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
Saleem Abdulrasool