Document restricted_std
This PR aims to pin down exactly what restricted_std is meant to achieve and what it isn't.
This commit fixes https://github.com/rust-lang/wg-cargo-std-aware/issues/87 by explaining why the error appears and what the choices the user has. The error describes how std cannot function without knowing about some form of OS/platform support. Any features of std that work without an OS should be moved to core/alloc (see https://github.com/rust-lang/rust/issues/27242https://github.com/rust-lang/rust/issues/103765).
Note that the message says "platform" and "environment" because, since https://github.com/rust-lang/rust/pull/120232, libstd can be built for some JSON targets. This is still unsupported (all JSON targets probably should be unstable https://github.com/rust-lang/wg-cargo-std-aware/issues/90), but a JSON target with the right configuration should hopefully have some partial libstd support.
I propose closing https://github.com/rust-lang/wg-cargo-std-aware/issues/69 as "Won't fix" since any support of std without properly configured os, vendor or env fields is very fragile considering future upgrades of Rust or dependencies. In addition there's no likely path to it being fixed long term (making std buildable for all targets being the only solution). This is distinct from tier 3 platforms with limited std support implemented (and as such aren't restricted_std) because these platforms can conceptually work in the future and std support should mainly improve over time.
The alternative to closing https://github.com/rust-lang/wg-cargo-std-aware/issues/69 is a new crate feature for std which escapes the restricted_std mechanism in build.rs. It could be used with the -Zbuild-std-features flag if we keep it permanently unstable, which I hope we can do anyway. A minor side-effect in this scenario is that std wouldn't be marked as unstable if documentation for it were generated with build-std.
cc ```@ehuss```
Skip `unused_parens` report for `Paren(Path(..))` in macro.
fixes#120642
In following code, `unused_parens` suggest change `<($($rest),*)>::bar()` to `<$rest>::bar()` which will cause another err: `error: variable 'rest' is still repeating at this depth`：
```rust
trait Foo {
fn bar();
}
macro_rules! problem {
($ty:ident) => {
impl<$ty: Foo> Foo for ($ty,) {
fn bar() { <$ty>::bar() }
}
};
($ty:ident $(, $rest:ident)*) => {
impl<$ty: Foo, $($rest: Foo),*> Foo for ($ty, $($rest),*) {
fn bar() {
<$ty>::bar();
<($($rest),*)>::bar()
}
}
problem!($($rest),*);
}
}
```
I think maybe we can handle this by avoid warning for `Paren(Path(..))` in the macro. Is this reasonable approach?
`f16` and `f128` step 4: basic library support
This is the next step after https://github.com/rust-lang/rust/pull/121926, another portion of https://github.com/rust-lang/rust/pull/114607
Tracking issue: https://github.com/rust-lang/rust/issues/116909
This PR adds the most basic operations to `f16` and `f128` that get lowered as LLVM intrinsics. This is a very small step but it seemed reasonable enough to add unopinionated basic operations before the larger modules that are built on top of them.
r? ```@Amanieu``` since you were pretty involved in the RFC
cc ```@compiler-errors```
```@rustbot``` label +T-libs-api +S-blocked +F-f16_and_f128
Propagate temporary lifetime extension into if and match.
This PR makes this work:
```rust
let a = if true {
..;
&temp() // used to error, but now gets lifetime extended
} else {
..;
&temp() // used to error, but now gets lifetime extended
};
```
and
```rust
let a = match () {
_ => {
..;
&temp() // used to error, but now gets lifetime extended
}
};
```
to make it consistent with:
```rust
let a = {
..;
&temp() // lifetime is extended
};
```
This is one small part of [the temporary lifetimes work](https://github.com/rust-lang/lang-team/issues/253).
This part is backwards compatible (so doesn't need be edition-gated), because all code affected by this change previously resulted in a hard error.
This reverts commit 049a917535.
The resolution to <https://github.com/rust-lang/rust/issues/123282> is
that the `f16`/`f128` regression in the beta compiler was fixable
without a revert, so the commit adding `#[cfg(not(bootstrap))]` is no
longer useful (added in
<https://github.com/rust-lang/rust/pull/123390>).
Revert this commit because not having these basic impls bootstrap-gated
simplifies everything else that uses them.
Rollup of 7 pull requests
Successful merges:
- #118391 (Add `REDUNDANT_LIFETIMES` lint to detect lifetimes which are semantically redundant)
- #123534 (Windows: set main thread name without re-encoding)
- #123659 (Add support to intrinsics fallback body)
- #123689 (Add const generics support for pattern types)
- #123701 (Only assert for child/parent projection compatibility AFTER checking that theyre coming from the same place)
- #123702 (Further cleanup cfgs in the UI test suite)
- #123706 (rustdoc: reduce per-page HTML overhead)
r? `@ghost`
`@rustbot` modify labels: rollup
Further cleanup cfgs in the UI test suite
This PR does more cleanup of cfgs in our UI test suite, in preparation for adding automatic always on check-cfg (but is IMO worth landing even without that follow up).
To be more specific this PR:
- replaces (the last remaining) never true cfgs by the `FALSE` cfg
- fix `proc-macro/derive-helper-configured.rs` *(typo in directive)*
- and comment some current unused `#[cfg_attr]` *(missing revisions)*
Follow-up to https://github.com/rust-lang/rust/pull/123577.
Only assert for child/parent projection compatibility AFTER checking that theyre coming from the same place
This assertion doesn't make sense until we check that these captures are actually equivalent.
Fixes#123697
<sub>Some days I wonder how I even write code that works...</sub>
Add support to intrinsics fallback body
Before this fix, the call to `body()` would crash, since `has_body()` would return true, but we would try to retrieve the body of an intrinsic which is not allowed.
Instead, the `Instance::body()` function will now convert an Intrinsic into an Item before retrieving its body.
Note: I also changed how we monomorphize the instance body. Unfortunately, the call still ICE for some shims.
r? `@oli-obk`
Add `REDUNDANT_LIFETIMES` lint to detect lifetimes which are semantically redundant
There already is a `UNUSED_LIFETIMES` lint which is fired when we detect where clause bounds like `where 'a: 'static`, however, it doesn't use the full power of lexical region resolution to detect failures.
Right now `UNUSED_LIFETIMES` is an `Allow` lint, though presumably we could bump it to warn? I can (somewhat) easily implement a structured suggestion so this can be rustfix'd automatically, since we can just walk through the HIR body, replacing instances of the redundant lifetime.
Fixes#118376
r? lcnr
Specialize many implementations of `Read::read_buf_exact`
This makes all implementations of `Read` that have a specialized `read_exact` implementation also have one for `read_buf_exact`.
Show mode_t as octal in std::fs Debug impls
Example:
```rust
fn main() {
println!("{:?}", std::fs::metadata("Cargo.toml").unwrap().permissions());
}
```
- Before: `Permissions(FilePermissions { mode: 33204 })`
- ~~After: `Permissions(FilePermissions { mode: 0o100664 })`~~
- After: `Permissions(FilePermissions { mode: 0o100664 (-rw-rw-r--) })`
~~I thought about using the format from `ls -l` (`-rw-rw-r--`, `drwxrwxr-x`) but I am not sure how transferable the meaning of the higher bits between different unix systems, and anyway starting the value with a leading negative-sign seems objectionable.~~
Rollup of 7 pull requests
Successful merges:
- #121884 (Port exit-code run-make test to use rust)
- #122200 (Unconditionally show update nightly hint on ICE)
- #123568 (Clean up tests/ui by removing `does-nothing.rs`)
- #123609 (Don't use bytepos offsets when computing semicolon span for removal)
- #123612 (Set target-abi module flag for RISC-V targets)
- #123633 (Store all args in the unsupported Command implementation)
- #123668 (async closure coroutine by move body MirPass refactoring)
Failed merges:
- #123701 (Only assert for child/parent projection compatibility AFTER checking that theyre coming from the same place)
r? `@ghost`
`@rustbot` modify labels: rollup
According to <https://caniuse.com/?search=svg%20favicon>,
SVG favicons are supported in everything but Safari.
When I actually try it in Safari, it's downloading all
three favicons, and nothing looks different when I disable
the 16x16 one.
<https://dev.to/masakudamatsu/favicon-nightmare-how-to-maintain-sanity-3al7>,
which is linked from caniuse above, recommends an ico.
However, the reason they recommend it is the apps that
only support /favicon.ico exactly, and rustdoc can't assume
it will be installed to the site root, so it's unfortunately
up to the webmaster to make sure it's set up.
async closure coroutine by move body MirPass refactoring
Unsure about the last commit, but I think the other changes help in simplifying the control flow
Store all args in the unsupported Command implementation
This allows printing them in the Debug impl as well as getting them again using the get_args() method. This allows programs that would normally spawn another process to more easily show which program they would have spawned if not for the fact that the target doesn't support spawning child processes without requiring intrusive changes to keep the args. For example rustc compiled to wasi will show the full linker invocation that would have been done.
Don't use bytepos offsets when computing semicolon span for removal
Causes problems when we recover confusable characters w/ a different byte width
Fixes#123607
Clean up tests/ui by removing `does-nothing.rs`
In [a previous PR](https://github.com/rust-lang/rust/pull/123297#issuecomment-2039887806), it was suggested that this test be removed:
> it's testing a basic diagnostic for an unknown variable (added over a decade ago for https://github.com/rust-lang/rust/issues/154) that is already covered by probably dozens or hundreds of other tests.
It was then suggested that [opening a new PR](https://github.com/rust-lang/rust/pull/123563#discussion_r1554654102) for this would be more organized.
I'm setting this as a draft, as:
1. The tests/ui directory is rather disorganized, a large quantity of tests are not even contained inside their own directories. This PR could turn into "clean up the UI tests directory", if I were to place everything into categories (for example, everything related to CLI flags could get placed in a cli directory).
2. This will have a merge conflict with #123563 should that get merged. I trust that _this time_, I won't run into [The Incident](https://github.com/rust-lang/rust/pull/123297#issuecomment-2041137569) while rebasing. Edit: Yay, I did it properly!
Unconditionally show update nightly hint on ICE
Instead of trying to guess if a update nightly hint should be shown (by checking for system time, querying version and channel info etc.), just show the update nightly hint for nightly compilers. This avoids breaking tests that match on ICE test outputs on nightly/dev channels.
> Another issue is that the outdated nightly hint triggers for ICE tests, causing a mismatch with the test expectation. There doesn't seem to be any env var to suppress this.
See <https://rust-lang.zulipchat.com/#narrow/stream/326414-t-infra.2Fbootstrap/topic/stage0.20compiletest.20broken/near/425543681> for context.
Port exit-code run-make test to use rust
As part of https://github.com/rust-lang/rust/issues/121876
~~As draft because formatting will fail because `x fmt` isn't working for me for some reason, I'll debug that later, just opening this now for review, will mark as ready when formatting is fixed~~ (misleading message from x fmt)
cc `@jieyouxu`
This commit does three things:
1. replaces (the last remaining) never true cfgs by the FALSE cfg
2. fix derive-helper-configured.rs (typo in directive)
3. and comment some current unused #[cfg_attr] (missing revisions)
León Orell Valerian Liehr