This is defined when we're compiling against the GNU C Library, whether
on Linux or on other kernels that glibc works on. More AK_LIBC_xxxx
definitions could be potentially added in the future.
Also add AK_LIBC_GLIBC_PREREQ(), which checks for a specific glibc
version.
While macOS backtrace(3) puts a space directly after the mangled symbol
name, some versions of glibc put a + directly after it. This new logic
accounts for both situations when trying to demangle.
Co-Authored-By: Andreas Kling <kling@serenityos.org>
On platforms that support it, enable using ``<execinfo.h>`` to get
backtrace(3) to dump a backtrace on assertion failure. This should make
debugging things like WebContent crashes in Lagom much easier.
This part of the spec is mostly useful for our debugging for now, but
could eventually be hooked up so that the user can see any reported
validation errors.
The main change here is that we now follow the spec by asserting the URL
is not special. Previously I could not find a way to enable this without
getting assertions when browsing the web - but that seems to no longer
be the case (probably from some other fixes which have since been made).
The main change is the simplification of the expression
`(10^precision * fraction) / 2^precision` to `5^precision * fraction`.
Those expressions overflow or not depends on the value of `precision`
and `fraction`. For the maximum value of `fraction`, the following table
shows for which value of `precision` overflow will occur.
Old New
u32 08 10
u64 15 20
u128 30 39
As of now `u64` type is used to calculate the result of the expression.
Meaning that before, only FixedPoints with `precision` less than 15
could be accurately rendered (for every value of fraction) in decimal.
Now, this limit gets increased to 20.
This refactor also fixes, broken decimal render for explicitly specified
precision width in format string, and broken hexadecimal render.
By default, `1` is of the type `int` which is 32-bits wide at max.
Because of that, if `precision` of a `FixedPoint` is greater than 32,
the expression `1 << precision` will get clamped at 32-bits and the
result will always be zero. Casting `1` to the wider underlying type
will make the expression not overflow.
Because of the off-by-one error, the second bit of the fraction was
getting ignored in differentiating between fractions equal to 0.5 or
greater than 0.5. This resulted in numbers like 2.75 being considered
as having fraction equal to 0.5 and getting rounded incorrectly (to 2).
This new Kernel StdLib function will be used to copy contents of a
FixedStringBuffer with a null character to a user process.
The first user of this new function is the prctl option of
PR_GET_PROCESS_NAME which would copy a process name including a null
character to a user provided buffer.
There was a small mishmash of argument order, as seen on the table:
| Traits<T>::equals(U, T) | Traits<T>::equals(T, U)
============= | ======================= | =======================
uses equals() | HashMap | Vector, HashTable
defines equals() | *String[^1] | ByteBuffer
[^1]: String, DeprecatedString, their Fly-type equivalents and KString.
This mostly meant that you couldn't use a StringView for finding a value
in Vector<String>.
I'm changing the order of arguments to make the trait type itself first
(`Traits<T>::equals(T, U)`), as I think it's more expected and makes us
more consistent with the rest of the functions that put the stored type
first (like StringUtils functions and binary_serach). I've also renamed
the variable name "other" in find functions to "entry" to give more
importance to the value.
With this change, each of the following lines will now compile
successfully:
Vector<String>().contains_slow("WHF!"sv);
HashTable<String>().contains("WHF!"sv);
HashMap<ByteBuffer, int>().contains("WHF!"sv.bytes());
The proper syntax for defining user-defined literals does not require a
space between the `operator""` token and the operator name:
> error: identifier 'sv' preceded by whitespace in a literal operator
> declaration is deprecated
This change introduces HeapFunction, which is intended to be used as a
replacement for SafeFunction. The new type behaves like a regular
GC-allocated object, which means it needs to be visited from
visit_edges, and unlike SafeFunction, it does not create new roots for
captured parameters.
Co-Authored-By: Andreas Kling <kling@serenityos.org>
IFF was a generic container fileformat that was popular on the Amiga
since it was the only file format supported by Deluxe Paint.
ILBM is an image format popular in the late eighties/nineties
that uses the IFF container.
This is a very first version of the decoder that only supports
(byterun) compressed files with bpp <= 8.
Only the minimal chunks are decoded: CMAP, BODY, BMHD.
I am planning to add support for the following variants:
- EHB (32 colours + lighter 32 colours)
- HAM6 / HAM8 (special mode that allowed to display the whole Amiga
4096 colours / 262 144 colours palette)
- TrueColor (24bit)
Things that could be fun to do:
- Still images could be animated using color cycle information
The web specs do not expect decoding or decoding to happen when calling
these helpers. This allows us to remove the raw_fragment helper function
from the URL class.
This encoder can handle all integer formats and sample rates, though
only two channels well. It uses fixed LPC and performs a
close-to-optimal parameter search on the LPC order and residual Rice
parameter, leading to decent compression already.
Just like with input buffered streams, we don't currently have a use
case for output buffered streams which aren't seekable, since the main
application are files.
To ensure this happens without duplicating code, we allow forcing a
StringBuilder object to only use the inline buffer, so the code in the
AK/Format.cpp file doesn't need to deal with different underlying
storage types (expandable or inline-fixed) at all.
I couldn't run the parser in a debugger like I normally would, so I
added printouts to understand where the parser is failing.
More could be added, but these are enough to get a good idea of what
the parser is doing. It's very spammy, though, so enable it by flicking
the IMAP_PARSER_DEBUG switch :^)
Instead, use the FixedCharBuffer class to ensure we always use a static
buffer storage for these names. This ensures that if a Process or a
Thread were created, there's a guarantee that setting a new name will
never fail, as only copying of strings should be done to that static
storage.
The limits which are set are 32 characters for processes' names and 64
characters for thread names - this is because threads' names could be
more verbose than processes' names.
This class encapsulates a fixed Array with compile-time size definition
for storing ASCII characters.
There are also new Kernel StdLib functions to copy user data into such
objects so this class will be useful later on.
The spec indicates we should support serializing opaque hosts, but we
were assuming the host contained a String. Opaque hosts are represented
with Empty. Return an empty string here instead to prevent crashing on
an invalid variant access.
Now that ""_string is infallible, the only benefit of explicitly
constructing a short string is the ability to do it at compile-time. But
we never do that, so let's simplify the API and remove this
implementation detail from it.
This could happen if a sequence of '0' parts was followed by a longer
sequence of '0' parts at the end of the host. The first sequence was
being used for the compress, and not the second.
For example, [1:1:0:0:1:0:0:0] was being serialized as: [1:1::1:0:0:0]
instead of [1:1:0:0:1::].
Fix this by checking at the end of the loop if we are in the middle of a
sequence of '0' parts that is longer than the current longest.
Everywhere only ever expects percent encoding to occur, so let's just
remove this flag altogether. At the same time, replace some
DeprecatedString with StringView.
Parsing 'data:' URLs took it's own route. It never set standard URL
fields like path, query or fragment (except for scheme) and instead
gave us separate methods called `data_payload()`, `data_mime_type()`,
and `data_payload_is_base64()`.
Because parsing 'data:' didn't use standard fields, running the
following JS code:
new URL('#a', 'data:text/plain,hello').toString()
not only cleared the path as URLParser doesn't check for data from
data_payload() function (making the result be 'data:#a'), but it also
crashes the program because we forbid having an empty MIME type when we
serialize to string.
With this change, 'data:' URLs will be parsed like every other URLs.
To decode the 'data:' URL contents, one needs to call process_data_url()
on a URL, which will return a struct containing MIME type with already
decoded data! :^)
By not clearing the buffer, we were leaking the path part of a URL into
the query for URLs without an authority component (no '//host').
This could be seen most noticeably in mailto: URLs with header fields
set, as the query part of `mailto:user@example.com?subject=test` was
parsed to `user@example.comsubject=test`.
data: URLs didn't have this problem, because we have a special case for
parsing them.
This is defined in the spec, but was missing in our table. Fix this, and
add a spec comment for what is missing. Also begin a basic text based
test for URL, so we can get some coverage of LibWeb's usage of URL too.
This takes the previous alternation optimisation and applies it to all
the alternation blocks instead of just the few instructions at the
start.
By generating a trie of instructions, all logically equivalent
instructions will be consolidated into a single node, allowing the
engine to avoid checking the same thing multiple times.
For instance, given the pattern /abc|ac|ab/, this optimisation would
generate the following tree:
- a
| - b
| | - c
| | | - <accept>
| | - <accept>
| - c
| | - <accept>
which will attempt to match 'a' or 'b' only once, and would also limit
the number of backtrackings performed in case alternatives fails to
match.
This optimisation is currently gated behind a simple cost model that
estimates the number of instructions generated, which is pessimistic for
small patterns, though the change in performance in such patterns is not
particularly large.
Similar to floor and ceil, we were forcing the values to be doubles here
Also adds a big FIXME about my findings trying to add a general
implementation for these
Both GCC and Clang inline this function to use bit-wise logic and/or
appropriate instructions even on -O0 and allow their use in a constexpr
context, see
https://godbolt.org/z/de1393vha
In order to follow spec text to achieve this, we need to change the
underlying representation of a host in AK::URL to deserialized format.
Before this, we were parsing the host and then immediately serializing
it again.
Making that change resulted in a whole bunch of fallout.
After this change, callers can access the serialized data through
this concept-host-serializer. The functional end result of this
change is that IPv6 hosts are now correctly serialized to be
surrounded with '[' and ']'.
This implementation will allow us to fix serialization of IPv6
addresses not being surrounded by '[' and ']'.
Nothing is calling this function yet - this will come in the next
(larger) commit where the underlying host representation inside of
AK::URL is changed from DeprecatedString to URL::Host.
This doesn't seem trivial enough to be defining in the header like this,
and should not be a performance critical function anyhow.
Also add spec comments while we are at it, and a FIXME since we do not
seem to exactly align.
And use them where applicable. This will allow us to store the host in
the deserialized format as the spec specifies.
Ideally these typdefs would instead be the existing AK interfaces, but
in the meantime, we can just use this.
These methods are slightly more convenient than storing the Bytes
separately. However, it it feels unsanitary to reach in and access this
data directly. Both of the users of these already have the
[Readonly]Bytes available in their constructors, and can easily avoid
using these methods, so let's remove them entirely.
Due to overload resolutions rules, this simple code provokes a crash:
ReadonlyBytes readonly_bytes{};
FixedMemoryStream stream{readonly_bytes};
ReadonlyBytes give_them_back{stream.bytes()};
// -> Panics on VERIFY(m_writing_enabled);
// but this is fine:
auto bytes = static_cast<FixedMemoryStream const&>(*stream).bytes()
If we need to be explicit about it, let's rename the overload instead of
adding that `static_cast`.
I misunderstood the spec step for checking whether the host 'ends with a
number'. We can't simply check for it if ends with a number, this check
is actually an algorithm which is required to avoid detecting hosts that
end with a number from an IPv4 host.
Implement this missing step, and add a test to cover this.
clamp_to_int clamps value to valid range of int values so resulting
value does not overflow.
It is going to be used to clamp float or double values to int that
represents fixed-point value of CSSPixels.
This reverts commit d48c68cf3f.
Unfortunately, this currently copies some warn() invocations that we do
*not* want in the debug console, such as test-js's use of OSC command 9
to report progress.
This is just a straight (and fairly inefficient) implementation of IPv6
parsing and serialization from the URL spec.
Note that we don't use AK::IPv6Address here because the URL spec
requires a specific serialization behavior.
The array which contains the actual parameters is always located
immediately after the base `TypeErasedFormatParams` object of
`VariadicFormatParams`. Hence, storing a pointer to it inside a `Span`
is redundant. Changing it to a zero-length array saves 8 bytes.
Secondly, we limit the number of parameters to 256, so `m_size` and
`m_next_index` can be stored in a smaller data type than `size_t`,
saving us another 8 bytes.
This decreases the size of a single-element `VariadicFormatParams` from
48 to 32 bytes, thus reducing the code size overhead of setting up
parameters for `dbgln()`.
Note that [arrays of length zero][1] are a GNU extension, but it's used
elsewhere in the codebase already and is explicitly supported by Clang
and GCC.
[1]: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
Xcode 15 betas 1-3 lack https://reviews.llvm.org/D135772, which fixes a
bug that causes trailing `requires` clauses to be evaluated twice,
failing the second time. Reported as FB12284201.
This caused compile errors when instantiating types derived from RefPtr:
> error: invalid reference to function 'NonnullRefPtr': constraints not
> satisfied
> note: because substituted constraint expression is ill-formed: value
> of type '<dependent type>' is not contextually convertible to 'bool'.
This commit works around the issue by moving the `requires` clauses
after the template parameter list.
In most cases, trailing `requires` clauses and those specified after the
template parameter list work identically, so this change should not
impact the code's behavior. The only difference is that trailing
requires clauses are evaluated *after* constrained placeholder types
(i.e. `Integral auto i` function parameter).
All elements of the vector were moved to the left, for each element to
remove. This patch makes the function move each element exactly once.
On the same test case as the previous commit, it makes the function
disappear from the profile. These two commits combined reduce the
decompression time by 12%.
As confusing as it may sound, reusing them is terrible performance wise.
When profiling the PNG decoder, the result (which is dominated by the
Zlib decompression) shows that the `cleanup_unused_chunks()` function
represented 14.26% of the profile before this patch and only 7.7%
afterward.
On a 6.5 MB PNG image, it reduces the decompression time by more than
5%.
This uses one of Sun OS's algorithms, for a comparison to other
algorithms please refer to
https://gist.github.com/Hendiadyoin1/f58346d66637deb9156ef360aa158bf9
This is used on aarch64 builds and for x86 floats and doubles
for performance gains check
https://quick-bench.com/q/_2jTykshP6cUqtgdepFaoQ53YC8
which shows approximately 2x gains
Co-Authored-By: Ben Wiederhake <BenWiederhake.GitHub@gmx.de>
Co-Authored-By: kleines Filmröllchen <filmroellchen@serenityos.org>
Co-Authored-By: Dan Klishch <danilklishch@gmail.com>
This now searches the memory in blocks, which should be slightly more
efficient. However, it doesn't make much difference (e.g. ~1% in LZMA
compression) in most real-world applications, as the non-hint function
is more expensive by orders of magnitude.
This factors out a lot of complicated math into somewhat understandable
functions.
While at it, rename `next_read_span_with_seekback` to
`next_seekback_span` to keep the naming consistent and to avoid making
function names any longer.
The "operation modes" of this function have very different focuses, and
trying to combine both in a way where we share the most amount of code
probably results in the worst performance.
Instead, split up the function into "existing distances" and "no
existing distances" so that we can optimize either case separately.
We will be adding extra logic to the CircularBuffer to optimize
searching, but this would negatively impact the performance of
CircularBuffer users that don't need that functionality.
By golly, this is a lot more spec comments than I originally thought
I would need to do! This has exposed some bugs in the implementation,
as well as a whole lot of things which we are yet to implement.
No functional changes intended in this commit (already pretty large
as is!).
ECMA-262 implies that `MIN_VALUE` should be a denormalized value if
denormal arithmetic is supported. This is the case on x86-64 and AArch64
using standard GCC/Clang compilation settings.
test262 checks whether `Number.MIN_VALUE / 2.0` is equal to 0, which
only holds if `MIN_VALUE` is the smallest denormalized value.
This commit renames the existing `NumericLimits<FloatingPoint>::min()`
to `min_normal()` and adds a `min_denormal()` method to force users to
explicitly think about which one is appropriate for their use case. We
shouldn't follow the STL's confusingly designed interface in this
regard.
Instead of checking the address of a temporary, grab the address of the
current frame pointer to determine how much memory is left on the stack.
This better communicates to the compiler what we're trying to do, and
resolves some crashes with ASAN in test-js while the option
detect_stack_use_after_return is turned on.
This was missed in 02b74e5a70
We need to disable consteval in AK::String as well as AK::StringView,
and we need to disable it when building both the tools build and the
fuzzer build.
These recursive templates have a measurable impact on the compile speed
of Variant-heavy code like LibWeb. Using these builtins leads to a 2.5%
speedup for the measured compilation units.
oss-fuzz ships a pre-release commit of clang-15 for all of their build
bots. Until they update to a release of clang-15 that includes the fix
for this bug, or a later release, we need to keep the workaround in
place.
The Windows CRT definition of assert() is not noreturn, and causes
compile errors when using it as the backing for VERIFY() in debug
configurations of applications like the Jakt compiler.
Apple Clang 14.0.3 (Xcode 14.3) miscompiles this builtin on AArch64,
causing the borrow flag to be set incorrectly. I have added a detailed
writeup on Qemu's issue tracker, where the same issue led to a hang when
emulating x86:
https://gitlab.com/qemu-project/qemu/-/issues/1659#note_1408275831
I don't know of any specific issue caused by this on Lagom, but better
safe than sorry.
GCC 14 (https://gcc.gnu.org/g:2b4e0415ad664cdb3ce87d1f7eee5ca26911a05b)
has added support for the previously Clang-specific add/subtract with
borrow builtins. Let's use `__has_builtin` to detect them instead of
assuming that only Clang has them. We should prefer these to the
x86-specific ones as architecture-independent middle-end optimizations
might deal with them better.
As an added bonus, this significantly improves codegen on AArch64
compared to the fallback implementation that uses
`__builtin_{add,sub}_overflow`.
For now, the code path with the x86-specific intrinsics stays so as to
avoid regressing the performance of builds with GCC 12 and 13.
The previous version had a sequence of calls that are likely not
optimized out, while this version is strictly a sequence of static type
conversion which are always fully optimized out.
The previous alignment would always resolve to 8-bytes, which is below
the required alignments of types that could exist in userspace (long
double, 128-bit integers, SSE, etc).
The FileSlash state was erroneously copying the base URL host, instead
of the base URL path excluding the last path component. This resulted in
invalid file URLs.
Calling `from_utf8` with a DeprecatedString will hide the fact that we
have a DeprecatedString, while using `from_deprecated_string` with a
StringView will silently and needlessly allocate a DeprecatedString,
so let's forbid that.
This does a few things:
- The decoder uses a 32- or 64-bit integer as a reservoir of the data
being decoded, rather than one single byte as it was previously.
- `read_bool()` only refills the reservoir (value) when the size drops
below one byte. Previously, it would read out a bit-sized range from
the data to completely refill the 8-bit value, doing much more work
than necessary for each individual read.
- VP9-specific code for reading the marker bit was moved to its own
function in Context.h.
- A debug flag `VPX_DEBUG` was added to optionally enable checking of
the final bits in a VPX ranged arithmetic decode and ensure that it
contains all zeroes. These zeroes are a bitstream requirement for
VP9, and are also present for all our lossy WebP test inputs
currently. This can be useful to test whether all the data present in
the range has been consumed.
A lot of the size of this diff comes from the removal of error handling
from all the range decoder reads in LibVideo/VP9 and LibGfx/WebP (VP8),
since it is now checked only at the end of the range.
In a benchmark decoding `Tests/LibGfx/test-inputs/4.webp`, decode times
are improved by about 22.8%, reducing average runtime from 35.5ms±1.1ms
down to 27.4±1.1ms.
This should cause no behavioral changes.
Change the name and return type of
`IPv6Address::to_deprecated_string()` to `IPv6Address::to_string()`
with return type `ErrorOr<String>`.
It will now propagate errors that occur when writing to the
StringBuilder.
There are two users of `to_deprecated_string()` that now use
`to_string()`:
1. `Formatted<IPv6Address>`: it now propagates errors.
2. `inet_ntop`: it now sets errno to ENOMEM and returns.
This has KString, KBuffer, DoubleBuffer, KBufferBuilder, IOWindow,
UserOrKernelBuffer and ScopedCritical classes being moved to the
Kernel/Library subdirectory.
Also, move the panic and assertions handling code to that directory.
This partially implements CSS-Animations-1 (though there are references
to CSS-Animations-2).
Current limitations:
- Multi-selector keyframes are not supported.
- Most animation properties are ignored.
- Timing functions are not applied.
- Non-absolute values are not interpolated unless the target is also of
the same non-absolute type (e.g. 10% -> 25%, but not 10% -> 20px).
- The JavaScript interface is left as an exercise for the next poor soul
looking at this code.
With those said, this commit implements:
- Interpolation for most common types
- Proper keyframe resolution (including the synthetic from-keyframe
containing the initial state)
- Properly driven animations, and proper style invalidation
Co-Authored-By: Andreas Kling <kling@serenityos.org>
This class takes on the duties of CLOCK_MONOTONIC, a time without a
defined reference point that always increases. This informs some
important design decisions about the class API: MonotonicTime cannot be
constructed from external time data, except as a computation based on
other monotonic time, or the current monotonic time. Importantly, there
is no default constructor, since the reference point of monotonic time
is unspecified and therefore without meaning as a default.
The current use of monotonic time (via Duration) includes some potential
problems that may be caught when we move most to all code to
MonotonicTime in the next commit.
The API restrictions have one important relaxation:
Kernel::TimeManagement is allowed to exchange raw time data within
MonotonicTime freely. This is required for the clock-agnostic time
accessors for timeouts and syscalls, as well as creating monotonic time
data from hardware in the first place.
"Wherever applicable" = most places, actually :^), especially for
networking and filesystem timestamps.
This includes changes to unzip, which uses DOSPackedTime, since that is
changed for the FAT file systems.
This is a generic wrapper for a time instant relative to the unix epoch,
and does not account for leap seconds. It should be used in place of
Duration in most current cases.
This is a trivial change, and since this batch of commits will make a
large-scale rebuild necessary anyways, it seems sensible. The feature is
useful for e.g. building compound constant durations at compile time in
a readable way.
That's what this class really is; in fact that's what the first line of
the comment says it is.
This commit does not rename the main files, since those will contain
other time-related classes in a little bit.
This attribute is used for functions in the kernel that are entirely
written in assembly, yet defined in C++ source files.
Without `__attribute__((naked))`, Clang might decide to inline these
functions, making any `ret` instructions within them actually exit the
caller, or discard argument values as they appear "dead". This issue
caused a kernel panic when using the `execve` syscall in AArch64
SerenityOS built by Clang.
While the empty definition so far appears to work fine with GCC, simpler
test cases do similarly suffer from unintended inlining, so define
`NAKED` as a synonym of `NEVER_INLINE` to avert future issues.
Perhaps we should move users of `NAKED` to plain assembly files?
This makes aarch64Clang builds boot :^)
This underlines that we still copy-construct and copy-assign HashMaps.
Primarily, this makes it easier to develop towards OOM-safe(r) internal
data structures, by providing a reminder (the FIXME) and an easy error-
checking switch (just change it to "delete" to see some of the errors).
See identical code in LittleEndianBitStream; even in the bytewise
reading BigEndianBitStream an offset of 8 is not inconsistent state and
handled just fine by read_bits.
Rather than tracking our position in the bit buffer, we can simply shift
away the bits that we read. This is mostly for simplicity, but also does
help performance a bit.
Using the "enwik8" file as a test (100MB uncompressed, commonly used in
benchmarks: https://www.mattmahoney.net/dc/enwik8.zip), compression time
decreases from:
3.96s to 3.79s on Serenity (cold)
1.08s to 1.04s on Serenity (warm)
0.83s to 0.82s on Linux
We have outln() and out(), warnln() and warn(),
now we have dbgln() and dbg().
This is useful for printing arrays element-by-element while still
only printing one line per array.
