Summary:
After putting this question up on cfe-dev I have decided that it would be best to allow the use of `<atomic>` in C++03. Although static initialization is a concern the syntax required to get it is C++11 only. Meaning that C++11 constant static initialization cannot silently break in C++03, it will always cause a syntax error. Furthermore `ATOMIC_VAR_INIT` and `ATOMIC_FLAG_INIT` remain defined in C++03 even though they cannot be used because C++03 usages will cause better error messages.
The main change in this patch is to replace `__has_feature(cxx_atomic)`, which only returns true when C++ >= 11, to `__has_extension(c_atomic)` which returns true whenever clang supports the required atomic builtins.
This patch adds the following macros:
* `_LIBCPP_HAS_C_ATOMIC_IMP` - Defined on clang versions which provide the C `_Atomic` keyword.
* `_LIBCPP_HAS_GCC_ATOMIC_IMP` - Defined on GCC > 4.7. We must use the fallback atomic implementation.
* `_LIBCPP_HAS_NO_ATOMIC_HEADER` - Defined when it is not safe to include `<atomic>`.
`_LIBCPP_HAS_C_ATOMIC_IMP` and `_LIBCPP_HAS_GCC_ATOMIC_IMP` are mutually exclusive, only one should be defined. If neither is defined then `<atomic>` is not implemented and including `<atomic>` will issue an error.
Reviewers: chandlerc, jroelofs, mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11555
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245463 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Throughout the libc++ headers, there are a few instances where
_VSTD::move() is used to return a local variable. Howard commented in
r189039 that these were there "for non-obvious reasons such as to help
things limp along in C++03 language mode".
However, when compiling these headers with warnings on, and in C++11 or
higher mode (like we do in FreeBSD), they cause the following complaints
about pessimizing moves:
In file included from tests.cpp:26:
In file included from tests.hpp:29:
/usr/include/c++/v1/map:1368:12: error: moving a local object in a return statement prevents copy elision [-Werror,-Wpessimizing-move]
return _VSTD::move(__h); // explicitly moved for C++03
^
/usr/include/c++/v1/__config:368:15: note: expanded from macro '_VSTD'
#define _VSTD std::_LIBCPP_NAMESPACE
^
Attempt to fix this by adding a _LIBCPP_EXPLICIT_MOVE() macro to
__config, which gets defined to _VSTD::move for pre-C++11, and to
nothing for C++11 and later.
I am not completely satisfied with the macro name (I also considered
_LIBCPP_COMPAT_MOVE and some other variants), so suggestions are
welcome. :)
Reviewers: mclow.lists, howard.hinnant, EricWF
Subscribers: arthur.j.odwyer, cfe-commits
Differential Revision: http://reviews.llvm.org/D11394
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245421 91177308-0d34-0410-b5e6-96231b3b80d8
std::packaged_task requires variadic templates and is #ifdef out in C++03.
This patch silences the tests in C++03. This patch also rewrites the .fail.cpp tests so that they use clang verify.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245413 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch attempts to fix the last 3 TSAN failures on the libc++ bot (http://lab.llvm.org:8011/builders/libcxx-libcxxabi-x86_64-linux-ubuntu-tsan/builds/143). This patch also adds a `Atomic` test type that can be used where `<atomic>` cannot.
`wait.exception.pass.cpp` and `wait_for.exception.pass.cpp` were failing because the test replaced `std::terminate` with `std::exit`. `std::exit` would asynchronously run the TLS and static destructors and this would cause a race condition. See PR22606 and D8802 for more details.
This is fixed by using `_Exit` to prevent cleanup.
`notify_all_at_thread_exit.pass.cpp` exercises the same race condition but for different reasons. I fixed this test by manually joining the thread before beginning program termination.
Reviewers: EricWF, mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11046
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245389 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch fixes __not_null's detection of nullptr by breaking it down into 4 cases.
1. `__not_null(Tp const&)`: Default case. Tp is not null.
2. `__not_null(Tp* __ptr);` Case for pointers to functions.
3. `__not_null(_Ret _Class::* __ptr);` Case for pointers to members.
4. `__not_null(function<Tp> const&);`: Cases for other std::functions.
Reviewers: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11111
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245335 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
See https://llvm.org/bugs/show_bug.cgi?id=22606 for more discussion.
Most of the changes in this patch are file reorganization to help ensure assumptions about how __thread_specific_pointer is used hold. The assumptions are:
* `__thread_specific_ptr<Tp>` is only created with a `__thread_struct` pointer.
* `__thread_specific_ptr<Tp>` can only be constructed inside the `__thread_local_data()` function.
I'll remove the comments before committing. They are there for clarity during review.
Reviewers: earthdok, mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D8802
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245334 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Normally people won't see warnings in libc++ headers, but if they compile with "-Wsystem-headers -Wnon-virtual-dtor" they will likely see issues in <locale>.
In the libc++ implementation `time_get' has a private base class, `__time_get_c_storage`, with virtual methods but a non-virtual destructor.
`time_get` itself can safely be used as a polymorphic base class because it inherits a virtual destructor from `locale::facet`. To placate the compiler we change `__time_get_c_storage`'s destructor from public to protected, ensuring that it will never be deleted polymorphically.
Reviewers: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11670
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245333 91177308-0d34-0410-b5e6-96231b3b80d8
When I was refactoring the unique_ptr.single.ctor tests I added a test
deleter, 'NCDeleter', to deleter.h. Other tests that include deleter.h
redefine the NCDeleter type causing test failures.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@243733 91177308-0d34-0410-b5e6-96231b3b80d8
One of the last sections of tests that still fail in C++03 are the unique_ptr
tests. This patch begins cleaning up the tests and fixing C++03 failures.
The main changes of this patch:
- The "Deleter" type in "deleter.h" tried to be "move-only" in C++03. However
the move simulation no longer works (see "__rv"). "Deleter" is now copy
constructible in C++03. However copying "Deleter" will "move" the test value
instead of copying it.
- Reduce the unique.ptr.single.ctor tests files from ~25 to 4. There is no
reason the tests were split through so many files.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@243730 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds the working parts of r243503. The difference with this patch
is that it doesn't include the HandleLLVMOptions.cmake file.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@243698 91177308-0d34-0410-b5e6-96231b3b80d8
This change was reverted in r243550 because it broke clang-format builds
(see PR24306).
This patch recommits a fixed version of the original.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@243574 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch contains the following changes:
1. Require that libc++ can find a LLVM source directory. This is done the same way as `libc++abi` currently does.
2. Cleanup ugly configuration code in CMakeLists.txt by using `add_flags`, `add_flags_if`, and `add_flags_if_supported` macros.
The goals for this patch are:
1. Help libc++ be more consistent with how LLVM handles CMake options (see PR23670 PR23671).
2. Make it easier to use sanitizers using the `LLVM_USE_SANITIZER` option.
3. Make libc++'s CMakeLists.txt file easier to understand and change.
4. Move towards allowing libc++ to create Sphinx documentation (see http://efcs.ca/libcxx-docs).
5. Move towards allowing libc++ to use other LLVM utilities such as `not` and `FileCheck`.
Reviewers: mclow.lists, jroelofs, danalbert
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11308
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@243503 91177308-0d34-0410-b5e6-96231b3b80d8
The key changes in this patch are:
1. Remove the zero-argument overload in mem_fn. A member function must always
be invoked with at least one argument, the class instance. The zero-argument
operator()() in mem_fn would cause mem_fn to fail to compile when because
the call to '__invoke(pm)' is not well formed.
2. Prevent evaluation of '__apply_cv<Tp, Ret>' when 'Ret' is a function type.
'Ret' is a function type whenever 'Ret Tp::*' is a pointer to member function.
Attempting to add cv and ref qualifiers to a function type can cause a hard
compile error.
3. Remove the dummy overload __invoke(Rp Tp::*). It was present to help work
around #1. It will be replaced with a different '__invoke' overload that
represents a bad call to invoke.
After applying this patch the test func.wrap.func.inv/invoke.pass.cpp now
passes.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@243370 91177308-0d34-0410-b5e6-96231b3b80d8
This patch does a couple of things to get __invoke working for free-functions
and call objects.
1. Turn all uses of declval<Tp>() into declval<Tp&>(). The C++03 __invoke only
supports lvalues but it will be used when the compiler supports rvalue
references but not variadic templates. This change makes sure we don't
generate an rvalue.
2. Call objects for bullet 5 are now passed by reference and not value. Copying
the functor is incorrect. It will fail to compile for non-copyable functors
and it will discard cv-qualifiers on the call object, possibly leading to the
wrong function being called. I suspect that the reason the call object
was originally taken by value was to support temporary call objects.
However __invoke is only used internally and it is never given a temporary.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@243368 91177308-0d34-0410-b5e6-96231b3b80d8
Before I start trying to fix __invoke in C++03 it needs better test coverage.
This patch adds a large amount of tests for __invoke.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@243366 91177308-0d34-0410-b5e6-96231b3b80d8
The implementation of mem_fn doesn't actually require any C++11 support.
For some reason there were 17 overloads for mem_fn in C++03 when only one
is needed. This patch removes the extra overloads and uses the same implementation
of mem_fn in C++03 and C++11.
__mem_fn does require variadics to implement the call operator. Instead of
having two entirely different implementations of the __mem_fn struct, this patch
uses the same __mem_fn struct but provides different call operators when
variadics are not available.
The only thing left in <__functional_03> is the C++03 implementation of
std::function.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@242959 91177308-0d34-0410-b5e6-96231b3b80d8
This patch removes a large amount of duplicate code found in both
<__functional_base> and <__functional_base_03>. The only code that remains
in <__functional_base_03> is the C++03 implementation of __invoke and
__invoke_return.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@242951 91177308-0d34-0410-b5e6-96231b3b80d8
