison implementation in that case, which
caused https://llvm.org/PR45549.
Instead, use a proper "switch" to select the RTTI comparison implementation.
Note that 0 can't be used as a value, because that is treated the same
by CMake as a variable that is just not defined.
Differential Revision: https://reviews.llvm.org/D80037
This commit adds missing support for constexpr in std::array under all
standard modes up to and including C++20. It also transforms the <array>
tests to check for constexpr-friendliness under the right standard modes.
Fixes https://llvm.org/PR40124
Fixes rdar://57522096
Supersedes https://reviews.llvm.org/D60666
Differential Revision: https://reviews.llvm.org/D80452
Summary: Update status page and test synopsis. Add synopsis in <cmath>.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D80456
Summary: a4b8ee6 made all MoveOnly members constexpr but, some members and constructors contain expressions that are only valid in C++14 and later. This patch prefixes those methods and constructors with TEST_CONSTEXPR_CXX14.
Reviewers: ldionne, #libc!
Subscribers: dexonsmith, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D80482
Don't use std::filesystem APIs for CWDGuard, use POSIX functions
instead. This way the tests don't rely on the correctness of
the functionality they're testing.
Differential Revision: https://reviews.llvm.org/D78200
Louis Dionne