Let's not be paying the function call overhead for these tiny ops.
Maybe there's an argument for having fewer gadgets in the kernel but
for now we're actually seeing stac() in profiles so let's put
that above theoretical security issues.
If these methods get inlined, the compiler is able to statically eliminate most
of the assertions. Alas, it doesn't realize this, and believes inlining them to
be too expensive. So give it a strong hint that it's not the case.
This *decreases* the kernel binary size.
LibLine should ultimately not care about what a "token" means in the
context of its user, so force the user to split the buffer itself.
This also allows the users to pick up contextual clues as well, since
they have to lex the line themselves.
This commit pacthes Shell and the JS repl to better handle completions,
so certain wrong behaviours are now corrected as well:
- JS repl can now complete "Object . getOw<tab>"
- Shell can now complete "echo | ca<tab>" and paths inside strings
We can do away with that shenanigans now that libstdc++ is gone.
Also, simplify the toolchain dependency hash calculation to only depend
on the toolchain build script(s) and the Patches files we use to modify
the toolchain itself.
Make sure that userspace is always referencing "system" headers in a way
that would build on target :). This means removing the explicit
include_directories of Libraries/LibC in favor of having it export its
headers as SYSTEM. Also remove a redundant include_directories of
Libraries in the 'serenity build' part of the build script. It's already
set at the top.
This causes issues for the Kernel, and for crt0.o. These special cases
are handled individually.
This is __cxa_guard_acquire, __cxa_guard_release, and __cxa_guard_abort.
We put these symbols in a 'fake' libstdc++ to trick gcc into thinking it
has libstdc++. These symbols are necessary for C++ programs and not C
programs, so, seems file. There's no way to tell gcc that, for example,
the standard lib it should use is libc++ or libc. So, this is what we
have for now.
When threaded code enters a block that is trying to call the constructor
for a block-scope static, the compiler will emit calls to these methods
to handle the "call_once" nature of block-scope statics.
The compiler creates a 64-bit guard variable, which it checks the first
byte of to determine if the variable should be intialized or not.
If the compiler-generated code reads that byte as a 0, it will call
__cxa_guard_acquire to try and be the thread to call the constructor for
the static variable. If the first byte is 1, it will assume that the
variable's constructor was called, and go on to access it.
__cxa_guard_acquire uses one of the 7 implementation defined bytes of
the guard variable as an atomic 8 bit variable. To control a state
machine that lets each entering thread know if they gained
'initialization rights', someone is working on the varaible, someone is
working on the varaible and there's at least one thread waiting for it
to be intialized, or if the variable was initialized and it's time to
access it. We only store a 1 to the byte the compiler looks at in
__cxa_guard_release, and use a futex to handle waiting.
In order to remove libstdc++ completely, we need to give up on their
implementation of abi::__cxa_demangle. The demangler logic will actually
have to be quite complex, and included in both the kernel and userspace.
A definite fixme for the future, to parse the mangled names into real
deal names.
This allows operator new and operator delete to be available to anyone
that links -lc (everyone) rather than just people that include
kmalloc.h (almost no one).
Use the AK version of std::initializer_list in AK::Vector, but only
when in serenity. When building AK for a non-serenity target, the header
<initializer_list> should be always available.
Instead, we now tell Windows to invalidate themselves. Window will then
pass on the requests to Compositor.
My basic idea here is that WindowManager should do window management,
dealing with incoming events, moving, resizing, etc. Compositor should
deal with painting the window stack in the right order with the least
amount of effort. :^)
