Multiple improvements to RwLocks
This PR replicates #77147, #77380 and #84650 on RWLocks :
- Split `sys_common::RWLock` in `StaticRWLock` and `MovableRWLock`
- Unbox rwlocks on some platforms (Windows, Wasm and unsupported)
- Simplify `RwLock::into_inner`
Notes to reviewers :
- For each target, I copied `MovableMutex` to guess if `MovableRWLock` should be boxed.
- ~A comment says that `StaticMutex` is not re-entrant, I don't understand why and I don't know whether it applies to `StaticRWLock`.~
r? `@m-ou-se`
Filesystems generally have a tree-ish structure which means
paths are more likely to share a prefix than a suffix. Absolute paths
are especially prone to share long prefixes.
Forwarding implementation for Seek trait's stream_position method
Forwarding implementations for `Seek` trait's `stream_position` were missed when it was stabilized in `1.51.0`
Add `Ipv6Addr::is_unicast`
Adds an unstable utility method `Ipv6Addr::is_unicast` under the feature flag `ip` (tracking issue: #27709).
Added for completeness with the other unicast methods (see also https://github.com/rust-lang/rust/issues/85604#issuecomment-848220455) and opposite of `is_multicast`.
Fix documentation style inconsistencies for IP addresses
Pulled out of #85655 as it is unrelated. Fixes some inconsistencies in the docs for IP addresses:
- Currently some addresses are backticked, some are not, this PR backticks everything consistently. (looks better imo)
- Lowercase hex-literals are used when writing addresses.
The "read more" sentence formatted "object safety" as inline code
instead of providing a link to more information. This PR adds a link
to the Reference about this matter, as well as the page regarding trait
objects.
Prior to this patch, the default panic message (resulting from calling
`panic_any(42);` for example), would print the following error message:
```
thread 'main' panicked at 'Box<Any>', ...
```
However, this should be `Box<dyn Any>` instead.
Possible errors when accessing file metadata are platform specific
In particular the `is_dir`, `is_file` and `exists` functions suggests that querying a file requires querying the directory. On Windows this is not normally true.
r? `@m-ou-se`
rustdoc: link to stable/beta docs consistently in documentation
This is an alternative to https://github.com/rust-lang/rust/pull/84941 which fixes the problem consistently by linking to stable/beta for *all* items, not just for primitives.
## User-facing changes
- Intra-doc links to primitives that currently go to rust-lang.org/nightly/std/primitive.x.html will start going to channel that rustdoc was built with. Nightly will continue going to /nightly; Beta will link to /beta; stable compilers will link to /1.52.1 (or whatever version they were built as).
- Cross-crate links from std to core currently go to /nightly unconditionally. They will start going to /1.52.0 on stable channels (but remain the same on nightly channels).
- Intra-crate links from std to std (or core to core) currently go to the same URL they are hosted at; they will continue to do so. Notably, this is different from everything else because it can preserve the distinction between /stable and /1.52.0 by using relative links.
Note that "links" includes both intra-doc links and rustdoc's own
automatically generated hyperlinks.
## Implementation changes
- Update the testsuite to allow linking to /beta and /1.52.1 in docs
- Use an html_root_url for the standard library that's dependent on the channel
This avoids linking to nightly docs on stable.
- Update rustdoc to use channel-dependent links for primitives from an
unknown crate
- Set DOC_RUST_LANG_ORG_CHANNEL from bootstrap to ensure it's in sync
- Include doc.rust-lang.org in the channel
cc Mark-Simulacrum - I know [you were dubious about this in the past](https://rust-lang.zulipchat.com/#narrow/stream/122651-general/topic/Rustdoc.20unconditionally.20links.20to.20nightly.20libstd.20docs/near/231223124), but I'm not quite sure why? I see this as "just a bugfix", I don't know why rustdoc should unconditionally link to nightly.
cc dtolnay who commented in https://github.com/rust-lang/rust/issues/30693:
> I would welcome a PR to solve this permanently if anyone has ideas for how. I don't believe we need an RFC.
Fixes https://github.com/rust-lang/rust/issues/30693 (note that issue is marked as feature-accepted, although I don't see where it was discussed).
## User-facing changes
- Intra-doc links to primitives that currently go to rust-lang.org/nightly/std/primitive.x.html will start going to channel that rustdoc was built with. Nightly will continue going to /nightly; Beta will link to /beta; stable compilers will link to /1.52.1 (or whatever version they were built as).
- Cross-crate links from std to core currently go to /nightly unconditionally. They will start going to /1.52.0 on stable channels (but remain the same on nightly channels).
- Intra-crate links from std to std (or core to core) currently go to the same URL they are hosted at; they will continue to do so. Notably, this is different from everything else because it can preserve the distinction between /stable and /1.52.0 by using relative links.
Note that "links" includes both intra-doc links and rustdoc's own
automatically generated hyperlinks.
## Implementation changes
- Update the testsuite to allow linking to /beta and /1.52.1 in docs
- Use an html_root_url for the standard library that's dependent on the channel
This avoids linking to nightly docs on stable.
- Update rustdoc to use channel-dependent links for primitives from an
unknown crate
- Set DOC_RUST_LANG_ORG_CHANNEL from bootstrap to ensure it's in sync
- Include doc.rust-lang.org in the channel
Support Android ndk versions `r23-beta3` and up
Since android ndk version `r23-beta3`, `libgcc` has been replaced with `libunwind`. This moves the linking of `libgcc`/`libunwind` into the `unwind` crate where we check if the system compiler can find `libunwind` and fall back to `libgcc` if needed.
Since android ndk version `r23-beta3`, `libgcc` has been replaced with
`libunwind`. This moves the linking of `libgcc`/`libunwind` into the
`unwind` crate where we check if the system compiler can find
`libunwind` and fall back to `libgcc` if needed.
- Split `sys_common::RWLock` between `StaticRWLock` and `MovableRWLock`
- Unbox `RwLock` on some platforms (Windows, Wasm and unsupported)
- Simplify `RwLock::into_inner`
To make way for a new IoSlice(Mut)::advance function that advances a
single slice.
Also changes the signature to accept a `&mut &mut [IoSlice]`, not
returning anything. This will better match the future IoSlice::advance
function.
Add #[track_caller] to panic_any
Report the panic location from the user code.
```rust
use std::panic;
use std::panic::panic_any;
fn main() {
panic::set_hook(Box::new(|panic_info| {
if let Some(location) = panic_info.location() {
println!(
"panic occurred in file '{}' at line {}",
location.file(),
location.line(),
);
} else {
println!("panic occurred but can't get location information...");
}
}));
panic_any(42);
}
````
Before:
`panic occurred in file '/rustc/ff2c947c00f867b9f012e28ba88cecfbe556f904/library/std/src/panic.rs' at line 59`
After:
`panic occurred in file 'src/main.rs' at line 17`
In particular the `is_dir`, `is_file` and `exists` functions says that querying a file requires querying the directory. On Windows this is not normally true.
Add inline attr to CString::into_inner so it can optimize out NonNull checks
It seems that currently if you convert any of the standard library's container to a pointer and then to a NonNull pointer, all will optimize out the NULL check except `CString`(https://godbolt.org/z/YPKW9G5xn),
because for some reason `CString::into_inner` isn't inlined even though it's a private function that should compile into a simple `mov` instruction.
Adding a simple `#[inline]` attribute solves this, code example:
```rust
use std::ffi::CString;
use std::ptr::NonNull;
pub fn cstring_nonull(mut n: CString) -> NonNull<i8> {
NonNull::new(CString::into_raw(n)).unwrap()
}
```
assembly before:
```asm
__ZN3wat14cstring_nonull17h371c755bcad76294E:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset %rbp, -16
movq %rsp, %rbp
.cfi_def_cfa_register %rbp
callq __ZN3std3ffi5c_str7CString10into_inner17h28ece07b276e2878E
testq %rax, %rax
je LBB0_2
popq %rbp
retq
LBB0_2:
leaq l___unnamed_1(%rip), %rdi
leaq l___unnamed_2(%rip), %rdx
movl $43, %esi
callq __ZN4core9panicking5panic17h92a83fa9085a8f73E
.cfi_endproc
.section __TEXT,__const
l___unnamed_1:
.ascii "called `Option::unwrap()` on a `None` value"
l___unnamed_3:
.ascii "wat.rs"
.section __DATA,__const
.p2align 3
l___unnamed_2:
.quad l___unnamed_3
.asciz "\006\000\000\000\000\000\000\000\006\000\000\000(\000\000"
```
Assembly after:
```asm
__ZN3wat14cstring_nonull17h9645eb9341fb25d7E:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset %rbp, -16
movq %rsp, %rbp
.cfi_def_cfa_register %rbp
movq %rdi, %rax
popq %rbp
retq
.cfi_endproc
```
(Related discussion on zulip: https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/NonNull.20From.3CBox.3CT.3E.3E)
doc: clarify Mutex::try_lock, etc. errors
Clarify error returns from Mutex::try_lock, RwLock::try_read,
RwLock::try_write to make it more obvious that both poisoning
and the lock being already locked are possible errors.
