Add s390x support
This adds support for building the Rust compiler and standard
library for s390x-linux, allowing a full cross-bootstrap sequence
to complete. This includes:
- Makefile/configure changes to allow native s390x builds
- Full Rust compiler support for the s390x C ABI
(only the non-vector ABI is supported at this point)
- Port of the standard library to s390x
- Update the liblibc submodule to a version including s390x support
- Testsuite fixes to allow clean "make check" on s390x
Caveats:
- Resets base cpu to "z10" to bring support in sync with the default
behaviour of other compilers on the platforms. (Usually, upstream
supports all older processors; a distribution build may then chose
to require a more recent base version.) (Also, using zEC12 causes
failures in the valgrind tests since valgrind doesn't fully support
this CPU yet.)
- z13 vector ABI is not yet supported. To ensure compatible code
generation, the -vector feature is passed to LLVM. Note that this
means that even when compiling for z13, no vector instructions
will be used. In the future, support for the vector ABI should be
added (this will require common code support for different ABIs
that need different data_layout strings on the same platform).
- Two test cases are (temporarily) ignored on s390x to allow passing
the test suite. The underlying issues still need to be fixed:
* debuginfo/simd.rs fails because of incorrect debug information.
This seems to be a LLVM bug (also seen with C code).
* run-pass/union/union-basic.rs simply seems to be incorrect for
all big-endian platforms.
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
The first branch of the if statement already checks if `buf.len() >= self.buf.capacity()`, which makes the `cmp::min(buf.len(), self.buf.capacity())` redundant: the result will always be `buf.len()`. Therefore, we can pass the `buf` slice directly into `Write::write`.
This adds support for building the Rust compiler and standard
library for s390x-linux, allowing a full cross-bootstrap sequence
to complete. This includes:
- Makefile/configure changes to allow native s390x builds
- Full Rust compiler support for the s390x C ABI
(only the non-vector ABI is supported at this point)
- Port of the standard library to s390x
- Update the liblibc submodule to a version including s390x support
- Testsuite fixes to allow clean "make check" on s390x
Caveats:
- Resets base cpu to "z10" to bring support in sync with the default
behaviour of other compilers on the platforms. (Usually, upstream
supports all older processors; a distribution build may then chose
to require a more recent base version.) (Also, using zEC12 causes
failures in the valgrind tests since valgrind doesn't fully support
this CPU yet.)
- z13 vector ABI is not yet supported. To ensure compatible code
generation, the -vector feature is passed to LLVM. Note that this
means that even when compiling for z13, no vector instructions
will be used. In the future, support for the vector ABI should be
added (this will require common code support for different ABIs
that need different data_layout strings on the same platform).
- Two test cases are (temporarily) ignored on s390x to allow passing
the test suite. The underlying issues still need to be fixed:
* debuginfo/simd.rs fails because of incorrect debug information.
This seems to be a LLVM bug (also seen with C code).
* run-pass/union/union-basic.rs simply seems to be incorrect for
all big-endian platforms.
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Fix argument to FIONBIO ioctl
The FIONBIO ioctl takes as argument a pointer to an integer, which
should be either 0 or 1 to indicate whether nonblocking mode is to
be switched off or on. The type of the pointed-to variable is "int".
However, the set_nonblocking routine in libstd/sys/unix/net.rs passes
a pointer to a libc::c_ulong variable. This doesn't matter on all
32-bit platforms and on all litte-endian platforms, but it will
break on big-endian 64-bit platforms.
Found while porting Rust to s390x (a big-endian 64-bit platform).
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
The FIONBIO ioctl takes as argument a pointer to an integer, which
should be either 0 or 1 to indicate whether nonblocking mode is to
be switched off or on. The type of the pointed-to variable is "int".
However, the set_nonblocking routine in libstd/sys/unix/net.rs passes
a pointer to a libc::c_ulong variable. This doesn't matter on all
32-bit platforms and on all litte-endian platforms, but it will
break on big-endian 64-bit platforms.
Found while porting Rust to s390x (a big-endian 64-bit platform).
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Replace `_, _` with `..` in patterns
This is how https://github.com/rust-lang/rust/issues/33627 looks in action.
Looks especially nice in leftmost/rightmost positions `(first, ..)`/`(.., last)`.
I haven't touched libsyntax intentionally because the feature is still unstable.
add mips64-gnu and mips64el-gnu targets
With this commit one can build no_core (and probably no_std as well)
Rust programs for these targets. It's not yet possible to cross compile
std for these targets because rust-lang/libc doesn't know about the
mips64 architecture.
These targets have been tested by cross compiling the "smallest hello"
program (see code below) and then running it under QEMU.
``` rust
extern {
fn puts(_: *const u8);
}
fn start(_: isize, _: *const *const u8) -> isize {
unsafe {
let msg = b"Hello, world!\0";
puts(msg as *const _ as *const u8);
}
0
}
trait Copy {}
trait Sized {}
```
cc #36015
r? @alexcrichton
cc @brson
The cabi stuff is likely wrong. I just copied cabi_mips source and changed some `4`s to `8`s and `32`s to `64`s. It was enough to get libc's `puts` to work but I'd like someone familiar with this module to check it.
Implement std::convert traits for char
This is motivated by avoiding the `as` operator, which sometimes silently truncates, and instead use conversions that are explicitly lossless and infallible.
I’m less certain that `From<u8> for char` should be implemented: while it matches an existing behavior of `as`, it’s not necessarily the right thing to use for non-ASCII bytes. It effectively decodes bytes as ISO/IEC 8859-1 (since Unicode designed its first 256 code points to be compatible with that encoding), but that is not apparent in the API name.
Use monotonic time in condition variables.
Configure condition variables to use monotonic time using
pthread_condattr_setclock on systems where this is possible.
This fixes the issue when thread waiting on condition variable is
woken up too late when system time is moved backwards.
This turns `..` into `::`, handles some more escapes and gets rid of
unwanted underscores at the beginning of path elements.
memrchr: Correct aligned offset computation
The memrchr fallback did not compute the offset correctly. It was
intentioned to land on usize-aligned addresses but did not.
This was suspected to have resulted in a crash on ARMv7!
This bug affected non-linux platforms.
I think like this, if we have a slice with pointer `ptr` and length
`len`, we want to find the last usize-aligned offset in the slice.
The correct computation should be:
For example if ptr = 1 and len = 6, and `size_of::<usize>()` is 4:
```
[ x x x x x x ]
1 2 3 4 5 6
^-- last aligned address at offset 3 from the start.
```
The last aligned address is ptr + len - (ptr + len) % usize_size.
Compute offset from the start as:
offset = len - (ptr + len) % usize_size = 6 - (1 + 6) % 4 = 6 - 3 = 3.
I believe the function's return value was always correct previously, if
the platform supported unaligned addresses.
Fixes#35967
Use arc4rand(9) on FreeBSD
From rust-lang-nursery/rand#112:
>After reading through #30691 it seems that there's general agreement that using OS-provided facilities for seeding rust userland processes is fine as long as it doesn't use too much from libc. FreeBSD's `arc4random_buf(3)` is not only a whole lot of libc code, but also not even currently exposed in the libc crate. Fortunately, the mechanism `arc4random_buf(3)` et al. use for getting entropy from the kernel ([`arc4rand(9)`](https://www.freebsd.org/cgi/man.cgi?query=arc4random&apropos=0&sektion=9&manpath=FreeBSD+10.3-RELEASE&arch=default&format=html)) is exposed via `sysctl(3)` with constants that are already in the libc crate.
>I haven't found too much documentation on `KERN_ARND`—it's missing or only briefly described in most of the places that cover sysctl mibs. But, from digging through the kernel source, it appears that the sysctl used in this PR is very close to just calling `arc4rand(9)` directly (with `reseed` set to 0 and no way to change it).
I expected [rand](/rust-lang-nursery/rand) to reply quicker, so I tried submitting it there first. It's been a few weeks with no comment, so I don't know the state of it, but maybe someone will see it here and have an opinion. This is basically the same patch. It pains me to duplicate the code but I guess it hasn't been factored out into just one place yet.
