Abort when foreign exceptions are caught by catch_unwind
Prior to this PR, foreign exceptions were not caught by catch_unwind, and instead passed through invisibly. This represented a painful soundness hole in some libraries ([take_mut](https://github.com/Sgeo/take_mut/blob/master/src/lib.rs#L37)), which relied on `catch_unwind` to handle all possible exit paths from a closure.
With this PR, foreign exceptions are now caught by `catch_unwind` and will trigger an abort since catching foreign exceptions is currently UB according to the latest proposals by the FFI unwind project group.
cc @rust-lang/wg-ffi-unwind
[AVR] Replace broken 'avr-unknown-unknown' target with 'avr-unknown-gnu-atmega328' target
The `avr-unknown-unknown` target has never worked correctly, always trying to invoke
the host linker and failing. It aimed to be a mirror of AVR-GCC's
default handling of the `avr-unknown-unknown' triple (assume bare
minimum chip features, silently skip linking runtime libraries, etc).
This behaviour is broken-by-default as it will cause a miscompiled executable
when flashed.
This patch improves the AVR builtin target specifications to instead
expose only a 'avr-unknown-gnu-atmega328' target. This target system is
`gnu`, as it uses the AVR-GCC frontend along with avr-binutils. The
target triple ABI is 'atmega328'.
In the future, it should be possible to replace the dependency on
AVR-GCC and binutils by using the in-progress AVR LLD and compiler-rt support.
Perhaps at that point it would make sense to add an
'avr-unknown-unknown-atmega328' target as a better default when
implemented.
There is no current intention to add in-tree AVR target specifications for other
AVR microcontrollers - this one can serve as a reference implementation
for other devices via `rustc --print target-spec-json
avr-unknown-gnu-atmega328p`.
There should be no users of the existing 'avr-unknown-unknown' Rust
target as a custom target specification JSON has always been
recommended, and the avr-unknown-unknown target could never pass the
linking step anyway.
Update docs for SystemTime Windows implementation
Windows now uses `GetSystemTimePreciseAsFileTime` (since #69858) on versions of Windows that support it.
Call into fastfail on abort in libpanic_abort on Windows x86(_64)
This partially resolves#73215 though this is only for x86 targets. This code is directly lifted from [libstd](13290e83a6/library/std/src/sys/windows/mod.rs (L315)). `__fastfail` is the preferred way to abort a process on Windows as it will hook into debugger toolchains.
Other platforms expose a `_rust_abort` symbol which wraps `std::sys::abort_internal`. This would also work on Windows, but is a slightly largely change as we'd need to make sure that the symbol is properly exposed to the linker. I'm inlining the call to the `__fastfail`, but the indirection through `rust_abort` might be a cleaner approach.
A different instruction must be used on ARM architectures. I'd like to verify this works first before tackling ARM.
Minor changes to Ipv4Addr
Minor changes to Ipv4Addr
* Impl IntoInner rather than AsInner for Ipv4Addr
* Add some comments
* Add test to show endiannes of Ipv4Addr display
Report an ambiguity if both modules and primitives are in scope for intra-doc links
Closes https://github.com/rust-lang/rust/issues/75381
- Add a new `prim@` disambiguator, since both modules and primitives are in the same namespace
- Refactor `report_ambiguity` into a closure
Additionally, I noticed that rustdoc would previously allow `[struct@char]` if `char` resolved to a primitive (not if it had a DefId). I fixed that and added a test case.
I also need to update libstd to use `prim@char` instead of `type@char`. If possible I would also like to refactor `ambiguity_error` to use `Disambiguator` instead of its own hand-rolled match - that ran into issues with `prim@` (I updated one and not the other) and it would be better for them to be in sync.
Switch to intra-doc links in `std::macros`
Part of #75080.
---
* Switch to intra-doc links in `std::macros`
* Fix typo in module docs
* Link to `std::io::stderr` instead of `std::io::Stderr` to match the
link text
* Link to `std::io::stdout`
---
@rustbot modify labels: A-intra-doc-links T-doc T-rustdoc
Document that slice refers to any pointer type to a sequence
I was recently confused about the way slices are represented in memory. The necessary information was not available in the std-docs directly, but was a mix of different material from the reference and book.
This PR should clear up the definition of slices a bit more in the documentation. Especially the fact that the term slice refers to the pointer/reference type, e.g. `&[T]`, and not `[T]`.
It also documents that slice pointers are twice the size of pointers to `Sized` types, as this concept may be unfamiliar to users coming from other languages that do not have the concept of "fat pointers" (especially C/C++).
I've documented why this was important to me and my findings in [this blog post](https://codecrash.me/understanding-rust-slices).
r? @lcnr
