Commit Graph

208645 Commits

Author SHA1 Message Date
Yuki Okushi
6383540130
Rollup merge of #103382 - compiler-errors:anon-apit-lt-region-ice, r=cjgillot
Don't ICE when reporting borrowck errors involving regions from `anonymous_lifetime_in_impl_trait`

The issue here is that when we have:

```
trait Trait<'a> { .. }

fn foo(arg: impl Trait) { .. }
```

The anonymous lifetime `'_` that we generate for `arg: impl Trait` doesn't end up in the argument type (which is a param) but in a where-clause of the function, in a predicate whose self type is that param ty.

Fixes #101660

r? ``@cjgillot``
2022-10-25 08:01:28 +09:00
Yuki Okushi
e47d222a94
Rollup merge of #103350 - clubby789:refer-to-assoc-method, r=wesleywiser
Change terminology for assoc method suggestions when they are not called

Fixes #103325

```@rustbot``` label +A-diagnostics
2022-10-25 08:01:27 +09:00
Yuki Okushi
11d11e3415
Rollup merge of #103333 - chenyukang:yukang/fix-103143, r=wesleywiser
Fix assertion failed for break_last_token and trailing token

Fixes #103143
2022-10-25 08:01:27 +09:00
Michael Goulet
1727c00f1a Assert if inference vars are leaking from fully_resolve 2022-10-24 18:53:32 +00:00
Michael Goulet
fa5cf90b8d Delay span bug when we can't map lifetimes back in collect_trait_impl_trait_tys 2022-10-24 18:45:50 +00:00
Martin Nordholts
5e624bf4ba rustdoc: Use unix_sigpipe instead of rustc_driver::set_sigpipe_handler
Start using `unix_sigpipe` instead of
`rustc_driver::set_sigpipe_handler`.

After this has been merged, we can completely remove
`rustc_driver::set_sigpipe_handler`.

Verification of this change
---------------------------

1. Remove `#[unix_sigpipe = "sig_dfl"]`
1. Run `./x.py build`
1. Run `./build/aarch64-apple-darwin/stage1/bin/rustdoc --help | false`
1. Observe ICE
1. Add back `#[unix_sigpipe = "sig_dfl"]`
1. Run `./x.py build`
1. Run `./build/aarch64-apple-darwin/stage1/bin/rustdoc --help | false`
1. Observe ICE fixed
2022-10-24 20:40:46 +02:00
Michael Howell
f0f0a7dbc2 rustdoc: remove redundant CSS a.test-arrow:hover
In 4b402dbe69, when this rule was added, it
was overriding a rule that made all links in docblock get an underline when
hovered. This became redundant when, after reordering the rules,
7585632052 changed the pro-underline rule to
exclude the test-arrow link anyway.
2022-10-24 11:39:19 -07:00
Michael Howell
4e1abcda1b rustdoc: remove unused .sidebar-logo DOM on source pages 2022-10-24 10:47:24 -07:00
bors
758f19645b Auto merge of #103337 - flip1995:clippyup, r=Manishearth
Update Clippy

r? `@Manishearth`
2022-10-24 16:50:15 +00:00
Guillaume Gomez
1dff99f46c Use functions in highlight-colors rustdoc GUI test 2022-10-24 17:44:17 +02:00
Cameron Steffen
c2bc3bcfb0 Document link to unstable book 2022-10-24 10:34:52 -05:00
Nixon Enraght-Moony
674cd6125d Clairify Vec::capacity docs
Fixes #103326
2022-10-24 15:01:58 +01:00
bors
c07a6a9c0c Auto merge of #94063 - Aaron1011:pretty-print-rental, r=lcnr
Only apply `ProceduralMasquerade` hack to older versions of `rental`

The latest version of `rental` (v0.5.6) contains a fix that allows it to
compile without relying on the pretty-print back-compat hack.

Hopefully, there are no longer any crates relying on the affected
versions of the (much less popular) `procedural-masquerade` crate. This
should allow us to target the pretty-print back-compat hack specifically
to older versions of `rental`, and specifically mention upgrading to
`rental` v0.5.6 in the lint message.
2022-10-24 13:35:48 +00:00
bors
1481fd964b Auto merge of #103471 - JohnTitor:rollup-tfmy6ab, r=JohnTitor
Rollup of 7 pull requests

Successful merges:

 - #99578 (Remove redundant lifetime bound from `impl Borrow for Cow`)
 - #99939 (Sort tests at compile time, not at startup)
 - #102271 (Stabilize `duration_checked_float`)
 - #102766 (Don't link to `libresolv` in libstd on Darwin)
 - #103277 (Update libstd's libc to 0.2.135 (to make `libstd` no longer pull in `libiconv.dylib` on Darwin))
 - #103437 (Sync rustc_codegen_cranelift)
 - #103466 (Fix grammar in docs for std::io::Read)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2022-10-24 10:54:40 +00:00
Yuki Okushi
a710f56e7d
Rollup merge of #103466 - jruderman:patch-2, r=Dylan-DPC
Fix grammar in docs for std::io::Read

Two independent clauses were incorrectly joined by a bare comma. The simplest fix would be to switch to a semicolon, but I think it's slightly better to keep the comma and use the coordinating conjunction "so".
2022-10-24 19:32:29 +09:00
Yuki Okushi
8e9d2b6971
Rollup merge of #103437 - bjorn3:sync_cg_clif-2022-10-23, r=bjorn3
Sync rustc_codegen_cranelift

r? `@ghost`

`@rustbot` label +A-codegen +A-cranelift +T-compiler
2022-10-24 19:32:28 +09:00
Yuki Okushi
413380fc20
Rollup merge of #103277 - thomcc:bump-libc-135, r=Mark-Simulacrum
Update libstd's libc to 0.2.135 (to make `libstd` no longer pull in `libiconv.dylib` on Darwin)

This is to pull in https://github.com/rust-lang/libc/pull/2944.

It's related to https://github.com/rust-lang/rust/pull/102766, in that they both remove unused dylibs from libstd on Darwin platforms. As a result, I'm marking this as relnotes since everybody agreed it was good to add it to the other as well. (The note should be about no longer linking against libiconv -- the libc update is irrelevant).

Might as well have the same reviewer too.

r? `@Mark-Simulacrum`
2022-10-24 19:32:27 +09:00
Yuki Okushi
413a82051d
Rollup merge of #102766 - thomcc:remove-resolv, r=Mark-Simulacrum
Don't link to `libresolv` in libstd on Darwin

Currently we link `libresolv` into every Rust program on apple targets despite never using it (as of https://github.com/rust-lang/rust/pull/44965). I had thought we needed this for `getaddrinfo` or something, but we do not / cannot safely use it.

I'd like to fix this for `libiconv` too (the other library we pull in. that's harder since it's coming in through `libc`, which is https://github.com/rust-lang/libc/pull/2944)).

---

This may warrant release notes. I'm not sure but I've added the flag regardless -- It's a change to the list of dylibs every Rust program pulls in, so it's worth mentioning.

It's pretty unlikely anybody was relying on this being pulled in, and `std` does not guarantee that it will link (and thus transitively provide access to) any particular system library -- anybody relying on that behavior would already be broken when dynamically linking std. That is, there's an outside chance something will fail to link on macOS and iOS because it was accidentally relying on our unnecessary dependency.

(If that *does* happen, that project could be easily fixed by linking libresolv explicitly on those platforms, probably via `#[link(name = "resolv")] extern {}`,` -Crustc-link-lib=resolv`, `println!("cargo:rustc-link-lib=resolv")`, or one of several places in `.config/cargo.toml`)

---

I'm also going to preemptively add the nomination for discussing this in the libs meeting. Basically: Do we care about programs that assume we will bring libraries in that we do not use. `libresolv` and `libiconv` on macOS/iOS are in this camp (`libresolv` because we used to use it, and `libiconv` because the `libc` crate was unintentionally(?) pulling it in to every Rust program).

I'd like to remove them both, but this may cause link issues programs that are relying on `std` to depend on them transitively. (Relying on std for this does not work in all build configurations, so this seems very fragile, and like a use case we should not support).

More generally, IMO we should not guarantee the specific set of system-provided libraries we use (beyond what is implied by an OS version requirement), which means we'd be free to remove this cruft.
2022-10-24 19:32:27 +09:00
Yuki Okushi
c1f9d985d7
Rollup merge of #102271 - lopopolo:lopopolo/stabilize-duration-try-from-secs-float, r=dtolnay
Stabilize `duration_checked_float`

## Stabilization Report

This stabilization report is for a stabilization of `duration_checked_float`, tracking issue: https://github.com/rust-lang/rust/issues/83400.

### Implementation History

- https://github.com/rust-lang/rust/pull/82179
- https://github.com/rust-lang/rust/pull/90247
- https://github.com/rust-lang/rust/pull/96051
- Changed error type to `FromFloatSecsError` in https://github.com/rust-lang/rust/pull/90247
- https://github.com/rust-lang/rust/pull/96051 changes the rounding mode to round-to-nearest instead of truncate.

## API Summary

This stabilization report proposes the following API to be stabilized in `core`, along with their re-exports in `std`:

```rust
// core::time

impl Duration {
    pub const fn try_from_secs_f32(secs: f32) -> Result<Duration, TryFromFloatSecsError>;
    pub const fn try_from_secs_f64(secs: f64) -> Result<Duration, TryFromFloatSecsError>;
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct TryFromFloatSecsError { ... }

impl core::fmt::Display for TryFromFloatSecsError { ... }
impl core::error::Error for TryFromFloatSecsError { ... }
```

These functions are made const unstable under `duration_consts_float`, tracking issue #72440.

There is an open question in the tracking issue around what the error type should be called which I was hoping to resolve in the context of an FCP.

In this stabilization PR, I have altered the name of the error type to `TryFromFloatSecsError`. In my opinion, the error type shares the name of the method (adjusted to accommodate both types of floats), which is consistent with other error types in `core`, `alloc` and `std` like `TryReserveError` and `TryFromIntError`.

## Experience Report

Code such as this is ready to be converted to a checked API to ensure it is panic free:

```rust
impl Time {
    pub fn checked_add_f64(&self, seconds: f64) -> Result<Self, TimeError> {
        // Fail safely during `f64` conversion to duration
        if seconds.is_nan() || seconds.is_infinite() {
            return Err(TzOutOfRangeError::new().into());
        }

        if seconds.is_sign_positive() {
            self.checked_add(Duration::from_secs_f64(seconds))
        } else {
            self.checked_sub(Duration::from_secs_f64(-seconds))
        }
    }
}
```

See: https://github.com/artichoke/artichoke/issues/2194.

`@rustbot` label +T-libs-api -T-libs

cc `@mbartlett21`
2022-10-24 19:32:26 +09:00
Yuki Okushi
779418deb4
Rollup merge of #99939 - saethlin:pre-sort-tests, r=thomcc,jackh726
Sort tests at compile time, not at startup

Recently, another Miri user was trying to run `cargo miri test` on the crate `iced-x86` with `--features=code_asm,mvex`. This configuration has a startup time of ~18 minutes. That's ~18 minutes before any tests even start to run. The fact that this crate has over 26,000 tests and Miri is slow makes a lot of code which is otherwise a bit sloppy but fine into a huge runtime issue.

Sorting the tests when the test harness is created instead of at startup time knocks just under 4 minutes out of those ~18 minutes. I have ways to remove most of the rest of the startup time, but this change requires coordinating changes of both the compiler and libtest, so I'm sending it separately.

(except for doctests, because there is no compile-time harness)
2022-10-24 19:32:25 +09:00
Yuki Okushi
fbb3650c89
Rollup merge of #99578 - steffahn:remove_redundant_bound, r=thomcc
Remove redundant lifetime bound from `impl Borrow for Cow`

The lifetime bound `B::Owned: 'a` is redundant and doesn't make a difference,
because `Cow<'a, B>` comes with an implicit `B: 'a`, and associated types
will outlive lifetimes outlived by the `Self` type (and all the trait's
generic parameters, of which there are none in this case), so the implicit `B: 'a`
implies `B::Owned: 'a` anyway.

The explicit lifetime bound here does however [end up in documentation](https://doc.rust-lang.org/std/borrow/enum.Cow.html#impl-Borrow%3CB%3E),
and that's confusing in my opinion, so let's remove it ^^

_(Documentation right now, compare to `AsRef`, too:)_
![Screenshot_20220722_014055](https://user-images.githubusercontent.com/3986214/180332665-424d0c05-afb3-40d8-a330-a57a2c9a494b.png)
2022-10-24 19:32:24 +09:00
Ralf Jung
84e6732d1e also smoke-test 'cargo miri test' 2022-10-24 11:49:40 +02:00
Ralf Jung
a61737ed6e add support for testing Miri on other targets, and do some cross-testing on CI 2022-10-24 11:49:36 +02:00
Ralf Jung
64f56d238c update lockfile 2022-10-24 11:49:32 +02:00
SparrowLii
0fca075ce8 suggest type annotation for local statement initialed by ref expression 2022-10-24 17:16:31 +08:00
bors
71e81ab674 Auto merge of #2615 - RalfJung:josh, r=oli-obk
point to my fork of josh for now

This is the version of josh that I used to create https://github.com/rust-lang/rust/pull/103392.
2022-10-24 08:14:12 +00:00
Jesse Ruderman
f53b32288c
Fix grammar in docs for std::io::Read 2022-10-24 01:06:34 -07:00
Jesse Ruderman
e3a091ad6a
Remove redundant sentence 2022-10-24 00:52:26 -07:00
bors
4b5fcae32d Auto merge of #102536 - scottmcm:lookup_line-tweak, r=jackh726
Shorten the `lookup_line` code slightly

The `match` looks like it's exactly the same as `checked_sub(1)`, so we might as well see if perf says we can just do that to save a couple lines.
2022-10-24 07:24:45 +00:00
Ralf Jung
0d0a603aab point to my fork of josh for now 2022-10-24 08:05:52 +02:00
Michael Howell
45a9d18969 rustdoc: remove no-op CSS .source pre.rust { white-space: pre }
This rule, added in 49e6db7f35, overrode a
rule in normalize.css.

49e6db7f35/src/librustdoc/html/static/normalize.css (L169-L175)

When normalize.css was updated, this rule went away.

a8edd0c5aa
2022-10-23 22:16:13 -07:00
bors
56f132565e Auto merge of #100848 - xfix:use-metadata-for-slice-len, r=thomcc
Use ptr::metadata in <[T]>::len implementation

This avoids duplication of ptr::metadata code.

I believe this is acceptable as the previous approach essentially duplicated `ptr::metadata` because back then `rustc_allow_const_fn_unstable` annotation did not exist.

I would like somebody to ping `@rust-lang/wg-const-eval` as the documentation says:

> Always ping `@rust-lang/wg-const-eval` if you are adding more rustc_allow_const_fn_unstable attributes to any const fn.
2022-10-24 04:14:46 +00:00
yukang
f54c336c80 fix #103425, remove extra type error after missing semicolon error 2022-10-24 09:20:07 +08:00
Aaron Hill
541128dcb3
Override linker in cargotest on windows 2022-10-23 19:33:03 -05:00
bors
7feb003882 Auto merge of #103452 - notriddle:rollup-peewevm, r=notriddle
Rollup of 11 pull requests

Successful merges:

 - #100462 (Clarify `array::from_fn` documentation)
 - #101644 (Document surprising and dangerous fs::Permissions behaviour on Unix)
 - #103005 (kmc-solid: Handle errors returned by `SOLID_FS_ReadDir`)
 - #103140 (Add diagnostic for calling a function with the same name with unresolved Macro)
 - #103254 (rustdoc: do not filter out cross-crate `Self: Sized` bounds)
 - #103347 (bootstrap: also create rustc-src component in sysroot)
 - #103402 (Fix wrapped valid-range handling in ty_find_init_error)
 - #103414 (Pretty print lifetimes captured by RPIT)
 - #103424 (rustdoc: remove no-op CSS `.code-header { border-bottom: none }`)
 - #103434 (Use functions for jump-to-def-background rustdoc GUI test)
 - #103447 (`MaybeUninit`: use `assume_init_drop()` in the partially initialized array example)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2022-10-24 00:29:51 +00:00
Michael Howell
ae2b1f096f
Rollup merge of #103447 - ajtribick:maybe_uninit_doc_update, r=scottmcm
`MaybeUninit`: use `assume_init_drop()` in the partially initialized array example

The `assume_init_drop()` method does the same thing as the pointer conversion, and makes the example more straightforward.
2022-10-23 14:48:19 -07:00
Michael Howell
296700eec5
Rollup merge of #103434 - GuillaumeGomez:gui-test-jump-to-def-background-cleanup, r=notriddle
Use functions for jump-to-def-background rustdoc GUI test

r? `@notriddle`
2022-10-23 14:48:18 -07:00
Michael Howell
88e0546a4c
Rollup merge of #103424 - notriddle:notriddle/code-header-border-bottom-none, r=GuillaumeGomez
rustdoc: remove no-op CSS `.code-header { border-bottom: none }`

The code headers are always h3 or h4, which don't have border-bottom by default anyway.
2022-10-23 14:48:18 -07:00
Michael Howell
039e9b6b94
Rollup merge of #103414 - compiler-errors:rpit-print-lt, r=cjgillot
Pretty print lifetimes captured by RPIT

This specifically makes the output in #103409 change from:

```diff
  error: `impl` item signature doesn't match `trait` item signature
    --> $DIR/signature-mismatch.rs:15:5
     |
  LL |     fn async_fn(&self, buff: &[u8]) -> impl Future<Output = Vec<u8>>;
     |     ----------------------------------------------------------------- expected `fn(&'1 Struct, &'2 [u8]) -> impl Future<Output = Vec<u8>>`
  ...
  LL |     fn async_fn<'a>(&self, buff: &'a [u8]) -> impl Future<Output = Vec<u8>> + 'a {
-  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ found `fn(&'1 Struct, &'2 [u8]) -> impl Future<Output = Vec<u8>>`
+  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ found `fn(&'1 Struct, &'2 [u8]) -> impl Future<Output = Vec<u8>> + '2`
     |
     = note: expected `fn(&'1 Struct, &'2 [u8]) -> impl Future<Output = Vec<u8>>`
-               found `fn(&'1 Struct, &'2 [u8]) -> impl Future<Output = Vec<u8>>`
+               found `fn(&'1 Struct, &'2 [u8]) -> impl Future<Output = Vec<u8>> + '2`
     = help: the lifetime requirements from the `impl` do not correspond to the requirements in the `trait`
     = help: verify the lifetime relationships in the `trait` and `impl` between the `self` argument, the other inputs and its output

  error: aborting due to previous error
```

Along with the UI tests in this PR, which I think are all improvements!

r? `@oli-obk` though feel free to re-roll
2022-10-23 14:48:17 -07:00
Michael Howell
9f06fbd1ad
Rollup merge of #103402 - joshtriplett:niche-wrap-fix, r=oli-obk
Fix wrapped valid-range handling in ty_find_init_error

Rust's niche handling allows for wrapping valid ranges with end < start;
for instance, a valid range with start=43 and end=41 means a niche of
42. Most places in the compiler handle this correctly, but
`ty_find_init_error` assumed that `lo > 0` means the type cannot contain a
zero.

Fix it to handle wrapping ranges.
2022-10-23 14:48:17 -07:00
Michael Howell
646e0d370d
Rollup merge of #103347 - RalfJung:rustc-src, r=Mark-Simulacrum
bootstrap: also create rustc-src component in sysroot

Fixes https://github.com/rust-lang/rust-analyzer/issues/12926
2022-10-23 14:48:16 -07:00
Michael Howell
28a1bafd48
Rollup merge of #103254 - fmease:fix-24183, r=GuillaumeGomez
rustdoc: do not filter out cross-crate `Self: Sized` bounds

All type parameters **except `Self`** are implicitly `Sized` ([via](https://doc.rust-lang.org/nightly/std/marker/trait.Sized.html)). Previously, we disregarded the exception of `Self` and omitted cross-crate `Sized` bounds of *any* type parameter *including* `Self` when rendering.
From now on, we *do* render cross-crate `Self: Sized` bounds.

Most notably, in `std` we now finally properly render the `Sized` bound of the `Clone` trait as well as the `Self: Sized` bound on `Iterator::map`.

Fixes #24183.

``@rustbot`` label T-rustdoc A-cross-crate-reexports
r? rustdoc
2022-10-23 14:48:16 -07:00
Michael Howell
3df030d441
Rollup merge of #103140 - chenyukang:yukang/fix-103112, r=estebank
Add diagnostic for calling a function with the same name with unresolved Macro

Fixes #103112
2022-10-23 14:48:15 -07:00
Michael Howell
23d1b05726
Rollup merge of #103005 - solid-rs:patch/kmc-solid/readdir-terminator, r=m-ou-se
kmc-solid: Handle errors returned by `SOLID_FS_ReadDir`

Fixes the issue where the `std::fs::ReadDir` implementaton of the [`*-kmc-solid_*`](https://doc.rust-lang.org/nightly/rustc/platform-support/kmc-solid.html) Tier 3 targets silently suppressed errors returned by the underlying `SOLID_FS_ReadDir` system function. The new implementation correctly handles all cases:

- `SOLID_ERR_NOTFOUND` indicates the end of directory stream.
- `SOLID_ERR_OK` + non-empty `d_name` indicates success.
- Some old filesystem drivers may return `SOLID_ERR_OK` + empty `d_name` to indicate the end of directory stream.
- Any other negative values (per ITRON convention) represent an error.
2022-10-23 14:48:15 -07:00
Michael Howell
214fa9fb9c
Rollup merge of #101644 - Timmmm:file_permissions_docs, r=thomcc
Document surprising and dangerous fs::Permissions behaviour on Unix

This documents the very surprising behaviour that `set_readonly(false)` will make a file *world writable* on Unix. I would go so far as to say that this function should be deprecated on Unix, or maybe even entirely. But documenting the bad behaviour is a good first step.

Fixes #74895
2022-10-23 14:48:14 -07:00
Michael Howell
acc269d65b
Rollup merge of #100462 - zohnannor:master, r=thomcc
Clarify `array::from_fn` documentation

I've seen quite a few of people on social media confused of where the length of array is coming from in the newly stabilized `array::from_fn` example.

This PR tries to clarify the documentation on this.
2022-10-23 14:48:13 -07:00
bors
7aa3613908 Auto merge of #103062 - cuviper:dist-mips, r=Mark-Simulacrum
Upgrade dist-mips*-linux to ubuntu:22.04 + crosstool-ng

These have no change in compatibility, still Linux 4.4 and glibc 2.23.

The main motivation for upgrading is that LLVM 16 will require at least GCC 7.1. Using crosstool-ng lets us choose our own toolchain versions, and then the Ubuntu version doesn't matter so much, just for the host compilation while we cross-compile.
2022-10-23 21:38:43 +00:00
Jakob Degen
be2401b8bf Split phase change from MirPass 2022-10-23 14:18:09 -07:00
bors
7fcf850d79 Auto merge of #103137 - dtolnay:readdir, r=Mark-Simulacrum
Eliminate 280-byte memset from ReadDir iterator

This guy:

1536ab1b38/library/std/src/sys/unix/fs.rs (L589)

It turns out `libc::dirent64` is quite big&mdash;https://docs.rs/libc/0.2.135/libc/struct.dirent64.html. In #103135 this memset accounted for 0.9% of the runtime of iterating a big directory.

Almost none of the big zeroed value is ever used. We memcpy a tiny prefix (19 bytes) into it, and then read just 9 bytes (`d_ino` and `d_type`) back out. We can read exactly those 9 bytes we need directly from the original entry_ptr instead.

## History

This code got added in #93459 and tweaked in #94272 and #94750.

Prior to #93459, there was no memset but a full 280 bytes were being copied from the entry_ptr.

<table><tr><td>copy 280 bytes</td></tr></table>

This was not legal because not all of those bytes might be initialized, or even allocated, depending on the length of the directory entry's name, leading to a segfault. That PR fixed the segfault by creating a new zeroed dirent64 and copying just the guaranteed initialized prefix into it.

<table><tr><td>memset 280 bytes</td><td>copy 19 bytes</td></tr></table>

However this was still buggy because it used `addr_of!((*entry_ptr).d_name)`, which is considered UB by Miri in the case that the full extent of entry_ptr is not in bounds of the same allocation. (Arguably this shouldn't be a requirement, but here we are.)

The UB got fixed by #94272 by replacing `addr_of` with some pointer manipulation based on `offset_from`, but still fundamentally the same operation.

<table><tr><td>memset 280 bytes</td><td>copy 19 bytes</td></tr></table>

Then #94750 noticed that only 9 of those 19 bytes were even being used, so we could pick out only those 9 to put in the ReadDir value.

<table><tr><td>memset 280 bytes</td><td>copy 19 bytes</td><td>copy 9 bytes</td></tr></table>

After my PR we just grab the 9 needed bytes directly from entry_ptr.

<table><tr><td>copy 9 bytes</td></tr></table>

The resulting code is more complex but I believe still worthwhile to land for the following reason. This is an extremely straightforward thing to accomplish in C and clearly libc assumes that; literally just `entry_ptr->d_name`. The extra work in comparison to accomplish it in Rust is not an example of any actual safety being provided by Rust. I believe it's useful to have uncovered that and think about what could be done in the standard library or language to support this obvious operation better.

## References

- https://man7.org/linux/man-pages/man3/readdir.3.html
2022-10-23 18:55:40 +00:00
Josh Stone
15cfeb33b0 Only test pthread_getname_np on linux-gnu 2022-10-23 11:53:39 -07:00