Support `#[unix_sigpipe = "inherit|sig_dfl"]` on `fn main()` to prevent ignoring `SIGPIPE`
When enabled, programs don't have to explicitly handle `ErrorKind::BrokenPipe` any longer. Currently, the program
```rust
fn main() { loop { println!("hello world"); } }
```
will print an error if used with a short-lived pipe, e.g.
% ./main | head -n 1
hello world
thread 'main' panicked at 'failed printing to stdout: Broken pipe (os error 32)', library/std/src/io/stdio.rs:1016:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
by enabling `#[unix_sigpipe = "sig_dfl"]` like this
```rust
#![feature(unix_sigpipe)]
#[unix_sigpipe = "sig_dfl"]
fn main() { loop { println!("hello world"); } }
```
there is no error, because `SIGPIPE` will not be ignored and thus the program will be killed appropriately:
% ./main | head -n 1
hello world
The current libstd behaviour of ignoring `SIGPIPE` before `fn main()` can be explicitly requested by using `#[unix_sigpipe = "sig_ign"]`.
With `#[unix_sigpipe = "inherit"]`, no change at all is made to `SIGPIPE`, which typically means the behaviour will be the same as `#[unix_sigpipe = "sig_dfl"]`.
See https://github.com/rust-lang/rust/issues/62569 and referenced issues for discussions regarding the `SIGPIPE` problem itself
See the [this](https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Proposal.3A.20First.20step.20towards.20solving.20the.20SIGPIPE.20problem) Zulip topic for more discussions, including about this PR.
Tracking issue: https://github.com/rust-lang/rust/issues/97889
This PR will fix some typos detected by [typos].
I only picked the ones I was sure were spelling errors to fix, mostly in
the comments.
[typos]: https://github.com/crate-ci/typos
Revert let_chains stabilization
This is the revert against master, the beta revert was already done in #100538.
Bumps the stage0 compiler which already has it reverted.
Remove separate indexing of early-bound regions
~Based on https://github.com/rust-lang/rust/pull/99728.~
This PR copies some modifications from https://github.com/rust-lang/rust/pull/97839 around object lifetime defaults.
These modifications allow to stop counting generic parameters during lifetime resolution, and rely on the indexing given by `rustc_typeck::collect`.
translations: rename warn_ to warning
## Description
This MR renames the the macro `warn_` to `warning`.
To give a little bit of context, as [explained](https://rust-lang.zulipchat.com/#narrow/stream/336883-i18n/topic/.23100717.20diag.20translation/near/295074146) by ```````@davidtwco``````` in the Zulip channel, `warn_` was named like that because the keyword `warn` is a built-in attribute and at the time this macro was created the word `warning` was also
taken.
However, it is no longer the case and we can rename `warn_` to `warning`.
Adds and removes some `visit_*` methods accordingly, improving
coverage, and avoiding some double counting. Brings it in line with the
AST stats collector.
This is based on `-Zprint-type-sizes` which does the same thing. It
makes the output provenance clearer, and helps with post-processing.
E.g. if you have `-Zhir-stats` output from numerous compiler invocations
you can now easily extract the pre-expansion stats separately from the
post-expansion stats.
This makes it possible to instruct libstd to never touch the signal
handler for `SIGPIPE`, which makes programs pipeable by default (e.g.
with `./your-program | head -n 1`) without `ErrorKind::BrokenPipe`
errors.
The macro warn_ was named like that because it the
keyword warn is a built-in attribute and at the time
this macro was created the word 'warning' was also
taken.
However it is no longer the case and we can rename
warn_ to warning.
Visit attributes in more places.
This adds 3 loosely related changes (I can split PRs if desired):
- Attribute checking on pattern struct fields.
- Attribute checking on struct expression fields.
- Lint level visiting on pattern struct fields, struct expression fields, and generic parameters.
There are still some lints which ignore lint levels in various positions. This is a consequence of how the lints themselves are implemented. For example, lint levels on associated consts don't work with `unused_braces`.
passes: load `defined_lib_features` query less
Hopefully addresses the perf regressions from #99212 (see #99905).
Re-structure the stability checks for library features to avoid calling `defined_lib_features` for any more crates than necessary for each of the implications or local feature attributes that need validation.
r? `@ghost` (just checking perf at first)
This helps simplify the code. It also fixes it to use the correct parent
when lowering. One consequence is the `non_snake_case` lint needed
to change the way it looked for parent nodes in a struct pattern.
This also includes a small fix to use the correct `Target` for
expression field attribute validation.
Attributes on struct expression fields were not being checked for
validity. This adds the fields as HIR nodes so that `CheckAttrVisitor`
can visit those nodes to check their attributes.
Attributes on pattern struct fields were not being checked for validity.
This adds the fields as HIR nodes so that the `CheckAttrVisitor` can
visit those nodes to check their attributes.
Currently it's reported as either `TraitItem` or `ImplItem`. This commit
changes it to `AssocItem`, because having the report match the type name
is (a) consistent with other types, and (b) the trait/impl split isn't
that important here.
This commit:
- Adds a comment explaining which `visit_*` methods should be
implemented.
- Adds and removes some `visit_*` methods accordingly, improving
coverage, and avoiding some double counting.
Re-structure the stability checks for library features to avoid calling
`defined_lib_features` for any more crates than necessary for each of
the implications or local feature attributes that need validation.
Implement `#[rustc_default_body_unstable]`
This PR implements a new stability attribute — `#[rustc_default_body_unstable]`.
`#[rustc_default_body_unstable]` controls the stability of default bodies in traits.
For example:
```rust
pub trait Trait {
#[rustc_default_body_unstable(feature = "feat", isssue = "none")]
fn item() {}
}
```
In order to implement `Trait` user needs to either
- implement `item` (even though it has a default implementation)
- enable `#![feature(feat)]`
This is useful in conjunction with [`#[rustc_must_implement_one_of]`](https://github.com/rust-lang/rust/pull/92164), we may want to relax requirements for a trait, for example allowing implementing either of `PartialEq::{eq, ne}`, but do so in a safe way — making implementation of only `PartialEq::ne` unstable.
r? `@Aaron1011`
cc `@nrc` (iirc you were interested in this wrt `read_buf`), `@danielhenrymantilla` (you were interested in the related `#[rustc_must_implement_one_of]`)
P.S. This is my first time working with stability attributes, so I'm not sure if I did everything right 😅
Check link ordinal to make sure it is targetted for foreign function
Fix#100009, when link ordinal is not target for foreign functions, emit an error.
cc `@dpaoliello`
Add test for raw-dylib with an external variable
All existing tests of link kind `raw-dylib` only validate the ability to link against functions, but it is also possible to link against variables.
This adds tests for linking against a variable using `raw-dylib` both by-name and by-ordinal.
Warn about dead tuple struct fields
Continuation of #92972. Fixes#92790.
The language team has already commented on this in https://github.com/rust-lang/rust/pull/92972#issuecomment-1021511970; I have incorporated their requests here. Specifically, there is now a new allow-by-default `unused_tuple_struct_fields` lint (name bikesheddable), and fields of unit type are ignored (https://github.com/rust-lang/rust/pull/92972#issuecomment-1021815408), so error messages look like this:
```
error: field is never read: `1`
--> $DIR/tuple-struct-field.rs:6:21
|
LL | struct Wrapper(i32, [u8; LEN], String);
| ^^^^^^^^^
|
help: change the field to unit type to suppress this warning while preserving the field numbering
|
LL | struct Wrapper(i32, (), String);
| ~~
```
r? `@joshtriplett`
Prevent ICE for `doc_alias` on match arm, statement, expression
Fixes#99777.
This is a pretty minimal fix that should be safe, since rustdoc doesn't generate documentation for match arms, statements, or expressions. I mentioned in the linked issue that the `doc_alias` target checking should probably be improved to avoid future ICEs, but as a new contributor, I'm not confident enough with the HIR types to make a larger change.
Some command-line options accessible through `sess.opts` are best
accessed through wrapper functions on `Session`, `TyCtxt` or otherwise,
rather than through field access on the option struct in the `Session`.
Adds a new lint which triggers on those options that should be accessed
through a wrapper function so that this is prohibited. Options are
annotated with a new attribute `rustc_lint_opt_deny_field_access` which
can specify the error message (i.e. "use this other function instead")
to be emitted.
A simpler alternative would be to simply rename the options in the
option type so that it is clear they should not be used, however this
doesn't prevent uses, just discourages them. Another alternative would
be to make the option fields private, and adding accessor functions on
the option types, however the wrapper functions sometimes rely on
additional state from `Session` or `TyCtxt` which wouldn't be available
in an function on the option type, so the accessor would simply make the
field available and its use would be discouraged too.
Signed-off-by: David Wood <david.wood@huawei.com>
This attribute allows to mark default body of a trait function as
unstable. This means that implementing the trait without implementing
the function will require enabling unstable feature.
This is useful in conjunction with `#[rustc_must_implement_one_of]`,
we may want to relax requirements for a trait, for example allowing
implementing either of `PartialEq::{eq, ne}`, but do so in a safe way
-- making implementation of only `PartialEq::ne` unstable.
Remove the unused StableSet and StableMap types from rustc_data_structures.
The current implementation is not "stable" in the same sense that `HashStable` and `StableHasher` are stable, i.e. across compilation sessions. So, in my opinion, it's better to remove those types (which are basically unused anyway) than to give the wrong impression that these are safe for incr. comp.
I plan to provide new "stable" collection types soon that can be used to replace `FxHashMap` and `FxHashSet` in query results (see [draft](69d03ac7a7)). It's unsound that `HashMap` and `HashSet` implement `HashStable` (see https://github.com/rust-lang/rust/issues/98890 for a recent P-critical bug caused by this) -- so we should make some progress there.
Improves the diagnostic when a feature attribute is specified
unnecessarily but the feature implies another (i.e. it was partially
stabilized) to refer to the implied feature.
Signed-off-by: David Wood <david.wood@huawei.com>
If part of a feature is stabilized and a new feature is added for the
remaining parts, then the `implied_by` attribute can be used to indicate
which now-stable feature previously contained a item. If the now-stable
feature is still active (if the user has only just updated rustc, for
example) then there will not be an stability error for uses of the item
from the implied feature.
Signed-off-by: David Wood <david.wood@huawei.com>
Improve the function pointer docs
This is #97842 but for function pointers instead of tuples. The concept is basically the same.
* Reduce duplicate impls; show `fn (T₁, T₂, …, Tₙ)` and include a sentence saying that there exists up to twelve of them.
* Show `Copy` and `Clone`.
* Show auto traits like `Send` and `Sync`, and blanket impls like `Any`.
https://notriddle.com/notriddle-rustdoc-test/std/primitive.fn.html
Implement `for<>` lifetime binder for closures
This PR implements RFC 3216 ([TI](https://github.com/rust-lang/rust/issues/97362)) and allows code like the following:
```rust
let _f = for<'a, 'b> |a: &'a A, b: &'b B| -> &'b C { b.c(a) };
// ^^^^^^^^^^^--- new!
```
cc ``@Aaron1011`` ``@cjgillot``
