The previous approach could leave behind uninitialized fields on
platforms which have additional fields in this structure (e.g. padding
fields on musl libc).
The format is quite simply the type index followed by the type in its
own native encoding; just implementing the receive side with static
typing is a bit convoluted. The only limitation of this implementation
is that the variant type has to contain an Empty somewhere as it is not
default constructible otherwise.
Co-authored-by: Ali Mohammad Pur <mpfard@serenityos.org>
This commit teaches BindingsGenerator to generate depfiles, which can be
used by CMake to ensure that bindings are properly regenerated when
imported IDL files change.
Two new options, `--depfile` and `--depfile-target` are added.
- `--depfile` sets the path for the dependency file.
- `--depfile-target` lets us set a target name different than the output
file in the depfile. This option is needed because generated files are
first written to a temporary file, but depfiles have to refer to the
final location.
These are analogous to GCC's `-MF` and `-MT` options respectively. The
depfile's syntax matches the ones generated by GCC.
Note: This changes the minimal required CMake version to 3.20 if the
Make generator is used, and to 3.21 for the Xcode generator. Ninja is
not affected.
The idea of reading some amount of data presumably was to check if the
stream is still operable. However, this permanently breaks the request
format, as those 64 bytes are just lost forever.
Instead, just let the request fail instantly for now and think about
making it retry some time in the future. Since `can_read_line` updates
the read buffer beforehand, this should only happen in the rarest of
cases anyways.
This allows us to either pass a reference, which keeps compatibility
with old code, or to pass a NonnullOwnPtr, which allows us to
comfortably chain streams as usual.
This essentially wraps a `NonnullOwnPtr` or a reference, allowing us to
either have a stream own a dependent stream that it uses or to just hold
a reference if a stream is already owned by somebody else and we just
want to use it temporarily.
This currently doesn't work when running Serenity through QEMU, as it
doesn't pass the side button events over to Serenity due to some bug or
missing feature.
This would previously crash with a heap UAF when storing the result of
`yield 1` into `e` on the second `next` call:
```js
function* a() { const e = yield 1; }
b = a();
b.next();
gc();
b.next();
```
This generally seems like a better name, especially if we somehow also
need a better name for "read the entire buffer, but not the entire file"
somewhere down the line.
Next to functions like `is_eof` these were really confusing to use, and
the `read`/`write` functions should fail anyways if a stream is not
readable/writable.
Some programs explicitly ask for a different initial stack size than
what the OS provides. This is implemented in ELF by having a
PT_GNU_STACK header which has its p_memsz set to the amount that the
program requires. This commit implements this policy by reading the
p_memsz of the header and setting the main thread stack size to that.
ELF::Image::validate_program_headers ensures that the size attribute is
a reasonable value.
