Remove vendored cbindgen, use cbindgen dependency to generate includes in build.rs

See merge request !261

Use Kernel mapped binaries when available.

See merge request redox-os/relibc!262

At least in linux kernel, assuming that a.out is an elf that is linked
against relibc's own ld.so. When a user attempts `./a.out`, Linux kernel
will map `./a.out`, then map `ld.so` and jump into ld.so entry point.
In relibc ld.so will simply ignore the kernel mapped a.out and create
its own mapping. This patch forces relic ld.so to use the already mapped
`a.out` when ever possible. This would normally have slight performance
improvement (especially that currently relibc doesn't map a.out but
instead copy the data into empty mmaped memory).

The real motivation behind this patch is while impelemnting Runtime
linker debugging protocol for relibc. part of the protocol is ld.so
inseting address of some ld.so managed data structure into .dynamic
seciton of a.out then the debugger would check it there. The thing is
that debuggers have information about the kernel loaded ./a.out and they
check that one specifically which is in our case totally ignored by
relibc.

Weak symbols

See merge request redox-os/relibc!260

This patch keep 2 lists, one for strong symbols and one for weak
symbols. First it will check for the symbol to be resolved in the strong
symbols' list, if it is not there it will then check in the weak symbol
list.

These files needs formating by the auto formatter and It keeps popping
up every time I format my own code.

This patch does basically two things:
- First make `global` variable not public, And make it accessable via a
function `get_sym`.
- Isolate the procedure that collect global symbols into single function
that does that and call it `collect_syms`.

The motivation of this patch is the second one where this procedure is
extended, thus it needs a seamless way to access those symbols

Stdc compatiability

See merge request !258

I faced many issues when compiling libstdC++-V3 and linking against
relibc mainly:
- Missing types (max_align_t)
- Different types definitions(ptrdiff_t , size_t)
- and the fact that wchar_t is part of standard C++ and it seams that we
  canno redefine standard types

Introduction:

The original implementation of `relibc_ld_so_start` assumes that
ld.so will always be invoked manually as in "/lib/ld64.so ./a.out"
The problem is regarding this snippet.
    if sp.argc < 2 {
      eprintln!("ld.so [executable] [arguments...]");
      unistd::_exit(1);
      loop {}
    }

As such, In linux when user types "./a.out" he will recieve the message
    ld.so [executable] [arguments...]

This patch makes use of AUXV, specifically AT_ENTRY. When invoking ld.so
manually, AT_ENTRY happens to be the entry point of ld.so. But when
running `./a.out` directly, AT_ENTRY becomes the entry point of `a.out`
this patch compares AT_ENTRY to the entry point of ld.so, if they are
equal only then it will assume that argv[1] is the real program and
adjust the stack, otherwise it will proceed with the stack unadjusted.

Fix make libs in CI

See merge request !256

There is no make libc

➜  relibc git:(master) make libc
make: *** No rule to make target 'libc'.  Stop.

Support AF_UNIX sockets

See merge request redox-os/relibc!255

As with the previous commit, accept() was calling inner_get_name() and
assuming only "tcp:" or "udp:" addresses would be received. Thus, in
order to support AF_UNIX sockets, inner_get_name() was split into two,
inner_af_inet() and inner_af_unix() - where the former keeps the
previous logic, dealing with "tcp:" and "udp:" addresses, and the latter
deals now with "chan:" addresses and filling in the sockaddr_un
appropriately.

Previously, domain AF_INET was assumed while processing bind() /
connect(), which end up calling bind_or_connect!. Instead, match on the
domain type and process the path for AF_UNIX domains.

To add support for UNIX sockets (AF_UNIX), of SOCK_STREAM type, the
"chan:" scheme is used, which will be supportedby the ipcd running in
userspace.

Later commits add similar AF_UNIX support for the rest of the methods in
impl PalSocket.

Future commits will make use of this, in order to support AF_UNIX
sockets.

Use lossless type conversion in ctype.h

See merge request !246

Fix fd dup tests to be more robust

See merge request redox-os/relibc!251

Replace occurences of uninitialized with MaybeUninit

See merge request !248

AdminXVII authored 5 years ago and Jeremy Soller committed 5 years ago

mem::uninitialized is deprecated, so move over the not-UB MaybeUninit.

Fix ar usage in Makefile for macOS compatibility

See merge request !253

Re-enable netdb tests, fix compiler warning, improve brk coverage

See merge request !254