* `-lc++` now implies `-lc`.
* `-lunwind` is now pulled out into a separate `link_libunwind` flag in
the frontend driver code. This allows a project to request zig to
provide libunwind even if the default situation that causes it to be
implicitly added, is not active.
* build.zig: ask for -lunwind when building the self-hosted compiler on
Linux. Otherwise we get linker errors with unresolved symbols to
libunwind.
* for cross testing stage2 tests, we use `darling shell` command
since the path to the tested binary is relative to cwd
* for the `zig test` command, we simply use `darling` since the
path to the binary is absolute
With this change, it is now possible to use zig-bootstrap as the
initial C/C++ compiler, and then build stage2 with the resultant
stage1 without the need to link any system libs!
5ac91794cce8bd53916a378815be01e4365d53d9 made Zig link against the
system libc when targeting the native C ABI. However this made it stop
putting libunwind.a on the linker line when it needed to sometimes,
causing undefined symbols when linking against C++ code.
Without this, and with `-Denable-qemu -Denable-foreign-glibc`,
i386-linux-gnu tests failed because the `-L` path passed to qemu
was "i386-linux-gnu" (nonexistent) rather than "i686-linux-gnu".
Fixes std lib and behavior tests when using these options to enable
test coverage with cross compiled glibcs.
The CPU detection code is nearly at feature parity, we do support
detecting the native CPU on Sparc systems and macos, our ARM/AArch64
model list is quite comprehensive and so is our PPC one.
The only missing pieces are:
- ARM32 detection on Darwin hosts (I don't think anybody is planning on
running the compiler on a old-ass iPhone)
- s390x detection on Linux hosts, this can be easily added at a later
stage.
The current spanZ() function will not scan for a 0 terminator if the
type is not 0 terminated. This encourages using 0 terminated array
types to bind C arrays which hold 0 terminated strings. However, this is
a big footgun as nothing in the C type system guarantees there to be a
0 terminator at the end of the array and if there is none this becomes
Illegal Behavior in Zig.
To solve this, deprecate spanZ() and lenZ(), adding a new sliceTo()
function that always scans for the given terminator even if the type is
not sentinel terminated.
Currently zig will always try to build its own libc and compile against
that. This of course makes sense for cross-compilation, but can cause
problems when targeting the native OS/ABI.
For example, if the system uses a newer glibc version than zig ships
zig will fall back to using the newest version it does ship. However
this causes linking system libraries to fail as they are built against a
different glibc version than the zig code is built against.
To remedy this, simply default to linking the system libc when targeting
the native OS/ABI.
It turns out that nothing in the test suite was exercising
preadv/pwritev and so the previous commits silently broke them.
Adding tests revealed readvAll and preadvAll were also broken and not
covered by any test.
While musl decided to hard-wire off_t to a 64bit quantity, glibc is much
older and defaults to 32bit offsets and offers some -64 suffixed
versions of I/O functions.
There's a weird mix-up of types: sometimes off_t is used, sometimes not,
sometimes it's defined as a signed quantity and sometimes as an unsigned
one, but we'll sort this problem later.
