[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
clarify documentation of remove_dir errors
remove_dir will error if the path doesn't exist or isn't a directory.
It's useful to clarify that this is "remove dir or fail" not "remove dir
if it exists".
I don't think this belongs in the title. "Removes an existing, empty
directory" is strangely worded-- there's no such thing as a non-existing
directory. Better to just say explicitly it will return an error.
Remove `#[cfg(miri)]` from OnceCell tests
They were carried over from once_cell crate, but they are not entirely
correct (as miri now supports more things), and we don't run miri
tests for std, so let's just remove them.
Maybe one day we'll run miri in std, but then we can just re-install
these attributes.
Move to intra doc links for std::io
Helps with #75080.
@rustbot modify labels: T-doc, A-intra-doc-links, T-rustdoc
r? @jyn514
I had no problems with those files so I added some small links here and there.
They were carried over from once_cell crate, but they are not entirely
correct (as miri now supports more things), and we don't run miri
tests for std, so let's just remove them.
Maybe one day we'll run miri in std, but then we can just re-install
these attributes.
Switch to intra-doc links in /src/sys/unix/ext/*.rs
Partial fix for #75080
@rustbot modify labels: T-doc, A-intra-doc-links, T-rustdoc
r? @jyn514
These two links are not resolving to either `crate::fs::File...` or `fs::File...`
```
# unix/ext/fs.rs
27: /// [`File::read`]: ../../../../std/fs/struct.File.html#method.read
130: /// [`File::write`]: ../../../../std/fs/struct.File.html#method.write
```
Move to intra doc links for ascii.rs and panic.rs
Helps with #75080.
@rustbot modify labels: T-doc, A-intra-doc-links, T-rustdoc
I also updated the doc to fix the wording in `AsciiExt` since it is now deprecated.
The two file are small changes so I bundled them together.
Some links could not be changed to make them work, I believe those are known issues with primitive types.
Move to intra doc links in std::net
Helps with #75080.
@rustbot modify labels: T-doc, A-intra-doc-links, T-rustdoc
The links for `true` and `false` had to stay else `rustdoc` complained, it is intended ?
Add sanitizer support on FreeBSD
Restarting #47337. Everything is better now, no more weird llvm problems, well not everything:
Unfortunately, the sanitizers don't have proper support for versioned symbols (https://github.com/google/sanitizers/issues/628), so `libc`'s usage of `stat@FBSD_1.0` and so on explodes, e.g. in calling `std::fs::metadata`.
Building std (now easy thanks to cargo `-Zbuild-std`) and libc with `freebsd12/13` config via the `LIBC_CI=1` env variable is a good workaround…
```
LIBC_CI=1 RUSTFLAGS="-Z sanitizer=address" cargo +san-test -Zbuild-std run --target x86_64-unknown-freebsd --verbose
```
…*except* std won't build because there's no `st_lspare` in the ino64 version of the struct, so an std patch is required:
```diff
--- i/src/libstd/os/freebsd/fs.rs
+++ w/src/libstd/os/freebsd/fs.rs
@@ -66,8 +66,6 @@ pub trait MetadataExt {
fn st_flags(&self) -> u32;
#[stable(feature = "metadata_ext2", since = "1.8.0")]
fn st_gen(&self) -> u32;
- #[stable(feature = "metadata_ext2", since = "1.8.0")]
- fn st_lspare(&self) -> u32;
}
#[stable(feature = "metadata_ext", since = "1.1.0")]
@@ -136,7 +134,4 @@ impl MetadataExt for Metadata {
fn st_flags(&self) -> u32 {
self.as_inner().as_inner().st_flags as u32
}
- fn st_lspare(&self) -> u32 {
- self.as_inner().as_inner().st_lspare as u32
- }
}
```
I guess std could like.. detect that `libc` isn't built for the old ABI, and replace the implementation of `st_lspare` with a panic?
std/sys/unix/time: make it easier for LLVM to optimize `Instant` subtraction.
This PR is the minimal change necessary to get LLVM to optimize `if self.t.tv_nsec >= other.t.tv_nsec` to branchless instructions (at least on x86_64), inspired by @m-ou-se's own attempts at optimizing `Instant` subtraction.
I stumbled over this by looking at the total number of instructions executed by `rustc -Z self-profile`, and found that after disabling ASLR, the largest source of non-determinism remaining was from this `if` taking one branch or the other, depending on the values involved.
The reason this code is even called so many times to make a difference, is that `measureme` (the `-Z self-profile` implementation) currently uses `Instant::elapsed` for its event timestamps (of which there can be millions).
I doubt it's critical to land this, although perhaps it could slightly improve some forms of benchmarking.
Change Debug impl of SocketAddr and IpAddr to match their Display output
This has already been done for `SocketAddrV4`, `SocketAddrV6`, `IpAddrV4` and `IpAddrV6`. I don't see a point to keep the rather bad to read derived impl, especially so when pretty printing:
V4(
127.0.0.1
)
From the `Display`, one can easily and unambiguously see if it's V4 or V6. Two examples:
```
127.0.0.1:443
[2001:db8:85a3::8a2e:370:7334]:443
```
Luckily the docs explicitly state that `Debug` output is not stable and that it may be changed at any time.
Using `Display` as `Debug` is very convenient for configuration structs (e.g. for webservers) that often just have a `derive(Debug)` and are printed that way to the one starting the server.
Improve documentation on process::Child.std* fields
As a relative beginner, it took a while for me to figure out I could just steal the references to avoid partially moving the child and thus retain ability to call functions on it (and store it in structs etc).
This solves several problems
- race conditions where a file is truncated while copying from it. if we blindly trusted
the file size this would lead to an infinite loop
- proc files appearing empty to copy_file_range but not to read/write
https://github.com/coreutils/coreutils/commit/4b04a0c
- copy_file_range returning 0 for some filesystems (overlay? bind mounts?)
inside docker, again leading to an infinite loop
As a relative beginner, it took a while for me to figure out I could just steal the references to avoid partially moving the child and thus retain ability to call functions on it (and store it in structs etc).
Expand function pointer docs
Be more explicit in the ABI section, and add a section on how to obtain a function pointer, which can be somewhat confusing.
Cc https://github.com/rust-lang/rust/issues/75239
Move to intra doc links whenever possible within std/src/lib.rs
Helps with #75080.
@rustbot modify labels: T-doc, A-intra-doc-links, T-rustdoc
There are some things like
```rust
`//! [`Option<T>`]: option::Option`
```
that will either be fixed in the future or have open issues about them.
Fix minor things in the `f32` primitive docs
All of these were review comments in #74621 that I first fixed in that PR, but later accidentally overwrote by a force push.
Thanks @the8472 for noticing.
r? @KodrAus
Fix wasi::fs::OpenOptions to imply write when append is on
This PR fixes a bug in `OpenOptions` of `wasi` platform that it currently doesn't imply write mode when only `append` is enabled.
As explained in the [doc of OpenOptions#append](https://doc.rust-lang.org/std/fs/struct.OpenOptions.html#method.append), calling `.append(true)` should imply `.write(true)` as well.
## Reproduce
Given below simple Rust program:
```rust
use std::fs::OpenOptions;
use std::io::Write;
fn main() {
let mut file = OpenOptions::new()
.write(true)
.create(true)
.open("foo.txt")
.unwrap();
writeln!(file, "abc").unwrap();
}
```
it can successfully compiled into wasm and execute by `wasmtime` runtime:
```sh
$ rustc --target wasm32-wasi write.rs
$ ~/wasmtime/target/debug/wasmtime run --dir=. write.wasm
$ cat foo.txt
abc
```
However when I change `.write(true)` to `.append(true)`, it fails to execute by the error "Capabilities insufficient":
```sh
$ ~/wasmtime/target/debug/wasmtime run --dir=. append.wasm
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 76, kind: Other, message: "Capabilities insufficient" }', append.rs:10:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: failed to run main module `append.wasm`
...
```
This is because of lacking "rights" on the opened file:
```sh
$ RUST_LOG=trace ~/wasmtime/target/debug/wasmtime run --dir=. append.wasm 2>&1 | grep validate_rights
TRACE wasi_common::entry > | validate_rights failed: required rights = HandleRights { base: fd_write (0x40), inheriting: empty (0x0) }; actual rights = HandleRights { base: fd_seek|fd_fdstat_set_flags|fd_sync|fd_tell|fd_advise|fd_filestat_set_times|poll_fd_readwrite (0x88000bc), inheriting: empty (0x0) }
```
Add Ipv6Addr::to_ipv4_mapped
* add Ipv6Addr::to_ipv4_mapped
* ~~deprecate Ipv4Addr::to_ipv6_compatible & Ipv6Addr::to_ipv4~~ reference: #75150
According to [IETF RFC 4291](https://tools.ietf.org/html/rfc4291#page-10), the "IPv4-Compatible IPv6 address" is deprecated.
> 2.5.5.1. IPv4-Compatible IPv6 Address
>
> The "IPv4-Compatible IPv6 address" was defined to assist in the IPv6
> transition. The format of the "IPv4-Compatible IPv6 address" is as
> follows:
>
> | 80 bits | 16 | 32 bits |
> +--------------------------------------+--------------------------+
> |0000..............................0000|0000| IPv4 address |
> +--------------------------------------+----+---------------------+
>
> Note: The IPv4 address used in the "IPv4-Compatible IPv6 address"
> must be a globally-unique IPv4 unicast address.
>
> The "IPv4-Compatible IPv6 address" is now deprecated because the
> current IPv6 transition mechanisms no longer use these addresses.
> New or updated implementations are not required to support this
> address type.
And the current implementation of `Ipv4Addr::to_ipv6_compatible`is incorrect: it does not check whether the IPv4 address is a globally-unique IPv4 unicast address.
Please let me know if there are any issues with this pull request.
Improve `f32` and `f64` primitive documentation
I noticed that the docs for the primitive floats were fairly short. I first only wanted to add the IEEE specification information (compare [the reference](https://doc.rust-lang.org/reference/types/numeric.html)), but then also added some more beginner-friendly docs. Let me know what you think!
Random doc team assign:
r? @rylev
Std panicking unsafe block in unsafe fn
Partial fix of #73904.
This encloses `unsafe` operations in `unsafe fn` in `libstd/ffi/panicking.rs`.
I also made a two lines change to `libstd/thread/local.rs` to add the necessary `unsafe` block without breaking everything else.
@rustbot modify labels: F-unsafe-block-in-unsafe-fn
Unfortunately, sanitizers do not support versioned symbols[1],
so they break filesystem access via the legacy, pre-ino64 ABI.
To use sanitizers on FreeBSD >= 12, we need to build the libc
crate with LIBC_CI=1 to use the new ABI -- including the libc
used for std. But that removes the st_lspare field std was
expecting for the deprecated metadata extension.
Add a way to skip that field to allow the build to work.
[1]: https://github.com/google/sanitizers/issues/628
