Summary:
The standard says the following: The <time.h> header shall define the
clock_t, size_t, time_t, types as described in <sys/types.h>. I couldn't
find one for `uchar.h` but it needs it once we define things like
`mbrtoc8`.
Summary:
This patch implements `clock_gettime` using the monotonic clock. This
allows users to get time elapsed at nanosecond resolution. This is
primarily to facilitate compiling the `chrono` library from `libc++`.
For this reason we provide both `CLOCK_MONOTONIC`, which we can
implement
with the GPU's global fixed-frequency clock, and `CLOCK_REALTIME` which
we cannot. The latter is provided just to make people who use this
header happy and it will always return failure.
This introduces mktime to LLVM libc, based on C99/C2X/Single Unix Spec.
Co-authored-by: Jeff Bailey <jeffbailey@google.com>
This change doesn't handle TIMEZONE, tm_isdst and leap seconds. It returns -1 for invalid dates. I have verified the return results for all the possible dates with glibc's mktime.
TODO:
+ Handle leap seconds.
+ Handle out of range time and date values that don't overflow or underflow.
+ Implement the following suggestion Siva - As we start accumulating the seconds, we should be able to check if the next amount of seconds to be added can lead to an overflow. If it does, return the overflow value. If not keep accumulating. The benefit is that, we don't have to validate every input, and also do not need the special cases for sizeof(time_t) == 4.
+ Handle timezone and update of tm_isdst
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D91551
