Hi all:
We decide change 'time_t' from unsigned type to signed type in PR:
https://github.com/apache/nuttx/pull/14460
Because when compile some POSIX library, there always be a warning on
comparison
between time_t and zero.
For example:
The following code will generate warnings:
auto now = time(nullptr);
auto last_active_time = GetEventService(self->ctx_)->getActiveTime(); if
(last_active_time + 60 * 1000 / 1000 <= now) {
src/ams/../controller/controller_timer.h: In lambda function:
src/ams/../controller/controller_timer.h:117:57: warning: comparison of
integer expressions of different signedness: 'long long int' and 'long long
unsigned int' [-Wsign-compare]
117 | if (last_active_time + 60 * 1000 / 1000 <= now) {
And we can find an reference on the official website:
https://www.gnu.org/software/libc/manual/html_node/Time-Types.html
On POSIX-conformant systems, time_t is an integer type.
The comparation of the merits and shortcomings:
Advantage:
For the most POSIX applications they assume the time_t as signed and do
compare with 0.
The code will become more compatible after this modification.
Disadvantage:
None.
If there is any question about this, please let me know.
Thanks,
Guiding
