Due to us using size_t for the length, the actual value will always be positive.
If, for example, we calculate the length as "0 - 1", we'll get SIZE_T_MAX. What
we can do is check that adding the characters pointer and the length together
doesn't overflow.
And switch the two-argument version of Checked::multiplication_would_overflow()
to use __builtin_mul_overflow_p(). This helps GCC optimize the code better.
There were some ideas about how to use this class but we never actually
started using it, so let's just simplify it and get it ready for use.
The basic idea is: a function returns a Result<ValueType, ErrorType>.
Callers check if the result object is_error(). If so, an ErrorType can
be fetched with the error() getter. Otherwise, a ValueType is fetched
with the value() getter. That's it. :^)
DWARF line number information, if generated, is stored in the
.debug_line section of an object file.
The information is encoded as instructions for a VM that is defined in
the DWARF specification.
By executing these instructions, we can extract the encoded line number
information.
We allow the ref-counting parts of an object to be mutated even when the
object itself is a const.
An important detail is that we allow invoking 'will_be_destroyed' and
'one_ref_left', which are not required to be const qualified, on const
objects.
This is an utility to create a URL from a given string, which may be either a
URL such as http://example.com (which will be used as-is), or a file path such
as /etc/fstab (which will be transformed into file:///etc/fstab).
Since the FlyString deduplication mechanism uses a HashTable, we know
that any StringImpl inside a non-null FlyString will already have its
lazily computed hash.
This turns into much less code in the most common cases, here's why:
The normal Optional usage pattern is something like:
auto foo = get_me_an_optional();
if (foo.has_value())
do_stuff_with(foo.value());
In this typical scenario, we check has_value() before calling value().
Without inlining, value() will double-check has_value() itself and
assert if it fails. Inlining allows the compiler to optimize all of
this away.
Clang keeps whining that NonnullFooPtrs are in "unknown" state and I'm
not sure how to resolve that right now. Disable the checking until we
can figure it out.
Our C++ code generator tools have been relying on host-side dbg() being
forwarded to stdout until now. Now they use out() instead.
Hopefully this will make it easier and more enticing to use streams in
userspace programs as well. :^)
AK::Bitmap is extended with find_next_range_of_unset_bits().
The function is implemented using count_trailing_zeroes_32(), which is
optimized on many platforms, that gives a huge performance boost.
Functions find_longest_range_of_unset_bits() and find_first_fit() are
implemented with find_next_range_of_unset_bits(). According to
benchmarks, they are 60-100% faster.
Same issue here as we had with RefPtr and NonnullRefPtr.
Since we can't make copies of an owning pointer, we don't get quite the
same static_ptr_cast<T> here. Instead I've only added a new templated
version of OwnPtr::release_nonnull() in this patch, to solve the only
issue that popped up.
I'm not sure what the best solution here is, but this works for now.
We were allowing this dangerous kind of thing:
RefPtr<Base> base;
RefPtr<Derived> derived = base;
This patch changes the {Nonnull,}RefPtr constructors so this is no
longer possible.
To downcast one of these pointers, there is now static_ptr_cast<T>:
RefPtr<Derived> derived = static_ptr_cast<Derived>(base);
Fixing this exposed a ton of cowboy-downcasts in various places,
which we're now forced to fix. :^)
Since ByteBuffer is a Buffer, it should allow us to overwrite parts of
it that we have allocated.
This comes in useful in handling unsequenced writes like handling
fragmented ip packets :^)
With relative filenames in the executable code, the executable is basically not
relocatable. This makes out-of-source builds unneccesery hard. This patchset moves
the relative link into the filesystem: that can be handled much easier :^)
This patchsets adds the semantic check of two values. One first approach
was to compare the (generated) json strings of the two values. This works
out in the most cases, but not with numbers, where "1.0" and "1" in JSON
format are semantically the same. Therefore, this patch adds deep (recursive)
check of two JsonValues.
This adds a replace functionality that replaces a string that contains
occurences of a "needle" by a "replacement" value. With "all_occurences"
enabled, all occurences are being replaced, otherwise only the first
occurence is being replaced.
* Add double number to object serializer
* Handle negative double numbers correctly
* Handle \r and \n in quoted strings independently
This improves the situation when keys contain \r or \n that currently
has the effect that "a\rkey" and "a\nkey" in an JSON object are the
same key value.
This patchset allows double numbers to be printed with the printf function.
The fraction will always be printed as 6 digit number. This can be improved :^)
This commit adds a basic implementation of
the ptrace syscall, which allows one process
(the tracer) to control another process (the tracee).
While a process is being traced, it is stopped whenever a signal is
received (other than SIGCONT).
The tracer can start tracing another thread with PT_ATTACH,
which causes the tracee to stop.
From there, the tracer can use PT_CONTINUE
to continue the execution of the tracee,
or use other request codes (which haven't been implemented yet)
to modify the state of the tracee.
Additional request codes are PT_SYSCALL, which causes the tracee to
continue exection but stop at the next entry or exit from a syscall,
and PT_GETREGS which fethces the last saved register set of the tracee
(can be used to inspect syscall arguments and return value).
A special request code is PT_TRACE_ME, which is issued by the tracee
and causes it to stop when it calls execve and wait for the
tracer to attach.
This patch adds the parsing of double values to the JSON parser.
There is another char buffer that get's filled when a "." is present
in the number parsing. When number finished, a divider is calculated
to transform the number behind the "." to the actual fraction value.
FlyString is a flyweight string class that wraps a RefPtr<StringImpl>
known to be unique among the set of FlyStrings. The class is very
unoptimized at the moment.
When to use FlyString:
- When you want O(1) string comparison
- When you want to deduplicate a lot of identical strings
When not to use FlyString:
- For strings that don't need either of the above features
- For strings that are likely to be unique
Move the "fast memcpy" stuff out of StdLibExtras.h and into Memory.h.
This will break a ton of things that were relying on StdLibExtras.h
to include a bunch of other headers. Fix will follow immediately after.
This makes it possible to include StdLibExtras.h from Types.h, which is
the main point of this exercise.
We can use __builtin_memset() without including <string.h>.
This is pretty neat, as it will allow us to reduce the header deps
of AK templates a bit, if applied consistently.
Note that this is an enabling change for an upcoming #include removal.
This was causing some obvious-in-hindsight but hard to spot bugs where
we'd implicitly convert the bool to an integer type and carry on with
the number 1 instead of the actual value().
Instead of set(const JsonValue&) and set(JsonValue&&), just do
set(JsonValue) and let callers move() if they want. This removes some
ambiguity and the compiler is smart enough to optimize it anyway.
Now it actually defaults to "a < b" comparison, instead of forcing you
to provide a trivial less-than comparator. Also you can pass in any
collection type that has .begin() and .end() and we'll sort it for you.
Add an extra out-parameter to shbuf_get() that receives the size of the
shared buffer. That way we don't need to make a separate syscall to
get the size, which we always did immediately after.
This feels a lot more consistent and Unixy:
create_shared_buffer() => shbuf_create()
share_buffer_with() => shbuf_allow_pid()
share_buffer_globally() => shbuf_allow_all()
get_shared_buffer() => shbuf_get()
release_shared_buffer() => shbuf_release()
seal_shared_buffer() => shbuf_seal()
get_shared_buffer_size() => shbuf_get_size()
Also, "shared_buffer_id" is shortened to "shbuf_id" all around.
This commit replaces SinglyLinkedListIterator::universal_end() with an
empty SinglyLinkedListIterator(). Piano needs this in order to
initialize a member array of iterators without 84 lines of
universal_end().
