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.
GCC determines whether the system's <limits.h> header is usable
and installs a different version of its own <limits.h> header
depending on whether the system header file exists.
If the system header is missing GCC's <limits.h> header does not
include the system header via #include_next.
For this to work we need to install LibC's headers before
attempting to build GCC.
Also, re-running BuildIt.sh "hides" this problem because at that
point the sysroot directory also already has a <limits.h> header
file from the previous build.
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
realpath(1) is specific to coreutils and its behavior can be had
with readlink -f
Create the Toolchain Build directory if it doesn't exist before
calling readlink, since realpath(3) on at least OpenBSD will error
on a non-existent path
The current version of our Python port (3.6.0) is over four years old by
now and has (or had, I haven't actually tried it in a while) some
limitations - time for an upgrade! The latest Python release is 3.9.1,
so I used that version. It's a from-scratch port, no patches are taken
from the previous port to ensure the smallest possible amount of code is
patched. The BuildPython.sh script is useful so I kept it, with some
tweaks. I added a short document explaining each patch to ease judging
their underlying problem and necessity in the future.
Compared to the old Python port, this one does support both the time
module as well as threading (at least _thread) just fine. Importing
modules written in C (everything in /usr/local/lib/python3.9/lib-dynload)
currently asserts in Serenity's dynamic loader, which is unfortunate but
probably solvable. Possibly related to #4642. I didn't try building
Python statically, which might be one possibility to circumvent this
issue.
I also renamed the directory to just "python3", which is analogous to
the Python 3.x package most Linux distributions provide. That implicitly
means that we likely will not support multiple versions of the Python
port at any given time, but again, neither do many other systems by
default. Recent versions are usually backwards compatible anyway though,
so having the latest shouldn't be a problem.
On the other hand bumping the version should now be be as simple as
updating the variables in version.sh, given that no new patches are
required.
These core modules to currently not build - I chose to ignore that for
now rather than adding more patches to make them work somehow, which
means they're fully unavailable. This should probably be fixed in
Serenity itself.
_ctypes, _decimal, _socket, mmap, resource, termios
These optional modules requiring 3rd-party dependencies do currently not
build (even with depends="ncurses openssl zlib"). Especially the absence
of a readline port makes the REPL a bit painful to use. :^)
_bz2, _curses, _curses_panel, _dbm, _gdbm, _hashlib, _lzma, _sqlite3,
_ssl, _tkinter, _uuid, nis, ossaudiodev, readline, spwd, zlib
I did some work on LibC and LibM beforehand to add at least stubs of
missing required functions, it still encounters an ASSERT_NOT_REACHED()
/ TODO() every now and then, notably frexp() (implementations of that
can be found online easily if you want to get that working right now).
But then again that's our fault and not this port's. :^)
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.
RTTI is still disabled for the Kernel, and for the Dynamic Loader. This
allows for much less awkward navigation of class heirarchies in LibCore,
LibGUI, LibWeb, and LibJS (eventually). Measured RootFS size increase
was < 1%, and libgui.so binary size was ~3.3%. The small binary size
increase here seems worth it :^)
* Add SERENITY_ARCH option to CMake for selecting the target toolchain
* Port all build scripts but continue to use i686
* Update GitHub Actions cache to include BuildIt.sh
A good number of contributors use macOS. However, we have a bit of
a tendency of breaking the macOS build without realising it.
Luckily, GitHub Actions does actually supply macOS environments,
so let's use it.
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.
This is necessary because cache reusability will be determined by Github Actions.
Note that we only cache if explicitly asked to do so,
which only happens on Github Actions.
