Use `Display` in top-level example for `PanicInfo`
Addresses https://github.com/rust-lang/rust/issues/110098.
This confused me as well, when I was writing a `no_std` panic handler for the first time, so here's a better top-level example.
`Display` is stable, prints the `.message()` if available, and falls back to `.payload().downcast_ref<&str>()` if the message is not available. So this example should provide strictly more information and also work for formatted panics.
The old example still exists on the `payload` method.
Add links from `core::cmp` derives to their traits
Fixes#109946
Adds intra-doc links from the `core::cmp` derives to their respective traits, and a link to their derive behaviour
`@rustbot` label +A-docs
Add Command environment variable inheritance docs
The interaction between the environment variable methods can be confusing. Specifically `env_clear` and `remove_env` have a side effects not mentioned: they disable inheriting environment variables from the parent process. I wanted to fully document this behavior as well as explain relevant edge cases in each of the `Command` env methods.
This is further confused by the return of `get_envs` which will return key/None if `remove_env` has been used, but an empty iterator if `env_clear` has been called. Or a non-empty iterator if `env_clear` was called and later explicit mappings are added. Currently there is no way (that I'm able to find) of observing whether or not the internal `env_clear=true` been toggled on the `Command` struct via its public API.
Ultimately environment variable mappings can be in one of several states:
- Explicitly set value (via `envs` / `env`) will take precedence over parent mapping
- Not explicitly set, will inherit mapping from parent
- Explicitly removed via `remove_env`, this single mapping will not inherit from parent
- Implicitly removed via `env_clear`, no mappings will inherit from parent
I tried to represent this in the relevant sections of the docs.
This is my second-ever doc PR (whoop!). I'm happy to take specific or general doc feedback. Also happy to explain the logic behind any changes or additions I made.
Add `tidy-alphabetical` to features in `alloc` & `std`
So that people have to keep them sorted in future, rather than just sticking them on the end where they conflict more often.
Follow-up to #110269
cc `@jyn514`
Add `tidy-alphabetical` to features in `core`
So that people have to keep them sorted in future, rather than just sticking them on the end where they conflict more often.
Rollup of 9 pull requests
Successful merges:
- #109225 (Clarify that RUST_MIN_STACK may be internally cached)
- #109800 (Improve safe transmute error reporting)
- #110158 (Remove obsolete test case)
- #110180 (don't uniquify regions when canonicalizing)
- #110207 (Assemble `Unpin` candidates specially for generators in new solver)
- #110276 (Remove all but one of the spans in `BoundRegionKind::BrAnon`)
- #110279 (rustdoc: Correctly handle built-in compiler proc-macros as proc-macro and not macro)
- #110298 (Cover edge cases for {f32, f64}.hypot() docs)
- #110299 (Switch to `EarlyBinder` for `impl_subject` query)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Cover edge cases for {f32, f64}.hypot() docs
Fixes#88944
The Euclidean distance is a more general way to express what these functions do, and covers the edge cases of zero and negative inputs.
Does not cover the case of non-normal input values (as the [POSIX docs](https://pubs.opengroup.org/onlinepubs/9699919799.2008edition/) do), but the docs for the rest of the functions in these modules do not address this, I assumed it was not desired.
Remove obsolete test case
This test case was supposed to cover issue #31109 at some point.
It never did anything, as the issue was still open at the time of its creation.
When the issue was resolved, the `issue31109` test case was created,
making the existence of this test pointless.
Improve safe transmute error reporting
This patch updates the error reporting when Safe Transmute is not possible between 2 types by including the reason.
Also, fix some small bugs that occur when computing the `Answer` for transmutability.
Clarify that RUST_MIN_STACK may be internally cached
For larger applications it's important that users set `RUST_MIN_STACK` at the start of their program because [`min_stack`](7d3e03666a/library/std/src/sys_common/thread.rs) caches the value. Not doing so can lead to their `env::set_var` call surprisingly not having any effect.
In my own testing `RUST_MIN_STACK` had no effect until I moved it to the top of `main()`. Hopefully this clarification in the docs will help others going forward.
linkat() not available in the system headers of Solaris 10
I've installed rustup on x86_64-unknown-linux-gnu and would like to use the target sparcv9-sun-solaris. For this, I have built a gcc from the source code for cross-compiling to sparcv9-sun-solaris2.10 with system headers of Solaris 10.
With the following hello word example:
main.rs:
```rust
fn main() {
println!("Hello, world!");
}
```
I had a compilation error:
```
$ rustc -v --target sparcv9-sun-solaris -C linker=/opt/cross-solaris/gcc730/bin/sparcv9-sun-solaris2.10-gcc main.rs
error: linking with `/opt/cross-solaris/gcc730/bin/sparcv9-sun-solaris2.10-gcc` failed: exit status: 1
|
= note: "/opt/cross-solaris/gcc730/bin/sparcv9-sun-solaris2.10-gcc" "-m64" "/tmp/rustcgebYgj/symbols.o" "main.main.89363361-cgu.0.rcgu.o" "main.main.89363361-cgu.1.rcgu.o" "main.main.89363361-cgu.2.rcgu.o" "main.main.89363361-cgu.3.rcgu.o" "main.main.89363361-cgu.4.rcgu.o" "main.main.89363361-cgu.5.rcgu.o" "main.csypsau9u2r8348.rcgu.o" "-Wl,-z,ignore" "-L" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib" "-Wl,-Bstatic" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libstd-fa47c8247d587714.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libpanic_unwind-5c87bbe223e6c2a3.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libobject-d484934062ff9fbb.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libmemchr-e8dbd5835abcbf43.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libaddr2line-909ad09329bde2f9.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libgimli-4d74a3be929697ac.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/librustc_demangle-47cbe1d7f7271ae1.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libstd_detect-239fd2d25fb32a00.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libhashbrown-c4a7ce45fb9dec19.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libminiz_oxide-fa6bc3d9bfb4e402.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libadler-419f5a82ddd339a3.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/librustc_std_workspace_alloc-7672b378962c11be.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libunwind-0f9e07f0a032c000.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libcfg_if-ede7757c356dfb28.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/liblibc-808d56fbc668148a.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/liballoc-784767fe059ad3fe.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/librustc_std_workspace_core-aa31d7ef0556bbe1.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libcore-81d07df07db18847.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libcompiler_builtins-313a510e63006db2.rlib" "-Wl,-Bdynamic" "-lsocket" "-lposix4" "-lpthread" "-lresolv" "-lgcc_s" "-lc" "-lm" "-lrt" "-lpthread" "-lsendfile" "-llgrp" "-L" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib" "-o" "main" "-nodefaultlibs"
= note: /opt/cross-solaris/gcc730/lib/gcc/sparcv9-sun-solaris2.10/7.3.0/../../../../sparcv9-sun-solaris2.10/bin/ld: warning: -z ignore ignored.
/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libstd-fa47c8247d587714.rlib(std-fa47c8247d587714.std.5c42d2c1-cgu.0.rcgu.o): In function `std::sys::unix::fs:🔗:h3683dfbfbb4995cb':
/rustc/897e37553bba8b42751c67658967889d11ecd120/library/std/src/sys/unix/fs.rs:1407: undefined reference to `linkat'
collect2: error: ld returned 1 exit status
= help: some `extern` functions couldn't be found; some native libraries may need to be installed or have their path specified
= note: use the `-l` flag to specify native libraries to link
= note: use the `cargo:rustc-link-lib` directive to specify the native libraries to link with Cargo (see https://doc.rust-lang.org/cargo/reference/build-scripts.html#cargorustc-link-libkindname)
```
linkat() is not available in the system headers of Solaris 10. The hello word example works fine when I build/use rust with this PR change.
This patch updates the error reporting when Safe Transmute is not
possible between 2 types by including the reason.
Also, fix some small bugs that occur when computing the `Answer` for
transmutability.
Added diagnostic for pin! macro in addition to Box::pin if Unpin isn't implemented
I made a PR earlier, but accidentally renamed a branch and that deleted the PR... sorry for the duplicate
Currently, if an operation on `Pin<T>` is performed that requires `T` to implement `Unpin`, the diagnostic suggestion is to use `Box::pin` ("note: consider using `Box::pin`").
This PR suggests pin! as well, as that's another valid way of pinning a value, and avoids a heap allocation. Appropriate diagnostic suggestions were included to highlight the difference in semantics (local pinning for pin! vs non-local for Box::pin).
Fixes#109964
Fix btree `CursorMut::insert_after` check
Fixes a check inside `BTreeMap`'s `CursorMut::insert_after`, where it would peek the previous element to check whether the inserted key is below the next one, instead of peeking the next element.
don't splice from files into pipes in io::copy
This fixes potential data ordering issue where a write performed after a copy operation could become visible in the copy even though it signaled completion.
I assumed that by not setting `SPLICE_F_MOVE` we would be safe and the kernel would do a copy in kernel space and we could avoid the read-write syscall and copy-to/from-userspace costs. But apparently that flag only makes a difference when splicing from a pipe, but not when splicing into it.
Context: https://lkml.org/lkml/2023/2/9/673
sync::mpsc: synchronize receiver disconnect with initialization
Receiver disconnection relies on the incorrect assumption that `head.index != tail.index` implies that the channel is initialized (i.e `head.block` and `tail.block` point to allocated blocks). However, it can happen that `head.index != tail.index` and `head.block == null` at the same time which leads to a segfault when a channel is dropped in that state.
This can happen because initialization is performed in two steps. First, the tail block is allocated and the `tail.block` is set. If that is successful `head.block` is set to the same pointer. Importantly, initialization is skipped if `tail.block` is not null.
Therefore we can have the following situation:
1. Thread A starts to send the first value of the channel, observes that `tail.block` is null and begins initialization. It sets `tail.block` to point to a newly allocated block and then gets preempted. `head.block` is still null at this point.
2. Thread B starts to send the second value of the channel, observes that `tail.block` *is not* null and proceeds with writing its value in the allocated tail block and sets `tail.index` to 1.
3. Thread B drops the receiver of the channel which observes that `head.index != tail.index` (0 and 1 respectively), therefore there must be messages to drop. It starts traversing the linked list from `head.block` which is still a null pointer, leading to a segfault.
This PR fixes this problem by waiting for initialization to complete when `head.index != tail.index` and the `head.block` is still null. A similar check exists in `start_recv` for similar reasons.
Fixes#110001
Custom MIR: Support `BinOp::Offset`
Since offset doesn't have an infix operator, a new function `Offset` is added which is lowered to `Rvalue::BinaryOp(BinOp::Offset, ..)`
r? ```@oli-obk``` or ```@tmiasko``` or ```@JakobDegen```
Initial support for loongarch64-unknown-linux-gnu
Hi, We hope to add a new port in rust for LoongArch.
LoongArch intro
LoongArch is a RISC style ISA which is independently designed by Loongson
Technology in China. It is divided into two versions, the 32-bit version (LA32)
and the 64-bit version (LA64). LA64 applications have application-level
backward binary compatibility with LA32 applications. LoongArch is composed of
a basic part (Loongson Base) and an expanded part. The expansion part includes
Loongson Binary Translation (LBT), Loongson VirtualiZation (LVZ), Loongson SIMD
EXtension (LSX) and Loongson Advanced SIMD EXtension(LASX).
Currently the LA464 processor core supports LoongArch ISA and the Loongson
3A5000 processor integrates 4 64-bit LA464 cores. LA464 is a four-issue 64-bit
high-performance processor core. It can be used as a single core for high-end
embedded and desktop applications, or as a basic processor core to form an
on-chip multi-core system for server and high-performance machine applications.
Documentations:
ISA:
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html
ABI:
https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html
More docs can be found at:
https://loongson.github.io/LoongArch-Documentation/README-EN.html
Since last year, we have locally adapted two versions of rust, rust1.41 and rust1.57, and completed the test locally.
I'm not sure if I'm submitting all the patches at once, so I split up the patches and here's one of the commits
Improve the floating point parser in dec2flt.
Greetings everyone,
I've benn studying the rust floating point parser recently and made the following tweaks:
* Remove all remaining traces of `unsafe`. The parser is now 100% safe Rust.
* The trick in which eight digits are processed in parallel is now in a loop.
* Parsing of inf/NaN values has been reworked.
On my system, the changes result in performance improvements for some input values.
