This commit does two things:
* Re-works the module-level documentation.
* Cleaning up wording and adding links to where error types are used.
Part of #29364
This commit does two things:
* Re-works the module-level documentation.
* Cleaning up wording and adding links to where error types are used.
Part of #29364
After [considerable
pushback](https://github.com/rust-lang/rfcs/issues/1451), it's clear
that there is a community consensus around providing `IpAddr` in the
standard library, together with other APIs using it.
This commit reverts from deprecated status directly to stable. The
deprecation landed in 1.6, which has already been released, so the
stabilization is marked for 1.7 (currently in beta; will require a backport).
The comment in the next line was already talking about `_guard`, and the
scope guard a couple lines further down is also called `guard`, so I
assume that was just a typo.
Also update the instability reason to include a note about a possible
bad interaction with condition variables on systems that allow
waiting on a RwLock guard.
Here's another go at adding emscripten support. This needs to wait again on new [libc definitions](https://github.com/rust-lang-nursery/libc/pull/122) landing. To get the libc definitions right I had to add support for i686-unknown-linux-musl, which are very similar to emscripten's, which are derived from arm/musl.
This branch additionally removes the makefile dependency on the `EMSCRIPTEN` environment variable by not building the unused compiler-rt.
Again, this is not sufficient for actually compiling to asmjs since it needs additional LLVM patches.
r? @alexcrichton
Backtraces, and the compilation of libbacktrace for asmjs, are disabled.
This port doesn't use jemalloc so, like pnacl, it disables jemalloc *for all targets*
in the configure file.
It disables stack protection.
It could return in the future if it returned a different guard type, which
could not be used with Condvar, otherwise it is unsafe as another thread
can invalidate an "inner" reference during a Condvar::wait.
cc #27746
These commits finish up closing out https://github.com/rust-lang/rust/issues/24237 by filling out all locations we create new file descriptors with variants that atomically create the file descriptor and set CLOEXEC where possible. Previous support for doing this in `File::open` was added in #27971 and support for `try_clone` was added in #27980. This commit fills out:
* `Socket::new` now passes `SOCK_CLOEXEC`
* `Socket::accept` now uses `accept4`
* `pipe2` is used instead of `pipe`
Unfortunately most of this support is Linux-specific, and most of it is post-2.6.18 (our oldest supported version), so all of the detection here is done dynamically. It looks like OSX does not have equivalent variants for these functions, so there's nothing more we can do there. Support for BSDs can be added over time if they also have these functions.
Closes#24237
Abort on stack overflow instead of re-raising SIGSEGV
We use guard pages that cause the process to abort to protect against
undefined behavior in the event of stack overflow. We have a handler
that catches segfaults, prints out an error message if the segfault was
due to a stack overflow, then unregisters itself and returns to allow
the signal to be re-raised and kill the process.
This caused some confusion, as it was unexpected that safe code would be
able to cause a segfault, while it's easy to overflow the stack in safe
code. To avoid this confusion, when we detect a segfault in the guard
page, abort instead of the previous behavior of re-raising SIGSEGV.
To test this, we need to adapt the tests for segfault to actually check
the exit status. Doing so revealed that the existing test for segfault
behavior was actually invalid; LLVM optimizes the explicit null pointer
reference down to an illegal instruction, so the program aborts with
SIGILL instead of SIGSEGV and the test didn't actually trigger the
signal handler at all. Use a C helper function to get a null pointer
that LLVM can't optimize away, so we get our segfault instead.
This is a [breaking-change] if anyone is relying on the exact signal
raised to kill a process on stack overflow.
Closes#31273
Also update the instability reason to include a note about a possible
bad interaction with condition variables on systems that allow
waiting on a RwLock guard.
We use guard pages that cause the process to abort to protect against
undefined behavior in the event of stack overflow. We have a handler
that catches segfaults, prints out an error message if the segfault was
due to a stack overflow, then unregisters itself and returns to allow
the signal to be re-raised and kill the process.
This caused some confusion, as it was unexpected that safe code would be
able to cause a segfault, while it's easy to overflow the stack in safe
code. To avoid this confusion, when we detect a segfault in the guard
page, abort instead of the previous behavior of re-raising the SIGSEGV.
To test this, we need to adapt the tests for segfault to actually check
the exit status. Doing so revealed that the existing test for segfault
behavior was actually invalid; LLVM optimizes the explicit null pointer
reference down to an illegal instruction, so the program aborts with
SIGILL instead of SIGSEGV and the test didn't actually trigger the
signal handler at all. Use a C helper function to get a null pointer
that LLVM can't optimize away, so we get our segfault instead.
This is a [breaking-change] if anyone is relying on the exact signal
raised to kill a process on stack overflow.
Closes#31273
This commit attempts to use the `pipe2` syscall on Linux to atomically set the
CLOEXEC flag for pipes created. Unfortunately this was added in 2.6.27 so we
have to dynamically determine whether we can use it or not.
This commit also updates the `fds-are-cloexec.rs` test to test stdio handles for
spawned processes as well.
This is necessary to atomically accept a socket and set the CLOEXEC flag at the
same time. Support only appeared in Linux 2.6.28 so we have to dynamically
determine which syscall we're supposed to call in this case.
Right now we only attempt to call one symbol which my not exist everywhere,
__pthread_get_minstack, but this pattern will come up more often as we start to
bind newer functionality of systems like Linux.
Take a similar strategy as the Windows implementation where we use `dlopen` to
lookup whether a symbol exists or not.
This commit adds support for creating sockets with the `SOCK_CLOEXEC` flag.
Support for this flag was added in Linux 2.6.27, however, and support does not
exist on platforms other than Linux. For this reason we still have the same
fallback as before but just special case Linux if we can.
Similar to the previous commit, if `F_DUPFD_CLOEXEC` succeeds then there's no
need for us to then call `set_cloexec` on platforms other than Linux. The bug
mentioned of kernels not actually setting the `CLOEXEC` flag has only been
repored on Linux, not elsewhere.
On Linux we have to do this for binary compatibility with 2.6.18, but for other
OSes (e.g. OSX/BSDs/etc) they all support this flag so we don't need to pass it.
It could return in the future if it returned a different guard type, which
could not be used with Condvar, otherwise it is unsafe as another thread
can invalidate an "inner" reference during a Condvar::wait.
cc #27746
These accessors are used to get at the last modification, last access, and
creation time of the underlying file. Currently not all platforms provide the
creation time, so that currently returns `Option`.
These accessors are used to get at the last modification, last access, and
creation time of the underlying file. Currently not all platforms provide the
creation time, so that currently returns `Option`.
- use `symlink_file` and `symlink_dir` instead of the old `soft_link`
- create a junction instead of a directory symlink for testing recursive_rmdir (as it causes the
same troubles, but can be created by users without `SeCreateSymbolicLinkPrivilege`)
- `remove_dir_all` was unable to remove directory symlinks and junctions
- only run tests that create symlinks if we have the right permissions.
- rename `Path2` to `Path`
- remove the global `#[allow(deprecated)]` and outdated comments
- After factoring out `create_junction()` from the test `directory_junctions_are_directories` and
removing needlessly complex code, what I was left with was:
```
#[test]
#[cfg(windows)]
fn directory_junctions_are_directories() {
use sys::fs::create_junction;
let tmpdir = tmpdir();
let foo = tmpdir.join("foo");
let bar = tmpdir.join("bar");
fs::create_dir(&foo).unwrap();
check!(create_junction(&foo, &bar));
assert!(bar.metadata().unwrap().is_dir());
}
```
It test whether a junction is a directory instead of a reparse point. But it actually test the
target of the junction (which is a directory if it exists) instead of the junction itself, which
should always be a symlink. So this test is invalid, and I expect it only exists because the
author was suprised by it. So I removed it.
Some things that do not yet work right:
- relative symlinks do not accept forward slashes
- the conversion of paths for `create_junction` is hacky
- `remove_dir_all` now messes with the internal data of `FileAttr` to be able to remove symlinks.
We should add some method like `is_symlink_dir()` to it, so code outside the standard library
can see the difference between file and directory symlinks too.
I have it set as stable right now under the rationale that it's extending an existing, stable API to another type in the "obvious" way.
r? @alexcrichton
cc @reem
This pull request adds support for [Illumos](http://illumos.org/)-based operating systems: SmartOS, OpenIndiana, and others. For now it's x86-64 only, as I'm not sure if 32-bit installations are widespread. This PR is based on #28589 by @potatosalad, and also closes#21000, #25845, and #25846.
Required changes in libc are already merged: https://github.com/rust-lang-nursery/libc/pull/138
Here's a snapshot required to build a stage0 compiler:
https://s3-eu-west-1.amazonaws.com/nbaksalyar/rustc-sunos-snapshot.tar.gz
It passes all checks from `make check`.
There are some changes I'm not quite sure about, e.g. macro usage in `src/libstd/num/f64.rs` and `DirEntry` structure in `src/libstd/sys/unix/fs.rs`, so any comments on how to rewrite it better would be greatly appreciated.
Also, LLVM configure script might need to be patched to build it successfully, or a pre-built libLLVM should be used. Some details can be found here: https://llvm.org/bugs/show_bug.cgi?id=25409
Thanks!
r? @brson
