Let's replace this bool with an `enum class` in order to enhance
readability. This is done by repurposing `MappedFile`'s `OpenMode` into
a shared `enum` simply called `Mode`.
For example, LibJS will need to parse date strings of the form:
Wed Dec 31 1969 19:00:00 GMT-0500 (Eastern Standard Time)
This string contains both the time zone offset (-05:00) and a display
name for the time zone (Eastern Standard Time). Because we will already
handle time zone adjustments when we handle the offsets, we will want to
just skip the time zone name. This patch will let us use a format string
of the form "GMT%z (%+)" to do so.
LibCore currently cannot depend on LibTimeZone directly. All build-time
code generators depend on LibCore, so there'd be a circular dependency:
LibCore -> LibTimeZone -> GenerateTZData -> LibCore.
So to support parsing time zone names and applying their offsets, add a
couple of weakly-defined helper functions. These work similar to the way
AK::String declares some methods that LibUnicode defines. Any user who
wants to parse time zone names (from outside of LibCore itself) can link
against LibTimeZone to receive full support.
There's no need to have separate syscall for this kind of functionality,
as we can just have a device node in /dev, called "beep", that allows
writing tone generation packets to emulate the same behavior.
In addition to that, we remove LibC sysbeep function, as this function
was never being used by any C program nor it was standardized in any
way.
Instead, we move the userspace implementation to LibCore.
This commit removes DeprecatedString's "null" state, and replaces all
its users with one of the following:
- A normal, empty DeprecatedString
- Optional<DeprecatedString>
Note that null states of DeprecatedFlyString/StringView/etc are *not*
affected by this commit. However, DeprecatedString::empty() is now
considered equal to a null StringView.
The internal reuse of FixedMemoryStream makes this straightforward.
There alread is one user of the new API, demonstrating the need for this
change beyond what I said out to use it for :^)
Since it will become a stream in a little bit, it should behave like all
non-trivial stream classes, who are not primarily intended to have
shared ownership to make closing behavior more predictable. Across all
uses of MappedFile, there is only one use case of shared mapped files in
LibVideo, which now uses the thin SharedMappedFile wrapper.
Previously, argument-less options could only set a boolean to true. This
lets them also set an enum variable to a specific value, as is currently
done by the `ls` utility.
Without using PATH_MAX :^)
To read a symlink, we can just open its file with O_NOLINK and read its
contents. To get the executable path, we could read the /proc/self/exe
link like the Linux version does; but that relies on procfs being
mounted. Instead, we could do what procfs itself does to get the path:
ask the proc server about it.
On FreeBSD and GNU/Hurd, SHM_ANON is a nice way to create anonymous
files using the usual shm_open() API. This is a lot like the fallback
shm_open() branch that follows, except we don't have to fool around
with choosing a unique name (with retrying) and unlinking the file
afterwards; it just does the right thing. Isn't this nice?
The Hurd supports sending file descriptors over local sockets using
the SCM_RIGHTS / cmsg mechanism just like the other systems. It doesn't
have anything like ucred/PEERCRED, though.
MAP_FILE is not in POSIX, and is simply in most LibCs as a "default"
mode. Our own LibC defines it as 0, meaning "no flags". It is also not
defined in some OS's, such as Haiku. Let's be more portable and not use
the unnecessary flag.
If stop_timer() is called from ~EventReceiver(), then the virtual
functions will end up calling the overload from the base class. As
EventReceiver::class_name() is pure virtual, this calls
__cxa_pure_virtual and crashes. We should not be calling virtual
functions from the destructor, and especially not pure virtual ones.
This "fixes" a crash in Piano, but the root cause of the problem is
still unfixed.
Instead of grabbing `uname -vr` on non-Serenity platforms, let's just
hardcode a version. This prevents Lagom builds of applications like
Shell or Ladybird from reporting their version as that of the host OS.
These syscalls are not necessary on their own, and they give the false
impression that a caller could set or get the thread name of any process
in the system, which is not true.
Therefore, move the functionality of these syscalls to be options in the
prctl syscall, which makes it abundantly clear that these operations
could only occur from a running thread in a process that sees other
threads in that process only.
