call_once is using relaxed atomic load to perform double-checked locking, which contains a data race. The fast-path load has to be an acquire atomic load.
Differential Revision: https://reviews.llvm.org/D24028
llvm-svn: 280621
Summary:
This patch allows threads not created using `std::thread` to use `std::notify_all_at_thread_exit` by ensuring the TL state has been initialized within `std::notify_all_at_thread_exit`.
Additionally this patch "fixes" a potential oddity in `__thread_local_pointer::reset(pointer)`, which would previously delete the old thread local data. However there should *never* be old thread local data because pthread *should* null it out on thread exit. Unfortunately it's possible that pthread failed to do this according to the spec:
>
> Upon key creation, the value NULL shall be associated with the new key in all active threads. Upon thread creation, the value NULL shall be associated with all defined keys in the new thread.
>
> An optional destructor function may be associated with each key value. At thread exit, if a key value has a non-NULL destructor pointer, and the thread has a non-NULL value associated with that key, the value of the key is set to NULL, and then the function pointed to is called with the previously associated value as its sole argument. The order of destructor calls is unspecified if more than one destructor exists for a thread when it exits.
>
> If, after all the destructors have been called for all non-NULL values with associated destructors, there are still some non-NULL values with associated destructors, then the process is repeated. If, after at least {PTHREAD_DESTRUCTOR_ITERATIONS} iterations of destructor calls for outstanding non-NULL values, there are still some non-NULL values with associated destructors, implementations may stop calling destructors, or they may continue calling destructors until no non-NULL values with associated destructors exist, even though this might result in an infinite loop.
However if pthread fails to delete the value it is probably incorrect for us to do it. Destroying the value performs all of the "at thread exit" actions registered with it but we are way past "at thread exit".
Reviewers: mclow.lists, bcraig, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D24159
llvm-svn: 280588
When <bitset> is compiled with warnings enabled, on a platform where
size_t is 4 bytes, it results in errors similar to:
bitset:265:16: error: non-constant-expression cannot be narrowed
from type 'unsigned long long' to '__storage_type' (aka 'unsigned
int') in initializer list [-Wc++11-narrowing]
: __first_{__v, __v >> __bits_per_word}
^~~
bitset:676:52: note: in instantiation of member function
'std::__1::__bitset<2, 53>::__bitset' requested here
bitset(unsigned long long __v) _NOEXCEPT : base(__v) {}
^
Fix these by casting the initializer list elements to __storage_type.
Reviewers: mclow.lists, EricWF
Differential Revision: https://reviews.llvm.org/D23960
llvm-svn: 280543
Microsoft removed gets from the CRT in Visual Studio 2015 onwards [1].
Attempting to reference it when targeting CRT versions 14 and above will cause
compile errors.
[1] https://msdn.microsoft.com/en-us/library/2029ea5f.aspx
Patch by Shoaib Meenai!
llvm-svn: 280417
`-fPIC` doesn't make much sense for Windows, since Windows DLLs aren't compiled
position independent and are instead relocated at runtime.
Patch by Shoaib Meenai!
llvm-svn: 280413
In r280108 I tried to make the headers copy relative to LLVM_BINARY_DIR, and the intent was that it would only happen on in-tree builds or runtimes directory builds. It didn't actually work that way.
This patch adds a check for CMAKE_SOURCE_DIR being equal to CMAKE_CURRENT_SOURCE_DIR. In this case we set a variable LIBCXX_USING_INSTLLED_LLVM. This doesn't necessarily mean the LLVM is installed (it could be a build directory), but it means we need to treat the LLVM directory as read-only.
llvm-svn: 280400
Summary: This copy phase is only needed for in-tree builds, so we should be copying to the LLVM build directory's include dir instead of the sub-project include dir.
Reviewers: bogner, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D24015
llvm-svn: 280108
Some of the mutex tests fail on machines with high load. This patch implements
the test directive "// FLAKY_TEST" which allows a test to be run 3 times
before it's considered a failure.
llvm-svn: 280050
We're compiling libc++ with -nodefaultlibs, so we should also pass this
option during the configuration checks to ensure those checks are
consistent with the actual build.
The primary motivation here is to ease cross-compilation against a
non-standard set of C++ libraries. Previously, the configuration checks
would attempt to link against the standard C++ libraries, which would
cause link failures when cross-compiling, even though the actual library
link would go through correctly (because of the use of -nodefaultlibs
and explicitly specifying any needed libraries). This is more correct
even ignoring the motivation, however.
Patch by Shoaib Meenai!
llvm-svn: 280015
Summary:
Currently a number of GCC warnings are emitted when building libc++. This patch fixes or ignores all of them. The primary changes are:
* Work around strict aliasing issues in `typeinfo::hash_code()` by using __attribute__((may_alias)). However I think a non-aliasing `hash_code()` implementation is possible. Further investigation needed.
* Add `_LIBCPP_UNREACHABLE()` to switch in `strstream.cpp` to avoid -Wpotentially-uninitialized.
* Fix -Wunused-value warning in `__all` by adding a void cast.
* Ignore -Wattributes for now. There are a number of real attribute issues when using GCC but enabling the warning is too noisy.
* Ignore -Wliteral-suffix since it warns about the use of reserved identifiers. Note Only GCC 7.0 supports disabling this warning.
* Ignore -Wc++14-compat since it warns about the sized new/delete overloads.
Reviewers: EricWF
Differential Revision: https://reviews.llvm.org/D24003
llvm-svn: 280007
This patch enables the `cxx-benchmarks` target by default. Note that the target
still has to be manually invoked since it isn't included in the default 'make'
rule.
This patch also gets the benchmarks building w/ GCC. The build previously
required the '-stdlib=libc++' flag but upstream patches to Google Benchmark
now allow the library to build w/ libc++ and GCC.
These changes should make the benchmarks easier to build and test.
llvm-svn: 279999
This assignment operator was previously broken since the SFINAE always resulted
in substitution failure. This caused assignments to turn into
copy construction + assignment.
This patch was originally committed as r279953 but was reverted due to warnings
in the test-suite. This new patch corrects those warnings.
llvm-svn: 279955
This assignment operator was previously broken since the SFINAE always resulted
in substitution failure. This caused assignments to turn into
copy construction + assignment.
llvm-svn: 279953
This patch implements the std::sample function added to C++17 from LFTS. It
also removes the std::experimental::sample implementation which now forwards
to std::sample.
llvm-svn: 279948
Libc++'s implementation of shuffle and sample already support lvalue and rvalue
RNG's. This patch adds tests for both categories and marks the issue as complete.
This patch also contains drive-by change for std::experimental::sample which
improves the diagnostics produced when the correct iterator categories are
not supplied.
llvm-svn: 279947
Similar to rL242623, move C++ version checks outside of _NOEXCEPT_()
macro invocation argument lists, to avoid "embedding a directive within
macro arguments has undefined behavior" warnings.
Differential Revision: https://reviews.llvm.org/D23961
llvm-svn: 279926
Summary:
The point of this patch is to have a consistent convention for naming build, check and install targets so that the targets can be constructed from the project name.
This change renames a bunch of CMake components and targets from libcxx to cxx. For each renamed target I've added a convenience target that matches the old target name and depends on the new target. This will preserve function of the old targets so that the change doesn't break the world. We can evaluate if it is worth removing the extra targets later.
Reviewers: EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D23699
llvm-svn: 279675
We're compiling libc++ with -nodefaultlibs, so we should also pass this option
during the configuration checks to ensure those checks are consistent with the
actual build.
The primary motivation here is to ease cross-compilation against a non-standard
set of C++ libraries. Previously, the configuration checks would attempt to link
against the standard C++ libraries, which would cause link failures when
cross-compiling, even though the actual library link would go through correctly
(because of the use of -nodefaultlibs and explicitly specifying any needed
libraries). This is more correct even ignoring the motivation, however.
Patch by Shoaib Meenai!
llvm-svn: 279584
Some tests uses 'long double' to/from conversions and for some targets
they are provided by compiler runtime (either compiler-rt or libgcc).
However when building libcxx with linunwinder current test configuration
at target_info.py do not include the required libraries, as:
not llvm_unwinder:
"-lc++" "-lm" "-lgcc_s" "-lgcc" "-lpthread" "-lc" "-lgcc_s" "-lgcc"
llvm_unwinder
"-lc++" "-lm" "-lpthread" "-lc" "-lunwind" "-ldl"
This causes some tests build issues with missing symbols on aarch64,
for instance, where 'long double' is a binary float with 128-bits with
mostly of internal operations being provided by software routines.
This patch changes how to define the default linker flags with libunwinder by
adding libgcc regardless.
I checked and aarch64 and x86_64 with libcxx and libunwind (with and without
LIBCXXABI_USE_LLVM_UNWINDER).
llvm-svn: 279552
Summary:
The new LLVM runtimes build directory requires some basic conventions across the runtime projects. These changes make libcxx build under the runtimes subdirectory. The general idea of the changes is that the runtimes subdirectory requires some conventions to be consistent across runtime projects.
I expect to have a few more small patches that build on this to tie up check targets and other things useful in development workflows.
Summary of changes in this patch:
* Renamed variable LLVM_CONFIG -> LLVM_CONFIG_PATH
* Renamed variable LIBCXX_BUILT_STANDALONE -> LIBCXX_STANDALONE_BUILD
* Add an include of AddLLVM in the tests subdirectory for add_lit_testsuite.
Reviewers: EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D23696
llvm-svn: 279151
The expected 'filesystem::path::compare' result states that for different
path only result sign contains the information about passed arguments
(not its integer value). This is due it uses the output of other compare
functions (basic_string_view and char_traits) without further handling and
char_traits uses memcmp for final buffer comparison.
However for GLIBC on AArch64 the code:
int ret = memcmp ("b/a/c", "a/b/c", 1);
Results in '64' where for x86_64 it results in '1'.
This patch fixes the expected 'filesystem::path::compare' by normalizing
all the results before assert comparison.
llvm-svn: 278745
Currently certain tests get killed when compiled with ASAN at -O0 because
they eat all of the systems memory. This doesn't happen at -O1, so enable that
to work around the issue.
llvm-svn: 278722
Although libc++ only requires C++11 to build, there are other
reasons to turn on a newer dialect in the build. For example
IDE's may not highlight any C++14/C++17 in the headers when
configured for C++11. This patch add's a private option for
changing this.
llvm-svn: 278638
Kuba Brecka