bors [Tue, 9 Feb 2016 02:27:58 +0000 (02:27 +0000)]
Auto merge of #31500 - steveklabnik:fix_cow, r=alexcrichton
When I last did a pass through the string documentation, I focused on
consistency across similar functions. Unfortunately, I missed some
details. This example was _too_ consistent: it wasn't actually accurate!
This commit fixes the docs do both be more accurate and to explain why
the return type is a Cow<'a, str>.
First reported here:
https://www.reddit.com/r/rust/comments/44q9ms/stringfrom_utf8_lossy_doesnt_return_a_string/
bors [Tue, 9 Feb 2016 00:19:45 +0000 (00:19 +0000)]
Auto merge of #31278 - alexcrichton:print-cfg, r=brson
This commit is an implementation of the new compiler flags required by [RFC
1361][rfc]. This specifically adds a new `cfg` option to the `--print` flag to
the compiler. This new directive will print the defined `#[cfg]` directives by
the compiler for the target in question.
Alex Crichton [Mon, 25 Jan 2016 19:36:18 +0000 (11:36 -0800)]
rustc: Implement a new `--print cfg` flag
This commit is an implementation of the new compiler flags required by [RFC
1361][rfc]. This specifically adds a new `cfg` option to the `--print` flag to
the compiler. This new directive will print the defined `#[cfg]` directives by
the compiler for the target in question.
bors [Mon, 8 Feb 2016 22:19:41 +0000 (22:19 +0000)]
Auto merge of #31397 - bradfirj:arc-docfix, r=steveklabnik
The documentation for the `make_mut` function on `Arc<T>` contains a somewhat impenetrable double-negative that I was only able to fully grasp by looking at the implementation. Here's a quick rewrite that reads a lot better.
The sentence "doesn't have one strong reference and no weak references." is a
hard to understand, and it can be much more easily explained. In particular, such a double-negative
could give English as a Second Language users even more trouble than native speakers.
Steve Klabnik [Mon, 8 Feb 2016 22:10:55 +0000 (17:10 -0500)]
Fix up docs for String::from_utf8_lossy()
When I last did a pass through the string documentation, I focused on
consistency across similar functions. Unfortunately, I missed some
details. This example was _too_ consistent: it wasn't actually accurate!
This commit fixes the docs do both be more accurate and to explain why
the return type is a Cow<'a, str>.
First reported here:
https://www.reddit.com/r/rust/comments/44q9ms/stringfrom_utf8_lossy_doesnt_return_a_string/
bors [Mon, 8 Feb 2016 19:04:25 +0000 (19:04 +0000)]
Auto merge of #31324 - nagisa:mir-transforms, r=nikomatsakis
Having a `MirPass` provides literally no benefits over `MutVisitor`. Moreover using `MirPass` for
`EraseRegions` basically makes the programmer to fix breakage from changing repr twice – in the
visitor and eraseregions. Since `MutVisitor` implements all the “walking” inside the trait, that can
be reused for `EraseRegions` too, basically resulting in less code duplication.
Split dummy in region inference graph into distinct source and sink nodes.
Why do this: The RegionGraph representation previously conflated all
of the non-variable regions (i.e. the concrete regions such as
lifetime parameters to the current function) into a single dummy node.
A single dummy node leads DFS on a graph `'a -> '_#1 -> '_#0 -> 'b` to
claim that `'_#1` is reachable from `'_#0` (due to `'a` and `'b` being
conflated in the graph representation), which is incorrect (and can
lead to soundness bugs later on in compilation, see #30438).
Splitting the dummy node ensures that DFS will never introduce new
ancestor relationships between nodes for variable regions in the
graph.
bors [Sun, 7 Feb 2016 23:31:46 +0000 (23:31 +0000)]
Auto merge of #31470 - alexcrichton:lets-find-jemalloc, r=brson
Both of these targets have jemalloc disabled unconditionally right now, so using
`maybe_jemalloc` here isn't right. This fixes the case where a Linux compiler
(which is itself configured to use jemalloc) attempts to cross-compile to MinGW,
causing it to try to find an `alloc_jemalloc` crate (and failing).
Alex Crichton [Sun, 7 Feb 2016 20:03:06 +0000 (12:03 -0800)]
rustc: Tweak exe allocator for MinGW/rumprun
Both of these targets have jemalloc disabled unconditionally right now, so using
`maybe_jemalloc` here isn't right. This fixes the case where a Linux compiler
(which is itself configured to use jemalloc) attempts to cross-compile to MinGW,
causing it to try to find an `alloc_jemalloc` crate (and failing).
bors [Sun, 7 Feb 2016 00:16:58 +0000 (00:16 +0000)]
Auto merge of #31440 - reem:rwlock-map-fix, r=alexcrichton
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.
bors [Sat, 6 Feb 2016 21:18:50 +0000 (21:18 +0000)]
Auto merge of #30629 - brson:emscripten-upstream, r=alexcrichton
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.
bors [Sat, 6 Feb 2016 19:16:10 +0000 (19:16 +0000)]
Auto merge of #31428 - reem:remove-mutexguard-map, r=alexcrichton
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.
bors [Sat, 6 Feb 2016 15:15:56 +0000 (15:15 +0000)]
Auto merge of #31417 - alexcrichton:cloexec-all-the-things, r=brson
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.
bors [Sat, 6 Feb 2016 09:24:04 +0000 (09:24 +0000)]
Auto merge of #31333 - lambda:31273-abort-on-stack-overflow, r=brson
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.
Jonathan Reem [Sat, 6 Feb 2016 01:11:17 +0000 (17:11 -0800)]
Fix RwLock*Guard::map to not allow escaping a reference to the data.
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.
Brian Campbell [Sun, 31 Jan 2016 23:30:32 +0000 (18:30 -0500)]
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 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.
bors [Sat, 6 Feb 2016 01:24:22 +0000 (01:24 +0000)]
Auto merge of #31307 - nagisa:mir-drop-terminator, r=nikomatsakis
The scope of these refactorings is a little bit bigger than the title implies. See each commit for details.
I’m submitting this for nitpicking now (the first 4 commits), because I feel the basic idea/implementation is sound and should work. I will eventually expand this PR to cover the translator changes necessary for all this to work (+ tests), ~~and perhaps implement a dynamic dropping scheme while I’m at it as well.~~
Alex Crichton [Thu, 4 Feb 2016 23:23:26 +0000 (15:23 -0800)]
std: Try to use pipe2 on Linux for pipes
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.
Alex Crichton [Thu, 4 Feb 2016 23:22:41 +0000 (15:22 -0800)]
std: Add support for accept4 on Linux
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.
Alex Crichton [Thu, 4 Feb 2016 21:56:59 +0000 (13:56 -0800)]
std: Add a helper for symbols that may not exist
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.
Alex Crichton [Thu, 4 Feb 2016 21:30:24 +0000 (13:30 -0800)]
std: Atomically set CLOEXEC for sockets if possible
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.
Alex Crichton [Thu, 4 Feb 2016 21:22:51 +0000 (13:22 -0800)]
std: When duplicating fds, skip extra set_cloexec
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.
Alex Crichton [Thu, 4 Feb 2016 19:59:31 +0000 (11:59 -0800)]
std: Only have extra set_cloexec for files on Linux
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.
bors [Fri, 5 Feb 2016 20:13:25 +0000 (20:13 +0000)]
Auto merge of #31304 - nikomatsakis:incr-comp-read-from-hir-map, r=michaelwoerister
This change also modifies the dep graph infrastructure to keep track of the number of active tasks, so that even if we are not building the full dep-graph, we still get assertions when there is no active task and one does something that would add a read/write edge. This is particularly helpful since, if the assertions are *not* active, you wind up with the error happening in the message processing thread, which is too late to know the correct backtrace.
~~Before landing, I need to do some performance measurements. Those are underway.~~
Niko Matsakis [Fri, 29 Jan 2016 20:00:46 +0000 (15:00 -0500)]
Add a local counter that tracks how many tasks are pushed or not pushed,
so that we can still get assertion failures even when dep-graph
construction is disabled.
bors [Fri, 5 Feb 2016 17:16:03 +0000 (17:16 +0000)]
Auto merge of #31349 - nikomatsakis:issue-31157-obligation-forest-cache, r=aturon
Have the `ObligationForest` keep some per-tree state (or type `T`) and have it give a mutable reference for use when processing obligations. In this case, it will be a hashmap. This obviously affects the work that @soltanmm has been doing on snapshotting. I partly want to toss this out there for discussion.
Fixes #31157. (The test in question goes to approx. 30s instead of 5 minutes for me.)
cc #30977.
cc @aturon @arielb1 @soltanmm
r? @aturon who reviewed original `ObligationForest`
bors [Fri, 5 Feb 2016 15:11:45 +0000 (15:11 +0000)]
Auto merge of #31400 - durka:civilized-deriving, r=alexcrichton
You can `#[derive(FromPrimitive)]`, but it [fails later in the compile](https://play.rust-lang.org/?gist=82cb8ad2fac49e3fe472&version=stable) due to hardcoding `std::num::FromPrimitive` which [was removed](https://github.com/rust-lang/rust/commit/eeb94886adccb3f13003f92f117115d17846ce1f) (for some reason Github doesn't show `FromPrimitive` in the diff, but `git show` does).
Anyway, this PR removes the code. I didn't mark it as a breaking change, even though [this extremely contrived code using highly unstable features](https://play.rust-lang.org/?gist=1e1b1bbff962837b228a&version=nightly) is broken by it -- should I?
bors [Fri, 5 Feb 2016 13:02:26 +0000 (13:02 +0000)]
Auto merge of #31390 - dotdash:fix_quadratic_drop, r=nagisa
If a new cleanup is added to a cleanup scope, the cached exits for that
scope are cleared, so all previous cleanups have to be translated
again. In the worst case this means that we get N distinct landing pads
where the last one has N cleanups, then N-1 and so on.
As new cleanups are to be executed before older ones, we can instead
cache the number of already translated cleanups in addition to the
block that contains them, and then only translate new ones, if any and
then jump to the cached ones, getting away with linear growth instead.
For the crate in #31381 this reduces the compile time for an optimized
build from >20 minutes (I cancelled the build at that point) to about 11
seconds. Testing a few crates that come with rustc show compile time
improvements somewhere between 1 and 8%. The "big" winner being
rustc_platform_intrinsics which features code similar to that in #31381.
Jonathan Reem [Fri, 5 Feb 2016 10:22:32 +0000 (02:22 -0800)]
Remove MutexGuard::map, as it is not safe in combination with Condvar.
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.
bors [Fri, 5 Feb 2016 08:54:46 +0000 (08:54 +0000)]
Auto merge of #31388 - gmbonnet:compiler-rt-werror, r=alexcrichton
Without this patch, `compiler-rt` fails to build when the `CFLAGS` environment variable contains a `-Werror=*` flag (for example `-Werror=format-security`).
The build system was removing only the `-Werror` part from the flag, thus passing an unrecognized `=*` (for example `=format-security`) argument to gcc.
bors [Fri, 5 Feb 2016 03:03:45 +0000 (03:03 +0000)]
Auto merge of #31321 - jseyfried:cleanup, r=nrc
The first commit improves detection of unused imports -- it should have been part of #30325. Right now, the unused import in the changed test would not be reported.
The rest of the commits are miscellaneous, independent clean-ups in resolve that I didn't think warranted individual PRs.
bors [Fri, 5 Feb 2016 01:00:31 +0000 (01:00 +0000)]
Auto merge of #30865 - alexcrichton:mtime-system-time, r=aturon
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`.
Steve Klabnik [Thu, 4 Feb 2016 21:39:05 +0000 (16:39 -0500)]
Rollup merge of #31007 - pra85:license, r=aturon
According to http://www.copyright.gov/circs/circ01.pdf (See screenshot of relevant section below) , listing the first year of publication in the copyright is enough
This commit reverts back those changes, so that license year is again 2014 (As it was, when this license was first introduced in commit 90ba013bde2396f200196 )
Alex Crichton [Wed, 13 Jan 2016 01:24:16 +0000 (17:24 -0800)]
std: Expose SystemTime accessors on fs::Metadata
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`.
bors [Thu, 4 Feb 2016 18:48:41 +0000 (18:48 +0000)]
Auto merge of #31360 - pitdicker:fs_tests_cleanup, r=alexcrichton
- 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.
The structure of the old translator as well as MIR assumed that drop glue cannot possibly panic and
translated the drops accordingly. However, in presence of `Drop::drop` this assumption can be
trivially shown to be untrue. As such, the Rust code like the following would never print number 2:
```rust
struct Droppable(u32);
impl Drop for Droppable {
fn drop(&mut self) {
if self.0 == 1 { panic!("Droppable(1)") } else { println!("{}", self.0) }
}
}
fn main() {
let x = Droppable(2);
let y = Droppable(1);
}
```
While the behaviour is allowed according to the language rules (we allow drops to not run), that’s
a very counter-intuitive behaviour. We fix this in MIR by allowing `Drop` to have a target to take
on divergence and connect the drops in such a way so the leftover drops are executed when some drop
unwinds.
Note, that this commit still does not implement the translator part of changes necessary for the
grand scheme of things to fully work, so the actual observed behaviour does not change yet. Coming
soon™.
We used to have CallKind only because there was a requirement to have all successors in a
contiguous memory block. Now that the requirement is gone, remove the CallKind and instead just
have the necessary information inline.
bors [Thu, 4 Feb 2016 13:41:42 +0000 (13:41 +0000)]
Auto merge of #31161 - sfackler:slice-to-socket-addrs, r=alexcrichton
This is useful when you have an API that takes a `T: ToSocketAddrs` and needs to turn that into an owned value which will be passed to another API taking `T: ToSocketAddrs` at a later time, for example: https://github.com/sfackler/rust-hyper-socks/blob/master/src/lib.rs#L15
Changed the description of the `make_mut` copy-on-write behaviour in arc.rs
The sentence "doesn't have one strong reference and no weak references." is a
hard to understand double negative, which can be much more easily explained.