compiletest: Document various parts of compiletest's `lib.rs`
This adds some much-needed comments to many of the items in compiletest's `lib.rs`, giving a better overview of how a compiletest invocation actually proceeds.
To make review easier I have refrained from renames or functional changes, though I couldn't resist getting rid of one obviously-redundant `Arc::clone` in `make_test_closure`.
Special treatment empty tuple when suggest adding a string literal in format macro.
For example:
```rust
let s = "123";
println!({}, "sss", s);
```
Suggest:
`println!("{:?} {} {}", {}, "sss", s);`
fixes#130170
Update precondition tests (especially for zero-size access to null)
I don't much like the current way I've updated the precondition check helpers, but I couldn't come up with anything better. Ideas welcome.
I've organized `tests/ui/precondition-checks` mostly with one file per function that has `assert_unsafe_precondition` in it, with revisions that check each precondition. The important new test is `tests/ui/precondition-checks/zero-size-null.rs`.
Fix clobber_abi and disallow SVE-related registers in Arm64EC inline assembly
Currently `clobber_abi` in Arm64EC inline assembly is implemented using `InlineAsmClobberAbi::AArch64NoX18`, but broken since it attempts to clobber registers that cannot be used in Arm64EC: https://godbolt.org/z/r3PTrGz5r
```
error: cannot use register `x13`: x13, x14, x23, x24, x28, v16-v31 cannot be used for Arm64EC
--> <source>:6:14
|
6 | asm!("", clobber_abi("C"), options(nostack, nomem, preserves_flags));
| ^^^^^^^^^^^^^^^^
error: cannot use register `x14`: x13, x14, x23, x24, x28, v16-v31 cannot be used for Arm64EC
--> <source>:6:14
|
6 | asm!("", clobber_abi("C"), options(nostack, nomem, preserves_flags));
| ^^^^^^^^^^^^^^^^
<omitted the same errors for v16-v31>
```
Additionally, this disallows SVE-related registers per https://github.com/rust-lang/rust/pull/131332#issuecomment-2401189142.
cc ``@dpaoliello``
r? ``@Amanieu``
``@rustbot`` label O-windows O-AArch64 +A-inline-assembly
Stabilize `Pin::as_deref_mut()`
Tracking issue: closes#86918
Stabilizing the following API:
```rust
impl<Ptr: DerefMut> Pin<Ptr> {
pub fn as_deref_mut(self: Pin<&mut Pin<Ptr>>) -> Pin<&mut Ptr::Target>;
}
```
I know that an FCP has not been started yet, but this isn't a very complex stabilization, and I'm hoping this can motivate an FCP to *get* started - this has been pending for a while and it's a very useful function when writing Future impls.
r? ``@jonhoo``
Also use outermost const-anon for impl items in `non_local_defs` lint
This PR update the logic for the impl paths (items) in the `non_local_definitions` lint to also consider const-anon in case the impl definition is wrapped inside const-anon it-self wrapped into a const-anon where the items are.
r? `@jieyouxu` *(since you interacted on the issue)*
Fixes *(after beta-backport)* #131643
merge const_ipv4 / const_ipv6 feature gate into 'ip' feature gate
https://github.com/rust-lang/rust/issues/76205 has been closed a while ago, but there are still some functions that reference it. Those functions are all unstable *and* const-unstable. There's no good reason to use a separate feature gate for their const-stability, so this PR moves their const-stability under the same gate as their regular stability, and therefore removes the remaining references to https://github.com/rust-lang/rust/issues/76205.
miri: avoid cloning AllocExtra
We shouldn't be cloning Miri allocations, so make `AllocExtra::clone` panic instead, and adjust the one case where we *do* clone (the leak check) to avoid cloning.
This is in preparation for https://github.com/rust-lang/miri/pull/3966 where I am adding something to `AllocExtra` that cannot (easily) be cloned.
r? ``@saethlin``
compiler: `{TyAnd,}Layout` comes home
The `Layout` and `TyAndLayout` types are heavily abstract and have no particular target-specific qualities, though we do use them to answer questions particular to targets. We can keep it that way if we simply move them out of `rustc_target` and into `rustc_abi`. They bring a small entourage of connected types with them, but that's fine.
This will allow us to strengthen a few abstraction barriers over time and thus make the notoriously gnarly layout code easier to refactor. For now, we don't need to worry about that and deliberately use reexports to minimize this particular diff.
core/net: add Ipv[46]Addr::from_octets, Ipv6Addr::from_segments.
Adds:
- `Ipv4Address::from_octets([u8;4])`
- `Ipv6Address::from_octets([u8;16])`
- `Ipv6Address::from_segments([u16;8])`
equivalent to the existing `From` impls.
Advantages:
- Consistent with `to_bits, from_bits`.
- More discoverable than the `From` impls.
- Helps with type inference: it's common to want to convert byte slices to IP addrs. If you try this
```rust
fn foo(x: &[u8]) -> Ipv4Addr {
Ipv4Addr::from(foo.try_into().unwrap())
}
```
it [doesn't work](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=0e2873312de275a58fa6e33d1b213bec). You have to write `Ipv4Addr::from(<[u8;4]>::try_from(x).unwrap())` instead, which is not great. With `from_octets` it is able to infer the right types.
Found this while porting [smoltcp](https://github.com/smoltcp-rs/smoltcp/) from its own IP address types to the `core::net` types.
~~Tracking issues #27709 #76205~~
Tracking issue: https://github.com/rust-lang/rust/issues/131360
std::fs::get_path freebsd update.
what matters is we re doing the right things as doing sizeof, rather than passing KINFO_FILE_SIZE (only defined on intel architectures), the kernel
making sure it matches the expectation in its side.
Rollup of 8 pull requests
Successful merges:
- #130356 (don't warn about a missing change-id in CI)
- #130900 (Do not output () on empty description)
- #131066 (Add the Chinese translation entry to the RustByExample build process)
- #131067 (Fix std_detect links)
- #131644 (Clean up some Miri things in `sys/windows`)
- #131646 (sys/unix: add comments for some Miri fallbacks)
- #131653 (Remove const trait bound modifier hack)
- #131659 (enable `download_ci_llvm` test)
r? `@ghost`
`@rustbot` modify labels: rollup
Clean up some Miri things in `sys/windows`
- remove miri hack that is only needed for win7 (we don't support win7 as a target in Miri)
- remove outdated comment now that Miri is on CI
Do not output () on empty description
When passing an explicitly empty description string, as explained here https://github.com/rust-lang/rust/blob/master/config.example.toml#L611-L613, my expectation is that the resulting rustc will be compatible with upstream.
However, it seems that instead, a `()` is added to the end of the version string, causing the version compatibility check to fail. My proposed fix here would be to instead only print `({description})` if `description` is a non-empty string.
Optimize `escape_ascii` using a lookup table
Based upon my suggestion here: https://github.com/rust-lang/rust/pull/125340#issuecomment-2130441817
Effectively, we can take advantage of the fact that ASCII only needs 7 bits to make the eighth bit store whether the value should be escaped or not. This adds a 256-byte lookup table, but 256 bytes *should* be small enough that very few people will mind, according to my probably not incontrovertible opinion.
The generated assembly isn't clearly better (although has fewer branches), so, I decided to benchmark on three inputs: first on a random 200KiB, then on `/bin/cat`, then on `Cargo.toml` for this repo. In all cases, the generated code ran faster on my machine. (an old i7-8700)
But, if you want to try my benchmarking code for yourself:
<details><summary>Criterion code below. Replace <code>/home/ltdk/rustsrc</code> with the appropriate directory.</summary>
```rust
#![feature(ascii_char)]
#![feature(ascii_char_variants)]
#![feature(const_option)]
#![feature(let_chains)]
use core::ascii;
use core::ops::Range;
use criterion::{criterion_group, criterion_main, Criterion};
use rand::{thread_rng, Rng};
const HEX_DIGITS: [ascii::Char; 16] = *b"0123456789abcdef".as_ascii().unwrap();
#[inline]
const fn backslash<const N: usize>(a: ascii::Char) -> ([ascii::Char; N], Range<u8>) {
const { assert!(N >= 2) };
let mut output = [ascii::Char::Null; N];
output[0] = ascii::Char::ReverseSolidus;
output[1] = a;
(output, 0..2)
}
#[inline]
const fn hex_escape<const N: usize>(byte: u8) -> ([ascii::Char; N], Range<u8>) {
const { assert!(N >= 4) };
let mut output = [ascii::Char::Null; N];
let hi = HEX_DIGITS[(byte >> 4) as usize];
let lo = HEX_DIGITS[(byte & 0xf) as usize];
output[0] = ascii::Char::ReverseSolidus;
output[1] = ascii::Char::SmallX;
output[2] = hi;
output[3] = lo;
(output, 0..4)
}
#[inline]
const fn verbatim<const N: usize>(a: ascii::Char) -> ([ascii::Char; N], Range<u8>) {
const { assert!(N >= 1) };
let mut output = [ascii::Char::Null; N];
output[0] = a;
(output, 0..1)
}
/// Escapes an ASCII character.
///
/// Returns a buffer and the length of the escaped representation.
const fn escape_ascii_old<const N: usize>(byte: u8) -> ([ascii::Char; N], Range<u8>) {
const { assert!(N >= 4) };
match byte {
b'\t' => backslash(ascii::Char::SmallT),
b'\r' => backslash(ascii::Char::SmallR),
b'\n' => backslash(ascii::Char::SmallN),
b'\\' => backslash(ascii::Char::ReverseSolidus),
b'\'' => backslash(ascii::Char::Apostrophe),
b'\"' => backslash(ascii::Char::QuotationMark),
0x00..=0x1F => hex_escape(byte),
_ => match ascii::Char::from_u8(byte) {
Some(a) => verbatim(a),
None => hex_escape(byte),
},
}
}
/// Escapes an ASCII character.
///
/// Returns a buffer and the length of the escaped representation.
const fn escape_ascii_new<const N: usize>(byte: u8) -> ([ascii::Char; N], Range<u8>) {
/// Lookup table helps us determine how to display character.
///
/// Since ASCII characters will always be 7 bits, we can exploit this to store the 8th bit to
/// indicate whether the result is escaped or unescaped.
///
/// We additionally use 0x80 (escaped NUL character) to indicate hex-escaped bytes, since
/// escaped NUL will not occur.
const LOOKUP: [u8; 256] = {
let mut arr = [0; 256];
let mut idx = 0;
loop {
arr[idx as usize] = match idx {
// use 8th bit to indicate escaped
b'\t' => 0x80 | b't',
b'\r' => 0x80 | b'r',
b'\n' => 0x80 | b'n',
b'\\' => 0x80 | b'\\',
b'\'' => 0x80 | b'\'',
b'"' => 0x80 | b'"',
// use NUL to indicate hex-escaped
0x00..=0x1F | 0x7F..=0xFF => 0x80 | b'\0',
_ => idx,
};
if idx == 255 {
break;
}
idx += 1;
}
arr
};
let lookup = LOOKUP[byte as usize];
// 8th bit indicates escape
let lookup_escaped = lookup & 0x80 != 0;
// SAFETY: We explicitly mask out the eighth bit to get a 7-bit ASCII character.
let lookup_ascii = unsafe { ascii::Char::from_u8_unchecked(lookup & 0x7F) };
if lookup_escaped {
// NUL indicates hex-escaped
if matches!(lookup_ascii, ascii::Char::Null) {
hex_escape(byte)
} else {
backslash(lookup_ascii)
}
} else {
verbatim(lookup_ascii)
}
}
fn escape_bytes(bytes: &[u8], f: impl Fn(u8) -> ([ascii::Char; 4], Range<u8>)) -> Vec<ascii::Char> {
let mut vec = Vec::new();
for b in bytes {
let (buf, range) = f(*b);
vec.extend_from_slice(&buf[range.start as usize..range.end as usize]);
}
vec
}
pub fn criterion_benchmark(c: &mut Criterion) {
let mut group = c.benchmark_group("escape_ascii");
group.sample_size(1000);
let rand_200k = &mut [0; 200 * 1024];
thread_rng().fill(&mut rand_200k[..]);
let cat = include_bytes!("/bin/cat");
let cargo_toml = include_bytes!("/home/ltdk/rustsrc/Cargo.toml");
group.bench_function("old_rand", |b| {
b.iter(|| escape_bytes(rand_200k, escape_ascii_old));
});
group.bench_function("new_rand", |b| {
b.iter(|| escape_bytes(rand_200k, escape_ascii_new));
});
group.bench_function("old_bin", |b| {
b.iter(|| escape_bytes(cat, escape_ascii_old));
});
group.bench_function("new_bin", |b| {
b.iter(|| escape_bytes(cat, escape_ascii_new));
});
group.bench_function("old_cargo_toml", |b| {
b.iter(|| escape_bytes(cargo_toml, escape_ascii_old));
});
group.bench_function("new_cargo_toml", |b| {
b.iter(|| escape_bytes(cargo_toml, escape_ascii_new));
});
group.finish();
}
criterion_group!(benches, criterion_benchmark);
criterion_main!(benches);
```
</details>
My benchmark results:
```
escape_ascii/old_rand time: [1.6965 ms 1.7006 ms 1.7053 ms]
Found 22 outliers among 1000 measurements (2.20%)
4 (0.40%) high mild
18 (1.80%) high severe
escape_ascii/new_rand time: [1.6749 ms 1.6953 ms 1.7158 ms]
Found 38 outliers among 1000 measurements (3.80%)
38 (3.80%) high mild
escape_ascii/old_bin time: [224.59 µs 225.40 µs 226.33 µs]
Found 39 outliers among 1000 measurements (3.90%)
17 (1.70%) high mild
22 (2.20%) high severe
escape_ascii/new_bin time: [164.86 µs 165.63 µs 166.58 µs]
Found 107 outliers among 1000 measurements (10.70%)
43 (4.30%) high mild
64 (6.40%) high severe
escape_ascii/old_cargo_toml
time: [23.397 µs 23.699 µs 24.014 µs]
Found 204 outliers among 1000 measurements (20.40%)
21 (2.10%) high mild
183 (18.30%) high severe
escape_ascii/new_cargo_toml
time: [16.404 µs 16.438 µs 16.483 µs]
Found 88 outliers among 1000 measurements (8.80%)
56 (5.60%) high mild
32 (3.20%) high severe
```
Random: 1.7006ms => 1.6953ms (<1% speedup)
Binary: 225.40µs => 165.63µs (26% speedup)
Text: 23.699µs => 16.438µs (30% speedup)
Rollup of 6 pull requests
Successful merges:
- #131086 (Update unicode-width to 0.2.0)
- #131585 (compiletest: Remove the one thing that was checking a directive's `original_line`)
- #131614 (Error on trying to use revisions in `run-make` tests)
- #131638 (compiletest: Move debugger setup code out of `lib.rs`)
- #131641 (switch unicode-data bitsets back to 'static')
- #131642 (Special case error message for a `build-fail` test that failed check build)
r? `@ghost`
`@rustbot` modify labels: rollup
Special case error message for a `build-fail` test that failed check build
A `build-fail` test requires that a check build (roughly `--emit=metadata`, no codegen) succeeds but fails later. Previously, if its check build failed, the user will see the error message
```
error: test compilation failed although it shouldn't!
```
which is confusing. Because the test is `build-fail`, we want the test compilation to fail! This error message doesn't account for the difference between a check build and a complete build, so let's special case the error message for a `build-fail` test whose check build failed to instead say
```
error: `build-fail` test is required to pass check build, but check build failed
```
Fixes#130894.
compiletest: Move debugger setup code out of `lib.rs`
These functions contain a few hundred lines of code for dealing with debuggers (for `debuginfo` tests), and don't really belong in the crate root.
Moving them out to their own module makes `lib.rs` easier to follow.
compiletest: Remove the one thing that was checking a directive's `original_line`
This special handling of `ignore-tidy*` was introduced during the migration to `//`@`` directives (#120881), and has become unnecessary after the subsequent removal of the legacy directive check (#131392).
