This reverts commit r312890 because the test case fails to compile for
older versions of Clang that reject initializing a const object without
a user defined constructor.
Since this patch should go into 5.0.1, I want to keep it an atomic change,
and will re-commit it with a fixed test case.
llvm-svn: 312891
This patch fixes llvm.org/PR34298. Previously libc++ incorrectly evaluated
the __invokable trait via the converting constructor `function(Tp)` [with Tp = std::function]
whenever the copy constructor or copy assignment operator
was required. This patch further constrains that constructor to short
circut before evaluating the troublesome SFINAE when `Tp` matches
std::function.
The original patch is from Alex Lorenz.
llvm-svn: 312890
_strftime_l is only available in the numbered msvcrt versions
(starting from msvcr80.dll). In the default configuration, mingw
targets the unversioned msvcrt.dll - and there, _strftime_l is
not available (not even on windows 10).
If __MSVCRT_VERSION__ is set to a higher value (indicating a
non-default target and wanting to link to msvcrXX.dll), use the
correct function.
Differential Revision: https://reviews.llvm.org/D37468
llvm-svn: 312617
This function template is referenced inside class basic_string as a
friend function. The extern template declaration needs to be above that
friend declaration to actually take effect.
This is important because this function was marked as exported in
r307966, so without the extern template taking effect, it can leak into
other DSOs as a visible symbol.
llvm-svn: 309474
Creating a function pointer with proper parameters pointing to std::next() or std::prev() should work.
This change moves the invented paramater for enable_if over to the return type to resolve this QoI issue.
Patch by Jason Liu.
Differential Revision: https://reviews.llvm.org/D34649
llvm-svn: 308932
Some targets (e.g. Darwin) might have the Win32 API available, but they
do not use MSVC CRT. Assume _LIBCPP_MSVCRT only when _MSC_VER is available
and __MINGW32__ isn't defined.
Differential Revision: https://reviews.llvm.org/D34588
rdar://problem/32628786
llvm-svn: 308225
Once upon a time, extern templates used to be a Microsoft extension, so
cl would warn about their usage, and libc++ suppressed that warning.
They've long since been standardized, so the warning is defunct. (libc++
also doesn't currently support building with cl anyway.)
llvm-svn: 307997
It has an extern template instantiation declaration in the headers and a
corresponding instantiation definition in the library, so we must mark
it with _LIBCPP_FUNC_VIS to make it available outside the library.
This doesn't cause any ABI changes as-is since we don't build libc++
with hidden visibility (so the function is exported anyway). It's needed
for building libc++ with hidden visibility, however.
Clarify the Windows behavior for extern function templates while I'm
here, since this exercises that behavior.
llvm-svn: 307966
When using LIBCXX_ABI_UNSTABLE=YES, clang-cl gave the following warning:
P:\llvm_master\src\llvm\projects\libcxx\include\string(683,51):
warning: enumerator value is not representable in the underlying type
'int' [-Wmicrosoft-enum-value]
Fixed by switching from enums to static const size_type.
https://reviews.llvm.org/D35174
llvm-svn: 307751
The libc++ <__refstring> headers has no real reason why it should
be a public header that libc++ ships. The only reason it was in the include
directory was because libc++abi needed it to build the library.
However keeping <__refstring> a header had other problems, like requiring its
dependancies to also be in the headers. For that reason this patch
moves it into the source directory.
To work around libc++abi's need for this header a duplicated copy was added
to libc++abi in r307748. While duplicating the code is an unfortunate solution
it's the best solution that's currently possible.
In the future I would like to start a discussion on the mailing lists about
making libc++abi build as a sub-project of libc++, requiring the libc++ sources
always be present.
llvm-svn: 307749
This is going to be used by the runtime build in the multi-target
setup to allow using different install prefix for each target.
Differential Revision: https://reviews.llvm.org/D33762
llvm-svn: 307615
r283051 added some functions to cmath (in namespace std) that have the
same name as functions in math.h (in the global namespace). Clang's
limited support for `-fdelayed-template-parsing` chokes on this. Rename
the ones in `cmath` and their uses in `complex` and the test.
rdar://problem/32848355
llvm-svn: 307357
This reverts commit r306310.
r306310 causes clang to reject a call to an aligned allocation or
deallocation function if it is not implemented in the standard library
of the deployment target. This is not the desired behavior when users
have defined their own aligned functions.
rdar://problem/32664169
llvm-svn: 306859
The string literal operators have implicit instantiations of
basic_string<char> and basic_string<wchar>, which prevent the dllimport
on the subsequent explicit instantiation declarations from having an
effect. Hoisting the explicit instantiations above the implicit ones
fixes the issue.
I think it's pretty unfortunate that the ordering has such an effect,
and I'd fixed the same issue for dllexport in r288682. dllimport is more
complicated from a codegen perspective, however, and clang's behavior of
ignoring the dllimport when there's a previous implicit instantiation is
consistent with cl, so changing the order is our only recourse.
llvm-svn: 306632
attribute.
This is needed because older versions of libc++ do not have these
operators. If users target an older deployment target and try to compile
programs in which these operators are explicitly called, the compiler
will complain.
The following is the list of minimum deployment targets for the four
OSes:
macosx: 10.13
ios: 11.0
tvos: 11.0
watchos: 4.0
rdar://problem/32664169
Differential Revision: https://reviews.llvm.org/D34556
llvm-svn: 306310
Remarks: This function shall not participate in overload resolution unless
`is_same_v<decay_t<T>, variant>` is false, unless `decay_t<T>` is
neither a specialization of `in_place_type_t` nor a specialization of
`in_place_index_t`, unless `is_constructible_v<Tj, T>` is true, and
unless the expression `FUN(std::forward<T>(t))` (with `FUN` being the
above-mentioned set of imaginary functions) is well formed.
Depends on D34111.
Reviewers: EricWF, K-ballo
Reviewed By: EricWF
Subscribers: fhahn
Differential Revision: https://reviews.llvm.org/D34112
llvm-svn: 305668
Fix an off-by-one in r302172, which triggered building local versions of
the iostreams when deploying to `<= macOS 10.9`, when it should have
been `< macOS 10.9`. 10.9 had the dylib support.
This defines `_LIBCPP_AVAILABILITY_NO_STREAMS_EXTERN_TEMPLATE` less
often, reducing code size for users with deployment targets of exactly
macOS 10.9 or iOS 7.0.
rdar://problem/32233981
llvm-svn: 305649
C99 at least. C89 still fails due to the use of block comments.
NOTE: Having libc++ on the include path when compiling C is not
recommended or ever really supported. However it happens often
enough that this change is warrented.
llvm-svn: 305539
It seems conceivable that a user would need to get a coroutine handle
having only a const reference to the promise_type, for example from
within a const member function of the promise.
This patch allows that use case. A coroutine_handle<const T> can be used
in essentially the same way a coroutine_handle<T>, ie to start and destroy
the coroutine. The constness of the promise doesn't/shouldn't propagate
to the handle.
llvm-svn: 305536
The function num_get<_CharT>::stage2_int_prep makes unnecessary copy of src
into atoms when char_type is char. This can be avoided by creating
a switch on type and just returning __src when char_type is char.
Added the test case to demonstrate performance improvement.
In order to avoid ABI incompatibilities, the changes are guarded
with a macro _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
Differential Revision: https://reviews.llvm.org/D30268
Reviewed by: EricWF
llvm-svn: 305427
Newlib 2.5 added the locale management functions, so it should not
include __nop_local_mgmt.h. This change adds proper guard around that
include statement.
For newlib 2.4, some releases contain these functions and some don't,
and they all have the same version numbers. This patch will work
properly with the initial "2.4.0" release which does not include these
functions and require __nop_local_mgmt.h.
This has been tested against newlib 2.2 and 2.5, and also sanity
checks against other different version numbers.
Patch by Martin J. O'Riordan and Walter Lee
Differential Revision: https://reviews.llvm.org/D32146
llvm-svn: 305394
r304862 changed how CTD handles deducing a non-primary class template
using a non-dependent constructor of the primary template. This change
requires libc++ to provide explicit deduction guides to make scoped_lock
work again.
llvm-svn: 304955
On Bionic PTHREAD_MUTEX_INITIALIZER contains the expression "<enum-type> & <integer-type>",
which causes ADL to perform name lookup for operator&. During this lookup Clang decides
that it requires the default member initializer for std::mutex while defining the DMI
for std::mutex::__m_.
If I'm not mistaken this is caused by the explicit noexcept declaration on the defaulted
constructor.
This patch removes the explicit noexcept and instead allows the compiler to declare
the default constructor implicitly noexcept. It also adds a static_assert to ensure
that happens.
Unfortunatly because it's not easy to change the value of _LIBCPP_MUTEX_INITIALIZER
for a single test there is no good way to test this patch.
The Clang behavior causing the trouble here was introduced in r287713, which first
appears in the 4.0 release.
llvm-svn: 304942
Summary:
- Removed the move-constructibe requirement from copy-assignable.
- Updated `__assign_alt` such that we direct initialize if
`_Tp` can be `nothrow`-constructible from `_Arg`, or `_Tp`'s
move construction can throw. Otherwise, construct a temporary and move it.
- Updated the tests to remove the pre-LWG2904 path.
Depends on D32671.
Reviewers: EricWF, CaseyCarter
Reviewed By: EricWF
Differential Revision: https://reviews.llvm.org/D33965
llvm-svn: 304891
Summary:
This patch improves how libc++ handles min/max macros within the headers. Previously libc++ would undef them and emit a warning.
This patch changes libc++ to use `#pragma push_macro` to save the macro before undefining it, and `#pragma pop_macro` to restore the macros and the end of the header.
Reviewers: mclow.lists, bcraig, compnerd, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits, krytarowski
Differential Revision: https://reviews.llvm.org/D33080
llvm-svn: 304357
from_address requires that the provided pointer refer to the suspended coroutine,
which doesn't have a type, or at least not one knowable by the user. Therefore
every use of `from_address` with a typed pointer is almost certainly a bug.
This behavior is a part of the TS specification, but hopefully it will be
in the future.
llvm-svn: 304172
More tests to come. I think that from_address overload should be deleted
or ill-formed, except for the 'void*' one; The user cannot possibly
have a typed pointer to the coroutine state.
llvm-svn: 304131
Clang supports coroutines in all dialects; Therefore libc++ should too,
otherwise the Clang extension is unusable.
I'm not convinced extending support to C++03 is a feasible long term
plan, since as the library grows to offer things like generators it
will be come increasingly difficult to limit the implementation to C++03.
However for the time being supporting C++03 isn't a big deal.
llvm-svn: 303963
Clang started providing -fcoroutines and defining __cpp_coroutines
way before it implemented the __builtin_coro_foo functions. This
means that simply checking if __cpp_coroutines is not a sufficient
way of detecting the actual feature.
This patch implements _LIBCPP_HAS_NO_COROUTINES which implements
a slightly more complex feature check. Specifically it requires
__cpp_coroutines >= 201703L, which only holds for Clang 5.0 built
after 2017/05/24.
llvm-svn: 303956
The original issues were caused because <experimental/coroutine>
didn't correctly #ifdef out enough of the header, which caused incomplete
types to be used.
This patch fixes the `#if defined(__cpp_coroutines)` guard and re-adds
the headers to the module map.
It also uglifies some incorrectly non-reserved names.
llvm-svn: 303936
This patch updates the promise() member to match the current spec.
Specifically it removes the non-const overload and make the return
type of the const overload non-const.
This patch also makes the ASSERT_NOT_NOEXCEPT tests libc++ specific,
since other implementations may be free to strengthen the specification.
llvm-svn: 303895
This patch removes the clear() member from <string_view>. The
modifier was removed from the TS before it ever landed in the standard.
There is no reason libc++ should be providing this method.
llvm-svn: 302869
Some MinGW configurations use WinPThread instead of the native
threading interfaces. When this happens libc++ doesn't build because
it tries to use the wrong threading API.
This patch attempts to correctly detect and enable pthreads; Selecting
them when __MINGW32__ is defined and __has_include(<pthread.h>) is true.
I'm not sure if this works correctly 100% of the time but it seemed
like the most correct approach available.
llvm-svn: 302734
This patch follows up on feedback received in the review for
D32988. Specifically that libc++ should not mess with the
__builtin namespace, and that libc++ should use __popcnt to implement
__pop_count under MSVC.
llvm-svn: 302731
Summary:
This patch refactors and tries to remove as much of the Windows support headers as possible. This is needed because they currently introduce super weird include cycles and dependencies between STL and libc headers.
The changes in this patch are:
* remove `support/win32/support.h` completely. The required parts have either been moved into `support/win32/msvc_support.h` (for `MSVC` only helpers not needed by Clang), or directly into their respective `foo.h` headers.
* Combine `locale_win32.h` and `locale_mgmt_win32.h` into a single headers, this header should only be included within `__locale` or `locale` to avoid include cycles.
* Remove the unneeded parts of `limits_win32.h` and re-name it to `limits_msvc_win32.h` since it's only needed by Clang.
I've tested this patch using Clang on Windows, but I suspect it might technically regress our non-existent support for MSVC. Is somebody able to double check?
This refactor is needed to support upcoming fixes to `<locale>` on Windows.
Reviewers: bcraig, rmaprath, compnerd, EricWF
Reviewed By: EricWF
Subscribers: majnemer, cfe-commits
Differential Revision: https://reviews.llvm.org/D32988
llvm-svn: 302727
Summary:
This patch fixes bugs.llvm.org/PR32979.
[util.smartptr.shared.const] says:
> In the constructor definitions below, enables shared_from_this with p, for a pointer p of type Y*, means
> that if Y has an unambiguous and accessible base class that is a specialization of enable_shared_from_-
> this.
This means that libc++ needs to respect the access specifier of the base class, and not attempt to construct
and enabled_shared_from_this base if it is private. However access specifiers don't affect overload resolution
so our current implementation will attempt to construct the private base.
This patch uses SFINAE to correctly detect if the shared_ptr input has an accessible enable_shared_from_this
base class.
Reviewers: mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D33033
llvm-svn: 302709
This patch fixes the test failures and unexpected passes that occur
when testing against GCC 7. Specifically:
* don't mark __gcd as always inline because it's a recursive function. GCC diagnoses this.
* don't XFAIL the aligned allocation tests. GCC 7 supports them but not the -faligned-allocation option.
* Work around gcc.gnu.org/PR78489 in variants constructors.
llvm-svn: 302488
Previously <locale> used std::unique_ptr<remove_ptr<locale_t>, locale-mgmt-function>
as a scope guard for (A) creating new locales, and (B) setting the thread specific locale
in RAII safe manner.
However using unique_ptr has some problems, first it requires that locale_t is a pointer
type, which may not be the case (Windows will need a non-pointer locale_t type that emulates _locale_t).
The second problem is that users of the guards had to supply the locale management function to the custom
deleter at every call site. However these locale management functions don't exist natively Windows, making
a good Windows implementation of locale more difficult.
This patch creates distinct and simply RAII guards that replace unique_ptr. These guards handle calling
the correct locale management function so that callers don't have too. This simplification will
aid in upcoming Windows fixes.
llvm-svn: 302474
Summary:
This patch implements exception_ptr on Windows using the `__ExceptionPtrFoo` functions provided by MSVC.
The `__ExceptionPtrFoo` functions are defined inside the C++ standard library, `msvcprt`, which is unfortunate because it requires libc++ to link to the MSVC STL. However this doesn't seem to cause any immediate problems. However to be safe I kept all usages within the libc++ dylib so that user programs wouldn't have to link to MSVCPRT as well.
Note there are still 2 outstanding exception_ptr/nested_exception test failures.
* `current_exception.pass.cpp` needs to be rewritten for the Windows exception_ptr semantics which copy the exception every time.
* `rethrow_if_nested.pass.cpp` need investigation. It hits a stack overflow, likely from recursion.
This patch also gets most of the `<future>` tests passing as well.
Reviewers: mclow.lists, compnerd, bcraig, rmaprath, majnemer, BillyONeal, STL_MSFT
Subscribers: mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D32927
llvm-svn: 302393
Summary:
In https://bugs.freebsd.org/207918, Daniel McRobb describes how using
std::showbase with ostreams can cause truncation of unsigned long long
when output format is octal. In fact, this can even happen with
unsigned int and unsigned long.
To ensure this does not happen, add one additional character to the
do_put buffers if std::showbase is on. Also add a test case.
Reviewers: EricWF, mclow.lists
Reviewed By: EricWF
Subscribers: cfe-commits, emaste
Differential Revision: https://reviews.llvm.org/D32670
llvm-svn: 302362
The ERROR_TIMEDOUT returned by the Windows API does not
have the same value as ETIMEDOUT. This caused condition_variable
to return timeouts as unknown errors.
llvm-svn: 302297
Libc++ is used as a system library on macOS and iOS (amongst others). In order
for users to be able to compile a binary that is intended to be deployed to an
older version of the platform, clang provides the
availability attribute <https://clang.llvm.org/docs/AttributeReference.html#availability>_
that can be placed on declarations to describe the lifecycle of a symbol in the
library.
See docs/DesignDocs/AvailabilityMarkup.rst for more information.
Differential Revision: https://reviews.llvm.org/D31739
llvm-svn: 302172
Summary: Seemed to have been overlooked in D24028.
This bug was found and brought to my attention by Paul Wankadia.
Reviewers: kubamracek, EricWF, dvyukov
Differential Revision: https://reviews.llvm.org/D32402
llvm-svn: 301132
For std::isinf, the standard requires effectively calling isinf as
double from Libc for integral types. But integral types are never
infinite; we don't need to call Libc to return false.
Also short-circuit other functions where Libc won't have interesting
answers: signbit, fpclassify, isfinite, isnan, and isnormal.
I added correctness tests for integral types since we're no longer
deferring to Libc.
In review it was pointed out that in future revisions of the C++
standard we may add more types to std::is_arithmetic (e.g.,
std::is_fixed_point). I'll leave it to a future commit to hack this to
allow using math functions on those. We'll need to change things like
__libcpp_fpclassify anyway, so I'm not sure anything here would really
be future-proof.
https://reviews.llvm.org/D31561
rdar://problem/31361223
llvm-svn: 301060
Previously the ATOMIC_<TYPE>_LOCK_FREE macros were implemented
using __GCC_ATOMIC_<TYPE>_LOCK_FREE but GCC specific macros
are defined when -fms-compatibility is specified.
To avoid this Libc++ now tries to use the newly added
__CLANG_ATOMIC_<TYPE>_LOCK_FREE macros instead, and only falls
back to the GCC versions when the Clang ones aren't available.
llvm-svn: 300920
This patch cleans up all usages of the following feature test macros inside
<vector> and its tests:
* _LIBCPP_HAS_NO_RVALUE_REFERENCES
* _LIBCPP_HAS_NO_VARIADICS
* _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
Where needed the above guards were replaced with _LIBCPP_CXX03_LANG.
llvm-svn: 300410
This patch overhauls both specializations of unique_ptr while implementing
the following LWG issues:
* LWG 2801 - This issue constrains unique_ptr's constructors when the deleter type
is not default constructible. Additionally it adds SFINAE conditions
to unique_ptr<T[]>::unique_ptr(Up).
* LWG 2905 - This issue reworks the unique_ptr(pointer, /* see below */ deleter)
constructors so that they correctly SFINAE when the deleter argument cannot
be used to construct the stored deleter.
* LWG 2520 - This issue fixes initializing unique_ptr<T[]> from nullptr.
Libc++ had previously implemented this issue, but the suggested resolution
still broke initialization from NULL. This patch re-works the
unique_ptr<T[]>(Up, deleter) overloads so that they accept NULL as well
as nullptr.
llvm-svn: 300406
Fuchsia's libc was forked from musl, but has evolved sufficiently
since then so it no longer makes sense to pretend it's musl. This
change implements direct support for Fuchsia rather than
piggybacking on musl support.
Differential Revision: https://reviews.llvm.org/D31970
llvm-svn: 300261
When the libc++ extern template macros were added, the intent was for it
to be possible for consumers of the headers to disable extern templates
(via `-D_LIBCPP_EXTERN_TEMPLATE(...)=`). Unfortunately, support for
specifying function-like macros varies on the command line varies across
compilers (e.g. MSVC doesn't support it at all), and cmake doesn't allow
it for the same reason. Add a non-function macro for this purpose.
The intended use is for libraries which want to use the libc++ headers
without taking a dependency on the libc++ library itself. I can name the
macro something which reflects its intent rather than its behavior (e.g.
`_LIBCPP_HEADER_ONLY`) if desired.
Differential Revision: https://reviews.llvm.org/D31725
llvm-svn: 300246
path::iterator isn't a strictly conforming iterator. Specifically
it stashes the current element inside the iterator. This leads to
UB when used with reverse_iterator since it requires the element
to outlive the lifetime of the iterator.
This patch adds a static_assert inside reverse_iterator to disallow
"stashing iterator types", and it tags path::iterator as such a type.
Additionally this patch removes all uses of reverse_iterator<path::iterator>
within the tests.
llvm-svn: 300164
The __unordered_map_equal and __unordered_map_hash wrappers
attempt to swap const qualified predicates whenever the predicate
is empty, and is subject to the EBO.
Swapping const values seems blatently incorrect. This patch removes
the const qualifier so the values are swapped as non-const.
llvm-svn: 300154
r300140 introduced a bunch of failures by changing the internal
interface provided by __compressed_pair. This patch fixes all of
the failures caused by the new interface by changing the existing
code to use it.
In addition to those changes this patch also fixes two separate
issues causing test failures:
1) Fix the member swap definition for __map_value_compare. Previously
the swap was incorrectly configured to swap the comparator as const.
2) Fix an assertion failure in futures.task.members/ctor_func_alloc.pass.cpp
that incorrectly expected a move to take place when a single copy is sufficient.
There is one remaining failure regarding make_shared. I'll commit a fix for that
shortly.
llvm-svn: 300148
Summary:
__compressed_pair takes and passes it's constructor arguments by value. This causes arguments to be moved 3 times instead of once. This patch addresses that issue and fixes `constexpr` on the constructors.
I would rather have this fix than D27564, and I'm fairly confident it's not ABI breaking but I'm not 100% sure.
I prefer this solution because it removes a lot of code and makes the implementation *much* smaller.
Reviewers: mclow.lists, K-ballo
Reviewed By: K-ballo
Subscribers: K-ballo, cfe-commits
Differential Revision: https://reviews.llvm.org/D27565
llvm-svn: 300140
For reference deleter types the const qualifier on the return type
of get_deleter() should be ignored, and a non-const deleter should
be returned.
This patch fixes a bug where "const deleter_type&" is incorrectly
formed.
llvm-svn: 300121
The inline function definition ABI macro is gated on COFF dllexport
semantics, so it's more appropriate to mark it with the object file
format macro rather than the generic _WIN32 macro. We now have no uses
of _WIN32 apart from those used to define the other Windows macros :)
Clarify the ABI macro comment and make the object file format check
exhaustive while I'm here.
llvm-svn: 300097
LLVM dropped support for Visual Studio versions older than 2015 quite
some time ago, so I consider it safe to drop libc++'s support for older
CRTs. The CRT in Visual Studio 2015 provides a lot of previously missing
functions, so targeting it requires less special casing.
Differential Revision: https://reviews.llvm.org/D31798
llvm-svn: 299743
Method specializations don't get exported even if there's an exported
extern template instantiation on Windows. Explicitly mark the methods
for export. They're already exported on Linux and Darwin, so there's no
ABI change on those platforms.
llvm-svn: 299348
This is effectively a partial revert of r278356, which started inlining
basic_string::__init. Even if we want to help the compiler along with
an inlinehint, we shouldn't hamstring it by forcing it to inline all the
time.
Libc++ uses always_inline widely as a limit-the-ABI-hack, but since
__init is already on the dylib boundary, it makes no sense here and just
harms the debugging experience at -O0.
rdar://problem/31013102
llvm-svn: 299290
r145698 introduced _LIBCPP_HAS_NO_STRONG_ENUMS by copy-pasting the
__has_feature check from objc_arc_weak/_LIBCPP_HAS_OBJC_ARC_WEAK, and
accidentally started defining _LIBCPP_HAS_NO_STRONG_ENUMS whenever
__has_feature(objc_arc_weak). This is totally bogus, and means that
Libc++ thinks Objective-C++ compilations with -fobjc-arc don't have
strong enums.
Delete the accidental line.
I thought about adding a test, but it would be entirely duplicative of
the patch (if has-feature strong enums, check that has-no-strong-enums
is not defined).
llvm-svn: 299236
Summary:
bad_function_call is currently an empty class, so any object files using
that class will end up with their own copy of its typeinfo, typeinfo
name and vtable, leading to unnecessary duplication that has to be
resolved by the dynamic linker. Instead, give bad_function_call a key
function and put a definition for that key function in libc++ itself, to
centralize the typeinfo and vtable.
This is consistent with the behavior for other exception classes. The
key functions are defined in libc++ rather than libc++abi since the
class is defined in the libc++ versioning namespace, so ABI
compatibility with libstdc++ is not a concern.
Guard this change behind an ABI macro, since it isn't backwards
compatible (i.e., clients built against the new libc++ headers wouldn't
be able to run against an older libc++ library).
Reviewers: mclow.lists, EricWF
Subscribers: mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D27387
llvm-svn: 298937
Summary:
By manipulating a local variable in the loop, when the loop can
be optimized away (due to no non-trivial destructors), this lets
it be fully optimized away and we modify the __end_ separately.
This results in a substantial improvement in the generated code.
Prior to this change, this would be generated (on x86_64):
movq (%rdi), %rdx
movq 8(%rdi), %rcx
cmpq %rdx, %rcx
je LBB2_2
leaq -12(%rcx), %rax
subq %rdx, %rax
movabsq $-6148914691236517205, %rdx ## imm = 0xAAAAAAAAAAAAAAAB
mulq %rdx
shrq $3, %rdx
notq %rdx
leaq (%rdx,%rdx,2), %rax
leaq (%rcx,%rax,4), %rax
movq %rax, 8(%rdi)
And after:
movq (%rdi), %rax
movq %rax, 8(%rdi)
This brings this in line with what other implementations do.
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D25241
llvm-svn: 298601
basic_string::replace() has the below line
__sz += __n2 - __n1;
which fails overflow checks if __n1 > __n2, as the negative result
from the subtraction then overflows the original __sz when added to
it.
This behavior is valid as unsigned integer overflow is defined to wrap
around the maximum value and that produces the correct final value for
__sz. Therefore, we disable this check on this function.
llvm-svn: 297355
Put proper guards around _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS.
No functional change on non-Windows. Avoids incorrect macro redefinition
on Windows.
llvm-svn: 297330
r296565 attempted to add better diagnostics when an unordered container
is instantiated with a hash that doesn't meet the Hash requirements.
However I mistakenly checked the wrong set of requirements. Specifically
it checked if the hash met the requirements for specializations of
std::hash. However these requirements are stricter than the generic
Hash requirements.
This patch fixes the assertions to only check the Hash requirements.
llvm-svn: 296919
Summary:
Most classes annotated with _LIBCPP_TYPE_VIS need to have at least some
of their members exported, otherwise we have a lot of link errors when
linking against a libc++ built with hidden visibility. This also makes
_LIBCPP_TYPE_VIS be consistent across platforms, since on Windows it
already exports members.
With this change made, any template methods of a class marked
_LIBCPP_TYPE_VIS will also get default visibility when instantiatied,
which is not desirable for clients of libc++ headers who wish to control
their visibility; this is the same issue as PR30642. Annotate all
problematic methods with an explicit visibility specifier to avoid this.
The problematic methods were found by running bad-visibility-finder [1]
against the libc++ headers after making the _LIBCPP_TYPE_VIS change. The
small methods were marked for inlining; the larger ones hidden.
[1] https://github.com/smeenai/bad-visibility-finder
Reviewers: mclow.lists, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D25208
llvm-svn: 296732
When building libc++ with hidden visibility, we want explicit template
instantiations to export members. This is consistent with existing
Windows behavior, and is necessary for clients to be able to link
against a hidden visibility built libc++ without running into lots of
missing symbols.
An unfortunate side effect, however, is that any template methods of a
class with an explicit instantiation will get default visibility when
instantiated, unless the methods are explicitly marked inline or hidden
visibility. This is not desirable for clients of libc++ headers who wish
to control their visibility, and led to PR30642.
Annotate all problematic methods with an explicit visibility specifier
to avoid this. The problematic methods were found by running
https://github.com/smeenai/bad-visibility-finder against the libc++
headers after making the _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS change. The
methods were marked with the new _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
macro, which was created for this purpose.
It should be noted that _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS was originally
intended to expand to default visibility, and was changed to expanding
to default type visibility to fix PR30642. The visibility macro
documentation was not updated accordingly, however, so this change makes
the macro consistent with its documentation again, while explicitly
fixing the methods which resulted in that PR.
Differential Revision: https://reviews.llvm.org/D29157
llvm-svn: 296731
D29157 will make explicit template instantiations expand to default
visibility, at which point these method templates will need to be
explicitly marked hidden visibility to avoid leaking into other DSOs.
Unfortunately, because of clang PR32114, they must be marked inline (in
conjunction with `-fvisibility-inlines-hidden`) to actually hide them,
since clang doesn't respect the hidden visibility annotation.
Since this involves an ABI change, mark these methods inline in a
separate change, so that the ABI changes can be reviewed separately and
verified to be safe.
Differential Revision: https://reviews.llvm.org/D30523
llvm-svn: 296729
This patch adds a static assertion that the specified hash meets
the requirements of an enabled hash, and it ensures that the static
assertion is evaluated before __compressed_pair is instantiated.
That way the static assertion diagnostic is emitted first.
llvm-svn: 296565
This patch fixes llvm.org/PR32097 by using the __is_abstract
builtin type-trait instead of the previous library-only implementation.
All supported compilers provide this trait. I've tested as far
back as Clang 3.2, GCC 4.6 and MSVC trunk.
llvm-svn: 296561
This reverts SVN r295329. Although `__libcpp_thread_sleep_for` should
be alertable, the implementation causes a large regression in the test
suite. Add a FIXME item there for now to get the test suite in a better
state before attempting to fix that behaviour.
llvm-svn: 295561
When building with MSVCRT, we need to manually provide the type
promoting overloads to allow the correct type deduced invocation for
signbit(Int) and fpclassify(int).
llvm-svn: 295559
GCC 7.0.1 started warning that __attribute__((__strong__)) is depricated.
This patch switches to using inline namespace with GCC instead. I believe
this wasn't done originally in order to support older GCC versions w/o
support for inline namespaces, or because earlier versions of GCC warned
users that the STL was using an inline namespace (even though it shouldn't affect users).
However I believe all of the above problems are gone for GCC 4.9 and greater.
Therefore switching to using inline namespaces instead of using __strong__
is the most correct behavior.
llvm-svn: 295428
Summary:
This patch implements [P0003R5](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0003r5.html) which removes exception specifications from C++17.
The only changes to the library are removing `set_unexpected`, `get_unexpected`, `unexpected`, and `unexpected_handler`. These functions can be re-enabled in C++17 using `_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS`.
@mclow.lists what do you think about removing stuff is this way?
Reviewers: mclow.lists
Reviewed By: mclow.lists
Subscribers: mclow.lists, cfe-commits
Differential Revision: https://reviews.llvm.org/D28172
llvm-svn: 295406
Summary:
This patch fixes http://llvm.org/PR31938. The description below is copy/pasted from the bug:
The standard says:
template<class charT, class traits = char_traits<charT>,
class Allocator = allocator<charT>>
class basic_string {
using value_type = typename traits::char_type;
// ...
basic_string(const charT* s, const Allocator& a = Allocator());
};
libc++ actually chooses to declare the constructor as
basic_string(const value_type* s, const Allocator& a = Allocator());
The implicit deduction guides from class template argument deduction make what was previously an implementation detail visible:
std::basic_string s = "foo"; // error, can't deduce charT.
The constructor in question is in the libc++ DSO, but fortunately it looks like fixing this will not result in an ABI break.
@rsmith How does this look? I did more than just the constructors mentioned in the PR, but IDK how far to take it.
Reviewers: mclow.lists, rsmith
Reviewed By: rsmith
Subscribers: cfe-commits, rsmith
Differential Revision: https://reviews.llvm.org/D29863
llvm-svn: 295393
On Windows, we were using `Sleep` which is not alertable. This means
that if the thread was used for a user APC or WinProc handling and
thread::sleep was used, we could potentially dead lock. Use `SleepEx`
with an alertable sleep, resuming until the time has expired if we are
awoken early.
llvm-svn: 295329
clang cannot properly handle __declspec and __attribute__ on classes
right now. This prevents the shared_mutex tests from working. Disable
the use of the annotation on COFF targets.
llvm-svn: 294958
Pull in the math functions from ucrt 14+ after auditing the library. It
seems that they are now complete for C99 math. Fixes more windows
tests!
llvm-svn: 294918
The newer versions of ucrt have the math routines. Use the CRT version
to determine if we should include the math routines. Fixes two tests
for Windows.
llvm-svn: 294899
This recommits r294707 with additional fixes. The main difference is
libc++ now correctly builds without any ABI library.
exception.cpp is a bloody mess. It's full of confusing #ifdef branches for
each different ABI library we support, and it's getting unmaintainable.
This patch breaks down exception.cpp into multiple different header files,
roughly one per implementation. Additionally it moves the definitions of
exceptions in new.cpp into the correct implementation header.
This patch also removes an unmaintained libc++abi configuration.
This configuration may still be used by Apple internally but there
are no other possible users. If it turns out that Apple still uses
this configuration internally I will re-add it in a later commit.
See http://llvm.org/PR31904.
llvm-svn: 294730
exception.cpp is a bloody mess. It's full of confusing #ifdef branches for
each different ABI library we support, and it's getting unmaintainable.
This patch breaks down exception.cpp into multiple different header files,
roughly one per implementation. Additionally it moves the definitions of
exceptions in new.cpp into the correct implementation header.
This patch also removes an unmaintained libc++abi configuration.
This configuration may still be used by Apple internally but there
are no other possible users. If it turns out that Apple still uses
this configuration internally I will re-add it in a later commit.
See http://llvm.org/PR31904.
llvm-svn: 294707
Summary:
Libcxx will define its own max_align_t when it is not available. However, the
availability checks today only check for Clang's definition and GCC's
definition. In particular, it does not check for musl's definition, which is the
same as GCC's but guarded with a different macro.
Reviewers: mclow.lists, EricWF
Reviewed By: EricWF
Subscribers: chandlerc, cfe-commits
Differential Revision: https://reviews.llvm.org/D28478
llvm-svn: 294683
A static assertion was misfiring since it checked
is_callable<Visitor, decltype(__variant_alt<T>.value)>. However
the decltype expression doesn't capture the value category as
required. This patch applies extra braces to decltype to fix
that.
llvm-svn: 294612
Different platforms implement the wait/sleep functions in difrerent ways.
It makes sense to externalize this into the threading API.
Differential revision: https://reviews.llvm.org/D29630
Reviewers: EricWF, joerg
llvm-svn: 294573
In addition to the PR for LWG 2773 this patch also ensures
that each of std::ignores constructors or assignment operators
are constexpr.
llvm-svn: 294165
It is my opinion that libc++ should never use `<cassert>`, including in the `dylib`.
This patch remove all uses of `assert` from within libc++ and replaces most of them with `_LIBCPP_ASSERT` instead.
Additionally this patch turn `LIBCXX_ENABLE_ASSERTIONS` off by default,
because the standard library should not be aborting user programs unless explicitly asked to.
llvm-svn: 294107
Visible definitions for basic_string::assign are sometimes emitted in
the dylib depending on the version of LLVM used to compile libc++.
This can cause the check-cxx-abilist target to fail.
This patch attempts marks the basic_string::assign templates as inline
to prevent this. That way the export list is consistent across LLVM
versions.
llvm-svn: 294100
While this change didn't really hurt, it does lead to spurious
warnings about not being able to override weak symbols if you end up
linking objects built with this change to ones built without it.
Furthermore, since __call_once_proxy is called indirectly anyway it
doesn't actually inline ever.
Longer term, it would probably make sense to give this symbol internal
visibility instead.
This reverts r291497
llvm-svn: 293581
These member functions were decorated with `_LIBCPP_FUNC_VIS` when the
class is also decorated with external visibility. This breaks down when
building for PE/COFF, where the member function cannot be decorated if
it is within a decorated class. The class attribute will propagate to
the member. Remove the extraneous decoration.
llvm-svn: 293454
Microsoft's SAL has a `__deref` macro which results in a compilation
failure when building the filesystem module on Windows. Rename the
member function internally to avoid the conflict.
llvm-svn: 293449
This causes unnecessary warnings when building with `cl`. Newer
versions of the C standard permit the redefinition of the macro to the
same value (which is the case here), unfortunately, `cl` does not yet
implement this. Add a check to prevent the redefinition.
llvm-svn: 293439
Many thread-related libc++ test cases fail on FreeBSD, due to the
following -Werror warnings:
In file included from test/std/thread/thread.threads/thread.thread.this/sleep_until.pass.cpp:17:
In file included from include/thread:97:
In file included from include/__mutex_base:17:
include/__threading_support:222:1: error: mutex '__m' is still held at the end of function [-Werror,-Wthread-safety-analysis]
}
^
include/__threading_support:221:10: note: mutex acquired here
return pthread_mutex_lock(__m);
^
include/__threading_support:231:10: error: releasing mutex '__m' that was not held [-Werror,-Wthread-safety-analysis]
return pthread_mutex_unlock(__m);
^
include/__threading_support:242:1: error: mutex '__m' is still held at the end of function [-Werror,-Wthread-safety-analysis]
}
^
include/__threading_support:241:10: note: mutex acquired here
return pthread_mutex_lock(__m);
^
include/__threading_support:251:10: error: releasing mutex '__m' that was not held [-Werror,-Wthread-safety-analysis]
return pthread_mutex_unlock(__m);
^
include/__threading_support:272:10: error: calling function 'pthread_cond_wait' requires holding mutex '__m' exclusively [-Werror,-Wthread-safety-analysis]
return pthread_cond_wait(__cv, __m);
^
include/__threading_support:278:10: error: calling function 'pthread_cond_timedwait' requires holding mutex '__m' exclusively [-Werror,-Wthread-safety-analysis]
return pthread_cond_timedwait(__cv, __m, __ts);
^
6 errors generated.
This is because on FreeBSD, the pthread functions have lock annotations.
Since the functions in __thread_support are internal to libc++ only, add
no_thread_safety_analysis attributes to suppress these warnings.
Reviewers: mclow.lists, EricWF, delesley, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: ed, aaron.ballman, joerg, emaste, cfe-commits
Differential Revision: https://reviews.llvm.org/D28520
llvm-svn: 293197
This reverts commit r292883. Unfortunately <string_view> uses
_LIBCPP_ASSERT in a way which is not compatible with the C++11 dylib
build. I'll investigate more tomorrow.
llvm-svn: 292923
Summary:
It is my opinion that libc++ should never use `<cassert>`, including in the `dylib`. This patch remove all uses of `assert` from within libc++ and replaces most of them with `_LIBCPP_ASSERT` instead.
Additionally this patch turn `LIBCXX_ENABLE_ASSERTIONS` off by default, because the standard library should not be aborting user programs unless explicitly asked to.
Reviewers: mclow.lists, compnerd, smeenai
Reviewed By: mclow.lists
Subscribers: mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D29063
llvm-svn: 292883
<string> uses `decltype` in a way incompatible with `__typeof__`.
This is problematic when compiling <string> with Clang 3.4 because
even though it provides `__decltype` libc++ still used `__typeof__`
because clang 3.4 doesn't provide __is_identifier which libc++
uses to detect __decltype.
This patch manually detects Clang 3.4 and properly configures
for it.
llvm-svn: 292833
Summary:
Exactly what the title says.
This patch also adds a `std::hash<nullptr_t>` specialization in C++17, but it was not added by this paper and I can't find the actual paper that adds it.
See http://wg21.link/P0513R0 for more info.
If there are no comments in the next couple of days I'll commit this
Reviewers: mclow.lists, K-ballo, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28938
llvm-svn: 292684
r292564 disabled the aligned new/delete overloads on platforms without
posix_memalign. Unfortunately that patch also disabled the align_val_t
definition in C++17 as well.
This patch causes align_val_t to be exposed in C++17 regardless
of if we have the new/delete overloads.
llvm-svn: 292582
Summary:
This patch disables the aligned new/delet overloads on Apple platforms without `posix_memalign`. This fixes libc++.dylib build regressions on such platforms.
This fixes http://llvm.org/PR31448.
This patch should also be merged into the 4.0 release branch
Reviewers: mclow.lists, rsmith, dexonsmith, jeremyhu
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28931
llvm-svn: 292564
Summary: This patch adjusts the newly added `msvc_stdlib_force_include.hpp` so that it also works when used with `clang++`.
Reviewers: STL_MSFT
Reviewed By: STL_MSFT
Differential Revision: https://reviews.llvm.org/D28917
llvm-svn: 292539
Adding `path::operator=(string_type&&)` made the expression `p = {}`
ambiguous. This path fixes that ambiguity by making the `string&&`
overload a template so it ranks lower during overload resolution.
llvm-svn: 292345
When support for `basic_string_view` was added to string it also
added new assignment operators from `basic_string_view`. These caused
ambiguity when assigning from a braced initializer. This patch fixes
that regression by making the basic_string_view assignment operator
rank lower in overload resolution by making it a template.
llvm-svn: 292276
In order to allow inlining of previously out-of-line functions without an ABI break
libc++ provides legacy definitions in the dylib that old programs can
continue to use. Unfortunatly Windows link.exe detects this hack and diagnoses the duplicate
definitions.
This patch disable the duplicate definitions on Windows by adding an ABI option
which disables all "legacy out-of-line symbols"
llvm-svn: 292190
Moves hot functions such as atomic add into the memory header file
so that they can be inlined, which brings performance benefits.
Patch by Kevin Hu, Aditya Kumar, Sebastian Pop
Differential Revision: https://reviews.llvm.org/D24991
llvm-svn: 292184
MSVC/clang-cl doesn't do a full EBO unless __declspec(empty_bases)
is applied to the derived type. This causes certain tuple tests
to fail.
This patch adds the empty_bases attribute to __tuple_impl in order
for tuple to fully provide the EBO.
llvm-svn: 292159
Summary: On Windows tests that use `_LIBCPP_ASSERT` fail to link because the assertion handler function isn't correctly exported from the libc++ dylib. This patch fixes the dll import/export issues by introducing a new visibility macro `_LIBCPP_EXTERN_VIS` for use on external variables.
Reviewers: compnerd, smeenai, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28728
llvm-svn: 292158
We have already refactored the underlying platform thread type into
__libcpp_thread_t, but there are few places in the source where we
still assume it is an integral type.
This patch refactores those points back into the threading API.
Differential revision: https://reviews.llvm.org/D28608
Reviewers: EricWF
llvm-svn: 292107
When -pedantic-errors is specified `__has_extension(<feature>)` is always
false when it would otherwise be true. This causes C++03 <atomic> to break
along with other issues.
This patch avoids the above problem by using __is_identifier(...) instead since
it is not affected by -pedantic-errors. For example instead of checking for
__has_extension(c_atomics) we now check `!__is_identifier(_Atomic)`, which
is only true when _Atomic is not a keyword provided by the compiler.
This patch applies similar changes to the detection logic for __decltype and
__nullptr as well.
Note that it does not apply this change to the C++03
`static_assert` macro since -Wc11-extensions warnings generated by expanding
that macro will appear in user code, and will not be suppressed as part of a
system header.
llvm-svn: 291995
Clang recently added a `diagnose_if(cond, msg, type)` attribute
which can be used to generate diagnostics when `cond` is a constant
expression that evaluates to true. Otherwise no attribute has no
effect.
This patch adds _LIBCPP_DIAGNOSE_ERROR/WARNING macros which
use this new attribute. Additionally this patch implements
a diagnostic message when a non-const-callable comparator is
given to a container.
Note: For now the warning version of the diagnostic is useless
within libc++ since warning diagnostics are suppressed by the
system header pragma. I'm going to work on fixing this.
llvm-svn: 291961
This tells whether or not the builtin function __builtin_memcmp is constexpr.
Only defined for clang 4.0 and later, and not true for any shipping version of Apple's clang.
llvm-svn: 291773
Although the CriticalSection itself doesnt need to be destroyed, there
may be debug data associated with it. Plug a possible small leak.
llvm-svn: 291536
Summary:
Some parts of the FreeBSD tree are still compiled with C++98, and until
rL288554 this has always worked fine. After that, a complaint about the
newly introduced local _PairT is produced:
/usr/include/c++/v1/memory:3354:27: error: template argument uses local type '_PairT' [-Werror,-Wlocal-type-template-args]
typedef __scalar_hash<_PairT> _HashT;
^~~~~~
/usr/include/c++/v1/memory:3284:29: error: template argument uses local type '_PairT' [-Werror,-Wlocal-type-template-args]
: public unary_function<_Tp, size_t>
^~~
/usr/include/c++/v1/memory:3356:12: note: in instantiation of template class 'std::__1::__scalar_hash<_PairT, 2>' requested here
return _HashT()(__p);
^
As far as I can see, there should be no problem moving the _PairT
struct to just before the __hash_combine() function, which fixes this
particular warning.
Reviewers: mclow.lists, EricWF
Subscribers: cfe-commits, emaste
Differential Revision: https://reviews.llvm.org/D28472
llvm-svn: 291476
Windows is greedy and it defines the identifier `__out` as a macro.
This patch renames all conflicting libc++ identifiers in order
to correctly work on Windows.
llvm-svn: 291345
Add an implementation for the Win32 threading model as a backing API for
the internal c++ threading interfaces. This uses the Fls* family for
the TLS (which has the support for adding termination callbacks),
CRITICAL_SECTIONs for the recursive mutex, and Slim Reader/Writer locks
(SRW locks) for non-recursive mutexes. These APIs should all be
available on Vista or newer.
llvm-svn: 291333
Summary:
On Windows the identifier `__deallocate` is defined as a macro by one of the Windows system headers. Previously libc++ worked around this by `#undef __deallocate` and generating a warning. However this causes the WIN32 version of `__threading_support` to always generate a warning on Windows. This is not OK.
This patch renames all usages of `__deallocate` internally as to not conflict with the macro.
Reviewers: mclow.lists, majnemer, rnk, rsmith, smeenai, compnerd
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28426
llvm-svn: 291332
This patch adds a libc++ configuration macro for the ABI we
are targeting, either Itanium or Microsoft. For now we configure
for the Microsoft ABI when on Windows with a compiler that defines
_MSC_VER. However this is only temporary until Clang implements
builtin macros we can use.
llvm-svn: 291329
This patch refactors the compiler detection done in `__config` by creating a
set of `_LIBCPP_COMPILER_<TYPE>` macros. The goal of this patch is to make
it easier to detect what compiler is being used outside of `__config`.
Additionally this patch removes workarounds for GCC in `__bit_reference`. I
tested GCC 4.8 and 4.9 without the workaround and neither seemed to need it
anymore.
llvm-svn: 291286
Summary:
This patch attempts to clean up the macro configuration mess in `<__threading_support>`, specifically the mess involving external threading variants. Additionally this patch adds design documentation for `<__threading_support>` and the configuration macros it uses.
The primary change in this patch is separating the idea of an "external API" provided by `<__external_threading>` and the idea of having an external threading library. Now `_LIBCPP_HAS_THREAD_API_EXTERNAL` means that libc++ should use `<__external_threading>` and that the header is expected to exist. Additionally the new macro `_LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL` is now used to configure for using an "external library" with the default threading API.
Reviewers: compnerd, rmaprath
Subscribers: smeenai, cfe-commits, mgorny
Differential Revision: https://reviews.llvm.org/D28316
llvm-svn: 291275
This is motivated by adding a third RTTI scheme to libc++. Split out
the two forms of the itanium RTTI representation. This is based on
suggestions from Eric Fiselier. NFC
llvm-svn: 291174
Split out the recursive and non-recursive mutex. This split is needed
for platforms which may use differing types for the two mutex (e.g.
Win32 threads).
llvm-svn: 291145
Summary:
This patch fixes llvm.org/PR31402 by replacing `map::__find_equal_key` with `__tree::__find_equal`, which has already addressed the same undefined behavior.
Unfortunately I haven't been able to write a test case which causes the UBSAN diagnostic mentioned in the bug report. I can write tests which exercise the UB but for some reason they do not cause UBSAN to fail. Any help writing a test case would be appreciated.
Reviewers: mclow.lists, vsk, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28131
llvm-svn: 291087
In ABI v1 libc++ implements std::pointer_safety as a class type instead
of an enumeration. However this class type does not provide
a default constructor as it should. This patch adds that default constructor.
llvm-svn: 291059
In the C++ standard `std::pointer_safety` is defined
as a C++11 strongly typed enum. However libc++ currently defines
it as a class type which simulates a C++11 enumeration. This
can be detected in valid C++ code.
This patch introduces an the _LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE ABI option.
When defined `std::pointer_safety` is implemented as an enum type.
Unfortunatly this also means it can no longer be provided as an extension
in C++03.
Additionally this patch moves the definition for `get_pointer_safety()`
out of the dylib, and into the headers. New usages of `get_pointer_safety()`
will now use the inline version instead of the dylib version. However in
order to keep the dylib ABI compatible the old definition is explicitly
compiled into it.
llvm-svn: 291046
The name _LIBCPP_TYPE_VIS_ONLY is no longer accurate because both
_LIBCPP_TYPE_VIS and _LIBCPP_TYPE_VIS_ONLY expand to
__attribute__((__type_visibility__)) with Clang. The only remaining difference
is that _LIBCPP_TYPE_VIS_ONLY can be applied to templates whereas
_LIBCPP_TYPE_VIS cannot (due to dllimport/dllexport not being allowed on
templates).
This patch renames _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS.
llvm-svn: 291035
Summary:
This patch attempts to re-implement a fix for LWG 2770, but not the actual specified PR.
The PR for 2770 specifies tuple_size<T const> as only conditionally providing a `::value` member. However C++17 structured bindings require `tuple_size<T const>` to be complete only if `tuple_size<T>` is also complete. Therefore this patch implements only provides the specialization `tuple_size<T CV>` iff `tuple_size<T>` is a complete type.
This fixes http://llvm.org/PR31513.
Reviewers: mclow.lists, rsmith, mpark
Subscribers: mpark, cfe-commits
Differential Revision: https://reviews.llvm.org/D28222
llvm-svn: 291019
MSVC 19+ and clang-cl with emulation version >= 19.00 will provide
char{16,32}_t as builtin types. Adjust the configuration accordingly.
llvm-svn: 290940
Introduce a `_LIBCPP_HAS_BITSCAN64` macro to specify if the 64-bit
variant of the bitscan family of APIs is available. This avoids
duplicating the check in the support header.
llvm-svn: 290924
Replace the use of _WIN32 in libc++. Replace most use with a C runtime
check _LIBCPP_MSVCRT or the new _LIBCPP_WIN32 to indicate that we are
using the Win32 API. Use a new _LIBCPP_WCHAR_IS_UCS2 to indicate that we
are on an environment that has a short wchar_t.
llvm-svn: 290910
after r290850
Before r290850, building libcxx with -DLIBCXX_HAS_EXTERNAL_THREAD_API=ON had two
uses:
- Allow platform vendors to plug-in an __external_threading header which
should take care of the entire threading infrastructure of libcxx
- Allow testing of an externally-threaded library build; where the thread API
is declared using pthread data structures, and the implementation of this
API is provided as a separate library (test/support/external_threads.cpp)
and linked-in when running the test suite.
r290850 breaks the second use case (pthread data structures are no longer
available). This patch re-stores the ability to build+test an
externally-threaded library variant on a pthread based system.
llvm-svn: 290878
Refactor the header to allow us to implement alternate threading models
with alternate data structures. Take the opportunity to clang-format
the area. This will allow us to avoid re-declaring the interfaces for
Win32 threading. NFC
llvm-svn: 290850
This patch implements the correct PR for LWG 2770. It also makes the primary
tuple_size template incomplete again which fixes part of llvm.org/PR31513.
llvm-svn: 290846
Currently libc++ compiles a special version of error_category()
into the dylib. This definition is no longer needed, and doesn't
work on Windows due to dllimport/dllexport semantics.
For those reasons this patch introduces an option to
disable/enable this definition. By default the definition
is provided in ABI v1 except on windows. This patch
also addresses D28210.
llvm-svn: 290840
In the previous fix I used a PMF type as a semi-safe bool type in C++03.
However immediately after committing I realized clang offered explicit
conversion operators as an extension. This patch removes the old fix and
enables _LIBCPP_EXPLICIT using __has_extension instead.
This change also affects the following other classes, which have
'_LIBCPP_EXPLICIT operator bool()'.
* shared_ptr
* unique_ptr
* error_condition
* basic_ios
* function (already C++11 only)
* istream::sentry
* experimental::string_view.
In all of the above cases I believe it is safe to enable the extension, except
in the experimental::string_view case. There seem to be some Clang bugs
affecting the experimental::string_view conversion to std::basic_string. To
work around that I manually disabled _LIBCPP_EXPLICIT in that case.
llvm-svn: 290831
Visual C++ 14 and newer split msvcrt into msvcrt and ucrt with flavours
of the ucrt for different environments. This changed the access to the
ctype table by introducing the `__pctype_func` and `__pwctype_func`
accessors. Use this rather than directly accessing `_ctype` which
allows us to be safer in threaded situations by going through the libc
locking.
llvm-svn: 290823
This is necessary to support cross-compiling a Windows libc++ from
Linux. The CMAKE_SYSTEM_HOST_NAME tells you what, in autotools
parlance, is known as the build as opposed to WIN32 which maps to, in
autotools parlance, host.
llvm-svn: 290800
These exception types are marked with `_LIBCPP_EXCEPTION_ABI` which
expands to `__attribute__((__visibility__("default")))` or
`__declspec(dllexport)`. When building for Windows, we would hit an
error:
cannot apply 'dllexport' to a 'dllexport' class
Remove the duplicate annotations as they will be inherited from the
class.
llvm-svn: 290785
There were two problems with the initial fix.
1. The added tests flushed out that we misconfigured _LIBCPP_EXPLICIT with GCC.
2. Because the boolean type was a member function template it caused weird link
errors. I'm assuming due to the vague linkage rules. This time the bool type
is a non-template member function pointer. That seems to have fixed the
failing tests. Plus it will end up generating less symbols overall, since
the bool type is no longer per instantiation.
original commit message below
-----------------------------
std::basic_ios has an operator bool(). In C++11 and later
it is explicit, and only allows contextual implicit conversions.
However explicit isn't available in C++03 which causes std::istream (et al)
to have an implicit conversion to int. This can easily cause ambiguities
when calling operator<< and operator>>.
This patch uses a "bool-like" type in C++03 to work around this. The
"bool-like" type is an arbitrary pointer to member function type. It
will not convert to either int or void*, but will convert to bool.
llvm-svn: 290754
std::basic_ios has an operator bool(). In C++11 and later
it is explicit, and only allows contextual implicit conversions.
However explicit isn't available in C++03 which causes std::istream (et al)
to have an implicit conversion to int. This can easily cause ambiguities
when calling operator<< and operator>>.
This patch uses a "bool-like" type in C++03 to work around this. The
"bool-like" type is an arbitrary pointer to member function type. It
will not convert to either int or void*, but will convert to bool.
llvm-svn: 290750
Back in r240527 I added a knob to prevent thread-unsafe functions from
being exposed. mblen(), mbtowc() and wctomb() were also added to this
list, as the latest issue of POSIX doesn't require these functions to be
thread-safe.
It turns out that the only circumstance in which these functions are not
thread-safe is in case they are used in combination with state-dependent
character sets (e.g., Shift-JIS). According to Austin Group Bug 708,
these character sets "[...] are mostly a relic of the past and which
were never supported on most POSIX systems".
Though in many cases the use of these functions can be prevented by
using the reentrant counterparts, they are the only functions that allow
you to query whether the locale's character set is state-dependent. This
means that omitting these functions removes actual functionality.
Let's be a bit less pedantic and drop the guards around these functions.
Links:
http://austingroupbugs.net/view.php?id=708http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2037.htm
Reviewed by: ericwf
Differential Revision: https://reviews.llvm.org/D21436
llvm-svn: 290748
In C++03 libc++ emulates nullptr_t using a class, and #define's nullptr.
However this makes nullptr_t mangle differently between C++03 and C++11.
This breaks any function ABI which takes nullptr_t.
Thanfully Clang provides __nullptr in all dialects. This patch adds
an ABI option to switch to using __nullptr in C++03. In a perfect world
I would like to turn this on by default, since it's just ABI breaking fix
to an ABI breaking bug.
llvm-svn: 290662
This patch implements changes to allow _LIBCPP_ASSERT to throw on failure
instead of aborting. The main changes needed to do this are:
1. Change _LIBCPP_ASSERT to call a handler via a replacable function pointer
instead of calling abort directly. Additionally this patch implements two
handler functions, one which aborts and another that throws an exception.
2. Add _NOEXCEPT_DEBUG macro for disabling noexcept spec on function which
contain _LIBCPP_ASSERT. This is required in order to prevent assertion
failures throwing through a noexcept function. This macro has no effect
unless _LIBCPP_DEBUG_USE_EXCEPTIONS is defined.
Having a non-aborting _LIBCPP_ASSERT is very important to allow sane testing of
debug mode. Currently we can only have one test case per file, since the test
case will cause the program to abort. Testing debug mode this way would require
thousands of test files, most of which would be 95% boiler plate. I don't think
this is a feasible strategy. Fortunately using a throwing debug handler solves
these issues.
Additionally this patch rewrites the documentation for debug mode.
llvm-svn: 290651
It's an internal function and shouldn't be exported. It's also a source
of discrepancy in the published ABI list; these symbols aren't exported
for me on CentOS 7 or Ubuntu 16.04, leading to spurious check-cxx-abilist
failures.
Differential Revision: https://reviews.llvm.org/D27153
llvm-svn: 290503
When libcxx isn't building with an installed LLVM we copy the libcxx headers into the LLVM build directory so that a clang in that build tree can find the headers relative to itself.
This is only important in situations where you don't have headers installed under /, which is common these days on Darwin.
llvm-svn: 289963
This patch reverts the changes to tuple which fixed construction from
types derived from tuple. It breaks the code mentioned in llvm.org/PR31384.
I'll follow this commit up with a test case.
llvm-svn: 289773
In list::remove we collect the nodes we're removing in a seperate
list instance. However we construct this list using the default
constructor which default constructs the allocator. However allocators
are not required to be default constructible. This patch fixes the
construction of the second list.
llvm-svn: 289735
Summary:
The standard requires tuple have the following constructors:
```
tuple(tuple<OtherTypes...> const&);
tuple(tuple<OtherTypes...> &&);
tuple(pair<T1, T2> const&);
tuple(pair<T1, T2> &&);
tuple(array<T, N> const&);
tuple(array<T, N> &&);
```
However libc++ implements these as a single constructor with the signature:
```
template <class TupleLike, enable_if_t<__is_tuple_like<TupleLike>::value>>
tuple(TupleLike&&);
```
This causes the constructor to reject types derived from tuple-like types; Unlike if we had all of the concrete overloads, because they cause the derived->base conversion in the signature.
This patch fixes this issue by detecting derived types and the tuple-like base they are derived from. It does this by creating an overloaded function with signatures for each of tuple/pair/array and checking if the possibly derived type can convert to any of them.
This patch fixes [PR17550]( https://llvm.org/bugs/show_bug.cgi?id=17550)
This patch
Reviewers: mclow.lists, K-ballo, mpark, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D27606
llvm-svn: 289727
This patch removes libc++'s tuple extension which allowed it to be
constructed from fewer initializers than elements; with the remaining
elements being default constructed. However the implicit version of
this extension breaks conforming code. For example:
int fun(std::string);
int fun(std::tuple<std::string, int>);
int x = fun("hello"); // ambigious
Because existing code may already depend on this extension it can be re-enabled
by defining _LIBCPP_ENABLE_TUPLE_IMPLICIT_REDUCED_ARITY_EXTENSION.
Note that the explicit version of this extension is still supported,
although it's somewhat less useful than the implicit one.
llvm-svn: 289158
Reverting because I didn't properly test this patch. Although it's probably
correct to add a stdbool_h module I thought the change fixed more than it did.
I'll re-commit after more investigation.
llvm-svn: 288789
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.
llvm-svn: 288728
It's useful to be able to disable visibility annotations entirely; for
example, if we're building libc++ static to include in another library,
and we don't want any libc++ functions getting exported out of that
library. This is a generalization of _LIBCPP_DISABLE_DLL_IMPORT_EXPORT.
Differential Revision: https://reviews.llvm.org/D26934
llvm-svn: 288690
Previously these hashes were 0 and -1 respectively. These seem like common
sentinel values and should be avoided to prevent needless collisions.
This patch changes those values to different arbitrary numbers, which should
hopefully cause less collisions. Because I couldn't help myself I choose the
fundamental constants for gravity and the speed of light.
llvm-svn: 288623
Summary: The `max_size()` method of containers should respect both the allocator's reported `max_size` and the range of the `difference_type`. This patch makes all containers choose the smallest of those two values.
Reviewers: mclow.lists, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D26885
llvm-svn: 287729
Libc++ internal uses <atomic> in C++03 code but the module map forbids its use.
This causes the libc++ 'std' module to fail to build in C++03.
This patch removes the requirement to fix this issue.
llvm-svn: 287693
Summary:
Because `locale.h` isn't part of the libc++ modules the class definitions it provides are exported as part of `__locale` (since it happens to be build first). This breaks `<clocale>` which exports `std::lconv` without including `<__locale>`.
This patch implements `locale.h` to fix this issue, it also adds support for testing libc++ with modules.
Reviewers: mclow.lists, rsmith, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D26826
llvm-svn: 287413
libc++ no longer supports C++11 compilers that don't implement `= default`.
This patch removes all instances of the feature test macro
_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS as well as the potentially dead code it hides.
llvm-svn: 287321
Fix a typo in the conditional. Caught by going through list of removed
symbols when building with hidden visibility.
Differential Revision: https://reviews.llvm.org/D26825
llvm-svn: 287309
This is a generalization of `_LIBCPP_NEW_DELETE_VIS`; the new macro name
captures the semantics better, and also allows us to get rid of the
`_WIN32` check in `include/new`. No functional change.
Differential Revision: https://reviews.llvm.org/D26702
llvm-svn: 287164
Summary:
This makes these functions available on host and device, which is
necessary to compile <complex> for the device.
Reviewers: hfinkel, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D25403
llvm-svn: 287012
This patch adds a `check-cxx-abilist` target which verifies the libc++.so ABI
when the current build configuration matches the configuration used to generate
the ABI lists.
In order to make this change `HandleOutOfTreeLLVM.cmake` needed to be modified
to include `LLVMConfig.cmake` so that `TARGET_TRIPLE` is defined. Hopefully
the changes needed to accommodate this won't break existing build
configurations.
llvm-svn: 286789
Visual Studio 2013 and up have these functions, and we don't need to
support older versions.
There are some remaining _LIBCPP_MSVCRT exclusions which are present on
Visual Studio 2015 but not 2013. Those will be addressed in a follow-up.
Differential Revision: https://reviews.llvm.org/D26377
llvm-svn: 286202
Previously __libcpp_is_constructible checked the validity of reference
construction using 'eat<To>(declval<From>())' but this doesn't consider
From's explicit conversion operators. This patch teaches __libcpp_is_constructible
how to handle these cases. To do this we need to check the validity
using 'static_cast<To>(declval<From>())'. Unfortunately static_cast allows
additional base-to-derived and lvalue-to-rvalue conversions, which have to be
checked for and manually rejected.
While implementing these changes I discovered that Clang incorrectly
rejects `static_cast<int&&>(declval<float&>())` even though
`int &&X(declval<float&>())` is well formed. In order to tolerate this bug
the `__eat<T>(...)` needs to be left in-place. Otherwise it could be replaced
entirely with the new static_cast implementation.
Thanks to Walter Brown for providing the test cases.
llvm-svn: 285786
Create this define in __config and use it elsewhere, instead of checking
the operating system/library defines in other files. The aim is to
reduce the usage of _WIN32 outside __config. No functional change.
Differential Revision: https://reviews.llvm.org/D25741
llvm-svn: 285582
Adding both 'inline' and 'always_inline' to the destructor has been contentious.
However most of the performance benefits can be gained by only adding 'inline',
and there is no reason to hold up that change while discussing the other.
llvm-svn: 285538
path uses string::append to construct, append, and concatenate paths. Unfortunatly
string::append has a strong exception safety guaranteed and if it can't prove
that the iterator operations don't throw then it will allocate a temporary
string copy to append to. However this extra allocation and copy is very
undesirable for path which doesn't have the same exception guarantees.
To work around this this patch adds string::__append_forward_unsafe which exposes
the std::string::append interface for forward iterators without enforcing
that the iterator is noexcept.
llvm-svn: 285532
This prevent the symbols from being both externally available and hidden, which
causes them to be linked incorrectly. This is only a problem when the address
of the function is explicitly taken since it will always be inlined otherwise.
This patch fixes the issues that caused r285456 to be reverted, and can
now be reapplied.
llvm-svn: 285531
This patch fixes a performance bug when constructing or appending to a path
from a string or c-string. Previously we called 'push_back' to append every
single character. This caused multiple re-allocation and copies when at most
one reallocation is necessary. The new behavior is to simply call
`string::append` so it can correctly handle reallocation.
For large strings this change is a ~4x improvement. This also makes our path
faster to construct than libstdc++'s.
llvm-svn: 285530
This patch entirely rewrites the parsing logic for paths. Unlike the previous
implementation this one stores information about the current state; For example
if we are in a trailing separator or a root separator. This avoids the need for
extra lookahead (and extra work) when incrementing or decrementing an iterator.
Roughly this gives us a 15% speedup over the previous implementation.
Unfortunately this implementation is still a lot slower than libstdc++'s.
Because libstdc++ pre-parses and splits the path upon construction their
iterators are trivial to increment/decrement. This makes libc++ lazy parsing
100x slower than libstdc++. However the pre-parsing libstdc++ causes a ton
of extra and unneeded allocations when constructing the string. For example
`path("/foo/bar/")` would require at least 5 allocations with libstdc++
whereas libc++ uses only one. The non-allocating behavior is much preferable
when you consider filesystem usages like 'exists("/foo/bar/")'.
Even then libc++'s path seems to be twice as slow to simply construct compared
to libstdc++. More investigation is needed about this.
llvm-svn: 285526
Author: laxmansole
Reviewers: howard.hinnant
mclow.lists
Subscribers: EricWF, flyingforyou, evandro
Differential Revision: https://reviews.llvm.org/D25624
Reapplying the patch as the bug https://llvm.org/bugs/show_bug.cgi?id=30341 is fixed.
Currently basic_string's destructor is not getting inlined. So adding 'inline' attribute to ~basic_string().
Worked in collaboration with Aditya Kumar.
llvm-svn: 285456
This patch does two seperate things. First it adds a file called
"__libcpp_version" which only contains the current libc++ version
(currently 4000). This file is not intended for use as a header. This file
is used by Clang in order to easily determine the installed libc++ version.
This allows Clang to enable/disable certain language features only when the
library supports them.
The second change is the addition of _LIBCPP_LIBRARY_VERSION macro, which
returns the version of the installed dylib since it may be different than
the headers.
llvm-svn: 285382
Summary:
Fixes PR19851.
alg.re.match/ecma.pass.cpp still XFAILS on linux, but after commenting out
locale-related tests, it passes. I don't have a freebsd machine to produce a
full pass.
Reviewers: mclow.lists
Subscribers: cfe-commits, emaste
Differential Revision: https://reviews.llvm.org/D26026
llvm-svn: 285352
Summary:
`__libcpp_refstring` currently has two different definitions. First there is the complete definition in `<__refstring>` but there is also a second in `<stdexcept>`. The historical reason for this split is because both libc++ and libc++abi need to see the inline definitions of __libcpp_refstrings methods, but the `<stdexcept>` header doesn't. However this is an ODR violation and breaks the modules build.
This patch fixes the issue by creating a single class definition in `<stdexcept>` and changing `<__refstring>` to contain only the inline method definitions. This way both `libcxx/src/stdexcept.cpp` and `libcxxabi/src/stdexcept.cpp` see the same declaration in `<stdexcept>` and definitions in `<__refstring>`
Reviewers: mclow.lists, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D25603
llvm-svn: 285100
These modules are necessary on Darwin to allow modules with
'no_undeclared_includes' (introduced in clang r284797) to work properly
while using libc++ headers.
Patch extracted from a suggested module.modulemap from Richard Smith!
llvm-svn: 284801
This fixes a small omission where even when __external_threading is provided,
we attempt to declare a pthread based threading API. Instead, we should leave
out everything for the __external_threading header to take care of.
The __threading_support header provides a proof-of-concept externally threaded
libc++ variant when _LIBCPP_HAS_THREAD_API_EXTERNAL is defined. But if the
__external_threading header is present, we should exclude all of that POC stuff.
Reviewers: EricWF
Differential revision: https://reviews.llvm.org/D25468
llvm-svn: 284232
Summary:
This patch implements the library side of P0035R4. The implementation is thanks to @rsmith.
In addition to the C++17 implementation, the library implementation can be explicitly turned on using `-faligned-allocation` in all dialects.
Reviewers: mclow.lists, rsmith
Subscribers: rsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D25591
llvm-svn: 284206
The behavior of this macro actually needs to apply universally on
Windows and not just when using the Microsoft CRT. Update the macro
definition and documentation accordingly.
Differential Revision: https://reviews.llvm.org/D25145
llvm-svn: 284016
Summary:
Adapt implementation of Library Fundamentals TS optional into an implementation of N4606 optional.
- Update relational operators per http://wg21.link/P0307
- Update to requirements of http://wg21.link/P0032
- Extension: Implement trivial copy/move construction/assignment for `optional<T>` when `T` is trivially copyable.
Audit P/Rs for optional LWG issues:
- 2756 "C++ WP optional<T> should 'forward' T's implicit conversions" Implemented, which also resolves 2753 "Optional's constructors and assignments need constraints" (modulo my refusal to explicitly delete the move operations, which is a design error that I'm working on correcting in the 2756 P/R).
- 2736 "nullopt_t insufficiently constrained" Already conforming. I've added a test ensuring that `nullopt_t` is not copy-initializable from an empty braced-init-list, which I believe is the root intent of the issue, to avoid regression.
- 2740 "constexpr optional<T>::operator->" Already conforming.
- 2746 "Inconsistency between requirements for emplace between optional and variant" No P/R, but note that the author's '"suggested resolution" is already implemented.
- 2748 "swappable traits for optionals" Already conforming.
- 2753 "Optional's constructors and assignments need constraints" Implemented.
Most of the work for this patch was done by Casey Carter @ Microsoft. Thank you Casey!
Reviewers: mclow.lists, CaseyCarter, EricWF
Differential Revision: https://reviews.llvm.org/D22741
llvm-svn: 283980
Eric Fiselier