This involved a little bit of yak shaving because one of the new tests
depends on MPC, and we didn't have targets for it yet, so I ended up
needing to add a similar setup to what we have for MPFR.
Add targets and tests for strfromf, strfromd and strfroml.
No idea why the standard committee decided that the long double function
should be "strfroml" instead of "strfromld" which would match "strtold"
and leave them space to add string from integer functions in future.
Adds targets for the stdbit functions. Since the names follow a strict
pattern, this is done via list comprehensions. I don't want to handwrite
all 50.
Add LIBC_ASSERT statements to FixedVector implementation, and zero out
the memory when the elements are removed to flag out-of-bound access and
dangling pointer/reference access.
This change unmasks the bug in one of FixedVector uses for atexit
handlers: dangling reference use, which was actually led to crashes in
the wild (with prod blockstore implementation). Fix it in this CL.
Get rid of the following arguments to libc_support_library and
libc_function rules:
* `defines` (for raw_mutex.h) - it wasn't used correctly (e.g. didn't
provide actual value for spin count), and we can instead fallback to
defaults set in the header itself (or rely on library-level configure
options).
* `features` - there's no need to disable sanitization for a subset of
memory functions -- it generally should be the vendor / user
responsibility to control it (e.g. don't include instrumented libc
functions in the build, since they would be provided by sanitizer
runtimes instead).
* `local_defines` (for printf_parser) - no longer needed, since
LIBC_COPT_MOCK_ARG_LIST has been removed in
e0be78be427931e94d287002b9c3910f6bc6a22c
This also removes two ad-hoc BUILD rules (strcpy_sanitized and
printf_mock_parser) which are no longer needed and can be replaced by
strcpy and printf_parser, respectively.
Co-authored-by: Alexey Samsonov <samsonov@google.com>
Add a `clock_gettime` emulation layer and use it to implement the `time`
entrypoint.
For windows, the monotonic clock is emulated using `QPC`.
The realtime clock is emulated using `GetSystemTimePreciseAsFileTime`.
The previous implementation of the ctype functions assumed ASCII.
This patch changes to a switch/case implementation that looks odd, but
actually is easier for the compiler to understand and optimize.
Downstream ther'es a user that needs the syscall wrappers to be weak. I
intend to set up a proper mechanism for just listing which functions
should be weak eventually, but for now this is necessary.
Follow-up on the `-mllvm --tail-merge-threshold=0` removal promised in
aeccc16497a84d61200f7ccfa3864096349260d3 (see
b2a9ea4420127d10b18ae648b16757665f8bbd7c commit message on why we don't
need this in Bazel, and will only keep in AArch64-specific compile flags
in CMake build).
Implements std::from_chars for float and double.
The implementation uses LLVM-libc to do the real parsing. Since this is
the first time libc++
uses LLVM-libc there is a bit of additional infrastructure code. The
patch is based on the
[RFC] Project Hand In Hand (LLVM-libc/libc++ code sharing)
https://discourse.llvm.org/t/rfc-project-hand-in-hand-llvm-libc-libc-code-sharing/77701
There are no more specializations `libc/src/math/x86_64` or
`libc/src/math/aarch64` anymore. All implementations are going through
the generic implementation.
This patch adds the necessary functions to send and receive messages
over a socket. Those functions are: recv, recvfrom, recvmsg, send,
sendto, sendmsg, and socketpair for testing.
This patch adds the %m conversion to printf, which prints the
strerror(errno). Explanation of why is below, this patch also updates
the docs, tests, and build system to accomodate this.
The standard for syslog in posix specifies it uses the same format as
printf, but adds %m which prints the error message string for the
current value of errno. For ease of implementation, it's standard
practice for libc implementers to just add %m to printf instead of
creating a separate parser for syslog.
This is a quick fix to unbreak Bazel build. The right solution would
probably add vdso.cpp in the support library which includes circular
dependency and needs more restructuring.
The wrapper for epoll_pwait2 has been difficult to enable since it
requires a very new version of the linux kernel (5.11). On cmake we
still need to create a mechanism to check if we can build it, but our
current bazel users are all on a new enough kernel version we can just
enable it.
Currently the nan* functions use nullptr dereferencing to crash with
SIGSEGV if the input is nullptr. Both `nan(nullptr)` and `nullptr`
dereferencing are undefined behaviors according to the C standard.
Employing `nullptr` dereference in the `nan` function implementation is
ok if users only linked against the pre-built library, but it might be
completely removed by the compilers' optimizations if it is built from
source together with the users' code.
See for instance: https://godbolt.org/z/fd8KcM9bx
This PR uses volatile load to prevent the undefined behavior if libc is
built without sanitizers, and leave the current undefined behavior if
libc is built with sanitizers, so that the undefined behavior can be
caught for users' codes.
The str_to_float conversion code doesn't need the features provided by
fenv and the dependency is creating a blocker for hand-in-hand. This
patch uses a workaround to remove this dependency.
