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.
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 :^)
ARCH() uses the AK_IS_ARCH_ macros internally since 349e54d537,
and all user code uses the ARCH() macro instead of AK_ARCH_.
(Why it's called ARCH() and not AK_ARCH(), I don't know.)
If any ports not in the main repo use AK_ARCH_, they should switch
to using ARCH() instead.
For whatever reason, when CLion does its code indexing thing, it doesn't
define __clang__ despite using Clang. This causes it to run into various
problems that we've solved by checking for Clang.
Since CLion does define __CLION_IDE__ (or sometimes __CLION_IDE_, no
idea why but I have seen this issue locally), let's make that part of
the AK_COMPILER_CLANG check.
This makes CLion stop highlighting various things as errors.
This patch adds the `USING_AK_GLOBALLY` macro which is enabled by
default, but can be overridden by build flags.
This is a step towards integrating Jakt and AK types.
Doesn't use them in libc headers so that those don't have to pull in
AK/Platform.h.
AK_COMPILER_GCC is set _only_ for gcc, not for clang too. (__GNUC__ is
defined in clang builds as well.) Using AK_COMPILER_GCC simplifies
things some.
AK_COMPILER_CLANG isn't as much of a win, other than that it's
consistent with AK_COMPILER_GCC.
This is the initial port of Lagom to win32. This will enable developers
to use Lagom as an alternative to vanilla STL/StandardC++Library - which
gives a much richer environment (think QtCore - but modern).
My main incentive - is to have a native Windows Ladybird working.
I am starting with AK, which does not yet fully compile (on mingw). When
AK is compiling (currently fails building StringBuffer.cpp) - I will
continue to LibCore and then the rest of the user space libraries
(excluding the GUI, which will be another different effort).
Most of the code is happily stollen from Andrew Kaster's fork - he
deserves the credit.
Co-authored-by: Andrew Kaster <akaster@serenityos.org>
JS::Value stores 48 bit pointers to separately allocated objects in its
payload. On x86-64, canonical addresses have their top 16 bits set to
the same value as bit 47, effectively meaning that the value has to be
sign-extended to get the pointer. AArch64, however, expects the topmost
bits to be all zeros.
This commit gates sign extension behind `#if ARCH(X86_64)`, and adds an
`#error` for unsupported architectures, so that we do not forget to
think about pointer handling when porting to a new architecture.
Fixes#15290FixesSerenityOS/ladybird#56
In order to reduce our reliance on __builtin_{ffs, clz, ctz, popcount},
this commit removes all calls to these functions and replaces them with
the equivalent functions in AK/BuiltinWrappers.h.
During the build process on macOS, multiple versions of <unistd.h> were
being included (Apple's version and GCC's version). It appears that
all other places #include the version from GCC, but in Platform.h the
Apple header was being used. GCC's <unistd.h> is wrapped in
`extern "C"`, while Apple's is not. This causes a conflicting
declaration, so we need to wrap the #include with extern "C".
Issue has been observed on macOS Mojave.
See https://github.com/microsoft/vcpkg/issues/11320 for a similar issue.
This implements a simple bootloader that is capable of loading ELF64
kernel images. It does this by using QEMU/GRUB to load the kernel image
from disk and pass it to our bootloader as a Multiboot module.
The bootloader then parses the ELF image and sets it up appropriately.
The kernel's entry point is a C++ function with architecture-native
code.
Co-authored-by: Liav A <liavalb@gmail.com>
This is a much more ergonomic option than getting a
`VERIFY_NOT_REACHED()` failure at run-time. I encountered this issue
with Clang, where sized deallocation is not the default due to ABI
breakage concerns.
Note that we can't simply just not declare these functions, because the
C++ standard states:
> If this function with size parameter is defined, the program shall
> also define the version without the size parameter.
This commit makes use of the conditionally trivial special member
functions introduced in C++20. Basically, `Optional` and `Variant`
inherits whether its wrapped type is trivially copy constructible,
trivially copy assignable or trivially destructible. This lets the
compiler optimize optimize a large number of their use cases.
The constraints have been applied to `Optional`'s converting
constructors too in order to make the API more explicit.
This feature is not supported by Clang yet, so we use conditional
compilation so that Lagom can be built on macOS. Once Clang has P0848R3
support, these can be removed.
This attribute tells compilers that the pointer returned by a function
is never null, which lets it optimize away null checks in some places.
This seems like a nice addition to `NonnullOwnPtr` and `NonnullRefPtr`.
Using this attribute causes extra UBSan checks to be emitted. To offset
its performance loss, some additional methods were marked ALWAYS_INLINE,
which lets the compiler optimize duplicate checks
Clang enforces the ordering that attributes specified with the
`[[attr_name]]` syntax must comes before those defines as
`__attribute__((attr_name))`. We don't want to deal with that, so we
should stick to a single syntax (for functions, at least).
This commit favors the latter, as it's used more widely in the code
(for declaring more "exotic" options), and changing those would be a
larger effort than modifying this single file.
The ASAN_[UN]POISON_MEMORY_REGION macros can be used to manually notify
the AddressSanitizer runtime about the reachability of instrumented code
accessing a memory region. This is most useful for manually managed
heaps and arenas that do not go directly to malloc or alligned_alloc.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
I overlooked a corner case where we might call the built-in ctz() on zero.
Furthermore, the calculation of the shift was wrong and the results were often
unusable.
Both issue were caused by a forgotten 36daeee34f.
This time I made sure to look at bmpsuite_files first, and now they look good.
Found by OSS-Fuzz:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=28985
This API was a mostly gratuitous deviation from POSIX that gave up some
portability in exchange for avoiding the occasional strlen().
I don't think that was actually achieving anything valuable, so let's
just chill out and have the same open() API as everyone else. :^)
The coarse clocks in time.h are a linux extension that we've adopted.
MacOS and the BSDs don't have it, so we need an alias in a platform
header for Lagom builds.
