This commit updates the Clang toolchain's version to 13.0.0, which comes
with better C++20 support and improved handling of new features by
clang-format. Due to the newly enabled `-Bsymbolic-functions` flag, our
Clang binaries will only be 2-4% slower than if we dynamically linked
them, but we save hundreds of megabytes of disk space.
The `BuildClang.sh` script has been reworked to build the entire
toolchain in just three steps: one for the compiler, one for GNU
binutils, and one for the runtime libraries. This reduces the complexity
of the build script, and will allow us to modify the CI configuration to
only rebuild the libraries when our libc headers change.
Most of the compile flags have been moved out to a separate CMake cache
file, similarly to how the Android and Fuchsia toolchains are
implemented within the LLVM repo. This provides a nicer interface than
the heaps of command-line arguments.
We no longer build separate toolchains for each architecture, as the
same Clang binary can compile code for multiple targets.
The horrible mess that `SERENITY_CLANG_ARCH` was, has been removed in
this commit. Clang happily accepts an `i686-pc-serenity` target triple,
which matches what our GCC toolchain accepts.
I locally modified Meta/serenity.sh to pass `--dev` to BuildIt.sh
in build_toolchain(). Then I ran `Meta/serenity.sh rebuild-toolchain`,
cd'd into Toolchain/Tarballs/binutils-2.37, `git add`ed unadded files in
`git status`, and then ran `git diff > ../../Patches/binutils.patch`.
Then I did the same for Toolchain/Tarballs/gcc-11.2.0 (and was careful
not to `git add` serenity-kernel.h, since that's created by
Toolchain/BuildIt.sh).
No behavior change. This just rewrites the patch like git writes it.
This contains all the bits and pieces necessary to build a Clang binary
that will correctly compile SerenityOS.
I had some trouble with getting LLVM building with a single command, so
for now, I decided to build each LLVM component in a separate command
invocation. In the future, we can also make the main llvm build step
architecture-independent, but that would come with extra work to make
library and include paths work.
The binutils build invocation and related boilerplate is duplicated
because we only use `objdump` from GNU binutils in the Clang toolchain,
so most features can be disabled.
CMake specifies -arch arm64 for our toolchain. Unfortunately that's an
option GCC only understands when built for macOS. This causes the build
to fail.
I haven't been able to get CMake to not specify that option so this adds
a dummy option to GCC.
This makes stdlib.h and stdio.h functions available in the std
namespace for C++.
libstdc++v3's link tests can fail if you don't have an up-to-date
build directory, for example:
1. Have libc with missing _Exit symbol because you haven't done
a build since that was added.
2. Run toolchain rebuild. libstdc++v3's configure script will
realize that it can do link tests in general but will fail
later on when it tries to link a program that tests for _Exit.
Even though this is a toolchain patch this does not necessarily
require rebuilding the toolchain right away. This is only required
once we start using any of these new members in the std namespace,
e.g. for ports.
This fixes the -nodefaultlibs flag for gcc which previously
linked against libgcc_s anyway. Even though this is a toolchain
patch we don't need to rebuild the toolchain right away.
Ordinarily this would force the compiler to not inline certain
symbols and call them via the PLT instead. To counteract this
I've also added -fno-semantic-interposition which disables
ELF symbol interposition. Our dynamic loader doesn't support
this anyway and we might even consider not implementing this
at all.
Even though this is a toolchain change this doesn't require
rebuilding the toolchain unless you're planning to build
for the x86_64 arch.
Previously the toolchain's binutils would not have been able to
build binaries on 32-bit host systems (not that this would be
much of an issue nowadays) because one of the #ifdefs was in
the wrong place.
I moved the #ifdef in the port's patch and this now updates
the toolchain's patch file to match the port's patch.
This enables building usermode programs with exception handling. It also
builds a libstdc++ without exception support for the kernel.
This is necessary because the libstdc++ that gets built is different
when exceptions are enabled. Using the same library binary would
require extensive stubs for exception-related functionality in the
kernel.
Instead GCC should be used to automatically link against crt0
and crt0_shared depending on the type of object file that is being
built.
Unfortunately this requires a rebuild of the toolchain as well
as everything that has been built with the old GCC.
Our TLS implementation relies on the TLS model being "initial-exec".
We previously enforced this by adding the '-ftls-model=initial-exec'
flag in the root CmakeLists file, but that did not affect ports - So
now we put that flag in the gcc spec files.
Closes#5366
We now configure gcc to always use the -fno-exceptions flag.
This does not affect our code since we do not use exceptions, and also
fixes the gcc port.
We now configure the gcc spec files to use a different crt files for
static & PIE binaries.
This relieves us from the need to explicitly specify the desired crt0
file in cmake scripts.
Turns out the reason GCC wasn't as smart about startup code for
shared objects as we hoped is because nobody told it to be :D
Change the STARTFILE_SPEC and ENDFILE_SPEC in gcc/config/serenity.h to
skip crt0.o and to link the S variants of crtbegin
and crtend for shared objects.
Because we're using the crtbegin and crtend from libgcc, also tell
libgcc in libgcc/config.host to compile crtbeginS and crtendS from
crtstuff.c.
Toolchain build makes git repo out of toolchain to allow patching
Fix Makefiles to use new libstdc++
Parameterize BuildIt with default TARGET of i686 but arm is experimental