This was non-obvious to me: with no example, I assumed `Electron {}` and
didn't know what else to try when it didn't work. The correct form is
weird because it looks like you're assigning the struct name rather than
an instance of the struct.
This is mainly to avoid infinite recursion and make debugging more convenient in the anomalous case in which `on_panic` panics.
I encountered such issues while changing libstd to debug/fix part of #28129.
While writing this I was wondering about which functions belong to `panicking` and which to `unwind`.
I placed them in this way mostly because of convenience, but I would strongly appreciate guidance.
This adds a new target property, `target_vendor`. It is to be be used as a matcher for conditional compilation. The vendor is part of the [autoconf target triple](http://llvm.org/docs/doxygen/html/classllvm_1_1Triple.html#details): `<arch><sub>-<vendor>-<os>-<env>`. `arch`, `target_os` and `target_env` are already supported by Rust.
This change was suggested in PR #28593. It enables conditional compilation based on the vendor. This is needed for the rumprun target, which needs to match against both, target_os and target_vendor.
The default value for `target_vendor` is "unknown", "apple" and "pc" are other common values.
Matching against the `target_vendor` is introduced behind the feature gate `#![feature(cfg_target_vendor)]`.
This is the first time I messed around with rustc internals. I just added the my code where I found the existing `target_*` variables, hopefully I haven't missed anything. Please review with care. :)
r? @alexcrichton
This makes the first lines of the print! and println! macros
different. Previously, they would show up exactly the same in the
documentation for the macros in libstd [1], with nothing about how
one of them also prints a newline.
[1]: https://doc.rust-lang.org/stable/std/#macros
The double-panic `abort` is run after the logging code, to provide
feedback in case of a double-panic. This means that if the panic
logging fails with a panic, the `abort` might never be reached.
This should not normally occur, but if the `on_panic` function detects
more than 2 panics, aborting *before* logging makes panic handling
somewhat more robust, as it avoids an infinite recursion, which would
eventually crash the process, but also make the problem harder to
debug.
This handles the FIXME about what to do if the thread printing panics.
Move the panic handling logic from the `unwind` module to `panicking`
and use a panic counter to distinguish between normal state, panics
and double panics.
[breaking-change]
`FixedSizeArray` is meant to be implemented for arrays of fixed size only, but can be implemented for anything at the moment. Marking the trait unsafe would make it more reasonable to write unsafe code which operates on fixed size arrays of any size.
For example, using `uninitialized` to create a fixed size array and immediately filling it with a fixed value is externally safe:
```
pub fn init_with_nones<T, A: FixedSizeArray<Option<T>>>() -> A {
let mut res = unsafe { mem::uninitialized() };
for elm in res.as_mut_slice().iter_mut() {
*elm = None;
}
res
}
```
But the same code is not safe if `FixedSizeArray` is implemented for other types:
```
struct Foo { foo: usize }
impl FixedSizeArray<Option<usize>> for Foo {
fn as_slice(&self) -> &[usize] { &[] }
fn as_mut_slice(&self) -> &mut [usize] { &mut [] }
}
```
now `init_with_nones() : Foo` returns a `Foo` with an undefined value for the field `foo`.
Reported by Moonlightning on #rust
> 17:13 EDT < Moonlightning> I think I found a bug in the str::matches() documentation. Was it copied from str::split()? :p
> 17:13 EDT < Moonlightning> Because it says “The pattern can be a simple `&str`, `char`, or a closure that determines the split.”
I changed "determines the split" to "determines if a character matches".
It's not super clear, "determines the split" is not super clear to begin with, maybe this can be made better? On the other hand following the link to Pattern provides enough details.
separate use code between openbsd/netbsd
netbsd use c_int and c_uint, but openbsd not, resulting a unused_import
error.
r? @alexcrichton
problem introduced by #28543
This adds a new target property, `target_vendor` which can be used as a
matcher for conditional compilation. The vendor is part of the autoconf
target triple: <arch><sub>-<vendor>-<os>-<env>
The default value for `target_vendor` is "unknown".
Matching against the `target_vendor` with `#[cfg]` is currently feature
gated as `cfg_target_vendor`.
