Commit Graph

18 Commits

Author SHA1 Message Date
JF Bastien
4b72294338 Revert "Add nonnull; use it for atomics"
That's r333325, as well as follow-up "Fix GCC handling of ATOMIC_VAR_INIT"
r333327.

Marshall asked to revert:

Let's have a discussion about how to implement this so that it is more friendly
to people with installed code bases. We've had *extremely* loud responses to
unilaterally adding warnings - especially ones that can't be easily disabled -
to the libc++ code base in the past.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@333351 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-26 19:44:45 +00:00
JF Bastien
895c4f3ec7 Fix GCC handling of ATOMIC_VAR_INIT
r333325 from D47225 added warning checks, and the test was written to be C++11 correct by using ATOMIC_VAR_INIT (note that the committee fixed that recently...). It seems like GCC can't handle ATOMIC_VAR_INIT well because it generates 'type 'std::atomic<int>' cannot be initialized with an initializer list' on bot libcxx-libcxxabi-x86_64-linux-ubuntu-cxx03. Drop the ATOMIC_VAR_INITs since they weren't required to test the diagnostics.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@333327 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-26 00:13:53 +00:00
JF Bastien
8bacb9422b Add nonnull; use it for atomics
Summary:
The atomic non-member functions accept pointers to std::atomic / std::atomic_flag as well as to the non-atomic value. These are all dereferenced unconditionally when lowered, and therefore will fault if null. It's a tiny gotcha for new users, especially when they pass in NULL as expected value (instead of passing a pointer to a NULL value). We can therefore use the nonnull attribute to denote that:

  - A warning should be generated if the argument is null
  - It is undefined behavior if the argument is null (because a dereference will segfault)

This patch adds support for this attribute for clang and GCC, and sticks to the subset of the syntax both supports. In particular, work around this GCC oddity:
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60625

The attributes are documented:

  - https://gcc.gnu.org/onlinedocs/gcc-4.0.0/gcc/Function-Attributes.html
  - https://clang.llvm.org/docs/AttributeReference.html#nullability-attributes

I'm authoring a companion clang patch for the __c11_* and __atomic_* builtins, which currently only warn on a subset of the pointer parameters.

In all cases the check needs to be explicit and not use the empty nonnull list, because some of the overloads are for atomic<T*> and the values themselves are allowed to be null.

<rdar://problem/18473124>

Reviewers: arphaman, EricWF

Subscribers: aheejin, christof, cfe-commits

Differential Revision: https://reviews.llvm.org/D47225

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@333325 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-25 23:43:53 +00:00
Volodymyr Sapsai
a382216407 Revert "Emit an error when mixing <stdatomic.h> and <atomic>"
It reverts commit r331379 because turned out `__ALLOW_STDC_ATOMICS_IN_CXX__`
doesn't work well in practice.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@331818 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-08 22:50:35 +00:00
Volodymyr Sapsai
8fc472d96a Emit an error when mixing <stdatomic.h> and <atomic>
Atomics in C and C++ are incompatible at the moment and mixing the
headers can result in confusing error messages.

Emit an error explicitly telling about the incompatibility. Introduce
the macro `__ALLOW_STDC_ATOMICS_IN_CXX__` that allows to choose in C++
between C atomics and C++ atomics.

rdar://problem/27435938

Reviewers: rsmith, EricWF, mclow.lists

Reviewed By: mclow.lists

Subscribers: jkorous-apple, christof, bumblebritches57, JonChesterfield, smeenai, cfe-commits

Differential Revision: https://reviews.llvm.org/D45470


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@331379 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-02 17:56:45 +00:00
Marshall Clow
b911dfd212 Disable the test I just added when testing C++03.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@330838 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-25 16:09:47 +00:00
Marshall Clow
727ed618db Fix static initialization of std::atomic_flag; Fixes PR#37226. Thanks to Ricky Zhou for the report and test case.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@330828 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-25 14:27:29 +00:00
Eric Fiselier
9f6e23c7c9 update XFAIL comments with more details
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@300944 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-21 03:09:40 +00:00
Eric Fiselier
c94dd0a571 XFAIL Windows test failures under test/libcxx
This patch XFAIL's a number of tests under test/libcxx when on Windows.
These failures need more investigation or patches to either Clang or libc++
but for now we don't want them to prevent the bot from going green.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@300941 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-21 01:48:02 +00:00
Eric Fiselier
5ed767588b Diagnose invalid memory orderings in <atomic>
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@291976 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-13 23:45:39 +00:00
Eric Fiselier
bca6de0e4e Adjust libc++ test infastructure to fully support modules
This patch overhalls the libc++ test format/configuration in order to fully support modules. By "fully support" I mean get almost all of the tests passing. The main hurdle for doing this is handling tests that `#define _LIBCPP_FOO` macros to test a different configuration. This patch deals with these tests in the following ways:

1. For tests that define single `_LIBCPP_ABI_FOO` macros have been annotated with `// MODULES_DEFINES: _LIBCPP_ABI_FOO`. This allows the test suite to define the macro on the command line so it uses a different set of modules.
2. Tests for libc++'s debug mode (which define custom `_LIBCPP_ASSERT`) are automatically detected by the test suite and are compiled and run with modules disabled.

This patch also cleans up how the `CXXCompiler` helper class handles enabling/disabling language features.

NOTE: This patch uses `LIT` features which were only committed to LLVM today. If this patch breaks running the libc++ tests you probably need to update LLVM.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@288728 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-05 23:16:07 +00:00
JF Bastien
d3ca9828e3 atomics.align: XFAIL GCC
It currently fails because GCC changed the mangling of templates, which affects std::atomic using __attribute__((vector(X))). The bot using GCC 4.9 generates the following message:

In file included from /home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/test/libcxx/atomics/atomics.align/align.pass.sh.cpp:24:0:
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic: In instantiation of 'atomic_test<T>::atomic_test() [with T = __vector(2) int]':
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/test/libcxx/atomics/atomics.align/align.pass.sh.cpp:66:3:   required from here
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: error: 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(2) int]' conflicts with a previous declaration
     __gcc_atomic_t() _NOEXCEPT = default;
     ^
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: previous declaration 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(1) int]'
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: -fabi-version=6 (or =0) avoids this error with a change in mangling
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: error: 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(2) int]' conflicts with a previous declaration
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: previous declaration 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(1) int]'
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: -fabi-version=6 (or =0) avoids this error with a change in mangling
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:939:5: note: synthesized method 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(2) int]' first required here
     __atomic_base() _NOEXCEPT = default;
     ^

GCC's docs say the following about ABI version 6:
Version 6, which first appeared in G++ 4.7, corrects the promotion behavior of C++11 scoped enums and the mangling of template argument packs, const/static_cast, prefix ++ and –, and a class scope function used as a template argument.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@277380 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-01 20:28:13 +00:00
JF Bastien
d836c0e3cb libc++: test lock-free atomic alignment
Summary:
libc++ implements std::atomic<_Tp> using __atomic_base<_Tp> with
`mutable _Atomic(_Tp) __a_`. That member must be suitably aligned on
relevant ISAs for instructions such as cmpxchg to work properly, but
this alignment isn't checked anywhere. __atomic_base's implementation
relies on _Atomic doing "the right thing" since it's under the
compiler's control, and only the compiler knows about lock-freedom and
instruction generation. This test makes sure that the compiler isn't
breaking libc++'s expectations.

I'm looking at a few odd things in the C++ standard, and will have a few
other fixes around this area in the future.

This requires building with `-DLIBCXX_HAS_ATOMIC_LIB=True`, the test
marks the dependency as REQUIRES and won't be run without.

Reviewers: cfe-commits

Subscribers: EricWF, mclow.lists

Differential Revision: http://reviews.llvm.org/D22073

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@277368 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-01 19:27:08 +00:00
Eric Fiselier
bdbae4cbad Revert r276506 - Diagnose invalid memory order arguments in <atomic>.
There is a bug in Clang 3.6 and earlier that causes compile failures.
I suspect it's due to the usage of member function parameter names in the
attributes.



git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@276507 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-23 01:43:53 +00:00
Eric Fiselier
ea213b96a6 [libcxx] Diagnose invalid memory order arguments in <atomic>. Fixes PR21179.
Summary:
This patch uses the __attribute__((enable_if)) hack suggested by @rsmith to diagnose invalid arguments when possible.

In order to diagnose an invalid argument `m` to `f(m)` we provide an additional overload of `f` that is only enabled when `m` is invalid. When that function is enabled it uses __attribute__((unavailable)) to produce a diagnostic message.

Reviewers: mclow.lists, rsmith, jfb, EricWF

Subscribers: bcraig, jfb, rsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D22557

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@276506 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-23 01:16:55 +00:00
Eric Fiselier
67ec8a281b Move more _LIBCPP_VERSION tests to test/libcxx.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@273365 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-22 02:07:26 +00:00
Eric Fiselier
219406e77f [libcxx] [test] Replace non-Standard "atomic_flag f(false);" with Standard "atomic_flag f;"
Summary:
Replace non-Standard "atomic_flag f(false);" with Standard "atomic_flag f;" in clear tests.
Although the  value of 'f' is unspecified it shouldn't matter because these tests always call `f.test_and_set()` without checking the result, so the initial state shouldn't matter.

The test init03.pass.cpp is explicitly testing this non-Standard extension; It has been moved into the `test/libcxx` directory.

Reviewers: mclow.lists, STL_MSFT

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D19758

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@268355 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-03 02:12:26 +00:00
Jonathan Roelofs
5e91fa1eec Misc drive-by cleanups. NFC
http://reviews.llvm.org/D12294


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245876 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-24 21:20:07 +00:00