Remove all functions with platform #if's from fenv, and
add arch dependent implementations instead. The build
system now selects the implementation based on the platform.
This is a minimal set of changes to allow `serenity.sh build riscv64` to
successfully generate the build environment and start building. This
includes some, but not all, assembly stubs that will be needed later on;
they are currently empty.
This is a prerequisite for upstreaming our LLVM patches, as our current
hack forcing `-ftls-model=initial-exec` in the Clang driver is not
acceptable upstream.
Currently, our kernel-managed TLS implementation limits us to only
having a single block of storage for all thread-local variables that's
initialized at load time. This PR merely implements the dynamic TLS
interface (`__tls_get_addr` and TLSDESC) on top of our static TLS
infrastructure. The current model's limitations still stand:
- a single static TLS block is reserved at load time, `dlopen()`-ing
shared libraries that define thread-local variables might cause us to
run out of space.
- the initial TLS image is not changeable post-load, so `dlopen()`-ing
libraries with non-zero-initialized TLS variables is not supported.
The way we repurpose `ti_module` to mean "offset within static TLS
block" instead of "module index" is not ABI-compliant.
Since https://reviews.llvm.org/D131441, libc++ must be included before
LibC. As clang includes libc++ as one of the system includes, LibC
must be included after those, and the only correct way to do that is
to install LibC's headers into the sysroot.
Targets that don't link with LibC yet require its headers for one
reason or another must add install_libc_headers as a dependency to
ensure that the correct headers have been (re)installed into the
sysroot.
LibC/stddef.h has been dropped since the built-in stddef.h receives
a higher include priority.
In addition, string.h and wchar.h must
define __CORRECT_ISO_CPP_STRING_H_PROTO and
_LIBCPP_WCHAR_H_HAS_CONST_OVERLOADS respectively in order to tell
libc++ to not try to define methods implemented by LibC.
libc++ disallows including LibC's complex.h in C++ mode. This means that
a C++ file cannot expect LibC's complex.h to be included, and thus
cannot use c-prefixed complex number functions. As a result,
complex.cpp is broken when libc++ has a higher include priority
than LibC.
A check for __cplusplus has been added to complex.h to warn users of
toolchains that don't use libc++.
Otherwise, we end up propagating those dependencies into targets that
link against that library, which creates unnecessary link-time
dependencies.
Also included are changes to readd now missing dependencies to tools
that actually need them.
The shared parts are now firmly compiled into LibC instead of being
defined as a static library and then being copied over manually.
The non-shared ("local") parts are kept as a static library that is
linked into each binary on demand.
This finally allows us to support linking with the -fstack-protector
flag, which now replaces the `ssp` target being linked into each binary
accidentally via CMake.
I'm not sure why this wasn't done to begin with, but let's see if this
resolves our "can't find libsystem.so while double-checking undefined
symbols" issues.
This lets us remove a glob pattern from LibC, the DynamicLoader, and,
later, Lagom. The Kernel already has its own separate list of AK files
that it wants, which is only a subset of all AK files.
Serenity does not support extended attributes (xattr) and the only port
that needed those were the GLib port. The GLib port has now been updated
to compiled without xattr support.
This is a LibC function that POSIX defines to help userspace programs
to get suboptions. An example of a suboption is the token "pixclk" from
a Shell command running "edid-decode --gtf w=1024,h=768,pixclk=48".
The function should be run in a while loop to acquire all suboptions
until the last one.
Some ports linked against posix_memalign, but didn't use it, and others
used it if it was Available. So I decided to implement posix_memalign.
My implementation adds almost no overhead to regular mallocs. However,
if an alignment is specified, it will use the smallest ChunkedBlock, for
which aligned chunks exist, and simply use one of the chunks that is
aligned. If it cannot use a ChunkedBlock, for size or alignment reasons,
it will use a BigAllocationBlock, and return a pointer to the first
aligned address past the start of the block. This implementation
supports alignments up to 32768, due to the limitations of the
BigAllocationBlock technique.
Most of the string.h and wchar.h functions are implemented quite naively
at the moment, and GCC's pattern recognition pass might realize what we
are trying to do, and transform them into libcalls. This is usually a
useful optimization, but not when we're implementing the functions
themselves :^)
Relevant discussion from the GCC Bugzilla:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102725
This prevents the infamous recursive `strlen`.
A more proper fix would be writing these functions in assembly. That
would likely give a small performance boost as well ;)
This option sets -fprofile-instr-generate -fcoverage-mapping for Clang
builds only on almost all of Userland. Loader and LibTimeZone are
exempt. This can be used for generating code coverage reports, or even
PGO in the future.
This commit addresses the following shortcomings of our current, simple
and elegant memset function:
- REP STOSB/STOSQ has considerable startup overhead, it's impractical to
use for smaller sizes.
- Up until very recently, AMD CPUs didn't have support for "Enhanced REP
MOVSB/STOSB", so it performed pretty poorly on them.
With this commit applied, I could measure a ~5% decrease in `test-js`'s
runtime when I used qemu's TCG backend. The implementation is based on
the following article from Microsoft:
https://msrc-blog.microsoft.com/2021/01/11/building-faster-amd64-memset-routines
Two versions of the routine are implemented: one that uses the ERMS
extension mentioned above, and one that performs plain SSE stores. The
version appropriate for the CPU is selected at load time using an IFUNC.
LibTimeZone will be needed directly within LibC for functions such as
localtime(). This change adds LibTimeZone directly within LibC, so that
LibTimeZone isn't its own .so library anymore.
LibTimeZone itself is compiled as an object library to make it easier to
give it generator-specific compilation flags.
libc++ uses a Pthread condition variable in one of its initialization
functions. This means that Pthread forwarding has to be set up in LibC
before libc++ can be initialized. Also, because LibPthread is written in
C++, (at least some) parts of the C++ standard library have to be linked
against it.
This is a circular dependency, which means that the order in which these
two libraries' initialization functions are called is undefined. In some
cases, libc++ will come first, which will then trigger an assert due to
the missing Pthread forwarding.
This issue isn't necessarily unique to LibPthread, as all libraries that
libc++ depends on exhibit the same circular dependency issue.
The reason why this issue didn't affect the GNU toolchain is that
libstdc++ is always linked statically. If we were to change that, I
believe that we would run into the same issue.
Before this change, we would generate the static C library by running
the command `ar -qcs` to collect the various `*.o` files into a single
archive.
The `q` option stands for "quick append", which simply appends new files
to the archive, without replacing any pre-existing entries for the same
file. The problem with this is obvious: each LibC rebuild would add
approximately 1 MB (the size of a cleanly built libc.a) to the size of
the file. It got so bad on my machine that the total file size ended up
being 3 gigabytes.
Note that this did not affect the GNU toolchain, because, as the `ar(1)`
manpage says:
> Note - GNU ar treats the command qs as a synonym for r - replacing
> already existing files in the archive and appending new ones at the
> end.
This was required before commit 5f724b6ca1
when we were building LibC before libstdc++ headers were available in
the sysroot. However as noted in that commit, we never actually needed
to be building LibC before libstdc++, so we can go ahead and remove this
ancient hack.
Replace the old logic where we would start with a host build, and swap
all the CMake compiler and target variables underneath it to trick
CMake into building for Serenity after we configured and built the Lagom
code generators.
The SuperBuild creates two ExternalProjects, one for Lagom and one for
Serenity. The Serenity project depends on the install stage for the
Lagom build. The SuperBuild also generates a CMakeToolchain file for the
Serenity build to use that replaces the old toolchain file that was only
used for Ports.
To ensure that code generators are rebuilt when core libraries such as
AK and LibCore are modified, developers will need to direct their manual
`ninja` invocations to the SuperBuild's binary directory instead of the
Serenity binary directory.
This commit includes warning coalescing and option style cleanup for the
affected CMakeLists in the Kernel, top level, and runtime support
libraries. A large part of the cleanup is replacing USE_CLANG_TOOLCHAIN
with the proper CMAKE_CXX_COMPILER_ID variable, which will no longer be
confused by a host clang compiler.
This adds a stub for fnmatch and the following defined values:
- FNM_PATHNAME
- FNM_NOESCAPE
- FNM_PERIOD
- FNM_FILE_NAME
- FNM_LEADING_DIR
- FNM_CASEFOLD
- FNM_EXTMATCH
GCC implements `fputc`, `fputs` and `fwrite` as builtin functions, whose
`FILE*` argument is implicitly marked `__attribute__((nonnull))`. This
causes our `VERIFY(stream)` statements to be removed. This does not
happen with Clang, as they do not use the `nonnull` attribute in this
way.
The POSIX C regex functions are expected to live in the C standard
library, but Serenity split off its regex library into LibRegex. Make a
compromise by implementing stub forwarders for the C regex library that
load libregex.so and call the real implementation.
This is needed for ports that expect these C functions to be available
inside the standard C library without introducing a strong coupling
between LibC and LibDl or LibRegex. The non-standard Serenity C++ regex
API still lives inside LibRegex as before.
We have had these for quite a while, but we didn't compile them, and
used GCC's version instead. Clang does not come with these, so we have
to provide our own implementation.
Our implementation follows what `musl` and `FreeBSD` do, so this should
work fine, even if documentation can hardly be found for them.
