NetBSD: link libstd with librt in addition to libpthread
Some aio(3) and mq(3) functions in the libc crate actually come from NetBSD librt, not libc or libpthread.
Use `Mmap` to open the rmeta file.
Because those files are quite large, contribute significantly to peak
memory usage, but only a small fraction of the data is ever read.
r? @eddyb
Speed up String::from_utf16
Collecting into a `Result` is idiomatic, but not necessarily fast due to rustc not being able to preallocate for the resulting collection. This is fine in case of an error, but IMO we should optimize for the common case, i.e. a successful conversion.
This changes the behavior of `String::from_utf16` from collecting into a `Result` to pushing to a preallocated `String` in a loop.
According to [my simple benchmark](https://gist.github.com/ljedrz/953a3fb74058806519bd4d640d6f65ae) this change makes `String::from_utf16` around **twice** as fast.
Add link to std::mem::size_of to size_of intrinsic documentation
The other intrinsics with safe/stable alternatives already have documentation to this effect.
Redox: Update to new changes
These are all cherry-picked from our fork:
- Remove the `env:` scheme
- Update `execve` system call to `fexec`
- Interpret shebangs: these are no longer handled by the kernel, which like usual tries to be as minimal as possible
std: Synchronize access to global env during `exec`
This commit, after reverting #55359, applies a different fix for #46775
while also fixing #55775. The basic idea was to go back to pre-#55359
libstd, and then fix#46775 in a way that doesn't expose #55775.
The issue described in #46775 boils down to two problems:
* First, the global environment is reset during `exec` but, but if the
`exec` call fails then the global environment was a dangling pointer
into free'd memory as the block of memory was deallocated when
`Command` is dropped. This is fixed in this commit by installing a
`Drop` stack object which ensures that the `environ` pointer is
preserved on a failing `exec`.
* Second, the global environment was accessed in an unsynchronized
fashion during `exec`. This was fixed by ensuring that the
Rust-specific environment lock is acquired for these system-level
operations.
Thanks to Alex Gaynor for pioneering the solution here!
Closes#55775
This commit, after reverting #55359, applies a different fix for #46775
while also fixing #55775. The basic idea was to go back to pre-#55359
libstd, and then fix#46775 in a way that doesn't expose #55775.
The issue described in #46775 boils down to two problems:
* First, the global environment is reset during `exec` but, but if the
`exec` call fails then the global environment was a dangling pointer
into free'd memory as the block of memory was deallocated when
`Command` is dropped. This is fixed in this commit by installing a
`Drop` stack object which ensures that the `environ` pointer is
preserved on a failing `exec`.
* Second, the global environment was accessed in an unsynchronized
fashion during `exec`. This was fixed by ensuring that the
Rust-specific environment lock is acquired for these system-level
operations.
Thanks to Alex Gaynor for pioneering the solution here!
Closes#55775
Co-authored-by: Alex Gaynor <alex.gaynor@gmail.com>
xLTO: Don't pass --plugin-opt=thin to LLD. That's not supported anymore.
It seems that `-plugin-opt=thin` is not needed anymore when invoking LLD for ThinLTO. Unfortunately, still passing the option makes LLD crash instead of giving a deprecation warning or something.
Check for negative impls when finding auto traits
Fixes#55321
When AutoTraitFinder begins examining a type, it checks for an explicit
negative impl. However, it wasn't checking for negative impls found when
calling 'select' on predicates found from nested obligations.
This commit makes AutoTraitFinder check for negative impls whenever it
makes a call to 'select'. If a negative impl is found, it immediately
bails out.
Normal users of SelectioContext don't need to worry about this, since
they stop as soon as an Unimplemented error is encountered. However, we
add predicates to our ParamEnv when we encounter this error, so we need
to handle negative impls specially (so that we don't try adding them to
our ParamEnv).
impl_stable_hash_for: support enums and tuple structs with generic parameters
Port a bunch of implementations over to the macro, now that that is possible.
Document optimizations enabled by FusedIterator
When reading this I wondered what “some significant optimizations” referred to. As far as I can tell from reading code, the specialization of `.fuse()` is the only case where `FusedIterator` has any impact at all. Is this accurate @Stebalien?
global allocators: add a few comments
These comments answer some questions that came up when I tried to understand how the control flow works for the global allocator, `Global` and `System`.
r? @alexcrichton
Reference count `crate_inherent_impls`s return value.
The repeated cloning of the result in `inherent_impls` queries has quite
an impact on crates with many inherent trait implementations.
For instance on https://github.com/jmesmon/stm32f429, `cargo check` went from 75 seconds to 38 seconds on my machine.
string: Add documentation for `From` impls
Hi this is part of #51430. I'm a first time contributor, so I started with a small task adding a bit of documentation for From impls.
Fix TLS errors when downloading stage0
While attempting to test #49878 on Windows I hit the following error when attempting to download stage0.
```
The request was aborted: Could not create SSL/TLS secure channel
```
Instead of using the shell, we can just use `urllib`, which seems to fix the issue.
Make PhantomData #[structural_match]
fixes https://github.com/rust-lang/rust/issues/55028
This makes `PhantomData<T>` structurally matchable, irrespective of whether `T` is, per the discussion on this week's language team meeting (the general consensus was that this was a bug-fix).
All types containing `PhantomData<T>` and which used `#[derive(PartialEq, Eq)]` and were previously not `#[structural_match]` only because of `PhantomData<T>` will now be `#[structural_match]`.
r? @nikomatsakis
