This change mostly converts poll to Userspace<T> with the caveat
of the fds member of SC_poll_params. It's current usage is a bit
too gnarly for me to take on right now, this appears to need a lot
more love.
In addition to enlightening the syscall to use Userspace<T>, I've
also re-worked most of the handling to use validate_read_and_copy
instead of just directly de-referencing the user pointer. We also
appeared to be missing a re-evaluation of the fds array after the
thread block is awoken.
If a thread is waiting but getting killed, we need to dequeue
the thread from the WaitQueue so that a potential wake before
finalization doesn't happen.
The emulator will now register signal handlers for all possible signals
and act as a translation layer between the kernel and the emulated
process.
To get an accurate simulation of signal handling, we duplicate the same
trampoline mechanism used by the kernel's signal delivery system, and
also use the "sigreturn" syscall to return from a signal handler.
Signal masking is not fully implemented yet, but this is pretty cool!
Instead of setting m_cursor directly to reset the cursor position,
TextEditor::set_document() now uses set_cursor() which will call cursor
change callback functions, if any.
This fixes a bug in HackStudio where the cursor information text would
not update immediately after changing the active TextDocument, even
though the cursor is always visibly being reset to 0, 0.
The text cursor follows slightly different "intuitive" rules than the
regular hit testing. Clicking past the right edge of a text box should
still "hit" the text box, and place the cursor at its end, for example.
We solve this by adding a HitTestType enum that is passed to hit_test()
and determines whether past-the-edge candidates are considered.
We should always leak to an observed variable, otherwise
it's an actual leak. This is similar to AK::RefPtr::leak_ref()
which is also marked as [[nodiscard]].
Utilizie Userspace<T> for the syscall argument itself, as well
as internally in the SC_futex_params struct.
We were double validating the SC_futex_params.timeout validation,
that was removed as well.
It looks like PR #2986 mistakenly removed this from both the
Clang and GCC CXX_FLAGS, when the intention seems to have been
to only disable it for Clang.
The [[nodiscard]] decorator enables us to have the compile emit a
warning anytime the decorated type or function's return value isn't
observed. It's very useful for catching error checking bugs in systems
which use C style error handling.
