The clock_gettime function is available when _POSIX_TIMERS is defined.
We check for this and set _LIBCPP_USE_CLOCK_GETTIME accordingly since
59b3102739. But check for _LIBCPP_USE_CLOCK_GETTIME was removed in
babd3aefc9. As a result, code is now trying to use clock_gettime even
on platforms where it is not available and it is causing build failure
with newlib.
This patch restores the checks to fix this.
Differential Revision: https://reviews.llvm.org/D88825
This increases the Mac OS requirement for building libc++ to 10.12.
Note that it doesn't change whether the *headers* still support older
platforms -- it's only that macOS >= 10.12 is required to build the
dylib from sources.
Differential Revision: https://reviews.llvm.org/D74489
unistd.h isn't guaranteed to exist when the target isn't Windows, in
particular if the target is bare-metal (i.e. no operating system).
Handle this by using __has_include instead, though in
filesystem/operations.cpp we already unconditionally include it so
just remove the extra include.
Differential Revision: https://reviews.llvm.org/D79784
clock_gettime is documented to be available when _POSIX_TIMERS is
defined. Add a check for this.
Differential Revision: https://reviews.llvm.org/D79305
Summary:
In D27429, we switched the Apple implementation of steady_clock::now()
from clock_gettime(CLOCK_MONOTONIC) to clock_gettime(CLOCK_UPTIME_RAW).
The purpose was to get nanosecond precision, and also to improve the
performance of the implementation.
However, it appears that CLOCK_UPTIME_RAW does not satisfy the requirements
of the Standard, since it is not strictly speaking monotonic. Indeed, the
clock does not increment while the system is asleep, which had been
mentioned in D27429 but somehow not addressed.
This patch switches to CLOCK_MONOTONIC_RAW, which is monotonic, increased
during sleep, and also has nanosecond precision.
https://llvm.org/PR44773
Reviewers: bruno, howard.hinnant, EricWF
Subscribers: christof, jkorous, dexonsmith, libcxx-commits, mclow.lists, EricWF
Tags: #libc
Differential Revision: https://reviews.llvm.org/D74341
This is a followup to 35bc5276ca. It fixes the dependent libs usage
in libcxx and libcxxabi to link pthread and rt libraries only if CMake
detects them, rather than based on explicit platform blacklist.
Differential Revision: https://reviews.llvm.org/D70888
r362048 added support for ELF dependent libraries, but broke Android
build since Android does not have libpthread. Remove the dependency on
the Android build.
Differential Revision: https://reviews.llvm.org/D65098
llvm-svn: 366734
This fixes the issue introduced by r362048 where we always use
pragma comment(lib, ...) for dependent libraries when the compiler
is Clang, but older Clang versions don't support this pragma so
we need to check first if it's supported before using it.
llvm-svn: 362055
As of r360984, LLD supports dependent libraries feature for ELF.
libunwind, libc++abi and libc++ have library dependencies: libdl librt
and libpthread, which means that when libunwind and libc++ are being
statically linked (using -static-libstdc++ flag), user has to manually
specify -ldl -lpthread which is onerous.
This change includes the lib pragma to specify the library dependencies
directly in the source that uses those libraries. This doesn't make any
difference when using linkers that don't support dependent libraries.
However, when using LLD that has dependent libraries feature, users no
longer have to manually specifying library dependencies when using
static linking, linker will pick the library automatically.
Differential Revision: https://reviews.llvm.org/D62090
llvm-svn: 362048
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351648
Summary:
The ``file_time_type`` time point is used to represent the write times for files.
Its job is to act as part of a C++ wrapper for less ideal system interfaces. The
underlying filesystem uses the ``timespec`` struct for the same purpose.
However, the initial implementation of ``file_time_type`` could not represent
either the range or resolution of ``timespec``, making it unsuitable. Fixing
this requires an implementation which uses more than 64 bits to store the
time point.
I primarily considered two solutions: Using ``__int128_t`` and using a
arithmetic emulation of ``timespec``. Each has its pros and cons, and both
come with more than one complication.
However, after a lot of consideration, I decided on using `__int128_t`. This patch implements that change.
Please see the [FileTimeType Design Document](http://libcxx.llvm.org/docs/DesignDocs/FileTimeType.html) for more information.
Reviewers: mclow.lists, ldionne, joerg, arthur.j.odwyer, EricWF
Reviewed By: EricWF
Subscribers: christof, K-ballo, cfe-commits, BillyONeal
Differential Revision: https://reviews.llvm.org/D49774
llvm-svn: 337960
Use CLOCK_UPTIME_RAW in case clock_gettime is available on Darwin.
On Apple platforms only CLOCK_UPTIME_RAW or mach_absolute_time are able
to time functions in the nanosecond range. Thus, they are the only
acceptable implementations of steady_clock.
Differential Revision: https://reviews.llvm.org/D27429
rdar://problem/29449467
llvm-svn: 291466
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
As pointed out by Howard, this is actually 134774 days (* 24 * 3600),
and therefore seconds, not 100ns units. Adjust the units to reflect
reality.
llvm-svn: 290824
Drawing some inspiration from code from Bill O'Neal as pointed out by
Howard, rework the code to avoid an overflow in the duration. Adjust
the style to match libc++ style as well.
Create a local typedef for the FILETIME duration (100-ns units). Use
this to define the difference between the NT and the UNIX epochs (which
previously overflowed due to the representation limits due to the
bouncing to ns). Return the FILETIME duration biased by the NT-to-UNIX
epoch conversion.
Use of the custom duration makes it easier to read and reason about the
code.
llvm-svn: 290806
system_clock::now is not entirely straight forward on Windows, which
does not have a clock_gettime function.
GetSystemTimeAsFileTime gives us the value relative to the NT epoch (Jan
1 1601) rather than the Unix epoch (Jan 1 1970). However, this function
has a low resolution (~10ms). Newer versions of Windows provide
GetSystemTimePreciseAsFileTime which gives us a much more accurate time
(<1us). Unfortunately, the latter is only available on Windows 8+ when
targeting desktop apps.
llvm-svn: 290803
The function definitions being guarded by the pragma were all static, so
they wouldn't be exported anyway. In any case, we should prefer the
visibility macros. No functional change.
Differential Revision: https://reviews.llvm.org/D26940
llvm-svn: 287768
The system_clock::now() function currently uses gettimeofday(). The
problem with gettimeofday() is that it is an obsolete XSI function,
hence unavailable on CloudABI. See:
http://pubs.opengroup.org/onlinepubs/9699919799/functions/gettimeofday.html
Change this code to use clock_gettime() with CLOCK_REALTIME instead,
which is more consistent, as clock_gettime() is already used for
steady_clock.
A previous version of this change actually attempted to change
system_clock::duration, but I reverted this part as it breaks the
existing ABI.
Differential Revision: http://reviews.llvm.org/D8253
Approved by: jroelofs
llvm-svn: 237390
Martin Storsjö