This patch is the first step of re-organizing the internal structure of
the libc. The original version involved many direct calls of global
functions (often with side effects) across compilation units, which
made the control flow (e.g., the initialization sequence) hard to
follow.
The new version replaces those ad-hoc interactions with dedicated
interfaces (like suspend.h, resume.h, select.h, current_time.h). The
underlying facilities are provided by the central Libc::Kernel and
selectively propagated to the various compilation units. The latter is
done by a sequence of 'init_*' calls, which eventually will be replaced
by constructor calls.
The addition of new headers increases the chance for name clashes with
existing (public) headers. To disambiguate libc-internal header files
from public headers, this patch moves the former into a new 'internal/'
subdirectory. This makes the include directives easier to follow and the
libc's source-tree structure more tidy.
There are still a few legacies left, which cannot easily be removed
right now (e.g., because noux relies on them). However, the patch moves
those bad apples to legacy.h and legacy.cc, which highlights the
deprecation of those functions.
Issue #3497
This patch implements 'execve' in Genode's libc.
The mechanism relies on the dynamic linker's ability to replace the
loaded binary while keeping crucial libraries - in particular the libc -
intact. The state outside the libc is wiped. For this reason, all libc
internal state needed beyond the 'execve' call must be allocated on a
heap separate from the application-owned malloc heap. E.g.,
libc-internal file-descriptor objects must not be allocated or refer to
any memory object allocated from the malloc heap.
Issue #3481
Replace the FreeBSD libm with OpenLibm, which is easier to port.
OpenLibm is used by Mirage's freestanding Ocaml runtime (sin POSIX).
https://openlibm.org/
Ref #3289
The minimal-footprint Ada runtime for implementing library-like
functionality in SPARK is now called "spark" runtime.
The full Ada runtime for entire components written in Ada and using the
libc as glue to the underlying system will move to the world repository
as "ada" runtime.
Issue #3144
